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Article: Reducing solder voids with copper-filled microvias: a study seeks to find out the frequency, location and size of voids with and without copper-filled vias.(Materials/Substrates)
- Article from:
- Circuits Assembly
- Article date:
- April 1, 2003
- Author:
CopyrightCOPYRIGHT 2003 UP Media Group, Inc. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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Utilizing microvias in surface-mount pads on printed wiring boards (PWBs) has created unique challenges for both PWB fabricators and assembles. Microvia structures of 50 top 100 microns are manufactured daily in high-volume production of ceramic chip carriers. In PWB fabrication, microvia structures are typically greater than 150 microns and utilize epoxy and polyimide-based substrates. These material sets require glass to limit z-axis expansion and, while providing cost savings, mandate stronger and more consistent copper deposits and solder joints.
Implementation of microvia-in-pad technology into PWB designs allows for tighter spacing of ball grid arrays ...