Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
  • G01R33/00—Arrangements or instruments for measuring magnetic variables
  • G01R33/02—Measuring direction or magnitude of magnetic fields or magnetic flux
  • G01R33/06—Measuring direction or magnitude of magnetic fields or magnetic flux using galvano-magnetic devices
  • G01R33/07—Hall effect devices
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
  • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
  • G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
  • G01D5/14—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage
  • G01D5/142—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage using Hall-effect devices
  • G01D5/145—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage using Hall-effect devices influenced by the relative movement between the Hall device and magnetic fields
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
  • G01R33/00—Arrangements or instruments for measuring magnetic variables
  • G01R33/0005—Geometrical arrangement of magnetic sensor elements; Apparatus combining different magnetic sensor types
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
  • G01R33/00—Arrangements or instruments for measuring magnetic variables
  • G01R33/0052—Manufacturing aspects; Manufacturing of single devices, i.e. of semiconductor magnetic sensor chips
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
  • G01R33/00—Arrangements or instruments for measuring magnetic variables
  • G01R33/02—Measuring direction or magnitude of magnetic fields or magnetic flux
  • G01R33/0206—Three-component magnetometers
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N52/00—Hall-effect devices
  • H10N52/01—Manufacture or treatment
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N52/00—Hall-effect devices
  • H10N52/101—Semiconductor Hall-effect devices
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N52/00—Hall-effect devices
  • H10N52/80—Constructional details
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N52/00—Hall-effect devices
  • H10N52/80—Constructional details
  • H10N52/85—Materials of the active region

