Piezoelectric vibrator

Abstract

The piezoelectric vibrator (1) of the present invention comprises a piezoelectric vibrating element (10), a piezoelectric vibrating element (10), a base part (30) and a cover part (40), wherein the cover part (40) has a top wall part (41) and a side wall part (42), the side wall part (42) has an opposing surface (43B) opposite to the base part (30), a power supply electrode connected to the piezoelectric vibrating element (10) and a grounding electrode for grounding are provided on the base part (30), the grounding electrode is electrically connected to the cover part (40) via a bonding part (50), the conductive adhesive comprises a resin-based adhesive (51) and a conductive filler (52), and the ratio of the volume of the conductive filler (52) to the total volume of the conductive adhesive is greater than 3 vol% and less than 18 vol%.

Description

Technical Field

[0001] The present invention relates to a piezoelectric vibrator. Background Art

[0002] Vibrators are used in various electronic devices, including mobile communication terminals, communication base stations, and home appliances, for applications such as timing devices, sensors, and oscillators. As electronic devices become more advanced in functionality, there is a demand for inexpensive, high-performance vibrating elements.

[0003] Patent Document 1 discloses a quartz crystal resonator in which a base member and a metal cover member are bonded via a conductive adhesive. The conductive adhesive electrically connects the cover member to a ground electrode of the base member to suppress noise caused by the entry and exit of electromagnetic waves.

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 2015-220749

[0005] However, in the crystal resonator described in Patent Document 1, there are cases where the crystal resonator element and the cover member are short-circuited due to positional displacement or penetration of the conductive adhesive. Summary of the Invention

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a piezoelectric vibrator capable of suppressing noise and preventing the occurrence of defective products.

[0007] A piezoelectric vibrator in one embodiment of the present invention comprises: a piezoelectric vibration element; a base component on which the piezoelectric vibration element is mounted; and a cover component made of a conductive material, which is joined to the base component via a joining component with a conductive adhesive sandwiched therebetween, and an internal space in which the piezoelectric vibration element is arranged is formed between the cover component and the base component, the cover component having a top wall portion and a side wall portion extending from the outer edge of the top wall portion toward the base component, the side wall portion having an opposing surface opposite to the base component, a power supply electrode connected to the piezoelectric vibration element and a grounding electrode for grounding are provided on the base component, the grounding electrode is electrically connected to the cover component via the joining component, the conductive adhesive comprises a resin-based adhesive and a conductive filler dispersed in the resin-based adhesive, and the ratio of the volume of the conductive filler to the total volume of the conductive adhesive is greater than 3 vol% and less than 18 vol%.

[0008] A piezoelectric vibrator according to one embodiment of the present invention comprises: a piezoelectric vibration element; a base component on which the piezoelectric vibration element is mounted; and a cover component made of a conductive material, which is joined to the base component by a bonding component with a conductive adhesive interposed therebetween, and an internal space in which the piezoelectric vibration element is arranged is formed between the cover component and the base component, the cover component having a top wall portion and a side wall portion extending from the outer edge of the top wall portion toward the base component, the side wall portion having an opposing surface opposite to the base component, a power supply electrode connected to the piezoelectric vibration element and a grounding electrode for grounding are provided on the base component, the grounding electrode is electrically connected to the cover component via the bonding component, the conductive adhesive comprises a resin-based adhesive and a conductive filler dispersed in the resin-based adhesive, a protective film of an insulating material is provided on the base component, the protective film is in contact with the bonding component, a gap G1 between the grounding electrode and the opposing surface, a gap G2 between the protective film and the opposing surface, and a particle size R of the conductive filler satisfy the following relationship: G1<R<G2.

[0009] According to the present invention, it is possible to provide a piezoelectric vibrator capable of suppressing noise and preventing the occurrence of defective products. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is an exploded perspective view schematically showing the structure of a crystal resonator according to the embodiment.

[0011] Figure 2 It is a plan view schematically showing the structure of a crystal resonator according to the embodiment.

[0012] Figure 3 It is a cross-sectional view schematically showing the structure of a crystal resonator according to the embodiment.

[0013] Figure 4 It is a plan view schematically showing the structure of the base member and the crystal resonator element.

[0014] Figure 5 This is an enlarged cross-sectional view of a quartz crystal resonator including a grounding electrode.

[0015] Figure 6 This is an enlarged cross-sectional view of a quartz crystal resonator including power supply electrodes.

[0016] Figure 7 This is a table summarizing Examples and Comparative Examples. DETAILED DESCRIPTION

[0017] The following describes embodiments of the present invention with reference to the accompanying drawings. The drawings of the embodiments are for illustration only, and the dimensions and shapes of the components are schematic. The technical scope of the present invention should not be limited to the embodiments.

[0018] Reference Figures 1 to 4, the structure of the crystal resonator 1 according to the embodiment of the present invention will be described. Figure 1 It is an exploded perspective view schematically showing the structure of a crystal resonator according to the embodiment. Figure 2 It is a plan view schematically showing the structure of a crystal resonator according to the embodiment. Figure 3 It is a cross-sectional view schematically showing the structure of a crystal resonator according to the embodiment. Figure 4 : is a top view schematically showing the structure of the base component and the quartz vibration element. Figure 3 It is along Figure 2 A cross-sectional view of the crystal resonator 1 taken along line III-III is shown.

[0019] In each of the drawings, an orthogonal coordinate system consisting of an X-axis, a Y'-axis, and a Z'-axis is sometimes added for convenience in order to clarify the relationship between the drawings and to help understand the positional relationship of the various components. In each of the drawings, the X-axis, the Y'-axis, and the Z'-axis correspond to each other. The X-axis, the Y'-axis, and the Z'-axis are respectively associated with the crystallographic axes (Crystallographic Axes) of the quartz plate 11 described later. The X-axis corresponds to the electrical axis (polar axis) of the quartz crystal, the Y-axis corresponds to the mechanical axis of the quartz crystal, and the Z-axis corresponds to the optical axis of the quartz crystal. The Y'-axis and the Z'-axis are the axes obtained by rotating the Y-axis and the Z-axis around the X-axis from the Y-axis to the Z-axis by 35 degrees 15 minutes ± 1 minute 30 seconds.

[0020] In the following description, the direction parallel to the X-axis is referred to as the "X-axis direction," the direction parallel to the Y'-axis is referred to as the "Y'-axis direction," and the direction parallel to the Z'-axis is referred to as the "Z'-axis direction." Furthermore, the directions indicated by the arrows for the X-axis, Y'-axis, and Z'-axis are referred to as "+ (positive)," and the directions opposite to the arrows are referred to as "- (negative)." For convenience, the description will be made with the +Y'-axis direction as upward and the -Y'-axis direction as downward. However, the vertical orientation of the crystal resonator 1 is not limited to this direction.

[0021] The crystal resonator 1 includes a crystal resonator element 10, a base member 30, a cover member 40, and a bonding member 50. The crystal resonator element 10 is disposed between the base member 30 and the cover member 40. The base member 30 and the cover member 40 form a holder for accommodating the crystal resonator element 10 and overlap along the Y′-axis direction. The crystal resonator element 10 is mounted on the base member 30.

