Piezoelectric vibration device

Abstract

Provided is a piezoelectric vibration device that supresses warping of a sealing member during resin molding. A piezoelectric vibration device 1 comprises: a vibrator 2 in which at least a vibrating portion 5 is sealed with a first sealing member 7 and a second sealing member 8 which are sealing members; an integrated circuit element 10 which is at least an electronic component element; a substrate 11 having a mounting surface 11a with the vibrator 2 and the integrated circuit element 10 mounted thereon; and a mold portion 12 covering at least the vibrator 2 with resin. The vibrator 2 includes a protection member 9 covering a part or all of at least one of the first sealing member 7 and the second sealing member 8.

Description

Technical Field

[0001] This invention relates to a piezoelectric vibration device.

Background Art

[0002] Piezoelectric vibration devices include, for example, crystal oscillators using a crystal vibrating piece. The crystal oscillator has a crystal vibrating piece that is a piezoelectric element, a holding member that holds the crystal vibrating piece, and a lid member that seals the holding member. The crystal vibrating piece is held in the box-shaped holding member made of an insulator such as ceramic. The crystal oscillator is sealed by a lid member in a state where the electrode of the crystal vibrating piece and the electrode in the holding member are joined.

[0003] Such a piezoelectric vibration device is expensive because the lid member made of metal or glass is joined to the holding member made of ceramic. Also, since the box-shaped holding member and the lid member are overlapped, the thickness of the piezoelectric vibration device increases. Therefore, a piezoelectric vibration device is known in which a piezoelectric vibration plate having a vibration portion having a first excitation electrode and a second excitation electrode, and an outer frame portion that is connected to the vibration portion via a connecting portion and surrounds the vibration portion, is sealed with a sealing material. For example, in the piezoelectric vibration device described in Patent Document 1, a sealing material made of a resin film is joined to the outer frame portion that is thicker than the vibration portion so as to cover the vibration portion.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The piezoelectric vibration device described in Patent Document 1 has at least the vibrating portion covered with a resin material for protecting the piezoelectric vibration device. In a device that combines a piezoelectric vibration device having the configuration described in Patent Document 1, or a vibrator having a box-shaped holding member containing a piezoelectric vibration plate sealed with a sealing material, and an electronic component element such as an integrated circuit element, in order to protect the crystal oscillator and the electronic component element from the external environment, these elements may be covered with resin. In such a device, it is molded (molded) with resin in a closed mold. At this time, a molding pressure is applied to the piezoelectric vibration device from the resin filled in the mold. Therefore, the Stop material elastically deforms toward the vibrating portion side due to the molding pressure. Therefore, the Stop material may contact the vibrating portion depending on the material, thickness of the Stop material , the size of the outer frame portion of the piezoelectric vibration plate, and the magnitude of the molding pressure.

[0006] An object of the present invention is to provide a piezoelectric vibration device capable of suppressing the deflection of a sealing member during molding with resin.

Means for Solving the Problems

[0007] The inventors of the present invention have studied a piezoelectric vibration device capable of suppressing the deflection of a sealing member during molding with resin. As a result of intensive studies, the inventors of the present invention have conceived the following configuration.

[0008] A piezoelectric vibration device having a vibrator in which at least the vibrating portion is sealed with a sealing member, at least an electronic component element, a substrate on which the vibrator and the electronic component element are mounted on its mounting surface, and a mold portion that covers at least the vibrator with resin. The vibrator has a protective member that covers at least a part of the sealing member.

[0009] In the above configuration, the PartThe vibrator sealed by the material has at least a part of the sealing member covered by the protective member. The resin filled in the mold does not contact the portion of the sealing member covered by the protective member. Therefore, the molding pressure from the resin filled in the mold does not act on the sealing member covered by the protective member. Thereby, the deflection of the sealing member during molding with the resin can be suppressed.

[0010] From another aspect, the piezoelectric vibration device of the present invention preferably includes the following configuration. The vibrator includes a frame portion, a piezoelectric vibration plate in which the vibration portion located within the frame of the frame portion is integrally formed, and sealing members respectively joined to one main surface and the other main surface of the frame portion of the piezoelectric vibration plate and closing the opening portions of the one main surface and the other main surface, and is configured as a laminate of three or more layers. A part or all of the sealing member that closes at least one of the opening portions of the one main surface and the opening portion of the other main surface of the vibrator is covered by a protective member.

[0011] In the above-described configuration, at least a part of the sealing member that closes the opening portion of the frame portion of the vibrator is covered by the protective member. The molding pressure from the resin filled in the mold acts on the protective member that covers the sealing member. Therefore, at least a part of the sealing member is covered by the protective member, thereby improving the resistance to the molding pressure from the resin filled in the mold. Thereby, the deflection of the sealing member during molding with the resin can be suppressed.

[0012] From another aspect, the piezoelectric vibration device of the present invention preferably includes the following configuration. The vibrator includes at least a piezoelectric element having the vibration portion, a box-shaped holding member having an opening on one main surface and forming a frame portion, and a sealing member closing the opening portion of the holding member holding the piezoelectric element within the frame portion, and a part or all of the sealing member is covered by a protective member.

[0013] In the above configuration, at least a part of the sealing member that closes the opening portion of the holding member is covered by the protection member for the vibrator. The molding pressure from the resin filled in the mold is applied to the protection member that covers the sealing member. Therefore, at least a part of the sealing member is covered by the protection member, thereby improving the resistance to the molding pressure from the resin filled in the mold. Thereby, the deflection of the sealing member during molding with the resin can be suppressed.

[0014] From another aspect, the piezoelectric vibration device of the present invention preferably includes the following configuration. The vibrator includes a piezoelectric vibration plate in which the vibration portion is integrally formed within the frame of the frame portion, and is joined to one main surface and the other main surface having an opening portion of the frame portion in the piezoelectric vibration plate, respectively, and seals the opening portion of the one main surface and the opening portion of the other main surface. It is configured as a laminate of three or more layers having a member, and at least the main surface of the frame portion One side A part or all of the sealing member that closes the opening portion of is covered by the protection member.

[0015] In the above configuration, the vibrator is configured as a three-layer laminated body in which both openings in the piezoelectric vibration plate in which the vibration portion is integrally formed within the frame of the frame portion are sealed by the sealing member. Further, the sealing member of the vibrator has improved resistance to the molding pressure by the protection member. Thereby, the deflection of the sealing member during molding with the resin can be suppressed. Therefore, even if the thickness of the piezoelectric vibration plate is adjusted to suppress the thickness in the stacking direction of the vibrator, the vibration portion and the sealing member do not come into contact with each other.

[0016] From another aspect, the piezoelectric vibration device of the present invention preferably includes the following configuration. A part of the vibration portion of the vibrator is connected to the frame portion via a connecting portion, and the sealing member is a resin film.

[0017] In the above configuration, the vibrator is covered with the resin film that easily elastically deforms the frame portion. Further, the vibrator covers at least a part of the sealing member, which is a resin film that easily elastically deforms, with the protection member, thereby improving the resistance of the sealing member to the molding pressure of the resin filled in the mold. Thereby, it is possible to suppress the deflection of the resin film during molding with the resin.

[0018] From another aspect, the piezoelectric vibration device of the present invention preferably includes the following configuration. The vibrator has recesses on one or both of the main surfaces of the piezoelectric vibration plate, and the recesses serve as the vibration portions.

[0019] In the above configuration, the piezoelectric vibration plate forms the vibration portion by the recesses that each recess a part of one or both of the main surfaces. Therefore, the vibration plate can be thinned in the vibration portion in, for example, an AT-cut crystal plate. Further, in a vibrator having such a piezoelectric vibration plate, by covering a part of the sealing member that covers the recess with the protection member, the resistance of the sealing member to the molding pressure of the resin filled in the mold is improved. Thereby, it is possible to suppress the deflection of the sealing member during molding with the resin.

[0020] From another aspect, the piezoelectric vibration device of the present invention preferably includes the following configuration. The vibrator and the Electronic component element are located on the same mounting surface of the substrate.

[0021] In the above configuration, Electronic component element since the vibrator and the Electronic component element are located on the same mounting surface of the substrate, the height of the substrate can be reduced compared to a configuration in which the vibrator is located on one main surface of the substrate and the

[0022] From another aspect, the piezoelectric vibration device of the present invention preferably includes the following configuration. The protection member at least partially overlaps the frame portion when viewed in the direction perpendicular to the main surface.

[0023] In the above configuration, the protection member covers a part of the sealing member while being supported by the frame portion. That is, the molding pressure of the resin applied to the protection member is received by the frame portion. Thereby, the deflection of the sealing member during molding with the resin can be suppressed.

