U.S. patent application number 12/023521 was filed with the patent office on 2008-05-22 for socket warpage reduction apparatus.
This patent application is currently assigned to Intel Corporation. Invention is credited to Brian C. Kluge, Jiteender P. Manik, Tim A. Renfro.
Application Number | 20080119081 12/023521 |
Document ID | / |
Family ID | 25508774 |
Filed Date | 2008-05-22 |
United States Patent
Application |
20080119081 |
Kind Code |
A1 |
Renfro; Tim A. ; et
al. |
May 22, 2008 |
SOCKET WARPAGE REDUCTION APPARATUS
Abstract
Socket warpage reduction apparatus and method including a socket
comprising a socket housing having a surface mount region for an
electrical device, and at least one rigid bar secured in a groove
in the socket housing and contiguous the surface mount region to
ensure the surface mount region is flat and remains flattened in
varying ambient conditions.
Inventors: |
Renfro; Tim A.; (Mesa,
AZ) ; Kluge; Brian C.; (Chandler, AZ) ; Manik;
Jiteender P.; (Chandler, AZ) |
Correspondence
Address: |
SCHWEGMAN, LUNDBERG & WOESSNER, P.A.
P.O. BOX 2938
MINNEAPOLIS
MN
55402
US
|
Assignee: |
Intel Corporation
|
Family ID: |
25508774 |
Appl. No.: |
12/023521 |
Filed: |
January 31, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10758055 |
Jan 15, 2004 |
7350299 |
|
|
12023521 |
Jan 31, 2008 |
|
|
|
09964619 |
Sep 28, 2001 |
6692280 |
|
|
10758055 |
Jan 15, 2004 |
|
|
|
Current U.S.
Class: |
439/342 |
Current CPC
Class: |
Y10T 29/49208 20150115;
H05K 7/1007 20130101; Y10T 29/49204 20150115; Y10T 29/53174
20150115 |
Class at
Publication: |
439/342 |
International
Class: |
H01R 13/625 20060101
H01R013/625 |
Claims
1. A socket comprising: a socket housing having a surface mount
region for an electrical device, and at least one rigid bar secured
in a groove in the socket housing and contiguous the surface mount
region to ensure the surface mount region is flat and remains
flattened in varying ambient conditions.
2. The socket as claimed in claim 1, wherein the groove is a
U-shaped channel.
3. The socket as claimed in claim 2, wherein the rigid bar is a
rod.
4. The socket as claimed in claim 1, wherein there is provided a
second rigid bar secured in another groove in the housing
substantially parallel to the rigid bar and disposed adjacent the
surface mount region such that an electrical device positioned on
the surface mount region is disposed between the one rigid bar and
the second rigid bar.
5. The socket as claimed in claim 4 wherein the groove and the
another groove are both U-shaped channels.
6. The socket as claimed in claim 4, wherein each rigid bar is a
rod.
7. An electrical socket to provide a flat surface mount region for
an electrical device, the socket comprising: a U-shaped rigid bar
secured in a mating U-shaped groove such that the surface mount
region for the electrical device is disposed within the U-shape of
the U-shaped bar to ensure the surface mount region is flat and
remains flattened in varying ambient conditions.
8. The socket as claimed in claim 7, wherein the U-shaped groove is
a channel having a U-shaped cross-section.
9. The socket as claimed in claim 8, wherein the U-shaped rigid bar
has a rod shaped cross-section.
Description
[0001] This application is a divisional of U.S. patent application
Ser. No. 10/758,055, filed Jan. 15, 2004, which is a divisional of
U.S. patent application Ser. No. 09/964,619, filed Sep. 28, 2001
and issued Feb. 17, 2004 as U.S. Pat. No. 6,692,280, both of which
are incorporated herein by reference.
FIELD
[0002] The present invention is directed to socket warpage
reduction. More particularly, the present invention is directed to
socket warpage reduction apparatus and methods.
BACKGROUND
[0003] Electrical sockets may be used to secure electronic packages
and/or integrated circuit (IC) devices, for example, onto a system
board (e.g. a mother board or a printed circuit board "PCB") of an
electronic system. These electrical sockets may be constructed for
easy installation and replacement of electronic packages (e.g.
electrical components) and/or IC devices such as complex memory
chips and advanced processor chips. The electrical sockets may also
be available in different sizes and configurations, including, for
example, LIF sockets and ZIF sockets.
