Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
  • G01P15/00—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration
  • G01P15/02—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses
  • G01P15/08—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values
  • G01P15/125—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values by capacitive pick-up
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
  • G01P15/00—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration
  • G01P15/02—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses
  • G01P15/08—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values
  • G01P2015/0805—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values being provided with a particular type of spring-mass-system for defining the displacement of a seismic mass due to an external acceleration
  • G01P2015/0808—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values being provided with a particular type of spring-mass-system for defining the displacement of a seismic mass due to an external acceleration for defining in-plane movement of the mass, i.e. movement of the mass in the plane of the substrate
  • G01P2015/0811—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values being provided with a particular type of spring-mass-system for defining the displacement of a seismic mass due to an external acceleration for defining in-plane movement of the mass, i.e. movement of the mass in the plane of the substrate for one single degree of freedom of movement of the mass
  • G01P2015/0814—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values being provided with a particular type of spring-mass-system for defining the displacement of a seismic mass due to an external acceleration for defining in-plane movement of the mass, i.e. movement of the mass in the plane of the substrate for one single degree of freedom of movement of the mass for translational movement of the mass, e.g. shuttle type

Definitions

• the invention is based on a micromechanical structure according to the preamble of claim 1.
• an acceleration sensor which has a substrate, a spring element and a seismic mass.
• the spring element is connected to a first end on the substrate and to a second end on the seismic mass, so that an acceleration of the acceleration sensor parallel to a surface of the substrate
• a spring stop is provided which limits a deformation of the spring element at an acceleration parallel to the surface of the substrate.
• the spring stop must be firmly connected to the substrate.
• a similar acceleration sensor is known from the publication DE 100 38 761 A1, which also has stops for limiting the deflection of the seismic mass, wherein the stops are formed here as part of the spring element.
• the micromechanical structures according to the independent claims have the advantage over the prior art that the interaction of the stop element and the counterstop element effectively limits a deflection of the seismic mass relative to the substrate, without a separate substrate connection for the stop element. is required and without the spring properties of the spring element are influenced by the stop element.
• the stop element is formed as part of the anchoring element, while the complementary counter-stop element is formed as part of the seismic mass.
• the anchoring element simultaneously serves to fasten the seismic mass, as well as to secure the stop element to the substrate in each case.
• the spring elements serve to ensure the mobility of the seismic mass relative to the substrate and also with respect to the anchoring element. The maximum deflection of the seismic mass relative to the substrate is limited by a mechanical contact between the stop element and the counter-stop element.
• the stop element and the counterstop element are in particular at the same electrical potential, so that a force effect and in particular adhesion between the stop element and the counterstop element due to electrostatic interactions is reliably excluded .
• the integration of the stop element in the anchoring element also has the advantage over the prior art that a comparatively space-compact integration of the stop element is realized, whereby in particular the manufacturing costs are reduced by the saving of wafer area. Furthermore, the
• the stop element does not require its own substrate anchoring.
• the stop element is not arranged in the region of the spring element or is not part of the spring element, since in this case, the spring properties, especially with regard to desired and undesirable vibration modes, greatly changed and thus new Spring geometries would be required.
• the design of the spring element remains uninfluenced by the stop element, so that the micromechanical structure is to be equipped with already known and proven spring geometries.
• the anchoring element does not only comprise a plane perpendicular to the substrate. indirectly connected to the substrate region, but also a connection region between this perpendicular to the substrate directly connected to the substrate region and the spring element, said connection region is formed, for example, freestanding or undercut.
• the stop element and the counterstop element are arranged opposite one another along and / or perpendicular to a sensing direction of the micromechanical structure.
• a maximum deflection of the micromechanical structure relative to the substrate along the sensing direction is thus limited.
• the sensing direction corresponds, for example, to the direction along which an acceleration is measured.
• the stop element are formed as a bulge of the anchoring element and / or the counter-stop element as a bulge of the seismic mass.
• the stop element and the counter-stop element are realized in a comparatively simple and space-compact manner.
