We often say that PCB nickel plating has smooth nickel and dumb nickel (also known as low-stress nickel or semi-bright nickel), usually requires uniform and fine coating, low porosity, low stress, good ductility characteristics.
In addition to the problems caused by the improper operation of wave soldering operators, the design defects of wave welding equipment itself and maintenance should also be paid attention to.
it can not be continuously found that the boot phenomenon, after maintenance, the cause of the fault has a certain common, basically is the bottom of the power board between the solder joint sticky dirt, resulting in circuit leakage caused by fault.
At the same time, make the direction of the power line, ground line and the direction of the current, which helps to enhance the anti-noise ability. Grounding is the bottom branch of the four current circuits of the switching power supply.
Practice has proved that even if the circuit schematic design is correct and the printed circuit board is improperly designed, the reliability of electronic equipment will be adversely affected.
The circuit board with devices on both sides should be taken into account the second time over reflux will be welded side of the side of the device off, serious will rub off the pad, destroy the circuit board.
Run Proteus ISIS 7 to enter the PCB design interface, and select required components according to the component library. The P0.0-P0.7 ports of lpc2138 are used as the output end of 8-bit data, and P0.8, P0.9 and P0.10 are used as the output end of contro
With the rise of the electronic industry, circuit board production and development has become a more and more important part of PCB proofing a circuit board is not simple, easy to say.
The impedance test template can automatically generate a custom impedance template that changes with time according to the circuit characteristics on PCB, as shown in Figure 5. In this way, the special PCB wiring can be accurately judged and detected, suc
At present, for PCB curing, the most suitable use or UV light source, because UV light source has the characteristics of other mercury lamps do not have, just take the light source, UV light source is a cold light source, the curing principle is that the
At present, PCB board manufacturers generally adjust PCB prices according to different payment methods, ranging from 5%-10%, which also causes the difference in price.
to see what is the surface treatment process, we commonly have: spray lead tin (hot air leveling), OSP(environmental protection board), spray pure tin, tin, silver, gold and so on, of course, the surface process is different, the price will be different.
Telegram