Double-sided aluminum substrate, is the through hole and inner aluminum layer insulated?

Double-sided aluminum substrate is a special printed circuit board, whose surface is covered with a thicker aluminum base material instead of the common fiberglass material. Since double-sided aluminum substrate is often used in high-power applications such as LED lighting, power modules, etc., the insulation problem between the through hole and the inner aluminum layer has become a key factor that needs to be paid attention to.

In double-sided aluminum substrates, circuit paths on different layers are connected by through holes. These through holes are usually metallized, such as copper or nickel-plated metal. Meanwhile, the inner aluminum is the aluminum layer located inside the board, which is used for heat dissipation and electrical connection. Therefore, it is very important to ensure the insulation between the through holes and the inner aluminum to avoid short circuits or other unexpected situations.

To achieve insulation between the through hole and the inner aluminum layer, the following methods can be used:

1、Use an insulating layer: When designing a double-sided aluminum substrate, an insulating layer can be applied around the through-holes and the contact area of the inner aluminum. This helps increase the insulation distance between the through-holes and the inner aluminum to prevent current leakage. Common insulating materials include polymer films and resins.

2、Control via size: The diameter of the via will also affect the insulation performance between the via and the inner aluminum layer. A smaller diameter via will reduce the contact area between the via and the inner aluminum layer, thereby reducing potential insulation problems. Therefore, the appropriate via size should be selected according to specific requirements during the design process.

3、Consider insulating pad design: The pad is the metal part connected to the through hole and is responsible for transferring current between different layers. In order to avoid short circuit between the through hole and the inner layer aluminum, you can consider adding an insulating layer on the pad to isolate the direct contact with the inner layer aluminum.

4、Strictly comply with manufacturing specifications: During the manufacturing process, strict compliance with relevant manufacturing specifications and standards is an important part of ensuring the insulation performance of double-sided aluminum substrates. This includes requirements for gold plating of through holes and inner aluminum layers, coating thickness of the insulation layer, etc.

5、It is important to note that although a series of measures have been taken to enhance the insulation performance between the through-hole and the inner aluminum layer, caution must still be exercised. Rigorous testing and verification are recommended during the design and manufacturing process to ensure full compliance with the required electrical and mechanical specifications.

6、In summary, in double-sided aluminum substrates, the insulation problem between the through-hole and the inner aluminum layer is crucial. The insulation problem between the through-hole and the inner aluminum layer can be effectively solved by using an insulating layer, controlling the through-hole size, considering the pad design for insulation, and strictly adhering to manufacturing specifications. However, in order to ensure the quality of design and manufacturing, sufficient testing and verification should also be carried out. Only after considering all these factors can it be ensured that the double-sided aluminum substrate has good insulation performance and reliability.