UK-based Hanover Displays manufactures and designs passenger information systems for the public transport industry, placing great emphasis on providing very high quality products.
The printed circuit boards (PCBs) in its display panels were originally produced in the Far East until recently, when Hanover decided to start manufacturing them in-house.
“We invested in high-speed production equipment to make the PCBs, a decision that gave us greater flexibility in our production control, but also enabled us to continue with product development,” said Reece Mills, the company’s Production Control Manager.
Automating the testing and inspection processes
However, moving production in-house presented Hanover Displays with a new set of challenges. It had to be able to both test and inspect the boards itself. Initially, this was a very manual process; even though it involved automated test equipment (ATE), the process was very hands-on and depended on complete operator concentration. Since the company processes some 240,000 printed circuit board assemblies (PCBAs) each year, there is a very high risk of the operators suffering from repetitive strain injury.
Hanover therefore took the decision to automate these processes more comprehensively, which required a new system for testing PCBAs. It chose Omron TM’s cobots for the tasks, supplied and installed by Absolute Robotics, a small robot integrator based in Bristol.
“As well as addressing the health and safety issue of our employees, we also wanted to guarantee a consistent cycle time. Unmanned running was really important to us, so we wanted to ensure that the cobots could run at night time, too, for more throughput, yet with less effort,” said Hanover Displays’s Operations Director, Sean Winter.
Omron TM cobots feature simple programming along with integrated vision capability. There are several models, offering different levels of payload and reach.
“One of the key drivers was that Hanover wanted the cobots to interact with the existing manual test equipment. The cobots therefore have special tooling that allows them to open and shut the manual testing equipment,” said Geoff Ferguson, Managing Director of Absolute Robotics.
Relying on cobots
Hanover wanted to use the cobots with both its processing and display boards, which meant exploiting their full potential. This included using the built-in vision systems, particularly for the display boards, to ensure that the LEDs were lighting up in correct sequence. Subsequently, the company invested in six more Omron TM cobots, installed in two production lines. These take the LED display boards from a standard storage rack and test them.
One of the challenges that Absolute Robotics faced was that Hanover Displays produces a wide variety of sizes and shapes of circuit boards for its display panels. The cobots needed to be able to handle these different types of boards, so Absolute Robotics built flexible tooling that can self-adjust, to successfully handle all of them. The programme can also handle any number of LEDs, from hundreds to tens of thousands.
“We realised the benefits of the cobots quite quickly, after implementing the first system,” said Hanover’s Mills. “What we’d planned and hoped for was that we’d be able to run unmanned and this happened quite quickly. The return on investment for the whole system was just two years. The tests involve very repetitive processes, and I think the biggest thing for me is being able to redeploy and upskill our staff.”
Winter added: “From a quality assurance point of view, we have full traceability of our PCBAs. This means every time we inspect a PCBA, we get a record that tells us if it’s passed or failed. We’ve also benefited from an additional 1,100 hours per year of unmanned running. At Hanover, we always want to invest in our future. It’s about looking at technology, how it’s moved forward and how we can apply it to our business.”
By Omron field application engineers
