A few weeks ago, Larry Adams asked if I’d like to comment about critical cleaning for “MicroManufacturing Magazine “ (see The Power of Knowledge Acted On section below). I replied: of course I would! His questions got me thinking; and I ended up discussing how critical cleaning impacts manufacturing, how changing materials have affected what I do, the way Ed and I meld our differing backgrounds and approaches to problems, and how critical cleaning has changed over the years. That last point got me speculating about the future.
—How does your work affect process control, product improvement, and yield?
Critical cleaning is an integral part of successful manufacturing, not an end in itself. The goal of critical cleaning is to improve yield and to improve both short and long-term product performance and reliability. Critical cleaning processes should be well documented and well controlled. Very often, the root cause of product performance problems or low yield can be traced back to a cleaning issue.
–Many new materials have entered the market over the years, how does that affect your job?
New materials make my job more interesting – in the sense of “may you live in interesting times.” Some materials of construction are porous or they are less well-defined in terms of surface, so there are issues such as particle entrapment, thin film removal, and outgassing. In addition, many plastics and elastomers are defined by performance characteristics, not by the way they behave during cleaning processes or other manufacturing process. This means that while materials compatibility tables provide a starting point, manufacturers cannot simply select a cleaning chemical or process without testing. You have to do dynamic compatibility studies that mimic the process under consideration. To make matters more complex, a manufacturer may obtain a new material of construction, or, even a new batch of supposedly-familiar material of construction; and unexpected materials compatibility problems occur.
–You and your husband, Ed, have diverse backgrounds. How does this help?
Ed has a background in physics and product development. My background includes biochemistry and process development. We see things from different perspectives. Ed is often able to look at a huge piece of complex, malfunctioning manufacturing equipment and figure out the location of the problem. I’m very sensitive to surfaces and reactivity. We have different perspectives, so we sometimes have, shall we say, animated discussions about the best way to help our clients. Fortunately, this verbal heat of reaction is rarely explosive; and it tends to result in a better resolution of the process problem.
–How has the profession changed over the years?
BFK Solutions has been around for 20 years; and I’ve had a number of years of experience in industry before that. On the positive side, industry recognizes the importance of cleaning, the rationale of cleaning. However, colleges and universities have been slow to recognize that development of miniature, micro, and nano devices will be enhanced by developing critical cleaning as a distinct field of study.
In 2014, those involved in manufacturing are more aware of the rationale of cleaning. Back in the day, cleaning was considered part of company lore. Processes worked (no one knew quite why) processes were written to require cleaning the way grandpa had. Miniaturization, cost constraints, and regulatory constraints on long-used chemicals changed all that. There is far more interest in understanding how cleaning impacts surface quality, on residue, on surface attributes. The medical device industry has changed immensely. Cleaning medical devices used to be thought of as synonymous with decontamination and sterilization – it’s not. Device manufacturers now understand the importance of minimizing leachable residue.
However, one thing that has not changed enough is recognition of critical product cleaning at the university level. Manufacturing professionals (of both genders) tell me they want to be a “cleaning lady.” The world of manufacturing needs a separate field of study, at the college and university level, that encompasses critical cleaning, surface attributes, and contamination control.
