Copper Base PCB
2023-01-05 15:57:54 Copper Base PCB 229 Viewed
The thermal conductivity of the thermoelectric separation copper base PCB is 398W/M.K, which overcomes the shortcomings of insufficient heat conduction and heat dissipation of the existing copper base PCB. This process directly conducts the heat generated by electronic components through the heat dissipation area, greatly improving the heat dissipation effect.
The formation process of thermoelectric separation copper base PCB includes: sticking protective tape on one side of the copper base layer; forming anti-etching ink through circuit board technology, exposure, development and etching, etc., so that the heat dissipation area forms a protrusion, and the height of the protrusion is equal to that of the insulating layer and the circuit layer The thickness of the aluminum surface is electroplated with a layer of copper plating through galvanizing and electroplating copper processes; the circuit layer (copper foil) and the insulating layer (prepreg) of the copper base PCB are stacked together; the circuit layer and the insulating layer The window is opened in the heat dissipation area, and the window can be opened by die cutting or CNC forming; the heat dissipation layer (copper-coated aluminum substrate), circuit layer (copper foil), and insulating layer (non-flowing epoxy prepreg) are passed through the hot-pressed press together; according to the copper base PCB processing flow, the circuit layer circuit can be formed to form the thermoelectric separation copper base PCB provided by the utility model.
Using the thermoelectric separation copper base PCB, the heat layer can be separated from the circuit layer through the above process, so that the heat generated by the components can be directly conducted out through the heat dissipation area, and the heat conduction efficiency has been greatly improved. Thereby improving the service life of copper base PCB products.
How is Copper Base PCB Produced?
Copper base PCB is divided into immersion gold copper base PCB, silver-plated copper base PCB, tin-sprayed copper base PCB, anti-oxidation copper base PCB, etc. The copper base PCB circuit layer is required to have a large current carrying capacity, so thicker copper foil should be used. The thickness is generally 35μm~280μm; the heat-conducting insulating layer is the core technology of copper base PCB, and the core heat-conducting components are aluminum oxide and Silicon powder composition and epoxy resin filled polymer composition, small thermal resistance (0.15), excellent viscoelastic properties, copper base PCB has the ability to resist thermal aging, and can withstand mechanical and thermal stress.
The metal base layer is the supporting component of the copper base PCB, which requires high thermal conductivity. It is generally a copper plate, which is suitable for conventional machining such as drilling, punching and cutting.
The Difference between Copper Base PCB and Aluminum PCB
1. The thermal conductivity of the copper base PCB is twice that of the aluminum substrate. The higher the thermal conductivity of the copper base PCB, the higher the heat conduction efficiency and the better the heat dissipation performance.
2. Copper base PCB can be processed into metallized holes, but aluminum substrate cannot.
3. The elastic modulus of copper and aluminum is quite different, so the warpage and shrinkage of copper base PCB will be smaller than that of aluminum substrate.
Copper Base PCB
Copper base PCB is the most expensive kind of metal substrate, and its heat conduction effect is many times better than that of aluminum substrate and iron substrate. Copper base PCB is suitable for high-frequency circuits and areas with large changes in high and low temperature, heat dissipation of precision communication equipment and architectural decoration industry.
Aluminum based PCB
Aluminum substrate is a metal-based copper-clad laminate with good heat dissipation function. Generally, a single-sided panel consists of three layers, which are circuit layer (copper foil), insulating layer and metal base layer. For high-end use, it is also designed as a double-sided board, and the structure is a circuit layer, an insulating layer, an aluminum base, an insulating layer, and a circuit layer. Very few applications are multilayer boards, which can be made by laminating ordinary multilayer boards with insulating layers and aluminum bases.
Difficulties in Copper Base PCB Drilling
As high-power electronic components have higher and higher requirements for PCB heat dissipation, higher processing requirements are also put forward for copper base PCB products. Especially in terms of drilling, more and more copper base PCBs require through holes less than 0.5mm to be drilled. If the conventional drilling method is used, it is very easy to break the tool and scrap it.
Due to the diverse needs of customers for heat dissipation or board making, there are also various copper materials used for copper base PCBs on the market, and the hardness of different types of copper base PCBs is also different. At present, the mainstream copper base PCB is made of red copper with high copper content. Red copper is characterized by better plasticity, lower strength and hardness, and its heat dissipation performance is the best among all kinds of copper base PCBs. From the perspective of copper base PCB drilling, the copper block has both "hard" and "soft" characteristics. On the one hand, the copper block is much harder than organic materials such as FR4 or organic composite materials, and the cutting difficulty is greatly increased when the drill is processed, and it is easy to break due to excessive wear; on the other hand, the copper block has certain plasticity, and the copper base PCB may be damaged during the drilling process. Make the copper shavings adhere to the cutter head, and it is easy to cause poor cutting chips and cause the cutter to break.
Especially when the tool diameter of the drill hole is less than 0.7mm, the copper base PCB can bear very limited lateral cutting force and axial force, and the ability to shed chips is very weak, which poses a great challenge to drilling.
Drilling bit selection
There are several main problems in the process of small hole processing of copper base PCB: large wear, easy to break the knife, and difficult heat dissipation. Although these problems are a headache, they can be effectively alleviated by selecting an appropriate drill bit, thereby improving all aspects of copper base PCB drilling small holes.