Patent application number | Description | Published |
20080273265 | Determining smear of a hard disk drive slider - A disk drive head slider for a magnetic disk drive is provided. The head slider includes a tunnel magnetic resistance device for reading data on a magnetic disk and a dedicated sensor for measuring resistance wherein the resistance corresponds to a level of smear associated with the head slider. | 11-06-2008 |
20090086380 | MAGNETIC RECORDING HEAD HAVING AN EXTENDED STRIPE HEIGHT AND A SHORTENED SHIELD HEIGHT - Magnetic recording heads and associated methods of fabrication are disclosed. A magnetic recording head has a first shield and a magnetoresistance (MR) read element formed on the first shield. The first shield has a shield height that is defined by a distance between the air bearing surface (ABS) of the recording head and a back edge of the first shield that is opposite the ABS. The MR read element has a stripe height that is defined by a distance between the air bearing surface (ABS) of the recording head and a back edge of the MR read element that is opposite the ABS. The magnetic recording heads as disclosed herein have a stripe height that is greater than the shield height. | 04-02-2009 |
20090167333 | Wafer level testing - A wafer comprises a kerf region and a test chip. The kerf is a region in a wafer designated to be destroyed by chip dicing. The test chip is located within the kerf region and is configured to provide parametric data for a wafer fabrication process of a head. The test chip comprises a shield portion of a first shield layer electrically coupled to an element, a first pad within a second shield layer electrically coupled to the element, and a second pad within the second shield layer electrically coupled to the shield portion. | 07-02-2009 |
20090168213 | VERIFICATION OF A GROUND CONNECTION FABRICATION PROCESS FOR ESD RESISTORS IN MAGNETIC HEADS - Test methods and components are disclosed for testing the quality of the ground connection fabrication process for ESD shunt resistors in magnetic heads. A wafer is populated with one or more test components along with magnetic heads. The test components are fabricated with ESD shunt resistor ground connections created by the same or similar process used to fabricate the ESD shunt resistor ground connections in magnetic heads on the wafer. The resistance of the test component ground connections may then be measured in order to determine the quality of the ground connections formed by the fabrication process. The quality of the ground connection fabrication process may then be determined based on the measured resistance of the test components. | 07-02-2009 |
20090168214 | VERIFICATION OF A FABRICATION PROCESS USED TO FORM READ ELEMENTS IN MAGNETIC HEADS - Test methods and components are disclosed for testing the quality of a fabrication process used to form read elements in magnetic heads. A wafer is populated with one or more test components along with magnetic heads. The test components are formed by the same or similar fabrication processes as the read elements, but do not include a conductive MR sensor between the test leads. By measuring the resistance of the test components, the formation of parasitic shunts can be identified in the test components, which may indicate the formation of parasitic shunts in the read elements. Thus, the quality of the fabrication process in forming read elements in magnetic head may be determined. | 07-02-2009 |
20090168215 | TEST COMPONENTS FABRICATED WITH LARGE AREA SENSORS USED FOR DETERMINING THE RESISTANCE OF AN MR SENSOR - Test methods and components are disclosed for testing resistances of magnetoresistance (MR) sensors in read elements. Test components are fabricated on a wafer with a first test lead, a test MR sensor, and a second test lead. The test leads and test MR sensor are fabricated with similar processes as first shields, MR sensors, and second shields of read elements on tie wafer. However, the test MR sensor is fabricated with an area that is larger than areas of the MR sensors in the read elements. The larger area of the test MR sensor causes the resistance of the test MR sensor to be insignificant compared to the lead resistance. Thus, a resistance measurement of the test component represents the lead resistance of a read element. An accurate resistance measurement of an MR sensor in a read element may then be determined by subtracting the lead resistance. | 07-02-2009 |
20090168216 | TEST COMPONENTS FABRICATED WITH PSEUDO SENSORS USED FOR DETERMINING THE RESISTANCE OF AN MR SENSOR - Test methods and components are disclosed for testing resistances of magnetoresistance (MR) sensors in read elements. Test components are fabricated on a wafer with a first test lead, a pseudo sensor, and a second test lead. The test leads and MR sensor are fabricated with similar processes as first shields, MR sensors, and second shields of read elements on the wafer. However, the pseudo sensor in the test component is fabricated with lead material (or another material having similar resistance properties) instead of an MR thin-film structure like an MR sensor. Forming the pseudo sensor from lead material causes the resistance of the pseudo sensor to be insignificant compared to the lead resistance. Thus, a resistance measurement of the test component represents the lead resistance of a read element. An accurate resistance measurement of an MR sensor in a read element may then be determined by subtracting the lead resistance. | 07-02-2009 |