[0004] LIF sockets may be suitable for detachably securing
traditional electronic packages and/or IC devices with low pin
counts onto a system board of an electronic system. However, ZIF
sockets are more desirable for advanced electronic packages and/or
IC devices which have larger pin counts, since no or zero insertion
force and removal force are required. For example, advanced
processor chips with high pin counts are typically installed in a
ZIF socket, which is soldered directly to a system board of an
electronic system. The ZIF sockets are commonly used to secure
advanced processor chips onto a PCB. This is because the advanced
processor chips may be accommodated without fear of damaging the
chips or the electrical pins (connections) of the processor chips
which provide electrical contacts from the processor chips to the
system board.
[0005] A ZIF socket may typically include a release handle/lever
which, when open, permits easy installation of an electronic
package and/or an IC device such as a processor chip into the
socket. Subsequent closure of the handle/lever may secure the
processor chip in place.
[0006] However, these commonly available LIF and ZIF sockets, used
for securing an electronic package and/or an IC device onto a
system board of an electronic system, contain several
disadvantages, especially when electrical devices such as
electronic packages or IC devices are inserted in LIF or ZIF
sockets that have been secured onto a PCB of an electronic system.
One disadvantage that arises is related to the process of
assembling a PCB. Some socket connectors are press-fit into the
PCBs or a LIF socket connector is employed. These press-fit
connectors are often used on double sided reflow circuit boards,
which are not processed through a wave solder machine. The presence
of delicate and easily bent large pin number arrays on electrical
and IC devices require the devices to sit flush and squarely on the
surface of socket connectors on the PCB. It follows that any planar
warpage of a socket surface mount region will not mate uniformly
with the planar electronic devices, and such significantly
increases the probability that the pin array may not align
perfectly with a pin aperture array in the surface mount region of
the socket. This results in a less than perfect interconnection of
the pins with the socket connector.
[0007] Socket connectors that have experienced a variety of
environmental conditions such as reflow and annealing may become
twisted or turned, that is warped out of shape, which exacerbates
pin insertion concerns. Accordingly, there is a need to provide an
apparatus and method to ensure that electrical sockets have a flat
surface mount region and, where warpage has arisen, there is a need
to provide both an apparatus and method to flatten the surface
mount region of the socket.
[0008] The problem of socket warpage is particularly vexing in ZIF
sockets of the type that include a lever or a cam to secure an
electrical device to the socket, especially where the surface mount
region is present on a movable portion of a socket housing.
[0009] Warpage in ZIF sockets has been identified as a concern
where socket designers have sought to ensure a flat surface mount
region by the inclusion of thin (e.g., sheet metal) reinforcing
frames which are co-extensive with the perimeter of a top plate of
the socket. The use of thin reinforcing frames requires that the
top plate to be reinforced is flat when the reinforcing frames are
fitted to the edges i.e., perimeter of the top plate. This less
advantageous approach at best, has limited rigidity characteristics
owing to the thin (sheet metal) frames, and thus does not provide
for any structure to flatten a surface mount region in the event
that warpage of a surface mount region arises during molding,
reflow or annealing processes routinely experienced in socket
manufacture and installation on a PCB.
[0010] Heretofore socket warpage has also been addressed by
modifying mold flow, mold compound or redesigning the socket so
that warpage is reduced. As a socket gets larger in size, this
becomes harder to accomplish.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The foregoing and a better understanding of the present
invention will become apparent from the following detailed
description of example embodiments and the claims, when read in
connection with the accompanying drawings, all forming a part of
the disclosure of this invention. While the foregoing and following
written and illustrated disclosure focuses on disclosing example
embodiments of the invention, it should be clearly understood that
the same is by way of illustration and example only and that the
invention is not limited thereto. The spirit and scope of the
present invention are limited only by the terms of the appended
claims.
