Thermal deformation measurement of electronic package using advanced moiremethods

In this paper, laser moire interferometry method, electron beam moire metho d, atomic force microscope (AFM) scanning moire method, as well as scanning electronic microscope (SEM) scanning moire method are used to measure the thermal deformation of electronic packages. The measurement principle and t he adaptability of these methods are discussed and compared. 1200 lines/mm holographic gratings in ultra low expansion (ULE) mold plate were replicate d onto the cross section of the measured sections in a ball grid array (BGA ) electronic package and a quad flat package (QFP). These holographic grati ngs were fabricated on ULE mold plates and were replicated onto measured ar ea at 100 degreesC and 150 degreesC, respectively. The deformation measurem ent principle and experimental techniques using these moire methods are des cribed. As application, the deformation in the different solder joints in t he EGA electronic package and in the area near the die corner of the QFP el ectronic package was measured using these methods. Some useful results were obtained.