JP2007288644A - Piezoelectric substrate, piezoelectric vibration element, surface mounted piezoelectric vibration element, method for manufacturing piezoelectric substrate, and surface mounted piezoelectric oscillator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent fluctuation of a resonance frequency or short circuiting between an element mounting pad and adjacent metal members which are caused by a conductive adhesive protruding to a vibration area of a piezoelectric vibration element by a pressurization power at bonding, when a cantilever support structure in which an under surface near one end of the piezoelectric vibration element is bonded by the conductive adhesive on the element mounting pad provided on a package is applied. <P>SOLUTION: A piezoelectric substrate comprises the vibration area 11a, and a connected area 11b which is continuously integrated with the vibration area 11a. In the connected area, a concave portion or a through-hole as an adhesive accommodating portion 20 is formed on one side of the connected area. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a piezoelectric substrate that is electrically and mechanically connected to a device mounting pad disposed on a surface mounting package by a conductive adhesive in a cantilever state, a piezoelectric vibration element, and a piezoelectric device including the piezoelectric vibration element. The present invention relates to a vibrator, a method for manufacturing a piezoelectric substrate, and a piezoelectric oscillator including the piezoelectric vibrator.

11A, 11B, and 11C are a longitudinal sectional view, a principal plan view, and a principal longitudinal sectional view of a conventional surface-mount type crystal resonator disclosed in Patent Document 1, for example. This crystal resonator 101 is formed by using a conductive adhesive 105 on an internal terminal (electrode pad) 104 disposed on the inner bottom surface of a cavity 103 formed on the upper surface of a package 102 made of an insulating material such as ceramic. 110 is supported in a cantilever state, and the opening of the cavity 103 is hermetically sealed with a metal lid 115. On the outer bottom surface of the package, the mounting terminal 1 connected to the internal terminal 104 is provided.
06 is arranged. The quartz resonator element 110 has a configuration in which excitation electrodes 112 and lead electrodes 113 extending from the excitation electrodes 112 to the substrate edge are formed on both the front and back surfaces of the quartz substrate 111.

This crystal resonator 101 is formed by forming a convex portion 120 at an appropriate position on the lower surface of a crystal resonator element (crystal substrate), so that the conductive adhesive 10 sandwiched between the inner bottom surface of the cavity and the lower surface of the crystal resonator element.
The amount of the front part of 5 is increased. That is, when this crystal resonator 101 is connected to the internal terminal 104 via the conductive adhesive 105, the thickness of the tip side of the conductive adhesive is the middle part thereof, or /
And it is comprised so that it may become thicker than the thickness of a rear part.

In this conventional example, the convex portion 120 is located at a position corresponding to the lead electrode 113 of the crystal resonator element 110.
Therefore, when the upper surface of the internal terminal 104 and the lower surface of the crystal resonator element (lead electrode) are connected by the conductive adhesive 105, the thickness and amount of the adhesive positioned in front of the convex portion 120 are reduced. Even if a moment occurs in the vertical direction (thickness direction) centering on the holding part by the adhesive, the stress can be absorbed and relaxed sufficiently due to the impact when dropping. It becomes possible. Therefore, no stress remains due to the elastic deformation of the adhesive, and no deformation occurs in the holding portion of the crystal vibration element by the adhesive. That is, due to stress concentration on the adhesive side, minute peeling or stress relaxation does not occur at the bonded portion between the crystal resonator element and the adhesive, and the holding state of the end portion of the crystal resonator element by the adhesive changes. Thus, there is no possibility of characteristic deterioration (frequency fluctuation, equivalent resistance change).

However, in this conventional example, since the lower surface of the convex portion 120 formed on the crystal resonator element side is entirely flat, the conductive adhesive 1 is similarly connected to the internal terminal 104 having a flat upper surface.
By pressing 05, the adhesive may be crushed and protrude to the vibration region side at the center of the crystal resonator element 110, thereby changing the resonance frequency.

Patent Document 2 discloses that the conductive adhesive spreads on the contact surface with the lead electrode on the package side by forming a protrusion made of a conductive adhesive on the lead electrode located at the end of the crystal piece. A surface-mount crystal resonator that prevents the support loss and prevents the loss is disclosed. Since this protrusion is an arc-shaped protrusion, when the protrusion having the optimum shape and size is always formed at the optimum position, the situation where the conductive adhesive is crushed and spreads to the periphery is avoided. It is not impossible. However, in actuality, since the protrusion is formed by dropping a conductive adhesive onto one end surface of the crystal piece with a dispenser or the like, the position, shape and dimensions of the formed protrusion are likely to vary, and the protrusion is When the crystal piece is displaced to the vibration region side, there is a possibility that the conductive adhesive for bonding is pushed out to the vibration region side by the projection and adheres to the vibration region.