Definitions

• the present invention relates to a method for
• Hall sensors are known as sensors to measure the strength of a magnetic field by measuring a voltage.
• a Hall sensor can also sense DC magnetic fields since the voltage output of a Hall sensor under current is proportional to the current and the strength of the magnetic field.
• Three-Dimensional Magnetic Field Sensors are disclosed in the British Patent Application GB 2 159 278 A. Hall sensors are used in a broad variety of scientific and commercial applications, such as in position sensing, in proton therapy, in NMR, in synchrotron and other particle accelerators or electromagnetic beam lines and magnets and so on.
• a Hall sensor assembly comprising a number of Hall sensors, each Hall sensor being disposed on a non-conducting, non-magnetic support part, wherein the support parts are formed to support the formation of three groups of Hall sensors, each group covering the measurement of the magnetic field for one of the three Cartesian directions wherein the three groups of Hall sensors, and in particular their Hall sensor active areas, are disposed adjacent to each other in order to share a common Hall sensor active volume that is smaller than or equal to 200 ym x 200 ym x 200 ym.
• step a) to e) in order to form three groups of Hall sensors, each group covering the measurement of the magnetic field for one of the three Cartesian directions wherein the three groups of Hall sensors are disposed
• the present invention provides for a Hall sensor assembly as a miniature Hall effect 3D magnetic field sensor because the Hall sensor active areas are all
• each of the three groups of sensors is dedicated to determine one component of the magnetic field vector. Due to the small design of Hall sensor active areas in the range of micrometers (i.e. less than 50 ym) , each group which can comprise one or more Hall sensor active areas is disposed in a tiny volume of less than or equal to 200 ym x 200 ym x 200 ym. This effectively means that all Hall sensor active areas yield, through averaging, the full magnetic field vector in a single point in space and time.
• the miniaturization of the Hall sensor active volume that is achieved with the present invention plays the key role in the improvement of the accuracy of 3D Hall sensors.
• the miniature spacing between adjacent Hall sensor active areas reduces significantly errors stemming from averaging the sensors output values in measurements of magnetic fields with a non-linear
• the support parts are formed as truncated pyramids wherein each Hall sensor is disposed on the peak of a pyramidal support part.
• This design allow to concentrate diverse Hall sensor active areas directly adjacent to each other wherein the support part may have a design to offer a reference surface when positioning the Hall sensor assembly for
• the pyramidal support parts represent a cube when assembled.
• Said pyramidal support then comprise a square ground area and angle of 45° and 90° in the peak of the pyramid.
• the Hall sensor active area as well as the sensor substrate can be made from a semiconductor material, preferably GaAs, and the four contact lines are made from a highly conducting material, preferably from gold.
• a preferred choice may provide for support parts that are made from a non-conducting and non-magnetic material, preferably from crystal (i.e. sapphire) or a ceramics or from a composite material.
• the surfaces of the support parts are at least partially coated with a conductive layer; said conductive layer being separated into four sections; each section being connected to one of the four contact lines.
• the support parts are at least partially coated with gold.
• the conductive layer is coated with an insulating layer prior to the assembling of the support parts in order to separate the contact lines from one Hall sensor to the other. This insulating layer may be rendered obsolete by spacing the support parts when
• the isolation among the different conductive layer is then achieved either just by the air gap or an additional insulation material filling the gaps.
• the calibration has to be performed properly.
• at least one of the support parts comprises a reference surface enabling the positioning of the Hall sensor assembly for a rotation during calibration of the Hall sensor assembly.
• a preferred design of the Hall sensor assembly provides for the support parts to be formed as truncated pyramids wherein the Hall sensor active areas are disposed with its sensor substrate on the upper surface of the truncated pyramids.
• the Hall sensor active areas are disposed with its sensor substrate on the upper surface of the truncated pyramids.
• six pyramids having a square ground area are assembled to form a cube wherein the Hall sensor active areas are all located in the spatial center of the cube.
• the support parts are formed as cuboids and the Hall sensors are comprised on a substrate; said substrate being mounted to one surface of the cuboidic support part wherein the Hall sensor active area is located at one corner of the substrate.
• the complete Hall sensor assembly then comprises for example six cuboidic support parts together with the substrates mounted to one surface of the cuboidic support parts which in the assembled form represent in general a cube when assembled with in the center a miniature common Hall sensor active volume.
• a tiny inner cube volume (of less than or equal to 200 ⁇ x 200 ym x 200 ym) comprising the active areas of orthogonally oriented Hall sensors is realized by designing the Hall sensor active area to be at the corner of each of the substrates and by the special assembly of the cuboidic support parts together with the Hall sensors mounted to one surface of each of the cuboidic support parts.
• Figure 1 a Hall sensor comprising a Hall sensor active area and a substrate
• Figure 2 the Hall sensor mounted onto a truncated support pyramid
• Figure 3 the Hall sensor on the truncated support pyramid with Ohmic contacts
• Figure 4 the assembly of six pyramids to form a miniature internal cube, said internal cube being the central Hall sensor active volume, comprised of six Hall sensor active areas, two for each component of the magnetic field vector;
• Figure 5 the assembly of three cuboidic support parts with an alignment of three Hall sensors in a central Hall sensor active volume;
• Figure 6 the assembly of Figure 5 comprising three pairs of
• Hall sensors being disposed on six cuboidic support parts
