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Test Carrier for "Leadless" Hybrid Diode Matrix Modules

IP.com Disclosure Number: IPCOM000081399D
Original Publication Date: 1974-May-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 2 page(s) / 53K

Publishing Venue

IBM

Related People

McNutt, CT: AUTHOR

Abstract

The purpose of this apparatus is to provide a low resistance, highly reliable, efficient and cost effective carrier, which is mounted on a printed-circuit test board for contacting a small land pattern of a "leadless" electronic device for testing at high (105 Degrees C), room and low (-55 Degrees C) temperatures. It may also be used on burn-in of the same devices, i.e., application of continuous voltage.

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Test Carrier for "Leadless" Hybrid Diode Matrix Modules

The purpose of this apparatus is to provide a low resistance, highly reliable, efficient and cost effective carrier, which is mounted on a printed-circuit test board for contacting a small land pattern of a "leadless" electronic device for testing at high (105 Degrees C), room and low (-55 Degrees C) temperatures. It may also be used on burn-in of the same devices, i.e., application of continuous voltage.

The apparatus achieves its purpose by alignment of the part circuit by the close tolerance alignment window. By closing the lid, it forces the part into the contacts while maintaining alignment. See Fig. 1. Most important, this action of closing the lid causes the contacts to deflect downward about a 0.25 inch radius, thereby creating a scrubbing action across the solder pad which results in removal of solder oxides for better contact resistance. See Fig. 2.

By controlling the thickness of the alignment window, the contacting force can be controlled. This design allows 0.015 inch minimal deflection, which has been experimentally determined to be sufficient to create repetitive reliable contact with the circuits at all times. The deflection of the spring contacts by 0.015 inch provides positive con contact with the module during the thermal excursions. This is of prime importance for reliable contact, due to the thermal coefficient of expansion differences.

This apparatus allows quick loading of parts for el...