JP6487169B2 - Piezoelectric device - Google Patents

Description

  The present invention relates to a piezoelectric device built in an electronic apparatus.

  The piezoelectric device includes, for example, a piezoelectric element, an element mounting member, a lid, and a spacer. In such a piezoelectric device, the piezoelectric element is mounted on the upper surface side of the element mounting member by a conductive adhesive, and the mounted piezoelectric element is hermetically sealed in a space formed by the element mounting member and the lid. Has been. At this time, the external terminal provided on the lower surface of the element mounting member and the terminal pad provided on the upper surface of the spacer are joined by a conductive member such as solder.

  Such a spacer has a rectangular flat plate shape, and has a terminal pad on the upper surface and a mounting terminal on the lower surface. The terminal pad and the mounting terminal are electrically connected by a wiring pattern or internal wiring provided on the surface of the spacer. The spacer is joined to the terminal pad by a conductive member such as solder and provided on the lower surface of the element mounting member.

  When such a piezoelectric device is built in an electronic device, a predetermined mounting pad provided on a mounting board inside the electronic device and a mounting terminal provided on the lower surface of the spacer are mounted by solder or the like. It is joined by a member and mounted on a mounting board (see, for example, Patent Document 1).

JP 2003-243814 A

  In a conventional piezoelectric device, a spacer having a rectangular flat plate shape is provided on the lower surface of the element mounting member, and an external terminal provided on the lower surface of the element mounting member and a terminal provided on the upper surface of the spacer The pad for use is joined by a conductive member. Such a piezoelectric device is mounted on a mounting substrate such as an electronic device via a spacer. Therefore, in the conventional piezoelectric device, when stress is applied from an external mounting substrate, distortion such as bending occurs in the spacer. For this reason, in the conventional piezoelectric device, when the spacer is distorted, stress is applied to the conductive member that joins the external terminal and the terminal pad, and the conductive member may be cracked or the conductive member may be peeled off. In the conventional piezoelectric device, the conduction between the external terminal and the terminal pad becomes poor due to cracking or peeling of the conductive member. Further, in the conventional piezoelectric device, when a stress is applied from an external mounting substrate, the stress is applied to the conductive member, and the output signal may be unstable.

  An object of the present invention is to provide a piezoelectric device that suppresses a conduction failure between an external terminal and a terminal pad and reduces an unstable output signal.

In order to solve the above-described problems, a piezoelectric device according to the present invention includes an element mounting member having a plurality of external terminals on the lower surface, a piezoelectric element mounted on the upper surface side of the element mounting member, and an element mounting A lid that is bonded to the upper surface of the member and hermetically seals the piezoelectric element, a spacer that has a through-hole penetrating from the upper surface to the lower surface, and a plurality of terminals provided on the upper surface of the spacer A pad, a mounting terminal provided on the lower surface of the spacer and electrically connected to the terminal pad, and a conductive member electrically bonding the external terminal and the terminal pad. In plan view, the opening of the through hole does not overlap with the terminal pad, and when the lower surface of the spacer is viewed in plan, the opening of the through hole does not overlap with the mounting terminal and is formed in the spacer. Have Opening the serial through hole, characterized in that has a circular shape.

  In the piezoelectric device according to the present invention, an external terminal and a terminal pad are joined by a conductive member, and a spacer is provided on the lower surface of the element mounting member. The spacer penetrates from the upper surface of the spacer to the lower surface of the spacer. A hole is formed. Therefore, in the piezoelectric device according to the present invention, when stress is applied from the external mounting substrate and stress is applied to the spacer, the stress is concentrated in the direction toward the opening of the through hole. For this reason, in the piezoelectric device according to the present invention, the stress is concentrated in the direction toward the opening of the through hole, so that the force applied to the conductive member that joins the external terminal and the terminal pad as compared with the conventional case. Can be reduced. As a result, the piezoelectric device according to the present invention can reduce the stress applied to the conductive member when stress is applied from the external mounting substrate, and therefore, the conduction failure between the external terminal and the terminal pad can be reduced. Can be suppressed. In addition, the piezoelectric device according to the present invention can reduce the stress applied to the conductive member when stress is applied from an external mounting terminal, so that the output signal can be prevented from becoming unstable. It becomes possible.

It is a perspective view of the piezoelectric device in a first embodiment. It is sectional drawing in AA of FIG. (A) is a top view of the upper surface of the spacer used with the piezoelectric device in 1st embodiment, (b) is a top view of the lower surface of the spacer used with the piezoelectric device in 1st embodiment. It is a perspective view of the piezoelectric device in a second embodiment. It is sectional drawing in BB of FIG. (A) is a piezoelectric device in 3rd embodiment, and is a top view which shows the state before providing an insulating member, (b) is sectional drawing in CC cross section of Fig.6 (a). It is a top view of the spacer used with the piezoelectric device in a third embodiment. (A) is a top view which shows the state before providing an insulating member, and is a piezoelectric device in 4th embodiment, (b) is sectional drawing in the DD cross section of Fig.8 (a). It is a top view of the spacer used with the piezoelectric device in 4th embodiment.

(First embodiment)
As shown in FIGS. 1, 2 and 3, the piezoelectric device according to the first embodiment includes an element mounting member 110, a piezoelectric element 120, a lid 130, a spacer 160, and a conductive member 170. The piezoelectric element 120 mounted on the member 110 is hermetically sealed in a space formed by the element mounting member 110 and the lid 130. A spacer 160 is provided on the lower surface of the element mounting member 110.

  Here, according to the drawing, the surface of the element mounting member 110 on which the external terminals 112 are provided is the lower surface of the element mounting member 110, and the surface facing the opposite side is the upper surface of the element mounting member 110.

  The element mounting member 110 is for mounting the piezoelectric element 120. The element mounting member 110 has, for example, a substantially rectangular flat plate shape, and an external terminal 112 is provided on the lower surface of the element mounting member 110, and a mounting pad 111 is provided on the upper surface of the element mounting member 110. The element mounting member 110 is provided with a wiring pattern (not shown) or an internal wiring (not shown), and the external terminal 112 and the mounting pad 111 are electrically connected by the wiring pattern or the internal wiring. ing. The element mounting member 110 is made of an insulating layer made of a ceramic material such as alumina ceramics or glass ceramics. The element mounting member 110 may be formed by laminating a plurality of insulating layers, or may be used in a single layer.

  The mounting pad 111 is electrically bonded to the piezoelectric element 120, specifically, is electrically bonded to the extraction electrode 123 of the piezoelectric element 120. The mounting pad 111 is provided on the upper surface side of the element mounting member 110. The mounting pads 111 are paired and are provided side by side along the short side of the upper surface of the element mounting member 110 when the upper surface of the element mounting member 110 is viewed in plan.

  The external terminal 112 is for electrical connection with the terminal pad 161 provided on the spacer 160 via the conductive member 170. The external terminals 112 are paired, for example, and are provided one by one along the short side of the lower surface of the element mounting member 110 when the lower surface of the element mounting member 110 is viewed in plan. Further, the external terminal 112 is electrically connected to the mounting pad 111 by a wiring pattern or internal wiring (not shown) of the element mounting member 110. The external terminal 112 is electrically connected to a terminal pad 161 provided on the upper surface of the spacer 160 by a conductive member 170.

  Here, the element mounting member 110 has a substantially rectangular flat plate shape, and the dimension of the long side when the upper surface of the element mounting member 110 is viewed in plan is 1.6 mm to 8.0 mm. The short side dimension is 1.2 mm to 4.5 mm. The external terminal 112 has a substantially rectangular shape, and the dimension of the side parallel to the short side of the element mounting member 110 is 1.0 mm to 4.0 mm when the upper surface of the element mounting member 110 is viewed in plan. The dimension of the side parallel to the long side of the element mounting member 110 is 1.0 mm to 2.0 mm.

  Here, a manufacturing method of the element mounting member 110 will be described. When the element mounting member 110 is made of alumina ceramic, first, a plurality of ceramic green sheets obtained by adding an appropriate organic solvent or the like to a predetermined ceramic material powder and mixing them are prepared. In addition, a predetermined conductive paste is formed on the surface of the ceramic green sheet or in a portion where the ceramic green sheet is punched and provided in advance, using a well-known screen printing or the like to form a conductor pattern. Apply. Next, when a plurality of insulating layers are laminated, ceramic green sheets are laminated, pressed, and fired at a high temperature. When the element mounting member 110 is made of a single insulating layer, it is fired at a high temperature as it is. After firing, the element mounting member 110 is manufactured by applying nickel plating, gold plating, or the like to predetermined portions of the conductor pattern, specifically, the mounting pad 111, the external terminal 112, and the wiring pattern. The conductive paste is made of, for example, a sintered body of metal powder such as tungsten, molybdenum, copper, silver, or palladium.

