JP2016158128A - Piezoelectric device and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piezoelectric device capable of reducing fluctuations of an oscillation frequency of a piezoelectric element, and a method of manufacturing that.SOLUTION: A piezoelectric device is equipped with: a piezoelectric element 120 which has a substrate 110a, a first conductive adhesive 140a, a piezoelectric elemental plate 121, an exciting electrode 122, a pair of extraction electrodes 123, first recessed portions 124 provided on upper surfaces of the pair of the extraction electrodes 123 so as to expose the piezoelectric elemental plate 121, and a second recessed portion 125 provided on lower surfaces of the pair of the extraction electrodes 123 so as to expose the piezoelectric elemental plate 121; and a cover body 130. The first recessed portion 124 and the second recessed portion 125 are provided so as to extend from one side facing the exciting electrode 122 side of the pair of the extraction electrodes 123 toward one side of the piezoelectric elemental plate 121 in a plane view. The first recessed portion 124 and the second recessed portion 125 are provided at positions superimposed in a plane view, and an outer peripheral edge of the first conductive adhesive 140a is provided in the second recessed portion 125 in a plane view.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a piezoelectric device used in, for example, electronic equipment and a manufacturing method thereof.

  A piezoelectric device uses a piezoelectric effect of a piezoelectric element to cause a thickness-shear vibration so that both surfaces of a piezoelectric base plate are displaced from each other, thereby generating a specific frequency. A piezoelectric device including a piezoelectric element mounted on an electrode pad provided on a substrate via a conductive adhesive has been proposed (for example, see Patent Document 1 below). The piezoelectric element has excitation electrodes on both main surfaces of the piezoelectric element plate, one end of the piezoelectric element is a fixed end connected to the upper surface of the substrate, and the other end is a free end spaced from the upper surface of the substrate. Cantilevered support structure.

  A method for manufacturing a piezoelectric device includes a step of applying a conductive adhesive on an electrode pad provided on an upper surface of a package, placing a piezoelectric element on the conductive adhesive, and heating and curing the conductive adhesive. A manufacturing method is known that includes a step of electrically bonding and fixing an electrode pad and a piezoelectric element and a step of bonding a lid and a package (for example, see Patent Document 2).

JP 2002-111435 A JP 2007-235340 A

  When the above-described piezoelectric device is bonded with a conductive adhesive between the extraction electrode provided adjacent to one side of the piezoelectric element and the electrode pad provided on the upper surface of the substrate, the lower surface of the extraction electrode is provided. However, a part of the conductive adhesive provided on the upper surface of the electrode pad protrudes from the electrode pad and adheres to the excitation electrode, thereby possibly changing the resonance frequency of the piezoelectric element.

  Further, in the above-described method for manufacturing a piezoelectric device, when the piezoelectric element is placed on the conductive adhesive, the position of the conductive adhesive is hidden by the lead electrode of the piezoelectric element. Therefore, the tip of the piezoelectric element may come into contact with the upper surface of the substrate.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a piezoelectric device capable of reducing fluctuations in the oscillation frequency of a piezoelectric element and a method for manufacturing the same.

  A piezoelectric device according to one aspect of the present invention includes a substrate, an electrode pad provided on the upper surface of the substrate, a conductive adhesive provided on the electrode pad, a rectangular piezoelectric element plate, and a piezoelectric element plate. Excitation electrodes provided on the upper and lower surfaces, a pair of rectangular extraction electrodes provided along one side of the piezoelectric element plate with a space between the excitation electrodes, and a piezoelectric element plate on the upper surfaces of the pair of extraction electrodes And a second recess provided so that the piezoelectric element plate is exposed on the lower surface of the pair of lead electrodes, and is disposed on the electrode pad via a conductive adhesive. And a lid provided to hermetically seal the piezoelectric element, and the first recess and the second recess have a pair of lead electrodes on the excitation electrode side in plan view. It is provided so as to extend from one side facing to one side of the piezoelectric element plate The first concave portion and the second concave portion are provided at a position overlapping in plan view, and the outer peripheral edge of the conductive adhesive is provided in the second concave portion in plan view. To do.

  A method of manufacturing a piezoelectric device according to an aspect of the present invention includes a rectangular piezoelectric element plate, excitation electrodes provided on the upper and lower surfaces of the piezoelectric element plate, and one side of the piezoelectric element plate with a gap between the excitation electrodes. A pair of lead electrodes provided along the upper surface of the pair of lead electrodes, and the piezoelectric element plate exposed on the upper surface of the pair of lead electrodes and from one side facing the excitation electrode side of the pair of lead electrodes to one side of the piezoelectric element plate The piezoelectric element plate is exposed from the side facing the excitation electrode side of the pair of extraction electrodes, and the piezoelectric element plate is exposed to the lower surface of the first concave portion provided to extend toward the bottom surface of the pair of extraction electrodes. A piezoelectric element forming step of forming a piezoelectric element having a second recess provided so as to extend toward one side of the electrode, and applying a first conductive adhesive on an electrode pad provided on the package One conductive adhesive application process and first A piezoelectric element mounting step of mounting the piezoelectric element on the first conductive adhesive so that the outer peripheral edge of the conductive adhesive is located in the second recess in plan view, and the first conductive adhesive A first conductive adhesive curing step for electrically curing the electrode pad and the piezoelectric element, and a lid bonding step for bonding the lid to the package so as to hermetically seal the piezoelectric element; It is characterized by including.

  A piezoelectric device according to one aspect of the present invention includes a substrate, an electrode pad provided on the upper surface of the substrate, a conductive adhesive provided on the electrode pad, a rectangular piezoelectric element plate, and a piezoelectric element plate. Excitation electrodes provided on the upper and lower surfaces, a pair of rectangular extraction electrodes provided along one side of the piezoelectric element plate with a space between the excitation electrodes, and a piezoelectric element plate on the upper surfaces of the pair of extraction electrodes And a second recess provided so that the piezoelectric element plate is exposed on the lower surface of the pair of lead electrodes, and is disposed on the electrode pad via a conductive adhesive. And a lid provided to hermetically seal the piezoelectric element, and the first recess and the second recess have a pair of lead electrodes on the excitation electrode side in plan view. It is provided to extend from one side facing toward one side of the piezoelectric element plate. A first recess and the second recess is provided to overlap in plan view, the outer peripheral edge of the conductive adhesive, in plan view, is provided in the second recess. By doing so, the piezoelectric element is bonded onto the electrode pad so that the conductive adhesive enters the second recess provided on the lower surface of the extraction electrode. It can suppress that a conductive adhesive protrudes, and it can reduce that a conductive adhesive adheres to the electrode for excitation. Therefore, such a piezoelectric device can suppress fluctuations in the oscillation frequency of the piezoelectric element caused by the conductive adhesive adhering to the excitation electrode.

