Hello, guys welcome to the new post. Here we will cover What is ENIG plating PCB. Full form of ENIG is electroless nickel immersion gold plating that is performed on the PCB boards that has a larger number of coppers pads. The component of projects connected to the PCB board get the current from the board. In ENIG there are 2 layers of the metal coating is done. At the ist layer of copper pads that exist on the PCB board, Nickle layer is coated after that thin layer of gold plated.
This type of plating is performed at the upper layer of the copper pad since this plating offered conductive behavior in well way. That also helps to give fine protection from oxidation and other environmental conditions. Either it is expensive but use due to fulfilling the RoHS criteria. Tehre are numerous PCB suppliers also fulfill the RoHS in their services such as PCBWAY. That is best in all services also offering ENIG plating services with reasonable prices and good quality since they equipped with professional engineers and machines. More than ten year they are fulfilling the prototype and fabrication demands of their customers with high-quality boards, fast delivery and less expensive products. Since it is the best and most featured PCB manufacturer in china they pride themselves to be your best business partners as well as good friends in every aspect of your PCB needs.
PCB is one of the most important components of any electrical and electronic equipment. PCB quality determines the quality of all these devices. Modern technology makes it possible to increase the miniaturization of composite circuits, higher packaging density, and smaller building size, which is why higher demands on PCBs arise.
Introduction to ENIG plating PCB
- The most commonly used PCB plating is ENIG. At the bare PCB board, coating application is called PCB surface finishing.
- The use of ENIG and other types of coating such as HASLis to save the board from external harsh conditions such as corrosion
- ENIG is plated on the pads of coppers existing on the board surface that helps to fight with external conditions not favorable for the board.
- First of all copper layers are plated with nickel then the gold layer. Use of ENIG helps to board get an easy soldering process and avoid from resistance and plane surface.
- Due to the complicated nature and high cost also used since fulfilling the RoHS.
- ENIG consists of two metal layers first is Nickle on the copper that helps to connect the components.
- Another is gold layer that reduces the connection with other parts. The value of the Nickle layer is four to seven micrometers and gold thickness lies 0.05 to 0.23 micrometers.
- The temperature needed for ENIG is eighty centigrade
Advantages of ENIG Plating PCB
- Some main advantages of ENIG plating are discussed here
Simple to Manufacture
- Its creation process is simple and easy. Numerous PCB board designers used this plating process for the creation of boards.
Flat surface
- This plating comprises on two layers having a metal coating of nickel that protects the surface nd easy to connects components.
- This plating fulfills the needs of flat surfaces like BGAs.
Resist to Environmental Conditions
- Every PCB manufacturer prefers to use such board that resists to oxidation this plating give this feature. BUt other surface finishing lack this feature.
- For protection from the oxidation gold layers with nickel is employed on the board.
Fine Electrical Behaviour
- This plating also offered a good electrical operation to board than other plating techniques this paramerts also covered with others such as the connection of wires, finishing design.
A large value of temperature resistance
- The board used in instruments used in medical and military purpose bear the larger value of temperature conditions.
- ENIG finish board comes with these features to handle high-temperature conditions.
Durable
- The finishing used on the board defines the operating life of the board. ENIG plating helps board to work for twelve months or more. So it is preferred for different project creations.
Lead-Free
- The use of lead inboard can be harmful for health and cause of different diseases such as kidney, heart, etc.
- But ENIG plating comes with lead free features and reduces the cause of harmful diseases due to the board.
Good for PTH
- It is considered as best finishing for PTH . That has wires coming out from the different parts of a breadboard.
Disadvantages of ENIG Plating
- With the some benefits of this plating also has some disadvantages that are described here
Expensive
- As it is considered s fine option for different boards but it is an expensive technique. Some customers used other plating techniques due to larger cost but also used in different projects.
Repairing is difficult
- As this plating is done through use of machines so engineers face difficulty making again the board if damaged.
- In some case damage is such that cannot be repaired again and users has to get new board.
Complex Manufacturing
- Its other drawback is that its manufacturing process is difficult. Other types of plating offered a less complex process than he ENIG.
- Since it was created with use of machines if machines are not configured accurately than cause serious problems during construction
Black pad of ENIG in PCB
During the permutation of the ENIG technique if there is a high value of oxidation reaction is existing on the nickel surface metal nickel can be transformed into nickel ions then larger size gold atoms get deposited in the shape of coarse and disturbed configuration that indicates that gold layer can completely cover the nickel layer. As a result nickel layer is exposed to air then nickel rust is created under a layer of gold. This nickel rust causes failure of soldering. Therefore other surface finish
In the permutation reaction of the ENIG process, if the nickel surface gets an excessive oxidation reaction, the metal nickel might convert into nickel ions, while the larger gold atoms (radius 144 pm) irregularly deposit to form a coarse and loose arrangement, which means the gold layer might fail to completely cover the nickel layer, allowing the nickel layer to contact with the air, which will finally create nickel rust under the gold layer. This kind of nickel rust will cause soldering failure. This problem called black pad that was solved through the use of ENEPIG which is another type of finish but it is costly that is now just considered for SCP, BGA, or HDI boards
As there is no chance of ENIG finishing to rework the best option is to black pad is a precaution. That is maintain strict control over the nickel bath, that is nickel to gold exchange must be under controlled conditions. The best point is to monitor the pH level of the nickel bath since in this way we can monitor the quantity of excessive phosphorus that is the main cause of the black pad of nickel produced by the nickel dissolution.
That is all about the ENIG plating PCB. all details has been discussing the ENIG plating PCB. If you have any further query ask inc comments. thanks for reading have a good day.
