Handbook of Solvents - George Wypych - ChemTech - Ventech!

894 Martin Hanek, Norbert Löw, Andreas Mühlbauer
14.8 ELECTRONIC INDUSTRY - CFC-FREE ALTERNATIVES FOR
CLEANING IN ELECTRONIC INDUSTRY
Martin Hanek, Norbert Löw
Dr. O. K. Wack Chemie, Ingolstadt, Germany
Andreas Mühlbauer
Zestron Corporation, Ashburn, VA, USA
14.8.1 CLEANING REQUIREMENTS IN THE ELECTRONIC INDUSTRY
The global ban of the CFCs has fundamentally changed cleaning in the electronic industry.
Manufacturing processes were developed with the goal of avoiding cleaning. However, this
objective has only be partially realized.
Furthermore, there are still a lot of different areas in the electronic industry where
cleaning of assemblies is highly recommended and necessary. Examples of such applications
can be found in the aviation and space industries and in addition in the rapidly growing
telecommunication industry. When investigating the production process of printed circuit
assemblies, there are several important cleaning applications that have varying degrees of
impact on the quality of the manufactured assemblies (see Figure 14.8.1).
Figure 14.8.1. Cleaning applications in the electronic production.
Cleaning applications in the SMT assembly line typically start with the cleaning of the
bare boards (1). The preliminary substrates have to be cleaned in order to remove a variety
of residues (particles, chemicals used in the manufacturing process of the bare boards).
These residues may have a negative impact on the subsequent production steps. A detailed
analysis 1 of different kinds of contamination which might occur on the bare boards revealed