As a long-time Sierra customer, FSI International , located in Minneapolis, MN, has focused on delivering semiconductor wafer cleaning products and processes that enable IC manufacturers to meet their cost, yield and device performance goals.  In a fascinating application, the Sierra Side-Trak 840H is used to control an argon carrier gas. The gas then carries frozen Argon crystals across the surface of a silicon wafer, effectively “sand blasting” contaminants away with the added benefit that the crystals then sublime into Argon gas.

John Smitherman

Terry Johnson

  Last quarter, FSI found the increasing flows demanded by larger wafers caused oscillation in the valve of the 840H. As a result, the valve exhibited limited control, or would fail prematurely. For this long-standing Sierra customer, the Sierra engineering team, led by Chief Engineer John Smitherman, joined by our rep partner Terry Johnson of  Berg-Johnson Associates, immediately began searching for a solution. After several site visits and numerous conference calls and brainstorming sessions, the valve problem was found to be a combination of variables inherent in the system (very high flow at very low pressure), as well as a (vertical mount) 90 degree shift in the orientation of the flow controller. To solve the problem, the team redesigned the 840H valve block so that the valve is oriented vertically with regard to gravity. This so called ‘L’ block design allowed FSI to retrofit their cabinets with updated units with no re-engineering of their system, extending the life of their product, and allowing for continued use of the Sierra 840H. Success stories like this happen every day at Sierra.  We would like to thank all the "Teamwork Hero's" involved in this great example of Sierra's Passion For Flow!