JP2015154410A - Method for manufacturing piezoelectric device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a piezoelectric device capable of being thinned.SOLUTION: On the sides of two short sides of a through-hole 21 of a substrate 2, two conductive layers 32A and 32B are separated from each other and formed so as to cover hole inner walls. A thermistor element 3 is temporarily fixed by a thermally peelable adhesive sheet 34 which blocks one opening side of the through-hole 21 and placed in the through-hole. Between the respective terminals 31A and 31B of the thermistor element 3 and conductive layers corresponding thereto, conductive adhesives DS are supplied and cured by heat, respectively, and the adhesive sheet 34 is thermally peeled off.

Description

  The present invention relates to a method for manufacturing a piezoelectric device used in an electronic apparatus or the like.

  A piezoelectric device is known in which a thermistor element is mounted in the same package in order to obtain temperature information of a piezoelectric vibration element provided in the package, for example, a crystal vibration element (see, for example, Patent Document 1). .

The element structure described in Patent Document 1 includes an element including a substrate portion, a first frame portion provided on one main surface of the substrate portion, and a second frame portion provided on the other main surface of the substrate portion. It has a mounting member.
The piezoelectric vibration element is mounted on one main surface of the substrate portion exposed in the first concave space formed by the substrate portion and the first frame portion in the element mounting member. On the other hand, the thermistor element is mounted on the other main surface of the substrate portion exposed in the second recessed space formed by the substrate portion and the second frame portion in the element mounting member.
The surface of the second frame portion far from the substrate portion is the bottom surface of the entire element mounting member, and a pair of external terminals of the piezoelectric vibration element and a pair of external terminals of the thermistor element are provided on the bottom surface. ing.

JP 2011-2111340 A

  Piezoelectric devices are mounted on thin electronic devices such as portable information terminals, and are becoming smaller and thinner.

  The element mounting member (package main member) described in Patent Document 1 protects the thermistor element and mounts external terminals in order to mount the thermistor element on the back surface (the other main surface) of the substrate portion. Since it is necessary to ensure, the second frame portion is an essential configuration. Accordingly, the presence of the second frame portion has a limit in reducing the thickness of the package itself, which hinders the piezoelectric device from being thinned.

  The objective of this invention is providing the manufacturing method of the piezoelectric device which can be reduced in thickness.

  A method for manufacturing a piezoelectric device according to one aspect of the present invention includes a step of disposing a two-terminal temperature-sensitive element in a through-hole penetrating a substrate on which a piezoelectric element is mounted in a thickness direction. A conductive layer forming step of separating and forming two conductive layers on the two inner wall sides facing in one direction of the through hole of the substrate, and thermal separation for closing one opening side of the through hole Temporarily fixing the temperature sensitive element to one main surface of the substrate with a possible adhesive sheet, and an element temporary fixing step of disposing the temperature sensitive element in the through-hole, and the temporarily fixed temperature sensitive element A conductive bonding step of supplying a conductive adhesive between each terminal and the corresponding conductive layer, and curing the conductive adhesive by heating, so that each terminal of the temperature-sensitive element becomes the corresponding conductive layer. Fix the element to fix and heat-release the adhesive sheet Has a degree, the.

  Preferably, after the element fixing step, a hole sealing step for sealing at least one opening side of the through-hole with a sealing material, and a piezoelectric element for mounting the piezoelectric element on any one of the main surfaces of the substrate And an element mounting process.

  Preferably, in the substrate used in the conductive layer forming step, two connection pads for connecting the piezoelectric element are formed in advance on a first main surface, and the two external terminals of the piezoelectric element and the sensitivity are formed on the second main surface. Two external terminals of the temperature element are formed in advance.

