Connectors are ever-changing form and structure, with the application object, frequency, power, application environment and so different, there are different forms of connectors. Despite the large number of connector types, but the basic properties of divided into three broad categories: namely, mechanical properties, electrical performance and environmental performance. Connector is an indispensable electronic equipment components, it has been blocked in the circuit at the circuit or isolated unreasonable between the bridge the communication gap, so that electric current flows, so that the circuit to achieve predetermined functions. Connectors are ever-changing form and structure, with the application object, frequency, power, application environment and so different, there are different forms of connectors. Despite the large number of connector types, but the basic properties of divided into three broad categories: namely, mechanical properties, electrical performance and environmental performance.
Mechanical Properties
On the connectivity, the plug is an important force in mechanical properties. Plug Power is divided into insertion force and pull-out strength (pull-out strength also known as separation of power), the two requirements are different. In the relevant standards, the maximum insertion force and the minimum separation of power provisions, which indicates that from the use of perspective, the insertion force is smaller (and thus have a low insertion force, LIF and non-insertion force ZIF structure), while the separation of power if it is too small, will affect the contact reliability.
Another important mechanical properties is the mechanical life of the connector. Mechanical life is actually a durability (durability) target in the national standard GB5095 Chinese it is called mechanical handling. It is based on an insertion and a pull out for a cycle to cycle, after the required plug connector can connect properly to fulfill its functions (such as contact resistance value) as a basis for judging. Plug power connector and mechanical life of the structure with the contacts (positive pressure size) contact area plating quality (sliding friction coefficient) as well as contacts arranged dimensional precision (alignment degrees) about.
Electrical
The main electrical performance of connectors, including contact resistance, insulation resistance and electric strength.
Contact resistance of high-quality electrical connectors should have a low and stable contact resistance. Connector contact resistance from a few dollars to tens of milli-Europe Europe ranges.
Insulation resistance to measure electrical connector contacts and contacts between the insulation between the parts and the case of indicators, their order of magnitude of several hundred to several thousand megohm megohm range.
Electric strength or resistance to anti-called voltage, medium voltage, is characterized by the connector contacts or contacts between the parts and the shell rated test voltage between the tolerance capability.
Other electrical performance. Leakage of electromagnetic interference attenuation is to evaluate the connector effects of electromagnetic interference shielding, electromagnetic interference attenuation is to evaluate the connector leakage of electromagnetic interference shielding effectiveness, generally in the 100MHz ~ 10GHz frequency range of tests. In terms of RF coaxial connectors, as well as characteristic impedance, insertion loss, reflection coefficient, voltage standing wave ratio (VSWR) and other electrical indicators. As digital technology, in order to connect and transmit high-speed digital pulse signal, there has been a new type of connector that the high-speed signal connectors, accordingly, in the electrical performance, in addition to the characteristic impedance, but also the emergence of new electrical indicator , such as crosstalk (crosstalk), propagation delay (delay), delay (skew) and so on.
Environmental Performance
Common environmental performance, including temperature, moisture, resistant to salt spray, vibration, and shock.
Temperature. The current connectors maximum operating temperature of 200 ‘ζ (except for a small number of high-temperature special connector) and the minimum temperature of -65 ‘ζ. As the connector work, the current point in contact with heat, resulting in temperature rise, it is generally believed that temperature should be equal to the ambient temperature and the contact temperature combined. In some specifications, clearly defined the connector at rated operating current to allow the maximum temperature rise.
Moisture. The intrusion of moisture will affect the connection h insulation performance and corrosion of metal parts. Constant hot and humid test conditions for the relative humidity 90% ~ 95% (based on product specifications, up to 98%), temperature +40 ± 20 ‘ζ, test time by product provides at least 96 hours. Alternating damp heat test is more stringent.
Resistant to salt spray. Connector in an environment containing moisture and salt to work, its metal structure to reach the surface treatment layer may produce the electrochemical corrosion, affecting the physical connectors and electrical performance. To evaluate the electrical connectors withstand such an environment the ability to provide a salt spray test.
Vibration and shock resistant to vibration and shock are important performance electrical connectors, in special environments such as aviation and aerospace, rail and road transport is particularly important, as it is the test electrical connectors mechanical robustness and reliability of electrical contact an important indicator. In the relevant test methods are clearly defined. Impact tests should be required to peak acceleration, duration and impact of pulse waveforms, as well as the interruption of electrical continuity of time.
Other environmental performance according to use requirements, electrical connectors are sealed to other environmental performance (air leak, the liquid pressure), liquid impregnation (for specific anti-abuse capabilities of liquid), low pressure and so on.
Source Electronic Components Technology
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