User Guide
30 of 46
Rev. 1.0
2022-03-09
48V Battery Switch Reference Design
R 48V BATT Switch10
System design
3.1.2
Power board layout
The power board PCB is manufactured in the QIT technology from Schweizer Electronics AG. It is a three-layer
board with an 800 µm inner copper core and two outer layers with 70 µm each.
In contrast to standard IMS (insulated metal substrate) boards the thick copper core can be structured and
used to route high current PCB traces.
For a high current connection between the top layer and the copper core densly stitched microvias are used.
Since these microvias are copper filled by design, SMD components can be soldered right on top of them,
providing an excellent electrical and thermal connection to the thick copper layer in the middle.
Figure 31
Power board PCB Layer Stack
Between the mid layer and the bottom layer a thermal prepreg with a conductivity of 1,8 W/mK provides
electric isolation while still maintaining a good thermal performance. Therefore, there is no need for electrical
isolation between the PCB and the heatsink, which allows the use of electrically conductive thermal interface
materials.
Figure 32
Power board top layer
