PASS-THROUGH TEST SOCKET FOR SEMICONDUCTOR DEVICES

Abstract: An apparauts for testing packaged integrated circuit devices includes an input track (10) into which untested devices are loaded for transfer by a fiber faced belt (12) to a reservoir (22). A test socket assembly includes a housing (32, 34, 36, 38, 40, 42) having a channel (52) therethrough, which channel (52) includes an entrance (32) adjacent the reservoir (22). A plurality of contact portions (82) extend into the channel intermediate the entrance (32) and the exit (40). A piston (72) acting under the influence of a linear motor (70) pushes untested semiconductor devices (104, 106, 108) through the entrance (32) so as to cause the leads thereof to sequentially engage the contact portions (82) at which time they are tested. As additional untested devices are placed into the channel (52), tested devices are forced out of the channel (52) and into a sorting mechanism (20).

Description: PASS-THROUGH TEST SOCKET FOR SEMICONDUCTOR DEVICES Background of the Invention This invention relates generally to an apparatus for handling a series of individual parts, and more 5 particularly, to an apparatus for the high speed handling of packaged integrated circuit parts. In the semiconductor industry, integrated circuits are given a series of final electrical tests before the circuits are used or sold. For economic reasons, especially in view 10 of the very large number of circuits manufactured and tested, it is necessary that the required handling time be kept short. The total time used for implementing the final test is the sum of the actual testing time plus the time required 15. for handling. Using sophisticated computer controlled testing, the actual test time has been reduced to the order of milliseconds. The handling time includes the- time to get the circuit package into position for the test plus the time it takes to remove the package from the test fixture. An 20 untested package must then be placed in the test fixture, and so on. Tested devices are then maneuvered into a proper bin by a sorting mechanism based on the results of the test performed. Using currently available equipment and techniques, 25 approximately 5000 (five thousand) parts may be tested in an hour. The need has arisen, however, to test as many as 30,000 (thirty thousand) parts per hour, and this requires that the individual semiconductor devices be transferred to the test socket, tested and sorted at a much higher speed. 30 Summary of the Invention It is an object of the present invention to provide an improved apparatus for the high speed handling of integrated circuit parts. It is a further object of the present invention to provide a test socket for quad-packaged integrated circuits wherein a tested device is ejected from a test socket and an untested device inserted into the socket simultaneously. According to a first aspect of the invention there is provided a test socket assembly for use " in an apparatus for testing semiconductor devices of the type which have a plurality of leads protruding therefrom, said assembly comprising a housing having a channel therethrough, said channel having an entrance and an exit; a plurality of contacts extending into said channel intermediate said entrance and said exit; and first means for urging untested semiconductor devices through said entrance such that said leads engage said contacts to permit testing of said devices and for pushing tested semiconductor devices out said exit. According to a further aspect of the invention there is provided an apparatus for handling and testing a plurality of packaged integrated circuit parts each having a body portion and a plurality of leads extending therefrom,- said apparatus comprising an input track for receiving untested parts; a reservoir for containing said untested parts; first means for transporting said parts from said input track to said reservoir; a test socket comprising a housing having a channel therethrough, said housing having an entrance and an exit, said entrance being proximate said reservoir; a plurality of contacts extending into said channel intermediate said entrance and said exit; and first means for urging untested parts through said entrance such that said leads engage said contacts, to permit testing of said parts and for pushing tested parts through said exit; and means for receiving tested parts from said exit and sorting said tested parts. The above, and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: Brief Description of the Drawings FIG. 1 is a perspective view of a high speed semiconductor device handling in test apparatus in accordance with the prior art; FIG. 2 is a partial cross-sectional view and partial cut-away view of a novel pass through test socket for use in the high speed apparatus shown in FIG. 1; FIG. 3 is an exploded perspective view of the novel test socket shown in FIG. 2; FIG. 4 is a detailed view illustrating the placement of the contacts in the test socket. FIG. 5 is a cross-sectional view taken along line 5-5 in FIG. 2; FIG. 6 is a perspective view of the contacts used in the novel test sockets; FIG. 7 is a perspective view of a semiconductor quad-package of the type which is tested in the novel test socket; and FIGS. 8A-8D illustrate in a step by step fashion how semiconductor packages to be tested are positioned within the test socket and then later ejected for processing by the sorting apparatus. Description of the Preferred Embodiment FIG. 1 shows a perspective view of a high speed semiconductor handler of the type which is shown and described in U.S. Patent Number 4,170,290 issued October 9, 1979, the teachings of which are hereby incorporated by reference. Semiconductor devices stored in sleeves in