1. Electrostatic leakage:

The rapid leakage of static charges generated during various operational processes is an effective method to prevent electrostatic hazards. Electrostatic leakage is achieved by replacing various insulating materials that come into contact with electronic production processes with anti-static materials and grounding them.

(1) Anti static materials:

Anti static materials, also known as ESD protective materials, can be divided into three aspects based on their anti-static principles: conductive, electrostatic dissipation, and electromagnetic shielding dissipation composite.

The first type is conductive materials; The second type is static dissipative materials; The third category is electromagnetic shielding materials. The principles and usage methods of electrostatic protection vary among different materials.

Static charges of conductive materials can be freely distributed on their surfaces, and when subjected to friction, positive and negative charges can quickly diffuse and leak without generating static electricity. Its characteristics are as follows:

2. Static conductive materials placed in an electrostatic field accumulate static charges on their surface area, and must be grounded in order to leak the accumulated static charges.

3. Conductive materials can be used in the production and assembly environment of ESDS devices.

4. Conductive materials with low electrical resistivity are not suitable for use as ESD protective packaging. Because this type of packaging is placed in an electrostatic field. The static charges accumulated on the surface can discharge into the device, leading to device failure.

The resistivity of electrostatic dissipative materials is higher than that of electrostatic materials, and the rate of static charge movement on their surface is much lower than that of electrostatic conductors. In terms of use, electrostatic dissipative materials have the following characteristics: when subjected to friction, the charges generated on their surface can diffuse and leak quickly.

5. Due to its high resistivity, it does not cause material discharge and can be used as ESD protective packaging.

6. Can be used in general ESDS device production and assembly environments.

Electromagnetic shielding dissipative composite materials are composed of shielding materials and electrostatic dissipative materials. The resistivity of shielding materials is lower than that of conductors, and they do not generate static charges on the friction surface. They can be used to shield radio frequency and low-frequency electromagnetic fields, but due to their low resistance, they are prone to static induction and damage to devices in electrostatic fields. Usually, a layer of electrostatic dissipation material is compounded inside the shielding material. This type of electrostatic dissipation composite material with shielding effect can be used as ESD protective packaging.

The preparation of protective materials is usually achieved by increasing the conductivity of the material. The main method to increase the conductivity of materials is to apply anti-static agents externally. Methods such as external spraying, immersion, and application of anti-static agents. Simple spray anti-static agents for records and clothing belong to this category.

7. No persistent anti-static agent method was used. If anti-static agents are added during the post-processing of plastics, rubber, etc., the surface of the material will become conductive due to the mutual attraction of cations and anions.

8. Internal anti-static agent method. When adding anti-static agents to rubber, fiber, paper, and coatings using different processes. After adding anti-static agents using this method, the material has a long-lasting anti-static effect.

9. The surface properties of the material. This method involves forming a hydrophilic polymer coating with anti-static properties on the surface of the material. For example, for polyester materials, a copolymer of polyethylene glycol and PET can be used as the coating.

10. Mixing with conductive materials. Mixing polymer materials with conductive materials to give them electrostatic conductivity

(2) Special situations of leakage and grounding, leakage and grounding.

The static electricity generated during the production process can be controlled by ESD protective materials and grounding protective materials with a sufficiently large area. For example, if the charge of a certain electrostatic source is 0.6 microcoulomb and its capacitance to the ground is 20 picofarads, the static voltage of the electrostatic source is 3000 volts. When leaked onto a conductive ground with a surface area of 10 square meters (ground capacitance of 1000 picofarads), the charge per square centimeter is only 0.6 picocoulombs, and the electrostatic voltage is almost non-existent. Therefore, it can be seen that when a small amount of electrostatic charge leaks onto it, it will not cause damage to the ESDS device. So in some cases, ESDS protective materials with a very large surface area can be considered as suspended grounding. Even if it is not directly grounded, it will not have any adverse effects on ESDS devices.