JP2015159453A - piezoelectric device - Google Patents

Abstract

Provided is a piezoelectric device in which the influence of gas generated when an insulating adhesive and a conductive adhesive are cured is reduced while securing a bonding strength between a vibration element and an element mounting member.
An element mounting member 110 having a first recess 113a formed on the top surface and a second recess 113b formed on the bottom surface of the first recess 113a, and a mounting pad 114 provided on the bottom surface of the first recess 113a. A piezoelectric piece 121, a pair of excitation electrodes 122, and a pair of extraction electrodes 123 having one end connected to the excitation electrode 122 and the other end positioned at the end of the main surface of the piezoelectric piece 121. The vibration element 120, the insulating adhesive 130 that holds and holds the vibration element 120 on the bottom surface of the first recess 113a, and the conductive adhesive 140 that electrically bonds the extraction electrode 123 and the mounting pad 114 to each other. And a lid 150 joined to the upper surface of the element mounting member 110.
[Selection] Figure 1

Description

  The present invention relates to a piezoelectric device built in an electronic device such as a mobile communication device.

  In the piezoelectric device, for example, a vibration element is connected and fixed to an element mounting member and mounted, and the element mounting member and a lid are joined to hermetically seal the vibration element. The vibration element used in the piezoelectric device includes, for example, a rectangular plate-shaped piezoelectric piece, a pair of excitation electrodes provided on the piezoelectric piece, one end connected to the excitation electrode, and the other end positioned on the upper surface of the piezoelectric piece. And a pair of extraction electrodes. In such a piezoelectric device, in order to secure the bonding strength between the vibration element and the element mounting member, the vibration element is fixed and held with an insulating adhesive, and then the lead electrode and the package mounting pad are bonded with the conductive adhesive. The extraction electrode and the mounting pad are bonded so as to be electrically connected to each other. At this time, the distance between the lower surface of the vibration element and the surface of the element mounting member facing the lower surface of the vibration element is the thickness of the insulating adhesive (for example, see Patent Document 1).

Japanese Utility Model Publication No. 6-81137

  In the conventional piezoelectric device, the distance between the lower surface of the vibration element and the surface of the element mounting member facing the lower surface of the vibration element is the thickness of the insulating adhesive. Therefore, in the conventional piezoelectric device, since there is only the thickness of the insulating adhesive, the gas generated when the insulating adhesive and the conductive adhesive are cured is the element facing the lower surface of the vibrating element and the lower surface of the vibrating element. It is easy to stay between the surface of the mounting member. Therefore, in the conventional piezoelectric device, the gas generated when the insulating adhesive and the conductive adhesive are cured adheres to the excitation electrode or the extraction electrode provided on the lower surface of the piezoelectric piece of the vibration element, and the vibration element There is a possibility that the output signal will become unstable and the output signal will become unstable.

  In the present invention, it is possible to reduce the influence of gas generated when the insulating adhesive and the conductive adhesive are cured, and to output a stable signal while ensuring the bonding strength between the vibration element and the element mounting member. It is an object of the present invention to provide a possible piezoelectric device.

  In order to solve the above-described problems, the piezoelectric device according to the present invention has a substantially rectangular parallelepiped shape, and includes an element mounting in which a first recess is formed on the top surface and a second recess is formed on the bottom surface of the first recess. A member, a mounting pad provided on the bottom surface of the first recess space of the element mounting member, a plate-like piezoelectric piece, a pair of excitation electrodes provided on the piezoelectric piece, and one end connected to the excitation electrode. A vibration element including a pair of lead electrodes, the ends of which are located at the ends of the main surface of the piezoelectric piece, and the lower surface of the piezoelectric piece and the bottom surface of the first recess of the element mounting member, An insulating adhesive for fixing and holding the piezoelectric vibration element, a conductive adhesive for bonding the lead electrode and the mounting pad and electrically connected thereto, and a lid bonded to the upper surface of the element mounting member And a body.

  The element mounting member used in the piezoelectric device according to the present invention has a substantially rectangular parallelepiped shape, a first recess is formed on the top surface, and a second recess is formed on the bottom surface of the first recess. Further, in the piezoelectric device according to the present invention, the vibration element is fixed and held with an insulating adhesive on the bottom surface of the first recess of the element mounting member, and is provided on the extraction electrode and the element mounting member of the vibration element. The mounted pad is electrically connected with a conductive adhesive. That is, in the piezoelectric device according to the present invention, when the vibration element is fixed and held on the bottom surface of the first recess and mounted on the element mounting member, the second recess is positioned on the lower surface of the vibration element. Yes. Therefore, the piezoelectric device according to the present invention has an element mounting that faces the lower surface of the vibration element and the lower surface of the vibration element as compared with the prior art while ensuring the bonding strength between the vibration element and the element mounting member by an insulating adhesive. The distance from the surface of the member can be increased by the depth in the vertical direction of the second recess. For this reason, in the piezoelectric device according to the present invention, as compared with the conventional device, the gas generated when the insulating adhesive and the conductive adhesive are cured is mounted on the element facing the lower surface of the vibration element and the lower surface of the vibration element. It becomes difficult to stay between the surfaces of the members. As a result, in the piezoelectric device according to the present invention, the amount of gas generated when the insulating adhesive and the conductive adhesive are cured adheres to the excitation electrode or the extraction electrode provided on the lower surface of the piezoelectric piece of the vibration element is reduced. It is possible to reduce the instability of the output signal due to fluctuations in the frequency of the vibration element.

