U.S. patent application number 11/166383 was filed with the patent office on 2005-11-10 for socket for semiconductor device.
This patent application is currently assigned to YAMAICHI ELECTRONICS CO., LTD.. Invention is credited to Kuroda, Toshitaka, Matsuoka, Noriyuki, Suzuki, Takeyuki, Wakabayashi, Yoshinori.
Application Number | 20050250363 11/166383 |
Document ID | / |
Family ID | 30002361 |
Filed Date | 2005-11-10 |
United States Patent
Application |
20050250363 |
Kind Code |
A1 |
Suzuki, Takeyuki ; et
al. |
November 10, 2005 |
Socket for semiconductor device
Abstract
The cap body of the pressing cap has lamellar pieces for
pressing portions of the substrate in the contact sheet, in which
ends of the respective sides of the bare chip are positioned.
Inventors: |
Suzuki, Takeyuki;
(Yokohama-shi, JP) ; Matsuoka, Noriyuki;
(Yokohama-shi, JP) ; Wakabayashi, Yoshinori;
(Tokyo, JP) ; Kuroda, Toshitaka; (Kawasaki-shi,
JP) |
Correspondence
Address: |
FINNEGAN, HENDERSON, FARABOW, GARRETT & DUNNER
LLP
901 NEW YORK AVENUE, NW
WASHINGTON
DC
20001-4413
US
|
Assignee: |
YAMAICHI ELECTRONICS CO.,
LTD.
|
Family ID: |
30002361 |
Appl. No.: |
11/166383 |
Filed: |
June 27, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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11166383 |
Jun 27, 2005 |
|
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10614196 |
Jul 8, 2003 |
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6910898 |
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Current U.S.
Class: |
439/266 |
Current CPC
Class: |
H05K 7/1023 20130101;
H01R 12/82 20130101 |
Class at
Publication: |
439/266 |
International
Class: |
H01R 011/22 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 9, 2002 |
JP |
2002-200459 |
Jan 10, 2003 |
JP |
2003-004977 |
Claims
1-20. (canceled)
21. A carrier unit for a semiconductor device comprising: a contact
sheet having a plurality of bumps to be electrically connected to a
terminal group of a semiconductor device, for inputting/outputting
signals relative to the semiconductor device; a pressing member for
pressing terminals of the semiconductor device onto the bumps of
the contact sheet; an accommodation portion for accommodating the
semiconductor device disposed on said contact sheet; and a
movement-amount controlling member provided as part of said contact
sheet and not electrically connectable to the terminal group, for
controlling a movement amount of said semiconductor device along
the direction of a projected height of said bump when said pressing
member disposed in said accommodation portion is in a pressed
state, wherein said movement-amount controlling member is disposed
on top of said contact sheet.
22. A carrier unit for a semiconductor device comprising: a contact
sheet having a bump group to be electrically connected to a
terminal group of said semiconductor device, for
inputting/outputting signals relative to said semiconductor device;
a pressing member for pressing terminals of said semiconductor
device onto a bump group of said contact sheet; and a contact sheet
pressing member for pressing said contact sheet in a direction of a
sinking of said contact sheet in the vicinity of said bump group is
restricted when the terminals of said semiconductor device are
pressed onto said bump group by said pressing member, wherein said
contact sheet pressing member engages the top of the contact
sheet.
23. A carrier unit for a semiconductor device comprising: a contact
sheet having a bump group to be electrically connected to a
terminal group of said semiconductor device, for
inputting/outputting signals relative to said semiconductor device;
a pressing member for pressing said terminal group of said
semiconductor device onto a bump group of said contact sheet; and a
sinking-amount adjustment section formed opposite to said bump
group of said contact sheet, for compensating an amount of sinking
of said bump group by applying a force in a direction opposite to
the sinking when said terminal group of said semiconductor device
is pressed by said pressing member.
24. A carrier unit for a semiconductor device comprising: a contact
sheet having a plurality of bumps to be electrically connected to a
terminal group of a semiconductor device, for inputting/outputting
signals relative to said semiconductor device, a pressing member
for pressing terminals of said semiconductor device onto said bumps
of said contact sheet; an accommodation portion for accommodating
said semiconductor device disposed on said contact sheet; and a
movement-amount restricting member, provided as part of said
contact sheet and electrically isolated from the terminal group,
for restricting a movement amount of said semiconductor device
along the direction of a projected height of said bump when said
pressing member disposed in said accommodation portion is in a
pressed state, wherein said movement-amount restricting member is
disposed on top of said contact sheet.
25. A carrier unit for a semiconductor device comprising: a contact
sheet having a bump group to be electrically connected to a
terminal group of said semiconductor device, for
inputting/outputting signals relative to said semiconductor device;
a pressing member for pressing said terminal group of said
semiconductor device onto a bump group of said contact sheet; and a
sinking-amount adjustment section formed opposite to said bump
group of said contact sheet, for adjusting an amount of sinking of
said bump group when said terminal group of said semiconductor
device is pressed by said pressing member, wherein the
sinking-amount adjustment section includes at least one convex seat
portion formed on a surface layer of said contact sheet opposite to
said bump group.
26. A carrier unit for a semiconductor device comprising: a contact
sheet having a bump group to be electrically connected to a
terminal group of said semiconductor device, for
inputting/outputting signals relative to said semiconductor device;
a pressing member for pressing said terminal group of said
semiconductor device onto a bump group of said contact sheet; and a
sinking-amount adjustment section formed opposite to said bump
group of said contact sheet, for adjusting an amount of sinking of
said bump group when said terminal group of said semiconductor
device is pressed by said pressing member, wherein the
sinking-amount adjustment section includes at least one convex seat
portion formed on a bottom of an accommodation portion for
accommodating said semiconductor device via said contact sheet.
27. A carrier unit for a semiconductor device comprising: a contact
sheet having a bump group to be electrically connected to a
terminal group of said semiconductor device, for
inputting/outputting signals relative to said semiconductor device;
a pressing member for pressing said terminal group of said
semiconductor device onto a bump group of said contact sheet; and a
contact sheet pressing member for pressing said contact sheet in a
direction of a sinking of said contact sheet in a vicinity of said
bump group is restricted when the terminal group of said
semiconductor device is pressed onto said bump group by said
pressing member, wherein said contact sheet pressing member engages
the contact sheet, and wherein said contact sheet pressing member
is disposed in an accommodation portion for accommodating said
semiconductor device and is formed integral with said pressing
member.
28. A carrier unit for a semiconductor device comprising: a contact
sheet having a bump group to be electrically connected to a
terminal group of said semiconductor device, for
inputting/outputting signals relative to said semiconductor device;
a pressing member for pressing terminals or said semiconductor
device onto said bump group of said contact sheet; and a contact
sheet pressing member for pressing said contact sheet together with
said pressing member in a direction of a sinking of said contact
sheet in the vicinity of said bump group is restricted and said
pressing member presses terminals of said semiconductor device when
the terminals of said semiconductor device are pressed onto said
bump group by said pressing member, wherein said contact sheet
pressing member engages the top of the contact sheet.