[0024] From another aspect, it is preferable that the piezoelectric vibration device of the present invention includes the following configuration. The peripheral edge of the sealing member is located inward of the outer peripheral edge of the frame portion, and the peripheral edge of the protection member is located outward of the peripheral edge of the sealing member.

[0025] In the above configuration, the end face of the sealing member is located in the gap between the frame portion and the protection member. Thereby, the resin enters the gap due to the pressure during molding. Therefore, the deformation of the end face of the sealing member located in the gap between the frame portion and the protection member is suppressed by the resin. Further, since the protection member is larger than the sealing member, even if the position with respect to the sealing member is slightly deviated, at least a part of the sealing member can be covered. Thereby, the deflection of the sealing member during molding with the resin can be more reliably suppressed.

[0026] From another aspect, it is preferable that the piezoelectric vibration device of the present invention includes the following configuration. The protection member is thicker than the sealing member.

[0027] In the above configuration, the second moment of inertia in the direction perpendicular to the main surface of the vibrator in the protection member is larger than the second moment of inertia in the direction perpendicular to the main surface in the sealing member. Therefore, even if the protection member is made of the same material as the sealing member, it has higher rigidity than the sealing member. Thereby, the deflection of the sealing member during molding with the resin can be suppressed.

[0028] From another perspective, the piezoelectric vibration device of the present invention preferably includes the following configuration. The substrate is made of a resin material. In this configuration, the substrate of the piezoelectric vibration device is made of a resin material that is easy to process such as cutting. Thereby, the piezoelectric vibration device having an arbitrary shape can be easily configured.

[0029] From another perspective, the piezoelectric vibration device of the present invention preferably includes the following configuration. The protective member is made of a brittle material. In this configuration, the protective member has a smaller amount of deflection with respect to the load compared to an elastic material. Thereby, the deflection of the sealing member during molding with the resin can be suppressed.

[0030] From another perspective, the piezoelectric vibration device of the present invention preferably includes the following configuration. The protective member is joined to the sealing member via a bonding material. In this configuration, the protective member is in close contact with the sealing member by the bonding material. Since the protective member is in close contact with the sealing member, the resistance of the sealing member to the molding pressure of the resin filled in the mold is further improved. Thereby, the deflection of the sealing member during molding with the resin can be suppressed.

[0031] From another perspective, the piezoelectric vibration device of the present invention preferably includes the following configuration. The electronic component element is at least an integrated circuit element having an oscillation circuit element of the oscillator. In this configuration, in the piezoelectric vibration device, the oscillator and the integrated circuit element for the oscillator are arranged on the same substrate. Thereby, the piezoelectric vibration device can be configured compactly.

[0032] From another perspective, the piezoelectric vibration device of the present invention preferably includes the following configuration. The protective member is constituted by an electronic component element. In this configuration, the sealing member is protected by the electronic component element necessary for the piezoelectric vibration device. That is, the protective member not only protects the sealing member but also has a function necessary for controlling the piezoelectric vibration device. Thereby, while protecting the vibrator, the piezoelectric vibration device can be configured compactly.

Effects of the Invention

[0033] According to an embodiment of the present invention, it is possible to suppress the deflection of the sealing member during resin molding.

Brief Description of the Drawings

[0034]

Figure 1

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Figure 16

BEST MODE FOR CARRYING OUT THE INVENTION

[0035] Hereinafter, each embodiment will be described with reference to the drawings. In each figure, the same reference numerals are given to the same parts, and the description of the same parts will not be repeated. Note that the dimensions of the constituent members in each figure do not faithfully represent the dimensions of the actual constituent members and the dimensional ratios of the constituent members. In the following embodiments, the "main surface" means the surface having the largest area in the target member, or the surface having the largest area visible when viewed in the thickness direction in a plate-like member.

[0036] In the description of the piezoelectric vibration device 1 which is an embodiment of the present invention below, the longitudinal direction of the oscillator 2 is the "X direction", the short-side direction is the "Y direction", and the opening direction of the frame portion 4 in the oscillator 2, which is perpendicular to the X direction and the Y direction, is the "Z direction". Also, in the present embodiment, the X direction and the Y direction are directions on a horizontal plane. The Z direction is a vertical direction. However, the intention is not to limit the orientation of the piezoelectric vibration device 1 during use by this definition of the direction.

[0037] In the following description, expressions such as "fixing", "connecting", "joining", and "attaching" (hereinafter referred to as fixing, etc.) include not only cases where members are directly fixed, etc., but also cases where they are fixed, etc. via other members. That is, in the following description, the expression of fixing, etc. includes the meanings of direct and indirect fixing, etc. of members to each other.

[0038] [Embodiment 1] <Configuration of the piezoelectric vibration device 1> The piezoelectric vibration device 1 according to Embodiment 1 of the present invention will be described with reference to FIGS. 1 to 5. FIG. 1 is a plan view showing an outline of the overall configuration of the piezoelectric vibration device 1. FIG. 2 is a bottom view showing an outline of the overall configuration of the piezoelectric vibration device 1. FIG. 3 is an exploded perspective view showing an outline of the overall configuration of the vibrator 2 in the piezoelectric vibration device 1. FIG. 4 is a plan view of the vibrator 2. FIG. 5 is a cross-sectional view taken along arrow A in FIG. 4.

[0039] As shown in FIG. 1, the piezoelectric vibration device 1 includes a vibrator 2, an integrated circuit element 10, a substrate 11, and a mold part 12 (see FIG. 6).

[0040] As shown in FIGS. 3 to 5, the vibrator 2 is a piezoelectric element having a piezoelectric body that converts an applied force into a voltage or converts an applied voltage into a force. The vibrator 2 includes a piezoelectric vibration plate 3, a first sealing member 7, a second sealing member 8, and a protection member 9.

[0041] The piezoelectric vibration plate 3 is a rectangular crystal vibration piece obtained by cutting crystal in a specific direction. The piezoelectric vibration plate 3 includes a frame part 4, a vibration part 5, and a connecting part 6. The piezoelectric vibration plate 3 has the frame part 4, the vibration part 5, and the connecting part 6 integrally formed. That is, the frame part 4, the vibration part 5, and the connecting part 6 are configured as a single member.

[0042] As shown in FIGS. 4 and 5, the frame portion 4 is a member that surrounds the periphery of the vibrating portion 5. The frame portion 4 is composed of a rectangular plate material in a plan view that is perpendicular to the pair of main surfaces with the largest area. The frame portion 4 is a frame-shaped member having rectangular opening portions on the pair of main surfaces when viewed in the Z direction which is the plan view. That is, the frame portion 4 has a rectangular through portion 4c that penetrates from one of the main surfaces to the other main surface.

[0043] The distance between the pair of main surfaces of the frame portion 4, which is the thickness of the frame portion 4, is a thickness t1. One main surface of the frame portion 4 has a first joint surface 4a that joins with the first sealing member 7. The other main surface of the frame portion 4 has a second joint surface 4b that joins with the second sealing member 8. Both longitudinal ends of the frame portion 4 each have a vibrator mounting terminal 4d.

[0044] The vibrating portion 5 is a piezoelectric body. The vibrating portion 5 is a substantially rectangular plate material in a plan view that is perpendicular to the pair of main surfaces with the largest area. The vibrating portion 5 is located within the frame of the frame portion 4. The vibrating portion 5 is positioned such that the pair of main surfaces face the opening portions of the frame portion 4 when viewed in the Z direction which is the plan view. Also, the main surface of the vibrating portion 5 is positioned substantially parallel to the main surface of the frame portion 4. The distance between the pair of main surfaces of the vibrating portion 5, which is the thickness of the vibrating portion 5, is a thinner thickness t2 than the thickness t1 of the frame portion 4. The vibrating portion 5 is located between the pair of main surfaces of the frame portion 4 within the frame of the frame portion 4.

[0045] A part of the vibrating portion 5 is connected to the frame portion 4 via a plate-shaped connecting portion 6. The vibrating portion 5 is held in a cantilever-supported state by the frame portion 4 via the connecting portion 6. That is, the vibrating portion 5 is surrounded by the frame portion 4 with the through portion 4c in between. One main surface of the vibrating portion 5 has a first exciting electrode 5a. The other main surface of the vibrating portion 5 has a second exciting electrode 5b. The first exciting electrode 5a is connected to one vibrator mounting terminal 4d. The second exciting electrode 5b is connected to the other vibrator mounting terminal 4d.