[0022] First, the crystal resonator element 10 will be described.

[0023] The quartz crystal resonator 10 is a piezoelectric resonator that converts electrical energy into mechanical energy by vibrating quartz crystal through the piezoelectric effect. The quartz crystal resonator 10 includes a thin quartz plate 11, a first excitation electrode 14a and a second excitation electrode 14b forming a pair of excitation electrodes, a first extraction electrode 15a and a second extraction electrode 15b forming a pair of extraction electrodes, and a first connection electrode 16a and a second connection electrode 16b forming a pair of connection electrodes.

[0024] The quartz plate 11 has an upper surface 11A and a lower surface 11B that face each other. The upper surface 11A is located on the side opposite to the side facing the base member 30, that is, on the side facing the top wall portion 41 of the cover member 40 described later. The lower surface 11B is located on the side facing the base member 30.

[0025] The quartz plate 11 is, for example, an AT-cut quartz crystal. The AT-cut quartz plate 11 is formed so that, in an orthogonal coordinate system consisting of intersecting X-, Y'-, and Z'-axes, the plane parallel to the plane defined by the X- and Z'-axes (hereinafter referred to as the "XZ' plane"; the same applies to planes defined by other axes) is the principal plane, and the direction parallel to the Y'-axis is the thickness.

[0026] The quartz vibration element 10 using the AT-cut quartz plate 11 has high frequency stability over a wide temperature range. In the AT-cut quartz vibration element 10, the thickness shear vibration mode is used as the main vibration. The quartz plate 11 can also be applied with a different cut other than the AT cut. For example, the BT cut, GT cut, SC cut, etc. can be applied. In addition, the quartz vibration element can also be a tuning fork type quartz vibration element using a quartz plate with a cut angle called a Z plate.

[0027] As an example, the quartz plate 11 is in the shape of a flat plate having a long side direction in which long sides extend parallel to the X-axis, a short side direction in which short sides extend parallel to the Z'-axis, and a thickness direction in which the thickness extends parallel to the Y'-axis. When viewed from above at its upper surface 11A, the planar shape of the quartz plate 11 is rectangular.

[0028] The quartz plate 11 is not limited to a flat plate and may also have a mesa structure or an inverted mesa structure. In this case, the quartz plate 11 may have a tapered shape with a continuously varying thickness, a stepped shape with a discontinuously varying thickness, a convex shape with a continuously varying thickness, or an inclined shape with a discontinuously varying thickness.

[0029] First excitation electrode 14a is provided on upper surface 11A of quartz plate 11, and second excitation electrode 14b is provided on lower surface 11B of quartz plate 11. First excitation electrode 14a and second excitation electrode 14b face each other across quartz plate 11. When viewed from above upper surface 11A of quartz plate 11, first excitation electrode 14a and second excitation electrode 14b each have a rectangular shape and are arranged so as to substantially entirely overlap each other.

[0030] First extraction electrode 15a is provided on upper surface 11A of quartz plate 11, and second extraction electrode 15b is provided on lower surface 11B of quartz plate 11. First extraction electrode 15a electrically connects first excitation electrode 14a and first connection electrode 16a. Second extraction electrode 15b electrically connects second excitation electrode 14b and second connection electrode 16b.

[0031] The first connection electrode 16 a and the second connection electrode 16 b are electrodes for electrically connecting the first excitation electrode 14 a and the second excitation electrode 14 b to the base member 30 , respectively, and are provided on the lower surface 11B of the quartz plate 11 .

[0032] The excitation electrode, extraction electrode, and connection electrode are, for example, a laminate consisting of a base layer that adheres well to the quartz plate 11 and an outermost layer that exhibits excellent chemical stability. The materials constituting the excitation electrode, extraction electrode, and connection electrode are preferably selected from metal materials such as chromium (Cr), gold (Au), titanium (Ti), molybdenum (Mo), aluminum (Al), nickel (Ni), indium (In), palladium (Pd), silver (Ag), copper (Cu), tin (Sn), and iron (Fe). The excitation electrode, extraction electrode, and connection electrode may also contain conductive ceramics, conductive resins, semiconductors, and the like.

[0033] Next, the base member 30 will be described.

[0034] The base component 30 includes a flat substrate 31, a first electrode pad 33a and a second electrode pad 33b constituting a pair of electrode pads, an upper surface electrode 33c, a first side electrode 34a, a second side electrode 34b, a third side electrode 34c, a fourth side electrode 34d, a first external electrode 35a, a second external electrode 35b, a third external electrode 35c, a fourth external electrode 35d and a protective film 39.

[0035] The base 31 has an upper surface 31A and a lower surface 31B that face each other. The upper surface 31A and the lower surface 31B correspond to a pair of principal surfaces of the base 31. The upper surface 31A is located on the side facing the quartz crystal resonator element 10 and the cover member 40. For example, when the quartz crystal resonator 1 is mounted on an external circuit board, the lower surface 31B is located on the side facing the circuit board. The base 31 is made of a sintered material such as insulating ceramic (alumina), but can also be made of quartz, silicon, or the like.

[0036] When looking down at the upper surface 31A, the base 31 has a pair of long sides extending in the X-axis direction and opposing each other in the Z'-axis direction, and a pair of short sides extending in the Z'-axis direction and opposing each other in the X-axis direction. Sector-shaped recesses are provided at the four corners of the base 31. These recesses are formed by dividing the through-holes that penetrate the base 31 from the upper surface 31A to the lower surface 31B.

[0037] The first electrode pad 33a and the second electrode pad 33b are provided on the upper surface 31A of the base 31. The first electrode pad 33a and the second electrode pad 33b are terminals for electrically connecting the quartz crystal vibration element 10 to the base member 30. In a plan view of the upper surface 31A of the base 31, the first electrode pad 33a and the second electrode pad 33b are surrounded by the bonding member 50.

[0038] The upper surface electrode 33c is an electrode electrically connected to the cover member 40. The upper surface electrode 33c is provided at a corner of the base member 30 on the +X axis direction side and the −Z′ axis direction side and is located on the outermost surface of the base member 30 on the cover member 40 side.

[0039] The first to fourth side electrodes 34a to 34d are provided on the side surfaces connecting the outermost edges of the upper surface 31A and the lower surface 31B of the base member 30. Specifically, they extend from the end of a recessed portion located at a corner of the base member 31 on the upper surface 31A side to the end on the lower surface 31B side, covering the recessed portion of the base member 31. The first to fourth side electrodes 34a to 34d each correspond to a castellation electrode. The first side electrode 34a is provided in the recessed portion, located at a corner of the base member 30 on the -X and +Z' axis sides. The second side electrode 34b is provided in the recessed portion, located at a corner of the base member 30 on the +X and -Z' axis sides. The third side electrode 34c is provided in the recessed portion, located at a corner of the base member 30 on the +X and +Z' axis sides. The fourth side electrode 34 d is provided in a recessed portion provided in a corner portion of the base member 30 on the −X axis direction side and the −Z′ axis direction side.

