Manufacture of high density interconnection substrates by colamination of inner layers and programmed interconnection joining layers

• Published in: Circuit world 1999-09, Vol.25 (3), p.9-12
• Main Authors: Fjelstad, Joseph, Karavakis, Konstantine, Haba, Belgacem
• Format: Article
• Language: English
• Subjects: Electronic packaging; HDIS circuits; Interconnection; Laminates; Printed circuit boards
• ISSN: 0305-6120
• DOI: 10.1108/03056129910268927

While promising significant improvements in the cost and performance of electronic systems, the advent of new area array packaging concepts such as the BGA and newer area array CSPs has placed significant new demands on the substrates used in their interconnection. New methods such as buildup multilayers and micro vias and colamination of inner layers have been described and implemented by a number of different firms in an attempt to address this important issue. One such method employs simple doublesided plated through hole flex circuits and the use of conductive pastes and bondplies to provide reliable electrical and mechanical connection between layers during a simple lamination cycle. The process, briefly described herein as a colaminated multilayer flex, is detailed in terms of both process steps and manufacturing flow. The structure of the interconnection substrate is also modeled and examined to determine its electrical performance potential according to electrical modeling software. Finally, detailed are the performance of the structure in reliability testing and an analysis of the expected design and performance advantages that might be obtained by such type constructions in combination with BGAs and area array CSPs.