Preferably, in the conductive layer forming step, by forming two conductive layers corresponding to the terminals of the temperature sensitive element, each conductive layer corresponds to one of the two external terminals of the temperature sensitive element. Electrically connected to two external terminals.
More preferably, in the element temporary fixing step, after the adhesive sheet is attached to the through hole from the first main surface or the second main surface side of the substrate, the through hole is closed with the adhesive sheet. The temperature sensitive element is supplied into the through-hole from the side that is not, and the temperature sensitive element is temporarily fixed to the adhesive surface of the adhesive sheet.

Preferably, each of the two conductive layers corresponding to each terminal of the temperature sensitive element corresponds to one of the two external terminals of the temperature sensitive element by the conductive adhesive supplied in the conductive adhesion step. Electrically connected to two external terminals.
More preferably, in the element temporary fixing step, after the adhesive sheet is attached to the through-hole from the first main surface side of the substrate, the temperature sensitive element is mounted from the second main surface side of the substrate. It supplies in a through-hole and the said temperature sensitive element is temporarily fixed to the adhesive surface of an adhesive sheet.

Preferably, the substrate has a rectangular main surface, and the one direction in which the two inner walls forming the conductive layer face each other coincides with the long side direction of the rectangle of the substrate.
Alternatively, preferably, the substrate has a rectangular main surface, and the one direction in which two inner walls forming the conductive layer face each other coincides with the short side direction of the rectangle of the substrate.

  According to said structure, the manufacturing method of the piezoelectric device which can fix a thermosensitive element inside a board | substrate reliably even if it becomes thin is provided.

It is a perspective view at the time of the assembly of the piezoelectric device which concerns on 1st Embodiment. It is the back view (A) and top view (B) of a board | substrate, and the top view of a board | substrate sealing cap. It is the reverse view and sectional drawing of a board | substrate after forming a through-hole. It is the back view and sectional drawing of a board | substrate after forming a conductive layer. It is the reverse view and sectional drawing of a board | substrate after temporarily fixing a thermistor element. It is the back view and sectional drawing of the board | substrate after supplying a conductive adhesive. It is the top view and sectional drawing of a board | substrate after forming the sealing material. It is the upper side figure of the board | substrate after joining a crystal element, and the schematic sectional drawing of the board | substrate after covering the board | substrate sealing cap. It is sectional drawing in the middle of manufacture of the piezoelectric device which concerns on 2nd Embodiment. It is sectional drawing in the middle of manufacture of the piezoelectric device concerning 3rd Embodiment. It is a reverse view in the middle of manufacture of the piezoelectric device concerning 4th Embodiment. 6 is a schematic cross-sectional view of a piezoelectric device according to Modifications 1 and 2. FIG.

Various embodiments and modifications of the present invention will be described with reference to the drawings, taking as an example the case where the temperature sensitive element is a thermistor element. The temperature sensitive element may be a two-terminal element such as a transistor or a diode that can change a physical quantity such as a resistance value depending on the environmental temperature, other than the thermistor element.
In the second and subsequent embodiments, the same or similar configurations as those already described may be described with the same reference numerals.

Hereinafter, description will be given in the following order.
1. 1st Embodiment: It is the form which temporarily fixes a thermistor element to a 1st main surface, and plugs a through-hole with a sealing material from the 1st main surface side after the electrical connection by a conductive adhesive and this fixing.
2. 2nd Embodiment: It is a form which expands the application | coating range of a conductive adhesive to the edge part of an electrode (external terminal).
3. Third embodiment: A thermistor element is temporarily fixed to the second main surface.
4). Fourth Embodiment: A mode in which the through holes and the substrate are arranged orthogonally.
5. Modifications 1 and 2: Modifications (Modification 1) in which the through hole is closed with the sealing material from both sides of the first and second main surfaces, and Modifications with the sealing material that closes the through hole from the second main surface side (Modification 2).

