U.S. patent application number 11/302932 was filed with the patent office on 2007-06-14 for low insertion force socket.
This patent application is currently assigned to Tyco Electronics Corporation. Invention is credited to Brian Patrick Costello, George Richard Defibaugh, Richard Elof Hamner.
Application Number | 20070134970 11/302932 |
Document ID | / |
Family ID | 38090095 |
Filed Date | 2007-06-14 |
United States Patent
Application |
20070134970 |
Kind Code |
A1 |
Costello; Brian Patrick ; et
al. |
June 14, 2007 |
LOW INSERTION FORCE SOCKET
Abstract
A socket assembly is shown as generally including a cover
assembly and a base frame assembly. A low insertion force (LIF)
package assembly is connectable to the socket assembly and is
comprised of a pin assembly, housing a package. The cover assembly
includes a socket cover frame array and the base frame assembly
includes a socket contact frame array. The cover assembly is spring
loadable relative to the base frame assembly to provide a low
insertion force application for the package.
Inventors: |
Costello; Brian Patrick;
(Scotts Valley, CA) ; Defibaugh; George Richard;
(Harrisburg, PA) ; Hamner; Richard Elof;
(Hummelstown, PA) |
Correspondence
Address: |
Robert J. Kalpalka;Tyco Technology Resources
Suite 140
4550 New Linden Hill Road
Wilmington
DE
19808-2952
US
|
Assignee: |
Tyco Electronics
Corporation
|
Family ID: |
38090095 |
Appl. No.: |
11/302932 |
Filed: |
December 14, 2005 |
Current U.S.
Class: |
439/342 |
Current CPC
Class: |
H05K 7/1007 20130101;
H01R 13/26 20130101 |
Class at
Publication: |
439/342 |
International
Class: |
H01R 4/50 20060101
H01R004/50 |
Claims
1. A socket for interconnection with a package having an array of
contact points, the socket comprising: a cover assembly having a
housing and a substrate, the cover assembly substrate having
apertures aligned in a like array as the package, the substrate
having a plurality of pin guides positioned therein; a base frame
assembly having a frame and a metallic substrate, the base frame
assembly substrate having a plurality of socket contact assemblies
positioned therein and insulated from said substrate, the socket
contact assemblies positioned in an overlapping manner with said
pin guides; said cover assembly being laterally movable relative to
said base frame assembly, from a position where said pin guides
overlap said socket contact assemblies, to a position where said
pin guides are spaced from said socket contact assemblies.
2. The socket of claim 1, wherein said cover assembly substrate
material is thermally matched to the package.
3. The socket of claim 2, wherein said cover assembly substrate is
metallic.
4. The socket of claim 2, wherein the pin guides are insulative
material and are positioned through apertures in said metallic
cover assembly substrate.
5. The socket of claim 4, wherein said pin guides have an enlarged
head portion, having a profile larger than the apertures, and a
lower portion received through said apertures.
6. The socket of claim 1, wherein said base frame assembly
substrate is thermally matched to the package.
7. (canceled)
8. The socket of claim 6, wherein said socket contact assemblies
are comprised of conductive contacts positioned in insulators, the
insulators being positioned in apertures of said base frame
assembly substrate.
9. The socket of claim 8, wherein said insulators are overmolded
over said conductive contacts.
10. The socket of claim 1, further comprising a pin carrier
assembly for receiving and interconnecting the package to the
socket.
11. The socket of claim 10, wherein the pin carrier assembly
includes a substrate holding a plurality of pins, said pins
including an upper contact portion positioned above said substrate,
and a pin contact positioned below said substrate.
12. The socket of claim 11, wherein said substrate is metallic and
said pins are surrounded by an insulating member.
13. The socket of claim 12, wherein said insulating member is an
overmolded member which is insertable through apertures of said pin
carrier assembly substrate.
14. A socket for interconnection with a package having an array of
contact points, the socket comprising: a cover assembly having a
housing and a metallic substrate, the cover assembly substrate
having etched apertures aligned in a like array as the package, the
substrate having a plurality of insulative pin guides positioned in
the apertures; a base frame assembly having a frame and a
substrate, the base frame assembly substrate having a plurality of
socket contact assemblies positioned therein, the socket contact
assemblies positioned in an overlapping manner with said pin
guides; and a pin carrier assembly for receiving and
interconnecting the package to the socket, the pin carrier assembly
includes a substrate holding a plurality of pins, said pins
including an upper contact portion positioned above said substrate,
and a pin contact positioned below said substrate.