Patent Document 3 discloses a flat bottom plate 130 made of ceramic as shown in FIG.
An annular seal ring 132 is erected and fixed by a conductive adhesive means on a metallized film 131 formed along the periphery of the upper surface of the substrate, and crystal vibration is generated by the conductive adhesive 105 with respect to the internal terminal 104 provided on the bottom plate. A type in which the lower surface of one end of the element 110 is cantilevered is disclosed.

However, in this conventional example, the seal ring 132 becomes smaller as the package becomes smaller.
11 and the internal terminal 104 must be close to each other, so that the adhesive is likely to stick out in all directions by pressurization from the convex portion to the conductive adhesive as in the quartz crystal vibration element shown in FIG. Of course, even in the conventional type where there is no convex part on the quartz resonator element or internal terminal side,
There is a possibility that a short circuit between the seal ring and the internal terminal may occur due to the adhesive sticking out to the seal ring side. When the seal ring and the internal terminal are short-circuited, the stray capacitance changes.
It causes electric characteristics to fluctuate.
Japanese Patent Laid-Open No. 2004-222006 JP 2004-363936 A JP 2002-26680 A

The bottom surface is flat when a convex adhesive provided at the end of a crystal resonator element and an internal terminal provided on the package side are bonded with a conductive adhesive like a conventional crystal resonator (piezoelectric resonator). Since the escape area of the conductive adhesive pressed between the convex part and the internal terminal with a flat upper surface is limited to the outer peripheral direction of the convex part, a part of the adhesive protrudes and the vibration of the crystal resonator element There is a possibility that the resonance frequency of the crystal unit may fluctuate due to adhesion to the conductor in the region or the nearest position.
In addition, when a projection is formed on the quartz substrate surface with a conductive adhesive, and the connection between the lead-out electrode on the package side using the projection is fixed with a conductive adhesive, the position, shape,
Since it is difficult to stabilize the dimensional accuracy, there arises a problem that the conductive adhesive for bonding protrudes to the periphery and causes the same problems as described above.
In addition, crystal vibration using a conductive adhesive on the internal terminals (element mounting pads) placed in the cavity formed inside the metal seal ring mounted on the top surface of the ceramic bottom plate with a flat top surface When the element is supported in a cantilever state, a part of the conductive adhesive pressurized between the internal terminal and the quartz crystal vibration element protrudes to the outer periphery, thereby causing a short circuit between the seal ring and the internal terminal. There is a possibility that the electrical characteristics of the device fluctuate.

The present invention has been made in view of the above, and a cantilevered support structure in which a lower surface near one end of a piezoelectric vibration element is bonded to an element mounting pad provided on a package side via a conductive adhesive. In addition, the conductive adhesive protrudes to the vibration region side of the piezoelectric vibration element due to the pressure applied at the time of bonding, and the resonance frequency is changed, or the protruding conductive adhesive is a metal member positioned in the vicinity of the element mounting pad. Piezoelectric substrate, piezoelectric vibration element, surface mount piezoelectric vibrator, piezoelectric, which can improve impact resistance by fully absorbing and mitigating impact when dropped by conductive adhesive A substrate manufacturing method and a surface-mount piezoelectric oscillator are provided.

In order to achieve the above object, a piezoelectric substrate according to the present invention is a piezoelectric substrate comprising a vibration region and a connected region that is connected and integrated with the vibration region, and is provided on one surface of the connected region. Is characterized in that an adhesive accommodating portion comprising a recess or a through hole is formed.
Since an adhesive container for receiving a part of the conductive adhesive is formed on the surface of the substrate edge (connected area) that is separated from the vibration area, the element mounting pad on the package side and the piezoelectric vibration element When the conductive adhesive is pressed, if it is a conventional structure, the adhesive containing portion is filled with the excess adhesive that protrudes in the outer peripheral direction due to the pressurization. For this reason, there is no problem that the protruding adhesive adheres to the vibration region of the piezoelectric vibration element and fluctuates the resonance frequency, or adheres to a conductor located in the vicinity and short-circuits with the element mounting pad. In addition, since it is not necessary to reduce the amount of adhesive used, the support strength of the piezoelectric vibration element by the package can be increased. That is, if the amount of adhesive increases, even if a moment is generated in the vertical direction (thickness direction) about the holding part by the adhesive, the stress is sufficiently applied to the piezoelectric vibration element due to the impact when dropped. Can be absorbed and relaxed.

