JP2013175935A - Parametric speaker and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a parametric speaker which eliminates the need of a metal lead wire that causes abnormal noise and disconnection, and to provide a manufacturing method of the parametric speaker.SOLUTION: A parametric speaker 100 emits ultrasonic waves from multiple oscillation sources and comprises: a plate like substrate 110 where first and second wiring patterns 113, 115 are provided; a piezoelectric vibrator 124 that is supposed by the substrate 110 and is electrically connected with the first and second patterns 113, 115 through first and second conductive adhesives 114, 116 that are elastic when being solidified; and a resonator 127 provided on the piezoelectric vibrator 124 and producing the ultrasonic waves. This structure eliminates the need of a metal lead wire. As a result, even when the piezoelectric vibrator 124 vibrates, abnormal noise such as rustling noise and disconnection are prevented. Further, the conductive adhesives 114, 116 electrically connect the piezoelectric vibrator 124 with the wiring patterns while supporting the piezoelectric vibrator 124.

Description

  The present invention relates to a parametric speaker that emits ultrasonic waves from a plurality of oscillation sources and a method for manufacturing the same.

  The ultrasonic sounding body includes a piezoelectric vibrator in which a metal plate and a piezoelectric element are bonded. The ultrasonic sounding body vibrates by applying an AC voltage having a resonance frequency unique to the piezoelectric vibrator to the piezoelectric vibrator, and generates a sound having the same frequency as the resonance frequency. Since the resonance frequency is included in the ultrasonic band (exceeding 20 kHz), it is called an ultrasonic sounding body.

  A sound pressure can be increased by attaching a conical cylinder-shaped resonator (including a parabolic shape and a funnel shape) made of aluminum or an aluminum alloy to the piezoelectric vibrator. As a result, directivity of 60 to 70 degrees ahead of the ultrasonic sounding body can be provided. In the ultrasonic sounding body, a node portion of a piezoelectric vibrator that does not move in bending vibration is bonded and fixed to a substrate with a silicon adhesive or the like so as to prevent the vibration as much as possible.

  A parametric speaker is composed of a plurality of ultrasonic sounding elements arranged side by side, and the parametric speaker switches from ultrasonic waves to audible sound when the ultrasonic waves generated by the ultrasonic sounding elements reach in excess of the sound pressure that overlaps in the air. It uses the phenomenon of being demodulated and audible. Since only the central part where the ultrasonic waves overlap is an audible sound, the speaker has a sharp directivity.

  Such an ultrasonic sounding body has the same structure as the ultrasonic sensor. The ultrasonic sensor transmits and receives ultrasonic waves, and the ultrasonic sounding body only transmits ultrasonic waves. FIG. 12 is a cross-sectional view showing a conventional ultrasonic element 800. The ultrasonic element 800 is provided with an ultrasonic sensor 820 on a terminal block 810 and covered with a cover 818 having a hole. A ring-shaped protrusion 811 is formed on the terminal block 810, and the ultrasonic sensor 820 is bonded on the protrusion 811 with an adhesive 812. The terminal 815 passes through the terminal block 810 and is connected by a metal lead wire 816.

  As described above, conventionally, the terminal 815 and the ultrasonic sensor 820 are connected by the metal lead wire 816, and a voltage is applied to the ultrasonic sensor 820. However, when the lead wire 816 is used, when the ultrasonic sensor 820 vibrates, the lead wire 816 is also caught and vibrates, and the lead wire 816 comes into contact with the piezoelectric vibrator, the terminal block 810, etc. There is a possibility that a sound may be emitted or a disconnection may occur. As a countermeasure against this, the lead wire 816 is fixed with a silicon adhesive 817 or the like to suppress vibration.

  Also, a super directional speaker having a structure similar to such a connection structure has been proposed. In the superdirective speaker described in Patent Document 1, the connection between the ultrasonic vibrator and the pattern on the double-sided printed circuit board is performed by lead wires.

JP-A-3-58600

  The structure of a conventional ultrasonic sensor or the speaker described in Patent Document 1 can be applied to a parametric speaker. FIG. 13 is a cross-sectional view showing a parametric speaker to which a conventional connection is applied. In the parametric speaker 900, a piezoelectric vibrator 920 is bonded to a ring-shaped protrusion 911 on a substrate 910 with a silicon adhesive 912. Wiring patterns 913 and 914 are provided on the substrate 910, and the wiring patterns 913 and 914 and the piezoelectric vibrator 920 are connected by lead wires 915 and 916. The lead wires 915 and 916 are fixed with silicon adhesives 917 and 918.

