U.S. patent application number 10/288536 was filed with the patent office on 2003-04-10 for semiconductor device, method of manufacturing semiconductor device, resin molding die, and semiconductor manufacturing system.
This patent application is currently assigned to Kabushiki Kaisha Toshiba. Invention is credited to Fukuda, Masatoshi, Harada, Susumu, Nakano, Atsushi, Sato, Hidenobu, Sato, Tetsuya.
Application Number | 20030068850 10/288536 |
Document ID | / |
Family ID | 18651959 |
Filed Date | 2003-04-10 |
United States Patent
Application |
20030068850 |
Kind Code |
A1 |
Fukuda, Masatoshi ; et
al. |
April 10, 2003 |
Semiconductor device, method of manufacturing semiconductor device,
resin molding die, and semiconductor manufacturing system
Abstract
In a semiconductor device manufacturing method, at least a
semiconductor element is arranged in a cavity of a resin molding
die. A resin is supplied to a resin reservoir in direct contact
with the cavity and is then injected in order to substantially fill
the cavity. The resin filled in the cavity forms a resin seal for
encapsulating the semiconductor element. The resin seal has a
recess or a protrusion as a remainder of the resin reservoir.
Inventors: |
Fukuda, Masatoshi;
(Kanagawa-ken, JP) ; Harada, Susumu;
(Kanagawa-ken, JP) ; Sato, Tetsuya; (Mie-ken,
JP) ; Sato, Hidenobu; (Kanagawa-ken, JP) ;
Nakano, Atsushi; (Kanagawa-ken, JP) |
Correspondence
Address: |
FINNEGAN, HENDERSON, FARABOW, GARRETT &
DUNNER LLP
1300 I STREET, NW
WASHINGTON
DC
20006
US
|
Assignee: |
Kabushiki Kaisha Toshiba
|
Family ID: |
18651959 |
Appl. No.: |
10/288536 |
Filed: |
November 6, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10288536 |
Nov 6, 2002 |
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09855529 |
May 16, 2001 |
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6498055 |
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Current U.S.
Class: |
438/200 ;
257/E21.504; 257/E23.179 |
Current CPC
Class: |
H01L 23/3128 20130101;
H01L 2924/1305 20130101; H01L 2224/48091 20130101; H01L 2924/1517
20130101; H01L 2223/54473 20130101; H01L 23/544 20130101; H01L
2924/07802 20130101; H01L 2224/45124 20130101; H01L 2224/32225
20130101; H01L 2223/5442 20130101; H01L 2224/48227 20130101; H01L
21/565 20130101; H01L 2924/1532 20130101; H01L 2924/15311 20130101;
H01L 2924/15153 20130101; H01L 2924/1815 20130101; H01L 24/48
20130101; H01L 2924/01078 20130101; H01L 24/45 20130101; H01L
2224/45144 20130101; H01L 2224/73265 20130101; H01L 2924/181
20130101; H01L 2924/00014 20130101; H01L 2924/01079 20130101; H01L
2223/54486 20130101; H01L 2224/48091 20130101; H01L 2924/00014
20130101; H01L 2224/73265 20130101; H01L 2224/32225 20130101; H01L
2224/48227 20130101; H01L 2924/00 20130101; H01L 2924/15311
20130101; H01L 2224/73265 20130101; H01L 2224/32225 20130101; H01L
2224/48227 20130101; H01L 2924/00 20130101; H01L 2224/45144
20130101; H01L 2924/00014 20130101; H01L 2924/07802 20130101; H01L
2924/00 20130101; H01L 2224/45124 20130101; H01L 2924/00014
20130101; H01L 2924/1305 20130101; H01L 2924/00 20130101; H01L
2224/45144 20130101; H01L 2924/00015 20130101; H01L 2924/00014
20130101; H01L 2224/05599 20130101; H01L 2924/181 20130101; H01L
2924/00012 20130101 |
Class at
Publication: |
438/200 |
International
Class: |
H01L 021/8238 |
Foreign Application Data
Date |
Code |
Application Number |
May 17, 2000 |
JP |
P2000-145453 |
Claims
What is claimed is:
1. A method of manufacturing a semiconductor device comprising:
arranging at least one semiconductor element in a cavity of a resin
molding die; supplying a resin to a resin reservoir in direct
contact with the cavity in order to substantially fill the cavity;
and injecting the resin into the cavity from the resin reservoir in
order to form a resin seal for encapsulating the semiconductor
element.
2. The method of claim 1, wherein supplying a resin to a resin
reservoir in direct contact with the cavity in order to
substantially fill the cavity comprises placing the resin reservoir
in contact with the cavity without via a cull and a runner.
3. The method of claim 1, wherein supplying a resin to a resin
reservoir in direct contact with the cavity in order to
substantially fill the cavity comprises determining a volume of the
resin to be substantially equal to a volume of the cavity with a
volume of the semiconductor element deducted.
4. The method of claim 1, wherein supplying a resin to a resin
reservoir in direct contact with the cavity in order to
substantially fill the cavity comprises determining a volume of the
resin to be slightly smaller than a volume of the cavity with a
volume of the semiconductor element deducted.
5. The method of claim 1, wherein supplying a resin to a resin
reservoir in direct contact with the cavity in order to
substantially fill the cavity comprises determining a volume of the
resin to be slightly larger than a volume the cavity with a volume
of the semiconductor element deducted.
6. A method of manufacturing a semiconductor device comprising:
arranging at least a base and a semiconductor element on the base
in a cavity of a resin molding die; supplying a resin to a resin
reservoir in direct contact with the cavity and above the
semiconductor element in order to substantially fill the cavity;
and injecting the resin into the cavity from the resin reservoir in
order to form a resin seal for encapsulating at least a part of the
base and the semiconductor element.
7. The method of claim 6, wherein arranging at least a base and a
semiconductor element on the base in a cavity of a resin molding
die comprises using the base constituted by at least a circuit
board, a printed circuit board, a wiring board an insulated
substrate, a tape substrate, a resin substrate, a ceramics
substrate, a power source substrate, a radiating substrate or a
lead.
8. The method of claim 6, where supplying a resin to a resin
reservoir in direct contact with the cavity and just above the
semiconductor element in order to substantially fill the cavity
comprises placing the resin reservoir in direct contact with the
cavity at a position above a circuit mounting surface of the
semiconductor element.
9. A resin molding die comprising: a cavity; a resin reservoir in
direct contact with the cavity and housing a resin for
substantially filling the cavity; and a pusher injecting the resin
into the cavity from the resin reservoir.
10. The resin molding die of claim 9, further comprising an upper
cavity block and a lower cavity block, wherein the cavity is
present between the upper and lower cavity blocks.
11. The resin molding die of claim 10, wherein the cavity is
present on either the upper or lower cavity block.
12. The resin molding die of claim 10, wherein either the upper or
lower cavity block is flat at a surface thereof facing with either
the lower or upper cavity block.
13. The resin molding die of claim 9, wherein the resin reservoir
is formed at the center of the cavity facing with an upper surface
a semiconductor element put in the cavity.
14. The resin molding die of claim 9, wherein the resin reservoir
is formed at a position displaced from the center of the cavity
facing with an upper surface a semiconductor element put in the
cavity.
15. The resin molding die of claim 9, wherein the pusher includes a
stop for controlling a resin injection stroke.
16. The resin molding die of claim 9, wherein the pusher has a
curved end opposite to the end thereof near the cavity.
17. A semiconductor manufacturing system comprising: a resin
molding die which includes a cavity, a resin reservoir in direct
contact with the cavity and housing a resin for substantially
filling the cavity, and a pusher injecting the resin into the
cavity from the resin reservoir; a plunger for driving the pusher
of the resin molding die; a plunger driving unit for driving the
plunger; and a control unit for driving the plunger driving
unit.
18. The semiconductor manufacturing system of claim 17 further
comprising a die driving unit for clamping and unclamping the resin
molding die.
19. The semiconductor manufacturing system of claim 17, wherein the
plunger is provided with a stop for controlling a resin injection
stroke of the pusher.
20. The semiconductor manufacturing system of claim 17, wherein the
pusher is in contact with the plunger via a curved end thereof.
21. The semiconductor manufacturing system of claim 17, wherein the
resin reservoir of the resin molding die is formed at the center of
the cavity facing with an upper surface a semiconductor element put
in the cavity.
22. The semiconductor manufacturing system of claim 17, wherein the
resin reservoir of the resin molding die is formed at a position
displaced from the center of the cavity facing with an upper
surface a semiconductor element put in the cavity.
23. A semiconductor device comprising: a base; a semiconductor
element arranged on the base; and a resin seal encapsulating the
semiconductor element and having a recess just above the
semiconductor element.
24. The semiconductor device of claim 23, wherein the base is
constituted by a circuit board, a printed circuit board, a wiring
board, an insulated substrate, a tape substrate, a resin substrate,
a ceramics substrate, a power source substrate or a lead.
25. The semiconductor device of claim 23, wherein the recess of the
resin seal is present just above the semiconductor element.
26. The semiconductor device of claim 23, wherein the recess of the
resin seal is present above an area displaced from the center of
the semiconductor element.
27. A semiconductor device comprising: a base; a semiconductor
element on the base; and a resin seal encapsulating at least a part
of the base and the semiconductor element, and having a protrusion
just above the semiconductor element.
28. The semiconductor device of claim 27, wherein the base is
constituted by a circuit board, a printed circuit board, an
insulated substrate, a tape substrate, a resin substrate, a
ceramics substrate, a power source substrate or a lead.
29. The semiconductor device of claim 27, wherein the protrusion of
the resin seal is present just above the semiconductor element.
30. The semiconductor device of claim 27, wherein the protrusion of
the resin seal is present above an area displaced from the center
of the semiconductor element.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims benefit of priority under 35 U.S.C.
.sctn.119 to Japanese Patent Application No. 2000-145453, filed on
May 17, 2000, the entire contents of which is incorporated by
reference herein.
DETAILED DESCRIPTION OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to a semiconductor device, a method
of manufacturing a semiconductor device, a resin molding die, and a
semiconductor manufacturing system, and more particularly relates
to a semiconductor device in which at least one semiconductor
element (e.g. a semiconductor chip) is encapsulated in a resin
seal, a method of manufacturing such a semiconductor device, a
resin molding die used in the methods, and a semiconductor
manufacturing system for carrying out the foregoing semiconductor
device manufacturing method.
