U.S. patent application number 09/777787 was filed with the patent office on 2001-08-16 for electronic component, method of sealing electronic component with resin, and apparatus therefor.
Invention is credited to Araki, Kouichi, Okamoto, Hirotaka, Osada, Michio, Takase, Shinji.
Application Number | 20010013424 09/777787 |
Document ID | / |
Family ID | 26585253 |
Filed Date | 2001-08-16 |
United States Patent
Application |
20010013424 |
Kind Code |
A1 |
Takase, Shinji ; et
al. |
August 16, 2001 |
Electronic component, method of sealing electronic component with
resin, and apparatus therefor
Abstract
A resin seal apparatus includes a movable bottom die vertically
moved by an elevator mechanism, a transport mechanism horizontally
moving the movable bottom die having placed thereon a printed
circuit board with a semiconductor chip mounted thereon, an
intermediate die abutting against a periphery of the printed
circuit board when the movable bottom die is moved upward, a film
of resin stretched by a film stretch mechanism over the
intermediate die and the printed circuit board, a die for a chip,
pressing a back surface of the semiconductor chip via the film of
resin, and a top die pressing a top surface of the intermediate die
via the film of resin. This apparatus allows a PCB with a
semiconductor chip mounted thereon in the form of a flip chip to be
sealed with resin in a reduced period of time to fabricate an
electronic component.
Inventors: |
Takase, Shinji; (Kyoto-shi,
JP) ; Okamoto, Hirotaka; (Kyoto-shi, JP) ;
Osada, Michio; (Kyoto-shi, JP) ; Araki, Kouichi;
(Kyoto-shi, JP) |
Correspondence
Address: |
FASSE PATENT ATTORNEYS, P.A.
P.O. BOX 726
HAMPDEN
ME
04444-0726
US
|
Family ID: |
26585253 |
Appl. No.: |
09/777787 |
Filed: |
February 5, 2001 |
Current U.S.
Class: |
174/260 ;
257/E21.503; 257/E21.504 |
Current CPC
Class: |
H01L 2224/73203
20130101; H01L 2224/73204 20130101; Y10T 29/49124 20150115; H01L
2924/181 20130101; H01L 21/563 20130101; H01L 2924/181 20130101;
H01L 2924/18161 20130101; H01L 2924/01029 20130101; H01L 21/565
20130101; H01L 24/743 20130101; Y10T 29/49128 20150115; Y10T
29/49171 20150115; H01L 2224/32225 20130101; H01L 2224/73204
20130101; H01L 2924/01005 20130101; H01L 2924/00 20130101; H01L
2924/00 20130101; H01L 2224/16225 20130101; H01L 2224/16225
20130101; H01L 2224/32225 20130101 |
Class at
Publication: |
174/260 |
International
Class: |
H05K 007/06 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 10, 2000 |
JP |
2000-034248(P) |
Feb 14, 2000 |
JP |
2000-034429(P) |
Claims
What is claimed is:
1. An electronic component comprising a printed circuit board, a
semiconductor chip mounted on said printed circuit board and a bump
electrically connecting said printed circuit board and said
semiconductor chip together, between said printed circuit board and
said semiconductor chip at a predetermined location there being
provided a resin seal integrally, wherein on at least one of a
surface of said printed circuit board and a surface of said
semiconductor chip opposite to said surface of said printed circuit
board there is provided a protrusion dimensioned to protrude to
have a height no more than said bump.
2. A method of sealing with resin a semiconductor chip mounted on a
printed circuit board, to fabricate an electronic component,
comprising the steps of: preparing a resin molding die divided into
a main die and an intermediate die opened and closed, as desired,
relative to said main die in arrangement; setting in any of said
main die at a predetermined position said printed circuit board
with said semiconductor chip mounted thereon; closing said main die
with said semiconductor chip set therein and said intermediate die
together, and also adjoining together said intermediate die and a
periphery of said printed circuit board in said main die to clamp
said molding die; after the step of closing and adjoining,
stretching a mold release film over a back surface of said
semiconductor chip and a front surface of said intermediate die;
after the step of stretching, closing together another said main
die and said intermediate die with said mold release film posed
therebetween, to further clamp said molding die; pressing said mold
release film into close contact with the back surface of said
semiconductor chip; at the step of closing together another said
main die and said intermediate die and the step of pressing,
introducing melted resin into a cavity and curing the introduced
resin therein to seal with the resin said semiconductor chip
mounted on said printed circuit board, said cavity being defined by
said printed circuit board, said intermediate die and said mold
release film; after said semiconductor chip is molded with resin,
opening said molding die; and removing said mold release film
stretched across the back surface of said semiconductor chip and
the front surface of said intermediate die.
3. The method of claim 2, wherein the step of closing another said
main die and said intermediate die and the step of pressing are
provided separately.
4. The method of claim 2, wherein said intermediate die and said
another main die are closed together by adjoining their respective
surfaces unleveled, as required, to allow said dies, when closed
together, to remove a wrinkle of at least said mold release film
stretched across the back surface (a heat-sink surface) of said
semiconductor chip.
5. The method of claim 2, further comprising the step of internally
vacuuming at least said cavity before the step of introducing.
6. An apparatus sealing with resin a semiconductor chip mounted on
a printed circuit board, to fabricate an electronic component,
comprising: a resin molding die divided into a main die and an
intermediate die opened and closed, as desired, relative to said
main die in arrangement; a printed circuit board feed and set
mechanism feeding and setting in any said main die at a
predetermined position said printed circuit board having said
semiconductor chip mounted thereon; a first clamp mechanism closing
said main die with said semiconductor chip set therein and said
intermediate die together, and also adjoining said intermediate die
and a periphery of said printed circuit board set in said main die;
a film stretch mechanism stretching a mold release film over a back
surface of said semiconductor chip mounted on said printed circuit
board set in said main die at said predetermined position and over
a front surface of said intermediate die; a second clamp mechanism
closing together another said main die and said intermediate die
with said mold release film posed therebetween; a resin seal
mechanism introducing melted resin into a cavity with said first
and second clamp mechanisms clamping said molding die, and curing
the introduced resin therein to seal with the resin said
semiconductor chip mounted on said printed circuit board, said
cavity being defined by said printed circuit board, said
intermediate die and said mold release film; and a printed circuit
board transport mechanism transporting a resin-molded product from
said predetermined position in said main die of said molding die
opened to output the resin-molded product from said molding
die.
7. The apparatus of claim 6, further comprising a die for a chip,
pressing said mold release film into close contact with the back
surface of said semiconductor chip.
