Properties silver-glass adhesives

By virtue of their high silver content, silver-glass adhesives have high electrical conductivities, typically 1.3 x 10 ohm-cm. Other typical properties are flexural modulus of 350 kpsi, die shear adhesion of 900 psi, and CTE of 20 ppm/°C. ... 

Engineering rework is possible with eutectic and solder materials, but impossible with silver—glass. This constraint severely limits the usefulness of the material. Tables 4 and 5 give the electrical, mechanical, and thermal properties for various adhesives. 

Adhesives play a critical role in the concepts developed for parabolic trough reflector modules. The need to develop adhesives that are compatible with silvered glass mirrors, that serve as structural members and can maintain these properties over 20 years has lead to a program to define appropriate candidates. 

Adhesives (128) play an important role in the construction of a solar parabolic trough reflector. The adhesives should be compatible with silvered glass mirrors and should be able to carry structural loads. Moreover the adhesives should be durable for at least twenty years without losing their properties. Adhesives screened for solar collectors were epoxies, urethanes, and acrylics. Three types of stress conditions were identified as the most likely causes of failure in the trough modules ... 

Epoxy adhesives are also easy to modify for special purposes. For example, they can be filled with carbon, silver, or gold to provide electrical conductivity. Other additives can enhance thermal conductivity, while maintaining electrical insulation. Additional performance properties of epoxy-based adhesives that can be modified include impact resistance, shrinkage, glass transition temperature, high-temperature strength, surface specific adhesion characteristics, and chemical or moisture resistance. 

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