[0004] 2. Description of Related Art
[0005] Semiconductor devices having the ball grid array structure
are well-known at present. Referring to FIG. 25 and FIG. 26 of the
accompanying drawings, such a semiconductor device comprises: a
substrate 1 made of a resin, a tape, ceramics or the like and
having a wiring circuit formed thereon; a semiconductor chip 2
fixedly mounted on the substrate 1 using an adhesive layer 3; a
bonding wire 5, e.g. a gold bonding wire, connecting a bonding pad
of the semiconductor chip 2 and a wiring circuit terminal 4 on the
substrate 1; and a resin seal 6 for encapsulating the semiconductor
chip 2. A resin gate scar 6G via which resin was injected for the
transfer molding process remains on a side surface of the resin
seal 6. External connection terminals 8 constituted by solder balls
are electrically connected to the wiring circuit terminal 4 on the
rear surface of the substrate 1.
[0006] FIG. 27 and FIG. 28 show a cavity-down type semiconductor
device having the ball grid array structure. The semiconductor
device comprises: a substrate 1 made of a resin, a tape, ceramics
or the like and having a wiring circuit and a through-hole on the
center thereof; a metal plate 10 or an insulated plate 10 stuck
onto the substrate 1 by an adhesive layer 9; a semiconductor chip 2
fixedly attached by an adhesive layer 3 in a recess defined by the
through-hole in the substrate 1 and the plate 10; a bonding wire 5,
e.g. a gold bonding wire, connecting a bonding pad of the
semiconductor chip 2 to a wiring circuit terminal 4 on the rear
surface of the substrate 1; and a resin seal 6 encapsulating the
semiconductor chip 2. A resin gate scar 6G via which resin was
injected for the transfer molding process remains on a side surface
of the resin seal 6. External connection terminals 8 constituted by
solder balls are electrically connected to the wiring circuit
terminal 4 on the rear surface of the substrate 1, i.e. where the
wiring circuit terminal 4 is provided.
[0007] The semiconductor device of FIG. 25 and FIG. 26 is resin
molded as shown in FIG. 29A and FIG. 29B. A resin molding die
including upper and lower dies 11 and 12 is heated to a temperature
of approximately 165.degree. C. to 185.degree. C. Thereafter, a
resin tablet or powder 14 is supplied to a pot 13 in the lower die
12. The substrate 1, on which the semiconductor chip 2 and the
bonding pad of the semiconductor chip 2 are provided and is
connected to the wiring circuit terminal 4 using the gold bonding
wire 5, is placed between the upper and lower dies 11 and 12. In
this state, the upper and lower dies 11 and 12 are clamped as shown
in FIG. 29A. The resin 14 in the pot 13 is pressurized using a
plunger 15 and melted, and is injected into a cavity 17 via a
runner 16 and the resin gate 7. The resin 14 is left as it is for
approximately 40 seconds to 180 seconds, and is hardened in order
to form the resin seal 6. Thereafter, the upper and lower dies 11
and 12 are unclamped, so that the resin seal 6 is removed from the
upper and lower dies 11 and 12. By this, the semiconductor device
is almost completed. The resin seal 6 includes superfluous resins
14A such as a cull 18, runner 17 and resin gate 7 formed when
injecting the resin 14, which are removed by the gate-breaking, and
are discharged.
[0008] In order to facilitate the peeling of the unnecessary resin
14A in the gate-breaking, a metal part 19 is sometimes provided
over the runner 16 and resin gate 7 on the substrate 1, as shown in
FIG. 30.
[0009] In the semiconductor device of FIG. 27 and FIG. 28, the
resin seal 6 is at the center of the rear surface of the substrate
1, and is surrounded by the external connection terminals 8.
Therefore, if the runner 16 extends over a part of the external
connection terminals 8 (solder balls), a part of the surplus resin
14A may stick on them. Some surplus resin 14A may scrape a part of
external connection terminals 8 which are being formed. Any of
resin molding processes shown in FIG. 31 to FIG. 34 is utilized in
order to overcome this problem.
[0010] In a first resin molding process shown in FIG. 31, a resin
is injected with a third die or a plate 20 inserted between upper
and lower dies 11 and 12. Specifically, the third die or plate 20
extends all over the external connection terminals 8 on the rear
surface of the substrate 1, so that the resin cannot stick onto the
external connection terminals 8.
[0011] According to a second resin molding process shown in FIG.
32, the resin is injected with a sheet 21 such as a film sandwiched
between the upper and lower dies 11 and 12. Similar to the third
die or plate 20, the sheet 21 extends all over the external
connection terminals 8 on the rear surface of the substrate 1,
which can prevent the resin from sticking onto the external
connection terminals 8.
[0012] A third resin molding process shown in FIG. 33 is described
in Japanese Patent Laid-Open Publication No. Hei 7-221132, for
example. In this method, a resin inlet 22 is in the shape of a
recess and extends between the pot 13 in the lower die 12 and the
plate 10 connecting to the pot 13. Further, a resin outlet 23
extends to the cavity 17 from the resin inlet 22. The resin 14 in
the pot 13 is pushed upward using a plunger 15 in order to fill the
cavity 17 via the resin inlet 22 and the resin outlet 23. Both the
resin inlet 22 and the resin outlet 23 are formed in the substrate
1. Since no resin 14 passes over the external connection terminals
8, it is possible to prevent the resin 14 from sticking onto the
external connection terminals 8.
[0013] A fourth resin molding process is similar to the third
method. However, the fourth method is applied to a cavity-up type
semiconductor device as shown in FIG. 34. This semiconductor device
comprises: a substrate 1 made of a resin, a tape, ceramics or the
like and having a wiring circuit provided thereon; a frame 24 made
of a metal plate or an insulated plate, having a through-hole at
the center thereof and stuck onto the front surface of the
substrate 1 using an adhesive layer 25; a semiconductor chip 2
fixedly attached using an adhesive layer 3 in a recess defined by
the substrate 1 and the through-hole in the frame 24; a bonding
wire 5, e.g. a gold bonding wire, connecting a bonding pad of the
semiconductor chip 2 to a wiring circuit terminal 4 on the front
surface of the substrate 1; and a resin seal (not shown)
encapsulating the semiconductor chip 2. In this method, a resin
inlet 22 in the shape of a recess is formed in the frame 24 and
around the semiconductor chip 2 and is connected to the pot 13
provided in the lower die 12. Further, a resin outlet 23 extends
from the resin inlet 22 to the cavity 17. The resin 14 in the pot
13 is pushed upward by the plunger 15, and injected into the cavity
17 via the resin inlet 22 and the resin outlet 23. Both the resin
inlet 22 and the resin outlet 23 are formed in the substrate 1, so
that no resin 14 passes over the external connection terminals 8.
This is effective in preventing the resin 14 from sticking onto the
external connection terminals 8.
[0014] However, the foregoing semiconductor device and the
foregoing manufacturing methods seem to suffer from the following
problems.
[0015] (1) In the resin molding process shown in FIG. 29A and FIG.
29B for the semiconductor device of FIG. 25 and FIG. 26, there are
formed not only the resin seal 6 but also the unnecessary resin 14A
such as the cull 18 of the molding die, runner 16 and resin gate
17. The unnecessary resin 14A is removed from the rein seal 6 after
the gate-breaking, and is discharged as waste. As a result, most of
the resin 14 housed in the pot 13 would be wasted, which not only
increases the manufacturing cost of the semiconductor devices but
also is not desirable in view of effective use of resources.
[0016] (2) During the gate-breaking, the resin seal 6 may peel off
from the substrate 1, or may crack, which would adversely affect
the reliability of the semiconductor device and reduce the
manufacturing yield of the semiconductor device.
[0017] (3) In the semiconductor device shown in FIG. 30, no wiring
circuit for the wiring circuit terminals 4, external connection
terminals 8 and so on can be arranged in the area where the metal
part 19 is provided in order to facilitate the gate-breaking, so
that the substrate 1 becomes large due to the metal part 19, which
makes it difficult to downsize the semiconductor device.
[0018] (4) With the resin molding process shown in FIG. 29A and
FIG. 29B, if the substrate 1 whose thickness is larger than the
predetermined value because of dispersion of manufacturing quality
is placed in the molding die, there may be a gap between the upper
and lower dies 11 and 12 near the pot 13 and the runner 16.
Conversely, if the substrate 1 is thinner than the predetermined
value, a gap is caused between the upper die 11 and the substrate
1. If the substrate 1 is too thick, the resin 14 tends to leak via
the gap when it is being injected. Especially, a substrate 1 made
of sintered ceramics and having a reduced dimensional tolerance has
low elasticity and is slow to be deformed during the die clamping.
This means that the resin frequently leaks if the substrate 1 has a
thickness deviating from the predetermined value. Further, the
thicker the ceramics substrate, the more easily it cracks.
[0019] (5) The first resin molding process shown in FIG. 31 for the
semiconductor device of FIG. 27 and FIG. 28 requires the provision
of the additional die or plate 20 between the upper and lower dies
11 and 12. Further, the second resin molding process of FIG. 32
needs the sheet 21 to be provided. It is extremely difficult to
automatically attach the additional die or plate 20, or the sheet
21 to a general purpose transfer molding system. For this purpose,
a new dedicated device has to be provided. In addition, the
additional die or plate 20, or the sheet 21 has to be prepared,
which would adversely increase the manufacturing cost and product
cost of the semiconductor device.
[0020] (6) In the third and fourth resin molding processes shown in
FIG. 33 and FIG. 34, both the substrate 1 and the frame 24 are
thickened in order to form the resin inlet 22 and the resin outlet
23. Further, no external connection terminals 8 can be provided on
the area for the resin inlet 22, so that not only the substrate 1
but also the frame 24 have to become large. Therefore, it is very
difficult to downsize the semiconductor device. Still further,
since the resin inlet 22 and the resin outlet 23 are provided in
the substrate 1 or the frame 24, the mechanical strength of the
substrate 1 where the rein inlet 22 and the resin outlet 23 are
positioned is reduced, which requires the substrate 1 or the frame
24 to be enlarged in order to secure sufficient mechanical
strength. In short, it is extremely difficult to downsize the
semiconductor device. In addition, the resin inlet 22 and the resin
outlet 23 should be machined by special processes, which adversely
increases the manufacturing cost and product cost of the
semiconductor device, and reduces the manufacturing yield of the
semiconductor device.
SUMMARY OF THE INVENTION
[0021] This invention has been devised in order to overcome the
foregoing problems of the related art. A first object of the
embodiment of the invention is to provide a method of manufacturing
a semiconductor device which is free from resin waste generated
during the formation of a resin seal, and is less expensive.
[0022] A second object of the embodiment of the invention is to
provide a method of manufacturing a reliable semiconductor device
which is protected against the peeling of a resin seal and shorting
of wires, and improves manufacturing yield.
[0023] It is a third object of the embodiment of the invention to
provide a resin molding die which is effective in carrying out the
foregoing semiconductor device manufacturing method.
