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Testing Printed Circuitry

IP.com Disclosure Number: IPCOM000051546D
Original Publication Date: 1981-Feb-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Meier, HE: AUTHOR

Abstract

It is very difficult to test printed circuit boards which have very narrow line widths. Imperfections which can cause defects include excessive undercutting of the copper, line thickness irregularities, pits in the carrier surface, and other visually hidden imperfections.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 100% of the total text.

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Testing Printed Circuitry

It is very difficult to test printed circuit boards which have very narrow line widths. Imperfections which can cause defects include excessive undercutting of the copper, line thickness irregularities, pits in the carrier surface, and other visually hidden imperfections.

The lines can be tested by energizing each circuit line with a predetermined level of current which produces heating where imperfections exist. The circuit is scanned with an infrared scanner which locates any hot spots. Automatic scanning devices and automatic data logging devices can be used to automate the process.

The infrared scan will locate the areas of the board that have been heated due to imperfections in the circuit lines, thereby locating the imperfections in the circuit lines. Unacceptability of the flaw may be established by the infrared scan spot intensity voltage level.

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