• the stop element and / or the counter stop element on a non-stick coating, which prevents sticking of the stop and counter-stop element.
• the stop element and / or the counter-stop element is partially elastic and preferably L-shaped.
• kinetic energy of the seismic mass is thereby converted into deformation energy shortly before reaching the maximum deflection of the seismic mass, and thus the seismic mass is braked before reaching the maximum deflection.
• the anchoring element is arranged in a central region of the micromechanical structure.
• a comparatively space-compact design of the micromechanical structure is thus made possible.
• a mirror-symmetrical structure of the micromechanical structure is realized with respect to a plane of symmetry, the plane of symmetry being perpendicular to the substrate plane and parallel or perpendicular to the sensing direction, and the measurement accuracy of the micromechanical structure as a whole is increased by such a mirror-symmetric structure.
• the micromechanical structure has fixed electrodes for interaction with counterelectrodes of the seismic mass, wherein the fixed electrodes and the counterelectrodes are preferably designed as comb electrodes meshing perpendicular to the sensing direction.
• the Sensierraum runs in particular parallel to the substrate plane. As the acceleration sensor accelerates along the sensing direction, the seismic mass moves anti-parallel to the acceleration due to inertial forces relative to the substrate. This leads to a change in distance between the fixed electrodes and the counterelectrodes parallel to the sensing direction, whereby a measurable change in the electrical capacitance between the fixed electrodes and the counterelectrodes is caused, which serves as a measure of the acceleration.
• a further subject of the present invention is a micromechanical structure, in particular an acceleration sensor, comprising a substrate, a seismic mass movable relative to the substrate and at least one anchoring element firmly connected to the substrate, the seismic mass being fixed to the substrate by means of the anchoring element and between at least one spring element is arranged in the seismic mass and the anchoring element, the micromechanical structure having fixed electrodes for interacting with counterelectrodes of the seismic mass, the seismic mass having at least one further stop element and at least one further counterstop element, and wherein the further counterstop element is firmly connected to a fixed electrode is.
• the further counterstop element is thus firmly connected to the fixed electrode structure, which is fastened to the substrate in particular by means of a further anchoring element.
• the further stop element and / or the further counter stop element is preferably elastic and particularly preferably L-shaped, so that advantageously a more cautious braking of the seismic mass is achieved before reaching the maximum deflection.
• the further counter-stop element comprises a fixed electrode and / or a further anchoring element, wherein the further anchoring element is preferably provided for fastening the fixed electrodes to the substrate, so that the
• the further stop element extends substantially parallel to the fixed electrodes and the counterelectrodes and in particular along the sensing direction is arranged between at least one fixed electrode and the further anchoring element.
• the further counter-stop element is automatically formed in this case by the fixed electrodes and / or the further anchoring element, so that no further structures are required for the realization of the further counter-stop element.
• FIGS. 2a and 2b show a schematic plan view and a schematic detail view of a micromechanical structure according to a first embodiment of the present invention
• FIGS. 3a and 3b a schematic top view and a schematic detail view of a micromechanical structure according to a third embodiment of the present invention
• FIGS. 5a and 5b show a schematic top view and a schematic detail view of a micromechanical structure according to a sixth embodiment 6 a and 6 b show a schematic plan view and a schematic detail view of a micromechanical structure according to a seventh embodiment of the present invention.
• FIG. 1 shows a schematic plan view of a micromechanical structure V in the form of an acceleration sensor according to the prior art, the micromechanical structure 1 'having a substrate 2 and a seismic mass 3 connected to the substrate 2 via two anchoring elements 4.
• the seismic mass 3 is designed to be movable relative to the substrate 2 along a sensing direction 100 parallel to the substrate plane 101.
• the fixed electrodes 8 are connected to the substrate 2 via a further anchoring element 12.
• the fixed electrodes 8 and the counter electrodes 9 are formed as interdigitated comb electrodes, wherein the fingers of the comb electrodes in the sensing direction 100 overlap each other and are spaced from each other.
• the seismic mass 3 moves relative to the substrate 2 in anti-parallel to the direction of acceleration due to inertial forces. This leads to a change in distance between the fixed electrodes 8 and the counter electrodes 9 parallel to the sensing direction 100, whereby a measurable
• the micro-mechanical structure 100 comprises two stop units 20 which each comprise an additional anchoring element 20 'for anchoring to the substrate 2 and which in each case in a recess 21 the seismic mass 3 is arranged.
• the deflection of the seismic mass 3 is limited by a mechanical contact between the stop unit 20 and the edge of the seismic mass 3 in the region of the recess 21.
• the micromechanical structure 1 according to the prior art therefore needs to provide the recesses 21 an enlarged seismic mass 3 and moreover two additional anchoring elements 20 '.
