Printing Technology

Electroplating pastes (Phase 2): Screens for water-soluble pastes, and their cleaning with water (Part 3)

The results of the research allow the manufacture of complete hybrid circuits in the area of technical screen printing, with a water-based paste system on AIN substrates. The elimination of organic solvents for cleaning reduces the hazard potential, and allows savings of energy and resources.

 

Summary

Circuits for the electrical industry are preferably manufactured using screen printing techniques, which still require the use of large quantities of organic solvent blends in all phases of cleaning. In contrast to other screen printing applications, water-based pastes and dyes cannot be used here, since the screens need to be structured with direct coatings, which do not meet the required high quality standards for the print master with regard to line weight, layer thickness and edge sharpness. 

The aim of the multi-stage association project was to develop a concept for the use of water in all areas of the printed circuit manufacturing process. As part of this sub-project, printing screens for water-soluble pastes were to be manufactured and tested under real-life conditions. 

Results: 

  • Sufficiently waterproof screens of optimal quality were successfully manufactured. They are suitable for the most sophisticated technical screen printing applications. Stainless steel wire cloth with a mesh size of 325 to 400 mesh, wire diameter of 0.018 to 0.030 mm and a weave angle of 22.5° or 45° was used. The screen was then structured using direct / indirect coating technology, with a film thickness of 20 µm. 
  • The screens showed good printing performance when used with the silver-palladium based conductor paste (FK 1205 W) developed by the project partner.

Project Participants

Implementing Institution

KOENEN GmbH

More Project Informations

Project title:  Electroplating pastes (Phase 2): Screens for water-soluble pastes, and their cleaning with water (Part 3)

Project number:  01RV0003

Project period:  2000 - 2002

Project region:  Germany (Bavaria)

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Source:  German National Library of Science and Technology Hannover (TIB)