Author: MP

Wrist straps and ESD footwear solve the same broad problem: they prevent electrostatic charge from building up on the human body. They are not always interchangeable. The correct choice depends on whether the operator is seated, standing, or moving through the EPA, which means ESD protected area.

Use wrist straps for seated assembly

For hand soldering, inspection, programming, PCB assembly, and repair benches, a wrist strap is usually the most direct method of grounding the person. The strap stays in contact with the skin and connects to ground through a cord. Marvel Products’ Antistatic Wrist Strap is suitable for bench work where the operator remains at one station.

Use ESD footwear for mobile personnel

Operators who move between benches, stores, trolleys, and test stations may not be able to remain connected by a wrist cord. In such areas, ESD footwear works with suitable flooring to dissipate body charge while the person walks. Marvel Products lists personnel grounding options under Personnel Grounding, including conductive sole slippers and other ESD footwear.

Test both systems regularly

A wrist strap can fail because of a broken cord, worn band, loose snap, or poor skin contact. Footwear can fail because of dirt, wear, wrong socks, poor flooring, or incorrect use. A combined tester such as the Wrist Strap and Footwear Tester helps verify resistance limits before the person enters the work area.

For many facilities, the best answer is not wrist strap or footwear, but both: wrist straps at fixed benches and footwear for movement through the ESD protected area. This creates coverage across the actual workflow instead of only at one workstation.

An ESD safe workbench gives static charge a controlled path away from sensitive components. The goal is not to make every object a direct short to earth; the goal is to dissipate charge safely, repeatably, and without creating a shock hazard for the operator.

Start with the work surface

The bench surface should be static dissipative or conductive as required by the process. Avoid ordinary plastic sheets, decorative laminates, cardboard, or packaging foam on the bench because these materials can hold charge. Marvel Products lists ESD work surface options under ESD Work Surfaces, including static dissipative and conductive rubber mats.

Add operator grounding

The operator must be connected to the common grounding point through a wrist strap or footwear system. A wrist strap is usually preferred for seated assembly and rework. The Antistatic Wrist Strap is designed to maintain conductive contact with the skin and includes a coiled ground cord with a series resistor.

Use a common point ground

Do not connect each item randomly to different locations. A common point ground keeps the mat, wrist strap, and bench accessories at the same reference. For a simple bench connection, review the Miscellaneous Products category, which includes grounding accessories such as bench mount connectors and 3 pin grounding plugs.

Monitor critical benches

For production benches that handle high-value or static-sensitive assemblies, daily testing may not be enough. A continuous monitor helps detect a disconnected wrist strap or mat during the actual work period. Marvel Products’ Single Cord Work Station Monitor monitors the operator wrist strap and the work surface connection.

Once the bench is set up, create a short daily check: inspect mat condition, confirm ground cord connection, test the wrist strap, remove unnecessary insulators, and record any failures before production starts.

An ESD audit is most useful when it checks the real movement of people, materials, tools, and components. A line may have wrist straps, mats, and packaging in place, but static control fails when one link in the daily process is missed. This checklist is written for electronics assembly supervisors who want a practical review before failures become expensive.

1. Check personnel grounding before entry

Operators are a major source of electrostatic charge because movement, clothing, chairs, and footwear can all create voltage on the body. At the start of each shift, verify wrist straps and footwear with an appropriate tester. For combined entry checks, see Marvel Products’ Wrist Strap and Footwear Tester. For spot checking charge carried by people, the Human Body Voltage Checker is a useful audit instrument.

2. Measure work surfaces, not just appearance

An ESD mat can look clean and still be unsafe if the path to ground is broken or the surface resistance has drifted. Check benches, tables, trolleys, racks, and any fixture that touches boards. Use a surface resistance instrument such as the Digital Surface Resistivity Meter and keep readings in your audit record.

3. Inspect packaging and storage movement

Assemblies often leave a controlled workbench and travel through stores, inspection, packing, and dispatch. Use ESD-safe packaging for finished boards and sensitive spares. Link the audit to the available Antistatic Packaging range and verify that operators know when to use antistatic bags, bubble bags, or shielding bags.

4. Look for process-specific static sources

Plastic films, rollers, dry air, ungrounded containers, ordinary tools, and moving sheets can create static away from the electronics bench. Where static is generated on moving surfaces, review the Static Eliminator AC Bar and the broader Static Eliminators category.

