Brief introduction of Aluminum Core PCB Thermal Conductivity:
The thermal conductivity of Aluminum Core PCB, is an aluminum substrate thermal performance parameter, which is one of the three major criteria for measuring the quality (the other two properties are the thermal resistance value and the withstand voltage value ).
The thermal conductivity of the aluminum substrate can be tested after lamination. At present, the high thermal conductivity is generally ceramics, copper, etc. However, the cost of ceramics and copper is high. So the most widely used is the aluminum substrate, which is a unique metal-based copper-clad aluminum substrate with good thermal conductivity, electrical insulation and mechanical properties.
Aluminum core PCB performance:
(1) Heat dissipation
The multilayer board has high density and high power, It is difficult to dissipate heat.
The conventional PCB substrates, such as FR4, CEM3, are thermal poor conductors. The local heating of the electronic equipment is not solved, resulting in high temperature and the electronic components will burn out. But the aluminum substrate can solve this heat dissipation problem.
(2) Thermal expansion
Thermal expansion and contraction are the common nature of matter, and the thermal expansion coefficients of different substances are different. The aluminum-based PCB can effectively solve the heat dissipation problem, thereby alleviating the thermal expansion and contraction of different materials on the printed board, and improving the durability and reliability of the whole machine and the electronic equipment. In particular, it solves the problem of thermal expansion and contraction of SMT ( Surface Mount Technology) .
(3) Dimensional stability
Aluminum core PCB is clearly much more stable than printed boards of insulating materials, which is heated from 30 ° C to 140 ~ 150 ° C, and the dimensional change is 2.5 ~ 3.0%.
(4) Other reasons
A. Replacing a brittle ceramic substrate;
B. Use surface mount technology with confidence;
C. Reduce the real effective area of the printed board;
D. Replaces components such as heat sinks to improve heat and physical properties of the product;
E. Reduce production costs and labor.
Aluminum substrate structure
(1) Metal base
Aluminum-based substrates, using LF, L4M, and Ly12 aluminum, require an expansion strength of 30 kgf/mm2 and an elongation of 5%. The US Begas aluminum base layer is divided into four types of 1.0, 1.6, 2.0, and 3.2 mm, and the aluminum type is 6061T6 or 5052H34.
(2) Insulation layer
Insulation, usually 50~200um. If it is too thick, it can act as an insulator to prevent short-circuiting with the metal base, but it will affect the heat dissipation; if it is too thin, it can dissipate heat well, but it is easy to cause the metal core and the component lead to be short-circuited.
Aluminum substrate thermal conductivity standard introduction
The thermal conductivity of aluminum substrate is one of the important indicators to evaluate the quality of aluminum substrate. The other two important factors are the thermal resistance of aluminum substrate and the withstand voltage of aluminum substrate. The thermal conductivity of aluminum substrate is generally on the market. Is 2.00.1, the specific thermal conductivity of the aluminum substrate can be measured by the instrument, the thermal conductivity of the aluminum substrate will directly affect the price of the aluminum substrate, in general, the higher the thermal conductivity of the aluminum substrate relative The price of the aluminum substrate will be higher. For the quality of the aluminum substrate, it is not unilateral to look at the thermal conductivity of the aluminum substrate. The performance of the aluminum substrate is determined by the thermal conductivity of the aluminum substrate, the thermal resistance of the aluminum substrate, and the withstand voltage. It is not determined by a single factor.
The thermal conductivity of the aluminum substrate is generally fixed and does not change with external factors. The thermal conductivity is determined mainly by the raw material of the aluminum substrate. If high thermal conductivity materials such as copper and silver are added, the thermal conductivity of the aluminum substrate material will definitely be higher. Thermal conductivity is a basic physical quantity, a fixed component of a material, and its thermal conductivity is independent of thickness or area.
At present, the high thermal conductivity is usually ceramics, copper, etc. However, due to the consideration of cost, most of the aluminum substrates are on the market today, and the corresponding thermal conductivity of the aluminum substrate is a parameter that everyone cares about. The higher the thermal conductivity is One of the symbols that represents the better function. The aluminum substrate is a common metal-based copper-clad aluminum substrate with good thermal conductivity, electrical insulation and mechanical processing functions. The thermal conductivity of aluminum substrates usually varies from 1.0, 1.5, and 2.0. The specific situation depends on the needs of the product.