29. A carrier unit for a semiconductor device comprising: a contact
sheet having a plurality of bumps to be electrically connected to a
terminal group of said semiconductor device, for
inputting/outputting signals relative to said semiconductor device,
a pressing member for pressing terminals of said semiconductor
device onto said bumps of said contact sheet; an accommodation
portion for accommodating said semiconductor device disposed on
said contact sheet; and a movement amount restricting member,
provided as part of said contact sheet and electrically isolated
from the terminal group, for restricting a movement amount of said
semiconductor device along a direction of a projected height of
said bump when said pressing member disposed in said accommodation
portion is in a pressed state, wherein said movement amount
restricting member is disposed on top of said contact sheet and
said movement amount restricting member is a dummy bump engaged
with said semiconductor device or said pressing member.
30. A carrier unit for a semiconductor device comprising: a contact
sheet having a plurality of bumps to be electrically connected to a
terminal group of said semiconductor device, for
inputting/outputting signals relative to said semiconductor device;
a pressing member for pressing terminals of said semiconductor
device onto said bumps of said contact sheet; an accommodation
portion for accommodating said semiconductor device disposed on
said contact sheet; and a movement amount restricting member for
restricting a movement amount of said semiconductor device along a
direction of a projected height of said bump when said pressing
member disposed in said accommodation portion is in a pressed
state, wherein said movement amount restricting member is disposed
on top of said contact sheet and said movement amount restricting
member interferes with said semiconductor device or said pressing
member.
Description
[0001] This application claims priority from Japanese Patent
Application No. 2002-200459 filed Jul. 9, 2002 and 2003-004977
filed Jan. 10, 2003, which are incorporated hereinto by
reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a socket for a
semiconductor device, having a contact sheet.
[0004] 2. Description of the Related Art
[0005] A semiconductor device mounted for an electronic equipment
or others has been subjected to various tests prior to being
mounted to the latter so that latent defects are removed. Such
tests are carried out in a non-destructive manner including tests
in which a voltage stress is applied thereto, or it is operated or
stocked in a high temperature environment in correspondence to the
thermal and mechanical environmental tests or the like. Of these
various tests, a burn-in test in which the operation test is
carried out in a high-temperature condition for a predetermined
period is particularly effective for removing integrated circuits
causing infant mortality failures.
[0006] A test jig used for this burn-in test is generally called as
an IC socket. As disclosed in a specification of Japanese Patent
Application No. 2002-200459 and Japanese Patent Application
Laid-open No. 9-017539 (1997), in a test for KGD (Known Good Die)
which is a non-defective bare chip passing the preceding test, it
is advanced a suggestion that such a bare chip is accommodated in
an accommodation portion of the IC socket by a carrier detachably
mounted thereto.
[0007] As shown, for example, in FIG. 20, the carrier unit is
comprised of a carrier housing 2 having a accommodation portion 2A
for accommodating a bare chip 12, a contact sheet 6 located on the
inner bottom wall of the accommodation portion 2A in the carrier
housing 2 via an elastic sheet 4, a pressing cap 14 for pressing an
electrode group in the bare chip 12 onto a bump group 6B of the
contact sheet 6, and a latch mechanism 10 for selectively holding
the pressing cap 14 relative to the carrier housing 2.
[0008] The contact sheet 6 has the bump group including a plurality
of bumps 6B formed of copper or others opposed to the electrode
group in the bare chip 12 to be electrically connected, as shown in
FIG. 20. In FIG. 20, two bumps 6B of which are illustrated in an
exaggerated manner as representative thereof. The plurality of
bumps 6B are arranged in a frame shape in correspondence to the
electrode group. A tip end of the respective bump projects from a
surface of the contact sheet 6 by a predetermined height level. In
this regard, in FIG. 21, of which two bumps 6B are shown as
representative of the group thereof for the purpose of simplifying
the drawing.
[0009] The pressing cap 14 is comprised of a pressing body 16
having a pressing surface to be brought into contact with a surface
facing a surface of the bare chip 12 on which the electrode group
are formed, a cap body 20 accommodating a base portion of the
pressing body 16, and a plurality of springs 18 disposed in a space
between the base portion of the pressing body 16 and the inner
surface of a recess in the cap body 20, for biasing the pressing
body 16 toward the bare chip 12.
[0010] The base portion of the pressing body 16 has hooks on the
outer periphery thereof and inserted into the recess of the cap
body 20 in a movable manner. The cap body 20 has step height 20N on
the outer surfaces at opposite ends thereof, with which tip ends of
hook members 10FA and 10FB of the latch mechanism 10 are engaged,
as shown in FIG. 20.
[0011] The latch mechanism 10 is comprised of the hook members 10FA
and 10FB supported rotational moveably by the carrier housing 2 to
be engageable with the step height 20N of the cap body 20 in the
pressing cap 14, and helical torsion springs (not shown) for
biasing the hook members 10FA and 10FB in the direction that they
are engaged with the step height 20N of the cap body 20.
[0012] Accordingly, when the pressing cap 14 is located over the
bare chip 12 positioned in advance relative to the bumps 6B of the
contact sheet 6, as shown in FIG. 21, the tip ends of the hook
members 10FA and 10FB of the latch mechanism 10 are made to rotate
by the edge of the step height of the cap body 20 of the pressing
cap 14 to be away from each other so that the pressing body 16 of
the pressing cap 14 is accommodated in the accommodation portion
2A.
[0013] When the pressing cap 14 is mounted to the interior of the
accommodation portion 2A in the carrier housing 2, the outer
periphery of the pressing body 20 is guided by a guiding member 8
provided in the carrier housing 2. Thereafter, by being biased by
the helical torsion spring, tip ends of the hook members 10FA and
10FB of the latch mechanism 10 is made to rotate in the mutually
approaching direction as shown in FIG. 20 and engaged with the
upper surfaces of the step height 20N of the cap body 20. As a
result, the pressing cap 14 is held by the carrier housing 2.
[0014] Since the respective bump 6B as described above is formed
with diameter-to-height ratios of 1:1, if the diameter becomes
smaller in correspondence to the high-density arrangement of the
electrode group in the bare chip 12, the height of the bump 6B is
also lower.
[0015] Accordingly, when a region in the vicinity of the bump group
opposed to the elastic sheet 4 in the contact sheet 6 sinks against
the elasticity of the elastic sheet 4 as shown in FIG. 22 in an
partially enlarged manner, there is a risk in that the outer
peripheral edge of the bare chip 12 is brought into contact with a
copper conductor layer 6C formed on the surface of the contact
sheet 6 and may be damaged thereby, as shown in FIG. 21. Also,
there is a risk in that a contact pressure of the bump group of the
contact sheet 6 with the electrode group of the bare chip 12 is
lower than a predetermined value.