  The piezoelectric element 120 can obtain a stable mechanical vibration and transmits a reference signal for an electronic device or the like. The piezoelectric 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 on both sides of the piezoelectric piece 121. And a pair of extraction electrodes 123 located at the edge. In addition, the piezoelectric element 120 is electrically connected to and held by a conductive adhesive 140 with a mounting pad 111 provided on the upper surface of the element mounting member 110, and the upper surface of the element mounting member 110. Has been implemented.

  Here, according to the drawing, when mounted on the element mounting member 110, the surface of the piezoelectric piece 121 facing the element mounting member 110 is a lower surface of the piezoelectric piece 121, and the piezoelectric piece facing the opposite side of the lower surface of the piezoelectric piece 121. The surface 121 is the 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 stable piezoelectric material that mechanically vibrates, for example, quartz. Here, a method for manufacturing the piezoelectric piece 121 will be described. After the piezoelectric piece 121 is cut from the artificial crystalline lens to a predetermined size, the thickness of the outer periphery of the piezoelectric piece 121 is reduced, and the central portion of the piezoelectric piece 121 is thicker than the outer peripheral portion of the piezoelectric piece 121. Nivel bevel processing is performed.

  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 piezoelectric 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 edge 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. The extraction electrode 123 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.

  Here, the operation of the piezoelectric element 120 will be described. When a voltage is applied to the extraction electrode 123 from the outside, the voltage is applied 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 due to the reverse voltage effect. As a result, since the piezoelectric piece 121 tends to return to the shape before deformation, a charge opposite to the charge initially accumulated in the excitation electrode 122 is accumulated due to the piezoelectric effect. That is, when a voltage is applied to the excitation electrode 122, the piezoelectric 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 piezoelectric 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 conductive adhesive 140 is for electrically bonding and holding the extraction electrode 123 of the piezoelectric element 120 and the mounting pad 111 of the element mounting member 110, and mounting the piezoelectric element 120 on the element mounting member 110. The conductive adhesive 140 is provided between the extraction electrode 123 and the mounting pad 111. The conductive adhesive 140 contains conductive powder as a conductive filler in a binder such as a silicone-based 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. 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 for electrically bonding the extraction electrode 123 and the mounting pad 111 using the conductive adhesive 140 will be described. First, the conductive adhesive 140 is applied onto the mounting pad 111 by, for example, a dispenser. Thereafter, the piezoelectric element 120 is conveyed onto the conductive adhesive 140, the piezoelectric element 120 is placed so that the conductive adhesive 140 is sandwiched between the extraction electrode 123 and the mounting pad 111, and is heated and cured in that state. Thereby, the extraction electrode 123 and the mounting pad 111 are electrically bonded.

  The lid 130 is composed of a sealing base 131 and a sealing frame 132. The lid member 130 is bonded to the upper surface of the element mounting member 110 by the bonding member 150 and hermetically seals the piezoelectric element 120 mounted on the upper surface of the element mounting member 110.

  The sealing base 131 is a rectangular flat plate, and the size of the main surface is larger than the main surface of the piezoelectric piece 121 of the piezoelectric element 120 and smaller than the size of the upper surface of the element mounting member 110. Yes. A recess space is formed by the sealing frame portion 132 on the lower surface of the sealing base 131.

  The sealing frame part 132 is comprised from the frame part 132a and the collar part 132b. The frame portion 132 a is for forming a recessed space in the lower surface of the lid 130, and is provided along the outer edge of the lower surface of the sealing base portion 131. The piezoelectric element 120 mounted on the upper surface of the element mounting member 110 is accommodated in the recessed space. The flange 132b is for securing an area for joining the lid 130 and the element mounting member 110 and increasing the joining strength. The flange portion 132b is annular along the outer peripheral surface of the frame portion 132a and extends to the outer peripheral side of the frame portion 132a.

  The sealing base 131 and the sealing frame 132 are made of, for example, an alloy containing at least one of iron, nickel, and cobalt, and are integrally formed. Such a lid 130 is for hermetically sealing a recessed space in a vacuum state or a recessed space filled with nitrogen gas or the like. Specifically, the lid body 130 is, in a predetermined atmosphere, the lower surface of the sealing frame portion 132, specifically, between the lower surface of the frame portion 132a and the upper surface of the element mounting member 110, and the flange portion 132b. By applying heat to the bonding member 150 provided between the lower surface of the element mounting member 110 and the upper surface of the element mounting member 110, the bonding member 150 is melted, and the lower surface of the sealing frame portion 132 and the upper surface of the element mounting member 110 are And are melt-bonded.

  Here, a method for manufacturing the lid 130 will be described. For the production of the lid 130, for example, conventionally known press working is used. First, a rectangular flat plate is prepared, and a pair of molds having a convex portion and a concave portion having the same shape as the concave space of the lid body 130 are pressed between the flat plate, the sealing base 131 and the sealing frame. The frame part 132a of the part 132 is provided, and a recessed part space is formed. In this manner, the lid body 130 plastically processes the flat plate using press working to form a recessed space, and the lid body 130 is produced.

  The joining member 150 includes a lower surface of the sealing frame portion 132 of the lid 130, specifically, between the frame portion 132a and the upper surface of the element mounting member 110, and a lower surface of the flange portion 132b and an upper surface of the element mounting member 110. The lid 130 and the element mounting member 110 are joined to each other. For example, in the case of glass, the bonding member 150 is a glass that melts at 300 ° C. to 400 ° C., and is made of, for example, low-melting glass containing vanadium or lead oxide glass. 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.

  Next, a joining method for joining the lid 130 and the element mounting member 110 using the joining member 150 will be described. The glass used as the raw material of the joining member 150 is a paste in which a binder and a solvent are added. After being melted, the glass is solidified and bonded to another member. The joining member 150 is provided by applying and drying glass frit paste on the lower surface of the sealing frame portion 132, specifically, the lower surface of the frame portion 132a and the lower surface of the flange portion 132b, for example, by screen printing. .

  In addition, in the case of an insulating resin, the joining member 150 is made of an epoxy resin or a polyimide resin, for example. At this time, the insulating resin is applied to the lower surface of the sealing frame portion 132 of the lid 130, specifically, the lower surface of the frame portion 132a and the lower surface of the flange portion 132b. The lid 130 to which the insulating resin is applied includes the insulating resin on the lower surface of the sealing frame portion 132, specifically, the lower surface of the frame portion 132a, the upper surface of the element mounting member 110, and the lower surface of the flange portion 132b. And the upper surface of the element mounting member 110. Thereafter, the insulating resin is heated and cured to join the lid 130 and the element mounting member 110 together.

  The spacer 160 has a substantially rectangular flat plate shape, and is provided with a terminal pad 161 on the upper surface and a mounting terminal 162 on the lower surface. The spacer 160 is provided on the lower surface of the element mounting member 110 by joining the terminal pad 161 provided on the upper surface and the external terminal 112 provided on the lower surface of the element mounting member 110 by the conductive member 170. Yes. Therefore, when the piezoelectric device according to the first embodiment is mounted on a mounting board such as an electronic device by the spacer 160, even if stress is applied from the mounting board, stress is applied to the element mounting member 110 via the spacer 160. As compared with the case where the spacer 160 is not provided, stress is applied to the element mounting member 110 and the amount of distortion of the element mounting member 110 can be reduced. For this reason, compared with the case where the spacer 160 is not provided, the stress applied to the conductive adhesive 140 can be suppressed and the conduction failure between the mounting pad 111 and the extraction electrode 123 can be reduced.

  The terminal pad 161 is to be joined to the external terminal 112 provided on the lower surface of the element mounting member 110 by the conductive member 170. The terminal pad 161 is provided at a position facing the external terminal 112. That is, in the drawing, the conductive member 170 is disposed between the lower surfaces of the external terminals 112.

  The mounting terminal 162 is for bonding to a predetermined mounting pad on the motherboard of the electronic device when the piezoelectric device according to the first embodiment is built in the electronic device. The mounting terminal 162 is electrically connected to the terminal pad 161 by a wiring pattern (not shown) of the spacer 160 or an internal wiring (not shown).

  In addition, a through hole 163 is formed in the spacer 160 from the upper surface to the lower surface. Therefore, when stress is applied to the spacer 160 and the spacer 160 is distorted and deformed, internal stress is applied toward the edge of the opening of the through hole 163. For this reason, when a stress is applied to the spacer 160, a part of the stress becomes an internal stress toward the edge of the opening of the through hole 163. Therefore, the terminal pad 161 of the spacer 160 and the external terminal 112 of the element mounting member 110. The stress applied to the conductive member 170 that is electrically connected to each other can be reduced as compared with the case where the through hole 163 is not provided. That is, by providing the through hole 163 in the spacer 160, the stress applied to the conductive member 170 that joins the terminal pad 161 and the external terminal 112 can be reduced as compared with the case where there is no through hole 163. it can.