[0040] The first side electrode 34a is electrically connected to the first electrode pad 33a via the wiring electrode 37a provided on the upper surface 31A, and the second side electrode 34b is electrically connected to the second electrode pad 33b via the wiring electrode 37b provided on the upper surface 31A. The third side electrode 34c is provided continuously from the upper surface electrode 33c and is electrically connected to the upper surface electrode 33c. The first side electrode 34a, the first electrode pad 33a, and the wiring electrode 37a connecting these components are equivalent to the power supply electrodes connected to the quartz crystal vibration element 10. The second side electrode 34b, the second electrode pad 33b, and the wiring electrode 37b connecting these components are also equivalent to the power supply electrodes. The third side electrode 34c and the upper surface electrode 33c are equivalent to the grounding electrodes used to ground the cover member 40.

[0041] The power supply electrode and the grounding electrode are, for example, a laminate consisting of a base layer with good adhesion to the substrate 31 and an outermost layer with good chemical stability. The materials constituting the power supply electrode and the grounding electrode are preferably selected from metal materials such as chromium (Cr), gold (Au), titanium (Ti), molybdenum (Mo), aluminum (Al), nickel (Ni), indium (In), palladium (Pd), silver (Ag), copper (Cu), tin (Sn), and iron (Fe). The power supply electrode and the grounding electrode may also contain conductive ceramics, conductive resins, semiconductors, etc.

[0042] The first to fourth external electrodes 35a to 35d are electrodes used to mount the quartz crystal resonator 1 on an external circuit board using solder or other materials. The first to fourth external electrodes 35a to 35d are provided on the lower surface 31B of the base 31. The first external electrode 35a is provided at a corner of the base member 30 on the -X and +Z' axis sides and is electrically connected to the first side electrode 34a. The first external electrode 35a is provided at a corner of the base member 30 on the +X and -Z' axis sides and is electrically connected to the second side electrode 34b. The third external electrode 35c is provided at a corner of the base member 30 on the +X and +Z' axis sides and is electrically connected to the third side electrode 34c. The fourth external electrode 35d is provided at a corner of the base member 30 on the -X and -Z' axis sides and is electrically connected to the fourth side electrode 34d. The first and second external electrodes 35a and 35b are used to supply electrical signals to the pair of power supply electrodes. The third external electrode 35c is used to ground the grounding electrode. The fourth external electrode 35d is a dummy electrode that does not input or output electrical signals. The fourth external electrode 35d may be used together with the third external electrode 35c to ground the cover member 40, or may be omitted.

[0043] The protective film 39 is provided on the side opposite to the cover part 40 of the base part 30 and in the area in contact with the bonding part 50. The protective film 39 is provided by an insulating material. The protective film 39 covers a portion of the power supply electrode (the area opposite to the opposing surface 43B of the cover part 40), electrically insulating the power supply electrode and the cover part 40. Specifically, the protective film 39 covers at least a portion of the wiring electrode 37a connecting the first side electrode 34a and the first electrode pad 33a, and covers at least a portion of the wiring electrode 37b connecting the second side electrode 34b and the second electrode pad 33b. The protective film 39 is provided in the area outside the upper surface electrode 33c, and the upper surface electrode 33c is exposed from the protective film 39. The protective film 39 is, for example, a solder resist.

[0044] Furthermore, if the conductivity of the bonding member 50 described later is sufficiently anisotropic and the conductivity along the upper surface 31A of the base 31 is sufficiently low, the protective film 39 may be omitted. In this case, even if the bonding member 50 contacts the power supply electrode, a short circuit between the quartz crystal resonator element 10 and the cover member 40 via the bonding member 50 is unlikely to occur.

[0045] The base member 30 includes a first conductive holding member 36a and a second conductive holding member 36b forming a pair of conductive holding members. The first conductive holding member 36a and the second conductive holding member 36b are spaced apart from the base member 30 and the cover member 40 to hold the quartz crystal vibrating element 10. The first conductive holding member 36a and the second conductive holding member 36b electrically connect the quartz crystal vibrating element 10 and the base member 30. Specifically, the first conductive holding member 36a electrically connects the first electrode pad 33a and the first connecting electrode 16a, and the second conductive holding member 36b electrically connects the second electrode pad 33b and the second connecting electrode 16b. The first conductive holding member 36a and the second conductive holding member 36b are, for example, a cured product of a conductive adhesive such as a thermosetting resin or a photocurable resin.

[0046] Next, the cover member 40 will be described.

[0047] The cover part 40 is joined to the base part 30. An internal space for accommodating the quartz vibration element 10 is formed between the cover part 40 and the base part 30. The cover part 40 has a recess 49 that opens on one side of the base part 30. The internal space in this embodiment corresponds to the space inside the recess 49. The recess 49 is liquid-tightly sealed. The material of the cover part 40 is a conductive material, and more preferably a metal material with high airtightness. By forming the cover part 40 from a conductive material, the cover part 40 is given an electromagnetic shielding function that reduces the entry and exit of electromagnetic waves into the internal space. From the viewpoint of suppressing the generation of thermal stress, the material of the cover part 40 is preferably a material having a thermal expansion coefficient close to that of the base 31, such as an Fe-Ni-Co alloy having a thermal expansion coefficient near room temperature that is consistent with that of glass and ceramics over a wide temperature range.

[0048] The cover member 40 includes a flat top wall portion 41 and a side wall portion 42 connected to the outer edge of the top wall portion 41. The top wall portion 41 extends along the upper surface 31A of the base body 31 and faces the base member 30 in the height direction with the crystal resonator element 10 interposed therebetween. Furthermore, the side wall portion 42 extends from the top wall portion 41 toward the base member 30, surrounding the crystal resonator element 10 in a direction parallel to the upper surface 31A of the base body 31. The cover member 40 may further include a flange portion connected to the front end of the side wall portion 42 on the base member 30 side and extending outward along the upper surface 31A of the base body 31.

[0049] The cover member 40 has an inner surface located on one side of the recess 49 and an outer surface opposite the recess 49 and exposed to the outside. The inner surface is the side of the top wall 41 and side wall 42 that faces the quartz crystal resonator element 10, while the outer surface is the side of the top wall 41 and side wall 42 that faces the quartz crystal resonator element 10. The cover member 40 also has an opposing surface 43B that faces the base member 30. The opposing surface 43B extends along the upper surface 31A of the base 31 at the front end of the side wall 42 of the base member 30. The area of ​​the opposing surface 43B can be expanded by providing a flange.

[0050] The planar shape of the cover member 40 when viewed from the normal direction of the main surface is, for example, a substantially rectangular shape. The planar shape of the cover member 40 is not limited to the above-mentioned shape, and may be a polygonal shape, a circular shape, an elliptical shape, or a combination of these shapes.

[0051] Next, the joining member 50 will be described.

