A Vapor-Phase Deposited Polymer Film to Improve the Adhesion of Electroless-Deposited Copper Layer onto Various Kinds of Substrates

Abstract

The adhesion of electrodeposited metal film to polymeric circuit board substrate is one of the key elements to successful miniaturization of electronic devices. However, as the size of the circuit pattern continuously decreases, a novel method is urgently required to increase the adhesion of the metal film on the substrate, especially on the smooth surface, which is critical to decrease the minimum feature size of the metal pattern. In this research, we developed an adhesion promoter layer by depositing metal chelating poly(4-vinylpyridine) (P4VP) film onto various organic and inorganic substrates via initiated chemical vapor deposition process (iCVD) to enhance the adhesion between the electroless deposited copper (Cu) layer and the substrate. The highest peel strength obtained between the electroless deposited Cu layer and P4VP coated substrate was 1.22 kgf/cm. Many advantageous characteristics of the adhesion promoter layer, including extreme thinness, the improved adhesion strength, conformal coverage, scalability of the deposition process, and short process time, will prompt the applicability of this adhesion promoter layer to industrial scale production.

Paper with Power: Engraving 2D Materials on 3D Structures for Printed, High‐Performance, Binder‐Free, and All‐Solid‐State Supercapacitors

“…Poly (4‐vinylpyridine) (P4VP) has been used in the past to modify substrates, allowing them to uptake silver ions. It achieves this through its strong ability to chelate with transitional metal ions . P4VP polymers can be directly coated onto substrate by physical absorption, however, these coating will eventually come off during the long‐time emersion in acrylic solution for chemical engraving.…”

Initiated Chemical Vapor Deposition: A Versatile Tool for Various Device Applications

“…You et al reported on a p4VP‐based adhesion promoter layer that uses the iCVD process. The adhesion promoter layer was found to be capable of metal chelation in inducing the adhesion of the metal layer to various organic and inorganic substrates . The adhesion promoter particularly enhanced adhesion between the electroless plated Cu layer and the printed circuit board (PCB) substrate over a short process period and with conformal coverage (Figure a).…”

“…a) Overall scheme and SEM image of the bonding between electroless deposited Cu layer and substrate using an adhesion promoter layer, p4VP . b) Digital image the PCB‐coated cloth and operational 7‐segment display using the PCB‐coated cloth before and after the washing cycle .…”

“…b) Digital image the PCB‐coated cloth and operational 7‐segment display using the PCB‐coated cloth before and after the washing cycle . a) reproduced with permission . Copyright 2014, American Chemical Society.…”

Preparation and properties of heat-sealable polyimide films with comparable coefficient of thermal expansion and good adhesion to copper matrix

“…The strong interand intra-molecular interactions in the molecular chains for standard PI films make it nearly impossible to be processed by hot-adhesion bonding procedures. In practical applications, such as in fabrication of flexible copper clad laminates (FCCLs) for advanced microelectronic assembly [6][7][8][9][10], PI film substrates have to be adhered to metals or other matrixes by the aid of additional epoxy, acrylic, silicone, or fluoro-polymer adhesives [11][12][13]. This would inevitably cause undesirable thickness increase for the components or severe reliability issues in extreme conditions.…”