accordance with well known techniques are dump-transferred from the sleeves into an input track 10. Input track 10 is a shallow U-shaped metal slide in which the semiconductor devices become loosely constrained. Untested devices slide down track 10 under the influence of gravity and soon engage a continuous fiber-faced belt 12 which is stretched around pulleys 14 and 16. Belt 12 may be a nylon fiber belt of approximately 1.9 centimeters in width and having bristles (approximately 0.32 centimeters in length) on a mat backing thereof. Pulley 14 is motor driven (motor not shown) to provide motion of the belt in a direction indicated by arrow 18. Thus, when an untested semiconductor device falls to the bottom of input track 10, the belt fiber's catch the device, and the part is lifted by fiberfaced belt 12. When an untested device is lifted to the top of pulley 16, it drops in a track portion 20 where it falls under the force of gravity into track portion 22. Untested devices then drop from track 22 into a test assembly 24 where their electrical characteristics are determined. Tested devices are then categorized by means of a sort assembly shown generally as 26 and which includes a test wheel 28 and a plurality of test shoots 30. A more detailed description of the assembly shown in FIG. 1 may be found in the above cited patent. A more detailed description of test apparatus 24 and sort apparatus 26 may be found in U.S. Patent No. 4,128,174 issued December 5, 1978, the teachings of which are hereby incorporated by reference. FIGS. 2 and 3 illustrate a novel test socket assembly for use in place of test assembly 24 shown in FIG. 1. The novel test socket assembly shown solves the problems associated with prior art devices as described above. It includes a housing comprising an input section 32, an input insulating plate (e.g. green glass) 34, a contact plate 36, an output insulating plate (e.g. green glass) 38, an output section 40 and an end plate 42 (e.g. aluminum) . Input section 32, insulating plates 34 and 38, contact plate 36 and output section 40 are secured together and to a load board 44 upon which the actual testing electronics are mounted by means of screws 46 which pass through apertures 48 and threadably engage internally threaded holes 50 in output section 40. Input section 32, insulating plate 34, contact plate 36, insulating plate 38 and output section 40 are each provided with a generally rectangular and grooved aperture therethrough through which untested semiconductor devices in the form of quad-pak packages are tested and exit. One such package is shown in FIG. 7 as comprising a semiconductor device which .is encapsulated in a plastic casing 54 and wherein a plurality of leads 56 protrude from the plastic. Still referring to FIGS. 2 and 3, track 19 having a channel 58 therein is coupled to the test socket and load board by means of screws 60 which pass through apertures 62 engage internally threaded aperture 64 in output section 40. The track 19 is secured to the remainder of the apparatus by means of nuts 66 and washers 68. For reasons to be described hereinbelow, a linear motor 70 is provided for imparting reciprocating translational movement to a ram or piston 72 which passes through aperture 74 in track 19. Aperture 74 is substantially adjacent the entrance of channel 52. Contact plate 36 is provided with a plurality of small apertures 76 therethrough which receive and position U-shaped contacts 78 of the type shown in FIG. 6. That is, each U-shaped contact 78 includes a post portion 80 which is received by one of apertures 76 in contact plate 36 and a • contact portion 82 which extends into channel 52 in a somewhat inclined manner. Post 80 of contacts 78 extend through apertures 76 in contact plate 36 into apertures 84 in load board 44 each of which has associated therewith a sleeve 86. FIG. 4 illustrates the positioning of the contacts relative to the contact plate and channel 52 in greater detail. As can be seen, post 80 of the contact extends through contact plate 36 and sleeve 86 in load board 44. Post 80 in sleeve 86 is made deliberately accessible in order to connect contact 78 with the testing electronics (now shown) on load board 44. Again referring to FIG. 4, contact portion 82 extends in a somewhat inclined manner in one of the grooves in channel 52. While only two contacts have been shown for clarity in FIGS. 2 and 3, it is to be appreciated that one contact will be provided for each groove in channel 52; i.e. one contact for each of leads 56- on. the semiconductor device shown in FIG.7. The contacts are spring tempered and may be made of an anealed beryllium such that when all the contacts are properly positioned, a semiconductor package of the type shown in FIG. 7 may be press fit within channel 52 such that each lead 56 of the package will engage one contact 78. The resilient contacts 78 will, in and of themselves, position the quad-package during the testing process. Furthermore, since each lead 56 which protrudes from plastic body 54 of the semiconductor package will be accommodated by a single groove in channel 52, the semiconductor package will be properly positioned throughout is journey through the test socket. This is more clearly illustrated in FIG. 5 which is a cross-sectional view taken along 5-5 (through input section 32) . As can be seen, channel 52 is provided with grooves 88. The contact portion 82 of a contact 78 is positioned in each of the grooves.. For the sake of clarity, contact sections 82 have not been shown in FIG. 5. The dotted outline of a quad-package 90 is shown in FIG. 5 to illustrate how the package is closely accomodated within channel 52 with each lead 56 extending into one of the grooves 88. Since ram 72 coupled