  However, when a plurality of ultrasonic sounding bodies are mounted on a substrate as a parametric speaker, if the terminals and the piezoelectric vibrator are connected with metal lead wires as described above, the number of lead wires increases, and abnormal noise and disconnection occur. Likely to happen.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a parametric speaker that eliminates the need for metal lead wires that cause abnormal noise and disconnection, and a method of manufacturing the same.

  (1) In order to achieve the above object, a parametric speaker according to the present invention is a parametric speaker that radiates ultrasonic waves from a plurality of oscillation sources, and is a flat substrate provided with first and second wiring patterns. A piezoelectric vibrator supported by the substrate and electrically connected to each of the first and second wiring patterns via first and second conductive adhesives that solidify and have elasticity; and And a resonator which is provided on the piezoelectric vibrator and oscillates an ultrasonic wave.

  As described above, the parametric speaker according to the present invention electrically connects the wiring pattern and the piezoelectric vibrator via the conductive adhesive, so that the metal lead wire can be dispensed with. As a result, even if the piezoelectric vibrator vibrates, no abnormal noise such as rubbing noise or disconnection occurs. Further, the piezoelectric vibrator can be electrically connected to the wiring pattern while being supported by the conductive adhesive.

  (2) Further, the parametric speaker of the present invention is characterized in that an insulating adhesive is further provided between the first conductive adhesive and the second conductive adhesive. Thereby, a short circuit between the first conductive adhesive and the second conductive adhesive can be prevented without disturbing the vibration of the piezoelectric vibrator.

  (3) Further, in the parametric speaker according to the present invention, the second conductive adhesive is provided between a support portion supporting the piezoelectric vibrator and the piezoelectric vibrator, and the second conductive adhesive is disposed on the support portion. It is characterized in that it is electrically connected to the second wiring pattern. Thereby, the adhesion area | region by a 2nd conductive adhesive can be restrict | limited small, the insulation with a 1st conductive adhesive and a 2nd conductive adhesive can be made easy, and workability | operativity of manufacture can be improved. .

  (4) Further, in the parametric speaker according to the present invention, the first conductive adhesive has a height that is approximately the same as the height at which the metal plate included in the piezoelectric vibrator is positioned with respect to the substrate. It is characterized by being provided. Thereby, the bonding position of the first conductive adhesive and the bonding position of the second conductive adhesive can be separated without interfering with the vibration of the piezoelectric vibrator, and a short circuit between them can be prevented.

  (5) The parametric speaker manufacturing method of the present invention is a method of manufacturing a parametric speaker that emits ultrasonic waves from a plurality of oscillation sources, and a resonator that oscillates ultrasonic waves is provided on a piezoelectric vibrator. A step of preparing a flat substrate provided with first and second wiring patterns based on an installation location of the ultrasonic sounding body, and a first and second wiring pattern respectively for the first and second wiring patterns. A step of placing the ultrasonic sounding body on a substrate while being connected to the piezoelectric vibrator via a conductive adhesive.

  Thereby, a metal lead wire can be made unnecessary. As a result, even if the piezoelectric vibrator vibrates, no abnormal noise such as rubbing noise or disconnection occurs. Further, the piezoelectric vibrator can be electrically connected to the wiring pattern while being supported by the conductive adhesive.

  According to the present invention, it is possible to eliminate the need for a metal lead wire that causes abnormal noise or disconnection.

It is sectional drawing which shows the parametric speaker which concerns on 1st Embodiment. It is a top view which shows the parametric speaker which concerns on 1st Embodiment. It is the schematic which shows the electric constitution of the parametric speaker of this invention. It is sectional drawing which shows the parametric speaker which concerns on 2nd Embodiment. It is sectional drawing which shows the parametric speaker which concerns on 3rd Embodiment. It is sectional drawing which shows the parametric speaker which concerns on 4th Embodiment. It is a top view which shows a board | substrate. It is sectional drawing which shows the parametric speaker which concerns on 5th Embodiment. It is sectional drawing which shows the parametric speaker which concerns on 6th Embodiment. It is a top view which shows a board | substrate. It is a bottom view which shows a board | substrate. It is sectional drawing which shows the conventional ultrasonic sensor. It is sectional drawing which shows the parametric speaker which applied the conventional connection.

  Next, embodiments of the present invention will be described with reference to the drawings. In order to facilitate understanding of the description, the same reference numerals are given to the same components in the respective drawings, and duplicate descriptions are omitted.