[0012] The following represents brief descriptions of the drawings,
wherein:
[0013] FIG. 1 is a perspective view of a background cam activated
ZIF socket that is useful in gaining a more thorough
understanding/appreciation of the present invention;
[0014] FIG. 2 is a perspective view of another background ZIF
socket that is useful in gaining a more thorough understanding of
the present invention;
[0015] FIG. 3 is an exploded view of the socket of FIG. 2;
[0016] FIG. 4 is a perspective view of yet another background
example of a ZIF socket useful in gaining a more thorough
understanding/appreciation of the present invention;
[0017] FIG. 5 illustrates a first portion of the example ZIF socket
of FIG. 4 with a lever rotated to a closed position;
[0018] FIG. 6 illustrates a corresponding mating portion of the ZIF
socket of FIG. 4 with a lever shown rotated in a closed
position;
[0019] FIG. 7 is a perspective view of a background example of a
ZIF socket and an electronic package;
[0020] FIG. 8 is a top view of an example advanced cam actuated ZIF
socket embodiment of the invention;
[0021] FIG. 9 is a cross-section taken along line 9-9 in FIG.
8;
[0022] FIG. 10 is a cross-section taken along line 10-10 in FIG.
8;
[0023] FIG. 11 is a top view of another example advanced cam
actuated ZIF socket;
[0024] FIG. 12 is a top view of yet another example advanced lever
activated ZIF socket embodiment of the invention;
[0025] FIG. 13 is a section taken along line 13-13 in FIG. 12;
[0026] FIG. 14 is a side view of FIG. 12;
[0027] FIG. 15 is a top view of the arrangement of FIG. 12 wherein
a lever of FIG. 15 is shown in a closed position;
[0028] FIG. 16 is a top view of still yet another example advanced
lever actuated ZIF socket embodiment of the invention;
[0029] FIG. 17 is a side view of FIG. 16; and
[0030] FIG. 18 is a top view of the arrangement of FIG. 16 wherein
a lever of FIG. 16 is shown in a closed position.
DETAILED DESCRIPTION
[0031] Before beginning a detailed description of the subject
invention, mention of the following is in order. When appropriate,
like reference numerals and characters may be used to designate
identical, corresponding or similar components in differing figure
drawings. It is important to note that the present invention is not
limited to the examples and the example embodiment shown and
described. In this regard, descriptive terms such as LIF socket and
ZIF socket are intended to suggest types of sockets wherein the
present invention finds utility. Accordingly, the term socket is
intended to describe a device designed to provide electrical
connections and mechanical support for an electronic or electrical
component requiring convenient replacement. It is to be further
understood that the present invention is applicable for use with
all types of sockets, and all electronic packages and IC devices,
including new processor chips which may become available as
computer technology develops in the future. Further, the present
invention is not limited to use in computer systems, but is
suitable for applications in many industries and/or environments
such as automotive, telecommunications, etc. However, for the sake
of simplicity, discussions will concentrate mainly on exemplary use
of a ZIF socket for use on a system board of an electronic system,
although the scope of the present invention is not limited
thereto.
[0032] Attention is now directed to the drawings and particularly
to FIG. 1, where there is shown a less advantageous ZIF socket 10
of a cam actuated type which is used to secure an electronic device
or electronic package such as a processor chip onto a system board
of an electronic system. As shown in FIG. 1, the ZIF socket 10 may
include socket housings comprised of a top plate (cover) 10a, a
base, 20, and a cam mechanism 30 (e.g., actuated through use of a
hexagonal key (e.g., Allen wrench)). The top plate 10a and the base
20 may be made from dielectric materials such as plastics, ceramics
and other insulators, and can be varied in sizes, shapes and
openings to secure different types of electronic packages or IC
devices onto a system board of an electronic system as desired. The
top plate 10a may be slidably mounted on the base 20, as indicated
by double headed arrow 21. The plate 20 may be movable over a top
surface of the base 20 between an open position and a closed
position in response to movement of the cam mechanism 30. The cam
mechanism 30 of the type illustrated will be explained ahead in
full detail in conjunction with the description of FIGS. 7 to 9.
The top plate 10a of an example ZIF socket 10 may contain a
plurality of pin-insertion apertures 12 for accepting electrical
pins from an electronic package or electrical device, not shown in
this figure, but shown and described in detail in other examples
hereinafter. The apertures 12 are shown deposed in a surface mount
region 11.
[0033] The ZIF socket 10 is a typical socket that experiences
warpage of the nature previously described and which the present
invention addresses, all in a manner to be explained more fully
hereinafter.