  A method of manufacturing a piezoelectric device according to an aspect of the present invention includes a rectangular piezoelectric element plate, excitation electrodes provided on the upper and lower surfaces of the piezoelectric element plate, and one side of the piezoelectric element plate with a gap between the excitation electrodes. A pair of lead electrodes provided along the upper surface of the pair of lead electrodes, and the piezoelectric element plate exposed on the upper surface of the pair of lead electrodes and from one side facing the excitation electrode side of the pair of lead electrodes to one side of the piezoelectric element plate The piezoelectric element plate is exposed from the side facing the excitation electrode side of the pair of extraction electrodes, and the piezoelectric element plate is exposed to the lower surface of the first concave portion provided to extend toward the bottom surface of the pair of extraction electrodes. A piezoelectric element forming step of forming a piezoelectric element having a second recess provided so as to extend toward one side of the electrode, and applying a first conductive adhesive on an electrode pad provided on the package One conductive adhesive application process and first A piezoelectric element mounting step of mounting the piezoelectric element on the first conductive adhesive so that the outer peripheral edge of the conductive adhesive is located in the second recess in plan view, and the first conductive adhesive A first conductive adhesive curing step for electrically curing the electrode pad and the piezoelectric element, and a lid bonding step for bonding the lid to the package so as to hermetically seal the piezoelectric element; Is included. In this way, it is possible to determine whether or not the piezoelectric element has been pressed too much against the conductive adhesive, so that the free end of the piezoelectric element is in contact with the upper surface of the substrate or the conductive adhesive is applied to the excitation electrode. Since the adhered material can be sorted before measuring the characteristics of the piezoelectric device, productivity can be improved.

It is a disassembled perspective view which shows the piezoelectric device in this embodiment. (A) It is sectional drawing in AA of the piezoelectric device shown by FIG. 1, (b) It is the elements on larger scale of X1 location of Fig.2 (a). It is a top view which shows the state which removed the cover body of the piezoelectric device in this embodiment. It is a perspective plan view showing a piezoelectric element constituting the piezoelectric device in the present embodiment. (A) It is sectional drawing of the piezoelectric device in the 1st modification of this embodiment, (b) It is the elements on larger scale of X2 location of Fig.5 (a). (A) It is the top view which looked at the piezoelectric element which comprises the piezoelectric device in the 2nd modification of this embodiment from the upper surface, (a) The piezoelectric element which comprises the piezoelectric device in the 2nd modification of this embodiment is a bottom surface It is the top view seen from. It is a perspective view which shows the piezoelectric element mounting apparatus used with the manufacturing method of the piezoelectric device of this embodiment. (A) It is sectional drawing which shows the state which has recognized the electrode pad in the 1st camera part in the 1st conductive adhesive application | coating process which is a manufacturing method of the piezoelectric device of this embodiment, (b) It is sectional drawing which shows the state which has apply | coated the 1st conductive adhesive with the 1st nozzle in the 1st conductive adhesive application | coating process which is a manufacturing method of a piezoelectric device, (c) Manufacture of the piezoelectric device of this embodiment It is sectional drawing which shows the state which has recognized the 1st electroconductive adhesive agent in the 2nd camera part in the piezoelectric element mounting process which is a method. (A) In the piezoelectric element mounting step, which is a manufacturing method of the piezoelectric device of the present embodiment, is a cross-sectional view showing a state where the piezoelectric element is mounted on the first conductive adhesive by the second nozzle, (B) It is sectional drawing which shows the state which has recognized the position of the 1st recessed part of a piezoelectric element in the 2nd camera part in the 2nd conductive adhesive application | coating process which is a manufacturing method of the piezoelectric device of this embodiment, c) It is sectional drawing which shows the state which has apply | coated the 2nd conductive adhesive with the 1st nozzle in the 2nd conductive adhesive application | coating process which is a manufacturing method of the piezoelectric device of this embodiment. (A) It is sectional drawing which shows the piezoelectric element adhering process which is a manufacturing method of the piezoelectric device of this embodiment, (b) It is sectional drawing which shows the cover body joining process which is a manufacturing method of the piezoelectric device of this embodiment.

(Piezoelectric device)
The piezoelectric device in this embodiment includes a package 110 and a piezoelectric element 120 joined to the package 110 as shown in FIGS. 1 and 2. The package 110 has an accommodation space K surrounded by the upper surface of the substrate 110a and the inner surface of the frame 110b. Such a piezoelectric device is used to output a reference signal used in an electronic device or the like.

  The substrate 110a has a rectangular shape and functions as a mounting member for mounting the piezoelectric element 120 mounted on the upper surface. A pair of electrode pads 111 for mounting the piezoelectric element 120 is provided on the upper surface of the substrate 110a.

  In addition, external terminals 112 are provided at the four corners of the lower surface of the substrate 110a. Further, two of the four external terminals 112 are electrically connected to the piezoelectric element 120. In addition, the pair of external terminals 112 that are electrically connected to the piezoelectric element 120 are provided to be positioned diagonally on the lower surface of the substrate 110a.

  The substrate 110a is made of an insulating layer made of a ceramic material such as alumina ceramic or glass-ceramic. The substrate 110a may be one using an insulating layer or may be a laminate of a plurality of insulating layers. A wiring pattern (not shown) for electrically connecting the electrode pads 111 provided on the upper surface of the frame 110b and the external terminals 112 provided on the lower surface of the substrate 110a on the surface and inside of the substrate 110a. And via conductors (not shown).

  The frame 110b is disposed on the upper surface of the substrate 110a, and is used to form the accommodation space K on the upper surface of the substrate 110a. The frame 110b is made of a ceramic material such as alumina ceramics or glass-ceramics, and is formed integrally with the substrate 110a.

  The electrode pad 111 is for mounting the piezoelectric element 120. A pair of electrode pads 111 are provided on the upper surface of the substrate 110a, and are provided adjacent to each other along one side of the inner periphery of the substrate 110a inside the frame 110b.

  The external terminal 112 is used for bonding to a mounting pad (not shown) on an external mounting substrate such as an electric device. The external terminals 112 are provided at the four corners of the lower surface of the substrate 110a. At least one of the external terminals 112 is electrically connected to the sealing conductor pattern 113 via a via conductor (not shown). In addition, at least one of the external terminals 112 is connected to a mounting pad connected to a ground potential that is a reference potential on a mounting substrate such as an electronic device. Thereby, the lid 130 bonded to the sealing conductor pattern 113 is connected to the external terminal 112 having the ground potential. Therefore, the shielding performance in the accommodation space K by the lid 130 is improved.

  The sealing conductor pattern 113 plays a role of improving the wettability of the bonding member 131 when bonded to the lid 130 via the bonding member 131. The sealing conductor pattern 113 is electrically connected to at least one of the external terminals 112 via a via conductor (not shown). The sealing conductor pattern 113 is formed to have a thickness of, for example, 10 to 25 μm by sequentially applying nickel plating and gold plating on the surface of the conductor pattern made of, for example, tungsten or molybdenum so as to surround the upper surface of the frame 110b in an annular shape. Has been.

