Electrostatic protective equipment is mainly divided into two categories
Static protection equipment is mainly divided into two categories: anti-static products and static eliminators. Anti-static products are articles made of anti-static materials. The main function is to prevent or reduce the generation of static electricity and to discharge the generated static electricity. The static eliminator is used to neutralize the electrostatic charge accumulated on the insulating material that cannot be eliminated by the discharge method.
1 Products made of antistatic materials
There are quite a variety of anti-static material products, but they can be mainly classified into the following categories:
1.1 Anti-static clothing and wrist straps
Anti-static clothing and wrist straps are an important part of the anti-static system of the human body, which can eliminate or control the generation of static electricity in the human body, thereby reducing the main source of static electricity in the manufacturing process.
Anti-static clothing includes anti-static suits, gowns, shoes, hats, anti-static gloves, anti-static finger cots, anti-static foot harnesses, etc. Anti-static clothing is made of anti-static cloth of different colors. The cloth yarn contains a certain proportion of conductive yarn, and the conductive yarn is blended with a certain proportion of stainless steel fiber or other conductive fibers and ordinary fibers. Eliminate static electricity on garments through corona discharge and leakage action of conductive fibers. Since stainless steel fiber is a metal fiber, the conductivity of the anti-static fabric woven from it is stable and does not change with the number of washings of the garment.
Anti-static wrist straps are the most important electrostatic protective equipment for operators when they come into contact with electronic components. Through the grounding path, the electrostatic charge carried by the human body can be safely discharged. It consists of an anti-static elastic band, a movable snap button, and a spring cord. It consists of protective resistor and plug or clip. The inner layer of the elastic band is knitted with anti-static yarn, and the outer layer is knitted with ordinary yarn.
1.2 Anti-static packaging and transportation products, etc.
There are many anti-static packaging products, such as anti-static shielding bags, anti-static packaging bags, anti-static sponges, anti-static IC packaging tubes, anti-static component boxes (boxes), anti-static bubble films and anti-static transport vehicles. In addition to electrostatic conductors for electrostatic shielding, most of these packaging products are made of static dissipative materials, and some are made of antistatic materials. The purpose is to protect the installed circuit or device and printed circuit from static electricity. Figure 2.7 shows some commonly used electrostatic packaging products.
(a) Anti-static packaging bag (b) Anti-static IC packaging tube
(c) Anti-static sponge (d) Anti-static storage box
Some commonly used electrostatic packaging products
1.3 Anti-static floor and table mat
Anti-static floors and table mats are also indispensable in electrostatic protection projects. There are also many kinds of anti-static floors, which are divided into permanent and temporary according to the timeliness; according to the material, there are conductive rubber, PVC, conductive ceramics, etc.; according to the laying method, there are direct laying on the ground and overhead activities floor. It can be decided according to actual needs and costs. If you need to walk a variety of cables and pipes on the ground, such as computer protection, it is better to choose an elevated raised floor. Figure 2.8 shows some anti-static floors.
Anti-static table mats are mainly anti-static composite rubber sheets, which are mainly used for trapping tabletops, assembly line work surfaces, shelves and making floor mats. The surface layer of the material is divided into grass green, and the conductive material is antistatic agent; the bottom layer is black, and the conductive material is carbon black.
(a) Anti-static laminate floor tile(b) Anti-static PVC floor board (c) Anti-static computer room raised floor
In addition to the above three categories of products, there are other anti-static products, such as anti-static electric irons, anti-static seats, chair covers, anti-static maintenance kits, etc. Among them, anti-static soldering irons are commonly used in post-processing and maintenance. The general electric soldering iron needs to unplug the power supply when welding static-sensitive components, while the anti-static soldering iron uses a DC temperature and voltage power supply. . In addition, the soldering iron can also be used for electrostatic grounding, which can further eliminate various signals on the soldering iron tip.