TW526334B - Test socket - Google Patents

Abstract

A test socket for an integrated circuit package having a housing secured to the top surface of a load board. The upper housing includes a plurality of angled channels. A plurality of spring probes are positioned in the channels of the housing to provide a spring force to bias the spring probes into electrical contact between the integrated circuit package and the load board.

Description

526334 A7 B7 V. Description of the invention (1) The relevant application is submitted with reference to the part of US patent application No. 09 / 139,543 filed on August 25, 1998, which is the United States filed on March 20, 1998 Partial continuation of Patent Application No. 09 / 〇44,874 'This is a partial continuation of US Patent Application No. 08 / 839,723 filed on April 15, 1997. FIELD OF THE INVENTION The present invention relates to a test socket used in an integrated circuit package (such as a ball grid array package), wherein the socket includes a housing on a loading board, and the housing extends through the housing and is driven into the integrated circuit package. Most oblique contact terminals that make bias contact with the loading board. BACKGROUND OF THE INVENTION The integrated circuit test in a ball grid array (BGA) package is achieved using a test socket commonly referred to in the art. BGA test sockets generally include a housing that is mounted on a filler board that interfaces with the test electronics. The loading board is a circuit board that sends signals from the integrated circuit in the BGA to the test electronics. Conventional methods for attaching a test socket to a filler board include through-hole technology and surface-mount technology (SMT). In a surface mount connection, the test socket includes a test pad ' which is in contact with the solder balls on the bottom of the BGA when the BGA is pressed against the test pad to send the test signal to the loading board. A related issue with surface mount test socket devices is that the solder balls at the bottom of the BGA may change height and may not ensure good electrical contact between each solder ball and the test pad. A second related issue with surface mounting is that the entire socket assembly must be replaced after the test pad becomes contaminated with solder balls. (Please read the precautions on the back before filling out this page), printed on --------- Order · --------- line ‘Printed by the Employees’ Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs

526334 Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs

A7 ----- B7 _ V. Description of the invention (2) The through-hole technology for connecting the socket to the filling plate includes: passing the hole through the filling plate to pass the spring-loaded contact terminals, these terminals are soldered to the above The ball is in contact with each other, and the test terminal is in contact with the hole in the loading board via the test terminal, and the test signal is sent to the loading board. One of the related problems of the through-hole socket device is that the test terminals that extend upwards through the filler board may be easily bent or damaged, which will adversely affect the test results. To avoid this problem, a receptacle can be located between the socket and the filler panel to protect the test terminals that extend beyond the filler panel. The use of a slot will cause the length of the test terminals in the socket to increase, leading to problems in testing high-speed integrated circuits. To solve this problem, a spring probe with a short stroke length and a short stroke spring has been used. The spring has a short life and requires constant replacement. In addition, the use of spring probes in the socket may cause impedance problems in the transmission of test signals from the BGA to the loading board. As a result, BGA packages require a new test socket that reduces the problems associated with conventional test sockets. SUMMARY OF THE INVENTION The present invention provides a newly designed test socket, particularly a test socket for ball grid array integrated circuit packaging, which reduces the problems associated with the conventional test socket device. In a preferred embodiment, although the test socket is designed to be used in a BGA package, the socket can also be used in other integrated circuit packages (such as QFp packages). In short, the test socket of the preferred embodiment of the present invention includes a housing on a loading plate, the housing having a plurality of inclined holes drilled through the housing. The spring probe is located in the hole to create a biased contact between the test site and the loading plate. Other embodiments of the present invention include an upper case and a lower case, which are fixed to the top and bottom surfaces of the loading plate, respectively. The loading board is tested with an external paper. Fine gauge of paper rule (21 "297 public love) 5