  Here, a method for manufacturing the substrate 110a and the frame 110b will be described. When the substrate 110a and the frame 110b are made of alumina ceramics, first, a plurality of ceramic green sheets obtained by adding and mixing an appropriate organic solvent or the like to a predetermined ceramic material powder is prepared. In addition, a predetermined conductor paste is applied to the surface of the ceramic green sheet or a through-hole previously punched by punching the ceramic green sheet by screen printing or the like. Further, these green sheets are laminated and press-molded and fired at a high temperature. Finally, it is produced by applying nickel plating, gold plating, silver palladium, or the like to predetermined portions of the conductor pattern, specifically, the portions to be the electrode pads 111, the external terminals 112, and the sealing conductor pattern 113. Moreover, the conductor paste is comprised from the sintered compact etc. of metal powders, such as tungsten, molybdenum, copper, silver, or silver palladium, for example.

  As shown in FIGS. 1 and 2, the piezoelectric element 120 is bonded onto the electrode pad 111 via a conductive adhesive 140. The piezoelectric element 120 plays a role of oscillating a reference signal of an electronic device or the like by stable mechanical vibration and a piezoelectric effect.

  2 and 4, the piezoelectric element 120 has a structure in which the excitation electrode 122 and the extraction electrode 123 are attached to the upper and lower surfaces of the piezoelectric element plate 121 made of crystal, respectively. doing. The excitation electrode 122 is formed by depositing and forming a metal in a predetermined pattern on each of the upper and lower surfaces of the piezoelectric element plate 121. The excitation electrode 122 includes a first excitation electrode 122a on the upper surface and a second excitation electrode 122b on the lower surface.

  The extraction electrode 123 extends from the excitation electrode 122 toward one side of the piezoelectric element plate 121. The extraction electrode 123 includes a first extraction electrode 123a on the upper surface and a second extraction electrode 123b on the lower surface. The first extraction electrode 123 a is extracted from the first excitation electrode 122 a and is provided so as to extend toward one side of the piezoelectric element plate 121. The second extraction electrode 123 b is extracted from the second excitation electrode 122 b and is provided so as to extend toward one side of the piezoelectric element plate 121. That is, the lead electrode 123 is provided in a shape along the long side or the short side of the piezoelectric element plate 121. The first extraction electrode 123 a is provided so as to go from the upper surface of the piezoelectric element plate 121 to the lower surface of the piezoelectric element plate 121 via the side surface of the piezoelectric element plate 121. The second extraction electrode 124 b is provided so as to go from the lower surface of the piezoelectric element plate 121 to the upper surface of the piezoelectric element plate 121 via the side surface of the piezoelectric element plate 121. In the present embodiment, one end of the piezoelectric element 120 connected to the first electrode pad 111a and the second electrode pad 111b is a fixed end connected to the upper surface of the substrate 110a, and the other end is between the upper surface of the substrate 110a. The piezoelectric element 120 is fixed on the substrate 110a by a cantilevered support structure with a free end.

  Further, as shown in FIG. 3, the first recess 124 is provided such that the piezoelectric element plate 121 is exposed to the first extraction electrode 123 a and the second extraction electrode 123 b on the upper surface of the piezoelectric element plate 121. The first recess 124 includes one first recess 124 a formed on the upper surface of the piezoelectric element plate 121 and the other first recess 124 b formed on the upper surface of the piezoelectric element plate 121. The first recess 124 extends from one side facing the excitation electrode 122 side of the pair of extraction electrodes 123 toward one side of the piezoelectric element plate 121 in plan view of the first extraction electrode 123a and the second extraction electrode 123b. It is provided as follows.

  The second recess 125 is provided such that the piezoelectric element plate 121 is exposed to the first extraction electrode 123 a and the second extraction electrode 123 b on the lower surface of the piezoelectric element plate 121. The crystal element 120 is mounted on the electrode pad 111 so as to accommodate a part of the conductive adhesive 140 provided on the electrode pad 111 in the second recess 125. The second recess 125 is constituted by one second recess 125 a formed on the lower surface of the piezoelectric element plate 121 and the other second recess 125 b formed on the lower surface of the piezoelectric element plate 121. The second recess 125 extends from one side facing the excitation electrode 122 side of the pair of extraction electrodes 123 toward one side of the piezoelectric element plate 121 in plan view of the first extraction electrode 123a and the second extraction electrode 123b. It is provided so that it can be put out.

  As described above, the first conductive adhesive 140 a is bonded onto the electrode pad 111 so as to enter the second recess 125 provided in the pair of lead electrodes 123 on the lower surface of the piezoelectric element plate 121. The first conductive adhesive 140a can be prevented from protruding from the second recess 125, and the first conductive adhesive 140a can be reduced from adhering to the second excitation electrode 122b. Therefore, such a piezoelectric device can suppress fluctuations in the oscillation frequency of the piezoelectric element 120 caused by the first conductive adhesive 140a adhering to the second excitation electrode 122b.

  Even if the first conductive adhesive 140 a wraps around the upper surface of the piezoelectric base plate 121 by providing the first concave portion 124 on the extraction electrode 123 on the upper surface of the piezoelectric base plate 121, the first concave portion 124. Therefore, the adhesion of the first conductive adhesive 140a to the first excitation electrode 122a provided on the upper surface of the piezoelectric element plate 121 can be reduced.

  Further, the opening area of the second recess 125 is provided to be larger than the opening area of the first recess 124 as shown in FIG. By doing so, it is possible to prevent the first conductive adhesive 140a from staying in the second recess 125 and further creeping up to the extraction electrode 123 provided on the upper surface of the piezoelectric element plate 121. Further, it is possible to further suppress the first conductive adhesive 140a from adhering to the first excitation electrode 122a.

  Here, the operation of the piezoelectric element 120 will be described. In the piezoelectric element 120, when an alternating voltage from the outside is applied from the extraction electrode 123 to the piezoelectric element plate 121 via the excitation electrode 122, the piezoelectric element plate 121 is excited in a predetermined vibration mode and frequency. ing.

  The lid 130 is made of, for example, an Fe—Ni alloy (42 alloy), an Fe—Ni—Co alloy (Kovar), or the like. Such a lid 130 is hermetically sealed in the accommodation space K in a nitrogen atmosphere or a vacuum atmosphere. Specifically, the lid 130 is placed on the frame 110b of the package 110 in a nitrogen atmosphere or a vacuum atmosphere, and the surface of the sealing conductor pattern 113 provided on the upper surface of the frame 110b and the lid The seam welding is performed by applying a predetermined current so that the joining member 131 of the body 130 is melted, thereby joining the frame body 110b.

  The first conductive adhesive 140a contains conductive powder as a conductive filler in a binder such as a silicone resin, and the conductive powder includes aluminum, molybdenum, tungsten, platinum, palladium, silver, Any one of titanium, nickel, nickel iron, or a combination thereof is used. Moreover, as a binder, a silicone resin, an epoxy resin, a polyimide resin, or a bismaleimide resin is used, for example.

  The outer peripheral edge of the first conductive adhesive 140a is provided so as to be located in the second recess 125 in plan view. Further, when the first conductive adhesive 140a has a viscosity of 35 to 45 Pa · s and is applied onto the electrode pad 111, the first conductive adhesive 140a exceeds the electrode pad 111. Thus, it does not flow onto the substrate 110a, but remains on the electrode pad 111, and the thickness of the first conductive adhesive 140a in the vertical direction is maintained. Also, the first conductive adhesive 140a can remain in the second recess 125 without flowing out of the second recess 125 toward the second excitation electrode 122b.

