Electroless Silver

Status date
Activity Code

The objective of this project is to finish the development of Polymer Kompositers electroless silver plating process, identify potential customers and make it commercially available. The process shall be evaluated for space requirements. The evaluation is divided in to 3 parts where electroless silver on Printed Wiring Boards for solderability and environmental protection shall be tested for space applications in one part. The second part shall evaluate the electroless silver on a metallic microwave component, a ku-band diplexer for space applications.


The third part of the project is to evaluate the application on plastics.


The key issues in the project are the following:


  • Evaluate the Electroless SilveMix as a coating for metallic microwave components for space applications.
  • Evaluate the Electroless SilveMix as a coating for printed wiring boards for space applications
  • Evaluate the ability to plate plastic parts with with Electroless Silverix.

For most purposes such as coatingson PWB's and microwave componens an extensive testing is required. The tests within this project will be performed in accordance with the requirements from the industry regarding. Since we will be working with internationally well-known companies and institutes the results will have a great reliability. The commercialization will be easier when the properties are documented.


We also believe that working with an institute with such good reputation as ESA will give us a great benefit.


The electroless silver process has several purposes. New areas of applications will appear in the developing process, for the moment the main areas are the following


  • Solderable and bondable coating on Printed Wiring Boards (PWB's).
  • Plating on microwave components.
  • Plating on plastic.
  • Conductive coating on solar cells.


For the area with PWB's there is a large potential since lead is to be banned in 2006 in most electronic equipment. Todeay lead is used in both the solder and coating. On the market there is no other process that can build thick layers (>0,5 micron) of electroless silver, the existing types are so called immersion silver that only builds layers of a tenth of a micron. Beside giving an environmental friendly alternative to the lead-based HASL process. Silver has also excellent electrical and thermal properties and is ideal for soldering. It gives also the ability to bond directly on the silver, i.e. electroless silver is a high preformance, low cost alternative to ENIG (Electroless Nickel Immersion Gold).


For metallic structures electroless silver can give a much more even layer than regular DC-plating. Also it will avoid edge-effects and a higher quality is achieved.


For plating of nonconductors/plastics whole new areas of applications will open up, especially the manufacturing of microwave components in plastics has a great potential.. The main reason for plating on plastics is great cost reducing benefits.


The process will be tested for PWB, microwave components and plating of plastics applications. Tests will be performed be industry/test institutes.

Current status

The Mid Term Review was held in May 2004.


Manufacturing and plating of PWBs and of microwave components has been completed. The components are waiting for tests to start at the test facilities.


The testing and evaluation of the pretreatment process for the plastics application has been completed and the silver-plating of the plastics has started.


Work on the quality assurance of the process is ongoing. A preliminary user manual is ready and the work is focusing on verification of operational data and of the preliminary process for maintenance.


A patent investigation has started and an application for patent is planned.

Prime Contractor
Polymer Kompositer AB