Method for assembling semiconductor switching elements and heat sink in rotary electric machine and rotary electric machine
View Patent ↗A method for assembling semiconductor switching elements and a heat sink in a rotary electric machine includes: a first step in which bare chips of the semiconductor switching elements are bonded to the heat sink using a good heat conductive bonding material; a second step which connects the bare chips to a wiring part by wire bonding; and a third step in which a resin which seals the bare chips and the wiring part is applied to the heat sink in a striding manner in a state that output terminal portions of the wiring part and fins of the heat sink are exposed to the outside of the resin.
1. A method for assembling semiconductor switching elements and a heat sink in a rotary electric machine, for an automobile, which has a plurality of phases and which includes a rotary electric machine part having a rotary shaft, an inverter which has an upper arm and a lower arm for each phase and which performs an electricity supply control of the rotary electric machine part, and a heat sink which is provided for each arm and each of which cools a plurality of respective semiconductor switching elements constituting the arm, each of the upper arm and the lower arm for each phase having the plurality of semiconductor switching elements, the plurality of semiconductor switching elements and the heat sink being mounted on the rotary electric machine part and surrounding the rotary shaft in the circumferential direction of the rotary shaft, wherein
the method includes:
a first step in which a plurality of bare chips of the plurality of semiconductor switching elements are arranged in parallel in a spaced apart manner and are directly bonded to each heat sink using a good heat conductive bonding material, and wiring parts are arranged in a spaced apart manner and are directly bonded to each heat sink using a good heat conductive bonding material;
a second step which connects the bare chips to the wiring parts by wire bonding, the second step being the step after the first step; and
a third step in which a resin collectively molds and seals the bare chips, the wiring parts, and the heat sink in a state that output terminal portions of the wiring parts and fins of the heat sink are exposed to the outside of the resin, the third step being the step after the second step.
2. A rotary electric machine, for an automobile, having a plurality of phases, and comprising
a rotary electric machine part having a rotary shaft;
an inverter which has an upper arm and a lower arm for each phase and which performs an electricity supply control of the rotary electric machine part; and
a heat sink which is provided for each arm and each of which cools a plurality of respective semiconductor switching elements which constitute the arm, each of the upper arm and the lower arm for each phase having the plurality of semiconductor switching elements, the plurality of semiconductor switching elements and the heat sink being mounted on the rotary electric machine part and surrounding the rotary shaft in the circumferential direction of the rotary shaft, wherein
a plurality of bare chips of the plurality of semiconductor switching elements are directly bonded to each heat sink by a good heat conductive bonding material,
the plurality of bare chips are arranged in parallel in a spaced-apart manner on the respective heat sink,
a plurality of wiring parts connected to the plurality of bare chips are directly bonded to each heat sink by a good heat conductive bonding material, the plurality of wiring parts being arranged in a spaced apart manner; and
a resin mold which collectively molds and seals the bare chips, the wiring parts, and the heat sink in a state that output terminal portions of the wiring parts and fins of the heat sink are exposed to the outside of the resin mold.
3. A rotary electric machine for an automobile according to claim 2 , wherein an interval among the plurality of bare chips is set uniform.
4. A rotary electric machine for an automobile according to claim 3 , wherein the heat sink includes a plurality of fins and a distal-end-portion shape of the whole of the plurality of fins as viewed in the extending direction of the fins is formed in a curved shape.
5. A rotary electric machine for an automobile according to claim 4 , wherein the distal-end-portion shape of the whole of the plurality of fins is formed in a curved shape along an inner peripheral surface of a casing of the rotary electric machine part.
6. A rotary electric machine for an automobile according to claim 3 , wherein the plurality of bare chips are connected to the common wiring portion by wire bonding.
7. A rotary electric machine for an automobile according to claim 2 , wherein the heat sink includes a plurality of fins and a distal-end-portion shape of the whole of the plurality of fins as viewed in the extending direction of the fins is formed in a curved shape.
8. A rotary electric machine for an automobile according to claim 7 , wherein the distal-end-portion shape of the whole of the plurality of fins is formed in a curved shape along an inner peripheral surface of a casing of the rotary electric machine part.
9. A rotary electric machine for an automobile according to claim 2 , wherein the plurality of bare chips are connected to the common wiring portion by wire bonding.