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Test Module Assembly

IP.com Disclosure Number: IPCOM000060870D
Original Publication Date: 1986-May-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 3 page(s) / 108K

Publishing Venue

IBM

Related People

Blair, EA: AUTHOR [+4]

Abstract

A technique is described whereby a test module assembly is capable of testing up to 12,000 contacts on the top surface of a substrate and up to 1,800 contacts on the bottom surface of the substrate. The test module assembly consists of five sub-assemblies: drive base assembly 10, as shown in Fig. 1, positioning carriage assembly 11, load and unload carriage assembly 12, probe base assembly 13 and probe yoke assembly 14. The function of each of the five sub-assemblies is as follows: 1. Drive base assembly 10 consists of mounting plate 15, as shown in Fig. 2, to support the main Z-drive motor 16 and its reduction gearing 16A, providing translation to two lead screws 17 which are phased to positioning carriage 18 to inhibit rotation.

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Test Module Assembly

A technique is described whereby a test module assembly is capable of testing up to 12,000 contacts on the top surface of a substrate and up to 1,800 contacts on the bottom surface of the substrate. The test module assembly consists of five sub-assemblies: drive base assembly 10, as shown in Fig. 1, positioning carriage assembly 11, load and unload carriage assembly 12, probe base assembly 13 and probe yoke assembly 14. The function of each of the five sub-assemblies is as follows: 1. Drive base assembly 10 consists of mounting plate 15, as shown in Fig. 2, to support the main Z-drive motor 16 and its reduction gearing 16A, providing translation to two lead screws 17 which are phased to positioning carriage 18 to inhibit rotation. To generate thrust forces on lead screws 17, there are two output pinions keyed to the lead screw nut that rotates so as to induce lead screw translation. An absolute encoder is utilized, and its drive gear is driven from the output pinions. 2. Positioning carriage assembly 11 consists of plate 19, as shown in Fig. 3, which has fixed to it and is driven by a pair of lead screws. During testing procedures, this assembly supports and clamps the substrate. It also optimizes positioning of the substrate through the X and Y theta ring plates 20. The axis positioning is conveyed by mapping data through a microcomputer to encoded gear boxes 21 through wedge drives 22, so as to convert rotary motion to linear and/or angular motion to the respective clamp ring
23. 180- degree ring 24 permits rotation of the substrate after the first test. After rotation, the substrate is again rotated for verification of the test results. 0 to 180- degree rotation switch 25 is provided to control the rotational function from the 180-degree drive 26. 3. Load/unload carriage assembly 12, as shown in Fig. 4, is a three-piece plate assembly that houses a "coin changer" type of member that is driven in and out so that substrates may be loaded and unloaded for test. Within carriage 12 is mounted insert assembly 27, one for each size of substrate. It is rotated about its outside diameter bearing. The center of insert arm 27 is open to expose the bottom of the substrate under test to the "Pogo" pin contacts housed in the probe arm or the positioning carriage 11. When the carriage is in the test position and before the start of the test cycle, leaf springs mounted under insert assembly 27 are used to support the substrate within the cavity of the insert arm. Rectangular slots 28 cut into the insert provide clearance for locator clamps and their housings during testing cycles. Insert assembly 27 is rotatable for 180 degrees. When the command to rotate is given, to the 180-degree drive ring of positioning carriage 11, the locator clamp housings mounted above the drive ring are engaged in the slots of the insert so as to drive the insert and housing to a new test position. After the second test, rotation is reversed 180 ...