It is a piezoelectric device in a first embodiment, and is a top view in the state where a lid is not provided. It is sectional drawing in AA of FIG. It is a piezoelectric device in the modification of 1st embodiment, Comprising: It is a top view in the state which does not provide the cover body. It is sectional drawing in BB of FIG. It is sectional drawing in CC of FIG. It is a piezoelectric device in a second embodiment, and is a plan view in a state where a lid is not provided. It is sectional drawing in DD of FIG. It is a top view in the state where it is a piezoelectric device in the modification of a second embodiment, and does not provide a lid. It is sectional drawing in EE of FIG.

(First embodiment)
As shown in FIGS. 1 and 2, the piezoelectric device in the first embodiment uses a substantially rectangular parallelepiped element mounting member 110, and the bottom surface of the first recess 113 a formed on the top surface of the element mounting member 110. The vibration element 120 is fixed and held on the surface. In the piezoelectric device according to the first embodiment, the element mounting member 110 and the lid 150 are joined, and the vibration element 120 is hermetically sealed.

  Here, in accordance with the drawing, a device mounting in which the first recess 113a is formed with a pair of surfaces provided at opposing positions of the device mounting member 110 having a substantially rectangular parallelepiped shape as the main surfaces of the device mounting member 110. The main surface of the member 110 is defined as the upper surface of the element mounting member 110, and the main surface of the element mounting member 110 facing away from the upper surface of the element mounting member 110 is defined as the lower surface of the element mounting member 110.

  The element mounting member 110 is for mounting the vibration element 120. The element mounting member 110 has a first recess 113a formed on the top surface, and a second recess 113b formed on the bottom surface of the first recess 113a. The element mounting member 110 is provided with a sealing conductor pattern 116 on the upper surface. The element mounting member 110 is provided with mounting pads 114 on the bottom surface of the first recess 113a, and mounting terminals 115 at least two of which are electrically connected to the mounting pads 114 are provided at the four corners of the lower surface. .

  The element mounting member 110 includes, for example, a flat plate portion 111, a first frame portion 112a, and a second frame portion 112b. A second frame portion 112b is provided along the edge of the upper surface of the flat plate portion 111, and a second concave portion 113b is formed. The first frame portion 112a is provided along the edge of the upper surface of the second frame portion 112b to form a first recess 113a. Therefore, here, the lower surface of the flat plate portion 111 is the lower surface of the element mounting member 110, and the upper surface of the first frame portion 112 a is the upper surface of the element mounting member 110.

  The flat plate portion 111 has a rectangular flat plate shape. On the upper surface of the flat plate portion 111, a second frame portion 112b is provided along the edge portion. In addition, mounting terminals 115 are provided at the four corners of the lower surface of the flat plate portion 111. The flat plate portion 111 is provided with internal wiring and wiring patterns (not shown). The flat plate portion 111 is made of an insulating layer made of a ceramic material such as alumina ceramic or glass-ceramic. The flat plate portion 111 may be one in which an insulating layer is used, or a plurality of insulating layers may be stacked.

  The second frame portion 112b is provided at the edge of the upper surface of the flat plate portion 111 and is used to form the second recess 113b. A mounting pad 114 is provided on the upper surface of the second frame portion 112b. At this time, the mounting pad 114 is provided at a position that does not overlap the first frame portion 112a in plan view. The second frame portion 112b is provided with internal wiring and wiring patterns (not shown). The second frame portion 112b is integrated with the flat plate portion 111 and the first frame portion 112a, and is made of an insulating layer made of a ceramic material such as alumina ceramics or glass ceramics. The second frame portion 112b may be formed by laminating a plurality of insulating layers or may be used in a single layer.

  The 1st frame part 112a is provided in the edge of the upper surface of the 2nd frame part 112b, and is for forming the 1st recessed part 113a. A sealing conductor pattern 116 is provided on the upper surface of the first frame portion 112a. The first frame portion 112a is provided with internal wiring and wiring patterns (not shown). The first frame portion 112a is integrated with the flat plate portion 111 and the second frame portion 112b, and is made of an insulating layer made of a ceramic material such as alumina ceramics or glass ceramics. The first frame portion 112a may be formed by laminating a plurality of insulating layers or may be used in a single layer.

  The 1st recessed part 113a is a space for accommodating the vibration element 120, and is formed of the 1st frame part 112a provided along the edge of the upper surface of the 2nd frame part 112b. Therefore, the first recess 113a is sized to accommodate the vibration element 120.

  The second recess 113b is for securing a distance between the lower surface of the vibration element 120 and the surface of the element mounting member 110 facing the lower surface of the vibration element 120. The second recess 113b has the same vertical depth as the first recess 113a. The second recess 113b is provided along the edge of the upper surface of the flat plate portion 111. Since it is formed by the second frame part 112b, the vibration element 120 is fixed and held on the upper surface of the second frame part 112b forming the second recess 113b, and compared with a conventional piezoelectric device, The distance between the lower surface of the vibration element 120 and the surface of the element mounting member 110 facing the lower surface of the vibration element 120 can be increased by the depth in the vertical direction of the second recess 113b. Accordingly, air convection easily occurs between the lower surface of the vibration element 120 and the bottom surface of the second recess 113b that is the surface of the element mounting member 110 facing the lower surface of the vibration element 120, and the conductive adhesive 140 or It is possible to reduce the amount of the gas generated when the insulating adhesive 130 is cured adheres to the excitation electrode 122 and the extraction electrode 123 of the vibration element 120.