[0052] The bonding member 50 bonds the base member 30 and the cover member 40. Specifically, the bonding member 50 bonds the protective film 39 and the opposing surface 43B, and also bonds the upper surface electrode 33c and the opposing surface 43B. Furthermore, the bonding member 50 seals the recess 49, which corresponds to the internal space. Specifically, the bonding member 50 extends over the entire circumference of the outer edges of the base member 30 and the cover member 40, forming a rectangular frame that surrounds the quartz crystal resonator element 10.

[0053] The bonding member 50 is a conductive adhesive that electrically connects the grounding electrode and the cover member 40. The electrical conductivity of the bonding member 50 is anisotropic. Specifically, in the region between the upper surface electrode 33c and the opposing surface 43B, the electrical resistance of the bonding member 50 in a direction intersecting the upper surface 31A of the substrate 31 is low, and the upper surface electrode 33c and the opposing surface 43B are electrically connected via the bonding member 50. On the other hand, the electrical resistance of the bonding member 50 along the upper surface 31A of the substrate 31 is high, and even when the bonding member 50 is in contact with the power supply electrode, the power supply electrode and the cover member 40 are electrically insulated.

[0054] Next, refer to Figure 5 and Figure 6 , a more detailed structure of the joining portion through the joining component 50 is described. Figure 5 This is an enlarged cross-sectional view of a quartz crystal resonator including a grounding electrode. Figure 6 This is an enlarged cross-sectional view of a quartz crystal resonator including power supply electrodes.

[0055] The conductive adhesive of the bonding member 50 includes a resin adhesive 51 , a plurality of conductive fillers 52 dispersed in the resin adhesive 51 , and a plurality of insulating fillers 53 dispersed in the resin adhesive 51 .

[0056] The resin adhesive 51 is, for example, an epoxy-based thermosetting resin. Alternatively, the resin adhesive 51 may be an epoxy-based, vinyl-based, acrylic-based, polyurethane-based, imide-based, or silicone-based thermosetting resin. The resin adhesive 51 may also include a photocurable resin.

[0057] The conductive filler 52 is, for example, a spherical filler having a spherical resin core covered with a metal film. The conductive filler 52 can be deformed, and the conductive filler 52 sandwiched between the upper surface electrode 33c and the opposing surface 43B is deformed into an ellipsoidal shape. As the shape is deformed, the conductive filler 52 reliably contacts both the upper surface electrode 33c and the opposing surface 43B. Thus, the upper surface electrode 33c and the opposing surface 43B are electrically connected via the conductive filler 52. In addition, as the shape is deformed, the contact area between the conductive filler 52 and the upper surface electrode 33c, and the contact area between the conductive filler 52 and the opposing surface 43B increase. Thus, the resistance between the conductive filler 52 and the upper surface electrode 33c is reduced. The material of the resin core is, for example, a styrene resin or an acrylic resin. Thus, the elastic modulus of the conductive filler 52 can be appropriately designed. The material of the metal film is, for example, Ni. Thus, it is possible to suppress the metal film from peeling off from the resin core and to suppress the increase in resistance.

[0058] Furthermore, as long as the resin core is deformable, it is not limited to styrene-based resins and acrylic resins. Furthermore, the metal film is not limited to Ni and can also be provided by metal materials such as Au, Ag, Cu, Al, and Ti. The metal film can also be a multilayer film composed of multiple metal layers. The conductive filler 52 can also be a structure formed by processing a conductive material such as Cu, Ni, C, or Si into a spherical shape.

[0059] Insulating filler 53 adjusts the viscosity of the pre-cured conductive adhesive and prevents contact with the power supply electrode due to unwanted wetting and spreading of the pre-cured conductive adhesive. An example of a material for insulating filler 53 is spherical silica. The material for insulating filler 53 is not limited to the aforementioned materials; it may also be an organic compound such as silicone, polyurethane, imide, epoxy resin, ethylene, amine, phenol, amino, acrylic acid, or styrene, or an inorganic compound such as titanium oxide, magnesium oxide, magnesium carbonate, magnesium hydroxide, aluminum oxide, boron nitride, aluminum nitride, glass fiber, or graphite.

[0060] The ratio of the volume of the conductive filler 52 to the total volume of the conductive adhesive of the bonding member 50 (hereinafter referred to as “volume ratio”) is 3 vol % or more and 18 vol % or less.

[0061] If the volume ratio is less than 3 vol%, there may be no conductive filler 52 in the region between the upper surface electrode 33c and the opposing surface 43B, and electrical connection between the upper surface electrode 33c and the opposing surface 43B may not be achieved. That is, if the volume ratio is 3 vol% or greater, the incidence of defective products due to the cover member 40 not being able to be grounded can be reduced.

[0062] When the volume ratio is greater than 18 vol%, the conductive fillers 52 may be close to or in contact with each other, thereby reducing the resistance of the bonding member 50 along the upper surface 31A of the base 31. In other words, when the volume ratio is less than 18 vol%, the incidence of defective products caused by short circuits between the quartz crystal resonator element 10 and the cover member 40 can be reduced.

[0063] Furthermore, to reduce the incidence of defective products due to the failure of the cover member 40 to connect to the ground, the volume ratio is preferably greater than 7 vol%. Furthermore, to reduce the incidence of defective products due to a short circuit between the quartz crystal resonator element 10 and the cover member 40, the volume ratio is more preferably less than 10 vol%.

[0064] The diameter of the conductive filler 52 when it is assumed to be a true sphere (hereinafter referred to as “particle diameter R”) satisfies the relationship of 4 μm≦R≦15 μm.

[0065] Due to the fluctuations of the cover member 40, the gap G1 between the upper surface electrode 33c and the opposing surface 43B fluctuates by an average of approximately 3.8 μm. Therefore, when R < 4 μm, the conductive filler 52 may not contact at least one of the upper surface electrode 33c and the opposing surface 43B. In other words, when 4 μm ≤ R, the incidence of defective products due to the cover member 40 not being able to connect to the ground can be reduced. Furthermore, since the maximum fluctuation of the gap G1 due to the fluctuations of the cover member 40 is approximately 6 μm, it is more preferable to satisfy 6 μm ≤ R.

[0066] Because conductive filler 52 functions as a spacer, when R is 15 μm < R, the thickness of bonding member 50 in the region between upper electrode 33 c and facing surface 43B may increase, reducing sealing performance. In other words, when R is ≤ 15 μm, the incidence of defective products due to frequency fluctuations caused by leakage can be reduced.

[0067] In addition, the particle size R is the arithmetic mean particle size calculated based on the particle size distribution of the resin core of the conductive filler 52 obtained by the Coulter counter method. Since the thickness of the metal film of the conductive filler 52 is sufficiently small compared to the particle size of the resin core, the particle size of the resin core can be regarded as the particle size R of the conductive filler 52. Here, as an example, the thickness of the metal film of the conductive filler 52 is greater than 10nm and less than 500nm. In the case where the thickness of the metal film is less than 10nm, there is a case where the resistance of the conductive filler 52 increases. In the case where the thickness of the metal film is greater than 500nm, there is a case where the metal film hinders the deformation of the conductive filler 52, and the metal film peels off from the resin core. That is, when the thickness of the metal film is greater than 10nm and less than 500nm, the generation rate of defective products in which the cover part 40 cannot be grounded can be reduced.

