Curing resistance change

Figure 6.12 Resistance change during curing of conductive adhesive.

Figure 6.13 Contact-resistance changes for three different cure degrees versus time at 30 k ...

The potential for corrosion caused by adhesives requires evaluations in both cured and uncured states. In one test, the adhesive components or the cured adhesive are applied to aluminized-Mylar film and examined after 48 hours for etching or transmittance of light through the Mylar. A second test involves embedding copper wire with the adhesive and measuring corrosion by resistance changes in copper wire. Because of the wide variety of tests and the fact that they are closely related to adhesive reliability issues discussed in Chapter 6, the reader is referred to that chapter. 

Adhesive No. Curing Agent T, (°C) Moistnre Absorption (%, 350 hrs of 85/85) Percent Resistance Change (85°C/85% RH Exposnre) (Relative to Initial Reading) ... 

Bulk adhesive resistivity and bonded sampie resistance change dnring cure... 

Melamine resins were introduced about ten years after the Beetle molding compound. They were very similar to those based on urea but had superior quaHties. Henkel in Germany was issued a patent for a melamine resin in 1936 (7). Melamine resins rapidly supplanted urea resins and were soon used in molding, laminating, and bonding formulations, as well as for textile and paper treatments. The remarkable stabiHty of the symmetrical triazine ring made these products resistant to chemical change once the resin had been cured to the insoluble, cross-linked state. 

The evaluation of the components of the tinplate container showed that the preferred enamel for irradiation processing was the epoxy phenolic the preferred end-sealing compound was the blend of cured and uncured isobutylene—isoprene copolymer. Component testing of tinplate and solder for possible changes in mechanical properties, microstructure, and corrosion resistance indicated that the radiation caused... 

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