[0046] The first sealing member 7 and the second sealing member 8, which are sealing members, are members for sealing the inside of the frame portion 4. The first sealing member 7 and the second sealing member 8 are resin films having a rectangular shape in a plan view in a direction perpendicular to the pair of main surfaces having the largest area. The first sealing member 7 and the second sealing member 8 are films made of polyimide resin having a heat resistance of about 300°C, for example. Further, the first sealing member 7 and the second sealing member 8 have a thickness t3 of about 20 μm to 50 μm.

[0047] The width X3 in the X direction, which is the longitudinal direction in the first sealing member 7 and the second sealing member 8, is smaller than the width X1 in the X direction at the outer edge of the frame portion 4 when viewed in the Z direction, which is the plan view, and larger than the width X2 in the X direction at the opening portion, which is the inner edge of the frame portion 4. Also, the width Y3 in the Y direction, which is the short-side direction perpendicular to the X direction when viewed in the Z direction in the first sealing member 7 and the second sealing member 8, is smaller than the width Y1 in the Y direction at the outer edge of the frame portion 4 and larger than the width Y2 in the Y direction at the opening portion, which is the inner edge of the frame portion 4. That is, the first sealing member 7 and the second sealing member 8 are smaller than the frame portion 4 and larger than the opening of the frame portion 4.

[0048] The first sealing member 7 is joined to the first joint surface 4a of one of the main surfaces of the frame portion 4 by a joining material 13, which is a thermoplastic adhesive. The peripheral edge of the first sealing member 7 is located inward of the outer edge of the frame portion 4 and outward of the inner edge of the frame portion 4. The end portion of the first sealing member 7 in the X direction is joined to the first joint surface 4a located in the X direction on one of the main surfaces of the frame portion 4. The end portion of the first sealing member 7 in the Y direction is joined to the first joint surface 4a located in the Y direction on one of the main surfaces of the frame portion 4. That is, when viewed in the Z direction, the portion of the first sealing member 7 that overlaps the first joint surface 4a is joined to the frame portion 4 by the joining material 13. The first sealing member 7 covers the opening portion of one of the main surfaces of the frame portion 4. Thereby, the first sealing member 7 closes the opening portion of one of the main surfaces of the frame portion 4.

[0049] The second sealing member 8 is joined to the second joint surface 4b of the other main surface of the frame portion 4 by a joining material 13. The periphery of the second sealing member 8 is located inward of the outer edge of the frame portion 4 and outward of the inner edge of the frame portion 4. The end portion of the second sealing member 8 in the X direction is joined to the second joint surface 4b located in the X direction on the other main surface of the frame portion 4. The end portion of the second sealing member 8 in the Y direction is joined to the second joint surface 4b located in the Y direction on the other main surface of the frame portion 4. That is, when viewed in the Z direction, the portion of the second sealing member 8 that overlaps the second joint surface 4b is joined to the frame portion 4 by the joining material 13. The second sealing member 8 covers the opening portion of the other main surface of the frame portion 4. Thus, the second sealing member 8 closes the opening portion of the other main surface of the frame portion 4. Others The second sealing member 8 covers the opening portion of the other main surface of the frame portion 4. Thus, the second sealing member 8 closes the opening portion of the other main surface of the frame portion 4.

[0050] The protection member 9 is a member that suppresses the deflection of at least the first sealing member 7 among the first sealing member 7 or the second sealing member 8 due to the molding pressure of the resin constituting the mold portion 12. The protection member 9 is a rectangular plate-like member in a plan view in which the direction perpendicular to the pair of main surfaces having the largest area. The protection member 9 is made of silicon, which is a brittle material. It is desirable that the protection member 9 has a rigidity such that the maximum deflection is 20 μm or less in a simply supported condition in the longitudinal direction when pressure generated during resin molding is applied.

[0051] Therefore, for the protection member 9, the longitudinal elastic modulus and the second moment of area in the Z direction, which is the direction in plan view, of the material are determined so as to be higher in rigidity than at least the first sealing member 7 among the first sealing member 7 or the second sealing member 8. In the present embodiment, the protection member 9 is made of silicon. Also, in the present embodiment, it is desirable that the protection member 9 has a thickness t4 of about 30 μm to 100 μm. The thickness t4 of the protection member 9 is thicker than the thicknesses t3 of the first sealing member 7 and the second sealing member 8.

[0052] When viewed in the Z direction, the width X4 in the X direction, which is the longitudinal direction of the protective member 9, is smaller than the width X1 in the X direction at the outer edge of the frame portion 4 of the piezoelectric diaphragm 3 and larger than the width X3 in the X direction of the first sealing member 7. Also, when viewed in the Z direction, the width Y4 in the Y direction, which is the direction perpendicular to the X direction in the protective member 9, is smaller than the width Y1 in the Y direction at the outer edge of the frame portion 4 and larger than the width Y3 in the Y direction of the first sealing member 7. That is, the protective member 9 is smaller than the frame portion 4 and larger than the first sealing member 7.

[0053] The protective member 9 is joined to the surface perpendicular to the Z direction of the first sealing member 7 by a thermoplastic adhesive or die attach agent, which is the bonding material 13. The peripheral edge of the protective member 9 is located between the peripheral edge of the first sealing member 7 and the outer edge of the frame portion 4. That is, the peripheral edge portion of the protective member 9 overlaps with the first bonding surface 4a of the frame portion 4 when viewed in the Z direction. Thereby, the protective member 9 is supported at the peripheral edge portion by the frame portion 4. Also, the protective member 9 covers the opening portion of one main surface of the frame portion 4 via the first sealing member 7. That is, the protective member 9 covers the entire first sealing member 7 including the portion overlapping with the opening portion when viewed in the Z direction.

[0054] The vibrator 2 configured as described above has a three-layer structure including the piezoelectric diaphragm 3, the first sealing member 7 that closes the opening portion on one main surface of the piezoelectric diaphragm 3, and the second sealing member 8 that closes the opening portion on the other main surface of the piezoelectric diaphragm 3. The vibrator 2 has an internal space S formed by the frame portion 4 of the piezoelectric diaphragm 3, the first sealing member 7, and the second sealing member 8. The vibrating portion 5 is located in the internal space S of the vibrator 2. Also, an inert gas such as nitrogen gas is enclosed in the internal space S. The vibrator 2 oscillates at a predetermined frequency by the voltage applied from each vibrator mounting terminal 4d.

[0055] As shown in FIG. 1, the integrated circuit element 10, which is an electronic component element, is an IC that controls the vibrator 2. The integrated circuit element 10 has an electronic circuit such as an oscillation circuit that is connected to a temperature sensing element (thermistor) that senses the ambient temperature state and generates a predetermined oscillation output. The integrated circuit element 10 outputs the oscillation output generated by the oscillation circuit to the outside through the integrated circuit element mounting terminal 10a as a reference signal such as a clock signal. The integrated circuit element 10 has a portion other than the integrated circuit element mounting terminal 10a covered with resin.

[0056] As shown in FIGS. 1 and 2, the substrate 11 is an insulating substrate that electrically connects and integrally configures the vibrator 2 and the integrated circuit element 10 by a wiring pattern (not shown). The substrate 11 is made of a resin material. The substrate 11 is based on, for example, a glass epoxy resin that is an insulator. One main surface of the substrate 11 is configured as a mounting surface 11a having a circuit formed by a conductor such as copper. The other main surface of the substrate 11 has substrate mounting terminals 11b for mounting on an external substrate. The circuit on the mounting surface 11a is electrically connected to the substrate mounting terminals 11b. In the present embodiment, the thickness of the substrate 11 is, for example, 0.17 mm.

[0057] The vibrator 2 and the integrated circuit element 10 are respectively mounted on the mounting surface 11a of the substrate 11. Both vibrator mounting terminals 4d of the vibrator 2 are electrically connected to the circuit on the mounting surface 11a by a conductive bonding material 13. At this time, the vibrator 2 is arranged with the main surface covered by the first sealing member 7 and the second sealing member 8 facing in the Z direction. The vibrator 2 is positioned such that the second sealing member 8 faces the mounting surface 11a. The second sealing member 8 is in contact with the mounting surface 11a. Similarly, the integrated circuit element mounting terminals 10a of the integrated circuit element 10 are electrically connected to the circuit on the mounting surface 11a of the substrate 11 by wires 10b. In this way, the vibrator 2 and the integrated circuit element 10 are arranged side by side on the mounting surface 11a of the substrate 11.

[0058] The oscillator 2 mounted on the substrate 11 is electrically connected to an external substrate via a wiring pattern (not shown) of the substrate 11 and a substrate mounting terminal 11b from an oscillator mounting terminal 4d. Further, the vibrating portion 5 of the oscillator 2 is held in a cantilever-supported state by a connecting portion 6 on a frame portion 4 of the piezoelectric vibrating plate 3. Thereby, the vibrating portion 5 oscillates at a predetermined frequency by a voltage applied from the external substrate.