The piezoelectric vibration element according to the present invention is a piezoelectric vibration element including a piezoelectric substrate, an excitation electrode formed on the piezoelectric substrate, and a lead electrode extending from the excitation electrode to one end edge of the piezoelectric substrate. An adhesive container containing a recess or a through hole is formed on a surface along one edge of the piezoelectric substrate including the end of the lead electrode.
Various shapes, numbers, arrangements, and the like of the concave portions constituting the adhesive accommodating portion can be selected. By forming the through hole, bubbles or the like are not left in the adhesive accommodating portion even when the piezoelectric vibration element is bonded onto the element mounting pad in an atmosphere not under reduced pressure. For this reason, stable connection strength can be maintained.

In the piezoelectric vibration element according to the present invention, the adhesive accommodating portion is formed on an adhesive surface with a thick portion adhesive formed at one end edge of the piezoelectric substrate including an end portion of the lead electrode. It is characterized by that.
The connected region of the piezoelectric substrate is configured to be thicker than the vibration region in advance, and an adhesive accommodating portion is formed on one surface of the thick portion.

Moreover, the piezoelectric vibration element according to the present invention is characterized in that the adhesive accommodating portion is surrounded by a thick annular portion.
By enclosing the outer periphery of the adhesive accommodating portion formed of the concave portion or the through hole with the annular portion (annular convex portion), it becomes easy to prevent the adhesive from flowing out in the outer peripheral direction.

In the piezoelectric vibration element according to the present invention, the adhesive accommodating portion is adjacent to a convex portion for adhesive damming formed on a surface along one edge of the piezoelectric substrate including the end portion of the lead electrode. It is a non-convex surface formed.
The adhesive accommodating part does not necessarily have to be a recess surrounded by an annular part. For example, by forming a convex portion that prevents the adhesive applied on the element mounting pad from flowing out to the vibration region side of the piezoelectric vibration element, the convex surface formed on the opposite side is used as the adhesive accommodating portion. Also good.

The surface-mount piezoelectric vibrator according to the present invention includes a package having two element mounting pads for electrically connecting to each excitation electrode of the piezoelectric vibration element on the upper surface, and a mounting terminal on the bottom. A connection conductor for applying a predetermined wiring between any of the mounting terminals and the element mounting pad, and an end portion of each lead electrode on the element mounting pad by a conductive adhesive. And the piezoelectric vibration element that is cantilevered on the package by being connected to each other.
Various types of piezoelectric vibrators can be constructed by using the piezoelectric vibration element having the above configuration.

Further, the surface-mount type piezoelectric vibrator according to the present invention has a cavity having at least an upper surface side cavity and a mounting terminal at the bottom, and a predetermined gap between any of the mounting terminals and the element mounting pad. A connecting conductor for wiring and a piezoelectric vibration element that is cantilevered on the package by electrically and mechanically connecting the end of each lead electrode to the element mounting pad by a conductive adhesive And.

The surface-mount piezoelectric vibrator according to the present invention includes a package having two element mounting pads for electrically connecting to each excitation electrode of the piezoelectric vibration element on the upper surface, and a mounting terminal on the bottom. An annular seal ring erected along the peripheral edge of the upper surface of the package; a connection conductor for providing a predetermined wiring between any of the mounting terminals and the element mounting pad; and the element mounting The piezoelectric vibration element is cantilevered on the package by electrically and mechanically connecting the end portions of the lead electrodes on the pads with a conductive adhesive.

A method for manufacturing a piezoelectric substrate according to the present invention is a method for manufacturing the piezoelectric substrate according to claim 1 by a photolithography technique, the step of preparing a piezoelectric original plate, and the connected region of the piezoelectric original plate; A step of masking a portion of the region excluding the region serving as the adhesive accommodating portion with a photoresist, and etching the vibration region of the piezoelectric original plate and one surface of the connected region not masked with the photoresist collectively And sequentially performing the steps.

In the piezoelectric substrate manufacturing method according to the present invention, the piezoelectric original plate is formed of an AT-cut quartz plate, and a deep adhesive is formed on one surface of the connected region by etching using the anisotropy of the AT-cut quartz plate. The housing portion is formed.

A surface-mount piezoelectric oscillator according to the present invention includes the piezoelectric vibrator and an oscillation circuit component.

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.
1A to 1F are an external perspective view, a longitudinal sectional view, a plan view of a state in which a metal lid is removed, and a longitudinal sectional view of a main part, as an example of a piezoelectric device according to an embodiment of the present invention. It is AA sectional drawing of a figure, (d), and a bottom view of a quartz-crystal vibrating element alone.
This crystal resonator (piezoelectric resonator) 1 is placed on an internal terminal (element mounting pad) 4 disposed on the inner bottom surface of a cavity 3 formed on the upper surface of a package (insulating container) 2 made of an insulating material such as ceramic. One end portion (connected region 11 b) of the quartz crystal vibration element (piezoelectric vibration element) 10 is supported in a cantilever manner using the conductive adhesive 5, and a metal lid (lid member) 15 is provided on the upper surface of the outer frame of the cavity 3.
The cavity 3 is hermetically sealed by fixing. On the outer bottom surface of the package, there are disposed mounting terminals 6 that are electrically connected to the internal terminals 4 and the like, and grounded mounting terminals 6. In the package 2, there is a connection conductor 7 for providing a predetermined wiring between any of the mounting terminals 6 and the internal terminal 4, or a connection conductor 7 for connecting any of the mounting terminals 6 and the grounding portion. Is formed.