  Here, the case where the long side dimension when the element mounting member 110 is viewed in plan is 1.2 to 5.0 mm and the short side dimension is 1.0 to 3.2 mm is taken as an example. The sizes of the first recess 113a and the second recess 113b will be described. The first recess 113a has a long side dimension of 0.8 to 4.6 mm, a short side dimension of 0.6 to 2.8 mm, and a vertical depth dimension of 0.8 mm. It is 2 to 0.5 mm. The second recess 113b has a long side dimension of 0.5 to 4.0 mm, a short side dimension of 0.5 to 2.8 mm, and a vertical depth dimension of 0.8 mm. It is 2 to 0.5 mm. The second recess 113b has a short side dimension longer than the short side of the piezoelectric piece 121 of the vibration element 120, and the vertical depth is the same as the vertical depth of the first recess 113a. Further, the distance between the lower surface of the piezoelectric piece 121 of the vibration element 120 and the bottom surface of the first recess 113a is 0.02 to 0.05 mm, and the lower surface of the piezoelectric piece 121 of the vibration element 120 and the second recess 113b are The distance from the bottom surface is 0.22 to 0.55 mm.

  The second recess 113b is provided at a position where the opening of the second recess 113b overlaps with the excitation electrode 122 of the vibration element 120 when viewed in plan with the lid 150 not provided. Therefore, the distance between the lower surface of the vibration element 120 and the surface of the element mounting member 110 facing the lower surface of the vibration element 120 is longer than the conventional piezoelectric device by the depth in the vertical direction of the second recess 113b. It becomes possible to do. Accordingly, the amount of gas generated when the insulating adhesive 130 and the conductive adhesive 140 are cured adheres to the excitation electrode 122 provided on the lower surface of the piezoelectric piece 121 of the vibration element 120 can be reduced. In addition, since the opening of the second recess 113b is provided at a position overlapping the excitation electrode 122 of the vibration element 120, the excitation electrode 122 of the vibration element 120 is prevented from coming into contact with the lower surface of the element mounting member 110, and vibration is generated. It is possible to suppress the excitation electrode 122 of the element 120 from coming into contact with the bottom surface of the element mounting member 110 and to reduce the fluctuation of the oscillation frequency.

  The mounting pad 114 is electrically bonded to the vibration element 120, specifically, is electrically bonded to the extraction electrode 123 of the vibration element 120. The mounting pad 114 is provided on the upper surface of the second frame portion 112b and in the first frame portion 112a. The mounting pads 114 are paired. For example, two mounting pads 114 are provided along the short side of the upper surface of the second frame portion 112b in the first frame portion 112a in plan view of the upper surface of the element mounting member 110. It has been.

  The mounting terminal 115 is for mounting on a mother board such as an electronic device. When the mounting terminal 115 is mounted on a mother board such as an electronic device, the mounting terminal 115 is connected and fixed to a predetermined mounting pad (not shown) of the mother board. For example, four mounting terminals 115 are provided, one at each of the four corners of the lower surface of the element mounting member 110.

  Two of the mounting terminals 115 are electrically connected to a pair of mounting pads 114 provided on the upper surface of the second frame portion 112b by internal wiring and wiring patterns (not shown). The remaining two of the mounting terminals 115 are electrically connected to the lid 150 via internal wiring and wiring patterns (not shown), the sealing conductor pattern 116 and the bonding member 151. Therefore, when the mounting terminal 115 electrically connected to the lid 150 is mounted on the motherboard, the lid is connected and fixed to the mounting pad connected to the ground potential which is the reference potential on the motherboard of the electronic device or the like. The body 150 can be set to the same potential as the ground potential.

  The sealing conductor pattern 116 is for improving the wettability of the bonding member 151 when the lid 150 is bonded by the bonding member 151. The sealing conductor pattern 116 is provided along the edge of the upper surface of the first frame portion 112a. In addition, the sealing conductor pattern 116 is formed by sequentially applying nickel plating and gold plating on the surface of a conductor pattern made of tungsten, molybdenum, or the like, and surrounding the first frame portion 112a in an annular shape.

  Here, a manufacturing method of the element mounting member 110 will be described. When the flat plate portion 111, the first frame portion 112a, and the second frame portion 112b constituting the element mounting member 110 are made of alumina ceramic, first, an appropriate organic solvent or the like is added to and mixed with a predetermined ceramic material powder. Prepare multiple ceramic green sheets. In addition, a predetermined conductive paste is applied on the surface of the ceramic green sheet or in a through hole that has been punched in the ceramic green sheet and provided in advance, using a well-known screen printing method, etc. To do. Next, the ceramic green sheet to be the second frame portion 112b is laminated on the upper surface of the ceramic green sheet to be the flat plate portion 111, and the first frame portion 112a and the upper surface of the ceramic green sheet to be the second frame portion 112b The resulting ceramic green sheets are laminated, pressed, and fired at a high temperature. After firing, elements are mounted by applying nickel plating or gold plating to predetermined portions of the conductor pattern, specifically, the mounting pad 114, the mounting terminal 115, the sealing conductor pattern 116, and the wiring pattern. The member 110 is produced. The conductive paste is made of, for example, a sintered body of metal powder such as tungsten, molybdenum, copper, silver, or palladium.

  The vibration element 120 can obtain a stable mechanical vibration and transmits a reference signal for an electronic device or the like. The vibration element 120 includes a piezoelectric piece 121, a pair of excitation electrodes 122 provided on the upper surface of the piezoelectric piece 121 and the lower surface of the piezoelectric piece 121, one end connected to the excitation electrode 122, and the other end the main surface of the piezoelectric piece 121. And a pair of extraction electrodes 123 located at the ends of the electrodes. Further, the vibration element 120 is formed on the upper surface of the second frame portion 112b by the insulating adhesive 130 positioned between the lower surface of the piezoelectric piece 121 of the vibration element 120 and the bottom surface of the first recess 113a. It is fixed and held on the bottom surface of the first recess 113a which is also in the first frame portion 112a. Further, in the vibration element 120, the mounting pad 114 and the end portion of the extraction electrode 123 of the vibration element 120 are electrically bonded by the conductive adhesive 140.

