JP2010082613A - Vibration motor and personal terminal device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration motor capable of attaining a thin profile. <P>SOLUTION: A vibration motor 100 is provided with: a multilayer substrate 10 having a first planar coil 12a and a second planar coil 12b arranged with a space therebetween; a permanent magnet 20, which has a magnetic pole surface facing the planar coils and is arranged movably on the planar coils in the planar coil arrangement direction; a movement control section (not shown in the figure) which reciprocates the permanent magnet 20; and plate springs which are arranged on both the end sections of the planar coil arrangement and urge the permanent magnet 20 in the moving direction when the permanent magnet 20 is reciprocated. The movement control section performs control to generate a thrust force due to a magnetic attracting force and a repulsive force between the permanent magnet 20 and the planar coil, by making a current flow in the planar coils, and the permanent magnet 20 is reciprocated in a state where the permanent magnet 20 is tilted from an upper surface 10a of the multilayer substrate 10. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vibration motor that generates vibration, and more particularly to a vibration motor and a portable terminal device using the vibration motor.

  Mobile terminals such as a mobile phone and a PDA (Personal Digital Assistant) having a function of notifying a user of an incoming call or e-mail by vibration of a housing are known. Such a portable terminal may incorporate a small motor that generates vibration. As such a motor, conventionally, an actuator as a motor including a mover that vibrates due to electromagnetic force from a coil is known (for example, see Patent Document 1 and Patent Document 2 below).

  The motor disclosed in Patent Document 1 includes a mover made of a disk-shaped magnet and a coil arranged so as to surround the mover, and the mover is moved in the vertical direction (electromagnetic force of the mover by electromagnetic force from the coil). Move linearly in the thickness direction.

The vibration device disclosed in Patent Document 2 includes a guide rail, and a movable coil formed in a rectangular tube shape as a traveling element is externally mounted on the guide rail. A transducer (inertial body) formed in a rectangular shape is connected to the upper surface of the movable coil. In addition, a permanent magnet is disposed apart from the movable coil, and the vibrator reciprocates along the guide rail together with the movable coil by switching the direction of the current supplied to the movable coil.
JP 2006-68688 A JP 2004-174309 A

  In recent years, mobile terminals have been made thinner, and it is therefore necessary to reduce the thickness of the motor incorporated therein. In the motor disclosed in Patent Document 1, since the disk-shaped mover is configured to move in the vertical direction, it is necessary to provide a moving space for the mover in the vertical direction. There is a problem that it is difficult to reduce the thickness.

  In the motor disclosed in Patent Document 2, it is necessary to increase the thickness of the case body by the thickness of the movable coil and the vibrator, and it is difficult to make the motor thinner structurally.

  The present invention has been made in view of such a situation, and an object thereof is to provide a vibration motor capable of being thinned.

  One embodiment of the present invention relates to a vibration motor. The vibration motor includes a substrate having a coil, a magnetic pole surface facing the coil on one surface side of the substrate, a movable part that moves on the substrate, a movement control unit that moves the movable part, and a movable part And an elastic member that urges the movable part in the movement direction. The movement control unit causes a magnetic thrust to be generated between the magnetic pole of the movable part and the coil by passing an electric current through the coil, and the magnetic pole surface facing the coil of the movable part is directed to one surface of the substrate. And tilt.

  Another aspect of the present invention is a mobile terminal device. This portable terminal device includes the above-described vibration motor.

  Note that any combination of the above-described constituent elements, and those obtained by replacing the constituent elements and expressions of the present invention with each other among methods, apparatuses, systems, etc. are also effective as an aspect of the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, the vibration motor which can achieve thickness reduction can be provided.

  In the following, the same or equivalent components and members shown in each drawing will be denoted by the same reference numerals, and repeated description will be omitted as appropriate. In addition, the dimensions of the members in each drawing are appropriately enlarged or reduced for easy understanding. Moreover, in each drawing, a part of member which is not important when describing each embodiment which concerns on this invention is abbreviate | omitted and displayed.

(First embodiment)
The vibration motor 100 according to the first embodiment is a linear drive vibration motor (linear motor) that is preferably used as a vibration generating motor in a mobile terminal device such as a mobile phone. In the vibration motor 100, the permanent magnets constituting the movable part reciprocate by an attracting magnetic force (hereinafter abbreviated as magnetic attraction) and a moving away magnetic force (hereinafter abbreviated as magnetic repulsive force) acting between the coils. Thereby, the vibration motor 100 vibrates.

  FIG. 1 is a top view of the vibration motor 100 according to the first embodiment. FIG. 1 shows a state where the cover 102 is removed. 2 is a cross-sectional view taken along line AA in FIG. Below, the structure of the vibration motor 100 is demonstrated, using FIG. 1 and FIG. The vibration motor 100 includes a laminated substrate 10 having a first planar coil 12a and a second planar coil 12b collectively referred to as a coil 12, a permanent magnet 20 constituting a movable portion, a guide frame 30, and a first plate. A spring 42 and a second plate spring 44, a cover 102, and a movement control unit 412 (not shown in FIGS. 1 and 2) are provided. Hereinafter, of the surfaces of the laminated substrate 10, the surface on which the permanent magnet 20 is mounted is referred to as the upper surface, and the opposite surface is referred to as the lower surface. Further, for convenience of explanation, consider a case where the lower surface of the laminated substrate 10 faces the ground surface and gravity works downward.

The laminated substrate 10 is a substrate obtained by laminating a first insulating resin layer 52, a wiring layer 54 on which the coil 12 is formed, and a second insulating resin layer 56 in this order from the upper surface side. The first insulating resin layer 52 is an insulating layer formed of a resist material or the like. On the upper surface of the first insulating resin layer 52, a low friction layer 58 formed of a material having a friction coefficient lower than that of the surface of the first insulating resin layer 52 is provided. In this case, since the frictional resistance with the permanent magnet 20 can be reduced, the efficiency of converting electric energy into vibration increases. Furthermore, the response time of the permanent magnet 20 (time until the permanent magnet 20 reaches a predetermined vibration amount) can be shortened. Here, the “vibration amount” is the acceleration of an object (for example, a mobile phone) to which a vibration motor is attached, or a value obtained by dividing the acceleration by the gravitational acceleration (9.8 m / s ² ). The material constituting the low friction layer 58 includes carbon-based materials such as diamond-like carbon (DLC) and fullerene, which are fluororesins such as polytetrafluoroethylene (PTFE), tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer. Examples thereof include titanium (titanium nitride), titanium nitride (titanium oxide), and the like such as coalesce (PFA), tetrafluoroethylene / hexafluoropropylene copolymer (FEP), polyolefin resin polyethylene, and polypropylene.

  The wiring layer 54 includes a first planar coil 12 a and a second planar coil 12 b that are collectively referred to as the coil 12. The first insulating resin layer 52 and the second insulating resin layer 56 insulate the first planar coil 12a and the second planar coil 12b included in the wiring layer 54 from the outside.

  Both the first planar coil 12 a and the second planar coil 12 b are flat spiral coils, and are arranged so that the surfaces of the coils are parallel to the upper surface 10 a of the multilayer substrate 10. Here, the term “parallel” includes not only the state of being parallel to each other but also the state of being deviated from the state of being parallel to such an extent that the permanent magnet 20 does not hinder the movement. One end corresponding to the center of the spiral of the first planar coil 12a is connected to the first connection wiring 62, and one end corresponding to the outside of the spiral of the first planar coil 12a is connected to the second connection wiring 64. One end corresponding to the center of the spiral of the second planar coil 12 b is connected to the fourth connection wiring 68, and one end corresponding to the outside of the spiral of the second planar coil 12 b is connected to the third connection wiring 66. The first planar coil 12a and the second planar coil 12b are arranged apart from each other along the moving direction of the permanent magnet 20.

  The first connection wiring 62 and the fourth connection wiring 68 are connected to the movement control unit 412 by appropriate connection means. Both the second connection wiring 64 and the third connection wiring 66 are connected to the input end 16. The input terminal 16 is connected to the movement control unit 412 by appropriate connection means. The direction of the spiral winding of the first planar coil 12a is different from the direction of the spiral winding of the second planar coil 12b. In such a configuration of the coil 12, when a drive current is passed from the input end 16, magnetic fluxes in opposite directions are generated in the first planar coil 12a and the second planar coil 12b. The direction of the magnetic flux generated in each coil 12 is reversed when the polarity of the drive current is reversed. As a result, the direction of the magnetic flux generated by each coil 12 also varies with time in accordance with the temporal variation of the polarity of the drive current.

