Connector Quality Assurance Technology
Blog | Jan 03,2023
The quality assurance technology of connectors from design to production is the most basic technology indispensable to manufacturing companies.
The upstream raw materials of the connector industry are non-ferrous metals, rare and precious metals, plastic materials, and other auxiliary materials.
Among them, non-ferrous metals are mainly used to make connection terminals.
In order to avoid excessive obstruction or degradation of signals during transmission, terminals mostly use copper alloy plates such as brass, beryllium copper, and phosphor bronze as raw materials;
Rare and precious metals are used as electroplating Materials, the most commonly used are gold, palladium gold, nickel, silver, etc.;
Plastic raw materials are mainly PBT, PCT, LCP, PPS, NYLON resin, etc., which are used to make the shell part of the connection;
Auxiliary materials are mainly chemical reagents required for electroplating, Also include shell parts such as ceramics and glass.
The cost of raw materials accounts for about 30% of the cost of connector products. Among them, non-ferrous metals and rare and precious metals account for the largest proportion of the cost of connectors, followed by plastic raw materials and other auxiliary materials.
The main downstream application fields of connectors are automobiles, communications, consumer electronics, industrial and other fields, accounting for 71% of the total.
The top four application areas of connectors are automobiles (23%), communications (21%), consumer electronics (15%), and industry (12%), accounting for a total of 71% of the market share, followed by transportation (7%), military aviation (6%), and other fields such as medical, commercial and office equipment accounted for a total of 16%.
The basic criteria for evaluating the quality of connectors include mechanical performance, electrical performance, environmental performance, etc.
Mechanical properties mainly refer to insertion force and mechanical life. Insertion force is divided into insertion force and extraction force (extraction force is also called separation force), and the requirements of the two are different.
There are regulations on the maximum insertion force and the minimum separation force in the relevant standards, which shows that from the perspective of use, the insertion force should be appropriately small (thus there are structures with low insertion force LIF and no insertion force ZIF), and if the separation force is too high 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 based on one insertion and one extraction as a cycle, and whether the connector can normally complete its connection function (such as contact resistance value) after the specified insertion and extraction cycle is used as the basis for evaluation.
The insertion force and mechanical life of the connector are related to the contact structure (positive pressure), the coating quality of the contact part (sliding friction coefficient), and the dimensional accuracy (alignment) of the contact arrangement.
Electrical properties include stable technical resistance, insulation resistance, dielectric strength, etc. One is that it should have low and stable contact resistance.
The contact resistance of the connector ranges from a few milliohms to tens of milliohms;
second, it has a stable insulation resistance, which is an index to measure the insulation performance between the contacts of the electrical connector and between the contacts and the shell.
It ranges from hundreds of megohms to thousands of megohms;
The third is to have a certain electric strength, which is the ability to withstand the rated test voltage between the contacts of the connector or between the contacts and the shell;
In addition, there are other properties such as electromagnetic interference, characteristic impedance, transmission delay, etc.:
EMI leakage attenuation is to evaluate the electromagnetic interference shielding effect of the connector, and electromagnetic interference leakage attenuation is to evaluate the electromagnetic interference shielding effect of the connector, 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, some new connectors such as high-speed signal connectors have appeared. Correspondingly, some new electrical indicators have also appeared, such as crosstalk, transmission delay, and time lag.
Environmental performance includes mainly temperature resistance and moisture resistance.
First, it has 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 -65°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. In some specifications, the maximum temperature rise allowed by the connector under the rated operating current is clearly specified.
The second is moisture resistance. The intrusion of moisture will affect the insulation performance of the connector and corrode the metal parts.
The above is an introduction to the quality assurance technology of connectors. Zhejiang Lianhe Electronics is a company specializing in the production of electronic connectors. Welcome new and old customers to come to buy
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