Ersa Rework
From Micro to Mega
Automated rework solutions for small components and XL boards – from 01005 components to 625 x 1,250 mm board size
E-mobility, automation, autonomous driving, 5G communications and Industry 4.0 are the megatrends that are leading to extensive digitization. This requires increasing computing power in systems and devices. Great potential for developers and manufacturers of such technologies. At the same time, demands on the electronics manufacturing process are growing. Reworking and repairing electronic assemblies is also becoming more demanding, new concepts and automated systems are in demand.
As a specialist in electronics manufacturing, Ersa has been involved in professional reworking since the late 1990s. At that time, when the BGA was still a young package type, the process knowledge for selective processing of SMDs in rework was developed. Today, BGA are an integral part of modern, high-performance electronics. Standard in numerous fields, essential for high performance electronics. For 5G applications BGA with 110 x 110 mm edge length and 0.6 to 1.0 mm pitch are used. At the opposite end are the tiny electronic circuits: passive, discrete, two-pole SMD components. 01005 chip capacitors or resistors with dimensions of 0.4 x 0.2 mm have long been common.
The challenge for electronics production in view of the flexible range of component shapes is to be able to process all components in the line process and to be able to fall back on appropriate repair concepts in case of failure. Although plant and process technology has become more and more sophisticated in recent decades, new challenges have been added all the time – such as steadily decreasing pitch dimensions or increasing circuit complexity. Solder paste printing is still responsible for many soldering defects on SMT assemblies. Therefore, modern stencil printers with sophisticated stencil technology and integrated 3D inspection are recommended.
What to do in case of defects?
Depending on the size and nature of the component, all electronics can be reworked successfully. With solder joints that are on a par with the quality of the faultless manufacturing process. The “Guide Rework of Electronic Assemblies” of the ZVEI (German Electrical and Electronic Manufacturers´ Association) proves that processes for rework can be qualified and reliably carried out. Whether very small assemblies (e.g. hearing aids) or extremely large assemblies (server boards, 5G modules) – the demands on the repair process are increasing. Current Ersa Rework Systems can process assemblies up to 625 x 1,250 mm (24 x 48 inch) in size. The now very high degree of automation ensures high process reliability and reproducibility. Whether 01005 or large BGA: The components are picked up for placement, automatically aligned by image processing, set down by means of an axis system and then soldered..
For processing chip components, the Ersa HR 600/3P is equipped with ultra-fine nozzles and a belt feeder. The solder paste depot can be refreshed by dip transfer. For large BGA such as Land Grid Array (LGA), the identification of the connections is also fully automatic. With the help of the Dip&Print Station, the component connections are automatically dipped in flux or printed with solder paste using a suitable stencil. While chips are usually easy to remove and insert, large components require a larger heating head and high pull-off force for desoldering – the solution here is offered by the Ersa HR 600 XL with a powerful vacuum system with large nozzles or double nozzles.
Homogeneous heating of assemblies
Especially for very large boards, the homogeneous heating of assemblies is important. An ingenious heating technology ensures homogeneous heating with minimal distortion – the IR matrix bottom heater on the HR 600 XL brings the assembly to temperature with 25 individually controllable heating elements, individually optimized. Peripheral areas of the board can be heated more than the center, while individual areas can be heated less than others (“cold spot”).
In profile-controlled soldering processes, Ersa system heaters follow the measurements of the leading control sensor on the board and automatically ensure reproducible results. In addition, the system user gets a clear view of the solder joints through reflow process cameras. With comprehensive process knowledge from line processes, Ersa offers suitable rework solutions for the rework of modern assemblies – from 01005 to 625 x 1,250 mm!
