Part of the manufacturing of integrated circuits requires laying down a layer of conductive material that connects the various devices that have been created on the wafer. Since the dimensions of the components on the wafer are extremely small, any extraneous particles in the conductive material can be detrimental, causing a significant reduction in conductivity and final part quality, and therefore, removing the particles is imperative.
As part of an automation project for a chemical company that makes products associated with these conductive materials, one of the more challenging requirements necessitated creating a method to get data from a Liquid Particle Counter via a standard port into the company’s DeltaV Distributed Control System (DCS).
Since the Liquid Particle Counter didn’t use an industry standard communication protocol, a custom solution to acquiring the data was needed. Although several options were explored to get data from the Liquid Particle Counter into DeltaV, the eventual solution took into account Avid Solutions’ process of Outcome-Based Engineering (OBE).
One method that was considered, was to develop custom code that would run in a serial module in the DeltaV rack. Although this would have been satisfactory in this unique application, investigating the customer’s future needs showed that a more flexible solution was needed. The solution that we implemented, involved using the Kepware U-CON driver, running on a DeltaV application station, which provided the tools to communicate with the Liquid Particle Counter, and any future devices that might also need to be pulled into the DCS.
Since the distance from the DeltaV application station to the Liquid Particle Counter exceeded the maximum distance for a standard port, we installed an Ethernet converter from Digi International. It looked like a COM port to the Kepware driver, but could send serial information over the control system’s existing Ethernet infrastructure.
Prior to this automation, the client relied on an operator to transfer data on particle counts from the Liquid Particle Counter’s custom software application running on a standalone PC. Now, by continually monitoring the particle count in the DCS, the system can immediately adjust to correct high counts, thereby ensuring a high quality finished product that meets the end user’s needs. Also, the particle count for each batch is now saved and historized in the company’s Historian software, providing the ability to show that the batch meets the end user’s quality requirements.
The success of the Liquid Particle Counter integration into DeltaV via the Kepware U-CON and Ethernet connection, has led the client to request similar solutions in other areas. We are currently gathering data from barcode scanners and additional Liquid Particle Counters. One of the key achievements of these projects is the ability to pull non-industry standard protocols into an industry standard control system. This ability can be replicated not only for this client but also for other industries across variety of areas.