  The lid 130 has a rectangular shape, and is for hermetically sealing the housing space K in a vacuum state or the housing space K filled with nitrogen gas or the like. Specifically, the lid 130 is placed on the upper surface of the sealing conductor pattern 113 provided on the frame 110b in a predetermined atmosphere. When heat is applied to the bonding member 131 provided on the lower surface of the lid 130, the bonding member 131 is melt-bonded to the sealing conductor pattern 113. The lid 130 is made of an alloy containing at least one of iron, nickel, and cobalt, for example.

  The joining member 131 is provided from the upper surface of the sealing conductor pattern 113 of the frame body 110 b to the lower surface of the lid body 130. For example, in the case of glass, the joining member 131 is a glass that melts at 300 ° C. to 400 ° C., and is made of, for example, low-melting glass or lead oxide-based glass containing vanadium. Glass is in the form of a paste to which a binder and a solvent are added. After being melted, the glass is solidified and joined to another member. The joining member 131 is provided by, for example, applying glass frit paste by a screen printing method and drying. In addition, when the joining member 131 is printed on the upper surface of the frame 110b, the joining member 131 is printed on the entire circumference of the frame 110b so that the joining members 131 overlap the four corners of the frame 110b. Therefore, the thickness of the bonding member 131 at the four corners is provided to be thicker than the thickness of other portions where the bonding member 131 is provided. The composition of the lead oxide glass is composed of lead oxide, lead fluoride, titanium dioxide, niobium oxide, bismuth oxide, boron oxide, zinc oxide, ferric oxide, copper oxide and calcium oxide.

  For example, in the case of an insulating resin, the bonding member 131 is made of an epoxy resin or a polyimide resin. The thickness of the joining member 131 provided between the frame body 110b and the lid body 130 is 30 to 100 μm.

  For example, when the joining member 131 is gold tin, the thickness of the layer of the joining member 131 is 10 to 40 μm. For example, the component ratio is 70 to 80% for gold and 20 to 30% for tin. May be used. For example, when the joining member 131 is silver brazing, the thickness of the layer of the joining member 131 is 10 to 40 μm. For example, the component ratio is 70 to 80% for silver and 20 to 30% for copper. May be used.

  The piezoelectric device in the present embodiment includes a substrate 110a, an electrode pad 111 provided on the upper surface of the substrate 110a, a first conductive adhesive 140a provided on the electrode pad 111a, a rectangular piezoelectric element plate 121, and the like. An excitation electrode 122 provided on the upper and lower surfaces of the piezoelectric element plate 121, and a pair of extraction electrodes 123 having a rectangular shape provided along one side of the piezoelectric element plate 121 with a space between the excitation electrode 122, and The first concave portion 124 provided so that the upper surface of the piezoelectric element plate 121 is exposed to the pair of extraction electrodes 123 on the upper surface of the piezoelectric element plate 121, and the piezoelectric element plate 121 to the pair of extraction electrodes 123 on the lower surface of the piezoelectric element plate 121. And a second recess 125 provided so that the lower surface of the piezoelectric element 120 is exposed, and the piezoelectric element 120 mounted on the electrode pad 111 via the first conductive adhesive 140a. A lid 130 provided to hermetically seal the piezoelectric element 120, and the first recess 124 and the second recess 125 are arranged on the excitation electrode 122 side of the pair of extraction electrodes 123 in plan view. The first concave portion 124 and the second concave portion 125 are provided at a position where the first concave portion 124 and the second concave portion 125 overlap each other in a plan view. The outer peripheral edge of the agent 140a is provided in the second recess 125 in plan view. By doing so, the first conductive adhesive 140 a is bonded onto the electrode pad 111 so as to enter the second recess 125 provided in the pair of lead electrodes 123 on the lower surface of the piezoelectric element plate 121. Therefore, the first conductive adhesive 140a can be prevented from protruding from the second recess 125, and the first conductive adhesive 140a can be reduced from adhering to the second excitation electrode 122b. . Therefore, such a piezoelectric device can suppress fluctuations in the oscillation frequency of the piezoelectric element 120 caused by the first conductive adhesive 140a adhering to the second excitation electrode 122b.

(First modification)
Hereinafter, the crystal resonator according to the first modification of the present embodiment will be described. Note that, in the crystal resonator according to the first modification of the present embodiment, the same portions as those of the above-described crystal resonator are denoted by the same reference numerals, and description thereof will be omitted as appropriate. As shown in FIG. 5, the crystal resonator according to the first modification of the present embodiment is different from the present embodiment in that it includes the second conductive adhesive 140 b provided in the first recess 124. Different.

  The second conductive adhesive 140 b is provided in the first recess 124 formed in the extraction electrode 123 on the upper surface of the crystal element 120. The second conductive adhesive 140b is bonded to the first conductive adhesive 140a provided in the second recess 125 formed in the extraction electrode 123 on the lower surface of the crystal element 120. Thereby, the 2nd conductive adhesive 140b is adhere | attached with the electrode pad 111 on the board | substrate 110a via the 1st conductive adhesive 140a. In addition, if the coating diameter of the conductive adhesive 140 is increased, there is a possibility that the adjacent first conductive adhesives 140a come into contact with each other, thereby causing a short circuit. The crystal element 120 and the electrode pad 111 can be stably electrically connected without increasing the application diameter of the first conductive adhesive 140.

  Further, the second conductive adhesive 140b is disposed in the first concave portion 124, and the second conductive adhesive 140b is applied so that the second conductive adhesive 140b enters the first concave portion 124. Agent 140b is provided. When the second conductive raw adhesive 140a enters the first recess 124, the contact area between the first conductive adhesive 140a and the second conductive adhesive 140b and the lead electrode 123 of the crystal element 120 is increased. The connection strength between the first conductive adhesive 140a and the second conductive adhesive 140b and the extraction electrode 123 of the crystal element 120 can be improved. Further, when the second conductive adhesive 140b is solidified and contracted, the free end of the crystal element 120 can be prevented from coming into contact with the upper surface of the substrate 110a by being separated from the substrate 110a. By doing in this way, productivity of a piezoelectric device can be improved.

(Second modification)
Hereinafter, the crystal resonator according to the second modification of the present embodiment will be described. Note that, in the crystal resonator according to the second modification of the present embodiment, the same portions as those of the above-described crystal resonator are denoted by the same reference numerals, and description thereof will be omitted as appropriate. In the quartz resonator according to the second modification of the present embodiment, as shown in FIG. 6, the first concave portion 224 and the second concave portion 225 have a semicircular shape or a semielliptical shape in plan view. However, this embodiment is different from the present embodiment.

  As shown in FIG. 6, the first recess 224 and the second recess 225 have a semicircular shape or a semi-elliptical shape in plan view. Distributing the stress applied from the conductive adhesive 140 to the inner wall of the first recess 224 or the second recess 225 evenly by forming the first recess 224 and the second recess 225 in a semicircular or semi-elliptical shape. Accordingly, it is possible to reduce peeling of the extraction electrode 223 from the crystal element 220.