  The permanent magnet 20 is formed in a disc shape having a diameter of 10 mm and a thickness of 1.4 mm made of a ferromagnetic material such as ferrite or neodymium. The permanent magnet 20 is magnetized in the thickness direction, the magnetic pole surface 20N facing the top surface 10a of the multilayer substrate 10 is an N pole, and the magnetic pole surface 20S opposite to the magnetic pole surface 20N is an S pole. . And the permanent magnet 20 switches the upper surface 10a side of the laminated substrate 10 by the arrangement direction of the coil 12 (in the direction of the arrow A1 or the arrow A2) by switching the magnetic force between each of the coils 12 and the N pole between the attractive force and the repulsive force. Direction).

  The edge 22 of the permanent magnet 20 is processed into a rounded shape, and its cross section forms part of an arc. Further, a thin magnetic fluid (not shown) is provided on the surface of the permanent magnet 20 so as to cover at least a part thereof. The magnetic fluid is a fluid having magnetism, and is attracted to the surface of the permanent magnet 20 by a magnetic attractive force with the permanent magnet 20. The magnetic fluid is produced by mixing fine particles of a ferromagnetic material such as magnetite, a surfactant that covers the surface of the fine particles, and a solvent such as water or oil.

  The guide frame 30 is provided on the upper surface 10 a of the multilayer substrate 10 so as to surround the arrangement of the permanent magnets 20 and the coils 12. The guide frame 30 is formed so as to transmit the reciprocating movement of the permanent magnet 20 together with the first plate spring 42 and the second plate spring 44 to the entire vibration motor 100 and has a constant width of 1.6 mm. A rectangular frame with a non-magnetic material such as aluminum or plastic. The length of the inner peripheral surface 30a of the guide frame 30 in the short direction is 10.5 mm, and is formed to be slightly larger than the diameter of the permanent magnet 20. Further, the length of the inner peripheral surface 30a in the longitudinal direction is 13.5 mm, and is formed so as to give a margin in the distance between the permanent magnet 20 and the inner peripheral surface 30a. Accordingly, the permanent magnet 20 reciprocates along the upper surface 10a of the laminated substrate 10 in the longitudinal direction of the guide frame 30 (the direction of the arrow A1 or the arrow A2).

  As shown in FIG. 2, the first insulating resin layer 52 is removed in a region on the upper surface 10 a of the laminated substrate 10 corresponding to the bonding surface 30 b of the guide frame 30. Then, the surface of the wiring layer 54 exposed there and the bonding surface 30b are bonded.

  A first leaf spring 42 is provided on one short side of the guide frame 30, and a second leaf spring 44 is provided on the other short side. Each leaf spring is a spring having a thickness of 350 μm, a length of 10 mm, and a width of 1.2 mm made of a non-magnetic material such as PET (PolyEthylene Terephthalate). One end of each of the first plate spring 42 and the second plate spring 44 is embedded in the guide frame 30. The permanent magnet 20 is sandwiched from the side surfaces by the other ends of the first plate spring 42 and the second plate spring 44. By doing so, each leaf spring can be bent and deformed with the attachment portion to the guide frame 30 as a supporting point, and has a function of biasing the permanent magnets 20 toward the other leaf spring. Each leaf spring holds the permanent magnet 20 at a substantially central portion in the longitudinal direction of the guide frame 30 in a stationary state (a state where no current is passed through the coil 12). Then, when the permanent magnet 20 reciprocates on the upper surface 10 a of the multilayer substrate 10, the first leaf spring 42 and the second leaf spring 44 are alternately pressed by the permanent magnet 20. Thereby, vibration is transmitted from these leaf springs to the guide frame 30. As a result, the guide frame 30 and the entire vibration motor 100 including the guide frame 30 vibrate.

A cover 102 is bonded to the upper surface of the guide frame 30 to prevent the permanent magnet 20 from popping out.
Further, a low friction layer formed of a material having a friction coefficient lower than the friction coefficient of the surface of the first insulating resin layer 52 may be provided on the surface of the cover 102 on the laminated substrate 10 side. As a material constituting such a low friction layer, the same material as that of the low friction layer 58 formed on the upper surface of the first insulating resin layer 52 is used. In this case, since the frictional resistance between the permanent magnet 20 and the cover 102 can be reduced, the efficiency of converting electric energy into vibration increases. Furthermore, the response time of the permanent magnet 20 (time until the permanent magnet 20 reaches a predetermined vibration amount) can be shortened.

  When driving the vibration motor 100, the movement control unit 412 supplies a drive current (alternating current) to the coil 12 from the input end 16. Thereby, a magnetic attractive force is generated between the N pole of the permanent magnet 20 and one of the coils 12, and a magnetic repulsive force is generated between the N pole of the permanent magnet 20 and the other of the coil 12. The movement control unit 412 thrusts the permanent magnet 20 by a magnetic attractive force and a magnetic repulsive force so that the permanent magnet 20 reciprocates while the magnetic pole surface 20N of the permanent magnet 20 is inclined with respect to the upper surface 10a of the laminated substrate 10. Work. The reciprocating movement of the permanent magnet 20 in an inclined state will be described later.

  The operation of the vibration motor 100 configured as described above will be described. When the vibration motor 100 is stationary, no driving current flows through the first planar coil 12a and the second planar coil 12b, and the permanent magnet 20 sandwiched between the first leaf spring 42 and the second leaf spring 44 is As shown in FIG. 1, the guide frame 30 is stationary at substantially the center in the longitudinal direction.

  When driving the vibration motor 100, the movement control unit 412 supplies a drive current whose polarity is inverted at a predetermined frequency from the input end 16. Thereby, magnetic flux is generated in the first planar coil 12a and the second planar coil 12b in a direction perpendicular to the coil surfaces, that is, a direction perpendicular to the upper surface 10a of the multilayer substrate 10. Here, the direction of the magnetic flux generated in the first planar coil 12a is opposite to the direction of the magnetic flux generated in the second planar coil 12b.

  Since magnetic fluxes in opposite directions are generated in the first planar coil 12a and the second planar coil 12b, the permanent magnet 20 is attracted to one side of the coil 12. Then, when the direction of the magnetic flux is reversed by the reversal of the polarity of the drive current, it is attracted to the other side of the coil 12 this time. By repeating this, the permanent magnet 20 reciprocates between the first planar coil 12a side and the second planar coil 12b side along the upper surface 10a of the laminated substrate 10.

  The magnetic force exerted from each of the coils 12 on the north pole of the permanent magnet 20 has a component in a direction perpendicular to the upper surface 10 a of the laminated substrate 10. Therefore, a torque that causes one side of the permanent magnet 20 to float with respect to the upper surface 10a of the multilayer substrate 10 is applied to the permanent magnet 20 by the vertical component. Further, the movement control unit 412 changes the magnetic force exerted from each of the coils 12 to the north pole of the permanent magnet 20 between attractive force and repulsive force by reversing the polarity of the drive current. Thereby, the movement control unit 412 varies the torque applied to the permanent magnet 20 and moves the permanent magnet 20 partially in a direction perpendicular to the upper surface 10 a of the laminated substrate 10.

  3A to 3D are conceptual diagrams showing how the permanent magnet 20 reciprocates. The permanent magnet 20 reciprocates as shown in FIGS. 3 (a), 3 (b), 3 (c), and 3 (d) and back to FIG. 3 (a). In FIG. 3, the first plate spring 42 and the second plate spring 44 are not shown and are omitted.

  FIG. 3A is a schematic cross-sectional view when the permanent magnet 20 is moving in the vicinity of the center in the longitudinal direction of the guide frame 30 in the direction of the arrow A1. Here, the movement control unit 412 allows a drive current to flow from the input end 16 toward the first connection wiring 62 and the fourth connection wiring 68. Therefore, the upper surface of the first planar coil 12a is an S pole, and the upper surface of the second planar coil 12b is an N pole. Since the surface of the permanent magnet 20 facing the laminated substrate 10 is an N pole, a magnetic attractive force is applied to the permanent magnet 20 by the first planar coil 12a and a magnetic repulsive force is applied by the second planar coil 12b. As a result, a thrust that moves the upper surface 10a of the laminated substrate 10 in the direction of the arrow A1 acts on the permanent magnet 20.

  At this time, the magnetic repulsive force between the second planar coil 12 b and the N pole of the permanent magnet 20 has a component that is vertically upward with respect to the upper surface 10 a of the multilayer substrate 10. The magnetic attractive force between the first planar coil 12 a and the north pole of the permanent magnet 20 has a component that is perpendicular to the upper surface 10 a of the laminated substrate 10. Therefore, when the movement control unit 412 moves the permanent magnet 20 toward the first planar coil 12a, the edge P2 on the second planar coil 12b side of the edge of the magnetic pole surface 20N moves the permanent magnet 20 to the side. The laminated substrate 10 is moved away from the upper surface 10a. Further, the movement control unit 412 moves the permanent magnet 20 in a state where the edge P1 on the first planar coil 12a side of the edge of the magnetic pole surface 20N is in contact with the upper surface 10a of the multilayer substrate 10. Since the edge of the magnetic pole surface 20N is substantially circular, the contact portion between the permanent magnet 20 and the laminated substrate 10 is substantially point-like. Thus, the permanent magnet 20 moves in a state where the magnetic pole surface 20N is inclined with respect to the upper surface 10a of the laminated substrate 10.