[0024] A fourth object of the embodiment of the invention is to
provide a semiconductor manufacturing system to which the foregoing
semiconductor device manufacturing method is applicable.
[0025] A final object of the embodiment of the invention is to
provide a reliable semiconductor device.
[0026] According to a first aspect of the invention, there is
provided a method of manufacturing a semiconductor device
comprising: (1) arranging at least one semiconductor element in a
cavity of a resin molding die; (2) supplying a resin to a resin
reservoir in direct contact with the cavity in order to
substantially fill the cavity; and (3) injecting the resin into the
cavity from the resin reservoir in order to form a resin seal for
encapsulating the semiconductor element.
[0027] In accordance with a second aspect of the invention, there
is provided a method of manufacturing a semiconductor device
comprising: (1) arranging at least a base and a semiconductor
element on the base in a cavity of a resin molding die; (2)
supplying a resin to a resin reservoir in direct contact with the
cavity and above the semiconductor element in order to
substantially fill the cavity; and (3) injecting the resin into the
cavity from the resin reservoir in order to form a resin seal for
encapsulating at least a part of the base and the semiconductor
element.
[0028] With a third aspect of the invention, there is provided a
method of manufacturing a semiconductor device comprising: (1)
arranging at least a base and a semiconductor element on the base
in a cavity of a resin molding die; (2) supplying a resin to a
resin reservoir at the center of the cavity facing with an upper
surface of the semiconductor element in order to substantially fill
the cavity; and (3) injecting the resin into the cavity from the
resin reservoir in order to form a resin seal for encapsulating at
least a part of the base and the semiconductor element.
[0029] According to a fourth aspect of the invention, there is
provided a resin molding die comprising: a cavity; a resin
reservoir in direct contact with the cavity and housing a resin for
substantially filling the cavity; and a pusher injecting the resin
into the cavity from the resin reservoir.
[0030] In accordance with a fifth aspect of the invention, there is
provided a semiconductor manufacturing system comprising: a resin
molding die which includes a cavity, a resin reservoir in direct
contact with the cavity and housing a resin for substantially
filling the cavity, and a pusher injecting the resin into the
cavity from the resin reservoir; a plunger for driving the pusher
of the resin molding die; a plunger driving unit for driving the
plunger; and a control unit for driving the plunger driving
unit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1 is a cross section of a semiconductor device
according to a first embodiment of the invention.
[0032] FIG. 2 is a top plan view of the semiconductor device of
FIG. 1.
[0033] FIG. 3 is a cross section of a resin molding die used in the
first embodiment and a block diagram of a semiconductor
manufacturing system.
[0034] FIG. 4A and FIG. 4B are cross sections of the semiconductor
device and the resin molding die, showing how the semiconductor
device is manufactured.
[0035] FIG. 5 is a cross section of a semiconductor device
according to a second embodiment of the invention.
[0036] FIG. 6 is a cross section of the semiconductor device of
FIG. 5 and a resin molding die, showing how the semiconductor
device is manufactured.
[0037] FIG. 7 is a cross section of a semiconductor device
according to a third embodiment of the invention.
[0038] FIG. 8 is a top plan view of the semiconductor device of
FIG. 7.
[0039] FIG. 9 a cross section of the semiconductor device of FIG. 7
and a resin molding die, showing how the semiconductor device is
manufactured.
[0040] FIG. 10 is a cross section of a semiconductor device
according to a fourth embodiment of the invention.
[0041] FIG. 11 is a cross section of a semiconductor device
according to fifth embodiment of the invention.
[0042] FIG. 12 is a cross section of a semiconductor device
according to sixth embodiment of the invention.
[0043] FIG. 13 is a cross section of a semiconductor device
according to seventh embodiment of the invention.
[0044] FIG. 14 is a top plan view of the semiconductor device of
FIG. 13.
[0045] FIG. 15A and FIG. 15B are cross sections of the
semiconductor device of FIG. 13 and a resin molding die, showing
how the semiconductor device is manufactured.
[0046] FIG. 16 is a cross section of a semiconductor device
according to an eighth embodiment of the invention.
[0047] FIG. 17 is a cross section of the semiconductor device of
FIG. 16 and a resin molding die, showing how the semiconductor
device is manufactured.
[0048] FIG. 18 is a cross section of a semiconductor device
according to a ninth embodiment of the invention.
[0049] FIG. 19 is a top plan view of the semiconductor device of
FIG. 18.
[0050] FIG. 20A and FIG. 20B are cross sections of the
semiconductor device of FIG. 18 and a resin molding die, showing
how the semiconductor device is manufactured.
[0051] FIG. 21 is a cross section of a semiconductor device
according to a tenth embodiment of the invention.
[0052] FIG. 22 is a cross section the semiconductor device of FIG.
21 and a resin molding die, showing how the semiconductor device is
manufactured.
[0053] FIG. 23 is a cross section of a resin molding die in an
eleventh embodiment of the invention.
[0054] FIG. 24 is a cross section of a resin molding die in a
twelfth embodiment of the invention.
[0055] FIG. 25 is a top plan view of a semiconductor device in the
related art.
[0056] FIG. 26 is a cross section of the semiconductor device of
FIG. 25.
[0057] FIG. 27 is a top plan view of another semiconductor device
in the related art.
[0058] FIG. 28 is a cross section of the semiconductor device of
FIG. 27.
[0059] FIG. 29A and FIG. 29B are cross sections showing how mold
encapsulation is performed for the semiconductor device of FIG. 25
and a resin molding die.
[0060] FIG. 30 is a top plan view of a semiconductor device of the
related art.
[0061] FIG. 31 is a cross section showing how a first resin molding
process is performed for the semiconductor device shown in FIG. 27
and FIG. 28.
[0062] FIG. 32 is a cross section showing how a second resin
molding process is performed for the semiconductor device shown in
FIG. 27 and FIG. 28.
[0063] FIG. 33 is a cross section showing how a third resin molding
process is performed for the semiconductor device shown in FIG. 27
and FIG. 28.
[0064] FIG. 34 is a cross section showing how a fourth resin
molding process is performed for the semiconductor device of the
related art.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0065] The invention will be described with reference to the
embodiments shown in the accompanying drawings.
[0066] (First Embodiment)
[0067] In this embodiment of the invention is applied to a
semiconductor device having the ball grid array structure, a method
of manufacturing the semiconductor device, a resin molding die used
by the foregoing method, and a semiconductor manufacturing system
for manufacturing semiconductor devices according to the foregoing
method.
[0068] [Structure of Semiconductor Device ]
[0069] Referring to FIG. 1 and FIG. 2, a semiconductor device 50
comprises: a base 51; a semiconductor element 52 provided on the
base 51; and a resin seal 55 encapsulating the semiconductor
element 52 on the base 51 and having a recess 550 positioned above
the semiconductor element 52.
[0070] The base 51 has a semiconductor element 52 mounted thereon
and is partially encapsulated together with the semiconductor
element 52 by a resin seal 55. The base 51 is constituted at least
by a circuit board, a wiring board, an insulated substrate, a tape
substrate, a resin substrate, a ceramics substrate, a power source
substrate, a radiating substrate, or a lead (i.e. a lead frame
which a resin is being filled). In this embodiment, the base 51 is
a wiring board, and includes an insulated substrate 510, a terminal
511 provided on the front surface thereof (upper surface in FIG.
1), and a terminal 512 provided on the rear surface thereof (lower
surface in FIG. 1). Although not shown in detail, the terminals 511
and 512 are electrically connected by a through-hole wiring
extending through the insulated substrate 510. The insulated
substrate 510 may be a plastic substrate made of an epoxy group
resin, polyimide group resin or the like, a tape substrate, a
ceramics substrate or the like. The terminals 511 and 512 may be
made of copper (Cu) foils, copper alloy foils, or composite films
including copper foils and copper alloy foils. All of these
materials have excellent electrical conductivity. The terminals 511
and 512 are deposited by the sputtering process and are patterned
by the etching. And, the terminals 511 and 512 are formed by
plating or printing process. External connection terminals 58 made
of solder balls are electrically and mechanically connected to the
terminal 512 on the rear surface of the base 51.
[0071] The semiconductor element 52 is constituted by a silicon
single crystal chip 520, and includes on its main surface (upper
surface in FIG. 1) a plurality of elements such as insulated gate
filed effect transistors (IGFET), bipolar transistors, resistance
elements, capacitance elements and so on, which are not shown in
FIG. 1. Between these elements, it is electrically connected by the
wirings. Further, the semiconductor element 52 is provided with
circuits such as a logic circuit or a memory circuit or a mixture
of the logic and memory circuits.
[0072] The semiconductor device 50 is preferable to encapsulate the
semiconductor element 52 of the semiconductor device 50 which
includes CPU, MPU circuits so on generating a lot of calories
during their operations. An external terminal (bonding pad) 521 is
provided on the main surface of the semiconductor element 52 in
order to electrically connect the foregoing circuits to the
terminal 511. The bonding pad 521 is flush with an uppermost wiring
for connecting the foregoing elements and is made of the material
same as that of the uppermost wiring, e.g. an aluminum alloy
(Al--Si, Al--Cu, or Al--Cu--Si) film.
[0073] The semiconductor element 52 is mounted on the front center
of the base 51 in a face-up state, i.e. is mounted on the front
surface of the insulated substrate 510 via a resin adhesive 53.
[0074] When an electrode is formed on the rear surface of the
semiconductor element 52, the terminal 511 is positioned on the
front center of the insulated substrate 510, the semiconductor
element 52 is electrically connected to and is mechanically mounted
on the terminal 511 via a jointing material layer made of a
gold-germanium alloy (Au--Ge), a gold-silicon alloy (Au--Si), a
gold-tin alloy (Au--Sn) or the like.
[0075] Alternatively, the semiconductor element 52 may be bonded or
mounted on the base 51 by the tape-automated bonding process (TAB),
flip-chip bonding method (FCB) or the like. In the case of the TAB
process, the base 51 is a tape substrate having an opening at the
center thereof in order to mount the semiconductor element 52
therein. The base 51 also has a lead (finger lead) projecting in
the foregoing opening. The external terminal 521 of the
semiconductor element 52 is electrically and mechanically bonded to
the lead by the thermo-compression process via a solder bump
electrode, an Au bump electrode or the like. The semiconductor
element 52 is bonded in the face-up or face-down state. With the
FCB process, a lead wiring is provided on the base 51 made of a
plastic substrate, a ceramics substrate or the like, and is bonded
to the external terminal 521 of the semiconductor element 52. The
lead wiring and external terminal 521 are electrically and
mechanically connected via a bump electrode. The semiconductor
element 52 is bonded in the face-down state.
[0076] The external terminal 521 of the semiconductor element 52
and the terminal 511 of the base 51 are electrically connected by
wires (e.g. bonding wires) 54 such as Au wires, Al wires or the
like.
