JP2018116702A - Electronic apparatus having vibration generating member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic apparatus having a piezoelectric vibration member which makes a thickness in the electronic apparatus thinner than a conventional one.SOLUTION: A vibration generating member 3 mounted onto a rear face of a liquid crystal touch input panel 10 has: a conductive diaphragm 30; a surface electrode layer 42 connected to the conductive diaphragm 30; a piezoelectric element 44 having the surface electrode layer 42 provided thereon and a piezoelectric vibration element 40 having a rear face electrode layer 46 provided on the rear face of the piezoelectric element 44; and a circuit board 20 having a surface side wiring pattern 24 including surface wiring 25 on a surface fixed to the liquid crystal touch input panel 10. The vibration generating member further includes a thorough conductive part 21 connecting the rear face electrode layer 46 of the piezoelectric vibration element 40 with the surface wiring 25 of the circuit board 20. The thorough conductive part 21 penetrates a central part of the circuit board 20 and the piezoelectric vibration element 40 in a state of being electrically insulated from a mounting electrode 27 to which the conductive diaphragm 30 is connected via a conductive bonding layer 32, the conductive diaphragm 30, and the surface electrode layer 42 of the piezoelectric vibration element 40.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an electronic device in which a vibration generating member is attached to the back surface of a panel member.

  Japanese Patent No. 5421500 (Patent Document 1) discloses an electronic device in which a vibration part is provided on the back side of a panel member, the vibration part is vibrated in a predetermined mode, and the vibration is transmitted to the panel member. Yes.

  Japanese Patent Laying-Open No. 2005-510815 (Patent Document 2) discloses an electronic device that vibrates a panel member using a piezoelectric vibrating member for a vibrating portion.

  Further, Japanese Patent No. 4426737 (Patent Document 3) discloses an electronic device (piezoelectric speaker system) in which an audible sound is generated from a panel member that is vibrated by a piezoelectric vibrating member and the panel member is used as a speaker.

Japanese Patent No. 5421500 JP 2005-510815 A Japanese Patent No. 4426737

  In conventional electronic devices that vibrate panel members, there is always a desire to reduce the thickness of the entire device. However, the structure of an electronic apparatus using a conventional piezoelectric vibration member as a vibration source cannot meet this demand.

  The objective of this invention is providing the electronic device provided with the piezoelectric vibration member which can make thickness of an electronic device thinner than before.

  An electronic apparatus to be improved by the present invention is an electronic apparatus including a panel member, a vibration generating member that is attached to the back surface of the panel member and vibrates, and a vibration control unit that controls vibration of the vibration generating member It is. In the present invention, the vibration generating member includes a conductive diaphragm, a surface electrode layer electrically connected to the conductive diaphragm, a piezoelectric element having the surface electrode layer provided on the surface, and a surface electrode on the back surface of the piezoelectric element. A plurality of piezoelectric vibration elements having a back electrode layer provided so as to face the layer, and a surface-side wiring pattern on the surface fixed to the panel member, and the conductivity of the plurality of piezoelectric vibration elements on the back surface A circuit board having a backside wiring pattern including a plurality of mounting electrodes to which a diaphragm is connected via a conductive bonding layer, a conductive diaphragm and a surface electrode layer of a piezoelectric vibration element, and a mounting electrode of the circuit board electrically In a state of being insulated, there is provided a through-connection structure portion that penetrates the center portion of the circuit board and the piezoelectric vibration element and connects the back electrode layer of the piezoelectric vibration element and the front electrode layer of the circuit board.

  According to the present invention, since the through-connection structure portion is provided, it is necessary to provide a lead wire for connection outside the piezoelectric vibration element in order to connect the back electrode layer of the piezoelectric vibration element and the front electrode layer of the circuit board. Disappear. As a result, the electronic device can be made thinner than before.

  When the panel member is a touch input panel member on which the user touches the surface, the vibration control unit vibrates the vibration generating member at a frequency that does not generate an audible sound from the touch input panel, thereby touching in conjunction with the touch. Since the input panel member can be vibrated, only a feeling of clicking can be given to the touching person.

