Antistatic purpose and general principles

       When an object with a certain amount of net positive charge or net negative charge, can be said to have static electricity. Static electricity is a relative term because, in many cases, static electricity will be reduced over time. The length of this period is related to the resistance of the object. The two extreme examples of practical applications are plastics and metals.

        In general, the resistance of the plastic is very high, so the plastic can be maintained for a long time with static electricity. But the metal resistance is very low, very short time grounding metal with static electricity. Static electricity is usually expressed in volts. Although the 220 volt AC power supply is dangerous, but the 100kV is very common static electricity. The voltage in an object is determined by two factors: the quantity of the object and the capacitance of the object. Can be expressed in a simple relationship, that is, Q=CV, which represents the amount of Q, V on behalf of the voltage, C represents the capacitance of the object.

        If the quantity of the given object, the lower the capacitance, the higher the voltage, and vice versa. Plastic is generally very low capacitance, so very little power can produce high voltage. On the contrary, the capacitance of the metal is very high, so that more power only produces a lower voltage. This is the reason why more attention has been paid to the use of plastics in the practical application of static electricity. High voltage will attract dust, causing the operator to be subject to electric shock or cause the object to change.

 

　　There are two main types of electrostatic: bulk electrostatic and surface electrostatic. Electrostatic charge refers to the charge distribution inside the body. Surface charge is the charge on the outermost surface of an object.

        In practical applications, the electrostatic problem is basically related to the surface electrostatic. Although there is no way to neutralize the body of static electricity, but the body is rarely caused by static electricity. In general, the effects of bulk static electricity are small compared with surface electrostatic.

        What are the hazards of static electricity to health?

Experts cautioned that, do not think that static electricity is just to make people uncomfortable, it has a negative impact on people's health. Medical experts have confirmed that the electrostatic interference of the skin can change the normal potential difference of the body             surface, affecting the normal electrophysiological process of the heart. This kind of static electricity can cause the patient to aggravate the condition, the lasting static electricity also can cause the blood alkalinity to raise, causes the skin to itch, the pigmentation, affects the human body physiological balance, the disturbance human mood and so on.

        Central South University, associate professor of the Department of Dermatology of Xiangya No.2 Hospital Xiao Rong said the incidence of office workers to operate the computer every day facial erythema, pigmentation and facial disease is much higher than that without a computer, this is due to the electrostatic generated by the computer screen to attract a large number of suspended dust, make facial irritation caused by.

 

　　Due to the relatively dry skin of the elderly and the aging of the elderly cardiovascular system, the ability to resist interference and other factors, the elderly are more likely to be affected by static electricity. Cardiovascular system has a variety of lesions in the elderly, static electricity will make it worse. High static electricity is often restless, headache, chest tightness, dyspnea, cough, etc.

 

　　How to prevent static electricity in daily life?

 

　　1, as far as possible in the bedroom or put less household appliances. This can avoid the human body and the electrical field in the near distance and touch static electricity, watching TV the best distance from 2 to 3 meters.

 

　　2, with the "third" to eliminate static electricity. In order to avoid ESD, can be a small metal device (such as keys), cotton cloth, etc. first touch can cause electrostatic doors, door handles, faucets, chair, bed etc. to eliminate static electricity, and then touch their hands.

 

　　3, with pure natural fabric. Underwear, bed sheets, quilt cover, as far as possible the use of cotton, linen and silk and other natural textile fabrics, home textiles and clothing as far as possible not to use or wear chemical fiber texture.

 

　　4, with wooden comb, conditioner lotion. Use hair comb, shampoo use conditioner lotion, can eliminate static electricity.

       
        5, to maintain the indoor temperature. This is not easy to generate static electricity. It is best to use the winter indoor humidifier, also placed flowers, to avoid static electricity.

        6, floor, wall, ceiling and so on the use of space anti-static materials.

        7, eat more vegetables, fruits, yogurt, drink more water, while calcium and vitamin C supplement in order to reduce the impact of static electricity.

　　Car owners how to prevent static electricity?

