JP2015156597A - Piezoelectric device and mounting structure thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piezoelectric device with a mounting structure in which stress is hard to be concentrated on individual joints due to an environmental temperature change and high reliability is achieved by enhancing joint strength.

SOLUTION: A mounting structure of a piezoelectric device includes: a package body 2 in which a piezoelectric element is housed in the inside and which has a plurality of external terminals on the bottom surface; and a package connection body 6 which is interposed between the package body 2 and a mounting substrate 100 and electrically connects the plurality of external terminals to a plurality of terminal joining pad parts 100A, 100B provided on the mounting substrate 100. A base material of the package connection body 6 is formed from a material having the thermal expansion coefficient in which the thermal expansion coefficient difference between the base material of the mounting substrate 100 is smaller than that between the base material of the package body 2.

COPYRIGHT: (C)2015,JPO&INPIT

Description

  The present invention relates to a piezoelectric device used in an electronic apparatus or the like and a mounting structure thereof.

  A surface-mount type piezoelectric device accommodates a piezoelectric element, for example, a crystal element in a package, and joins the package to a mounting substrate by soldering or the like.

The mounting substrate is formed by providing a metal wiring on a base substrate material such as glass epoxy resin. The wiring includes a plurality of terminal bonding pad portions for bonding a plurality of external terminals of the piezoelectric device with solder.
In the case of a piezoelectric vibrator, the number of external terminals is generally two or four, and a plurality of terminal bonding pads are formed in advance on the mounting substrate in accordance with the arrangement and the number.

  Patent Document 1 below discloses a technique for mounting a small package device on a mounting substrate having a terminal bonding pad portion of a large (old) device specification in a crystal oscillator. Specifically, in the device mounting structure disclosed in Patent Document 1 below, a surface-mount printed wiring in which terminal pitch pads with a narrow pitch are formed on the top surface and terminal pitch pads with a relatively large pitch of the old specifications are formed on the bottom surface The substrate is interposed between the small package and the mounting substrate. This makes it possible to provide a crystal oscillator that can be mounted on a conventional mounting board even if the package size is changed.

JP 2011-2111340 A

  Piezoelectric devices are required to have high reliability, particularly for in-vehicle applications, in addition to miniaturization (and thinning) by reducing the package size described in Patent Document 1 and the like.

  For example, in an in-vehicle application, a piezoelectric device having a structure capable of withstanding such an environment is required assuming an environment where there is a large temperature change and constantly receives vibration. A highly reliable device that can withstand such a large environmental change cannot be obtained by simply adopting a mounting structure corresponding to different terminal pitches as in the crystal oscillator described in Patent Document 1.

  An object of the present invention is to provide a piezoelectric device mounting structure in which stress is less likely to concentrate on individual joints due to environmental temperature changes and a piezoelectric device with high joint strength for high reliability.

  A mounting structure of a piezoelectric device according to an aspect of the present invention includes a package body that houses a piezoelectric element and has a plurality of external terminals on a bottom surface, and is interposed between the package body and the mounting substrate. A package connection body for electrically connecting external terminals to a plurality of terminal bonding pad portions provided on the mounting board, and the base material of the package connection body is a heat with the base material of the mounting board. The expansion coefficient difference is formed from a material having a smaller thermal expansion coefficient than that of the package body.

Here, even in the case where “the package connection body and the package body have a difference in thermal expansion coefficient between the base materials, and the package connection body and the mounting substrate have no difference in thermal expansion coefficient between the base materials” "The base material of the package connector is formed of a material having a thermal expansion coefficient difference smaller than that of the base material of the package main body and the thermal expansion coefficient difference from the base material of the package body." This is an example.
Therefore, preferably, the base material of the package connector and the base material of the mounting substrate may be formed of the same resin material.

Preferably, the package connection body includes a base material, a plurality of first electrodes arranged on a first main surface of the base material, connected to the plurality of external terminals of the package body, and a first of the base material. 2 and a plurality of second electrodes connected to a plurality of conductive pad portions of the mounting substrate, and each of the plurality of first electrodes is provided on a side surface of the substrate. It is electrically connected to any of the plurality of second electrodes by a conductive electrode connection portion.
More preferably, the side surface of the base material has a side surface recess that is recessed from the side surface toward the center of the base material, and the side surface of the base material in the side surface recess is integrated with the first electrode and the second electrode. The electrode connection portion made of a conductive material is provided.