  FIG. 3B is a schematic cross-sectional view when the permanent magnet 20 is closest to the first planar coil 12a side and the direction of movement thereof is changed there. First, the permanent magnet 20 pushes the first leaf spring 42 (see FIGS. 1 and 2) from the state of FIG. 3A and pushes it to the extent that it cannot be pushed any further. The permanent magnet 20 at this time is indicated by a chain line in FIG. At the same time, the movement control unit 412 reverses the direction of the drive current. As a result, the upper surface of the first planar coil 12a has an N pole, and the upper surface of the second planar coil 12b has an S pole. In this state, the N pole of the magnetic pole surface 20N receives a magnetic attractive force from the second planar coil 12b and a magnetic repulsive force from the first planar coil 12a. 3B, the edge P1 of the magnetic pole surface 20N on the first planar coil 12a side is separated from the upper surface 10a of the multilayer substrate 10, and the edge of the magnetic pole surface 20N on the second planar coil 12b side is separated. The part P2 comes into contact with the upper surface 10a of the multilayer substrate 10. Then, the permanent magnet 20 starts to move in the direction of the arrow A2 by a component parallel to the upper surface 10a of the laminated substrate 10 of the magnetic attractive force from the second planar coil 12b and the magnetic repulsive force from the first planar coil 12a. .

  FIG. 3C is a schematic cross-sectional view when the permanent magnet 20 is moving in the vicinity of the center in the longitudinal direction of the guide frame 30 in the direction of the arrow A2. Since the operation at this time is the same as the operation described with reference to FIG.

  FIG. 3D is a schematic cross-sectional view when the permanent magnet 20 is closest to the second planar coil 12b side and the direction of movement thereof is changed there. The operation at this time is the same as the operation described with reference to FIG.

  In this manner, the permanent magnet 20 reciprocates in the direction along the upper surface 10a of the multilayer substrate 10 while the contact portion of the permanent magnet 20 is switched at substantially the same frequency as the inversion of the drive current. The period of these two operations (contact portion switching operation and reciprocating operation of the permanent magnet 20) is the same as can be seen from FIGS. Since the mass of the permanent magnet 20 cannot be ignored with respect to the mass around it, for example, the laminated substrate 10 and the guide frame 30 around it vibrate in accordance with the reciprocating movement of the permanent magnet 20.

  In the vibration motor 100 according to the first embodiment, for example, the following effects can be obtained.

  (1) The permanent magnet 20 is configured to move on the upper surface 10a side of the multilayer substrate 10 along the arrangement direction of the coils 12 (the direction of the arrow A1 or the arrow A2). Therefore, it is not necessary to provide a space for moving the permanent magnet 20 in the direction perpendicular to the upper surface 10a of the multilayer substrate 10 as compared with the conventional vibration motor of only the vertical vibration type (vibration in the direction perpendicular to the substrate surface). The degree of freedom in design for reducing the thickness in that direction can be ensured. As a result, a vibration motor that can be reduced in thickness can be provided.

  (2) Since the permanent magnet 20 is moved in a state where the magnetic pole surface 20N is inclined with respect to the upper surface 10a of the multilayer substrate 10, when the permanent magnet 20 moves between the coils 12, the permanent magnet 20 The contact portion between the laminated substrate 10 and the laminated substrate 10 is substantially point-like. Therefore, compared to the case where the entire magnetic pole surface 20N of the permanent magnet 20 moves in contact with the upper surface 10a of the multilayer substrate 10, the frictional resistance generated at the contact portion can be reduced.

  (3) Since the edge 22 of the permanent magnet 20 that contacts the contact portion between the permanent magnet 20 and the laminated substrate 10 is processed into a rounded shape, the frictional resistance can be reduced as compared with, for example, corner contact. Further, by making the cross section of the edge portion 22 a part of the arc, the frictional resistance there can be further reduced.

  (4) When the permanent magnet 20 moves on the coil 12, the permanent magnet 20 moves in a state where the leading portion of the permanent magnet 20 is inclined downward toward the coil 12 with respect to the moving direction. Therefore, the air resistance with respect to the permanent magnet 20 decreases, and the movement of the permanent magnet 20 becomes smooth.

  (5) When the movement direction of the permanent magnet 20 is switched, the permanent magnet 20 is switched to a state in which the leading portion of the permanent magnet 20 is lowered toward the coil 12 and is inclined with respect to the movement direction of the permanent magnet 20. Therefore, since the kinetic energy when the portion of the permanent magnet 20 that contacts the laminated substrate 10 is switched is given to the laminated substrate 10, the vibration amount of the vibration motor 100 as a whole further increases.

  (6) By providing a thin magnetic fluid on the surface of the permanent magnet 20 so that at least a part of the permanent magnet 20 is covered, the magnetic fluid reduces the frictional resistance between the upper surface 10a of the laminated substrate 10 and the permanent magnet 20. Therefore, generation of heat and sound due to frictional resistance can be reduced, and electric energy can be more efficiently converted into vibration.

  (7) Since the surface of the permanent magnet 20 is provided with a thin magnetic fluid so that at least a part of the permanent magnet 20 is covered, the permanent magnet 20 is used as the first leaf spring 42 or the second leaf spring 44 by the magnetic fluid. Acts as a cushioning material when it collides. Therefore, noise generated at the time of a collision can be reduced.

  (8) Since the magnetic fluid tries to adhere to the permanent magnet 20 by the magnetic attraction between the magnetic fluid and the permanent magnet 20, in order to obtain a desired frictional resistance reduction effect compared to the case of using normal oil. The amount to be applied is small. As a result, the manufacturing cost of the vibration motor 100 can be reduced.

  (9) When the current is supplied to the coil 12, the first planar coil 12a and the second planar coil 12b are configured such that magnetic fluxes in opposite directions are generated in the first planar coil. Attraction and repulsion can be easily applied between 12a and the permanent magnet 20, and between the second planar coil 12b and the permanent magnet 20.

  (10) A flat coil 12 is used, and the surface of the coil 12 is arranged so as to be parallel to the upper surface 10 a of the multilayer substrate 10. Therefore, since the laminated substrate 10 can be made thin, it contributes to the thinning of the vibration motor 100 as a whole.

  (11) Since the guide frame 30 is made of a nonmagnetic material, the magnetic force acting between the permanent magnet 24 and the guide frame 30 is negligibly small. Therefore, the movement of the permanent magnet 20 becomes smoother.

  (12) Since the first plate spring 42 and the second plate spring 44 are made of a nonmagnetic material, the magnetic force acting between the permanent magnet 20 and the first and second plate springs 42 and 44 can be ignored. Small enough. Therefore, smoother movement of the permanent magnet 20 is realized.

  (13) The surface of the wiring layer 54 and the bonding surface 30b are bonded. Thereby, the adhesive strength between the guide frame 30 and the laminated substrate 10 can be further increased.

  (14) Since the frictional resistance is reduced when the permanent magnet 20 is moved, the current flowing through the coil 12 can be reduced by the amount of thrust that opposes the reduced frictional resistance. As a result, a vibration motor capable of reducing power consumption can be provided.

  (15) The magnetic pole surface of the permanent magnet 20 is arranged so as to face the surfaces of the first and second planar coils 12a and 12b. As a result, the lines of magnetic force generated from the permanent magnet 20 side (the magnetic pole surface where the lines of magnetic force are generated) and the magnetic flux lines generated when an electric current is passed through the first and second planar coils 12a and 12b (the coil surface where the magnetic flux lines are generated). Become parallel. On the other hand, in the structure of the said patent document 2, the magnetic force line from a magnet and the magnetic flux line from a coil are orthogonally crossed. Therefore, compared with the configuration described in Patent Document 2, the configuration of the vibration motor 100 has a large amount of overlapping of the magnetic lines of force and the lines of magnetic flux, and accordingly, the driving force when moving the permanent magnet 20 can be increased accordingly. it can.

(Second Embodiment)
FIG. 4 is a perspective view showing a portable terminal device 400 according to the second embodiment. The mobile terminal device 400 is a mobile terminal such as a mobile phone or a PDA, and has a communication function.