[0059] The mold portion 12 protects at least the oscillator 2 among the substrate 11, the oscillator 2 mounted on the substrate 11, and the integrated circuit element 10 (see FIG. 6). The mold portion 12 is a thermosetting resin such as an epoxy resin 12a. The mold portion 12 covers at least the oscillator 2 among the substrate 11, the oscillator 2 mounted on the substrate 11, and the integrated circuit element 10 with the thermoset epoxy resin 12a. In the present embodiment, the mold portion 12 covers the substrate 11, the oscillator 2 mounted on the substrate 11, and the integrated circuit element 10.

[0060] Next, with reference to FIG. 6, the state of the first sealing member 7 when the oscillator 2 and the substrate 11 are covered by the mold portion 12 will be described. It is assumed that the oscillator 2 and the substrate 11 are located in the cavity of the mold W. FIG. 6 is a cross-sectional view taken along the arrow A in FIG. 4 in a state where the piezoelectric vibration device 1 is being resin-molded in the mold W.

[0061] As shown in FIG. 6, the mold portion 12 is formed by a transfer method in which the molten resin is filled into the cavity of the mold W. The cavity is filled with the epoxy resin 12a melted by a plunger (not shown). The epoxy resin 12a is filled into the cavity at a predetermined filling pressure by the plunger. When the epoxy resin 12a is filled over the entire area of the cavity, it is pressurized at a predetermined molding pressure for a predetermined time. The epoxy resin 12a thermosets while being held at the predetermined molding pressure. The thermoset epoxy resin 12a covers the oscillator 2 and the substrate 11 as the mold portion 12.

[0062] The vibrator 2 located in the cavity filled with the epoxy resin 12a and the substrate 11 are in contact with the epoxy resin 12a at the frame portion 4 of the piezoelectric vibrating plate 3, the protective member 9, and the substrate 11. On the other hand, the main surface of the first sealing member 7 is covered by the main surface of the protective member 9 when viewed in the Z direction. The first sealing member 7 and the protective member 9 are joined by a bonding material 13. The protective member 9 is in close contact with the first sealing member 7. Therefore, the epoxy resin 12a does not contact the main surface of the first sealing member 7. Also, the second sealing member 8 is covered by the substrate 11 when viewed in the Z direction. Therefore, the epoxy resin 12a does not contact the main surface of the second sealing member 8. Further, the connecting portion 6 and the vibrating portion 5 of the piezoelectric vibrating plate 3 are sealed in the internal space S by the first sealing member 7 and the second sealing member 8, so they do not contact the epoxy resin 12a.

[0063] While the epoxy resin 12a is held by the molding pressure, a molding pressure is applied to the frame portion 4 of the piezoelectric vibrating plate 3, the protective member 9, and the substrate 11 where the epoxy resin 12a contacts the vibrator 2 and the substrate 11 from a direction perpendicular to the contact surface of the epoxy resin 12a. A holding pressure is applied in the Z direction to the main surface of the protective member 9 perpendicular to the Z direction (see the arrow). Note that the second moment of area in the Z direction of the protective member 9 in the direction perpendicular to the main surface of the vibrator 2 is larger than the second moment of area in the Z direction of the first sealing member 7. Also, the protective member 9 is made of a brittle material having a larger longitudinal elastic modulus than a resin-based material. Therefore, the protective member 9 has a higher rigidity than the first sealing member 7 due to its shape and material.

[0064] Such a protective member 9 deflects about 20 μm toward the piezoelectric vibrating plate 3 side in the Z direction by a predetermined molding pressure. At this time, the first sealing member 7 joined to the protective member 9 deflects about 20 μm toward the piezoelectric vibrating plate 3 side in the Z direction along the deflection of the protective member 9 in the Z direction. The first sealing member 7 before deflection is located more than 20 μm away from the vibrating portion 5 of the piezoelectric vibrating plate 3 in the Z direction. Therefore, the first sealing member 7 does not contact the vibrating portion 5 even when it deflects toward the piezoelectric vibrating plate 3 side in the Z direction due to the molding pressure.

[0065] The periphery of the protective member 9 is located outside the periphery of the first sealing member 7 and inside the periphery outside the frame portion 4. That is, a gap G equal to the thickness t3 of the first sealing member 7 and the thickness of the bonding material 13 is formed between the peripheral portion of the protective member 9 outside the first sealing member 7 and the joint surface of the frame portion 4. The epoxy resin 12a has entered the gap G. Therefore, the epoxy resin 12a is in contact with the end faces perpendicular to the X direction and the end faces perpendicular to the Y direction of the first sealing member 7. The movement of the first sealing member 7 in the X direction and the Y direction is restricted by the thermosetting of the epoxy resin 12a.

[0066] The vibrator 2 of the piezoelectric vibration device 1 configured as described above has a three-layer structure vibrator 2 in which a piezoelectric vibration plate 3 that supports a vibration portion 5 thinner than the frame portion 4 inside the frame of the frame portion 4 is covered with a first sealing member 7 and a second sealing member 8 that are resin films. Further, the first sealing member 7 that closes the main surface including the opening portion of the frame portion 4 is covered with a protective member 9. Therefore, the epoxy resin 12a that constitutes the mold portion 12 does not contact the main surface of the first sealing member 7 perpendicular to the Z direction. Further, the protective member 9 covers the first sealing member 7 with its periphery supported by the frame portion 4. That is, the molding pressure of the epoxy resin 12a applied to the protective member 9 is received by the frame portion 4.

[0067] The molding pressure applied to the first sealing member 7 is reduced according to the ratio of the area of the protective member 9 to the area of the first sealing member 7 that covers the opening portion of the frame portion 4 in the vibrator 2. In the present embodiment, the protective member 9 covers all of the portions of the first sealing member 7 that cover the opening portion of the frame portion 4. Therefore, the vibrator 2 receives all of the molding pressure of the epoxy resin 12a applied to the first sealing member 7 by the protective member 9. Thereby, it is possible to suppress the deflection of at least the first sealing member 7 among the first sealing member 7 and the second sealing member 8 during molding with the epoxy resin 12a.

[0068] Also, in a state where the vibrator 2 and the integrated circuit element 10 are joined to the substrate 11, the upper surface of the vibrator 2 is higher than the upper surface of the integrated circuit element 10. Therefore, the thickness of the piezoelectric vibration device 1 is the sum of the thickness of the vibrator 2, the substrate 11, and the thickness of the mold resin (epoxy resin 12a). At this time, the resistance of the first sealing member 7 against the molding pressure from the mold resin is improved because it is covered with the protective member 9. Thus, the piezoelectric vibration device 1 can suppress the deflection of the first sealing member 7 during molding with the epoxy resin 12a. Thereby, the thickness of the piezoelectric vibration device 1 can be suppressed by forming a three-layer structure in which the frame portion 4 having the vibration portion 5 therein is covered with the first sealing member 7 and the second sealing member 8 which are resin films.

[0069] Also, the vibrator 2 of the piezoelectric vibration device 1 has a gap G formed by the first sealing member 7 between the frame portion 4 and the protective member 9. The epoxy resin 12a enters the gap G due to the molding pressure. Thus, the first sealing member 7 located between the frame portion 4 and the protective member 9 is suppressed from deforming by the thermoset epoxy resin 12a. Also, since the protective member 9 is larger than the first sealing member 7, even if the position of the first sealing member 7 in the X direction and the Y direction is slightly deviated, at least a part of the first sealing member 7 can be covered. Thereby, during molding with the epoxy resin 12a, the deflection of at least the first sealing member 7 among the first sealing member 7 and the second sealing member 8 can be suppressed.

[0070] Also, the substrate 11 of the piezoelectric vibration device 1 is made of a glass epoxy resin material that is easy to process such as cutting. Thereby, the piezoelectric vibration device 1 having an arbitrary shape can be easily configured.

[0071] [Modification Example of Embodiment 1] In the above-described Embodiment 1, the vibrator 2 has a through portion 4c between the frame portion 4 and the vibration portion 5 and supports the vibration portion 5 in a cantilever manner. However, as shown in FIG. 7, the vibrator 2 may be configured not to have the through portion 4c between the frame portion 4 and the vibration portion 5. FIG. 7 is a cross-sectional view taken along the arrow A in FIG. 4 in a modification example of the piezoelectric vibration device 1.