<1. First Embodiment>
FIG. 1 is an assembly diagram when a crystal element is mounted on a substrate on which a thermistor element is already fixed in the piezoelectric device according to the first embodiment of the present invention. 2A and 2B are a back view and a top view of the substrate of the piezoelectric device, and FIG. 2C is a top view of the substrate sealing cap of the piezoelectric device.
First, the structure of the piezoelectric device will be mainly described with reference to FIGS. 1 and 2A to 2C.

  A piezoelectric device 1 shown in FIG. 1 has, as main components, a substrate 2, a thermistor element 3 as an example of a temperature sensitive element mounted in a through hole 21 of the substrate 2, and one main surface of the substrate 2. It has a crystal element 4 as an example of a mounted piezoelectric element, and a substrate sealing cap (not shown, see FIG. 2C) that covers the substrate 2 from the side where the crystal element 4 is mounted.

  The crystal element 4 includes a rectangular plate-shaped crystal element plate 41 and a pair of electrodes formed on both surfaces of the crystal element plate 41. As shown in FIG. 1, each electrode has a rectangular excitation electrode 42 widely disposed on the main surface of the crystal base plate 41, and covers both corners of the crystal base plate 41 on both sides of the crystal base plate 41. The connection electrode 43A is disposed, and the extraction electrode 44 that connects the connection electrode 43A to the excitation electrode 42 is provided. These electrodes (42, 43A, 44) are formed from an integral conductive layer (for example, a metal film). In FIG. 1, a connection electrode 43 </ b> B of another electrode is illustrated at the other corner of the short side of the crystal base plate 41. In this other electrode, the connection electrode 43B and the excitation electrode and the extraction electrode arranged on the other surface of the crystal base plate 41 (not shown) are formed from an integral conductive layer. In the crystal element 4, when an alternating voltage from the outside is applied from the connection electrode 43 to the crystal base plate 41 through the extraction electrode 44 and the excitation electrode 42, the crystal base plate 41 is excited in a predetermined vibration mode and frequency. It is like that.

  The substrate 2 can be formed by laminating one layer or a plurality of insulating layers made of a ceramic material such as alumina ceramics or glass-ceramics and firing the laminated layers.

  The board | substrate 2 has the through-hole 21 which penetrates 1st main surface S1 and 2nd main surface S2 in thickness direction. Here, the first main surface S1 is a main surface on the side where the crystal element 4 is mounted, and the second main surface S2 is arranged with four external terminals (25B and the like) of the crystal element 4 and the thermistor element 3, It is the other main surface which comprises the bottom face of the whole piezoelectric device.

  The substrate 2 has an approximately rectangular plate-like outer shape, and the through hole 21 is also formed in a rectangle whose long side direction is aligned with the substrate 2. It is not essential that the through hole 21 is rectangular. However, since a two-terminal electronic component such as a thermistor element generally has a rectangular box-shaped outer shape, the through-hole 21 is also formed in a rectangular shape as a shape suitable for the element outer shape. Further, the through hole 21 is formed at a position where it does not interfere with the connection pads and wirings of the first main surface S1 and the external terminals of the second main surface S2, for example, near the center of the substrate 2. The position of the through hole 21 can be appropriately changed according to the arrangement mode of the electrodes and the external terminals.

  Connection pads 22 </ b> A and 22 </ b> B are arranged on the first main surface S <b> 1 of the substrate unit 2. The connection pad 22A is connected to the connection electrode 43A of the crystal element 4, and the connection pad 22B is connected to the connection electrode 43B of the crystal element 4. Further, the connection pad 22B is connected to a via land 23B near a nearby corner, and the connection pad 22A is connected to a via land 23A that is away from the via land 23B on the diagonal side via a wiring 24. These connection pads and via lands (and wirings) are formed from an integral conductive layer (for example, a metal film).