  When the panel member is a display panel member that displays an image or video, the vibration control unit vibrates the vibration generating member at a frequency that generates audible sound from the display panel, thereby using the display panel member as a speaker. can do.

  The outer peripheral contour shapes of the conductive diaphragm, the front electrode layer, the piezoelectric element, and the back electrode layer may have a concentric disk shape. By adopting such a configuration, a piezoelectric vibration member can be configured at low cost by using a piezoelectric vibration element that can be used for an existing piezoelectric buzzer or the like.

  The mounting electrode, the conductive diaphragm, and the surface electrode layer are electrically separated from the through connection structure portion and the main body portion of the mounting electrode, the main body portion of the conductive diaphragm, and the main body portion of the surface electrode layer around the through connection structure portion. Each of the annular separation grooves is formed. By adopting such a configuration, it is possible to reliably prevent a short circuit from occurring when forming the through-connection structure portion.

  It is preferable that the main body portion of the attachment electrode is formed in a state where a plurality of through holes or through grooves into which the bonding agent constituting the conductive bonding layer enters are dispersed. According to this structure, the bonding agent can enter the dispersed through holes or through grooves to increase the bonding strength.

  When a multilayer circuit board having an internal wiring pattern therein is used as the circuit board, it is preferable that a ground conductive layer is further provided on the back surface of the multilayer circuit board via an insulating layer. When such a ground conductive layer is provided, the conductive layer exhibits a shielding effect.

  The touch input panel member may be an electrostatic touch input panel.

  When the plurality of mounting electrodes on the circuit board are arranged to form a plurality of electrode rows and two or more electrode columns, the vibration control unit is the same for a predetermined time when the user touches the touch input panel member. The operation of vibrating a plurality of piezoelectric vibration elements included in an electrode row at the same phase and vibrating a plurality of piezoelectric vibration elements included in other adjacent electrode columns at a phase opposite to the same phase is performed at a constant cycle. Can be done. If it does in this way, a touch input panel member can be vibrated entirely.

  In addition, when the plurality of mounting electrodes on the circuit board are arranged to form a plurality of electrode rows and two or more electrode columns, the vibration control unit is configured to be predetermined when the user touches the touch input panel member. The operation of driving the plurality of piezoelectric vibration elements so that two piezoelectric vibration elements adjacent in the time, row direction, or column direction vibrate in opposite phases can be performed by changing the phase for each fixed period. If it does in this way, a touch input panel member can be vibrated entirely.

  What is used as a speaker is the common-mode drive mode in which the sound pressure is maximized. The two-row drive mode in which the two rows of phases are alternately changed has some vibration and low sound. What is necessary is just to select a drive mode according to a use.

  As described above, according to the electronic device provided with the vibration generating member according to the present invention, since the through connection structure portion is provided, the thickness of the electronic device can be made thinner than the conventional one.

It is a cross-sectional view showing a layered configuration of an embodiment of an electronic device provided with a vibration generating member according to the present invention, and the thickness and other dimensions of each layer are appropriately changed for explanation (FIG. 2). The same applies to the following). FIG. 2 is an enlarged cross-sectional view of the electronic device of FIG. 1. It is the cross-sectional view which expanded further the circuit board part of embodiment of the electronic device provided with the vibration generation member of this invention. (A), (B), and (C) are respectively a perspective view and an exploded perspective view of a state in which a part of the vibration generating member including the piezoelectric vibration element of FIG. FIG. (A) is the cross-sectional view similar to FIG. 3 of the circuit board part in other embodiment of this invention, (B) is a cross-sectional view of the modification of FIG. 5 (A). (A), (B), (C), and (D) are respectively a perspective view and an exploded perspective view of a state where a part of a vibration generating member including another piezoelectric vibration element is cut from the back side, It is the disassembled perspective view seen from the side, and the perspective view seen from the surface side. It is a figure which shows the example which has arrange | positioned the several piezoelectric vibration element on the circuit board. FIGS. 8A and 8B are vibration distribution diagrams of the touch input panel member when the embodiment of FIG. 1 using the circuit board of FIG. 7 is driven in a waveform driving mode. FIGS. 8A and 8B are vibration distribution diagrams of the touch input panel member when the embodiment of FIG. 1 using the circuit board of FIG. 7 is driven in the staggered drive mode.