  Here, according to the drawing, when mounted on the element mounting member 110, the surface of the piezoelectric piece 121 facing the flat plate portion 111 side of the element mounting member 110 is the lower surface of the piezoelectric piece 121, and is opposite to the lower surface of the piezoelectric piece 121. A surface of the piezoelectric piece 121 facing the side is defined as an upper surface of the piezoelectric piece 121. The upper surface of the piezoelectric piece 121 and the lower surface of the piezoelectric piece 121 are defined as the main surface of the piezoelectric piece 121.

  The piezoelectric piece 121 is made of a piezoelectric material that performs stable mechanical vibration. For example, quartz is used. Here, a method for manufacturing the piezoelectric piece 121 will be described. The piezoelectric piece 121 is cut from the artificial crystalline lens to a predetermined size at a predetermined cut angle, and then polished and processed to have a predetermined thickness.

  The excitation electrode 122 is for applying a voltage to the piezoelectric piece 121. The excitation electrode 122 is a pair, and is provided so as to face the upper surface of the piezoelectric piece 121 and the lower surface of the piezoelectric piece 121. The excitation electrode 122 is formed by depositing a metal layer on a predetermined position of the piezoelectric piece 121 by a photolithography technique, a vapor deposition technique, or a sputtering technique.

  The extraction electrode 123 is for applying a voltage to the excitation electrode 122 from the outside of the vibration element 120. The extraction electrode 123 is provided so that one end is connected to the excitation electrode 122 and the other end is located at the end of the main surface of the piezoelectric piece 121. In addition, the lead electrode 123 is arranged side by side along one short side of the piezoelectric piece 121 in plan view. In the extraction electrode 123, a metal layer is formed at a predetermined position of the piezoelectric piece 121 at the same time as the excitation electrode 122 by a photolithography technique, a vapor deposition technique, or a sputtering technique.

  Here, the operation of the vibration element 120 will be described. When a voltage is applied to the extraction electrode 123 from the outside, the vibration element 120 applies a voltage to the excitation electrode 122 to which the extraction electrode 123 is connected. As a result, different charges are accumulated in the excitation electrode 122, and a part of the piezoelectric piece 121 sandwiched between the excitation electrodes 122 is distorted and deformed by the inverse piezoelectric effect. As a result, since the piezoelectric piece 121 tends to return to its original shape, electric charges opposite to the electric field initially accumulated in the excitation electrode 122 are accumulated due to the piezoelectric effect. That is, when a voltage is applied to the excitation electrode 122, the vibration element 120 vibrates a part of the piezoelectric piece 121 sandwiched between the excitation electrodes 122 due to the piezoelectric effect and the inverse piezoelectric effect. Therefore, when an AC voltage is applied to the vibration element 120, different charges are alternately accumulated and deformed in the excitation electrode 122, and a part of the piezoelectric piece 121 sandwiched between the excitation electrodes 122 can be vibrated.

  The insulating adhesive 130 is for fixing and holding the vibration element 120. The insulating adhesive 130 is located between the lower surface of the piezoelectric piece 121 and the bottom surface of the first recess 113 a of the element mounting member 110. The insulating adhesive 130 holds the vibration element 120 at two corners of the four corners of the piezoelectric piece 121 and two corners on the other short side of the piezoelectric piece 121 in plan view, for example. .

  The insulating adhesive 130 is a resin adhesive, for example, a silicone resin adhesive. The silicone-based resin adhesive is a rubber-like elastic body after curing. Therefore, the vibration element 120 can be connected and fixed by the rubber-like elastic body while securing the bonding strength between the vibration element 120 and the bottom surface of the first recess 113a. For this reason, when receiving vibration or impact from the outside of the piezoelectric device of the first embodiment, the interface between the insulating adhesive 130 and the bottom surface of the first recess 113a, or between the insulating adhesive 130 and the vibration element 120. It is possible to reduce stress concentration at the interface. Further, since the vibration element 120 is fixed and held by the rubber-like elastic body by using the silicone-based resin adhesive, it is possible to reduce vibration inhibition on the vibration element 120 by the insulating adhesive 130. It becomes possible.

  A method of connecting and fixing the vibration element 120 to the bottom surface of the first recess 113a using the insulating adhesive 130 will be described. First, the insulating adhesive 130 is applied to a predetermined position on the bottom surface of the first recess 113a by, for example, a dispenser. Thereafter, the vibration element 120 is conveyed onto the insulating adhesive 120, and in plan view, the extraction electrode 123 of the vibration element 120 and a part of the mounting pad 114 provided on the bottom surface of the first recess 113a overlap, And it is mounted on the insulating adhesive 130 such that the insulating adhesive 130 is sandwiched between the lower surface of the piezoelectric piece 121 of the vibration element 120 and the bottom surface of the first recess 113a. In this state, the insulating adhesive 130 is cured by heating. Accordingly, the vibration element 120 is connected and fixed to the bottom surface of the first recess 113 a by the insulating adhesive 130 and mounted on the element mounting member 110.

  The conductive adhesive 140 is for electrically bonding the extraction electrode 123 of the vibration element 120 and the mounting pad 114. The conductive adhesive 140 is not in contact with the insulating adhesive 130. For example, in a plan view, the conductive adhesive 140 is two of the four corners of the piezoelectric piece 121, and is on one short side of the piezoelectric piece 121. It is electrically bonded at the two corners. The conductive adhesive 140 contains conductive powder as a conductive filler in a binder such as a silicone-based resin. Examples of the conductive powder include aluminum, molybdenum, tungsten, platinum, palladium, silver, A material containing any one of titanium, nickel, nickel iron, or a combination thereof is used. As the binder, for example, a silicone-based resin, an epoxy-based resin, a polyimide-based resin, or a bismaleimide-based resin is used.

