Small impact attenuators at the forefront of semiconductor manufacturing

The semiconductor industry is increasingly working on smaller, more efficient, faster and cheaper-produced integrated switching circuits. With advances in microelectronics, there are increasing demands on the handling systems responsible for the clean and safe transport of wafers. In a custom application, ten small shock absorbers from ACE Stoßdämpfer protect all linear axes

Photolithography is a key technology in the manufacture of microelectronic components and switching circuits and in the production of microsystems. In this process, a pattern is transferred from a photomask to a light-sensitive, thin layer of photoresist on a wafer. To ensure flawless production, engineers take the greatest care in both programming and monitoring the automated processes. Because of the high demand for microprocessors and memory chips, and because limiting failure risk is of paramount importance in wafer production, many chip manufacturers work with their own handling system suppliers. These typically equip their designs with high-quality, proven standard components for drives, controls and linear axes. In order to optimally protect these axes with robust, mechanical machine components, ACE Stoßdämpfer GmbH was contacted. This is because the shock absorber specialist from Langenfeld, Germany, also offers customized solutions. An experienced team of engineers from ACE develops these exactly according to the requirements of semiconductor manufacturers. Using special software, a solution is worked out, which is tested on ACE's test bench. This allows all production axes to be properly protected and prevents damage during handling.

Design, simulation, test bench: from standard muffler to custom specimen

For chip production, high-precision, frictionless axes are installed in a handling system. According to the manufacturer, in the event of a crash, the X and Y axes and the central axis must only be loaded with the maximum permissible forces to ensure 100 percent that the system is not damaged. Therefore, the three axes here had to be equipped with three different types of small impact absorbers from ACE's range of products. For the Y axis, four small shock absorbers with M20 threads were used; for the X axis also four, but with M18 threads; and for the central axis two with M25 threads. ACE's engineers were also given information about the maximum reaction force in a crash. For the Y axis, for example, the parameters per damper were as follows: mass, m = 95.85 kg and velocity, v = 1.08 m/s, and thus corresponds to a kinetic energy of 55.90 Nm. The maximum allowable reaction force for this axle was 5,700 Nm. Based on this information, the corresponding drilling pattern for the appropriate types of small impact absorbers was simulated at ACE's R&D department in a second step. They succeeded in slowing down the energy and speed evenly over the entire stroke length of 14 mm, reducing the maximum reaction force to about 5,300 Nm. ACE was also able to meet the specified values for the best possible protection of the other two axes using mechanical components. In a third and final step, the small shock absorbers, which were custom-made based on the simulation, were delivered to the customer after extensive testing. ACE's ten small impact attenuators now protect all three axes of motion of a handling system used for wafer production.

Small shock absorbers from ACE: damping solutions for many applications

The three different small threaded shock absorbers in sizes M18 to M25 in the application described are exemplary of ACE's ten product series of small shock absorbers. These include damping and braking elements made of stainless steel, which not only meet the stringent requirements of the semiconductor industry, but also the hygiene regulations in medical technology or the food industry. 

Certain models of the compact, maintenance-free, hydraulic machine components also operate directly in pneumatic cylinders when necessary. They reduce loads there as well as when used in miniature guides in handling equipment and in many other industrial applications. Innovative sealing techniques and the shock absorber housings, made of alloyed high-strength steel, guarantee high service lives. In addition to a range of accessories, such as guide pins, ACE also offers shock absorbers with special thread sizes, fluids, other stroke lengths and in special designs.