PCB Technical - PCB manufacturers-urgent proofing of circuit boards

China is a global electronic product manufacturing center and a global electronic product consumer market, which provides sufficient market depth for the domestic PCB industry. At the same time, the domestic PCB industry chain is complete, and the advantages of sufficient labor resources enable domestic PCB companies to still have obvious advantages. Competitive advantage.
What do aluminum substrate manufacturers need to pay attention to when discussing aluminum substrates?
1. Common structures of metal substrates Metal substrates, common structures are
1: Conductive layer (also known as copper foil layer), used for line layout and component pad positions;
2: Insulation and heat dissipation layer (usually ceramic powder PP glue), as the name implies, exerts insulation and heat dissipation effect
3: Metal base layer (usually aluminum base, copper base), as the carrier of copper foil and insulating layer, aluminum base leads the metal substrate market share with its high cost performance and good machining performance.
2. Changsha aluminum substrate manufacturers tell you that the conventional performance of aluminum substrates is commonly used as PCB for LED lighting fixtures. We are interested in knowing more about aluminum substrates. The aluminum substrate uses aluminum alloy as the carrier, and its thermal, electrical and mechanical properties are particularly important. Common parameters such as: specific heat capacity, thermal conductivity, melting point range, linear expansion coefficient, electrical conductivity, resistivity, hardness, fatigue strength, tensile strength, Elastic modulus, elongation, cutting force, etc. In the case of meeting the national standard, the thermal conductivity is particularly important.
At present, the thermal conductivity of aluminum-based copper-clad laminates produced by different PCB manufacturers is quite different. If the above measurement method is used, the thermal conductivity of the mainstream aluminum-based copper-clad laminates in the domestic market is mostly between, and the cost difference is likely to induce unequal thermal conductivity, so consider heat conduction When it comes to the coefficient, you may wish to refer to the price positioning of aluminum substrates and third-party testing.

Common PCB layout problems and confusion
The success of a product requires good function and quality on the one hand, and beauty on the other. It is necessary to lay out your circuit board like carving a handicraft. There are often these questions and troubles in the layout of PCB components.
Does the PCB need to be imposition, whether to reserve process edges, whether to reserve mounting holes, and how to arrange the positioning holes?
Does the PCB shape match the whole machine? Is the spacing between the components reasonable? Is there any level or height conflict?
How to consider impedance control, signal integrity, power signal stability, and power module heat dissipation?
Is the distance between the thermal element and the heating element considered?
The EMC performance of the whole board, how to layout can effectively enhance the anti-interference ability?
Is it easy to replace components that need to be replaced frequently, and are adjustable components easy to adjust? PCB The main factors affecting flexibility of FPC materials are the type of material and the thickness of the material. The molecular structure and direction of copper foil, the bending resistance of rolled copper is obviously better than that of electrolytic copper foil; for the same variety, the thinner the thickness of copper foil, the better the bending resistance; generally speaking, epoxy resin is better than The flexibility of acrylic adhesive is better, and the highly flexible materials are mainly epoxy; the thinner the thickness of the adhesive, the better the flexibility of the material, which can increase the flexibility of the FPC; the thinner the thickness of the insulating substrate PI is the material The better the flexibility of the FPC, the better the flexibility of the FPC. The better the flexibility of the FPC is to use PI with a low tensile modulus.