8. The apparatus of claim 6, further comprising a portion provided
to remove a wrinkle of at least said mold release film stretched
across the back surface of said semiconductor chip mounted on said
printed circuit board, said portion corresponding to said
intermediate die and said another main die each having a surface
unleveled, as required, adjoined each other to remove the wrinkle
of said mole release film.
9. The apparatus of claim 6, further comprising a vacuum mechanism
vacuuming at least said cavity internally.
10. A method of introducing resin for a flip chip, said flip chip
being formed of a semiconductor chip and a printed circuit board
connected together via a bump, said flip chip being set in a resin
molding die at a predetermined position, the resin being introduced
into a gap provided between said semiconductor chip and said
printed circuit board, comprising the steps of: with said printed
circuit board and said semiconductor chip each having a surface
covered with a mold release film, fitting said semiconductor chip
into a cavity of said molding die to set said semiconductor chip
therein; adjoining opposite parting surfaces of said molding die
together to close said molding die; introducing fluid pressure into
said cavity and exerting the fluid pressure via a mold release film
onto at least a member attaching surface of said semiconductor chip
in said cavity to press said mold release film into close contact
with said member attaching surface; after said mold release film is
pressed into close contact with said member attaching surface,
pressurizing and thus introducing a molding source material of
resin into said cavity to cover with said resin a surface of said
semiconductor chip excluding at least said member attaching surface
and fill with said resin a gap provided between said semiconductor
chip and said printed circuit board.
11. The method of claim 10, wherein in the step of introducing,
said fluid is gas, said gas applying pressure toward a surface of
said semiconductor chip via said mold release film to press said
mold release film into close contact with said semiconductor chip
at at least said member attaching surface.
12. The method of claim 10, wherein in the step of introducing,
said fluid pressure is pressure applied to mold resin, said
pressure applied to mold resin being applied toward a surface of
said semiconductor chip via said mold release film to press said
mold release film into close contact with said semiconductor chip
at at least said member attaching surface.
13. The method of claim 10, wherein in the step of introducing,
said fluid pressure is adapted to be adjustable to correspond to
pressure applied to introduce resin in the step of pressurizing and
introducing.
14. The method of claim 10, wherein the step of pressurizing and
introducing includes the step of internally vacuuming a portion to
be filled with resin, including at least a die cavity.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to electronic
components, methods of sealing electronic components with resin and
apparatus therefor, and particularly to electronic components
including a semiconductor chip mounted on a printed circuit board
in the form of a flip chip, methods of sealing the same with resin
and apparatus therefor.
[0003] 2. Description of the Background Art
[0004] Conventionally a semiconductor chip is mounted on a glass
epoxy board or a similar printed circuit board (hereinafter
referred to as a PCB) in the form of a flip chip and then sealed
with resin to produce an electronic component in such a process as
follows: initially, a PCB with a semiconductor chip mounted thereon
is placed on a stage. Then, a dispenser is used to apply a
thermosetting resin having liquid phase cold, such as epoxy resin,
along one side of the semiconductor chip. The epoxy resin permeates
through capillarity into the entirety of a gap formed between the
PCB and the semiconductor chip and also forms a fillet along
another side of the semiconductor chip. Then the resin is heated
and cured. Thus a resin mold is formed in the gap between the PCB
and the semiconductor chip and in a region extending along each
side of the semiconductor chip.
[0005] Sealing a flip chip with resin, as conventional, however, is
disadvantageous; first of all, utilizing capillarity to allow epoxy
resin to permeate into the entirety of a gap provided between a PCB
and a semiconductor chip, is time consuming and thus increases the
process time. Furthermore, the resin seal may have dimensions with
insufficient precision. Such disadvantages are increasingly serious
as in recent years electronics are reduced in weight, thickness and
size and accordingly there exists an increasing demand for
electronic components reduced in size. More specifically, a PCB and
a semiconductor chip have therebetween further smaller a gap and
the PCB and the semiconductor chip have their respective electrodes
electrically connected via bumps further increased in number, and
allowing epoxy resin to permeate thus requires a long period of
time. Furthermore, as an electronic component is reduced in size it
is required to have a dimension with high precision.
[0006] Secondly, although gradually cold, thermosetting resin
having liquid phase cold cures and thus varies in viscosity while
it is used. As such, its delivery rate must be monitored constantly
and the resin thus has a poor level of workability. Furthermore,
there are constraints in handling thermosetting resin. For example,
if thermosetting resin having liquid phase cold is stored it must
be stored in an atmosphere of no more than-40.degree. C. and when
it is used it must be used cold. In addition, thermosetting resin
having liquid phase cold is more expensive than that having solid
phase cold which is used in normal transfer-molding.
SUMMARY OF THE INVENTION
[0007] The present invention contemplates a high-quality electronic
component, a method of sealing the electronic component with resin
in a reduced period of time and a resin seal apparatus, wherein in
transfer-molding, a liquid, thermosetting resin is introduced.
[0008] To achieve the above object the present invention provides
an electronic component including a printed circuit board, a
semiconductor chip mounted on the printed circuit board and a bump
electrically connecting the printed circuit board and the
semiconductor chip together, and between the printed circuit board
and the semiconductor chip at a predetermined location there is
provided a resin seal integrally. On at least one of a surface of
the printed circuit board and a surface of the semiconductor chip
opposite to the surface of the printed circuit board there is
provided a protrusion dimensioned to protrude to have a height no
more than the bump.
[0009] As such in the step of sealing the chip with resin when
melted resin is heated and cured if the bump softens the pressure
received via the semiconductor chip can be distributed to and
applied on not only the bump but the protrusion and the printed
circuit board and the semiconductor chip would never have a gap
therebetween smaller in dimension than the height of the
protrusion. This can prevent such defects as deformation of a
softened bump, short circuit between adjacent bumps, and the
like.
[0010] Furthermore the present invention provides a method of
sealing an electronic component with resin, wherein a semiconductor
chip mounted on a printed circuit board is sealed with resin to
fabricate the electronic component, including the steps of:
preparing a resin molding die divided into a main die and an
intermediate die opened and closed, as desired, relative to the
main die in arrangement; setting in any of the main die at a
predetermined position the printed circuit board with the
semiconductor chip mounted thereon; closing the main die with the
semiconductor chip set therein and the intermediate die together,
and also adjoining together the intermediate die and a periphery of
the printed circuit board in the main die to clamp the molding die;
after the step of closing and adjoining, stretching a mold release
film over a back surface of the semiconductor chip and a front
surface of the intermediate die; after the step of stretching,
closing together another main die and the intermediate die with the
mold release film posed therebetween, to further clamp the molding
die; pressing the mold release film into close contact with the
back surface of the semiconductor chip; at the step of closing
together another main die and the intermediate die and the step of
pressing, introducing melted resin into a cavity and curing the
introduced resin therein to seal with the resin the semiconductor
chip mounted on the printed circuit board, the cavity being defined
by the printed circuit board, the intermediate die and the mold
release film; after the semiconductor chip is molded with resin,
opening the molding die; and removing the mold release film
stretched across the back surface of the semiconductor chip and the
front surface of the intermediate die.
