Controlling Dimensional Change During Lamination of Multilayer Polyimide Printed Wiring Boards

Rigid multilayer polyimide printed wiring boards exhibit unusually large dimensional change during the lamination process. Therefore, the use of large polyimide multilayer panels for high density circuitry is often limited. This study examined ten probable causes for dimensional instability and how each affected the shrinkage/growth in the laminated panel. The report shows that a combination of methods and materials can reduce the resultant dimensional change experienced during lamination from 0·001 inch/inch to less than 0·0002 inch/inch in planar directions.