  Hereinafter, embodiments of an electronic device including a vibration generating member according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view for illustrating a configuration of an electronic device 1 including a vibration generating member according to the present invention. Specifically, the electronic device is a portable terminal such as a notebook computer, and FIG. It is a cross section of a display part. FIG. 2 shows a cross-sectional view of the main part of the piezoelectric vibrating member 3. In FIG. 1 and FIG. 2, hatching indicating a cross section is omitted.

  In FIG. 1, a liquid crystal touch input panel 10 is exposed on the surface of an electronic device, and a circuit board 20, a conductive diaphragm 30, and a piezoelectric vibration element 40 are laminated in that order from the front side on the lower layer on the back side. The configured vibration generating member 3 is configured. The liquid crystal touch input panel 10 has a capacitive touch switch function. The vibration generating member 3 is attached to the back surface of the liquid crystal touch input panel 10 so that vibration can be transmitted to the liquid crystal touch input panel 10.

  A plate-like damper 11 is provided below the vibration generating member 3, a metal bottom plate 12 is provided below the plate-like damper 11, and a synthetic resin base material 13 that constitutes a casing of the electronic device together with the frame 15 is provided below the plate-like damper 11. Yes. The plate-shaped damper 11 is provided with a projecting damper 14 projecting upward, and each of the dampers 11 and 14 may be excessively deformed by the external force of the liquid crystal touch input panel 10 or the vibration generating member may vibrate rapidly. This prevents damage and accidents from occurring. The thickness of the frame 15 is adjusted so that the gap between the dampers 11 and 14 in the stacking direction becomes an appropriate size.

  The conductive diaphragm 30 of the vibration generating member 3 is a brass thin plate. When a vibration control unit (not shown) generates an output signal and the piezoelectric vibration element 40 vibrates, the vibration is transmitted to the liquid crystal touch input panel 10. .

  In the present embodiment, the liquid crystal touch input panel 10 is a display panel / touch input panel, and a vibration control unit (not shown) vibrates the vibration generating member 3 from the liquid crystal touch input panel 10 at a frequency that does not generate an audible sound. In response to the touch, the liquid crystal touch input panel 10 is vibrated to give a click feeling to the person making the touch. The vibration control unit vibrates the vibration generating member 3 at a frequency at which audible sound is generated from the liquid crystal touch input panel 10, whereby the liquid crystal touch input panel 10 can be used as a speaker.

  As shown in FIG. 2, the piezoelectric vibration element 40 is provided so as to face the surface electrode layer 42 on the back surface of the piezoelectric element 44, and the surface electrode layer 42 provided on the front side of the piezoelectric element 44. And the back electrode layer 46. The surface electrode layer 42 is electrically connected to the conductive diaphragm 30. The piezoelectric element 44 is made of lead zirconate titanate (PZT), and the front electrode layer 42 and the back electrode layer 46 are formed by screen-printing silver paste on both surfaces of the piezoelectric element 44 or vapor-depositing silver. .

  In the present embodiment, the circuit board 20 is configured by forming a copper foil wiring pattern on both surfaces of a plate-like insulating layer 22. That is, the double-sided wiring patterns are the surface-side wiring pattern 24 printed on the surface fixed to the liquid crystal touch input panel 10 and the back-side wiring pattern to which the conductive diaphragms 30 of the plurality of vibration generating units 3 are connected. 26. The backside wiring pattern 26 and the conductive diaphragm 30 are connected via a conductive bonding layer 32 made of a conductive bonding material.