The quartz resonator element 10 has excitation electrodes 12 on both the front and back surfaces of a quartz substrate (piezoelectric substrate) 11.
And a lead electrode 13 extending from each excitation electrode 12 to one edge of the substrate. A pad 13 a connected to the internal terminal 4 via the conductive adhesive 5 is disposed at the end of the lead electrode 13.
A quartz substrate 11 constituting the quartz resonator element 10 has a vibrating region 11 in which an excitation electrode 12 is formed.
a and a thick connected region (thick portion) 11b integrated with the vibration region 11a. In this example, a total of two connected regions 11b are provided so as to correspond one-on-one to the positions corresponding to the two pads 13a on the crystal resonator element side. On the lower surface of the connected region 11b, an adhesive accommodating portion 20 consisting of a recess or a through hole is formed by etching. That is, the lower surface of the connected region 11b where the adhesive accommodating portion 20 is formed, and the adhesive accommodating portion 20
A metal film constituting the pad 13 a located at the end of the lead electrode 13 is formed on the inner wall.

The quartz crystal resonator element 10 using the quartz substrate 11 having the above-described configuration has the end portions of the lead electrodes 13 respectively drawn from the excitation electrodes 12 formed on the front and back surfaces of the quartz substrate 11 toward one end edge of the substrate. The pad 13a located at the bottom is formed on the lower surface of the thick connected region 11b, and the adhesive accommodating portion 20 is formed on the lower surface of the connected region 11b. The metal film constituting the pad 13a may extend to the inner wall of the adhesive accommodating portion 20.
For example, as shown in FIG. 1F, the dimension of one side of the connected region 11b is 0.2 mm.
When the dimension of the other side is 0.3 mm, the thickness of the vibration region 11a is 60 μm and the thickness of the connected region 11b is 100 μm, while the depth of the adhesive accommodating portion as the recess is 60 μm,
By making it deeper than that, it is configured to accommodate more adhesive.

By increasing the amount of the conductive adhesive that can be accommodated in the adhesive accommodating portion 20, the support stability by the adhesive is increased and the impact resistance is increased, and the amount of protrusion of the adhesive to the outer periphery is reduced and the vibration region It is possible to prevent inconveniences such as fluctuations in the resonance frequency due to adhesion to the surface and deterioration in electrical characteristics of the crystal resonator due to short-circuits with conductors arranged in close proximity.
If the adhesive container 20 is a recess, the conductive adhesive 5 cannot enter the inner part of the recess and a space (bubble) may be formed in the inner part of the recess. By forming a through hole in the ceiling surface of the agent accommodating part 20 or by forming a through hole in the side wall (that is, by using the adhesive accommodating part 20 as a through hole), the adhesive is placed inside the recess. Can penetrate. In addition, when the adhesion | attachment by a conductive adhesive is implemented under pressure reduction, an adhesive agent can be osmose | permeated to the inner back part of a recessed part. When a through hole is formed in the side wall of the adhesive accommodating portion 20, the adhesive that has flowed out of the through hole has a problem by providing the through hole at a position different from the vibration region side or the conductor side that is disposed in proximity. Be careful not to provoke it.

As shown in FIG. 1 (e), the connected region 11b is formed in a protruding shape (thick portion) and is spaced apart via a non-projecting surface, whereby the bonding surface of one connected region 11b and the package side Even if the conductive adhesive 5 pressurized with the internal terminal (element mounting pad) 4 protrudes, it does not reach the other connected region 11b.

As described above, in the crystal resonator element 10 (quartz substrate 11) according to the present embodiment, the adhesive accommodating portion 20 including a recess or a through hole at an appropriate position on the lower surface of the connected region 11b that is thicker than the vibration region 11a. And a part of the conductive adhesive 5 is accommodated in the adhesive accommodating portion, thereby increasing the amount of the conductive adhesive 5 sandwiched between the bottom surface of the cavity and the bottom surface of the crystal resonator element. ing. For this reason, even if a moment occurs in the vertical direction (thickness direction) centering on the adhesive holding part due to the impact when dropped, the stress can be sufficiently absorbed and relaxed. Become. Therefore, no stress remains due to the elastic deformation of the adhesive, and no deformation occurs in the holding portion of the crystal vibration element by the adhesive. That is,
Due to stress concentration on the adhesive side, minute peeling or stress relaxation does not occur at the bonded part between the crystal resonator element and the conductive adhesive, and the holding state of the end part of the crystal resonator element by the conductive adhesive changes. There is no possibility of characteristic deterioration (frequency fluctuation, change in equivalent resistance value) due to the occurrence of the above.