[0077] The resin seal 55 hermetically encapsulates the
semiconductor element 52, wires 54 and terminal 511 at the front
center of the base 51 in order to protect them against ambient
conditions. The resin seal 55 is molded by the direct transfer
molding process (as will be described later), and is made of an
epoxy group resin.
[0078] The recess 550 at the upper center of the resin seal 55,
i.e. just above the semiconductor element 52, is formed by removing
a part of the resin seal 55 in order to reduce the volume of the
resin seal 55. In the direct transfer molding process, the recess
550 is formed at a contact area between a cylindrical resin
reservoir (622) and a cavity (621) of a resin molding die (60), and
is intentionally made by slightly reducing an amount of a resin
(55A) to be filled in the cavity (621) (refer to FIG. 3).
[0079] The resin seal 55 is thinner at the recess 550 than at the
other part of the resin seal 55. Therefore, the recess 550 easily
radiates heat generated during the operation of the semiconductor
element 52 compared with the other part of the resin seal 55, and
serves as a radiating path. As a whole, the resin seal 55 is thick
enough to keep its own mechanical strength. By the way, the resin
seal 55 sometimes has recesses which are caused by ejection pins
(602) used to unclamp the resin molding die (60) after the mold
encapsulation process is completed (refer to FIG. 3). However, the
recess 550 of the resin seal 55 is formed at the position where the
resin seal 55 is in direct contact with the resin reservoir (622)
of the resin molding die, and fundamentally differs from the
recesses caused by the ejection pins (602). In other words, the
recess 550 is wider than the recesses caused by the ejection pins
(602).
[0080] The resin seal 55 is thin at its recess 550 which serves as
the radiating path, so that the radiating function of the
semiconductor device 50 is improved. Further, the resin seal 55 is
thick at the area surrounding the recess 550, thereby improving the
mechanical strength thereof. Therefore, the semiconductor device 50
can be reliably mounted on a mounting board (e.g. a mother board, a
daughter board and so on) or on equipment (e.g. a computer, a game
machine and so on) in which the semiconductor device 50 is
incorporated and assure reliable operation.
[0081] [Structure of Resin Molding Die]
[0082] Referring to FIG. 3, the resin molding die 60 for forming
the resin seal 55 of the semiconductor device 50 comprises at
least: a cavity 621; a resin reservoir 622 housing the resin 55A
for substantially filling the cavity 621 and being in direct
contact with the cavity 621; and a pusher 603 injecting the resin
55A in the cavity 621. In the resin molding die 60, a upper cavity
block 61, a lower cavity block 62, a lower cavity base 63 and a
mold base 64 are stacked one over after another with the mold base
64 positioned at the bottom.
[0083] The upper cavity block 61 has on its lower surface a base
cavity 610 for receiving the base 51.
[0084] The lower cavity block 62 has on its upper surface the
cavity 621 for molding the resin seal 55 and facing with the base
cavity 610. In the lower cavity block 62, an upper end of the
cylindrical resin reservoir 622 is in direct contact with the
bottom center of the cavity 621. The pusher 603 is housed in the
resin reservoir 622, and slides up and down therein in order to
inject the resin 55A into the cavity 621. In the resin molding die
60, the pusher 603 has its top slightly projecting into the cavity
621, thereby forming the recess 550 on the resin seal 55. A volume
derived by multiplying an inner diameter of the resin reservoir 622
and a slide stroke of the pusher 603 is approximately equal to a
volume of the cavity 621. A volume of the resin 55A or the resin
reservoir 622 is designed to be slightly smaller than the volume of
the cavity 621 since the recess 550 is formed on the resin seal 55.
In other words, the resin reservoir 622 is independent from the
cavity 621 in order that the resin 55A can be directly injected
into the cavity 621 without via a cull, a runner and a resin
gate.
[0085] The pusher 603 is housed in a container (or a box) 605
extending between the lower cavity block 62 and the mold base 64
with a resilient member 604 fitted therein, which urges the pusher
603 toward the bottom of the resin reservoir 622. The resilient
member 604 is preferably a coil spring. The pusher 603 is
independent from a plunger 71, and is in contact with the plunger
71 via its rounded lower end. The plunger 71 pushes the pusher 603
upward, which then fills the cavity 621 with the resin 55A from the
resin reservoir 622.
[0086] The lower cavity block 62 includes a pilot pin 601 for
alignment with the upper cavity block 61, and ejection pins 602 for
separating the resin seal 55 out of the cavity 621. For example,
four ejection pins 602 are provided around the resin reservoir 622.
An open top of each ejection pin 602 is smaller than an open top of
the resin reservoir 622 and is not filled with the resin 55A
because the ejection pins 602 are used only to separate the resin
seal 55.
[0087] Still, in this embodiment, the ejection pin 602 would be
pushing the base 51. When the ejection pin 602 pushes the resin
seal 55, the scar of the ejection pin 602 is formed for the resin
seal 55. An area of the scar of the ejection pin 602 is smaller
than an open top of the resin reservoir 622.
[0088] In this embodiment, the resin molding die 60 includes at
least the resin reservoir 622 in direct contact with the cavity
621, and the pusher 603 for injecting the resin 55A into the cavity
621, and is used to produce the resin seal 55 for the semiconductor
device 50. Further, since the pusher 603 is included in the resin
molding die 60, it is not necessary to assemble the plunger 71 in
such a manner that it enters into the resin molding die 60.
Therefore, resin molding can be performed only by setting the resin
molding die 60 above the plunger 71 such that it is in contact with
the pusher 603.
[0089] [Structure of Semiconductor Manufacturing System]
[0090] Referring to FIG. 3, a semiconductor manufacturing system
(i.e. a direct transfer molding system) 70 for molding the resin
seal 55 comprises at least: the resin molding die 60 (which is
detachable); the plunger 71 for vertically moving the pusher 603 of
the resin molding die 60; a plunger driving unit 72; a die driving
unit 74 for driving at least the upper or lower cavity block 61 or
62 (i.e. the lower cavity block 62 in the first embodiment); and a
control unit 73 for controlling the plunger driving unit 72 and the
die driving unit 74.
[0091] The plunger 71 is not mechanically coupled to but is in
contact with the pusher 603 as described above. In the resin
molding die 60, the pusher 603 is designed to slide up and down.
Therefore, the plunger 71 has an axial length to exert a force to
the pusher 603 for injecting the resin 55A. The pusher 603 has a
round bottom in order to alleviate anti-axial stress which is
applied to the plunger 71 and is caused by a sliding resistance
during the injection of the resin 55A or minute assembly errors. As
a result, only the axial stress is applied to the plunger 71. It is
possible to protect the pusher 603 against damages caused by the
inclination of the plunger 71 and so on. Further, the pusher 603 is
usually urged downward by the resilient member 604, so that
substantially no stress is applied to the plunger 71 when it
retracts after the resin 55A is filled. This feature is effective
in protecting the pusher 603 against damages caused by the
inclination of the plunger 71.
[0092] Each of the plunger driving unit 72 and die driving unit 74
may be constituted by a pneumatic cylinder, a hydraulic cylinder,
or a combination of an electric motor and a hoisting mechanism. The
control unit 73 is constituted at least by a micro-processor, a
memory, a control panel and so on in order to control the plunger
driving unit 72 and the die driving unit 74.
[0093] This semiconductor manufacturing system 70 can mold the
resin seal 55 and manufacture the semiconductor device 50.
[0094] [Method of Manufacturing Semiconductor Device]
[0095] The method of manufacturing the semiconductor device 50
(i.e. the direct transfer molding process) will be described with
reference to FIG. 4A and FIG. 4B.
[0096] (1) First of all, the base 51 is placed on the lower cavity
block in such a manner that the semiconductor element 52 as well as
a part of the base 51 is fitted in the cavity 621 of the resin
molding die 60 (see FIG. 4A). In this state, the semiconductor
element 52 has been mounted on the base 51, and the terminal 511 of
the base 51 and the external terminal 521 of the semiconductor
element 52 have been electrically connected by the wires 54. Since
the cavity 621 is present on the lower cavity block 62, the base 51
is placed on the lower cavity block 62 with the semiconductor
element 52 facing down.
[0097] (2) The resin 55A is supplied to the resin reservoir 622,
which is at the center of the cavity 621 and is above the center of
the semiconductor element 52 (see FIG. 4A). The resin 55A is then
injected in order to substantially fill the cavity 621. The amount
of the resin 55A is determined on the basis of the volume of the
cavity 621 after deducting the volume of the components such as the
semiconductor element 52 and the wire 54 a and so on in the cavity
621. Further, the amount of the resin 55A is slightly reduced
taking the recess 550 into consideration. The resin 55A may be a
tablet or powder resin. Still further, before or after injecting
the resin 55A into the resin reservoir 622, the lower cavity block
62 is heated by a heater (not shown), and is maintained at a
temperature of 165.degree. C. to 185.degree. C. in order to melt
the resin 55A.
[0098] (3) The lower cavity block 62 is raised toward the upper
cavity block 61 by the operation of the die driving unit 74 and the
control unit 73 (which are shown in FIG. 3), so that the upper and
lower cavity blocks 61 and 62 are clamped as shown in FIG. 4A.
Therefore, the base 51 is received in the base cavity 610 of the
upper cavity block 61.
[0099] (4) Since the resin molding die 60 remains hot, the resin
55A is melted in the resin reservoir 622, and is injected into the
cavity 621 by the pusher 603 via the resin reservoir 622 as shown
in FIG. 4B. The pusher 603 is moved upward by the plunger driving
unit 72 and the control unit 73. Specifically, the pusher 603
injects the resin 55A into the cavity 621 with a pressure of
approximately 5 MPa to 15 MPa and a sufficient injection stroke via
the resin reservoir 622. Further, the pusher 603 slightly projects
into the cavity 621 in order to form the recess 550. In this state,
the resin 55A is heated for approximately 40 seconds to 180
seconds, and is then hardened in order to form the resin seal 55
which encapsulates at least the semiconductor element 52 as well as
a part of the base 51, and has the recess 550.
[0100] (5) Thereafter, the lower cavity block 62 is lowered by the
die driving unit 74 and the control unit 73. The upper and lower
cavity blocks 61 and 62 are unclamped, so that the molded
semiconductor device 50 is removed from the resin molding die 60
using the ejection pins 602.
[0101] In this state, the semiconductor device 50 is completed by
the direct transfer molding process.