As shown in FIG. 2A, four electrodes (external terminals) made of a conductive layer such as a metal film are arranged on the four corner sides of the second main surface S2 of the substrate 2.
Specifically, the first electrodes 25A and 25B arranged diagonally so as to avoid the through hole 21 near the center, and the two second electrodes 26A that are in contact with the through hole 21 from the other diagonal side. 26B is arranged. The first electrodes 25A and 25B are for crystal elements, and the second electrodes 26A and 26B are for thermistor elements.
The first electrode 25A is connected to the via land 23A through a via (not shown) embedded through the substrate 2 in the thickness direction. Similarly, the first electrode 25B is connected to the via land 23B through another via (not shown).

  Details of the connection between the second electrodes 26A and 26B and the thermistor element 3 will be described later.

  As shown in FIG. 1, the thermistor element 3 is disposed substantially at the center of the through hole 21, with the long sides and the through holes 21 being aligned. The thermistor element 3 has element terminals 31A and 31B in advance covering the end face, part of both side faces, and part of the upper and lower faces on each side of both short sides. The thermistor element 3 desirably has a thickness that is slightly thinner than the substrate 2. Alternatively, the thickness of the substrate 2 is determined according to the thickness of the thermistor element 3 to be used.

For example, when the long side length of the substrate 2 is 1.2 to 2.0 mm and the short side length is 1.0 to 1.6 mm, the through-hole 21 has a long side length of 0.5. The length of the short side can be about 0.3 to 0.5 mm. In this case, the thermistor element 3 having a long side length of 0.4 to 0.6 mm and a short side length of 0.2 to 0.3 mm can be suitably used. Further, when the thickness of the substrate 2 (depth of the through hole 21) is 0.15 to 0.5 mm, the thermistor element 3 having a thickness of about 0.1 to 0.3 mm is preferably used. it can.
Although the thickness of the substrate 2 and the thermistor element 3 can be approximately the same, in order to suppress the influence of heat transfer from the substrate 2, a difference in thickness of at least about 0.05 mm between the two. Therefore, it is desirable that voids are formed.

  On each short side of the through hole 21, two conductive layers 32 </ b> A and 32 </ b> B are formed separately from each other from the inner wall of the hole to the vicinity of the short side of the bottom surface (second main surface S <b> 2) of the substrate 2. The conductive layer 32A and the element terminal 31A, and the conductive layer 32B and the element terminal 31B are electrically connected to each other through the conductive adhesive DS. Since the conductive adhesive DS is thermally cured, it also serves as a mechanical fixing member.

Regarding the bonding of the crystal element 4 and the substrate 2, the conductive adhesive DS can be used also when the connection electrode 43A and the connection pad 22A and the connection electrode 43B and the connection pad 22B are bonded. However, in this embodiment, solder is used.
As the conductive adhesive DS, for example, a conductive powder is contained as a conductive filler in a binder such as a silicone resin. As the conductive powder, aluminum (Al), molybdenum (Mo), tungsten (W ), Platinum (Pt), palladium (Pd), silver (Ag), titanium (Ti), nickel (Ni), nickel iron (NiFe), or any combination thereof is suitably used. be able to.

Although not shown in FIG. 1, it is desirable to provide a sealing material that covers the through hole 21 of the substrate 2 from, for example, the first main surface S1 side. As a result, impurities and the like from the mounting portion of the thermistor element adhere to the crystal element 4 at a short distance, and the thickness-shear vibration of the crystal element 4 is inhibited, thereby preventing the oscillation frequency from changing. It is possible. Note that the sealing material can be provided to cover the thermistor element from the outside even when it is not necessary to block impurities from the mounting portion of the thermistor element. Therefore, the structure which the sealing material covers the through-hole 21 from the 2nd main surface S2 side may be sufficient, and a sealing material may be provided in both the 1st main surface S1 and the 2nd main surface S2 (modification example). 1 and 2).
As the sealing material, for example, a thin glass material formed by printing or the like can be suitably used.

