The strength of plastic encapsulants is analyzed from the viewpoint of crack propagation. Fatigue crack propagation rates da/dN of the encapsulants were measured with laboratory test specimens, and it was found that the da/dN of encapsulants can be expressed as functions of the stress intensity factor range DELTA K. The crack propagation behavior in the package was estimated from the values of da/dN and DELTA K at the lowest temperature of the test cycles. Reasonable correlation is found between the estimated crack propagation behavior and the observed one, and the applicability of fracture mechanics to the package cracking problem is demonstrated.
|Number of pages
|Proceedings - Electronic Components and Technology Conference
|Published - 1987