Suitably, the base material of the said package connection body has at least 1 through-hole which penetrates a 1st main surface and a 2nd main surface in thickness direction.
More preferably, the package connection body includes a base material, a plurality of first electrodes disposed on the first main surface of the base material and connected to the plurality of external terminals of the package body, and the base material A plurality of second electrodes disposed on the second main surface and connected to the plurality of conductive pad portions of the mounting substrate, wherein each of the plurality of first electrodes includes a side surface of the base material and the through hole The plurality of conductive electrode connection portions provided on the inner wall surface of the hole are electrically connected to any one of the plurality of second electrodes.
More preferably, the side surface of the substrate has a side surface recess recessed from the side surface toward the center of the substrate, and the through hole has an inner wall surface on one side sandwiching the first and second electrodes. The electrode connection portion made of a conductive material integrated with the first electrode and the second electrode is provided on each of the side surface and the inner wall surface of the base material in the side surface recess, corresponding to the recess. Yes.

  Preferably, the plurality of external terminals of the package body and the plurality of first electrodes are connected by a conductive adhesive, and the plurality of conductive pad portions of the mounting substrate and the plurality of second electrodes are formed of a conductive bonding material. Each of the electrode connecting portions is provided with a conductive bonding material with an inclination so that the thickness in the vertical direction decreases toward the upper surface of the mounting substrate.

  A piezoelectric device according to one embodiment of the present invention has a ceramic package body that houses a piezoelectric element and has a plurality of external terminals on a bottom surface, and main portions of side surfaces that are aligned with the package body. A resin base material having a size, a plurality of first electrodes arranged on the first main surface of the base material and connected to the plurality of external terminals, and a second main surface of the base material, A package connector including a plurality of second electrodes connected to any one of the plurality of first electrodes on the side surface side of the substrate, and each of the plurality of first electrodes is disposed on a side surface of the substrate. The conductive electrode connection portion provided is electrically connected to any of the plurality of second electrodes.

Suitably, the base material of the said package connection body has at least one through-hole which penetrates the said 1st main surface and the said 2nd main surface in thickness direction.
More preferably, each of the plurality of first electrodes is electrically connected to any one of the plurality of second electrodes by a plurality of conductive electrode connection portions provided on a side surface of the base material and an inner wall surface of the through hole. Connected.
More preferably, the side surface of the base material has a side surface recess recessed from the side surface toward the base material center side,
In the through hole, an inner wall surface of one side is located corresponding to the side surface recess with the first and second electrodes interposed therebetween,
The electrode connection portion made of a conductive material integral with the first electrode and the second electrode is provided on each of the side surface and the inner wall surface of the base material in the side recess.

  According to the above configuration, a piezoelectric device mounting structure in which stress is less likely to be concentrated in individual joints due to environmental temperature changes and a piezoelectric device having high joint strength are provided for high reliability.

1 is a schematic cross-sectional view of a piezoelectric device mounting structure according to a first embodiment. The top view (A) and back view (B) of the piezoelectric device which illustrate the outline internal structure which removed the package cover part. The top view (A) and side view (B) of a short side of a package connection body. The schematic sectional drawing of the mounting structure before mounting (A) and after mounting (B) when mounting the package connection body which bonded the package main body on the mounting substrate. The top view (A) and side view (B) of a long side of the package connection body which concern on 2nd Embodiment. The top view (A) and side view (B) of a short side of the package connection body which concern on 3rd Embodiment. The schematic sectional drawing of the mounting structure after mounting the package connection body which bonded the package main body on the mounting board. The top view (A) and long side side view (B) of the package connection body which concern on 4th Embodiment.

Various embodiments and modifications of the present invention will be described with reference to the drawings, taking as an example the case where the piezoelectric device is a crystal resonator.
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 of the mounting structure which interposed the package connection body (without a through-hole) of the electrode arrangement corresponding to the piezoelectric device of 2 terminals.
2. Second Embodiment: This is a form of a mounting structure in which a package connection body (without a through hole) having an electrode arrangement corresponding to a four-terminal piezoelectric device is interposed.
3. Third Embodiment: A mounting structure in which a package connection body (with a through hole) having an electrode arrangement corresponding to a two-terminal piezoelectric device is interposed.
4). Fourth Embodiment: A mounting structure in which a package connection body (with a through hole) having an electrode arrangement corresponding to a four-terminal piezoelectric device is interposed.
5. Modification 6 Another invention

<1. First Embodiment>
FIG. 1 is a schematic cross-sectional view of a piezoelectric device mounting structure according to a first embodiment of the present invention. 2A and 2B are a top view and a back view of the piezoelectric device. Note that the top view of FIG. 2A illustrates an internal schematic configuration with the uppermost package lid 5 removed.
First, the structure of a piezoelectric device and a simple manufacturing method will be described with reference to FIGS. 2 (A) and 2 (B).