[0016] FIG. 23 illustrates another example of the conventional
carrier unit. The carrier unit shown in FIG. 23 is comprised of a
carrier housing 2' having an accommodation portion 2A' for
accommodating a bare chip 12', a contact sheet 6' disposed on the
inner bottom of the accommodation portion 2A' of the carrier
housing 2' via an elastic sheet 4', a pressing cap 14' for pressing
the electrode group in the bare chip 12' onto the bump group of the
contact sheet 6', and a latch mechanism 10' for selectively holding
the pressing cap 14' on the carrier housing 2'.
[0017] The contact sheet 6' has a plurality of bumps 6b' made of
copper or others and opposed to the electrode group in the bare
chip 12' to be electrically connected thereto. In this regard, in
FIG. 23, of which two bumps 6b' are shown in an exaggerated manner
as representative. A tip end of the respective bump 6b' projects
from the surface of the contact sheet 6 by a predetermined
height.
[0018] The pressing cap 14' is comprised of a pressing body 16'
having a pressing surface to be brought into contact with a surface
of the bare chip 12' opposite to the surface of the bare chip 12'
on which the electrode group are formed, a cap body 20' for
accommodating a base portion of the pressing body 16' and a
plurality of springs 18' disposed in a space between the base
portion of the pressing body 16' and the inside surface of the cap
body 20', for biasing the pressing body 16' toward the bare chip
12'.
[0019] The base portion of the pressing body 16' is inserted into a
recess of the cap body 20' in a movable manner, and has hooks on
the outer periphery thereof.
[0020] The cap body 20' has projections at opposite ends thereof to
be engaged with hook members 10' of the latch mechanism.
[0021] The latch mechanism includes hook members 10' supported
rotational moveably by the carrier housing 2' to be engageable with
the projections of the cap body 20' in the pressing cap 14', and
helical torsion springs for biasing the hook members 10' in the
direction that they engage with the projections of the cap body
20'.
[0022] Accordingly, when the pressing cap 14' is located over the
bare chip 12' positioned in advance relative to the bumps 6b' in
the contact sheet 6', tip ends of the hook members 10' of the latch
mechanism are made to rotate by the slanted surface of the
projection of the cap body 20' in the pressing cap 14' in the
mutually parting direction, whereby the pressing body 16' of the
pressing cap 14' is accommodated. When the pressing cap 14' is
mounted into the accommodation portion 2A' of the carrier housing
2', the outer periphery of the cap body 20' is guided by guide
members 8' provided at the carrier housing 2'. Thereafter, by the
biasing force of the helical torsion springs, the tip ends of the
hook members of the latch mechanism 10' are made to rotate in the
mutually approaching direction and engage with the upper surface of
the projection of the cap body 20'. As a result, the pressing cap
14' is held by the carrier housing 2'.
[0023] The carrier unit, the bumps 6b' in the contact sheet 6' or
others are preferably durable against the repeated use of several
times. Particularly, by the repeated use, a contact area between
the tip end of the bump 6b' in the contact sheet 6' and the
electrode of the bare chip 12' will be liable to be gradually
larger because the bare chip 12' is pressed at a predetermined
pressure.
[0024] As described above, the cap body 20' of the pressing cap 14'
is mounted to the accommodation portion in the carrier housing 2'
while being guided by the guide member 8' provided in the carrier
housing 2'. However, since a gap is actually formed between the
outer periphery of the carrier housing 2' and the guide member 8',
the tip ends of the bumps 6b' are pressed by a deviated pressure
generated on the chip 12' by the pressing cap 14' inclined toward
one side.
[0025] Accordingly, the distribution of heights and contact areas
or the like of the plurality of bumps 6' is varied to exceed the
allowable value, whereby there is a risk in that the electric
connection the tip ends of a portion among the bumps 6b' with the
electrodes of the bare chip 12' becomes unreliable.
SUMMARY OF THE INVENTION
[0026] In view of the above problems in the prior art, a first
object of the present invention is to provide a socket for a
semiconductor device comprising a contact sheet, capable of
restricting the contact of a bare chip with the contact sheet
caused by the sinking of the contact sheet in the vicinity of a
bump group accompanied with the high-density arrangement of a
electrode group in the bare chip.
[0027] A second object of the present invention is to provide a
socket for a semiconductor device capable of avoiding the
inconvenience in that the undesirable deviated pressure is applied
to part of a plurality of bumps in the contact sheet.
[0028] In a first aspect of the present invention, there is
provided a socket for a semiconductor device comprising: a contact
sheet having a plurality of bumps to be electrically connected to a
terminal group of a semiconductor device, for inputting/outputting
signals relative to the semiconductor device, a pressing member for
pressing terminals of the semiconductor device onto the bumps of
the contact sheet, an accommodation portion for accommodating the
semiconductor device disposed on the contact sheet, and a
movement-amount controlling member for controlling a movement
amount of the semiconductor device along the direction of a
projected height of the bump when the pressing member disposed in
the accommodation portion is in a pressed state.
[0029] In a second aspect of the present invention, there is
provided a socket for a semiconductor device comprising: a contact
sheet having a bump group to be electrically connected to a
terminal group of a semiconductor device, for inputting/outputting
signals relative to the semiconductor device, a pressing member for
pressing terminals of the semiconductor device onto a bump group of
the contact sheet, and a contact sheet pressing member for pressing
the contact sheet in the direction in which the sinking of the
contact sheet in the vicinity of the bump group is restricted when
the terminals of the semiconductor device are pressed onto the bump
group by the pressing member.
[0030] In a third aspect of the present invention, there is
provided a socket for a semiconductor device comprising: a contact
sheet having a plurality of bumps to be electrically connected to a
terminal group of a semiconductor device, for inputting/outputting
signals relative to the semiconductor device, a pressing member for
pressing terminals of the semiconductor device onto the bumps of
the contact sheet, an accommodation portion for accommodating the
semiconductor device disposed on the contact sheet, and a
movement-amount restricting member for restricting a movement
amount of the semiconductor device along the direction of a
projected height of the bump when the pressing member disposed in
the accommodation portion is in a pressed state.
[0031] As apparent from the above description, according to the
socket for a semiconductor device according to the present
invention, since the contact sheet pressing member is provided for
pressing the contact sheet in the direction for suppressing the
sinking of an area on the periphery of the bump group in the
contact sheet when the terminals of the semiconductor device are
pressed onto the bump group, it is possible to restrict the contact
of the bare chip with the contact sheet due to the sinking of the
area in the contact sheet in the vicinity of the bump group
accompanied with the high-density arrangement of the terminal group
in the bare chip.
[0032] Also, according to the socket for a semiconductor device
according to the present invention, since an amount of the movement
of the semiconductor device in the height direction of the bump is
restricted when the pressing member disposed in the accommodation
portion is in a pressed state, it is possible to avoid the
application of the undesirable deviated pressure to part of the
plurality of bumps in the contact sheet.
