Browse Prior Art Database

USE OF C-MODE SCANNING ACOUSTICAL MICROSCOPY IN IMAGING INTERNAL LAYERS IN PRINTED CIRCUIT BOARDS

IP.com Disclosure Number: IPCOM000007063D
Original Publication Date: 1993-Oct-01
Included in the Prior Art Database: 2002-Feb-22
Document File: 1 page(s) / 157K

Publishing Venue

Motorola

Related People

Frank Juskey: AUTHOR [+2]

Abstract

The shrinking size ofconsumer electronic prod- ucts coupled with the need for increasing features on these products places serious processing require- ments on the manufacture of printed circuit boards (PCB). As lines, vias and ground plates are pushed closer together incidences of shorting become increas- ingly likely and are sometime only discovered once costly surface mount operations have been com- pleted. Properly developed, acoustical imaging offers the ability to screen PCB's for fatal internal defects prior to surface mounting components.

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MOTOROLA INC. Technical Developments Volume 20 October 1993

USE OF C-MODE SCANNING ACOUSTICAL MICROSCOPY IN IMAGING INTERNAL LAYERS IN PRINTED CIRhIT BOARDS

by Frank Juskey and Robert Carson

  The shrinking size ofconsumer electronic prod- ucts coupled with the need for increasing features on these products places serious processing require- ments on the manufacture of printed circuit boards (PCB). As lines, vias and ground plates are pushed closer together incidences of shorting become increas- ingly likely and are sometime only discovered once costly surface mount operations have been com- pleted. Properly developed, acoustical imaging offers the ability to screen PCB's for fatal internal defects prior to surface mounting components.

  Using c-mode scanning acoustical microscopy (C-SAM), individual internal metallized layers can be nondestructively imaged. During operation, the C-SAM generates high frequency sound and directs it at the PCB. As the sound passes through the PCB, echoes are returned to the sensor from each of the layers and displayed on an oscilloscope. As the sen- sor sweeps in the x-y plane echo intensity variations from several layers may be monitored simultaneously and displayed in the form of a color map. In this way, invisible internal features (i.e. lines, vias, ground plates, etc.) can be nondestructively observed.

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