to linear motor 70 will be repeatedly and rapidly passing through aperture 74 in track 19, L-shaped unit alignment springs 92 are secured to track 19 by means of screws 94 to align units for insertion into 52. Finally, end-plate 42 is secured to the output end of output section 40 by means of screws 96 passing through aperture 98 in end-plate 42 and threadably engaging internally thread apertures (not shown) in output section 40. Channel 100 in the output end of output section 40 becomes closed by end plate 42 forming an exit shoot 102 through which the semiconductor devices may fall after testing into sorter 26 (shown in FIG. 1) . The operation of the novel test socket will now be described in connection with FIGS. 8A-8D. First, semiconductor packages e.g. 104, 106, and 108 in FIG. 8A may be electro-optically detected in track 19 thus activating the linear motor and ram 72. Referring to FIG. 8A, ram 72 is shown in its retracted position. Having detected the presence of semiconductor packages in track 19, the linear motor will cause the ram to move to the left an amount sufficient to push semiconductor package 104 into channel 52 as is shown in FIG. 8B. Ram 72 will now return to its extracted position under the influence of the linear motor permitting the remainder of semiconductor packages in track 19 to fall. Next, ram 72 will again be moved to the left urging semiconductor package 106 into the entrance of channel 52 thus pushing semiconductor package 104 into the channel. This process continues until the first package 104 reaches contacts 78 as is shown in FIG. 8C. The leads of semiconductor package 104 make contact with contacts 78 in channel 52 and the device is tested. The situation thus far described is shown in FIG. 8C. Upon completion of the test, ram 72 urges another package into the mouth of channel 52 placing semiconductor package 106 in the contact region and urging semiconductor package 104 towards exit shoot 102. This process continues and the semiconductor packages are tested until the train of semiconductor packages in channels 52 reach exit shoot 102 at which point they drop through shoot 102 to the sorting apparatus 26 shown in FIG. 1. FIG. 8D illustrates the situation a moment after semiconductor package 104 has been pushed into shoot 102. Using the above process, the wasted motion and time of removing a tested device prior to placing an untested device in the test socket is avoided. A singular movement of ram 72 causes an untested semiconductor package to be placed into channel 52, an untested package to be placed into the test region and a tested device to fall from channel 52 through shoot 102 to the sorter. The above description is given by way of example only. Changes in form and details may be made by one skilled in the art without the parting from the scope of the invention.

Claims: CLAIMS 1. A test socket assembly for use in an apparatus for testing semiconductor devices of the type which have a plurality of leads protruding therefrom, said assembly comprising: a housing having a channel therethrough, said channel having an entrance and an exit; a plurality of contacts extending into said channel intermediate said entrance and said exit; and first means for urging untested semiconductor devices through said entrance such that said leads engage ' said contacts to permit testing of said devices and for pushing tested semiconductor devices out said exit. . 2. An assembly according to claim 1 further comprising second means for guiding and maintaining the orientation of said semiconductor devices as they pass through said channel. 3. An assembly according to claim 2 wherein said second means includes a plurality of longitudinal grooves in said channel each one for receiving one of said plurality of leads. 4. An assembly according to claim 3 wherein each of said contacts resides in one of said grooves. 5. An assembly according to claim 4 further comprising a reservoir for containing untested semiconductor devices proximate said entrance. 6. An assembly according to claim 5 wherein said reservoir is in the form of a track having an opening therein adjacent said entrance. 7. An assembly according to claim 6 wherein said first means includes a motor driven reciprocating piston which passes through said opening to engage a semiconductor device in said track and push it into said entrance. 8. An apparatus for handling and testing a plurality of packaged integrated circuit parts each having a body portion and a plurality of leads extending therefrom, said apparatus comprising: an input track for receiving untested parts; a reservoir for containing said untested parts; first means for transporting said parts from said input track to said reservoir; a test socket comprising: a housing having a channel therethrough, said housing having an entrance and an exit, said entrance being proximate said reservoir; a plurality of contacts extending into said channel intermediate said entrance and said exit; and first means for urging untested parts through said entrance such that said leads engage said contacts to permit testing of said parts and for pushing tested parts through said exit; and means for receiving tested parts from said exit and sorting said tested parts. 9. An apparatus according to claim 8 further comprising: second means for guiding ' and maintaining the orientation of said parts as they pass through said channel. 10. An apparatus according to claim 9 wherein said second means includes a plurality of longitudinal grooves in said channel each one for receiving one of said plurality of leads.

Inventors: FRISBIE MILO W, FRISBIE, MILO, W.
Applicants: MOTOROLA INC, MOTOROLA, INC.
Application year: 1985
Main classification: B07C5
IPC codes: B07C5, G01R1