15. The socket of claim 14, wherein said cover assembly is
laterally movable relative to said base frame assembly, from a
position where said pin guides overlap said socket contact
assemblies, to a position where said pin guides are spaced from
said socket contact assemblies.
16. (canceled)
17. A socket for interconnection with a package having an array of
contact points, the socket comprising: a cover assembly having a
housing and a substrate, the cover assembly substrate having
apertures aligned in a like array as the package. the substrate
having a plurality of pin guides positioned in the apertures: a
base frame assembly having a frame and a metallic substrate. the
base frame assembly substrate having a plurality of socket contact
assemblies comprised of conductive contacts positioned in
insulators, the insulators being positioned in apertures of said
base frame assembly substrate, the socket contact assemblies
positioned in an overlapping manner with said pin guides; and a pin
carrier assembly for receiving and interconnecting the package to
the socket, the pin carrier assembly including a substrate holding
a plurality of pins, said pins including an upper contact portion
positioned above said substrate, and a pin contact positioned below
said substrate.
18. The socket of claim 17, wherein the pin carrier assembly
includes a substrate holding a plurality of pins, said pins
including an upper contact portion positioned above said substrate,
and a pin contact positioned below said substrate.
19. The socket of claim 18, wherein said substrate is metallic and
said pins are surrounded by an insulating member.
20. The socket of claim 19, wherein said insulating member is an
overmolded member which is insertable through apertures of said pin
carrier assembly substrate.
Description
FIELD OF THE INVENTION
[0001] The preferred embodiments of the present invention generally
relate to electrical sockets, such as sockets for receiving chip
packages. More specifically, the preferred embodiments of the
present invention generally relate to low insertion force
(LIF)/zero extraction force processor package sockets.
BACKGROUND OF THE INVENTION
[0002] Heretofore, sockets have been proposed that include a base
having a cover slidably mounted thereon. The sliding motion between
the base and cover is controlled in numerous manners in
conventional zero insertion force (ZIF) or low insertion force
(LIF) sockets. For example, U.S. Pat. No. 5,256,080 discloses a
bail actuated ZIF socket. U.S. Pat. No. 5,730,615 describes a ZIF
PGA socket that uses a flat or plate tool that is inserted into
receiving slots in the cover and base. The flat tool is moved
between two positions in order to open and close the ZIF socket.
U.S. Pat. No. 4,498,725 discloses a prior art PGA socket having a
base housing and a moveable cover. An L-shaped lever moves the
cover across a top surface of the housing. The lever includes a
first arm that is rotatably received in a passage in the socket and
a second arm that provides a handle for rotating the first arm.
[0003] However, existing sockets have experienced limited
applicability to certain processor designs. For instance, many
circuit designs are conditioned on PGA chips being arranged in a
closely packed manner with respect to one another. At least one
conventional socket uses an actuation lever located along one side
of the socket and moved in the same direction as the direction of
relative movement between the cover and base housing. The lever is
moved forward along the side of the socket to drive the cover
forward and vice versa. However, as components decrease in size and
are located closer to one another, space constraints no longer
permit the lever to be located along the side of the socket. Thus,
it is desirable to minimize the width of sockets holding the PGA
chips.
[0004] Also, as chip technology evolves, the number of pins on a
single chip increases. The socket achieves a separate electrical
contact with each pin on a chip and thus the number of electrical
contacts to be maintained by a socket is increased. As the
pin/contact count increases, the force required to electrically
engage the chip and socket similarly increases. Conventional
sockets focus significant actuation forces on small areas on the
cover and housing. As the actuation forces increase, various socket
designs experience more faults as the housing and cover are unable
to withstand the increased loads.
[0005] Conventional sockets for high pin count PGA chips generally
fall into two categories: Low Insertion Force (and extraction
force) also known as LIF, and Zero Insertion Force (and extraction
force) also known as ZIF. Due to the high forces of LIF sockets, a
tool such as an arbor press is needed to insert the package into
the socket and another tool is needed to pull the package from the
socket. Insertion is relatively simple since typical chips are able
to withstand large forces in compression. Extraction is much more
difficult since the package can only be held around the perimeter
of the pin field. This can lead to damage to the package due to
warping and bending of the package during extraction. This
difficulty helped lead to the development of ZIF sockets. ZIF
sockets typically employ features such as a sliding cover that
actuate and de-actuate the socket. The cover of such sockets must
be able to withstand the forces of both actuation and de-actuation.