  A method of electrically bonding the extraction electrode 123 and the mounting pad 114 using the conductive adhesive 140 will be described. First, the conductive adhesive 140 is applied onto the pair of mounting pads 114 provided on the bottom surface of the first recess 113a by, for example, a dispenser. Thereafter, the vibration element 120 is conveyed onto the conductive adhesive 140, the vibration element 120 is placed so that the conductive adhesive 140 is sandwiched between the extraction electrode 123 and the mounting pad 114, and is heated and cured in that state. Thereby, the extraction electrode 123 and the mounting pad 114 are electrically bonded.

  In the first embodiment, after the insulating adhesive 130 and the conductive adhesive 140 are applied to the bottom surface of the first recess 113a, the vibration element 120 is placed, and the insulating adhesive 130 and the conductive adhesive are bonded. Although the case where the adhesive 140 is simultaneously heat-cured is described, the insulating adhesive 130 may be heat-cured, and then the conductive adhesive 140 may be applied, heat-cured, and electrically bonded. In this case, the conductive adhesive 140 is first applied to the upper surface of the extraction electrode 123 and the upper surface of the mounting pad 114 by, for example, a dispenser. At this time, when the vibration element 120 is connected and fixed to the bottom surface of the first recess 113a of the element mounting member 110 by the insulating adhesive 130, the bottom surface of the first recess 113a is viewed in plan view, and the vibration element 120 is pulled out. Since the electrode 123 and a part of the mounting pad 114 are disposed so as to overlap each other, the conductive adhesive 140 can be easily applied so as to come into contact with the extraction electrode 123 and the mounting pad 114. Next, the conductive adhesive 140 is heat-cured while being applied so as to contact the extraction electrode 123 and the mounting pad 114. Thereby, the lead electrode 123 and the mounting pad 114 are electrically bonded by the conductive adhesive 140.

  The lid 150 is bonded to the sealing conductor pattern 116 provided on the upper surface of the element mounting member 110 by the connection member 151, and is in a vacuum state or filled with nitrogen gas in the first recess 113a and the second recess 113b. The vibration element 120 mounted on the bottom surface of the first recess 113a is hermetically sealed. Specifically, the lid 150 is provided with a bonding member 151 between the lower surface of the lid 150 and the upper surface of the sealing conductor pattern 116 provided on the upper surface of the element mounting member 110 in a predetermined atmosphere. Then, the bonding member 151 is melted and then solidified, whereby the lower surface of the lid 150 and the sealing conductor pattern 116 provided on the upper surface of the element mounting member 110 are melt bonded.

  The bonding member 151 is for bonding the sealing conductor pattern 116 provided on the lower surface of the lid 150 and the upper surface of the element mounting member 110. Further, the bonding member 151 is between the lower surface of the lid 150 and the upper surface of the sealing conductor pattern 116 provided on the upper surface of the element mounting member 110 and is opposed to the sealing conductor pattern 116. It is provided in the place. The joining member 151 is made of, for example, silver solder or gold tin.

  In the piezoelectric device according to the first embodiment, the vibration element 120 is connected and fixed to the bottom surface of the first recess 113a formed on the upper surface of the substantially rectangular parallelepiped element mounting member 110 by the insulating adhesive 130 while being electrically conductive. The extraction electrode 123 and the mounting pad 114 are electrically bonded by the adhesive 140. In the piezoelectric device according to the first embodiment, the second recess 113b is formed on the bottom surface of the first recess 113a of the element mounting member 110. That is, in the piezoelectric device according to the first embodiment, when the vibration element 120 is fixed and held on the bottom surface of the first recess 113 a and mounted on the element mounting member 110, the second recess 113 b is formed on the lower surface of the vibration element 120. Is located. Therefore, the piezoelectric device according to the first embodiment secures the bonding strength between the vibration element 120 and the element mounting member 110 with the insulating adhesive 140, and compared with the conventional case, the lower surface of the vibration element 120 and the vibration element. The distance between the lower surface of 120 and the surface of the element mounting member 110 facing each other can be increased by the depth in the vertical direction of the second recess 113b. For this reason, in the piezoelectric device according to the first embodiment, air convection is more likely to occur between the lower surface of the vibration element 120 and the surface of the element mounting member 110 facing the lower surface of the vibration element 120, as compared with the related art. In addition, the gas generated when the insulating adhesive 130 and the conductive adhesive 140 are cured is less likely to stay. As a result, in the piezoelectric device according to the first embodiment, the gas generated when the insulating adhesive 130 and the conductive adhesive 140 are cured is the excitation electrode 122 provided on the lower surface of the piezoelectric piece 121 of the vibration element 120 or the extraction electrode 122. The amount attached to the electrode 123 can be reduced, and it is possible to reduce the fluctuation of the frequency of the vibration element 120 and the output signal becoming unstable.

  In the piezoelectric device according to the first embodiment, the insulating adhesive 130 and the conductive adhesive 140 are not in contact with each other. Therefore, in the piezoelectric device according to the first embodiment, the vibration element 120 is fixed and held by the insulating adhesive 130, and at the same time, the vibration element 120 is fixed and held by the conductive adhesive 140. For this reason, in the piezoelectric device according to the first embodiment, the vibration element 120 can be fixed and held at at least three or more locations, so that the bonding strength can be ensured as compared with the conventional case.