  The opening of the through hole 163 is disposed at a position that does not overlap the terminal pad 161 when the top surface of the spacer 160 is viewed in plan. Therefore, when the terminal pad 161 of the spacer 160 and the external terminal 112 of the element mounting member 110 are joined by the conductive member 170, the conductive member 170 and the opening of the through hole 163 do not overlap in plan view. be able to. For this reason, when stress is applied to the spacer 160, it is possible to reduce the application of internal stress in the direction toward the edge of the opening of the through hole 163 to the conductive member 170.

  The opening of the through hole 163 is arranged at a position that does not overlap the mounting terminal 162 when the lower surface of the spacer 160 is viewed in plan. Therefore, when the piezoelectric device according to the first embodiment is mounted in the mother mode of the electronic device by a mounting member (not shown), the mounting member and the opening of the through hole 163 are not overlapped in plan view. be able to. For this reason, when stress is applied to the spacer 160, it is possible to reduce the internal stress in the direction toward the edge of the opening of the through hole 163 from being applied to the mounting member.

  The through hole 163 is formed at or near the center of the upper surface of the spacer 160 when the upper surface of the spacer 160 is viewed in plan. For example, when the opening of the through hole 163 is circular, the center of the opening of the through hole 163 overlaps with the center of the upper surface of the spacer 160, or the through hole 163 is positioned near the center of the upper surface of the spacer 160. A hole 163 is formed. For this reason, when stress is applied to the spacer 160, when internal stress is generated in the direction toward the edge of the opening of the through hole 163, the distance from the four corners of the spacer 160 to the edge of the through hole 163 is made the same. Therefore, the amount of distortion generated at the four corners of the spacer 160 can be made substantially uniform. Therefore, the stress applied to the conductive member 170 joining the external terminals 112 provided one by one along the short side of the lower surface of the element mounting member 110 and the terminal pads 161 can be made equal. It becomes possible.

  The opening of the through hole 163 has a circular shape, for example. Therefore, when stress is applied to the spacer 160, the internal stress generated in the direction toward the edge of the opening is dispersed in the opening, and the stress concentrates on the edge of the opening and breaks. Can be reduced.

  The spacer 160 is made of, for example, a glass epoxy resin. Since a glass epoxy resin is generally used for a motherboard of an electronic device, the thermal expansion coefficient of the motherboard and the spacer 160 can be made substantially the same by using the glass epoxy resin for the spacer 160. . Accordingly, when the mounting terminal 162 provided on the lower surface of the spacer 160 and the predetermined mounting pad of the motherboard are electrically joined by the mounting member, the thermal expansion coefficient is substantially the same between the spacer 160 and the motherboard. By contraction, the force applied from the spacer 160 to the mounting member and the force applied from the mother board to the mounting member can be made substantially the same.

  Here, the spacer 160 has a long side dimension of 1.6 mm to 8.0 mm and a short side dimension of 1.2 mm to 4.5 mm when the upper surface of the spacer 160 is viewed in plan. Further, when the upper surface of the spacer 160 is viewed in plan, the terminal pad 161 has a side dimension parallel to the short side of the spacer 160 of 1.0 mm to 4.0 mm. The dimension of the side parallel to the side is 1.0 mm to 2.0 mm. Further, when the bottom surface of the spacer 160 is viewed in plan, the mounting terminal 162 has a side dimension parallel to the short side of the spacer 160 of 1.0 mm to 4.0 mm. The dimension of the side which is parallel to is 1.0 mm to 2.0 mm. Further, when the top surface of the spacer 160 is viewed in plan, the through hole 163 has a circular opening, and the circular diameter is 0.5 mm to 2.0 mm. The thickness of the spacer 160 in the vertical direction is, for example, 0.2 mm to 1.0 mm.

  Here, a method for manufacturing the spacer 160 will be described. Here, for example, by a photolithography technique and an etching technique, a predetermined conductor pattern, specifically, a terminal pad 161, a mounting terminal 162, and a wiring pattern are formed on a flat base material made of glass epoxy resin. The spacer 160 is manufactured.

  The conductive member 170 is provided between the external terminal 112 of the element mounting member 110 and the terminal pad 161 of the spacer 160, and joins the external terminal 112 and the terminal pad 161. The conductive member 170 is made of, for example, silver paste or lead-free solder.

  When the conductive member 170 is made of silver paste, the conductive member 170 is applied to the terminal pad 161 on the upper surface of the spacer 160 or the external terminal 112 on the lower surface of the element mounting member 110, and is electrically conductive between the terminal pad 161 and the external terminal 112. It is provided between the terminal pad 161 and the external terminal 112 by curing with the member 170 sandwiched therebetween.

  When the conductive member 170 is made of lead-free solder, the conductive member 170 is printed on the terminal pad 161 or the external terminal 112 with solder paste having a suitable viscosity by adding flux to the solder powder. And the external terminal 112 are provided between the terminal pad 161 and the external terminal 112 by heating. In addition, the component ratio of lead-free solder is 95 to 97.5% for tin, 2 to 4% for silver, and 0.5 to 1.0% for copper.

  In the piezoelectric device according to the first embodiment, the external terminal 112 and the terminal pad 161 are joined by the conductive member 170, and the spacer 160 is provided on the lower surface of the element mounting member 110. Through holes 163 are formed from the upper surface of the spacer to the lower surface of the spacer 160. Further, in the piezoelectric device according to the first embodiment, when the upper surface of the spacer 160 is viewed in plan, the terminal pad 161 and the opening of the through hole 163 are disposed at a position that does not overlap. Therefore, in the piezoelectric device according to the first embodiment, when stress is applied from the external mounting substrate and stress is applied to the spacer 160, the stress can be concentrated in the direction toward the opening of the through hole 163. Compared with the prior art, it is possible to reduce the force applied to the conductive member 170 that joins the external terminal 112 and the terminal pad 161. As a result, in the piezoelectric device according to the first embodiment, when the stress is applied from the external mounting substrate, the stress applied to the conductive member 170 can be reduced as compared with the conventional case. Therefore, the external terminal 112 and the terminal pad The conduction failure with 161 can be suppressed. Moreover, since the piezoelectric device according to the first embodiment can reduce the stress applied to the conductive member 170 when stress is applied from an external mounting substrate, the externally output signal becomes unstable. It can be reduced.

  In the piezoelectric device according to the first embodiment, when the upper surface of the spacer 160 is viewed in plan, the through hole 163 is formed at or near the center of the upper surface of the spacer 160. For example, an opening of the through hole 163 is formed. When the portion is circular, the through hole 163 is formed so that the center of the opening of the through hole 163 overlaps the center of the upper surface of the spacer 160. For this reason, in the piezoelectric device according to the first embodiment, the distance from the four corners of the spacer 160 to the center of the opening of the through hole 163 can be made the same. When is added, the amount of distortion generated at the four corners of the spacer 160 can be made substantially uniform. Therefore, in the piezoelectric device according to the first embodiment, the stress applied to the conductive member 170 that joins the external terminal 112 and the terminal pad 161 can be made equal. As a result, in the piezoelectric device according to the first embodiment, stress concentration on a part of the conductive member 170 can be reduced. Cracks and peeling of the conductive member 170 can be reduced, and poor conduction between the external terminal 112 and the terminal pad 161 can be suppressed.

  In the piezoelectric device according to the first embodiment, the opening of the through hole 163 formed in the spacer 160 has a circular shape. Therefore, in the piezoelectric device according to the first embodiment, when stress is applied to the spacer 160, the stress generated in the direction toward the edge of the opening is dispersed in the opening, and the opening of the through hole 163 is thus performed. It can reduce that stress concentrates on the edge of a part and breaks. As a result, in the piezoelectric device according to the first embodiment, it is possible to reduce the stress applied to the conductive member 170 while reducing breakage of the spacer 160, thereby reducing the instability of the output signal. It becomes possible.

  Further, in the piezoelectric device according to the first embodiment, the spacer 160 is made of glass epoxy resin like the motherboard of the electronic device, so that the thermal expansion coefficients of the motherboard and the spacer 160 can be made substantially the same. It becomes. Therefore, in the piezoelectric device according to the first embodiment, when the mounting terminal 162 provided on the lower surface of the spacer 160 and the predetermined mounting pad of the motherboard are electrically joined by the mounting member, the degree of expansion or contraction due to heat. However, since the spacer 160 and the mother board are the same, the force applied from the spacer 160 to the mounting member and the force applied from the mother board to the mounting member can be made substantially the same. As a result, in the piezoelectric device according to the first embodiment, it is possible to reduce the concentration of stress on a part of the conductive member 170. Therefore, the crack of the conductive member 170 due to the stress concentration on a part of the conductive member 170. And the peeling of the conductive member 170 can be reduced, and poor conduction between the external terminal 112 and the terminal pad 161 can be suppressed.