[0068] The width W of the facing surface 43B in the short-side direction and the particle diameter R of the conductive filler 52 satisfy the following relationship: 4 μm≦R≦W / 2.

[0069] To establish electrical continuity between the grounding electrode and cover member 40, pressure is applied to conductive filler 52, which is sandwiched between upper surface electrode 33c and opposing surface 43B. When W / 2 < R, conductive filler 52 may be squeezed out of the area between upper surface electrode 33c and opposing surface 43B. In other words, when R ≤ W / 2, the incidence of defective products due to cover member 40 failing to connect to the ground can be reduced.

[0070] In the case of 4 μm≦R, the occurrence rate of defective products in which the cover member 40 cannot be grounded can be reduced as described above.

[0071] The diameter of the insulating filler 53 when it is assumed to be a true sphere (hereinafter referred to as “particle diameter r”) and the particle diameter R of the conductive filler 52 satisfy the relationship r<R.

[0072] When R ≤ r, the insulating filler 53 may act as a spacer and hinder the deformation of the conductive filler 52. For example, if the elastic modulus of the insulating filler 53 is greater than that of the conductive filler 52, then if R = r, the deformation of the conductive filler 52 is hindered by the insulating filler 53. Furthermore, even if the elastic modulus of the insulating filler 53 is less than that of the conductive filler 52, if R < r, the deformation of the conductive filler 52 is hindered by the insulating filler 53. Therefore, when r < R, the occurrence rate of defective products where the cover member 40 fails to connect to the ground can be reduced.

[0073] The particle size r is a median diameter D50 calculated from a particle size distribution obtained by a microtrack method.

[0074] The particle size R and the particle size r satisfy the relationship of R / 20≤r≤R×8 / 10.

[0075] When r < R / 20, insulating filler 53 may intrude between conductive filler 52 and upper surface electrode 33c, hindering contact between conductive filler 52 and upper surface electrode 33c. Similarly, contact between conductive filler 52 and opposing surface 43B may be hindered. In other words, when R / 20 ≤ r, the incidence of defective products resulting from failure to ground cover member 40 can be reduced.

[0076] When R×8 / 10<r, the insulating filler 53 may act as a spacer in the region between the upper surface electrode 33c and the opposing surface 43B, hindering the deformation of the conductive filler 52. That is, when r≤R×8 / 10, the incidence of defective products where the cover member 40 fails to connect to the ground can be reduced.

[0077] Furthermore, from the perspective of reducing the occurrence rate of defective products where the cover member 40 cannot be grounded, the particle diameter R and the particle diameter r preferably further satisfy the relationship R / 10≤r. Furthermore, it is preferable to further satisfy the relationship r≤R / 2.

[0078] The gap G1 between the upper surface electrode 33 c and the facing surface 43B, the gap G2 between the protective film 39 and the facing surface 43B, and the particle size R of the conductive filler 52 satisfy the relationship G1 < R < G2.

[0079] When R≤G1, the conductive filler 52 may not contact at least one of the upper surface electrode 33c and the facing surface 43B. That is, when G1<R, the occurrence rate of defective products where the cover member 40 cannot be grounded can be reduced.

[0080] When G2 ≤ ​​R, the conductive filler 52 sandwiched between the protective film 39 and the opposing surface 43B deforms. Furthermore, when the conductive filler 52 sandwiched between the upper surface electrode 33c and the opposing surface 43B deforms, a portion of the conductive filler 52 is squeezed out from the area between the protective film 39 and the opposing surface 43B. As a result, the conductive fillers 52 may come close to each other in an undesirable area, reducing the resistance of the bonding member 50 along the upper surface 31A of the base 31. In other words, when R < G2, the incidence of defective products resulting from a short circuit between the quartz crystal resonator element 10 and the cover member 40 can be reduced.

[0081] The gap G1 and the gap G2 satisfy the relationship of 0≤G2−G1≤13 μm.

[0082] When G2 - G1 < 0, that is, G2 < G1, the conductive filler 52 located in the region between the protective film 39 and the opposing surface 43B may function as a spacer, hindering sufficient deformation of the conductive filler 52 in the region between the upper surface electrode 33c and the opposing surface 43B. In other words, when 0 ≤ G2 - G1, the incidence of defective products due to the cover member 40 failing to connect to the ground can be reduced.

[0083] When 13 μm < G2 - G1, the sealing performance may decrease as the thickness of the bonding member 50 increases in the region between the protective film 39 and the facing surface 43B. In other words, when G2 - G1 ≤ 13 μm, the rate of defective products due to leakage and frequency fluctuations can be reduced.

[0084] The gap G2 satisfies the relationship of 2 μm ≤ G2 ≤ ​​20 μm.

[0085] Gap G2 is limited by particle diameter R. Therefore, to reduce gap G2, particle diameter R must be reduced. When G2 is less than 2 μm, particle diameter R is too small, so variations in gap G1 caused by undulations in cover member 40 may prevent conductive filler 52 from contacting at least one of upper surface electrode 33 c and opposing surface 43B. In other words, when 2 μm ≤ G2, the incidence of defective products resulting from failure of cover member 40 to connect to the ground can be reduced.

[0086] When 20 μm < G2, the sealing performance may decrease as the film thickness of the bonding member 50 increases in the region between the protective film 39 and the facing surface 43B. In other words, when G2 ≤ ​​20 μm, the rate of defective products due to leakage can be reduced.

[0087] Next, refer to Figure 7 , Examples and Comparative Examples are described. Figure 7 This is a table summarizing Examples and Comparative Examples.

[0088] Each of the quartz crystal resonators in Examples 1 to 3 and Comparative Examples 1 and 2 is the quartz crystal resonator 1 of the embodiment, and has a structure in which the volume ratio of the conductive filler 52 is varied. The "volume ratio of the conductive filler 52" is the ratio of the volume of the conductive filler 52 to the total volume of the conductive adhesive, and the "addition rate of the conductive filler 52" is the ratio of the weight of the conductive filler 52 to the total weight of the conductive adhesive.

[0089] (Example 1)

[0090] The volume ratio of the conductive filler 52 was 7.3 vol %. The particle size R of the conductive filler 52 was 5 μm. The addition rate of the conductive filler 52 was 10 wt %.

[0091] (Example 2)

[0092] The volume ratio of the conductive filler 52 was 7.6 vol %. The particle size R of the conductive filler 52 was 10 μm. The addition rate of the conductive filler 52 was 10 wt %.

[0093] (Example 3)

[0094] The volume ratio of the conductive filler 52 was 9.4 vol %. The particle size R of the conductive filler 52 was 20 μm. The addition rate of the conductive filler 52 was 10 wt %.

[0095] (Comparative Example 1)

[0096] The volume ratio of the conductive filler 52 was 2.2 vol %. The particle size R of the conductive filler 52 was 5 μm. The addition rate of the conductive filler 52 was 3 wt %.