[0072] As shown in FIG. 7, the vibrator 14 without the through portion 4c includes a piezoelectric vibrating plate 15, a first sealing member 7, a second sealing member 8, and a protective member 9. The piezoelectric vibrating plate 15 has a frame portion 16 and a vibrating portion 17 integrally formed therewith. That is, the frame portion 16 and the vibrating portion 17 are configured as a single member. In the following embodiments, the specific description of the same points as those in the embodiments already described will be omitted, and the description will focus on the different parts.

[0073] The frame portion 16 is a member that surrounds the periphery of the vibrating portion 17. The frame portion 16 is composed of a rectangular plate material in a plan view that is perpendicular to the pair of main surfaces having the largest area. The frame portion 16 is a frame-shaped member having rectangular opening portions in the pair of main surfaces when viewed in the Z direction in the plan view. The frame portion 16 has a first joint surface 16a that joins with the first sealing member 7 and a second joint surface 16b that joins with the second sealing member 8. Further, both end portions in the longitudinal direction of the frame portion 16 each have a vibrator mounting terminal 16d. The frame portion 16 has a rectangular recess 16e on one of the main surfaces and a rectangular recess 16f on the other main surface when viewed in the Z direction. Also, the recess 16e on one of the main surfaces and the recess 16f on the other main surface do not communicate with each other. That is, the frame portion 16 does not have a through portion.

[0074] The vibrating portion 17 is a piezoelectric body. The vibrating portion 17 is a substantially rectangular plate material in a plan view that is perpendicular to the pair of main surfaces having the largest area. One main surface of the vibrating portion 17 is the bottom surface of one recess 16e in the frame portion 16. The other main surface of the vibrating portion 17 is the bottom surface of the other recess 16f in the frame portion 16. The vibrating portion 17 is positioned such that the pair of main surfaces face the opening portion of the frame portion 16 when viewed in the Z direction in the plan view. Also, the main surface of the vibrating portion 17 is positioned substantially parallel to the main surface of the frame portion 16. The vibrating portion 17 is positioned between the pair of main surfaces of the frame portion 16 within the frame of the frame portion 16. The periphery of the vibrating portion 17 is connected to the frame portion 16. That is, the vibrating portion 17 is supported by the frame portion 16 at the entire periphery. One main surface of the vibrating portion 17 has a first exciting electrode 17a. The other main surface of the vibrating portion 17 has a second exciting electrode 17b.

[0075] In this way, the vibrator 14 of the piezoelectric vibration device 1 has a recess 16e on one main surface of the frame portion 16 and a recess 16f on the other main surface. The bottom surfaces of the recess 16e and the recess 16f constitute the vibrating portion 17. Further, the vibrator 14 has a three-layer structure in which the opening of the recess 16e of the frame portion 16 is covered with the first sealing member 7 and the opening of the recess 16f is covered with the second sealing member 8. Since the first sealing member 7 is covered with the protective member 9, the resistance to the molding pressure from the epoxy resin 12a is improved. Therefore, Piezoelectric vibration device 1 it is possible to suppress the deflection of the first sealing member 7 during molding with the epoxy resin 12a.

[0076] [Embodiment 2] <Configuration of the piezoelectric vibration device 21> Next, with reference to FIGS. 8 to 13, the piezoelectric vibration device 21 according to Embodiment 2 of the present invention will be described. FIG. 8 is a plan view showing an outline of the overall configuration of the piezoelectric vibration device 21 according to Embodiment 2 of the present invention. FIG. 9 is a side view of the vibrator 22 in the piezoelectric vibration device 21. FIG. 10 is a cross-sectional view taken along the D arrow in FIG. 9. FIG. 11 is a bottom view of the vibrator 22. FIG. 12 is a plan view showing the size of the integrated circuit element 28 with respect to the vibrator 22. FIG. 13 is a side view of the piezoelectric vibration device 21. FIG. 14 is a side view of a modified example of the piezoelectric vibration device 21. In the following embodiments, the specific description of the same points as those in the already described embodiments will be omitted, and the description will be centered on the different parts.

[0077] As shown in FIG. 8, the piezoelectric vibration device 21 includes a vibrator 22, an integrated circuit element 28, a substrate 29, and a mold portion (not shown).

[0078] As shown in FIGS. 9 to 11, the vibrator 22 is a piezoelectric vibrator having a piezoelectric vibration plate 23, a first sealing member 26, and a second sealing member 27. The vibrator 22 is a three-layer laminate having a sandwich structure in which the piezoelectric vibration plate 23 is sandwiched between the first sealing member 26 and the second sealing member 27.

[0079] As shown in FIG. 10, the piezoelectric diaphragm 23 is a rectangular plate-like member made of quartz, which is a piezoelectric material. The piezoelectric diaphragm 23 has a frame portion 24 and a vibrating portion 25. The piezoelectric diaphragm 23 has the frame portion 24 and the vibrating portion 25 integrally formed. That is, the frame portion 24 and the vibrating portion 25 are configured as a single member.

[0080] The frame portion 24 is a member that surrounds the periphery of the vibrating portion 25. The frame portion 24 is formed at the outer edge portion of a pair of main surfaces having the largest area in the piezoelectric diaphragm 23. The portion surrounded by the frame portion 24 is recessed from the main surface of the piezoelectric diaphragm 23. That is, the frame portion 24 is a frame-shaped portion having rectangular opening portions when viewed in the Z direction perpendicular to the main surface.

[0081] A pair of exciting electrodes 25a are located in the portions surrounded by the frame portion 24 on one main surface and the other main surface of the piezoelectric diaphragm 23. The pair of exciting electrodes 25a are positioned so as to face each other in the thickness direction of the piezoelectric diaphragm 23. Further, when viewed in the Z direction, which is the direction perpendicular to the pair of main surfaces having the largest area, the piezoelectric diaphragm 23 has a through portion 23a that penetrates from one main surface toward the other main surface so as to surround the pair of exciting electrodes 25a in the portion surrounded by the frame portion 24. The through portion 23a penetrates so as to surround the pair of exciting electrodes 25a leaving one place. Thereby, the portion where the pair of exciting electrodes 25a are located is configured as a plate-like member having a cantilever structure. That is, the portion where the pair of exciting electrodes 25a are located is configured as a vibrating portion 25 that can vibrate in the Z direction.

[0082] The vibrating portion 25 is a piezoelectric body. The vibrating portion 25 is a plate-like portion that is substantially rectangular in plan view in the direction perpendicular to the pair of main surfaces having the largest area. The vibrating portion 25 is located within the frame of the frame portion 24. The vibrating portion 25 is positioned such that the pair of main surfaces face the opening portion of the frame portion 24 when viewed in the Z direction. Further, the main surface of the vibrating portion 25 is positioned substantially parallel to the main surface of the frame portion 24. The thickness of the vibrating portion 25 is thinner than the thickness of the frame portion 24. The vibrating portion 25 is located between the pair of main surfaces of the frame portion 24 within the frame of the frame portion 24.

[0083] One main surface of the frame portion 24 has a bonding material 23b that is joined to the first sealing member 26 so as to surround the vibrating portion 25. Similarly, the other main surface of the frame portion 24 has a bonding material 23b that is joined to the second sealing member 27 so as to surround the vibrating portion 25. Each bonding material 23b is configured in an annular shape. The bonding material 23b is a PVD film formed of the same metal as the metal constituting the pair of exciting electrodes 25a.

[0084] The first sealing member 26 is a member that seals the vibrating portion 25 of the piezoelectric vibrating plate 23. The first sealing member 26 is a rectangular plate-like member made of the same crystal as the piezoelectric vibrating plate 23. The first sealing member 26 has substantially the same shape as the piezoelectric vibrating plate 23. That is, when one main surface of the first sealing member 26 faces one main surface of the piezoelectric vibrating plate 23, it has a shape that can cover the entire surface of one main surface of the piezoelectric vibrating plate 23. That is, the first sealing member 26 has a shape that can cover the entire surface of the opening portion of the frame portion 24. The first sealing member 26 has a bonding material on one main surface that is joined to the bonding material 23b of the piezoelectric vibrating plate 23. The bonding material of the first sealing member 26 is a PVD film formed of the same metal as the metal constituting the bonding material 23b of the piezoelectric vibrating plate 23.

[0085] As shown in FIG. 9, the first sealing member 26 has an external mounting terminal 26a on the other main surface that is electrically connected to the integrated circuit element mounting terminal 28a of the integrated circuit element 28. The external mounting terminal 26a is a plate-like terminal made of a conductive metal.