  Here, the manufacturing method of the piezoelectric device according to the first embodiment will be described. The method for manufacturing a piezoelectric device according to the first embodiment includes, for example, an element forming process, an element mounting process, a sealing process, and a spacer bonding process.

  The element forming step is a step of forming the piezoelectric element 120 by providing the piezoelectric piece 121 with the excitation electrode 122 and the extraction electrode 123. After the piezoelectric piece 121 is cut from the artificial crystalline lens to a predetermined size, the thickness of the outer periphery of the piezoelectric piece 121 is reduced, and the central portion of the piezoelectric piece 121 is thicker than the outer peripheral portion of the piezoelectric piece 121. The bevel is processed and formed. In the element formation step, the excitation electrode 122 and the extraction electrode 123 are formed by depositing a metal film on a predetermined position of the piezoelectric piece 121 by a photolithography technique, a vapor deposition technique, or a sputtering technique.

  The element mounting process is a process of mounting the piezoelectric element 120 on the element mounting member 110 with the conductive adhesive 140. In the element mounting step, first, the conductive adhesive 140 is applied onto the mounting pad 111 of the element mounting member 110 by, for example, a dispenser. Next, the piezoelectric element 120 is conveyed onto the conductive adhesive 140, and the piezoelectric element 120 is placed so that the conductive adhesive 140 is sandwiched between the extraction electrode 123 and the mounting pad 111, and is heated and cured in that state. . Thereby, the extraction electrode 123 and the mounting pad 111 are electrically bonded. In the element mounting process, the lead electrode 123 of the piezoelectric element 120 and the mounting pad 111 of the element mounting member 110 are electrically bonded and fixed by the conductive adhesive 140 in this way, so that the piezoelectric element 120 is fixed. It is mounted on the upper surface side of the element mounting member 110.

In the sealing step, the upper surface of the element mounting member 110 is mounted on the upper surface side of the element mounting member 110 by bonding the upper surface of the element mounting member 110 and the lower surface of the lid 130 with the bonding member 150. This is a step of hermetically sealing the piezoelectric element 120. Here, the case where the raw material of the joining member 150 is made of glass will be described. In the sealing step, first, a paste-like glass frit paste to which a binder and a solvent have been added is applied to the lower surface of the sealing frame portion 132 of the lid body 130 by screen printing, specifically, the lower surface of the frame portion 132a and It is provided by being applied and dried on the lower surface of the collar 132b. Next, the glass frit paste is provided so as to be positioned between the upper surface of the element mounting member 110 and the lower surface of the lid body 130. In this state, the glass frit paste is heated to melt and solidify. In the sealing step, the bonding member 150 is provided between the upper surface of the element mounting member 110 and the lower surface of the lid 130,
The element mounting member 110 and the lid 130 are joined by heating, melting, and solidifying again.

  The spacer bonding step is a step of bonding the external terminal 112 of the element mounting member 110 and the terminal pad 161 of the spacer 160 by the conductive member 170. Silver paste or lead-free solder is used for the conductive member 170. When the conductive member 170 is made of a silver paste, in the conductive member bonding step, first, it is applied to the terminal pads 161 on the upper surface of the spacer 160 or the external terminals 112 on the lower surface of the element mounting member 110 by a dispenser or the like. Thereafter, the applied silver paste is cured while being sandwiched between the terminal pad 161 and the external terminal 112, whereby the terminal pad 161 and the external terminal 112 are bonded to each other by the conductive member 170. When the conductive member 170 is made of lead-free solder, in the conductive member joining step, first, a solder paste is prepared by adding flux to the solder powder to have an appropriate viscosity. Next, this solder paste is printed on the terminal pad 161 or the external terminal 112, and the solder paste is heated and sandwiched between the terminal pad 161 and the external terminal 112, whereby the solder powder is melted and solidified. Thus, the terminal pad 161 and the external terminal 112 are joined.

(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. As shown in FIGS. 4 and 5, the piezoelectric device in the second embodiment is the first in that the insulating member 180 is provided between the lower surface of the element mounting member 110 and the upper surface of the spacer 160. Different from the embodiment.

  The insulating member 180 is made of a resin adhesive, and in particular, a resin adhesive having a small volume shrinkage when cured. As the insulating member 180, for example, an epoxy resin adhesive or a silicone resin adhesive is used. Thereby, when the insulating member 180 is cured, the stress applied from the insulating member 180 to the spacer 160, the element mounting member 110, and the conductive member 170 can be suppressed.

  The insulating member 180 is provided between the lower surface of the element mounting member 110 and the upper surface of the spacer 160, and bonds the lower surface of the element mounting member 110 and the upper surface of the spacer 160. Therefore, the element mounting member 110 and the spacer 160 are bonded to each other by the conductive member 170 and the insulating member 180, and the bonding strength between the element mounting member 110 and the spacer 160 can be increased as compared with the conventional case. . In addition, by bonding the element mounting member 110 and the spacer 160 with the insulating member 180, when stress is applied to the spacer 160, the stress is also applied to the insulating member 180. The stress applied to 170 can be reduced.

  The insulating member 180 is provided inside the through hole 163. At this time, the insulating member 180 is also provided between the lower surface of the element mounting member 110 and the upper surface of the spacer 160. Since the insulating member 180 is provided inside the through hole 163, even if stress is applied to the outer peripheral edge of the through hole 163, the outer peripheral edge of the through hole 163 is protected by the insulating member 180. Chipping and cracking can be reduced along the outer peripheral edge of the hole 163. Further, since the insulating member 180 is provided between the lower surface of the element mounting member 110 and the upper eye of the spacer 160 and is provided in the through hole 160, the vertical thickness of the spacer 160 itself is increased. Thus, the rigidity of the spacer 160 can be increased. For this reason, compared with the case where the insulating member 180 is not provided in the through-hole 163, the rigidity of the spacer 160 can be increased. Therefore, when stress is applied to the spacer 160, the amount of distortion generated in the spacer 160 is reduced. It becomes possible to make it. As a result, compared to the conventional case, the stress applied to the conductive member 170 that joins the external terminal 112 and the terminal pad 161 can be reduced.

  In addition, since the insulating member 180 is provided inside the through hole 163, it is possible to reduce contamination of foreign matters such as dust from the through hole 163. When foreign matter such as dust enters from the through-hole 163 and adheres to the conductive member 170, noise is superimposed on signals input / output between the external terminal 112 and the terminal pad 161, and output from the mounting terminal 162 of the second embodiment. Noise is also superimposed on the output signal, and as a result, the output signal may become unstable. Therefore, by providing the insulating member 180 inside the through hole 163, it is possible to reduce the adhesion of foreign matters such as dust to the conductive member 170, and signals input and output between the external terminal 112 and the terminal pad 161. It is possible to suppress the noise from being superimposed on the signal, and to reduce the noise from being superimposed on the signal output from the mounting terminal 162. Therefore, it is possible to reduce the unstable output signal.

  Further, the insulating member 180 covers the surface of the conductive member 170 facing the center side of the element mounting member 110. Here, the surface of the conductive member facing the center side of the element mounting member 110 is the surface of the conductive member 170 facing the opening side of the through hole 163 in plan view. That is, the insulating member 180 is provided on the surface of the conductive member 170 facing the opening side of the through hole 163 in plan view, and the lower surface of the element mounting member 110, the upper surface of the spacer 160, and the element mounting. It is in a state provided in a space formed by the surface of the conductive member 170 facing the center side of the member 110. In other words, the insulating member 180 is filled between the lower surface of the element mounting member 110 and the upper surface of the spacer 160. Therefore, the insulating member 180 is filled between the lower surface of the element mounting member 110 and the upper surface of the spacer 160 by the insulating member 180, so that the element mounting member 110 and the spacer 160 can be regarded as one unit. It becomes possible to increase the rigidity of the piezoelectric device.

  In addition, the insulating member 180 covers the surface of the conductive member 170 facing the center side of the element mounting member 110. Therefore, the insulating member 180 bonds the lower surface of the element mounting member 110, the upper surface of the spacer 160, and the surface of the conductive member 170 facing the center side of the element mounting member 110. For this reason, since the insulating member 180 can increase the area to be bonded as compared with the conventional case, the bonding strength between the element mounting member 110 and the spacer 160 can be increased.

