How To Efficiently Choose PCB Materials And Electronic Components

Publish Time: January 05,2019

The choice of PCB materials and electronic components is quite knowledgeable, because customers need to consider many factors, such as the performance indicators and functions of the components and the quality and grade of the components. Today we will give a systematic introduction, how to choose PCB materials and electronic components correctly?

1. PCB material selection

For general electronic products, FR4 epoxy fiberglass substrate is used, for high ambient temperature or for flexible circuit boards, polyimide fiberglass substrates are used, and for high-frequency circuits, PTFE fiberglass substrates are required; Electronic products with high heat dissipation requirements should use metal substrates.

Factors to consider when choosing PCB materials:

(1) A substrate with a higher glass transition temperature (Tg) should be appropriately selected, and the Tg should be higher than the operating temperature of the circuit.

(2) The coefficient of thermal expansion (CTE) is required to be low. 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.

(3) High heat resistance is required. Generally, PCBs are required to have a heat resistance of 250°C/50S.

(4) Good flatness is required. SMT PCB warpage requirements are <0.0075mm/mm.

(5) 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.

2. Selection of electronic components

In addition to meeting the requirements of electrical performance when selecting components, it should also meet the requirements of surface assembly for components. The packaging form of the components, the size of the components, and the packaging form of the components should also be selected according to the equipment conditions of the production line and the process flow of the product. For example, you need to choose thin and small-sized components when high-density assembly. If the placement machine does not have a wide-sized tape feeder, you cannot choose the SMD packaged with tape.