Printed Circuit Boards knowledge

Printed Circuit Boards knowledge:

Names of circuit boards are: ceramic circuit boards, alumina ceramic circuit boards, aluminum nitride ceramic circuit boards, circuit boards, PCB boards, aluminum substrates, high frequency boards, thick copper boards, impedance boards, PCBs, ultra-thin circuit boards, ultra Thin circuit boards, printed (copper etching technology) circuit boards, etc. The circuit board miniaturizes and visualizes the circuit, which plays an important role in the mass production of fixed circuits and the optimization of electrical layout. The circuit board may be referred to as a printed circuit board or a printed circuit board, a printed circuit board (PCB), or a flexible printed circuit board (FPC) circuit board (an FPC circuit board is also referred to as a flexible circuit board. The flexible circuit board is a polyimide. A highly reliable, flexible printed circuit board made of a polyester film with a high degree of wiring density, light weight, thin thickness, and good bending properties. The birth and development of FPC and PCB, reechas, Soft and hard combination plate, gave birth to the new product of soft and hard bonded board. Therefore, the soft and hard bonded board is a flexible circuit board and a rigid circuit board. After the laminating and other processes are performed, the circuit board with the characteristics of the FPC and the characteristics of the PCB is formed in accordance with the relevant process requirements.

Classification

When the circuit board is divided according to the number of layers, it is divided into three major categories: single-panel, double-panel, and multilayer circuit board.

The first is a single panel. On the most basic PCB, parts are concentrated on one side and wires are on the other side. Because the wire only appears on one side, the PCB is called a single-sided circuit board. A single panel is usually simple to make and has a low cost, but the disadvantage is that it cannot be applied to products that are too complex.

Double-sided panels are single-panel extensions. When single-layer wiring does not meet the needs of electronic products, double-sided panels are used. Both sides have copper-clad traces, and can pass through the vias to open the lines between the two layers to form the desired network connection.

Multi-layer board refers to a printed board with three or more layers of conductive pattern layers and insulating material between them laminated and laminated with the conductive patterns therebetween as required. Multi-layer circuit boards are the products of electronic information technology to high speed, multi-function, large capacity, small size, thin and light weight.

According to the characteristics of the circuit board is divided into soft board (FPC), hard board (PCB), soft and hard board (FPCB).

Technical status

The domestic research on the automatic detection system for printed circuit boards began in the early to mid 90s and has just begun. The number of scientific research institutes engaged in this research is also relatively small, and because of the influence of various factors, the research on the automatic optical inspection system for printed circuit board defects remains at a relatively early level. It is precisely because the automatic detection system for printed circuit boards in foreign countries is too expensive, and domestic companies have not developed automatic testing equipment for printed circuit boards in the true sense. Therefore, most domestic manufacturers of circuit boards still use artificial magnifiers or projectors to view The way to check the side. Due to the labor intensity of manual inspection, the eyes are prone to fatigue and the missed rate is high. In addition, as electronic products move toward miniaturization and digitization, printed circuit boards are also developing toward high density and high precision, and manual inspection methods cannot be used. For higher density and precision circuit boards (0.12~0.10mm), it is completely impossible to test. The backwardness of testing methods has led to the current domestic multilayer board (8-12 layers) product qualification rate of only 50 to 60%.