U.S. patent number RE35,693 [Application Number 08/406,734] was granted by the patent office on 1997-12-16 for leadless chip carrier socket.
This patent grant is currently assigned to Wells Electronics, Inc.. Invention is credited to Joseph A. Kerul, Donald E. Ralstin.
United States Patent |
RE35,693 |
Kerul , et al. |
December 16, 1997 |
Leadless chip carrier socket
Abstract
A leadless chip carrier socket which includes conductive
contacts which electrically contact the carrier. The contacts
include an outwardly extending cantilevered projection to allow the
contacts to be shifted outwardly on downward engaging movement of
the top of the socket to allow insertion or removal of the
carrier.
Inventors: |
Kerul; Joseph A. (Girard,
OH), Ralstin; Donald E. (South Bend, IN) |
Assignee: |
Wells Electronics, Inc. (South
Bend, IN)
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Family
ID: |
24891084 |
Appl.
No.: |
08/406,734 |
Filed: |
March 20, 1995 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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Reissue of: |
719718 |
Apr 3, 1985 |
04623208 |
Nov 18, 1986 |
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Current U.S.
Class: |
439/266 |
Current CPC
Class: |
H05K
7/1076 (20130101); H01L 2924/0002 (20130101); H01L
2924/0002 (20130101); H01L 2924/00 (20130101) |
Current International
Class: |
H05K
7/10 (20060101); H01R 009/09 (); H01R
013/629 () |
Field of
Search: |
;439/68-73,266,264 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
IBM Bulletin, Brearley, vol. 13, No. 9, p. 2590, Feb.
1971..
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Primary Examiner: Abrams; Neil
Attorney, Agent or Firm: Baker & Daniels
Claims
We claim:
1. A socket for a leadless chip carrier, said socket including a
base member having a central opening therein, a plurality of
conductive resilient contacts for engaging conductive pads on said
carrier, each contact anchored in said base member and including an
upwardly extending part, said contacts positioned on at least two
side edges of said base member opening, and constituting opposing
clamp means for engaging said carrier within said socket, the
improvement wherein each contact includes a cantilevered part
projecting from its upwardly extending part outwardly of said base
member opening, and a movable top overlying said base member, said
top including an abutment means in contact with each said contact
cantilevered part for moving and flexing said contacts in an
outward direction relative to said base member opening upon
movement of the top in a substantially straight line downward
direction to space said contacts from said carrier to allow
insertion thereof into the socket.
2. The socket of claim 1 wherein said leads are positioned at each
side of said base support central opening.
3. The socket of claim 1 wherein said base support includes finger
latches extending toward said top, each finger latch including a
tab, said top including a shoulder for accepting said tabs and
securing said finger latches whereby said top is secured to said
base support.
4. The socket of claim 1 wherein each contact includes a lead
anchored in said base member, said contact upwardly extending part
including an integral curved neck extending from said contact lead,
and a head integrally formed atop said neck having inner and outer
edges, said cantilevered platform projecting outwardly from said
head outer edge, said head inner edge being bevelled and
terminating in a lower chin part offset from said contact neck.
5. The socket of claim 1 wherein said top is of a one-piece
construction.
6. The socket of claim 5 wherein said abutment means is an abutment
part extending from an outer peripheral edge of said top toward
said base. .Iadd.
7. A socket for a leadless chip carrier, said socket including a
base member having a central opening therein, a plurality of
conductive resilient contacts for engaging conductive pads on said
carrier, each contact anchored in said base member and including an
upwardly extending part and a head part, said contacts positioned
on at least two side edges of said base member opening with the
head parts thereof constituting means for engaging said carrier
from opposite sides to compressively clamp the carrier between the
head parts when within said socket, each contact including a
cantilevered part projecting from its upwardly extending part
outwardly of said base member opening, a movable top overlying said
base member, said top including abutment means in contact with each
said contact cantilevered part for moving and flexing said contacts
in an outward direction relative to said base member opening upon
movement of the top in a substantially straight line downward
direction to space the contacts from said carrier to allow
insertion of the carrier within the socket..Iaddend..Iadd.8. The
socket of claim 7 wherein each head part includes a chin part for
contacting said carrier, each cantilevered part
extending above the level of each chin part..Iaddend..Iadd.9. The
socket of claim 8 wherein said base member includes a table means
for supporting said carrier within said socket..Iaddend..Iadd.10. A
socket for a leadless chip carrier, said socket including a base
member having a central opening therein, a plurality of conductive
resilient contacts for engaging conductive pads on said carrier,
each contact anchored in said base member and including an upwardly
extending part and a head part, said contacts positioned on at
least two side edges of said base member opening with the head
parts thereof constituting opposing clamp means for engaging said
carrier when within said socket, each contact including a
cantilevered part projecting from its upwardly extending part
outwardly of said base member opening, a movable top overlying said
base member and including abutment means in contact with each
contact cantilevered part for moving and flexing said contacts in