20090168217 | Test-device system for independent characterization of sensor-width and sensor-stripe-height definition processses - A test-device system and method for deconvoluting measurements of effects of a sensor-width definition process from measurements of effects of a sensor-stripe-height-definition process in a manufacture of a magnetic sensor. The test-device system comprises a first test device for generating data to characterize a sensor-width-definition process. The test-device system also comprises a second test device for generating data to characterize a sensor-stripe-height-definition process. The test-device system allows independent characterization of a sensor-width parameter and a sensor-stripe-height parameter. | 07-02-2009 |
20090168254 | Test device and method for measurement of tunneling magnetoresistance properties of a manufacturable wafer by the current-in-plane-tunneling technique - A combined manufacturable wafer and test device for measuring a tunneling-magnetoresistance property of a tunneling-magnetoresistance, sensor-layer structure. The combined manufacturable wafer and test device comprises a tunneling-magnetoresistance, sensor-layer structure disposed on a substrate. The combined manufacturable wafer and test device also comprises a plurality of partially fabricated tunneling-magnetoresistance sensors; at least one of the partially fabricated tunneling-magnetoresistance sensors is disposed at one of a plurality of first locations. The test device is disposed on the substrate at a second location different from the plurality of first locations. The test device allows measurement of the tunneling-magnetoresistance property of the tunneling-magnetoresistance, sensor-layer structure using a current-in-plane-tunneling technique. | 07-02-2009 |
20090168268 | Dedicated noncorrosive smear detector - A disk drive head slider for a magnetic disk drive is provided. The head slider includes a tunnel magnetic resistance device for reading data on a magnetic disk and a dedicated noncorrosive smear detector for measuring resistance wherein the resistance corresponds to a level of smear associated with the head slider. | 07-02-2009 |
20110261487 | MATERIAL FOR USE IN A TMR READ GAP WITHOUT ADVERSELY AFFECTING THE TMR EFFECT - Structures and methods for fabrication servo and data heads of tape modules are provided. The servo head may have two shield layers spaced apart by a plurality of gap layers and a sensor. Similarly, the data head may have two shield layers spaced apart by a plurality of gap layers and a sensor. The distance between the shield layers of the servo head may be greater than the distance between the shield layers of the data head. The material of the gap layers may include tantalum or an alloy of nickel and chromium. The material for the gap layers permits deposition of gap layers with sufficiently small surface roughness to prevent distortion of the tape module and increase the stability of the tape module operation. | 10-27-2011 |
20120105999 | INTEGRATED TOUCH-DOWN PAD AND TOUCH-DOWN SENSOR - In one general embodiment, a magnetic head includes a touch-down pad, comprising at least one shielding element positioned between a leading edge of a main magnetic pole and a trailing edge of a lower return pole; an embedded contact sensor (ECS) in an electrically isolating layer, the ECS positioned near an ABS side of the magnetic head and between the leading edge of the main magnetic pole and the trailing edge of the lower return pole; and a first thermal fly-height control (TFC) element positioned away from the ABS side of the magnetic head. Additional systems and methods are also presented. | 05-03-2012 |
20120152891 | METHOD FOR MANUFACTURING A MAGNETIC TAPE HEAD USING A TMR SENSOR - A method for manufacturing a magnetic tape head having a data sensor and a servo sensor. The data sensor and servo sensor are each separated from first and second magnetic shields by a non-magnetic gap layer, and the gap thickness for the servo sensor is larger than the gap thickness for the data sensor. The method involves depositing a first gap layer over shield structures, then depositing a second gap layer using a liftoff process to remove the second gap layer over the data sensor region. A plurality of sensor layers are then deposited, and a stripe height defining mask structure is formed over the data and servo sensor regions, the mask having a back edge that is configured to define a stripe height of the data and servo sensors. An ion milling is then performed to define the stripe height and to remove gap material from the field. | 06-21-2012 |
20130083430 | MULTIPLE-SENSE THERMO-RESISTIVE SENSOR FOR CONTACT DETECTION OF READ-WRITE HEADS - Techniques of the present invention include detecting a touchdown between a read/write head of a disk drive and a surface of a magnetic disk using multiple touchdown sensors located at an air-bearing surface (ABS). The multiple sensors increase the likelihood that a touchdown event—i.e., a portion of the ABS of the head contacting the underlying magnetic disk surface—will be detected. During touchdown, the portion of the head contacting the magnetic disk generates frictional heat which changes a characteristic (e.g., the electrical resistance) of at least one of the sensors located at the ABS. When the sensors are connected to a detection circuit, the changing characteristic may be monitored to identify a touchdown event. The touchdown sensors may be, for example, electrically connected in either series or parallel to the detection circuit. Thus, as long as the electrical resistance of one of the sensors is changed, a touchdown event may be detected. | 04-04-2013 |
