Protecting Electronics & PCBs with Antistatic Foam

Ethafoam anti-static, a pink foam being used to package and protect an electronic board

What is PCB Packaging?

Antistatic or Static-dissipative foam packaging to protect intricate and sensitive printed circuit boards (PCBs), keeping them safe from physical damage, dust, moisture, and especially static electricity, which can harm the delicate circuits.

PCB packaging requires materials that protect against moisture, static discharge (ESD), and physical damage. Common materials include antistatic bags and padded boxes. The choice of packaging depends on the sensitivity of the PCB and the intended storage or shipping environment.

Why is Anti-Static Packaging Important?

Static electricity can lead to electrostatic discharge (ESD), a sudden zap that can damage electronics.

Two key metrics are import for anti-static packaging: Static Decay and Surface Resistivity. These metrics are measured according to standards set by the Electrostatic Discharge Association (EIA Std. 541), which ensures the foam’s suitability for protecting sensitive electronic components from electrostatic discharge (ESD).

1. Static Decay (seconds) (Anti-Static Grade foam)

What is Electrolysis and galvanic corrosion?

Galvanic Corrosion is the corrosion that occurs when two dissimilar metals are used together in a structure and exposed to an electrolyte (salt water, chemical, petrol) and the less noble of the 2 metals will corrode. For example; aluminum sheet with steel fasteners on a boat. Some pairings of metals are more at risk of . Check a galvanic series or chart.

Electrolysis is the acceleration of the galvanic corrosion when electricity is introduced to the metals in question. Connected by an , the less metal experiences accelerated galvanic corrosion.

while both processes involve metals and electrolytes, their dependence on an external voltage source distinguishes them.

Static Decay measures the time it takes for an induced electrostatic charge on the foam’s surface to dissipate to a safe level (typically 10% of the initial charge). It indicates how quickly the foam can neutralize static electricity, which is critical for protecting ESD-sensitive electronics.

This test typically involves applying a 5,000-volt charge (positive or negative) to the foam and measuring how long it takes for the charge to drop to 500 volts or less.

^The Static Decay Rate for Ethafoam AS

2. Surface Resistivity (ohms/sq) (Anti-Static Grade foam)

What is ohms/sq?
Ohms per square (ohms/sq) measures how easily electricity moves across a material’s surface. Higher numbers mean more resistance (harder for electricity to flow), and lower numbers mean better conductivity (easier for electricity to flow)

High resistance >10¹² ohms/sq (insulative foam):
Strongly resists electricity, preventing it from flowing through. However, it can trap static charges on its surface, which might lead to harmful zaps if not handled carefully.

Medium resistance 10⁵ to 10¹² ohms/sq (antistatic foam):
The material allows some controlled flow of electricity, letting static charges leak away slowly without sudden zaps.
For example, when shipping a computer chip or circuit board, antistatic foam cushions the PCB in a box, safely draining any static electricity that might build up during transport or handling.

Low resistance <10⁵ ohms/sq (conductive foam):
The material conducts electricity very well, redirecting to a grounding point and avoiding the senstive electronics in question.

Insulative Foam

Polyurethane foam with no conductive additives, often used in packaging for sensitive electronics to prevent electrical conduction and protect components from static discharge.

Ethafoam® Antistatic/Static-Dissipative Options

Polyethylene foam impregnated with carbon black or antistatic agents, commonly used in electronic device packaging to safely dissipate static charges without allowing rapid conduction.

zotefoams plstazote many different colors stacked on top of each other

Zotefoams® Conductive Options

Carbon-loaded polyurethane foam, used in applications like grounding pads or EMI shielding, where high electrical conductivity is needed for rapid charge transfer.

Available Ethafoams

Name

Density

Standard Size