[0033] The above and other objects, effects, features and
advantages of the present invention will become more apparent from
the following description of embodiments thereof taken in
conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] FIG. 1 is a structural drawing showing a configuration in a
first embodiment of a carrier unit used in an example of a socket
for a semiconductor device according to the present invention;
[0035] FIG. 2 is a structural drawing showing a configuration of a
pressing cap in the carrier unit shown in FIG. 1;
[0036] FIG. 3 is a plan view of the embodiment shown in FIG. 2;
[0037] FIG. 4 is an enlarged partially sectional view of an
important part of the embodiment shown in FIG. 1;
[0038] FIG. 5 is a plan view of a contact sheet in the embodiment
shown in FIG. 1;
[0039] FIG. 6 is a structural drawing schematically showing an
overall structure in the embodiment of the socket for a
semiconductor device according to the present invention;
[0040] FIG. 7 is an exploded structural drawing schematically
showing an overall structure in the embodiment shown in FIG. 6;
[0041] FIG. 8 is a structural drawing showing a configuration in a
second embodiment of a carrier unit used for the socket for a
semiconductor device according to the present invention;
[0042] FIG. 9 is a structural drawing made available for explaining
the operation of the embodiment shown in FIG. 8;
[0043] FIG. 10 is a plan view of a contact sheet in the embodiment
shown in FIG. 8;
[0044] FIG. 11 is a structural drawing showing a configuration in a
third embodiment of a carrier unit used for the socket for a
semiconductor device according to the present invention;
[0045] FIG. 12 is a structural drawing made available for
explaining the operation of the embodiment shown in FIG. 11;
[0046] FIG. 13 is a plan view of a base member in the embodiment
shown in FIG. 11;
[0047] FIG. 14 is a partially sectional view showing an important
part in a fourth embodiment of a carrier unit used for the socket
for a semiconductor device according to the present invention;
[0048] FIG. 15 is a plan view of the embodiment shown in FIG.
14;
[0049] FIG. 16 is a partially sectional view made available for
explaining the operation of the embodiment shown in FIG. 14;
[0050] FIG. 17 is a partially sectional view of the carrier unit of
the fourth embodiment used for the socket for a semiconductor
device according to the present invention, with the carrier unit
removed from the body of the IC socket;
[0051] FIGS. 18A and 18B are partially sectional views,
respectively, schematically showing an important part of a carrier
unit in a fifth embodiment of the carrier unit used for the socket
for a semiconductor device according to the present invention;
[0052] FIG. 19 is a partially sectional view schematically showing
a important part of a sixth embodiment of the a carrier unit used
for the socket for a semiconductor device according to the present
invention;
[0053] FIG. 20 is a structural drawing showing a configuration of a
carrier unit used for the conventional socket for a semiconductor
device;
[0054] FIG. 21 is a structural drawing made available for
explaining the operation of the embodiment shown in FIG. 20;
[0055] FIG. 22 is an enlarged partially sectional view of part of
the contact sheet shown in FIG. 20; and
[0056] FIG. 23 is a partially sectional view showing structure of
the conventional socket for a semiconductor device.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0057] FIG. 6 illustrates one embodiment of the socket for a
semiconductor device according to the present invention.
[0058] In the socket for a semiconductor device shown in FIG. 6 is
comprised of a carrier unit 40 for accommodating a bare chip 60
therein as a semiconductor device, and an IC socket 30 to which is
detachably mounted the carrier unit 40.
[0059] The IC socket 30 is mainly comprised of a body section 32
disposed on a printed wiring board 38 for inputting test signals to
the bare chip 60 and outputting detected output signals from the
bare chip 60, having an accommodation portion for accommodating the
carrier unit 40, a contact group 34 consisting of a plurality of
contacts to be electrically connected to pads, respectively, on a
contact sheet 44 described later, and a cover member 36 disposed to
be movable upward/downward relative to the body section 32 so that
the respective contact sections in the contact group 34 are
selectively electrically connected to the respective pads of the
contact sheet.
[0060] The body section 32 molded of resinous material is disposed
at a predetermined position in correspondence to the electrode
portion of the printed wiring board 38. The body section 32 has an
accommodation portion 32A for accommodating the carrier unit 40
therein as shown in FIG. 7. The accommodation portion 32A is
surroundedly defined by the inner periphery of a lower base portion
32a to be engaged to a lower portion of a base of the carrier unit
40 described later and the inner periphery of an upper base portion
32b contiguous to the lower base portion 32a to be engaged to an
upper portion of the base. The contact group 34 are held by the
lower base portion 32a. Slits are formed in the lower base portion
32a and the upper base portion 32b at a predetermined pitch in the
vertical direction relative to a paper surface so that the
respective contacts 34ai (wherein i=1 to n, n is a positive
integer) in the contact group 34 are inserted therein. The contact
group 34 are provided on each side while encircling the
accommodation portion 32A. In this regard, in FIGS. 6 and 7, only
one group among the four contact groups 34 encircling four sides of
the accommodation portion 32A are illustrated.
[0061] The respective contact 34ai (wherein i=1 to n, n is a
positive integer) is comprised of a terminal section 34T press-fit
into the lower base portion 32a, a fixed contact section 34f
contiguous to the terminal section 34T and electrically connected
to a pad 44P of the contact sheet 44 described later from below, an
elastic movable contact section 34m contiguous to the terminal
section 34T and electrically connected to the pad 44P from above,
and a portion being engaged 34e bifurcated from the movable contact
section 34m and selectively engageable with a slant of a cover
member 36 described later to rotate the movable contact section 34m
to be away from the fixed contact section 34f.
[0062] The contacts 34ai are arranged at a predetermined pitch in
correspondence to the pads 44P of the contact sheet 44 described
later in the direction generally vertical to the paper surface,
respectively. The cover member 36 molded of resinous material has
an opening 36a through which the carrier unit 40 passes. A frame
portion defining the periphery of the opening 36a is supported by
legs guided by grooves provided on the outer periphery of the body
section 32 to be movable upward and downward. In this regard, the
cover member 36 is biased by elastic members (not shown) to be away
from the body section 32. At a lower end of the respective side of
the frame portion, a slant section 36s is formed, respectively.
When the cover member 36 is lowered to a predetermined position as
shown by a chain double-dashed line in FIG. 6, the slant section
36s is engaged with the portion being engaged 34e of the contact
34ai as above to rotate the movable contact section 34m against the
elasticity thereof to be away from the fixed contact section
34f.
[0063] When the carrier unit 40 described later is mounted to the
body section 32 of the IC socket 30, the cover member 36 is pushed
down by a given distance and maintained there so that the
respective movable contact sections 34m in the contact group 34 are
moved to a waiting position away from the accommodation portion
32A, then the carrier unit 40 is inserted and positioned in the
accommodation portion 32A from above through the opening 36a. At
this time, the fixed contact section 34f is brought into contact
with the lower surface of the pad 44P of the contact sheet 44 in
the carrier unit 40.