[0102] In the foregoing manufacturing method, all of the resin 55A
in the resin reservoir 622 is injected into the cavity 621 in order
to form the resin seal 55, so that there is no superfluous resin
which might form a cull, runner or resin gate. In other words, the
molded resin seal 55 itself can be treated as the complete product
which does not need any gate-breaking. Therefore, it is possible to
reduce an amount of the resin to be used and an amount of the resin
to be discarded. Further, it is possible to remarkably reduce the
manufacturing cost of the semiconductor device 50 since no post
treatment is required. This also leads to the reduction of the
product cost of the semiconductor device 50.
[0103] Further, the resin seal 55 does not peel off or is not
cracked since no gate-breaking is performed after the resin 55A is
filled in the cavity 621. As a result, the manufactured
semiconductor device 50 becomes more resistant against external
conditions, which improves the manufacturing yield thereof.
[0104] Still further, all of the resin 55A in the resin reservoir
622 is uniformly injected into the cavity 62 with a sufficient
injection stroke, so that it is possible to reduce voids in the
resin seal 55, to strengthen an adhesive force between the resin
seal 55 and the base 51, and improve the manufacturing yield of the
semiconductor device 50.
[0105] Since the resin 55A is injected into the cavity 621 via the
resin reservoir 622 above the semiconductor element 52, it is
possible to obviate the resin 55A passing over the base 51 via a
runner and a resin gate. In other words, the base 51 of the
semiconductor device 50 is free from a metal part which promotes
the gate-breaking. The base 51 can be downsized as a whole (since
the terminal 511 is arranged at a position where the metal part may
be provided), which means that the semiconductor device 50 can be
downsized in this manufacturing method.
[0106] This manufacturing method requires neither the additional
die or the plate 20 used in the first resin molding process for the
semiconductor device shown in FIG. 31 nor the sheet 21 used in the
second resin molding process for the semiconductor device shown in
FIG. 32, which means that no dedicated device for attaching the
foregoing components is also necessary. This can reduce the
manufacturing cost of the semiconductor device 50.
[0107] In the third and fourth resin molding processes for the
semiconductor devices shown in FIG. 33 and FIG. 34, it is necessary
to provide the special resin inlet 22 and resin outlet 23 in the
substrate 1, plate 10 and frame 24. However, the manufacturing
method of this invention does not require any resin inlet and resin
outlet in the base 51. Therefore, the manufacturing cost of the
semiconductor device 50 can be reduced. In addition, it is possible
to improve the mechanical strength of the base 51, and reliability
and manufacturing yield of the semiconductor device 50.
[0108] According to the first embodiment, all of the resin 55A
stored in the resin reservoir 622 is injected into the cavity 621
from the center thereof (i.e. from the center of the cavity 621
facing with the upper surface of the semiconductor element 52) to
the peripheral part of the cavity 621. As a result, the resin 55A
can be uniformly filled in the cavity 621, voids are reduced, and
the manufacturing yield of the semiconductor device 50 can be
improved.
[0109] When a plurality of wires 54 are radially bonded from the
center of the semiconductor element 52, they can be made to extend
in the same direction in which the resin 55A is injected (i.e.
substantially in parallel). Therefore, shorting of adjacent wires
54 can be prevented because the resin 55A does not flow in the
direction which intersects the extending direction of the wires 54.
This is effective in improving the manufacturing yield.
[0110] (Second Embodiment)
[0111] This embodiment differs from the first embodiment in the
shape of the resin seal 55 of the semiconductor device 50.
[0112] [Structure of Semiconductor Device ]
[0113] Referring to FIG. 5, the semiconductor device 50 comprises
the base 51, the semiconductor element 52 on the base 51, and the
resin seal 55 which encapsulates a part of the base 51 as well as
the semiconductor element 52 and has a protrusion 551. The base 51
and semiconductor element 52 are identical to those of the first
embodiment, and will not be described in detail.
[0114] The resin seal 55 hermetically encapsulates the
semiconductor element 52, wires 54 and the terminal 511 on the
center of the base 51 in order to protect them against ambient
conditions. The resin seal 55 is molded by the direct transfer
molding process similarly to the resin seal 55 of the first
embodiment, and is made of an epoxy group resin, for example.
[0115] The resin seal 55 has the protrusion 551 at the center
thereof just above the semiconductor element 52, and is in contact
with other components only via the protrusion 551 with a gap
maintained around itself. Here, the "other components" refer to
equipment in which the semiconductor device 50 is incorporated, a
wiring board mounted on the semiconductor device 50, and so on.
With semiconductor devices 50 of ninth and tenth embodiments to be
described later (shown in FIG. 18, FIG. 19 and FIG. 21), the "other
components" refer to equipment in which the semiconductor device 50
is incorporated, a wiring board mounted on the semiconductor device
50, and so on if semiconductor elements 52 and resin seals 55 are
provided on rear surfaces of bases 51. The gap has a size for
enabling a cleaning agent or air to flow therethrough. The
protrusion 551 is formed while the resin seal 55 is made by the
direct transfer molding process, as in the semiconductor device 50
of the first embodiment. Specifically, the protrusion 551 is
intentionally formed at a position where the resin reservoir 622 is
in direct contact with the cavity 621. The amount of the resin 55A
to be injected into the cavity 621 is somewhat increased in order
to form the protrusion 551 (refer to FIG. 6).
[0116] In the semiconductor device 50 of the second embodiment, the
protrusion 551 serves as a radiating path, thereby assuring
excellent radiating performance. Especially, the protrusion 551 is
positioned above and extends over the semiconductor element 52, so
that it is possible to radiate heat, which is generated by the
circuit operation of the semiconductor element 52, through the
shortest radiating path (with a minimum heat resistance). Further,
there is the gap around the protrusion 551, which enables the
cleaning agent or air to smoothly flow therethrough during the
cleaning and drying processes after the semiconductor device 50 is
mounted on a mounting board or equipment in which the semiconductor
device is incorporated. This is effective in improving the
manufacturing yield, reducing mounting errors and producing the
reliable semiconductor device 50.
[0117] [Method of Manufacturing Semiconductor Device]
[0118] The semiconductor device 50 is produced by the direct
transfer molding process as shown in FIG. 6. The resin seal 55 is
molded by the resin molding die 60 and the semiconductor
manufacturing system 70 which are used in the first embodiment, so
that their structures will not be described in detail.
[0119] (1) First of all, the base 51 is placed on the lower cavity
block 62 in such a manner that the semiconductor element 52 as well
as a part of the base 51 is fitted in the cavity 621 of the resin
molding die 60 (see FIG. 4A).
[0120] (2) The resin 55A is supplied to the resin reservoir 622,
which is at the center of the cavity 621 and is above the center of
the semiconductor element 52. The resin 55A is then injected in
order to substantially fill the cavity 621. Further, the amount of
the resin 55A is somewhat increased for the protrusion 551. Still
further, before or after supplying the resin 55A to the resin
reservoir 622, the lower cavity block 62 is maintained at a
temperature to melt the resin 55A.
[0121] (3) The upper and lower cavity blocks 61 and 62 are clamped
as shown in FIG. 4A. Thereafter, the resin 55A is injected into the
cavity 621 by the pusher 603 via the resin reservoir 622. In this
case, the pusher 603 injects the resin 55A with an appropriate
pressure to the resin 55A and a sufficient injecting stroke. The
volume of the resin 55A is slightly larger than the volume of the
cavity 621. When the pressure applied by the pusher 603 reaches a
predetermined value, the control unit 73 detects the load of the
plunger driving unit 72 of the semiconductor manufacturing system
70 shown in FIG. 3. The pusher 603 stop injecting the resin 55A
slightly before it reaches the cavity 621. Then, the resin 55A is
hardened, thereby forming the resin seal 55 which encapsulates a
part of the base 51 as well as the semiconductor element 52, and
has the protrusion 551.
[0122] (4) Thereafter, the upper and lower cavity blocks 61 and 62
are unclamped in order to remove the semiconductor device 50 having
the resin seal 55, from the resin molding die 60.
[0123] In this state, the semiconductor device 50 is completed by
the direct transfer molding process.
[0124] The method of manufacturing the semiconductor device 50 of
the second embodiment is as effective and advantageous as that of
the first embodiment.
[0125] (Third Embodiment)
[0126] In this embodiment, a semiconductor device 50 is
substantially identical to the semiconductor device 50 of the first
embodiment except for the shape of the base 51.
[0127] [Structure of Semiconductor Device]
[0128] Referring to FIG. 7 and FIG. 8, the semiconductor device 50
comprises the base 51, the semiconductor element 52 on the base 51,
and the resin seal 55 encapsulating the semiconductor element 52
and having the recess 550. The semiconductor element 52 is
identical to that of the first embodiment, and will not be
described here.
[0129] The base 51 is constituted at least by: an insulated
substrate 510, in this embodiment; a frame 516 which is positioned
on the front surface (upper surface in FIG. 7) of the insulated
substrate 510, and has an opening 516H at the center thereof in
order to house the semiconductor element 52 and the resin seal 55;
an adhesive layer 515 provided between the insulated substrate 510
and the frame 516; a terminal 511 provided on the front surface of
the insulated substrate 510 (upper surface in FIG. 7); and a
terminal 512 provided on the rear surface of the insulated
substrate 510 (lower surface in FIG. 7). The terminal 511 is
positioned in the opening 516H of the frame 516. Although not shown
in detail, the terminals 511 and 512 are electrically connected by
a through-hole wiring extending through the insulated substrate
510. The insulated substrate 510 is a plastic substrate made of an
epoxy group resin, a polyimide resin or the like, a tape substrate,
a ceramics substrate or the like. The terminals 511 and 512 are
made of Cu foils, Cu alloy foils, or a composite film made of the
foregoing foils.
[0130] The frame 516 is made of an epoxy group resin, ceramics,
silicon carbide, a film, a tape, rubber, metal, alloy, or the like.
The frame 516 protects the semiconductor element 52 against
external stress, improves the mechanical strength of the base 51
and the overall flatness of the semiconductor device 50, and
functions as a dam during the molding of the resin seal 55. The
adhesive 515 is an insulated resin adhesive, for example.
[0131] The resin seal 55 has the recess 550 at the center thereof
similarly to the resin seal 55 of the first embodiment. However,
the periphery of the resin seal 55 is in contact with an inner wall
of the opening 516H of the frame 516. The resin seal 55 is
positioned in the opening 516H, and is designed such that the upper
periphery thereof is flush with the upper surface of the frame 516.
Therefore, the semiconductor device 50 is in the shape of a plate
since the resin seal 55 is substantially flat. The recess 550 at
the center of the resin seal 55 is set back toward the insulated
substrate 510 with respect to the upper surface of the frame 516.
The resin seal 55 is molded by the direct transfer molding process,
and is made of the epoxy group resin, similarly to the resin seal
55 of the first embodiment.
[0132] The semiconductor device 50 of the third embodiment is as
effective and advantageous as the semiconductor device 50 of the
first embodiment.
