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Design Engineers Pushing Boundaries with Laser Processing

Small parts that were laser cut from ultra-thin film material
Photo courtesy of A-Laser

As parts continue to shrink in size, engineers are finding the precision they need in a cost-cutting process

Mark Shortt
Editorial Director
Design-2-Part Magazine

Often seen as a good method for prototyping parts, laser cutting is sometimes thought to be too expensive for use in production. But if you believe the process is too pricey, you're mistaken, according to A-Laser, a laser cutting service specializing in the ablation of ultra-thin metals and plastics. The Milpitas, Calif.-based company is putting engineers on notice that laser cutting technology has taken the precision parts industry to new levels by enabling greater design complexity, higher cut quality, and the ability to maintain tighter tolerances. Another key message is that the company's laser cutting services can actually help customers--including companies that require precise micro-machined parts--to lower their total costs.

A-Laser Vice President Josh Saunders says the company can help customers reduce costs in a number of ways. For one, laser cutting provides non-contact material processing that allows tighter spacing of parts, ultimately saving material. The process also allows customers to make design changes without having to purchase hard tooling. And because lasers don't wear out and become dull over time, they can avoid the product fall-out issues and eventual tool replacement costs that occur as hard tools deteriorate.

"In the prototyping stage, our quick turn times, experience, and ease of design change speed up the process, decreasing the timetable with which [customers] can take the product to market," said Saunders in an email to Design-2-Part Magazine. "In production, the consistency of our process helps reduce fallout, our ability to reduce part spacing increases material yield, and quick turn times increase efficiency."

A New World of Possibilities

A-Laser (www.a-laser.com) is the precision parts division of FCT Assembly (www.fctassembly.com), which also manufactures stencils and lead-free solder products for the electronics industry through two other divisions--Fine Line Stencil and FCT Solder--that share a new, expanded facility with A-Laser in Milpitas. FCT Assembly expects that the additional space and design of the new facility, which opened in June, will allow the company to add new equipment and capabilities to meet growing customer demands for services.

A-Laser traces its roots to 1994, when it began serving the Northwest stencil and precision parts market. As A-Laser's business grew, FCT Assembly liked what it saw of the company's capabilities, and eventually brought A-Laser into the FCT Assembly family of companies in 2006 to focus specifically on the precision parts industry at the national and international levels. Today, A-Laser provides tight-tolerance laser cutting for a wide range of industries, fulfilling prototype and production needs. With experienced customer service engineers and a well-controlled manufacturing process, the company can respond to orders quickly, offering same-day quotes and 24-hour turnarounds on high-precision parts and prototypes.

"This is something that we have always seen as a priority, and we have modeled the business around the idea of being a high-quality and responsive option for prototype and production needs," says Saunders. "We have an outstanding customer service and CAD group that stays on top of their responsibilities. The production group flexes between two and three shifts, and our ownership group has committed to making sure our equipment stays ahead of capacity."

Saunders says that because A-Laser offers a unique service, prospective customers often aren't initially aware of what the company is capable of creating, and they don't necessarily design with the laser cutting process in mind. But finding A-Laser, he says, is like opening up a whole new world of possibilities for them. "Our customer service and laser specialists work hand-in-hand with the customers, because there really isn't another way for us to run the business," he explains. "This could be to assist with material questions, cut paths, hole diameter, and pitch, just to name a few. This adds value by increasing throughput to end product, pushing the products to new levels of efficiency, and allowing products to shrink their footprint."

Smaller products and the accompanying miniaturization of components, ranging from spacers for test socket applications to LEDs for backlit flat panel displays, are creating greater demand for the degree of manufacturing precision that lasers--more than many other processes--can deliver. The demand for laser cutting of DuPont Kapton spacers, for example, is currently high, and A-Laser is seeing a lot of this laser-friendly material. "With the appropriate parameter settings of the laser, we are able to ablate this material very well," says company founder Ahne Oosterhof. "Ablation means that we are 'explosively' removing thin layers of the material without applying significant amounts of heat."

In addition to Kapton, A-Laser specializes in cutting ultra-thin film materials such as Cirlex, PEEK, and ultra-thin metal foils. The company also processes titanium for thin-part applications in the "few thousandths of an inch" range. A-Laser's expertise with a variety of foils, films, and material combinations enables the firm to provide customers with added value during their design and engineering processes. They can, for instance, let a customer know ahead of time how certain materials will react to laser processing, and how this may affect their end products. They can also offer alternatives if a particular material isn't laser-friendly or, perhaps, could be processed faster.

Technology, Service Are Key to Meeting Customer Requirements

The technology that A-Laser employs, along with its experienced staff and customer service, sets the company apart from other precision parts manufacturers, according to both Saunders and Oosterhof. The company meets the demand for more precise and highly detailed parts by keeping a close eye on improvements in laser and measurement technologies, and upgrading its equipment lineup as improved machines become available. Replacing the older, more costly, and less precise manufacturing methods with newer laser systems enables A-Laser to deliver the high precision and complex designs that customers seek in thin materials.

"A-Laser's willingness to make significant investments in the most modern laser systems makes us unique," says Oosterhof. "With the newer laser systems, it has become relatively easy to cut precise and intricate parts from very thin materials. The more modern equipment allows us to meet increased performance demands more quickly and more economically."

Saunders adds that a number of settings on the machines can be adjusted to match the qualities of the materials being cut, ensuring that heat-affected zones and material distortion don't occur. "The laser tables have been constructed to hold the materials in place and steady throughout the process," he says. "And our laser operators work with these materials every day and understand the requirements of our most demanding applications.