[0086] As shown in FIG. 11, the second sealing member 27 is a member that seals the vibrating portion 25 of the piezoelectric diaphragm 23. The second sealing member 27 is a rectangular plate-like member made of the same crystal as the piezoelectric diaphragm 23. The second sealing member 27 has substantially the same shape as the piezoelectric diaphragm 23. That is, when one main surface of the second sealing member 27 faces the other main surface of the piezoelectric diaphragm 23, it has a shape that can cover the entire other main surface of the piezoelectric diaphragm 23. That is, the second sealing member 27 has a shape that can cover the entire opening portion of the frame portion 24. The second sealing member 27 has a bonding material on one main surface that bonds to the bonding material 23b of the piezoelectric diaphragm 23. The bonding material of the second sealing member 27 is a PVD film formed of the same metal as the metal constituting the bonding material 23b of the piezoelectric diaphragm 23.

[0087] The second sealing member 27 has four oscillator mounting terminals 27a on the other main surface that are electrically connected to the electrodes of the substrate 29. The four oscillator mounting terminals 27a are plate-like terminals made of a conductive metal. The four oscillator mounting terminals 27a are configured in a substantially L shape when viewed in the Z direction.

[0088] As shown in FIG. 9, the first sealing member 26 is located on one main surface of the piezoelectric diaphragm 23. One main surface of the piezoelectric diaphragm 23 is covered by the first sealing member 26. At this time, the bonding material 23b on one main surface of the piezoelectric diaphragm 23 and the bonding material of the first sealing member 26 are diffusion-bonded. As a result, the excitation electrode on one main surface side of the piezoelectric diaphragm 23 25a is hermetically sealed by the first sealing member 26.

[0089] The second sealing member 27 is located on the other main surface of the piezoelectric diaphragm 23. The other main surface of the piezoelectric diaphragm 23 is covered by the second sealing member 27. At this time, the bonding material 23b on the other main surface of the piezoelectric diaphragm 23 and the bonding material of the second sealing member 27 are diffusion-bonded. As a result, the excitation electrode on the other main surface side of the piezoelectric diaphragm 23 25a is hermetically sealed by the second sealing member 27.

[0090] The oscillator 22 configured as described above is configured as a package having a sandwich structure in which both main surfaces of the piezoelectric vibrating plate 23 are sealed by a first sealing member 26 and a second sealing member 27, respectively. Further, the oscillator 22 covers both main surfaces of the piezoelectric vibrating plate 23 with the first sealing member 26 and the second sealing member 27, thereby forming an internal space that includes the vibrating portion 25 of the piezoelectric vibrating plate 23 inside. That is, in the internal space of this package, the vibrating portion 25 including the pair of exciting electrodes 25a is hermetically sealed in the oscillator 22.

[0091] As shown in FIG. 9, the integrated circuit element 28 is an IC that controls the oscillator 22 Since the configuration of the integrated circuit element 28 is the same as that of the integrated circuit element 10 in the first embodiment, the description thereof will be omitted. The integrated circuit element 28 has a portion other than the integrated circuit element mounting terminal 28a covered with resin. The integrated circuit element 28 is mounted on the other main surface of the first sealing member 26. The integrated circuit element mounting terminal 28a of the integrated circuit element 28 is electrically connected to the external mounting terminal 26a of the first sealing member 26 by solder or the like.

[0092] The integrated circuit element 28 is a rectangular plate-like member in a plan view in a direction perpendicular to the pair of main surfaces having the largest area. It is desirable that the integrated circuit element 28 has a rigidity such that the maximum deflection is 5 μm or less in a simply supported condition in the longitudinal direction when pressure generated during resin molding is applied. Therefore, for the integrated circuit element 28, the longitudinal elastic modulus of the material and the second moment of area in the Z direction, which is the direction in the plan view, are determined so as to be higher in rigidity than at least the first sealing member 26 among the first sealing member 26 and the second sealing member 27. In the present embodiment, it is desirable that the integrated circuit element 28 has a thickness of 80 μm or more. The thickness of the integrated circuit element 28 is thicker than the thicknesses of the first sealing member 26 and the second sealing member 27.

[0093] As shown in FIG. 12, when viewed in the Z direction, the width X13 in the X direction, which is the longitudinal direction in the integrated circuit element 28, is smaller than the width X11 in the X direction at the outer edge of the frame portion 24 and larger than the width X12 in the X direction at the inner edge of the frame portion 24. Also, when viewed in the Z direction, the width Y13 in the Y direction, which is the direction perpendicular to the X direction in the integrated circuit element 28, is smaller than the width Y11 in the Y direction at the outer edge of the frame portion 24 and larger than the width Y12 in the Y direction at the inner edge of the frame portion 24. That is, the integrated circuit element 28 is smaller than the frame portion 24 and larger than the opening of the frame portion 24. Therefore, the outer edge portion of the integrated circuit element 28 is supported by the frame portion 24 of the piezoelectric diaphragm 23 via the first sealing member 26.

[0094] As shown in FIGS. 8 and 13, the substrate 29 is an insulating substrate that electrically connects and integrally forms the vibrator 22 and the integrated circuit element 28 by a wiring pattern (not shown). One main surface of the substrate 29 has connection terminals 29b for mounting the vibrator 22. The other main surface of the substrate 29 has substrate mounting terminals 29c for mounting on an external substrate (see FIG. 13). The connection terminals 29b are electrically connected to the substrate mounting terminals 29c. Since the other configuration of the substrate 29 is substantially the same as that of the substrate 11 in the first embodiment, the description thereof is omitted.

[0095] On the mounting surface 29a, the vibrator 22 on which the integrated circuit element 28 is mounted is mounted. The vibrator 22 is disposed on the substrate 29 such that the second sealing member 27 faces the mounting surface 29a. The vibrator mounting terminals 27a of the second sealing member 27 are electrically connected to the connection terminals 29b of the mounting surface 29a respectively by conductive solder or the like. The integrated circuit element mounting terminals 28a of the integrated circuit element 28 are electrically connected to the circuits of the mounting surface 29a of the substrate 29 respectively by wires 28b.

[0096] The vibrator 22 and the integrated circuit element 28, which is an electronic component element, mounted on the substrate 29 are electrically connected to an external substrate via the vibrator mounting terminals 27a, a wiring pattern (not shown) of the substrate 29, and the substrate mounting terminals 29c. Also, the vibrating portion 25 of the vibrator 22 oscillates at a predetermined frequency by a voltage applied from the external substrate.

[0097] The mold part (not shown) protects at least the vibrator 22 among the substrate 29, the vibrator 22 mounted on the substrate 29, and the integrated circuit element 28 with an epoxy resin. Since the mold part is the same as the mold part 12 in Embodiment 1, the description thereof is omitted.

[0098]

[0097] Next, with reference to FIG. 13, the state of the first sealing member 26 when the vibrator 22 and the substrate 29 are covered with a mold part (not shown) will be described.

[0099] As shown in FIG. 13, when the vibrator 22 and the substrate 29 are molded with an epoxy resin (not shown), while the epoxy resin is being injected, a molding pressure is applied to the vibrator 22 and the integrated circuit element 28 from the Z direction perpendicular to the contact surface of the epoxy resin (see the arrow). The portion of the first sealing member 26 that covers the opening of the piezoelectric vibrating plate 23 is covered by the integrated circuit element 28. Therefore, when viewed in the Z direction, the molding pressure applied to the portion of the first sealing member 26 that covers the opening of the piezoelectric vibrating plate 23 is applied to the integrated circuit element 28. Further, the integrated circuit element 28 has a both-end supported structure in which the outer edge portion is supported by the frame portion 24. Therefore, the amount of deflection of the first sealing member 26 that covers the opening of the piezoelectric vibrating plate 23 is suppressed by being covered by the integrated circuit element 28. Therefore, the first sealing member 26 does not contact the vibrating portion 25 even if it deflects in the Z direction due to the molding pressure. In this way, the integrated circuit element 28 functions as a protection member that covers the first sealing member 26 so that the molding pressure is not applied to the first sealing member 26.

[0100] The vibrator 22 of the piezoelectric vibration device 21 configured as described above has a three-layer structure in which a piezoelectric vibrating plate 23 that supports a vibrating portion 25 thinner than the frame portion 24 inside the frame of the frame portion 24 is covered with a first sealing member 26 and a second sealing member 27 made of quartz, and an integrated circuit element 28 is mounted on the mounting surface 29a of the substrate 29. Further, in the piezoelectric vibration device 21, at least the vibrator 22 is covered with an epoxy resin. In the vibrator 22, the first sealing member 26 that closes the opening of the frame portion 24 in the piezoelectric vibrating plate 23 is covered by the integrated circuit element 28.

