Pogo pins are usually arranged in a dense array, connecting together many individual nodes of two circuit boards.
Although these little tiny pogo pins seem uncomplicated, the whole manufacturing process is worth paying attention to. Because unqualified products have short service life cycles and will increase costs, which leads to the reduction of efficiency.
Manufacturing good pogo pins is up to:
- the quality of pins and
- the plating process
The following paragraphs will show you some key steps to monitor the quality of pogo pins. Hope it will be helpful!
1. The quality of pins
Pogo pin consists of three basic parts: plunger, tube and spring. The quality of these three parts straight determines the whole pin’s reputation.
1.1 How to manufacture a good plunger
Brass material with good electrical conductivity is always the best suit for plungers.
In order to ensure that the plunger possesses good hardness and corrosion resistance, most manufacturers plate gold to the surface of plunger.
1.2 How to manufacture a good tube
The main function of tube is to conduct signals, so the conductivity and elasticity (falling strength) of material must be excellent.
Most of tubes are made of copper alloy. The commonly used copper alloy is as follows:
A. Brass: copper-zinc alloy, which has good electrical conductivity (about 26%~29%, IACS). According to different rations of cooper, there are 3 common types: C2680 (JIS) and C3604, C3601. Heat treatment required.
B. Phosphor bronze: copper-tin alloy, which is less conductive than brass and has a conductivity rate of about 13%.
But it has good elasticity and good ductility, which means really suitable for making tubes applied stretching process. According to different tin contents, C5440, C5191 and C5210, are 3 types of phosphor bronzes. Higher the tin content, worse the conductivity and better the elasticity.
C. Heat-treated copper alloy: it has a good conductivity and elasticity, but the price is high.
1.3 How to make a good spring
Beryllium copper, stainless steel and steel wire are raw materials for pogo pin springs. Each material has its own unique characteristics.
The spring used to assemble a pin needs to have following effects: small installation volume, good elasticity, high rigidity and nice shape.
2. The plating process
In this part, we will recommend the plating methods possessing excellent electrical conductivity and outstanding efficiency, which are suitable for plunger, tube and spring.
2.1 Plunger plating
The plunger of pogo pin is basically gold-plated, which is the preferred treatment method for manufacturers because gold has excellent electrical conductivity and oxidation resistance.
In addition, the thickness of gold plating absolutely affects product’s life. Considering product costs, manufacturers sometimes choose to use nickel base to handle the thickness of gold plating.
According to different needs, some other plating solutions like rhodium plating and palladium plating are also very useful.
2.2 Tube plating
The tube is a deep-processed part with 2 steps of nickel plating and gold plating.
First of all, a nickel substrate treatment is necessary, and the usual thickness is 1 to 2 μm. Then plating the surface with gold, and thickness is substantially 0.1 to 1.0 μm.
For a tube with a small diameter and a relatively long length, manufacturers usually open a side hole at the bottom, so that the plating solution can sufficiently reflow at the bottom of the tube to ensure the precipitation of gold at the bottom of inner wall.
2.3 Spring plating
The spring’s surface is basically silver. For better conductivity, gold plating is sometimes necessary because gold can improve electrical conductivity and has high thermal performance as well as oxidation and corrosion resistance.
3. Precautions for using the spring pin
A. Be careful of the contact direction of pogo pins
When working, the direction of pogo pins should be vertical. Avoid stressing the spring pin from sides and other non-vertical directions.
B. Bear in mind that he battery contacting with pins should not be oxidized
- No residual sealing liquid;
- No other residual residues;
- Avoid touching the plastic barrier during assembly.
C. Pay attention to Pogo pin’s amount of compression
The compression of pogo pin is generally 2/3 of the total stroke. If the press is too small, positive force is not enough, which will lead to unstable impedance; if the press is too much, tube will be injured and pin will be stuck.
Those are some important tips you should focus on, when you are trying to choose the best pogo pin for your products. Feel Free to leave you comment below if you have any questions.
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