A high spring force on the test probe does not equate to good contact. According to past experience, the elastic force of the test probe should be as low as possible, so as to make the load of the test sample as small as possible. But the spring force should be high enough to ensure good electrical contact when introduced with the double-ended spring charging pin (Figure 1). In addition, factors such as needle shape and test environment need to be considered. After this, the correct spring force can be selected for the required test probe.
1. Size selection of double-ended spring charging needle:
The size of the pin is determined by the strength of the design, the current load, and the shape, but a large diameter usually increases the cost significantly. In addition, the double-ended spring charging needle has two needles, and the price is naturally much more expensive than the vertical spring charging needle.
2. Height selection of double-ended spring charging pin:
The height of the pin is determined by the working height, that is, the height of the working compression and the accuracy of the installation of the matching parts. Usually, the compression stroke is about 70% of the total stroke.
3. Selection of current load of double-ended spring charging needle:
The current load requirements are different, and the entire design parameters should be changed and adjusted accordingly.
4. Durability selection of double-ended spring charging needle:
Durability, Life: Durability is based on dynamic testing, not static testing. The difference between the results of static testing and dynamic testing is very large, which can reach dozens of times. Durability is related to many factors. Usually, 10,000 lifespans are cost-effective. If you want to increase durability, you need to customize.
Generally speaking, the spring charging pins have different appearances according to different applications, but as a whole, there is a precise spring structure inside the spring charging pins. The surface of the product is generally gold-plated, and the spring should also be gold-plated when the process requires.