The substrate sealing cap 5 shown in FIG. 2C is, for example, a ceramic or metal sealing member, and has a box plate shape that is open on one side to form a housing space for the crystal element 4. The substrate sealing cap 5 has a sealing joint edge 51 having a shape in which the entire peripheral edge portion of the open end is bent outward.
In FIG. 1, after bonding the crystal element 4 to the substrate 2, the substrate sealing cap 5 is attached by airtightly bonding the sealing bonding edge portion 51 to the peripheral edge portion of the first main surface S <b> 1 of the substrate 2.

  Next, for the piezoelectric device 1 having the above-described configuration, the manufacturing method of the present embodiment will be described with reference to FIG.

A substrate 2 made of a ceramic material, a crystal element 4 and a substrate sealing cap 5 shown in FIGS. 1 and 2 are formed. However, the through hole 21 of the substrate 2 is not perforated at this stage.
In the formation of the crystal element 4, first, a quartz base plate 41 is obtained by cutting from an artificial crystalline lens at a predetermined cut angle and performing external processing. Thereafter, for example, both main surfaces of the quartz base plate 41 are processed by depositing a metal film by sputtering or the like, or by printing or the like, the excitation electrode 42, the connection electrode 43A (or 43B), and the extraction electrode 44 are provided. A pair of electrodes is formed.
For the substrate 2 made of a ceramic material, via openings are previously opened with a drill or the like before firing, and then two vias are formed by embedding a metal material in the via openings. Further, using the same electrode forming technique as described above, the connection pads 22A and 22B, the via lands 23A and 23B and the wiring 24 are formed on the first main surface S1, and the first electrodes 25A and 25B and the second electrode are formed on the second main surface S2. 26A and 26B are formed.

3A and 3B are a back view and a cross-sectional view after the step of opening the through hole 21 in the substrate 2. FIG. 3B is a cross-sectional view along the line AA shown in FIG. The relationship between the rear view and the cross-sectional view is the same in FIG.
The formation of the through-hole 21 is preferably a method of extracting with a mold before firing the ceramic. In addition, after ceramic firing, hole formation by laser processing is suitable, and in addition, a hole formation method by sandblasting can also be adopted.

  As shown in FIGS. 4A and 4B, the conductive layer forming step covers the inner wall of the two short sides of the formed through-hole 21 and a part of the back surface (second main side). Conductive layers 32A and 32B extending on the surface S2) are formed. The conductive layers 32A and 32B can be formed by printing and baking a conductive paste made of, for example, silver palladium (AgPd), gold (Au), or the like. In the present embodiment, the conductive layer 32 </ b> A and the second electrode 26 </ b> A are partially overlapped to establish mutual conduction. Similarly, the conductive layer 32 </ b> B and the second electrode 26 </ b> B are partially overlapped to establish electrical continuity. Further, by preventing the conductor layers 32A and 32B from extending on the upper surface of the substrate 2, it is possible to prevent the excitation electrode 42 of the crystal element and the conductor layers 32A and 32B from coming into contact with each other and causing a short circuit. .

In the element temporary fixing step, as shown in FIGS. 5A and 5B, for example, heat peeling is possible so as to close the opening of the through hole 21 from the upper surface (first main surface S1) side of the substrate 2. A sticky adhesive sheet 34 is attached to the substrate 2. As the heat-peelable pressure-sensitive adhesive sheet 34, for example, “Riva Alpha” (trade name) manufactured by Nitto Denko can be used.
Further, the thermistor element 3 is supplied from the back surface (second main surface S2) side of the substrate 2, aligned with the through hole 21, and disposed at the center thereof. Thereby, the thermistor element 3 is temporarily fixed to the first main surface S <b> 1 of the substrate 2 through the adhesive sheet 34. By doing so, the thermistor element 3 can be reliably connected to the conductive layers 32A and 32B without detaching in the element fixing step described later. It is also possible to employ a method in which the adhesive sheet 34 is attached to the substrate 2 with the thermistor element 3 attached in advance to the adhesive sheet 34.

