“Both prototype and production suppliers provide valuable services that target a specific market niche and product development cycle, but as separate entities, they represent a gap and risk when transitioning from prototype to production,” said Brian Morrison, director of value engineering and technology for SMTC Corporation, a Markham, Ontario-based provider of electronics manufacturing and testing services for the medical device industry.
Bridging this gap usually involves selecting a prototype provider first and then, as volume increases, finding a compatible production partner to meet capacity needs and global footprint requirements. “Because no two partners approach manufacturing the same way, what may have worked for one supplier may not work for another, often resulting in the need for some level of re-engineering, re-tooling, or additional costs to make the transition successful,” Morrison added.
One way to avoid the gap altogether—including the associated risks and delays—is by teaming up with a contract manufacturer (CM) that provides both prototyping and production. This is a growing trend in the medical device industry, which is why more vendors are expanding their services to provide both.
“The most challenging part of the product development cycle is often manufacturing transfer,” said Tim Hopper, chief marketing officer for EG-GILERO, a Durham, N.C.-based contract design, development, and manufacturing company that works with the medical device industry. “Thus, the ability to execute this efficiently can differentiate a contract design firm/contract manufacturer in the marketplace.”
Having access to these services through one provider is a big benefit to OEMs, which increasingly rely on supply chain partners for end-to-end solutions to help navigate the product transition through the product ramp cycle. Utilizing prototype and production equipment under the same roof shortens time to market, minimizes risk, improves reliability and communication, and ultimately saves money by shortening the supply chain. This is especially true when in-house engineers, technicians, and operators can take what they learn during prototyping and apply it to the production process.
“We do most of our prototyping using ‘production-like’ processes on production equipment, with production operators whenever possible,” said Ed Barbeau, tool room supervisor for Cadence Inc., a full-service contract manufacturer for the medical device industry. “This way we learn as much as we can about the processes, before we flip to production.”
Faster, Better, Cheaper
OEMs are transparent about what they want from their contract manufacturers—faster production, faster time to market, improved quality, and lower costs—even as the products they design become more complex and challenging to manufacture. This means CMs must find ways to shorten cycle times and still maintain quality. This is where rapid prototyping has a huge role to play.
“From a design perspective, the rapid prototyping technology now available allows designers to iterate and prototype faster and cheaper,” said Hopper. “This enables designers to ‘get it right’ in a more efficient manner, saving development time.”
One way to enhance rapid prototyping and production is to utilize equipment that streamlines these processes and saves time, such as versatile pre-production tooling that can also be used during production. “Clients want tooling that can produce components that can be used from engineering builds through regulatory approval and the initial commercial launch—for example, one- and two-cavity soft or pre-hard tooling that is made accurately enough to be validated,” commented John Rugari, vice president of sales for Technimark LLC, an Asheboro, N.C.-based provider of design, engineering, and injection molding services for the medical device industry. “This saves considerable time and money and gets products into the marketplace faster.”
Depending on the project, sometimes the tooling can even be 3D-printed—saving weeks of time and thousands of dollars in engineering costs.
Limited quantity injection molding, for example, is a preferred method for projects that produce a limited number of plastic parts. Companies sometimes only need 50 samples or less of a product to send to developers, review experts, test labs, or selected customers for trial use and feedback. By using limited quantity injection molding, a vendor can design and make a temporary 3D-printed mold for the job, typically within a few days. “This is an ideal approach for making up to 10,000 parts,” said Morrison. “Some stronger plastic polymers can be machined by computerized numerical control equipment into molds that can withstand up to 10,000 cycles of plastic injection.”
Integrating Prototyping and Production
Medical device concepts can go from the modeling stage to the pre-prototype stage in a matter of weeks, so speed is absolutely essential. Bringing prototyping and production together under one roof is a great start, but OEMs want even more—they want their contract manufacturers to use technologies that integrate these two processes as seamlessly as possible, for even faster results.
“It is desirable for medical device manufacturers [MDMs] to choose a prototype house that can also execute the production volumes they need,” said Steve Hartzog, rapid prototyping/manufacturing engineering technician at Cadence’s Staunton, Va., headquarters. “Processes used for prototypes are often not the same ones that are cost- and process-effective for production. Therefore, it is important to select a vendor that can speed the transition from prototype to production by being able to visualize the ideal production model, while going through the prototype process.”
Increasingly popular prototyping and production manufacturing technologies include 3D printing/additive manufacturing, quick-turn prototyping, limited quantity injection molding, and rapid printed circuit board (PCB) prototyping. 3D printing continues to evolve at a rapid pace, with a steady stream of announcements about new capabilities and materials. For example, products can now be printed from a wide range of materials, including polymers, metal and steel alloys, ceramics, and porcelains.
3D printing of metal, however, still has some tolerance issues that need to be worked out. “3D printing does have difficulty holding tolerances tighter than ±0.002 in. in many cases, and relationships between features may be altered because parts are sintered after creation,” said Barbeau. “We do, however, envision almost 100 percent of early prototypes going to 3D printing in the future, with some secondary operations such as sharpening, machining tight tolerance dimensions, and enhancing surface finish.”