20130163121 | MAGNETIC SENSOR HAVING HARD BIAS STRUCTURE FOR OPTIMIZED HARD BIAS FIELD AND HARD BIAS COERCIVITY - A magnetic read sensor having a hard bias structure that extends beyond the back edge of the sensor stack by a controlled, distance that is chosen to maximize both hard bias field and hard bias magnetic coercivity and anisotropy. The hard bias structure has a back edge that is well defined and that has a square corner at its innermost end adjacent to the sensor stack. The magnetic sensor can be constructed by a process that includes a separate making an milling process that is dedicated to defining the back edge of the hard bias structure. | 06-27-2013 |
20140153138 | SCISSOR MAGNETIC READ HEAD WITH WRAP-AROUND MAGNETIC SHIELD - A magnetic scissor type magnetic read head having magnetic side shielding for reduced effective track width and having side biasing for improved stability. The read head includes first and magnetic side shields that each include first and second magnetic layers and an anti-parallel exchange coupling layer sandwiched there-between. The magnetic layers of the side shields are anti-parallel coupled with one another such that one of the magnetic layers has its magnetization oriented in a first direction parallel with the air bearing surface and the second magnetic layer has its magnetization oriented in a second direction that is opposite to the first direction and also parallel with the air bearing surface. These magnetizations of the first and second magnetic layers provide a bias field that stabilizes the magnetization of the free magnetic layers of the sensor stack to prevent flipping of the magnetizations of these layers. | 06-05-2014 |
20140154951 | COMMON GROUND FOR ELECTRONIC LAPPING GUIDES - Embodiments described herein generally relate to connecting Electronic Lapping Guides (ELG) to a lapping controller such that the number of wire bonds from the controller to a row of read heads is minimized. When lapping the air bearing surface of the read heads, the electrical resistances of the ELGs are monitored to adjust the lapping process and set the stripe height for read sensors in the read heads. Once the resistance corresponds to the desired stripe height, the lapping process is stopped. To measure the resistance, each ELG may be electrically coupled to the same substrate—i.e., share the same common ground. The lapping controller applies a voltage potential across the ELGs using a wire bonded to a pad in the respective read head and one or more connections to the grounded substrate. This configuration avoids having to bond two wires onto each read head. | 06-05-2014 |
20140154952 | WAFER GROUNDING DESIGN FOR SINGLE PAD LAPPING - Embodiments described herein generally relate to connecting Electronic Lapping Guides (ELG) to a lapping controller to reduce resistance from current crowding while reducing connections to the ELG. A device and a system can include a wafer with peripheral grounding vias having a radius of at least 10 μm, a plurality of sliders with a magnetoresistive (MR) elements; a plurality of ELG electrically coupled to the lapping controller through a combination of the wafer and grounding pads and a bonding pad electrically coupled to the ELG. The ELG or the bonding pad can be positioned in the kerf or the device region of a row. If the ELG and the bonding pad are positioned in separate regions, a noble metal should be used to connect. Further, the number of grounding pads can be reduced by using grounding vias at specific intervals and specific sizes. | 06-05-2014 |
20140154953 | CORRECTING CURRENT CROWDING IN ROW BAR AND VIAS FOR SINGLE PAD BONDING - Embodiments described herein generally relate to connecting electronic lapping guides (ELGs) to a lapping controller to prevent the effects of current crowding while reducing connections to the ELGs in single pad lapping. Devices and systems can include a row of sliders including a magnetoresistive (MR) element, a plurality of high resistance ELGs connected to both the wafer and to at least one bonding pad and at least two peripheral grounding vias connected to the wafer. Methods and systems include a wafer comprising a plurality of sliders wherein each slider is connected to a lapping controller and the delivery of current to the ELGs is sequential to groups of sliders such that only one group of ELGs is being measured at any time. | 06-05-2014 |
20140175048 | ELECTRICAL LAPPING GUIDE FOR MANUFACTURE OF A SCISSOR STYLE MAGNETIC SENSOR - A method of manufacturing a magnetic sensor having a hard bias structure located at a back edge of the sensor. The method forms an electrical lapping guide that is compatible for use with such a sensor having a back edge hard bias structure and which can accurately determine a termination point for a lapping operation that forms an air bearing surface of the slider and determines the sensor stripe height. | 06-26-2014 |
20140342085 | MATERIAL FOR USE IN A TMR READ GAP WITHOUT ADVERSELY AFFECTING THE TMR EFFECT - Structures and methods for fabrication servo and data heads of tape modules are provided. The servo head may have two shield layers spaced apart by a plurality of gap layers and a sensor. Similarly, the data head may have two shield layers spaced apart by a plurality of gap layers and a sensor. The distance between the shield layers of the servo head may be greater than the distance between the shield layers of the data head. The material of the gap layers may include tantalum or an alloy of nickel and chromium. The material for the gap layers permits deposition of gap layers with sufficiently small surface roughness to prevent distortion of the tape module and increase the stability of the tape module operation. | 11-20-2014 |