[0011] Since melted resin introduced into a cavity is cured to form
a resin seal, the resin seal can be formed in a shorter period of
time than when capillarity is employed. Furthermore, the melted
resin can be introduced into a cavity defined by a film of resin,
the intermediate die and the printed circuit board and even if the
melted resin has low viscosity it can be prevented from entering a
gap provided between the group of dies and the intermediate
die.
[0012] Furthermore the present invention in one embodiment provides
the present method with the step of closing another main die and
the intermediate die and the step of pressing performed
separately.
[0013] As such the semiconductor chip can be pressed with
appropriate pressure. Thus the bump of solder can be free from
pressure otherwise applied more than required and thus softening
and deforming the bump. Furthermore, with the film of resin
interposed the die for a chip can initially press the semiconductor
chip and the top die can then press the intermediate die. As such,
the film of resin can be free of wrinkle in a region defining the
cavity. As such the resultant electronic component can
aesthetically be less defective.
[0014] Furthermore the present invention in a preferred embodiment
provides the present method wherein the intermediate die and
another main die are closed together by adjoining their respective
surfaces inclined or similarly unleveled, as required, to allow the
dies, when closed together, to remove a wrinkle of at least the
mold release film stretched across the back or heat-sink surface of
the semiconductor chip.
[0015] As such before the dies are completely closed the
inclinations sandwich the film of resin and thus stretch it tight.
This ensures that the film of resin can be free of wrinkle in a
region defining the cavity. Thus the resultant electronic component
can aesthetically be less defective.
[0016] Furthermore the present invention provides the present
method preferably further including the step of internally
vacuuming at least the cavity before the step of introducing.
[0017] The cavity previously vacuumed can receive melted resin with
low pressure. This allows less viscous melted resin to be used. As
such, if the printed circuit board and the semiconductor chip have
a small gap therebetween and there are also a large number of bumps
the resin can reliably underfill the semiconductor chip provided in
the form of a flip chip. In addition the present feature can
advantageously limit occurrence of a void in a resultant resin
seal.
[0018] The present invention provides an apparatus sealing an
electronic component with resin, wherein a semiconductor chip
mounted on a printed circuit board is sealed with resin to
fabricate the electronic component, including: a resin molding die
divided into a main die and an intermediate die opened and closed,
as desired, relative to the main die in arrangement; a PCB feed and
set mechanism feeding and setting in any main die at a
predetermined position the printed circuit board having the
semiconductor chip mounted thereon; a first clamp mechanism closing
the main die with the semiconductor chip set therein and the
intermediate die together, and also adjoining the intermediate die
and a periphery of the printed circuit board set in the main die; a
film stretch mechanism stretching a mold release film over a back
or heat-sink surface of the semiconductor chip mounted on the
printed circuit board set in the main die at the predetermined
position and over a front surface of the intermediate die; a second
clamp mechanism closing together another main die and the
intermediate die with the mold release film posed therebetween; a
resin seal mechanism introducing melted resin into a cavity with
the first and second clamp mechanisms clamping the molding die, and
curing the introduced resin therein to seal with the resin the
semiconductor chip mounted on the printed circuit board, the cavity
being defined by the printed circuit board, the intermediate die
and the mold release film; and a PCB transport mechanism
transporting a resin-molded product from the predetermined position
in the main die of the molding die opened to output the
resin-molded product from the molding die.
[0019] The present apparatus can introduce melted resin into the
cavity and cure it therein to form a resin seal. As such, the
present apparatus can provide the resin seal in a shorter period of
time than when capillarity is employed. Furthermore, the melted
resin is introduced into the cavity defined by the film of resin,
the intermediate die and the printed circuit board and if the
melted resin has low viscosity it can be prevented from entering a
gap provided between the group of dies and the intermediate
die.
[0020] The present invention in a preferred embodiment provides the
present apparatus further including a die for a chip, pressing the
mold release film into close contact with the back surface of the
semiconductor chip, i.e., a heat-sink surface thereof.
[0021] Thus the semiconductor chip can be pressed with appropriate
pressure. As such, the bump can be free from pressure otherwise
applied more than required and thus softening and deforming the
bump when the introduced melted resin is heated and cured to form a
resin seal.
[0022] Furthermore the present invention provides the present
apparatus preferably further including a portion provided to remove
a wrinkle of at least the mold release film stretched across the
back surface of the semiconductor chip mounted on the printed
circuit board. The portion corresponds to the intermediate die and
another main die each having a surface unleveled, as required,
adjoined each other to remove the wrinkle of the mole release
film.
[0023] As such before the dies are completely closed the
inclinations sandwich the film of resin and stretch it tight. This
ensures that the film of resin can be free of wrinkle in a region
defining the cavity. Thus the present apparatus can provide an
aesthetically less defective electronic component.
[0024] The present invention in another preferable embodiment
provides the present apparatus further including a vacuum mechanism
vacuuming the cavity.
[0025] The cavity previously vacuumed can receive melted resin with
low pressure. This allows less viscous melted resin to be used. As
such, if the printed circuit board and the semiconductor chip have
a small gap therebetween and there are also a large number of bumps
the apparatus still can reliably underfill with the resin the
semiconductor chip provided in the form of a flip chip. In addition
the present feature can advantageously limit occurrence of a void
in a resultant resin seal.
[0026] The present invention provides a method of introducing resin
for a flip chip, the flip chip being formed of a semiconductor chip
and a printed circuit board connected together via a bump, the flip
chip being set in a resin molding die at a predetermined position,
the resin being introduced into a gap provided between the
semiconductor chip and the printed circuit board, comprising the
steps of: with the printed circuit board and the semiconductor chip
each having a surface covered with a mold release film, fitting the
semiconductor chip into a cavity of the molding die to set the
semiconductor chip therein; adjoining opposite parting surfaces of
the molding die together to close the molding die; introducing
fluid pressure into the cavity and exerting the fluid pressure via
a mold release film onto at least a member attaching surface of the
semiconductor chip in the cavity to press the mold release film
into close contact with the member attaching surface; after the
mold release film is pressed into close contact with the member
attaching surface, pressurizing and thus introducing a molding
source material of resin into the cavity to cover with the resin a
surface of the semiconductor chip excluding at least the member
attaching surface and fill with the resin a gap provided between
the semiconductor chip and the printed circuit board.
