Thermal Design of an MCM with the Implanted Temperature Sensor

Abstract

Since the debut of Multi-chip Modules (MCM), many research and development works have brought the technology from the physical design, test to mass production, but still lacking thermal data to support the schematic designs; especially in the area of thermal design related junction temperature. This method proposes a new approach to implant the temperature sensor into the MCM thus to sense the substrate and to probe the junction temperature. Further, to explore the possibility of using the IEEE1149.7 based cJTAG of the function test in conjunction of the IEEE1149.1 based boundary scan test coherently. This method is to activate a pair of I2C bus as per SCL/SDA lines and to drive and sense the master chip in response of its slave chip. The test platform used in this proposal is to apply the JTAG Technologies based Provision and Core-commander test systems, both of which working together to trouble-shooting and debugging. This is accomplished through manipulating the core logic of the customized IP code amid the Python functions in order to retract the temperature reading from the sensor via the I2C bus. Both JTAG and cJTAG use the common netlist and BSDL files (Boundary Scan Descriptive Language) to generate the test files and firmware coding through the JTAG’s Test Access Port (TAP). The formula implemented here has its theoretic roots in a function of the resistance networks which equal to the temperature difference over the the heat flow. This development work uses the high-level GUI language from the core-commander to instruct the Python based functional calls invoking the device drivers, and that has greatly simplified the complex electronic designs with reduced programming, and this exercise has obtained the junction temperature presumably at 71 degrees C on the threshold of temperature gradients, and it’s one step closer towards the case temperature from the thermal management point of view.