Questions about poor contact of electronic products
As the application field of electronic technology is expanding, the problem of poor contact with electronic products increasingly plagues users, bringing a lot of inconvenience and confusion to users.
Each machine consists of multiple connected components. Due to the long use time of the machine, poor contact between connectors is often caused by metal oxidation, dust adhesion or excessive insertion and removal times, which brings inconvenience to people’s lives.
Contact failures in electronic products include contact failures inside the components themselves, contact failures when the components are interconnected, and contact failures caused by virtual soldering (usually between the component and the printed circuit board). The following are examples of the most common contacts between connectors (connectors) to analyze poor contact issues.
A connector is usually a connection between a pin contact and a hole contact. We know that the pins or terminals of components are usually plated with a layer of plating, such as lead-tin alloy plating, pure tin plating, nickel plating, silver plating, silver-palladium alloy plating, gold plating, etc. Therefore, the contact between parts is actually the contact between these plated metals. Of course, the conductivity of different electroplated metals is different, and the corresponding contact resistance is also different. Generally, gold is more conductive than silver. In the welding process, since welding is actually a process of forming an alloy, and the alloy itself is a good conductor, the reliability of the welding itself is relatively high, unless it is poor welding. However, the connection between the connectors depends on the contact between the surfaces, which easily leads to poor contact.
Whether the contact between two metal surfaces is good depends mainly on the combination of material (different metals have different electrical conductivity), contact pressure, and actual contact surface. As far as the type of material is concerned, the coating materials of general devices are basically made of good conductors. Good conductors have a small effect on bad contact and at most affect contact resistance (of course, it will further affect whether they are easily oxidized). With regard to the contact pressure of the connector, the connector relies on the elastic force of the hole contact to apply a certain pressure to the pin contact. Generally, the higher the pressure, the better the contact. In general, small and thin hole contacts are unlikely to provide excessive pressure. In addition, if the hole contact itself is not elastic enough, the pressure is small and the contact is not so good. At the same time, if the hole contact or needle contact deforms, the actual contact area will also become smaller, which may cause poor contact. Of course, the hole or pin contacts of a connector are usually connected to plastic. If the number of feet is too large, the position of one or more contacts on the plastic may be misaligned. Therefore, when inserting two connectors, the bias contacts may not make good contact.
In order to ensure that the electronic products are more durable and avoid the problem of poor contact as much as possible, we need to pay special attention to some matters during use:
First, because the insulation of electronic products is affected by humidity and air, it will reduce the degree of insulation, resulting in leakage current or poor intermittent contact. Therefore, the place where electronic products are stored or rotated must be dry, have adequate moisture-proof measures, and should be avoided in high humidity or concrete walls.
Secondly, due to the contact of electronic products with air, oxidation, rust and resistance changes will occur, resulting in poor contact and rusted metal or soldered parts. These parts should be painted and protected. It should be reminded that if the acidic flux used in soldering is not removed after use, it will still cause corrosion and poor contact of metal parts of electronic components. Adequate anticorrosive measures should be taken in places with corrosive gas.
Third, the environment in which the device is located is also prone to poor contact due to some kind of shock or impact. The installation or wiring of equipment parts should be protected against shock and shock. When using, avoid collision and rough, do not collide during handling, pay attention to handling.