Measurement and Control of Coating Thickness and Porosity in Printed Wiring Manufacture

Most of the basic requirements for the manufacture of printed wiring are, of course, well known; so much so that literally hundreds of companies or divisions of larger companies are formed annually to produce these products. However, a high percentage of such companies fail, especially when new specifications are introduced or existing specifications are adhered to by the purchasing authority. There is a wide diversity of reasons for failure of printed wiring products to meet the requirements of quality and performance. Since some of these can be attributed to coating thickness and/or coating porosity, it is therefore the purpose of this article to outline the ways and means to control these parameters.