[0097] (Comparative Example 2)

[0098] The volume ratio of the conductive filler 52 was 18.9 vol %. The particle size R of the conductive filler 52 was 20 μm, and the addition rate of the conductive filler was 20 wt %.

[0099] In each quartz crystal resonator 1, the production rate of defective products in which the cover part 40 and the power supply electrode are not electrically connected (hereinafter referred to as the "grounding defect rate"), and the production rate of defective products in which a short circuit occurs between the quartz crystal resonator element 10 and the cover part 40 (hereinafter referred to as the "short circuit defect rate") were measured. The number of samples for each measurement was 20. In determining the grounding defect rate, samples in which the resistance between the grounding electrode and the cover part 40 was less than 10Ω were determined to be qualified products, and samples in which the resistance between the grounding electrode and the cover part 40 was greater than 10Ω were determined to be defective products. In determining the short circuit defect rate, samples in which the resistance between the grounding electrode and the power supply electrode was less than 10Ω were determined to be qualified products, and samples in which the resistance between the grounding electrode and the cover part 40 was greater than 10Ω were determined to be defective products. 9 The samples with the resistance between the grounding electrode and the power supply electrode should be less than 10 9 Samples with a grounding failure rate and a short circuit failure rate of less than 5% were marked as 0, and samples with a grounding failure rate and a short circuit failure rate of 5% or more were marked as ×.

[0100] In Comparative Example 1, where the volume ratio of the conductive filler 52 was less than 3 vol%, the short-circuit failure rate was low, but the grounding failure rate was high, failing to sufficiently reduce the rate of defective products. In Comparative Example 2, where the volume ratio of the conductive filler 52 was greater than 18 vol%, the grounding failure rate was low, but the short-circuit failure rate was high, failing to sufficiently reduce the rate of defective products. In Examples 1 to 3, where the volume ratio of the conductive filler 52 was between 3 vol% and 18 vol%, both the grounding failure rate and the short-circuit failure rate were low, effectively reducing the rate of defective products.

[0101] As described above, in the present embodiment, the volume ratio of the conductive filler 52 is 3 vol % or more and 18 vol % or less.

[0102] This allows the conductive filler 52 to contact both the upper surface electrode 33c and the opposing surface 43B, thereby preventing the conductive fillers 52 from approaching or contacting each other along the upper surface 31A of the base 31. This reduces the incidence of defective products due to the cover member 40 not being grounded, and also reduces the incidence of defective products due to a short circuit between the quartz crystal resonator element 10 and the cover member 40.

[0103] In other embodiments, the relationship G1 < R < G2 is satisfied.

[0104] This allows the conductive filler 52 to contact both the upper surface electrode 33c and the opposing surface 43B, while preventing the conductive filler 52 from approaching or contacting each other outside the region between the upper surface electrode 33c and the opposing surface 43B. Consequently, the incidence of defective products due to the cover member 40 not being grounded can be reduced, as can the incidence of defective products due to a short circuit between the quartz crystal resonator element 10 and the cover member 40.

[0105] The particle size R and the particle size r satisfy the relationship of r<R.

[0106] This can suppress the insulating filler 53 from hindering the deformation of the conductive filler 52. Therefore, the occurrence rate of defective products in which the cover member 40 cannot be grounded can be reduced.

[0107] Hereinafter, some or all of the embodiments of the present invention will be supplemented to explain their effects. However, the present invention is not limited to the following supplementary notes.

[0108] According to one embodiment of the present invention, a quartz resonator is provided, comprising: a quartz resonator element, a base component on which the quartz resonator element is mounted, and a cover component made of a conductive material that is joined to the base component via a joining component sandwiching a conductive adhesive and forms an internal space between the cover component and the base component in which the quartz resonator element is arranged, the cover component having a top wall portion and a side wall portion extending from the outer edge of the top wall portion toward the base component, the side wall portion having an opposing surface opposite to the base component, a power supply electrode connected to the quartz resonator element and a grounding electrode for grounding are provided on the base component, the grounding electrode is electrically connected to the cover component via the joining component, the conductive adhesive comprises a resin-based adhesive and a conductive filler dispersed in the resin-based adhesive, and the ratio of the volume of the conductive filler to the total volume of the conductive adhesive is greater than 3 vol% and less than 18 vol%.

[0109] Thus, the cover member, which can be grounded to provide electromagnetic shielding, can reduce noise caused by the ingress and egress of electromagnetic waves. Furthermore, the conductive filler can be brought into contact with both the power supply electrode and the cover member, while preventing the conductive fillers from coming into proximity or contact with each other. This reduces the incidence of defective products due to the cover member not being grounded, as well as the incidence of defective products due to short circuits between the quartz resonator element and the cover member.

[0110] As one method, a protective film of an insulating material is provided on the base component to cover at least the area of ​​the power supply electrode opposite to the opposing surface, the protective film is in contact with the joining component, and the gap G1 between the grounding electrode and the opposing surface, the gap G2 between the protective film and the opposing surface, and the particle size R of the conductive filler satisfy the following relationship: G1<R<G2.

[0111] According to another embodiment of the present invention, a quartz resonator is provided, comprising: a quartz resonator element, a base component on which the quartz resonator element is mounted, and a cover component of a conductive material joined to the base component by a bonding component sandwiching a conductive adhesive and forming an internal space in which the quartz resonator element is arranged, the cover component having a top wall portion and a side wall portion extending from the outer edge of the top wall portion toward the base component, the side wall portion having an opposing surface opposite to the base component, a power supply electrode connected to the quartz resonator element and a grounding electrode for grounding are provided on the base component, the grounding electrode is electrically connected to the cover component via the bonding component, the conductive adhesive comprises a resin-based adhesive and a conductive filler dispersed in the resin-based adhesive, a protective film of an insulating material is provided on the base component, the protective film is in contact with the bonding component, a gap G1 between the grounding electrode and the opposing surface, a gap G2 between the protective film and the opposing surface, and a particle size R of the conductive filler satisfy the following relationship: G1<R<G2.

[0112] Thus, the cover member, which can be grounded to provide electromagnetic shielding, can reduce noise caused by the ingress and egress of electromagnetic waves. Furthermore, the conductive filler can be brought into contact with both the power supply electrode and the cover member, while preventing the conductive fillers from approaching or contacting each other. This reduces the incidence of defective products due to the cover member not being grounded, as well as the incidence of defective products due to short circuits between the quartz resonator element and the cover member.

[0113] In one embodiment, the conductive filler has a spherical resin core and a metal film covering the resin core.

[0114] In one embodiment, the resin core is a styrene resin or an acrylic resin, and the metal film is nickel.

[0115] In one embodiment, the resin adhesive is an epoxy-based thermosetting resin.

[0116] In one embodiment, the conductive adhesive further includes an insulating filler dispersed in the resin-based adhesive, and the particle size R of the conductive filler and the particle size r of the insulating filler satisfy the relationship r<R.