[First Embodiment]
(Configuration of parametric speaker)
1 to 3 are a cross-sectional view, a plan view, and a schematic diagram showing an electrical configuration of the parametric speaker 100, respectively. FIG. 3 is a schematic diagram in which the control circuit and the like are omitted. The parametric speaker 100 includes a substrate 110 and an ultrasonic sound generator 120, and the ultrasonic sound generator 120 is supported by a ring-shaped protrusion 112 formed on the substrate 110 with a vibration node of the piezoelectric vibrator 124. Yes. The protrusion 112 protrudes from the bottom of the substrate 110 to the extent that the piezoelectric vibrator 124 does not come into contact with the substrate 110 even when bending.

  The ultrasonic sounding body 120 includes a piezoelectric vibrator 124 and a resonator 127, and the piezoelectric vibrator 124 includes a piezoelectric element 125 and a metal plate 126. The piezoelectric element 125 expands and contracts when a voltage is applied from the AC power supply 130, and the piezoelectric vibrator 124 bends and vibrates accordingly. The resonator 127 is provided on the piezoelectric vibrator 124 and oscillates an ultrasonic wave. In this manner, the plurality of ultrasonic sounding bodies 120 serve as oscillation sources, emit ultrasonic waves, and can transmit sound in a directional manner.

  The substrate 110 is formed in a flat plate shape and provided with a pair of wiring patterns 113 and 115. The wiring patterns 113 and 115 are connected to the AC power supply 130 on the one hand and connected to the piezoelectric vibrator 124 on the other hand. The wiring pattern 113 (first wiring pattern) is connected to the metal plate 126 via a conductive adhesive 114 (first conductive adhesive), and the wiring pattern 115 (second wiring pattern) is conductive. The piezoelectric element 125 is connected via an adhesive 116 (second conductive adhesive).

  The piezoelectric vibrator 124 and the wiring patterns 113 and 115 are connected using conductive adhesives 114 and 116 instead of lead wires. Use of the conductive adhesives 114 and 116 eliminates the need for lead wires that cause abnormal noise and disconnection. The conductive adhesives 114 and 116 also serve to bond the piezoelectric vibrator 124 to the substrate 110, and can perform both conduction and adhesion at the same time. The conductive adhesive is obtained by dispersing a conductive filler in a binder. Examples of the conductive filler include silver powder, gold powder, copper powder, nickel powder, aluminum powder, plating powder, carbon powder, and graphite powder. Examples of the binder include silicon resin, epoxy resin, urethane resin, acrylic resin, and polyimide resin. It is preferable to use a conductive adhesive having a Young's modulus of 30 MPa or less in a solidified state. Thereby, since the conductive adhesive is sufficiently soft, vibration is not hindered.

  When the wiring pattern 113 is connected to the metal plate 126 using the conductive adhesive 114, the conductive adhesive 114 exists in the vicinity of the side surface of the piezoelectric element 125, and thus the conductive adhesive 116 connected to this and the piezoelectric element 125. There is a risk of short circuit. Therefore, the parametric speaker 100 is preferably filled with an insulating adhesive 117 between the conductive adhesive 114 and the conductive adhesive 116.

  In that case, the conductive adhesives 114 and 116 and the insulating adhesive 117 are made of a sufficiently soft material so as not to suppress the vibration of the piezoelectric vibrator. Thereby, a short circuit between the conductive adhesive 114 and the conductive adhesive 116 can be prevented without disturbing the vibration of the piezoelectric vibrator 124. For example, a silicon adhesive is used as the insulating adhesive 117.

(Manufacturing method of parametric speaker)
A method for manufacturing the parametric speaker configured as described above will be described. First, the ultrasonic sounding body 120 and the substrate 110 are prepared. The flat substrate 110 is designed so that the installation location of the ultrasonic sounding body 120 is determined in advance and a ring-shaped protrusion 112 is formed at the installation position. The wiring patterns 113 and 115 are preferably provided at positions where they can be easily connected to the piezoelectric vibrator 124 and printed on the substrate 110 in a comb-like shape.

  Next, the ultrasonic sounding body 120 is placed on the substrate. A piezoelectric vibrator 124 is connected to each of the wiring patterns 113 and 115 via conductive adhesives 114 and 116, and the piezoelectric vibrator 124 is bonded onto the protrusion 112. This eliminates the need for metal lead wires that have been used in the past, and no abnormal noise such as rubbing or disconnection occurs even when the piezoelectric vibrator vibrates. Further, the conductive vibrators 114 and 116 can be electrically connected to the wiring patterns 113 and 115 while supporting the piezoelectric vibrator 124.

