Hardware, Design PCB for ESD

Describe the Failure / Bug
A clear and concise description of what the failure / bug is. Describe the problem NOT the fix.

Design for ESD, Electro Static Discharge

See for example: EN 61000-4-2

Summary

EN 61000-4-2, which is harmonized with the International Electrotechnical Commission (IEC) standard IEC 61000-4-2. This standard outlines the test methods and performance criteria for evaluating the electrostatic discharge (ESD) immunity of electronic devices. It's crucial for ensuring that electronic products can withstand ESD events encountered in real-world environments.

Details

Elaboration:
The EN 61000-4-2 standard, which is equivalent to IEC 61000-4-2, defines the requirements for ESD testing to assess the immunity of electrical and electronic equipment to ESD events. The standard specifies two types of discharge: contact discharge and air discharge.
Contact Discharge:
In this test, the ESD generator's discharge electrode is directly touched to the equipment under test (EUT). The standard defines four test levels for contact discharge:
Level 1: 2 kV
Level 2: 4 kV
Level 3: 6 kV
Level 4: 8 kV
Air Discharge:
In this test, the ESD generator's discharge electrode is brought close to the EUT until a sparkover occurs. The standard defines four test levels for air discharge:
Level 1: 2 kV
Level 2: 4 kV
Level 3: 8 kV
Level 4: 15 kV
The choice of test level depends on the intended operating environment of the equipment and the severity of ESD events it is expected to encounter, according to www.mpbelectronic.com. For example, Level 4 (8 kV contact/15 kV air) is often considered sufficient for most applications, but higher levels might be necessary for environments with higher ESD risk.