[Piezoelectric device structure and manufacturing method]
The piezoelectric device 1 shown in FIG. 2 has a package body 2 and a crystal element 4 mounted inside a recess 2A of the package body 2 as main components. In the case of a four-terminal device as in the second and fourth embodiments described later, a thermistor element or the like as an example of a temperature sensitive element that detects the environmental temperature of the crystal element 4 may be provided in the package body 2. However, in this embodiment, since it is a two-terminal device, it does not have a temperature sensitive element.

  The package body 2 can be formed mainly by laminating one or more insulating layers made of a ceramic material such as alumina ceramics and glass-ceramics, and firing them.

  The package body 2 has a recess 2 </ b> A for forming an internal space when the upper side is sealed with the package lid 5. As a preferred configuration for forming the recess 2A, the package body 2 has a substrate portion and a frame portion, and the frame portion is attached to the upper surface of the substrate portion when the frame portion is attached to the upper surface of the substrate portion. It is possible to adopt a configuration in which a recess surrounded by is formed. In this configuration, the substrate portion and the frame portion may be formed from the above-described ceramic material, or the substrate portion is formed from the above-described ceramic material, and the frame portion is made of a metal such as an Fe—Ni—Co alloy. You may form so that it may form a ring.

  The package lid 5 may be formed from a rectangular flat plate-shaped ceramic material, or may be formed from a rectangular flat plate-shaped Fe—Ni alloy or Fe—Ni—Co alloy. The package lid 5 functions as a sealing portion for hermetically sealing the recess 2A filled with nitrogen gas or the like in a state close to a vacuum.

As shown in FIG. 2A, connection pads 22A and 22B made of a metal material are disposed on the bottom surface of the recess 2A of the package body 2 in order to join the crystal element 4.
On the other hand, as shown in FIG. 2B, on the back surface of the package body 2, for example, two external terminals 23A and 23B made of a metal material, which are electrically connected to the respective terminals of the crystal element 4, are arranged. .
The connection between the connection pad 22A and the external terminal 23A is achieved by a wiring (or a wiring embedded in the ceramic material) formed on the inner bottom surface of the recess 2A and a via thereunder, although not particularly shown. Further, the connection between the connection pad 22B and the external terminal 23B is achieved by a via.

  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. 2A, each electrode covers a rectangular excitation electrode 42 widely disposed on the main surface of the crystal base plate 41 and one corner of the crystal base plate 41 so as to cover the crystal base plate 41. The connection electrode 43A is disposed on both surfaces, and the extraction electrode 44 connects the connection electrode 43A to the excitation electrode 42. These electrodes (42, 43A, 44) are formed from an integral conductive layer (for example, a metal film). In FIG. 2A, a connection electrode 43B of another electrode is shown at the corner on the other side of the short side of the quartz 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.

Regarding the bonding of the crystal element 4 and the package body 2, the conductive adhesive DS is used when the connection electrode 43A and the connection pad 22A and the connection electrode 43B and the connection pad 22B are bonded.
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.

In the manufacture of the piezoelectric device 1, a package body 2 made of a ceramic material, a crystal element 4, and a package lid 5 are formed.
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. After that, for example, a metal film is deposited on both main surfaces of the quartz base plate 41 by sputtering or the like, or by printing or the like, a pair of excitation electrodes 42, connection electrodes 43A (43B), and extraction electrodes 44 are provided. The electrodes are integrally formed.

The crystal element 4 is bonded to the connection pads 22A and 22B formed in the recess 2A of the package body 2 with a conductive adhesive DS so as to have a cantilever structure.
The package lid 5 is placed on the package body 2 so that the recess 2A is closed, and the package lid 5 and the package body 2 are firmly joined so as to be sealed by heating or the like. When the package lid 5 is made of the above alloy, for example, it is joined to the package body 2 by seam welding or the like in a predetermined atmosphere.

[Board mounting of piezoelectric devices]
Next, the mounting structure and mounting method of the piezoelectric device will be described with reference to FIGS.
The mounting structure shown in FIG. 1 is characterized in that when the piezoelectric device 1 having the above-described configuration is mounted on a mounting board 100 called a printed wiring board or the like, a package connection body 6 is interposed therebetween.
In FIG. 1, the external terminals of the package body 2 and the electrodes of the package connector 6 are not shown.

In the mounting substrate 100, a base material called a core is made of, for example, glass epoxy resin, and a metal wiring is formed on one or both main surfaces of the base material. In addition to the main surface of the base material, the metal wiring may be formed inside the base material.
In the cross-sectional view of FIG. 1, two terminal bonding pad portions 110 </ b> A and 100 </ b> B that are electrically connected to the external terminals of the piezoelectric device 1 through the package connection body 6 among the wirings on the upper surface of the mounting substrate 100 are shown.

