In the pcb board proofing surface treatment used in different ways, each surface treatment method has its unique characteristics, to chemical silver, for example, its process is extremely simple, recommended for lead-free soldering and smt use, especially for fine lines better results, the most important thing is to use chemical silver surface treatment, will greatly reduce the overall cost of lower costs. The following is a small number of common surface treatment of pcb board proofing for you by the editor of the circuit.

1.HASL hot air leveling (i.e., often referred to as tin spray)

Spray tin is pcb board proofing early commonly used processing methods. Now divided into leaded tin spray and lead-free tin spray. Advantages of spray tin: PCB is completed, the copper surface is completely wetted (completely covered with tin before soldering), suitable for lead-free soldering, process maturity and low cost, suitable for visual inspection and electrical testing, but also belongs to one of the high-quality and reliable pcb board prototyping processing.

2. Electroless nickel gold (ENIG)

Chemical nickel gold is a relatively large application of a pcb board proofing surface treatment process, remember: the nickel layer is a nickel-phosphorus alloy layer, based on the phosphorus content is divided into high-phosphorus nickel and phosphorus nickel, application is not the same, here does not introduce the difference. Advantages of nickel gold: suitable for lead-free soldering; very flat surface, suitable for SMT, suitable for electrical testing, suitable for switching contact design, suitable for aluminum wire bonding, suitable for thick boards, resistance to environmental attacks.

3. Electroplated nickel gold

Electroplated nickel gold is divided into "hard gold" and "soft gold", hard gold (such as: gold-cobalt alloy) commonly used in gold fingers (contact design), soft gold is pure gold. Electroplated nickel gold in the IC carrier board (such as PBGA) on the application of more, mainly applicable to the gold and copper wire binding, but the carrier IC carrier board plating is suitable for binding the gold finger area need to do extra conductive line out to plating. Advantages of nickel gold plating pcb board prototyping: suitable for contact switch design and gold wire binding; suitable for electrical testing

4. Nickel-palladium gold (ENEPIG)

Nickel-palladium gold is now gradually beginning to start in the field of pcb board prototyping began to apply, before the semiconductor on the application of more. Suitable for gold, aluminum wire binding. Advantages of using nickel-palladium pcb board proofing: applied in IC carrier board, suitable for gold wire binding, aluminum wire binding. Suitable for lead-free soldering; compared with ENIG, there is no nickel corrosion (black disk) problem; the cost is cheaper than ENIG and electro-nickel gold, suitable for a variety of surface treatment processes co-exist on the board.