How to design thread Pogo pin?

The design of thread Pogo pin (spring top pins) requires comprehensive consideration of multiple factors such as material selection, structural design, manufacturing process and specification parameters. The following is a detailed introduction from the perspectives of materials, structure, process, specifications and future trends, and integrates industry technical standards and cases from multiple sources:

I. Material Selection
The core material of the threaded Pogo pin needs to meet the requirements of electrical conductivity, wear resistance, corrosion resistance and mechanical strength:
1. Plunger and Barrel
Base material: Usually, brass alloy (such as C3604) or beryllium copper is adopted. Brass is low in cost and easy to process, making it suitable for general scenarios. Beryllium copper (such as C17200) is more suitable for high-reliability applications (such as aerospace and medical equipment) due to its high elasticity and fatigue resistance.
Electroplating: Nickel plating (50-100U") on the surface as the base layer, followed by gold plating (3-20U") to reduce contact resistance and enhance corrosion resistance. In scenarios with high current, the thickness of the coating needs to be increased (such as gold plating >16U").

2. Spring
Commonly used stainless steel (SUS304) or piano steel wire needs to be electroplated with gold or nickel to improve electrical conductivity and corrosion resistance.

3. Plastic parts (Housing)
High-temperature resistant halogen-free materials (such as LCP, PA9T, PPS) are selected to meet the UL94V-0 fire resistance rating and ensure stability in high-temperature environments.

Ii. Structural Design
The unique structure of the threaded Pogo pin needs to take into account both mechanical stability and electrical performance:
1. Threaded connection design
The outer wall of the needle tube or the plastic shell is designed with a threaded structure to enhance the mechanical locking of the interface with the equipment, making it suitable for scenarios with frequent vibration or frequent plugging and unplugging (such as industrial equipment).
The thread fit requires precise calculation of the pitch and diameter to avoid wear caused by being too tight or poor contact caused by being too loose.

2. Coordination of core components
Bevel/reverse drilling structure: The bottom of the needle adopts a bevel or reverse drilling design to ensure close contact with the inner wall of the needle tube, reducing impedance (<30mΩ) and supporting high current (such as above 10A).
Spring preload design: The spring force needs to be adjusted according to the working stroke (such as >60gf) to ensure contact stability and service life (>10,000 insertions and removals).

Iii. Manufacturing Process
Precision machining
CNC turning: The thread structure of the needle tip and needle tube needs to be processed by high-precision CNC, with the tolerance controlled within ±0.01mm to ensure the thread fit accuracy.
Mirror polishing: The inner wall of the needle tube is treated with hairline process or mirror turning to reduce friction loss and enhance contact stability.

2. Electroplating process
Pulse electroplating technology is adopted to ensure the uniformity of the coating. For example, the nickel layer thickness is greater than 60U" and the gold layer thickness is greater than 4U" to enhance wear resistance.

3. Automated assembly
Spring preloading and the assembly of needles and syringes are accomplished through automated equipment, avoiding human errors and enhancing consistency.

Iv. Specifications and Parameters
1. Electrical performance
Current carrying capacity: The conventional design is 1.5-2A, and for high-current structures (such as ball-assisted), it can reach 10A.
Contact impedance: Initial contact impedance <30mΩ, and within the working life <100mΩ.
Withstand voltage: 500V AC/1 minute, leakage current <0.3mA.

2. Mechanical and environmental performance
Operating temperature: -40℃ to +85℃, resistant to salt spray for 24 hours without rust.
Vibration test: At a frequency of 10-500Hz for 15 minutes, the contact impedance fluctuation is less than 100 M Ω.

V. Future Trends
Miniaturization and high density
Nanoscale threaded Pogo pins can be applied to wearable devices and micro-sensors, with the spacing reduced to less than 1.0mm.
2. Intelligent integration
By integrating optical fiber or wireless transmission functions, it expands its application in smart wearables and medical devices.

Vi. Design Considerations
Application scenario adaptation: Select materials and structures based on requirements such as current, vibration, and temperature (for example, beryllium copper is preferred in the military field).
Test verification: It is necessary to pass thermal shock (-40℃ to 85℃ cycle), salt spray, durability tests, etc., to ensure reliability.

Through the above design points, the threaded Pogo pin can achieve stable connection in high vibration, large current and harsh environments. The specific parameters need to be customized in combination with the customer's requirements. It is recommended to cooperate with the professional manufacturer (Cnomax Pogo pin Factory) and utilize its mature technology and testing capabilities to optimize the design.