[0133] [Method of Manufacturing Semiconductor Device]
[0134] The semiconductor device 50 is manufactured by the direct
transfer molding process as shown in FIG. 9. The resin molding die
60 and the semiconductor manufacturing system 70 of the first
embodiment are also used in this embodiment, and will not be
described here.
[0135] (1) First of all, the base 51 is placed on the lower cavity
block 62 in such a manner that the semiconductor element 52 as well
as a part of the base 51 is fitted in the cavity 621 of the resin
molding die 60 (see FIG. 9). Since the base 51 includes the frame
516 having the opening 516H, the cavity 621 is defined by the front
center of the insulated substrate 510 of the base 51, the frame 516
and the upper surface of the lower cavity block 62. Therefore, the
lower cavity block 62 is not required to have the cavity 621 and is
flat, contrary to the lower cavity block 62 of the first
embodiment. It is possible to simplify the structure of the resin
molding die 60, and to reduce the manufacturing cost thereof.
[0136] (2) The resin 55A is supplied into the resin reservoir 622,
which is at the center of the cavity 621 and is above the center of
the semiconductor element 52 (see FIG. 9). The resin 55A is then
injected into the cavity 621 in order to fill it substantially. The
amount of the resin 55A is determined on the basis of the volume of
the cavity 621, and the volume of the recess 550 of the resin seal
55. The lower cavity block 62 is maintained at a temperature to
melt the resin 55A.
[0137] (3) The upper and lower cavity blocks 61 and 62 are clamped
as shown in FIG. 9. Thereafter, the melted resin 55A is injected
into the cavity 621 by the pusher 603 via the resin reservoir 622.
The pusher 603 injects all of the resin 55A into the cavity 621
with an appropriate pressure and a sufficient injection stroke.
Further, the pusher 603 slightly projects into the cavity 621 in
order to form the recess 550. In this state, the resin 55A is
hardened in order to form the resin seal 55 which encapsulates at
least the semiconductor element 52 as well as a part of the base 51
and has the recess 550 (see FIG. 4B).
[0138] (4) Thereafter, the upper and lower cavity blocks 61 and 62
are unclamped in order to remove the semiconductor device 50 having
the resin seal 55, from the resin molding die 60.
[0139] In this state, the semiconductor device 50 is completed by
the direct transfer molding process.
[0140] The method of manufacturing the semiconductor device 50 of
the third embodiment is as effective and advantageous as that of
the first embodiment.
[0141] In this embodiment, the base 51 includes the frame 516
having the opening 516H which serves as the cavity 621, so that the
lower cavity block 62 does not have the cavity 621. This is
effective in simplifying the resin molding die 60.
[0142] (Fourth Embodiment)
[0143] In this embodiment, the semiconductor devices 50 of the
second and third embodiments are combined.
[0144] [Structure of Semiconductor Device ]
[0145] Referring to FIG. 10, the semiconductor device 50 comprises
the base 51, the semiconductor element 52 on the base 51, and the
resin seal 55 which encapsulates the semiconductor element 52 and
the base 51, and has the protrusion 551. The semiconductor element
52 is identical to the semiconductor element 52 in the first
embodiment, and will not be described in detail.
[0146] The base 51 is identical to the base 51 of the third
embodiment, and is constituted at least by: the insulated substrate
510; the frame 516 which is positioned on the front surface (upper
surface in FIG. 10) of the insulated substrate 510, and has the
opening 516H at the center thereof in order to house the
semiconductor element 52 and the resin seal 55; an adhesive layer
515 provided between the insulated substrate 510 and the frame 516;
the terminal 511 provided on the front surface of the insulated
substrate 510 (upper surface in FIG. 10); and the terminal 512
provided on the rear surface of the insulated substrate 510 (lower
surface in FIG. 10).
[0147] The resin seal 55 has the protrusion 551 at the center
thereof similarly to the resin seal 55 of the second embodiment.
However, the periphery of the resin seal 55 is in contact with the
inner wall of the opening 516H of the frame 516. The resin seal 55
is positioned in the opening 516H, and is designed such that the
upper periphery of the resin seal 55 is flush with the upper
surface of the frame 516. Therefore, the semiconductor device 50 is
in the shape of a plate since the resin seal 55 is substantially
flat. The protrusion 551 at the center of the resin seal 55 extends
upward with respect to the upper surface of the frame 516. The
resin seal 55 is molded by the direct transfer molding process and
is made of the epoxy group resin, similarly to the resin seal 55 of
the third embodiment.
[0148] The semiconductor device 50 of the fourth embodiment is as
effective and advantageous as the semiconductor devices 50 of the
second and third embodiments.
[0149] [Method of Manufacturing Semiconductor Device]
[0150] The semiconductor device 50 of this embodiment is
manufactured by the direct transfer molding process as in the
second embodiment. Referring to FIG. 9, the amount of the resin 55A
to be injected into the cavity 621 of resin molding die 60 is
slightly increased. In the fourth embodiment, when the injecting
pressure reaches the predetermined value, the pusher 603 is stopped
slightly before it gets into the cavity 621, thereby forming the
protrusion 551. Therefore, the fourth embodiment differs from the
third embodiment in this respect.
[0151] The structures of the resin molding die 60 and the
semiconductor manufacturing system 70 are the same as the resin
molding die 60 of the first embodiment and the semiconductor
manufacturing system 70 of the first embodiment. Therefore, their
descriptions will not be given here.
[0152] The semiconductor device manufacturing method of the fourth
embodiment is as effective and advantageous as that in the third
embodiment.
[0153] (Fifth Embodiment)
[0154] In this embodiment, the semiconductor device 50 is
substantially identical to the semiconductor device 50 of the third
embodiment, except for the shape of the base 51.
[0155] Referring to FIG. 11, the semiconductor device 50 comprises
the base 51, the semiconductor element 52 on the base 51, and the
resin seal 55 encapsulating the semiconductor element 52 and having
the recess 550. The semiconductor element 52 is identical to that
of the first embodiment, and will not described here.
[0156] The base 51 is constituted at least by: the insulated
substrate 510; a frame 518 which is positioned on the front surface
(upper surface in FIG. 11) of the insulated substrate 510, and has
an opening 518H at the center thereof in order to house the
semiconductor element 52 and the resin seal 55; an adhesive layer
517 provided between the insulated substrate 510 and the frame 518;
the terminal 511 provided on the front surface of the insulated
substrate 510 (upper surface in FIG. 11); and the terminal 512
provided on the rear surface of the insulated substrate 510 (lower
surface in FIG. 11). The frame 518 is mainly used as a dam when
forming the resin 55A. When made of an elastic epoxy group resin or
a rubber material, the frame 518 is coated on the insulated
substrate 510. In such a case, no adhesive layer 517 will be
necessary between the insulated substrate 510 and the frame 518.
The terminal 511 is positioned in the opening 518H of the frame
518. Although not shown in detail, the terminals 511 and 512 are
electrically connected by a through-hole wiring extending through
the insulated substrate 510.
[0157] The frame 518 slightly differs from the frame 516 of the
third embodiment because the frame 518 is positioned in such a
manner that a part of the peripheral surface of the insulated
substrate 510 is exposed. The frame 518 also functions as the dam
which prevents the resin 55A filled in the cavity 621 from flowing
in a horizontal direction. Alternatively, the frame 518 may be made
of a metal or an alloy similarly to the frame 516 of the third or
fourth embodiment. In such a case, the adhesive layer 517 is
necessary, and is made of an insulating adhesive.
[0158] The resin seal 55 has the recess 550 at the center thereof
similarly to the resin seal 55 of the third embodiment. The
peripheral surface of the resin seal 55 is in contact with an inner
wall of the opening 518H of the frame 518. The resin seal 55 is
positioned in the opening 518H, and is designed such that the upper
periphery of the resin seal 55 is flush with the upper surface of
the frame 518. Therefore, the semiconductor device 50 is in the
shape of a plate since the resin seal 55 is substantially flat. The
recess 550 at the center of the resin seal 55 is set back toward
the insulated substrate 510 with respect to the upper surface of
the frame 518. The resin seal 55 is molded by the direct transfer
molding process, and is made of the epoxy group resin, similarly to
the resin seal 55 of the third embodiment.
[0159] The semiconductor device 50 of the fifth embodiment is as
effective and advantageous as the semiconductor device 50 of the
third embodiment.
[0160] The structures of the resin molding die 60, the
semiconductor manufacturing system 70 and the semiconductor device
manufacturing method are the same as those of the third embodiment,
so that they will be not described here.
[0161] (Sixth Embodiment)
[0162] In this embodiment, the semiconductor device 50 is
substantially identical to the semiconductor device 50 of the
fourth embodiment except for the shape of the base 51.
[0163] Referring to FIG. 12, the semiconductor device 50 comprises
the base 51, the semiconductor element 52 on the base 51, and the
resin seal 55 which encapsulates the semiconductor element 52 and
has the protrusion 551. The semiconductor element 52 is identical
to the semiconductor element 52 of the fourth embodiment, and will
not be described in detail.
[0164] The base 51 is identical to that of the semiconductor device
50 of the fifth embodiment, and is constituted at least by: the
insulated substrate 510; the frame 518 which is positioned on the
front surface (upper surface in FIG. 12) of the insulated substrate
510, and has the opening 518H the center thereof in order to house
the semiconductor element 52 and the resin seal 55; the adhesive
layer 517 provided between the insulated substrate 510 and the
frame 518; the terminal 511 provided on the front surface of the
insulated substrate 510 (upper surface in FIG. 12); and the
terminal 512 provided on the rear surface of the insulated
substrate 510 (lower surface in FIG. 12). Although not shown in
detail, the terminals 511 and 512 are electrically connected by a
through-hole wiring.
[0165] The frame 518 serves at least as a dam similarly to the
frame 518 of the fifth embodiment. Depending upon the material of
the frame 518, no adhesive layer 517 will be necessary between the
insulated substrate 51 and the frame 518 as in the fifth
embodiment.
[0166] The resin seal 55 has the protrusion 551 at the center
thereof similarly to the resin seal 55 of the fourth embodiment.
However, the periphery of the resin seal 55 is in contact with the
inner wall of the opening 518H of the frame 518. The resin seal 55
is positioned in the opening 518H, and is designed such that the
upper periphery thereof is flush with the upper surface of the
frame 518. The protrusion 551 at the center of the resin seal 55 is
above the upper surface of the frame 518. The resin seal 55 is
molded by the direct transfer molding process, and is made of the
epoxy group resin, similarly to the resin seal 55 of the fourth
embodiment.
[0167] The semiconductor device 50 of the sixth embodiment is as
effective and advantageous as the semiconductor devices 50 of the
fourth embodiment.
