JP6315115B2 - Vibration element, vibrator, electronic device, electronic device, and moving object - Google Patents

Description

  The present invention relates to a vibration element, a vibrator, an electronic device, an electronic apparatus, a moving body, and a method for manufacturing a vibration element that excite thickness shear vibration.

Quartz crystal resonators that use crystal vibration elements that are excited by thickness shear vibration are suitable for miniaturization and high frequency, and have excellent frequency temperature characteristics. Used in. In particular, in recent years, with the reduction in size and thickness of various electronic devices such as mobile phones and computers, there has been an increasing demand for further downsizing and thickness reduction of crystal units used therefor.
Patent Document 1 discloses a method of manufacturing a plurality of crystal resonator elements from a large crystal substrate by a batch processing method by using a photolithographic technique and an etching technique for forming the external shape of the crystal resonator element and the excitation electrode. ing.

  However, when trying to reduce the size of the crystal unit, the distance between the vibration region and the holding portion becomes close, so that the vibration energy leaks and the CI (crystal impedance = equivalent resistance of the crystal unit) is reduced or the main vibration is reduced. In the vicinity of the resonance frequency of the thickness-shear vibration, unnecessary spurious such as a thickness bending vibration depending on the contour size of the vibration part is generated, and the frequency and CI discontinuous fluctuation with respect to the temperature change, the so-called singular phenomenon (Anomalous Activity Dip) etc. occurred. Therefore, Patent Document 2 proposes that the crystal resonator element has a mesa structure to avoid CI reduction and peculiar phenomena associated with miniaturization, and in order to achieve mass production and cost reduction, A method of manufacturing a plurality of crystal resonator elements from a large crystal substrate by a batch processing method using a photolithographic technique and an etching technique for forming the outer shape of the resonator element and the excitation electrode is disclosed.

JP 2011-19206 A JP 2010-62723 A

When the crystal resonator element is manufactured by the manufacturing method disclosed in Patent Documents 1 and 2 described above, the outer shape is uniform and the excitation electrode is disposed at a predetermined position with high accuracy. A crystal resonator element that sufficiently satisfies the specification standards can be obtained. However, the DLD (Drive Level Dependence) characteristic of the crystal resonator element that affects the start-up of the oscillator on which the crystal resonator element is mounted is very bad, and there is a problem that the manufacturing yield is significantly reduced.
Therefore, in a method of manufacturing a plurality of vibration elements from a large substrate by photolithography technique and etching technique, a small vibration element and a method for manufacturing the vibration element that can improve the yield of DLD characteristic inspection are provided. To do.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  Application Example 1 The vibration element according to this application example includes a substrate, a lower conductive layer provided on the surface, and a surface of the lower conductive layer when viewed from a direction orthogonal to the surface of the substrate. And an electrode made of an upper conductive layer having a shape that fits within the outer edge of the lower conductive layer.

  According to this application example, in the vibration element excited by the thickness shear vibration, there is no gap between the upper conductive layer and the lower conductive layer of the electrode, which causes deterioration of the DLD characteristics, so that there is no DLD. It is possible to obtain a vibration element that can prevent deterioration of characteristics and improve the yield of DLD characteristic inspection.

  Application Example 2 In the resonator element according to the application example described above, when viewed from a direction orthogonal to the surface of the substrate, an outer shape of the upper conductive layer is smaller than an outer shape of the lower conductive layer. Features.

  According to this application example, since the upper conductive layer and the lower conductive layer are all in close contact with each other, it is possible to prevent the deterioration of the DLD characteristics and to obtain a vibration element that improves the yield of the DLD characteristics inspection. effective.

  Application Example 3 In the resonator element according to the application example described above, the electrode is an excitation electrode.

  According to this application example, since the electrode in which the upper conductive layer and the lower conductive layer are in close contact with each other is used as the excitation electrode, it is possible to prevent the deterioration of the DLD characteristics and obtain a vibration element having stable resonance characteristics. There is an effect.