Sometimes 3D printing is the only way to make unique or complex parts or products, or customized or personalized products, in low quantities. Products can often be turned around within a few days, depending on complexity and any needed post-printing treatments. Although 3D printing is mostly used to make prototype parts, some production-ready, U.S. Food and Drug Administration-approved products have already been manufactured with 3D printing. Several 3D printing materials and processes have passed 10993 biocompatibility tests. Even electro-plated plastic parts for radio-frequency applications, which are typically manufactured with expensive hard tooling and complex processes, can be made with 3D printing.
Manufacturers can also use 3D printing to make limited-quantity samples or prototypes of in-development PCBs of varying complexity within a matter of days. The idea is the same as with regular 3D printers. “3D circuit-board printers have the capability to print multi-layer boards with complex circuits,” said Morrison. “This demonstrates how a traditionally parts-based technology has branched out into different industries and is revolutionizing the way items are manufactured.”
Another approach for PCBs is rapid PCB prototyping, where PCB manufacturers use online design for manufacturability (DFM) tools to calculate proper board stack-up, minimum spacing, minimum feature size, inner layer edge clearance, solder-mask violations, and missing files. Some suppliers use their own proprietary PCB design software.
“Quick-turn PCB is best for samples and prototypes, or limited quantity production—typically from 100 to 5,000 PCBs, depending on the number of layers or custom specifications,” said Morrison. “Turnaround can vary from one day for two-layer, quick-turn PCBs to three days for more than four layers to several weeks for custom-spec PCBs or high-quality, low-volume PCBs.”
Boosting Production Through DFM
Design for manufacturability is an effective way to bring prototyping and production closer together. DFM studies are designed to test how the design, materials, and processes all interact with each other through the production process. Does the material behave the way it is expected to? Where are the design weak points? If there is a problem in prototyping, will it be a problem in production? Design for supply chain, design for assembly, and design for testing are also helpful for identifying the opportunities and risk early in the design cycle. Finite element analysis is essential for identifying stress points under internal and external loads. Design and development services such as electrical design, layout, mechanical design, and test development are also helpful for optimizing prototyping and production.
The more comprehensive the DFM, the better. Individual design elements for a product are typically developed from different entities and organizations; when they are assembled, there is often some degree of interference, incompatibility, or stack-up tolerance issues present. Without DFM analysis and virtualization, these issues are typically discovered on the prototype or production floor and, in some cases, not until volume production, where variances in part fabrication start showing up as the sample size increases.
“To address these issues, our value engineering teams request the native design files from the customer and working models from our suppliers to create an assembly model of the product,” said Morrison. “Once the model is created, we can perform a number of initial reviews to quickly identify critical assembly issues that would otherwise result in scrap and related manufacturing costs. Once identified, design solutions and concepts can be virtualized and, with 3D printing technology, fabricated very quickly to create various options and concepts and to validate engineering solutions.”
Design rule checks and virtualization can identify fabrication, manufacturing, assembly, and mechanical fit issues prior to any parts fabricated or parts being placed, saving hundreds of dollars and numerous man hours, representing a best-in-class approach to provide maximum value for the client. “After a design has been checked, it must be validated through a level of design verification testing consisting of a small prototype volume and subsequent testing to ensure the requirements are met,” said Morrison. “The ability to support small-volume prototype quickly, cost-effectively, and as close as possible to a production-quality sample utilizing the latest technology and materials is an area of growth in the manufacturing industry.”
DFM is increasingly valuable to undertake as products become smaller and more complex, which makes it tougher to figure out the best ways to create the needed design enhancements, intricate features, and tight tolerances. OEMs are asking for shorter lead times and tighter tolerances, even when the parts are still in early design phases. They also feel more comfortable with a fully developed process, including inspection data and certifications.
“Five years ago, typical tolerances were ±0.005 in.,” said Barbeau. “Now tolerances start at ±0.001 in. and ±0.0005 in. is not out of the ordinary. We are always looking at prototyping with future production in mind—for example, typically machines repeat within 0.0002 in. which can limit statistical capabilities on tolerances tighter than ±0.001 in. in production.”
DFM also helps identify the most efficient tooling approaches for the prototyping and production stages, saving money and shortening the lead time for bringing the product to market. “Having in-house tooling capabilities provides a significant time and cost advantage for accomplishing this, as well as protecting the flow of information and controlling confidentiality,” added Rugari. “This is especially true for prototype tooling for complex multicomponent devices.”
Every material has its own challenges, depending on the application and the product design, including any complexities related to the required functionality and interaction with other components. Tight-tolerance parts require tight-tolerance raw material. Many new designs require materials that are not common in the marketplace and involve longer lead times, such as 17-7 stainless steel bar stock, materials with special heat-treat requirements, and bar stock with tight outside diameter tolerance (±0.0002 in.) and straightness requirements.