       
         Installation of electrostatic discharge equipment. Electrostatic discharge is divided into ground and air discharge, but according to experts, the trend is now two sets are installed, so the effect of eliminating static electricity than a single set of ideal much more.

        Spray and anti electrostatic spray. There is a new name for "anti-static spray" products, put it evenly sprayed on the body with a towel wipe, the car has anti-static effect magic, and the period of validity is not short!

Less use cosmetics. For the female owner, in a dry environment should pay attention to minimize the use of cosmetics, makeup will make the skin more dry.

        Less open air conditioning. In particular, the internal circulation air conditioning, so that it has been very dry car can not save a little water. Proposal to open the window (to avoid the wind blowing directly on the body), even if the body does not matter a little sweat, appropriate to promote the secretion of sweat glands on the skin is better.

 
        Wet towel. With a wet towel on the dashboard, sunlight makes the water in the towel evaporated quickly, so as to improve the humidity inside the car electronic products in the production process of electrostatic antistatic engineering is a kind of objective natural phenomena, resulting in many ways, such as contact, friction, basic process flow and so on. It can be summarized as: transfer, contact, charge, the electrical double layer formation and charge separation.

 

　　The electrostatic device or on the human body up to tens of thousands of volts to hundreds of thousands of volts to normal operating conditions are often up to hundreds or thousands of volts, because the body's own movements and contact with other objects - separation, friction or electrostatic induction and other factors, can bring thousands of volts or even tens of thousands of volts of static electricity is positive. Negative charge imbalance in the local area. It is a kind of power, retained object has the characteristics of high performance, low power consumption, small voltage, current and short duration.

 

　　Electrostatic control of the main measures are: electrostatic leakage and dissipation, electrostatic neutralization, electrostatic shielding and grounding, humidification and so on

 

　　Component breakdown caused by electrostatic discharge damage is the electrostatic hazard of electronic industry the most common and most serious, it is divided into hard and soft breakdown breakdown. Disposable hard breakdown is caused by components of dielectric breakdown, burned or permanent failure; soft breakdown is caused by the degradation of device performance parameters or indicators declined.

        Electrostatic sensitive components and printed circuit board in the production process of the transmission and storage, you must use anti-static material box, box assembly, turnover boxes and pallets. In order to prevent the accumulation of static electricity damage. As the finished product must be packaged with anti-static shielding bags, packaging bags, packaging boxes, the basket, to prevent electrostatic damage during transport.

        Electronic products in the production process, its components, and component products often come into contact with the equipment and tools, separation, friction and static electricity, must use anti-static cushion, working car, repair kits, tools, work chair, and through appropriate grounding, electrostatic discharge quickly.

        The friction from static electricity and the human body is electronic and microelectronic industry in the two major hazard sources, but not the electrostatic hazards where the harm lies in the accumulation of static electricity and electrostatic charge discharge resulting from the charged objects, the formation of electrostatic field around it, will produce mechanical effects, electrostatic discharge effect and induction effect, therefore must be controlled..

        Due to the mechanical effects of static electricity, dust particles floating in the air will be absorbed on the silicon wafer and other components, seriously affect the quality of electronic products, therefore, electrostatic prevention of purification. Space must be clean room walls, ceilings and floors should not use anti-static dust in the material, the operators and the workpiece, electrostatic protective equipment should also take a series of measures.

In order to understand the process of electrostatic electrification in the production process, to determine the degree of influence of static electricity in the production process, and to test the quality of electrostatic protective equipment and equipment, we need to measure the static electricity and related parameters

 

　　Electrostatic measurement is to measure the static electricity voltage, material resistance, grounding resistance, static electricity shut, static electricity, static eliminator eliminate electrical properties, surface charge density of the fabric.