(Piezoelectric device mounting device)
As shown in FIG. 7, the piezoelectric element mounting apparatus includes a first nozzle NZ1 for applying the conductive adhesive 140 and a first camera unit CA1 for recognizing the position of the electrode pad 111. And a second camera unit CA2 for recognizing the position of the electrode pad 111 or the conductive adhesive 140 and the second nozzle NZ2 for adsorbing the piezoelectric element 120 and placing it on the conductive adhesive 140 Based on the image data obtained from the means JS and the first camera unit CA1, the positional deviation width of the electrode pad with respect to the package 110 is obtained, and the application position of the conductive adhesive 140 is corrected for the positional deviation, and the second camera The positional deviation width of the conductive adhesive 140 with respect to the electrode pad 111 is obtained from the image data obtained from the part CA2, and the mounting position of the piezoelectric element 120 with respect to this positional deviation. And and a control unit SS for controlling the implementation means JS for correcting.

  Further, as shown in FIG. 7, the piezoelectric element mounting apparatus is provided with a first guide rail R1, and the first guide rail R1 is provided with a coating means TS and a mounting means JS. Further, the second guide rail is connected to the first guide rail R1 via the support column PL. In this piezoelectric element mounting apparatus, the direction parallel to the second guide rail R2 is the Y direction, the direction parallel to the first guide rail R1 is the X direction, and the direction perpendicular to both the X direction and the Y direction is the Z direction. And The direction of the angle formed by the intersection of the X-direction axis and the Y-direction axis is the θ direction.

  The application means TS is provided on the first guide rail R1. The application unit TS includes a first nozzle NZ1, a first camera unit CA1, a first arrangement unit HB1, and a first movable unit. In addition, the first movable portion is configured by an X-direction movable portion KB11, a Y-direction movable portion KB12, and a Z-direction movable portion KB13. In addition, the application unit TS recognizes the positions of the first nozzle NZ1 and the electrode pad 111 for applying the conductive adhesive 140 to the electrode pad 111 of the package 110 arranged in the package arrangement jig PJ. One camera unit CA1. The first nozzle NZ1 and the first camera part CA1 are arranged in parallel to the first arrangement part HB1 of the coating means TS.

  These application means TS can move back and forth in the Z direction, and move in the Z direction when the conductive adhesive 140 is applied to the package 110 of the package arranging jig PJ. Further, when moving to the package 110, it moves in the X direction.

  The first camera unit CA1 plays a role of capturing image data indicating the state of the electrode pad 111 of the package 110. Image data captured by the first camera unit CA1 is stored in the storage unit ME. The storage unit ME plays a role of storing image data indicating the position of the electrode pad 111 of the package 110 obtained from the first camera unit CA1.

  The mounting means JS is provided on the first guide rail R1. The mounting means JS includes a second nozzle NZ2, a second camera part CA2, a second arrangement part HB2, and a second movable part. The second nozzle NZ2 and the second camera part CA2 are arranged at the tip of the second arrangement part HB2. Further, the second movable part is configured by an X-direction movable part KB21, a Y-direction movable part KB22, and a Z-direction movable part KB23. The mounting means JS attracts the piezoelectric elements 120 arranged in the element arrangement jig XJ, and conducts the electrode pads 111 provided in the accommodation spaces K of the packages 110 arranged in the package arrangement jig PJ. A second nozzle NZ2 for mounting on the conductive adhesive 140, and a second camera unit CA2 for recognizing the positions of the electrode pad 111 and the conductive adhesive 140. The second nozzle NZ2 is connected to a vacuum pump (not shown), and air is sucked from an adsorption hole (not shown) provided in the second nozzle NZ2 by operating the vacuum pump. . Therefore, the piezoelectric elements 120 arranged in the element arrangement jig XJ are attracted to the second nozzle NZ2.

  These mounting means JS can move back and forth in the Z direction, and move in the Z direction when the piezoelectric element 120 is attracted from the element arranging jig XJ and mounted on the package 110. Further, when moving to the package 110 and newly attracting the piezoelectric element 120, it moves in the X direction.

  The second nozzle NZ2 is arranged at the tip of the second arrangement portion HB2 so as to face the piezoelectric elements 120 arranged in the element arrangement jig XJ. Further, the second nozzle NZ2 includes an X-direction movable portion KB21, a Y-direction movable portion KB22, a Z-direction movable portion KB23, and a rotating portion (not shown), so that the X-direction, Y-direction, Z-direction, θ Is able to work in the direction.

  The second camera unit CA1 plays a role of photographing image data indicating the state of the electrode pad 111 of the package 110 and the first conductive adhesive 140a or the second conductive adhesive 140b applied on the electrode pad 111. Image data captured by the second camera unit CA2 is stored in the storage unit ME. The storage unit ME plays a role of storing image data indicating the position of the electrode pad 111 obtained from the second camera unit CA2 and the position of the first conductive adhesive 140a or the second conductive adhesive 140b.

  The control means SS is constituted by a computer, and is connected to the coating means TS, the suction means JS, and the storage unit ME. The control means SS controls the entire piezoelectric element mounting apparatus. That is, the control means SS obtains numerical data of the distance between the provided electrode pad 111 and the frame 110b from the image data obtained from the first camera unit CA1, and based on the numerical data, the control means SS of the coating means TS. It plays the role of controlling to correct the position of the first nozzle NZ1. Further, the control means SS obtains numerical data of the distance between the provided conductive adhesive and the frame 110b from the image data obtained from the second camera unit CA2, and based on the numerical data, the mounting means JS. It plays a role of controlling to correct the position of the second nozzle NZ2.

(Piezoelectric device manufacturing method)
Hereinafter, a method for manufacturing the above-described piezoelectric device will be described. As shown in FIGS. 6 to 8, the piezoelectric device manufacturing method includes a rectangular piezoelectric element plate 121, an excitation electrode 122 provided on the upper and lower surfaces of the piezoelectric element plate 121, and the excitation electrode 122. A pair of extraction electrodes 123 provided along one side of the piezoelectric element plate 121, and the piezoelectric element plate 121 exposed on the upper surface of the pair of extraction electrodes 123 and for exciting the pair of extraction electrodes 123 in plan view. The piezoelectric element plate 121 is exposed on the lower surface of the first recess 124 provided to extend from one side facing the electrode 122 side toward one side of the piezoelectric element plate 121 and the pair of lead electrodes 123, and in plan view. And a second recess 125 provided so as to extend from one side of the pair of extraction electrodes 123 facing the excitation electrode 122 side to one side of the piezoelectric element plate 121, a pressure for forming the piezoelectric element 120 The element forming step, the first conductive adhesive applying step of applying the first conductive adhesive 140a on the electrode pad 111 provided on the package 110, and the outer periphery of the first conductive adhesive 140a are viewed in plan view. Then, the piezoelectric element placement step of placing the piezoelectric element 120 on the first conductive adhesive 140 a so as to be positioned in the second recess 125, and the first recess 124 of the piezoelectric element 120 so as to be positioned A second conductive adhesive applying step for applying the second conductive adhesive 140b to the electrode, and a piezoelectric element fixing step for heating and curing the first conductive adhesive 140a to electrically fix the electrode pad 111 and the piezoelectric element 120 to each other. A lid joining step for joining the lid 130 to the package 110 so as to hermetically seal the piezoelectric element 120.

