PCB Tech - What is the use of the PCB circuit board?

1. Circuit board {PCB circuit board}, also known as printed circuit board, is a provider of electrical connections for electronic components. Its design is mainly layout design; the main advantage of using circuit boards is to greatly reduce wiring and assembly errors, and improve the level of automation and production labor rate.

According to the number of circuit boards, it can be divided into single-sided boards, double-sided boards, four-layer boards, six-layer boards and other multilayer circuit boards.

Since the printed circuit board is not a general terminal product, the definition of the name is a little confusing. For example, the motherboard used in personal computers is called the main board, and cannot be directly called the circuit board. Although there are circuit boards in the main board, They are not the same, so when evaluating the industry, the two are related but cannot be said to be the same. Another example: because there are integrated circuit parts mounted on the circuit board, it is called an IC board, but in fact it is not equivalent to a printed circuit board. We usually say that the printed circuit board refers to the bare board-that is, the circuit board without upper components.

2. Common specifications and requirements of PCB circuit board positioning holes

1. The diameter range of the positioning hole of the PCB board is generally within 0.01MM. When the PCB is manufactured, the error is large, which will cause inaccurate contact of the probe and inaccurate alignment of the interface connector.

   
   

2. The diameter of the positioning hole of the PCB board: Try to be above 2MM and below 10MM, so that the positioning column will not be deformed, and it is too large for easy operation.

3. The type of PCB board positioning hole: probably part of the positioning hole needs non-sink copper mechanical hole, so that the circuit can be connected and the accuracy will be high, except for the grounding fixing hole.

4. The layout of the positioning holes on the PCB board: it needs to be on the four corners or diagonal lines of the PCBA to be accurately positioned, and the farther the better.

5. The distance between the positioning hole of the PCB board and the test point must be at least 2mm or more, so as to prevent accidental short circuit during the test.

6. The distance between the positioning hole of the PCB board and the board edge: at least 2mm or more, in order to ensure the strength of the PCB, and it is not easy to break.