526334 A7 B7 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs. 5. Description of the Invention (3) The test electronic device of the device is a small circuit board with an electrical interface. The upper housing includes a cavity to receive the BGA and includes a hole in the lower surface to accommodate most solid socket plungers and to contact the solder balls on the bottom of the BGA. The socket plungers are located in most of the channels formed in a row in the lower case, and extend through the plurality of holes also in a row through the loading plate to contact the solder balls. An elastomer diaphragm is located between the upper surface of the lower casing and the lower surface of the loading plate, and extends above and enters the lower casing below the plunger to provide a spring force to bias the jack plunger upward toward the BGA. The flexible diaphragm provides independent pop-up bias pressure contact for the removable socket plunger mounted in the lower housing. In addition, the poppet is preferably located in the lower housing below the plunger to bias the plunger. A non-conductive ball is located between the plunger and the spring to prevent interference with high-frequency applications. In addition, the insulated terminal can be located under the socket and an insulating cover can be located above the loading board for south-frequency applications. The conductive cylindrical eyelet is located in the hole of the loading plate to guide the travel of the socket plunger ’and send the test signal from the socket plunger to the loading plate. In addition, the through holes in the loading board are plated to transmit the test signal. The socket plunger of the present invention utilizes a solid plunger biased by an elastomeric diaphragm to eliminate problems associated with conventional BGA test socket devices. This device also provides a long stroke length to the plunger to compensate for the lack of coplanar solder balls on the BGA. Compared to mechanical springs, the use of elastomer diaphragms will also increase the effective life of the test socket. For tightly distributed test locations, the test socket of the present invention includes a structure in which the holes are cut into the loading board and a thinner daughter board is shielded by a shield probe or soldered by a frame and a flexible printed circuit board. Connect to the loading plate. The Su system is connected to the daughter board so that the socket plunger can be accommodated (please read the precautions on the back before filling this page), and install ------

-I I tr --------- line This paper size is applicable to China National Standard (CNS) A4 (210 X 297 mm) 526334 Printed by the Consumer Cooperative of Intellectual Property Bureau of the Ministry of Economic Affairs

A7 ______ Β7__ V. Description of the invention (4) In the compact distribution device, referring to the following detailed description, the above and other advantages of the present invention can be more clearly understood. Brief description of the drawings. Figure 1 is a cross-sectional view of the BGA test socket of the present invention in a biased state; Figure 2 is a front sectional view of the test socket of Figure 1 in a non-biased state) Figure 3 is a socket plunger assembly An enlarged detail view; FIG. 4 is a perspective view of a refill cassette for a test socket; FIG. 5 is a front cross-sectional view of another first test socket device; and FIG. 6 is another structure for biasing a plunger Partial sectional detail view; Figure 7 is a partial sectional detail view of another socket plunger structure; Figure 8 is a top view of another second socket socket of the present invention; Figure 9 is a view of Figure 8 Fig. 10 is a side sectional view of another first embodiment of Fig. 8; Fig. Π is a side sectional view of another second embodiment of the test socket of Fig. 8; Fig. 12 is Front view detail view of another third preferred embodiment of the test socket of the present invention. Detailed description Figures 1 and 2 show test sockets 10 'for ball grid array integrated circuit package 12. The invention is described and shown for BGA packages. The new design of the test socket is also suitable for testing other integrated circuit packages. For the sake of clarity, the size of the large paper applies to the Chinese National Standard (CNS) A4 specification (210 X 297 public love)

