General Topic

Terra Universal manufactures a vast selection of stainless steel products for cleanrooms, hospitals, laboratories, and other controlled environments. Among these steel-constructed products, you'll find tables, workstations, glove boxes, pass-throughs, doors, and more.

Electricity is in the air all the time; we can clearly see it during a lightning storm. But what happens when it’s in your cleanroom, glovebox or hood? Electrostatic discharge will damage components and materials, so get a better understanding of this phenomena and learn what you can do about it.

Controlled environments act as secluded clean spaces for performing select applications in a manner that protects the internal samples or materials and/or the workers involved. Air pressure is a key component of a cleanroom. The internal pressure and, by design, the differential pressure, are closely regulated and maintained.  Basic chemistry tells us that high pressure air has greater mass than low pressure air, and given the opportunity, will flow into the less dense environment.

Ascending or descending pressure differentials are part of the foundation of most controlled environments. Maintaining a specific differential between adjacent areas reduces the inflow of airborne particulates and/or prevents hazardous materials from escaping. The type of application dictates whether a positive or negative pressure space is required. So, how do these two pressure types differ?

Isolation

High-tech industries have long been plagued by an unseen foe. From semiconductors to medical devices, manufacturers are forced to accept high product rejection rates due to particle contamination or critical defects. Oftentimes, contamination issues and product damage in these industries can be traced back to uncontrolled static electricity. When static is allowed to build-up, it becomes a double threat to a cleanroom, increasing the chances of ESA-induced contamination and electrostatic discharge (ESD) damage.

ESA Contamination in Cleanrooms

Electrostatic attraction (ESA) is the phenomenon that causes dust to stick to the glass screen of an old vacuum tube television. When particles become statically charged by friction or contact with another material, they adhere to surfaces that have the opposite charge. While this may seem harmless in the example of the TV monitor, the semiconductor industry works on a microscopic