-
- News
- Books
Featured Books
- smt007 Magazine
Latest Issues
Current IssueIPC 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.
The Cost of Rework
In this issue, we investigate rework's current state of the art. What are the root causes and how are they resolved? What is the financial impact of rework, and is it possible to eliminate it entirely without sacrificing your yields?
- Articles
- Columns
Search Console
- Links
- Events
||| MENU - smt007 Magazine
From the Editor
Welcome!
December 31, 1969 |
Estimated reading time: 4 minutes
San Jose is a city that respects and, more importantly, loves technology and electronics. This was evident from the moment I stepped off the plane, with "San Jose Welcomes IMAPS 2007" signs along the baggage claim and taxi bays. Cordial letters from the mayor and governor welcome IMAPS attendees as well. Restaurants in the vicinity of the show posted "Welcome IMAPS!" signs in their windows. The Tech, Museum of Innovation (check it out at thetech.org) was bustling with people of all ages. In this tech-friendly atmosphere, surrounded by circuit boards and silicon wafers inside and outside the IMAPS show, I was in the right mood to study harsh-environment medical electronics during "Biomedical Materials, Devices, and Packaging."
The Body Worlds exhibit at The Tech down the street real cadavers preserved to expose the makeup of the human body was a fitting backdrop to a discussion of the challenges and potential breakthroughs in medical engineering. As evidenced by the failure of complete synthetic hearts, perfect mechanical and electronic performance can mean nothing in a medical device if the body rejects the implanted system. Z. Joan Delalic, Ph.D., of Temple University, began the session with the mantra of "the body is one of the worst environments for electronics." A host of conditions are working against medical devices: acidity, electromagnetic interference (EMI), fluctuating pressure, vibration, humidity, and the list continues. The dangers range from electrical failure to corrosion, resulting in everything from restricted mobility to toxicity and infection. Hemorrhaging is a constant worry with implanted medical electronics, notes Delalic.
OEMs and EMS providers in the U.S. should consider the medical market a higher-profit-margin option, but the list of considerations for engineering a medical device, particularly one that goes inside a human body, is long. Implanted devices need to communicate with external instruments, either with connecting leads or wireless transmission. The FCC regulates the frequency range of biomedical devices, but the risk of signal interference is still a factor. Interaction with other machinery hospitals and EMS vehicles are rife with electronic devices operating and transmitting passive or active interaction with the user, thermal management, and other issues typically encountered with electronic devices are magnified in the medical sector. Recalls can be costly, if not devastating. And the standard concerns of high-reliability electronics apply: acceptable solder joints, functioning IC components, long in-field life, etc. The testing period for a new or revised medical assembly comprises EMS, OEM, and government stages.
"Bio/medical electronics production is a sector of EMS and packaging services that remains in the U.S., while most other electronics production moves abroad," Delalic says. This is the result of intensive R&D, Food and Drug Administration (FDA) regulations, and lengthy test periods. Within this sector, medical OEMs are increasingly lowering costs by turning to stacked assemblies. Equipment called a body sensing network (BSN) incorporates various sensor assemblies inside the body with dedicated, off-the-shelf daughter boards for each sensor. These PCB assemblies (PCBAs) are then stackable on a motherboard, creating a network of sensors that can be added to and adapted as needed without design respins or unnecessarily invasive devices. Delalic sees this stackable assembly system as "the future of sensing."
More research is desired into new sensors, particularly into sensors comprised of bio-neutral or inert materials, to enable accurate readings and lower human risk. As sensor components are "the building blocks of medical equipment," there is a big push in this industry to engineer more accurate sensors with less irritation to the patient and wider scope. These could lead to everything from killing cancer cells to regulating organs like the kidneys and bladder. Materials science is key to future generations of sensing modules, everywhere from the gates of an individual sensing circuit to a complex miniaturized system like a cardiac-assist device. Drug-delivery devices also factor into this arena.
The ideal medical electronic device should be 100% biocompatible, small and noninvasive, safe, effective, and reliable. While this is still in the future, nanomaterials are enabling more biocompatible assemblies. Carbon-based coatings that are deposited nanometer-thin provide a hermetic barrier between living tissue and functioning electronics. Conformal coatings will figure in to this equation, allowing devices like sensor arrays to be insulated and smaller. Advanced medical devices will use carbon nanotubes (CNTs) as a moldable interface connecting electronic sensors, transmitters, and signal conditioning modules to human tissue. Today, the majority of implantable medical electronics are coated with engineered polymers. These, and nanomaterials under development, can be extremely costly and difficult to manufacture, Delalic acknowledges, though the advantages of increased biocompatibility offset costs.
Device design and packaging in the biomedical sector is a far cry from most electronics segments, even other harsh-environment areas. "Packaging is less about interconnection and encapsulation, and more about protecting the body and the device from each other," says Delalic, but the aim of packaging a component or assembly remains the same: to ensure that the device functions as accurately and effectively as possible, for as long as possible, without detrimental effects. With everything from sensors to nanoscale electromechanical systems (NEMS) to lab-on-chip to organ assisting devices appearing in the medical sector, packaging, encapsulation, system design, and materials engineering are at a premium.
Meredith Courtemanche, managing editor