Electrostatic protection is a system engineering, any part of the omissions or errors will lead to the failure of static protection work, must always guard against, everyone prevention. Electrostatic problems have appeared in our life and work. How to correct and proper use of anti-static anti electrostatic products is our present concern of course. Kinds of anti-static material anti-static products very many, but mainly can be classified as anti-static pad Taiwan, anti-static tools: first from the fundamental human needs to use the following anti-static anti-static product * * *

        Antistatic clothing and anti-static wrist strap

Anti-static clothing and wristband is an important part of the body to eliminate the anti-static system, can make the body to eliminate or control the generation of static electricity, thereby reducing the main electrostatic source in the manufacturing process.

        Anti-static clothing including anti-static coveralls, anti-static body clothing, anti-static coats, anti-static shoes, hats, anti-static gloves, anti-static finger sets, anti-static wrist belt. Antistatic clothing is made of different colors of anti-static cloth. The cloth yarn contains a certain proportion of conductive yarn, and the conductive yarn is made of a certain proportion of stainless steel fiber or other conductive fiber and the ordinary fiber. Elimination of static electricity on clothing by corona discharge and leakage of conductive fiber. As the stainless steel fiber is a kind of metal fiber, so the antistatic property of the fabric made of it is stable, and does not change with the number of washing times.

        Anti-static wrist strap is anti-static products operators on the most important contact of electronic components, through the grounding path, can be a static charge carried by human body safely let xie. It is made of antistatic elastic tape, snap fastener, spring cord. Activities of protective resistance and plug or collet. The inner layer of the elastic band is woven with antistatic yarn.

 

　　Antistatic packaging and transport products.

Anti-static packaging products very much, such as anti-static shielding bag, anti-static bag, anti-static sponge, IC anti-static packaging tubes, anti-static component boxes, anti-static turnover box, anti-static bubble film and anti-static vehicles etc.. Most of them are made of electrostatic dissipative material, and some of them are made of antistatic material. The purpose is to protect the circuit or device and

        printed circuit

How to prevent static electricity (how anti-static)

        Anti static floor and anti-static pad

Anti-static flooring and anti-static pad Taiwan also has a variety of, according to the time points, there are permanent and temporary; according to the material with conductive rubber, PVC, conductive ceramics; by way of laying, laying ground directly and the overhead floor. According to actual needs and cost decisions. If you need to walk on the ground a variety of cables, pipes, such as the environment of the computer to select the overhead laying of the floor is better.

        Anti-static pad Taiwan mainly anti-static composite plate, mainly used for capturing the pad desktop, line countertops, shelves and making cushion etc.. The material surface layer is divided into green, conductive material is antistatic agent; the bottom layer is black, conductive material is carbon black.

        In addition to the above three categories of products, there are some other anti-static products such as anti-static, electric iron, anti-static chairs, anti-static maintenance package etc.. The antistatic soldering iron in the process and is commonly used in maintenance. The general need to unplug the electric iron in the welding of electrostatic sensitive components, and antistatic soldering iron by DC power supply temperature and pressure, the heating element has the characteristic of constant temperature, electrostatic capacitance, small material, can greatly reduce the interference of various clutter signal. In addition, iron can also be used as a static grounding, can further eliminate various signals on the iron head. Therefore, no need to unplug the power supply when welding.

 

　　Antistatic purpose and general principles

        The fundamental purpose of anti-static is in the process of manufacture and use of electronic components and equipment, through various means of protection, to prevent harm or may arise due to mechanical and electrostatic discharge effect, or the harm to a minimum level, to ensure that the design and application properties of components, components and equipment not induced damage due to electrostatic interaction.

        As we all know, the main form of electrostatic hazard in electronic industry is the sudden failure and potential failure of the components caused by electrostatic discharge. Therefore, the main purpose of anti-static and electrostatic control is to control the electrostatic discharge, that is, to prevent the occurrence of electrostatic discharge or electrostatic discharge energy to all sensitive devices under the damage threshold. Said from the anti-static two aspects to control the generation of static electricity and electrostatic dissipation from the control principle, control of electrostatic control is the main material process and in the process of selection; control of electrostatic dissipation is quickly and safely to electrostatic discharge and neutralization; interaction between the two results is likely to make the electrostatic level does not exceed the limit of safety, achieve the purpose of anti-static