  The insulating member 180 covers the surface of the conductive member 170 facing the outer peripheral edge of the element mounting member 110. That is, the insulating member 180 is provided so as to cover the surface of the conductive member 170 exposed in the piezoelectric device according to the first embodiment. At this time, the insulating member 180 reduces adhesion of foreign matters such as dust to the conductive member 170. When foreign matter such as dust adheres to the conductive member 170, noise is superimposed on signals input / output between the external terminals 112 and the terminal pads 161, and noise is also superimposed on signals output from the mounting terminals 162. As a result, the output signal may become unstable. That is, by covering the surface of the conductive member 170 facing the outer peripheral edge of the element mounting member 110 with the insulating member 180, the amount of foreign matter such as dust attached to the conductive member 170 is reduced, and the external terminal 112, the terminal pad 161, Thus, it is possible to reduce the superimposition of noise on the input / output signal, and to reduce the instability of the output signal.

  In addition, since the insulating member 180 covers the surface of the conductive member 170 facing the outer peripheral edge of the element mounting member 110, the bonding area between the lower surface of the element mounting member 110 and the upper surface of the spacer 160 is larger than in the conventional case. It is possible to increase the adhesive strength.

  Further, since the insulating member 180 covers the surface of the conductive member 170 facing the outer peripheral edge of the element mounting member 110, the insulating member 180 is bonded by the insulating member 180 on the outer peripheral edge side of the element mounting member 110 in plan view. be able to. For this reason, since the element mounting member 110 and the spacer 160 can be regarded as one body by the insulating member 180 also on the outer peripheral edge side of the element mounting member 110 from the conductive member 170, the rigidity can be increased.

  In the piezoelectric device according to the second embodiment, since the insulating member 180 is provided between the lower surface of the element mounting member 110 and the upper surface of the spacer 160, the lower surface of the element mounting member 110 and the upper surface of the spacer 160 are bonded. ing. Therefore, in the piezoelectric device according to the second embodiment, the adhesive strength between the element mounting member 110 and the spacer 160 can be increased as compared with the related art. For this reason, in the piezoelectric device according to the second embodiment, when stress is applied to the spacer 160, stress is also applied to the insulating member 180, and the conductive member 170 joining the external terminal 112 and the terminal pad 161. It is possible to reduce the stress applied to the. As a result, in the piezoelectric device according to the second embodiment, the stress applied to the conductive member 170 can be reduced, so that the external terminal 112 and the terminal pad 161 are caused by the crack of the conductive member 170 or the peeling of the conductive member 170. It becomes possible to reduce conduction failure.

  In the piezoelectric device according to the second embodiment, the insulating member 180 is also provided inside the through hole 163 formed in the spacer 160. Therefore, in the piezoelectric device according to the second embodiment, the rigidity of the spacer 160 can be increased as compared with the case where the insulating member 180 is not provided in the through hole 163. For this reason, in the piezoelectric device according to the second embodiment, when stress is applied to the spacer 160, the amount of distortion generated in the spacer 160 is smaller than when the insulating member 180 is not provided in the through hole 163. It can be reduced. As a result, in the piezoelectric device according to the second embodiment, since the amount of distortion generated in the spacer 160 is reduced, the stress applied to the conductive member 170 that joins the external terminal 112 and the terminal pad 161 can be reduced. In addition, it is possible to reduce poor conduction between the external terminal 112 and the terminal pad 161 due to the crack of the conductive member 170 or the peeling of the conductive member 170.

  In the piezoelectric device of the second embodiment, since the insulating member 180 covers the surface of the conductive member 170 facing the center side of the element mounting member 110, the lower surface of the element mounting member 110 and the upper surface of the spacer 160 are included. And the surface of the conductive member 170 facing the center side of the element mounting member 110 are bonded. For this reason, since the piezoelectric device of the second embodiment can increase the area to be bonded by the insulating member 180, the bonding strength between the element mounting member 110 and the spacer 160 can be increased. As a result, in the piezoelectric device according to the second embodiment, since the stress applied to the conductive member 170 can be reduced, the conduction between the external terminal 112 and the terminal pad 161 due to the crack of the conductive member 170 or the peeling of the conductive member 170. Defects can be reduced.

  Also. In the piezoelectric device of the second embodiment, the surface of the conductive member 170 facing the outer peripheral edge of the element mounting member 110 is covered with an insulating member 180. Therefore, the piezoelectric device of the second embodiment reduces the amount of foreign matters such as dust adhering to the conductive member 170 and reduces noise superimposed on signals input / output between the external terminal 112 and the terminal pad 161. As a result, the output signal is prevented from becoming unstable.

  Further, in the piezoelectric device of the second embodiment, the insulating member 180 covers the surface of the conductive member 170 facing the outer peripheral edge of the element mounting member 110, so that the lower surface of the element mounting member 110 and the spacer 160 are compared with the conventional one. It is possible to increase the bonding area with the upper surface of the film, and to increase the bonding strength. As a result, in the piezoelectric device according to the second embodiment, since the stress applied to the conductive member 170 can be reduced, the conduction between the external terminal 112 and the terminal pad 161 due to the crack of the conductive member 170 or the peeling of the conductive member 170. Defects can be reduced.

  In the piezoelectric device of the second embodiment, since the insulating member 180 covers the surface of the conductive member 170 facing the outer peripheral edge of the element mounting member 110, the outer periphery of the element mounting member 110 from the conductive member 170 in plan view. It can be bonded by an insulating member 180 on the edge side. For this reason, the piezoelectric device of the second embodiment has high rigidity because the element mounting member 110 and the spacer 160 can be regarded as one body by the insulating member 180 on the outer peripheral edge side of the element mounting member 110 from the conductive member 170. It becomes possible. As a result, in the piezoelectric device according to the second embodiment, since the stress applied to the conductive member 170 can be reduced, the conduction between the external terminal 112 and the terminal pad 161 due to the crack of the conductive member 170 or the peeling of the conductive member 170. Defects can be reduced.

  Here, a manufacturing method of the piezoelectric device according to the second embodiment will be described. In addition, the same code | symbol is attached | subjected about the part similar to the manufacturing method of the piezoelectric device in 1st embodiment among the manufacturing methods of the piezoelectric device in 2nd embodiment, and description is abbreviate | omitted suitably. The method for manufacturing a piezoelectric device according to the second embodiment differs from the first embodiment in that an insulating member forming step is provided in which the insulating member 180 is provided between the lower surface of the element mounting member 110 and the upper surface of the spacer 160.

  The insulating member forming step is a step of providing the insulating member 180 between the lower surface of the element mounting member 110 and the upper surface of the spacer 160. In the insulating member forming step, the insulating member 180 is provided so as to be positioned in the through hole 163 of the spacer 160 while being provided between the lower surface of the element mounting member 110 and the upper surface of the spacer 160 after the conductive bonding step. At this time, the insulating member 180 covers the surface of the conductive member 170 facing the center of the element mounting member 110 and the surface of the conductive member 170 facing the outer peripheral edge of the element mounting member 110.

  In the insulating member forming step, for example, the insulating member 180 is injected from the through hole 163 of the spacer 160 after the conductive member bonding step. Accordingly, it is possible to easily provide the insulating member 180 so as to cover the surface of the conductive member 170 facing the center side of the element mounting member 110. In addition, by injecting the insulating member 180 from the through hole 163 as described above, the insulating member 180 can be easily provided in the through hole 163.

  The case where a pair of external terminals is described has been described. For example, four external terminals may be provided, and one may be provided at each of the four corners of the lower surface of the element mounting member 110. At this time, predetermined two of the external terminals are electrically connected to the mounting pad 111.

  Although the case where the element mounting member 110 has a flat plate shape is described, if the piezoelectric element can be hermetically sealed in the space formed by the element mounting member 110 and the lid, for example, a recess is formed. An element mounting member and a flat lid may be used.

(Third embodiment)
Hereinafter, the piezoelectric device in the third 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 3rd embodiment, and description is abbreviate | omitted suitably. In the piezoelectric device according to the third embodiment, as shown in FIG. 6, the element mounting member 310 on which the piezoelectric element 320 is mounted includes a base 313, a fixing part 311, and legs 312 (312 a, 312 b, 312 c). This is different from the second embodiment.

  The element mounting member 310 includes a flat base 313, a leg 312 extending from a predetermined surface of the base 313, and a fixing portion 311 extending from a predetermined other surface of the base 313. The tip of the leg 312 extending from the base 313 is an external terminal.

