This test is used for identifying unknown chemical compounds in a material by comparing them to a reference library of known chemical compounds. For example, it can be used for determining the material used to over-mold a BGA or a stain on a PWB. Materials have unique properties that can be identified through the absorption and transmission of infrared radiation, as it is passed through the sample. Absorption peaks that are revealed are unique to the material tested. By comparing the peaks to reference materials and gathered data, we are able to find the solution to the failure.
(Fig. 1) Comparison of “Control” Lexan polycarbonate to library reference spectrum of Lexan FL-900 polycarbonate.
(Fig. 2) Comparison of “Control” Lexan polycarbonate to “Sample” of questionable composition.