CATalysis – Process Gas Cleaning System


■ LEFT Andree Niewöhner, production management at Miele, RIGHT Dr. Christian Ulzhöfer, CEO at SMT.


In 1748, Benjamin Franklin stated “Time is money.” Saving time is an important aspect in modern electronics manufacturing, especially when maintaining equipment. The less downtime due to cleaning processes at a reflow soldering system, the higher the productivity for customers.

SMT Maschinen- und Vertriebs GmbH & Co. KG from Germany, a recognized expert in the field of mechanical engineering for thermal processes is constantly working to improve its efficient, powerful and energy-saving soldering systems. Every year, approximately 12.5% of revenue is reinvested in research and development. Innovations for higher efficiency and environmental friendliness are often developed in collaboration with customers and research institutes. SMT holds several patents in this area and has successfully field-tested its newest innovation, the SMT CATalysis process gas cleaning system at Miele & Cie. KG in Gütersloh, Germany.

Miele, a family-owned company based in Westphalia, Germany is the world’s leading supplier of premium home appliances for cooking, baking, cooling and freezing as well as dishwashers, washers and dryers. Miele has over ten thousand employees at eight German facilities.

At their headquarters in Gütersloh, Miele is using the SMT Quattro Peak reflow soldering systems with the high-temperature ABS process gas cleaning system. The customer requested a 50% reduction of time spent for maintenance by increasing the time between maintenance cycles from four to six weeks, working in a three shifts per day operation.

The Research and Development department of SMT, under the leadership of Andreas Stemmler, worked intensely to fulfill these requirements. The chemical reactions were analyzed and evaluated in details down to the basics level. After extensive research, in close cooperation with chemical companies and numerous in-house tests, the solution was found in the implementation of the newly developed SMT CATalysis – process gas cleaning system.

Catalysis is defined as the kinetic change of a chemical reaction by means of adding a catalyst. Due to the changed kinetics, the chemical reaction of splitting long hydrocarbon chains is started or acc elerated. The CATalysis cleaning system in the reflow system operates similar to the exhaust gas treatment in a vehicle, where the exhaust gases of the internal combustion engine are cleaned.

Long-chain hydrocarbon chains, which are released during the reflow process, can condense at colder areas inside of the oven, causing resinous and oily contaminations. With the SMT CATalysis process gas cleaning system, gas from the process chamber is pulled through heated catalyst granulates and reintroduced back into the process chamber. Circulating the process gas over the large surface of the precious metal coating of the catalyst granulates ensures an optimum cleaning effect.

Andreas Stemmler, head of the Technical Department at SMT says, “Each of the SMT Quattro Peak L Plus reflow soldering systems at Miele has three high-temperature ABS systems, which are distributed over the entire heating zone length. All of these cleaning systems were modified for the new process gas cleaning system. The cleanliness and efficiency of the soldering process should therefore be guaranteed while a significant reduction of the maintenance will be ensured.”

Figures 1 and 2 show contamination in the inlet condensate trap, which has been collected during a period of six weeks in a three-shift/day operation (Monday through Friday).

The substantially lower contamination of the inlet condensate trap (see in figure 2) demonstrates the significant improvements that have been achieved due to the use of catalytic granulates. Contamination in the inlet area and in the cooling zones had also been reduced significantly.

Andree Niewöhner, Production Manager of Miele & Cie. KG, confirmed: “We are very satisfied with the SMT reflow soldering system and the integrated CATalysis process gas cleaning system which we operate in an environment of three shifts per day for five days per week since January 2016. Our target to increase the maintenance interval from four to six weeks has been exceeded by almost 20%. We are reaching seven weeks between maintenance cycles, achieving an improvement of 75%. The process chamber stays cleaner, the maintenance intervals can be significantly increased, downtime is significantly reduced which increases productivity. This is a very important factor.”

The CATalysis process gas cleaning system can be installed in all SMT reflow and vacuum reflow soldering systems in the Quattro Peak series from size L and can be retrofitted into existing ABS process gas cleaning systems in the field. Customers with existing SMT reflow soldering systems can also benefit from this innovation.

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