How to eliminate the harm of static electricity in the production process of electronic equipment
1. The hazards of static electricity can be divided into two categories: one is the adsorption of floating dust caused by electrostatic gravity; the other is the dielectric breakdown caused by electrostatic discharge.
Electrostatic adsorption
In the manufacturing process of semiconductor components, due to the large use of quartz and polymer materials and materials, its insulation is very high, and some inevitable friction during use can cause its surface charge to accumulate
And the potential is getting higher and higher. Due to the mechanical effect of static electricity, in this case, it is easy to make the floating dust in the workplace adsorb to the surface of the chip, and the small dust adsorption may affect the good performance of the semiconductor device.
2. Electrostatic discharge and dielectric breakdown
The starting and discharging power source of electrostatic discharge is space charge, so the energy it stores is limited, so it can only provide local breakdown energy that occurs briefly. Although the energy of electrostatic discharge is small,
However, the discharge waveform is very complicated, and it is more troublesome to control. The soft breakdown of semiconductor devices is related to it.
Second, the anti-static of electronic equipment that should attract attention
Due to the rapid development of electronic equipment, small-sized and highly-integrated devices have been mass-produced, resulting in smaller and smaller wire pitches and thinner and thinner insulation films, resulting in lower breakdown voltages. However, the static voltage generated by electronic equipment during production, transportation, storage, and transshipment far exceeds its breakdown voltage threshold, which may cause breakdown or failure of the device, affecting the technical indicators of the equipment and reducing its reliability. .
Preventing static electricity mainly suppresses the generation of static electricity, accelerates the leakage of static electricity, and neutralizes static electricity. When people wear non-conductive shoes, charges will be generated and accumulated due to activities such as walking, and can reach a potential of kilovolts. When two different objects are in contact with each other, a charge movement occurs at the interface, and positive and negative charges are arranged relative to each other to form an electric double layer. If the objects are separated, equal charges with different polarities will be generated on the two objects. The principle of preventing such static electricity is to eliminate the main factors (static characteristics, surface state, charging history, contact area and pressure, separation speed, etc.) of static electricity generation; The position should be as close as possible; the contact area and pressure between the objects should be small, the temperature should be low, the number of contacts should be small, the separation speed should be small, and the contact state should not change drastically. Powders, liquids, and gases will generate static electricity due to friction during transportation. Therefore, measures such as limiting the flow rate, reducing the bending of the pipe, increasing the diameter, and avoiding vibration should be taken.
Third, the way to eliminate static electricity in the production process of electronic equipment
Anti-static is mainly to prevent electrostatic discharge. Controlling electrostatic discharge should start with controlling the generation of static electricity and controlling the elimination of static electricity. Controlling the generation of static electricity is mainly to control the process and the selection of materials in the process; controlling the elimination of static electricity is mainly to accelerate the leakage and neutralization of static electricity. The combination of these two points can make the electrostatic voltage not exceed the safety threshold to achieve the purpose of electrostatic protection.
Static electricity can cause harm to electrostatic sensitive devices, but it is controllable and can be eliminated.