The basic performance of electronic connector can be divided into three major categories: mechanical performance, electrical performance and environmental performance.
1. Mechanical properties In terms of connection function, plugging and unplugging force is an important mechanical property. Plug-in force is divided into insertion force and extraction force, and the requirements for the two are different. There are regulations on the maximum insertion force and the minimum separation force in relevant standards, which shows that the insertion force should be small, and if the separation force is too small, it will affect the reliability of the contact.
Another important mechanical property is the mechanical life of electronic connector. Mechanical life is actually a durability indicator, which is called mechanical operation in the national standard GB5095. It takes one insertion and one extraction as a cycle, and is judged based on whether the connector can normally complete its connection function after the specified insertion and extraction cycle.
The insertion and extraction force and mechanical life of the connector are related to the plating quality of the contact parts of the contact structure and the dimensional accuracy of the contact arrangement.
2. Electrical performance The main electrical properties of the connector include contact resistance, insulation resistance and electrical strength.
① Contact resistance A high-quality electronic connector should have low and stable contact resistance. The contact resistance of connectors varies from a few milliohms to tens of milliohms.
② Insulation resistance is an index that measures the insulation performance between the contacts of an electronic connector and between the contacts and the shell. Its order of magnitude ranges from hundreds of megohms to thousands of megohms.
③ Electrical strength, also known as withstand voltage and dielectric withstand voltage, represents the ability to withstand the rated test voltage between the connector contacts or between the contacts and the shell.
④ Other electrical properties.
Electromagnetic interference leakage attenuation is to evaluate the electromagnetic interference shielding effect of the connector. Electromagnetic interference leakage attenuation is to evaluate the electromagnetic interference shielding effect of the connector. It is generally tested in the frequency range of 100MHz~10GHz.
For RF coaxial connectors, there are also electrical indicators such as characteristic impedance, insertion loss, reflection coefficient, and voltage standing wave ratio. Due to the development of digital technology, in order to connect and transmit high-speed digital pulse signals, a new type of connector, namely a high-speed signal connector, has emerged. Correspondingly, in terms of electrical performance, in addition to characteristic impedance, some new electrical indicators have also emerged. , such as crosstalk hysteresis, etc.
3. Environmental performance Common environmental performance includes temperature resistance, moisture resistance, vibration and impact, etc.
① Temperature resistance: The current maximum operating temperature of the connector is 200℃, and the minimum temperature is -65℃. Because when the connector is working, the current generates heat at the contact point, causing a temperature rise. Therefore, it is generally believed that the operating temperature should be equal to the sum of the ambient temperature and the temperature rise of the contact. In some specifications, the maximum allowable temperature rise of the connector at rated operating current is clearly specified.
② Resistance to moisture intrusion will affect the insulation performance of the connection and corrode metal parts. The constant humidity and heat test conditions are relative humidity 90%~95%, temperature +40±20℃, and the test time is as specified by the product, which is at least 96 hours. The alternating damp heat test is more stringent.
③ Salt spray resistance When the connector works in an environment containing moisture and salt, the surface treatment layer of its metal structural parts and contacts may cause galvanic corrosion, affecting the physical and electrical properties of the connector. In order to evaluate the ability of electrical connectors to withstand this environment, the salt spray test is specified. It suspends the connector in a temperature-controlled test chamber to form a salt spray atmosphere, and its exposure time is specified by the product specification, which is at least 48 hours.
④ Vibration and impact Vibration and impact resistance are important properties of electrical connectors. It is an important indicator for testing the robustness of the mechanical structure of the electrical connector and the reliability of the electrical contact. There are clear regulations in the relevant test methods. The peak acceleration and the time for interruption of electrical continuity should be specified in the impact test.
⑤ Other environmental properties: According to the usage requirements, other environmental properties of electronic connectors include sealing, low air pressure, etc.
