Green Technologies in PCB Fabrication


Reading time ( words)

“Green” and “environmentally friendly” are ill-defined terms. In general, these terms refer to manufacturing that involves the replacement of toxic substances with less toxic materials, the elimination of materials or processing steps, and less consumption of chemicals (i.e., more efficient or higher yield processing, reduction of water use, reduction of energy use, less space requirement, smaller equipment foot print, and recycling and on-site recovery of materials).

Direct Metallization

This family of processes eliminates the electroless copper process. These processes typically have fewer process steps, use less rinse water, have less floor space requirement, and use less toxic chemicals. Direct metallization processes include:

Palladium-based

These processes pretty much follow the classic electroless copper processing step sequence, except the sequence ends with the application of the palladium catalyst, followed by the activation, then skips the electroless bath and proceeds to copper electro-plating.

Carbon or Graphite-based

Using small carbon or graphite particles to render the dielectric hole-wall electro-platable, this process involves very few steps.

Conductive Polymer-based

The process of using a non-conductive monomer to coat the board surface follows an oxidation step that forms a conductive polymer from the non-conductive monomer. The polymer then facilitates copper electro-plating on the non-conductive dielectric hole wall. An example of such a conductive polymer formation is the oxidation of pyrrole to poly-pyrrole, using permanganate as the oxidation agent. The permanganate is reduced to manganese dioxide, which is insoluble and needs to be further reduced to the soluble manganese Mn2+ ion. Another example is the polymerization of “EDOT” (3,4-ethylenedioxy-thiophene) to poly-EDOT.

Read the full column here.


Editor's Note: This column originally appeared in the April 2014 issue of The PCB Magazine.

Share




Suggested Items

ICAPE: Staying on Top During ‘Interesting’ Times

12/05/2022 | Nolan Johnson, PCB007 Magazine
Recently, we met with Nathan Martin, group purchasing director; Jean-Christophe Miralles, supply chain director for Europe and U.S., and Lea Maurel, Americas marketing manager. This wide-ranging conversation dug into market drivers, supply chain challenges and how ICAPE creates consistency on its manufacturing floor. Complementing the supply chain control is ICAPE’s engineering experise, which it uses to increase customer yields and quality. Corporate sustainability is a key strategic initiative for ICAPE, and it was enlightening to learn just how holistic ICAPE’s approach to sustainability is.

Optimize Your Etcher for Best Image Quality

11/03/2022 | Christopher Bonsell, Chemcut
When it comes to obtaining high-quality images, many different factors come into play. Typically, most of these factors come down to your imaging equipment and cleanroom; however, there are factors involved in the etching process that can affect the quality of your image. Here are five steps to ensure your etching process is optimized for the best image quality.

Millennium Circuits on The Move

10/31/2022 | Andy Shaughnessy, Design007 Magazine
I recently met with Daniel Thau, CEO of Millennium Circuits Limited, at PCB West. This Pennsylvania-based PCB distributor has been on an expansion path lately, so I asked Daniel to introduce us to MCL and explain where the company is headed. As Daniel says, it’s all about impacting the world in a positive way.



Copyright © 2022 I-Connect007 | IPC Publishing Group Inc. All rights reserved.