[0034] Attention is now directed to the perspective view of FIG. 2
and FIG. 3, in which there is depicted a ZIF socket 10 which
includes a base 20, a top plate or cover 10a movably supported on
the base 20 and adapted to retain an external electronic device,
such as a processor (not shown). The base 20, best seen in FIG. 3,
defines a plurality of receptacles 13 for receiving and retaining
contact pins (not shown) therein. The top plate 10a defines a
plurality of pin insertion apertures 12 corresponding to the
receptacles 13 for receiving pins of the external device whereby
the pins extend through the apertures 12 and are partially received
in the receptacles 13. Activation means (not shown), such as a
caming mechanism or screwdriver, may be incorporated in or used
with the cam mechanism 30 for moving the top plate/cover 10a with
respect to the base 20 in a diagonal direction along a line between
the two ears 14, 15 of the base 20 thereby engaging the pins of the
external device that extend through the apertures 12 of the top
plate 10a and into the receptacles 13 of the base 20. The cover or
top plate 10a is made of insulative material, such as plastic, and
includes thin (sheet metal) reinforcing frames 17, 19, which are
shown co-extensive with the perimeter of the top plate 10a. The
frames 17, 19 are intended to protect the top plate 10a from an
actuation force, but also to a limited extent, to enhance the
rigidity thereof and suppress warpage during manufacture and
operation. The reason that the thin frames 17, 19 only provided
limited rigidity and warpage protection was because the IC device
may have had a smaller pin array with fewer pins (than present day
devices), and the LIF/ZIF sockets may have had thicker bodies
(i.e., space/thickness/weight were low concerns), such that
rigidity/warpage were not high concerns.
[0035] Attention now is directed to FIGS. 4, 5, 6 and 7 where
specifically FIG. 4 illustrates another less advantageous ZIF
socket 10 used to secure an electronic package onto an electronic
system board. The ZIF socket 10 may include a top plate (cover)
10a, a base 20, and a cam mechanism 30. The top plate 10a may be
slidably mounted on the base 20 as is indicated by double-headed
arrow 21. The top plate 10a may be movable over a top surface of
the base 20 between an open position and a closed position in
response to movement induced by the cam mechanism 30.
[0036] The top plate 10a may contain a plurality of pin insertion
apertures 12 for accepting electrical pins from an electronic
package such as an open die processor chip. The base 20 may contain
a corresponding plurality of openings (receptacles) 22, housing
spring elements 24, each of which has a tail portion 26. The tail
portions 26 may protrude through a plurality of corresponding
openings formed in the system board (not shown) and may be
soldered, for example, to the system board circuitry of an
electronic system. When the top plate 10a is in an open position,
that is, when the top plate 10a moves in a first direction toward
an open position, the electrical pins (e.g. connections) of an
electronic package such as a processor chip may be freely inserted
through the apertures 12 in the top plate 10a and into their
respective openings (receptacles) 22 in the base 20 and the spring
elements 24. When the top plate 10a is in a closed position, that
is, when the top plate moves in a second, opposite direction toward
a closed position, the electrical pins of an electronic package may
be engaged physically (e.g. pinched or welded) and electrically
engage the respective spring elements 24 of the base 20.
Conversely, when the top plate 10a moves again back toward an open
position, the pins of an electronic package may be physically
disengaged from the respective spring elements 24 of the base 20
for ease of removal of the electronic package from the ZIF socket
10.
[0037] The cam mechanism 30 provides a means for sliding the top
plate 10a over the base 20 between the open and closed positions.
The cam mechanism may be mounted in a tunnel shaped space between
the top plate 10a and the base 20, and may be located inside a
raised portion 37 of the top plate 10a. The cam mechanism 30 may
include a lever 32, which is transversely connected to rotate a cam
element to cause the top plate 10a to translate relative to the
base 20. The lever 32 may contain an end portion 34, which is bent
at an angle of approximately 15.degree.-45.degree. from the axis of
the lever 32. The bent end 34 of the lever may allow for the lever
32 to be easily grasped for rotation in the horizontal direction to
translate the top plate 10a over the base 20 between open and
closed positions.
[0038] Refer now to FIG. 5, which depicts the base 20 disassembled
from the top plate 10a of the ZIF socket 10. In this illustration a
channel 28 has a generally T-shaped configuration that accommodates
a camshaft 29. The camshaft 29 is shown as a rod having a circular
cross-section with a jog 31 that functions as a cam lobe that
provides an eccentric portion that can deliver an inward thrust for
purposes of translating the top plate 10a over the base 20, when
lever 32 of the cam mechanism 30 is rotated in a predetermined
direction (e.g. horizontal direction). Alongside the channel 28 the
base 20 includes an array of pin receiving receptacles/openings 22
adapted to accommodate springs not shown and/or the electrical pins
from an electronic package such as a processor chip.
