When we design the PCB, we will send it to the PCB board factory for online production through PCB pricing, and then there will be a series of subsequent welding, assembly and so on. However, with the increasingly fierce market competitiveness, the price of raw materials for PCB has also increased with the supply and demand of the market. PCB manufacturers have to reduce material costs in order to make their own competitiveness in the market. The cost of the process keeps itself competitive and attracts customers with ultra-low price. Therefore, the inevitable performance, density and quality of the PCB produced in the future will be greatly reduced. When welding, there will be many problems, and the reliability of the product itself will of course be Will receive the suspicion of the majority of users.
Therefore, when we face the PCB circuit boards produced by various board manufacturers in the market, how to judge naturally becomes a top priority. There are two ways to judge whether the circuit board is good or bad. One is to pass the appearance, and the other is to judge according to the quality of the board itself.
By discriminating the appearance of the PCB circuit board, there are usually three ways to discriminate
The color and luster of the board, the outside of the PCB circuit board is wrapped by ink of various colors, the ink can play the role of insulation protection on the line. If the surface gloss is dim, the ink is thin and the circuit board itself is not Ok.
The size of the board and the accuracy of the board thickness, the dimensional accuracy of the board and the tolerance of the board thickness determine the quality of the production.
For a circuit board with many soldered parts, observe the sharpness and microscopic fineness of the surface package gap. In these places, many soldering operations are performed, and the easier it is to distinguish, the better the fabrication.
For the other part of the PCB, the quality specifications are:
1. After the components are installed, the electrical performance is not abnormal, then the surface circuit board is ok.
2. The copper surface is not easily oxidized, affecting the speed of placement, and the oxidation rate is too fast, which may cause problems soon.
3. When the welding encounters high temperature, the ink will not fall, and the copper will not fall.
4. Whether the actual pitch and line width of the fabricated PCB circuit board are made according to the document, which affects the heating, open circuit and open circuit of the line.
5. Whether the war page of the board is too large, often encounters a high temperature environment during re-production, and a certain degree of war page is caused by stress deformation. Serious deformation will seriously affect the placement welding.
6. Whether the PCB circuit board can reach the standard under high temperature and high pressure environment, whether its own raw material can reach the TG value is also an important factor for judgment.
Hungarian designer Martzi Hegedűs has created the original font, named Frustro, which is based on the idea of impossible objects. This is one of the types of optical illusions. Like the classic Penrose Triangle, the letters of this font appears to be facing two different directions simultaneously, and it is impossible to create a 3D-model for them.