Basic properties of connectors

Basic properties of connectors

What are the basic properties of the connector? What is a connector? The connector is also called a plug-in connector, which is a component that electronic engineering technicians often contact. Also known as connectors, plugs and sockets in China. The connector is the core basic element necessary for the electrical connection of the whole circuit system. Its function is to realize connection, disconnection or conversion by means of electrical/optical signals and mechanical force. For more information, please contact us.

The basic properties of connectors can be divided into three categories: mechanical properties, electrical properties and environmental properties.

Mechanical behavior

Mechanical Properties Insertion force is an important mechanical property in terms of connection function. The insertion force is divided into the insertion force and the extraction force (the extraction force is also called the separation force), and the requirements of the two are different. In the relevant standards, there are provisions for the maximum insertion force and the minimum separation force, which means that from the point of view of use, the insertion force should be small (thereby a structure with low insertion force LIF and no insertion force ZIF), and if the separation force is too small, will affect the reliability of the contact.

Another important mechanical property is the mechanical life of the connector. Mechanical life is actually a durability index, which is called mechanical operation in the national standard GB5095. It takes one insertion and one extraction as a cycle, and judges whether the connector can normally complete its connection function (such as contact resistance value) after the specified insertion and extraction cycle. The insertion force and mechanical life of the connector are related to the contact structure (positive pressure), the coating quality (sliding friction coefficient) of the contact part, and the dimensional accuracy (alignment) of the contact arrangement.

Electrical properties

Electrical properties The main electrical properties of connectors include contact resistance, insulation resistance and electric strength.

1. Contact resistance High-quality electrical connectors 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 to measure the insulation performance between the contacts of the electrical connector and between the contacts and the shell, and its magnitude ranges from hundreds of megohms to several gigaohms.

3. Dielectric strength, or withstand voltage, dielectric withstand voltage, is to characterize the ability of the connector to withstand the rated test voltage between the contacts or between the contacts and the shell.

Environmental performance Environmental performance Common environmental performance includes temperature resistance, humidity resistance, salt spray resistance, vibration and shock.

1. Temperature resistance At present, the maximum working temperature of the connector is 200 °C (except for a few high-temperature special connectors), and the minimum temperature is -40 °C. Since the current generates heat at the contact point when the connector is working, resulting in a temperature rise, 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 point. In some specifications, the maximum rise allowed by the connector at the rated operating current is specified.

2. The intrusion of moisture resistance will affect the insulation performance of the connection H and corrode metal parts. The constant damp heat test conditions are relative humidity 90%~95% (according to product specifications, up to 98%), temperature +40±20℃, and the test time is at least 96 hours according to product regulations. The alternating damp heat test is more severe.

3. When the salt spray-resistant connector works in an environment containing moisture and salt, the surface treatment layer of its metal structural parts and contact parts may cause galvanic corrosion, which affects the physical and electrical properties of the connector. To evaluate the ability of electrical connectors to withstand this environment, the salt spray test is specified. It is to hang the connector in a temperature-controlled test box, and spray the sodium chloride solution with the specified concentration with compressed air to form a salt fog atmosphere. The exposure time is specified by the product specification, at least 48 hours.

4. Vibration and shock Vibration and shock resistance is an important performance of electrical connectors, especially in special application environments such as aviation and aerospace, railway and road transportation. It is to test the robustness and electrical contact of the mechanical structure of electrical connectors. important indicator of reliability. There are clear provisions in the relevant test methods. The shock test shall specify the peak acceleration, duration and shock pulse shape, as well as the time of interruption of electrical continuity.

5.?Other environmental properties According to the requirements of use, other environmental properties of the electrical connector include sealing (air leakage, liquid pressure), liquid immersion (the ability to resist deterioration of specific liquids), low air pressure, etc. In addition, different types of connectors have their own unique technical characteristics and difficulties. Connectors used in different industries have different requirements. In the future, connector engineers and manufacturers will continue to pose new challenges. In general, At present, the biggest technical difficulty of connectors is to ensure the reliability of products under the premise of miniaturization, but according to relevant industry experts, it will not pose a big threat to some large professional connector manufacturers. The "miniaturization", "high-speed mobility" and intelligentization of connector products are the trends of future development.

Learn more about electronic components industry news：

Click on Asourcing Electronics Ltd. Website