[0039] In FIG. 6 there is illustrated an underside view of the top
plate 10a as it would be seen when the top plate 10a is
disassembled from the base 20. Note here that the jog/cam lobe 31
is positioned adjacent to a retaining post 16, 18 which thereby
allows the transmission of a caming force to the retaining posts
16, 18 so as to generate a force necessary to translate the top
plate 10a over the base 20, when the lever 32 of the cam mechanism
30 is rotated in the predetermined direction between open and
closed positions.
[0040] FIG. 7 illustrates an example of a ZIF socket used for
securing an electronic package 33 onto a system board 500 of an
electronic system. Such a system board 500 may be a commonly used
board, known as a printed circuit board (PCB) or a mother board
which may contain a plurality of through-holes 38 for solder
mounting the ZIF socket for easy installation and replacement of
electronic packages and/or IC devices from the system board 500.
The ZIF socket may include a top plate 10a, a base 20 and a cam
mechanism 30 assembled and ready for supporting the electronic
package 33. Here the electronic package 33 is shown having an open
die processor chip 35 disposed thereon. Optionally, position pins
36 of the electronic package 33 and corresponding pin insertion
apertures 12 of the ZIF socket 10 may be utilized to retain the
electronic package 33 relative to the ZIF socket 10.
[0041] FIG. 8 and FIG. 9, when studied in conjunction with the
description that follows, will make apparent that FIG. 9 is a top
view of an example advanced ZIF socket 10' that includes a socket
housing comprised of a top plate (cover) 10a' and a base 20'. The
top plate 10a' is movable in the direction indicated by the
double-headed arrow 21'. The top plate 10a' further includes a
surface mount region 11' for an electrical or electronic device not
shown. Within the surface mount region 11' of the top plate 10a'
there is provided an array of pin insertion apertures, such as the
referenced aperture 12'.
[0042] In the manufacture and use of sockets or socket connectors,
as they are sometimes called, the sockets experience planar warpage
that involves the twisting or turning out of shape of the socket,
which results in the socket's surface mount region no longer
remaining flat as is necessary for the mounting thereon of large
pin array electrical or electronic devices.
[0043] The problem of warpage reduction in sockets is addressed in
the practice of the invention in the example of the advanced ZIF
socket of FIG. 8. In the practice of the present invention the
sockets can be made flatter when independent (rigid) bars or rods
40, 41 are inserted into grooves 42, 43 (see FIG. 9) after the
molding of the socket. (Hereinafter, within the description and
claims, the term "bars" may be used generically to represent all
viable types of rigid/warpage-reducing members, e.g., rods, boards,
tubes, etc.) The insertion of the bars 40, 41 into the grooves 42,
43 flattens the surface mount region 11' which guarantees the
socket will meet flatness requirements, which will improve yields,
simplify contact insertion and ease of actuation by reducing
warpage-induced friction that would arise between a warped top
plate 10a' and a top surface of the base 20'. The grooves 42, 43
may be of a U-shaped cross-section and the bars 40, 41 may be rod
shaped. Clips 46, 47 may also be employed for clipping and
retaining the bars into the grooves.
[0044] It is important to appreciate that the warpage bars 40, 41
may be inserted into the top plate 10a' contiguous to the surface
mount region 11' before or after any reflow processes, depending on
needed assembly flow. Alternative to insertion, the warpage bars
may have the top plate 10A' injection-molded around such bars.
Should the ZIF socket 10 experience an annealing process, the
process may benefit from the bars 40, 41 being inserted or included
before reflow, whereas warpage correction effects may be more
beneficial after reflow.
[0045] The simple action of securing a socket to a printed circuit
board (PCB) by means of solder balls (e.g., a socket having a ball
grid array (BGA) thereon), which are eutectic in nature, inherently
involves a reflow of the solder, that is the melting and
resolidification of solder to form an electrical connection between
the socket and PCB. It is not uncommon to discover after the reflow
process that the socket has become warped and the surface mount
region is no longer flat. Accordingly, an increase in warpage
usually occurs during reflow. It follows therefore that the
insertion of the rigid bars will be most advantageous. Sockets that
have experienced reflow often benefit from an annealing process
that relieves internal stress in the socket material.