[0027] As such, the resin can be efficiently introduced into and
thus fill a gap provided in the flip chip between the semiconductor
chip and the printed circuit board. Thus not only can productivity
be increased but the present feature can effectively prevent melted
source material of resin from adhering to the semiconductor chip on
a member attaching surface thereof, such as a heat sink, when the
resin is introduced to fill the gap between the semiconductor chip
and the printed circuit board.
[0028] The present invention in one embodiment provides the method
of introducing resin for a flip chip, wherein in the step of
introducing, the fluid is gas applying pressure toward a surface of
the semiconductor chip via the mold release film to press the mold
release film into close contact with the semiconductor chip at at
least the member attaching surface.
[0029] Furthermore the present invention in another embodiment
provides the method of introducing resin for a flip chip, wherein
in the step of introducing, the fluid pressure is pressure applied
to mold resin, the pressure applied to mold resin being applied
toward a surface of the semiconductor chip via the mold release
film to press the mold release film into close contact with the
semiconductor chip at at least the member attaching surface.
[0030] Furthermore the present invention in a preferable embodiment
provides the method of introducing resin for a flip chip, wherein
in the step of introducing, the fluid pressure is adapted to be
adjustable to correspond to pressure applied to introduce resin in
the step of pressurizing and introducing.
[0031] Furthermore the present invention provides the method of
introducing resin for a flip chip, wherein the step of pressurizing
and introducing preferably includes the step of internally
vacuuming a portion to be filled with resin, including at least a
die cavity.
[0032] The foregoing and other objects, features, aspects and
advantages of the present invention will become more apparent from
the following detailed description of the present invention when
taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] In the drawings:
[0034] FIG. 1 is a cross section of an electronic component in a
first embodiment of the present invention;
[0035] FIG. 2 is a cross section of a resin seal apparatus of the
first embodiment in a closed position;
[0036] FIGS. 3A-3C are cross sections illustrating a process
provided by the FIG. 2 apparatus from the step of moving an
intermediate die through the step of moving a top die downward;
[0037] FIGS. 4A-4C are cross sections showing a process provided by
the FIG. 2 apparatus from the step of introducing melted resin
through the step of outputting an electronic component;
[0038] FIG. 5 is a cross section of a resin seal apparatus in a
second embodiment of the present invention in a closed
position;
[0039] FIG. 6 is a cross section of a resin seal apparatus in a
third embodiment of the present invention in a closed position;
[0040] FIG. 7 is a cross section showing a condition immediately
before introducing melted resin into a cavity in sealing with resin
an electronic component in a fourth embodiment of the present
invention;
[0041] FIG. 8 is a cross section showing a condition before closing
a resin seal apparatus in a fifth embodiment of the present
invention;
[0042] FIG. 9 is a cross section showing a condition after closing
a resin seal apparatus in a sixth embodiment of the present
invention;
[0043] FIG. 10 illustrates a general configuration of a resin seal
apparatus shown in FIG. 9;
[0044] FIG. 11 is a vertical cross section schematically showing a
main portion of a resin receiving die in a seventh embodiment of
the present invention, opened, with a mold release film and a flip
chip interposed before resin is introduced and molded, as seen in a
developed view;
[0045] FIG. 12 is a vertical cross section enlarging the main
portion of the resin receiving die of the seventh embodiment, for
illustrating an effect of introducing and molding resin;
[0046] FIG. 13 is a partially notched, front view of a flip chip
after it is molded with resin introduced into the die of the
seventh embodiment; and
[0047] FIG. 14 is a vertical cross section of the main portion of
the die of the seventh embodiment, opened, with a mold release film
and a flip chip interposed before resin is introduced and molded,
as seen in a developed view, for illustrating another effect of
introducing and molding resin.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0048] First Embodiment
[0049] A first embodiment of the present invention provides an
electronic component, as described with reference to FIG. 1. The
present embodiment provides an electronic component 5 including a
PCB 1 formed for example of glass epoxy and a semiconductor chip
mounted on PCB 1. PCB 1 and semiconductor chip 2 have their
respective electrodes (not shown) electrically connected together
via a bump 3 formed for example of solder. PCB 1 and semiconductor
chip 2 have therebetween a gap provided with a resin seal covering
a side surface of semiconductor chip 2 while exposing a back
surface of semiconductor chip 2, i.e., a surface thereof free of
bump 3 connected thereto. Resin seal 4 is formed by introducing and
curing melted resin in a cavity (not shown) defined by closing a
molding die (not shown) to contain semiconductor chip 2. PCB 1,
semiconductor chip 2, bump 3 and resin seal 4 together configure
electronic component 5.
[0050] Reference will now be made to FIG. 2 to describe a resin
seal apparatus sealing the FIG. 1 electronic component with
resin.
[0051] The present resin seal apparatus, as shown in FIG. 2,
includes a top die 6 and a bottom die 7 configuring a group of
resin sealing dies. Between top die 6 and bottom die 7 there exist
intermediate dies 8A and 9A laterally advancing and retreating, as
desired, and contacting an upper peripheral surface of PCB 1 when
the intermediate die advances. A resin film 10 is stretched tight
in contact with an upper surface of intermediate die 8A and that of
intermediate die 9A and a back surface of semiconductor chip 2.
Bottom die 7 is provided with a recess 11 receiving PCB 1. A cavity
12 is a space defined by PCB 1, intermediate dies 8A and 9A and
resin film 10. It receives semiconductor chip 2, although spaced,
as predetermined, from a side surface of semiconductor chip 2.
Intermediate die 8A is provided with a gate 13 introducing melted
resin (not shown) into cavity 12, and a resin channel 14 passing
the melted resin toward gate 13. Intermediate die 9A is provided
with an air vent 15 communicating with cavity 12.
[0052] Although not shown in FIG. 2, the present resin seal
apparatus also includes a pot accommodating a solid, resin tablet
and a plunger exerting pressure on melted resin produced by heating
the resin tablet to feed the melted resin to resin channel 14.
There are also provided a film stretch mechanism having a reel and
driver to feed and stretch resin film 10 tight and wind up the film
used. In addition, there is also provided a transport mechanism
provided to suck an electronic component sealed with resin, extract
it from recess 11 and transport it to a predetermined position.
[0053] The FIG. 2 apparatus operates as described with reference to
FIGS. 3A-4C. FIGS. 3A-3C are cross sections showing process steps
provided by the present resin seal apparatus, from the step of
moving the intermediate dies through the step of moving the top die
downward.