[0117] This can suppress the insulating filler from hindering the deformation of the conductive filler, thereby reducing the incidence of defective products where the cover member cannot be grounded.

[0118] The embodiments of the present invention are not limited to quartz resonators, but can also be applied to piezoelectric resonators. An example of a piezoelectric resonator (Piezoelectric Resonator Unit) is a quartz resonator (Quartz Crystal Resonator Unit) having a quartz resonator element (Quartz Crystal Resonator). The quartz resonator element utilizes a quartz crystal element as a piezoelectric piece excited by the piezoelectric effect. The piezoelectric piece can also be formed of any piezoelectric material such as a piezoelectric single crystal, a piezoelectric ceramic, a piezoelectric film, or a piezoelectric polymer film. As an example, a piezoelectric single crystal can include lithium niobate (LiNbO3). Similarly, piezoelectric ceramics can include barium titanate (BaTiO3), lead titanate (PbTiO3), lead zirconate titanate (Pb(Zr xTi 1-x)O3; PZT), aluminum nitride (AlN), lithium niobate (LiNbO3), lithium metaniobate (LiNb2O6), bismuth titanate (Bi4Ti3O 12 ), lithium tantalate (LiTaO3), lithium tetraborate (Li2B4O7), lanthanum gallium silicate (La3Ga5SiO 14 ), or tantalum pentoxide (Ta2O5), etc. Examples of piezoelectric thin films include the piezoelectric ceramics described above formed on substrates such as quartz or sapphire by sputtering. Examples of piezoelectric polymer films include polylactic acid (PLA), polyvinylidene fluoride (PVDF), or vinylidene fluoride / trifluoroethylene (VDF / TrFE) copolymers. The various piezoelectric materials described above can be used in layers or with other components.

[0119] The embodiments of the present invention are not particularly limited and can be appropriately applied to any device that performs electromechanical energy conversion using the piezoelectric effect, such as a timing device, a sound generator, an oscillator, and a load sensor.

[0120] As described above, according to one embodiment of the present invention, it is possible to provide a piezoelectric vibrator capable of suppressing noise and preventing the occurrence of defective products.

[0121] In addition, the embodiment described above is a way to make the understanding of the present invention easy, not a way to explain the present invention in a limiting manner. The present invention can be changed / improved without departing from its purport, and its equivalents are also included in the present invention. That is, as long as the method formed by those skilled in the art has the characteristics of the present invention, it is included in the scope of the present invention. For example, each element and its configuration, material, condition, shape, size, etc. possessed by each embodiment are not limited to the structure shown in the example, and can be appropriately changed. In addition, as long as each element possessed by each embodiment is technically feasible, it can be combined, and the structure formed by combining these elements is included in the scope of the present invention as long as it comprises the characteristics of the present invention.

[0122] Description of Reference Numerals

[0123] 1…quartz resonator, 10…quartz resonator element, 30…base member, 31…substrate, 33a, 33b…electrode pads, 33c…upper surface electrode, 34a to 34d…side electrodes, 35a to 35d…external electrodes, 39…protective film, 40…cover member, 41…top wall portion, 42…side wall portion, 43B…opposing surface, 50…joining member, 51…resin-based adhesive, 52…conductive filler, 53…insulating filler

Claims

1. A piezoelectric vibrator comprising: Piezoelectric vibration element; A base component equipped with the piezoelectric vibration element; a cover member made of a conductive material, wherein an internal space is formed between the cover member and the base member, and the piezoelectric vibration element is arranged in the internal space; and a bonding member bonding the base member and the cover member, wherein the bonding member is provided with a conductive adhesive, The cover member includes a top wall portion and a side wall portion extending from an outer edge of the top wall portion toward the base member, the side wall portion having an opposing surface facing the base member. The base member is provided with a power supply electrode connected to the piezoelectric vibration element and a grounding electrode for grounding. The grounding electrode is electrically connected to the cover member via the bonding member. The conductive adhesive comprises a resin-based adhesive and a conductive filler dispersed in the resin-based adhesive. The volume ratio of the conductive filler to the total volume of the conductive adhesive is 3 vol% or more and 18 vol% or less, On the base member, a protective film is provided made of an insulating material, wherein The protective film covers at least the region of the power supply electrode facing the opposing surface, and the protective film is in contact with the bonding member. The gap G1 between the grounding electrode and the opposing surface, the gap G2 between the protective film and the opposing surface, and the particle size R of the conductive filler satisfy the following relationship: G1<R<G2.

2. The piezoelectric vibrator according to claim 1, wherein The conductive filler includes a spherical resin core and a metal film covering the resin core.

3. The piezoelectric vibrator according to claim 2, wherein: The resin core is a styrene resin or an acrylic resin. The above-mentioned metal film is nickel.

4. The piezoelectric vibrator according to any one of claims 1 to 3, wherein The resin-based adhesive is an epoxy-based thermosetting resin.

5. The piezoelectric vibrator according to any one of claims 1 to 3, wherein The conductive adhesive further comprises an insulating filler dispersed in the resin-based adhesive. The particle size R of the conductive filler and the particle size r of the insulating filler satisfy the following relationship: r＜R。 6. The piezoelectric vibrator according to claim 4, wherein The conductive adhesive further comprises an insulating filler dispersed in the resin-based adhesive. The particle size R of the conductive filler and the particle size r of the insulating filler satisfy the following relationship: r＜R。 7. The piezoelectric vibrator according to any one of claims 1 to 3, wherein A portion of the conductive filler is deformed by being sandwiched between the grounding electrode and the cover member.

8. The piezoelectric vibrator according to claim 4, wherein A portion of the conductive filler is deformed by being sandwiched between the grounding electrode and the cover member.

9. The piezoelectric vibrator according to claim 5, wherein: A portion of the conductive filler is deformed by being sandwiched between the grounding electrode and the cover member.

10. The piezoelectric vibrator according to claim 6, wherein A portion of the conductive filler is deformed by being sandwiched between the grounding electrode and the cover member.

11. The piezoelectric vibrator according to any one of claims 1 to 3, wherein The power supply electrode has: an electrode pad provided on an upper surface of the base member on the cover member side and surrounded by the bonding member when the upper surface is viewed from above; a side electrode disposed on a side surface of the base member; and The wiring electrode is provided on the upper surface and electrically connects the electrode pad and the side electrode.

12. The piezoelectric vibrator according to claim 4, wherein The power supply electrode has: an electrode pad provided on an upper surface of the base member on the cover member side and surrounded by the bonding member when the upper surface is viewed from above; a side electrode disposed on a side surface of the base member; and The wiring electrode is provided on the upper surface and electrically connects the electrode pad and the side electrode.

13. The piezoelectric vibrator according to claim 5, wherein The power supply electrode has: an electrode pad provided on an upper surface of the base member on the cover member side and surrounded by the bonding member when the upper surface is viewed from above; a side electrode disposed on a side surface of the base member; and The wiring electrode is provided on the upper surface and electrically connects the electrode pad and the side electrode.

