A mechanical properties
On connectivity, the insertion force is important to mechanical properties. Insertion force divided insertion and extraction force (also known as pull-out strength separating force), the two requirements are different. In the standard have a maximum and minimum insertion force required separation force, which indicates, from the use point of view, the insertion force to be small (and thus with low insertion force and no insertion force ZIF LIF structure), and if the separation force is too small, will affect the reliability of the contact.
Another important mechanical properties of the connector mechanical life. Mechanical life is actually a durability (durability) indicators in the national standard GB5095 called it mechanically operated. It is based on insertion and once again pulled out of a cycle to cycle in the specified plug connector can normally complete its connectivity features (such as contact resistance value) as a basis for judgment.
Insertion force connector contacts and mechanical lifetime and structure (positive pressure size) contact parts coating quality (coefficient of sliding friction) and contact arrangement dimensional accuracy (aligned degrees) about.
Second, the electrical properties
The main electrical connector performance including contact resistance, insulation resistance and dielectric strength.
① high contact resistance of the electrical connector should have a low and stable contact resistance. Connector contact resistance from a few milliohms to tens of milliohms range.
② measure electrical insulation resistance between the connector contacts and contact between the shell insulation performance indicators, on the order of hundreds to thousands of megohms megohms range.
③ said dielectric strength or resistance, voltage, medium voltage, is the characterization of the connector contacts or between contacts between the shell's ability to withstand the rated test voltage.
④ Other electrical performance.
Attenuation of electromagnetic interference of the connector is to evaluate the effect of electromagnetic interference shielding, electromagnetic interference of the connector is to evaluate the attenuation of the electromagnetic interference shielding effect, generally in the frequency range of 100MHz ~ 10GHz testing.
RF coaxial connectors, as well as the 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, the emergence of a new type of connector that is high-speed signal connectors, accordingly, the electrical properties, in addition to the characteristic impedance, but also there are some new electrical indicator such as crosstalk (crosstalk), propagation delay (delay), delay (skew) and so on.
Third, the environmental performance
Common environmental performance, including temperature, humidity, salt spray, vibration and shock.
① Temperature currently connectors maximum operating temperature of 200 ℃ (except for a few special high-temperature connector), the lowest temperature of -65 ℃. Because the connector work, the current generates heat at the contact point, causing temperature rise, it is generally considered to be equal to the ambient temperature and the junction temperature rise and temperature. In some regulation which expressly provides connectors rated operating current maximum allowable temperature rise.
② moisture intrusion of moisture will affect the connection h insulating properties, and corrosion of metal parts. Damp heat test conditions relative humidity of 90% ~ 95% (based on product specification, up to 98%), temperature +40 ± 20 ℃, according to the specified test time, a minimum of 96 hours. Damp heat test is more stringent.
③ connector resistant to salt spray and salt in the presence of moisture in the work environment, its metal structure, the contact surface treatment layer may produce galvanic corrosion, affecting the physical and electrical connector performance. To evaluate the tolerance of the electrical connector such environments, the salt spray test requirements. It is suspended in the connector inside the temperature-controlled trial, the concentration of sodium chloride solution with a predetermined compressed air is ejected to form salt atmosphere, the exposure time from the product specification of at least 48 hours.
④ vibration and shock resistance to vibration and shock are important properties of electrical connectors, in particular application environments such as aviation and aerospace, rail and road transport is particularly important, it is the test of the electrical connector mechanical ruggedness and reliable electrical contact important indicator. In the relevant test methods are clearly defined. Impact test shall be provided that the peak acceleration, duration and impact pulse waveform, as well as electrical discontinuity of time.
⑤ Other environmental performance according to requirements, the electrical connector and sealing other environmental performance (air leakage, fluid pressure), liquid immersion (a liquid for a particular abuse resistance capabilities), and low pressure. |
