Which is better for medical device assembly: A lamp-based UV spot-curing system or an LED-based one? "The answer to that depends on your process, the parts you're joining, and the application," says Mike Kay of Lumen Dynamics (Mississauga, ON, Canada). In his presentation, "High-Throughput, Low-Temperature UV Assembly of Medical Devices" at the MD&M West Innovation Briefs Theater last week, Kay addressed the pros and cons of each technology.

LED systems are up-and-comers of sorts, according to Kay. He notes that the technology has been around for about 10 years, though it has mainly caught on in the past five. Interestingly enough, Kay says, the medical device industry lags behind in terms of LED adopters, however. While about 40% of companies in general industry have made the move to an LED-based technology, less than 10% of medical device manufacturers have embraced it. The potential high cost of changes to established processes are likely a contributing factor, Kay suggests. Currently, LED systems in the medical device industry are primarily employed in R&D and for newly established processes.

But LED curing technology is a good fit for many medical device assembly applications, Kay says. For applications in which the adhesive is not exposed to air, the LED system can provide low-temperature curing and good curing of free-radical adhesives. Additional advantages of LED technologies are a longer lifetime, less degradation in the first 500 hours, lower power, and a more environmentally friendly process than lamp-based technologies.

Lamp-based systems, in contrast, offer better curing power and a larger range of spot sizes. In terms of spectral content, each technology has its own advantages, however. "LED has the advantage of low heat where a lamp system has the advantage of better compatibility with adhesives, although more and more adhesives are now being designed to specifically work with LED curing systems," Kay says.

While Kay concluded with the assessment that both technologies are characterized by distinct advantages and disadvantages, he did impart some advice to companies that may be looking to make the leap to LED systems. Curing with an LED system is very different from curing with a lamp system, he stresses. Thus, it is important to conduct thorough analytical testing to ensure that the same cure is achieved. --Shana Leonard