G04600 - SEMI G46 - Test Method for Thermal Transient Testing for Die Attachment Evaluation of Integrated Circuits

Evaluation of semiconductor die attachment integrity using the thermal transient techniques as implemented by the Electrical Test Method on either thermal test chips or active devices. Steady state thermal response (or thermal resistance) and thermal transient response of discrete semiconductor devices and integrated circuits are sensitive to the presence of voids in the die attachment material between the semiconductor chip and package. These voids impede the flow of heat from the chip to the substrate (package). Due to the difference in the thermal time constants of the chip and package, the measurement of transient thermal response can be made more sensitive to the presence of voids than can the measurement of steady state thermal response. This is because the chip thermal time constant is generally several orders of magnitude shorter than that of the package. Thus, the heating power pulse width can be selected so that only the chip and the chip to substrate interface are heated during the pulse by using a pulse width somewhat greater than the chip thermal time constant, but less than that of the substrate. Heating power pulse widths ranging from 10 to 400 milliseconds have been found to satisfy this criterion. This enables the detection of voids to be greatly enhanced, with the added advantage of not having to heat sink the device under test. Thus, the transient thermal response technique is less time consuming than the measurement of thermal resistance for use as a manufacturing screen, process control or incoming inspection measure for die attachment integrity evaluation.　Referenced SEMI StandardsNone.