  Referring to the enlarged sectional view shown in FIG. 3, a plurality of attachment electrodes 27 are formed on the back side wiring pattern 26. The attachment electrode 27 is connected to the conductive diaphragm 30 through the conductive bonding layer 32, and is further electrically connected to the surface electrode layer 42 of the piezoelectric vibration element 40. As shown in FIGS. 2 and 4B, the attachment electrode 27 is formed with a plurality of through holes h dispersed therein. The plurality of through holes h are formed by etching copper foil. According to such a structure of the mounting electrode 27, the conductive bonding material enters the dispersed through holes h, and the bonding strength between the mounting electrode 27 and the conductive diaphragm 30 can be increased.

  As shown in FIG. 3, the portion other than the attachment electrode 27 of the back surface side wiring pattern 26 constitutes a back surface electrode lead 28. The back electrode lead 28 is connected to the back electrode layer 46 of the piezoelectric vibration element 40 through the through conductive part 29, the surface wiring 25, and the through conductive part 21 constituting the through connection structure part.

  2 and 3 is formed by filling the through hole 50 with a conductive paste or the like, and reaches the back electrode layer 46 of the piezoelectric vibration element 40 from the surface wiring 25 of the circuit board 20. The back electrode layer 46 and the surface wiring 25 of the circuit board 20 are connected. The through-hole 50 passes through the central portion of the circuit board 20, the conductive diaphragm 30 and the piezoelectric vibration element 40, and the through-conductive portion 21 passes therethrough.

  A ground conductive layer 23 is formed in a portion other than the surface wiring 25 of the surface side wiring pattern 24. When such a ground conductive layer 23 is provided, the ground conductive layer 23 exhibits a shielding effect.

  The vibration control unit is connected to the back electrode lead 28 and the attachment electrode 27, and vibrates the piezoelectric vibration element 40 by applying a drive voltage of a predetermined frequency between the front electrode layer 42 and the back electrode layer 46. . Thereby, the liquid crystal touch input panel 10 is vibrated through the conductive diaphragm 30 and the circuit board 20. An operator's touch on the liquid crystal touch input panel 10 is detected by a change in capacitance and input to the vibration control unit.

  As shown in FIG. 4, the outer peripheral contour shapes of the conductive diaphragm 30, the surface electrode layer 42, the piezoelectric vibration element 40, and the back electrode layer 46 are concentric disk shapes. When such a configuration is employed, the piezoelectric vibrating member 3 can be configured at low cost by using a piezoelectric vibrating element that can be used for an existing piezoelectric buzzer or the like.

  Further, as shown in FIGS. 4A to 4C, the mounting electrode 27, the conductive diaphragm 30, and the surface electrode layer 42 have a through conductive portion 21 (shown in FIGS. 2 and 3) around the through hole 50. (Not shown in FIG. 4) and annular separation grooves 52, 54 and 56 for electrically separating the main body portion of the mounting electrode 27, the main body portion of the conductive diaphragm 30 and the main body portion of the surface electrode layer 42. Are formed respectively. By adopting such a configuration, it is possible to prevent a short circuit from occurring even if the through conductive portion 21 is formed.

  FIG. 5A shows a cross-sectional view of a circuit board portion in another embodiment of the present invention. The circuit board portion of FIG. 5A performs the same function as the circuit board portion shown in FIG. 3, and is compatible as a constituent member of the vibration generating member. The circuit board 60 includes three insulating layers, that is, a surface insulating layer 62, an intermediate insulating layer 64, and a back surface insulating layer 66 in order from the front surface side. A wiring pattern is provided between both surfaces and between layers of each insulating layer. The surface of the surface insulating layer 62 is the ground conductive layer 70, and the surface insulating layer 62 and the intermediate insulating layer 64 are between the surface side wiring pattern 71 and the intermediate insulating layer. An intermediate wiring pattern 72 is provided between 64 and the back insulating layer 66, and a back wiring pattern 73 is provided on the back of the back insulating layer 66. A mounting electrode 74 and a back electrode lead 75 are formed on the back wiring pattern 73. The back electrode lead 75 is connected to the back electrode layer 46 of the piezoelectric vibration element 40 through the through conductive portion 76, the surface wiring 77 of the front side wiring pattern 71, and the through conductive portion 78. As shown in FIG. 5B, the ground conductive layer 70 on the circuit board portion in FIG. 5A may be removed.

