Chemical Etching Challenges Manufacturers to Provide Ultra-thin, Precision Parts with Extreme Flatness
Although etched parts are inexpensive, their reliability and repeatability must be high-end.
Even though chemically etched parts are sold for pennies per part on the dollar, they must still be very precise and have perfect flatness to fit into products that usually cost thousands or even millions of dollars. An example of this would be some little blades that cauterize blood vessels for heart bypass surgery. If the part comes off in the body during the procedure it would problematic, so the parts must be very precise. Dealing with challenges like this one is routine for a chemical etching company in Santa Clara, Calif., Italix Company Inc.
"The machined part that our part goes into is about $30, whereas ours is only about 15 cents, but it still has to be close to perfect in tolerances and flatness," says Tony Atella, vice president of Italix Company. "Even though our parts might only cost pennies, these parts can go into a multimillion dollar piece of equipment." Italix is an ISO 9001:2000 compliant and MIL STD-45662 compliant chemical etching company that has been in business since 1977. The company supplies its customers with a multitude of extremely thin, burr- and stress-free parts on a repeatable basis. Everything that Italix makes is custom made, from toys to electronics parts to surgical equipment, Mars Rover parts, and components in submarines that cruise the ocean floor.
Stock Ownership Program Brings Quality Dividends to Company
Interestingly, 33% of the company is owned by the employees through an Employee Stock Ownership Program (ESOP). It is reported to help the company develop long-term employees, it maintains a retirement program for them, and it gives employees more incentive to do a good job. "We've had the program in effect since '92, which allows the employees to participate in the benefits of the good times, but they also have to deal with the not-so-good times," says Atella.
What is unique about this etching company, says Atella, is its involvement in projects that other companies might shy away from--projects that take more thought, patience, or know-how, and even different ways of handling the materials or the parts. "Our biggest difficulty is trying to manufacture a product that looks great on paper, but can't be manufactured in real life," Atella explains. "So I think we're a bridge for these difficult projects, we'll try to make them viable and economical, and repeatable on a long-term basis."
Italix considers itself a one-stop-shop, where chemical etching is often combined with other processes like wire EDM machining. For example, the company will often rough etch the parts to hit a few critical dimensions, and then afterwards cut the shape more precisely with a wire EDM machine--where parts can be stacked up and processed with one operation. "Combining processes makes the parts more doable: It eliminates a lot of expensive costs, it reduces the per-part price, and it holds the quality and perameters that they want," Atella insists. Italix uses its CNC machining equipment mostly to make fixturing and hard steel tooling, for parts like gauge pins that hold down the sheets of material for greater repeatability. The company will often heat treat the fixtures to create greater flatness for the etched parts, and will sometimes make hard steel tooling for metal stamped parts that will also be heat treated. "We also do the metal stamping in-house to bend and form the etched parts," says Atella. "Later on they might get plated with silver, gold, or nickel, or anodized. We do most of the plating in-house, except for the higher-end work with materials like palladium and rhodium."
Critical Medical Parts Exemplify Company's Quest for Excellence
Parts or components with critical performance requirements aren't turned away at this etching company. One example are the parts it produces that cauterize blood vessels during heart surgery. These parts require a press fit, so the two prongs open up into an orifice that secure it from coming out when it's inside the cavity of the chest. The critical dimensions on these parts were much different than what the 3D computer model originally stated. "The computer said to check the radius, but we found the radius was totally irrelevant," Atella maintained. "The distance from edge to edge inside of the radius was much more critical. So we came up with fixturing to be able to press fit this in to verify that it would fit. And we designed a force test to see how much force it would take to pull it out of the orifice afterwards to verify that it would stay in during surgery."
Since flatness is so important with these precision parts, the manufacturer has come up with a way to maintain flatness and to measure the degree of flatness, regardless of whether they are designed properly or not. The average gap for flatness tolerance, Atella explains, is about 0.003-inch. With the added technology and time involved, flatness tolerances are very repeatable. "Now that we're measuring the flatness more carefully, we don't have to worry about if the design we were given is workable," says Atella. "Now our customers can take them out of the box, mount them, and then ship them."
Italix has an on-site environmental staff that has just updated the entire facility to reduce discharge of chemical-laden production water. The company's intent is to reduce environmental impact and save a great deal of money for water usage. Accordingly, Italix is now cleaning and recycling most of the water used in production. It has gone from using about 10,000 gallons of water a day to about 600 gallons, and after completion of the project in January 2009, it expects to be down to zero discharge.
Secondary and Finishing Processes Offer Added Value to Etched Parts
To complement its chemical etching, Italix offers are large variety of secondary and finishing processes, including abrasive blasting, lapping, spot welding, assembly, laser cutting, and soldering. The company also offers clean room packaging, laser drilling, stacked laminations, conventional machining, laser welding, metal stamping, and passivation cleaning. Other processes available include shearing, electroplating, four slide forming, wire EDM machining, heat treating, and roll forming.
"We'll do anything we have to do to make a part complete, and most of it is handled in-house," says Atella. "We probably have 50 different types of plating that we offer. We can even do spot plating and then handle welding, since a weld will not hold with plating."