an outward direction relative to said base member opening upon
movement of the top in a substantially straight line downward
direction to space said contacts from said carrier to allow
insertion of the carrier within the socket, said top further
including a plurality of grooves each accommodating the
cantilevered part and at least a portion of the head part of each
contact, each contact when moving in said outward direction further
moving relative to said top within its said
accommodating groove..Iaddend..Iadd.11. The socket of claim 10
wherein each head part includes a chin part for contacting said
carrier, each cantilevered part extending above the level of each
chin part..Iaddend..Iadd.12. A socket for a leadless chip carrier,
said socket including a base member having a central opening
therein, a plurality of conductive resilient contacts for engaging
conductive pads on said carrier, each contact anchored in said base
member and including an upwardly extending part and a head part,
said contacts positioned on at least two side edges of said base
member opening with the head parts thereof constituting means for
engaging said carrier from opposite sides to compressively clamp
the carrier between the head parts when within said socket, each
contact including a cantilevered part projecting from its upwardly
extending part outwardly of said base member opening, movable top
overlying said base member, said top including abutment means for
contacting each said contact cantilevered part to move and flex
said contacts in an outward direction relative to said base member
opening upon movement of the top in a substantially straight line
downward direction to space the contacts from said carrier to allow
insertion of the carrier
within the socket..Iaddend..Iadd.13. The socket of claim 12 wherein
each head part includes a chin part for contacting said carrier,
each cantilevered part extending at least to the level of each chin
part..Iaddend..Iadd.14. The socket of claim 13 wherein said base
member includes a table means for supporting said carrier within
said
socket..Iaddend..Iadd.15. A socket for a leadless chip carrier,
said socket including a base member constituting means for
supporting said carrier and having a central opening therein, a
plurality of conductive resilient contacts for engaging conductive
pads on said carrier, each contact anchored in said base member and
including an upwardly extending part, said contacts positioned on
at least two side edges of said base member opening and
constituting opposing clamp means for engaging said carrier within
said socket, each contact including a cantilevered part projecting
from its upwardly extending part outwardly of said base member
opening, and a moveable top overlying said base member, said top
including an abutment means in contact with each said contact
cantilevered part for moving and flexing said contacts in an
outward direction relative to said base member opening upon
movement of the top in a substantially straight line downward
direction to space said contacts from said carrier to allow
insertion thereof into the socket and into supporting contact with
said
base member..Iaddend..Iadd.16. A socket for a leadless chip
carrier, said socket including a base member having a central
opening therein, a plurality of conductive resilient contacts for
engaging conductive pads on said carrier, each contact anchored in
said base member and including an upwardly extending part, said
contacts positioned on at least two side edges of said base member
opening and constituting opposing clamp means for engaging said
carrier within said socket, each contact including a cantilevered
part projecting from its upwardly extending part outwardly of said
base member opening, and a moveable top overlying said base member,
said top including an abutment means in contact with each said
contact cantilevered part for moving and flexing said contacts in
an outward direction relative to said base member opening upon
movement of the top in a substantially straight line downward
direction to space said contacts from said carrier to allow
insertion thereof into the socket, said top thereafter being
moveable relative to said carrier in an upward direction to allow
said contacts to flex in an inward direction relative to said base
member opening and engage said carrier..Iaddend.
Description
BACKGROUND OF THE INVENTION
This invention relates to a socket and will have application to a
carrier socket for a leadless integrated circuit.
During the last several years the integrated circuit (IC) has
completely revolutionized the electronics industry. An IC in its
miniaturized form is made into a chip which is normally mounted to
a carrier. Recently, leadless chip carriers, which are of
relatively thin plate forms having multiple pads formed upon their
surfaces, have become popular due to their compactness in relation
to the dual-in-line carrier package. Leadless chip carriers take up
less space on the printed circuit board which is important in
modern compact circuit design.
Leadless chip carriers are formed of ceramic materials which have a
thermal coefficient of expansion which is not ideally suited for
the epoxy/glass material from which printed circuit boards are
normally constructed. Therefore, in order to utilize a leadless
chip carrier, a receiving device is used to connect the carrier
onto a printed circuit board. These receiving devices or sockets
are designed to accomodate the differential in thermal expansion of
the carriers and printed circuit boards. Sockets are also utilized
in testing chip carriers and have been developed to accomodate such
carriers for burn-in and similar testing.
U.S. Pat. No. 4,491,377 discloses a socket having conductive
elongated contacts for holding the carrier within the socket. A
spreader cams the inner edge of the contacts outwardly to allow
insertion of the carrier. The contacts are then released to hold
the carrier firmly within the socket.
