Reducing Warpage of Printed Circuit Boards by Using Wavy Traces
Author:
Hutapea Parsaoran1, Grenestedt Joachim L.1
Affiliation:
1. Department of Mechanical Engineering and Mechanics, Lehigh University, Bethlehem, PA 18015
Abstract
Printed circuit boards (PCB’s) often warp when subjected to temperature changes, associated with either the manufacturing process or the usage. In order to reduce the warpage, waviness was introduced in the electric traces. Model PCB’s were manufactured and tested. The elastic stiffnesses of the PCB’s were determined using a coupled experimental-analytical vibration method, whereas coefficient of thermal expansions (CTE’s) and warpage were measured by placing strain-gage instrumented specimens in an environmental chamber and varying the temperature. Unit cell finite element (FE) analyses of PCB’s with both straight and wavy traces were performed to predict thermoelastic behavior. Both experimental tests and numerical analyses conclude that the PCB’s with wavy traces warped approximately 40% to 60% less than the PCB’s with straight traces.
Publisher
ASME International
Subject
Electrical and Electronic Engineering,Computer Science Applications,Mechanics of Materials,Electronic, Optical and Magnetic Materials
Reference18 articles.
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