Ceramic substrate – a complete guide

Ceramic substrates can be divided into alumina ceramic substrates, aluminum nitride ceramic substrates, silicon nitride ceramic substrates, silicon carbide ceramic substrates, etc. according to different ceramic substrate materials. According to different processes, they can be divided into DPC ceramic substrates, DBC ceramic substrates, AMB ceramic substrates, HTCC ceramic substrates, LTCC ceramic substrates, etc.; according to the number of layers, they can be divided into single-sided, double-sided ceramic substrates, and multi-layer ceramic substrates.

The more common types of ceramic heat dissipation substrates at this stage include HTCC, LTCC, DBC, DPC, AMB, etc.

HTCC (High Temperature Co-fired Ceramic):

It is an earlier-developed technology. It is a multi-layer ceramic substrate obtained by co-firing ceramics with metal patterns such as W and Mo with high melting points. However, the high sintering temperature limits the choice of electrode materials and the production cost is relatively high, which has prompted the development of LTCC.

LTCC (Low Temperature Co-fired Ceramic): LTCC technology reduces the co-firing temperature to about 850°C. By stacking and co-firing multiple ceramic diaphragms printed with metal patterns, circuits can be routed in three-dimensional space.

LTCC has outstanding advantages in the field of passive integration and is widely used in 3C, communications, automotive, military and other markets. It can realize the packaging of three major passive devices (resistors, capacitors, inductors) and various passive devices (such as filters, transformers, etc.) in multi-layer wiring substrates, and integrate them with active devices (such as power MOS, transistors, IC modules, etc.) are integrated into a complete circuit system (such as SiP). It is now widely used in various types of mobile phones, Bluetooth, GPS modules, WLAN modules, WIFI modules, etc.; in addition, due to the high reliability of its products, it has been widely used in automotive electronics, communications, aerospace and military, micro-electromechanical systems, and sensor technology. Applications in other fields are also increasing.

DPC (Direct Plating Copper): It is a ceramic circuit processing technology developed on the basis of ceramic thin film processing. Ceramics are used as the circuit substrate, a metal layer is compounded on the surface of the substrate using a sputtering process, and the circuit is formed using electroplating and photolithography processes.

DBC (Direct Bonded Copper):

A composite substrate is made by directly sintering copper foil to the surface of Al2O3 and AlN ceramics at high temperatures through a hot-melt bonding method.

AMB (Active Metal Brazing): AMB is developed on the basis of DBC technology. At a high temperature of about 800°C, AgCu solder containing active elements Ti and Zr wets the interface between ceramic and metal and reacts to achieve heterogeneous bonding of ceramics and metals.