Simplified socket for ZIF PGA

A ZIF PGA socket (10) includes a base (12) and a slidable cover (18) attached thereon wherein a plurality of first passageways (14) extend through the base (12), and a corresponding number of second passageways (20) extend through the cover (18) in alignment with the first passageways (14), respectively. A tool receiving structure is formed on the base (12) and the cover (18), respectively, and includes expansion sections (28, 30) respectively integrally formed on the rear side of the base (12) and the cover (18) wherein each expansion section (28, 30) further includes a receiving slot (32, 34) extending in a lateral direction so that the cover (18) can be actuated to be moved in a front-to-end direction by inserting a flat or plate tool (38) into both the receiving slots (32, 34) of the base (12) and of the cover (18) and successively rearwardly or forwardly swinging such flat tool (38) in the slots (32, 34) wherein this pivotal movement of the flat tool (38) generally has its pivot point set around the bottom surface (36) of the receiving slot (32) of the base (12).

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The invention relates to a ZIF (Zero Insertion Force) socket for use with a 
PGA (Pin Grid Array) chip, and particularly to a ZIF socket without a 
lever for horizontally moving the sliding plate with regard to the base 
but with a tool receiving area for cooperation with an external tool for 
implementation of such horizontal movement of the sliding plate and 
achievement of ZIF purpose. 
2. The Prior Art 
The conventional ZIF PGA socket in the industry includes a base with a 
slidably moving cover or sliding plate attached thereto and actuated by a 
cam lever wherein the base and the cover commonly define a channel for 
allowing the camming section of such cam lever to be rotatably seated 
therein. Thus, through up-and-down movement of the exposed actuation bar 
of the cam lever, the cover can be moved horizontally regard to the base 
in a front-to-end direction by means of the camming section of the cam 
lever. This basic structure of the ZIF PGA can be referred to U.S. Pat. 
No. 5,489,217 or FIG. 1. 
Recently, for consideration of lowering the cost of the socket, it is 
intended to eliminate the parts of the socket assembly. On the other hand, 
the exposed actuation bar takes too much space along its rotation path 
even though such elongated design of the actuation bar may result in 
force-saving from a mechanical viewpoint. It is understood that in an 
interior of the computer case, every minor space should be struggled for, 
and no significant rotation or linear movement of any sized parts can be 
ignored. This is the key issue for obtaining a thinner and thinner 
computer set. 
Therefore, an object of the invention is to provide a ZIF PGA socket 
removing the cam lever therefrom for not only saving the cost of the 
components, but also avoid any interference occurring due to the 
rotatively up-and-down the elongated actuation bar of the cam lever 
against the lower frame structure or against other electrical parts 
mounted close to such ZIF PGA socket. 
SUMMARY OF THE INVENTION 
According to an aspect of the invention, a ZIF PGA socket includes a base 
and a slidable cover attached thereon wherein a plurality of first 
passageways extend through the base, and a corresponding number of second 
passageways extend through the cover in alignment with the first 
passageways, respectively. A tool receiving structure is formed on the 
base and the cover, respectively, and includes expansion sections 
respectively integrally formed on the rear side of the base and the cover 
wherein each expansion section further includes a receiving slot extending 
in a lateral direction so that the cover can be actuated to be moved in a 
front-to-end direction by inserting a flat or plate tool into both the 
receiving slots of the base and of the cover and successively rearwardly 
or forwardly swinging such flat tool in the slots wherein this pivotal 
movement of the flat tool generally has its pivot point set around the 
bottom surface of the receiving slot of the base.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
References will now be in detail to the preferred embodiments of the 
invention. While the present invention has been described in with 
reference to the specific embodiments, the description is illustrative of 
the invention and is not to be construed as limiting the invention. 
Various modifications to the present invention can be made to the 
preferred embodiments by those skilled in the art without departing from 
the true spirit and scope of the invention as defined by appended claims. 