  Application Example 4 In the resonator element according to the application example described above, the substrate is a substrate that vibrates by thickness shear vibration.

  According to this application example, the thickness-shear vibration is suitable for downsizing and high frequency, and a frequency temperature characteristic having an excellent cubic curve can be obtained. Therefore, a vibration element having a small size and high frequency and excellent frequency temperature characteristics can be obtained. There is an effect.

  Application Example 5 In the vibration element according to the application example described above, the vibration element that vibrates by thickness shear vibration and an outer edge portion that is integrated with an outer edge of the vibration portion and is thinner than the thickness of the vibration portion. It is characterized by.

  According to this application example, since the vibration part has a mesa structure, it is possible to avoid coupling with the contour system spurious and confine the vibration energy of only the main vibration, so that the CI is small and spurious near the resonance frequency is suppressed. Thus, there is an effect that an obtained vibration element can be obtained.

  Application Example 6 The vibration element according to the application example described above includes a vibrating portion that vibrates by thickness-shear vibration and an outer edge portion that is integrated with an outer edge of the vibrating portion and is thicker than the thickness of the vibrating portion. It is characterized by.

  According to this application example, even if the vibration part is a very thin high-frequency vibration element, it can be mounted with a thick outer edge integrated with the vibration part, so it is highly reliable with excellent impact resistance and vibration resistance. There is an effect that an oscillating element having the property can be obtained.

  Application Example 7 A vibrator according to this application example includes the vibration element according to the application example described above and a package that accommodates the vibration element.

  According to this application example, since the vibration element is accommodated in the package, it is possible to prevent the influence of disturbance such as a temperature change and a humidity change and the influence due to the contamination. Therefore, the frequency reproducibility, the frequency temperature characteristic, the CI temperature characteristic, There is an effect that a small vibrator having excellent frequency aging characteristics and good DLD characteristics can be obtained.

  Application Example 8 An electronic device according to this application example includes the vibration element according to the application example, the electronic element, and the package on which the vibration element and the electronic element are mounted. .

  According to this application example, there is an effect that an electronic device such as an oscillator having excellent start-up characteristics can be obtained by mounting a vibration element having good DLD characteristics on an oscillation circuit configured using various electronic elements.

  Application Example 9 In the electronic device according to the application example described above, the electronic element is at least one of a thermistor, a capacitor, a reactance element, and a semiconductor element.

  According to this application example, the oscillation characteristics including the temperature compensation circuit and the voltage control circuit configured using various electronic elements are mounted on the oscillation circuit having excellent frequency temperature characteristics and excellent DLD characteristics, thereby improving the startup characteristics. An excellent electronic device such as a temperature-compensated oscillator or a voltage-controlled oscillator can be obtained.

  Application Example 10 An electronic apparatus according to this application example includes the vibration element described in the application example.

  According to this application example, a vibration element having a good DLD characteristic can be directly mounted on a mounting board by COB (Chip On Board) technology, so that the mounting area is reduced, the oscillation starting characteristic is excellent, and a good reference frequency source is provided. There exists an effect that the small electronic device provided with can be comprised.

  Application Example 11 The electronic device described in the application example includes the vibrator described in the application example.

  According to this application example, a vibrator having a vibration element having a satisfactory DLD characteristic and sufficiently satisfying specifications and specifications such as CI and temperature characteristics is used, and has an excellent oscillation start characteristic and a good reference frequency source. There is an effect that an electronic device can be configured.

  [Application Example 12] The electronic apparatus described in the application example includes the electronic device described in the application example.

  According to this application example, by using an electronic device that has a vibration element with satisfactory DLD characteristics and sufficiently satisfies specifications and specifications such as CI and temperature characteristics, excellent oscillation start characteristics and good standards. There exists an effect that the electronic device provided with the frequency source can be comprised.

  Application Example 13 A moving object according to this application example includes the vibration element described in the application example.

  According to this application example, it is possible to configure a stable reference frequency source by using a vibration element having a good frequency temperature characteristic, and it is possible to configure a movable body including a stable and accurate electronic control unit.

