What is a ceramic substrate?

Abstract: What is a ceramic substrate? Ceramic substrate refers to a special process board in which copper foil is directly bonded on the surface (single surface or double surface) of alumina (Al2O3) or aluminum nitride (AlN) ceramic substrate at high temperature. Where are ceramic substrates commonly used? Ceramic substrate What is a ceramic substrate? Application of ceramic substrate.

What is a ceramic substrate?

Ceramic substrate refers to a special process board in which copper foil is directly bonded on the surface (single surface or double surface) of alumina (Al2O3) or aluminum nitride (AlN) ceramic substrate at high temperature. The ultra-thin composite substrate has excellent electrical insulation, high thermal conductivity, excellent solderability and high adhesive strength, can etch various patterns like a PCB, and has great current carrying capacity. Therefore, ceramic substrate has become the basic material of high power electronic circuit structure technology and interconnection technology.

Characteristics of ceramic substrates

1, strong mechanical stress and stable shape; High strength, high thermal conductivity and high insulation; Strong adhesion and corrosion resistance.

2. Excellent thermal cycle performance, 50,000 cycles and high reliability.

3. Like PCB (or IMS substrate), structures with various patterns can be etched; No pollution, no pollution.

4. The working temperature range is from -55℃ to 850℃; The thermal expansion coefficient is close to that of silicon, which simplifies the production process of power module.

Advantages of ceramic substrate

1, the thermal expansion coefficient of ceramic substrate is close to that of silicon wafer, which can save the transition layer Mo, save labor and materials and reduce the cost;

2, reducing the number of welding layers, reducing thermal resistance, reducing cavities and improving the yield;

3. Under the same current carrying capacity, the line width of 0.3mm thick copper foil is only10% of that of ordinary printed circuit board;

4. Excellent thermal conductivity makes the package of the chip very compact, thus greatly improving the power density and improving the reliability of the system and devices;

1, ultra-thin (0.25mm) ceramic substrate can replace BeO, and there is no environmental toxicity problem;

2. The current carrying capacity is large, and the current of 100A continuously passes through the copper body with the width of 1mm and the thickness of 0.3mm, and the temperature rise is about17℃; The current of 100A continuously passes through a copper body with a width of 2mm and a thickness of 0.3mm, and the temperature rise is only about 5℃;

3. Low thermal resistance: 10× 10mm ceramic substrate, 0.3 1K/W for 0.63mm ceramic substrate, 0.65432+0/9k/w for 0.38mm ceramic substrate and 0.25mm ceramic substrate.

4. High insulation and high voltage resistance, ensuring personal safety and protective ability of equipment.

5. New packaging and assembly methods can be realized, so that the product is highly integrated and the volume is reduced.

Application of ceramic substrate

1, high power semiconductor module; Semiconductor refrigerator, electronic heater; Power control circuit, power hybrid circuit.

2. Intelligent power components; High frequency switching power supply, solid state relay.

3. Automotive electronics, aerospace and military electronic components.

4. Solar panel assembly; Telecommunication special switching and receiving system; Laser and other industrial electronic products.

Performance requirements of ceramic substrates

1, mechanical properties

The ceramic substrate has high enough mechanical strength, and can be used as a support besides bearing elements. Good machinability and high dimensional accuracy; Easy to achieve multi-layer; Smooth surface, no warping, bending, microcracks, etc.

2. Electrical characteristics

High insulation resistance and insulation breakdown voltage; Low dielectric constant; Low dielectric loss; Stable performance under high temperature and high humidity conditions, ensuring reliability.

3. Thermal properties

High thermal conductivity; The thermal expansion coefficient should match the relevant materials (especially the thermal expansion coefficient of Si); Excellent heat resistance.

4. Other attributes

Good chemical stability; Easy metallization and strong adhesion between circuit patterns and them; No hygroscopicity; Oil resistance and chemical resistance; A-ray emission is very small; The materials used are pollution-free and non-toxic; The crystal structure does not change in the use temperature range; Rich in raw materials; Mature technology; Easy to manufacture; Low price.