The high temperature test was divided into two groups, and the test was carried out in the range of 105 ± 2 ° C for 96 hours. One group of tests is that the test sample is directly inserted through the board to board connector without fixing it on the aluminum shell of the walkie talkie with screws; Another group of test samples were fixed with screws to increase the contact pressure between the board connectors. At the end of the experiment, it was found that the results of the two groups were very different. There are two pairs of contact pairs failure in the unfixed sample, but only two pairs of contact terminals failure in the fixed sample. Combined with the application of board connector in walkie talkie, the next environmental stress test will fix the test sample through aluminum shell.

During the test, put the test sample into the high and low temperature alternating damp heat test chamber, then raise the temperature to the highest temperature and keep it unchanged until the temperature is stable, and then power on the test sample for test. After the high temperature test, stop the power supply and return to the normal test atmosphere condition in the test chamber until the temperature of the test sample is stable, then carry out the test and record the results. Figure 3-5 shows the change of contact resistance of connector contact terminal after high temperature test. Statistical test results show that the contact pair 1 and contact pair 2 of the first circuit board are invalid.