In order to support these forces on both tension and compression,
ZIF socket covers need to be thicker. This is a problem since
higher speed electrical signals require the socket to be shorter,
not taller.
[0006] Other socket designs are shown in U.S. Pat. Nos. 5,013,256;
5,123,855; 6,217,361; 6,350,142; and 6,347,951, the disclosures of
which are incorporated herein by reference. All of these references
show LIF or ZIF style sockets for receiving various style packages.
One of the difficulties that exists is that when the packages have
high volume arrays, on the order of 1000 positions or more, the
typical ZIF or LIF style connectors cannot be used. Multiple design
issues compound to cause difficulty in this design, including the
tolerances of molding of the housing parts which receive the
packages, together with the tolerances of the stamping of the
contacts and their alignment in the housing. Thus, with 1000
contacts, even with small frictional insertion forces per contact,
the overall extraction or actuation/de-actuation force for the
package is unacceptable.
[0007] A need remains for an improved socket. It is an object of
the preferred embodiments of the present invention to meet this and
other needs that will become apparent from the following
description, drawings and claims.
SUMMARY OF THE INVENTION
[0008] The disclosure provides for a socket for interconnection
with a package having an array of contact points. The socket
comprises a cover assembly having a housing and a substrate, the
cover assembly substrate has apertures aligned in a like array as
the package, the substrate having a plurality of pin guides
positioned therein. A base frame assembly has a frame and a
substrate, the base frame assembly substrate has a plurality of
socket contact assemblies positioned therein, and the socket
contact assemblies are positioned in an overlapping manner with the
pin guides. The cover assembly is laterally movable relative to the
base frame assembly, from a position where the pin guides overlap
the socket contact assemblies, to a position where the pin guides
are spaced from the socket contact assemblies.
[0009] In another embodiment, a socket is provided for
interconnection with a package having an array of contact points. A
cover assembly has a housing and a substrate, the cover assembly
substrate has apertures aligned in a like array as the package, and
the substrate has a plurality of pin guides positioned therein. A
base frame assembly has a frame and a substrate, the base frame
assembly substrate has a plurality of socket contact assemblies
positioned therein, the socket contact assemblies are positioned in
an overlapping manner with the pin guides. A pin carrier assembly
is provided for receiving and interconnecting the package to the
socket, the pin carrier assembly includes a substrate holding a
plurality of pins, the pins including an upper contact portion
positioned above the substrate, and a pin contact positioned below
the substrate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 depicts a low insertion force, zero extraction force
socket assembly shown with a package assembly poised above the
socket;
[0011] FIG. 2 shows another perspective of the socket assembly of
FIG. 1;
[0012] FIG. 3 shows a partially exploded view with the cover
assembly exploded away from the socket base frame assembly;
[0013] FIG. 4 shows an underside perspective of the exploded view
of FIG. 3;
[0014] FIG. 5 shows an enlarged view of the portion denoted in FIG.
4;
[0015] FIG. 6 shows an exploded view of the cover assembly of FIG.
3;
[0016] FIG. 7 shows an enlarged view of the area denoted in FIG. 6
with one of the pin guides exploded from the frame;
[0017] FIG. 8 shows the frame of FIG. 7 from an underside
perspective with one of the pin guides exploded from the frame;
[0018] FIG. 9 shows the frame of FIG. 6 with all of the pin guides
removed;
[0019] FIG. 10 shows an exploded view of the base frame assembly of
FIG. 3;
[0020] FIG. 11 shows an enlarged view of the portion of FIG. 10
with two of the socket contacts removed;
[0021] FIG. 12 is an underside perspective of the socket contact
frame assembly of FIG. 11;
[0022] FIG. 13 shows the etched frame of FIGS. 10-12 with all of
the socket contacts removed;
[0023] FIG. 14 shows an underside perspective view of the socket
assembly as assembled;
[0024] FIG. 15 shows an enlarged view of the portion denoted in
FIG. 14;
[0025] FIG. 16 shows an enlarged view of the portion denoted in
FIG. 14;
[0026] FIG. 17 shows the package assembly of FIG. 1 with the
package exploded away;
[0027] FIG. 18 shows an enlarged view of the portion denoted in
FIG. 17;
[0028] FIG. 19 shows an underside perspective of the package
assembly of FIG. 17;
[0029] FIG. 20 shows an enlarged view of the portion denoted in
FIG. 19;
[0030] FIG. 21 shows the pin frame assembly removed from the
package assembly of either FIGS. 17 or 19 with one of the pins
removed from the frame;
[0031] FIG. 22 is an enlarged view of the exploded pin of FIG.
