应变计测试允许对表面安装封装在组装、测试和运行期间可能受到的应变和应变率水平进行客观分析。过度应变会导致不同焊料合金、封装类型、表面光洁度或层压板材料的各种故障模式。本文件描述了印制电路板制造过程中应变计测试的具体指南，包括电路板组装、测试、系统集成和其他可能导致电路板弯曲的操作类型。本文件还涵盖了测试设置和设备要求、应变测量技术和测试报告格式。修订版A包含22张全彩色照片和插图，描绘了仪表板和量规的位置，并已更新以解决无铅组装技术问题

Strain gage testing allows for objective analysis of the strain and strain rate levels to which a surface mount package may be subjected to during assembly, test and operation. Excessive strain can result in various failure modes for different solder alloys, package types, surface finishes or laminate materials. This document describes specific guidelines for strain gage testing during the printed board manufacturing process, including board assembly, test, system integration and other types of operations that may induce board flexure. This document also provides coverage of test setup and equipment requirements, strain measurement techniques and test report formats. Revision A contains 22 full-color photographs and illustrations depicting instrumented boards and gage placement and has been updated to address lead-free assembly technology