PCB Blog - Introduction to Hard Gold PCB Technology

A hard gold PCB includes a layer of gold and an additional hardener to help improve durability. Hard gold is a durable material and an ideal material for electroplating circuit boards. In the manufacturing process of circuit boards, gold is used in high-wear areas, such as edge connectors. Most circuit boards have metal contacts made of gold.

Hard gold is an example of PCB surface treatment. Due to the high cost and poor weldability of hard metal, it is not an ideal weldable area. Hard gold PCBs are very suitable for applications that require friction.

Compared to other surface treatments, hard gold treatment provides essentially tough frictional resistance. It is used to create gold fingers/edge fingers on circuit boards. When a PCB is designed to insert another board (such as RAM), this surface treatment is the best choice.

Application of Hard Gold PCB

Hard gold PCB is an ideal choice for some applications. This type of circuit board is commonly used in industrial intelligent machines. You can find them in entertainment, artificial intelligence, and educational robots. Various electronic devices use this type of PCB. For example, mobile phones, computers, and other devices all use this type of PCB. Hard gold PCBs can maintain electrical connections. This makes it a suitable choice for various types of applications.

1. Computer system

Gold PCBs are commonly used in computer systems. These circuit boards can be used for laptops and desktops. Signal integrity and data transmission are key aspects of computer systems.

2. Telecommunication system

Hard gold PCB is an ideal material for use in telecommunications systems. These circuit boards can be used for mobile phones, GPS, and satellite systems.

3. Industrial system

You will find gold-plated hard circuit boards in mechanized equipment. Industrial machines controlled by computers are characterized by this type of PCB due to its unique characteristics. Due to its corrosion resistance and wear resistance, this type of plate is ideal for this application.

4. Consumer electronics

Hard gold PCB will not corrode or rust. Gold has good conductivity, which enables them to withstand high temperatures. Consumer electronics such as smartphones, televisions and smart watches all use hard gold PCBs.

The Effect of Bottom Layer on Hard Gold PCB

Gold is more useful when used together with other metals. The characteristic of the gold-plated plate is that there is a layer of nickel on the substrate. Nickel is usually placed below the gold plating layer. There are several benefits to using bottom gold plating. The substrate layer serves as an additional protective layer against any form of corrosion. Sometimes, corrosion may pass through pores in certain areas of gold plating.

The lower layer can also prevent the oxidation of metals such as copper and zinc. When these metals diffuse into gold, they may oxidize. In addition, the substrate layer increases the thickness of the coating. This additional thickness improves the durability of the coating. Nickel or cobalt can be added to gold to improve the durability of the coating.

Introduction to Hard Gold PCB Technology

1. Purpose and function: As a precious metal, gold has good weldability, oxidation resistance, corrosion resistance, low contact resistance, and good wear resistance as an alloy.

At present, the main method for electroplating gold on circuit boards is a citrate gold bath, which is widely used due to its simple maintenance and easy operation.

3. The gold content in water should be controlled at around 1 gram/liter, with a pH value of around 4.5, a temperature of 35 degrees Celsius, a specific gravity of around 14 waves, and a current density of around 1ASD.

4. The main added drugs include acid salt and alkali salt for adjusting pH value, conductive salt for adjusting specific gravity, gold plating supplementary additives, and gold salt.

5. To protect the gold cylinder, a citric acid immersion tank should be added in front of the cylinder to effectively reduce pollution and maintain its stability.

6. After electroplating the gold plate, rinse it with pure water as recycled water. At the same time, it can also be used to supplement the evaporation changes of the liquid level in the gold cylinder. After washing with water, it is connected to the second stage countercurrent pure water washing. After washing the gold plate, put the alkaline solution into a 10g/pulverizer. Prevent gold plate oxidation.

7. The gold cylinder should use platinum-plated titanium mesh as the anode. Generally, stainless steel 316 is easy to dissolve, causing nickel iron chromium and other metals to pollute the gold cylinder, resulting in defects such as white plating, exposed plating, and blackening.

8. Organic pollution in the gold cylinder should be continuously filtered with carbon cores and supplemented with an appropriate amount of gold plating additives.

Hard gold PCBs are widely used in intelligent AI, entertainment, educational robots, or other industrial intelligent devices. They expand and contract, with rich movement and frequent separation and contact of local ports in the equipment. This requires the PCB in the port contact area to have good wear resistance. Sexual and not easily oxidized.

Hard gold PCBshave a hard surface and are resistant to friction, making them suitable for areas that do not require welding but are subjected to stress and friction. Commonly used for selective gold plating on specific parts of circuit boards, it reduces the use of gold while balancing manufacturing costs and product performance.