  In the piezoelectric device according to the first embodiment, since the insulating adhesive 130 and the conductive adhesive 140 are not in contact with each other, the insulating adhesive 130 and the conductive adhesive 140 are in contact with each other before being cured. It is possible to prevent the conductive adhesive 140 from becoming unconductive. Therefore, in the piezoelectric device according to the first embodiment, since the insulating adhesive 130 and the conductive adhesive 140 can be cured at the same time, man-hours can be reduced and productivity can be improved.

  In the piezoelectric device according to the first embodiment, the insulating adhesive 130 is located in the vicinity of two corners of the four corners of the piezoelectric piece 121 having a rectangular flat plate shape in plan view. Since the adhesive 140 is located at the remaining two corners of the four corners of the piezoelectric piece 121, the four corners of the vibration element 120 are fixed and held by the insulating adhesive 130 and the conductive adhesive 140. Yes. Therefore, since the piezoelectric device in the first embodiment is fixed and held at the four corners, it is possible to fix and hold the vibration element 120 at the position where the vibration is the smallest, and to reduce the inhibition of vibration due to the fixation and holding. The bonding strength can be ensured.

  In the piezoelectric device according to the first embodiment, since the silicone adhesive is used as the insulating adhesive 130, the insulating adhesive 130 in which the cured form is a rubber-like elastic body. Thus, the vibration element 120 can be fixed and held. For this reason, in the piezoelectric device according to the first embodiment, when receiving vibration or impact from the outside of the piezoelectric device according to the first embodiment, the interface between the insulating adhesive 130 and the bottom surface of the first recess 113a, or The concentration of stress at the interface between the insulating adhesive 130 and the vibration element 120 can be reduced. Therefore, in the piezoelectric device according to the first embodiment, when the vibration or impact is applied from the outside, the stress is concentrated on the interface of the insulating adhesive 130, and the holding state of the vibration element 120 is changed and the frequency is suppressed. Therefore, it is possible to reduce the unstable output signal.

  In the piezoelectric device according to the first embodiment, since the silicone adhesive is used as the insulating adhesive 130, the insulating adhesive 130 in which the cured form is a rubber-like elastic body. Thus, the vibration element 120 can be fixed and held. For this reason, the piezoelectric device according to the first embodiment can reduce vibration inhibition on the vibration element 120 due to bonding and holding with the insulating adhesive 130.

(Modification)
Hereinafter, a piezoelectric device according to a modification of the first embodiment will be described. In addition, the same code | symbol is attached | subjected about the part similar to the piezoelectric device mentioned above among the piezoelectric devices in the modification of 1st embodiment, and description is abbreviate | omitted suitably. As shown in FIGS. 3, 4, and 5, the piezoelectric device according to the modification of the first embodiment includes one of the vibrating element 120 and the insulating adhesive 130 and the conductive adhesive 140 in plan view. This is different from the first embodiment in that it is provided on the short side.

  The insulating adhesive 130 is located between the lower surface of the piezoelectric piece 121 and the bottom surface of the first recess 213a. Specifically, the insulating adhesive 130 is formed between the pair of mounting pads 214 provided on the bottom surface of the first recess 213 a and the lower surface of the piezoelectric piece 121 and at the center of one short side of the piezoelectric piece 121. It is provided at a position sandwiched between. At this time, when the upper surface of the element mounting member 210 is viewed in plan, a part of the extraction electrode 123 of the vibration element 120 and a part of the mounting pad 214 overlap.

  The conductive adhesive 140 is applied and heat-cured so that the extraction electrode 123 located at the end of the upper surface of the piezoelectric piece 121 and the mounting pad 214 are in contact with each other, and the extraction electrode 123 and the mounting pad 214 are electrically connected. Connected.

  In the piezoelectric device according to the modification of the first embodiment, since the insulating adhesive 130 and the conductive adhesive 140 are provided on one short side of the vibration element 120 in a plan view, the first recess 213a The opening part of the 2nd recessed part 213b formed in a bottom face can be enlarged. Therefore, in the piezoelectric device in the modification of the first embodiment, the vibration element 120 can be fixed and held without blocking the opening of the second recess 213b, and the inside of the second recess 213b located on the lower surface of the vibration element 120 The air can be easily moved to the upper surface side of the vibration element 120. For this reason, in the piezoelectric device according to the modification of the first embodiment, air convection is likely to occur between the lower surface of the vibration element 120 and the surface of the element mounting member 110 facing the lower surface of the vibration element 120. It is possible to make it difficult for the gas generated when the adhesive 130 and the conductive adhesive 140 are cured to stay.

  In the piezoelectric device according to the modification of the first embodiment, after the vibration element 120 is fixed and held by the insulating adhesive 130, the extraction electrode 123 and the mounting pad 214 are electrically bonded by the conductive adhesive 140. ing. Therefore, compared with the case where the vibration element 120 is connected and fixed to the bottom surface of the first recess 213a only with the conductive adhesive 140 including a component different from the adhesive component such as the conductive filler, the vibration element 120 and the first Bonding strength with the bottom surface of one recess 213a can be ensured.

(Second embodiment)
Hereinafter, the piezoelectric device in the second embodiment will be described. In addition, the same code | symbol is attached | subjected about the part similar to the piezoelectric device mentioned above among the piezoelectric devices in 2nd embodiment, and description is abbreviate | omitted suitably. The piezoelectric device in the second embodiment is different from that in the first embodiment in that the electronic component element 360 is mounted on the bottom surface of the second recess 313b as shown in FIGS.

  The element mounting member 310 used in the piezoelectric device in the second embodiment is for mounting the vibration element 120 and the electronic component element 360, and is the piezoelectric device in the first embodiment in that a connection pad 317 is provided. Different from the element mounting member 110 used.

