Modular receptacle pin grid array

A modular receptacle housing is formed by four identical housing modules of molded rigid insulative material, which modules are interlocked to form a single housing. Each housing module carries a plurality of receptacle terminals. The arrangement of modules can readily be adopted to accommodate a wide variety of pin counts and configurations.

BACKGROUND OF THE INVENTION 
The present invention relates to a modular receptacle for high density pin 
grid arrays and in particular to a modular receptacle which can be readily 
adopted for pin arrays of different pin counts and configurations. 
Since the advent of the integrated circuit chip there has been a constant 
problem of providing an adequate means to interface the chip with other 
circuitry, sometimes referred to as the outside world. The problem arises 
in the high number of closely spaced leads which come from the chip and 
which must be able to interface in a relatively high density 
configuration. However, the wide variety in the configurations of chips 
that are available does not always lend itself to making a uniform 
receptacle in that there may be varying numbers of pins and various arrays 
of pins. The heretofore known receptacles have generally been useful only 
for single IC chip configurations and they are not readily adaptable for 
expansion and/or revision. 
SUMMARY OF THE INVENTION 
The present invention overcomes the difficulties of the prior available 
receptacles by providing four identical molded modules of rigid insulative 
material which fit together to make a single receptacle housing thus 
reducing the molding costs while adding versatility to the configuration 
of the housing. The four identical housing modules interlock to form a 
complete receptacle connector and each module is loaded with a plurality 
of receptacle contacts each positioned to receive a respective lead of the 
IC chip carrier. 
BRIEF DESCRIPTION OF THE DRAWINGS 
An embodiment of the present invention will now be described by way of 
example with reference to the accompanying drawings in which: 
FIG. 1 is a perspective view showing a chip carrier exploded from a 
partially exploded modular receptacle connector according to the present 
invention; 
FIG. 2 is a perspective view, partly in section and partly broken away, 
showing the receptacle of the present invention receiving an IC chip 
carrier therein; 
FIG. 3 is a partial transverse section taken along line 3--3 of FIG. 2; and 
FIG. 4 is a perspective view of a receptacle pin of the type used in the 
present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIGS. 1-4 the subject receptacle connector 10 is mounted on a 
known circuit board or the like 12 and receives therein a known integrated 
circuit chip carrier 14. 
The chip carrier 14 is typically a square of ceramic 16 having an 
integrated circuit chip 18,18' mounted on either the upper or lower 
surface thereof and with a plurality of pins 20 connected to the chip and 
depending from the carrier in a spaced array. Usually the pins depend from 
near the marginal portions of the module 16. 
The receptacle 10 is formed by four identical modules 22, 24, 26, 28 each 
of which is formed from rigid insulative material and has a plurality of 
contact passages 30 extending between a mating face 32 and a mounting face 
34. Each module has, at the end portions thereof, an inwardly directed 
stepped profile, each step corresponding to a row of passages 30. At the 
innermost end of the module there is a keying block 36 which is also 
recessed from the mating surface 32 so as to accommodate a chip 18 mounted 
on the bottom side of the carrier module 16. Each module also has an 
outwardly directed slot 38 on the outer marginal edge thereof. 
A plurality of receptacle terminals 40 are provided, each mounted in a 
respective passage 30. Each terminal 40 has an elongated receptacle 
portion 42, here shown as a generally cylindrical shape with at least two 
opposed spring arms 44 formed from the sides thereof to extend into the 
barrel portion of the receptacle so as to make a wiping engagement with 
pin terminals 20 inserted therein. Side portions of the receptacle portion 
are coined at 48 so as to provide an anti-overstress feature for the 
cantilever spring arms 44. Each terminal 40 is also provided with at least 
one lance 50 for making an interference fit with the inside rows of the 
passages 30 or a snap fit into slot 38 on the outside rows as best seen in 
FIG. 3. Each terminal 40 is also provided with a mounting tail 52 which is 
profiled to be received in a plated hole 54 of the circuit board 12. This 
mounting tail 52 can be formed in any one of many configurations, such as 
a compliant pin section or with a simpler section adopting it for solder 
mounting to the circuit board. 
It will be noted from FIG. 3 that the carrier 14 is also provided with at 
least one keying pin 56 which is received in the appropriate keying 
passage 58 of the receptacle connector to properly align the chip carrier 
thereon. 
It will be appreciated by those skilled in the art that the present 
housing, by its interlocking configuration, can be readily expanded to 
accommodate a wide variety of pin arrangements. For example, four modules 
of 33 positions could be interlocked to form a 132 position pin grid array 
receptacle. Simply by making minor adjustments to the mold, housing 
modules could be molded having higher pin counts and assembled to form 
higher pin count receptacles.