[0101] Therefore, the epoxy resin constituting the mold part does not contact the main surface perpendicular to the Z direction of the part covering the opening of the piezoelectric diaphragm 23 in the first sealing member 26. Further, the integrated circuit element 28 covers the first sealing member 26 while being supported by the frame part 24 at the periphery. That is, the molding pressure of the epoxy resin applied to the integrated circuit element 28 is received by the frame part 24. Thereby, it is possible to suppress the deflection of at least the first sealing member 26 among the first sealing member 26 and the second sealing member 27 during molding with the epoxy resin.

[0102] [Modification of Embodiment 2] Further, in the above-described Embodiment 2, an integrated circuit element 28 is mounted as a protection member on the main surface of the first sealing member 26 of the vibrator 22 (see FIG. 13). However, as shown in FIG. 14, the integrated circuit element 28 may be mounted on the protection member 9 joined to the first sealing member 26 of the vibrator 22. That is, the first sealing member 26 is protected from the molding pressure of a mold part (not shown) by the protection member 9. Therefore, the piezoelectric vibration device 21 can mount an integrated circuit element 28 of an arbitrary size on the vibrator 22. The protection member 9 may have electrical connection means such as a wiring pattern and a through hole and may be configured to be electrically connected to the vibrator 22.

[0103] [Embodiment 3] [Configuration of Piezoelectric Vibration Device 41] The piezoelectric vibration device 41 according to Embodiment 3 of the present invention will be described with reference to FIGS. 15 and 16. FIG. 15 is a plan view showing an outline of the overall configuration of the piezoelectric vibration device 41. FIG. 16 is a side view showing an outline of the overall configuration of the piezoelectric vibration device 41.

[0104] As shown in FIGS. 15 and 16, the piezoelectric vibration device 41 includes a vibrator 42, an integrated circuit element 51, a substrate 52, and a mold part (not shown).

[0105] The vibrator 42 includes a holding member 43, a piezoelectric element 48, a sealing member 49, and a protective member 50.

[0106] The holding member 43 is a box-shaped container made of an insulator for holding the piezoelectric element 48. In this embodiment, the holding member 43 is a housing made of ceramics. The holding member 43 is formed by sintering ceramic powder. Note that the holding member 43 may be formed by laminating a plurality of insulators. The holding member 43 has a bottom portion 44, an electrode pad 45, a frame portion 46, and an external terminal 47.

[0107] The bottom portion 44 is a portion constituting the bottom surface of the holding member 43. The bottom portion 44 is formed of a rectangular plate-like member. On the upper surface, which is one surface of the bottom portion 44, an electrode pad 45 made of a conductive metal is formed along one short side of the rectangular plate-like member. The electrode pad 45 is electrically connected to the piezoelectric element 48. The electrode pad 45 is a part of an electric circuit for applying a voltage to the piezoelectric element 48. On the lower surface, which is the other surface of the bottom portion 44, an external terminal 47 made of a conductive metal is vapor-deposited. The external terminal 47 is electrically connected to the substrate 52. The external terminal 47 is a terminal for transmitting a signal from the substrate 52 to the piezoelectric element 48 and applying a voltage. The electrode pad 45 and the external terminal 47 are electrically connected by a wiring pattern (not shown).

[0108] The frame portion 46 is a portion constituting the side surface of the holding member 43. The frame portion 46 is located at the outer edge of the bottom portion 44. The frame portion 46 is a frame-shaped wall surrounding the bottom portion 44. The frame portion 46 extends upward from the upper surface of the bottom portion 44. Further, the frame portion 46 has a predetermined thickness from the outer surface to the inner surface. At the upper end portion of the frame portion 46, there is a joint surface 46a for joining with the sealing member 49. The holding member 43 configured in this way forms an internal space for accommodating the piezoelectric element 48 by the upper surface of the bottom portion 44 and the inner surface of the frame portion 46. The holding member 43 is open upward from the upper surface of the bottom portion 44. The electrode pad 45 is located inside the internal space.

[0109] The piezoelectric element 48, which is a vibrating part, is a piezoelectric body that converts the applied force into voltage or the applied voltage into force. In this embodiment, the piezoelectric element 48 is a rectangular crystal vibrating piece (for example, an AT-cut crystal piece) obtained by cutting crystal in a specific direction. Electrodes (not shown) are vapor-deposited on both of the pair of main surfaces with the largest area of the piezoelectric element 48. The piezoelectric element 48 is located within the internal space of the holding member 43. The electrodes of the piezoelectric element 48 are adhered to the electrode pads 45 of the holding member 43. Thereby, the piezoelectric element 48 can be electrically connected to the substrate 52 via the electrode pads 45, a wiring pattern (not shown), and the external terminals 47 from the electrodes. Also, the piezoelectric element 48 is held in a cantilever-supported state by the holding member 43. Thereby, the piezoelectric element 48 oscillates at a predetermined frequency by the voltage applied from the external substrate.

[0110] The sealing member 49 is a lid member that makes the internal space of the holding member 43 a sealed space. The sealing member 49 is made of, for example, a metal material such as Kovar. Also, the sealing member 49 is, for example, subjected to electrolytic nickel plating or electroless nickel plating. The sealing member 49 is positioned at the upper end of the holding member 43 with its lower surface, which is one of its surfaces, facing the holding member 43. The sealing member 49 has a size that covers the opening portion of the holding member 43 when viewed in the Z direction in a plan view. Also, when viewed in the Z direction, the sealing member 49 is smaller than the holding member 43. A frame-shaped sealing material is provided on the sealing member 49 at a portion that overlaps the joint surface 46a of the frame portion 46 in the holding member 43 when viewed in the Z direction. The sealing member 49 is joined to the joint surface 46a of the frame portion 46. Thereby, the piezoelectric element 48 is hermetically sealed within the internal space of the holding member 43 by the sealing member 49.

[0111] The protective member 50 is a member that suppresses the deflection of the sealing member 49 due to the molding pressure of the resin that constitutes the mold part (not shown). Since the configuration of the protective member 50 is the same as that of the protective member 9 in Embodiment 1, the description thereof is omitted. The protective member 50 is configured to have substantially the same size as the holding member 43 when viewed in the Z direction. The protective member 50 is joined to the surface of the sealing member 49 perpendicular to the Z direction by a thermoplastic adhesive or a die attach agent, which is a joining material. The protective member 50 covers the entire sealing member 49 including the portion that overlaps the opening portion when viewed in the Z direction.

[0112] The integrated circuit element 51 is an IC that controls the vibrator 42. Since the configuration of the integrated circuit element 51 is the same as that of the integrated circuit element 10 in Embodiment 1, the description thereof is omitted. The integrated circuit element 51 outputs the oscillation output generated by the oscillation circuit to the outside through the integrated circuit element mounting terminal 51a as a reference signal such as a clock signal.

[0113] The substrate 52 is an insulating substrate that electrically connects and integrally configures the vibrator 42 and the integrated circuit element 51 by a wiring pattern (not shown). One main surface of the substrate 52 is configured as a mounting surface 52a having connection terminals 52b for mounting the vibrator 42. The integrated circuit element mounting terminals 51a of the integrated circuit element 51 are electrically connected to the circuits on the mounting surface of the substrate 52 by wires 51b respectively. 52a The other main surface of the substrate 52 has substrate mounting terminals 52c for mounting on an external substrate. Since the other configuration of the substrate 52 is substantially the same as that of the substrate 11 in Embodiment 1, the description thereof is omitted.

[0114] The mold part (not shown) protects at least the vibrator 42 among the substrate 52, the vibrator 42 mounted on the substrate 52, and the integrated circuit element 51 with epoxy resin. Since the mold part is the same as the mold part 12 in Embodiment 1, the description thereof is omitted.

[0115] When the vibrator 42 and the substrate 52 are molded by an epoxy resin (not shown), the molding pressure applied to the vibrator 42 is applied to the protective member 50 covering the sealing member 49 of the vibrator 42. Therefore, the amount of deflection of the sealing member 49 covering the opening portion of the holding member 43 is suppressed by being covered with the protective member 50. Thus, the sealing member 49 does not contact the piezoelectric element 48 even if it deflects in the Z direction due to the molding pressure.

[0116] [Other Embodiments] Also, in the above-described Embodiment 1, the resin films constituting the first sealing member 7 and the second sealing member 8 are films made of polyimide resin. However, the first sealing member and the second sealing member are not limited to films made of polyimide resin, and films made of resins classified as super engineering plastics, for example, polyamide resin and polyether ether ketone resin, may be used.