(Piezoelectric element forming process)
The piezoelectric element forming step is performed along one side of the piezoelectric element plate 121 with a space between the rectangular piezoelectric element plate 121, the excitation electrode 122 provided on the upper and lower surfaces of the piezoelectric element plate 121, and the excitation electrode 122. The pair of lead electrodes 123 provided, and the piezoelectric element plate 121 exposed from the upper surface of the pair of lead electrodes 123 and in plan view, the piezoelectric element plate 121 from one side facing the excitation electrode 122 side of the pair of lead electrodes 123. And the piezoelectric substrate 121 is exposed to the lower surface of the pair of extraction electrodes 123 and extends in a plan view, and the excitation electrodes 122 of the pair of extraction electrodes 123 are viewed in plan view. This is a step of forming a piezoelectric element 120 having a second recess 125 provided so as to extend from one side facing the side toward one side of the piezoelectric element plate 121.

  A flat plate-like quartz wafer (not shown) having crystal axes which are composed of an X axis, a Y axis and a Z axis and which are orthogonal to each other is formed. As the quartz wafer, an artificial crystalline lens having crystal axes which are composed of an X axis, a Y axis and a Z axis and which are orthogonal to each other is used. The main surface of the quartz wafer is, for example, a plane parallel to the X-axis and the Z-axis, and a predetermined angle, for example, about 37, counterclockwise around the X-axis and viewing the negative direction of the X-axis. ° Parallel to the rotated surface. In addition, after the quartz wafer is cut from the artificial crystalline lens at a predetermined cut angle, both main surfaces are polished so that the thickness in the vertical direction is a predetermined thickness.

  Here, the quartz wafer has, for example, a substantially rectangular flat plate shape. When viewed in plan, the dimension of a predetermined side is 10.0 to 101.6 mm, and is connected to the predetermined side. The size of one side is 10.0 to 101.6 mm. At this time, the thickness of the quartz wafer in the vertical direction is 0.020 to 0.070 mm. In addition, although the case where the quartz wafer has a substantially rectangular flat plate shape has been described, it may be a circular plate shape or an elliptical flat plate shape. 0.0 to 101.6 mm.

  The piezoelectric element plate 121 is fixed to a predetermined position of the crystal wafer at a predetermined one side of the main surface of the portion to be the piezoelectric element plate 121 by a photolithography technique and an etching technique, and the portion to be the piezoelectric element plate 121 is fixed. A portion to be a quartz base plate 121 having an m-plane formed on a part of the side surface is formed. First, using a conventionally well-known photolithography technique, a metal film is deposited on the entire surface of both main surfaces of a quartz wafer, a resist is applied on the metal film, and a predetermined pattern is exposed and developed. Thereafter, etching is performed by immersing the quartz wafer in a predetermined etching solution using a conventionally known etching technique. At this time, by utilizing the fact that etching is performed differently depending on the axial direction of the crystal axis, an m-plane parallel to the Z-axis can be easily formed on a part of the side surface of the portion that becomes the piezoelectric element plate 121.

  A metal film is deposited on the upper and lower surfaces of the piezoelectric element plate 121 to form the excitation electrode 122 and the extraction electrode 123. When the excitation electrode 122 and the extraction electrode 123 are formed, the crystal wafer is deposited by a vapor deposition technique or a sputtering technique in a state where the crystal wafer is placed between a pair of masks in which through holes having a predetermined pattern are formed. In a space formed by the main surface and the surface facing the inside of the through-hole, a metal film is deposited at a predetermined position of a portion that becomes the piezoelectric element plate 121 of the quartz wafer. At this time, a first recess 124 is formed on the upper surface of the extraction electrode 123 by removing a part of the extraction electrode 123 or using a mask that prevents the metal film from being deposited. A second recess 125 is formed.

  Further, the opening area of the second recess 125 may be formed so as to be larger than the opening area of the first recess 124. In this way, even if a slight misalignment occurs when forming the first recess 124, the area of the second recess 125 is larger than the area of the first recess 124. It can suppress that the two recessed parts 125 do not overlap. Therefore, it can be easily determined whether or not the outer peripheral edge of the conductive adhesive 140 is located in the second recess 125. Moreover, the opening part of the 1st recessed part 124 or the 2nd recessed part 125 is rectangular shape, semicircle shape, or semi-elliptical shape.

  Finally, a predetermined one side of the main surface of the portion that becomes the piezoelectric element plate 121 is folded or cut, and the portion that becomes the piezoelectric element plate 121 is singulated. In the quartz wafer 160, a portion that becomes the piezoelectric element plate 121 on which the excitation electrode 122 and the extraction electrode 123 are formed is fixed on a predetermined side of the main surface of the portion that becomes the piezoelectric element plate 121. The piezoelectric element 120 is formed by folding or cutting the fixed portion.

(First conductive adhesive application process)
The first conductive adhesive application step is a step of applying the first conductive adhesive 140a on the electrode pad 111 provided on the package 110 as shown in FIG. 8B. The first conductive adhesive 140a is applied to the upper surface of the electrode pad 111 by the first nozzle NZ1.

  First, as shown in FIG. 8A, the position of the electrode pad 111 in the accommodation space K of the package 110 is photographed by the first camera unit CA1 of the coating unit TS, and the image data is stored in the storage unit ME. When the electrode pad 111 is photographed by the first camera unit CA1 of the coating unit TS, the package 110 and the electrode pad 111 are not provided with the same material, so that the position of the electrode pad 111 can be determined. Next, as shown in FIG. 8B, the first nozzle NZ1 of the application means TS is moved in accordance with the position of the electrode pad 111, and the first conductive adhesive 140a is applied. Further, the first nozzle NZ1 can apply the first conductive adhesive 140a by spraying the first conductive adhesive 140a by applying pressure.

  As the first conductive adhesive 140a, a conductive powder is contained as a conductive filler in a binder such as a silicone resin. Examples of the conductive powder include aluminum (Al), molybdenum (Mo), A material containing any one of tungsten (W), platinum (Pt), palladium (Pd), silver (Ag), titanium (Ti), nickel (Ni), nickel iron (NiFe), or a combination thereof is used. It has been. Depending on the particle size of the conductive powder, the inner diameter of the first nozzle NZ1 corresponds as appropriate.