[0054] Initially, as shown in FIG. 3A, with top die 6 and bottom
die 7 opened, PCB 1 with chip 2 mounted thereon via bump 3 is
placed in recess 11. Then, intermediate dies 8A and 9A moves along
the bottom die 7 parting plane toward semiconductor chip 2.
[0055] Then, as shown in FIG. 3B, intermediate dies 8A and 9A
contact PCB 1 on an upper peripheral surface thereof and stop to be
spaced, as predetermined, from a side surface of semiconductor chip
2 and resin film 10 is then moved downward.
[0056] Then, as shown in FIG. 3C, with resin film 10 brought into
contact with a back surface of semiconductor chip 2 and an upper
surface of intermediate die 8A and that of intermediate die 9A and
also stretched tight, top die 6 moves downward to clamp top die 6
and bottom die 7 together.
[0057] Reference will now be made to FIGS. 4A-4C to describe a
process provided by the resin seal apparatus of the present
embodiment, from the step of introducing melted resin through the
step of extracting an electronic component.
[0058] As shown in FIG. 4A, with top die 6 pressing the top
surfaces of intermediate dies 8A and 9A and the back surface of
semiconductor chip 2 with resin film 10 posed therebetween, a
plunger (not shown) is used to introduce melted resin into cavity
12 via resin channel 14 and gate 13, as indicated by the arrow in
the figure. As the melted resin is introduced, the air in cavity 12
is exhausted, output from cavity 12 via an air vent.
[0059] Then, the dies are heated to heat the melted resin in cavity
12 for example to approximately 175.degree. C. and cure the resin
to form resin seal 4. Then, as shown in FIG. 4B, top die 6 moves
upward to open top die 6 and bottom die 7 and resin film 10 is
moved upward and thus removed from the back surface of
semiconductor chip 2 and the top surfaces of intermediate dies 8A
and 9A. Furthermore, intermediate dies 8A and 9A move along the
parting plane of bottom die 7 away from resin seal 4.
[0060] Then, as shown in FIG. 4C, a chuck 16 moves and it is thus
positioned on electronic component 5. Chuck 16 sucks electronic
component 5 via a sucking tubing 17, extracts electronic component
5 from recess 11 and transports electronic component 5 to a
predetermined position, such as a tray.
[0061] Thus the present embodiment provides an electronic component
including resin seal 4 transfer-molded and exposing a back surface
of semiconductor chip 2. As such, melted resin introduced into
cavity 12 can cure to allow completed resin seal 4 to have
dimensions with significantly satisfactory and constant precision.
Since semiconductor chip 2 has an exposed back surface it can
provide an enhanced heat sink effect when electronic component 5 is
used.
[0062] Furthermore, the present embodiment can provide a resin seal
method and apparatus employing transfer-molding to exert pressure
on melted resin to introduce the resin into cavity 12 so as to
provide a resin seal in a reduced period of time.
[0063] Furthermore, melted resin is introduced into and thus cures
in cavity 12 defined by intermediate dies 8A and 9A and resin film
10 and thus formed to contain semiconductor chip 2. As such, if
less viscous resin is used to ensure that melted resin is
introduced into a gap provided between PCB 1 and semiconductor chip
2, the melted resin does not ingress into the gaps provided between
top die 6 and intermediate dies 8A and 9A.
[0064] Furthermore, an inexpensive, solid resin tablet that is
heated, melted can be used. As such, the source material can be
readily stored and handled to facilitate controlling its viscosity
in the process and also reduce the cost for the material.
[0065] Second Embodiment
[0066] Reference will now be made to FIG. 5 to describe a resin
seal apparatus and method in a second embodiment of the present
invention. In the present embodiment, top die 6 has a throughhole
provided with a die 18 for a chip operating independently of top
die 6.
[0067] The FIG. 5 apparatus operates as follows: initially, with
resin film 10 stretched tight over a back surface of semiconductor
chip 2 and a top surface of intermediate die 8A and that of
intermediate die 9A, die 18 for a chip moves downward to press the
back surface of semiconductor chip 2 with resin film 10 posed
therebetween. Then, top die 6 moves downward to press the top
surfaces of intermediate dies 8A and 9A with resin film 10 posed
therebetween.
[0068] The present embodiment can provide a resin seal apparatus
that is not only as effective as the first embodiment but also
effective as follows:
[0069] First of all, semiconductor chip 2 has its back surface
pressed by die 18 for a chip that is provided independently of top
die 6 pressing the top surfaces of intermediate dies 8A and 9A. As
such, semiconductor chip 2 can be pressed with appropriate
pressure. As such, solder bump 3 can be free from pressure
otherwise applied more than required and thus softening and
deforming the bump when melted resin that is introduced is heated
to approximately 175.degree. C. and cured to form resin seal 4.
[0070] Furthermore, with resin film 10 interposed, die 18 for a
chip can presses semiconductor chip 2 before top die 6 presses
intermediate dies 8A and 9A. As such, resin film 10 can be free of
wrinkle in a region defining cavity 12. Thus the electronic
component can aesthetically be less defective.
[0071] Third Embodiment
[0072] Reference will now be made to FIG. 6 to describe resin seal
apparatus and method in a third embodiment of the present
invention. In the present embodiment, intermediate dies 8B and 9B
have an inclination 20 and top die 19 has a parting surface facing
inclination 20 and provided with an inclination 21. Inclinations 20
and 21 are provided annularly to surround semiconductor chip 2.
Inclinations 20 and 21 are positioned and angled to allow resin
film 10 to be sandwiched between inclinations 20 and 21 when the
dies are clamped.
[0073] In the FIG. 6 apparatus operation, immediately before the
dies are completely clamped, as top die 19 moves downward
inclinations 20 and 21 sandwich and thus stretch resin film 10
tight. This ensures that resin film 10 can be free of wrinkle in a
region defining cavity 12. Thus the electronic component can
aesthetically be further less defective.
[0074] Fourth Embodiment
[0075] The present invention in a fourth embodiment provides an
electronic component, as described with reference to FIGS. 7 and
8.
[0076] With reference to FIG. 7, an electronic component includes
PCB 1 having a top surface provided with a protrusion 22.
Protrusion 22 is formed of a material which does not soften at a
temperature applied to heat and thus melt solder bump 3 in the step
of mounting semiconductor chip 2 onto PCB 1 via bump 3 nor at a
temperature applied to heat and cure melted resin in the step of
sealing the chip with the resin. Protrusion 22 is dimensioned to
protrude to be level with or slightly lower in height than bump
3.
[0077] Protrusion 22 is provided for example by processing PCB 1,
as follows: more specifically, on PCB 1 in a region free of any
wiring pattern at a dummy pattern formed of Cu, Cu is plated to
have a predetermined thickness and thus adheres thereto to provide
protrusion 22. Alternatively, a refractory source material of
resin, such as polyimide, that is previously formed in a lattice
may be placed on PCB 1. Alternatively, a refractory source material
of resin may be screen-printed on PCB 1 in the form of a
lattice.
