1. What tests are usually conducted on power connectors?

In addition to general tests such as contact resistance, insulation resistance, voltage withstand, solderability, insertion/withdrawal force, vibration, environmental tests, power connectors also require the following special tests:

1. Temperature rise and current relationship test: This test measures the temperature rise of the connector under high current load to ensure that the connector does not overheat under normal operating conditions.

2. Hot-plug test: If there are hot-plug requirements, a hot-plug test is conducted to simulate the performance of the connector under continuous insertion and withdrawal.

Compared to signal connectors, power connectors focus more on current transmission and stability, while signal connectors focus more on signal integrity.

2. What are the reasons for the pins of a connector not being tinned? How should it be handled?

If soldering process issues (such as soldering temperature, appropriate flux, excessive soldering time, etc.) are ruled out, the pins of a connector not being tinned may be caused by contact surface oxidation or contamination. The following measures can be taken to address this issue:

1. Ensure that the connector is used as soon as possible after opening the package to prevent contact surface oxidation.

2. Pay attention to the storage environment, keep it dry, and avoid moisture affecting the connector.

3. Check the coating of the connector to ensure that the substrate is not exposed.

First, it is necessary to determine the specific cause of the pins not being tinned. If it is a process issue, the soldering process needs to be improved. If the pins are contaminated, they need to be cleaned. If the contact surface is oxidized, there is currently no effective reductant to remove the oxide layer, and it may be necessary to consider scrapping the connector. In practice, for small batches, some companies use the method of scraping off the oxide layer before soldering, but the reliability of this approach has not been fully validated.

3. In the whole machine test, automatic shutdown failure occurs, and it has been confirmed that it is caused by poor contact of the connectors on the mainboard. The supplier now provides improved products. How to test whether this batch of new materials has been improved? Are there any relevant standards?

It is recommended to first identify the root cause and find the real problem instead of just addressing surface phenomena. The wires should be disconnected first, and then the connectors, wires, and crimping should be tested and evaluated separately to determine if they contribute to the problem.

At the same time, it is necessary to check whether the supplier has taken improvement measures for this issue and evaluate the rationality and effectiveness of these measures.

To test whether this batch of new materials has been improved, the following steps can be taken:

1. Conduct contact resistance tests: Test the contact resistance of the connectors to ensure good connectivity.

2. Conduct reliability tests: Simulate actual usage scenarios to test the stability and reliability of the connectors under prolonged use and high load conditions.

3. Conduct hot-plug tests: If there are hot-plug requirements, test the performance of the connectors under frequent insertion and withdrawal.

Relevant standards can be referenced, such as those from the International Electrotechnical Commission (IEC), to ensure the accuracy and comparability of the testing process and results.