Browse Prior Art Database

BALL GRID ARRAY (BGA) X-RAY IDENTIFICATION

IP.com Disclosure Number: IPCOM000009439D
Original Publication Date: 1999-Sep-01
Included in the Prior Art Database: 2002-Aug-23
Document File: 1 page(s) / 51K

Publishing Venue

Motorola

Related People

Stephen Harrison: AUTHOR [+3]

Abstract

The testing of electronic assemblies is becoming more and more complex due to the smaller compo- nents being used. The industry standard for initial test has been In-Circuit test, however test point access is becoming extremely difficult to achieve. Alternative test and inspection methods are being investigated for process verification. One of these new techniques is Ball Grid Array (BGA) identifica- tion by X-ray inspection. Although X-ray is good for establishing that a component is not fitted or that a problem exists with the solder joint, it cannot determine the orientation of many of today's elec- tronic packages such as BGA's, QFP's & SIOC's. Therefore the problem exists of finding a solution of how package orientation can be detected using x-ray inspection.

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Developments Technical 0 M MOTOROLA

BALL GRID ARRAY (BGA) X-RAY IDENTIFICATION

by Stephen Harrison, Brian Cosgrove and Martin Mason

BACKGROUND

  The testing of electronic assemblies is becoming more and more complex due to the smaller compo- nents being used. The industry standard for initial test has been In-Circuit test, however test point access is becoming extremely difficult to achieve. Alternative test and inspection methods are being investigated for process verification. One of these new techniques is Ball Grid Array (BGA) identifica- tion by X-ray inspection. Although X-ray is good for establishing that a component is not fitted or that a problem exists with the solder joint, it cannot determine the orientation of many of today's elec- tronic packages such as BGA's, QFP's & SIOC's. Therefore the problem exists of finding a solution of how package orientation can be detected using x-ray inspection.

SUMMARY

  The proposed change to component pad design allows X-ray inspection equipment to identify com- ponent orientation by modifying the solder joint shape on one device pin.

DETAILED DESCRIPTION

  The idea modifies the shape of the land pad on the device to be soldered to a PCB. This new pad design modifies the shape of the actual solder joint so that x-ray inspection equipment can differentiate between the pin 1 joint shape and any other. In a typical BGA joint x-ray picture, it can be clearly seen that the solder joints are symmetrical and no orientation featu...