Experimental measurements of surface mount component lead stiffness

40th Conference Proceedings on Electronic Components and Technology Pub Date : 1990-05-20 DOI:10.1109/ECTC.1990.122301

D. E. Pope, K. Byrd

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引用次数: 2

Abstract

An approach to the experimental determination of lead stiffness (the straddle board method) has been used to assess surface-mount package leads of actual service dimensions. Correlation was observed between the experimental data and trends of predicted values from the linear elastic beam model. However, the simplified model cannot be used to predict actual performance. Current 3D finite-element analysis shows good correlation and predictive capability. Lead stiffness values of PLCC (plastic leaded chip carrier), cerquad (ceramic quad flat pack), and PQFP (plastic quad flat pack) packages have been measured. Transverse values exceed lateral for PLCC and cerquad packages. Cerquad packages exhibit lower stiffness than PLCC. This behavior can be attributed to the longer shoulder length of the cerquad lead and thinner lead thickness, which offsets the effect of the elastic modulus. PQFP leads are in order of magnitude more compliant than the 50-mil pitch J-lead configuration due to the smaller lead cross section and the gull-wing configuration. The board-level solder-joint reliability of PQFP packages is expected to exceed that of the established PLCC component because of the increased lead compliancy.<>

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表面贴装元件引线刚度的实验测量

一种测定引线刚度的实验方法(跨板法)已被用于评估实际使用尺寸的表面贴装封装引线。实验数据与线弹性梁模型预测值的变化趋势具有相关性。然而，简化后的模型不能用于预测实际性能。目前的三维有限元分析具有较好的相关性和预测能力。测量了PLCC(塑料带铅芯片载体)、cerquad(陶瓷四元平板封装)和PQFP(塑料四元平板封装)封装的引线刚度值。PLCC和cerquad封装的横向值超过横向值。Cerquad封装比PLCC具有更低的刚度。这种行为可以归因于较长的铅肩长度和较薄的铅厚，这抵消了弹性模量的影响。由于更小的引线截面和鸥翼结构，PQFP引线比50毫米间距的j引线配置更顺从。PQFP封装的板级焊点可靠性预计将超过现有的PLCC组件，因为铅的合规性增加了。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

40th Conference Proceedings on Electronic Components and Technology

CiteScore

3.10

自引率

0.00%

发文量