[0117] Also, in the above-described embodiment, the protective member 9 is made of silicon. However, the protective member may be made of a brittle material such as glass, crystal, quartz, ceramic, etc., or a ductile material such as alumina. Also, the protective members 9, 50 and the integrated circuit element 28 only need to cover a part or all of the sealing member.

[0118] Also, in the above-described Embodiment 1, the peripheral edge of the protective member 9 is located inward of the outer peripheral edge of the frame portion 4 of the piezoelectric vibrating plate 3. However, the peripheral edge of the protective member may be located outward of the outer peripheral edge of the frame portion of the piezoelectric vibrating plate.

[0119] Also, in the above-described Embodiment 1, the peripheral edge of the first sealing member 7 is located inward of the outer peripheral edge of the piezoelectric vibrating plate 3 and the peripheral edge of the protective member 9. However, the first Sealing member may be located outward of the outer peripheral edge of the piezoelectric vibrating plate and the peripheral edge of the protective member.

[0120] Also, in the above-described embodiment, the substrates 11, 29 are glass EpoxyIt is composed of resin. However, as the substrate, Others a glass composite substrate, a fluororesin substrate, a ceramic substrate, or the like may be used.

[0121] Also, in the above-described embodiments, the piezoelectric vibration devices 1 and 21 have the vibrators 2 and 22 having a three-layer structure in which the piezoelectric vibration plates 3 and 23, the first sealing members 7 and 26, and the second sealing members 8 and 27 are laminated. However, the piezoelectric vibration device may have a vibrator having a three-layer structure or more. The vibrator may be a four-layer vibrator in which a sensor such as a thermistor is further mounted on the main surface of the first sealing member.

[0122] Also, in the above-described Embodiment 3, the vibrator 42 has a piezoelectric element 48 composed of a rectangular crystal vibration piece (for example, an AT-cut crystal piece) which is a vibrating portion. However, the vibrator is not limited to an AT-cut crystal plate, and a crystal vibration plate having a cut angle other than AT-cut, such as a tuning fork type crystal vibration plate or an SC-cut crystal vibration plate having a vibrating portion, may be used.

[0123] Also, in the above-described Embodiment 1, the piezoelectric vibration device 1 has a vibrating portion 5 is positioned within the internal space S of the piezoelectric vibration plate 3. However, the piezoelectric vibration device may be a so-called H-type piezoelectric vibration device having a bottom portion and frame-shaped side wall portions extending in a direction perpendicular to the plane on two opposing planes of the bottom portion. In the H-type piezoelectric vibration device, the piezoelectric element is positioned on one plane of the bottom portion and inside one of the side wall portions. Also, in the H-type piezoelectric vibration device, an electronic component element is mounted on the other plane of the bottom portion and inside the other side wall portion. In the H-type piezoelectric vibration device, the first sealing member is joined to the tip of one side wall portion, and the second sealing member is joined to the tip of the other side wall portion.

[0124] Also, in the above-described Embodiment 2, the thickness of the vibrating portion 25 located within the frame portion 24 is thinner than the thickness of the frame portion 24. However, the vibrating portion may have the same thickness as the frame portion. In this case, the first sealing member and the second sealing member joined to the frame portion have recesses on the main surfaces facing the vibrating portion. As a result, a gap is formed between the first sealing member, the second sealing member, and the vibrating portion of the vibrator.

[0125] Also, in the above-described Embodiment 2, the integrated circuit element 28 is joined onto the first sealing member 26 by solder. However, the integrated circuit element may be joined to the first sealing member by a die attach tape, a conductive adhesive, or the like.

[0126] Also, in each of the above-described embodiments, integrated circuit elements 10, 28, and 51 having an oscillation circuit element, which is an electronic component element for controlling the vibrator, are mounted on substrates 11, 29, and 52. Further, an integrated circuit element 28, which is an electronic component element as a protection member, is mounted on the vibrator 22. However, the electronic component elements mounted on the substrate and the vibrator may be electronic components such as an oscillation circuit element thermistor and various sensors.

[0127] Although the embodiments of the present invention have been described above, the above-described embodiments are merely examples for carrying out the present invention. Therefore, the present invention is not limited to the above-described embodiments, and it is possible to appropriately modify and implement the above-described embodiments without departing from the spirit thereof.

Explanation of Reference Numerals

[0128] 1, 21, 41 Piezoelectric vibration device 2, 14, 22, 42 Vibrator 3, 15, 23 Piezoelectric vibration plate 4, 16, 24, 46 Frame portion 16e, 16f Recess 4a First joint surface 4b Second joint surface 46a Joint surface 4c, 23a Through-hole 4d, 16d, 27a Vibrator mounting terminal 5, 17, 25 Vibration Parts 5a First Excitation Electrode 5b Second Excitation Electrode 6 Connection Part 25a Pair of Excitation Electrodes 7, 26 First Sealing Member 26a External Mounting Terminal 8, 27 Second Sealing Part Material 9 , 50 Protection Member 10, 28, 51 Integrated Circuit Element 10a, 28a, 51a Integrated Circuit Element Mounting Terminal 10b, 28b, 51b Wire 11, 29, 52 Substrate 11a, 29a, 52a Mounting Surface 29b, 52b Connection Terminal 11b, 29c, 52c Substrate Mounting Terminal 12 Molded Part 13, 23b Bonding Material 43 Holding Member 48 Piezoelectric Element 49 Sealing Member S Internal Space G Gap

Claims

1. A piezoelectric vibration device having at least a vibrator in which a vibrating portion is sealed by a sealing member, at least an electronic component element, a substrate on which the vibrator and the electronic component element are mounted on its mounting surface, and having at least a molding portion that covers the vibrator with resin, wherein the vibrator has a protective member that covers at least a part of the sealing member not facing the substrate. Piezoelectric vibration device.

2. In the piezoelectric vibration device according to Claim 1, the protective member has higher rigidity than the sealing member. Piezoelectric vibration device.

3. In the piezoelectric vibration device according to Claim 1, the vibrator is composed of a laminated body of three or more layers including a frame portion, a piezoelectric vibration plate in which the vibrating portion located within the frame of the frame portion is integrally formed, and the sealing member joined to one main surface and the other main surface of the piezoelectric vibration plate respectively to close the opening portion of one main surface and the opening portion of the other main surface, and at least a part or all of one of the sealing members closing the opening portion of one main surface and the opening portion of the other main surface is covered by the protective member. Piezoelectric vibration device.

4. In the piezoelectric vibration device according to Claim 1, the vibrator includes at least a piezoelectric element having the vibrating portion, a box-shaped holding member having an opening on one main surface and forming a frame portion, and the sealing member closing the opening portion of the holding member holding the piezoelectric element within the frame portion, and a part or all of the sealing member is covered by the protective member. Piezoelectric vibration device.

5. In the piezoelectric vibration device according to Claim 3, the vibrator has a part of the vibrating portion connected to the frame portion via a connecting portion, and the sealing member is a resin film. Piezoelectric vibration device.

6. In the piezoelectric vibration device according to Claim 3, the vibrator has recesses on one or both of one main surface and the other main surface of the piezoelectric vibration plate, and the recesses are used as the vibrating portion. Piezoelectric vibration device.

7. In the piezoelectric vibration device according to any one of Claims 1 to 6, the vibrator and the electronic component element are located on the same mounting surface of the substrate. Piezoelectric vibration device.

8. In the piezoelectric vibration device according to Claim 3, the protective member at least partially overlaps the frame portion when viewed in a direction perpendicular to the main surface. Piezoelectric vibration device.

9. In the piezoelectric vibration device according to claim 3, the vibrator is such that the periphery of the sealing member is located inward of the outer periphery of the frame portion, and the periphery of the protection member is located outward of the periphery of the sealing member, a piezoelectric vibration device.

10. In the piezoelectric vibration device according to any one of claims 1 to 9, the protection member is thicker than the sealing member, a piezoelectric vibration device.

11. In the piezoelectric vibration device according to any one of claims 1 to 10, the substrate is made of a resin material, a piezoelectric vibration device.

12. In the piezoelectric vibration device according to any one of claims 1 to 11, the protection member is made of a brittle material, a piezoelectric vibration device.

13. In the piezoelectric vibration device according to any one of claims 1 to 12, the protection member is joined to the sealing member via a bonding material, a piezoelectric vibration device.

14. In the piezoelectric vibration device according to any one of claims 1 to 13, the electronic component element is at least an integrated circuit element having an oscillation circuit element of the vibrator, a piezoelectric vibration device.

15. In the piezoelectric vibration device according to any one of claims 1 to 14, the protection member is constituted by an electronic component element, a piezoelectric vibration device.

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