scope:

1. Scope

1.1 This method covers nondestructive procedures for determining the radial and tangential stresses in plastic-embedded simulated components caused by shrinkage of the molding or casting embedment material. These procedures can be used to evaluate the stress behavior of simulated electronic components under various controlled conditions. Effects of creep behavior, elevated-temperature aging, elevated-humidity aging, plastic compositions, molding or casting conditions, and conformal underlayers on the stresses may be evaluated by these techniques.

NOTE 1--It should be emphasized that when the composite cylinder contains a conformal underlayer the cylindrical specimen is not an exact model of an encapsulated electronic component with a conformal layer. This is due to the fact that the underlayer material is not constrained in the test specimen and is constrained in the encapsulated electronic component. Therefore, only qualitative conclusions may be drawn when this test method is used to evaluate conformal underlayer materials.

1.2 This method is to be used as a referee method for plastic material inspection by examining the embedment stress properties of plastic materials. The method is also useful as a research tool to study the stress behavior of plastic embedment materials due to changes in processing parameters and controlled environmental ambients.

NOTE 2--The values stated in inch-pound units are to be regarded as the standard. The metric equivalents of inch-pound units given in the standard may be approximate.