Customer Story: Die Bonder for the Stacking of Membrane Chips with One Micron Post-bond Accuracy
The Institute for Microelectronics in Stuttgart, Germany, is using a die bonder system from Finetech for the stacking of fragile membrane chips with a post-bond accuracy of less than one micrometer.
The Institute for Microelectronics Stuttgart (IMS Chips) is engaged in business-oriented research in the fields of silicon technology, application-specific circuits (ASIC), nanostructuring and image sensor technology and provides professional training. The institute partners with small and medium-sized enterprises, especially in the German federal state of Baden-Württemberg, and cooperates with leading international semiconductor companies and suppliers.
For a new application, key requirement was the stacking of a number of membrane chips, each several cm in size, on top of each other with very high precision. After completion of all placement and stacking steps, the post-bond accuracy of the overall process had to be less than 1 µm.
The previous system, an in-house design based on an old 3-inch mask aligner, reached its limits here due to a lack of spare parts and flexibility. For example, the lens distance could not be reduced, which limited the number of membranes which could be stacked on top of each other. The bonding force could not be controlled, which endangered the fragile membrane chips. Also, the adhesive for bonding the chips could not be applied in a defined manner and the overall process stability was not consistently given.
Therefore, IMS Chips were in the market for a new assembly system that would continue to ensure the highest assembly precision, but offer more flexibility in terms of supported substrate and component dimensions. The bonding force should be process-controlled and adjustable over a wide force range, and the system should also have the option of precisely applying adhesive with a dispenser.