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Short Circuit Tester for Module Substrate

IP.com Disclosure Number: IPCOM000081002D
Original Publication Date: 1974-Mar-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 2 page(s) / 33K

Publishing Venue

IBM

Related People

Ayers, RL: AUTHOR

Abstract

In many instances substrates for modules are received from a vendor with connections and circuits preprinted thereon. If such substrates are used as received, any short circuits between the printed wiring caused by smearing of circuit paste, excessive deposits or the like, will not normally be detected until a first product test after a number of processing operations have attached expensive circuit components.

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Short Circuit Tester for Module Substrate

In many instances substrates for modules are received from a vendor with connections and circuits preprinted thereon. If such substrates are used as received, any short circuits between the printed wiring caused by smearing of circuit paste, excessive deposits or the like, will not normally be detected until a first product test after a number of processing operations have attached expensive circuit components.

A preassembly testing of the substrates can eliminate those with defective circuit deposits and avoid such unnecessary loss of parts. The tester indicated in the drawing has a socket to receive a substrate and to make connections indicated at 1 to the wiring on the substrate. The tester has a voltage supply comprising a battery 2 or other DC voltage source, an on-off switch 3, normally a "push to test" button, and a polarity reversing switch 4 between the output leads of the power source and leads 5 and 6 of the tester. Lead 5 is connected to all of the even numbered ones of the connections 1 through diodes 8 and 9 alternately, so that adjacent ones of the even numbered connections are not energized at the same time but only on oppositely phased voltages on line 5.

Each of the odd numbered connections 1 is connected to lead 6 through a pair light-emitting diodes (LED's) 7 in parallel. The diodes 7 of each pair are oppositely poled so that only one will illuminate on each voltage polarity. Only one LED 7 is needed f...