Electrostatic Discharge Protection from 3M: Ground Master, Ground Man and Iron Man Grounding is the most important component of electrostatic discharge (ESD) protection. Good grounding assures that all conductive parts of the tool are at the same potential and do not introduce electric overstress (EOS) or electrostatic discharges during the tool’s operation. In critical environments, a broken ground connection may result in personnel exposure to dangerous voltage, equipment lockup or malfunction, and damage to sensitive components. At the EMPF, our factory floor is under the protective watch of three products from 3M: the Ground Master, the Ground Man Plus, and the Iron Man (Figure 5-1).

The Ground Master device from 3M offers continuous monitoring of the proper ground connection for up to eight tools, and up to 16 tools in tandem with another Ground Master. With individual status indication, the Ground Master shows which ground connection is being monitored, which one is OK, and which one has failed. Enabling switches for each ground connection allow for accurate and safe indication and each ground connection has an individual fuse to prevent dangerous voltages from propagating to other equipment. Ground Master also offers monitoring of electromagnetic interface (EMI) on each ground, providing diagnostics for lockups and malfunctions and detailed status to a facility monitoring system.

The Ground Man device offers continuous monitoring of proper ground connection of up to three points in the tools. Applications for Ground Man include surface mount technology (SMT) pick-and-place tools, integrated circuit (IC) handlers, wire bonders, and die attach. In order to further improve reliability of ground connections, Ground Man Monitors provide logic level signal to the host tool so the tool can be shut down in case of ground failure. The Ground Man Plus Monitor adds wrist strap monitoring to assure that only properly grounded operators work with the sensitive devices. The operator is monitored for proper connectivity and for excessive body voltage.

The Iron Man Workstation Monitors from 3M measure voltage directly on the circuit board during assembly. If there is any electrical overstress on the board, they provide both an audio and a visual alarm to the operator. Soldering irons touch the most sensitive components in electronics assemblies; yet, if the iron is not grounded properly, the components may be exposed to significant overvoltage that can cause severe damage and affect reliability. Poor grounding may be caused by many factors, including ground failure in an electrical outlet, internal failure of the soldering iron, and oxidation of the tip. Soldering irons are not the only threat; metal tools such as tweezers and screwdriver bits can also induce significant overvoltage to the circuit. Iron Man Monitors will detect most occurrences so that corrective action can be immediately applied. The Iron Man Plus Workstation Monitor adds complete monitoring of the entire workbench; wrist strap, and dissipative mat monitoring for ESD and EOS. The operator is monitored for proper connectivity and for excessive body voltage. The dissipative or conductive mat is monitored for its proper connectivity.

Visit the EMPF to learn more about and to see ESD protection devices from 3M in action. Contact Ken Friedman at 610.362.1200, extension 279 or via email at kfriedman@aciusa.org.