Cleaning, an integral part of many manufacturing and maintenance processes, is often critical to the performance of a broad range of technologies. In many industries, such as semiconductors, defense, MEMS, and biotech, an effective and efficient cleaning process is of critical importance to the performance of equipment and systems that play vital roles in industry, research and even national security.
“Cleaning” in the process industry and research labs refers to the use of agents such as solvents, acids or bases to remove unwanted particulates and other contaminates from products ranging from optics to semiconductor and electronic devices. Cleaning may be an automated process on the finished product or it may entail the surface preparation of a material prior to the next manufacturing process.
In many instances, even though there may be proven cleaning tools and systems on the market, a specific application – particularly sensitive products – may benefit from a secondary evaluation of the cleaning parameters or processes detailed in an RFP.
“The specifiers, such as product or process engineers commissioning the RFP, are aware of the importance of cleaning their products,” says Louise Bertagnolli, president of JST Manufacturing (Boise, ID), a specialist in wet processing and precision cleaning equipment. “However, they may not realize that cleaning technologies have become so sophisticated that it is usually possible for cleaning system vendors to improve on the initial design of a cleaning tool or process, making it more efficient, cost-effective and robust.”
Bertagnolli explains that cleaning system specialists have a broader view and experience with the tools and technologies available, as well as the expertise required to select and integrate them. She adds that whether or not the cleaning process involves automation it may be highly beneficial to work with a cleaning specialist who has an applications lab equipped to test a variety of cleaning systems and also demonstrate their performance.
“Having the equipment required for this kind of facility is indicative of the commitment of the cleaning system specialist,” Bertagnolli says. “A facility capable of performing demonstrations will have specialized metrology equipment such as a scanning electron microscope and laser-based surface particle measurement systems in a state-of-the-art cleanroom.”
The world’s largest laser
One such application that validates Bertagnolli’s viewpoint on cleaning systems is the design evolution of a specialized cleaning tool for the National Ignition Facility (NIF) at Lawrence Livermore National Laboratories (LLNL), Livermore, CA.
NIF, the world’s highest-energy laser system – a stadium-size machine – consists of 192 laser beams that will focus nearly two million joules of energy and create temperatures and pressures that exist in the cores of stars and giant planets. By harnessing the massive power generated by its lasers, NIF is able to create conditions and conduct a wide range of experiments never before possible on earth.
NIF is also a cornerstone of the National Nuclear Security Administration’s effort to maintain the United States’ nuclear deterrent without nuclear testing and plays a vital role in reshaping national security in the 21st century. Other NIF missions include finding new sources of pollution-free energy, and studying physics such as fusion and other sciences in a manner more advanced than ever before.
Each of NIF’s 192 beams is supported by an array of optics (lenses) – up to 50 lenses for each beam – depending on the type of experiment being performed. Maintaining the cleanliness of thousands of optics is crucial to the success of the various types of laser-based experiments.
“If these lenses were not as clean as possible then we would start to degrade the performance of our laser,” explains Patrick Williams, NIF optics maintenance manager. “The cleanliness of our optics is crucial to our ability to produce maximum fluency (energy in joules) that is required to perform many tests.”
Transporting the chemistry
To maintain the large inventory of optics, LLNL partnered with JST Manufacturing in the development of a unique cleaning tool.
“The optics are heavy and rather large, so we don’t want to handle them a lot,” Williams explains. “So, after we developed an RFP and showed it to JST, they suggested that there might be an easier and more cost-effective way to transport, clean and inspect the optics. JST did a beautiful job with the alternate design. They came back from the drawing board with an original design, and then we tweaked it into a system that has worked for over 16 years.”
One of the innovations in the NIF cleaning tool, which was a tank-like configuration, was to eliminate the need to move the optics to different locations in order to perform the washing, rinsing and drying functions.
“Our engineers suggested that rather than transport these heavy optics for such functions, we could simply transport the chemistry (solutions) to the optics in a fixed location,” explains Louise Bertagnolli. “We also designed a sling-like device to hold the optics and also let technicians rotate them during the inspection process.”
To date JST has built two cleaning tools for NIF. The first tool was used for the very beginning of the facility. “A second tool was built to provide us with dual capacity,” Williams explains. Because NIF has become a production facility, where many scientists and companies are performing research, we also wanted to be able to clean a higher volume of optics and also get away from single-point failure.”
Precision process cleaning
In some instances cleaning is an adjunct of the manufacturing process, Bertagnolli says. For example, her firm has been involved with designing cleaning systems and etching systems for the production of crystals used in aerospace guidance systems.
“Etching is surprisingly related to cleaning, and that is an area where we are involved in applications such as wafer production in the microprocessor field.” she explains. “Etching involved the precision removal of material from a component, which is a form of cleaning just like the removal of unwanted material from the surface of an object, whether it’s particulate debris, corrosion or contaminants, or a layer of material.”
Bertagnolli feels that like other cleaning devices, whether simple or fully automated, the ability of the cleaning system vendor to innovate, even if it means going beyond the RFP, is what creates more efficient solutions that may well save the customer on costs. If the vendor has a sophisticated application lab to demonstrate that solution in advance of production, all the better.