  The mobile terminal device 400 includes a display unit 402, a power switch 404, an antenna 406, a housing 408, and the vibration motor 100 according to the first embodiment. Other configurations are omitted for the sake of clarity. The display unit 402 includes a liquid crystal panel and a touch panel that covers the liquid crystal panel. The user operates the portable terminal device 400 by pressing down a part of the touch panel corresponding to a button or the like displayed on the liquid crystal panel. The user turns on the power switch 404 to turn on the mobile terminal device 400. The antenna 406 transmits and receives radio signals.

  FIG. 5 is a functional block diagram of the mobile terminal device 400. The mobile terminal device 400 includes the vibration motor 100, an antenna 406, and a communication unit 414. The communication unit 414 is connected to the antenna 406.

The movement control unit 412 controls the vibration of the vibration motor 100 by supplying a drive current whose polarity changes at a predetermined frequency to the coil 12 via the input end 16, the first connection wiring 62 and the fourth connection wiring 68. . The movement control unit 412 causes the vibration motor 100 to vibrate when it is detected that the touch panel portion is pressed or when the manner mode is set when a call or e-mail is received.
The communication unit 414 transmits and receives radio signals via the antenna 406 and controls communication with the outside.

  The operation of the mobile terminal device 400 configured as described above will be described. When the communication unit 414 detects a wireless signal that notifies the mobile terminal device 400 of an incoming call through the antenna 406, the communication unit 414 transmits a signal that causes the movement control unit 412 to start vibration. When the movement control unit 412 receives the signal, the movement control unit 412 supplies a driving current whose polarity is inverted at a predetermined frequency to the coil 12. The vibration motor 100 vibrates as described in the operation section of the first embodiment. Since the vibration motor 100 is fixed to the housing 408, the vibration of the vibration motor 100 is transmitted to the housing 408, and the housing 408 vibrates.

  According to the mobile terminal device 400 according to the second embodiment, for example, the following effects can be obtained.

  (16) By mounting the vibration motor 100 as a vibration source, it is possible to reduce the thickness of the entire apparatus by reducing the thickness of the vibration motor 100.

  (17) By mounting the vibration motor 100 as a vibration source, it is possible to reduce the power consumption of the entire apparatus as much as the power consumption of the vibration motor 100 is reduced.

(Third embodiment)
The vibration motor 500 according to the third embodiment is a linear drive type vibration motor (linear motor) similarly to the vibration motor 100 according to the first embodiment. Among the differences between the vibration motor 100 according to the first embodiment and the vibration motor 500 according to the third embodiment, the characteristic is the number of pairs of magnetic poles of the permanent magnet and the arrangement of the planar coils. In the vibration motor 500, a permanent magnet having two magnetic poles that form a pair and forming a movable part has an attractive magnetic force (hereinafter abbreviated as magnetic attractive force) acting between the coils and a magnetic force (hereinafter abbreviated as magnetic repulsive force). Move back and forth with. Thereby, the vibration motor 500 vibrates. The two planar coils are arranged so as to overlap in the thickness direction of the substrate.

  FIG. 7 is a top view of a vibration motor 500 according to the third embodiment. 8 is a cross-sectional view taken along line AA in FIG. FIG. 7 shows a state where the cover substrate 502 is removed. Further, FIG. 7 shows the first planar coil 512a, the first via 504, and the second via 506 under the first insulating resin layer 551. A portion hidden under the guide frame 530 and the mover 520 is indicated by a broken line, and the other portion is indicated by a solid line. Below, the structure of the vibration motor 500 is demonstrated, using FIG. 7 and FIG.

  The vibration motor 500 includes a laminated substrate 510 including a first planar coil 512a and a second planar coil 512b collectively referred to as a planar coil 512, a moving element 520, a guide frame 530, a first leaf spring 542, and a first planar coil 512b. 2 leaf springs 544 and a cover substrate 502. Hereinafter, of the surfaces of the multilayer substrate 510, the surface on which the moving element 520 is mounted is the upper surface, and the opposite surface is the lower surface. Further, for convenience of explanation, consider a case where the lower surface of the multilayer substrate 510 faces the ground surface and gravity works downward.

  The multilayer substrate 510 includes a first insulating resin layer 551, a first wiring layer 552 on which the first planar coil 512a is formed, a second insulating resin layer 553, and a second plane on which the second planar coil 512b is formed. A substrate in which a wiring layer 554 and a third insulating resin layer 555 are laminated in this order from the upper surface side. The first insulating resin layer 551, the second insulating resin layer 553, and the third insulating resin layer 555 are insulating layers formed of a resist material or the like. The second insulating resin layer 553 is provided with a first via 504 that electrically connects the first planar coil 512a and the second planar coil 512b. The first insulating resin layer 551 insulates the first planar coil 512a from the outside. The third insulating resin layer 555 insulates the second planar coil 512b from the outside.

Both the first planar coil 512 a and the second planar coil 512 b are flat spiral coils, and are formed so that the surfaces of the coils are parallel to the upper surface 510 a of the multilayer substrate 510. Here, the term “parallel” includes not only a state parallel to each other but also a state deviated from a parallel state to the extent that the moving element 520 does not hinder the movement. The first planar coil 512a and the second planar coil 512b are both rectangular and have sides along the moving direction of the mover 520 described later.
The first planar coil 512a and the second planar coil 512b are formed so that images obtained by projecting them onto the upper surface 510a of the multilayer substrate 510 overlap each other.

Of the sides of the first planar coil 512a, the width d2 of the wiring group included in the side along the moving direction of the movable element 520 is smaller than the width d1 of the wiring group included in the side intersecting the moving direction. In addition, the first planar coil 512a is formed. This is achieved by making the wiring width, pitch, or both of the wiring group included in the side along the moving direction smaller than that of the wiring group included in the side crossing the moving direction.
The second planar coil 512b is formed similarly.
Further details of the planar coil 512 will be described later with reference to FIGS.

The mover 520 includes a first magnetic shield member 522, a first permanent magnet 524, and a second permanent magnet 526.
Each of the first permanent magnet 524 and the second permanent magnet 526 is formed in a rectangular shape made of a ferromagnetic material such as ferrite or neodymium, and is magnetized so as to form a pair of magnetic poles in the thickness direction. The first permanent magnet 524 and the second permanent magnet 526 are formed to have substantially the same area and thickness.

  The first permanent magnet 524 and the second permanent magnet 526 are bonded and fixed so that there is no deviation in the thickness direction. The first permanent magnet 524 and the second permanent magnet 526 thus bonded and fixed together are collectively referred to as bonded permanent magnets. A direction from the center of gravity of the second permanent magnet 526 to the center of gravity of the first permanent magnet 524 is indicated by an arrow A1, and the opposite direction is indicated by an arrow A2.

The bonded permanent magnet has a first magnetic pole surface 560 that faces the laminated substrate 510 and faces the coil surface of the planar coil 512, and a second magnetic pole surface 562 on the opposite side. The north pole of the first permanent magnet 524 and the south pole of the second permanent magnet 526 are disposed on the first magnetic pole surface 560. The S pole of the first permanent magnet 524 and the N pole of the second permanent magnet 526 are disposed on the second magnetic pole surface 562.
Of the side surfaces of the bonded permanent magnet, a portion where the first plate spring 542 contacts is referred to as a first contact portion E, and a portion where the second plate spring 544 contacts is referred to as a second contact portion F.
A first magnetic shield member 522 is attached to the second magnetic pole surface 562.

  The mover 520 including the bonded permanent magnet is disposed on the upper surface 510a side of the laminated substrate 510 by the magnetic force exerted from the planar coil 512 to the bonded permanent magnet, in the direction of the magnetic pole arrangement on the first magnetic pole surface 560 (arrow A1 or arrow A2). (Hereinafter abbreviated as the magnetic pole arrangement direction).

The first magnetic shield member 522 is a rectangular plate-shaped member formed so as not to protrude from the second magnetic pole surface 562 of the bonded permanent magnet, and is formed of a material having a relatively high magnetic permeability. This material includes soft ferrite (soft iron), silicon steel plate, permalloy (iron-nickel alloy), supermalloy (iron-nickel-molybdenum alloy), permendur (iron-cobalt alloy), sendust (iron and iron) A soft magnetic material such as an alloy of silicon and aluminum is suitable. Since the first magnetic shield member 522 has a high magnetic permeability, there are more surrounding magnetic flux lines and selectively pass through the inside. Thereby, the magnetic flux from the bonded permanent magnet is prevented from spreading beyond the first magnetic shield member 522.
As described above, the first permanent magnet 524 and the second permanent magnet 526 are rectangular, and the first magnetic shield member 522 does not protrude from the second magnetic pole surface 562. Therefore, the moving element 520 has a rectangular shape as a whole. is there.
Hereinafter, the case where the mass of the first magnetic shield member 522 is smaller than the mass of the bonded permanent magnet, and the center of gravity G of the bonded permanent magnet and the center of gravity of the moving element 520 substantially coincide is considered. Therefore, the center of gravity of the mover 520 is referred to as the center of gravity G for convenience.