(Piezoelectric element mounting process)
As shown in FIG. 9A, the piezoelectric element mounting step is performed by placing the piezoelectric element 120 in such a manner that the outer peripheral edge of the first conductive adhesive 140a is positioned in the second recess 125 in a plan view. This is a step of placing on one conductive adhesive 140a. First, as shown in FIG. 8C, the position of the first conductive adhesive 140a formed on the electrode pad 111 is photographed by the second camera unit CA2 of the mounting means JS, and the image data is stored in the storage unit ME. To do. When the first conductive adhesive 140a is photographed by the second camera unit CA2 of the piezoelectric element mounting apparatus, the electrode pad 111 and the first conductive adhesive 140a are not made of the same material, and therefore the first conductive adhesive 140a The position of the adhesive 140a can be determined. The second nozzle NZ2 that adsorbs the piezoelectric element 120 is moved in accordance with the position of the first conductive adhesive 140a, and the outer peripheral edge of the first conductive adhesive 140a applied to the electrode pad 111 is the piezoelectric element 120. The piezoelectric element 120 is placed on the first conductive adhesive 140 a so as to be positioned in the second recess 125 provided in the lead electrode 123.

  After mounting the piezoelectric element 120, the first conductive adhesive is used because the piezoelectric element 120 is transmitted by being formed of quartz by photographing with the second camera unit CA <b> 2 from the first concave portion 124 side. It can be determined whether the outer peripheral edge of 140a is located in the second recess 125. By doing so, it can be determined whether or not the piezoelectric element 120 is pressed too much against the first conductive adhesive 140a, so that the free end of the piezoelectric element 120 is in contact with the upper surface of the substrate 110 or the first conductive Since the adhesive adhesive 140a attached to the excitation electrode 122 can be selected before the characteristics of the piezoelectric device are measured, productivity can be improved.

(Second conductive adhesive application process)
The second conductive adhesive application step is a step of applying the second conductive adhesive 140b so as to be positioned in the first recess 124 of the piezoelectric element 120, as shown in FIG. 9C. The second conductive adhesive 140b is applied so as to be located in the first recess 124 of the piezoelectric element 120, and is applied on the lead electrode 123 of the piezoelectric element 120 so as to be in contact with the first conductive adhesive 140a. The

  First, as shown in FIG. 9B, the position of the first recess 124 of the piezoelectric element 120 mounted in the accommodation space K of the package 110 is photographed by the first camera unit CA1 of the coating unit TS, and image data is obtained. Store in the storage unit ME. When the first recess 124 is photographed by the first camera unit CA1 of the coating unit TS, the first recess 124 and the extraction electrode 123 are not provided with the same material, and therefore the position of the first recess 124 can be determined. it can. Next, as shown in FIG. 9C, the first nozzle NZ1 of the application means TS is moved in accordance with the position of the first recess 124, and the second conductive adhesive 140b is applied. The first nozzle NZ1 can apply the second conductive adhesive 140b by spraying the second conductive adhesive 140b by applying pressure.

  As the second conductive adhesive 140b, a conductive powder is contained as a conductive filler in a binder such as a silicone resin. Examples of the conductive powder include aluminum (Al), molybdenum (Mo), A material containing any one of tungsten (W), platinum (Pt), palladium (Pd), silver (Ag), titanium (Ti), nickel (Ni), nickel iron (NiFe), or a combination thereof is used. It has been. Depending on the particle size of the conductive powder, the inner diameter of the first nozzle NZ1 corresponds as appropriate.

(Piezoelectric element fixing process)
In the piezoelectric element fixing step, as shown in FIG. 10A, the first conductive adhesive 140a and the second conductive adhesive 140b are heated and cured, and the electrode pad 111 and the piezoelectric element 120 are conductively fixed. is there. In the piezoelectric element fixing step, the first conductive adhesive 140a and the second conductive adhesive 140b are heated and cured in a state in which the package 110 is housed in the internal space of the curing annealing furnace in the air atmosphere or nitrogen atmosphere, The pad 111 and the piezoelectric element 120 are conductively fixed.

  A curing annealing furnace (not shown) includes a furnace body, a heating unit, a supply unit, and a control unit. The furnace body has an internal space and serves to store the package 110. The heating unit plays a role of heating the internal space to a predetermined temperature. For example, a halogen lamp or a xenon lamp is used as the heating unit. The supply unit serves to supply gas to the internal space. For example, nitrogen is used as the gas. The control unit controls the temperature and oxygen concentration of the internal space of the furnace body, the temperature increase rate of the heating unit, and the gas supply amount of the supply unit.

(Cover body joining process)
The lid bonding process is a process of bonding the lid 130 to the package 110 so as to hermetically seal the piezoelectric element 120 as shown in FIG. The lid 130 is made of, for example, an Fe—Ni alloy (42 alloy) or an Fe—Ni—Co alloy (Kovar), and is used when the piezoelectric element 120 is hermetically sealed in a nitrogen gas atmosphere or a vacuum atmosphere. It is done.

  Specifically, when the bonding member 131 is made of glass, insulating resin, or gold tin, the lid 130 is for sealing provided on the surface of the frame 110b of the package 110 in a nitrogen gas atmosphere or a vacuum atmosphere. It is placed on the conductor pattern 113 and irradiated with a heat source such as a halogen lamp from the upper surface of the lid 130 to melt the bonding member 131, thereby being bonded to the frame portion 110 b via the sealing conductor pattern 113.

  When the joining member 131 is silver solder, the lid 130 is placed on the frame 110b of the package 110 in a nitrogen gas atmosphere or a vacuum atmosphere, and is sealed on the surface of the frame 110b. A roller electrode (not shown) of a seam welder (not shown) is brought into contact with the lid 130 so that the metal of the stopping conductor pattern 113 and the joining member 131 of the lid 130 are melted. It is joined to the frame 110b by moving along the outer edge of the lid 130 while supplying power.

  The piezoelectric device manufacturing method according to the present invention includes a rectangular piezoelectric element 121, excitation electrodes 122 provided on the upper and lower surfaces of the piezoelectric element 121, and the excitation electrode 122. The piezoelectric element plate 121 is exposed to a pair of extraction electrodes 123 provided along one side and the pair of extraction electrodes 123 on the upper surface of the piezoelectric element plate 121, and the excitation electrodes 122 of the pair of extraction electrodes 123 are viewed in plan view. The piezoelectric element plate 121 is exposed to the first recess 124 provided so as to extend from one side facing the side toward one side of the piezoelectric element plate 121 and the pair of lead electrodes 123 on the lower surface of the piezoelectric element plate 121 and is planar. And a second recess 125 provided so as to extend from one side of the pair of extraction electrodes 123 facing the excitation electrode 122 side toward one side of the piezoelectric element plate 121. A piezoelectric element forming step for forming the piezoelectric element 120, a first conductive adhesive applying step for applying the first conductive adhesive 140a on the electrode pad 111 provided on the package 110, and a first conductive adhesive 140a. A piezoelectric element mounting step of mounting the piezoelectric element 120 on the first conductive adhesive 140a so that the outer peripheral edge of the piezoelectric element 120 is positioned in the second recess 125 in plan view, and the first conductive adhesive 140a is thermally cured to electrically fix the electrode pad 111 and the piezoelectric element 120, and a lid joining process for joining the lid 130 to the package 110 so as to hermetically seal the piezoelectric element 120. And. By doing so, it is possible to determine whether or not the piezoelectric element 120 is pressed too much against the first conductive adhesive 140a, so that the tip of the piezoelectric element 120 is in contact with the upper surface of the substrate 110a or the first conductive Since the adhesive 140a attached to the excitation electrode 122 can be selected before measuring the characteristics of the piezoelectric device, the productivity can be improved.

