Packaging, Handling, and Storage

 

Transporting and proper material handling procedures are typically the weakest link in an ESD program. Many companies drop their guard when it comes to correct packing, handling, and storage techniques. Adequate protection requires attention to the details.

 

ESDS devices can be protected from ESD as they travel throughout the factory with packaging materials such as bags, corrugated, and rigid or semi-rigid packages. In addition, material handling products such as trays, tote boxes and other containers can provide protection during inter or intra facility transport.

 

Function of packaging, handling, and storage products is to limit possible impact of ESD on the ESDS from:

 

1.                 triboelectric charge generation

2.                 direct discharge

3.                 electrostatic field

 

Materials should have anti-static properties, be able to shield against direct electrostatic discharges and electrostatic fields, and be conductive (dissipative range).

 

Applications

1.     Receiving / inspection

-Are components properly packaged from vendor?

-Remove all non-ESD packaging from area:

Standard bubble wraps, packing peanuts, plastic bags, Styrofoam.

-Purchasing should insist that all ESDS items be packaged in a shielded package.

†††† -Repackage if necessary

††††††††† -Use of ESD labels / tape ††††††††

ESD Markings alert handlers of contents. Important if sending sensitive components through uncontrolled areas.

 

-Receiving station should be ESD safe

 

Products:

Bags: antistatic poly, shielding bags, bubble wrap, ESD tape, mat / wrist strap or heel grounders.

 

2.     Storage

-Open parts bins, dissipative storage boxes

-Grounded shelving areas with conductive paint, shelf liner,

††††

-Items to use: bins / storage boxes

 

Precautions to take:

Shelving should be grounded and operators should be grounded while stocking or picking items.

 

Products to use:

-Dissipative bins, storage boxes

-Shelving: shelf liner, conductive paint

-Heel grounders / ESD floor

 

3.     Transporting

Movement of carts and other wheeled equipment through the facility can also generate static charges that can transfer to products being transported

 

-Transporting ESDS from workstation to workstation

†††† -Covered totes

-Racks / carts grounded to ESD floor. ESD safe cart covers can keep dust off without generating charge.

-Personnel should be grounded

-Workstation should be ESD safe

 

Products to use:

 

ESD safe carts:

-Drag chains (donít get as dirty as dissipative wheels)

-Make sure all shelves are grounded.

-Covers

Tote boxes

Inplant handlers

 

4.     Production

Automated lines vs. manual line

-Any workstations on production line should be ESD safe

-ESD safe areas should be well-marked (signage, floor tape)

-Boards / components from storage to be removed from shielding bags at ESD safe workstation using proper handling methods.

-Components/board can be stored on board rack or in-plant handler as they move through production line

-Conveyor / rollers

†††† -Dissipative trays

†††† -System should be grounded

 

5.     Inspection / QC

Follow similar precautions as handling in production

 

6.     Packing / shipping

Different packing techniques for finished goods or contract board items

-ESD safe workstation

††††††††† -ESD safe packaging

ESDS boards /components should be packaged in shielding bags or ESD safe component shippers

 

Additional precautions include ESD safe packing peanuts, foam padding

 

ESD packing tape alerts recipients that items inside need to be handles in ESD safe area


 

ESD Protection in the Plant

a.      Awareness

-Training / education

 

-Signage

 

 

b.     Top down

-         participation by all levels operators/supervisors/management

 

-         Must have participation and buy in from all levels. Everyone must understand cost savings and recognize ESD as QC issue.

 

-         documentation of the reality of ESD

-         Ted Danglemayerís book ESD Program Management

-         Trade publication articles documenting costs of ESD

 

 

c.     Developing an ESD Control Program:

-EIA-625, Requirements for Handling Electrostatic-Discharge-Sensitive Devices (ESDS)

 

 

-Appendix K of Mil Handbook 263B

ESD damage prevention checklist

 

 

-MIL-STD-1686C, ESD Control Program

Electrostatic discharge control program for protection of electrostatic parts, assemblies and equipment.

 

-ESD Association Advisory, ESD ADV-2.0-1994

-Overview of ESD fundamental guidelines from effective control of electrostatic caused problems.

-Discusses the causes of ESD and the different types of device failure.

††††††††† -Material electrical characteristics

-Device sensitivity: How much static protection is needed

††††††††† -Chapters on:

-Points of control

-Implementing an ESD control program

-Audits and checklists

-Symbols

-Device testing

 

 

The handbook also has sections that focus on specific areas of ESD Control.