News:

MCPCB refers to Metal core PCB (MCPCB), that is, the original printed circuit board attached to another metal with better heat conduction effect can improve the heat dissipation at the circuit board level.

However, MCPCB also has some limitations, in the circuit system operation can not exceed 140 ° C, this is mainly from the dielectric layer (Dielectric Layer, also known as Insulated Layer, insulating layer) characteristics limit, in addition to the manufacturing process should not exceed 250 ° C ~300 ° C, which must be understood in advance before the tin furnace.

Although MCPCB has better heat dissipation effect than FR4 PCB, the dielectric layer of MCPCB does not have too good thermal conductivity, and the conduction bottleneck between the heat sink and the metal core board. But it is still better than FR4 PCB, the existing MCPCB has reached 3W/m.K, while FR4 is only 0.3 W/m.K.

Aluminum substrate has good thermal conductivity, electromagnetic shielding performance, and light weight, has become the choice of metal substrate. At present, aluminum base copper clad laminate is used more in the market.

1. The main functions of aluminum-based copper clad laminate:

The first is heat dissipation. At present, many double-panel, multi-layer boards have high density, high power and high heat dissipation requirements. Conventional printed board substrate FR4 is a poor conductor of heat, interlayer insulation, heat can not be effectively dissipated in time, resulting in high-speed failure of electronic components, and the installation of heat dissipation equipment fans not only takes up a lot of space, but also increases the size of the equipment. The heat dissipation problem is solved by adopting aluminum substrate, and it does not occupy space.

In addition, thermal expansion and contraction are common properties of substances, and the coefficient of thermal expansion (CTE) of different substances is different. Generally, PCB is a composite of resin, glass fiber cloth and copper foil. The coefficient of thermal expansion in X-Y axis is 13 ~ 18 PPM/℃, while in Z axis it is 80~90PPM/0C. The CTE of copper is 16.8 PPM/. C, the CTE of flaky ceramics is 6 PPM/~. It can be seen from the above data that the difference between FR4 insulation layer and hole metallization copper in the Z axis direction is 5 times. If the heat generated cannot reach B,I~I}, thermal expansion and contraction will lead to hole metallization fracture. In the X~Y axis direction, due to the surface mount technology SMT is to directly solder ceramic chips on the pad, the chip material for ceramic carrier CTE and FR4 CTE#! EI difference more than 2 times, such as high temperature, long-term stress will lead to fatigue fracture. The aluminum substrate can effectively solve the heat dissipation, so that the thermal expansion and contraction problems of different substances of the components of the printed board are alleviated, and the durability and reliability of the whole machine and electronic equipment are improved.

In addition, the aluminum substrate also has the electromagnetic shielding function unique to the metal substrate, which can effectively shield other electromagnetic signals and interference sources to ensure the integrity of the signal transmission process.

2. Basic Structure of Aluminum Based Copper Clad Laminate

A general single-sided aluminum substrate is composed of a copper layer, an insulating layer, an aluminum-based metal layer, and a protective film.

3. General specification for aluminum-based copper clad laminate

At present, the specifications and size of aluminum-based copper clad laminate produced in the market are: 500x600, 500x1200, 600x1000; with the development of technology, the specifications of 1000x1200 will also enter the market.