[0168] The structures of the resin molding die 60 and the
semiconductor manufacturing system 70, and the semiconductor device
manufacturing method of this embodiment are the same as those of
the fourth embodiment, so that they will be not described here.
[0169] (Seventh Embodiment)
[0170] A seventh embodiment is identical to the first embodiment
except for the position of the recess 550 of the resin seal 55 of
the semiconductor device 50 and the position of the resin reservoir
622 of the resin molding die 60.
[0171] [Structure of Semiconductor Device]
[0172] As shown in FIG. 13 and FIG. 14, the semiconductor device 50
comprises: the base 51; the semiconductor element 52 provided on
the base 51; and the resin seal 55 encapsulating the semiconductor
element 52 on the base 51 and having a recess 552. The
semiconductor element 52 and the base 51 are structured similarly
to those of the first embodiment, and will not described here.
[0173] The resin seal 55 has the recess 552 displaced from the
center thereof, i.e. the recess 552 is present in the resin seal 55
and overlaps with the semiconductor element 52 or is completely
outside the semiconductor element 52. The recess 552 functions
similarly to the recess 550 of the first embodiment.
[0174] The semiconductor device 50 of this embodiment is as
effective and advantageous as that of the first embodiment.
[0175] Further, this semiconductor device 50 is especially
effective when wires 54 do not radially extend from the center of
the resin seal 55 but when they extend in a particular direction,
i.e. in a direction which is substantially in agreement with a
direction in which the resin 55A is injected. For instance,
referring to FIG. 14, when the wires 54 are arranged at a corner of
the semiconductor elements 52 and diagonally extend thereon, the
recess 552 is positioned at one corner of the resin seal 55 (e.g.
at the left upper corner in FIG. 14). In this case, most of main
component vector in the injecting direction of the resin 55A can be
made to substantially agree with the direction in which the wires
54 extend. Therefore, the adjacent wires 54 can be protected
against shorting caused by the resin 55A flowing across them. This
is effective in improving the manufacturing yield of the
semiconductor device 50.
[0176] [Structure of Resin Molding Die]
[0177] The resin molding die 60 is identical to that of the first
embodiment except for the resin reservoir 622 displaced from the
center of the cavity 621, and will not be described here.
[0178] [Structure of Semiconductor Manufacturing System]
[0179] Further, the semiconductor manufacturing system 70 is
identical to that of the first embodiment, and will not be
described here.
[0180] [Method of Manufacturing Semiconductor Device]
[0181] The semiconductor device 50 is manufactured by the direct
transfer molding process as shown in FIG. 15A and FIG. 15B.
[0182] (1) First of all, the base 51 is placed on the lower cavity
block 62 in such a manner that the semiconductor element 52 as well
as a part of the base 51 is fitted in the cavity 621 of the resin
molding die 60 (see FIG. 15A). In this state, the semiconductor
element 52 has been mounted on the base 51, and the terminal 511 of
the base 51 and the terminal 521 of the semiconductor element 52
have been electrically connected by the wires 54.
[0183] (2) The resin 55A is supplied into the resin reservoir 622
which is present above the semiconductor element 52 (see FIG. 15A)
at a position displaced from the center thereof, i.e. the resin
reservoir 622 is positioned near a side wall of the cavity 621.
[0184] Before or after supplying the resin 55A to the resin
reservoir 622, the lower cavity block 62 is heated by a heater (not
shown), and is maintained at a temperature to melt the resin
55A.
[0185] (3) The lower cavity block 62 is raised toward the upper
cavity block 61 by the operation of the die driving unit 74 and the
control unit 73, so that the upper and lower cavity blocks 61 and
62 are clamped as shown in FIG. 15A. Therefore, the base 51 is
received in the base cavity 610 of the upper cavity block 61.
[0186] (4) Since the resin molding die 60 remains hot, the resin
55A is melted in the resin reservoir 622, and is injected into the
cavity 621 via the resin reservoir 622 as shown in FIG. 15B. The
pusher 603 is moved upward by the plunger driving unit 72 and the
control unit 73. Specifically, the pusher 603 injects the resin 55A
into the cavity 621 with an appropriate pressure and a sufficient
injection stroke via the resin reservoir 622. Further, the pusher
603 slightly projects into the cavity 621 in order to form the
recess 552. In this state, the resin 55A is heated, and is then
hardened in order to form the resin seal 55 which encapsulates at
least the semiconductor element 52 as well as a part of the base 51
and has the recess 552.
[0187] (5) Thereafter, the lower cavity block 62 is lowered by the
die driving unit 74 and the control unit 73. The upper and lower
cavity blocks 61 and 62 are unclamped, so that the molded
semiconductor device 50 is removed from the resin molding die
60.
[0188] In this state, the semiconductor device 50 is completed by
the direct transfer molding process.
[0189] The method of the seventh embodiment is as effective and
advantageous as that of the first embodiment.
[0190] (Eighth Embodiment)
[0191] A semiconductor device 50 of this embodiment is identical to
that of the seventh embodiment except for the shape of the resin
seal 55.
[0192] [Structure of Semiconductor Device]
[0193] As shown in FIG. 16, the semiconductor device 50 comprises:
the base 51; the semiconductor element 52 provided on the base 51;
and the resin seal 55 encapsulating the semiconductor element 52 on
the base 51 and having a protrusion 553. The semiconductor element
52 and the base 51 are structured similarly to those of the first
embodiment, and will not described here.
[0194] The resin seal 55 has the protrusion 553 which is similar to
the protrusion 551 of the second embodiment. The protrusion 553 is
displaced from the center of the resin seal 55, similarly to the
protrusion 552 of the seventh embodiment.
[0195] The semiconductor device 50 of this embodiment is as
effective and advantageous as those of the second and seventh
embodiments.
[0196] [Method of Manufacturing Semiconductor Device]
[0197] The semiconductor device 50 is manufactured by the direct
transfer molding process as shown in FIG. 17, using the resin
molding die 60 and the semiconductor system manufacturing system 70
of the first embodiment, which will not be described here.
[0198] (1) The direct transfer molding process of this embodiment
is identical to that of the seventh embodiment. First of all, the
base 51 is placed on the lower cavity block 62 in such a manner
that the semiconductor element 52 as well as a part of the base 51
is fitted in the cavity 621 of the resin molding die 60 (see FIG.
15A).
[0199] (2) The resin 55A is supplied into the resin reservoir 622
in order to substantially fill the cavity 621. The resin reservoir
662 is present above the semiconductor element 52 (see FIG. 15A) at
the position displaced from the center thereof. The amount of the
resin 55A to be filled in the cavity 621 is somewhat increased in
order to form the protrusion 553. The lower cavity block 62 is
heated to a certain temperature in order to melt the resin 55A.
[0200] (3) The upper and lower cavity blocks 61 and 62 are clamped
as shown in FIG. 15A, and the melted resin 55A is injected into the
cavity 621 by the pusher 603 via the resin reservoir 622.
Specifically, the pusher 603 applies an appropriate pressure to the
resin 55A and injects it into the cavity 621 with a sufficient
stroke. The amount of the resin 55A is somewhat increased. The
pusher 603 is stopped slightly before it gests into the cavity 621,
thereby forming the protrusion 553. In this state, the resin 55A is
heated, and is then hardened in order to form the resin seal 55
which encapsulates at least the semiconductor element 52 as well as
a part of the base 51 and has the recess 553 (see FIG. 17).
[0201] (4) Thereafter, the upper and lower cavity blocks 61 and 62
are unclamped, so that the semiconductor device 50 with the resin
seal 55 is removed from the resin molding die 60.
[0202] In this state, the semiconductor device 50 is completed by
the direct transfer molding process.
[0203] The method of the eighth embodiment is as effective and
advantageous as that of the second and seventh embodiment.
[0204] (Ninth Embodiment)
[0205] This embodiment relates to a modified structure of the base
51 and modified mounting of the semiconductor element 52 of the
seventh embodiment.
[0206] [Structure of Semiconductor Device]
[0207] As shown in FIG. 18 and FIG. 19, the semiconductor device 50
is identical to that of the seventh embodiment, and comprises: the
base 51; the semiconductor element 52 provided on the base 51; and
the resin seal 55 encapsulating the semiconductor element 52 on the
base 51 and having the recess 552 above the semiconductor element
52. The semiconductor element 52 and the base 51 are structured
similarly to those of the first embodiment, and will not be
described here.
[0208] The base 51 is constituted at least by: the insulated
substrate 510 which has the opening 510H at the center thereof in
order to house the semiconductor element 52 and the resin seal 55;
a radiating plate 519 extending all over the front surface of the
insulated substrate 510 (on the upper surface in FIG. 18); an
adhesive layer 517 sandwiched by the insulated substrate 510 and
the radiating plate 519; a terminal 513 provided on the center
front surface (upper surface in FIG. 18) of the insulated substrate
510, and the terminal 512 provided on the rear peripheral surface
(lower surface in FIG. 18) of the insulated substrate 510. The
terminal 513 is arranged around the opening 510H, and is
electrically connected to the terminal 512 by a wiring (not
shown).
[0209] The semiconductor element 52 is mounted in the opening 510H
on the rear surface of the radiating plate 519 via the adhesive
layer 53. Different from the semiconductor devices 50 of the first
to eighth embodiments, the semiconductor element 52 is mounted with
its main surface (where the circuits are mounted) facing with a
device mounting surface (lower surface in FIG. 18). The radiating
plate 519 efficiently radiates heat generated by the operation of
the circuits mounted on the semiconductor element 52. In this
embodiment, the radiating plate 519 may be a copper (Cu) plate
having a nickel (Ni)-plated layer with excellent heat
conductivity.
[0210] The insulated substrate 510 with the opening 510H has the
semiconductor element 52 mounted therein, and functions at least as
a dam similarly to the frame 516 of the semiconductor device 50 in
the third embodiment.
[0211] The adhesive layer 517 may be made of an insulated resin
adhesive.
[0212] The resin seal 55 has the recess 552 displaced from the
center thereof as in the seventh embodiment. Further, the resin
seal 55 is via its periphery in contact with the inner wall of the
opening 510H of the base 51, i.e. the resin seal 55 is positioned
in the opening 510H. The resin seal 55 is made by the direct
transfer molding process similarly to the resin seal 55 of the
third embodiment, and is made of an epoxy group resin, for
example.
[0213] Alternatively, the resin seal 55 of the semiconductor device
50 may have the recess 550 at the center thereof as in the first
embodiment.
[0214] The semiconductor device 50 of this embodiment is as
effective and advantageous as that of the third embodiment and
seventh embodiment.
