The Reasons And Solutions For Easy Pad Drop
The reason why the pad is easy to fall off when the board is soldered
1. Material quality problems. Since the adhesion of the resin glue between the copper foil of the copper clad laminate and the epoxy resin is relatively poor, even if the copper foil of the large-area copper foil is slightly heated or under mechanical external force, it is very easy to be epoxy resin. Separation causes problems such as peeling of the pad and peeling of the copper foil.
2. The influence of storage conditions on the circuit board. If it is 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 extend. Such soldering conditions tend to cause the wiring board copper foil to be layered with the epoxy resin.
3. Soldering iron welding problem. The general circuit board adhesion can meet the ordinary welding. There will be no peeling off the phenomenon of the pad. But the electronic products are generally likely to be repaired. When repair, generally it is repaired with a soldering iron, due to the local high temperature of the soldering iron often reaches a temperature of 300-400 degrees, causing 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 also causes the falling off of the pad.
According to the this phenomena, the circuit board manufacturer can take the following methods to improve the soldering resistance of the circuit board pad as much as possible to meet the needs of customers.
1. CCL is made of genuine substrate with quality assurance. Generally, the selection of the glass fiber cloth of the copper clad laminate and the pressing process can ensure that the soldering resistance of the printed circuit board meets the requirements of the customer.
2. Using standard vacuum packed before leaving the factory, and the desiccant is placed to keep the circuit board in a dry state. To reduce the need for solder joints and improve solder ability.
3. For the thermal impact of the soldering iron on the pad, we increase the thickness of the pad copper foil by electroplating as much as possible, so that when the soldering iron is heated to the pad, the thermal conductivity of the copper foil thick pad is obviously enhanced, effectively The reduced local temperature of the pad, while the heat conduction makes the pad easier to disassemble. The solder resistance of the pad is reached.
In a word, each circuit board supplier need to control the pcb/pcba board quality. That will help you win the more chance to cooperate with good company.