In addition to the supply of equipment, as well as technical and service support, DISCO HI-TEC EUROPE has its own experienced production, which serves about 500 customers from around the world.
DISCO Corporation (Japan) is the world's leading developer and manufacturer of equipment for wafer grinding and dicing. The European division of the corporation is located near Munich (Germany), in the town of Kirchheim. In addition to the supply of equipment, as well as technical and service support, DISCO HI-TEC EUROPE has its own experienced production, which serves about 500 customers from around the world. Thanks to the kind assistance of Russian representatives of DISCO – the Ikar-Impulse – we visited the production facility in Kirchheim and got acquainted with its work.
The regional representation of a major equipment manufacturer, as a rule, has a demonstration center where samples of equipment are presented. The history of the development of production in Kirchheim began precisely with such a center. Initially, potential customers came to get acquainted with the machines, and then began to bring test orders to check the capabilities of equipment and technology. Then commercial orders began to arrive, and DISCO HI-TEC EUROPE (DHE) built the first clean room of 32 m2. At present, the area of the clean room is 450 m2, the enterprise operates two shifts seven days a week, processing about 10 thousand wafers a month. Moreover, in Kirchheim in the middle of this year a new clean room with the area of 900 m2 will be launched. The production using the latest DISCO solutions can be divided into the following parts: wafer thinning, including grinding and polishing; blade and laser dicing. Clean room is also equipped with machines for inspection of wafers after thinning and dicing.
WAFER THINNING: GRINDING, DRY AND WET POLISHING DISCO produces several series of equipment for wafer backgrinding and polishing. In Kirchheim they are represented by the DAG810, DFG8540, DGP8761, DFP8140 and DTG8440. The DAG810 is a universal automatic single spindle grinder. This compact model, occupying only about 1 m2 of production space, allows grinding wafers with a size of up to 200 mm. Silicon, compound semiconductors, sapphire, lithium tantalate, lithium niobate, ceramics, polymers and other materials can be processed with high quality. The automatic two-spindle grinding machine DFG8540 is designed for high-performance processing of 200 mm wafers. The system provides the possibility of thinning (down to 20 μm) and simultaneous dicing (Dicing Before Grinding, DBG), and can also be integrated with plasma processing and polishing equipment to relieve stresses in thinned chips. The three-spindle high-performance automatic machine DGP8761 allows to perform both grinding and polishing of the wafers. Thickness of substrates after thinning can reach 25 μm. In Kirchheim, the DGP8761 is integrated with the DFM2800 fully automatic wafer mounter. The DFP8140 is an automatic wafer polisher. During processing, surface roughness is minimized, mechanical stresses and defects appearing at the grinding stage are eliminated. Chemicals are not used for dry polishing, which improves the environmental characteristics of the entire production. The compact automatic planarization system DAS8920 intended for high-precision processing of soft materials (metals and polymers), as well as for special tasks, for example, for leveling bump height, should be specially highlighted. This machine can also be used for carrier film planarization when working with wafers on which bumps are formed. In Kirchheim, the technological innovations of DISCO in the field of thinning are successfully used in practice. These include the DBG technology mentioned above, in which half-cuts are made first along the chips separation lines, and the separation itself is performed during backside grinding. DBG minimizes damage during transportation of the thinned wafers, eliminates backside chipping when separating the chips and ensures high strength of the chips. The greatest effect is achieved in the case of low thickness (down to 20–30 μm) and large size (300 mm) wafers. Another demanded innovation is TAIKO technology, which increases the reliability of work with ultra-thin wafers. As a result of using a special thinning algorithm, the edge of the wafer has a greater thickness than its remaining area. This "stiffener" of about 3 mm in width increases the strength of the wafer and reduces the likelihood of its mechanical damage during processing and transportation. MECHANICAL WAFER DICING For the mechanical wafer dicing the DFD6341, DFD6361 and DFD6560 are used in Kirchheim. The fully automatic compact two-spindle system DFD6341 with dicing speed up to 1,000 mm/s is designed for 200 mm wafers. Optional system with xenon flash lamp and CCD shutter provides high-speed alignment without the need to stop the chuck table. The DFD6361 is a fully automatic two-spindle system for 300 mm wafers. The maximum dicing speed is 600 mm/s. The facing dual spindle layout and a condition monitoring system with wear compensation of the blades contribute to increased productivity. The fully automatic two-spindle DFD6560 machine is also designed for processing wafers with a size of up to 300 mm. Its design is characterized by the reduced footprint, and all maintenance can be performed from the front of the equipment. With installation of several such machines, you can achieve a 20% savings in production area compared to the DFD6362. In Kirchheim, mechanical dicing of wafers of a large range of thicknesses (up to ultrathin) made of the widest range of materials, is performed. LASER WAFER DICING The laser dicing area is equipped with the DFL7160 and DFL7341 systems. The DFL7160 is an automatic ablation system for 300 mm wafers. When using laser ablation, the material is removed by powerful laser radiation. The absence of mechanical load on the wafer eliminates the defects inherent in mechanical dicing. Laser ablation can be used when working with complex materials and in some cases can reduce the width of the streets between the chips to 10 μm, increasing the efficiency of using the wafer area. DFL7160 is compatible with DBG technology and can be used for cutting a wide range of materials, including sapphire, gallium arsenide, low-k dielectrics. The automatic laser system DFL7341 for 200 mm wafers implements Stealth technology, in which a brittle modified layer is formed in the material. The main advantage of this technology is purity, since there are no products of ablation or mechanical destruction, and there is no need to remove them. In addition, it is possible to reduce the width of the streets between the chips. DFL7341 is designed, first of all, for the production of MEMS and the separation of chips on sapphire. Also, this device is widely used for cutting test wafers with chips of different sizes (Multichip wafers), since the laser beam can be instantly turned off and turned on without damaging the suitable chips. *** The production organized by DISCO HI-TEC EUROPE demonstrates the effectiveness of a fairly obvious idea when the demonstration center is the base not only for the presentation of equipment and technologies, but also for the organization of a new profitable business area. ■