  In addition, the method for manufacturing a piezoelectric device of the present invention includes a second conductive adhesive application step of applying the second conductive adhesive 140b so as to be positioned in the first recess 124 of the piezoelectric element 120. . By doing so, the first conductive adhesive 140a and the second conductive node are brought into contact with the first conductive adhesive 140a while the second conductive raw adhesive 140b enters the first recess 124. The contact area between the adhesive 140b and the lead electrode 123 of the crystal element 120 is increased, and the connection strength between the first conductive adhesive 140a and the second conductive adhesive 140b and the lead electrode 123 of the crystal element 120 is improved. Can be made.

  In the piezoelectric device manufacturing method of the present invention, the opening area of the second recess 125 is formed to be larger than the opening area of the first recess 124 in the piezoelectric element forming step. In this way, even if a slight misalignment occurs when forming the first recess 124, the area of the second recess 125 is larger than the area of the first recess 124. It can suppress that the 2 recessed part 125 is arrange | positioned in the position which does not overlap. Therefore, it is possible to easily determine whether or not the outer peripheral edge of the first conductive adhesive 140a is located in the second recess 125.

  In addition, it is not limited to this embodiment, A various change, improvement, etc. are possible in the range which does not deviate from the summary of this invention. In the above embodiment, the case where the frame 110b is integrally formed of a ceramic material in the same manner as the substrate 110a has been described. However, the frame 110b may be made of metal. In this case, the frame is joined to the conductor film of the substrate via a brazing material such as silver-copper. In the present embodiment, the case where the sealing conductor pattern 113 is formed on the upper surface of the frame 110b has been described. However, when the bonding member 131 is made of glass or insulating resin, the sealing conductor pattern is formed. 113 may be joined to the frame 110b without providing it.

  In the above embodiment, the case where the frame 110b is provided on the upper surface of the substrate 110a has been described. However, after the piezoelectric element is mounted on the substrate, the lid having the sealing frame provided on the lower surface of the sealing base is provided. It is possible to use a structure in which the piezoelectric element is hermetically sealed. The lid is composed of a rectangular sealing base and a sealing frame portion provided along the outer peripheral edge of the lower surface of the sealing base. The lower surface of the sealing base and the inner side of the sealing frame portion An accommodation space is formed with the side surface. The sealing frame portion is for forming an accommodation space on the lower surface of the sealing base. The sealing frame part is provided along the outer edge of the lower surface of the sealing base.

  In the above embodiment, the case where the piezoelectric element is an AT piezoelectric element has been described. However, a tuning fork type having a crystal base and two flat plate-shaped crystal vibrating parts extending in the same direction from the side surface of the crystal base. A bent piezoelectric element may be used. The piezoelectric element is composed of a piezoelectric element plate, an excitation electrode provided on the surface of the piezoelectric element plate, an extraction electrode, and a frequency adjusting metal film. The piezoelectric element plate includes a crystal base portion and a crystal vibration portion, and the crystal vibration portion includes a first crystal vibration portion and a second crystal vibration portion. The crystal base has an orthogonal coordinate system in which the electrical axis is the X axis, the mechanical axis is the Y axis, and the optical axis is the Z axis as the crystal axis direction, within a range of −5 ° to + 5 ° around the X axis. This is a flat plate having a substantially rectangular shape in a plan view in which the direction of the rotated Z ′ axis is the thickness direction. The first crystal vibrating part and the second crystal vibrating part are extended in parallel with the Y′-axis direction from one side of the crystal base part. Such a piezoelectric element plate has a tuning fork shape in which a quartz base and each quartz vibrating part are integrated, and is manufactured by a photolithography technique and a chemical etching technique.

DESCRIPTION OF SYMBOLS 110 ... Package 110a ... Board | substrate 110b ... Frame body 111 ... Electrode pad 112 ... External terminal 113 ... Conductive pattern for sealing 120 ... Piezoelectric element 121 ... Piezoelectric base plate 122 ... excitation electrode 123 ... extraction electrode 124 ... first recess 125 ... second recess 130 ... lid body 131 ... joining member 140a ... first conductive adhesive 140b ... Second conductive adhesive K ... Storage space

Claims (5)

A substrate,
An electrode pad provided on the upper surface of the substrate;
A first conductive adhesive provided on the electrode pad;
A pair of rectangular piezoelectric elements, a pair of rectangular electrodes provided along one side of the piezoelectric element with a gap between the excitation electrodes provided on the upper and lower surfaces of the piezoelectric element, and the excitation electrodes A first recess provided to expose the upper surface of the piezoelectric element plate to the pair of extraction electrodes, and to expose the lower surface of the piezoelectric element plate to the pair of extraction electrodes. A piezoelectric element mounted on the electrode pad via the first conductive adhesive,
A lid provided to hermetically seal the piezoelectric element,
The first recess and the second recess are provided so as to extend from one side facing the excitation electrode side of the pair of lead electrodes toward one side of the piezoelectric element plate in plan view,
The first concave portion and the second concave portion are provided at a position overlapping in plan view,
A piezoelectric device, wherein an outer peripheral edge of the first conductive adhesive is provided in the second recess in plan view. The piezoelectric device according to claim 1,
A piezoelectric device comprising a second conductive adhesive provided in the first recess. The piezoelectric device according to claim 1 or 2, wherein
The piezoelectric device, wherein the first recess and the second recess have a semicircular shape or a semi-elliptical shape in plan view. A rectangular piezoelectric element plate, excitation electrodes provided on the upper and lower surfaces of the piezoelectric element plate, and a pair of lead electrodes provided along one side of the piezoelectric element plate with the excitation electrode therebetween The upper surface of the piezoelectric element plate is exposed to the pair of extraction electrodes and is extended from one side facing the excitation electrode side of the pair of extraction electrodes toward one side of the piezoelectric element plate in plan view. The lower surface of the piezoelectric element plate is exposed to the first concave portion provided in the pair and the pair of lead electrodes, and the one side of the pair of lead electrodes facing the excitation electrode side in plan view, A piezoelectric element forming step of forming a piezoelectric element having a second recess provided to extend toward one side;
A first conductive adhesive application step of applying a first conductive adhesive on an electrode pad provided in the package;
A piezoelectric element mounting step of mounting the piezoelectric element on the first conductive adhesive such that an outer peripheral edge of the first conductive adhesive is located in the second recess in plan view;
A piezoelectric element fixing step of thermally curing the first conductive adhesive, and electrically fixing the electrode pad and the piezoelectric element;
And a lid joining step for joining a lid to the package so as to hermetically seal the piezoelectric element. A method for manufacturing a piezoelectric device according to claim 4,
And a second conductive adhesive application step of applying a second conductive adhesive so as to be positioned in the first recess of the piezoelectric element.

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