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

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

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 mainstay of PCB development. trend. PCB board is a necessary carrier 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 life, 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.

When selecting a base material, the first consideration should be the temperature, electrical properties, soldering components, connectors, structural strength and circuit density during use in the later welding 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 appropriately selected, 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. In the case of 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.

iPCB is a high-tech manufacturing enterprise focusing on the development and production of high-precision PCBs. iPCB is happy to be your business partner. Our business goal is to become the most professional prototyping PCB manufacturer in the world. Mainly focus on microwave high frequency PCB, high frequency mixed pressure, ultra-high multi-layer IC testing, from 1+ to 6+ HDI, Anylayer HDI, IC Substrate, IC test board, rigid flexible PCB, ordinary multi-layer FR4 PCB, etc. Products are widely used in industry 4.0, communications, industrial control, digital, power, computers, automobiles, medical, aerospace, instrumentation, Internet of Things and other fields.