“We are seeing more requests for shape setting, high-strength alloys, and very small parts with intricate features—for example, slots and holes in the 0.02 in. and smaller range,” said Barbeau. “We can achieve these features using a variety of methods, including laser cut, wire electrical discharge machining (EDM), sink EDM, and Swiss machining.”
Customers are also pushing their contract manufacturers to use the lightest metals and the newest plastics in their parts, including polyether ether ketone (PEEK) and nitinol. Design and/or machining challenges often extend beyond the material itself to the material/component combination or interface—what performs well in one application may not necessarily hold up or function well in another. For example, a material that meets the design performance specifications may not be commercially available in the size or shape needed to manufacture a new prototype or production part (which would be revealed through DFM).
“We see this a lot with some nitinol requests, especially those requiring ultra-thin (<0.01 in.) material,” said Hartzog.
New materials for advanced 3D-printing processes and nano-coatings enable more design options, especially for PCB fabrication, flexible components, complex metal structures, and direct metal additives. Innovative solutions for complex assemblies can quickly reduce the time needed for verification and validation. For example, conformal coating traditionally requires manual masking of interconnections and contact areas and dispensing of material to protect the surface of electronics from environmental elements—a labor-intensive process that creates inconsistency in quality and uniformity.
“New nano-coating technologies, which atomize the material and electro-deposit it uniformly over all surfaces of a printed circuit board, have revolutionized environmental protective surfaces,” said Morrison. “This process requires no masking and covers all surfaces, resulting in electronics that are completely waterproof.”
As attractive as the engineered properties are of advanced materials, they often do not have a well-defined body of performance data, accumulated over years of testing and use. This can represent a level of risk to product development. Even though new advanced materials may provide a way to expedite prototyping and development, the resulting product could have significant performance differences compared to their production counterparts, including variances in thermal, elongation, flex, and rigidity properties. This makes prototypes and initial runs even more important for identifying design flaws or supporting certification requirements. MDMs should understand the risks involved when using new and advanced materials in their product development cycles; under the right conditions, and with the right development team in place, these materials can provide significant advantages for a successful product launch.
Into the Future
Robotics and automation, previously reserved for ultra-high volume production, continue to become more affordable and flexible, enabling automation at much lower volumes than previously considered. Programmable and quick-change robot cells can be configured to perform accurate and repeatable operations, which is attractive to manufacturers in higher mix environments, where lower-volume products can also enjoy the benefits of automation.
“Automation can be used in cleanrooms to improve quality, complexity, and throughput for otherwise complex and precision assembly operations such as screw driving, dispensing, pick and place, tactile sensing, parts handling, assembly operations, testing and inspection, and custom operations,” said Morrison.
Additive manufacturing technologies such as 3D printing will continue to create operational advantages for OEMs and suppliers, such as producing complex, production-type parts in a matter of hours or days. This completely changes the dynamics of small-volume production, including the amount of development required to bring new products to market. Carbon3D has introduced an innovative new 3D-printing process, which is up to 100 times faster than what is currently available on the market.
Instead of building a product layer by microscopic layer, a Carbon3D machine pulls a solid object from a tub of liquid plastic and cures it with UV light, creating a much stronger product—essentially turning a traditional mechanical production technique into a tunable photochemical process.
With the constant pressure to reduce costs, more MDMs are taking a closer look at “creative sourcing”—using combinations of foreign and domestic suppliers to control costs on some components, while still being able to develop complex manufacturing processes close to home. For example, a company may not want to outsource production work outside the United States, but must in order to meet cost targets. “We have worked to create sub-assemblies outside the U.S. and then finish the product in the U.S.,” said Hopper. “Thus, the more labor-intensive assemblies are ‘pre-made’ and shipped to the U.S. for final assembly, sterilization, and delivery to the customer.”
This process can work in a reverse direction as well.
“We have a customer with an internal development manufacturing process that it did not want to have outside its four walls, but needed cost reductions to remain competitive in the market,” Hopper continued. “We worked with them to develop a model where they do the proprietary work at home, and then we send the components to our lower-cost assembly locations for final assembly, allowing them to meet their cost targets.”
Thanks to the creative and technical abilities of responsive CMs that continuously push the limits of technology and material performance, OEMs have ever-increasing levels of expectation for both delivery and execution of prototypes—shortening the timeline to production and getting products into the marketplace faster.
Time is, and will always be, a driving factor.
“If a client’s designs can be flexible at the onset, there are many available options for finding the best manufacturing solution,” said Hartzog. “However, the more the client locks into any given idea, speed can be affected. Defined processes can force the prototype manufacturer into a more expensive, less-than-optimal process for manufacturing, which then increases lead times. Working with an experienced prototype partner, combined with flexible design parameters, will put the parts in their hands much faster.”
Mark Crawford is a full-time freelance business and marketing/communications writer based in Madison, Wis. His clients range from startups to global manufacturing leaders. He also writes a variety of feature articles for regional and national publications and is the author of five books. Contact him at firstname.lastname@example.org.