In the conductive bonding step, as shown in FIGS. 6A and 6B, a conductive adhesive DS such as AgPd paste or Au paste is printed or printed from the back surface (second main surface S2) side of the substrate 2. Then, supply to the element terminal side two places by dispensing. Thereby, the element terminal 31A and the conductive layer 32A of the thermistor element 3 are connected, and the element terminal 31B and the conductive layer 32B are connected.
In the element fixing step, the element terminal 31A and the conductive layer 32A of the thermistor element 3 are fixed and the element terminal 31B and the conductive layer 32B are fixed by curing the conductive adhesive DS by heating at 150 to 300 ° C. Is done. At this time, the adhesive sheet 34 is peeled off from the first main surface S1 of the substrate 2 by heat.

  In the hole sealing step, as shown in FIGS. 7A and 7B, the sealing material 35, for example, so as to close the through-hole 21 from the first main surface S1 side after the pressure-sensitive adhesive sheet 34 has been peeled off. Glass material is coated by printing. The sealing material 35 is made of a material having a melting point of 400 ° C. or higher, more preferably 500 to 800 ° C., and whose shape does not change by heating in the subsequent steps. Specifically, considering the heating temperature when the crystal element 4 is bonded to the substrate 2 with the conductive adhesive DS, it is desirable to use crystallized glass having a melting point of 500 to 800 ° C. as the sealing material 35. In addition, when using the method in which the crystal element 4 can be joined at a lower temperature other than the conductive adhesive DS, the sealing material 35 having a lower melting point can be used. Moreover, the thickness of the sealing material 35 in the vertical direction is 0.01 to 0.03 mm.

Moreover, in the example shown in FIG. 7, since the sealing material 35 is formed only on the first main surface S1, it is necessary to ensure the airtightness of the crystal element 4 at the sealing portion. Since the characteristics of the crystal element 4 are related to the hermeticity of the package, the hermeticity needs to be 10 ⁻⁹ m · Pa / S or less. In the case of one-side sealing of the through hole with the sealing material 35, the sealing method and the sealing material are selected so that airtightness equal to or lower than the above value is obtained.

In the piezoelectric element mounting step, as shown in FIG. 8A, the crystal element 4 is bonded to the substrate 2 with a conductive adhesive DS so as to have a cantilever structure. Further, as shown in FIG. 8B, the substrate sealing cap 5 is covered with a cap sealing material 52 interposed between the sealing bonding edge portion 51 and the substrate, and sealed by heating or the like. . The cap sealing material 52 is made of, for example, low melting glass or lead oxide glass containing vanadium that is a glass that melts at 300 ° C to 400 ° C. Glass is pasty with a binder and a solvent added, and is melted and then solidified to adhere to other members.
In FIG. 8B, the illustration of the configuration of the back side electrode and the like is omitted.

In the above embodiment, since the thermistor element 3 is temporarily fixed in the through hole 21 by the adhesive sheet 34, the conductive adhesive DS is supplied and thermally cured, so that the element can be easily positioned. Since the pressure-sensitive adhesive sheet 34 is peeled off when the conductive adhesive DS is thermally cured, holes can be sealed from the side on which the pressure-sensitive adhesive sheet 34 is pasted.
In the piezoelectric device 1, the thermistor element 3 is embedded in the substrate 2, and the package can be made thin. In addition, since the airtightness is ensured by the sealing material 35 that closes the through hole 21, the characteristics of the crystal element 4 are also maintained.

<2. Second Embodiment>
FIG. 9 shows a cross-sectional view of the piezoelectric device according to the second embodiment in the middle of manufacture. This cross-sectional view is after supply of the conductive adhesive DS and corresponds to FIG. 6B according to the first embodiment.

  In the first embodiment shown in FIG. 3, the second electrodes 26 </ b> A and 26 </ b> B and the through hole 21 are connected in a diagonal direction, and the conductive layer formed for the through hole 21 in the subsequent process is brought into contact with the electrode. .