[0215] [Method of Manufacturing Semiconductor Device]
[0216] The semiconductor device 50 is manufactured by the direct
transfer molding process as shown in FIG. 20A and FIG. 20B, using
the resin molding die 60 and the semiconductor manufacturing system
70, which are substantially identical to those used in the first
embodiment, and will not be described here.
[0217] (1) The direct transfer molding process of this embodiment
is identical to that of the first embodiment. First of all, the
base 51 is placed on the lower cavity block 62 in such a manner
that the semiconductor element 52 as well as a part of the base 51
is fitted in the cavity 621 of the resin molding die 60 (see FIG.
20A). In this embodiment, the insulated substrate 510 of the base
51 has the opening 510H and the radiating plate 519, so that the
cavity 621 is defined by the rear center of the insulated substrate
510, a peripheral wall of the opening 510H, the rear center of the
radiating plate 519, and the upper surface of the lower cavity
block 62 of the resin molding die 60.
[0218] (2) The resin 55A is supplied to the resin reservoir 622,
which is above a position displaced from the center of the
semiconductor element 52 (see FIG. 20A). The resin 55A is then
injected into the cavity 621 in order to fill it substantially. The
amount of the resin 55A is somewhat reduced taking the recess 552
into consideration. Further, the lower cavity block 62 is
maintained at a certain temperature to melt the resin 55A.
[0219] (3) The upper and lower cavity blocks 61 and 62 are clamped
as shown in FIG. 20A. The melted resin 55A is injected into the
cavity 621 via the resin reservoir 622 as shown in FIG. 20B.
Specifically, the pusher 603 injects the resin 55A into the cavity
621 with an appropriate pressure and a sufficient injection stroke
via the resin reservoir 622. Further, the pusher 603 slightly
projects into the cavity 621 in order to form the recess 552. In
this state, the resin 55A is hardened in order to form the resin
seal 55 which encapsulates at least the semiconductor element 52 as
well as a part of the base 51 and has the recess 552. (See FIG.
20B.)
[0220] (4) Thereafter, the upper and lower cavity blocks 61 and 62
are unclamped in order to remove the semiconductor device 50 having
the resin seal 55, from the resin molding die 60.
[0221] In this state, the semiconductor device 50 is completed by
the direct transfer molding process.
[0222] The method of the ninth embodiment is as effective and
advantageous as that of the first and seventh embodiment.
[0223] (Tenth Embodiment)
[0224] In this embodiment, a semiconductor device 50 is a
combination of the semiconductor devices 50 of the eighth and ninth
embodiments.
[0225] [Structure of Semiconductor Device]
[0226] Referring to FIG. 21, the semiconductor device 50 comprises
the base 51, the semiconductor element 52 mounted on the base 51
similarly to that of the ninth embodiment, and further includes the
resin seal 55 having the protrusion 553 above the semiconductor
element 52, similarly to that of the eighth embodiment. Therefore,
the base 51 and semiconductor element 52 will not be described in
detail here.
[0227] Alternatively, the resin seal 55 may be formed just above
the center of the semiconductor element 52 and has the recess 551
as that in the second embodiment.
[0228] [Method of Manufacturing Semiconductor Device]
[0229] The direct transfer mold process for manufacturing the
semiconductor device 50 of this embodiment is substantially
identical to that of the ninth embodiment except for the following:
as shown in FIG. 20B, the pusher 603 of the resin molding die 60 is
stopped slightly before it gets into the cavity 621, in order to
form the protrusion 553.
[0230] The resin molding die 60 and the semiconductor manufacturing
system 70 of the first embodiment are also applied to the tenth
embodiment, and will not be described here.
[0231] The semiconductor device 50 of the tenth embodiment is as
effective and advantageous as that of the eight and ninth
embodiment.
[0232] In this embodiment, the protrusion 553 (or the protrusion
551) of the resin seal 55 is also usable as a radiating path, which
is effective in improving the radiating performance. Further, the
protrusion 553 can form a gap between the resin seal 55 and a
mounting board (on which the semiconductor device 50 is mounted) or
equipment in which the semiconductor device 50 is incorporated.
Such a gap is effective in promoting flow of a cleaning agent or
air during the cleaning or drying process after the semiconductor
device 50 has been mounted. Therefore, it is possible to improve
the manufacturing yield, reduce erroneous mounting, and assure the
reliability of the semiconductor device 50.
[0233] (Eleventh Embodiment)
[0234] This embodiment relates to a modified structure of the resin
molding die 60 used in the first to tenth embodiments.
[0235] [Structure of Resin Molding Die]
[0236] As shown in FIG. 23, the resin molding die 60 is
substantially identical to that of the first embodiment, and
comprises at least: the upper and lower cavity blocks 61 and 62;
the cavity 621 on the lower cavity block 62; the resin reservoir
622 in direct contact with to the cavity 621 and housing the resin
55A to be injected into the cavity 621 in order to fill it
substantially; the pusher 603 for injecting the resin 55A into the
cavity 621; and an air vent 623 for discharging air from the cavity
621.
[0237] The air vent 623 is present on the upper surface of the
lower cavity block 62, and discharges air from the cavity 621 to
sides of the lower cavity block 62. Alternatively, the air vent 623
may be provided on the upper cavity block 61. Further, the air vent
623 may be provided on the flat upper surface of the lower cavity
block 62 of the resin molding die 60 of the third embodiment.
[0238] In this embodiment, a stop 603S is provided at the bottom
(at the lower side in FIG. 23) of the pusher 603 in order to
control the injection stroke thereof. The stop 603S is thicker than
the pusher 603 and the resin reservoir 622. When reaching the
bottom of the lower cavity block 62, the stop 603S prevents the
pusher 603 from sliding upward to the cavity 621.
[0239] Therefore, it is possible to mechanically control the
injection stroke of the pusher 603 by the stop 603S, i.e. the
pusher 603 is prevented from getting into the cavity 621 more than
necessary, coming into contact with the semiconductor element 52 or
the upper cavity block 61, and damaging or breaking the resin
molding die 60. This is effective in improving the manufacturing
yield of the semiconductor device 50, and further improving the
rate of operation of the semiconductor manufacturing system since
it can operate without problems caused by the mal-operation of the
resin molding die 60.
[0240] (Twelfth Embodiment)
[0241] In this embodiment, a resin molding die 60 of the eleventh
embodiment is provided with a plurality of resin reservoirs.
[0242] [Structure of Resin Molding Die]
[0243] Referring to FIG. 24, the resin molding die 60 comprises at
least: the upper cavity block 61; the lower cavity block 62 having
the cavity 621; a plurality of resin reservoirs 622A and 622B in
direct contact with the cavity 621 and used for housing resins 55B
and 55C; and pushers 603A and 603B injecting the resins 55B and 55C
into the cavity 621 via the resin reservoirs 622A and 622B,
respectively. Further, the air vent 623 is provided in order to
discharge air from the cavity 621.
[0244] The resin reservoirs 622A and 622B are positioned in order
to uniformly inject the resins 55B and 55C into the cavity 621.
Specifically, the former is positioned at the left center of the
cavity 621 while the latter is positioned at the right center of
the cavity 621 so that they uniformly inject the resins 55B and 55C
to the left and right halves of the cavity 621, respectively.
[0245] The pushers 603A and 603B are provided with stops 603S,
respectively, as in the resin molding die 60 of the eleventh
embodiment.
[0246] The resin molding die 60 of this embodiment is as effective
and advantageous as that of the eleventh embodiment.
[0247] Further, the resin molding die 60 of this embodiment is
preferable to a semiconductor device 50 having a large resin seal
55, e.g. to a resin seal of a multi-chip module type semiconductor
device in which a plurality of semiconductor elements 52 are
mounted on the base 51.
[0248] (Other Embodiments)
[0249] The embodiments of the invention has been described with
reference to the semiconductor devices 50 which include the
semiconductor elements 52 mounted on the bases 51 having at least
the insulated substrate 510, the resin molding dies 60 and
semiconductor manufacturing systems 70 for molding the resin seals
55 for the semiconductor devices 50, and the semiconductor device
manufacturing methods.
[0250] Further, the embodiment of the invention is applicable to a
semiconductor device 50 in which a semiconductor element 52 is
mounted on a base 51 made of a lead frame, a resin molding die 60
and a semiconductor manufacturing system 70 for molding a resin
seal 55 for such a semiconductor device 50, and a method of
manufacturing the semiconductor device 50.
[0251] Further, the embodiment of the invention is applicable to a
semiconductor device 50 which includes a plurality of recesses 550
or 552 or a plurality of protrusions 551 and 553.
[0252] The resin molding die 60 having the two resin reservoirs
622A and 622B of the twelfth embodiment may include three or more
resin reservoirs, in the embodiment of the invention.
[0253] According to the embodiment of the invention it is possible
to provide the methods of manufacturing the semiconductor devices
which are free from resin waste generated during the formation of
the resin seals, and are less expensive.
[0254] Further, it is possible to provide methods of manufacturing
the reliable semiconductor devices which are protected against the
peeling of the resin seals and shorting of wires, and improve
manufacturing yield.
[0255] The embodiment of the invention can provide the methods of
manufacturing the semiconductor devices by which the resin seals
can be reliably formed without cracking of the substrates or
leakage of the resins even if the substrates have various degrees
of thickness. That is to say, the resin encapsulation is possible
using the direct transfer mold process regardless of the thickness
of the substrate (e.g. the ceramics substrate), because the resin
is directly made in the necessary position. In short, the resin
does not leakage, because the clearance of between the resin
molding die and the substrate does not occur, when the substrate is
thin, because the resin molding die does not contain the cull, the
runner and the resin gate. When the substrate is thick, it is usual
that the resin molding die is clamped and the substrate is deformed
in order to obviate a gap around a cull or runner and to prevent
the resin from leaking. In such a case, a substrate made of
ceramics having a high elasticity is easily cracked and damaged.
However, in the embodiment of the present invention, since there is
no cull or runner, it is not necessary to clamp the resin molding
die by applying a load which may deform the substrate. Therefore,
the substrate is not cracked.
[0256] It is possible to provide the resin molding dies which are
effective in carrying out the foregoing semiconductor device
manufacturing methods.
[0257] The embodiment of the invention can provide the
semiconductor manufacturing systems which can realize the foregoing
semiconductor manufacturing methods.
[0258] In accordance with the embodiment of the invention, it is
possible to downsize the semiconductor devices.
[0259] It is possible to provide the reliable semiconductor devices
which can reduce mounting errors.
[0260] Finally, it is possible to provide the reliable
semiconductor devices which can assure excellent radiating
performance.
[0261] The invention has been described in detail with particular
reference to preferred embodiments, but it will be understood that
variations and modifications can be effected within the spirit and
scope of the invention as set forth in the claims.
* * * * *