Furthermore, in the configuration example shown in FIG. 1, even if the conductive adhesive 5 is pressed between the convex surface (lower surface) 21 of the connected region 11 b and the internal terminal 4, a large amount of the conductive adhesive is in the outer circumferential direction. No leakage. In particular, the adhesive accommodating portion 20 composed of a plurality (four) of rectangular recesses is formed as an annular portion 2.
Since 2 surrounds, the amount of leakage in the outer peripheral direction can be reduced, and there is a possibility that the conductive adhesive adheres to the vibration region 11a or causes a short circuit with other conductors located in the vicinity. Disappear.
In the above embodiment, the adhesive accommodating portion 20 is configured by four square recesses or through holes. However, this is only an example, and any shape of recesses or through holes may be used. However, there is no limit to the number.

Next, FIGS. 2 to 4 show modifications of the adhesive accommodating portion.
First, FIGS. 2A and 2B are bottom views showing the configuration of the adhesive accommodating portion 20 formed of a concave portion or a through hole formed on the adhesive surface (surface facing the internal terminal) of the thick connected region 11b. It is a figure and sectional drawing, and the adhesive agent accommodating part 20 which concerns on this embodiment is equipped with the structure which has arrange | positioned the narrow rectangular recessed part or two through holes (or 2 or more) in parallel. According to the adhesive accommodating part of this embodiment, it becomes possible to accommodate a larger amount of adhesive than the adhesive accommodating part of the configuration example of FIG.

FIGS. 3A and 3B are a bottom view and a cross-sectional view showing a configuration of an adhesive accommodating portion 20 according to another embodiment of the present invention. The adhesive accommodating portion 20 according to this embodiment is a circular recess or a through hole. Since the configuration of the adhesive accommodating portion is simple, processing by etching is facilitated and more adhesive can be held.

FIGS. 4A and 4B are a bottom view and a cross-sectional view showing a configuration of an adhesive accommodating portion 20 according to another embodiment of the present invention. The adhesive accommodating portion 20 according to this embodiment is based on the premise that an AT-cut quartz plate is used as the quartz substrate 11, and the adhesive accommodation according to another embodiment is performed using the anisotropy of the AT-cut quartz plate. It is possible to etch deeper than the portion.
When the area of the quartz substrate is reduced, the area of the connected region 11b that is a portion to be etched is also reduced. In such a case, as shown in FIG. 4, it is possible to form an adhesive container having a large amount of adhesive because the crystal substrate has anisotropy and is deep with a narrow recess.

Next, FIGS. 5A, 5 </ b> B, and 5 </ b> C are diagrams illustrating a process of manufacturing a quartz substrate provided with an adhesive container according to the present invention by a photolithography technique. Here, the case where the quartz substrate shown in FIG. 1 is manufactured will be described as an example.
5A, a flat crystal original plate 30 having a thickness t is prepared, and in FIG. 5B, the crystal original plate 3 is prepared.
A photoresist film 31 is applied in a range corresponding to the connected region 11b on the one side along the portion that becomes the convex surface 21 (including the annular portion 22) excluding the region that becomes the concave portion. In (c), the quartz substrate surface not masked by the photoresist film 31 is etched in this state, thereby processing the range to be the vibration region 11a and the range to be the recess until the thickness t ′ is reached.

In the quartz substrate 11 manufactured by this manufacturing method, the range to be the vibration region 11a and the range to be the recess have the same thickness t ′.
If t ′> t1, the depth of the adhesive accommodating portion as the recess becomes deeper than that in the case of FIG. 5C, so that more adhesive can be accommodated. Further, if t ′ <t1, the thinned portion in the connected region becomes thicker than in the case of FIG. 5C, so that the connected region is not easily damaged.
In the case where the adhesive accommodating portion 20 is a through hole, etching may be performed until the inner bottom surface of the concave portion penetrates in a state where the vibration region, the convex surface 21 and the annular portion 22 are masked. Alternatively, the through hole can be formed in a shorter time by applying the photoresist film 31 also to the lower surface side of the connected region 11b and simultaneously performing etching from both the front and back surfaces.

