TABLE OF CONTENTS Many test methods, as they relate to assuring reliability, were discussed in Ch. 5. In this chapter, specific details of some of the more widely used methods for testing coatings are given.
Test methods for organic coatings may be characterized at various levels, for example, those used for initial selection and design, qualification, receiving inspection, in-process control, final inspection, and, if necessary, for failure analysis. Test methods may also be broadly classified as: Physical, Electrical, Environmental, Thermal, and Chemical/Analytical (Table 6.1). Only a few of the hundreds of methods used to test the quality and properties of organic coatings and only those most applicable to electronics will be discussed in this chapter. Properties more applicable to commercial and industrial paints and finishes, such as gloss, color, and transparency are omitted. Information on these procedures may be obtained from other sources such as ASTM, IPC, and ISO documents; from paint, varnish, and coatings associations such as the National Paint and Coatings Association, the Paint Research Association, or the Coatings Division of the American Chemical Society; or from companies that supply test instruments such as BYK-Gardner of Columbia, MD and Paul N. Gardner Co., Pompano Beach, FL.
| Physical/Mechanical | Electrical | Environmental | Thermal | Chemical/Anly |
|---|---|---|---|---|
| Viscosity Density Surface Tension/Wettability Adhesion Thickness Hardness Film Integrity/Coverage Abrasion Resistance Flexibility Water Absorption and MVTR Tensile Strength and Elongation Tear Strength Stresses (cure shrinkage, CTE mismatches) | Insulation Resistance Volume Resistivity Dielectric Constant Dissipation Factor Dielectric Breakdown Voltage Arc Resistance | Humidity Resistance Salt... |
