ESD Knowledge

Location:Home > News Center > ESD Knowledge

Anti-static materials

Anti-static materials or anti-static materials in the anti-static and control engineering played an important role in the anti-static anti-static materials such as container supplies, clothing, belt, and so is essential to the manufacturing process. 

And anti-static materials related to the basic concept first introduced here in a number of anti-static and control technologies and materials used in the basic concept. 

Resistance and resistivity: This is the electrostatic technology to control the most important of the two concepts, they are often confused, not only material that is used also used to describe the evaluation of the test materials. 

Body resistance: a material refers to the thickness of the unit on the DC voltage drop and the per unit area through the current ratio. Body resistance coefficient is one of the basic parameters of materials, said its electrical conductivity properties, as the unit ohm / cm. 

Surface resistivity: the parameters for a certain thickness of the film, which is defined as the length of the unit on the surface of the DC voltage drop and current flow width of the units in the previous year. 

It refers to the square edge between two pairs of resistance as long as the area is far greater than the thickness of the film, the resistance has nothing to do with the size of the square. Surface resistivity of the unit is ohm. 

Resistance: On the other hand, said different shapes (the size and length) and resistivity of the material on the current obstacles, at the same time it shows that the material or surface to surface and the connectivity between the circuit and the object of the discharge capacity of the unit is ohm . 

Surface resistance: According to the EOS / ESD S11.11 "ESD flat surface measuring resistance" in the definition of the surface resistance of a material refers to the surface between the two voltage direct current through the current ratio to Ohm said. Surface resistance has nothing to do with the structure of the material. 

Body resistance: According to the ESD DS11.12 "ESD flat-material measurement Resistance" in the definition of body resistance is the material between the two ends of the DC voltage and current through the ratio, it is also a unit of Ohm. Insulation materials: generally refers to the surface resistance coefficient in the 1 × 1012 ohm resistors factor in the body or 1 × 1011 ohm / cm above the material. Insulation material or surface was virtually no current within the mobile, and its great resistance, hard ground. This material inside the electrostatic charge will be to retain the top for a long time. 

Conductive material: generally refers to the surface resistivity of less than 1 × 105-ohm resistors, or less than 1 × 104 ohms / cm material. 

This small resistance materials, electronics, in its surface and the flow is easy to flow into contact with any other conductor or the earth. 

Dissipative materials: generally refers to the surface resistivity greater than or equal to 1 × 105 and less than 1 × 1012 ohms, or body resistance coefficient greater than or equal to 1 × 104 and less than 1 × 1011 ohm / cm material. 

Shielding material: general guidance mm thickness of each layer of the surface resistivity of less than 1 × 104 ohms or body resistance coefficient is less than 1.0 × 103 ohms / cm material, the use of such materials produced by the Faraday shield to prevent static-sensitive devices By static electricity. 

Anti-static: usually refers to the suppression of friction material from the properties of electricity. 

Anti-static materials of their resistance or resistivity is no causal link. 

Some, such as anti-static materials, high resistance, high-insulation, but since electricity is very small, the friction will not be many times the accumulation of static electricity. 

And to understand the proper use of electrostatic control of these basic concepts, you can use more accurate language, which contribute to the effective implementation of ESD control.

2 anti-static materials of the main parameters (1) characterization of the parameters of electrification capacity: electrostatic surface-U, with electricity Q or surface charge density s. 

(2) characterization of the ability of the attenuation parameters: surface resistance RS, leakage resistance R (of products); surface resistivity rS, body resistance, rV (of materials); t time constant or static half-life of t1 / 2: medium of t = er, conductor of t = RC (1 / e); t1 / 2 = 0.69t 2.4.3 anti-static materials such as the classification of the basic concepts of set, according to the anti-static properties of conductive material, static electricity can be divided into insulation , Dissipation, conductive and shielding of the four, such as surface resistivity (in W / e) as follows: 104 105 1012 static dissipative electrostatic shield insulation material static electricity conductor Note: The specific boundaries of different values or different standards for enterprises Different, and some more detailed categories. There are the standards body in charge density as a division of the parameters according to the source of anti-static materials, natural materials and can be divided into two major categories of man-made materials. Natural materials such as metals, cotton fabrics and so on; in anti-static works, using a large number of artificial or man-made transformation of the material. 

Man-made materials, there are two main methods of manufacture: first, in the original material added to the live material or substance, such as carbon black, graphite, carbon fiber types of carbon, or metal powder, metal fibers, such as metal or anti-static compounds, etc. Category. Add the materials or products with permanent; is another way to the surface coating, such as hand tools, such as surface coating of surfactant, the use of elements of the water-polarization and the formation of a single molecule on the surface so that the conductive layer to anti-static The purpose of this method is time-sensitive, and will wear away. 

Now there are durable polymer surfactant.
close
close