Junichi Ikeno

Development of chipping-free dicing technology applying electrophoretic deposition of ultrafine abrasives

Summary It is very important to decrease the amount of chipping in the dicing process of brittle materials for the reduction of material loss and the improvement of surface integrity in the production of optical and electrical components. The use of ultrafine abrasives reduces the grain depth of cut which results in the minimization of subsurface damage. Thus, a new dicing technology has been developed by applying electrophoretic deposition of ultrafine abrasives. During the process, the abrasives cohered around a conductive thin blade used as the anode in an electric field and polished the side surfaces of grooves. Consequently, chipping-free dicing was accomplished and an optically smooth surface was obtained on the side surfaces of the groove.

Nanometer grinding using ultrafine abrasive pellets ― Manufacture of pellets applying electrophoretic deposition

Summary The existence of numerous active grains, which results in a minute grain depth of cut, is an important feature for obtaining a supersmooth surface by grinding. It is desirable to apply a grinding wheel with a large grit number in order to increase the number of active grains, but it is difficult to mold homogeneous grinding wheels composed of fine grains due to the cohesion of the grains. Abrasive pellets composed of 10 to 20nm ultrafine grains have been newly developed by applying electrophoretic deposition. In the manufacturing process, dispersive fine abrasives wrapped by electrolytic bonding agents cohered around an electrode due to an electrodynamic notion. which resulted in the formation of homogeneous and dense abrasive pellets. Therefore, the pellets had a higher bonding strength than those produced merely by desiccation so that a surface finish of less than 10nm without any cutting marks was obtained in a short time by grinding a silicon wafer using the silica pellets.

Development of Highly Homogeneous Pellets Applying Electrophoretic Deposition of Ultrafine Abrasives for Nanometer Grinding

Summary This paperis concerned with how to fabricate highly homogeneous pellets for nanometer grinding. The realization of a minute grain depth of cut is an important feature for obtaining a smooth surface by grinding. Hence it is profitable to apply a grinding wheel composed of ultrafine abrasives of diameters of 10 to 20nm. The grinding wheel with suitable bonding strength brings about grain-sized self-sharpening in a grinding process. Hence it can prevent the occurrence of swarf loading and grain dulling which weaken the grinding ability. As a result, the highly homogeneous grinding wheel can yield a smooth surface of less than 10nm, p-v for both hard and brittle materials. Ultrafine abrasives which are negatively charged can be deposited uniformly on an anode by applying electrophoretic deposition. Hence a homogeneous ultrafine grinding wheel can be fabricated by applying this technique.

Study on Manufacturing Method fo Ultrafine Abrasive Pellets Applying Electrophoretic Deposition for Nanometer Grinding. Application of conventional bonding agent to manufacturing of Ultrafine Abrasive Pellets.

The realization of a minute grain depth of cut is an important feature for obtaining a supersmooth surface by grinding. It is desirable to apply a grinding wheel composed of ultrafine abrasives which the diameters areφ10 to 20 nm. but it is difficult to mold homogeneous one due to cohesion of the grains. We have already reported that homogeneous ultrafine abrasive pellets could be manufactured applying electrophoretic deposition and that grinding using the pellets accomplished supersmooth surface less than 10 nmRmax for hard and brittle materiales. However, the bonding agent was sodium alginate which was not familier to grinding wheel makers. Thus the manufacture of ultrafine abrasive pellets using conventional bonding agent was examined in this paper in order to apply their knowledge to production of the pellets, As a result, homogeneous ultrafine abrasive pellets using PVA bonding agents could be developed and accomplished nanometer grinding of silicon wafers.

Damage-free grinding using ultrafine abrasives

Both low bonding strength and high density of active grains are iiportant features for carrying out daiage-free grinding. Hoiogeneous ultrafine abrasive pellets were developed by applying electrophoretic deposition. Face grinding of brittle saterials using the pellets enabled creation of a supersiooth surface finish less than lOni peak to valley with no cutting iarks. Moreover, chippingfree grooving was accoiplished using a thin conductive blade on which ultrafine abrasive layer was grown under an electric field.