Abstract: A method and apparatus for nondestructive inspection of packaged integrated circuits and defect detection in the integrated circuits. In a scanning acoustic microscopy system, a packaged integrated circuit under test 31 is placed in a tank containing an acoustic transmission medium such as de-ionized water. An acoustic reflector 29 is placed beneath the integrated circuit 31. A pulse-echo mode transducer 17 is used to scan the area containing the integrated circuit 31 with ultrasonic energy. The reflective signal energy is captured by the transducer 17 and the signals are digitized and stored. A computer system analyzes the reflective signal amplitude, and presents a visual image based on where the reflective signal was strong and where it was weak. In a preferred embodiment the image is presented so that the signal from the reflective plate is shown as a dark region where the reflection was weak or zero.

Abstract: The invention is to an array of stacked devices utilizing vertical surface mounted semiconductor devices stacked side by side and inserting the stack of devices into a casing. The packaged stack of devices creates a cube package which is capable of replacing SIMM boards, and saves considerable space. The casing dissipates heat generated in the devices, and may be of metal or thermally conductive plastic.