[0064] Subsequently, when the cover member 36 is released from the
retention state, the cover member 36 is moved upwardly due to a
resultant force of the above recovery force of the elastic body and
the elastic force of the portion being engaged 34e of each contact
34ai. At this time, the respective movable contact section 34m in
the contact group 34 returns to the original position and is
brought into contact with the upper surface of the pad 44P of the
contact sheet 44 in the carrier unit 40. Thereby, as shown in FIG.
6, the contact sheet 44 is electrically connected to the four
contact groups 34.
[0065] As shown in FIG. 7, the carrier unit 40 in the first
embodiment is comprised of a carrier housing 46 having an
accommodation portion 46A for accommodating the bare chip 60, the
contact sheet 44 disposed on the base member 42 defining a bottom
of the accommodation portion 46A of the carrier housing 46 via an
elastic sheet 58 made of the rubber material, a pressing cap 52
including a pressing body for pressing the electrode group of the
bare chip 60 onto the bump group 44B of the contact sheet 44, and a
latch mechanism 50 for selectively holding the pressing cap 52 on
the carrier housing 46.
[0066] The latch mechanism 50 is comprised of hook members 48A and
48B supported rotational moveably at opposite ends of the carrier
housing 46, for holding a cap body of the pressing cap 52, helical
torsion springs 66 for biasing the hook members 48A and 48B in the
direction shown by an arrow in FIG. 7, that is, in the direction
that engages them with projections of the cap body, and pins 68 for
supporting the hook members 48A and 48B and the helical torsion
springs 66.
[0067] At each of the opposite ends of the carrier housing 46, a
guide section 46g is formed for guiding an outer periphery of a
lower portion of the cap body 64 when the pressing cap 52 is
mounted. On the periphery of the guide section 46g, opposite ends
of the pin 68 is supported.
[0068] The contact sheet 44 has a plurality of bumps 44B in a
substrate 44 arranged in correspondence to the electrode group of
the bare chip 60 to be electrically connected thereto, as
schematically illustrated in an partially enlarged manner in FIG.
1. In this regard, in FIG. 1, two in the plurality of bumps 44B are
shown in an exaggerated manner as representatives. For example, the
bump 44B made of copper or others has a diameter of approximately
100 .mu.m at a root thereof and projects from the surface of the
substrate 44M by a predetermined height, for example, of
approximately 50 .mu.m. The substrate 44M is made, for example, of
polyimide resin as thin as about several tens .mu.m.
[0069] The respective bump 44B is connected to the respective pad
44p via a conductor layer 44c made of copper foil. As shown in FIG.
6, the plurality of pads 44p are formed in opposite end portions of
the substrate 44M extended outward from the opposite ends of the
base member 42.
[0070] The pressing cap 52 is comprised of, as shown in FIGS. 1 and
2, a pressing body 56 having a pressing surface 56a to be brought
into contact with the upper surface of the bare chip 60, a cap body
64 for accommodating a base portion of the pressing body 56, and a
plurality of springs 54 disposed in a space between recesses 56r in
the base portion of the pressing body 56 and recesses 64r in the
cap body 64, for biasing the pressing body 56 toward the bare chip
60. In this regard, FIG. 2 illustrates the pressing cap 52 in a
pressed state.
[0071] The bare chip 60 of a generally square shape has the
electrode group on the lower surface opposed to the bumps in the
contact sheet 44.
[0072] The cap body 64 has projections 64p on the outer periphery
thereof, as shown in FIG. 1, to be engaged with the hook members
48A and 48B, respectively, in the latch mechanism 50.
[0073] In a recess of the cap body 64, to which the recesses 64r
open, lamellar pieces 64t are formed integral with the cap body 64
at a plurality positions as contact sheet pressing members. The
lamellar piece 64t having a predetermined thickness is provided,
for example, at four positions in correspondence to the respective
sides of the bare chip 60 to intersect the base portion of the
pressing body 56 in the generally vertical direction thereto as
shown in FIG. 5. The respective lamellar piece 64t is provided to
define a predetermined gap CL between the same and the end of the
respective side of the bare chip 60, for example, in a range from
approximately 0.1 mm to 1 mm. Also, a projected length of the
lamellar piece 64t is determined such that the surface of the
substrate 44M of the contact sheet 44 sinks to a depth
corresponding to the height of the bump 44B as shown in FIG. 4 in
an enlarge manner when the lamellar piece 64t passes through the
slit 56s in the base portion of the pressing body 56 and presses
the substrate 44M of the contact sheet 44 as shown in FIG. 1.
[0074] The base portion of the pressing body 56 is inserted in the
recess in the cap body 64 in a movable manner. At an end of a
portion of the pressing body 56 inserted into the recess, a
plurality of hooks 56n engageable with hooks 64n provided at a
lower end of the cap body 64 are formed. Thereby, the pressing body
56 is held in the interior of the cap body 64 while being biased
with the springs 54, for example.
[0075] In such a structure, when the bare chip 60 is mounted into
the carrier unit 40, the electrode group of the bare chip 60 are
first positioned to the bumps 44B in the contact sheet 44 so that
the electrode group of the bare chip 60 are brought into contact
with the bumps 44B.
[0076] Then, the pressing cap 52 is inserted into the accommodation
portion 46A of the carrier housing 46. At this time, tip ends of
the hook members 48A and 48B of the latch mechanism 50 are made to
rotate in the direction away from each other against the biasing
force of the helical torsion springs 66. Also, the pressing surface
56a of the pressing body 56 is pressed onto the upper surface of
the bare chip 60 against the biasing force of the springs 54, while
the outer peripheral surface of the cap body 64 is guided by the
inner surface of the guide section 46g.
[0077] At this time, as shown in FIGS. 1 and 4, the portion close
to an end portion of the respective side of the bare chip 60 on the
substrate 44M of the contact sheet 44 is pressed by one end of the
lamellar piece 64, and sinks. Accordingly, it is possible to avoid
the interference between the conductor layer 44c formed on the
surface of the substrate 44M in the contact sheet 44 and the end
portion of the bare chip 60.
[0078] Subsequently, due to the biasing force of the helical
torsion springs 66, the tip ends of the hook members 48 are made
rotate in the mutually approaching direction and engaged with the
projections 64p of the cap body 64. As a result, as shown in FIG.
1, the pressing cap 52 is held by the carrier housing 46.
[0079] FIG. 8 illustrates a second embodiment of a carrier unit
used for the socket for a semiconductor device according to the
present invention. In FIG. 8, the same reference numerals are used
for denoting the same constituent elements in the embodiment shown
in FIG. 1 and the explanation thereof will be eliminated.
[0080] The carrier unit shown in FIG. 8 is comprised of a carrier
housing 46 having an accommodation portion 46A for accommodating a
bare chip 60 as shown in FIG. 1, a contact sheet 70 disposed on a
base member 42 defining a bottom of the accommodation portion 46A
in the carrier housing 46 via an elastic sheet 58, a pressing cap
72 including a pressing body for pressing an electrode group in the
bare chip 60 onto a bump group 70B in the contact sheet 70, and a
latch mechanism 50 for selectively holding the pressing cap 72 in
the carrier housing 46.
