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Testing Bare Board Printed Circuit Product Using a Stepping Head Technique, Without Regard for Close Head to Head Tolerancing

IP.com Disclosure Number: IPCOM000036952D
Original Publication Date: 1989-Nov-01
Included in the Prior Art Database: 2005-Jan-29

Publishing Venue

IBM

Related People

Seward, MF: AUTHOR

Abstract

A testing method that can be used to perform a shorts and opens test on any bare board product is accomplished using a stepping test head technique. This method will allow the testing of printed circuit panels with close center-to-center distances with stepping heads of a (Image Omitted) conventional spring probe design. It also will allow a gap to exist between the test heads at all times, thus eliminating or reducing the possibilities of head-to-head collisions. This separation gap will (Image Omitted) always be equal to the WX and WY dimensional differences between head 1 and head 2. (Image Omitted)

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Testing Bare Board Printed Circuit Product Using a Stepping Head Technique, Without Regard for Close Head to Head Tolerancing

A testing method that can be used to perform a shorts and opens test on any bare board product is accomplished using a stepping test head technique. This method will allow the testing of printed circuit panels with close center-to-center distances with stepping heads of a

(Image Omitted)

conventional spring probe design. It also will allow a gap to exist between the test heads at all times, thus eliminating or reducing the possibilities of head-to- head collisions. This separation gap will

(Image Omitted)

always be equal to the WX and WY dimensional differences between head 1 and head 2.

(Image Omitted)

This method compensates for the inability of stepping head testers to contact adjacent rows of test nodes, because of the close head- to-head tolerancing required. This method will allow the testing of

(Image Omitted)

adjacent rows of test nodes without precision toleranced special design test heads or the fear of head collisions. By using this method a head-to-head cushion or gap between the heads can be maintained and

(Image Omitted)

still achieve a 100% opens and shorts test. Conventional methods of testing a high density product with two separate stepping heads may be impossible. See Fig. 1.

(Image Omitted)

The head design involves two test heads of conventional design, using wired spring probes isolated by a non-conductive medium such as

(Image Omitted)

epoxy or G10. One head must be...