Tit -------- ^ --------- line (please read the notes on the back before filling this page) 526334 A7 B7 V. Description of the invention (5) (Please read the notes on the back first Please fill in this page for more details) Most of the detailed descriptions are limited to BGA packaging. The test socket 10 of the present invention includes an upper case 14 and a lower case 16 which are respectively fixed to the top and bottom surfaces 18, 20 of a loading board. The upper case 14 and the lower case 16 are preferably made of plastic and rigidly fixed to the loading plate by screws 24 passing through the case and enter the loading plate. The loading plate is connected to an external tester (not shown). The test electronic device forms a circuit board with an electrical interface. The upper case includes a cavity 26 inside the upper case to receive the ball grid array package 12. The ball grid array package includes an integrated circuit 28, which is located on a substrate 3o. And has a plurality of solder balls 32 on the lower surface of the substrate opposite to the integrated circuit and in electrical communication with the integrated circuit via the substrate 30. The solder ball 32 is used as a test pad to test the integrated circuit, and the substrate 30 is in the cavity 26 base The seat rests on a flange 34, and the solder ball 32 extends beyond the flange 34 defined by the upper surface 18 of the loading plate 22孑 L 3 ό 〇 The hole 36 in the upper housing base printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs also provides an opening for most solid socket plungers 38 to contact the solder balls 32. The socket plungers are located below The plurality of channels 40 formed in the matrix 16 in the matrix 16 extend through the plurality of holes 41 through the filling plate and contact the solder balls 32 as shown in Fig. 3. The holes 41 are also arranged in rows and columns in a pattern similar to the solder balls 32 on the BGA. The solid socket plunger 38 includes an enlarged head portion 42 and a smaller diameter elongated arm portion 44. The arm portion extends through the hole 41 in the loading plate 22 while the enlarged head portion 42 is held in the channel 40 in the lower housing 16 An elastomer diaphragm 46 is located between the upper surface 48 of the lower casing 16 and the lower surface 20 of the loading plate, and extends above and enters the channel 40 in the lower casing below the head of the socket plunger to provide a spring. The socket plunger is biased upwards toward the BGA, so that the inclined top surface 50 of the plunger arm 44 and the solder ball 32 have a good paper size. The Chinese national standard (CNS) A4 specification (210 X 297 mm) is applicable. 526334 Economy Printed by the Consumer Cooperatives of the Ministry of Intellectual Property Bureau A7 _____B7 Five Description of the invention (6) Electrical contact. The inclined surface 50 on the end of the plunger arm is processed to provide bias contact with the solder ball, and the flexible diaphragm 46 provides an independent spring for the movable socket plunger installed in the lower housing. The position of the biased pressure contact 1 conductive cylindrical eyelet 52 is through the holes 41 in the loading plate 22 to guide the movement of the socket plunger arm, and the test signal generated by the solder ball is sent to the loading plate through the socket plunger. The hole is better Manufactured from a conductive material (such as copper beryllium or nickel silver). The through-holes 41 in the filler plate are often electroplated and the eyelets include a soldered pre-plastic ring 53 that welds the eyelets to the through-holes of the electric money, making the eyelet rigid. Connect to the loading plate. The elastic diaphragm 46 is held between the lower case and the loading plate with screws 24, and the elastic body 12 is preferably a thin flexible sheet-like expandable latex rubber that is in direct contact with the socket plunger head 42. Although the elastomer diaphragm is preferably made of latex rubber, other materials can be used to make the diaphragm provide a bias spring force to the socket plunger. The diaphragm in the normal position is stretched to conform to the shape of the head of each plunger, and an axial force applied to each plunger in the direction of the diaphragm in use causes the diaphragm to stretch 'and end the plunger in a similar manner. The way of the common return spring provides compliance t. In response to the axial movement of the plunger, the thin flexible diaphragm is free to expand into the channels 40 in the lower casing, so the diaphragm can freely expand or stretch into the void space of each channel. As shown in the embodiment of FIG. 1, an axial force is applied to the socket plunger by a housing cover 54 which is connected to the upper housing 14 and has a buckle (not shown) in a closed position. ) Fixed to the upper case. The cover 54 includes an enlarged center section 56 sized to push the Bga package down against the socket plunger, thereby stretching the resilient diaphragm. In addition, an axial force can be applied to the BGA package via a robot arm 58 located above the BGA package and extending into the upper housing through the cavity 26 as shown in FIG. 2. No cover or solid is required in this structure. The paper size is in accordance with China National Standard (CNS) A4 (21 × X j 9

------------- ^ (Please read the notes on the back before filling this page) Order --------- line- 526334 A7 B7 V. Description of the invention In the open position, a robotic arm can be used in an automated test configuration. In Figure 2, before the axial force is applied to the BGA package, the elastic diaphragm is in the normal position. The test socket device of the present invention is 2 It is easy to replace the socket plunger when it is contaminated, so it can provide simple and cheap repair for the test socket. After repeated use, the inclined surface 50 of the socket plunger can be polluted by the tin and lead deposits of the solder ball. The re-boxing 60 shown is easily refurbished, and the re-boxing 60 is preferably a plastic block that includes a plurality of recesses 62 that extend into the rows of the re-boxing to receive the socket plunger 64 for replacement. Figure 4 shows six socket plungers for replacement that extend upward from the recess 62. It can be seen that a separate socket plunger 64 is located in each recess 62 and is flush with the top surface 66 of the repacking box. Includes locating holes 68 to allow repackaging to align during refurbishment procedures. For refurbishment testing Holder, by removing the lower casing and the elastic diaphragm, and simply replacing the contaminated socket plunger, so that the contaminated plunger can be freely dropped from the test signal. Then the box is placed above the lower surface of the loading plate, and then inverted The test socket is fitted with a new plunger. The elastic diaphragm and the lower housing are then mounted to the loading plate for further testing. Referring now to Figure 5, another first test socket device is shown. Test socket 70 in Figure 5 Similar to the test sockets 1 and 2 except that the compliance device is a spring 72 in the channel 40 in the lower casing 16. In this embodiment, the upper surface 48 of the lower casing is adjacent to the loading plate 22. Lower surface 20. The channel 40 in the lower casing is a blind hole that terminates in a ground surface 74 without extending through the lower casing. Although this test socket can be used to test the BGA package, Figure 5 shows: other paper Standards are applicable to China National Standard (CNS) A4 specifications (210x 297 mm) -10-(Please read the precautions on the back before filling this page) · II I --- II Order · III ----. Ministry of Economic Affairs Wisdom Printed by the Consumer Bureau of Property Bureau A7

Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs

526334 V. Description of the invention (8) The body circuit package can be tested at multiple test locations 76 (such as test pads or leads). Figure 6 shows another second test socket configuration 80. The test socket 80 is substantially similar to the first, second, and fifth sockets and includes a different device for biasing the plunger 82. Each plunger is biased by a spring yellow 84 located in one of the holes 86 extending through the lower housing 80. The spring 84 is fastened by a buckle cover 90 in the hole 86. The buckle cover 90 is fixed to the lower surface 92 of the lower case with screws (not shown). The buckle cover 90 is a row of holes 86 covering the lower case. . A ball 94 is located between the plunger head 96 and the spring 84. The ball is biased against the plated through hole or eyelet in the loading plate 100 by contacting an inclined surface 102 on the bottom of the plunger head 96. 98. The ball can be made of metal or non-conductive material (such as ceramic) for high frequency applications to prevent interference with the test signal. The plunger also has an oblique end 104 to contact the solder ball 106 of the integrated circuit 108. The oblique end 104 is to ensure good contact with the test site. The test signal is emitted into the plunger from the top of the stain or the bottom of the loading board before going to the solder ball of the B G A package. For high frequency test signal applications, another plunger device is provided as shown in Figure 7. In this device, a non-conductive push rod 110 is placed below the plunger 112, and a non-conductive cover 114 is placed above the plunger. The push rod 110 has an enlarged base 116 that is snapped into a hole in the lower housing 88. 86 and above spring 84. A smaller diameter arm 118 extends into the plated through hole 98, and the arm U8 has a circular end surface 120 which is in biased contact with the slanted end 122 of the plunger 112. The non-conductive cover 114 is located on the upper surface of the loading plate 100, and has an enlarged head 124 to hold one of the plungers 112. One of the plungers 112 has a reduced diameter portion 126. 210 X 297 mm) 11 (Please read the notes on the back before filling in this page) Binding ---- Order -------- line 526334 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs A7 B7 5 Explanation of the invention (9) Extending through the hole in the head 124, the larger diameter portion 128 of the plunger 112 rests against the cover of the uncompressed state 130. The plunger in the compressed state 132 is also shown in FIG. For high-frequency applications, the test signal is transmitted from the bottom of the loading plate to the solder ball through the plug. In this way, no signal goes to the spring 84 to prevent signal loss. In order to accommodate tightly distributed test points, the test socket of the present invention uses a daughter board 134 as shown in FIGS. 8 and 9. The filling plate 136 for the test socket connection has a thickness of 0 · 12 5 忖. It is difficult to make the required holes for tightly distributed test places to accommodate the test plunger of the test place style. The daughter board is 30 inches thick, so it is easy to drill holes through the daughter board to accommodate the requirements of tightly distributed test sites (can be tightly distributed into 0.020 inch procedures). In order to accommodate the daughter board ', a hole 138 is cut into the center of the loading board 136 so that the daughter board overlaps with the hole cut in the loading board and is welded to the surface of the loading board. The upper case 14o includes a flange 142 for further structural integrity and connection of the daughter board to the loading board. The lower case 144 and end cap 14 are connected to the daughter board by screws 148. Figures 10 and 11 show another method of attaching the daughter board 134 to the loading plate 136. In Figure 10, a masking probe 150 is rigidly attached to the loading plate 136, and the daughter board 134 is then leaned against the shielding plate 136. On the opposite end of the needle. In the figure, the daughter board 13 4 is electrically connected to the loading board 136 by a pullable printed circuit board 15 2. In this embodiment, the upper case 14 does not need the flange 142. For structural integrity, the frame member 154 is rigidly fixed to the bottom of the loading plate to attach the lower case 144 and the end cap 146. Referring to Fig. 12, a third embodiment and a preferred embodiment test socket 160 are shown. The test socket 160 includes a housing 162, which is made of screws (not shown). This paper size applies to the Chinese National Standard (CNS) A4 specification (210 X 297 public love)-one: 1? ·-(Please read the back Please fill in this page again) ▼ --------- Order --------- line {526334 A7 B7 V. Description of the invention (10) or other appropriate fasteners and fixed to the loading board 164. The housing 162 has a plurality of holes 166 that are drilled through the housing at an angle. The hole 166 receives a spring probe 168 for biasing contact between the test site 170 on the unit 172 and the loading plate 164 during the test. Although the test socket 160 in the figure has only one upper case, the new concept of the inclined test terminal in the case is also suitable for other socket structures described above. Although the present invention has been described and shown with reference to different embodiments, it can be seen

