Abstract: A method and apparatus for modulating multilevel data arrays to make them suitable for storage in multidimensional storage media, such as in holographic storage. In order to get a uniform signal of constant energy at the recording plane, first the multilevel data array, Vout, displayed on a spatial light modulator, has frequent transitions between symbols of different levels, and second it has constant energy. The energy is defined as the summation of the values of the symbols in the data array. The first constraint is achieved using V?in=Vin?qM(q, ZO), where ?q stands for the modulo-q addition operation; M(q, Zo) is a data array with randomly distributed symbols of q levels, where q is the number of levels and ZO is the seed used to generate the random multilevel data array.

Abstract: This invention relates to a method and apparatus for deflashing integrated circuit (IC) packages by laser irradiation. The method and apparatus include two lasers scanning flash area for performing deflashing operation. CO2 laser is used to remove top layer of flash and YAG laser is used to remove the thin layer of flash remained after CO2 laser deflashing. CO2 laser deflashing and following YAG laser deflashing can effectively remove flash and avoid damage of heat sinks as well as leads and bars in the IC packages.

Abstract: A data processing apparatus having a partial response forward equalizer (filter) with sufficient number of taps to result in 7-tap target response, designed by jointly optimizing the target response and the target coefficients to maximize an appropriate signal-to-noise ratio (SNR) at the detector input, followed by a new post-processing scheme enhances performance of the threshold based bit-by-bit detector designed for the d=2 optical channels. The resulting performance of the proposed scheme over a range of channel densities of 4.5 and below (used on EFM/EFMPlus coded channels for CD/DVD), is close to maximum-likelihood bound (MLB), and it is better than that of other schemes at channel densities of 4.5 and higher. Advantageously, the detector of the invention is simple in structure compared to conventional partial response Viterbi detector schemes. By processing the detected data in accordance with a set of data correction rules, the invention provides advantageous enhanced detection capacity.

Abstract: This invention relates to a method and apparatus for deflashing integrated circuit (IC) packages by laser irradiation. The method and apparatus include two lasers scanning flash area for performing deflashing operation. CO2 laser is used to remove top layer of flash and YAG laser is used to remove the thin layer of flash remained after CO2 laser deflashing. CO2 laser deflashing and following YAG laser deflashing can effectively remove flash and avoid damage of heat sinks as well as leads and bars in the IC packages.

Abstract: A method for dynamically measuring the spatial position and orientation of a slider used in a magnetic disk drive operates by directing one or more beams of light through a microscope to an interface between the slider and the magnetic disk. The light beam reflected from the slider-disk interface is used to derive the spacing between the surface of the disk and the multiple points on the slider so that the spatial position of the slider can be determined. The number of measured points on the slider is at least equal to the number of degrees of freedom of the slider so that the spatial position of the slider can be fully determined.

Abstract: This invention relates to a method and apparatus for deflashing integrated circuit (IC) packages by laser irradiation. The method and apparatus include two lasers scanning flash area for performing deflashing operation. CO2 laser is used to remove top layer of flash and YAG laser is used to remove the thin layer of flash remained after CO2 laser deflashing. CO2 laser deflashing and following YAG laser deflashing can effectively remove flash and avoid damage of heat sinks as well as leads and bars in the IC packages.

Abstract: A method of patterning a substrate includes forming a liquid film on the substrate surface and directing laser energy from a laser through the film to etch the substrate surface. Etched material is carried away from the substrate surface via evaporation of the film during the etching. The liquid film may be formed on the substrate surface by jetting a liquid vapor onto the substrate.

Abstract: This invention relates to a method and apparatus for removing surface contamination on a flexible circuit 34 for an inkjet printer cartridge by pulsed laser irradiation in air. The contamination 3 around and inside the tiny inkjet nozzles 4 can be completely removed without any damage on the flexible circuit 34 by the laser irradiation. The cleaning mechanisms are laser-induced ablation of the contamination and fast momentum transferring from the laser beam to the contamination materials. Compared with chemical solution cleaning and plasma etching, this technique has high throughput and does not cause flexible circuit damage, due to the fact that there are no water and chemical solutions involved in the process. Meanwhile, the laser irradiation is only limited in a small area around the tiny inkjet nozzles 4. There is no laser interaction with the thin conductive circuit 34.

Abstract: A method of producing a thin film magnetic device comprising forming a thin film of magnetic material over a surface of a substrate having a controlled surface topography, wherein the surface of the substrate is first subject to isotropic etching so as to increase the capacity of the substrate surface to induce a high orientation ratio in a thin film of magnetic material formed over the substrate surface without a reduction in the smoothness of the substrate; and a method of modifying a thin film magnetic device comprising a thin film of a magnetic material, the method comprising the step of subjecting a surface of the thin film magnetic device having a controlled surface topology to isotropic etching so as to increase the orientation ratio of the thin film magnetic device without reducing the smoothness of the surface of the thin film magnetic device.

Abstract: A method of laser marking, suitable for the marking of hard transparent materials without causing microcracking, includes arranging a sample of target material and a sample of markable material such that they are spaced apart; directing irradiation having an energy fluence above the ablation threshold of the target material onto the target material so that some of it is ablated and thrown onto a surface of the markable material; and subjecting the surface of the markable material to irradiation having an energy fluence below the ablation threshold of the markable material to induce an interaction between the ablated material and the surface which marks the surface of the ablated material. Different colours of mark can be obtained by using different target materials, and the tone of the mark can be controlled as desired. Apparatus for implementing the method permits control of the method in real time.