  As shown in FIGS. 6A to 6D, the mounting electrode 74 has a disk shape that is concentric with the outer peripheral contour of the conductive diaphragm 30 and the piezoelectric vibration element 40 and is slightly larger, and penetrates around the through-conductive portion 78. An annular separation groove 79 that electrically separates the conductive portion 78 and the main body portion of the attachment electrode 74 is formed.

  Next, application to a portable terminal such as a notebook computer which is an electronic apparatus according to the present embodiment will be described. On the surface of the liquid crystal touch input panel 10 that is a display of the notebook computer, buttons, keys, images, and the like for the user to touch and input are displayed. A vibration control unit interlocked with a central control unit (not shown) of the personal computer that performs this display detects a location touched by the user on the capacitive liquid crystal touch input panel 10 from a change in capacitance. Then, the central control unit is informed of the touched location, and the vibration control unit receives a command from the central control unit, vibrates each piezoelectric vibration element 40, and inputs the liquid crystal touch through the conductive diaphragm 30 and the circuit board 20. The panel 10 is vibrated.

  When the frequency for vibrating the liquid crystal touch input panel 10 is low enough not to generate an audible sound, a click feeling is given to the touching person, and when the frequency is high enough to generate an audible sound, the clicking sound is supplied to the touching person. . If the touched part is incorrect or cannot be operated, in this embodiment, a click feeling or a warning sound different from the case of correct touch is generated and the user has an error or invalid operation. It can be set to notify that. In addition, based on the user's operation, it is possible to stop the generation of vibration and mute the click sound, or select the strength of the click feeling.

  When a plurality of mounting electrodes 27 are provided as in the present embodiment, the click feeling and the clicking sound can be obtained even by using the AC voltage of the same frequency by adjusting the phase of the AC voltage applied to each mounting electrode 27. The magnitude of vibration and sound pressure can be changed.

  As shown in FIG. 7, when a plurality of attachment electrodes are arranged so as to form a matrix of 5 rows × 2 columns and 10 piezoelectric vibration elements 40 are attached, the vibration control unit is attached to the touch input panel 10 by the user. Touches, a plurality of piezoelectric vibration elements included in the same electrode row are vibrated at the same phase for a predetermined time, and a plurality of piezoelectric vibration elements included in other adjacent electrode rows are vibrated at a phase opposite to the same phase. The operation can be performed by changing the phase every certain period. When driven in such a waveform drive mode, as shown in FIG. 8, the touch input panel 10 can be vibrated as a whole, and vibration and sound pressure are maximized. The waveform driving mode is suitable for the vibration of the touch input panel (generation of click feeling).

  In addition, when the user touches the touch input panel, the vibration control unit operates to drive a plurality of piezoelectric vibration elements so that two piezoelectric vibration elements adjacent in the row direction or the column direction vibrate in opposite phases for a predetermined time. The eight piezoelectric vibration elements 40 can be driven in the staggered drive mode in which the phase is changed at regular intervals. When the eight piezoelectric vibration elements 40 are driven in such a staggered drive mode, the touch input panel 10 can be vibrated as a whole as shown in FIGS. In this staggered drive mode, the vibration is small and the sound pressure is also small, which is suitable for a purpose of generating a click feeling in a quiet state.

  In the in-phase drive mode in which all the piezoelectric vibrating elements 40 are driven in the same phase, the sound pressure is the highest, so that it is suitable for use as a speaker. In the two-row drive mode in which the phases of the two rows of piezoelectric vibration elements are alternately changed, there is some vibration and sound is low. Thus, when a plurality of attachment electrodes are arranged in a matrix, each drive mode can be selected according to the application.

  As described above, according to the electronic apparatus of the present embodiment, since the through connection structure portion (the through hole 50, the through conductive portion 21, and the through conductive portion 78) is provided, the back electrode layer 46 and the circuit of the piezoelectric vibration element 40 are provided. In order to electrically connect the surface wiring 25 of the substrate 20, it is not necessary to provide a connection lead wiring outside the piezoelectric vibration element 40. As a result, the electronic device can be made thinner than before.

