In the precision construction of modern electronic devices, the PCB printed circuit board plays a central role, and the Gold Finger, as a key part of the high-reliability connection, its surface quality directly affects the performance and service life of the board.

Gold finger refers to the gold contact bar on the edge of the PCB, which is mainly used to establish a stable electrical connection with other electronic components (such as memory and motherboard, graphics card and host interface, etc.). Due to its excellent electrical conductivity, corrosion resistance and low contact resistance, gold is widely used in such connection parts that require frequent insertion and removal and maintain long-term stability.

Gold plating rough effect

Decreased electrical performance: The rough surface of the gold finger will increase the contact resistance, resulting in increased attenuation in signal transmission, which may cause data transmission errors or unstable connections.

Reduced durability: The rough surface is easy to accumulate dust and oxides, which accelerates the wear of the gold layer and reduces the service life of the gold finger.

Damaged mechanical properties: The uneven surface may scratch the contact point of the other party during insertion and removal, affecting the tightness of the connection between the two parties, and may cause normal insertion or removal.

Aesthetic decline: although this is not a direct problem of technical performance, the appearance of the product is also an important reflection of quality, and rough gold plating will affect customers’ overall evaluation of the product.

Acceptable quality level

Gold plating thickness: In general, the gold plating thickness of the gold finger is required to be between 0.125μm and 5.0μm, the specific value depends on the application needs and cost considerations. Too thin is easy to wear, too thick is too expensive.

Surface roughness: Ra (arithmetic mean roughness) is used as a measurement index, and the common receiving standard is Ra≤0.10μm. This standard ensures good electrical contact and durability.

Coating uniformity: The gold layer should be uniformly covered without obvious spots, copper exposure or bubbles to ensure the consistent performance of each contact point.

Weld ability and corrosion resistance test: salt spray test, high temperature and high humidity test and other methods to test the corrosion resistance and long-term reliability of gold finger.

The gold-plated roughness of the Gold finger PCB board is directly related to the connection reliability, service life and market competitiveness of electronic products. Adherence to strict manufacturing standards and acceptance guidelines, and the use of high-quality gold plating processes are key to ensuring product performance and user satisfaction.

With the advancement of technology, the electronics manufacturing industry is also constantly exploring more efficient, environmentally friendly and economical gold-plated alternatives to meet the higher requirements of future electronic devices.