  Since a relatively strong magnetic attractive force acts between the first magnetic shield member 522 and the bonded permanent magnet, the first magnetic shield member 522 is fixed to the bonded permanent magnet by this magnetic attractive force.

Although details will be described later, the first plate spring 542 and the second plate spring 544 are provided with bent portions. In the bent portion, when the first contact portion E and the second contact portion F shown in FIG. 7 are arranged along the magnetic pole arrangement direction (the direction of the arrow A1 or the arrow A2) and viewed from the upper surface of the vibration motor 500. A line segment EF connecting them to each other passes through the center of gravity G of the moving element 520. Further, during the reciprocating movement of the moving element 520, the positions of the first contact portion E and the second contact portion F do not change on the side surface of the bonded permanent magnet.
Note that the line segment EF may be sufficiently close to the center of gravity G of the mover 520, for example, within a range of about a tenth of the short side of the bonded permanent magnet from the center of gravity G. Further, the first contact portion E and the second contact portion F may be surfaces having a width.

  The four corners 520a of the movable element 520 when the movable element 520 is viewed from above are processed into a rounded shape. The edge 520b on the moving direction side of the moving element 520 is also processed into a rounded shape.

  The guide frame 530 is provided on the upper surface 510 a of the multilayer substrate 510 so as to surround the moving element 520 and the planar coil 512. The guide frame 530 is a rectangular frame formed so as to transmit the reciprocating movement of the moving element 520 to the entire vibration motor 500 together with the first leaf spring 542 and the second leaf spring 544, and is made of aluminum or plastic. It is made of a non-magnetic material.

  Here, for the sake of convenience, the guide frame 530 is positioned on the first guide portion 532 along the magnetic pole arrangement direction, the second guide portion 534 facing the first guide portion 532 along the magnetic pole arrangement direction, and one end side in the magnetic pole arrangement direction. The first spring mounting portion 536 is divided into a second spring mounting portion 538 located on the other end side in the magnetic pole arrangement direction.

As shown in FIG. 7, the first guide portion 532 and the second guide portion 534 overlap the wiring group included in the side along the moving direction of the moving element 520 among the sides of the planar coil 512.
FIG. 7 shows a case where all the wiring groups along the moving direction are under the first guide portion 532 and the second guide portion 534, but even if only a part of the wiring groups overlap. Good.

  A first leaf spring 542 is attached to the inner surface 536 a of the first spring attachment portion 536. The first leaf spring 542 is a spring made of a nonmagnetic material such as PET. A part of the first leaf spring 542 is bonded and fixed to the inner surface 536a. Of the first leaf spring 542, a bent portion 542a that is folded once is provided from the inner surface 536a to the first contact portion E.

A second leaf spring 544 is attached to the inner surface 538 a of the second spring attachment portion 538. Similar to the first plate spring 542, the second plate spring 544 is a spring made of a nonmagnetic material such as PET. A part of the second leaf spring 544 is bonded and fixed to the inner surface 538a. Of the second leaf spring 544, a bent portion 544a that is folded once is provided from the inner surface 538a to the second contact portion F.
When viewed from above, the first plate spring 542 and the second plate spring 544 have a rotational symmetry of 180 degrees with respect to an axis that passes through the center of the guide frame 530 and is perpendicular to the laminated substrate 510.

  Each leaf spring holds the moving element 520 at a substantially central portion in the magnetic pole arrangement direction in a stationary state as shown in FIG. 7 (a state in which no current flows through the planar coil 512). When the movable element 520 reciprocates on the upper surface 510 a of the multilayer substrate 510, the first leaf spring 542 and the second leaf spring 544 are alternately pressed by the movable element 520. As a result, pressure is transmitted from these leaf springs to the guide frame 530. As a result, the guide frame 530 and the entire vibration motor 500 including the guide frame 530 vibrate.

A cover substrate 502 is bonded to the upper surface of the guide frame 530 to prevent the mover 520 from popping out.
A second magnetic shield member 570 is attached to the lower surface 510 b of the multilayer substrate 510. The second magnetic shield member 570 is formed of the same material as the first magnetic shield member 522. Since the second magnetic shield member 570 has a high magnetic permeability, there are more surrounding magnetic flux lines and selectively pass through the inside thereof. Thereby, the magnetic flux from the bonded permanent magnet is prevented from spreading beyond the second magnetic shield member 570.

  FIG. 9 is a top view of the first wiring layer 552 of FIG. One end corresponding to the center of the spiral of the first planar coil 512a is connected to one end corresponding to the center of the spiral of the second planar coil 512b via the first via 504. One end of the first planar coil 512 a that contacts the outside of the spiral is connected to the second via 506. The second via 506 is connected to the first electrode pad 506 a provided on the lower surface 510 b of the multilayer substrate 510.

  FIG. 10 is a top view of the second wiring layer 554 of FIG. One end of the second planar coil 512b that is outside the spiral is connected to the third via 508. The third via 508 is connected to the second electrode pad 508 a provided on the lower surface 510 b of the multilayer substrate 510.

  The second via 506 and the third via 508 are connected to the drive circuit of the vibration motor 500 via the first electrode pad 506a and the second electrode pad 508a, respectively. As shown in FIGS. 9 and 10, the spiral direction of the first planar coil 512a is formed different from the spiral direction of the second planar coil 512b. In such a configuration of the planar coil 512, when a drive current is passed from the second via 506 or the third via 508, magnetic fluxes in the same direction are generated in the first planar coil 512a and the second planar coil 512b. The direction of the magnetic flux generated in each planar coil 512 is reversed when the polarity of the drive current is reversed. As a result, the direction of the magnetic flux generated by each planar coil 512 also varies with time in accordance with the temporal variation of the polarity of the drive current.

  FIG. 11 is a bottom view of the vibration motor 500 of FIG. The second magnetic shield member 570 is provided with a cutout portion so that the first electrode pad 506a and the second electrode pad 508a are not covered. This makes it possible to connect a power supply terminal or the like from the outside to the first electrode pad 506a and the second electrode pad 508a.

  FIG. 12 is a top view showing a state in which the moving element 520 is close to the first leaf spring 542 side. The mover 520 is biased toward the second plate spring 544 by the first plate spring 542. In addition, the bent portion 542a of the first leaf spring 542 is folded compared to the stationary state. Therefore, the moving element 520 is further biased toward the second leaf spring 544 by the force of the bent portion 542a returning to the original state. As shown in FIG. 12, even when the moving element 520 is close to one leaf spring, the moving element 520 has a line segment EF passing through the center of gravity G of the moving element 520 when viewed from the upper surface of the vibration motor 500. Move while maintaining state. The same applies to the case of approaching the second leaf spring 544 side.

  The operation of the vibration motor 500 configured as described above will be described. When the vibration motor 500 is stationary, no driving current flows through the first planar coil 512a and the second planar coil 512b, and the movable element 520 sandwiched between the first leaf spring 542 and the second leaf spring 544 As shown in FIG. 7, the guide frame 530 is stationary at a substantially central portion in the magnetic pole arrangement direction.

  When driving the vibration motor 500, a drive current (AC current) whose polarity is inverted at a predetermined frequency is supplied from the second via 506 or the third via 508. Thereby, magnetic flux is generated in the first planar coil 512a and the second planar coil 512b in a direction perpendicular to the coil surfaces, that is, a direction perpendicular to the upper surface 510a of the multilayer substrate 510. Here, the direction of the magnetic flux generated in the first planar coil 512a is the same as the direction of the magnetic flux generated in the second planar coil 512b.

  When a driving current flows through the planar coil 512 so as to generate a magnetic flux upward, a force in a direction away from the center of the planar coil 512 is applied to the north pole of the permanent magnet facing the planar coil 512 as a resultant force of the reaction force of the Lorentz force. It is done. On the contrary, a force directed toward the center of the planar coil 512 is applied to the south pole. When a drive current flows through the planar coil 512 so that a magnetic flux is generated downward, the direction of the applied force is reversed.