Abstract: This invention relates to a method and apparatus for cleaning solid surfaces like Si substrate, disk or magnetic head slider where contaminants, including organic contaminants, especially particles in the micron or sub-micron scale are effectively remove from the solid surfaces. The invention achieves this by generating a strong laser-induced liquid jet and shock wave near the solid surfaces immersed in liquid. The liquid is a solution of water and other solvents to help reduce adhesion force and enhance cleaning efficiency.

Abstract: A configuration for laminated antiferromagnetically coupled magnetic recording layers for a magnetic recording medium is described. For this purpose, a stabilization layer (top layer) is put on top of the main magnetic recording layer (middle layer) and another stabilization layer (bottom layer) is put under the main magnetic recording layer. The top layer, middle layer and bottom layer are antiferromagnetically coupled. This configuration can double the antiferromagnetic coupling on the recording layer and thus increase the thermal stability. This configuration can also further reduce the remnant magnetization thickness product (Mr&dgr;), which is critical for low noise media. A traditional or new intermediate layer, underlayer and seedlayer can be used under magnetic layers of the present invention. Further, a tradition or new overcoat and lubricant can be used over the magnetic layers of the present invention.

Abstract: This invention relates to a method and apparatus for cleaning solid surfaces like Si substrate, disk or magnetic head slider where contaminants, including organic contaminants, especially particles in the micron or sub-micron scale are effectively remove from the solid surfaces. The invention achieves this by generating a strong laser-induced liquid jet and shock wave near the solid surfaces immersed in liquid. The liquid is a solution of water and other solvents to help reduce adhesion force and enhance cleaning efficiency.

Abstract: The invention relates to a method and apparatus for cutting a substrate using laser irradiation. A laser beam is scanned over a substrate. The beam ablates a first layer of the substrate. The beam is then refocused onto the newly revealed second layer and a further pass is performed. The process is repeated until complete separation occurs. The method and apparatus are particularly suitable for singulation of IC packages.

Abstract: An oblique sputtering deposition apparatus is provided for preparing a thin film. A collimator having angled passages for filtering out particles from stray directions is placed between the substrate and the incident particle flux. The angle of the passages can be adjusted from about 0 to about 90° with respect to the substrate normal according to requirements. The oblique incidence of particle flux brings forms a column structure which is also angled.

Abstract: A method of fabricating a high-density magnetic data-storage medium, the method comprising the steps of: (a) forming a plurality of nanodots of non-magnetic material in a regular array on a surface of a substrate, said array being notionally dividable into a plurality of clusters that each comprise a plurality of nanodots, wherein each nanodot of a said cluster overlaps with neighbouring nanodots of that cluster to form a well between them; (b) depositing magnetic material onto said substrate to at least partly fill the wells of each cluster; and (c) removing material to reveal a regular array of wells filled with magnetic material, each of said wells being separated from neighbouring wells by non-magnetic material.

Abstract: A high precision spindle suitable for hard disk drives, optical disk drives, such as DVDs, CD drives, and other applications includes a hub, a hybrid hydrodynamic an aerodynamic bearing system, a brushless motor, a starting/stopping assistant device and a base. The hybrid fluid film bearing system ensures that the spindle works at high precision, low acoustic noise and low power consumption. The starting/stopping assistant device lifts the rotating portion of the spindle and its load by means of magnetic force, hence, reduces the friction between the contacted surfaces of thrust air bearing. It reduces the starting/stopping time and lessens the wear of bearing, therefore, effectively suppresses the contamination caused by wear particles. Magnetic seals are also provide to prevent journal bearing fluid from leaking.

Abstract: Precoders and their corresponding logic schemes, together with a method of using the precoders and their schemes to generate a media code sequence of symbols for data storage channels, with partial response equalization and a multilevel encoding/modulation scheme. Partial responses are defined by the classical and modified target polynomials, while the multilevel encoding/modulation schemes include: 1) Structured Set Partitions (SSP), 2) a set of conventional block codes with different error correcting capabilities, and 3) a variety of iterative decoding such as the List Trellis Decoder (LTD), the BCJR algorithm, and soft decoding of low-density parity check codes. The precoders are derived from the SSP's, and combined with conventional ECC encoders designed for error detection, or error correction, or both.

Abstract: A method of producing a magnetic recording medium comprising the steps of providing a substrate having a layer of a non-magnetic material that can be converted into a magnetic state by annealing, and then converting selected portions of the non-magnetic layer to a magnetic state by subjecting them to annealing by directing a focussed beam of radiation onto the substrate to form a patterned magnetic layer comprising an ordered array of magnetic regions separated by non-magnetic regions.

Abstract: The invention provides an apparatus (10) and method for monitoring the load/unload process of a head-gimbal assembly (HGA) (14), disk (12) and ramp (16) combination. A ramp strain arm (18) is used to monitor the entire load/unload process. The ramp strain arm (18), on which the ramp (16) is mounted, includes force sensors (46,48) that measure the friction force between the HGA (14) and ramp (16) as well as the air-bearing force on the slider (30) of the HGA (14) during the load/unload process. The signals form the force sensors (46,48) are input to a computer (22) through an interface circuit (24) for recording and analysis in order to evaluate the performance of the combination of the HGA (14), disk (12) and ramp (16).