Detailed description of PCB golden finger
Author:lingling Time:2021-06-07 14:36 Browse(55)
PCB gold finger detailed description, touch screen and OLED Forum
1、 What golden finger 5 W $V9 Z1 T2 U. V (_ 2 R5 S1. Explanation of gold finger: the pad with finger arrangement is used to insert into the slot and contact with the metal spring in the slot. Because this kind of design has higher requirements on the wear resistance and conductivity of the pad surface, it will be plated with a layer of nickel and a layer of gold on the pad surface, so it is generally called gold finger: m3 ^4 g& o2 ?& X / J /] 2. The function of golden finger is to connect the golden finger with the spring plate in the card slot.

Detailed description of PCB golden finger

to realize the interconnection between the external PCB and the motherboard, and at the same time, it is convenient to remove and replace due to the difference of user's performance requirements.
the most common golden finger design appears in the display card and memory module in the computer.
as shown in the figure below: 6 R2 W7 ~) q% s                                                         .# F9 z" b* o; o; E + I% E 2. Characteristics of golden finger: G    e+ T7 {4 M/ v7 f1. Why do you want to make golden finger 5 i'w^& E1 GA unique PCBA needs to be interconnected with the motherboard, but it also needs to be easily replaced.
the connection between gold finger and socket is designed, which is similar to the relationship between power plug and socket- E* \/ m# Q' O$ e: m    Because gold has good conductivity and strong inertia, it can ensure the conductive effect without oxidation. At the same time, because gold is wear-resistant, it can also ensure good enough conductivity after frequent plugging.
6 Q '] - t. w5h; t4 ?2. According to different scenarios.
2How to select the technical requirements of golden finger 9 p+ DGenerally speaking, the gold finger refers to the hard gold plated 5-30u "on the fingers, which has better wear resistance and can ensure 20000 times of insertion and removal without affecting the quality, and must be more than 5u" thick.
however, the processing technology of hard gold is relatively complex.
the requirement of gold thickness is high, and more gold salt is consumed, which directly results in high cost.
in fact, many PCBs do not need frequent insertion and removal, There is no need to make thicker gold, or even replace it with chemical gold instead of hard gold, which can effectively reduce the purchase price of PCBProcessing method of gold finger! j5 k* _& O- [6 ? The standard hard gold plated finger is electroplated, which requires all fingers to conduct electricity during electroplating. Therefore, wires will be added under the gold finger. First, a layer of dielectric nickel is plated on the copper surface, and then gold is plated on the nickel layer according to the required thickness.
the standard hard gold plated finger is electroplated    o2 O3 k7 u) M   \( a    Before gold plating on fingers.
cover all other non gold plated pads with adhesive tape. After gold plating, tear off the adhesive tape and then cover the gold fingers with adhesive tape. Other pads shall be treated with tin spraying, OSP and gold melting as required, and the adhesive tape on the gold fingers shall be torn off after the pad treatment.
after the gold plating, the adhesive tape on the gold fingers shall be removed* I$ n    1. I / C "G5 z7 B ★ when forming, the golden finger grinds the beveled edge.
it is convenient to insert the card slot.
it is convenient to insert the card slot; J. ~2 E1 R* f! `/ G / [/ R 3. Precautions for golden finger design    m.
p( c4 \; ? 9 N1. First, make sure that the length, width and position of the gold finger are completely corresponding to the card slot to ensure correct interconnection   {+ y1 R$ D   ^( C3 m    2. The width, height, position and bulge in the card slot of the anti dummy key slot designed on the PCB completely match 5g + I    r. m8 Q3. Some PCBs need to be designed with short fingers. If it is impossible to add wires directly under the fingers, it is necessary to consider how to conduct 0 K8 V & V when gilding_/ p9 E6 w    Z4. The bevel angle and depth of the gold finger are consistent with the finger length, so it is not necessary to make the finger too short after the bevel or the residual thickness too thin after the bevel to be used.
more PCB related contents can be found on jiepei's official website.
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