The ceramic substrate has the following advantages.
1. Good insulation performance and high reliability.
2. The dielectric coefficient is small and the high frequency characteristic is good.
3. Small thermal expansion coefficient and low thermal mismatch rate.
4. High thermal conductivity.
Difficulties in processing traditional ceramic substrates.
The traditional processing methods of ceramic substrate are mainly divided into two categories, namely, molding and machining (turning, milling, drilling, grinding, etc.).
1. Moulding method: the ceramic powder and plasticizer are mixed and poured into the abrasive tool, and the pressure is applied in a line. Only simple ceramic substrates can be made, and the production efficiency is not high, and the production cycle is long. This method was basically eliminated when making ceramic substrate, and now it is mainly used to make embryo of ceramic substrate.
2. Mechanical processing: because ceramic materials have the characteristics of high hardness, high brittleness and easy fragmentation, traditional processing is very difficult. However, traditional machining can still basically meet the production of ceramic substrates, but the processing efficiency is low, the yield is not high, and the processing loss is large.
Advantages and Choices of Laser Processing
1. Laser processing belongs to non-contact processing, with high cutting accuracy and controllable scribing depth.
2. The processing drawing can be edited at will, and the CAD drawing can be imported. There is no need to open the mold, and the production cycle is short.
3. High processing quality, no burr, no edge collapse.
4. Fast processing speed and low processing cost.
5. Precise machining can be realized, small holes with a diameter of 0.15 mm can be machined, and there is less processing waste.
CO2 laser and QCW pulse laser are mainly used for laser processing.
CO2 laser: alumina ceramic chip has a high absorption rate to the laser emitted by CO2 laser, but due to its large light spot, it is unable to cut small patterns, the width of scribing is wide, and the processing efficiency is lower than that of QCW pulse laser, so it is not recommended to use now.
QCW pulse laser: The QCW pulse laser is a fiber laser with a wavelength of 1070nm. The absorption rate of alumina ceramics for beams with a wavelength of about 1070nm is about 25%. However, due to its high beam quality, the light spot is smaller than that of CO2 lasers. Therefore, compared with CO2 laser, its cutting speed is fast, it can cut tiny patterns, and its efficiency is higher than CO2 laser.
