Abstract: A large non-hermetic packaging approach that produces a large multichip module or SuperMCM package. The present invention integrates a plurality of multichip module technologies including removable and/or standard high density multilayer interconnect (HDMI) decal substrates, and a reworkable chip on board coating, housed in a mechanically sound, thermally conductive non-hermetic multichip package. A metal substrate has an HDMI substrate and one or more edge printed wiring boards bonded thereto which are interconnected using wire bonds. The HDMI substrate has one or more electronic chips bonded thereto that are connected thereto using wire bonds or other attachment scheme. Components on the one or more edge printed wiring boards are connected to the using edge printed wiring boards wire bonds. The edge printed wiring boards have external attachment pads exposed at their outside edges. A removable cover is disposed over the package except for the external attachment pads at the edges of the package.

Abstract: A system for preheating electronic components on a printed wiring board or other interconnecting substrate prior to application of voltage to the components in extreme cold temperature environments. Copper traces are employed as embedded heater elements. A control circuit disables operation of an on-board DC/DC switching converter used to provide power to the electronic components until the board has reached a threshold temperature during a preheating period. Thereafter, the heater operation is synchronized with the operation of the switching converter, such that the temperature can be maintained, yet total power supply current to the board never exceeds a predetermined maximum level.