Therefore, when a drive current flows from the second via 506 toward the third via 508, a force is applied to the first permanent magnet 524 whose N pole faces the planar coil 512 in the direction of the arrow A1. A force is also applied to the second permanent magnet 526 whose S pole faces the planar coil 512 in the direction of arrow A1. As a result, a force is applied to the mover 520 to move the first plate spring 542 in the direction of the arrow A1 on the upper surface 510a of the multilayer substrate 510.
When the direction of the drive current is reversed, a force is applied to the first permanent magnet 524 whose N pole faces the planar coil 512 in the direction of the arrow A2. A force is also applied to the second permanent magnet 526 whose S pole faces the planar coil 512 in the direction of the arrow A2. As a result, a force is applied to the mover 520 to move the second plate spring 544 in the direction of the arrow A2 on the upper surface 510a of the multilayer substrate 510. In this way, the moving element 520 reciprocates around the moving substrate 520, for example, with respect to the laminated substrate 510 and the guide frame 530 at substantially the same frequency as the reversal of the driving current. Since the mass of the moving element 520 is not negligible with respect to the surrounding mass, the surrounding area vibrates in accordance with the reciprocating movement of the moving element 520.

  The magnetic force exerted from the planar coil 512 to the first permanent magnet 524 and the second permanent magnet 526 has a component in a direction perpendicular to the upper surface 510 a of the laminated substrate 510. This is understood by regarding the planar coil 512 as a magnet. In other words, when a drive current flows so that the top of the planar coil 512 has an N pole, the first permanent magnet 524 tries to float by the magnetic repulsion, while the second permanent magnet 526 has a magnetic attraction force. It is attracted to the upper surface 510a. Therefore, a torque is applied to the moving element 520 so that the first permanent magnet 524 side is lifted with respect to the upper surface 510 a of the multilayer substrate 510. When a driving current flows so that the top of the planar coil 512 is an S pole, a torque is applied to the moving element 520 so that the second permanent magnet 526 side is lifted with respect to the upper surface 510 a of the multilayer substrate 510.

  FIGS. 13A to 13D are conceptual diagrams showing how the moving element 520 reciprocates. The mover 520 performs a reciprocating movement as shown in FIG. 13A, FIG. 13B, FIG. 13C, and FIG. 13D and returning to FIG. 13A again. In FIG. 13, the cover substrate 502, the second magnetic shield member 570, the first leaf spring 542, and the second leaf spring 544 are not shown and are omitted. For the sake of clarity, the first planar coil 512a and the second planar coil 512b are shown as one planar coil 512.

  FIG. 13A is a schematic cross-sectional view when the mover 520 is moving in the direction of the arrow A1 around the center of the guide frame 530 in the magnetic pole arrangement direction. Here, a drive current flows from the second via 506 toward the third via 508. Therefore, as described above, the moving element 520 has a thrust force that moves the upper surface 510a of the multilayer substrate 510 in the direction of the arrow A1.

  At this time, as described above, the first permanent magnet 524 repels the plane coil 512 and tends to float, and the second permanent magnet 526 is attracted to the laminated substrate 510. Therefore, when the mover 520 moves toward the first spring attachment portion 536, the edge portion P2 on the second spring attachment portion 538 side of the edge portion 520b of the mover 520 is in contact with the upper surface 510a of the multilayer substrate 510. Move in state. Further, the edge portion P1 on the first spring mounting portion 536 side of the edge portion 520b of the moving element 520 moves in a state where it is separated from the upper surface 510a of the multilayer substrate 510. As described above, the mover 520 moves in a state where the first magnetic pole surface 560 is inclined with respect to the upper surface 510 a of the multilayer substrate 510.

  FIG. 13B is a schematic cross-sectional view when the moving element 520 is closest to the first spring mounting portion 536 side and the direction of the movement is changed there. First, the moving element 520 pushes the first leaf spring 542 (see FIGS. 7 and 8) from the state of FIG. 13A, and pushes it to the extent that it cannot be pushed any more. The moving element 520 at this time is indicated by a chain line in FIG. Here, when the direction of the drive current is reversed, the directions of the forces acting on the first permanent magnet 524 and the second permanent magnet 526 are reversed. In this state, as described above, the second permanent magnet 526 is repelled by the planar coil 512 and tends to float, and the first permanent magnet 524 is attracted to the laminated substrate 510. Accordingly, as shown in FIG. 13B, the edge P2 on the second spring mounting portion 538 side is separated from the upper surface 510a of the multilayer substrate 510, and the edge P1 on the first spring mounting portion 536 side is the upper surface of the multilayer substrate 510. 510a comes into contact. Then, the mover 520 starts moving in the direction of the arrow A2.

  FIG. 13C is a schematic cross-sectional view when the mover 520 is moving in the direction of the arrow A2 in the vicinity of the center of the guide frame 530 in the magnetic pole arrangement direction. Since the operation at this time is the same as the operation described with reference to FIG.

  FIG. 13D is a schematic cross-sectional view when the moving element 520 is closest to the second spring mounting portion 538 side and the direction of movement is changed there. Since the operation at this time is the same as the operation described in FIG.

  In this way, the moving part 520 reciprocates in the direction along the upper surface 510a of the multilayer substrate 510 while the contact portion of the moving part 520 is switched at substantially the same frequency as the inversion of the drive current. The periods of these two operations (contact portion switching operation and reciprocating operation of the moving element 520) are the same as can be seen from FIGS.

  In the vibration motor 500 according to the third embodiment, for example, the following effects can be obtained.

  (18) The moving element 520 is configured to move on the upper surface 510a side of the multilayer substrate 510 along the magnetic pole arrangement direction (the direction of the arrow A1 or the arrow A2). Therefore, it is not necessary to provide a moving space for the mover 520 in a direction perpendicular to the upper surface 510a of the multilayer substrate 510, compared to a conventional vibration motor of only a vertical vibration type (vibration in a direction perpendicular to the substrate surface). The degree of freedom in design for reducing the thickness in that direction can be ensured. As a result, a vibration motor that can be reduced in thickness can be provided.

  (19) A flat planar coil 512 is used, and the surface of the planar coil 512 is disposed so as to be parallel to the upper surface 510 a of the multilayer substrate 510. Therefore, since the laminated substrate 510 can be made thin, it contributes to the thinning of the vibration motor 500 as a whole.

  (20) The N pole of the first permanent magnet 524 and the S pole of the second permanent magnet 526 are arranged on the first magnetic pole surface 560. Therefore, most of the magnetic flux emitted from the north pole of the first permanent magnet 524 is returned to the south pole of the second permanent magnet 526, so that leakage of the magnetic flux from the first magnetic pole surface 560 to the outside of the vibration motor 500 is reduced. can do. In particular, even if the second magnetic shield member 570 is provided on the lower surface 510b of the multilayer substrate 510, the movement of the mover 520 is reduced to such an extent that the magnetic attractive force between the second magnetic shield member 570 and the bonded permanent magnet is not hindered. be able to.

  (21) The S pole of the first permanent magnet 524 and the N pole of the second permanent magnet 526 are disposed on the second magnetic pole surface 562. Therefore, most of the magnetic flux emitted from the N pole of the second permanent magnet 526 returns to the S pole of the first permanent magnet 524, and thus leakage of the magnetic flux from the second magnetic pole surface 562 to the outside of the vibration motor 500 is reduced. can do.

  (22) The second magnetic pole surface 562 of the bonded permanent magnet is covered with the first magnetic shield member 522. Therefore, leakage of magnetic flux from the second magnetic pole surface 562 to the outside of the vibration motor 500 can be reduced.

  (23) The first magnetic shield member 522 is attached to the bonded permanent magnet, and the first magnetic shield member 522 and the bonded permanent magnet move together. Accordingly, the magnetic attractive force between the first magnetic shield member 522 and the bonded permanent magnet does not act on the movement of the moving element 520, so that a smoother operation can be realized.

  (24) Since a relatively strong magnetic attractive force acts between the first magnetic shield member 522 and the bonded permanent magnet, the first magnetic shield member 522 is fixed to the bonded permanent magnet by this magnetic attractive force. That is, since they are fixed to each other without any other member, the manufacturing process of the vibration motor 500 can be simplified and the cost can be reduced.

  (25) The second magnetic shield member 570 is attached to the lower surface 510b of the multilayer substrate 510. Therefore, leakage of magnetic flux from the first magnetic pole surface 560 to the outside of the vibration motor 500 can be reduced.

  (26) A plate spring is used as a member for urging the mover 520. Therefore, for example, the space occupied by the spring can be reduced as compared with the case where a helical spring is used. This contributes to an improvement in the amount that the moving element 520 can be displaced in the moving direction, and as a result, the vibration amount of the vibration motor 500 can be increased.

  (27) The first leaf spring 542 is provided with a bent portion 542a, and the second leaf spring 544 is provided with a bent portion 544a. Therefore, the elastic force of the leaf spring is improved by the bent portion, and the reciprocating movement of the moving element 520 is further stabilized.

