How to identify the golden finger in the circuit board?
Gold Finger refers to inserting one end of the pcb into the connector slot, using the plug pin of the connector as the outlet of the external connection of the pcb, making the pad or copper skin contact with the plug pin at the corresponding position to achieve the purpose of conduction, and plating nickel gold on the pad or copper skin of the PCB, so it is called gold finger because it is finger-shaped. Gold is chosen because of its superior electrical conductivity, oxidation resistance and wear resistance, but it is only used for local gold plating such as gold fingers because of its extremely high cost.
Golden finger classification:
1. Regular golden finger (flush finger)
Rectangular pads with the same length and width are arranged neatly at the edge of the board. Commonly used in network cards, graphics cards and other types of physical objects, these golden fingers are more.
2. Long and short golden fingers (i.e. uneven golden fingers)
Rectangular pads with different lengths at the edge of the board are often used for physical objects such as memory, USB flash drive and card reader.
3. Segmented golden finger (intermittent golden finger)
Rectangular pads with different lengths are located at the edge of the board, and the front section is disconnected.
What are the characteristics of the golden finger?
Gold finger has no character frame and logo. Usually, windows are opened for solder mask, and most of them have grooves. In addition, some gold fingers protrude from the edge of the board, or are close to the edge of the board, and some boards have gold fingers at both ends. Normal gold fingers are on both sides, some pcb boards only have single gold fingers, and some gold fingers are wider.
Attention should be paid to whether electroplating leads can be drawn, whether bevel edges are needed, whether the inner layer of the gold finger position is covered with copper, the requirements of gold and nickel thickness of the gold finger, the counting rules of the number of gold fingers and the size specifications of the gold finger.