FIGS. 3A and 3B are a back view and a side view of the short side of the package connection body 6. Here, the back surface refers to the second main surface S <b> 2 that faces the mounting substrate 100 when bonded to the mounting substrate 100. On the other hand, the first main surface S1 (upper surface) facing the package body 2 has the same configuration as that of the back surface side, and is not shown.
In addition, the definition of this back surface (2nd main surface S2) and upper surface (1st main surface S1) is the same also after 2nd Embodiment mentioned later.

The package connector 6 has a rectangular flat base 61.
The base material 61 of the package connector 6 is such that the difference in thermal expansion coefficient between the base material 61 and the base material of the mounting substrate 100 is smaller than the difference in thermal expansion coefficient between the base material 61 and the base material of the package body 2. It is formed from a material having a thermal expansion coefficient.
For example, when the base material of the package body 2 is made of ceramic and the base material of the mounting substrate 100 is made of glass epoxy resin, the base material 61 of the package connector 6 can be made of glass epoxy resin. Thus, the difference of thermal expansion coefficient can be made smaller by making the base material of the package connector 62 and the base material of the mounting substrate 100 be made of the same resin material. In addition, as long as the requirements for the difference in thermal expansion coefficient are satisfied, the base material 61 of the package connection body 6 can also be formed from another resin or the like.

The substrate 61 of the package connector 6 has two electrodes on each of the first main surface S1 and the second main surface S2.
More specifically, the second electrodes 63A and 63B are disposed apart from each other in the longitudinal direction of the base material on the second main surface S2 shown in FIG. Similarly, on the first main surface S1, the first electrodes 64A and 64B are arranged apart from each other in the longitudinal direction of the base material. The first electrode 64A and the second electrode 63A are opposed to each other with the base material 61 interposed therebetween, and the first electrode 64B and the second electrode 63B are opposed to each other with the base material 61 interposed therebetween. Hereinafter, the electrodes facing each other with the base material interposed therebetween are referred to as “one pair of electrodes” or “electrode pairs”.

The substrate 61 of the package connector 6 includes a side recess 62 that is recessed from the short side S3 toward the center of the substrate on each of the side surfaces, for example, the short side S3. Each side recess 62 is formed such that the corner portion inside the base material has a gently curved surface.
An electrode connection portion 65 that connects a pair of electrodes facing each other with the base material 61 interposed therebetween is provided on the side surface of the base material inside each side surface recess 62. By doing so, the first electrodes 64A and 64B and the second electrodes 63A and 63B are electrically connected, and when mounted on the mounting substrate 100, the bonding area of the conductive bonding material SL is increased and the bonding strength is improved. Can be made. Further, the electrode connection portion 65 and the pair of electrodes are preferably formed of an integral metal film. For this reason, the first electrode 64A and the second electrode 63A are reliably connected by the electrode connecting portion 65 provided on the one short side surface S3, and the conduction failure can be reduced. Similarly, the 1st electrode 64B and the 2nd electrode 63B are reliably connected by another electrode connection part 65 provided in other short side S3, and can reduce conduction failure.

In the package connection body 6 having such a configuration, the two first electrodes 64A and 64B are connected to the external terminals 23A and 23B shown in FIG. 2B on a one-to-one basis by, for example, a conductive adhesive DS having heat resistance. The piezoelectric device 1 is bonded in advance so as to be bonded (see FIG. 1).
The package connection body 6 to which the piezoelectric device 1 is bonded is mounted on the mounting substrate 100 with the two second electrodes 63A and 63B via the terminal bonding pad portions 110A and 100B and the conductive bonding material SL.

4A and 4B are schematic cross-sectional views of the mounting structure before and after mounting.
In FIG. 4A showing the state before mounting, the conductive bonding material SL is supplied onto the terminal bonding pad portions 110A and 100B of the mounting substrate 100 by a dispenser or the like. At this time, the conductive bonding material SL has a mountain shape with more conductive bonding material SL at the center.
At the time of mounting, the conductive bonding material SL is crushed and spreads around. At this time, in this embodiment, since the side surface recess 62 is formed in the base material 61, the side surface recess 62 is filled with the conductive bonding material SL before the conductive bonding material SL spreads outside the base material 61 (FIG. 4 (B)). Alternatively, even if not completely filled, the conductive bonding material SL crawls up along the conductive electrode connection portion 65 (not shown) formed in the side recess 62. The conductive bonding material SL is inclined so that the thickness in the vertical direction of the conductive bonding material SL decreases from each of the electrode connection portions 65 to the upper surface of the mounting substrate 110. In addition, the slope in which the conductive bonding material SL is provided so that the thickness in the vertical direction is thin is defined as a fillet. In this way, a fillet is formed in the side recess 62, so that the strength against the peeling of the conductive bonding material SL is improved and a strong bonding is achieved. The conductive bonding material SL is made of, for example, silver paste or lead-free solder. In addition, the conductive bonding material SL contains an added solvent for adjusting the viscosity to be easily applied. The component ratio of the 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 present embodiment, in addition to the improvement in the strength against peeling of the conductive bonding material SL, the following desirable effects can be expected by defining the difference in thermal expansion coefficient between the substrates as described above.

