Identifying Plastic Encapsulant Materials by Pyrolysis Infrared Spectrophotometry

Most semiconductor devices are sealed in plastic. Virtually all plastic encapsulated microcircuits (PEMs) look alike. The particular electronic molding compound (EMC) used to encapsulate a device cannot be known except from production records or firsthand knowledge of people familiar with the device. For a variety of reasons, an EMC may need to be explicitly identified. Pyrolysis of the EMC, followed by Fourier Transform Infrared (FT-IR) chemical analysis of the condensates of organic substances evolved by the pyrolysis, and comparison of the spectra with a reference library of known EMCs, provides a rapid means of specific EMC identification.