ESD protection equipment in the production environment of the electronics industry
(1) ESD protection workbench
The workbench made of ESD protection material and grounded is called ESD protection workbench. The table top is made of static conductive or static dissipative materials (table mats made of ESD protective materials are also used). The table top is in good contact with the ground wire. The connection between the ESD protection workbench surface and the ground wire adopts soft grounding (with 1 MΩ resistance in series). The system resistance of the general ESD protection workbench surface should be in the range of 105-109 ohms, and the system resistance of the workbench surface in the I-level ESD protection area should not be higher than 108 ohms.
(2) Shunt rod, wire clamp, conductive foam material
In order to ensure that the ESD device does not fail, it is necessary to use metal shunt bars, metal wires or non-corrosive conductive foam materials to short the leads of the ESDS device or its components when preventing ESD devices. In order to function as a shunt, the resistance of the above-mentioned materials should be at least one order of magnitude lower than the smallest resistance between any two pins of the ESDS device.
(3) ESD protection floor
The protective floor is made of static conductive or static dissipative materials, such as carpet, ethylene floor, terrazzo, rubber, PVC, and raised floor. For safety and good static leakage, ESD protection floors should be grounded. The system resistance should be within 105～1010 ohm.
(4) ESD protection electric soldering iron, solder suction device
The electric soldering iron and tin sucker used for ESD device operation should be connected with the soldering iron tip and the shell to the ground to prevent the electric soldering iron and the shell from being charged by induction.
(5) ESD fixtures, maintenance kits, maintenance tools used by storage racks in the ESD protection zone, and ESD protection fixtures, etc. should be made of static dissipative materials or take electrostatic leakage measures.
(6) There are many types of ESD protection packaging and containers. According to preliminary statistics, there are 20 types. It can be summarized into two categories: one is antistatic hard plastic products, which are mainly composed of synthetic resin plastics and conductive materials. Like synthetic plastics, there are thermoplastics such as polyethylene (PE), polypropylene (PP), ABS, and polycarbonate (PC). Thermosetting resins include polyester, phenolic and other types. As antistatic fillers, there are carbon black, metal fibers, antistatic agents and so on.
The above-mentioned materials have good mechanical strength and are mostly used to make component boxes, turnover boxes, pallet tooling racks, pallet integrated circuit packaging tubes, etc. In order to protect ESDS devices, the volume resistance of these materials should not be greater than 108 ohms or the surface resistivity of the materials should not be greater than 109 ohms. The other is soft ESD protective packaging materials. These materials are also made by modifying the above-mentioned materials. Soft ESD protective packaging materials are different in terms of conductivity, so the scope of use is also different. There are three types of flexible packaging: static electricity, static electricity dissipation, and shielding and dissipation composite types.
The protection provided by all kinds of ESD protective packaging is: provide equipotential and shunt the pins of various ESDS devices; leak and diffuse the static charge generated by the friction of the insulation surface of the ESDS device in time; shielding materials provide shielding against electrostatic induction. Protect ESDS devices.
(7) ESD protection transfer vehicle, seat
In the ESD protection zone, all the seats of the wedding car used by operators when transporting ESDS devices should take anti-static measures. The structure of the running car is a metal frame, on which is a box made of static dissipative materials. The box body and the metal frame have good electrical contact. The metal frame and the conductive rubber wheels form an electrical connection. Under normal circumstances, it is required that the system resistance of the metal frame of the moving vehicle to the static conductive ground of the protective area is not more than 108 ohms.
The electrostatic leakage principle of the seat used in the ESD protection area is the same as that of a running car. The cushion used should be made of anti-static fabrics and other static dissipative materials and keep good contact with the metal body.