14. The piezoelectric vibrator according to claim 6, wherein The power supply electrode has: an electrode pad provided on an upper surface of the base member on the cover member side and surrounded by the bonding member when the upper surface is viewed from above; a side electrode disposed on a side surface of the base member; and The wiring electrode is provided on the upper surface and electrically connects the electrode pad and the side electrode.

15. The piezoelectric vibrator according to claim 7, wherein The power supply electrode has: an electrode pad provided on an upper surface of the base member on the cover member side and surrounded by the bonding member when the upper surface is viewed from above; a side electrode disposed on a side surface of the base member; and The wiring electrode is provided on the upper surface and electrically connects the electrode pad and the side electrode.

16. The piezoelectric vibrator according to claim 8, wherein The power supply electrode has: an electrode pad provided on an upper surface of the base member on the cover member side and surrounded by the bonding member when the upper surface is viewed from above; a side electrode disposed on a side surface of the base member; and The wiring electrode is provided on the upper surface and electrically connects the electrode pad and the side electrode.

17. The piezoelectric vibrator according to claim 9, wherein The power supply electrode has: an electrode pad provided on an upper surface of the base member on the cover member side and surrounded by the bonding member when the upper surface is viewed from above; a side electrode disposed on a side surface of the base member; and The wiring electrode is provided on the upper surface and electrically connects the electrode pad and the side electrode.

18. The piezoelectric vibrator according to claim 10, wherein The power supply electrode has: an electrode pad provided on an upper surface of the base member on the cover member side and surrounded by the bonding member when the upper surface is viewed from above; a side electrode disposed on a side surface of the base member; and The wiring electrode is provided on the upper surface and electrically connects the electrode pad and the side electrode.

19. A piezoelectric vibrator comprising: Piezoelectric vibration element; A base component equipped with the piezoelectric vibration element; a cover member made of a conductive material, wherein an internal space is formed between the cover member and the base member, and the piezoelectric vibration element is arranged in the internal space; and a bonding member bonding the base member and the cover member, wherein the bonding member is provided with a conductive adhesive, The cover member includes a top wall portion and a side wall portion extending from an outer edge of the top wall portion toward the base member, the side wall portion having an opposing surface facing the base member. The base member is provided with a power supply electrode connected to the piezoelectric vibration element and a grounding electrode for grounding. The grounding electrode is electrically connected to the cover member via the bonding member. The conductive adhesive comprises a resin-based adhesive and a conductive filler dispersed in the resin-based adhesive. On the base member, a protective film is provided made of an insulating material, wherein The protective film covers at least the region of the power supply electrode facing the opposing surface, and the protective film is in contact with the bonding member. The gap G1 between the grounding electrode and the opposing surface, the gap G2 between the protective film and the opposing surface, and the particle size R of the conductive filler satisfy the following relationship: G1<R<G2.

20. The piezoelectric vibrator according to claim 19, wherein The conductive filler includes a spherical resin core and a metal film covering the resin core.

21. The piezoelectric vibrator according to claim 20, wherein The resin core is a styrene resin or an acrylic resin. The above-mentioned metal film is nickel.

22. The piezoelectric vibrator according to any one of claims 19 to 21, wherein The resin-based adhesive is an epoxy-based thermosetting resin.

23. The piezoelectric vibrator according to any one of claims 19 to 21, wherein The conductive adhesive further comprises an insulating filler dispersed in the resin-based adhesive. The particle size R of the conductive filler and the particle size r of the insulating filler satisfy the following relationship: r＜R。 24. The piezoelectric vibrator according to claim 22, wherein: The conductive adhesive further comprises an insulating filler dispersed in the resin-based adhesive. The particle size R of the conductive filler and the particle size r of the insulating filler satisfy the following relationship: r＜R。 25. The piezoelectric vibrator according to any one of claims 19 to 21, wherein A portion of the conductive filler is deformed by being sandwiched between the grounding electrode and the cover member.

26. The piezoelectric vibrator according to claim 22, wherein: A portion of the conductive filler is deformed by being sandwiched between the grounding electrode and the cover member.

27. The piezoelectric vibrator according to claim 23, wherein A portion of the conductive filler is deformed by being sandwiched between the grounding electrode and the cover member.

28. The piezoelectric vibrator according to claim 24, wherein A portion of the conductive filler is deformed by being sandwiched between the grounding electrode and the cover member.

29. The piezoelectric vibrator according to any one of claims 19 to 21, wherein The power supply electrode has: an electrode pad provided on an upper surface of the base member on the cover member side and surrounded by the bonding member when the upper surface is viewed from above; a side electrode disposed on a side surface of the base member; and The wiring electrode is provided on the upper surface and electrically connects the electrode pad and the side electrode.

30. The piezoelectric vibrator according to claim 22, wherein The power supply electrode has: an electrode pad provided on an upper surface of the base member on the cover member side and surrounded by the bonding member when the upper surface is viewed from above; a side electrode disposed on a side surface of the base member; and The wiring electrode is provided on the upper surface and electrically connects the electrode pad and the side electrode.

31. The piezoelectric vibrator according to claim 23, wherein The power supply electrode has: an electrode pad provided on an upper surface of the base member on the cover member side and surrounded by the bonding member when the upper surface is viewed from above; a side electrode disposed on a side surface of the base member; and The wiring electrode is provided on the upper surface and electrically connects the electrode pad and the side electrode.

32. The piezoelectric vibrator according to claim 24, wherein: The power supply electrode has: an electrode pad provided on an upper surface of the base member on the cover member side and surrounded by the bonding member when the upper surface is viewed from above; a side electrode disposed on a side surface of the base member; and The wiring electrode is provided on the upper surface and electrically connects the electrode pad and the side electrode.

33. The piezoelectric vibrator according to claim 25, wherein: The power supply electrode has: an electrode pad provided on an upper surface of the base member on the cover member side and surrounded by the bonding member when the upper surface is viewed from above; a side electrode disposed on a side surface of the base member; and The wiring electrode is provided on the upper surface and electrically connects the electrode pad and the side electrode.

34. The piezoelectric vibrator according to claim 26, wherein: The power supply electrode has: an electrode pad provided on an upper surface of the base member on the cover member side and surrounded by the bonding member when the upper surface is viewed from above; a side electrode disposed on a side surface of the base member; and The wiring electrode is provided on the upper surface and electrically connects the electrode pad and the side electrode.

35. The piezoelectric vibrator according to claim 27, wherein The power supply electrode has: an electrode pad provided on an upper surface of the base member on the cover member side and surrounded by the bonding member when the upper surface is viewed from above; a side electrode disposed on a side surface of the base member; and The wiring electrode is provided on the upper surface and electrically connects the electrode pad and the side electrode.

36. The piezoelectric vibrator according to claim 28, wherein The power supply electrode has: an electrode pad provided on an upper surface of the base member on the cover member side and surrounded by the bonding member when the upper surface is viewed from above; a side electrode disposed on a side surface of the base member; and The wiring electrode is provided on the upper surface and electrically connects the electrode pad and the side electrode.

Images