September: Power Combi Board

What does SCHWEIZER understand by Power Combi Board?

SCHWEIZER understands the Power Combi Board to mean a combination of a power part with copper layer thicknesses up to 400 µm on inner layers and a logic part with usually 35 µm on inner layers, while the number of layers in the logic part is usually higher. Thus, the logic part can be manufactured as a 6-layer board, while the power part has only 4 layers. The electrical connection between the two parts is provided via the mutual outer layers.

How is the Power Combi Board manufactured?

In the power part, the heavy copper technology is applied to manufacture the pre-structured inlay part. This heavy copper inlay is placed into an FR4 frame featuring matching cavities. The layup is completed by commonly used prepregs and copper foils on the upper and lower side. In the subsequent lamination process, the logic and power parts are combined to the Power Combi Board.

What technical advantages does a Power Combi Board offer for the application?

Designers of power applications frequently face the challenge of placing increasing functionality and performance within an ever decreasing volume. As a result conventional strategies, such as separation into a power and a logic board or use of a logic board in combination with lead frames or DCBs are hardly expedient. The Power Combi Boards enable the integration of complete functional groups, minimisation of the required volume and improvement of the system reliability by a considerable reduction of screwed, clamped and soldered connection points.

Does a Power Combi Board have commercial advantages?

Apart from the technical advantages, a Power Combi Board can also help to lower cost. Essential is the size of the power part compared to that one of the logic part. Generally speaking, the commercial advantage is significant when the area percentage of the logic part exceeds that of the power part.

Which applications are ideal for the use of the Power Combi Board?

Suitable applications are the ones requiring compact ECUs which are operated in the power part at continuous currents of more than 80 A and simultaneously require a complex logic. Among those applications are e.g. motor control ECUs and voltage converters.

What are the concrete advantages that a Power Combi Board has in comparison with a conventional heavy copper PCB with 400 µm copper thickness in the inner layers?

The conventional heavy copper PCB significantly limits the layout design of logic structures even if they are only present on the outer layers. This is due to the design rules for 400 µm copper layers which do not allow a net distance below 2.5 mm. In the Power Combi Board, the power and logic structures are located next to each other so that the logic part is not subject to such restrictions. Altogether, this makes it possible to reduce the logic part significantly and decrease the required total available space of the application.

Can the Power Combi Board technology also be combined with other technologies?

The demonstrator on the picture shows the combination of two SCHWEIZER technologies. The high current part for the three-phase fan motor control is located in the area of the Power Combi Board technology (image foreground). Use of the FR4 Flex technology allows to position the logic part of the PCB at a defined angle to the high current area. Thus, logic and power can be placed within the available space for a control unit in the most space-saving way.