Circuit assembly including gallium nitride devices
A circuit assembly includes a first printed circuit board (PCB), a switching device located on a first side of the first PCB, a heatsink attached to a second side surface of the first PCB opposite to the first side, and an L-shaped metal plate attached to the heatsink and to the first PCB.
1 . A circuit assembly comprising:
a first printed circuit board (PCB);
a switching device located on a first side of the first PCB;
a first thermal interface material (TIM) in contact with the switching device;
a heatsink attached to a second side surface of the first PCB opposite to the first side; and
an L-shaped metal plate including a first portion attached to the heatsink and a second portion directly attached to the first PCB through the first TIM to define a thermal path between the first and the second sides of the first PCB.
2 . The circuit assembly according to claim 1 , wherein the L-shaped metal plate contacts a top surface of the switching device through the first TIM.
3 . The circuit assembly according to claim 1 , further including a second TIM between the heatsink and the first PCB.
4 . The circuit assembly according to claim 1 , wherein the L-shaped metal plate includes copper.
5 . The circuit assembly according to claim 1 , wherein the first and the second portions of the L-shaped metal plate define a bend with an angle less than 90°.
6 . The circuit assembly according to claim 1 , wherein the first PCB is 1-mm thick.
7 . The circuit assembly according to claim 1 , wherein the first PCB includes a middle metal plane as an interior layer.
8 . The circuit assembly according to claim 7 , wherein
the middle metal plane includes multiple portions, and
each of the multiple portions is connected to a different circuit node on the first PCB.
9 . The circuit assembly according to claim 7 , wherein the middle metal plane of the first PCB is connected to the switching device through microvias in the first PCB.
10 . The circuit assembly according to claim 1 , wherein the first PCB includes copper-filled microvias located beneath the switching device.
11 . The circuit assembly according to claim 10 , wherein
the first PCB includes a copper inlay; and
the copper-filled vias provide a thermal path between the switching device and the copper inlay.
12 . The circuit assembly according to claim 1 , further comprising:
a second PCB; and
driver circuitry on the second PCB that drives the switching device.
13 . The circuit assembly according to claim 12 , wherein the second portion of the L-shaped plate is located between the first PCB and the second PCB.
14 . A circuit assembly comprising:
a first printed circuit board (PCB);
a switching device located on the first PCB;
a thermal interface material (TIM) in contact with the switching device;
a heatsink attached to the first PCB;
an L-shaped metal plate including a first portion attached to the heatsink and a second portion directly attached to the first PCB through the TIM to define a thermal path between first and second sides of the first PCB; and
a second PCB including gate driver circuitry attached to the first PCB.
15 . The circuit assembly according to claim 14 , further comprising a connector to route signals between the first PCB and the second PCB.
16 . The circuit assembly according to claim 14 , wherein the second portion of the L-shaped metal plate is located between the first PCB and the second PCB.
17 . The circuit assembly according to claim 14 , further comprising a transformer integrated into the second PCB.
18 . The circuit assembly according to claim 14 , wherein the gate driver circuitry is isolated.
19 . The circuit assembly according to claim 14 , wherein the switching device is a gallium nitride switching device.
20 . A circuit assembly comprising:
a first printed circuit board (PCB);
a switching device located on the first PCB;
a thermal interface material (TIM) in contact with the switching device;
a heatsink attached to the first PCB;
a second PCB including gate driver circuitry attached to the first PCB; and
an L-shaped metal plate including:
a first leg located between the first PCB and the second PCB, directly attached to the first PCB through the TIM, and directly attached to the second PCB; and
a second leg attached to the heatsink.