If you’re having PCB produced for your business for the first time, it can be a little overwhelming since taking decisions about varying manufacturing options such as substrate material, fire rating, soldermask, board thickness, copper thickness and a lot more is perplexing.
However, one of the most important and sensitive decisions that you need to make during the PCB manufacturing process is about its surface finish. Unfortunately, there isn’t a ‘perfect surface finish’ for printed circuit boards as every finish has its upsides and downsides.
Stated below are some of the most commonly utilized surface finishes that you can consider for your PCB needs:
ENIG
All the freetronics PCBs that you see around have an ENIG surface finish. ENIG stands for Electroless Nickel Immersion Gold. Consisting of an underlying layer of nickel and a thin layer of gold at the top, this surface finish has a high resistance to corrosion. While the gold layer is very thin, it doesn’t provide a supportive structure to the board. However, it plays a vital role of protecting the nickel so that it doesn’t get tarnished before getting soldered.
Summing up the good points of ENIG, it can be touched with bare fingers without any chances of being tarnished, it has a prolonged shelf life, it has flat and square-edged tracks that are a great thing for fine-pitch surface mount components.
However, one downside to ENIG is that it requires extra solder to complete a joint because the surface isn’t pre-tinned.
HASL
This is one of the most common types of surface finishes that you will find on PCBs. HASL stands for Hot Air Solder Leveling. The HASL boards are dipped into the model solder paste while the excess is cleaned away using hot-air knives. As a result, a very thin layer solder is left behind. The solder then protects the underlying pads from corrosion and simplifying the process of soldering on parts as the pad is pre-tinned. HASL is one of the cheapest options available when it comes to finishing and is an ideal choice for general-purpose boards. One downside associated with HASL is that even after the hot-air knives have cleaned away excess solder, the arc of the solder still remains slightly rounded.
Immersion Silver
Immersion silver is one of the most remarkable-looking finish options that are available. However, it has a very limited shelf life. It gets impacted by a slight touch and discolors quickly. So, immersion silver is not a good option for boards that are supposed to undergo long storages and hand assembly.
Super PCB is the leading source for printed circuit boards offering a range of surface finishing including HAL, HAL lead free, Immersion silver, Immersion tin, Immersion Gold, ENIG and lots more. Gain more insight about our capabilities or email us at info@superpcb.com today!