DCB (Direct Copper Bonded) Ceramic PCB
DCB (Direct Copper Bonded) sometimes also named as DBC (Direct Bonded Copper) technology denotes a special process in which the copper foil and the Al2O3 or AIN (one or both sides) are directly bonded under appropriate high temperature.
The super-thin DCB substrate has excellent electrical isolation, high thermal conductivity, fine solderability and high bonding strength. It can be etched like normal FR4 PCB, but has a high current loading capability. Therefore DCB ceramic PCB has become the base materials of construction and interconnection technology of high power semiconductor telectronic circuits and also have been the basis for the "Chip On Board" (COB) technology which represent the packaging trend in the future.
|Characteristic of DCB Ceramic PCB|
High mechanical strength, mechanically stable shapes. Hight strength, fine thermal conductivity, excellent electrical isolation. Good adhesion, corrosion resistant;
Excellent thermal cycling capabilities (up to 50,000 cycles), high reliability;
Can be etched to various layout like normal FR4 PCB;
No contamination, free of environmental problem;
Wide application temperature: -55C~850C. The thermal expansion coefficient is closed to that of silicon, simplify the production technology of power module.
|Compared to thin or thick film ceramic board, DCB has much thicker conductor (copper ) which thickness will be 0.1mm~0.3mm. Here are more advantage to use DCB Ceramic printed circuit board.|
|Advantage of DCB Ceramic PCB|
The thermal expansion coefficient of DBC substrate is close to that of silicon chip, so chip can be directely soldered on DCB board, to save the interface layer (Mo plate), save labour and reduce the cost;
Reduce the solder layer, low down thermal resistance, reduce cavities, and increase the yield of finished products;At the same loading current density, for 0.3mm thickness copper conductor, trace width only to be 10% of the normal PCB;
Excellent thermal conductivity provides the posiblity of small packaging of the chips, result in increasing of power per unit of volume, improving reliablity of systems and equipment;
The super-thin (0.25mm) DCB substrate can be substituted for BeO, eliminating the problem of environmental protection and toxicity; but seldom be used, as it is extreme expensive!
Large current loading capability, lower temperature increase. For a 100A current continuously pass through the 0.3mm thickness copper conductor, on 1mm trace width, the temperature only rise 17C, on 2mm trace width, temperature only rise 5C;
Lower thermal resistance. Here are details for 10mm x 10mm DCB substrate:
0.38mm thickness: 0.19K/W
0.63mm thickness: 0.31K/W
The high insulation voltage results in improved personnel safety and increased equipment protect capability;
The new packaging and assembly methods can be realized with DCB PCB, and it makes the product a higher degree of integration and volume reduction.