Technical Articles From Intrinsiq Materials Inc.

Factors Affecting the Adhesion of Thin Film Copper on Polyimide

Nov 22, 2017 | David Ciufo, Hsin-Yi Tsai and Michael J. Carmody

The use of copper foils laminated to polyimide (PI) as flexible printed circuit board precursor is a standard practice in the PCB industry. We have previously described[1] an approach to very thin copper laminates of coating uniform layers of nano copper inks and converting them into conductive foils via photonic sintering with a multibulb conveyor system, which is consistent with roll-to-roll manufacturing. The copper thickness of these foils can be augmented by electroplating. Very thin copper layers enable etching fine lines in the flexible circuit. These films must adhere tenaciously to the polyimide substrate.

In this paper, we investigate the factors which improve and inhibit adhesion. It was found that the ink composition, photonic sintering conditions, substrate pretreatment, and the inclusion of layers (metal and organic) intermediate between the copper and the polyimide are important....

Nanocopper Based Paste for Solid Copper Via Fill

Mar 03, 2016 | David Ciufo, Sujatha Ramanujan, Janet Heyen, Michael Carmody; Intrinsiq Materials, Sunny Patel; Candor Industries.

This paper discusses a nano copper based paste for use in via filling. The company manufactures nano copper and disperses the coated nano copper into a paste in combination with micron copper. The resultant paste is injected or fills a via. The via is subsequently sintered by means of photonic sintering, or by heat in a reducing environment. The process will be accomplished in under an hour and results in filled solid copper vias....