[0081] As shown in FIG. 9, the contact sheet 70 has a plurality of
bumps 70B disposed in a substrate 70M in correspondence with the
arrangement of the electrode group in the bare chip 60 to be
electrically connected thereto. In FIG. 9, two in the plurality of
bumps 70B are shown as representatives in the exaggerated manner.
The bump 70B made, for example, of copper has a diameter in a root
portion of approximately 100 .mu.m, and is projected from the
surface of the substrate 70M at a predetermined height, for
example, of approximately 50 .mu.m. The substrate 70M is made, for
example, of polyimide resin to be a sheet of approximately several
tens .mu.m thick.
[0082] The respective bump 70B is connected to the respective pad
(not shown) via a conductor layer made of copper. A plurality of
pads are formed in opposite end portions of the substrate 70M
extended outward from the opposite ends of the base member 42.
[0083] As shown in FIG. 10, a frame-shaped convex seat 70d having a
predetermined width is provided in an area of a surface of the
substrate 70M opposed to the elastic sheet 58 corresponding to the
arrangement of the bumps 70B, as a sinking-adjustment area for
adjusting an amount of sinking of the respective bump 70B. The seat
70d is made, for example, of resin, metal or resist to have a
predetermined height. As shown in FIG. 9, a height thereof is
determined so that a predetermined gap S is formed between the
surface of the contact sheet 70 and that of the elastic sheet 50
when no pressure is applied; that is, the height is, for example,
in a range from 5 to 200 .mu.m in accordance with the amounts of
sinking of the respective bumps 70B.
[0084] As shown in FIG. 8, the pressing cap 72 is constituted by a
pressing body 78 having a pressing surface 78a to be brought into
contact with the upper surface of the bare chip 60, a cap body 76
for accommodating a base portion of the pressing body 78, and a
plurality of springs 74 arranged in a space between recesses 78r in
the base portion of the pressing body 78 and recesses 76r in the
cap body 76, for biasing the pressing body 78 toward the bare chip
60. In this regard, the pressing cap 72 is in a pressed state in
FIG. 8.
[0085] The cap body 76 has projections 76p on the outer periphery
thereof to be engaged with hook members 48A and 48B, respectively
as shown in FIG. 8.
[0086] A base portion of the pressing body 78 is inserted in a
movable manner into a recess of the cap body 76 to which the
recesses 76r open. At an end of a portion of the pressing body 78
inserted into the recess, a plurality of hooks 78n are formed
opposite to hooks 76n provided at a lower end of the cap body 76 so
that both of them are engaged with each other. Thereby, the
pressing body 78 is held in the interior of the cap body 76 while
being biased by the springs 74.
[0087] In such a structure, when the bare chip 60 is mounted to the
carrier unit, first, the electrode group in the bare chip 60 are
positioned to the bumps 70B in the contact sheet 70 so that the
electrode group in the bare chip 60 are brought into contact with
the bumps 70B as shown in FIG. 9.
[0088] Then, the pressing cap 72 is inserted into the accommodation
portion 46A in the carrier housing 46. At this time, tip ends of
the hook members 48A and 48B in the latch mechanism 50 are made to
rotate to be away from each other against the bias of the helical
torsion springs. Also, the pressing surface 78a of the pressing
body 78 is pressed onto the upper surface of the bare chip 60
against the biasing force of the springs 74, while the outer
peripheral surface of the cap body 76 is guided by the inner
surface of the guide sections 46g.
[0089] At this time, the gap S formed between the surface of the
contact sheet 70 and that of the elastic sheet 58 is eliminated and
the amount of sinking of the substrate 70M in the contact sheet 70
in the vicinity of the bump 70B is restricted not to exceed the
predetermined value, whereby the interference is avoidable between
the conductor layer of the substrate 70M and the end portion of the
bare chip 60.
[0090] Subsequently, the tip ends of the hook members 48A and 48B
are made to rotate in the mutually approaching direction due to the
biasing force of the helical torsion springs and engaged with the
projections 76p in the cap body 76. As a result, as shown in FIG.
8, the pressing cap 72 is held in the carrier housing 46.
[0091] FIG. 11 illustrates a third embodiment of a carrier unit
used for the socket for a semiconductor device according to the
present invention. In FIG. 11, the same reference numerals are used
for denoting the same constituent elements in the embodiment shown
in FIG. 8 and the explanation thereof will be eliminated.
[0092] The carrier unit shown in FIG. 11 is constituted by a
carrier housing 46 having an accommodation portion 46A for
accommodating a bare chip 60 as shown in FIG. 8, a contact sheet 78
disposed on a base member 82 defining a bottom of the accommodation
portion 46A in the carrier housing 46 via an elastic sheet 58, a
pressing cap 72 including a pressing body for pressing an electrode
group in the bare chip 60 onto a bump group 80B in the contact
sheet 70, and a latch mechanism 50 for selectively holding the
pressing cap 72 in the carrier housing 46.
[0093] As shown in FIG. 11, the contact sheet 80 has a plurality of
bumps 80B disposed in a substrate 80M in correspondence with the
arrangement of the electrode group in the bare chip 60 to be
electrically connected thereto. In FIG. 9, two in the plurality of
bumps 80B are shown as representatives in the exaggerated manner.
The bump 80B made, for example, of copper has a diameter in a root
portion of approximately 100 .mu.m, and is projected from the
surface of the substrate 80M at a predetermined height, for
example, of approximately 50 .mu.m. The substrate 80M is made, for
example, of polyimide resin to be a sheet of approximately several
tens .mu.m thick.
[0094] The respective bump 80B is connected to the respective pad
(not shown) via a conductor layer made of copper. A plurality of
pads are formed in opposite end portions of the substrate 80M
extended outward from the opposite ends of the base member 82.
[0095] As shown in FIG. 12, in a portion of the base member 82 in
which the elastic sheet 58 is disposed and corresponding to the
arrangement of the bumps 80B in the substrate 80M, a convex seat
82d in a frame shape having a predetermined width is formed as a
sinking-adjustment section for adjusting an amount of sinking of
the respective bump 80B. The seat 82d is made, for example, of the
same material as that of the base member 82. The height thereof is
determined such that when no pressure is applied, a predetermined
gap S is formed between the surface of the contact sheet 80 and the
surface of the elastic sheet 58, in a range from 5 to 200 .mu.m in
accordance with the amount of sinking of the respective bump 80B.
In this regard, the seat 82d may be formed separately from the base
member 82.
[0096] In the above structure, when the bare chip 60 is mounted to
the carrier unit, first, the electrode group in the bare chip 60
are positioned in correspondence to the bumps 80B in the contact
sheet 80, as shown in FIG. 12, so that the electrode group in the
bare chip 60 are brought into contact with the bumps 80B,
respectively.
