Papers by Keyword: Fixed-Abrasive

Abstract: Magnetic recording technologies are continuing to advance toward higher areal densities, driven by the availability of tunneling magnetoresistive (TMR) heads. However, high areal density heads require smaller physical dimensions, and this can render TMR heads more vulnerable to mechanical stresses generated during the lapping process. Although is important to verify the durability of TMR heads against lapping, it is very difficult to perform a crystallographic analysis of the affected layer because of the small dimensions involved. In this study, we attempted to establish an advanced TMR head verification method based on a magnetic performance analysis involving micro-Kerr hysteresis loops and the magnetic noise spectrum. We found that the magnetic performance changed when nanoscale scratches were removed from the lapped surface using ion beam etching. This indicates that the lapping process produces an affected layer which deteriorates the magnetic characteristics of the TMR head. A correlation was also found between the change in magnetic performance and the morphology of lapped surface.

Abstract: The necessity of fixed abrasive CMP in polishing semiconductor materials processing was analyzed. Compared the shortcomings of traditional free abrasive polishing with the advantages of fixed abrasive polishing, the applications of fixed abrasive polishing technology in semiconductor processing were described. A variety of fixed abrasive polishing pad production methods were introduced. The development trend of fixed abrasive polishing was prospected.

Abstract: In the lapping of magnetic heads and other electronic components composed of multiple materials, differences in the processing characteristics of the composite materials produce residual steps on the surface at composite interfaces. Residual step heights have been reduced to as small as a few nanometers. We investigated using fine abrasives in fixed abrasive lapping to further reduce the residual step height. This requires highly secure, high-density embedding of abrasives on the lapping plate. To this end, we evaluated the surface morphology of the lapping plate after diamond abrasive charging and investigated the embedding mechanism of diamond abrasive charging. The results obtained will assist in determining the direction of future research and development. A prototype charging ring that uses a vibrating system was developed to increase the density of abrasives embedded on the lapping plate. This diamond charging using a vibrating system was able to increase the embedded abrasive density and improve the flatness of the charging plate.

Abstract: This paper shows the removal rate and lifetime data of glass lapping process using 3M Trizact^TM Diamond Tile Abrasive Pads. 3M Trizact^TM Diamond Tile Abrasive Pads is a structured fixed abrasive grinding technology developed by 3M Company, it consists of a polymeric binder and diamond composite that is used with a water-based coolant. It can be applied in both single and double side grinding applications. Grinding results of 4S-4 micron grade of Trizact^TM Diamond Tile abrasive pads on Corning Gorilla^TM glass will be presented.

Abstract: The surface roughness and surface morphology of silicon wafers polished by three different polishing methods were analyzed in this paper. A polishing pad was prepared by means of sol-gel technology as semi-fixed abrasive tool. An electroplated polishing pad was chosen as fixed abrasive tool. And a polishing cloth was chosen as free abrasive tool. The results showed that the surface of silicon wafer polished by the sol-gel polishing pad was superior to the other two. It was easy to get mirror effect with few scratches while the free abrasive and fixed abrasive got lots of scratches on 23silicon wafers. The surface roughness of silicon wafer polished by the sol-gel polishing pad reached 1.41nm measured by atomic force microscope (AFM).

Abstract: In the lapping of magnetic heads and other electronic components composed of multiple materials, differences in the processing characteristics of the composite materials result in “residual steps” forming on the surface at composite interfaces. Residual step heights have been reduced to as little as a few nanometers. We investigated using fine abrasives in fixed abrasive lapping for this purpose, which requires highly secure, high-density embedding of the abrasives on the lapping plate. To this end, we modeled the abrasive embedding process and investigated the relationship between the mechanical properties of the lapping plate and the retention of the abrasive, to determine the direction of further research and development. The results of this investigation revealed a correlation between the work hardening in the plate and the resulting abrasive density and cutting edge height. The investigation also showed that it is possible to suppress the reduction in lapping rate that occurs during use by increasing the work hardening coefficient of the plate.

Abstract: Diamond wire saw is the leading technology for use in slicing hard brittle material. This paper provides a brief review of its research progress in the most recent years. According to the bonding material kinds of diamond wire saw, it can be classified into three main categories, i.e. metallic bonding materials, organic bonding materials, and resin bonding materials. In the past decade, several new major technical developments in fixed abrasive diamond wire saw have emerged. This paper investigates the related literature on four different types of fixed abrasive diamond wire saws, presents their manufacturing processes and machining performance, and compares the tension and anti-abrasion of the wire saws, removal efficiency of slicing, and their applications in silicon slicing.

Abstract: We investigated the durability of giant magnetoresistive (GMR) heads to nanoscale scratches created during the lapping process. Analysis using high-field transfer curves after deliberate scratching with an atomic force microscope (AFM) identified changes in the magnetization of the head and a reduction in pinning strength, which is a magnetic performance indicator. Additionally, finite element method (FEM) analysis suggested that the overall effects on the GMR head following nanoscale scratching increased with scratch depth.

Abstract: Diamond wire saw is the leading technology for use in cutting hard brittle material. Its smaller kerf and faster cutting time make it replacing the conventional slurry technology for those materials. Turned over the traditional router, this paper presents a novel approach that replaces the typical metallic core with a nonmetallic core, for manufacturing of ultraviolet curing resin fixed-abrasive diamond wire saw (DWS). The experiments show that the diamond wire saw made by this manufacturing method can obtain a good performance as well as taking many other advantages.

Abstract: Series of simulation of planetary precise ball lapping modes are put forward in this article, which use solid abrasives to get a high lapping efficiency. In this case, it is very important to obtain a better quality especially a better uniformity. Based on the simulation. of this new lapping mode, it is found that the lapping trace are mainly influenced by the eccentric distance and other factors.