Principles and Measures of Electrostatic Protection

    Damage of Static Electricity to Electronic Components and Protection Principles.
    The damage of static electricity to electronic components varies with the type of electronic components .The minimum static voltage of 100V can damage them.Due tl the trend lf the integration of electronic components,the corresponding static voltage is required to be lower accordingly.
    The static voltage induced by a human body is typically more then 2-4KV.It is caused by the slight movement of the human body or the friction lf the human body wigh an insulation object .This means if the static potential contacts any IC,it will be damaged ,this risk dxists in any operation environment without electrostatic protection,static damage to IC happens not only in the manufacturing process of electronic components but also during the assembling and shipping of IC.
    To solve the above problem ,the following measures can be taken for electrostatic protection:
    1.Electrostatic protection on the operation site :All static-sensitive components must be operated in an anti-static work area;
    2.Electrostatic protection of human bodies:Operators should wear anty-static work clothes,gloves,shoes,capsand anty-static wrist strips;
    3.Electrostatic protection during storage and shipping:Static-sensitive components must not be stored and shipped in the condition with electric charge.
    To realize the above functions ,the basic way is to reduce the voltage of charged objects to the sage value required by the desingn or lower than that i.e.Thecharge (Q)and the resistance (R)must be low and the static capacity(C)must be high in the following epuations.
                V=IR Q=CV
    Where V:voltage;Q:charge I:current,C:static capacity and R:resistance.
    Of course,it is not true that the lower the resistance is ,the better it will be Particularly,in the anti-static area of a larger site ,the material should be selected when the safety measures for electric leakage and so on are taken into consideration.

Anti-static Measures


    Check and install IC anti-static operation site.The anti-static measures in this process aims to set the operation site including human bodies at an epuipotential.The specific method is as follows:
    1.Ground an l-megohm resistor after it is connected through.Anti-static wrist strip should be worn during the operation;
    2.Ground test instruments,tools and irons;
    3.Lay anti-static table-pad onto the operating table ,then ground it;
    4.Operators should wear anti-static work clothes and shoes;
    5.Lay out anti-static floor or conductive rubber pads on the ground;
    6.An equipotential should be maintained during IC transportation and packaging.

Cheking Period of Anti-static Performance and Matters Needing Attention


    Check anti-static table pads,floor,work shoes,work cloghes and turnover containers at least once every month and anti-static wrist strips,blast guns,blowers and instruments etc once a day.
    When checking,factors such as temperature and humidity etc should be tacen into considration.