On the other hand, the second embodiment is a form in which the conductive adhesive DS contributes to the connection with the electrode instead of or together with the conductive layer.
Specifically, as shown in FIG. 9, when the second electrodes 26 </ b> A and 26 </ b> B are formed away from the through hole 21, the range in which the conductive adhesive DS is applied by printing is set to the end portions of the second electrodes 26 </ b> A and 26 </ b> B. Expand to. As a result, the conductive adhesive DS also functions as a means for electrode connection. By doing so, since the conductive layers 32A and 32B and the second electrodes 26A and 26B are electrically connected by the conductive adhesive DS, it is possible to reliably conduct without fear of disconnection. In FIG. 9, the conductive layers 32A and 32B do not overlap the second electrodes 26A and 26B. However, like the first embodiment, the conductive layers 32A and 32B are overlapped with each other, and the conductive adhesive DS is further added to the second electrode 26A. , 26B.

  Except for the description with reference to FIG. 9, the description is omitted here because it is common to the first embodiment.

<3. Third Embodiment>
FIG. 10 shows a cross-sectional view of the piezoelectric device according to the third embodiment in the course of manufacturing. This cross-sectional view is after supply of the conductive adhesive DS and corresponds to FIG. 6B according to the first embodiment.

  The adhesive sheet 34 is pasted from the side of the second main surface S2 of the substrate 2 on which the second electrodes 26A and 26B are formed so as to close the through hole 21. Then, the thermistor element 3 and the conductive adhesive DS are supplied from the first main surface S1 side. Even if it does in this way, it has an effect similar to 1st Embodiment. Other steps are the same as those in the first embodiment, and a description thereof is omitted here. Note that it is difficult in this embodiment to expand the application range of the conductive adhesive to the second electrode as in the second embodiment.

<4. Fourth Embodiment>
FIG. 11 shows a back view of the piezoelectric device according to the fourth embodiment in the course of manufacturing. This back view is the one after the adhesive sheet has been thermally peeled off.

In the first to third embodiments, the direction in which the two inner walls forming the conductive layers 32A and 32B are opposed to each other is provided so as to coincide with the long side direction of the rectangle of the substrate 2. In the embodiment, one direction in which the two inner walls forming the conductive layers 32 </ b> A and 32 </ b> B are opposed to each other coincides with the rectangular short side direction of the substrate 2. That is, in the first to third embodiments, the long side direction of the through hole 21 and the thermistor element 3 and the long side direction of the substrate 2 are matched, but in the present embodiment, they are orthogonal to each other as illustrated. It is arranged.
Depending on the size and aspect ratio of the main surface of the substrate and the through-holes, if the long side directions of the substrate 2 and the through-holes 21 are different by 90 degrees in this way, the arrangement efficiency may be good. Applicable to configuration.

In FIG. 11, one side of the conductive layers 32A, 32B is extended to the second electrodes 26A, 26B side to realize direct connection with each electrode.
However, the connection pattern is not limited to that shown in the figure, and a conductive adhesive can be used as the connection means as in the second embodiment. Further, as in the first and third embodiments, it is also arbitrary from which main surface side the adhesive sheet is pasted.
Since the configuration other than the orthogonal arrangement is the same as that of the first embodiment, the description thereof is omitted here.

<5. Modifications 1 and 2>
FIG. 12A shows a schematic cross-sectional view of the piezoelectric device according to the first modification, and FIG. 12B shows a schematic cross-sectional view of the piezoelectric device according to the second modification.
In FIG. 12A, the sealing material 35 is pasted from both sides of the first main surface S1 and the second main surface S2. In FIG. 12B, the sealing material 35 is pasted from the second main surface S2. Thus, by sealing both surfaces of the through hole 21 of the substrate 2 with the sealing material 35, the hermetic sealing performance of the substrate 2 can be further improved.
These modified examples are applicable to any of the first to fourth embodiments.