Next, FIGS. 6A to 6E are diagrams showing another process for manufacturing a quartz substrate provided with an adhesive container according to the present invention by a photolithography technique. Here, the case where the quartz substrate shown in FIG. 1 is manufactured will be described as an example.
6A, a flat crystal original plate 30 having a thickness t is prepared, and in FIG. 6B, the crystal original plate 3 is prepared.
A photoresist film 31 is applied over the entire surface in a range corresponding to the connected region 11b on one side of 0. In (c), one surface of the unmasked vibration region 11a is etched until the required thickness t ″ is obtained, thereby forming the quartz original plate 30 in which only the vibration region 11a is thinned.
In (d), a photoresist 32 is applied to the connected region 11 b of the crystal original plate 30 along the portion that becomes the convex surface 21 (including the annular portion 22) excluding the region that becomes the concave portion 20. In (e), the substrate surface of the connected region 11b that is not masked by the photoresist 32 is etched in this state until the vibration region 11a has a thickness t ′.

In the quartz substrate 11 manufactured by this manufacturing method, the range to be the vibration region 11a and the range to be the recess have different thicknesses. Therefore, while the vibration area can be thinned to a desired thickness, the overall strength of the connected area can be increased by appropriately controlling the depth of the recess formed in the connected area 11b. it can.
In the case where the adhesive accommodating portion 20 is a through hole, etching may be performed until the inner bottom surface of the concave portion penetrates in a state where the vibration region, the convex surface 21 and the annular portion 22 are masked. Alternatively, if the photoresist film 32 is applied also to the lower surface side of the connected region 11b and etching is performed simultaneously from both the front and back surfaces, the through hole can be formed in a shorter time.
Note that the quartz substrate 11 according to the other embodiment shown in FIGS. 2 to 4 can also be processed by the same process as in FIG. 5 or FIG.
When the crystal resonator element 10 is manufactured using the crystal substrate 11 manufactured by the above process, the excitation electrode 12 and the lead electrode 13 are formed on both main surfaces of the crystal substrate 11.

Next, FIG. 7 is a longitudinal sectional view showing a configuration example in which the crystal resonator element according to the present invention is applied to a package of a type using a seam ring.
In this quartz crystal resonator, an annular seal ring 42 is erected and fixed by a conductive bonding means on a metallized film 41 formed along the periphery of the upper surface of a flat plate 40 made of ceramic, and provided on the bottom plate. The inner terminal 43 is cantilevered by adhering the lower surface of one end (connected region 11b) of the crystal resonator element 10 to the internal terminal 43 with a conductive adhesive 45. The package 2 constituting the crystal resonator includes a bottom plate 40, a metallized film 41, and a seal ring 4
2 is provided.

By using the type shown in FIG. 1 or FIG. 2 to FIG. 4 as the crystal vibrating element 10, the impact resistance effect due to the increase in the amount of adhesive used and the trouble due to the outflow of the conductive adhesive are eliminated. it can. In particular, in this crystal resonator, the internal terminal 43 and the seal ring 42 are provided.
Since the distance between the internal terminals 43 is close, the internal terminals 43 are reduced as the package size is reduced.
The distance between the seal ring 42 and the seal ring 42 is closer, but by using a crystal resonator element (crystal substrate) provided with the adhesive container 20 to prevent the conductive adhesive from flowing out, the internal terminal and the seal ring 42 are sealed. The trouble (deterioration of electrical characteristics) due to a short circuit with the ring can be solved.

Next, FIGS. 8A and 8B are a longitudinal sectional view showing a configuration of a crystal resonator according to another embodiment of the present invention, and a plan view of a main part (a plan view with a cover member removed). is there. In addition, the same code | symbol is attached | subjected and demonstrated to the same part as said each embodiment.
The crystal resonator according to this embodiment is characterized by the shape of the crystal resonator element 10 (crystal substrate 11). That is, the crystal resonator element 10 (crystal substrate 11) according to this embodiment has an internal terminal when the connected region 11b of the crystal resonator element is bonded onto the internal terminal (element mounting pad) 4 provided on the package 2 side. By forming the convex portion 50 for damming the adhesive so that the conductive adhesive 5 applied thereon does not flow out to the vibration region 11a side of the crystal resonator element, the convex portion 5 is formed.
The structure using the non-convex surface 51 located on the opposite side of 0 as the adhesive accommodating portion is characteristic.

The convex portion 50 according to this embodiment is a single plate-like body protruding orthogonally from the lower surface of the quartz substrate 11 and extends along the entire length in the width direction of the quartz substrate. The protrusion 50 is formed at a position (vibration region 11 a side) avoiding each pad 13 a located at the end of each lead electrode 13. Therefore, when the edge of the crystal substrate is bonded onto the internal terminal (element mounting pad) 4 using the conductive adhesive 5 as shown in the figure, the conductive adhesive 5 is closer to the pad 13a than the convex portion 50. By working so as to accumulate, it is possible to prevent the conductive adhesive 5 from flowing over the convex portion 50 to the vibration region side.

