Archived Newsletters
Back to the Future - Cleaning, Communication, Conferences
Barbara Kanegsberg BFK Solutions LLC
For over a decade, there have been predictions of the death of meetings, of face-to-face conferences. Has electronic communication eliminated the relevance of conferences? Have budget cuts and the hassle of travel chained us to our desks? Based on recent events, our answer is: no. In fact, the most efficient route to productive manufacturing processes, to high quality cleaning processes, and to superior product involves judicious use of face to face workshops/conferences in conjunction with electronic resources such as websites, ezines, and webinars.
Two recent conferences, the ITSA Technical Program and the APEX Expo, illustrate a growing interest in face-to-face, interactive communication as well as education. Program topics that expedites successful manufacturing included:
- Critical and precision cleaning
- Industrial cleaning
- Surface quality and properties
- Contamination control
- Certification, standardization
- Global manufacturing
- Regulatory constraints on manufacturing (local, national, and international)
Why are conferences a way “back to the future?” Workshops and conferences are often the best venues for asking the right questions, getting the most useful answers, and distinguishing productive solutions from “excrement of male cow.”
A good conference brings everyone up to speed and up to date really fast. This is important with the current makeup of the workforce and with the current economic situation; one attendee commented that over half of the designers at his company have less than 5 years of experience. Design, cleaning, and materials issues are closely interrelated. Cleaning – critical cleaning, precision cleaning, industrial cleaning, whatever – is pragmatic and based on experience.
ITSA Technical Program; Cleaning and Surface Quality
In mid-April, I discussed essentials of critical cleaning prior to thermal spray and provided a regulatory update at the Annual Membership Technical Program of the International Thermal Spray Association (ITSA) in Orlando, FL.
Thermal spray covers a wide range of techniques in which metals or non-metals are deposited in a molten or semi-molten condition to form a coating. The technique has wide applicability. For certain applications, it can be a substitute for chrome plating. For an introduction, please see
http://www.thermalspray.org/
Despite the fact that my presentation was the only barrier separating attendees from a truly excellent lunch, there were wonderful, insightful questions and comments about the nature of cleaning, how cleaning works, solvency, and what the surface ought to look like.
We discussed conventional wisdom about cleaning prior to thermal spray; and then we went beyond conventional wisdom. For example, conventional wisdom holds that the most important cleaning step is abrasive blast. However, abrasive blast may simply move oils around. Oily surface residue can cause failure of the thermal spray coating. Abrasive blast can also drive particles into the surface, resulting in a poor quality surface. By conventional wisdom, acid pickling and oven baking are considered cleaning steps. In reality, cleaning is accomplished using basic (moderately high to high pH) cleaning agents. In contrast, while acid pickling may remove some salts, it primarily serves to modify the surface. In addition, while heat treatment can remove some soils, too often it serves to embed soils in the surface. These embedded soils are often modified and reacted as a result of heat treatment; they can be nearly impossible to remove. Embedded, burnt on soils can compromise the coating.
Attendees commented about California regulations, probably realizing that what happens in California tends to migrate at least nationally. For recent news about proposed Cal/OSHA changes to PEL’s (Permissible Exposure Limits for workers), please have a look at our March newsletter (Part 1, Part 2, Part 3). Nationally, there is a consideration to list cobalt-tungsten carbide powders and hard metals as “reasonably anticipated to be a human carcinogen.” (Federal Register, Vol. 74, No. 27 {February 11, 2009}). Some were surprised that materials that were introduced as safer substitutes after exhaustive and costly technical studies might be a problem.
We see a recurrent problem that chemical “witch hunts,” where chemicals are sequentially targeted for control or extinction in manufacturing processes, does not really address the root issues needed to protect workers and the environment. The witch hunt approach serves primarily to make manufacturers jump through the latest regulatory hoop. A more holistic approach that includes process control and an understanding of process alternatives is likely to be more productive.