21;
[0032] FIG. 23 shows a perspective view similar to that of FIG. 1
with the package assembly fully installed in the socket and shown
in the actuated condition;
[0033] FIG. 24 is a view similar to that of FIG. 23 showing the
socket de-actuated;
[0034] FIG. 25 shows a cross-sectional view through a portion of
FIG. 23; and
[0035] FIG. 26 shows a cross-sectional view through a portion of
FIG. 24.
DETAILED DESCRIPTION OF INVENTION
[0036] With respect first to FIGS. 1 and 2, the socket assembly is
shown generally at 2 and includes a cover assembly 4 and a base
frame assembly 6. FIG. 1 also shows a low insertion force (LIF)
package assembly 10 comprised of a pin assembly 12, housing a
package 14. With respect to FIG. 3, the socket assembly 2 is shown
in an exploded manner, showing the cover assembly 4 poised above
the base frame assembly 6. As shown in FIG. 3, cover assembly 4
includes a socket cover frame array 16 while the base frame
assembly 6 includes a socket contact frame array 18.
[0037] With respect now to FIGS. 4, 5 and 6, the cover assembly 4
will be described in greater detail. As shown in FIGS. 4 and 5,
cover assembly 4 shows the socket cover frame array 16 attached to
a bottom of a cover frame 20. As best shown in FIG. 5, socket cover
frame array 16 is shown attached to cover frame 20 by way of heat
stake lugs 22 which both locates the socket cover frame array and
retains the socket cover frame array relative to the cover frame
20. It should be understood that cover frame array 16 can be
attached to cover frame 20 in any known manner. As also shown in
FIG. 5, cover frame 20 includes a spring thrust plate 24 positioned
on either side of a rear wall 26 which opens onto a rear opening
30. As also shown in FIG. 6, cover frame 20 includes an actuation
slot 32 for actuating the socket assembly as will be described
herein.
[0038] As shown in FIGS. 7, 8 and 9, socket cover frame array 16 is
comprised of a substrate 36 having at one edge thereof openings 38,
which receive the heat stake lugs 22 described above, and further
include a plurality of apertures 40 which receive insulator pin
guides 44. Substrate 36 is comprised of a material to thermally
match with the device connected. The substrate could be a metallic
plate, a copper alloy or a stainless steel plate. FIG. 9 shows the
substrate 36 with all of the insulator pin guides 44 removed, and
shows an array of apertures 40. Preferably, the array of openings
40 is provided in a precise alignment. An etching process can be
used to precisely align and form the array of apertures 40. As
shown in FIGS. 7 and 8, the insulator pin guides 44 include an
upper head section 50 having a lead in section 52 and a lower
section 54 profiled for receipt through one of the apertures 40.
Openings 56 are defined through the pin guides extending through
the entirety thereof, from the lead in section, through the lower
section 54.
[0039] It should be appreciated that insulator pin guides 44 could
be molded to the apertures 40, could be rubber type grommets
received through the apertures 40 or could be insulative plastic
positioned in the openings and then crimped or otherwise deformed
to be retained in the apertures 40. With respect to the latter
crimping step, applicants refer to, and incorporate by reference,
U.S. Pat. No. 6,945,788.
[0040] With respect now to FIG. 10, the base frame assembly 6 is
shown as comprised of the socket contact frame array 18 and a base
frame housing 60. As best shown in FIGS. 11 and 12, socket contact
frame array 18 is comprised of a plate or substrate 70 having a
plurality of apertures 72 which align and retain a plurality of
socket contact assemblies 74. The material composition of substrate
70 and the considerations are similar to that described above with
respect to substrate 36. Socket contact assemblies 74 are comprised
of contacts 76 and over molded insulators 78. As shown in both
FIGS. 11 and 12, molded insulator 78 are rectangular in
configuration having a large base portion 80 and a reduced cross
section portion 82. Meanwhile contact portions 76 include a contact
surface 88 extending from a central molded in section 90 and a
contact portion 92 (FIG. 12) protruding from the opposite side of
molded insulator 78. Once again, the over molded insulators 78 can
be attached to the substrate 70 as described in U.S. Pat. No.
