Circuits Assembly Online Magazine - Driving Toward Static-Free Electronics

A new roadmap highlights electrostatic discharge trends and needs.

To help the industry cope with electrostatic discharge (ESD) sensitivity, the ESD Association developed and made available through its Web site the “Electrostatic Discharge Technology Roadmap.” The Roadmap, which became available in March 2005, details projected ESD sensitivity trends brought about by changes in device design.

One way to understand the future is to review the past. The Roadmap begins with a look at the history of ESD, noting

In the late 1970s, electrostatic discharge became a problem in the electronics industry. Low level ESD events from people were causing device failures and yield losses. As the industry learned about this phenomenon, both device/design improvements and process changes were made to make the devices more robust and processes more capable of handling these devices.

During the 1980s and early 1990s, device engineers were able to create protection structures that made the devices less sensitive to ESD events. Technology changes during this time also helped design engineers to develop more robust devices.

In the mid to late 1990s however, the requirements for increased performance (devices that operate in Giga-Hz range) and the increase in the density of circuits on a device caused problems for traditional ESD protection circuits. To achieve the performance and density numbers required by industry, the devices have become more sensitive to ESD events since the late 1990s. The current trend, which is expected to continue, is circuit performance at the expense of ESD protection levels. This is especially the case for RF circuit applications.

In developing the Roadmap, it was determined that as devices become more sensitive over the next five years, it will be imperative that companies begin to determine the ESD capabilities for their handling processes.

According to Charvaka Duvvury of Texas Instruments, a contributor to the Technology Roadmap, the purpose of the Roadmap is to project the impact of technology scaling in the IC industry. It also encompasses the challenges that will be faced in providing adequate ESD protection at the chip level.

To develop the Roadmap, ESD device and design experts from several major corporations – IBM, Intel, TI and Celestica to name a few – collaborated through brainstorming. Contributors included Duvvury; Ron Gibson of Celestica; Steve Voldman and John Kinnear of IBM; and Tim Maloney of Intel. The projections they formulated are based on industry trends and technology constraints and are not representative solely of the design methods used at their respective companies.

The collaborative team developed their conclusions after review of new design functions such as RF circuit applications. As an example of new design function, Duvvury cites, “RF circuits for wireless applications are expected to be a major thrust in the IC industry for the next decade.” He adds that “the projected ESD protection capability for these applications was arrived at after considering factors such as the high speed RF operation and its tolerance to the ESD protection parasitics such as capacitance and noise injection.”

The “Electrostatic Discharge (ESD) Technology Roadmap” was developed for manufacturers that provide ESD protection limitations. The Roadmap is also for companies that handle ESD-sensitive products and must make handling decisions based on these precautions and protection limitations.

According to Duvvury, industry “must use the roadmap to enhance their technical expertise to find better solutions as well as implement thorough ESD control processes at production lines.”

This column is a regular contribution of the ESD Association, Rome, NY; (315) 339-6937; email: info@esda.org.