PVA Pushes Its Fluid Dispensing Machines Into New Markets

Aug. 9, 2012
Innovation Brings Different Challenges, Teaches Lessons That Could Be Applied to New Fields
About the Author
Aaron Hand is Managing Editor of Control Design and Industrial Networking. He joined Putman Media recently after almost 20 years covering high-tech industries, including semiconductor, photovoltaics and related manufacturing technologies.Since its early days at an incubator center near New York's state capital, Precision Valve & Automation (PVA) has been focused on innovation, creating a customized approach to conformal coating and fluid-dispensing automation.

It's involved in a wide array of industries, each of which has brought different challenges and taught lessons that could be applied to new fields. PVA has its eye on still-growing opportunities, and is looking to control and programming improvements to make its systems better and easier to use.

Anthony Hynes began selling dispensing valves for automated and manual dispensing applications from his home 20 years ago, but later that year he moved his company to Rensselaer Polytechnic Institute's (RPI) Incubator Center in Troy, N.Y., and began building XYZ robots to automate the company's growing valve technology. By the end of October 1992, PVA had sold its first automated dispensing system.

Now headquartered in Cohoes, N.Y., with an Asian base in Singapore, PVA has since become a serious contender in the fluid-dispensing market, serving customers in electronics, aerospace, automotive, medical device, military/defense, renewable energy and general packaging applications.

PVA's bread-and-butter market is automotive, says Joe Baj, controls engineer, noting that PVA has major — some exclusive — contracts with automotive parts makers, focused in large part on dispensing thermally conductive coatings. Pick-and-place machines also place PCBs into housings, and any time there's adhesive needed, PVA's machines are generally there. "We do the hot melt on microphone assemblies for Mercedes, for example," Baj adds.

Pick and Place

PVA's machines perform a variety of dispense and pick-and-place operations, such as this example for automotive speakers.

Within the consumer electronics sector, PVA's machines flow chip encapsulants, glue for housings, perimeter beads, and occasionally still do conformal coatings. The sector demands a push to further innovate with control and automation, Baj says. "Typically high-end consumer electronics require higher accuracies and better repeatability, compared with automotive just dispensing gaskets," he explains.

PVA is attempting to gain a foothold in the field of surface-mount devices, which are highly popular in cellphones, Baj notes. Dispensing opportunities there include underfilling ICs with material, which is common with ball grid array (BGA) chips. "We've attempted to expand our presence in there," Baj says. "But the market is already saturated with competitors."

The machine builder also is trying to pursue glass bonding, which is common on cellphones, TV screens, etc., bonding glass screens onto the back of liquid crystal, for example. "The challenges now are pick and placement of the glass," Baj says. "We have to try to avoid air pockets and other aesthetic issues. A lot of it is just trial and error. We're working in different environments, heating materials to decrease the viscosity, placing the glass at different angles. We've finally come to some sort of success which seems to be repeatable."

Repeatability, though extremely important in electronics specialties such as surface-mount devices and glass bonding, is something that PVA actually came to terms with years ago while working with a customer in the food industry, Baj recalls. "We were working on timing shot sizes for food items, and it really showed us the limitation of our own technology," he says. "The on/off times of our controllers were not fast enough. What we deemed small variation turned out to be huge variation. The valve needed to turn on and off for 60 ms, which is extremely fast. There was actually some variance in several of our components that made that sometimes 60, sometimes 80, sometimes 70 ms. That was affecting the size of the dispense, making it totally out of spec. It made us realize the shortcomings of our machines."

PVA's standard dispensing machine uses a Galil motion controller as the brains. "That's because of cost, and they give you a lot of power," Baj says. "The amount of axes per dollar is very cost-effective. The base unit is a four-axis controller, and there's lots of embedded I/O."
But PVA saw limits to that controller as its customers began looking for new capabilities. "They want more out of the machines, like vision systems," Baj says, explaining the incorporation of more PC-based control. "It serves as our HMI. It also does vision fiducial corrections (using National Instruments software), and sends offsets to the Galil controller."

PVA writes its own vision software, which gives the machine builder flexibility to buy whichever camera is best suited to a job at a given time. This not only lets the engineers be more flexible in their camera choice, but gives its customers a more consistent user interface across its machines.

PVA has been writing its own software for almost 10 years, and prefers that over third-party software options, Baj says. The company has its own programming software, PathMaster, that it developed in-house. "The Galil controller didn't really have anything to teach and program controls," he explains, adding, however, that PathMaster is nearing the end of its lifecycle. "It doesn't handle vision. And there are a lot of connectivity options that customers want today."

Programming is the biggest challenge that PVA's engineers face now, Baj says. They lack an easy way to tweak machine process parameters, and are exploring the best approach for achieving that going forward. "We want the customer to not have to be an NI expert," he says. "We want them to be able to use a more common means of massaging machines here and there."

PLC-based control is used for curing ovens and board-trafficking stations — a relatively small portion of the company's sales. The motion controllers used for the dispense equipment couldn't handle the necessary conveyor adjustments, Baj says, so instead the machines use primarily Allen-Bradley PLCs.

The machine builder would like to make a switch to Unitronics PLCs, but end users typically demand the better-known A-B brand. "Unitronics has a PLC and HMI all in one," Baj says. "They're extremely cost-effective. They have a touchscreen, and color, and are a great price. And they're big into connectivity. They default with CANopen, but you can add Ethernet. We used the CANopen aspect to talk to the servo amplifier drive. You can do motion in a seamless fashion. It's a low-cost PLC/HMI talking to a motion controller, and the programming is fairly cut and dried. But Unitronics isn't a brand name like Allen-Bradley."