I "Thus limited, because there can be changes and modifications within the full scope of the invention as claimed in the patent. Comparison of component numbers: 10, 70, 160 " _ test sockets 32, 106 solder balls 12 ... ball grid array integrated circuit packages 34, 142 flanges 14, 140 ... upper housing 36, 41, 86, 138, 166 holes 16,88,144 ··· Lower case 38 solid socket plunger 18,20 ·· Top and bottom surface 40 Most channels 20,92… Lower surface 42,124 Enlarge head 22,100,136,164 ". Loading plate 44 plunger arm 24, 148 ... screws 46 elastomer diaphragm 26 ... cavity 48, 66 upper surface 28, 108 ... integrated circuit 50 slant surface 30 base plate 52 ... conductive cylindrical eyelet This paper applies Chinese national standards (CNS) A4 size (210 X 297 mm) (Please read the notes on the back before filling out this page) Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs

13 526334 A7 _B7 V. Description of the invention (11) Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 53 ... Welded pre-plastic rings 98 ... Plated through holes or eyelets 54 ... Shell cover 102 ... Inclined surface 56 ... Enlarge center section 104 , 122 ... oblique end 58 ... robotic arm 110 ... non-conductive push rod 60 ... repacking 114 ... non-conductive cover 62 ... recessed portion 116 ... enlarged base 64 ... socket plunger 118 ... smaller diameter arm 6 8 ... Position 孑 L 120 ... Circular end surface 72,84 ... Spring 126 ... Diameter portion 7 4 ... Floor surface portion 128 ... Large diameter portion 76,170 ... Test point 134 ... Sub board 80 ... Second test socket structure 150 ... covering probe 82, 112 ... plunger 152 ... flexible printed circuit board 90 ... buckle cover 154 ... structural member 94 ... ball 162 ... housing 96 ... plunger head 168 ... spring probe (please read the note on the back first) Please fill in this page again for the items), install ------ 5--order --------- line ▲ This paper size is applicable to China National Standard (CNS) A4 (210 X 297 mm) 14

Claims (1)

526334 tremor D8 6. Application for patent scope 1. A test socket for integrated circuit packaging, which has most of the test places 'contains: the housing' is located on a circuit board with most oblique holes; most test terminals are located in the oblique holes And compliance devices for driving the test terminals into electrical contact with the test site and the mounting board on the integrated circuit package. 2. The test socket according to item 丨 of the patent application, wherein the compliance device is a spring located in the test terminal. 3 · —A test socket for integrated circuit packaging, which has most test locations, including: an upper case located on a circuit board, the upper case having a cavity to receive the integrated circuit package; the circuit board has Most of the oblique holes; the lower case is located under the circuit board and there are most oblique channels to receive the solid test terminal; and printed by the consumer cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs (please read the precautions on the back before filling this page) A compliance device is located below the circuit board to drive the test terminals across the circuit board and into electrical contact with a test location on the integrated circuit package. 4. The test socket according to item 3 of the scope of patent application, wherein the compliance device is a spring in each channel of the lower case below the test terminals. 5. If the test socket of the scope of patent application No. 3, the compliance device is extended between the circuit board and the lower case, and entered into this paper standard applicable to China National Standard (CNS) A4 specifications (210 X 297 male Chu) ----- 526334 6. Scope of patent application In the channel of the casing below the test terminal. The test socket of item 3 of the patent scope of claim 1 wherein the elastomeric spacer film is a thin latex sheet. : * The test socket of the third scope of the patent application, wherein the inclined hole in the circuit board includes a conductive eyelet for guiding the test terminals to pass through the circuit board and test from the integrated circuit package. Send m to the board. 8. The test socket of item 3 of the scope of patent application still includes a cover, which is located above the upper case to compress the integrated circuit package against the test terminal. ---------------- I ---- Order · I ------- " 5 ^ (Please read the notes on the back before filling this page) Ministry of Economy Printed by the Intellectual Property Bureau Staff Consumer Cooperatives Paper size applicable to Chinese National Standard (CNS) A4 (210 X 297 mm)