  In general, when the package connection body 6 is not provided, a stress due to a large difference in thermal expansion coefficient between the package body 2 and the mounting substrate 100 may be applied to the conductive bonding material SL, and a crack or the like may occur in the conductive bonding material SL. In particular, when the bonding area of the conductive bonding material SL is reduced due to the miniaturization of the device, the possibility of causing a bonding failure even with a small crack increases.

In the present embodiment, the base material 61 of the package connector 6 has a difference in thermal expansion coefficient between the base material 61 and the base material of the mounting substrate 100, so that the thermal expansion between the base material 61 and the base material of the package body 2 is the same. It is made of a material having a thermal expansion coefficient smaller than the difference in coefficient.
For this reason, even when the mounting substrate 100 is deformed by heating, the stress due to the deformation is relieved by the presence of the package connection body 6, and as a result, the stress applied to the conductive bonding material SL is also relieved. For this reason, it becomes difficult to generate | occur | produce a conductive joining material crack.

  As the mounting substrate 100 is deformed, the package connector 6 having the same or close thermal expansion coefficient is also slightly deformed. For this reason, a certain amount of stress is also applied to the conductive adhesive DS that joins the package connector 6 to the package body 2. However, the conductive adhesive DS has heat resistance and is resistant to breakage due to stress application (high flexibility) because it uses a resin such as a silicone resin as a base material. Moreover, the area from the mounting substrate 100 is small, and the stress from the mounting substrate 100 is not applied as it is to the package connection body 6 bonded through the conductive bonding material SL. Therefore, the stress from the mounting substrate 100 is dispersed on the conductive bonding material SL side and the heat-resistant conductive adhesive DS side, and as a result, generation of conductive bonding material cracks is suppressed or prevented.

<2. Second Embodiment>
FIGS. 5A and 5B are a back view and a side view of the long side of the package connection body 6A according to the second embodiment. In the following description of the second and subsequent embodiments, the same components as those in the previous embodiments are denoted by the same reference numerals, and the description thereof is omitted or simplified.

The package connector 6A includes a rectangular flat plate-shaped substrate 61A made of the same material as that of the first embodiment.
In the base material 61A of the package connector 6A, the difference in thermal expansion coefficient between the base material 61A and the base material of the mounting substrate 100 is smaller than the difference in thermal expansion coefficient between the base material 61A and the base material of the package body 2. It is formed from a material having a thermal expansion coefficient.

While the first embodiment corresponds to a two-terminal device, the package connector 6A of the second embodiment has an electrode arrangement corresponding to a four-terminal device.
The two electrode pairs (63A, 64A) and (63B, 64B) described in the first embodiment and connected to the two external electrodes of the crystal element 4 are one of both main surfaces in the second embodiment. It is arranged on the diagonal side. In addition, in the second embodiment, another electrode pair (second electrode 63C, first electrode 64C) and (second electrode 63D, first electrode 64D) are provided on the other diagonal side of both main surfaces. Is arranged. Here, the first electrodes 64C and 64D are formed on the first main surface S1, and the second electrodes 63C and 63D are formed on the second main surface S2.
Here, the two electrode pairs (63C, 64C) and (63D, 64D) may be connected to the ground or may be used for the temperature sensitive element.

The base 61A of the package connector 6A includes two side recesses 62 that are recessed from the long side S4 toward the center of the base, two on each side, for example, the long side S4. As in the first embodiment, each side recess 62 is provided with an electrode connection portion 65 that connects a pair of electrodes facing each other with the base material 61 interposed therebetween, on the side surface of the base material inside.
Similar to the two electrode pairs (63A, 64A) and (63B, 64B), the first electrode 64C and the second electrode 63C are securely connected by the electrode connecting portion 65 provided on one long side surface S4, and are conductive. Defects can be reduced. Similarly, the first electrode 64D and the second electrode 63D are reliably connected by another electrode connecting portion 65 provided on the other long side surface S4, and the conduction failure can be reduced.

Although not shown in particular, the external terminals on the back surface side of the package body are configured with a size and an arrangement suitable for the size and arrangement of the four first electrodes 64A to 64D of the package connector 6A.
In addition, the terminal connection pad portion of the mounting substrate is also configured with a size and arrangement suitable for the size and arrangement of the four second electrodes 63A to 63D of the package connection body 6A.
The other mounting structure in the second embodiment is the same as the mounting structure in the first embodiment. The mounting method is basically the same.