A good audit ends with action: record failures, assign ownership, retest after correction, and repeat the audit at a fixed interval. ESD control is not a single product purchase; it is a maintained system.

Many ESD programs focus strongly on the workbench and then lose control after the board is assembled. This is a common gap. A PCB can pass inspection and still be damaged later during movement to stores, testing, customer dispatch, or field service.

The danger after production

Finished assemblies often move through areas where operators are not wearing wrist straps, ordinary cartons are used, labels are applied, or plastic trays are placed on trolleys. A sensitive device may be exposed to charge from packaging film, foam, clothing, or ungrounded containers. Because ESD damage can be latent, the product may fail only after installation.

Use packaging according to risk

Antistatic packaging helps reduce static generation and surface charge during handling. For more sensitive parts, shielding protection may be needed to protect the contents from external electrostatic fields. Marvel Products lists options in Antistatic Packaging, including antistatic bags, antistatic air bubble bags, and static shielding bags.

Build packaging into the route card

Packaging should not be an operator’s guess at the end of the line. The route card or work instruction should state the correct bag, tray, label, and storage method. Stores and dispatch teams should follow the same ESD rules as production. This is especially important for repaired boards, customer returns, programmable modules, and spare PCB kits.

Where individual connectors or openings need protection during movement, products such as Conductive Dust Caps can protect sensitive components from electrostatic discharge while also helping keep internal surfaces clean.

A completed board is still an ESD-sensitive item. Treat packaging as part of the manufacturing process, not as a final housekeeping step.

Visual inspection cannot prove that an ESD surface is working. A bench mat, floor mat, rack, tray, or laminate may look acceptable while its resistance value has moved outside the safe range. Surface resistivity testing gives the ESD team a measurable way to find these hidden gaps.

What should be tested

Common test points include workbench mats, floor mats, table tops, trolleys, storage racks, PCB carriers, conveyor surfaces, and packaging areas. Any surface that touches sensitive components should be included in the test plan. Do not limit testing to new installations; ageing, contamination, cleaning chemicals, and physical wear can change performance over time.

Why records matter

Single readings are useful, but trends are better. If a bench surface is slowly drifting, maintenance can act before it fails. If one area repeatedly shows high readings, it may point to a broken ground path, incorrect cleaning method, or non-ESD material introduced into the process.

Use the correct instrument

Marvel Products’ Digital Surface Resistivity Meter measures surface resistance and resistance to ground over a wide range for ESD protective materials. For a broader list of audit instruments, see ESD Instruments.

Surface testing should be part of incoming inspection for new ESD materials, routine audits for production areas, and corrective action after any ESD event. It replaces guesswork with evidence and helps maintain the ESD control plan across the full shop floor.

Static charge is not only an electronics assembly problem. In processes that handle plastic film, paper, laminates, labels, foils, or other moving webs, static can cause sticking, dust attraction, misfeeding, operator shocks, and quality problems. These applications often need ionization because grounding alone cannot remove charge from insulating materials.

Why moving material builds charge

When two surfaces contact and separate, charge can transfer from one to the other. Rollers, unwind stands, slitting machines, conveyors, and packaging lines create many such contact points. If the material is an insulator, the charge remains on the surface and may increase as speed rises.

How an AC static eliminator helps

An ionizing bar produces ions of both polarities near the charged surface. The surface attracts the opposite polarity ions and neutralizes the charge. Marvel Products’ Static Eliminator AC Bar is designed for charge elimination on moving surfaces and is supported by a high-voltage power source.

Installation points to consider

• Place the bar near the charged surface and after the point where static is generated.
• Keep the operating distance within the recommended range.
• Clean the emitters periodically because dust reduces ion output.
• Check whether charge is actually reduced with a static charge meter.

For related products, see Marvel Products’ Static Eliminators category. A correctly placed ionizing bar can improve material flow, reduce contamination, and make the process easier to control.

Static is invisible until it causes a failure, a shock, or a process defect. A static charge meter helps maintenance and quality teams identify where charge is present, how much is present, and whether the polarity is positive or negative.

Where to take readings

Start with the places where charge is likely to be generated: plastic trays, tape reels, film rolls, work chairs, packaging tables, conveyor belts, component bins, and moving sheets. In electronics assembly, also check areas where boards are removed from packaging or transferred between benches.