In this example, the convex portion 50 is a single long plate member extending over the entire length in the width direction of the quartz substrate, but one short convex portion 50 is provided at a position corresponding to each internal terminal 4. You may make it arrange | position and divide | segment. Thus, the convex part 50 is comprised shortly, and each internal terminal 4 and the vibration area | region 11a are comprised.
By limiting the arrangement to the region between the protrusions 50, it is less likely that the convex portion 50 interferes with the vibration region 11a and affects the resonance frequency.

Next, FIG. 9 is a plan view of a principal part of the modified embodiment of FIG. 8, and the convex portions 50 according to this embodiment are short plate members, one at a time corresponding to each internal terminal 4. Thus, the conductive adhesive which is crushed by the quartz substrate 11 and tends to flow in the direction of the vibration region 11a from each internal terminal 4 is dammed. The convex portion 50 according to this embodiment is not parallel to the width direction of the quartz substrate 11 but is inclined so that the inner end portion of the convex portion 50 approaches the pad 13a side as shown in the figure. By configuring in this way, the possibility that the convex portion 50 interferes with the vibration region 11a and fluctuates its resonance frequency is further reduced.
In the above embodiment, the convex portion 50 is configured in a straight line, but the holding force of the conductive adhesive may be increased as a bent or curved shape.

Next, FIG. 10 shows a surface-mounted crystal oscillator (piezoelectric oscillator) by assembling an oscillation circuit component (IC component) to a crystal resonator according to an embodiment of the present invention (embodiment of FIG. 1).
FIG. Of the constituent elements constituting the crystal resonator, FIG.
The same parts as those in the embodiment will be described with the same reference numerals.
The crystal oscillator 60 includes an upper cavity 6 of a package (insulating container) 61 having an H-shaped cross section.
In addition, the quartz resonator element 10 is mounted in 2, and an IC component (bare chip) 64 that constitutes an oscillation circuit, a temperature compensation circuit, and the like is housed in the lower cavity 63.
The crystal oscillator 60 includes an adhesive accommodating portion 20 on the lower surface of the thick connected region 11 b and is bonded and fixed to the internal terminal (element mounting pad) 4 by the conductive adhesive 5. The upper cavity 62 is hermetically sealed by a metal lid (lid member) 15.
A mounting terminal 65 is disposed on the lower surface of the outer frame forming the lower cavity 63. An IC mounting pad 66 for flip-chip mounting the IC component 64 is formed on the ceiling surface of the lower cavity 63.

As described above, the crystal resonator 1 including the crystal resonator element 10 (crystal substrate 11) according to the present invention includes an IC.
By adding the component 64, a surface-mount crystal oscillator can be constructed.
Note that the above configuration example is merely an example, and the assembly structure when the IC component is assembled to the package can be variously modified. For example, an IC component can be accommodated in a cavity of a crystal resonator.
Although a quartz crystal resonator is illustrated as an example of a piezoelectric resonator, the present invention can be applied to general piezoelectric devices using a piezoelectric material other than quartz.
The structure of the piezoelectric vibration element (piezoelectric substrate) provided with the adhesive container according to the present invention is not only a flat plate type (strip shape) as illustrated, but also a tuning fork type in which the vibration region is bifurcated. Alternatively, the present invention can be applied to all types of piezoelectric vibration elements such as a type in which a concave portion is provided at the center of a thick piezoelectric substrate.

(A) thru | or (f) are the external appearance perspective view of a crystal oscillator as an example of the piezoelectric device which concerns on one Embodiment of this invention, a longitudinal cross-sectional view, the top view in the state which removed the metal cover, a principal part longitudinal cross-sectional view, It is AA sectional drawing of (d), and a bottom view of a single crystal vibration element. (A) And (b) is a bottom view and B-B which shows composition of adhesive storage part 20 which consists of a crevice formed in an adhesion surface (opposite surface to an internal terminal) of a thick connection area, or a penetration hole. It is sectional drawing. (A) And (b) is the bottom view and CC sectional drawing which show the structure of the adhesive agent accommodating part which concerns on other embodiment of this invention. (A) And (b) is a bottom view which shows the structure of the adhesive agent accommodating part which concerns on other embodiment of this invention, and DD sectional drawing. (A) (b) And (c) is a figure which shows the process of manufacturing the quartz substrate provided with the adhesive agent accommodating part which concerns on this invention by a photolithographic technique. (A) thru | or (e) is a figure which shows the other process of manufacturing the quartz substrate provided with the adhesive agent accommodating part which concerns on this invention by a photolithographic technique. It is a longitudinal cross-sectional view which shows the structural example which applied the crystal vibration element which concerns on this invention to the type package which uses a seam ring. (A) And (b) is a longitudinal cross-sectional view which shows the structure of the crystal oscillator based on other embodiment of this invention, and a principal part top view (plan view of the state which removed the cover member). It is a principal part top view of deformation | transformation embodiment of FIG. 1 is a longitudinal sectional view showing a configuration example of a surface-mounted crystal oscillator by assembling an oscillation circuit component to a crystal resonator according to an embodiment of the present invention. (A), (b), and (c) are the longitudinal cross-sectional view, the principal part top view, and the principal part longitudinal cross-sectional view of the conventional surface mount-type crystal resonator etc. which were disclosed by patent document 1. FIG. It is explanatory drawing of the prior art example disclosed by patent document 3. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Quartz crystal resonator, 2 ... Package, 3 ... Cavity, 4 ... Internal terminal, 5 ... Conductive adhesive, 6 ... Mounting terminal, 7 ... Connection conductor, 10 ... Quartz crystal vibration element, 11 ... Quartz substrate, 11a ... Vibration Area 11b ... connected area 12 excitation electrode 13 lead electrode 13a pad 20
Adhesive accommodating part, 21 ... convex surface, 22 ... annular part, 30 ... crystal original plate, 31 ... photoresist film,
32 ... Photoresist, 40 ... Bottom plate, 41 ... Metallized film, 42 ... Seal ring, 43 ...
Internal terminal 45 ... conductive adhesive 50 ... convex part 51 ... non-convex surface 60 ... crystal oscillator 62 ...
Upper cavity 63 ... Lower cavity 64 ... IC component 65 ... Mounting terminal 66 ... IC
Mounting pad.