SUMMARY OF THE INVENTION
The socket of this invention includes a plurality of opposed
cantilevered contacts positioned about the socket's central
opening. Each contact includes an upper platform of diving board
form which extends outwardly of the socket central opening. When
the platforms are depressed, the contacts are flexed outwardly To
allow insertion of a carrier. By releasing pressure on the
platforms, the contacts are closed to secure the carrier within the
socket.
Accordingly, it is an object of this invention to provide an
electrical connector for an IC which is of simple and reliable
construction.
Another object of this invention is to provide a socket which is
for a leadless chip carrier.
Another object of this invention is to provide for a leadless chip
carrier socket which has an improved carrier contacting member.
Other objects of this invention will become apparent upon a reading
of the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred embodiment of the invention has been depicted for
purposes of illustration wherein:
FIG. 1 is a perspective view of the socket.
FIG. 2 is an exploded view of the socket components.
FIG. 3 is a top plan view of the socket with an integrated circuit
device inserted.
FIG. 4 is a side view of the socket.
FIG. 5 is a side view of the socket.
FIG. 6 is a bottom view of the socket.
FIG. 7 is a sectional view of the socket showing a carrier being
inserted.
FIG. 8 is a sectional view taken along 8--8 of FIG. 3 showing the
carrier in its clamped position.
FIG. 9 is a sectional view taken along line 9--9 of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment herein described is not intended to be
exhaustive or to limit the invention to the precise form disclosed.
It is chosen and described to explain the principles of the
invention, its application and its practical use to enable others
skilled in the art to utilize the invention.
The socket 10 shown in the drawings includes a base member 12
having a top face 14 and bottom face 16. Base member 12 includes a
central opening 18 and a plurality of peripheral bores 20 about
opening 18 which extended through faces 14 and 16. A plurality of
grooves 22 are cut in base member face 14. A raised table section
24 extends about central opening 18 and includes grooves 26 which
are aligned with grooves 22. Base member 12 also includes two pairs
of opposed finger latches 30 each of which is flexible and includes
an upper camming face 32 and lock tab 34.
Socket 10 also provides for a plurality of contacts 36. Each
contact 36 is constructed of resilient electrically conductive
material and is of the general cross-sectional configuration shown
in FIGS. 7-8. Each contact 36 has lower leads 38 which extend
through base member bores 20. An integral curved neck 40 of each
contact 36 is fitted into aligned grooves 22 and 26. Each contact
36 includes an integral upper head 42 having a bevelled inner edge
44 which terminates in a chin part 46 offset from the contact's
neck 40 as seen in FIG. 8 and an outwardly extending integral
platform 48.
Socket 10 also includes a top 50 having the general configuration
shown in FIG. 2 and includes shoulder parts 58. Top 50 includes a
central opening 60 to allow for the insertion of an integrated
circuit carrier 62 into socket 10 and an abutment part 64 at each
of its sides 54. As seen in FIGS. 4 and 5, top 50 includes an open
channel 66 at each of its side faces 54 into center opening 60
below abutment parts 64. A plurality of grooves 72 are formed in
the top next to abutment parats 64 and over channels 66.
With contacts 36 positioned in grooves 22, 26 of base member 12 and
with leads 38 extending through base member bores 20, top 50 is
placed over and pushed downwardly upon base member 12 until finger
latches 30 of the base member engage shoulder parts 58 to secure
the top of the base member. The heads 42 of contacts 36 fit into
top grooves 72 with each contact platform 48 bearing against a top
abutment part 64 to urge the top into its upper position as seen in
FIG. 1.
To operate socket 10, top 50 is pushed downwardly towards base
member 12 into its lower position as seen in FIG. 7. Abutment parts
64 urge contact platforms 48 downwardly, as shown be arrows 51 in
FIG. 7. This creates a moment about contact necks 40 which causes
contact heads 42 to shift outwardly so as to allow integrated
circuit carrier 62 when inserted into top opening 60 to be
supported atop table section 24 of the base member. Top 50 is then
released. Contact platforms 48, under the influence of flexed
contacts 36, urge the top upwardly away from base member 12 to
allow contact chin parts 46 to compressively contact the pads of
carrier 62 as shown by arrows 75 in FIG. 8. Carrier 62 is released
from clamping engagement with contacts 36 by pushing top 50
downwardly into its lower position. This causes the spreading of
contact heads 42 away from the carrier.
Carrier 62 may be inserted and clamped within socket 10 without
pushing downwardly upon top 50. This is accomplished by simply
pushing the carrier downwardly against the bevelled inner edges 44
of the contacts which in turn cams the contacts outwardly until the
carrier leads engage the contact chin parts 46. The carrier is then
released.
It is understood that the invention is not limited to the details
above-given, but may be modified within the scope of the appended
claims.
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