[0078] As such, if in the step of sealing semiconductor chip 2 with
resin when melted resin is heated and cured bump 3 softens, the
pressure received by bump 3 via semiconductor chip 2 is also
distributed to and thus applied on protrusion 22, and the gap
between PCB 1 and semiconductor chip 2 would never be smaller than
the height of protrusion 22. This can prevent softened bump 3 from
deforming and, in the worst case, short-circuiting with adjacent
bump 3.
[0079] While as described in the present embodiment protrusion 22
is provided on PCB 1, alternatively or in addition thereto
protrusion 22 may be provided on a surface of semiconductor chip 2
that is provided with bump 3.
[0080] Fifth Embodiment
[0081] Reference will now be made to FIGS. 3A-3C, 4A-4C and 8 to
describe a resin seal apparatus and method in a fifth embodiment of
the present invention. FIG. 8 is a cross section of the resin seal
apparatus of the present embodiment before it is closed. In the
present embodiment, a vacuum mechanism is provided to vacuum cavity
12.
[0082] In the present embodiment, as shown in FIG. 8, bottom die 7
is provided with an exhaust tubing 23 connected to a vacuum pump
(not shown), and PCB 1, intermediate dies 8A and 9A and resin film
10 together define a closed space 24.
[0083] The resin seal apparatus of the present embodiment operates,
as follows: initially, with reference to FIG. 3A, before
intermediate dies 8A and 9A are moved, resin film 10 is brought
into contact with a back surface of semiconductor chip 2 and a top
surface of each of intermediate dies 8A and 9A. Then, closed space
24 is vacuumed via exhaust tubing 23. Then, intermediate dies 8A
and 9A are moved to form cavity 12 as shown in FIG. 3C and the
apparatus thereafter operates as shown in FIGS. 4A-4C.
[0084] Thus, cavity 12 previously vacuumed receives melted resin at
low pressure. This allows less viscous melted resin to be used. As
such, the present embodiment ensures underfiling semiconductor chip
2 in the form of a flip chip if PCB 1 and semiconductor chip 2 have
a small gap therebetween and there are also a large number of bumps
3. In addition the present embodiment can also limit occurrence of
a void in the resin seal.
[0085] Sixth Embodiment
[0086] Reference will now be made to FIGS. 9 and 10 to describe a
resin seal apparatus and method in a sixth embodiment of the
present invention.
[0087] The present embodiment provides a resin seal apparatus, as
shown in FIG. 9, including intermediate dies 8C and 9C fixed in
contact with a periphery of PCB 1, and also including a movable
bottom die 25 mounting PCB 1 thereon and capable of ascending and
descending, a plunger 26 pushing and thus introducing melted resin
(not shown) into cavity 12, a sealing block 27 provided to seal
cavity 12 against the atmosphere external thereto, and a sealing
member 28 provided between intermediate die 9C and sealing block
27.
[0088] The FIG. 9 apparatus operates, as follows: initially,
movable bottom die 25 with PCB 1 placed thereon moves upward to
allow a top surface of PCB 1 to impinge onto a bottom surface of
intermediate die 8C and that of intermediate die 9C. Then, cavity
12 is vacuumed and sealing block 27 is then moved downward and die
18 for a chip and top die 6 are also successively moved downward.
Thus, resin film 10 provided across the plane of FIG. 9 can be
stretched tight by inclinations 20 and 21 to be free of
wrinkles.
[0089] Then, cavity 12 defined by PCB 1, intermediate dies 8C and
9C and resin film 10 receives melted resin introduced by plunger 26
and the introduced melted resin is cured to form a resin seal.
Then, movable bottom die 25 is moved downward and the resin seal is
removed from intermediate dies 8C and 9C and an electronic
component is then extracted.
[0090] The resin seal apparatus of the present embodiment, as
generally configured, as shown in FIG. 10, includes a mechanism 29
feeding resin film 10 to span over intermediate die 8C and
semiconductor chip 2, and a mechanism 30 allowing movable bottom
die 25 to ascend and descend, a mechanism 31 horizontally moving
movable bottom die 25 to extract an electronic component, and a
loader/unloader 32 feeding PCB 1 onto movable bottom die 25 and
also transporting an electronic component to a tray.
[0091] Thus the present embodiment can employ transfer-molding to
exert pressure on melted resin to introduce the resin into cavity
12 so as to seal a chip with the resin in a reduced period of
time.
[0092] Furthermore, if less viscous resin is used to ensure that
melted resin is introduced into a gap provided between PCB 1 and
semiconductor chip 2 the melted resin can be prevented from
entering gaps between top die 6 and intermediate dies 8C and
9C.
[0093] Furthermore, an inexpensive, solid resin tablet heated and
thus melted can be used. As such, the source material can be
readily stored and handled, its viscosity can be readily controlled
in the process and its cost can also be reduced.
[0094] Furthermore, resin film 10 can be free of wrinkles in a
region defining cavity 12, to provide an aesthetically less
defective electronic component.
[0095] Furthermore, vacuuming cavity 12 allows melted resin to be
introduced with low pressure. This ensures underfilling
semiconductor chip 2 in the form of a flip chip. This can also
prevent occurrence of a void otherwise created in a resin seal.
[0096] While in each of the embodiments described hereinbefore a
single semiconductor chip is mounted on a single PCB, the present
invention is similarly applicable if a plurality of semiconductor
chips are mounted on a single PCB and after they are sealed with
resin the PCB is divided to provide a plurality of electronic
component.
[0097] Furthermore, while a single cavity is provided for a single
plunger, a plurality of cavities may alternatively be provided for
a single plunger.
[0098] Seventh Embodiment
[0099] A seventh embodiment of the present invention will now be
described with reference to FIGS. 11-14.
[0100] The present embodiment, as shown in FIGS. 11-14, provides
the step of bringing a mold release film in close contact with a
surface of a semiconductor chip 117. In this step, a die cavity 118
receives fluid pressure which is applied via a mold release film
111 to at least a member attaching surface A of semiconductor chip
117 fit and thus set in cavity 118, to press mold release film 111
into close contact with member attaching surface A of semiconductor
chip 117.
[0101] The step of bringing the mold release film in close contact
with the surface of semiconductor chip 117 is followed by the step
of introducing resin. In this step, die cavity 118 receives a
pressurized and thus introduced, sealing source material of resin
to introduce melted source material of resin R to cover a surface
of semiconductor chip 117 excluding at least member attaching
surface A thereof and fill a gap provided between semiconductor
chip 117 and PCB 115.
