Key Hazards in Process Ovens & Dryers

Experience has shown that explosions in ovens and dryers can happen very quickly. The key hazard is an explosion from the build up of solvent vapors in the oven or dryer atmosphere. This buildup could occur by a malfunction in the production process such as:

  • a sudden or improper amount of coating 
  • a change in ventilation controls 
  • excessive speed

In any of these cases, the concentration of flammable vapor has an opportunity to rise above safe levels, creating a potentially explosive mixture of vapor in air.

Area Monitoring of Storage Areas in Semiconductor Facilities

Hazardous gases are stored and distributed in the semiconductor plant, which includes:

  1. Storage Areas
  2. Distribution
  3. Delivery Piping

In these operations there exists the possibility that the hazardous gas could accidentally leak or spill into the surrounding area. Pumps, control valves, manifolds, piping junctions, fittings and connections are some of the potential sources for leaks or spills. With so many opportunities for leakage, continuous monitoring of such hazards is an essential part of keeping the plant safe.

Flammability Monitoring of LFL/LEL Levels in Semiconductor Facilities

Process tools are enclosed areas in which specific wafer processing functions occur. Any process tools handling flammable gases require a hazardous gas detection system to ensure safety and be in compliance to codes. The FM standard states that “ventilation shall be provided for all tools handling flammable and combustible liquids. Ventilation shall be provided to ensure the atmosphere does not exceed 25% of the LEL (LFL) in the event of the largest possible leak.”

Parts Per Million Detection in Semiconductor Facilities

Containers of hazardous gases, both flammable and toxic, are often isolated from the surrounding environment by safety enclosures (gas cabinets). Some process tools have a gas control enclosure section that serves the same purpose as a gas cabinet. It is important to monitor these enclosures for leaking gas to save product as well as prevent a toxic condition. The cabinets and enclosures are ventilated to prevent the buildup of any leaking gas.

Pollution Control: Solvent Recovery

Solvent recovery systems recover and re-use solvents from manufacturing processes. Solvent laden air from the processes is passed through an activated carbon bed. When the carbon bed is nearly saturated with solvent, a steam-down cycle occurs to condense out the solvent for re-use. The carbon is then regenerated for another collection phase. Two carbon beds are used so that one bed can process the solvent-laden air while the other one is regenerating.