  Also in the second embodiment, as in the first embodiment, the conductive bonding material SL is crushed during the mounting and spreads around. At this time, in this embodiment, since the side surface recess 62 of the base material 61A is formed, the side surface recess 62 is filled with the conductive bonding material SL before the conductive bonding material SL spreads outside the base material 61A (FIG. 4 (B)). Or even if it is not completely filled, it crawls up along the conductive electrode connecting portion 65 (not shown in FIG. 4B) formed in the side recess 62. The fillet formed in the side recess 62 in this way improves the strength against peeling of the conductive bonding material SL and achieves strong bonding.

  In addition to improving the strength against peeling of the conductive bonding material SL, a desirable effect similar to that of the first embodiment can be expected by defining the difference in thermal expansion coefficient between the substrates in the first embodiment.

<3. Third Embodiment>
FIGS. 6A and 6B are a rear view and a side view of the long side of the package connection body 6B according to the third embodiment.

The package connection body 6B has a rectangular flat plate-like base material 61B made of the same material as that of the first embodiment.
In the base material 61 of the package connector 6B, the difference in thermal expansion coefficient between the base material 61B and the base material of the mounting substrate 100 is smaller than the difference in thermal expansion coefficient between the base material 61B and the base material of the package body 2. It is formed from a material having a thermal expansion coefficient.

  The package connection body 6B has the same electrode arrangement configuration as that of the first embodiment, but has a through-hole 66B penetrating from the first main surface S1 to the second main surface S2 at substantially the center of the base material 61B. Different from the substrate 61 in the first embodiment.

Further, similarly to the first embodiment, two side surface recesses 62 are provided on the two short side surfaces S3.
Here, the through hole 66B has an outer shape and a position in which both end portions in one direction provide the same shape as the side recess 62 with respect to each electrode. For this reason, one of both end portions of the through hole 66B forms a recess facing the one side recess 62 across the electrode pair (63A, 64A). Further, the other of both end portions of the through-hole 66B forms a recess facing the other side surface recess 62 across the other electrode pair (63B, 64B).

  Moreover, the electrode connection part 65 similar to the side surface recessed part 62 is provided in the inner wall surface (inner side surface of a base material) of two said recessed parts which the both ends of the through-hole 66B form. Therefore, each of the two electrode pairs is more reliably connected between the electrodes by the two electrode connection portions 65 than in the first embodiment, so that the conduction failure can be further reduced. The through-hole 66B has an inner wall surface on one side positioned corresponding to the side recess 62 with the first electrodes 64A and 64B and the second electrodes 63A and 63B interposed therebetween, Each of the wall surfaces is formed of a conductive material that is integral with the first electrodes 64A and 64B and the second electrodes 63A and 63B. By doing in this way, since between electrodes are connected reliably, conduction | electrical_connection defect can be reduced further.

FIG. 7 is a schematic cross-sectional view of the mounting structure according to the third embodiment. This sectional view shows a structure along a line passing through the two side recesses 62 in FIG. 6A and the through hole 66B therebetween.
As in the first embodiment, each side recess 62 is completely or partially filled with the conductive bonding material SL and a fillet is formed at the time of mounting. Furthermore, in the present embodiment, since the electrode connection portions 65 are similarly formed on both end sides of the through-hole 66B that forms the concave portion for the electrode pair, the conductive bonding material SL crawls up along therewith, and a fillet is formed. The Therefore, the strength against peeling of the conductive bonding material SL is further increased than that of the first embodiment, and extremely strong bonding is achieved.

  In addition to improving the strength against peeling of the conductive bonding material, the same desirable effect as in the first embodiment can be expected by defining the difference in thermal expansion coefficient between the substrates in the first embodiment.

<4. Fourth Embodiment>
FIGS. 8A and 8B are a back view and a side view of the long side of the package connection body 6C according to the fourth embodiment.
This package connection body 6C is equivalent to the package connection body 6B described in the second embodiment in which two through holes 66C are further added. For this reason, in the following description, the same configurations as those in the first and second embodiments are denoted by the same reference numerals, and the description thereof is omitted or simplified.

Of the two through holes, one through hole 66C is located between the electrode pair (63A, 64A) and the electrode pair (63D, 64D). The one through hole 66C has a size of the through hole such that both ends of the base 61C in the short side direction (opposite direction of the long side surfaces S4) form a recess with respect to each electrode pair, The shape and position are determined.
Similarly, the other through-hole 66C is located between the other two electrode pairs, that is, between the electrode pair (63B, 64B) and the electrode pair (63C, 64C). The size, shape, and position of the through hole 66C are determined such that both end portions in the short side direction of the base 61C form a recess with respect to each electrode pair.

