Ersa GmbH develops rework systems to make printed circuit board repair sustainable – using igus® readychains®

The global chip shortage poses challenges for entire industries. If there is little available to start with, nothing had better go wrong in production. But if something does go wrong, it is all the more important to correct the error quickly. Ersa GmbH, an electronics company, creates rework systems for automatic printed circuit board repair. For safe, reliable cable guidance, Ersa use ready-harnessed energy chains – in this case, igus® readychains.

Jörg Nolte stands in front of the HR 600 XL rework system. The product manager for soldering tools, rework, and inspection systems at Ersa GmbH in Wertheim, Baden-Württemberg, clamps a large printed circuit board into the machine. A 15-kilowatt matrix heater provides the necessary base temperature needed to de-solder faulty processors and other electronic components and to automatically re-solder the working parts. This is how defective components are reworked. The primary aim is to keep financial damage and resource waste to a minimum. Rework is a very big issue, especially in the electronics industry, because mistakes happen quickly. “If a single component in the series is rotated 90 degrees and placed on the circuit board, the 2,000 other boards in a production batch are defective,” says Nolte. Instead of throwing away 2,000 expensive circuit boards, manufacturers must rework them. This requires technically sophisticated, robust, precise machines – like Ersa’s. The HR 600/3P and the larger HR 600 XL ensure reliable rework so that even large printed circuit board quantities can be reworked quickly and with little effort. To move the heating head and component precisely, Ersa uses a motorised axis system. And to ensure that the camera, pick-and-place unit, and all necessary cables survive the movements, Ersa rework systems use ready-to-install igus energy chains with highly flexible cables.

Rework combats the chip shortage

The chip shortage has shown how important smooth electronic component production is for industries around the world. As a system supplier of soldering machines, solder paste printers, soldering tools, and rework and inspection systems, Ersa GmbH, founded in 1921, specialises in electronic component production requirements. No application is the same as another: Machines have to be equipped differently for different printed circuit board sizes. The original HR 600/2 model was quickly well received in the market: “The number of inquiries increased, and the components kept getting larger,” says Nolte. Inevitably, the company had to develop a machine that can process even large boards. Circuit boards over 60 centimetres can be clamped and processed in the HR 600 XL. But size says nothing about the necessary precision. Even on large components, work must be very precise. The rework systems are used for BGA and SMT components. BGA (ball grid array) refers to the shape of the solder balls on the bottom of the component. SMT (surface-mounted technology) components are soldered directly to the top of the circuit board via their connections. The rework systems handle both component types with ease. Is important to Ersa to have a comprehensive rework option so as to conserve resources: “We want to retain added value,” says Nolte. The machines can be used for repairs, and components can also be extracted from old assemblies and used for prototyping. To be able to handle all these requirements, Ersa has chosen a modular concept: In addition to the standard functions, the HR 600 systems are now often retrofitted with a scavenger module. The scavenger sucks off the excess soldering material, ensuring clean rework. Ersa has igus to thank for the fact that this retrofitting is possible at all.

Ready-to-install energy chains make retrofitting easy

When the system was designed, the electronics company turned to the motion plastics specialist igus for a simple, suitable solution for cable guidance. “Of course, our core competence is not correctly designing energy chains. We are happy for any help we can get with that,” says Ferdinand Bozem, Product Owner Rework at Ersa. Ersa got that help in the person of Bastian Lenz, technical sales consultant at igus: “Our readychains give customers a ready-to-install complete solution,” he says. “This reduces assembly time by up to 95 percent, and manufacturing costs and assembly time also fall.” Nor do companies need to provide any on-site storage space, so the logistics effort is very low. Ultimately, Ersa also benefited from comprehensive igus consulting: When the scavenger module for the rework systems was to be retrofitted, Bastian Lenz recommended the successful expedient of having two chains running one inside the other. If the cables for the scavenger module had been put into the existing chain, a much wider chain would have been necessary, and the machine would have required modification. “We can also retrofit existing systems without a scavenger module,” says Nolte.

Energy chains made of conductive ESD material – more than ten million cycles of testing

igus E4 ESD-series e-chains are used. The chains are made of conductive igumid ESD material and therefore prevent static charges during electronic component handling. igus energy supply systems are made of high-performance plastics that are tribologically optimised (that is, optimised for friction and wear). Special additives incorporated into the ESD material allow long-term, continuous, maintenance-free conductivity. The material was extensively tested (more than ten million cycles) in the in-house test laboratory. igumid ESD even surpasses igumid G, the standard material, in some mechanical requirements and has proven itself in various customer applications for years. Data from the test laboratory even allows calculation of igus energy supply system service life in the customer-specific application, and the online service life calculator makes it extremely easy. More than 4,000 tests per year are incorporated into the calculation tool for e-chains alone. More are added every day so that even more precise service life predictions can be made. Users also benefit from the well-known advantages of energy chains made of high-performance plastic: They are light while remaining robust, and are quiet, low-maintenance, and easy to open and assemble.

Highly flexible, abrasion-resistant special cables specifically for energy chains

To minimise on-site production effort, the readychain is equipped with the necessary cables at the factory. This benefited Ersa during development. Nolte continues, “We are not a cable assembly specialist. Everything came ready for assembly from igus, which was the decisive reason for us to choose the readychain.” Besides the power supply, the HR 600 rework systems require bus cables for the built-in camera, LAN cables, and nitrogen or vacuum lines. Ersa must have high quality there. “Having the right cables greatly reduces the machine’s susceptibility to failure,” says Nolte. As an example, he cites factories in Egypt with poor electromagnetic compatibility. It is important that all components in the rework systems be robust. That is why highly flexible igus chainflex control, bus, and measuring system cables are used in the readychain. With more than 1,350 products from stock, igus offers the widest range of cables specifically for constant movement in energy chains. The chainflex cables are also put through their paces in the igus test laboratory. This makes igus the only supplier to grant a guarantee of up to 36 months on its energy chains and cables. Ersa chose cables with a PVC jacket for its rework systems. PVC not only has high abrasion resistance, but is also very easy to assemble while remaining inexpensive. The material is the ideal partner in applications with high cycle numbers in dry areas in energy chains. In addition to technical considerations, the igus readychain design impresses Nolte. Ersa has found that many customers want components to be aesthetically pleasing. The readychain is.

Additional automation solutions planned

For the future, Ersa is aiming for a higher degree of rework automation. While one person per machine must currently be scheduled, that person could someday operate several, with the work performed largely automatically. So far, igus energy chains have been installed in every generation of the HR 600 rework systems. “We are very happy to have igus at our side as a technical contact,” says Nolte. For the machines, the readychains are not just one component among many; they are core elements for smooth rework functioning in electronic component production.