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EPTE Newsletter: Electroless Plating for Flexible Circuits

Electroless plating is a popular method in manufacturing printed circuits or flexible circuits. The electroless plating concept is not new; it is used to protect conductors against oxidation. However, it is not the default process for printed circuit manufacturing. Many circuit manufacturers do not have in-house plating capabilities and rely on plating shops for surface finishing.

Over the last decade, there has been remarkable progress with electroless plating. Nowadays, material supplies have many new chemicals available for the plating process, especially for surface treatments. Chemical suppliers are confident that circuit manufacturers can secure metallizing on plastic substrates without making a large investment.

I participated in R&D projects during the ‘90s, where we tried to produce flexible copper laminates without adhesive layers. Manufacturers employed different processes, such as casting and sputtering, to generate new laminates. The combination of electroless plating and electrical plating was considered a candidate because it called for very little investment. Unfortunately, the chemical plating processes could not provide a secure enough bond strength between the base film and copper conductors and was not worth pursuing.

New plating chemicals are available to use with the plating process and provide a reliable bond strength with flexible laminates. However, plating shops do not follow the recipe line by line and create their own process conditions by adding supplemental treatments to increase the cost performance. Usually, chemical costs are significant.

To read this entire column, which appeared in the November 2019 issue of Design007 Magazine, click here.