  (28) When viewed from above, the first plate spring 542 and the second plate spring 544 have a rotational symmetry of 180 degrees with respect to an axis that passes through the center of the guide frame 530 and is perpendicular to the laminated substrate 510. Thereby, the symmetry of the force applied to the moving element 520 increases, and the moving of the moving element 520 becomes smoother.

  (29) The bent portion 542a of the first leaf spring 542 so that the first contact portion E and the second contact portion F of the moving element 520 are aligned along the magnetic pole arrangement direction (the direction of the arrow A1 or the arrow A2) A bent portion 544a of the second leaf spring 544 is formed. Therefore, during the reciprocating movement of the moving element 520, a force along the moving direction is applied to the moving element 520 regardless of its position. Thereby, the mover 520 can be reciprocated more efficiently. Further, the movement of the moving element 520 in the moving direction can be reduced, and a more stable operation of the vibration motor 500 can be realized.

  (30) Folding of the first leaf spring 542 so that the line segment EF connecting the first contact portion E and the second contact portion F of the moving element 520 passes through the center of gravity G of the moving element 520 or sufficiently close to the center of gravity G. A bent portion 544a and a bent portion 544a of the second leaf spring 544 are formed. Accordingly, the force applied by each leaf spring to the moving element 520 is directed to the center of gravity G of the moving element 520 and does not induce rotation around the center of gravity G. Thereby, the rotation of the moving element 520 around the center of gravity G hardly occurs, and the reciprocating movement of the moving element 520 can be realized more efficiently and stably.

  (31) In the vibration motor 500, the leaf spring is integrally formed and further fitted along the guide frame 530. As a result, even if the vibration operation is repeated for a long period of time, the notch portion of the guide frame that becomes the support point (support portion) will not be deformed, for example, and the operational reliability of the vibration motor will be degraded (deteriorated) due to the looseness of the leaf spring. ) Can be prevented.

  (32) The edge 520b on the moving direction side of the moving element 520, which corresponds to the contact portion between the moving element 520 and the multilayer substrate 510, is processed into a rounded shape, so that the frictional resistance there is compared with a case where the contact is angular contact. Can be reduced.

  (33) When the movable element 520 moves on the planar coil 512 by moving the movable element 520 in a state where the first magnetic pole surface 560 is inclined with respect to the upper surface 510a of the multilayer substrate 510, The contact portion between the mover 520 and the laminated substrate 510 is substantially linear. Therefore, the frictional resistance generated at the contact portion can be reduced as compared with the case where the entire first magnetic pole surface of the mover moves in contact with the upper surface of the multilayer substrate.

  (34) The moving element 520 switches the state of the inclination when the moving direction is switched. Therefore, since the kinetic energy when the portion of the moving element 520 that contacts the laminated substrate 510 is switched is given to the laminated substrate 510, the vibration amount of the vibration motor 500 as a whole further increases.

  (35) The guide frame 530 is formed so that the mover 520 moves along the magnetic pole arrangement direction. Therefore, the thrust by magnetic force can be efficiently transmitted by the mover 520.

  (36) The coil surface of the planar coil 512 and the first magnetic pole surface 560 are configured to face each other. Therefore, by making the planar coil 512 thinner, the vibration motor 500 can be further reduced in thickness.

  (37) The laminated substrate 510 includes a rectangular moving element 520. Accordingly, the rotation of the mover 520 is further suppressed by the first guide part 532 and the second guide part 534, so that the movement of the mover 520 is more stable. Moreover, by making it rectangular, for example, it can be made heavier than a circular moving element having the same diameter as its long side, and the amount of vibration can be increased.

  (38) The four corners 520a of the mover 520 when the mover 520 is viewed from above are processed into a rounded shape. Therefore, even if the corner portion 520a of the moving element 520 hits the guide frame 530, it becomes difficult to be caught there, and the movement of the moving element 520 becomes more stable.

  (39) Of the sides of the first planar coil 512a, the width d2 of the wiring group included in the side along the moving direction of the mover 520 is greater than the width d1 of the wiring group included in the side intersecting the moving direction. The first planar coil 512a is formed to be smaller. The same applies to the second planar coil 512b. Therefore, for example, as compared with the case where the width d1 and the width d2 are equal, the length of the wiring group included in the side intersecting with the moving direction can be increased by reducing the width d2. As a result, a larger thrust can be applied to the moving element 520 with the same driving current, which is efficient.

  (40) The first guide part 532 and the second guide part 534 overlap the wiring group included in the side along the moving direction of the moving element 520 among the sides of the planar coil 512. Therefore, the mover 520 is further away from the wiring group included in the side along the moving direction. As a result, a component in a direction other than the moving direction of the moving element 520 out of the force applied to the moving element 520 can be reduced, so that the moving element 520 moves more smoothly.

  (41) The magnetic pole surface of the mover 520 is arranged so as to face the surfaces of the first and second planar coils 512a and 512b. As a result, there are magnetic lines of force (magnetic pole surface where magnetic lines of force are generated) generated from the mover 520 side and magnetic flux lines (coil surfaces where magnetic flux lines are generated) generated by passing current through the first and second planar coils 512a and 512b. Become parallel. On the other hand, in the structure of the said patent document 2, the magnetic force line from a magnet and the magnetic flux line from a coil are orthogonally crossed. Therefore, compared with the configuration described in Patent Document 2, the configuration of the vibration motor 500 has a large amount of overlapping of the magnetic field lines and the magnetic flux lines, and accordingly, the driving force when moving the moving element 520 can be increased accordingly. it can.

  (42) The first planar coil 512a and the second planar coil 512b are formed so that images obtained by projecting them onto the upper surface 510a of the multilayer substrate 510 overlap each other. Further, when a drive current is passed from the second via 506 or the third via 508, magnetic fluxes in the same direction are generated in the first planar coil 512a and the second planar coil 512b. Therefore, since the magnetic field generated in the planar coil 512 can be increased, the driving force of the mover 520 is improved. As a result, the response time of the mover 520 (time until the mover 520 reaches a predetermined vibration amount) can be shortened.

  When only one planar coil is provided, one of the two electrodes of the planar coil must be taken out from the center of the planar coil. Therefore, it is necessary to provide the second magnetic shield member with an opening corresponding to the electrode pad provided near the center of the lower surface of the multilayer substrate. However, in the vibration motor 500 according to the third embodiment, both of the two electrodes of the planar coil can be taken out from the outside of the planar coil. Therefore, as shown in FIG. 11, it is only necessary to provide a cutout in the second magnetic shield member 570, which is advantageous in manufacturing the second magnetic shield member 570 as compared with the case where the opening is provided.

  In the second embodiment, the mobile terminal device may be mounted with the vibration motor 500 according to the third embodiment instead of the vibration motor 100 according to the first embodiment. In this case, a thin portable terminal device with little leakage magnetic flux can be realized.

  The configuration and operation of the vibration motor and the mobile terminal device according to the embodiment have been described above. It is to be understood by those skilled in the art that these embodiments are exemplifications, and that various modifications can be made to combinations of the respective components, and such modifications are also within the scope of the present invention.

  In the first embodiment, the case where the guide frame 30 is provided on the upper surface 10a of the multilayer substrate 10 so as to surround the permanent magnet 20 and the coil 12 has been described. However, the present invention is not limited to this. For example, the guide frame 30 does not have to surround the entire coil 12, and the coil 12 may be provided under the guide frame 30.

  In the first embodiment, the case where the single-layer coil 12 is employed as the wiring layer 54 of the multilayer substrate 10 has been described. However, the present invention is not limited to this. For example, a laminated coil having two layers or three or more layers may be adopted as the coil 12. In this case, since the magnetic field generated in the coil 12 can be enhanced, the driving force of the permanent magnet 20 is improved. As a result, the response time of the permanent magnet 20 (time until the permanent magnet 20 reaches a predetermined vibration amount) can be shortened.

  In the first embodiment, the case where the laminated substrate 10 is present on one magnetic pole surface side of the permanent magnet 20 and the cover is present on the other magnetic pole surface side is described, but the present invention is not limited to this. For example, instead of the cover 102, a structure similar to the laminated substrate 10 may be adopted. By comprising in this way, the permanent magnet 20 is driven from the both magnetic pole surface side, and the driving force of the permanent magnet 20 improves. As a result, the response time of the permanent magnet 20 (time until the permanent magnet 20 reaches a predetermined vibration amount) can be shortened.

  In the first embodiment, the case where the magnetic fluid is thinly applied to the surface of the permanent magnet 20 so as to cover at least a part thereof has been described. It is desirable that the amount is such that it covers the entire surface of the magnet and does not significantly shield the magnetic flux generated by the permanent magnet 20. In this case, the above-mentioned effect of reducing the frictional resistance can be obtained without disturbing the magnetic flux generated by the permanent magnet 20 so much.

