Engineers from ON Semiconductor, Japan, reported at the ASM International ISTFA 2019 conference in Portland, Oregon, that that two of the most challenging tasks in analyzing fractures are a die that has not been fully cracked apart and a cracked die with electrical overstress damage.
Traditional tools such as a simple magnifying lens or an optical microscope, and even up to the scanning electron microscope, are not enough to study the internal fractures or markings that could lead back to the origin of the crack. In order to study these internal fractures, the analyst tends to break the sample into pieces. However, this method creates additional mechanical stress and leads to a secondary crack where the point of origin will be difficult to analyze.
This paper introduced infrared microscopy in fractography (mainly on silicon) using case studies and various techniques to minimize the occurrence of secondary cracks when analyzing internal fractures.
Internal fractures, due to either electrical damage or mechanical stress, would be difficult to analyze by means of the usual fractography methods without inducing additional stress on the sample. The infrared microscopy techniques described in the presentation can reduce the additional stress as well the generation of a secondary crack where the point of origin would be difficult to analyze.
A Novel Approach on Fractography through Infrared Microscopy
Allan Norico and Rommel Estores, ON Semiconductor, Belgium BVBA
www.onsemi.com