Not only is flatness important in this type of work, but also tolerances that can be repeated. As with all manufactured parts, the tolerances are very different for every part depending on the type of metal, thickness, geometry, and critical areas. "We guarantee that there will only be a one-thousandth variation from part to part," says Atella, "which is very precise in the etching world."
Etching can create unique challenges for parts with certain geometries. "If we're etching a square part with a hole, we can't stop etching the outside of the square and continue etching the hole to make it larger," Atella explains. "It's an all-or-nothing situation. If we have to hold +/- 0.005-inch on a given dimension, we'll get to within one thousandth in that range."
As with any process, there are limitations. Thickness and part size are two that are associated with chemical etching. Atella says that 0.125-inch is about as thick as the process can go and still be economical, and a part size of about 24 inches x 29 inches is the largest that can be processed. The company can make a 32-inch-long part, but it will only be about a half- inch wide. In addition, most metals don't even come in 36-inch-wide sizes, making it difficult to produce a part this large even if the equipment would go that big. Typically, most of this material comes in roll form, but some of the thicker metals -- 30 thousandths or more--come in sheets.
Italix's vice president says it would be quicker to list the materials that the company doesn't work with than those that it handles. "Three that we don't work with are titanium, tungsten, and molybdenum," says Atella. "They are very popular metals with medical device customers. However, the reason we don't work with them is that the chemicals are extremely hazardous to work with--not only to the environment, but also to our employees. If an employee splashed one of them on their body, it would eat away their skin and bones very quickly."
Exotic Materials Complement the Production Process
The company has a book with about 31,000 metal alloys listed, and there are only a couple of hundred that Italix doesn't process. The metals most common to the etching process are: brass, copper, beryllium-copper, copper-nickel, Constantan® , cold rolled steel, copper-clad Duroid®, HyMu® (80 and 800), Inconel® 600, Inconel® X 750, Invar® 36, Kovar®, ni-silver, nickel 200 and 201, PermaNickel®, phosphor-bronze, spring steel, stainless steel, and vanadium. "We have a very wide knowledge of materials, so we can give our customers advice on their properties and uses," Atella mentions. "For instance, if someone wants to use titanium, we can steer them to another metal--say, stainless steel--that can be plated with gold afterwards. Gold is expensive, but not nearly as expensive as titanium."
Problem-solving constitutes much of the philosophy of this 31-year-old etching company. One such problem was with some parts on bar code scanning machines -- a problem with the mirrors. The mirrors were not moving back and forth far enough to pick up the average bar code. Movement of the mirrors is actuated by one spring that pushes the mirror and one that pulls it. The existing springs were not working properly, so the machine's management looked for a solution -- which came to be Italix. "Our springs were able to move the required amount of space because they had the required amount of thickness and flatness," according to Atella.
"First of all, we had to help them come up with the proper thicknesses. They needed a thickness tolerance of 0.000007-inch," Ateller continued. "We came to the conclusion that we didn't have the ability to test or measure a tolerance with that thickness accurately. So we had to go out and source a $10,000 tabletop micrometer that goes to the ninth decimal place. Then we came up with a way to heat treat the material prior to manufacturing with a special fixture to give them the exact amount of flatness. With the parts that we made they were able to continue with the project. This wouldn't have happened without our parts."
The Italix marketplace is as varied and diverse as the manufacturing processes that it offers. The company's markets include, but are not limited to, aerospace, military, computers, electronics and micro-electronics, fuel cells, lasers, medical equipment, optics, and semiconductors. For the computer and aerospace industries, Italix turns out a large variety of switches and contacts and solder stencils and electronic devices. Parts and components for the medical industry include cauterizing blades, cutting blades, surgical tools for heart and stomach surgery, and contacts in pacemakers.
"We can make specialized, precision parts with chemical etching that not too many manufacturing processes are capable of doing," Atella affirms. "Chemical etching is perfect for these parts because they are too thin to stamp, and you can't punch them or use fourslide to bend them. And if someone wants a part with hundreds of holes on it, it would cost a small fortune for the tooling, but with an etched part we can make the tooling for about $225, and we can make a sheet of parts and get them out to the customer in one week."
Customer service is high on Italix's priority list. "We need to make enough time for all of our customers, not just one or two big customers," Atella urges. "Our largest customer is only 8% of our business, so obviously we don't give all of our attention to just the biggest customers. We have the ability to service all of our customers. The $100 orders are just as important to us, since most of our customers started out giving us small orders. Therefore, we treat everyone equally in terms of turnarounds and quality."
For more information on Italix, visit www.italix.com.
Duroid is a licensed trademark of Rogers Corp.
HyMu and Kovar are registered trademarks of Carpenter Technology Corp.
Inconel is a registered trademark of Special Metals Corp.
Invar is a registered trademark of Arcelor Mittal.
PermaNickel is a registered trademark of Inco Alloys/Special Metals Corp.
Constantan is a registered trademark of Hoskins Mfg. Co.
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