[0046] By way of review it should be apparent that the highly
advanced example of the socket depicted in FIG. 8 and FIG. 9 is
comprised of socket housing top plate 10a' having a surface mount
region 11' for an electrical device and at least one rigid bar,
such as bars 40, 41, secured in grooves 42, 43 and contiguous to
the surface mount region 11', to thereby ensure the surface mount
region 11' is flat and remains flattened in varying ambient
conditions.
[0047] Attention is now directed to FIG. 8 and FIG. 10, which, when
studied in conjunction with the description that follows, will
explain the nature of the cam mechanism 30'. In this example of the
present invention the cam mechanism 30' is not structurally
significant to the warpage reduction function of the warpage bars
40, 41. However, the movement of the top plate 10a' will now be
explained in order to facilitate a better comprehension of a ZIF
socket environment in which the present example of the invention
finds utility.
[0048] FIG. 10 illustrates a cross-section taken along line 10-10
in FIG. 8 and reveals a cam 50 that includes a cam lobe 51 that
engages the top plate 10a'. The cam 50 further includes a cam stop
52 to make sure the cam 50 does not over rotate. The cam is
provided with an opening 53 into which a tool (not shown) may be
inserted to rotate the cam mechanism 30'. A base cam post 54 is
provided on which the cam 50 is mounted for rotation.
[0049] Turning now to FIG. 11 which is a top view of another
example advanced ZIF socket 10'' it will be observed that the top
plate 10a'' is provided with a flat surface mount region 11'' for
an electrical device. In this advantageous example a rigid U-shaped
bar 60 is fitted into a U-shaped groove 61 in the same fashion that
the rigid bars 40, 41 of FIG. 8 were secured in grooves 42, 43 of
FIG. 9. The U-shaped rigid bar 60 is secured in the U-shaped groove
61 such that the surface mount region 11'' for the electrical
device is deposed within the U-shape of the U-shaped bar, to
thereby ensure the surface mount region 11'' is flat and remains
flattened in varying ambient conditions.
[0050] Turn now to FIGS. 12, 13, 14 and 15, which illustrate yet
another example of an advanced ZIF socket. FIG. 12 is a top view of
a socket 10''' that provides a flat surface mount region 11''' for
an electrical device. The socket 10''' is comprised of a top plate
10a''' adapted to provide the flat surface mount region 11''',
which includes a plurality of pin insertion apertures 12''' adapted
to permit insertion of electrical pin connections from the
electrical device. The base 20''', FIG. 10 includes a plurality of
receptacles not shown in this figure of the nature shown and
described earlier with respect to receptacles 13 in FIG. 3. The top
plate 10a''' is slidably mounted on the base 20'''. A cam mechanism
30''' cooperates with the base 20''' to slide the top plate 10a'''
over the base between an open and closed position in the manner
shown and described in structural detail and function in FIGS. 4,
5, and 6 hereinbefore.
[0051] A cam mechanism 30''' is secured to the base 20'''' and
cooperates with the top plate 10a''' to slide the top plate 10a'''
over the base 20''' between an open and closed position.
[0052] A lever 65 is coupled as shown to the cam mechanism 30'''
and is pivotally movable from an open position as shown in FIGS. 12
and 14 to a closed position in FIGS. 13 and 15 to permit, in the
open position, the insertion of the electrical pin connections of
the electrical device through the top plate apertures 12''' into
the base receptacles (not shown). Pivotal movement of the lever 65
causes the top plate 10a''' to move in relation to the base 20'''
to a closed position thereby causing the electrical pin connectors
to be secured in the receptacles in the base.
[0053] The surface mount region 11''' in the top plate 10a'''
includes a first groove 66 having a U-shaped cross-section. The
first groove 66 is located contiguous to the surface mount region
11'''. Movement of the lever 65 from the open to closed positions
causes the lever to securely engage the groove 66 (see FIG. 15) in
the top plate 10a''' to thereby ensure that the top plate and
surface mount region is flat and remains flattened in varying
ambient environments. Again, clips 46, 47 may be used for clipping
and retaining the lever 65 into the groove 66. In the event that
there is a need for an even greater assurance that surface mount
region 11''' is flat, the present invention may also employ a rigid
bar 40' secured in a second groove 67 (FIG. 13) parallel to the
first groove 66, such that an electrical device positioned on the
surface mount region 11''' is deposed between the rigid bar 40' in
the second groove 67 and the lever 65 when the lever 65 is in the
closed position and occupying the first groove 66.
