What are the common sizes for ceramic substrates? How should they be selected for different applications?

In the electronics industry, many ceramic substrates use relatively standardized dimensions for ease of fabrication and circuit design. Common dimensions include:

These dimensions are very common in the LED packaging, power module, and power electronics industries.

Besides length and width, thickness is also an important parameter for ceramic substrates. Different thicknesses directly affect strength, heat dissipation capacity, and processing costs.

Common thicknesses include:

In practical applications, 0.38mm, 0.5mm, and 0.63mm are the most common thickness specifications.

Different ceramic materials also vary in their dimensional capabilities.

1. Alumina ceramic substrate (Al₂O₃)

The most common electronic ceramic substrate material.

Features:

Low cost

Mature processing technology

Wide size range

Common size range: 10 mm ~ 200 mm

Common thickness: 0.25 mm ~ 3 mm

2. Aluminum nitride ceramic substrate (AlN)

Aluminum nitride has extremely high thermal conductivity, so it is widely used in power electronics and semiconductor heat dissipation.

Common size range:

20 mm ～ 150 mm

Common thicknesses:

0.3 mm ～ 2 mm

3. Silicon nitride ceramic substrate (Si₃N₄)

Silicon nitride ceramic substrates have higher strength and better thermal shock resistance.

Common sizes: 30 mm ~ 120 mm

Common thickness: 0.32 mm ~ 1 mm

4. Why do ceramic substrates need to be customized in size?

While some common specifications exist, most ceramic substrates still require custom fabrication in practical industrial applications. The main reasons include:

Different circuit layouts

Different power module structures

Heat dissipation design requirements

Package size limitations

Therefore, ceramic substrates typically support:

Laser cutting

Precision grinding

Hole drilling

Special shape machining

Modern ceramic processing technology can achieve the following:

Dimensional tolerance ±0.02 mm

Micro-hole machining (0.1 mm or even smaller)

Complex irregular structures

When designing and sourcing ceramic substrates, it is recommended to focus on the following factors:

1. Power Density

The higher the power, the larger the heat dissipation area, and the larger the substrate size is usually required.

2. Circuit Layout

The complexity of the circuit layout will affect the design of the substrate size.

3. Heat dissipation requirements

The choice of material (alumina or aluminum nitride) also affects the dimensions.

4. Mechanical Strength

The greater the thickness, the higher the bending strength, but the cost will also increase.

In general, the common size range for ceramic substrates is as follows:

10 mm – 150 mm (general electronic applications)
Thickness 0.25 mm – 1.5 mm (most common)

As electronic devices develop towards higher power and higher density, the design of ceramic substrates is becoming increasingly customized to meet specific needs.

Therefore, when selecting a ceramic substrate, the most important thing is to design it reasonably according to the specific application scenario, rather than simply applying a fixed size.