How to distinguish the quality of PCB circuit board
Everyone is familiar with the application of PCB circuit boards, which can be seen in almost all electronic products. The development of science and technology has promoted the continuous growth of the PCB circuit board industry. People have higher and higher requirements for the number of layers, precision and reliability of components. . There are many types of PCB circuit boards on the market, and it is difficult to distinguish good quality from bad. So how should we distinguish the quality of PCB circuit boards?
distinguish the quality of the circuit board from the appearance
1. Light and color. Usually the external PCB circuit board is covered with ink to insulate it. If the color of the board is not bright and the ink is less, the insulation board itself is not good.
2. Standard rules for size and thickness. Since PCB circuit boards have different sizes to the thickness of standard circuit boards, users can measure and check according to their own needs.
3. The appearance of the weld. Since there are many PCB circuit board parts, if the welding is not good, the parts are easy to fall off, which seriously affects the welding quality and appearance of the circuit board. Therefore, it is very important that the welding is firm.
Judging from the board
1. Ordinary HB cardboard is cheap and easy to deform and break. It can only be used as a single-sided board. The color of the surface is dark yellow with an irritating smell, and the copper coating is rough and thin.
2. Single-sided 94V0, CEM-1 board, the price is relatively higher than that of cardboard, the color of the surface is light yellow, and it is mainly used for industrial boards and power boards with fire-proof requirements.
3. The glass fiber board has high cost, good strength, green on both sides, and is often used in the production of double-sided and multi-layer boards. Basically, most of the PCB circuit boards use this material, and the copper can be very precise and thin, but the unit board is relatively heavier. No matter what color ink is printed on the PCB circuit board, it should be smooth and flat, and there should be no false copper exposed and blistering.
Judgment after use
1. After using the pcb board, it came out through performance feedback. First of all, it can be used normally after the components are installed. This requires that the circuit board is not short-circuited or open-circuited. The factory has an electrical test process during production to detect whether the board is open or short-circuited. However, some board manufacturers are saving the cost does not carry out electrical testing (in POE proofing, 100% electrical testing is promised), so when proofing the circuit board, you must ask this point clearly.
2. When using, check whether the circuit board has heat, which involves whether the line width/line distance of the circuit on the board is reasonable. When soldering the patch, check whether the pad has fallen off under high temperature conditions, which makes it impossible to solder.
3. In addition, the high temperature resistance of the board is also very important. An important index of the board is the TG value. When making the plate, the engineer needs to instruct the board factory to use the corresponding board according to different usage conditions.
4 Finally, the normal use time of the board is also an important indicator to measure the quality of a board.
High-quality PCB circuit boards need to meet the following requirements.
1. The copper surface is not easy to oxidize, which affects the installation speed, and it will be broken soon after being oxidized;
2. The components are required to be easy to use after installation, that is, the electrical connection must meet the requirements;
3. The copper skin is not easy to fall off under high temperature;
4. The line width, line thickness, and line distance of the line meet the requirements to prevent the line from heating, breaking, and short-circuiting;
5. No additional electromagnetic radiation;
6. High temperature, high humidity and special environment resistance should also be considered;
7. The shape is not deformed, so as to avoid deformation of the shell and dislocation of screw holes after installation. Now they are all mechanized installations, the hole position of the circuit board and the deformation error of the circuit and design should be within the allowable range;
8. The mechanical properties of the surface must meet the installation requirements;
The above is the way to judge the quality of the PCB circuit board. We must be cautious when purchasing PCB circuit boards. If you need to know more, please pay attention to us. POE PCB has always strictly required itself to complete every customer's project with quality and quantity.