by Debra Vogler, senior technical editor, Solid State Technology
July 14, 2009 – Norcimbus FCIV Inc. has introduced its NBlend variable flow gas mixing system at SEMICON West. The new system allows manufacturers to transition away from using specialty gas cylinders and achieve cost savings by blending their own specialty gases in-house, implementing a facility’s existing bulk gas supply infrastructure. The company says its new system has been demonstrated to achieve a return-on-investment (ROI) in as little as 60 days (see the ROI calculation and comparison of a sample fab set-up in the figure below).
Sample ROI calculation and illustration. (Source: Norcimbus)
CLICK HERE to view larger image
Typical savings achieved by the NBlend system over one 24-hour period, with a 60 day ROI for a 40 slpm system: For the set-up shown in the figure, the system replaces 10 specialty gas cylinders; accuracy has a standard deviation <0.05% with a variable gas flow to accommodate actual fab demand over the 24-hour period. The system adjusts with fab gas requirements, instead of providing gas at a fixed rate and venting the excess to maintain performance levels. Cost savings are greater and ROI faster on higher flow systems; the system can accommodate up to 250 slpm.
The system’s closed-loop feedback and analysis capabilities enable it to maintain an extremely tight specification on the blended gases of ±0.3% accuracy ratio, according to the company. Mass flow controller (MFC)-based systems must mix continuously at a set flow rate, which results in the venting of excess gas. Norcimbus’ system measures the actual blend and performs the mixing in real-time, allowing gas to be delivered as needed and eliminating wasted materials.
Key to the NBlend’s capabilities, according to Norcimbus operations manager Brian Ebert, is an expansion on existing gas mixing technology — combining an MFC mixing system, surge tank, concentration analyzer, and a proprietary Power Purge V controller. The system is designed to mix two gases to an adjustable ratio and supply a variable flow up to 250 slpm continuously, while the concentration analyzer monitors and adjusts the blend ratio to maintain the concentration set point. In particular, the controller has been designed for continuous system monitoring, and the safe delivery and purging of ultra high purity (UHP) process gas systems. — D.V.