[0097] Next, the pressing cap 72 is inserted into the accommodation
portion 46A of the carrier housing 46. At this time, tip ends of
the hook members 48A and 48B in the latch mechanism 50 are made to
rotate to be away from each other against the biasing force of the
helical torsion springs. Also, while the outer peripheral surface
of the cap body 76 is guided by the inner surfaces of the guide
sections 46g, the pressing surface 78a of the pressing body 78 is
pressed onto the upper surface of the bare chip 60 against the
biasing force of the springs 74.
[0098] At this time, the predetermined gap S between the surface of
the contact sheet 80 and that of the elastic sheet 58 is eliminated
and the amount of sinking solely in the vicinity of the bumps 80B
in the substrate 80M of the contact sheet 80 is restricted not to
exceed the predetermined value, whereby the interference is
avoidable between the conductor layer of the substrate 80M and the
end portion of the bare chip 60.
[0099] Subsequently, tip ends of the hook members 48A and 48B are
made to rotate to be closer to each other and engaged with the
projections 76p of the cap body 76, respectively. As a result, the
pressing cap 72 is held in the carrier housing 46.
[0100] FIG. 17 illustrates, together with a socket for a
semiconductor device, an important part of a fourth embodiment of a
carrier unit used for the socket for a semiconductor device
according to the present invention.
[0101] In FIG. 17, the same reference numerals are used for
denoting the same constituent elements as in the embodiment shown
in FIG. 7, and the explanation thereof will be eliminated.
[0102] The socket for a semiconductor device shown in FIG. 17 is
comprised of a carrier unit 140 for accommodating a bare chip as a
semiconductor device in the interior thereof, and an IC socket 30
for mounting the carrier unit 140 in an accommodation portion
thereof in a detachable manner.
[0103] As shown in FIG. 17, the carrier unit 140 is comprised of a
carrier housing 146 having an accommodation portion 146A for
accommodating a bare chip 160, a contact sheet 144 disposed on a
base member 142 defining the bottom of the accommodation portion
146A in the carrier housing 146 via an elastic sheet 158, a
pressing cap 152 including a pressing body 156 for pressing an
electrode group of the bare chip 160 onto a bump group 144B in the
contact sheet 144, and a latch mechanism 150 for selectively
holding the pressing cap 152 in the carrier housing 146.
[0104] As shown in FIG. 14, the pressing cap 152 is comprised of a
pressing body 156 having a pressing surface 156a to be brought into
contact with the upper surface of the bare chip 160, a cap body 164
for accommodating a base portion of the pressing body 156, and a
plurality of springs 154 arranged in a space between recesses in
the base portion of the pressing body 156 and recesses in the cap
body 164, respectively, for biasing the pressing body 156 toward
the bare chip 160.
[0105] The bare chip 160 of a generally square shape has an
electrode group, for example, on a lower surface confronting the
bumps 144B of the contact sheet 144.
[0106] The base portion of the pressing body 156 is inserted into a
recess in the cap body 164 in a movable manner. At an end of the
inserted portion of the pressing body 156, a plurality of hooks
156n are formed to be engageable with hooks provided at a lower end
of the cap body 164, both of which hooks are opposite to each
other. Thereby, the pressing body 156 is held in the cap body 164
while being biased by the springs 154.
[0107] The cap body 164 is provided at opposite ends thereof with
projections 164P to be engaged with the hook members 148A and 148B
in the latch mechanism 150. The projection 164P has a slant 164PS
engageable with a slant at a tip end portion of the hook member
148A, 148B to push the latter away from each other when the
pressing cap 152 is mounted as described later.
[0108] The latch mechanism 150 is comprised of the hook members
148A and 148B supported rotational moveably at opposite ends of the
carrier housing 146 to hold the cap body 164, helical torsion
springs 166 for biasing the hook members 148A and 148B in the
direction shown by an arrow in FIG. 17 so that they are engaged
with the projections 164p in the cap body 164, and pins 168 for
supporting the hook members 148A, 148B and the helical torsion
springs 166.
[0109] At the opposite ends of the carrier housing 146, the guide
sections 146g are formed for guiding the outer periphery of the
lower portion of the cap body 164 when the pressing body 152 is
mounted.
[0110] Opposite ends of the pin 168 are supported by guide sections
146g.
[0111] As shown in FIGS. 14 and 15, the contact sheet 144 has a
plurality of bumps 144B in a substrate 144M, arranged in
correspondence to the electrode group of the bare chip 160 to be
electrically connected thereto. In FIG. 14, two in the plurality of
bumps 144B are shown as representatives in the exaggerated manner.
For example, the respective bump 144B made of copper or others has
a diameter of approximately 100 .mu.m at a tip end thereof and a
predetermined height from the surface of the substrate 144M, for
example, of approximately 50 .mu.m. The substrate 144M is made of
polyimide resin as thin as approximately several tens .mu.m.
[0112] As shown in FIG. 15, the respective bump 144B is connected
to the pad 144P via the conductor layer 144C made of copper foil.
The pads 144P are formed in the opposite end portions of the
substrate 144M extended outward from the opposite ends of the base
member 142.
[0113] Also, as shown in FIGS. 14 and 15, in portions on the
substrate 144M corresponding to four corners of the bare chip 160,
dummy bumps 162 are provided, respectively, as a moving amount
restriction member. The dummy bump 162 is made, for example, of
metal such as palladium (Pd), platinum (Pt), cobalt (Co), iron
(Fe), Nickel (Ni), ruthenium (Ru), rhodium (Rh), osmium (Os),
iridium (Ir), hassium (Hs), meinerium (Mt) or Unununium (Uun), or
alloys mainly composed thereof.
[0114] When the dummy bump 162 is formed, as disclosed in Japanese
Patent Application Laid-open No. 11-326379 (1999), first, a tip end
of a wire made of the above metal is wire-bonded to a pad formed in
advance on the substrate 144M by a ultrasonic welding. Then, the
bonded tip end portion of the wire is torn. Thereby, a stud bump is
formed on the substrate 144M. Finally, the upper end of the stud
bump thus formed is flattened with a forming tool to complete the
dummy bump 162 on the substrate 144M.
[0115] A height of the dummy bump 162 from the surface is
determined to be equal to or slightly lower than the height of the
bump 144B from the surface, for example.