• Figure 7 an enlarged view on the Hall sensor active volume in Figure 5.
• FIG. 4 one preferred example of the present invention is presented: a design of a Hall sensor assembly cube 2 of a few mm in size, made in such a way to form in the spatial centre 4 of the cube an inner cube of sub-millimeter dimension with a Hall sensor active area on each of its surfaces.
• a semiconductor Hall sensor active area 6 has four electrical connections 8 to 14, two connections for the driving current (AC or DC) and two connections for the output voltage signal.
• the Hall sensor active area 6 and the electrical connections 8 to 14 build a Hall element disposed on a semiconductor sensor substrate 16.
• the Hall sensor active area 6 is epitaxially grown on the sensor substrate 16.
• the semiconductor sensor substrate 16 is in the present example mounted to a truncated pyramid support part 18 made from a crystal or a ceramic or a composite material, as presented in Figure 2.
• FIG. 3 the situation is shown after the removal of excess material from the sensor.
• the contact lines 8 to 14 are each connected with conductive layers 20 to 26 deposited on parts of the surfaces of the pyramid support part 18.
• the conductive layers 20 to 26 may be coated with an insulator layer in order to separate each contact line 8 to 14 and its respective conductive layer 20 to 26 from those of another support pyramid.
• the supports parts 18 are being spaced relatively to each other when assembled by connection elements 19a, 19b that are formed in the lower part 21 of the truncated pyramid support part 18. Due to the relative spacing, an insulation of the conductive layers 20 to 26 is resulting by air gap. Alternatively, an insulation material can be filled into the air gap.
• each conductive layer 20 to 26 shall represent the connection to a control electronics (not shown) which usually resides apart from the truncated pyramid support part 18.
• a control electronics not shown
• the geometry of the cube 2 is presently obtained by a precise assembly of six truncated pyramids 18.
• the miniature size and the geometrical precision of the epitaxially grown semiconductor Hall sensors active areas 6 are superior to the classical approach of gluing commercially available Hall sensors.
• the large benefit is the possibility of achieving a small distance ( ⁇ 200 ⁇ ) between two opposite (perpendicular) _Hall sensor active areas 6 within the Hall sensor active volume thus considerably reducing the errors stemming from averaging the measured values from two perpendicular Hall sensors in magnetic fields with a nonlinear distribution, like in sextupoles and higher multipole magnets or in fringe fields.
• Each of the three pairs of Hall elements from opposite internal cube surfaces is dedicated to determine one component of the magnetic field vector.
• the Hall sensor active volume 4 in the center of the cube 2 with six Hall sensors has a size of less than 200 ⁇ x 200 ⁇ x 200 ⁇ .
• the flat square ground area 28 of each pyramid 18 serves as a reference surface in order to precisely position the Hall sensor assembly cube 2 during measurements and during calibration of the Hall sensor assembly cube 2.
• the Hall sensor assembly may comprise a holder member, such as a glass cube, that comprises a number of bore holes, such as conical bore holes each tapering versus the center of the holder member.
• the support parts themselves will also have a conical shape accordingly with the Hall sensor active area and the Hall sensor substrate being located at the tip of the conical support part.
• Figure 5 shows one half of a substantially cubic structure ( Figure 6) comprising three Hall sensors 34, 36, 38 which are each mounted on an
• Each Hall sensor active area 32 is contacted by four contact lines 8 to 14.
• the support parts 40, 42, 44 are formed as cuboids and the Hall sensor active areas 32 are comprised on the substrates 34, 36, 38; said substrates 34, 36, 38 are each mounted to one surface of the cuboidic support parts 40, 42, 44 wherein the Hall sensor active areas 32 are located at one corner of the substrate 34, 36 and 38.
• the three Hall sensor active areas 32 are disposed centrally within a Hall sensor active volume of less than or equal to 200 ⁇ x 200 ⁇ x 200 ⁇ .
• Figure 6 shows an assembly of Figure 5 and its mirror image which leads to a substantially cubic with a miniature internal cube; said internal cube being the central Hall sensor active volume, comprised of six Hall sensor active areas, two for each component of the magnetic field vector.
• a tiny inner cube volume (of less than or equal to 200 ⁇ x 200 ym x 200 ym) comprising the active areas of orthogonally oriented Hall sensors is realized by designing the Hall sensor active area to be at the corner of each of the
• Figure 7 illustrates the alignement of the Hall sensor active areas for three Hall sensors 32 (one half of the substantially cubic) .
• the present invention provides for a Hall sensor assembly as a miniature Hall effect 3D magnetic field sensor because the Hall sensor active areas are all
• Hall sensor active volume wherein each of the three groups of Hall sensors is dedicated to determine one component of the magnetic field vector. Due to the small design of Hall sensor active areas in the range of
• each group which can comprise one or more Hall sensor active areas is disposed in a tiny volume of less than or equal to 200 ⁇ x 200 ym x 200 ym. This effectively means that all Hall sensor active areas yield, through averaging, the full magnetic field vector in a single point in space and time.
• the miniaturization of the Hall sensor active volume that is achieved with the present invention plays the key role in the improvement of the accuracy of 3D Hall sensors.
• the miniature spacing between adjacent Hall sensor active areas reduces significantly errors stemming from averaging the sensors output values in measurements of magnetic fields with a non-linear

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Condensed Matter Physics & Semiconductors (AREA)
• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Hall/Mr Elements (AREA)
• Measuring Magnetic Variables (AREA)
• Transmission And Conversion Of Sensor Element Output (AREA)

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• 2013
  • 2013-12-06 EP EP13810913.7A patent/EP2948730B1/en not_active Not-in-force
  • 2013-12-06 US US14/763,296 patent/US9915708B2/en active Active
  • 2013-12-06 WO PCT/EP2013/075827 patent/WO2014114401A1/en active Application Filing

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