Esd Control And Handling Procedure : Places Where Esd Controls Required

6. Places where ESD control is required:

1. Suppliers:

Suppliers need to take appropriate ESD precautions as per the requirement of their product range. The likelihood of poor controls along the way is increased as more intermediaries become involved in the supply chain. Therefore is preferred to purchase the products directly or atleast to buy from authorized agents.

2. Receiving:

The receiving department workers rarely need to open the package and therefore the incidence of ESD damage can be ruled out for all practical purposes. If there is any practice of opening the packages at the receiving dept., the personnel there are to be trained in handling components and static free bench is to be provided if necessary.

3. Incoming inspection:

Incoming inspection is the first place where susceptible items are likely to come into danger. It can be limited by taking the following precautions:

i. Personnel in the incoming inspection department are to be trained for safe handing of electronic components

ii. Static control stations are to be provided at inspection benches and maintained properly.

iii. Often it is assumed that the components with anti-static labels only are susceptible to damage, and other electronic components are not treated with proper care to prevent static damage. It should be noted that all electronic components are to be handled at static-free work benches, though other components are not as sensitive to static as those labeled ‘static-sensitive’.

iv. Personnel will often discard the usually present outer shield provided by vendors because of the opinion that the inner antistatic package is sufficient. When small numbers of ICs are requested from stores they may be transported in plastic bags or cut DIP tubes rather than in shielding containers.

v. Proximity of receiving various items tend to bring insulating packing materials to the incoming inspection area. It is important that this area is free of any insulating packaging materials.

4. Kitting:

Parts are sometimes stored here without proper shielding packages resulting in damage during storage/handling of these components.

Parts such as ICs are to be taken to static-free work station before removing from conductive bags for kitting.

Insulative materials such as plain plastic boxes, bags, or insulative tapes may be in kitting boxes with improperly packaged sensitive parts.

If susceptible item is received in nonrecongnizable or nonexistant static protective packaging, it would have been kitted and forwarded as nonsusceptible. This can be minimized by proper training of both incoming inspection and kitting personnel.

Use of plastic weighing balances to count ICs, use of plastic bags and trays for kitting of components may result in damage to the components. Use of static shielding trays and bags is necessary to prevent damage due to ESD during kitting.