DESCRIPTION OF SYMBOLS 10 Liquid crystal touch input panel 20 Circuit board 22 Insulating layer 21 Through-conductive part (through-connection structure part)
24 Front-side wiring pattern 25 Front-side wiring 26 Back-side wiring pattern 27 Mounting electrode 28 Back-side electrode lead 30 Conductive diaphragm 32 Conductive bonding layer 40 Piezoelectric vibration element 42 Front-surface electrode layer 44 Piezo-electric element 46 Back-side electrode layer 50 Through-holes 52 and 54 56 Separation groove

Claims (10)

A panel member;
A vibration generating member that is attached to the back surface of the panel member and vibrates;
An electronic device including a vibration control unit that controls vibration of the vibration generating member,
The vibration generating member is
A conductive diaphragm; a surface electrode layer electrically connected to the conductive diaphragm; a piezoelectric element provided with the surface electrode layer on a surface; and a back surface of the piezoelectric element so as to face the surface electrode layer A plurality of piezoelectric vibration elements having a back electrode layer provided;
A back surface including a plurality of mounting electrodes having a front-side wiring pattern on the surface fixed to the panel member and connected to the back surface of the plurality of piezoelectric vibration elements through the conductive bonding layer. A circuit board having a side wiring pattern;
The conductive diaphragm and the surface electrode layer of the piezoelectric vibration element, and the center of the circuit board and the piezoelectric vibration element are penetrated through the piezoelectric substrate while being electrically insulated from the mounting electrode of the circuit board. An electronic apparatus comprising: a through-connection structure that connects the back electrode layer of the vibration element and the surface electrode layer of the circuit board. The panel member is a touch input panel member that a user touches the surface,
The electronic apparatus according to claim 1, wherein the vibration control unit vibrates at a frequency that does not generate an audible sound from the vibration generating member. The panel member is a display panel member that displays images and videos.
The electronic apparatus according to claim 1, wherein the vibration control unit vibrates the vibration generating member at a frequency that generates an audible sound from the display panel member.   4. The electronic device according to claim 1, wherein outer peripheral contour shapes of the conductive diaphragm, the surface electrode layer, the piezoelectric element, and the back electrode layer are concentric discs. 5.   The mounting electrode, the conductive diaphragm, and the surface electrode layer include a through connection structure portion, a body portion of the mounting electrode, a body portion of the conductive diaphragm, and a surface electrode layer around the through connection structure portion. The electronic device according to claim 4, wherein an annular separation groove for electrically separating the main body from each other is formed.   2. The electronic device according to claim 1, wherein a plurality of through holes or through grooves into which a bonding agent constituting the conductive bonding layer enters are dispersed in the main body portion of the attachment electrode. The circuit board is composed of a multilayer circuit board having an internal wiring pattern therein,
4. The electronic device according to claim 1, wherein a ground conductive layer is further provided on the back surface of the multilayer circuit board via an insulating layer. 5.   The electronic device according to claim 2, wherein the touch input panel member is an electrostatic touch input panel. The plurality of mounting electrodes of the circuit board are arranged to form a plurality of electrode rows and two or more electrode columns,
When the user touches the touch input panel member, the vibration control unit vibrates the plurality of piezoelectric vibration elements included in the same electrode row at the same phase for a predetermined time, and is included in another adjacent electrode row. The electronic apparatus according to claim 2, wherein an operation of vibrating a plurality of piezoelectric vibration elements at a phase opposite to the same phase is performed by changing a phase at a constant period.   The plurality of attachment electrodes of the circuit board are arranged so as to form a plurality of electrode rows and two or more electrode columns, and the vibration control unit touches the touch input panel member when the user touches the touch input panel member. The operation of driving the plurality of piezoelectric vibration elements so that the two piezoelectric vibration elements adjacent in the row direction or the column direction vibrate in opposite phases for a predetermined time is performed by changing the phase at regular intervals. 2. The electronic device according to 2.