  The base 313 is for forming a space for hermetically sealing the piezoelectric element 320 mounted on the element mounting member 310 together with the lid 330. The base 312 is made of an alloy containing any of iron, cobalt, nickel, and copper, or stainless steel. For example, an alloy made of iron, nickel, and cobalt is used. The base 313 has a flat plate shape, for example, has a substantially rectangular parallelepiped shape, and when one main surface is viewed in plan, the short side portion has a semicircular shape.

  The leg 312 is for applying a voltage to the piezoelectric element 320 mounted on the element mounting member 310, and extends from a predetermined surface of the base 313 while being insulated from the base 313. At this time, the leg portions 312 are, for example, a pair, and are arranged side by side so as to be parallel to the long side of the predetermined surface of the base portion 313. For the leg 312, any one of iron, cobalt, nickel, copper, silver, and gold, or an alloy containing any one of them is used. For example, an alloy made of iron, nickel, and cobalt is used.

  Moreover, when the alloy which consists of iron, cobalt, and nickel is used for the leg part 312, the thermal expansion coefficient of the leg part 312 can be 48-62x10 ^ -7K, and when other metal materials are used As compared with the above, it is possible to reduce the difference in thermal expansion coefficient with the spacer 360. Therefore, when the conductive member 370 is joined to electrically connect the terminal pad 361 of the spacer 360 and the leg 312, the stress applied to the conductive member 370 from the leg 312 and the spacer 360 to the conductive member 370. The difference from the applied stress can be reduced.

  The leg portion 312 is bent a plurality of times, and includes a first leg portion 312a, a second leg portion 312b, and a third leg portion 312c. The first leg 312a is connected to a predetermined surface of the base 313 in a state where one end is insulated from the base 313, and the other end is connected to one end of the second leg 312b. At this time, the first leg 312a is substantially parallel to the upper surface of the spacer 360, for example. The second leg 312b has one end connected to the other end of the first leg 312a and the other end connected to one end of the third leg 312c. At this time, the second leg 312b is, for example, perpendicular to the upper surface of the spacer 360. One end of the third leg portion 312 c is connected to the second leg portion 312 b, and the other end is electrically connected to a terminal pad 361 provided on the upper surface of the spacer 360 by a conductive member 370. Accordingly, the third leg portion 312 c corresponds to an external terminal of the element mounting member 310.

  The fixing portion 311 is for mounting the piezoelectric element 320 on the element mounting member 310, and is insulated from the base portion 313 and is opposite to a predetermined other surface of the base portion 313, for example, a predetermined one surface of the base portion 313. It extends from the surface of the base 313 facing the surface. At this time, the fixing portions 311 are, for example, a pair, and are arranged side by side so as to be parallel to the long side on the other predetermined surface of the base portion 313. For the fixing portion 311, any one of iron, cobalt, nickel, copper, silver, and gold, or an alloy containing any one of them is used. For example, an alloy made of iron, cobalt, or nickel is used. The leg portion 312 is integrally formed. A state in which the piezoelectric element 320 is bonded and fixed to the end of the fixing portion 311 opposite to the base portion 313 in the fixing portion 311 by a conductive adhesive (not shown) so that the piezoelectric element 320 does not contact the base portion 313. Is held by. At this time, the fixing portion 311 and the extraction electrode of the piezoelectric element 320 are electrically connected by the conductive adhesive.

  Here, the other predetermined surface of the base portion 313 where the fixing portion 311 extends is the first surface M1 of the base portion 313, and the predetermined one surface of the base portion 313 where the leg portion 312 is extended is the first surface of the base portion 313. Let it be a two-sided M2. The first surface M1 of the base portion 313 and the second surface M2 of the base portion 313 are defined as the main surface of the base portion 313. Although different from the vertical direction on the actual drawing, only in the third embodiment, the first surface M1 of the base portion 313 is the upper surface of the element mounting member 310, and the second surface M2 of the base portion 313 is the element mounting member 310. The lower surface of

  Although not particularly illustrated, the element mounting member 310 has a fine hole (not shown) penetrating from the first surface M1 of the base portion 313 to the second surface M2 of the base portion 313. After the leg portion 312 and the fixing portion 311 are inserted into the hole, an insulating bonding member (not shown) is inserted. Thus, the leg 312 can be extended from the base 313 in a state where the base 313 and the leg 312 are insulated, and the base 313 and the fixing portion 311 are insulated from the base 313 and the fixing portion 311. 311 can be extended.

  The lid 330 is for hermetically sealing the piezoelectric element 320 that is bonded to the base 313 and mounted on the base 313, and includes a sealing base 331, a sealing frame 332, and lid terminals 333 (333a, 333b). , 333c). The lid 330 is made of any one of iron, cobalt, nickel, copper, silver, and gold, or an alloy containing any one of them, for example, an alloy made of iron, nickel, and cobalt. The lid 330 includes a sealing base 331, a sealing frame 332, and a lid terminal 333.

  The sealing base 331 is formed in a flat plate shape, for example, has a substantially rectangular parallelepiped shape, and has a semicircular shape on the short side in plan view. At this time, the main surface of the sealing base 331, specifically, the surface of the sealing base 331 facing the base 313 side has the same shape as the main surface of the base 313.

  The sealing frame portion 332 has a flat frame shape, is provided along the edge of the surface of the sealing base portion 332 facing the base portion 313 side, and the surface of the lid 330 facing the base portion 313 side has a piezoelectric element. A space for accommodating 320 is formed. The sealing frame portion 332 is joined to the base portion 313 by cold pressure bonding, and the piezoelectric element 320 is hermetically sealed in a recess formed by the sealing frame portion 332 and the sealing base portion 331.

  The lid terminal 333 is for bringing the lid 330 to the same potential as the ground, and extends from the lid 330. The lid terminal 333 is bent a plurality of times, and includes a first lid terminal 333a, a second lid terminal 333b, and a third lid terminal 333c. The first lid terminal 333a is connected in a state where one end is electrically connected to the surface of the sealing base 331 facing the base 313 side and the other side of the sealing base 331 facing the opposite side. The lid terminal 333b is connected. At this time, the first lid terminal 333a is parallel to the upper surface of the spacer 360, for example. The second lid terminal 333b has one end connected to the other end of the first lid terminal 333a and the other end connected to one end of the third lid terminal 333c. At this time, the second lid terminal 333b is, for example, perpendicular to the upper surface of the spacer 360. One end of the third lid terminal 333c is connected to the second lid terminal 333b. The other end is connected to a terminal pad provided on the spacer 360 by a conductive member 370 and 361. Note that the terminal pad 361 to which the third lid terminal 333 c is connected is different from the terminal pad 361 to which the leg portion 312 of the element mounting member 310 is connected. Therefore, the lid terminal 333 of the lid 330, specifically, the third lid terminal 333c also functions as an external terminal. By setting the terminal pad 361 to which the lid terminal 333 is connected to the same potential as the ground, the piezoelectric element 320 mounted on the element mounting member 310 can be shielded in a pseudo manner by the lid 330. For this reason, the stray capacitance generated between the excitation electrode of the piezoelectric element 320 and the outside of the piezoelectric device can be reduced, and the signal of the piezoelectric device can be stabilized.

  By using an alloy made of iron, cobalt, and nickel for the lid terminal 333, the thermal expansion coefficient of the lid terminal 333 can be set to 48 to 62 × 10 ^ −7K, compared with the case where other metal materials are used. Thus, the difference in thermal expansion coefficient with the spacer 360 can be reduced. Therefore, when the conductive member 370 is joined to electrically connect the terminal pad 361 and the leg portion 312 of the spacer 360, the stress applied to the conductive member 370 from the lid terminal 333, and the spacer 360 to the conductive member 370. The difference from the applied stress can be reduced.

  For example, as shown in FIG. 7, the spacer 360 has a substantially rectangular flat plate shape, and three terminal pads 361 are provided on the upper surface thereof, for example. Two of the terminal pads 361 are arranged along the one long side of the upper surface of the spacer 360 so as to face the third leg 312c. The remaining one of the terminal pads 361 is arranged at the edge of the other long side of the upper surface of the spacer 360 and at a position facing the third lid terminal 333c. On the lower surface of the spacer 360, a mounting terminal 362 that is electrically connected to the terminal pad 361 by an internal wiring or wiring portion of the spacer 360 (not shown) is provided. These mounting terminals 362 are arranged at positions where the mounting terminals 362 overlap the terminal pads 361 when the lower surface of the spacer 360 is viewed from above.