"The fact that more and more engineers are designing to laser capabilities shows that our processes are very good," Saunders continues. "I think we're not far from being considered a traditional process, if we're not there already."

Intricate, Highly Detailed Parts

A-Laser's precision capabilities were on display this spring at the Santa Clara Design-2-Part Show, where design and manufacturing engineers got a close-up look at a number of custom parts manufactured by the company. The show, held at the Santa Clara Convention Center in May, was attended by engineers, purchasers, and manufacturing managers looking for cost-effective answers to a variety of design and parts-manufacturing challenges.

"We exhibit a wide variety of designs and materials to give OEMs an idea of the broad spectrum of industries we work with," said Saunders, referring to the parts on display. "Most of these are shims, gaskets, contact holders, et cetera, which share two common threads--they are very thin and they require very high precision."

The exhibit offered a glimpse of the company's ability to manufacture intricate, highly detailed parts. "When a beam can be concentrated to less than 20 microns in diameter, it becomes capable of creating just about any pattern you need," continues Saunders. "The limiting factor, though, is that we can't cut metals thicker than 0.025 inch and plastics thicker than 0.060 inch."

Applications for A-Laser's parts-cutting services include medical devices, aerospace components, and automotive parts, as well as electronic components. The company processes washers for aerospace applications; spacers and shims for interconnect devices; and chip carriers for medical devices, for example. "Most of these applications require very stable and very clean parts," notes Oosterhof. "The materials we use, especially the polyimides, provide the stability the customer requires. The UV ablation process gives us a very clean cut with hardly any debris, a requirement for medical and space applications, especially."

Other parts produced by the company include fluidic channels, screens, flat springs, flexible circuits, and shadow masks--all of which require precision and a high level of detail. "An additional advantage of ablation is that we can remove a layer of material without cutting through the material," says Oosterhof. "This allows us to make channels in a material or, for example, to remove the solder mask from specific areas of a circuit board."

One of the processes that A-Laser uses--ultraviolet (UV) laser cutting--is capable of producing metals and plastics with fine contours and virtually radius-free internal edges, as well as cleaner edges and minimal taper. Because UV frequency lasers ablate materials, rather than burning through them, the company is able to provide "virtually carbon-free parts with great edge quality," according to Saunders. And by using an extremely thin beam of light, the laser system provides high precision and sharp details without the expense and preparation times required with precision dies. "UV lasers provide a different product than other laser processes, mainly seen in the cleanliness of cuts," says Saunders. "And the systems we use, in particular, achieve an incredible tightness of tolerance. The bottom line is that we offer a higher level of quality and can take on projects that others have to steer clear of.

"Again, when a beam is concentrated to less than 20 microns and it cuts a corner, there isn't much keeping that corner from being truly 90 degrees, even when looked at under magnification," he continues. "This gives design engineers a great amount of freedom, and again, with the ease of design changes, they are given the ability to push the envelope."

Oosterhof says the UV laser, like all lasers, can be thought of as a milling machine, with a bit that's less than 15um (0.6mil) round. As a result, it's capable of cutting a square corner that has a radius of less than 7.5um (0.3mil). "With such a small 'bit,' we can cut really fine contours with very little rounding in the corners," he explains. "The beam introduces very little heat into the material, so there is no melting to produce a taper, and the beam has a relatively long waist (area of minimum diameter), again minimizing the tendency to form a taper."

Saunders calls the company's laser cutting equipment, which also includes infrared (IR) frequency lasers, "second to none in the precision laser cutting world." A-Laser's UV and IR frequency lasers are capable of maintaining +/- 12 micron tolerances across the full range of the table, a capability that becomes increasingly important as end products get smaller and smaller. "The cut quality we get from the equipment is a big advantage," Saunders emphasizes. "On the UV side, this comes from ablating, rather than melting, material. At a 355 nm wavelength, using repetition rates up to 50 kHz and pulse lengths less than 140 nanoseconds, materials basically explode (or are ablated) incrementally. This is done little by little, though at a very high speed, yielding burr-free parts with very little thermal influence or carbon residue."

When processing ultra-thin parts with infrared (IR) lasers, A-Laser achieves high levels of repeatability and large thickness ranges without material distortion. The company uses the IR lasers to manufacture the majority of its metal parts. In order to cut with the precision and detail required, relatively low-power lasers are used, which limits the cutting of various steel types to about 0.5mm. "We get the same consistency and quality from these (IR) systems as we do from the UV frequency lasers," says Saunders. "The difference is that 1064nm wavelength. This wavelength makes it ideal for metals, such as stainless steel, between 1 and 25 mil thick. Thin metal parts are a large and diverse market, and we have our niche within that. When the designs go beyond the capabilities of other methods, or when they change rapidly or require quick delivery, we are an ideal company to partner with."

Much of A-Laser's consistent growth through the years can be attributed to what the company calls "a culture of curiosity and experimentation," which has encouraged its personnel to take time to "play" with the machines and try to cut the most unlikely parts. "We see so many new materials and material combos that we couldn't operate if we viewed the business with anything other than curiosity," says Saunders. "We build in time for our laser operators to be able to experiment on the lasers. They are encouraged to stay up-to-date on material advances and to find new techniques. All of this only makes our team stronger, and we have reaped benefits from this point of view."
 

David Gaines contributed reporting for this article.