On-board connectors are common products in the electronic market. They have extremely strong transmission capabilities and can be widely used in many fields, mainly in communication networks, power systems, industrial automation, medical equipment, office equipment, and smart home appliances, military manufacturing and many other industries. This article mainly explains the test analysis and test inspection of on-board PCB connectors.
Test Analysis
1. Under working condition, current generates heat at the contact point, causing the temperature to rise. Therefore, it is generally believed that the working temperature should be equal to the sum of the ambient temperature and the contact temperature rise, and the allowable temperature rise under the rated working current is stipulated.
2. When connector works in an environment containing moisture and salt, the surface treatment layer of metal structural parts and contacts may produce electrochemical reaction, which will affect the physical use and electrical performance of the connector on PCB.
3. The intrusion of moisture will affect the insulation performance of connection and corrode the metal parts. Constant damp heat test conditions are 90%~95% relative humidity , +40±20°C temperature. Test time is changed according to product regulations. And alternating damp heat test is more strict.
4. Troubleshooting. When a fault occurs, it may be caused by broken wires, poor connection, loose connector terminals, etc. Since wires rarely break in the middle, most break at the connector side. Therefore, during the inspection process, we should pay attention to carefully check whether the connection between the sensor and the wires along the line is loose or not.
5. Open circuit faults caused by poor contact are often due to corrosion at the end of the connector, external dirt enters the terminal or connecting socket resulting in a decrease in contact pressure. At this time, we just need to remove and reinstall, change its connection status, and then restore normal contact.
Inspection Instruction
1. Note that the loaded voltage should not exceed 50% of its rated voltage.
2. Installation size for plug-in connectors, the length of the solder leg welded to the PCB requires that the exposed part of the PCB be ＞0.5mm.
3. For on-board connectors with high precision, try to choose the model with alignment pins if the PCB space allows, so as to facilitate manual soldering.。
4. Check whether there is a stay-proof design.
5. Check if the materials contain lead.
6. Connectors on small volume plates have low contact pressure. It is recommended to use gold-plated or silver-plated connectors when using in low current and low voltage occasions to avoid the influence of film resistance on the signal.
7. Pay attention to check whether the height after matching conforms to the welding height of components around the PCB. The matching height must be greater than the welding height of components around the PCB, and there must be a certain margin to ensure no interference. In particular, attention should be paid to the possible height error of the components after PCB soldering.
