Balance the demand for conservative spending with the right consumables to safeguard yield
By Peter K. Kang, PhD, and David Hildreth, Milliken
Cost-cutting is a reality within many companies that utilize cleanrooms. Whether it’s a result of pressure from above to please investors or increased competition, cleanroom engineers are more than ever called upon to decrease costs and increase efficiency.
Cleanroom engineers know, however, that cost-cutting must be carefully monitored to prevent contamination issues within the cleanroom. What good is cutting costs on the front end if fiber, particle, and liquid contamination cause detriment to yields?
Choosing bargain-basement consumables is sometimes seen as an easy way to cut costs in a hurry. But consumables safeguard yields by correcting the inevitable contamination that will find its way into even the best of cleanroom manufacturing facilities, and cleanroom wipers especially should arrive clean and leave dirty.
Imagine a photolithography operation with silicone contamination, or increased particle count in a semiconductor facility. Cheap raw materials in inferior cleanroom wipers or gloves can contaminate a biopharm manufacturer, leading to biological proliferation and ruined product.
With a drop in yield of even 1 percent, contamination issues can affect the bottom line in a hurry for a variety of cleanrooms in a wide range of industries. The trick is balancing an increasing demand for conservative spending with the changing landscape in contamination issues and the obvious importance of keeping yields high.
As lines of circuitry become narrower, smaller contaminants become problematic in semiconductor manufacturing. A 300 mm wafer has more potential for detrimental particle contamination than its 200 mm predecessor. And critical products in the biopharmaceutical industry, such as the newest heart stents currently in high demand, and new microtechnologies currently under development require higher standards for biological and sometimes particle contamination.
In the biopharm arena, large research facilities must compete with start-ups, while the big guys also face rising development costs for new drugs and products. Major players in the semiconductor industry face competition where none existed a few years ago-dueling computer processor companies, for example, must compete with cost-cutting while churning out innovations.
There is pressure to cut costs closer to home as well. Companies must answer to investors and keep profits high. Also, purchasing agents rather than cleanroom engineers choose materials. But without intimate knowledge of how cleanrooms work, and constant communication and cooperation with engineers, purchasing agents may not see when cost-cutting sacrifices cleanliness and, therefore, yields. When the big picture is lost, and quality control departments are not in good communication with the purchasing arm of a manufacturer, both sides can miss the connection between purchasing decisions and yields.
As the cleanroom industry ages, rigid specifications within companies may also become relaxed; cleanroom administrators may be willing to test the waters and cut costs, using cheaper materials that are only adequate, rather than the best for the job.
Efficiency is a multi-dimensional proposition: While costs are under control on the front end, productivity cannot drop on the back end. Cost-cutting only translates to a profitable decision if yields don’t drop in the process. So how can cleanroom industries cut costs without sacrificing cleanliness and yields?
Tips for cutting costs in consumable use:
1. Buy in bulk. Consider the number of consumables your facility uses. Can you save by buying larger packages? Do your distributors have new options that may work better for you?
2. Select the right wiper for the job. For many cleanrooms, wipers are by far the largest expense in consumables and a clear target for cost cutting. Rather than switching to a cheaply made wiper, consider changing wiper size or moving to a lighter-weight product. A smaller sized or lighter wiper may produce the same results and cost less; for example, choose a 7-by-8 instead of a 9-by-9, or a 120 g/m2 instead of 140 g/m2, if the size or weight works for your particular application.
3. Train, train, and retrain. Workers should be taught to use wipers and other consumables sparingly and correctly. Monitor consumable use, and consider retraining the “fold and wipe” technique for cleanroom wipers if worker compliance is lax. Considering the amount of investment your company has in cleanroom consumables, retraining may be worth it.
4. Keep an eye on new technology. New consumable technologies can sometimes raise yields and offset costs.
5. Try before you buy. Thoroughly test any change in consumables and closely monitor yield rates; ask your supplier to provide internal or outside testing, and perform an audit on the facility as well if it’s feasible. Companies that institute a change without testing risk both losses in yield and the wasteful costs of replacing inferior stock.
6. Packaging. Consider a change to the packaging of your product. Less expensive materials, labels, and cheaper printing techniques may cut costs without affecting the product itself.
Peter K. Kang, PhD, is a senior development engineer for Anticon Products by Milliken, a leading manufacturer of cleanroom wipers. Kang holds a doctorate in chemical engineering from the University of Florida. He has authored 10 journal articles and conference proceedings and holds four U.S. Patents.
David Hildreth is a senior development engineer for Anticon Products by Milliken. Hildreth has 16 years of experience in textile product development, has authored two journal articles, and holds three U.S. Patents. He received a bachelor’s degree in textile chemistry from Clemson University.
For information about Anticon Products with Particle Attraction Technology (P.A.T.), visit www.anticonwipers.com.