ESD Control, Return On Investment

Having ESD awareness and following through with an ESD Control program is essential in reducing quality failures due to ESD. ESD can affect product reliability with catastrophic damage which is readily apparent to latent degradation. Latent degradation is particularly expensive requiring costly inspection and rework cycles in-house or product failure in the field. Maintaining good ESD controls will improve product throughput or yield, increasing reliability in the field which improves customer satisfaction leading to increased future business.

One test equipment manufacturer noted that GMR heads were being damaged during or after testing. These heads are extremely sensitive to ESD, and require additional handling precautions.

It is very important when designing and implementing an ESD Control program to know the ESD susceptibility of the ESD Sensitive (ESDS) devices you are trying to protect. Classification of these devices should include all simulation models human body model (HBM), Machine Mode (MM), and Charged-device Model (CDM) that will properly characterize the devices' sensitivity when handled at various locations within the facility [6]. This will allow for the most economical program design.

Gene Chase, an ESD Consultant with ETS Inc., is quoted as saying "Millions of dollars are lost every year due to ESD [4]. Many of these incidents occur within the computer and communications industry." Examples of losses from ESD may be any of the following:

• Lost Time
• Loss of Connection
• Loss of Data
• Shocks to Personnel
• Upset to A System Requiring A Re-Boot
• Damage to Equipment
• Equipment Hardware Failure

To properly determine the return on investment (ROI) from your ESD Control program, you must collect return, repair and scrap cost data before and after implementation.

Terry O’Malley, former AT&T ESD Manager, had collected data from several AT&T facilities both before and after instituting an ESD Control program. The data speaks for itself; see figure 1 for a graph of two facilities that were monitored. There was over a 50% savings in return and repair costs found at both facilities after initiating their ESD Control programs.

Figure 1 – Cost Reduction From ESD Program, AT&T Office Location

2 - ESD Design and Manufacturing Cost Analysis:

Combined Cost Benefits of ESD Program Management [2]

Figure 2 abstractly represents the relative cost benefits of Lucent’s ESD Control program with the relative compliance to this program [2]. A typical return on investment (ROI) for a strict ESD Control program, like that used at Lucent Technologies, is typically 1,000 %. The design of the ESD Control program should be well thought out to minimize unnecessary costs in the program, but with this knowledge, major quality and reliability failures have been known to cost up to $10 million dollars each and jeopardize sales.

Protecting an ESDS device at all but one of the workstations is not acceptable. For the ESD Control program to be effective, it must be comprehensive and followed with discipline throughout the manufacturing, transport, and storage cycle. Management commitment is an important element of any effective ESD Control Program. ESD damage is not simple or inexpensive to identify. To improve quality and profits, management should be involved. Over 21% of failure analysis is due to electronics and industry studies showing that 30% of all electronic failures can be attributed to ESD.

Major companies including AT&T, Motorola, Hewlett Packard and IBM have been able to successfully track ESD damage cost and the resulting benefits of their ESD Control Programs. These companies have determined that ESD Control is an essential part of their success, one that results in significant investment pay-back, refer to Figure 1.

Even with an ESD Control program in place, a typical electronics company may lose 5% of revenue from all causes of product failure. Cost avoidance is the biggest issue when it comes to implementing an ESD Control program. Another source [5] states that a typical pay-back on an ESD control program is 95:1. For every one-dollar invested in ESD control, ninety-five dollars comes back as money saved [5].

V Increased Sensitivity to ESD Control and some causes

Difference in component sensitivity between through-hole and surface mount devices is dependent on the architecture and technology packaged. Typically, surface mount devices have much smaller architecture making them more susceptible to ESD than through-hole packaged devices. The width of the circuitry conductors is as small as 0.10 micrometer (equal to 0.0001millimeter or 0.000004 inch). To pack more and more circuitry into small packages, the spacing isolating circuitry has been reduced and can be as little as 300 m m. A human being cannot feel ESD voltage until it reaches approximately 3,000 volts. A discharge of static electricity is literally a little lighting bolt, producing heat that can easily burn through microelectronic architecture some rated with a withstand voltage as low as volts.