The most common cause of electrostatic damage to sensitive components
1. Hand Covering
Plain plastic, or even pink antistatic or black conductive fingertips, gloves have a notorious history of charging EDS handles, especially the insulating parts of printed circuit boards. Many believe that no material will become charged when in contact with pink anti-static black conductive finger cots or gloves. In fact, most PCB materials charge prohibitively high hand coverage, even for ESD-safe versions, when in contact with bare skin. When the product starts charging, this is a CDM failure waiting to happen.
1.1 Ungrounded operators, ESD projects
Even though the printed circuit boards are held by the plastic sides, operators are often charged when shipping the components. This causes the subsequent PCB to discharge when the CDM fails.
2 With ESDS items in open bags, boxes, pallets and containers, go ungrounded operators
The principle of Faraday containers really works. Various damages occur when ESDS items are shipped in open static shielding bags, conductive containers without lids, and metal pallets without lids.
3 Shipping ESDS items on an ungrounded shopping cart
ESDS products, if stored and shipped in ungrounded shopping carts without proper Faraday shielding, can become highly charged. The failure of the CDM is often a consequence.
4 ESDS items on NonESD surfaces
It is very important to combine ESDS products with ESD protection mats and laminates. Chargeable products can become readily available on nonESD safe surfaces, especially within facilities with low humidity conditions.
5 Containers that generate charges
We are still amazed to walk away with what appears to be excellent ESD control, only to discover that ESDS products generate high charges within the base of the container, routinely placed as part of a standard handling practice. Major offenders include quartz boats and Teflon containers.
6 Anti-static packaging for the elderly
Many antistatic materials, especially those that gain their chemical properties during loading, lose their noncharge properties over time. They will restore the charge generating material. When the protection is lost and the ESDS products inside become charged, causing damage multiple times, the operator releases them and they are removed from the packaging.
7 Blow-off operation
All air blow-off operations should be checked periodically to determine if they result in ESDS data becoming chargeable during the operation. Many times, a simple on-site instrument check can alert auditors that such significant damage could have been avoided. We've seen significant damage due to this issue.
8 Conformal coating
Our files are loaded, and conformal coatings are applied to account for product damage. Most conformal coatings charge ESDS items in significant applications. Discharge and subsequent damage are common.
9 IC handler
It took us a considerable amount of time to detect and eliminate CDM revenue losses due to the inner workings of modern IC processing equipment. For example, ICs can become, deducted internally, part of the normal operation of these machines by moving and sliding, and then discharging, damaging, them. Extensive expertise and special measuring equipment are required to detect and eliminate these problems.
10 IC tube IC handler
This is a very serious problem, but in the past, it is decreasing as more and more IC handlers use tape and reel instead of IC tubes. Historically, clear, antistatic IC straight tubes would lose their ESD performance over time, causing charging within the IC as they slipped out. This integrated circuit will be the input slot for the metal handling equipment that will be touched upon discharge.
11 Tape and Reel Assemblies
The problem continues with the use of tape and reel components, charging ESDS IC handlers on the reel.
12 semiconductor wafer container
A major ESD failure mode is created when ESDS wafers are placed in highly charged containers as part of normal processing. Inductive charging of wafers resting in plastic containers, which can then be discharged by mechanisms including host operator contact, by hand or tweezers or other wafer grabbing device, mechanical parts, or conductive containers