What is the difference between DPC ceramic and DBC ceramic board?

There are total 7 types of ceramic PCBs in the industry, AMB ceramic, HTCC ceramic, LTCC ceramic, Thick film ceramic, Thin film ceramic, DPC ceramic and DBC ceramic board. There is only one word difference between DPC and DBC, so what is the difference between the two? Let me explain for you.

What is DPC and DBC ceramic?

In the world of ceramic PCB, DPC means Direct Plated Ceramic, while the full name of DBC is Direct Bond Ceramic. From their full name, we can easily know the DPC ceramic circuit is made by plated process and DBC is made by bond process. But in other ways, these two have big differences in the manufacturing process.

Fabricating Process Difference

Though the conductor of DBC and DPC ceramic is copper, however, their combination mode is different, so as the manufacturing process is different.

• DBC Ceramic PCB:

DBC ceramic circuit is by adding the addition of oxygen between copper and ceramic in the temperature of 1065~1083^oC to obtain Cu-O eutectic liquid. And then reaction to get the intermediate phase (CuAIO2 or CuAI2O4), so as to achieve the chemical metallurgical combination/bond of Cu and ceramic substrate. Through lithography technology to generate circuits on ceramic substrate.

Actually, the DBC can be divided into 3 layers, and the intermediate insulation material is Al2O3 or AlN. Al2O3 usually has a thermal conductivity of 24W/ (m-k) and AlN has a thermal conductivity of 170W/ (m-k). The thermal expansion coefficient (CTE) of Al2O3 or AlN is similar to that of the LED epitaxial material, which can significantly reduce the thermal stress generated between the chip and the substrate. That’s why DBC ceramic board is a go-to-choice for high power applications.

• DPC Ceramic PCB:

Direct copper-plated ceramic is to make the ceramic substrate to be pre-cleaned, using semiconductor technology sputtering copper seed layer on the ceramic substrate. And then through exposure, development, etching, film removal and other photolithography process to achieve the circuit pattern. Finally, proceed electroplating or electroless plating to increase the copper thickness, after removing the photoresist to complete the metallization production.

Conductor thickness difference

Due to the different manufacturing methods, the conductor thickness of these two ceramic PCBs also is different. For DBC circuit board, the copper thickness can be made from 100um to 300um, up to 600um, while by DPC technology, the copper thickness only can be made from 10um to tens of microns. Just because of this, the flatness of DPC surface is better than DBC, and it can be made fine circuitry (15um line width, surface flatness less than 500um and line alignment accuracy tolerance under 10%). In addition, DPC can etch more precision patterns on the ceramic substrate than DBC technical.

Capability difference

As we all know, both DPC and DBC technology were developed and mature in recent years, and popular in high-end applications. But from technical capacity aspect, DBC is slightly limited than DPC. Why? Below are some reasons.

Firstly, the fabricating process of DBC uses the eutectic reaction between Cu and Al2O3 at high temperature (1065^oC), which requires high equipment and process control. Compared to DPC technical, DBC increases the manufacturing cost. For DPC ceramic PCB, it is made at a lower temperature, around 300^oC, while enable to completely avoid the adverse impact of high temperature on the material or circuitry structure, but also reduce the cost of manufacturing process.

Secondly, DBC ceramic PCB is limited by its copper bonding process. Due to the copper of DBC is directly bonded on its surface, the plated through hole (PTH) can’t be made by this technology. Because holes on ceramic substrate always drilled before copper combination, but for DBC, if drill holes before, then the holes still will be covered by copper in combination. However, PTH is available in DPC technology because its copper is by electroplating. So, if you want to design PTH on your ceramic circuit board, DPC technology is your best choice.

Thirdly, the different copper thickness leads to the different fields that they can be used for. Because the copper foil has good electrical and thermal conductivity, and alumina can effectively control the expansion of the Cu-Al2O3-Cu, so that the DBC substrate has a similar thermal expansion coefficient of alumina, therefore, DBC has good thermal conductivity, strong insulation, high reliability, and has been widely used in IGBT, LD and CPV packaging. Especially because the copper foil is thicker (100~600um), it has obvious advantages in the field of IGBT and LD packaging.

In another way, DPC ceramic board using thin film and lithographic development technology, making the circuitry fine and precision than DBC substrate, so the DPC substrate is very suitable for electronic device packaging with high alignment accuracy requirements.

Above are the main differences between DBC and DPC ceramic circuit, hope this article can help you to choose right ceramic board for your project. If you have any questions about them, welcome to contact us at your convenience or leave your message below.