  The present invention is not limited to the above embodiments and modifications, and may be implemented in various ways.

  DESCRIPTION OF SYMBOLS 1 ... Piezoelectric device, 2 ... Board | substrate, 3 ... Thermistor element, 4 ... Crystal element, 5 ... Board | substrate sealing cap, 21 ... Through-hole, 22A, 22B ... Connection pad, 23A, 23B ... Via land, 24 ... Wiring, 25A, 25B ... 1st electrode, 26A, 26B ... 2nd electrode, 31A, 31B ... Element terminal, 32A, 32B ... Conductive layer, 34 ... Adhesive sheet, 51 ... Sealing joint edge, S1 ... 1st main surface, S2 ... Second main surface, DS: conductive adhesive

Claims (9)

A method for manufacturing a piezoelectric device, comprising a step of disposing a two-terminal temperature sensitive element in a through hole penetrating a substrate on which a piezoelectric element is mounted in a thickness direction,
A conductive layer forming step of separately forming two conductive layers on the two inner wall sides opposite to one direction of the through hole of the substrate;
Temporarily fixing the temperature-sensitive element to one main surface of the substrate with a heat-peelable adhesive sheet that closes one opening side of the through-hole, and temporarily fixing the element in the through-hole Process,
A conductive bonding step of supplying a conductive adhesive between each terminal of the temporarily fixed temperature-sensitive element and a corresponding conductive layer;
An element fixing step of curing the conductive adhesive by heating, fixing each terminal of the temperature sensitive element to the corresponding conductive layer, and thermally peeling the adhesive sheet;
A method of manufacturing a piezoelectric device having After the element fixing step,
A hole sealing step of sealing at least one opening side of the through hole with a sealing material;
A piezoelectric element mounting step for mounting the piezoelectric element on any main surface of the substrate;
The method for manufacturing a piezoelectric device according to claim 1, comprising: In the substrate used in the conductive layer forming step, two connection pads for connecting the piezoelectric element are formed in advance on a first main surface, and two external terminals of the piezoelectric element and the temperature sensitive element on the second main surface. Two external terminals are formed in advance.
A method for manufacturing a piezoelectric device according to claim 1 or 2. In the conductive layer forming step, by forming two conductive layers corresponding to the terminals of the temperature sensitive element, each conductive layer corresponds to one external terminal corresponding to the two external terminals of the temperature sensitive element. Electrically connected to the
The method for manufacturing a piezoelectric device according to claim 3. In the element temporary fixing step, after the adhesive sheet is attached to the through hole from the first main surface or the second main surface side of the substrate, the through hole is not covered with the adhesive sheet. Supplying the temperature sensitive element into the through-hole, and temporarily fixing the temperature sensitive element to the adhesive surface of the adhesive sheet;
The method for manufacturing a piezoelectric device according to claim 4. Due to the conductive adhesive supplied in the conductive bonding step, each of the two conductive layers corresponding to the terminals of the temperature sensitive element is one corresponding external terminal of the two external terminals of the temperature sensitive element. Electrically connected to the
The method for manufacturing a piezoelectric device according to claim 3. In the element temporary fixing step, after the adhesive sheet is attached to the through hole from the first main surface side of the substrate, the temperature sensitive element is inserted into the through hole from the second main surface side of the substrate. Supply and temporarily fix the temperature sensitive element to the adhesive surface of the adhesive sheet,
The method for manufacturing a piezoelectric device according to claim 6. The substrate has a rectangular main surface,
The one direction in which the two inner walls forming the conductive layer face each other coincides with the long side direction of the rectangle of the substrate.
The manufacturing method of the piezoelectric device as described in any one of Claim 1 to 7. The substrate has a rectangular main surface,
The one direction in which the two inner walls forming the conductive layer face each other coincides with the short side direction of the rectangle of the substrate.
The manufacturing method of the piezoelectric device as described in any one of Claim 1 to 7.

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