• FIG. 2 a shows a schematic plan view of a micromechanical structure 1 according to a first embodiment of the present invention, which essentially corresponds to the micromechanical structure according to the prior art shown in FIG. 1, furthermore the micromechanical structure 1 according to the first embodiment of the present invention has two stop elements 6, which are each formed as part of one of the two anchoring elements 4. These stop elements 6 are formed as a bulge in the respective anchoring element 4. Each of the stop elements 6 cooperate with a complementary counter stop element 7 of the seismic mass 3, which is formed opposite the stop element 6 along the sensing direction 100, so that the deflection of the seismic mass 3 relative to the substrate 2 and parallel to the sensing direction 100 is limited.
• the counter-stop elements 7 are therefore designed as complementary bulges in the seismic mass 3.
• FIG. 1 shows a schematic plan view of a micromechanical structure 1 according to a first embodiment of the present invention, which essentially corresponds to the micromechanical structure according to the prior art shown in FIG. 1, furthermore the micromechanical structure 1 according to the first embodiment of the present invention has two stop
• FIG. 2b shows an enlarged partial view 102 of the micromechanical structure 1 depicted in FIG. 2a according to the first embodiment of the present invention.
• FIG. 2c shows a schematic detail view of a micromechanical structure 1 according to a second embodiment of the present invention, which is essentially identical to the first embodiment illustrated in FIG. 2b, wherein each of the two anchoring elements 4 has two stop elements 6, each with two complementary counter stop elements 7 of the seismic mass 3 cooperate.
• the micromechanical structure 1 in the sense of the present invention can alternatively also be realized with any other arbitrary plurality of stop and counterstop elements 6, 7.
• FIGS. 3a and 3b show a schematic top view and a schematic detail view 103 of a micromechanical structure 1 according to a third embodiment of the present invention, the third embodiment being substantially identical to the first embodiment illustrated in FIGS. 2a and 2b, wherein FIG Anchoring elements 4 next to itself with
• FIG. 3c shows a schematic detailed view 103 of a micromechanical structure 1 according to a fourth embodiment of the present invention which is essentially identical to the third embodiment illustrated in FIG. 3b, wherein only the number of stop and counter stop elements 6, 7, 6 ', T is different.
• FIG. 4 is a schematic plan view of a micromechanical structure 1 according to a fifth embodiment of the present invention, wherein the fifth embodiment is substantially identical to one of the first, second, third or fourth embodiment, wherein the micromechanical structure 1 according to the fifth embodiment, no stop units 20th in that case the maximum deflection of the seismic mass 3 relative to the substrate 2 is limited parallel and / or perpendicular to the sensing direction 100 by the plurality of cooperating abutment and counterstop elements 6, 7 6 ', T. Furthermore, no additional anchoring elements 20 'and no recesses 21 are required due to the saving of the abutment units 20, so that the micromechanical structure 1 is designed to be significantly less bulky overall without a change in functionality.
• FIGS. 5a and 5b show a schematic top view and a schematic detailed view 104 of a micromechanical structure 1 according to a sixth
• the counter-stop elements 1 1 are formed as part of the further anchoring elements 12, which serve for fastening the fixed electrodes 8 to the substrate 2, and in particular comprise a further recess 1 V on the further anchoring elements 12.
• the further stop elements 10 comprise an elastic L-shape, which in each case proceeding from the seismic mass 3 perpendicular to the sensing direction 100 and parallel to the
• a movement of seismic Mass 3 along the Sensierraum 100 is braked before reaching the maximum deflection, ie in particular before the formation of a mechanical contact between parallel to the Sensiercardi 100 stop and counter-stop elements 6, 7, from the other stop and counter-Antsch elements 10, 11.
• the anchoring elements 4 are arranged in particular in a central region of the micromechanical structure 1, wherein on each side of the anchoring elements 4 comb electrode structures and in particular each exactly a few of further stop and counter-stop elements 10, 11 are arranged.
• FIGS. 6a and 6b show a schematic plan view and a schematic detail view 105 of a micromechanical structure 1 according to a seventh embodiment of the present invention, the seventh embodiment substantially corresponding to the sixth embodiment illustrated in FIGS. 5a and 5b, wherein on each side the anchoring elements 4 two
• Pairs of further stop and counter-stop elements 10, 1 1 are arranged.
• the stop and counter-stop elements 10, 1 1 are thus arranged mirror-symmetrically with respect to a plane of symmetry perpendicular to the substrate plane and centrally along the respective further anchoring element 12, so that when the seismic beam is decelerated

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• General Physics & Mathematics (AREA)
• Micromachines (AREA)
• Pressure Sensors (AREA)

Applications Claiming Priority (2)

Publications (1)

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• 2009
  • 2009-05-26 DE DE102009026476A patent/DE102009026476A1/de not_active Withdrawn
• 2010
  • 2010-01-20 US US13/259,392 patent/US20120073370A1/en not_active Abandoned
  • 2010-01-20 JP JP2012512261A patent/JP5606523B2/ja active Active
  • 2010-01-20 EP EP10702076A patent/EP2435786A1/de not_active Withdrawn
  • 2010-01-20 CN CN2010800229006A patent/CN102449488A/zh active Pending
  • 2010-01-20 WO PCT/EP2010/050634 patent/WO2010136222A1/de active Application Filing
  • 2010-05-24 TW TW099116450A patent/TW201115149A/zh unknown

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