[0054] By way of summary it will be readily appreciated in this
advanced example of the present invention that the lever 65 works
as both an actuation mechanism and a warpage reduction bar. The
rigid lever 65 and the rigid bar 40' together can make sockets
flatter when other answers are not workable. Independent bars or
rods make it possible to mold the housing and then flatten it.
Where a warpage feature such as the aforementioned (BACKGROUND)
thin (sheet metal) frame is secured to a top plate perimeter, the
molding process may also warp the warpage frame features. The
present invention using rigid bars or rods advantageously ensures a
straightening effect to a socket surface mount region that
guarantees the socket will meet flatness requirements, thereby
improving yields, simplifying contact insertion and actuation by
reducing warpage induced friction.
[0055] It is to be further noted that in the event an annealing
process is involved in the manufacture and use of the present FIGS.
12-15 invention, then the annealing process may benefit from
warpage bars being inserted before reflow, whereas warpage
correction effects may be more beneficial after reflow.
[0056] Turn now to yet another example of an advanced ZIF socket
illustrated in FIGS. 16, 17 and 18. Here again, as in FIG. 12,
there is a top view of a zero-insertion force socket 10'''' that
provides a flat surface mount region 11'''' on a top plate 10a''''.
A cam mechanism 30'''' is secured to a base 20'''', as shown in
FIG. 17 and cooperates with the top plate 10a'''' to slide the top
plate over the base between an open and closed position. A U-shaped
lever 69, best seen in FIG. 18 in a closed position and in an open
position in FIGS. 16, 17, is coupled to the cam mechanism 30'''' at
ends 68, 71 of the U-shaped lever 69 and is pivotally movable from
an open position, (FIG. 16) to a closed position (FIG. 18). The top
plate 10a'''' is provided with a U-shaped groove 70, as best
observed in FIG. 16. The U-shaped groove 70 is located on the top
plate 10a'''' such that legs of the U-shaped groove 70 thereby
cause, upon movement of the lever from the open to the closed
position, the U-shaped lever to securely engage the U-shaped groove
70 in the top plate 10''''. The pressure of the U-shaped lever 69
in the U-shaped groove 70 ensures that the top plate 10a'''' and
the surface mount region is flat and remains flattened.
[0057] In the broadest sense, the present invention involves a
method comprising the forming of at least one groove in a socket
housing contiguous to a surface mount region for an electrical
device and inserting one of a rigid bar and rod in the groove to
thereby ensure that the surface mount region is flat and remains
flat in varying ambient conditions. The method just set forth also
contemplates as following within the spirit of the present
invention, forming a second groove in the top plate and inserting a
one of a second bar and rod in the top plate parallel to the one
groove and bar such that the surface mount region is deposed
between rigid bars or rods in parallel grooves.
[0058] The inventive method of the present invention also involves
forming a U-shaped groove in a socket housing contiguous to a
surface mount region for an electrical device, and inserting a
U-shaped rigid bar or rod in a mating relationship in the U-shaped
groove to provide a surface mount region for an electrical device
within the U-shape of the U-shaped groove to thereby ensure that
the surface mount region is flat and remains flattened in varying
ambient conditions.
[0059] Another advanced method of the present invention involves
establishing a flat surface mount region in a zero-insertion force
socket that includes:
[0060] a socket housing having a top plate adapted to provide the
flat surface mount region, the top plate providing a plurality of
pin insertion apertures adapted to provide for insertion of
electrical pin connections from the electrical device;
[0061] a base that has a plurality of receptacles adapted to
receive pin electrical connections provided by the electrical
device, the pin connections extending through the apertures in the
top plate and into the receptacles;
[0062] the socket housing top plate and base have the capacity to
slide relative to each other;
[0063] a cam mechanism that is secured to the base and cooperates
with the top plate to slide the top plate over the base from an
open to a closed position; and
[0064] a lever coupled to the cam mechanism, wherein the lever is
pivotally movable from an open position to a closed position to
provide in the open position the insertion of the electrical pin
connectors of the electrical device through the top plate apertures
and into the base receptacles, whereupon pivotal movement of the
lever to the closed position causes the electrical pin connectors
to be secured in the receptacles in the base.