  The spacer 360 has a long side dimension of 5 to 15 mm and a short side dimension of 4.5 to 14.5 mm, as viewed from above. The terminal pads 361 are two of the three terminal pads 361 that are electrically connected to the third leg portion 312c when the upper surface of the spacer 360 is viewed in plan (terminal pads 361). The dimension of the side parallel to the long side of the spacer 360 is 1.0 to 3.0 mm, and the dimension of the side parallel to the short side of the spacer 360 is 1.0. The remaining one of the three terminal pads 361 electrically connected to the third lid terminal 333c (the terminal pad 361) is the length of the spacer 360. The dimension of the side parallel to the side is 1.0 to 3.0 mm, and the dimension of the side parallel to the short side of the spacer 360 is 1.0 to 3.0 mm. Further, the through hole 363 formed from the upper surface to the lower surface of the spacer 360 has a circular opening when the upper surface of the spacer 360 is viewed in plan, and the circular diameter is 0.5-4. It is 0 mm. Further, the thickness of the spacer 360 in the vertical direction is, for example, 0.2 to 1.0 mm.

  In this embodiment, although not particularly illustrated in FIGS. 6 and 7, the insulating member is provided in the same manner as in the second embodiment, but the insulating member is provided between the lid 330 and the upper surface of the spacer 360. This is different from the second embodiment in that it is also provided. The insulating member fills the inside of the through hole 363 formed in the spacer 360, and between the base portion 313 of the element mounting member 310 and the upper surface of the spacer 360, and the upper surfaces of the lid 330 and the spacer 360. It is also provided between. By doing so, the stress applied to the conductive member 370 when the stress is applied to the spacer 360 can be further reduced while increasing the bonding strength between the spacer 360 and the element mounting member 310 and between the spacer 360 and the lid 330. .

  The insulating member covers the surface of the conductive member 370 facing the outer peripheral edge of the spacer 360 while covering the surface of the conductive member 370 facing the center side of the spacer 360. Here, the surface of the conductive member 370 facing the center side of the spacer 360 is a surface of the conductive member 370 facing the opening of the through hole 363 formed in the spacer 360 in plan view. The surface of the conductive member 370 facing the periphery is the surface of the conductive member 370 facing the outer peripheral side of the spacer 360 in plan view. Thus, by providing the insulating member so as to cover the surface of the conductive member 370 facing the center side of the spacer 360 and the surface of the conductive member 370 facing the outer peripheral edge side of the spacer 360, the insulating member covers the conductive member 370. While being provided, the space formed by the lid 330, the element mounting member 310, the spacer 360, and the conductive member 370 is filled. Therefore, the spacer 360, the lid 330, and the element mounting member 310 can be regarded as one body by the insulating member, and the rigidity of the piezoelectric device can be further increased.

  The insulating member is provided so as to cover the leg portion 312. As a result, it is possible to reduce the superimposition of noise on the signal transmitted through the leg 312 due to foreign matters such as dust adhering to the leg 312, resulting in an unstable output signal. Is reduced. The insulating member is provided so as to cover the lid terminal 333. Thereby, the adhesion area by an insulating member can be enlarged, and it becomes possible to make adhesive strength higher.

  The piezoelectric device according to the third embodiment includes a base 313, a leg 312 extending from a predetermined surface of the base 313, and a fixing portion 311 extending from a predetermined other surface of the base 313. The element mounting member 310 is used, and the piezoelectric element 320 is bonded and fixed to the fixing portion 311 of the element mounting member 310 by the conductive adhesive 340, so that the piezoelectric element 320 is attached to the upper surface of the element mounting member 310. Has been implemented. Further, the piezoelectric device according to the third embodiment uses a lid 330 including a sealing base 331, a sealing frame 332, and a lid terminal 333. The sealing frame 332 of the lid 330 and the element mounting are used. The piezoelectric element 320 mounted on the element mounting member 310 is hermetically sealed by joining the base 311 of the member 310. Further, the piezoelectric device according to the third embodiment uses a spacer 360 in which a through hole 363 penetrating from the upper surface to the lower surface is formed, and a plurality of terminal pads 361 are formed on the upper surface of the spacer 360. The terminal pad 361 and an external terminal, specifically, the leg portion 312 and the lid terminal 333 are joined so as to be electrically connected by a conductive member 370. At this time, the external terminal is electrically connected to the mounting terminal 362 provided on the lower surface of the spacer 360 via the conductive member 370 and the terminal pad 361. In the piezoelectric device according to the third embodiment, an insulating member is provided in a space surrounded by the base 313 of the element mounting member 310, the lid 330, the conductive member 370, and the spacer 360. At this time, the insulating member is provided so as to cover not only the surface of the conductive member 370 facing the center side of the spacer 360 and the surface facing the outer peripheral edge of the spacer 360 but also the leg portion 312 and the lid terminal 333.

  In the third embodiment, with the configuration as described above, as in the case of the first embodiment and the second embodiment, the leg 312 corresponding to the external terminal and the terminal pad 361 of the spacer 360 are electrically connected. Defects can be suppressed. In the third embodiment, the mounting terminal 362 electrically connected to the lid terminal 333 via the terminal pad 361 and the conductive member 370 is connected to the ground serving as the reference potential of the mounting substrate (not shown). By doing so, the lid 330 can be set to the same potential as the ground. Therefore, in the third embodiment, the piezoelectric element 320 mounted on the element mounting member 310 can be artificially shielded by the lid 330. For this reason, in the third embodiment, the stray capacitance generated between the excitation electrode of the piezoelectric element 320 and the outside of the piezoelectric device can be reduced, and the signal of the piezoelectric device can be stabilized.

(Fourth embodiment)
Hereinafter, the piezoelectric device according to the fourth 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 4th embodiment, and description is abbreviate | omitted suitably. As shown in FIG. 8, the piezoelectric device according to the fourth embodiment is the third embodiment in that the element mounting member 410 includes a base part 413, a leg part 412, a fixing part 411 and a flat plate part 414. And different.

  The element mounting member 410 includes a flat base portion 413, leg portions 412 extending from a predetermined surface of the base portion 413, fixed 411 portions extending from a predetermined other surface of the base portion 413, a flat plate Part 414.

  The base 413 is for forming a space for hermetically sealing the piezoelectric element 420 mounted on the element mounting member 410 together with the lid 430. The base 413 is made of an alloy containing iron, cobalt, nickel, or copper, or stainless steel. For example, an alloy made of iron, nickel, or cobalt is used. The The base 413 has a flat plate shape, for example, a substantially rectangular parallelepiped shape. When one main surface is viewed in plan, the short side portion has a semicircular shape.

  The leg portion 412 is for applying a voltage to the piezoelectric element 420 mounted on the element mounting member 410, and extends from a predetermined surface of the base portion 413 while being insulated from the base portion 413. At this time, the leg portions 412 are, for example, a pair, and are arranged side by side so as to be a predetermined one surface of the base portion 413 and parallel to the long side. For the leg 412, any one of iron, cobalt, nickel, copper, silver, and gold, or an alloy containing any one of them is used. For example, an alloy made of iron, nickel, and cobalt is used.

  The leg portion 412 is electrically connected to the terminal pad 461 provided on the spacer 460 as shown in FIG. 9 by the conductive member 470. Further, the leg portion 412 is bent and configured by a first leg portion 412a and a second leg portion 412b. The first leg portion 412a is connected to a predetermined surface of the base portion 413 with one end insulated from the base portion 413, and the other end is connected to one end of the second leg portion 412b. At this time, the first leg 412a is in a state of being accommodated in a leg through hole (not shown) formed in a flat plate part 414 described later. One end of the second leg portion 412 b is connected to the first leg portion 412 a, and the other end is electrically connected to a terminal pad 461 provided on the upper surface of the spacer 460 by a conductive member 470. That is, the second leg portion 412 b corresponds to an external terminal of the element mounting member 410 and is positioned so as to be sandwiched between the lower surface of the flat plate portion 414 of the element mounting member 410 and the upper surface of the spacer 460. The leg portion 414 is bent once using the leg through hole formed in the flat plate portion 414, and the flat plate portion of the base portion 414 is provided with the flat plate portion 414 between the lower surface of the base portion 413 and the upper surface of the spacer 460. The case where the leg portion 412 extending from the surface facing the 414 side and the terminal pad 461 provided on the upper surface of the spacer 460 are electrically connected is described. In a state where the flat plate portion 414 is provided between the upper surface of the spacer 460, a leg portion 412 extending from the surface of the base portion 413 facing the flat plate portion 414 side, and a terminal pad 461 provided on the upper surface of the spacer 460, Can be bent a plurality of times along the surface of the flat plate portion 414.