[Second Embodiment]
In the above embodiment, the ring-shaped protrusion is formed on the substrate 110, but a ring-shaped spacer may be provided instead. FIG. 4 is a cross-sectional view showing a parametric speaker 200 provided with a ring-shaped spacer.

  In the parametric speaker 200, a ring-shaped conductive spacer 212 is provided at the installation position of the ultrasonic sounding body 120 on the substrate 210. The conductive spacer 212 supports the piezoelectric vibrator 124 and functions as a support portion for the piezoelectric vibrator 124. The conductive adhesive 116 is provided between the ring-shaped conductive spacer 212 and the piezoelectric vibrator 124, and is electrically connected to the wiring pattern 215 (second wiring pattern) on the conductive spacer 212. . The electrode of the piezoelectric element 125 included in the piezoelectric vibrator 124 and the wiring pattern 115 are electrically connected via the conductive spacer 212 and the conductive adhesive 116. Thereby, the adhesion area | region by the conductive adhesive 116 can be restrict | limited small, insulation of the conductive adhesive 114 and the conductive adhesive 116 can be made easy, and workability | operativity of manufacture can be improved.

  It should be noted that the parametric speaker 200 can be manufactured in the same manner as in the first embodiment except that the ring-shaped conductive spacer 212 is previously bonded to a predetermined position on the substrate 210 with a conductive adhesive. In the embodiment in which the wiring pattern 115 is next to the ring-shaped conductive spacer 212, the conductive adhesive 116 must be spread and applied. In this embodiment, the conductive spacer 212 is on the wiring pattern 115. Since both are connected to each other, it is not necessary to spread the conductive adhesive 116 during manufacture.

[Third Embodiment]
In the above embodiment, the bonding range of the conductive adhesive 116 is narrowed using the conductive spacer 212. However, a wiring pattern is provided on the ring-shaped protrusion, and the wiring pattern and the electrode of the piezoelectric element 125 are provided. May be adhered. FIG. 5 is a cross-sectional view showing a parametric speaker 300 in which a wiring pattern is provided on the protrusion.

  In the parametric speaker 300, a ring-shaped protrusion 312 is formed on the substrate 310, and the wiring pattern 315 (second wiring pattern) is provided on the ring-shaped protrusion 312. The ring-shaped protrusion 312 supports the piezoelectric vibrator 124. Thereby, the adhesion area | region by the conductive adhesive 116 can be restrict | limited small, and the conductive adhesive 114 and the conductive adhesive 116 can be insulated easily. That is, it is not necessary to spread the conductive adhesive as in the above embodiment. The parametric speaker 300 can be manufactured in the same manner as in the first embodiment except that the protrusion 312 is formed and the wiring pattern 315 is provided thereon.

[Fourth Embodiment]
In the above embodiment, there is a height difference between the wiring pattern 113 provided on the substrate and the metal plate 126, and the height difference is filled with the conductive adhesive 114, but the bonding range is set at a higher position. It may be limited. FIG. 6 is a cross-sectional view showing a parametric speaker 400 in which the metal plate and the wiring pattern are bonded at a high position. FIG. 7 is a plan view showing a substrate 410 constituting the parametric speaker 400.

  In the parametric speaker 400, conductive pins 413 are provided on the wiring pattern 113 of the substrate 410. The metal plate 126 and the wiring pattern 113 are electrically connected via the pin 413 and the conductive adhesive 114. Therefore, the position of the conductive adhesive 114 is limited to a height similar to the height at which the metal plate 126 is positioned with respect to the substrate 110. As a result, the bonding position of the conductive adhesive 114 and the bonding position of the conductive adhesive 116 can be separated without hindering the vibration of the piezoelectric vibrator 124, and a short circuit between them can be prevented. In this case, it is not necessary to sandwich an insulator between the conductive adhesives 114 and 116, and workability in the manufacturing process is improved. The parametric speaker 400 can be manufactured in the same manner as in the first embodiment except that the pins 413 are provided on the wiring pattern 113 in advance.

[Fifth Embodiment]
In the above embodiment, the conductive plate 413 connects the metal plate 126 and the wiring pattern 113 at the same position as the metal plate 126 by the conductive adhesive 114. However, instead of the pin 413, the wiring pattern is used. The substrate may be raised at the position. FIG. 8 is a cross-sectional view showing a parametric speaker 500 formed by raising a substrate.