  The element mounting member 310 has a first recess 313a formed on the upper surface of the element mounting member 310, and a second recess 313b formed on the bottom surface of the first recess 313a. The element mounting member 310 is provided with a sealing conductor pattern 316 on the upper surface. The element mounting member 310 is provided with a mounting pad 314 on the bottom surface of the first recess 313a and a connection pad 317 on the bottom surface of the second recess 313b. The element mounting member 310 is provided with mounting terminals 315 at the four corners of the lower surface.

  The connection pad 317 is for mounting the electronic component element 360. For example, six connection pads 317 are provided on the bottom surface of the second recess 313b formed on the bottom surface of the first recess 313a. Due to the internal wiring and wiring pattern (not shown) of the element mounting member 310, two of the connection pads 317 are electrically connected to a pair of mounting pads 314 provided on the bottom surface of the first recess 313a. The remaining four of 317 are electrically connected to mounting terminals 315 provided one by one at the four corners of the lower surface of the element mounting member 310.

  The electronic component element 360 is for oscillating the vibration element 120, for example, and an integrated circuit element having an oscillation circuit function is used. The electronic component element 360 is mounted on the bottom surface of the second recess 313b so as to be accommodated in the second recess 312b. For example, six connection terminals 361 are provided on the lower surface of the electronic component element 360.

  For example, six connection terminals 361 are provided on the lower surface of the electronic component element 360, and are electrically connected to the connection pads 317 provided on the bottom surface of the second recess 313b by the conductive member 370. Two of the connection terminals 361 are electrically connected to the mounting pad 314 provided on the bottom surface of the first recess 313a through the conductive member 370, the connection pad 317, the internal wiring (not shown) and the wiring pattern (not shown). The remaining four of the connection terminals 361 are electrically connected to mounting terminals 315 provided one by one at the four corners of the lower surface of the element mounting member 310.

  The conductive member 370 is for electrically connecting the connection pad 317 and the connection terminal 361. For the conductive member 370, an alloy having a melting point lower than that of the metal constituting the connection pad 317 and the connection terminal 361 is used, and for example, solder is used. The conductive member 370 is provided between the connection pad 317 and the connection terminal 361, and is electrically melted and solidified again to electrically connect the connection pad 317 and the connection terminal 361 while being fixed.

  Here, a mounting method for mounting the electronic component element 360 on the bottom surface of the second recess 313b will be described. In the second embodiment, using the conductive member 370, the connection pad 317 and the connection terminal 361 are fixed and mounted while being electrically connected. First, a protruding solder is provided on the connection terminal 361 of the electronic component element 360, and is placed so that the protruding solder is sandwiched between the connection terminal 361 and the connection pad 317. Thereafter, the solder is melted by heating and then solidified. Thereby, the connection pad 317 and the connection terminal 361 are fixed while being electrically connected, and the electronic component element is mounted on the bottom surface of the second recess 313b.

  In the piezoelectric device according to the second embodiment, the electronic component element 360 is mounted on the bottom surface of the second recess 313b, but the electronic component element 360 is housed in the second recess 313b. Therefore, in the piezoelectric device according to the second embodiment, when the vibration element 120 is mounted on the bottom surface of the first recess 313 a of the element mounting member 310, the lower surface of the vibration element 120, the lower surface of the vibration element 120, and the electronic component element 360. The distance from the upper surface of the piezoelectric element can be made longer than the distance between the lower surface of the vibration element 120 of the conventional piezoelectric device and the surface of the element mounting member 310 facing the lower surface of the vibration element 120. For this reason, in the piezoelectric device according to the second embodiment, air convection is more likely to occur on the lower surface of the vibration element 120 as compared with the conventional case, and occurs when the insulating adhesive 130 and the conductive adhesive 140 are cured. Gas becomes difficult to stay. As a result, in the piezoelectric device according to the second embodiment, as compared with the conventional case, the gas generated when the insulating adhesive 130 and the conductive adhesive 140 are cured is provided on the lower surface of the piezoelectric piece of the vibration element 120. The amount attached to the electrode 122 or the extraction electrode 123 can be reduced, and it is possible to reduce the fluctuation of the frequency of the vibration element 120 and the output signal becoming unstable.

(Modification)
Hereinafter, a piezoelectric device according to a modification of the second embodiment will be described. In addition, the same code | symbol is attached | subjected about the part similar to the piezoelectric device of 2nd embodiment mentioned above among the piezoelectric devices in the modification of 2nd embodiment, and description is abbreviate | omitted suitably. As shown in FIGS. 8 and 9, the piezoelectric device in the modification of the second embodiment has a third recess 413c formed on the bottom surface of the second recess 413b and is accommodated in the third recess 413c. The second embodiment is different from the second embodiment in that an electronic component element 460 is mounted on the bottom surface of the third recess 413c.

  The element mounting member 410 used in the piezoelectric device in the modification of the second embodiment is different from the second embodiment in that a third recess 413c is formed on the bottom surface of the second recess 413b. The element mounting member 410 has a substantially rectangular parallelepiped shape, and a first recess 413a is formed on the top surface, and a pair of mounting pads 414 are provided on the bottom surface of the first recess 413a. Moreover, the 2nd recessed part 413b is formed in the bottom face of the 1st recessed part 413a, and the connection pad 417 is provided in the bottom face of this 2nd recessed part 413b. Furthermore, a third recess 413c having a size capable of accommodating the electronic component element 460 is formed on the bottom surface of the second recess 413b. The element mounting member 410 is provided with mounting terminals 415 at the four corners of the lower surface.

