Adhesion of Thick Films to Ceramic and Its Measurement by Both Destructive and Nondestructive Means
SourceTechniques for the measurement of adhesion of thick films to alumina have been evaluated. One method is to solder a connection into a thick film pad and measure strength using a force gage. By this method it is not possible to differentiate between inherent adhesion problems and soldering effects. Another method is to use a wire peel test, but it requires optimized procedures or the effects of soldering can mask the adhesion characteristics. Metallurgical sectioning with use of a scanning electron microscope (SEM) and energy dispersive X-ray (EDAX) attachment is an invaluable aid for examining the interface and determining the characteristics of glass and metal components. Bondability tests are also a means of evaluating adhesion but are affected by bonding technique and wire size. Standardized methods are needed for adhesion measurements which, coupled with a comprehensive quality-assurance procedure, can give full process control.