  Each of these two through-holes 66C has an electrode connection portion 65 that short-circuits between the electrodes at each of both ends forming a recess for the corresponding electrode pair, similar to the through-hole 66B in the third embodiment. is there.

Other configurations of the package connection body, the mounting structure other than the package connection body, and the mounting method are the same as those in the first and second embodiments.
Further, in mounting, not only the side surface recess 62 but also the fillet is formed on the inner wall side of the through hole 66C (see the through hole 66B in FIG. 7), and the third embodiment is achieved in that a stronger bond is achieved. The same effect as the form can be obtained.

  In addition to improving the strength against peeling of the conductive bonding material SL, a desirable effect similar to that of the first embodiment can be expected by defining the difference in thermal expansion coefficient between the substrates in the first embodiment.

<5. Modification>
The above 1st-4th embodiment is not limited to the said description, For example, the various deformation | transformation illustrated below is possible.

  The electrode connecting portion 65 may be formed of a conductive material different from the first and second electrodes (a pair of electrodes).

  Further, the bases 61, 61A, 61B, 61C of the package connectors 6, 6A, 6B, 6C have a side recess 62 formed on one of the short side surface S3 and the long side surface S4. Side surface recesses 62 can be formed on both side surfaces S4. Further, even when one side recess 62 is provided for the electrode pair, the position itself is not limited to the above description.

For example, in the package connector for a two-terminal device shown in FIGS. 3 and 6, in addition to the side recess 62 on the short side S3 side, one or the other of the two long sides S4 has a side recess 62 for each electrode pair. May be formed to increase the number of short-circuited portions between the electrodes by the electrode connecting portion 65. Further, for each electrode pair, the side surface recess 62 may be formed on one or the other of the two long side surfaces S4 without forming the side surface recess 62 on the short side surface S3 side.
The point where the position and the number of the short-circuit portions between the electrodes by the side recess 62 are arbitrary is the same as in the package connection body for a four-terminal device.

  Further, each side recess 62 does not have the electrode connection portion 65 and does not contribute to the inter-electrode short circuit as a configuration having a conductive layer that extends from the electrode on the back surface to the middle of the inner wall of the recess, but only for the formation of the fillet. Contributing deformations are also possible.

Here, the side recess 62 is not an essential component. In the above-described embodiment, since the position of each electrode is slightly away from the side surface of the substrate, the side recess 62 is formed to facilitate the short circuit between the electrodes by the electrode connection portion 65, but this is limited to this short-circuit structure. Not.
For example, when the side recess 62 is not provided, the electrode connection portion 65 may be formed so as to extend from the side surface of the base material to each electrode on the front and back surfaces. In this case, a fillet is formed at the base material side surface portion of the electrode connection portion 65.

In addition to the interelectrode connection on the side surface of the base material by the electrode connection portion 65, or instead of the interelectrode connection on the base material side surface side, a pair of electrodes may be plug-connected.
For example, in the step of forming the base material of the package connector, at least one through hole is formed for each electrode pair at the base material position where the electrode is to be arranged. The hole formation for the plug is preferably performed at the same time when the side surface recess 62 is formed by punching a rectangular base material, for example. After the formed through hole is filled with a conductive plug material (for example, metal), an electrode short circuit structure is formed by forming an electrode connection portion 65 that short-circuits between a pair of electrodes and, if necessary, a pair of electrodes. Is feasible.

  In addition, the present invention may be implemented in various modes.

The first to fourth embodiments and the modified examples describe preferred embodiments of the present invention mainly from the viewpoint of “mounting structure”.
However, the configuration having the configuration in which the interelectrode connection is achieved by the electrode connecting portion on the side surface of the base material, regardless of the presence or absence of the side surface concave portion, has been re-examined as follows from the viewpoint of the “piezoelectric device”. Embodiments of other inventions are also substantially described throughout the above description, including the first to fourth embodiments and modifications.

<6. Another invention>
“A ceramic package body containing a piezoelectric element therein and having a plurality of external terminals on the bottom surface, and a resin base material having a size in which main portions of the side surfaces are aligned when overlapped with the package body, A plurality of first electrodes arranged on the first main surface of the base material and connected to the plurality of external terminals; and a base electrode arranged on the second main surface of the base material and any one of the plurality of first electrodes and the base A package connection body including a plurality of second electrodes connected on the side surface side of the material, and each of the plurality of first electrodes is formed by a conductive electrode connection portion provided on the side surface of the base material. A piezoelectric device electrically connected to any one of the plurality of second electrodes. ]

