Selective Gold Plating PCB

Selective gold plating manufacture

Gold finger/hard gold plating factory

ENIG Plating/Immersion gold plating



What is Selective Gold Plating PCB

Firstly you need to know that Gold plating is frequently used to improve electrical conductivity while making printed circuit boards (PCBs). Gold plating, a new method of PCB manufacturers for bonding gold atoms to PCBs, has gained popularity. However, the cost of gold plating for the manufacturers/factory will be more expensive and more difficult for pollution treatment. So the manufacturer will only select to do the gold plating for those Pads and holes that need to be soldered, which is called Selective Gold Plating

How does selective gold plating work?

In order to increase the conductivity of other metals on PCBs, gold plates are applied during the gold plating manufacturing process. The most popular and user-friendly method of putting gold onto a PCB is gold plating, which is a rather simple process.

It functions by generating a gold-plating solution with a very high concentration of gold ions. Gold atoms with at least one missing electron are known as gold ions. When the gold solution is applied to a surface with positively charged atoms or the cathode, the negatively charged atoms join chemically with the positively charged atoms.

So you need to use the gold plating process, but you also don’t want to pay the high cost for the gold plating. then we do the selective gold plating on some areas to make sure it keeps the advantage of the gold plating of your board, but also it is more environmentally friendly.

Why it is called selective gold plating?

As you are aware, gold is a fantastic material for the manufacturer to use when making PCBs. Gold-plated edge connections offer a consistent surface quality for applications that can experience heavy wear, including board insertion edge points. Hardened gold has a solid surface that is especially resistant to wear from regular use.

  • Gold is an excellent material for electrical applications because of its nature.
  • It is easy to design and use for relay contacts, connections, and cables.
  • Gold can withstand a small amount of current, which is required for today’s modern gadgets.
  • As gold won’t corrode or tarnish, it makes it possible to be an unfailing connection medium;
  • It’s a relatively simple process to recover and melt gold for reuse;
  • It can provide dependable and stable contacts with low resistance despite thin applications of gold;
  • It can withstand high temperatures and variations

So as we mentioned before, selective gold plating is just on some areas you need to solder to keep your boards has the advantages of the boards.

Introduction of the gold fingers

A PCB case will have graphics cards installed in the slots when you open it. These PCB assemblies have a clean row of PCB pads along the edge that is both long and thin. Because the conductive pads utilized for connection in the rectangular row of PCB pads resemble fingers, we refer to them as “gold fingers.”

PCB gold fingers are thicker in gold compared to other PCB pads. IPC-4556 states that the standard PCB gold finger thickness is 32u” (microinch), and that PCB gold finger thicknesses can range from 3u” to 50u”.

The gold on PCB gold fingers is an alloy of gold with a harder surface than immersion gold.

gold finger

PCB gold fingers are divided into three categories:

  • Common PCB gold fingers: They are the most prevalent PCB gold fingers. The dimensions of the PCB pads are uniform in terms of size.
  • Uneven PCB gold fingers: The PCB pads are the same width but vary in length and, occasionally, in space.
  • Segmented PCB gold fingers – The gold fingers are segmented and the PCB pads have various lengths.

For connecting PCB boards, PCB gold fingers are an excellent choice

The system or device’s PCB boards are directly connected by PCB gold fingers. Compared to PCB connections and wires, this connection offers higher mechanical strength and conductivity. Commercial and industrial systems and devices connect with slots and interfaces using PCB gold fingers because they offer the following benefits:

  • Excellent conductivity due to the direct board connection and greater gold thickness;
  • Strong wear resistance so that the PCB can be plugged in and out thousands of times;
  • Good oxidation resistance due to the hard-gold plating process to the PCB pads.

Difference between hard gold plating and flash gold plating

To make a less valuable metal appear gold, a layer of gold that is less than 0.25 microns thick is electroplated on top of it. Flash plating is of poor quality and has very little wear resistance.

  • Gold flash and hard gold plates differ mostly in thickness. Actually, each of them can be gold-plated using the same gold-plating solution. Simply said, the thickness depends on how long the part is kept in the tank.
  • Gold flash, which is typically between 5 and 10 microns thick, is mostly used for color. Hard gold plate, which typically ranges from 12 to 65 microns, protects the component “thick, though it could be thicker in some uncommon situations.
  • Cheap decorative items like fake jewelry and stainless steel cutlery frequently feature a gold flash. Electronic components that don’t need wear protection can also use it. Although you can’t entirely rely on appearance, a gold flash will typically appear paler than a hard gold plate on e-parts.
  • The thickness of the hard gold plating on pins, fingers and most other objects that may become worn from repeated insertions is roughly 30 microns ” thick.

No matter which technology you want to use, hard gold plating, selective gold plating, or flash gold plating. Just choose the one that most suitable for your products

Where to get the best Selective gold plating and gold finger services in China?

Whether it’s a single prototyping board or a batch for small-scale production, FX PCB manufacture for your PCB service is the perfect solution. We take care to accurately reproduce the technical parameters of the projects delivered to us. Thanks to our partnership with FXPCB, we can produce selective gold plating, and gold finger PCB as low as 1 piece with no upfront cost and with high industrial quality.