-
- News
- Books
Featured Books
- smt007 Magazine
Latest Issues
Current IssueBox Build
One trend is to add box build and final assembly to your product offering. In this issue, we explore the opportunities and risks of adding system assembly to your service portfolio.
IPC APEX EXPO 2024 Pre-show
This month’s issue devotes its pages to a comprehensive preview of the IPC APEX EXPO 2024 event. Whether your role is technical or business, if you're new-to-the-industry or seasoned veteran, you'll find value throughout this program.
Boost Your Sales
Every part of your business can be evaluated as a process, including your sales funnel. Optimizing your selling process requires a coordinated effort between marketing and sales. In this issue, industry experts in marketing and sales offer their best advice on how to boost your sales efforts.
- Articles
- Columns
Search Console
- Links
- Events
||| MENU - smt007 Magazine
From the Editor: Technology is in the Eye of the Beholder
December 31, 1969 |Estimated reading time: 4 minutes
What is the difference between low-tech and high-tech? Being in a decidedly high-tech industry, we should be able to answer that question easily. Unfortunately, it isn't so simple. Most often, the difference exists in the user, not in the technology. In this way, knowledge marks the line between high- and low-tech, allowing a skilled user to get more data out of lower-tech equipment than an untrained user could glean from a top-of-the-line piece. Speakers from the rework and X-ray groups at VJ Electronix took on the role of educators during the company's recent open house, providing valuable information on advanced rework tasks and the various forms and merits of 3D X-ray inspection.
If you can't rework a high-tech PCB assembly, you're risking a lot in terms of investment, yields, and quality product released to the market. Challenges exist in nearly every rework scenario, but Mark Walz, product manager, Summit Rework Systems, VJ Electronix, focused on the four areas he hears customers asking about most often: lead-free site dressing, 01005s, high-mass connectors, and underfilled components. Two elements come into play here for smart rework: good equipment (often specialized), and a strong understanding of the processes at work. With proper use of high-tech equipment, difficult rework tasks can be accomplished. Even the best use of low-tech solder wicking, Walz notes, can't prevent damage to densely populated areas, where a small passive can be pulled off its pad while a worker wicks solder from nearby BGA pads, for example. With lead-free solder scavenging, the technological advances include advanced tip designs and non-contact nozzles that integrate sensors to maintain proper board-to-tip distances. Walz also found that using nitrogen, even in a low flow, is so beneficial to the process that flux is unnecessary. Here, an in-depth knowledge of each factor (flux, air, temperature, nitrogen) is equally important to the technological possibilities. Human and machine go hand-in-hand.
Extremely-low- and extremely-high-mass components present further issues, which again are resolved through human ingenuity and mechanical precision. Advanced pick technology is vital when reworking 01005s, as is control of air flow. Programming your heating sequence properly is key to 01005 rework, Walz asserts. To do this, users need to understand thermal profiles, the PCB materials they're working with, and the capabilities of thermal control available in the rework system. With high-mass connectors, thermal control also is critical high mass means high heat to remove the component, right? But high-mass connectors generally have plastics coating metal parts. Now the plastic's properties are equally important in the rework sequence. In both scenarios, the operator has choices about what kind of heat to use, nozzle shapes and sizes that will help the process, whether or not to incorporate bottom heating, etc. Sophisticated software is your friend in these complex situations, and yet so is a low-tech element like a silicone blanket. Walz tests out all these scenarios continuously so that he can share codified rules and benchmarks with rework customers.
Walz also discussed an emerging rework challenge: corner-bonded and underfilled components. Underfill is more common in each generation of higher-end consumer, computing, and high-reliability products, often protecting an important and expensive component. How to remove the component safely; how to scavenge underfill from the site; and other questions are yet to be answered fully. VJ Electronix often collaborates with materials suppliers to develop these solutions.
VJ Electronix manufactures X-ray inspection systems as well as rework models at its Littleton facility. Frank Cosentino, special systems and business development at the company, took the opportunity during his presentation to define the various and sometimes confusing options for 3D inspection. Each has its own rules and specialized techniques, so how you use them is key. Sound familiar? Cosentino explained that "virtual 3D" or "pseudo-3D" is not a true reconstruction technique. Instead, the system interprets a grayscale with assigned values. Is full reconstruction better? Well, it depends on your ability to interpret virtual 3D with software and data. Computerized tomography (CT) is a true reconstruction, Cosentino notes, but "people can get hung up on all the fancy images." He looked in-depth at the three CT techniques most suited to electronics assembly inspection and the methodologies behind them. Voxels, resolution, and energy are all part of a balancing act. This means that the highest resolution and smallest focal spot won't necessarily produce the most accurate and usable data. Cosentino's advice includes using programs that compare data between the acquired images and CAD data for the assembly, and determining the X-ray kVs, resolution, and software programs that enable clear, quality reconstructions to analyze an assembly or region of interest.
Collaboration between suppliers and users is the most direct and effective path to educating operators and programming systems to maximize usage. Open houses like the one hosted by VJ Electronix, tradeshows, seminars, and similar outlets disseminate this advice on a broader scale. Knowledge for knowledge's sake is trivial knowledge you can apply to improve your business is enticing, and there were plenty of satisfied attendees at Walz's and Cosentino's talks. VJ Electronix staff took visitors through some demonstrations on rework and X-ray systems to put these ideas into action. So, can you improve the technology simply by improving the user operating it? Not necessarily, but you can push that technology to it's maximum usefulness its "highest tech" by ensuring that the most advanced and skilled element of the process is the operator directing it.
Meredith Courtemanche, managing editor