  The fixing portion 411 is for mounting the piezoelectric element 420 on the element mounting member 410, and is insulated from the base portion 413 and is opposite to a predetermined other surface of the base portion 413, for example, a predetermined one surface of the base portion 413. It is the state extended and bent from the surface of the base 413 which faces the direction. At this time, the fixed portions 411 are, for example, a pair, and are arranged side by side so as to be parallel to the long side on another predetermined surface of the base portion 413. For the fixing part 411, any one of iron, cobalt, nickel, copper, silver, and gold, or an alloy containing any one of them is used. For example, an alloy made of iron, cobalt, or nickel is used. The leg portion 412 is integrally formed. The piezoelectric element 420 is bonded and fixed to the end of the fixing part 411 opposite to the base part 413 by the conductive adhesive 440, and the piezoelectric element 420 is held without being in contact with the base part 413. At this time, the fixing portion 411 and the extraction electrode of the piezoelectric element 420 are electrically connected by the conductive adhesive 440.

  Here, a predetermined one surface of the base portion 413 where the leg portion 412 is extended is defined as a lower surface of the base portion 413, and a surface of the base portion 413 facing the predetermined one surface of the base portion 411 is defined as an upper surface of the base portion 413. Therefore, the fixing portion 411 is extended from the upper surface of the base portion 413. The upper surface of the base portion 411 and the lower surface of the base portion 411 are defined as the main surface of the base portion 413. Further, according to the drawing, the lower surface of the base portion 411 is defined as the lower surface of the element mounting member 410, and the upper surface of the base 413 portion is defined as the upper surface of the element mounting member 410.

  Although not particularly illustrated, the element mounting member 410 has a fine hole (not shown) penetrating from the upper surface of the base 413 to the lower surface of the base 413. After the leg portion 412 and the fixing portion 411 are inserted into the hole, an insulating bonding member (not shown) is inserted. Thus, the leg 412 can be extended from the base 413 in a state where the base 413 and the leg 412 are insulated, and the base 413 and the fixing portion 411 are insulated from each other. 411 can be extended.

  The flat plate portion 414 is, for example, a substantially rectangular flat plate shape, and leg through holes (not shown) are formed from the upper surface to the lower surface. The flat plate portion 414 is made of, for example, an insulating material made of resin. A leg portion 412 is inserted into the leg through hole formed in the flat plate portion 414 from the upper surface side of the flat plate portion 414, and one leg portion 412 accommodated inside the leg through hole is inserted. The part corresponds to the first leg part 412a. Here, although the case where the through hole for a leg part is formed in the flat plate part 414 is described, the flat plate part 414 is placed between the lower surface of the base part 413 and the upper surface of the spacer 460. If the leg portion 412 extending from a predetermined surface and the terminal pad 461 provided on the upper surface of the spacer 460 on the lower surface of the flat plate portion 414 can be provided at opposing positions, for example, a flat plate The leg portion 412 may be bent a plurality of times along the surface of the flat plate portion 414 without forming the leg through hole in the portion 414.

  Here, the surface of the flat plate portion 414 facing the base portion 413 is defined as the upper surface of the flat plate portion 414, and the surface of the flat plate portion 414 facing away from the upper surface of the flat plate portion 414 is defined as the lower surface of the flat plate portion 414. Further, the upper surface of the flat plate portion 414 and the lower surface of the flat plate portion 414 are defined as main surfaces, and the surface of the flat plate portion 414 in contact with the upper surface of the flat plate portion 414 and the lower surface of the flat plate portion 414 is defined as a side surface of the flat plate portion 414.

  The lid body 430 includes a sealing base portion 431 and a sealing frame portion 432. The sealing base 431 is formed in a flat plate shape, for example, has a substantially rectangular parallelepiped shape, and has a semicircular shape on the short side in plan view. At this time, the main surface of the sealing base 431, specifically, the surface of the sealing base 431 facing the base 431 side has the same shape as the main surface of the base 413. The sealing frame portion 432 has a flat frame shape, is provided along the edge of the surface facing the base 413 side of the sealing base 431, and has a piezoelectric element on the surface facing the base 413 side of the lid 430. A space for accommodating 420 is formed. The sealing frame part 432 is joined to the base part 413 by cold pressure bonding, and the piezoelectric element 420 is hermetically sealed in a recess formed by the sealing frame part 432 and the sealing base part 431.

  The piezoelectric device according to the fourth embodiment includes a base portion 413, leg portions 412, a fixing portion 411, and a flat plate portion 414, has an element mounting member 410, and a fixing portion 411 extending from the lower surface of the base portion 413. In addition, the piezoelectric element 420 is mounted on the upper surface of the element mounting member 410 by bonding and fixing the piezoelectric element 420 with the conductive adhesive 440. The piezoelectric element 420 is hermetically sealed in a space formed by the base 413 and the lid 430 by joining the lid 430 and the base 413 of the element mounting member 410. In the piezoelectric device according to the fourth embodiment, the flat plate portion 414 is placed between the lower surface of the base portion 413 and the upper surface of the spacer 460, and the leg is inserted into the leg through hole formed in the flat plate portion 414. The portion 412 is inserted, and the leg portion 412 and the terminal pad 461 provided on the upper surface of the spacer 460 are provided at a position facing each other. In the piezoelectric device according to the fourth embodiment, the leg portion 412 and the terminal pad 461 are electrically joined by the conductive member 470, whereby the excitation electrode of the piezoelectric element 420 is formed on the lower surface of the spacer 460. The mounting terminals 462 are electrically connected. In addition, the piezoelectric device according to the fourth embodiment has an insulating member, and this insulating member is filled in the through hole 463 of the spacer 460, and the lower surface of the flat plate portion 414 of the element mounting member 410 and the spacer. Between the upper surface of 460, the surface of the conductive member 470 facing the center side of the spacer 460 and the surface of the conductive member 470 facing the outer edge side of the spacer 460 are provided.

  In the fourth embodiment, with the above-described configuration, it is possible to suppress poor conduction between the leg portion 412 corresponding to the external terminal and the terminal pad 461 of the spacer 460 as in the third embodiment. In the fourth embodiment, since the flat plate portion 414 is placed between the base portion 413 and the spacer 460, the conductive member 470 that electrically connects the terminal pad 461 and the leg portion 412 is provided at the base portion. It can be reduced that the conductive member 470 and the base 413 are electrically connected to each other by contacting the 413. Therefore, in 4th embodiment, it can reduce that the signal of a piezoelectric device becomes unstable because the electrically-conductive member 470 contacts the base part 413. FIG.

  In addition, although the case where the insulating member is provided is demonstrated in 3rd embodiment and 4th embodiment, the insulating member does not need to be provided.

110, 310, 410 ... element mounting member 111 ... mounting pad 112 ... external terminals 311, 411 ... fixed portions 312, 412 ... leg portions 313, 413 ... base portion 414 ... Flat plate portion 120, 320, 420 ... Piezoelectric element 121 ... Piezoelectric piece 122 ... Excitation electrode 123 ... Extraction electrode 130, 330, 430 ... Lid 131, 331, 431 ... Sealing Base part 132, 332, 432 ... Sealing frame part 132a ... Frame part 132b ... ridge part 333 ... Lid terminal 140, 340, 440 ... Conductive adhesive 150 ... Joining member 160 360, 460 ... spacers 161, 361, 461 ... terminal pads 162, 362, 462 ... mounting terminals 163, 363, 463 ... through holes 170, 370, 470 ... conductive Wood 180 ... insulating member

Claims (4)

An element mounting member provided with a plurality of external terminals on the lower surface;
A piezoelectric element mounted on the upper surface side of the element mounting member;
A lid bonded to the upper surface of the element mounting member and hermetically sealing the piezoelectric element;
A spacer in which a through-hole penetrating from the upper surface to the lower surface is formed;
A plurality of terminal pads provided on the upper surface of the spacer;
A mounting terminal provided on the lower surface of the spacer and electrically connected to the terminal pad;
A conductive member that electrically bonds the external terminal and the terminal pad;
With
In plan view of the upper surface of the spacer, the opening of the through hole does not overlap the terminal pad,
In plan view of the lower surface of the spacer, the opening of the through hole does not overlap the mounting terminal ,
The piezoelectric device, wherein an opening of the through hole formed in the spacer has a circular shape . The piezoelectric device according to claim 1,
  An insulating member provided between the upper surface of the spacer and the lower surface of the element mounting member, and bonding the spacer and the element mounting member;
  The insulating member is provided in the through hole.
A piezoelectric device characterized by that.   The piezoelectric device according to claim 1,
  It is provided between the upper surface of the spacer and the lower surface of the element mounting member, and includes the insulating member that bonds the spacer and the element mounting member.
  The insulating member covers the surface of the conductive member facing the center side of the element mounting member.
A piezoelectric device characterized by that. The piezoelectric device according to claim 1,
  It is provided between the upper surface of the spacer and the lower surface of the element mounting member, and includes the insulating member that bonds the spacer and the element mounting member.
  The insulating member covers the surface of the conductive member facing the outer peripheral side of the element mounting member.
A piezoelectric device characterized by that.

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