Stress level evaluation of a Printed Wiring Assembly containing large hybrid packages
Abstract
A simple iterative technique for the improvement or verification of the mechanical design of a Board Pair Assembly, a specialized type of Printed Wiring Assembly (PWA), is described. The minimum frequencyrequirement is determined by analytical evaluation of stress levels due to random vibration inputs into the PWA. Variations of reinforcement are applied to the PWAs to optimize the assembly, and the results are evaluated for the optimum PWA configuration. Three steps of random vibrational stress are applied and the improvement in board strength is evaluated. Evaluation criteria include lead stress level, principal natural vibration frequencies, and assembly transmissibility. The results indicate that stiffener ribs or stringers parallel to the short axis of the board pair assembly and tied between the connector support and edge board beam yield the desired improvement. Extrapolation of the technique to other environments and board types is discussed.
- Publication:
-
IN: Environmental stress impact and environmental engineering methods; Proceedings of the Twenty-seventh Annual Technical Meeting on Emerging Environmental Solutions for the Eighties
- Pub Date:
- 1981
- Bibcode:
- 1981esie....1...77S
- Keywords:
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- Assembly;
- Hybrid Circuits;
- Printed Circuits;
- Random Vibration;
- Vibration Tests;
- Vibrational Stress;
- Circuit Boards;
- Data Reduction;
- Electric Connectors;
- Electronic Equipment Tests;
- Electronic Packaging;
- Iterative Solution;
- Stress Analysis;
- Stress Distribution;
- Electronics and Electrical Engineering