Electronic device identifier ESD: Electronic Discharge EPA: Electrostatic Protected Area SSD: Static-Sensitive Devices ESDS: Electrostatic Discharge Sensitive EOS: Electrical Over Stress
Normal Anti-static Equipment Consideration of human body resistance device setting Researches show that when different
electricity pass though human body mild current can make nerve by mild stimulation, make people feel numb and uncomfortable. If the electricity
turns stronger, human body loses muscle shrinking capacity and can’t control
their own behavior. When the electricity reaches a certain degree, it make a
systemic muscle paralysis, respiratory arrest instantly, and people will die in
few minutes. Generally, when the electricity reaches 25-30mA, not only harmful
to the body but also put life in danger, 100mA above electricity is fatal.
Therefore, considering human safety, the U.S. defense department file stipulated
to control less than 5mA electricity pass though human body and the protection
resistance mainly chose from 0.1-1MΩ, this
is also consistent with the relevant British standard BS5783. Practically, 1MΩ
is the most common choice. Accordingly, 5mAx1MΩ=5000V,
that means under 5000V electricity the resistance also can provide enough
Conductive wrist strap and human ESD protective equipment
Operators who contact with static sensitive components must wear ESD wrist strap, this is the most simple and effective way to release the static. Conductive wrist strap is mainly composed of - conductive composites wrist strap and ground device. For human safety, make a series connection resistance around 1M. Generally the wrist strap’s discharging time is less than 0.1 seconds, the operator’s electrostatic potential can keep below 2v. Conductive wrist strap is one of the traditional and important static protection method, but sometimes also appears poor contact situation. So we should check whether the conductive wrist strap is reliable during wearing, and we need more reliable measures such as anti-static clothing, anti-static gloves and anti-static shoes, etc. The overall protection measures has a dual role in static shielding and static discharge, so can have a better anti-static effect.
During the operation of the electrostatic sensitive devices, the ground of working area mainly uses mats which is made of anti-static materials. Make all contact with the terminal of electrostatic sensitive devices, assembly tools, instruments, human body all achieve the basic uniform potential, and with proper grounding release the static quickly.
Ionic wind generator
In static sensitive devices operating area, static damage may come from non-conductive materials such as printing board, ceramic components, artificial fabric survey, common plastic plate, styrene shock-proof material, etc. Once these materials have accumulated a large number of static charge can form an electric field, even without direct contact can damage the components next to it. In order to eliminate this part of the static charge, generally adopts the ion wind to neutralize, by using ion wind generator. The generator applied DC pulse current generated by the method of point discharge and alternating hot and cold cycle of positive and negative ion wind blowing gently into the surrounding area, and its discharge cycle time can be controlled, ideally the air can reach 6 x 103 / cm3 ion orders of magnitude. This not only can effectively eliminate the static charge on the conductive material, and the whole space, including dust particle counting also decreased by 50%, it has played an important role to purify the air.