Checking Compressed Air at the Electronics Process Point of Use

Air used directly on a board or in a material process should be assessed where it is delivered. The compressor’s specification does not fully describe the downstream piping, hose, regulator and nozzle. Define the point of use before deciding what air-quality evidence is required.

Identify how the air contacts the process

List the operations that expose material or assemblies to compressed air. Distinguish direct surface contact from enclosed pneumatic actuation. Use the product and equipment requirements to establish relevant contamination limits rather than assigning one universal class to every connection.

Atlas Copco’s air-quality guidance identifies point-of-use sampling and separate checks for particles, water and oil. It notes that downstream equipment can introduce contamination, supporting verification at the actual process connection.

Map the final delivery path

Confirm that the sampling method represents the required condition without bypassing relevant downstream components. A measurement upstream of the final hose cannot independently establish what leaves that hose.

Keep the properties separate

Record the pressure and temperature basis of moisture evidence. A dew-point value needs its pressure context. Keep oil and particle results distinct rather than treating a dry-air result as proof of every other quality attribute.

For example, a replaced hose may change the delivered condition while the central dryer trend remains unchanged. Include such maintenance events when investigating a new surface residue or dispensing irregularity.

If the process experiences intermittent demand, represent the operating states relevant to production. A quiet-system sample should not be assumed to cover an untested peak-demand condition without a technical basis.

Identify temporary hoses used during maintenance or troubleshooting as part of the delivery path. Returning to the normal connection should include the required readiness check, especially when a temporary source has contacted an exposed board surface or material reservoir.

Control changes after qualification

Retain the approved delivery configuration with the process instruction. Review substitutions in filters, hoses, lubricators or nozzles before assuming earlier air-quality evidence still applies.

When contamination is detected, identify the affected route and production interval, then verify recovery at the relevant point. A central-system correction should be followed by evidence that the downstream path is suitable.

The surface-measurement guide can support a targeted surface investigation, while FTIR reference selection helps examine an observed residue without guessing its origin.