[0065] The other advanced method further involves forming a groove
in the socket top plate of the socket housing contiguous to the
surface mount region, and then moving the lever from its open
position to the closed position to thereby cause the lever to
securely engage the groove in the top plate and thereby ensure that
the top plate and surface mount region are flat and remain
flattened in varying ambient conditions.
[0066] The present invention involves yet another method of
establishing a flat surface mount region a zero-insertion force
socket that includes:
[0067] a socket housing having a top plate adapted to provide the
flat surface mount region, the top plate providing a plurality of
pin insertion apertures adapted to provide for the insertion of
electrical pin connections from the electrical device;
[0068] a base that has a plurality of receptacles adapted to
receive pin electrical connections provided by the electrical
device, the pin connections extending through the apertures in the
top plate and into the receptacles;
[0069] the socket housing top plate and base with the capacity to
slide relative to each other;
[0070] a cam mechanism that is secured to the base and cooperates
with the top plate to slide the top plate over the base from an
open to a closed position; and
[0071] a U-shaped lever coupled to the cam mechanism at the ends of
the U-shaped lever, wherein the U-shaped lever is pivotally movable
from an open position to a closed position to provide in the open
position the insertion of the electrical pin connections of the
electrical device through the top plate apertures and into the base
receptacles, whereupon pivotal movement of the lever to the closed
position causes the electrical pin connectors to be secured in the
receptacles in the base.
[0072] This method further involves forming a U-shaped groove in
the socket top plate of the socket housing such that the surface
mount region for the electrical device is disposed within the legs
of the U-shaped groove, and then moving the U-shaped lever from its
open position to a closed position, thereby causing the U-shaped
lever to securely engage the U-shaped groove in the top plate when
the U-shaped lever is moved from the open to the closed position,
thereby ensuring that the top plate and surface mount region is
flat and remains flattened in varying ambient conditions.
[0073] In concluding, reference in the specification to an example
embodiment, etc., means that a particular feature, structure, or
characteristic described in connection with the embodiment is
included in at least one embodiment of the invention. The
appearances of such phrases in various places in the specification
are not necessarily all referring to the same embodiment. Further,
when a particular feature, structure, or characteristic is
described in connection with any embodiment, it is submitted that
it is within the purview of one skilled in the art to effect such
feature, structure, or characteristic in connection with other ones
of the embodiments. Furthermore, for ease of understanding, certain
method procedures may have been delineated as separate procedures;
however, these separately delineated procedures should not be
construed as necessarily order dependent in their performance,
i.e., some procedures may be able to be performed in an alternative
ordering, simultaneously, etc.
[0074] This concludes the description of the example embodiments.
Although the present invention has been described with reference to
a number of illustrative embodiments thereof, it should be
understood that numerous other modifications and embodiments can be
devised by those skilled in the art that will fall within the
spirit and scope of the principles of this invention. More
particularly, reasonable variations and modifications are possible
in the component parts and/or arrangements of the subject
combination arrangement within the scope of the foregoing
disclosure, the drawings and the appended claims without departing
from the spirit of the invention. In addition to variations and
modifications in the component parts and/or arrangements,
alternative uses will also be apparent to those skilled in the
art.
[0075] For example, the electrical contacts of the pin insertion
apertures may be available in a variety of size and shapes with
different projections. The cam mechanism may include different
driving elements such as worn gears, wedges, ratchets, etc.
Moreover, the camshaft of the cam mechanism may be positioned at
various angles and may work with different sized and/or shaped
levers. The overall dimensions of the ZIF socket may be altered
depending upon the electrical elements used, the desired strength,
the structural rigidity, and the thermal stability.
[0076] Of equal importance it is to be understood that the base
upon which a top plate of the socket may slide will also benefit
from the use of bars/rods inserted into grooves on the surface of
the base to ensure that the top plate and base slide freely with
respect to each other. Many modifications may be made to adapt the
teachings of the present invention to a particular situation
without departing from the scope thereof. Therefore, it is intended
that the present invention not be limited to the various exemplary
embodiments disclosed, but that the present invention includes all
embodiments falling within the scope of the appended claims.
* * * * *