APEX Expo
Speaking of back to the future, this past fall, we explained that cleaning after fluxing, an issue that many thought had disappeared, is an important upcoming issue in electronics manufacturing. Please refer to “Electronics in 2010+: Cleaning Challenges.”
At the IPC APEX in Las Vegas in late-March/early April, cleaning continued to grow as an essential manufacturing issue.
Defluxing, another term that means cleaning, has become a major issue for electronics assembly. Electronics assemblies consist of the bare board plus the various components that are soldered onto the board to provide specificity and functionality. Flux is used to remove surface oxides prior to soldering; so flux acts as a cleaning agent. Some low-residue or “no-clean” fluxes can remain on the assembly without damage. However, for many high-reliability assemblies, the flux must itself be removed in a process step termed defluxing. Defluxing is increasingly important in electronics assembly with the increase in
- Miniaturization
- Densely-populated assemblies
- Lead free fluxes and associated higher process temperatures
Cleaning program
There was a half-day cleaning program on the final day of APEX. Despite the lure of the casinos and the opportunity to vegetate by the pool, the program was well attended, with enthusiastic participation. I was able to observe the program dispassionately because, as the program moderator, I was not hyperventilating prior to a presentation (I still get butterflies.) The presentations were great; monitoring the Q&A section was the challenging part, because attendees asked tough, incisive questions about how to optimize the defluxing process in terms of both the cleaning agent and the cleaning process. They also wanted to know how to monitor cleanliness; it is apparent that we will need a new generation of tests to augment current tests for conductive residues.
Consolidated Post Solder Cleaning Handbook
The IPC Cleaning & Alternatives Subcommittee (IPC 5-31) is melding four cleaning handbooks into a single document. They are also doing a major update. The documents and drafts are distributed electronically to expedite getting the information and drafts out in a timely manner.
However, a face-to-face meeting at APEX was essential for brainstorming. A conference call would not have had the same impact or efficiency. The revision is a monumental effort. It involves assemblers, vendor suppliers, and consultants. In fact, I am one of the Section leaders for the Materials Compatibility Section; and I may call on you for insight – or, feel free to speak up.
Your input to the Handbook is most appreciated.
New: Potting and Encapsulation Guidance
At another face-to-face meeting, potting and encapsulation were discussed. Given the number of variables and unknowns, a standard is impractical; therefore a guidance document is under development.
A range of topics was covered during the short brainstorming system. For example, there may be significant differences between vendor-recommended curing procedures versus what is spelled out by assemblers. This disparity is recognized by suppliers of the compounds; it may be productive to have frank interchange between assemblers and formulators. Another issue is the impact of encapsulation on subsequent process steps like conformal coating (or vice versa). Conformal coating is applied to an electronics assembly; it serves as protection against environmental damage from particulates, water, organic chemicals, etc.
The impact of cleaning on the success of encapsulation was a recurrent theme; and, no, I did not instigate the conversation. Some managers at electronics assembly facilities have the erroneous impression that encapsulation replaces the need for cleaning. Instead, attempts to eliminate or reduce cleaning can lead to poor adherence of the encapsulant, outgassing, and breakdown of the encapsulant.
For more information about the IPC activities please see
http://ipc.org/CommitteeDetail.aspx?Committee=5-30
I am pro-electron
Let me say that I am firmly in favor of electrons; I am delighted with instant communication. I spend considerable effort perusing websites for cleaning agents and cleaning processes; I depend on email; and I enjoy webinars and ezines. However, there are limits to the nuances of opinions that can be expressed using electronic communication. It is harder to say “none of the above” on-line. I regularly participate in conference calls; if more than 5 people attempt to meet, it can be difficult for viewpoints to be expressed; and/or things can get confusing. To achieve effective growth in manufacturing, we also need the occasional conference, complete with face-to-face interchanges, and yes, even committee meetings.
At both ITSA and APEX, I saw the continued value of the conference in the era of electrons. There was interchange, immediate response, the opportunity to argue creatively (always great for problem-solving), and an opportunity to achieve clarity and synthesis.
