Fully automatic FOSB packaging with cleanroom robots

The view from above of the facility emphasizes the space-saving layout. (Copyright: Stäubli Tec-Systems GmbH Robotics)

Two Stäubli six-axis robots of the TX2-160 type handle all handling processes in FOSB packaging. (Copyright: Stäubli Tec-Systems GmbH Robotics)

The robot presents the packaged box to an image processing system for quality control. (Copyright: Stäubli Tec-Systems GmbH Robotics)

The ABT systems for fully automatic FOSB packaging are very popular worldwide. (Copyright: Stäubli Tec-Systems GmbH Robotics)

The robots are equipped with special grippers, allowing a variety of FOSB formats to be handled without retooling. (Copyright: Stäubli Tec-Systems GmbH Robotics)

The packaging of wafers into so-called FOSB, an acronym for Front Opening Shipping Boxes, is an elaborate process that must take place under cleanroom conditions. To completely avoid human intervention, a Bavarian company has developed a fully automatic solution that is unmatched. Two Stäubli cleanroom robots handle the entire handling of the boxes.

In the far south of Bavaria, in the picturesque town of Burgkirchen, a small but fine high-tech special machine builder was established in 2006, whose innovative automation solutions quickly gained international recognition. With well-designed systems, the young cts GmbH managed to establish a foothold even in demanding industries such as automotive, electronics, semiconductors, life sciences, and more, building up corresponding expertise. After strong growth, cts now employs more than 350 people at several locations – but its innovative spirit remains unchanged, as once again demonstrated by the AutoBaggingTool, or ABT for short.

Alfred Pammer, authorized signatory at cts, summarizes what the ABT is all about: “The ABT is a complex robotic cell with two cleanroom-compatible Stäubli six-axis robots that fully automatically handle the complete bag-in-bag packaging of FOSB containers filled with wafers. This groundbreaking solution replaces the partly manual packaging process and offers a significant advantage in process safety, efficiency, and quality.” To meet the ever-increasing demand for this solution, cts recently built a completely new, state-of-the-art manufacturing facility.

In contrast, manual packaging of the FOSB, which can weigh up to ten kilograms, is physically very demanding. The employees first need to check the correct seating of the wafers in the box, then verify whether the various attachments on the FOSB are correctly mounted, and finally perform the difficult packaging with inner and outer bags – all under cleanroom conditions and in cleanroom suits.

Fully automatic instead of manual

How fast, simple, and efficient the fully automatic packaging with the two Stäubli cleanroom robots of the TX2-160 type is, is demonstrated by looking at the compact complete cell from cts, in which all components such as packaging stations, inspection chambers, robots, vision systems, printers, and more are integrated. Before the FOSB, usually loaded with 25 wafers, begins its journey through the total of 15 stations of the system, they are identified via RFID, as is common in the semiconductor industry. The necessary parameters are queried from the host system via the SECS/GEM interface. Based on the received information, all necessary process steps are then carried out.

Initially, the containers filled with wafers are provided by an overhead hoist transport system, or OHT, and conveyed to the system via an input conveyor. The first step is the so-called Cross Slot Check at an inspection station, where the correct position of all wafers in the box is verified.

Subsequently, the first Stäubli six-axis robot picks up the FOSB and presents it to a vision system that checks the correct positioning of the attachments on the box. Next, the labeling process and subsequent quality control of the label are performed. Both process steps are handled by the TX2-160, which safely holds the container in its hand and supplies it to the labeling and BV stations. To keep cycle times short, the TX2-160 performs all movements with high dynamics and precision.

An elaborate process: the bag-in-bag packaging

The first packaging process with the inner bag is now on the agenda. The six-axis robot places the container at a fully automatic station where the packaging and sealing of the inner bag take place. The next process steps include folding and gluing the excess material and conducting a leak test of the vacuum packaging.

This test station also serves as the transfer position of the FOSB from robot one to robot two. While the first TX2-160 places the box there for inspection, the second six-axis robot picks it up after the test is completed. Then, robot two takes over the entire handling for packaging with the outer bag, performing the same work steps as with the inner bag packaging, including further labeling with quality check of the label. Finally, the robot places the fully packaged and inspected FOSB onto the output conveyor.

“The system not only guarantees a significant increase in quality and process safety but also a markedly higher output. The AutoBaggingTool ABT can achieve a throughput of up to 8,000 FOSB per month,” says Alfred Pammer. Another major advantage of the system is its ability to handle a variety of FOSB formats with different attachments. Thanks to the flexibility of the Stäubli robots and the gripper technology developed by cts itself, ABT can package almost all variants without any retooling. This unique feature is highly valued by customers worldwide.

The required cleanroom classification ISO 6 also poses no challenge for the two Stäubli robots. They already meet this classification in their standard configuration. “We generally rely on Stäubli robots for our semiconductor systems because they are considered a reference in cleanroom environments and are extremely precise and reliable at the same time. These systems mainly operate in Asia and other parts of the world around the clock, so we cannot afford any disruptions or failures,” emphasizes Alfred Pammer.