6,945,788.
[0041] With respect again to FIG. 10, base frame housing 60 is
shown with a rear wall portion 90 having side wall portions 92, 94
and end wall portion 96. As shown, walls 90-96 define a frame work
with a reduced shoulder at 98. It should be appreciated that the
shoulder 98 is defined to receive the socket contact frame array
18. As also shown, rear wall portion 90 includes upstanding wall
sections 100 having a spring locator peg 102 extending integrally
there from. Pegs 102 extend into T-shaped openings 104 having slots
106. Springs may be received in T-shaped openings 104 over pegs 102
as described below. Finally rear wall portion 90 includes a bearing
surface at 110 which communicates with actuator slot 32 described
below.
[0042] With respect now to FIGS. 10, and 14-16, the assembly of
socket assembly 2 will be described. It should be appreciated that
socket contact frame array 18 is positioned within the base frame
housing 60 along the shoulder 98. Springs 108 are thereafter
positioned over pegs 102 and cover assembly 4 is then positioned
over base frame assembly 6. As shown best in FIGS. 14 and 16,
thrust plates 24 extending from cover frame 20 (FIG. 5) are
positioned within T-shaped slots 106 with springs 108 positioned
there between. It should be understood that the width of the slots
106 is greater than the thickness of the thrust plates 24, in order
that the springs 108 can provide relative movement between the
cover assembly 4 and base frame assembly as described below.
[0043] Spring 108 is a compression spring and is compressed between
the cover assembly 4 and the base spring assembly 6. That is,
spring 108 is compressed against thrust plate 24 of the cover
assembly 4 and is compressed against upstanding wall section 100 of
the base frame housing 60. When in this position, the openings 56
(FIGS. 7, 8) are spring loaded into an overlapping position with
the contact portions 88 (FIG. 12) as will be described herein.
[0044] With respect now to FIGS. 17 and 18, the LIF package
assembly 10 will be described in greater detail. As shown in FIG.
17, the LIF package assembly 10 is comprised of a package 14, such
as ASIC package having a polarizing comer at 122. The ASIC package
14 will be profiled to be received in a pin assembly 12, where pin
assembly 12 includes a package frame housing 132 and a pin frame
assembly 134. As shown in FIGS. 21 and 22, pin frame assembly 134
is shown comprising a plate or substrate 136 having a plurality of
apertures such as 138, through which pin assemblies 140 are
positioned. The material composition of substrate 136 and the
considerations are similar to that described above with respect to
substrate 36. Pin assemblies 140 are comprised of pins 142 having
elongate contact portions 144 and upper contact surfaces 146.
Assemblies 140 further include insulators 150 having an enlarged
portion 152, and a reduced cross section 154. Insulators 150 are
positioned within apertures 138 and attached thereto in a similar
way as described above with respect to either insulator pin guides
44 or insulators 78. As configured, pin frame assembly 134 is
positioned within frame housing 132, with contact surfaces 146
poised for receipt of package 120 as best shown in FIGS. 17 and 18.
An alternate embodiment of the integrated circuit package that
mates to the socket is for pins, similar to 144 but without the
plastic insulator, to be directly attached to the integrated
circuit package.
[0045] Thus as shown in FIG. 23, package assembly 10 is shown
positioned within socket assembly 2 whereby package 10 would be
interconnected to contact surfaces 146, and where contact portions
144 would protrude through pin guides 44 and into contact with
contact portions 88 (FIG. 12). Thus, as shown in FIG. 23, the
package 120 would be interconnected to contacts 76 as described
above. This state corresponds to the cross-sectional view of FIG.
25. However when in the de-actuated position of FIG. 24, which can
be de-actuated for example with a screw driver blade in
de-actuation slot 32, base frame assembly 6 and cover assembly 4
can be moved to a relative position where pins are spaced away from
the contact portions, as shown in FIG. 26, and whereby the package
assembly 10 can be removed, with zero extraction force.
* * * * *