It will be noted here that for a better understanding, most of like 
components are designated by like reference numerals throughout the 
various figures in the embodiments. Attention is directed to FIGS. 2-4, 
wherein the subject socket 10 includes a base 12 defining a plurality of 
first passageways 14 extending therethrough in a vertical direction for 
receiving a plurality of contacts 16 (FIG. 3(A)) therein. The cover 18 has 
the similar configuration with the base 12, and also defines a 
corresponding number of second passageways 20 therethrough in alignment 
with the corresponding first passageways 14 in the vertical direction. 
To avoid the cover 18 to be vertically taken from the base 12, retention 
barbs 22 are formed on the side surface 24 of the base 12 to be properly 
engaged within recesses 26 (FIG. 4) formed in the interior portion of the 
cover 18. 
The feature of the invention is to eliminate the cam lever structure and 
the corresponding round channel positioned on the rear portion of the 
socket in the prior art socket, Differently, the base 12 and the cover 18 
include respectively expansion sections 28, 30 around the rear portion of 
the socket 10 and each expansion section includes a tool receiving slot 
32, 34 wherein, also referring to FIG. 5, the slot 32 in the base 12 is of 
a closed type having a bottom surface 36 while the slot 34 of the cover 18 
is of a through type. 
Referring to FIGS. 5-7, when the cover 18 and the base 12 are positioned in 
the closed state with regard to each other as shown in FIGS. 5 and 7, the 
slot 32 of the base 12 is aligned with the slot 34 of the cover 18. 
Therefore, if a PGA chip 70 is ready to be installed to the socket 10, a 
flat tool 38 can be first inserted into the both the slot 34 of the cover 
18 and the slot 32 of the base 12 until the bottom edge section 40 of the 
tool 38 confronts the bottom surface 36 in the slot 32 of the base 12. 
Successively, the flat tool 38 is rotatably rearward moved by means of the 
bottom edge section 40 incorporating the bottom surface 36 in the slot 32 
regarded as the pivotal point, so that the cover 18 can be correspondingly 
moved rearwardly as shown in FIG. 6, and the PGA chip 70 may be loaded 
onto the cover 18 of the socket 10 from the top in a ZIF manner. After the 
PGA chip 70 has fully loaded onto the socket 10, then the cover 18 can be 
back to its original vertical aligned position with the base 12, as shown 
in FIG. 7, by means of the reverse operation of the flat tool 38, i.e., 
rotatably forward movement of the flat tool 38 with regard to the base 12. 
Thus, the pins (not shown) of the PGA chip 70 can be electrically and 
mechanically engaged with the contacts 16 of the socket 10. 
Referring to FIG. 5, it can be seen that to facilitate actuation of the 
flat tool 38 with regard to the cover 18 and the base 12, adjacent the 
corresponding slot 34, the cover includes a first chamfer 44 on the rear 
top portion and a second chamfer 46 on the front bottom portion. 
Similarly, the base 12 includes a third chamfer 48 around the rear top 
portion in the slot 32. 
Moreover, referring to FIGS. 3 and 4, to properly retain the cover 18 with 
regard to the base 12 in either an open (rear) position or a closed 
(front) position, the base 12 includes a vertical protrusion 50 on the 
side surface 24 to cooperate with a pair of spaced shallows 52 and 54 
formed in the interior portion of the cover 18. Therefore, the protrusion 
50 of the base may be received within the front shallow 52 in the cover 18 
when the socket 10 is in an open state, and within the rear shallow 54 
when the socket is in a closed state. This structure provides more 
stability of the cover 18 with regard to the base 12. 
While the present invention has been described with reference to specific 
embodiments, the description is illustrative of the invention and is not 
to be construed as limiting the invention. Various modifications to the 
present invention can be made to the preferred embodiments by those 
skilled in the art without departing from the true spirit and scope of the 
invention as defined by the appended claims. 
Therefore, person of ordinary skill in this field are to understand that 
all such equivalent structures are to be included within the scope of the 
following claims.