| Infinitum Solutions, Inc. Patent applications |
| Patent application number | Title | Published |
|---|
| 20120092972 | MAGNETO-OPTIC WRITE-HEAD CHARACTERIZATION USING THE RECORDING MEDIUM AS A TRANSDUCER LAYER - A magneto-optical transducer including a magnetic layer on a transparent, non-magnetic substrate is used to characterize the performance of a write head based on optically detected magnetization in the magnetic layer. The write head sample is held in contact with or near the magnetic layer, which is illuminated through the substrate with linearly polarized light. Magnetization in the write head produces a magnetization in the magnetic layer, which alters the polarization state in reflected light. The reflected light is analyzed and the intensity detected using an optical detector, such as one or more photo-detectors or a camera. The performance of the write head can then be characterized using the detected intensity. | 04-19-2012 |
| 20120057446 | SUB-OPTICAL-RESOLUTION KERR SIGNAL DETECTION FOR PERPENDICULAR WRITE-HEAD CHARACTERIZATION - A property, such as a quality parameter, of a write pole in a write head is determined using an optical metrology device, where the write pole is smaller than the optical resolution limit of the metrology device. The metrology device produces polarized light that is reflected off the write pole while the write pole is magnetized either during or after excitation with a write current. The magnetization alters the polarization state of the light, which can be analyzed to transform the altered polarization state into intensity. The intensity of the light is detected over the point spread function of the optics in the metrology device and an intensity value is generated. The intensity value is used to determine the quality parameter of the write pole, e.g., by comparison to a threshold or reference intensity value, which may be generated empirically or theoretically. | 03-08-2012 |
| 20120056619 | WRITE HEAD TESTER USING INDUCTANCE - A write head is tested by measuring the effect that magnetic fields have on the inductance of the write head. For example, a perpendicular write head may be placed in a magnetic field with a first angle, e.g., non-parallel and non-perpendicular, to the air bearing surface and the inductance is measured. After altering the angle of the magnetic field the inductance is again tested. In another embodiment, the angles may be parallel and perpendicular to the air bearing surface. The difference in the inductance value can be used to determine a characteristic of the write head, such as the presence of a recording pole. In some embodiments, the inductance may be measured while applying a bias current to the write head while the write head is in an external magnetic field. | 03-08-2012 |
| 20120056618 | WRITE HEAD TESTER USING INDUCTANCE - A write head is tested by measuring the effect that magnetic fields have on the inductance of the write head. For example, a perpendicular write head may be placed in a magnetic field with a first angle, e.g., non-parallel and non-perpendicular, to the air bearing surface and the inductance is measured. After altering the angle of the magnetic field the inductance is again tested. In another embodiment, the angles may be parallel and perpendicular to the air bearing surface. The difference in the inductance value can be used to determine a characteristic of the write head, such as the presence of a recording pole. In some embodiments, the inductance may be measured while applying a bias current to the write head while the write head is in an external magnetic field. | 03-08-2012 |
| 20110095766 | TESTING FLEX AND APFA ASSEMBLIES FOR HARD DISK DRIVES - A tester for a testing a Hard Disk Drive (HDD) flex circuit prior to electrical installation of a Head Gimbal Assembly (HGA) includes a shorting block that makes electrical contact to the bondpads on the sample. The shorting block includes one or more electrical contacts that are electrically grounded and have a size and/or configuration to contact the bondpads as well as the surface of the sample around the bondpads to accommodate positioning tolerances of the sample under test, without need for optics, precise probes, or precision stages. The electrical contacts of the shorting block may be, e.g., a matrix of pogopins or a flexible electrically-conductive material. During testing, the bondpads are shorted together and to ground with the shorting block while it is determined whether Short failures are properly detected. While the shorting block is not engaged with the bondpads, it is determined whether open failures are properly detected. | 04-28-2011 |
| 20100170017 | Magneto-Optical Detection of a Field Produced by a Sub-Resolution Magnetic Structure - A polarization microscope optically detects the effect of the magnetic field from a sub-optical resolution magnetic structure on a magneto-optical transducer. The magneto-optical transducer includes a magnetic layer with a magnetization that is changed by the magnetic field produced by the magnetic structure. The saturation field of the magnetic layer is sufficiently lower than the magnetic field produced by the magnetic structure that the area of magnetization change in the magnetic layer is optically resolvable by the polarization microscope. A probe may be used to provide a current to the sample to produce the magnetic field. By analyzing the optically detected magnetization, one or more characteristics of the sample may be determined. A magnetic recording storage layer may be deposited over the magnetic layer, where a magnetic field produced by the sample is written to the magnetic recording storage layer to effect the magnetization of the magnetic layer. | 07-01-2010 |
| 20100079908 | Determining A Magnetic Sample Characteristic Using A Magnetic Field From A Domain Wall - A magnetic field generator that is formed from a magnetic thin film, e.g., of ferrimagnetic garnet with a two magnetic domains with a domain wall between the two magnetic domains, is provided. A localized magnetic field is produced by the domain wall and is used as a magnetic field source for a sample held on or near the surface of the magnetic thin film. The sample response to the magnetic field is measured for one or more positions of the domain wall with respect to the sample. From the measured response, a desired parameter may be determined and stored. The position of the domain wall may be oscillated at high frequency to produce a voltage signal in the inductive sample. Alternatively, distortions in the domain wall may be imaged and used to identify or characterize structures in the sample. | 04-01-2010 |
| 20090147389 | Read sensor testing using thermal magnetic fluctuation noise spectra - A read head is tested by measuring the thermal magnetic fluctuation noise spectrum. A non-uniformity in the magnetic field of the free layer is produced and the thermal magnetic fluctuation noise spectrum is measured, with and/or without an external magnetic field applied. A peak in the thermal magnetic fluctuation noise spectrum can be used to derive the desired dimension of the free layer, such as track width and stripe height. The resulting measurement may then be fed back into the process control for the production of the read heads if desired. Additionally, the stiffness of the free layer and the strength of the reference layer may be determined using ferromagnetic resonance peaks in the thermal magnetic fluctuation noise spectrum. | 06-11-2009 |
| 20090128941 | Write Head Tester Using Inductance - A write head is tested by measuring the effect that magnetic fields have on the inductance of the write head. For example, a perpendicular write head may be placed in a magnetic field with a first angle, e.g., non-parallel and non-perpendicular, to the air bearing surface and the inductance is measured. After altering the angle of the magnetic field the inductance is again tested. In another embodiment, the angles may be parallel and perpendicular to the air bearing surface. The difference in the inductance value can be used to determine a characteristic of the write head, such as the presence of a recording pole. In some embodiments, the inductance may be measured while applying a bias current to the write head while the write head is in an external magnetic field. | 05-21-2009 |
