Juding PCB proofing multilayer impedance PCB circuit board manufacturing plant
Juding PCB proofing multi-layer impedance PCB circuit board manufacturing plant, about the introduction of multi-layer impedance PCB circuit board.
There are two basic ways to cover copper. It is a large area of copper and grid copper. It is often asked that large areas of copper are good or grid copper is good. It is not easy to generalize. why? Large-area copper-clad, with the dual function of increasing current and shielding, but a large area of copper, if the wave soldering, the board may be tilted up, and even foaming. Therefore, a large area of copper, generally will open a few slots to ease the blistering of copper foil, the simple grid copper is mainly shielding, the effect of increasing the current is reduced, from the perspective of heat dissipation, the grid is beneficial (It reduces the heating surface of copper) and plays a role in electromagnetic shielding.
The reason why the pad is easily peeled off when the PCB board is soldered
1: PCB board quality problem:
Since the adhesive adhesion between the copper foil and the epoxy resin of the copper clad laminate is relatively poor, even if the copper foil of the PCB of the large-area copper foil is slightly heated or under mechanical external force, it is very easy to be epoxy. Separation of the resin causes problems such as peeling of the pad and peeling of the copper foil.
2. The influence of PCB storage board storage conditions:
Affected by the weather or stored in a humid place for a long time, the moisture absorption of the circuit board is too high. In order to achieve the desired welding effect, the heat of the volatilization should be compensated for the welding of the patch, and the temperature and time of the welding must be Extending, such soldering conditions are liable to cause delamination of the copper foil of the wiring board and the epoxy resin.
3. Soldering iron welding problem:
Generally, the adhesion of the PCB circuit board can meet the ordinary soldering, and the pad peeling phenomenon does not occur. However, the electronic products are generally likely to be repaired. The repair is usually repaired by soldering iron, because the local high temperature of the soldering iron often reaches 300-400 degrees. The temperature causes the local temperature of the pad to be too high, and the resin glue under the copper foil of the pad is detached at a high temperature, and the pad is detached. When the soldering iron is removed, it is easy to attach the physical force of the soldering iron to the pad, which is also the cause of the falling off of the pad.
Juding Circuit Technology provides you with the best quality 1-3-4 layer PCB manufacturing