How to use the reading

A meter reading should trigger a practical question: why is charge present here? The cause may be an insulator in the area, poor grounding, unsuitable packaging, low humidity, or a process that separates two materials quickly. Once the cause is corrected, take another reading to confirm improvement.

Link measurements to corrective action

If charge is found on personnel, review Personnel Grounding products and entry testing. If charge is found on work surfaces, check the surface with the Digital Surface Resistivity Meter. If charge is generated on moving insulating material, review the Static Eliminator AC Bar.

Marvel Products lists static measurement tools under ESD Instruments. A meter is not only for failure investigation; used regularly, it becomes a preventive maintenance tool for the entire ESD program.

ESD control must continue after an item leaves the workbench. PCBs, components, assemblies, and ESD-sensitive tools often spend more time in storage and movement than in active assembly. Conductive storage products help maintain protection during these stages.

Why ordinary storage creates risk

Plastic boxes, open shelves, mixed bins, and random cartons can hold charge or allow sensitive boards to rub against insulating materials. Even if the operator is grounded, the stored item may be exposed to static during picking, counting, kitting, inspection, or transport.

Storage options to consider

• Use conductive bins for components and small assemblies.
• Use conductive trays when items need to move between workstations.
• Use PCB carriers where boards must be kept separated and upright.
• Use conductive tool boxes for ESD-safe tools and service kits.

Marvel Products lists these items in Conductive Storage. For board movement, the Conductive Fixed PCB Carrier provides an economical rack for handling boards of different sizes.

Make storage part of the work instruction

Operators should know where a board goes at every stage: before inspection, after rework, before conformal coating, after programming, and before packing. A clearly defined storage method prevents the common mistake of placing good assemblies in unsafe trays for convenience.

The best ESD storage system is visible, labelled, and easy to use. If the safe option is the easiest option, people will follow it more consistently.

An ESD program is easier to manage when records are simple and consistent. Good records show that controls are working, reveal trends before failures happen, and support customer or internal audits.

What to record daily

Daily records should include wrist strap and footwear test results, entry failures, corrective action, and release back to work. For combined checks, use an entry-point instrument such as the Wrist Strap and Footwear Tester.

What to record periodically

Weekly or monthly checks can include bench mat resistance, floor resistance, work surface condition, storage area compliance, and packaging availability. Use suitable products from ESD Instruments, including the Digital Surface Resistivity Meter, to keep values measurable.

Calibration and confidence

Measurement instruments should be calibrated at a defined interval. Many facilities use a 12-month calibration cycle, but the exact schedule should match customer requirements, internal quality systems, and instrument usage. Record calibration dates, due dates, instrument IDs, and who performed each check.

Use records to improve

Do not keep records only for audits. Use them to find repeated failures, problem shifts, damaged cords, unsuitable footwear, or areas where mats fail earlier than expected. Link corrective actions to product categories such as Personnel Grounding, ESD Work Surfaces, Conductive Storage, and Antistatic Packaging.

The best ESD record system is short enough for operators to use and detailed enough for engineers to act on.

ESD mats are not simply protective table covers. Their job is to control charge on the work surface and provide a defined path to ground. Two common choices are static dissipative mats and conductive rubber mats, and the right choice depends on the parts handled, test method, operator safety, and grounding arrangement.

What a static dissipative mat does

A static dissipative mat allows charge to bleed away at a controlled rate. This is useful on electronics benches because sudden discharge can damage sensitive components. Dissipative surfaces are often chosen for assembly, inspection, rework, and packing benches where PCBs and ICs are handled manually.

What a conductive rubber mat does

A conductive rubber mat offers a lower resistance path and may be selected where a stronger grounding path is required. It should still be used as part of a safe grounding system, not as an isolated sheet on a bench. A mat without a correct ground cord and common point connection cannot protect the process.

How to choose

• Use the process risk: IC handling and PCB assembly usually need controlled dissipation.
• Check the work style: seated operators normally require wrist straps along with the mat.
• Verify the surface: periodic readings matter more than the mat’s age or appearance.
• Keep records: surface resistance values should be logged during audits.

Marvel Products groups these solutions under ESD Work Surfaces. For measurement and verification, use an instrument such as the Digital Surface Resistivity Meter.

The practical rule is simple: select the mat for the risk, ground it correctly, keep it clean, and test it on a schedule.