What problems should be paid attention to when selecting pcb materials?

by:A-TECH      2021-03-23
With the rapid development of domestic electronic technology, electronic products tend to be compact, portable and multi-functional. From the previous single-panel development to double-panel and multi-layer boards, high-precision, high-reliability, and complication have become the major development of PCB trend. PCB boards are necessary carriers for equipment, electrical appliances and software. Different PCB materials are used in different equipment. The raw materials for PCB are still seen everywhere in our daily lives, that is, glass fiber and resin. The glass fiber and resin are combined and hardened to become a heat-insulating, insulating, and not easy to bend board, which is the PCB substrate. The first consideration when selecting a base material is the temperature, electrical properties, soldering components, connectors, structural strength and circuit density during use in the later soldering process, followed by material and processing costs. Therefore, what factors should be considered when choosing PCB materials? A substrate with a higher glass transition temperature should be selected appropriately, and the Tg should be higher than the circuit operating temperature. High heat resistance and good flatness are required. In addition, in terms of electrical performance, high-frequency circuits require materials with high dielectric constant and low dielectric loss. Insulation resistance, withstand voltage strength, and arc resistance must meet product requirements. It also requires a low coefficient of thermal expansion. Due to the inconsistency of the thermal expansion coefficients in the X, Y, and thickness directions, it is easy to cause PCB deformation, and in severe cases, the metallized hole will break and the components will be damaged. One more thing to add is that the copper clad laminate is the substrate material for making printed circuit boards. It is used to support various components, and can achieve electrical connection or electrical insulation between them. There is also a composite material circuit board that is also used more. It has high hardness, high fiber strength, high toughness, low interlayer shear strength, anisotropy, poor thermal conductivity, and the thermal expansion coefficient of fiber and resin is very different. When the cutting temperature is high, it is easy to generate thermal stress at the interface between the fiber and the matrix around the cutting area. When the temperature is too high, the resin melts and sticks to the cutting edge, causing difficulties in processing and chip removal. The cutting force of drilling composite materials is very uneven, and it is easy to produce defects such as delamination, burrs and splitting, and the processing quality is difficult to guarantee. Therefore, PCB composite materials are difficult to process non-metal composite materials, and their processing mechanism is completely different from that of metal materials. However, it is worth mentioning that, in addition to 5G high-end products, ordinary products are still facing the dilemma of oversupply. For copper foil substrates, the market prospects have not improved significantly, and FR4 materials are used as always. It may face the pressure of price competition. PCB has always insisted on using superb technical force, sophisticated production equipment, perfect testing methods, product quality higher than industry standards, and warm and thoughtful service, which has won praise and welcome from global merchants and users. Here to enter the pricing page https://www./QB
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