Benefits of Gold Plating on PCBs

If you need a PCB surface finish that resists corrosion, gold plating is an option. It has a number of benefits, and the thickness of the hard gold plate can vary depending on your needs.

It can be used for both touch and sliding contacts, and it is suitable for many applications. It also does not suffer from fretting corrosion, which can cause wear and tear to the PCB surface.

Durability

Durability is an important consideration when choosing the right material for a printed circuit board. PCBs need to be durable enough to withstand the wear and tear of repeated contacts and insertion/removal processes.

Gold is an excellent choice for PCBs because it has a high level of durability. This is because it doesn’t lose its strength over time as a result of friction or rubbing. It also does not suffer from fretting corrosion, which occurs when a material deteriorates at the interface of two contacting surfaces.

Another reason to consider using gold for a PCB is because it is an environmentally friendly option. This is because it doesn’t contain any toxic elements like lead, which are commonly used in other metals.

Nevertheless, there are some drawbacks to using gold for a PCB. First of all, the gold used for this process is expensive. It is also difficult to maintain and control the thickness of the gold-plated layer.

A thin layer of gold can easily cause failure, which is why it’s a good idea to use a thicker underlayer of hard metal or alloy to increase its resistance to wear and tear.

You can achieve this by adding an extra layer of nickel or cobalt to the gold. This can help reduce the cost of the plating while boosting its overall durability.

The surface of the gold-plated board is then sprayed with an epoxy that gold plating pcb prevents the deposition of ionic and nonionic residues. These residues can interfere with the plating process and decrease conductivity.

Once the surface is ready, it’s time to apply the gold plating. Usually, this is done with a chemical solvent, although water-based systems are also available.

After the gold plating has set, you’ll need to check its adhesion to the copper pads. You can do this by placing a strip of tape along the contact edges. If it doesn’t stick, then the gold plating is not strong enough to resist the insertion/removal processes that occur on a PCB.

You can use different types of gold to finish a PCB, including soft and hard gold. The choice of gold depends on the design of the PCB and its application. Generally, soft gold is cheaper and more malleable than hard gold. This is especially true for applications that require a lot of recurrent contact and sliding insertion/removal.

Resistance to Corrosion

Gold is an excellent option for circuit boards, as it can withstand corrosion and has great conductivity. Unlike copper, gold doesn’t react to chemicals or rust. It also has a melting point of 1062 °C, so it can withstand high temperatures without deteriorating.

Printed circuit boards are often coated with gold to provide them with protection against oxidation and tarnishing. There are several surface treatment procedures that create external layers with different properties.

One of the most popular coatings is ENIG (Electroless Nickel Immersion Gold). It has a flat surface and good oxidation resistance. It’s typically plated at a thickness of 1-3 micro inches. However, some designers request a thicker layer measuring 4-8 micro inches for better protection against oxidation and tarnishing.

Another gold coating process is ENEPIG (Electroless Nickel Electroless Palladium Immersion Gold). This process is similar to ENIG, but it has an additional palladium layer. The layer is generally thinner than ENIG, with a thickness of 1-2 micro inches.

Many PCBs use gold fingers to connect peripherals to the main circuit board. The connector edges are plated with hard gold and are usually alloyed with nickel or cobalt to enhance their wear and tear resistance.

There are several different ways to plate these contact points, but the most common method is to add a layer of nickel first and then finish with a layer of gold. This technique can improve the performance of the circuit board and increase its lifespan.

Moreover, you can choose to add an underlayer to the gold plating to prevent it from corroding in certain areas. The underlayer prevents oxidizing metals like copper and zinc from diffusing into the gold and causing it to corrode.

The underlayer also provides an extra layer of protection against corrosion that may creep in through pores located in thin areas of the gold plating. This helps prevent existing corrosion from spreading and protects the entire surface of the board.

The most important thing to keep in mind when plating a PCB with gold is that you must remove the old plating before starting the new process. This ensures that your circuit board will not have any traces of previous plating. This will help your new gold plated PCB look as close to the original design as possible.

Weldability

Gold is one of the most widely used surface finishes for PCBs. It offers a number of benefits, including excellent corrosion resistance, good solderability and durability.

The surface finish can be applied to the entire PCB, a single area or a specific gold plating pcb segment of a circuit board. For example, the connecting edges of a printed circuit board may be gold plated, known as the “gold fingers.”

Immersion gold is a commonly selected surface finish because it offers excellent corrosion resistance and superior solderability. However, it is also expensive and requires several steps.

Electro-less nickel immersion gold (ENIG) is another often selected surface finish. It is a more cost-effective alternative to electroplated gold, but its soft, thin composition makes it susceptible to the abrasive effects of circuit board insertion and removal.

Compared to hard gold, ENIG is less prone to oxidation and has a denser crystal structure, making it more difficult to produce short circuits in wires. Additionally, it does not cause corrosion on the surface of the copper layer like hard gold, which allows it to be stored for longer periods without causing an oxidation problem.

Selective hard gold is a type of PCB plating that involves utilizing hard gold to plate only a small section of a circuit board. This is usually done for PCBs that are subject to repeated rubbing or sliding wear.

The application process is similar to full body hard gold but with the added requirement of an extremely active flux to make efficient soldering. In addition, this PCB surface finish is very difficult to achieve, so it must be performed at a high-speed machine with specialized tools and equipment.

Hard gold is typically used in heavy-wear zones such as edge connector fingers and keyboards, although it can also be used for other areas where the surface of the PCB is subjected to rubbing or sliding wear. It is not usually used in areas where the surface of the circuit board is exposed to water, as it has a relatively poor solderability and corrosion resistance.

Price

Gold is a valuable metal that can be used in a variety of electronic devices. It can be plated on PCBs to improve conductivity and help connect circuit boards together. It also helps prevent corrosion and tarnishing, which can cause electrical resistance.

It is important to choose the right material for the PCB because it can affect the performance of your device. Gold is a good choice because it is conductive and can resist tarnishing and corrosion. It can be plated onto copper, nickel or silver.

However, it is a costly process. It is usually cheaper to add nickel or cobalt to the gold to increase its durability.

The price of a gold-plated PCB depends on the design, thickness and quality of the plating. It is also influenced by the number of layers and the number of holes and SMDs on the board.

Hard gold is a more durable finish than ENIG, and it is often used for PCBs that require high wear-resistance. It is also a better option for visible interconnect projects because it offers smoother edges than ENIG.

There are two main ways to plate gold: immersion gold and flash gold. Immersion gold involves a chemical reaction to deposit particles of gold onto the surface of the circuit board. This can be a costly process, but it can be done in larger quantities than flash gold.

Flash gold, on the other hand, uses a high-powered current and a solution that contains a higher amount of gold to form a dense but thinner layer of hard gold upon the nickel layer. The result is a lower cost, faster production time and a smoother final product.

The downside to flash gold is that it can be dangerous and must be performed in a licensed factory. It must also be stored in a separate area from other chemicals to avoid contamination.

This process discharges a chemical wastewater that can be hazardous to humans and the environment. Therefore, it is a difficult process to operate and only a few factories have the required qualifications to buy and store this precious metal.