POWER MODULE WITH OVERLAPPING TERMINALS
A single side direct cooling (SSDC) package is disclosed for use in high-power electronic device modules in electric vehicles and industrial applications. The power modules route large currents through a set of metal power tabs instead of passing high currents through conductive layers of a direct bonded metal structure. By orienting the metal power tabs in a mini-heart design, stray inductance and resistance can both be reduced, thereby improving performance while simultaneously reducing the footprint of the high power module. In addition, wire bonds between chip assemblies in a high-power semiconductor device module can be replaced by solid metal clips that can better withstand high currents and voltages. The SSDC package incorporates the metal power tabs and provides heat dissipation via a metal base plate that includes a heat sink. The heat sink can be immersed in a cooling fluid to provide faster heat dissipation.
1 . An apparatus, comprising:
a direct bonded metal substrate;
a first power tab electrically coupled to the direct bonded metal substrate;
a second power tab electrically coupled to the direct bonded metal substrate;
a distal end of the first power tab aligned with a first longitudinal axis; and
a distal end of the second power tab aligned with a second longitudinal axis non-parallel to the first longitudinal axis, the first power tab having a proximal end overlapping a proximal end of the second power tab, wherein the distal end of the first power tab does not overlap the distal end of the second power tab.
2 . The apparatus of claim 1 , further comprising a heat transfer mechanism coupled to the direct bonded metal substrate.
3 . The apparatus of claim 1 , further comprising at least two semiconductor dies electrically coupled via a wire bond or a clip.
4 . The apparatus of claim 1 , further comprising an output tab electrically coupled to the direct bonded metal substrate.
5 . The apparatus of claim 4 wherein, in operation, current flows from the first power tab to the output tab and from the output tab to the second power tab without flowing through the direct bonded metal substrate.
6 . The apparatus of claim 1 , further comprising heat dissipating pins that are oriented perpendicular to a plane of the direct bonded metal substrate and a plane of the first power tab and the second power tab.
7 . The apparatus of claim 1 , wherein a thickness of the first power tab and the second power tab is about three times greater than a thickness of a current path within a conductive layer of the direct bonded metal substrate.
8 . The apparatus of claim 1 , further comprising a first opening in the distal end of the first power tab and a second opening in the distal end of the second power tab.
9 . The apparatus of claim 1 , wherein a perimeter of the first power tab and the second power tab forms a heart shape.
10 . An apparatus, comprising:
a direct bonded metal substrate;
a metal base plate attached to a bottom layer of the direct bonded metal substrate;
an array of heat dissipating pins attached to the metal base plate;
a first metal tab and a second metal tab coupled to the direct bonded metal substrate, the first metal tab oriented in a transverse direction with respect to the second metal tab; and
a plastic case surrounding a top layer of the direct bonded metal substrate.
11 . The apparatus of claim 10 , wherein the plastic case is attached to the metal base plate without screws.
12 . The apparatus of claim 10 , further comprising power tabs extending over the direct bonded metal substrate.
13 . The apparatus of claim 10 , wherein the first metal tab includes a negative terminal, and the second metal tab includes a positive terminal, and further comprising a third metal tab including an output terminal opposite the first metal tab and the second metal tab.
14 . The apparatus of claim 13 , wherein the apparatus is configured for current to flow from the positive terminal to the output terminal and back to the negative terminal via a central region of the direct bonded metal substrate.
15 . The apparatus of claim 10 , wherein the first metal tab is oriented at a right angle with respect to the second metal tab.
16 . A method, comprising:
overlapping proximal ends of a first power tab and a second power tab
coupling clips of the first power tab to a central region of a substrate;
coupling clips of the second power tab to an edge region of the substrate; and
coupling clips of a third power tab to the central region of the substrate.
17 . The method of claim 16 , wherein the first power tab, the second power tab, and the third power tab are configured as integral elements of a plastic case.
18 . The method of claim 17 , wherein coupling the clips of the first power tab and the clips of the third power tab to a central region of the substrate comprises overlaying the clips above circuitry on the substrate by positioning the plastic case relative to the substrate.
19 . The method of claim 16 , wherein the overlapping includes aligning a first hole in the first power tab with a second hole in the second power tab to produce aligned first and second holes.
20 . The method of claim 19 , further comprising attaching a heat dissipating pin to the substrate, wherein the heat dissipating pin extends through the aligned first and second holes.