  The third recess 413c is for mounting the electronic component element 460 on the bottom surface of the third recess 413c while accommodating the electronic component element 460 in the third recess 413c. The electronic component element 460 is mounted on the bottom surface of the third recess 413c in a state where the electronic component element 460 is fixed and held by the fixing member 480.

  In the electronic component element 460, for example, a connection terminal 461 is provided on the top surface, and the connection terminal 461 is electrically connected to the connection pad 417 provided on the bottom surface of the second recess 413b by the conductive member 470. It has become. Further, the electronic component element 460 is provided with a fixing member 480 between the lower surface of the electronic component element 460 and the bottom surface of the third recess 413c, and the electronic component element 460 is connected to the bottom surface of the third recess 413c by the fixing member 480. It is fixed and held.

  The conductive member 470 is for electrically connecting the connection terminal 417 and the connection pad 471, and for example, a gold wire is used. One end of the conductive member 470 is joined to the connection terminal 461 by wire bonding and the other end is joined to the connection pad 417 by wire bonding.

  The fixing member 480 is, for example, for fixing and holding the electronic component element 460 on the bottom surface of the third recess 413c. The fixing member 480 is located between the lower surface of the electronic component element 460 and the bottom surface of the third recess 413c. For the fixing member 480, a resinous adhesive is used, and an epoxy resin adhesive is used.

  Here, a method for electrically connecting the connection pad 417 and the connection terminal 461 by the conductive member 470 while the electronic component element 460 is housed in the third recess 413c and fixed to and held on the bottom surface of the third recess 413c will be described. To do. First, the fixing member 480 is applied to the bottom surface of the third recess 413c of the element mounting member 410, the connection terminal 461 of the electronic component element 460 faces the top surface, and the bottom surface of the electronic component element 460 and the bottom surface of the third recess 413c. The fixing member 480 is placed so as to be sandwiched, and the fixing member 480 is cured by heating in that state. Next, one end of the conductive member 480 is joined to the connection terminal 461 of the electronic component element 460 by wire bonding, and the other end of the conductive member 470 is mounted on the bottom surface of the second recess 413b of the element mounting member 410. It joins by 417 and wire bonding joining. In this way, the electronic component element 460 is fixed and held on the bottom surface of the third recess 413c, and the connection pad 417 and the connection terminal 461 are electrically connected.

  In the piezoelectric device of the modified example of the second embodiment, the vibration element 120 is mounted on the bottom surface of the first recess 413a of the element mounting member 410, and the electronic component element 460 is fixed while being accommodated in the third recess 413c. Is retained. The third recess 413c is formed on the bottom surface of the second recess 413b formed on the bottom surface of the first recess 413a. Therefore, in the piezoelectric device of the modification of the second embodiment, the distance between the lower surface of the vibration element 120 and the upper surface of the electronic component element 460 facing the lower surface of the vibration element 120 can be further increased. For this reason, in the piezoelectric device in the modification of the second embodiment, the distance between the lower surface of the vibration element 120 and the upper surface of the electronic component element 460 facing the lower surface of the vibration element 120 can be ensured by the second recess 413b. Therefore, air convection can be easily generated on the lower surface of the vibration element 120. As a result, in the piezoelectric device according to the modification of the second embodiment, the gas generated when the insulating adhesive 130 and the conductive adhesive 140 are cured is the excitation electrode provided on the lower surface of the piezoelectric piece of the vibration element 120 or The amount attached to the extraction electrode can be further reduced, and it is possible to reduce the fluctuation of the frequency of the vibration element 120 and the unstable output signal.

110, 210, 310, 410 ... element mounting members 1111, 211, 311, 411 ... flat plate portions 112a, 212a, 312a, 412a ... first frame portions 112b, 212b, 312b, 412b ... first 2nd frame part 412c ... 3rd frame part 113a, 213a, 313a, 413a ... 1st recessed part 113b, 213b, 313b, 413b ... 2nd recessed part 413c ... 3rd recessed part 114, 214, 314, 414 ... mounting pads 115, 215, 315, 415 ... mounting terminals 116, 216, 316, 416 ... sealing conductor patterns 317, 417 ... connection pads 120 ... vibration elements 121 ... Piezoelectric piece 122 ... excitation electrode 123 ... extraction electrode 130 ... insulating adhesive 140 ... conductive adhesive 150 ... lid 151 And joining members 360,460 ... electronic component element 361,461 ... connection terminal 370 and 470 ... conductive member 480 ... fixing member

Claims (3)

An element mounting member having a substantially rectangular parallelepiped shape, in which a first recess is formed on an upper surface, and a second recess is formed on a bottom surface of the first recess;
A mounting pad provided on the bottom surface of the first recess of the element mounting member;
A plate-shaped piezoelectric piece, a pair of excitation electrodes provided on the piezoelectric piece, and a pair of extraction electrodes, one end of which is connected to the excitation electrode and the other end is located at an end of the main surface of the piezoelectric piece And a vibration element comprising:
An insulating adhesive that is located between the lower surface of the piezoelectric piece and the bottom surface of the first recess of the element mounting member, and holds and holds the vibration element;
A conductive adhesive electrically bonding the extraction electrode and the mounting pad;
A lid joined to the upper surface of the element mounting member;
A piezoelectric device comprising: The piezoelectric device according to claim 1,
The piezoelectric device, wherein the insulating adhesive and the conductive adhesive are not in contact with each other. The piezoelectric device according to claim 2,
The piezoelectric piece of the vibration element has a substantially rectangular shape,
The extraction electrode is located near two of the four corners of the piezoelectric piece;
The insulating adhesive is a lower surface of the piezoelectric piece, and holds and holds the remaining two corners of the piezoelectric piece and the bottom surface of the first recess of the element mounting member. Piezoelectric device.

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