  In the first and third embodiments, the case of using a permanent magnet has been described. However, the present invention is not limited to this, and any member having a magnetic pole may be used. It goes without saying that the same argument holds even when the magnetic poles of the permanent magnet are reversed. In the first embodiment, the case where the permanent magnet 20 has one pair of magnetic poles has been described. However, the present invention is not limited to this, and the permanent magnet 20 may have any number of pairs of magnetic poles.

  In the first and third embodiments, the case where the laminated substrate includes two coils has been described, but the number of coils is not limited thereto.

  In the first and third embodiments, the case where the lower surface of the vibration motor faces the ground surface has been described. However, the present invention is not limited to this, and the upper surface of the vibration motor may face the ground surface. In this case, the permanent magnet reciprocates in contact with the inner surface of the cover (the cover substrate in the case of the third embodiment).

  In the first embodiment, the case where the permanent magnet 20 is formed in a disk shape has been described. However, the present invention is not limited thereto, and may be formed in an oval shape, for example. FIG. 6 is a top view showing a permanent magnet 28 according to a modification. The permanent magnet 28 has a shape in which two parts (parts indicated by broken lines) are cut off from the disk along two mutually parallel strings. The permanent magnet 28 is mounted on the vibration motor so as to move in the directions of arrows A1 and A2 in FIG. In this case, since the movement amount (movement range) of the permanent magnet 28 is expanded only by the cut-off portion, the permanent magnet 28 is further accelerated by that amount, so that the vibration amount of the vibration motor increases. Further, when the permanent magnet 28 moves between the coils 12, the contact portion between the permanent magnet 28 and the laminated substrate 10 is linear, but the frictional resistance is reduced as compared with the case where the permanent magnet 28 is not inclined but is in surface contact. Is done.

  In the first embodiment, both the second connection wiring 64 and the third connection wiring 66 are connected to the input end 16, and the direction of the spiral of the first planar coil 12a and the second planar coil 12b The case where the spirals are formed in different directions has been described. However, the present invention is not limited to this. For example, one end of the first planar coil 12a and one end of the second planar coil 12b are connected and common to both coils. When a driving current is applied, both coils may be configured to generate magnetic fluxes in different directions. In this case, both coils can be driven simultaneously by one drive current source, which contributes to simplification of the drive circuit.

  In the first embodiment, the case where the movement control unit 412 supplies the drive current to both the first planar coil 12a and the second planar coil 12b has been described. However, the present invention is not limited to this. For example, the first planar coil 12a and the second planar coil 12b may each include a separate movement control unit. In this case, since both coils are embedded in the laminated substrate, it is difficult to change the pitch of the spirals. The difference in the characteristics, for example, the inductance, can be easily compensated so that the performance of the vibration motor is improved.

  In the third embodiment, the case where the magnetic shield member is fixed to the permanent magnet by magnetic attraction has been described. However, the present invention is not limited to this. For example, the magnetic shield member is fixed to the permanent magnet by fixing means such as an adhesive. Also good. In this case, the reliability of fixing between the magnetic shield member and the permanent magnet can be further enhanced.

  In the third embodiment, the case where the magnetic shield member and the permanent magnet are in contact with each other has been described. However, the present invention is not limited to this, and the magnetic shield member may be moved along with the permanent magnet.

  In the vibration motor 500 according to the third embodiment, the surface of the first insulating resin layer 551 (or the cover substrate 502) is on the surface of the first insulating resin layer 551 and / or the cover substrate 502 or both on the moving element 520 side. There may be provided a low friction layer formed of a material having a lower coefficient of friction than the coefficient of friction it has. In this case, since the frictional resistance with the moving element 520 can be reduced, the efficiency of converting electric energy into vibration increases. Furthermore, the response time of the mover 520 (time until the mover 520 reaches a predetermined vibration amount) can be shortened. As a material constituting the above-described low friction layer, the same material as that of the low friction layer 58 in the first embodiment is used.

  In the third embodiment, the case where the first magnetic shield member 522 is formed so as not to protrude from the second magnetic pole surface 562 of the bonded permanent magnet is described, but the present invention is not limited to this. For example, the first magnetic shield member has at least a side surface of the bonded permanent magnet from a portion attached to the second magnetic pole surface 562 opposite to the first magnetic pole surface 560 facing the planar coil 512 of the bonded permanent magnet. You may extend so that a part may be covered. In this case, the first magnetic shield member fixes the bonded permanent magnet in the radial direction. Therefore, when the mover 520 reciprocates, the bonded permanent magnet and the first magnetic shield member are not easily displaced from each other in the radial direction. Thereby, the reliability of fixation between the first magnetic shield member and the bonded permanent magnet is improved.

  Further, the leakage of magnetic flux in the radial direction of the moving element 520 can be reduced by the portion extending to the side surface. Further, the height of the inner side surface of the first magnetic shield member may be formed so as to be equal to the thickness of the bonded permanent magnet. In this case, the leakage of the magnetic flux in the radial direction is further reduced.

  In the third embodiment, the case where the multilayer substrate 510 includes the first planar coil 512a and the second planar coil 512b has been described. However, the present invention is not limited to this. For example, the laminated substrate may include only one planar coil. In this case, the configuration of the laminated substrate is simplified.

  In the third embodiment, the case where the first permanent magnet 524 and the second permanent magnet 526 are directly bonded and fixed to each other has been described. However, the present invention is not limited to this. For example, a spacer may be inserted between the first permanent magnet 524 and the second permanent magnet 526, and the first permanent magnet 524 and the second permanent magnet 526 may be bonded and fixed to the spacer. In this case, the mass of the movable element 520 can be increased by the mass of the spacer, which contributes to an increase in the vibration amount.

  In the third embodiment, one end of the leaf spring is not fixed to the mover, which is one factor that causes the mover to move while being inclined with respect to the laminated substrate. The means for moving them is not limited to this. For example, the pitch of the wiring of the planar coil may be made dense on the center side and sparse on the outside. Further, when the second magnetic shield member is removed, the magnetic attractive force between the second magnetic shield member and the mover is lost, and the mover is more easily inclined.

  In the third embodiment, the configuration in which the bonded permanent magnet has two pairs of magnetic poles has been described. However, the present invention is not limited to this, and the configuration has an N pole and an S pole on the surface facing the planar coil. I just need it.

  In the third embodiment, the case where both the first plate spring 542 and the second plate spring 544 are springs made of a nonmagnetic material such as PET has been described. However, the present invention is not limited to this.

It is a top view of the vibration motor according to the first embodiment. It is the sectional view on the AA line of FIG. FIGS. 3A to 3D are conceptual diagrams showing how the permanent magnets reciprocate. It is a perspective view which shows the portable terminal device which concerns on 2nd Embodiment. It is a functional block diagram of the portable terminal device of FIG. It is a top view of the permanent magnet which concerns on a modification. It is a top view of the vibration motor which concerns on 3rd Embodiment. It is the sectional view on the AA line of FIG. FIG. 8 is a top view of the first wiring layer in FIG. 7. FIG. 8 is a top view of a second wiring layer in FIG. 7. It is a bottom view of the vibration motor of FIG. It is a top view which shows the state which the slider of FIG. FIGS. 13A to 13D are conceptual diagrams showing the reciprocal movement of the mover shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 100 Vibration motor, 10 Laminated board, 12 Coil, 12a 1st plane coil, 12b 2nd plane coil, 20 Permanent magnet, 30 Guide frame, 42 1st leaf | plate spring, 44 2nd leaf | plate spring, 400 Portable terminal Apparatus, 402 display unit, 404 power switch, 406 antenna, 408 housing, 412 movement control unit, 414 communication unit.

Claims (7)

A substrate having a coil;
A movable portion having a magnetic pole surface facing the coil on one surface side of the substrate and moving on the substrate;
A movement control unit for moving the movable unit;
An elastic member that urges the movable part in the movement direction when the movable part moves.
The movement control unit causes a magnetic thrust to be generated between the magnetic pole of the movable part and the coil by causing a current to flow through the coil, and the magnetic pole surface facing the coil of the movable part is A vibration motor characterized by being inclined with respect to one surface of a substrate.   2. The vibration motor according to claim 1, wherein an N pole and an S pole are arranged on the magnetic pole surface of the movable part in a moving direction of the movable part.   The vibration motor according to claim 1, wherein the movement control unit reciprocates the movable unit.   The vibration motor according to any one of claims 1 to 3, wherein an edge portion of the movable portion is processed into a rounded shape.   The vibration motor according to claim 1, wherein the coil is a spiral coil.   The vibration motor according to claim 1, wherein the movable portion moves on a single coil.   A portable terminal device comprising the vibration motor according to claim 1.

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