[0102] Thus, resin can be efficiently introduced and fill a gap
provided between semiconductor chip 117 in the form of a flip chip
and PCB 115. This can enhance productivity as well as efficiently
prevent the introduced melted source material of resin R from
adhering to semiconductor chip 117 on member attaching surface A,
such as a heat sink, when the resin is introduced and thus fills
the gap provided between semiconductor chip 117 and PCB 115.
[0103] FIG. 11 schematically shows a die 110 receiving resin to
mold a flip chip with the resin, and mold release film 111 fed
between opened dies and a flip chip 112 before it is molded with
resin.
[0104] Furthermore, the resin receiving die is defined by a fixed
top die 113 and a movable bottom die 114 arranged opposite to fixed
top die 113 and vertically moved by an appropriate vertically
driving mechanism (not shown).
[0105] Furthermore, bottom die 114 has a parting surface provided
with a recess 116 receiving and fitting PCB 115 of flip chip 112
thereinto to set PCB 115 therein, and top die 113 has a parting
surface provided with cavity 118 receiving and thus fitting and
thus setting therein semiconductor chip 117 mounted on PCB 115 of
flip chip 112 and a gate 119 passing a pressurized and thus
introduced, sealing, melted source material of resin to cavity
118.
[0106] Note that gate 119 is connected to communicate with a resin
channel transporting melted source material of resin R, the resin
channel is connected to communicate with a pot supplying the source
material of resin when top and bottom dies 113 and 114 are clamped
together, and that when a plunger fit into the pot exerts pressure
the source material of resin heated and melted in the pot receives
pressure and it is thus introduced into cavity 118 through the
resin channel and gate 119.
[0107] Furthermore, in top die 113 cavity 118 is adjacent to an
attachment 120 provided with a vent member 121 which is resistant
to heat and keeps a form, as required. Furthermore, attachment 120
is connected to communicate via an appropriate gas feeding channel
123 with a mechanism provided to compress and thus deliver gas 122
into attachment 120.
[0108] Thus, when the gas compression and delivery mechanism
operates, gas 122 is compressed and thus delivered to attachment
120 via gas feeding channel 123 and gas 122 thus delivered is
immediately fed through pressure into cavity 118 via vent member
121.
[0109] Furthermore, vent member 121 can be detachably attached to
attachment 120 and vent member 121 can thus be readily
exchanged.
[0110] Note that gas 122 may be air, gaseous nitrogen and any other
appropriate gas, and vent member 121 may for example be of a
material having successive pores capable of passing gas 122 or it
may be provided in the form of a large number of tubes for passing
gas.
[0111] Furthermore, mold release film 111 spans across the parting
surfaces of the top and bottom dies heated to a temperature applied
to mold resin and it is accordingly formed of a material that is at
least resistant to heat, flexible and has excellent removability
with respect to the parting surfaces of the top and bottom dies, as
required, and, as will be described hereinafter, when the top and
bottom dies are clamped together the film can span along the
geometry of the parting surfaces of the dies adjoined and thus
clamped and after resin has been introduced and molded the film can
be readily removed from the parting surfaces of the dies.
[0112] Although not shown in the figure, known feeding and winding
rolls are used to provide mold release film 111 between top and
bottom dies 113 and 114, and an appropriate input and output
mechanism is used to feed the film automatically to a predetermined
position between the top and bottom dies before resin is introduced
to mold a flip chip, and also to wind the film up and transport and
output it from the top and bottom dies after the flip chip is
molded with the injected resin.
[0113] Furthermore in flip chip 112 PCB 115 and semiconductor chip
117 are electrically connected together by a bump 124 and PCB 115
and semiconductor chip 117 thus have a small gap 125
therebetween.
[0114] Although not shown in the figure, a known input and output
mechanism is used to automatically feed flip chip 112 onto bottom
die 114 to set it in recess 116 before resin is introduced and the
flip chip is thus molded therewith, as will be described
hereinafter, and also to extract the flip chip from recess 116 and
automatically transport and output it from the top and bottom dies
after the flip chip is molded with the injected resin.
[0115] Top and bottom dies 113 and 114 are used in introducing
resin to mold flip cihp 112 therewith, as will now be
described.
[0116] Initially, appropriate heating means is used to heat top and
bottom dies 113 and 114 to a temperature for molding a chip with
resin. Then, the vertically driving mechanism is used to move
bottom die 114 downward and thus away from top die 113, as shown in
FIG. 11. Then, the flip chip feeding mechanism is employed to fit
PCB 115 of flip chip 112 into recess 116 of bottom die 114.
Simultaneously or not simultaneously with the step of feeding a
flip chip a source material of resin in the pot is supplied.
Furthermore, simultaneously or not simultaneously with the step of
feeding a flip chip or feeding a source material of resin the
mechanism feeding and outputting the mold release film is used to
allow mold release film 111 wound around a feeding roll to be fed
to a predetermined position between the top and bottom dies.
[0117] Then, the vertically driving mechanism is used to move
bottom die 114 upward to join and thus clamp top and bottom dies
113 and 114 together, as shown in FIG. 12. In this step, due to its
flexibility, mold release film 111 adjoins and thus covers PCB 115
of flip chip 112 and a surface of semiconductor chip 117 and the
film is also stretched along the geometry of the parting surface of
top die 113. Furthermore, that portion of semiconductor chip 117
covered with mold release film 111 is fit into cavity 118 of top
die 113. As such, in the step of clamping the top and bottom dies a
flip chip can be set in the dies such that semiconductor chip 117
can be fit into cavity 118 of top die 113 with mold release film
111 covering PCB 115 of flip chip 112 and a surface of
semiconductor chip 117.
[0118] Then the gas compression and delivery mechanism operates to
compress and deliver gas 112 to attachment 120 via gas feeding
channel 123 of top die 113 and further deliver gas 122 through
pressure to cavity 118 via vent member 121. Thus, gas 122 provides
fluid pressure applied via mold release film 111 to semiconductor
chip 117 at least on member attaching surface A, such as a heat
sink, which, as shown in the figure by way of example, corresponds
to a top surface of semiconductor chip 117 that is denoted in FIG.
11 by a reference character A, to press and thus bring mold release
film 111 into close contact with semiconductor chip 117 on member
attaching surface A.
[0119] Then when the plunger exerts pressure a source material of
resin heated and thus melted in the pot is pressurized and thus
introduced through the resin channel and gate 119 to cavity 118.