  DESCRIPTION OF SYMBOLS 1 ... Piezoelectric device, 2 ... Package main body, 2A ... Recessed part, 22A, 22B ... Connection pad, 4 ... Crystal element, 5 ... Package lid, 6 ... Package connection body, 22A, 22B ... Connection pad, 23A, 23B ... External Terminals 41... Crystal base plate 42. Excitation electrodes 43 A and 43 B Connection electrodes 44 Extraction electrodes 61 Substrates 62 Side recesses 63 A and 63 B Second electrodes 64 A and 64 B First electrodes , 65 ... electrode connection part, 66 ... through hole, 100 ... mounting board, 110A, 100B ... terminal bonding pad part, S1 ... first main surface, S2 ... second main surface, S3 ... short side surface, S4 ... long side surface, DS ... conductive adhesive, SL ... conductive bonding material

Claims (12)

A package body containing a piezoelectric element therein and having a plurality of external terminals on the bottom surface;
A package connection body interposed between the package body and the mounting substrate, and electrically connecting the plurality of external terminals to a plurality of terminal bonding pad portions provided on the mounting substrate;
Have
The base material of the package connection body is formed of a material having a thermal expansion coefficient smaller than that of the base material of the package body.
Mounting structure of piezoelectric device. The base material of the package connector and the base material of the mounting substrate are made of the same resin material,
The mounting structure of the piezoelectric device according to claim 1. The package connector is
A substrate;
A plurality of first electrodes disposed on the first main surface of the substrate and connected to the plurality of external terminals of the package body;
A plurality of second electrodes disposed on the second main surface of the base material and connected to a plurality of conductive pad portions of the mounting substrate;
Have
Each of the plurality of first electrodes is electrically connected to any one of the plurality of second electrodes by a conductive electrode connecting portion provided on a side surface of the substrate.
The mounting structure of the piezoelectric device according to claim 1 or 2. The side surface of the substrate has a side recess recessed from the side surface to the substrate center side,
The electrode connection portion made of a conductive material integral with the first electrode and the second electrode is provided on the side surface of the base material in the side surface recess,
The mounting structure of the piezoelectric device according to claim 3. The base material of the package connector has at least one through-hole penetrating the first main surface and the second main surface in the thickness direction.
The mounting structure of the piezoelectric device according to any one of claims 1 to 4. The package connector is
A substrate;
A plurality of first electrodes disposed on the first main surface of the substrate and connected to the plurality of external terminals of the package body;
A plurality of second electrodes disposed on the second main surface of the base material and connected to a plurality of conductive pad portions of the mounting substrate;
Have
Each of the plurality of first electrodes is electrically connected to any one of the plurality of second electrodes by a plurality of conductive electrode connection portions provided on a side surface of the base material and an inner wall surface of the through hole. ing,
The mounting structure of the piezoelectric device according to claim 5. The side surface of the substrate has a side recess recessed from the side surface to the substrate center side,
In the through hole, an inner wall surface of one side is located corresponding to the side surface recess with the first and second electrodes interposed therebetween,
The electrode connection portion made of a conductive material integral with the first electrode and the second electrode is provided on each of the side surface and the inner wall surface of the base material in the side surface recess,
The mounting structure of the piezoelectric device according to claim 6. The plurality of external terminals of the package body and the plurality of first electrodes are connected with a conductive adhesive,
The plurality of conductive pad portions of the mounting substrate and the plurality of second electrodes are bonded with a conductive bonding material,
The conductive bonding material is provided with an inclination so that the thickness in the vertical direction decreases from each of the electrode connection portions to the upper surface of the mounting substrate.
The mounting structure of the piezoelectric device according to claim 3 or 6. A package body made of ceramic containing a piezoelectric element inside and having a plurality of external terminals on the bottom surface;
Resin base material having a size such that main parts of side surfaces are aligned with each other when overlapped with the package body, and a plurality of first electrodes arranged on the first main surface of the base material and connected to the plurality of external terminals And a package connector including a plurality of second electrodes arranged on the second main surface of the base material and connected to any one of the plurality of first electrodes on the side surface side of the base material,
Have
Each of the plurality of first electrodes is electrically connected to any one of the plurality of second electrodes by a conductive electrode connecting portion provided on a side surface of the substrate.
Piezoelectric device. The base material of the package connector has at least one through-hole penetrating the first main surface and the second main surface in the thickness direction.
The piezoelectric device according to claim 9. Each of the plurality of first electrodes is electrically connected to any one of the plurality of second electrodes by a plurality of conductive electrode connection portions provided on a side surface of the base material and an inner wall surface of the through hole. ing,
The piezoelectric device according to claim 10. The side surface of the substrate has a side recess recessed from the side surface to the substrate center side,
In the through hole, an inner wall surface of one side is located corresponding to the side surface recess with the first and second electrodes interposed therebetween,
The electrode connection portion made of a conductive material integral with the first electrode and the second electrode is provided on each of the side surface and the inner wall surface of the base material in the side surface recess,
The piezoelectric device according to claim 11.

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