PCB News - Learn about different aluminum substrates

Learn about different aluminum substrates

The aluminum substrate is a metal-based copper clad laminate with good heat dissipation function. Generally, a single-sided board is composed of a circuit layer (copper foil), an insulating layer and a metal base layer. The double-sided board is mainly used for high-end use, and the structure is a circuit layer, an insulating layer, an aluminum base, an insulating layer, and a circuit layer.

1. The composition of aluminum substrate

1. Line layer
The circuit layer (usually electrolytic copper foil) is etched to form a printed circuit, which is used to realize the assembly and connection of the device and can carry higher current.

2. Insulation layer
The insulating layer is the core technology of the aluminum substrate, which mainly plays the role of bonding, insulation and heat conduction. The insulating layer of the aluminum substrate is the largest thermal barrier in the power module structure. The better the thermal conductivity of the insulating layer, the more conducive to the diffusion of heat generated during the operation of the device, and the more conducive to reducing the operating temperature of the device, so as to achieve the purpose of increasing the power load of the module, reducing the volume, extending the life, and improving the power output. .

3. Metal base layer
What kind of metal is used for the insulated metal substrate depends on the thermal expansion coefficient, thermal conductivity, strength, hardness, weight, surface condition and cost of the metal substrate.

Under normal circumstances, considering the cost and technical performance, aluminum plate is an ideal choice. Available aluminum plates are 6061, 5052, 1060, etc.

2. Advantages of aluminum substrate:

The aluminum base plate is a low-alloyed Al-Mg-Si series high-plasticity alloy plate. It has good thermal conductivity, electrical insulation properties and mechanical processing performance. Compared with the traditional FR-4, the aluminum base plate can carry higher current, Its withstand voltage can reach 4500V, the thermal conductivity is greater than 2.0, and aluminum substrates are the main industry in the industry.

Aluminum substrates also have the following unique advantages:
.Using surface mount technology (SMT);
.Extremely effective treatment of thermal diffusion in the circuit design scheme;
.Reduce product operating temperature, improve product power density and reliability, and extend product service life;
.Reduce product volume, reduce hardware and assembly costs;
.Replace fragile ceramic substrates to obtain better mechanical durability.

The application of aluminum substrates is very wide, such as audio equipment input, output amplifiers, balance amplifiers; computer CPU boards, floppy disk drives, power supply devices; automotive electronic regulators, igniters, power controllers; LED lights for lighting fixtures, etc. All use aluminum substrates.

InPCB proofing, aluminum substrates are special plates, which have certain technical thresholds, operational difficulties, and high costs. Therefore, some PCB manufacturers find it troublesome or think that the number of customers' orders is small, and they don't want to do it or do less.