Since semiconductor chip 117 has at least member attaching surface
A pressed by mold release film 111 in close contact therewith, the
source material of resin introduced into cavity 118 is introduced
and covers a surface of semiconductor chip 117 fit in cavity 118
excluding at least member attaching surface A of the chip and fills
gap 125 provided between the chip and PCB 115.
[0120] Then, the vertically driving mechanism is employed to move
bottom die 114 again downward and thus away from top die 113 to
open top and bottom dies 113 and 114. Herein, top die 113 has its
parting surface with mold release film 111 spanning thereacross and
flip chip 112 molded with the injected resin can thus be readily
removed from the top die's cavity 118. The removal of flip chip 112
from the die can be facilitated by operating the gas compression
and delivery mechanism to compress and thus supply gas 122 into
cavity 118 when the top and bottom dies are opened.
[0121] Then, the mechanism feeding and outputting the mold release
film is used to wind up mold release film 111 around a winding roll
and thus transport and output the film from the top and bottom dies
after the chip is molded with injected resin, and the mechanism
feeding and outputting flip chip 112 is used to extract
resin-molded flip chip 112 from the bottom die 114 recess 116 and
transport and output the chip from the top and bottom dies.
[0122] Flip chip 112 extracted from the bottom die 114 recess 116
has cured resin 126 integrally adhering to a surface of
semiconductor chip 117 excluding at least member attaching surface
A thereof and gap 125 provided between semiconductor chip 117 and
PCB 115 and it also has residual cured resin 127 integrally
adhering to a (top) surface of PCB 115 corresponding to the resin
channel and gate 119, as shown in FIG. 13. Note that residual cured
resin 125 is not required for a product and it is thus separated
and removed from PCB 115, as appropriate.
[0123] Such a series of process steps can efficiently introduce
resin and fill therewith gap 125 provided between semiconductor
chip 117 and PCB 115 of flip chip 112. As a result, not only can
productivity be significantly increased but the series of steps can
efficiently prevent resin introduced to fill gap 125 from adhering
to semiconductor chip 117 on member attaching surface A such as a
heat sink. This ensures that in a subsequent step the heat sink or
a similar member can be efficiently bonded to member attaching
surface A.
[0124] Furthermore, the mold release film may be brought into
contact with a surface of semiconductor chip 117 with any type of
fluid that can act and function to exert fluid pressure onto the
surface of semiconductor chip 117 via mold release film 111 to
press the film to bring it in close contact with semiconductor chip
117 on at least member attaching surface A.
[0125] Furthermore, such fluid pressure may be pressure applied to
mold resin.
[0126] For example alternatively in top die 113 attachment 120
adjacent to cavity 118 may be used as a cavity for providing a
resin mold having a required thickness and the mechanism
compressing and thus transporting gas to attachment 20 and channel
23 feeding gas to the attachment may be used as a mechanism heating
and melting a source material of resin and a channel passing the
melted source material of resin. In this example, vent member 121
can be dispensed with.
[0127] Thus with such a configuration as above when the top and
bottom dies are clamped together attachment 120 provides a cavity
receiving a melted source material of resin pressurized and thus
introduced thereinto to form in the cavity a resin mold having a
required thickness. As such, semiconductor chip 117 has surface A
receiving via mold release film 111 a required level of pressure
applied to mold the melted source material of resin pressurized and
thus introduced into the cavity. As a result, semiconductor chip
117 can have the surface in close contact with the mold release
film. As such in this condition a source material of resin can be
pressurized and thus introduced into cavity 118 to introduce the
resin to cover therewith a surface of semiconductor chip 117
excluding at least member attaching surface A thereof and fill
therewith gap 125 provided between semiconductor chip 117 and PCB
115.
[0128] Note that resin cured and molded in the attachment 120
cavity can be removed as required for each molding cycle.
[0129] Furthermore in each embodiment the mold release film may be
brought into contact with semiconductor chip surface A with fluid
pressure adapted to be adjustable to correspond to pressure applied
to introduce resin.
[0130] For example, the mold release film may be brought into close
contact with surface A with fluid pressure that can appropriately
and automatically vary for different levels of pressure applied to
introduce resin.
[0131] Furthermore in each embodiment the mold release film may be
brought into close contact with semiconductor chip surface A with
fluid pressure set to be lower in level than pressure applied to
introduce resin, to ensure that the film is brought into close
contact with surface A.
[0132] Furthermore, in each embodiment when resin is introduced,
with mold release film 111 stretched across the parting surfaces of
the top and bottom dies, cavity 118 (a portion filled with the
resin) is blocked from the outside and air can hardly communicate
from inside to outside and vice versa. As such, when the top and
bottom dies are clamped together, cavity 18 tends to have residual
air or residual burnt gases generated when a source material of
resin is heated and melted, and, attributed thereto, the resin may
fail to completely fill gap 125 of flip chip 112 or air bubbles or
other disadvantages may result in a resin mold.
[0133] Such disadvantages can be overcome simply for example by
vacuuming a portion to be filled with resin including at least
cavity 118 when the resin is introduced.
[0134] This step is advantageous as vacuuming at least cavity 118
(a portion to be filled with resin) to externally exhaust air or
the like advantageously ensures that resin can be efficiently
introduced to fill gap 125 of flip chip 112 and also prevents the
resin from failing to fill gap 125 and also prevents air
bubbles.
[0135] Furthermore while in each embodiment a member attaching
surface A such as a heat sink corresponds to a top surface of
semiconductor chip 117, it is not limited thereto.
[0136] Furthermore, while the mold release film is brought into
close contact with a surface of the semiconductor chip with fluid
pressure applied to member attaching surface A via mold release
film 111 to press the same, the range pressed by such fluid
pressure is not limited to that as shown in FIG. 11. More
specifically, the fluid pressure may be applied to cover a range
extended to cover a surface of PCB 115 of flip chip 112, as denoted
by reference character B in FIG. 14.
[0137] In this example, the fluid pressure can cover a surface of
PCB 115 via mold release film 111. This can advantageously prevent
disadvantages such as resin flash otherwise disadvantageously
resulting on the surface of PCB 115 when a source material of resin
pressurized and thus introduced into cavity 118 flows out of cavity
118.
[0138] Furthermore, gas 122 when the top and bottom dies are
clamped together, as shown in FIG. 12, is compressed and thus
supplied through vent member 121 to cavity 118. Vent member 121
passing compressed air 122 and mold release film 111 have
therebetween a gap set as desired, although required to prevent
vent member 121 and mold release film 111 from contacting each
other when the top and bottom dies are clamped together.
[0139] Although the present invention has been described and
illustrated in detail, it is clearly understood that the same is by
way of illustration and example only and is not to be taken by way
of limitation, the spirit and scope of the present invention being
limited only by the terms of the appended claims.
* * * * *