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IPC - IPC Standard - IPC-9704

Printed Circuit Assembly Strain Gage Test Guideline

File Format PDF  
Price $35  
Language English  Chinese  
Number of page 32  
Date of Publication 2012  

This document is meant to be used as a methodology for strain gage placement and subsequent testing of Printed Circuit Assemblies (PCAs) using strain gages. The method describes specific guidelines for strain gage testing of PCAs during the printed board manufacturing process, including assembly, test, system integration, and other types of operations that may induce board flexure. 

The suggested procedure enables printed board assemblers to conduct strain gage testing independently, and provides a quantitative method for measuring board flexure, and assessing risk levels. 

• The topics covered include: 

• Test setup and equipment requirements 

• Strain measurement 

• Report format 

This document assumes the methodology is being used to test a surface mount device such as Ball Grid Array (BGA), Small Outline Package (SOP), Chip Scale (Size) Package (CSP), and area-array surface mount (SMT) connectors/sockets. In certain cases, the described test approach may be used for non-area-array discrete SMT devices such as capacitors or resistors. 


Strain gage testing allows objective analysis of the strain and strain rate levels to which a surface mount component may be subjected during PCA assembly, test, and operation. 

Characterization of worst-case PCA strain is critical due to the susceptibility of component interconnects to strain-induced failures. Excessive strain can result in various failure modes for different solder alloys, package types, surface finishes, or laminate materials. Such failures include solder ball cracking, trace damage, laminate related adhesive failure (pad lifting) or cohesive failure (pad cratering) and package substrate cracking

IPC-9704A Download/View table of contents

IPC-A-610  IPC-A-600 IPC-A-620 IPC-7711/7721