Claims (11)

A piezoelectric substrate comprising a vibration region and a connected region integrally connected to the vibration region,
1. A piezoelectric substrate according to claim 1, wherein an adhesive accommodating portion comprising a recess or a through hole is formed on one surface of the connected region. A piezoelectric vibration element comprising: a piezoelectric substrate; an excitation electrode formed on the piezoelectric substrate; and a lead electrode extending from the excitation electrode to one end edge of the piezoelectric substrate,
A piezoelectric vibration element characterized in that an adhesive accommodating portion including a recess or a through hole is formed on a surface along one edge of the piezoelectric substrate including an end portion of the lead electrode. The said adhesive agent accommodating part is formed in the adhesive surface with the adhesive agent of the thick part formed in the one end edge of the said piezoelectric substrate containing the edge part of the said lead electrode. Piezoelectric vibration element. 3. The adhesive accommodating portion is surrounded by a thick annular portion.
Or the piezoelectric vibration element of 3. The adhesive accommodating portion is a non-convex surface adjacent to a convex portion for adhesive damming formed on a surface along one edge of the piezoelectric substrate including an end portion of the lead electrode. 2. The piezoelectric vibration element according to 2. A package having two element mounting pads for electrically connecting to each excitation electrode of the piezoelectric vibration element on the upper surface, and a mounting terminal on the bottom,
A connection conductor for applying a predetermined wiring between any of the mounting terminals and the element mounting pad;
The end of each lead electrode is electrically and mechanically connected to the element mounting pad by a conductive adhesive, and is cantilevered on the package. A surface-mount type piezoelectric vibrator comprising: a piezoelectric vibration element according to claim 1; A package having at least an upper surface side cavity and a mounting terminal at the bottom;
A connection conductor for applying a predetermined wiring between any of the mounting terminals and the element mounting pad;
The end of each lead electrode is electrically and mechanically connected to the element mounting pad by a conductive adhesive, and is cantilevered on the package. A surface-mount type piezoelectric vibrator comprising: a piezoelectric vibration element according to claim 1; A package having two element mounting pads for electrically connecting to each excitation electrode of the piezoelectric vibration element on the upper surface, and a mounting terminal on the bottom,
An annular seal ring erected along the periphery of the upper surface of the package;
A connection conductor for applying a predetermined wiring between any of the mounting terminals and the element mounting pad;
The end of each lead electrode is electrically and mechanically connected to the element mounting pad by a conductive adhesive, and is cantilevered on the package. A surface-mount type piezoelectric vibrator comprising: a piezoelectric vibration element according to claim 1; A method of manufacturing the piezoelectric substrate according to claim 1 by photolithography technology,
Preparing a piezoelectric master plate;
Applying a mask with a photoresist to a portion excluding the region to be the adhesive container of the region to be connected of the piezoelectric original plate; and
Etching the vibration region of the piezoelectric original plate and one surface of the connected region not masked by the photoresist in a batch;
Are sequentially carried out. A method for manufacturing a piezoelectric substrate, comprising: 10. The piezoelectric original plate is formed of an AT-cut quartz plate, and a deep adhesive container is formed on one surface of the connected region by etching using the anisotropy of the AT-cut quartz plate. A method for producing a piezoelectric substrate as described in 1. A surface-mount piezoelectric oscillator comprising the surface-mount piezoelectric vibrator according to claim 6, 7 or 8 and an oscillation circuit component.

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