  The substrate 510 is formed such that a portion where the wiring pattern 513 (first wiring pattern) is provided is raised from a portion where the wiring pattern 115 is provided. For this reason, the conductive adhesive 114 is limited to a range having a height comparable to the height at which the metal plate 126 is positioned with respect to the substrate 510, and the bonding position of the conductive adhesive 114 and the bonding of the conductive adhesive 116. A position can be isolate | separated and both short circuit can be prevented. The parametric speaker 500 can be manufactured in the same manner as in the first embodiment except that the wiring pattern 513 is provided on the raised portion 512 in advance.

[Sixth Embodiment]
In the above embodiment, the position of the conductive adhesive 114 is maintained at the same level as that of the metal plate 126 by the pins and the raised portions of the substrate, but a hole is provided in the substrate so that the ultrasonic sounding body can enter. An ultrasonic sounding body may be installed in the hole. FIG. 9 is a cross-sectional view showing a parametric speaker 600 in which holes are provided in the substrate. 10 and 11 are a plan view and a bottom view showing the substrate 610, respectively.

  A hole 611 is formed in the substrate 610 with a portion where the wiring pattern 613 (first wiring pattern) is provided as an edge and a portion supporting the piezoelectric vibrator 124 as a bottom. Actually, a conductive through hole 616 is exposed at the bottom of the hole, and a ring-shaped protrusion 112 is also formed at the bottom of the hole.

  The wiring pattern 615 (second wiring pattern) is provided on the main surface opposite to the main surface of the substrate 610 on which the wiring pattern 613 is provided, and is electrically conductive by a through hole 616 penetrating through the substrate 610. It is electrically connected to the adhesive 116. Thereby, in design, the bonding position of the conductive adhesive 114 and the bonding position of the conductive adhesive 116 can be easily separated, and the wiring pattern 615 can be easily formed.

  The embodiments for separating the conductive adhesive 114 described above are all preferable examples. If the wiring pattern and the metal plate 126 can be connected to each other by the conductive adhesive 114 at the height of the metal plate 126, it is easy. Short circuit can be prevented.

100 Parametric speaker 110 Substrate 112 Projection 113 Wiring pattern (first wiring pattern)
114 conductive adhesive (first conductive adhesive)
115 wiring pattern (second wiring pattern)
116 conductive adhesive (second conductive adhesive)
117 Insulating adhesive 120 Ultrasonic sound generator 124 Piezoelectric vibrator 125 Piezoelectric element 126 Metal plate 127 Resonator 130 AC power source 200 Parametric speaker 210 Substrate 212 Conductive spacer 215 Wiring pattern (second wiring pattern)
300 Parametric speaker 310 Substrate 312 Protrusion 315 Wiring pattern (second wiring pattern)
400 Parametric speaker 410 Substrate 413 Pin 500 Parametric speaker 510 Substrate 512 Raised portion 513 Wiring pattern (first wiring pattern)
600 Parametric speaker 610 Substrate 611 Hole 613 Wiring pattern (first wiring pattern)
615 wiring pattern (second wiring pattern)
616 Through hole

Claims (5)

A parametric speaker that emits ultrasonic waves from a plurality of oscillation sources,
A flat substrate provided with first and second wiring patterns;
A piezoelectric vibrator supported by the substrate and electrically connected to each of the first and second wiring patterns via first and second conductive adhesives that solidify and have elasticity;
A parametric speaker comprising: a resonator provided on the piezoelectric vibrator and configured to oscillate ultrasonic waves.   The parametric speaker according to claim 1, further comprising an insulating adhesive between the first conductive adhesive and the second conductive adhesive.   The second conductive adhesive is provided between a support portion that supports the piezoelectric vibrator and the piezoelectric vibrator, and is electrically connected to the second wiring pattern on the support portion. The parametric speaker according to claim 1 or 2, characterized by the above.   The said 1st conductive adhesive is provided in the position which has the height comparable as the height in which the metal plate contained in the said piezoelectric vibrator is located with respect to the said board | substrate. The parametric speaker according to claim 3. A method of manufacturing a parametric speaker that emits ultrasonic waves from a plurality of oscillation sources,
Preparing a plate-like substrate provided with first and second wiring patterns based on an installation location of an ultrasonic sounding body provided with a resonator that oscillates ultrasonic waves on a piezoelectric vibrator;
Placing the ultrasonic sounding body on the substrate while connecting to the piezoelectric vibrator via the first and second conductive adhesives to the first and second wiring patterns, respectively. A method for manufacturing a parametric speaker.

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