[0116] In this regard, a region in which the dummy bump 162 is
positioned is not limited to that shown in this embodiment, but may
be a region having no pads or wires, or that in which pads or wire
meshes are coated, with an insulation coating. Also, material and
the number of dummy bumps 162 are not limited to those shown in
this embodiment, but other suitable material may be selected, of
course, such as solder used for the bumps 144B, having no risk of
being crushed while exceeding a predetermined value even if each
dummy bumps are subjected to a total load applied to all the bumps
144B with the assumption that a load is applied to the bumps 144B
under a pressure of about 10 g per a bump. In this structure, when
the bare chip 160 is mounted into the carrier unit 140, the
electrode group in the bare chip 160 are positioned to the bumps
144B in the contact sheet 144 so that the electrode group in the
bare chip 160 are brought into contact with the bumps 144B,
respectively. Then, the pressing cap 152 is inserted into the
accommodation portion 146A of the carrier housing 146. At this
time, by the slants 164ps of the cap body 164 in the pressing cap
152, tip ends of the hook members 148A and 148B are made to rotate
to be away from each other against the bias of the helical torsion
springs 166. Also, while the outer peripheral surface of the cap
body 156 is guided by the inner surface of the guide sections 146g,
the pressing surface 156a of the pressing body 156 is pressed onto
the upper surface of the bare chip 160 against the bias of the
springs 154.
[0117] Subsequently, the tip ends of the hook members 148 are made
to rotate to be closer to each other due to the bias of the helical
torsion springs 166, and engaged with the projections 164p of the
cap body 164. As a result, the pressing cap 152 is held by the
carrier housing 146.
[0118] At this time, since a predetermined gap actually exists
between the outer peripheral surface of the cap body 164 and the
inner surface of the guide section 146g, there is a risk in that
the pressing surface 156a of the pressing body 156 presses the bare
chip 160 and the bumps 144B in an inclined posture as shown in FIG.
16.
[0119] However, in such a case, since the dummy bump 162 is
provided in the vicinity of the bump 144B, part of the bare chip
160 may interfere with the tip end of the bump 144B to restrict a
mount of pressing such as for example a movement distance of the
bare chip 160 in the height direction of the bump 144B or a contact
area of the tip end of the bump 144B with the electrode surface of
the bare chip 160. As a result, the deviated crush of the plurality
of bumps 144B is avoidable.
[0120] FIGS. 18A and 18B schematically illustrate a fifth
embodiment of a carrier unit used for the socket for a
semiconductor device according to the present invention. In this
regard, in FIGS. 18A and 18B, the same reference numerals are used
for denoting the same constituent elements as in the embodiment
shown in FIG. 14, and the explanation thereof will be
eliminated.
[0121] While the dummy bump 162 in the contact sheet 144 shown in
FIG. 14 is made of relatively rigid material free from a risk of
crush, in the embodiment shown in FIGS. 18A and 18B, four dummy
bumps 172 made of elastic material such as silicone rubber are
provided in a contact sheet 170.
[0122] The contact sheet 170 has a plurality of bumps 170B, in a
substrate 170M, arranged in correspondence to the electrode group
in the bare chip 160 electrically connected thereto. For example,
the respective bump 170B made of solder or others has a diameter at
a tip end thereof of approximately 100 .mu.m, and a height from the
surface of the substrate 170M of approximately 50 .mu.m. The
substrate 170M is made, for example, of polyimide resin to be a
sheet of approximately several tens .mu.m thick.
[0123] Not illustrated, the respective bump 170B is connected to a
pad via a conductor layer made of copper foil. The pads are formed
in the opposite end portions of the substrate 170M extended outward
from the opposite ends of the base member 142.
[0124] The dummy bumps 172 used as a moving amount restriction
member are projected from the substrate 170M at positions
corresponding to four corners of the bare chip 160. The lowermost
end of the dummy bump 172 is fixed to the base member 142 and the
upper end thereof is projected outward through small holes 170a and
158a in the substrate 170M of the contact sheet 170 and the elastic
body 158, respectively. As shown in FIG. 18A, when the biasing
force of the coil springs 154 is not applied, the projected height
of the dummy bump 172 is determined to be slightly higher than that
of the bump 170B. In addition, as shown in FIG. 18B, when the
biasing force of the coil springs 154 is applied, the projected
height of the dummy bump 172 is determined to be equal to or
slightly lower than that of the bump 170B.
[0125] Also in this embodiment, a region in which the dummy bump
162 is positioned is not limited to that shown in this embodiment,
but may be a region having no pads or wires, or that in which pads
or wire meshes are coated with an insulation coating. Also,
material and the number of dummy bumps 172 are not limited to those
shown in this embodiment, but other suitable material may be
selected, of course, such as solder used for the bumps 170B, having
no risk of being crushed while exceeding a predetermined value even
if each dummy bumps are subjected to a total load applied to all
the bumps 170B with the assumption that a load is applied to the
bumps 170B under a pressure of about 10 g per a bump.
[0126] In this structure, when the pressing cap 152 is mounted to
the carrier housing 46, there is a risk in that the pressing
surface of the pressing body 156 presses the bare chip 160 and the
bumps 170B in an inclined posture.
[0127] In such a case, however, since the dummy dump 172 is
provided in the vicinity of the bump 170B, part of the slanted bare
chip 160 is brought into contact with a tip end of the dummy dump
172 and presses the same. At this time, a pushed amount of the bare
chip 160 is restricted to a predetermined value due to the
repulsion of the dummy bump 172.
[0128] Further, FIG. 19 schematically illustrates a sixth
embodiment of a carrier unit used for the socket for a
semiconductor device according to the present invention. In this
regard, in FIG. 19, the same reference numerals are used for
denoting the same constituent elements as in the embodiment shown
in FIG. 14, and the explanation thereof will be eliminated.
[0129] In the preceding embodiment, the dummy bump 162 in the
contact sheet 144 directly restricts the amount of movement of the
bare chip 160 by the contact of the upper end of the dummy bump 172
with a surface of the bare chip 160 opposite to the bump 144B. In
FIG. 19, however, dummy bumps 180 are provided at four positions in
the contact sheet 144' for restricting the movement of the pressing
body 156 for the purpose of indirectly restricting an amount of the
movement of the bare chip 160. The respective dummy bump 180 is
provided in a region directly opposed to the pressing surface 156a
of the pressing body 156 while avoiding the interference with the
bare chip 160.
[0130] A projected height of the dummy bump 180 as a moving amount
restriction member from the surface of the substrate 144M' is
determined such that a distance between the electrode surface of
the bare chip 160 and the surface of the substrate 144M' is equal
to or slightly lower than the projected height of the bump 144B
when the pressing cap 52 is inserted into the accommodation portion
146A of the carrier housing 146 and held there.
[0131] The dummy bump 180 is made of the same material as that of
the preceding dummy bump 162 and formed in the same manner as
described with reference to FIG. 14.
[0132] Accordingly, in this embodiment, the same operation and
effect are obtainable as in the preceding embodiment.
[0133] In this regard, while the present invention is applied a
system in which the carrier unit is mounted to the body section 32
of the IC socket 30 in the preceding embodiments, the present
invention should not be limited to this, but may be applied to
other systems as a contact sheet itself, of course.
[0134] The present invention has been described in detail with
respect to preferred embodiments, and it will now be apparent from
the foregoing to those skilled in the art that changes and
modifications may be made without departing from the invention in
its broader aspects, and it is the intention, therefore, in the
appended claims to cover all such changes and modifications as fall
within the true spirit of the invention.
* * * * *