Chip-scale packaging of power devices and its application in integrated power electronics modules

A power electronics packaging technology utilizing chip-scale packaged (CSP) power devices to build three-dimensional (3-D) integrated power electronics modules (IPEMs) is presented in this paper. The chip-scale packaging structure, termed die dimensional ball grid array (D²BGA), eliminates wire bonds by using stacked solder joints to interconnect power chips. D²BGA package consists of a power chip, inner solder caps, high-lead solder balls, and molding resin. It has the same lateral dimensions as the starting power chip, which makes high-density packaging and module miniaturization possible. This package enables the power chip to combine excellent thermal transfer, high current handling capability, improved electrical characteristics, and ultralow profile packaging. Electrical tests show that the V_CE(sat) and on-resistance of the D²BGA high speed insulated-gate-bipolar transistors (IGBTs) are improved by 20% and 30% respectively by eliminating the device wirebonds and other external interconnections, such as the leadframe. In this paper, we present the design, reliability, and processing issues of D²BGA package, and the implementation of these chip-scale packaged power devices in building 30 kW half-bridge power converter modules. The electrical and reliability test results of the packaged devices and the power modules are reported