  [Application Example 14] A method for manufacturing a resonator element according to this application example includes a step of preparing a substrate on which two or more conductive layers of different materials are laminated, and an upper layer of the laminated conductive layers. Etching the conductive layer; etching the lower conductive layer provided on the substrate side of the upper conductive layer; and etching the upper conductive layer into the lower conductive layer. And an etching process with an etching solution having a higher etch rate than the upper conductive layer.

  According to this application example, the under-etched portion of the upper conductive layer generated when the lower conductive layer of the excitation electrode is etched can be removed by performing the step of etching the side surface of the upper conductive layer again. Accordingly, there is an effect that the adhesion between the upper conductive layer and the lower conductive layer can be improved, and a vibration element having good DLD characteristics can be manufactured.

  Application Example 15 In the method for manufacturing a vibration element according to the application example described above, the etching rate of the lower conductive layer is higher than the upper layer with respect to the etching solution used in the etching process of the upper conductive layer. The etching rate of the upper conductive layer is lower than the etching rate of the lower conductive layer with respect to the etchant used in the step of etching the lower conductive layer. Characterized by being slow.

  According to this application example, the upper conductive layer and the lower conductive layer can be selectively etched, so that an excitation electrode with high dimensional accuracy of each conductive layer can be formed, variation in various characteristics is small, and DLD characteristics are obtained. There is an effect that a small-sized vibration element with good quality can be manufactured.

  Application Example 16 In the method for manufacturing a vibration element according to the application example, the upper conductive layer and the lower conductive layer are made of different materials.

  According to this application example, since the upper conductive layer and the lower conductive layer are made of different materials, an etching solution corresponding to each conductive layer can be used. Therefore, each conductive layer is selectively etched, An excitation electrode with high external dimensional accuracy can be formed, and variations in various characteristics are small, and a small vibration element having good DLD characteristics can be produced.

  Application Example 17 In the method for manufacturing a vibration element according to the application example described above, the material of the upper conductive layer is Au, Ag, or Pt, and the material of the lower conductive layer is Cr, Ni , Ti, or NiCr alloy.

  According to this application example, the material of the upper conductive layer and the lower conductive layer can be combined so as to have frequency temperature characteristics and CI suitable for the intended use. There is an effect that a small vibration element with a small size can be manufactured.

It is the schematic which showed the structure of the vibration element which concerns on one Embodiment of this invention, (a) is a top view, (b) is PP sectional drawing. The figure for demonstrating the relationship between an AT cut quartz substrate and a crystal axis. The schematic sectional drawing of the flowchart which shows an example of the manufacturing method of the vibration element which concerns on one Embodiment of this invention. It is an expanded sectional view explaining composition of an electrode of a vibration element concerning one embodiment of the present invention, (a) is a sectional view of a vibration element manufactured by a manufacturing method concerning this embodiment, and (b) is conventional manufacture. Sectional drawing of the vibration element manufactured by the method. It is a DLD characteristic of a vibration element manufactured by the manufacturing method concerning one embodiment of the present invention, (a) shows a frequency change amount, and (b) shows a CI change amount. It is a DLD characteristic of the vibration element manufactured with the conventional manufacturing method, (a) is a figure which shows frequency change amount, (b) is a figure which shows CI change amount. It is the schematic which showed the structure of the vibration element which concerns on one Embodiment of this invention, (a) is a top view, (b) is PP sectional drawing. It is the schematic which showed another structure of the vibration element which concerns on one Embodiment of this invention, (a) is a top view of the modification 1, (b) is a top view of the modification 2, (b) is a modification. FIG. It is the schematic which showed the structure of the modification 4 of the vibration element which concerns on one Embodiment of this invention, (a) is a top view, (b) is PP sectional drawing. It is the schematic which showed the structure of the vibrator | oscillator which concerns on one Embodiment of this invention, (a) is a top view, (b) is a longitudinal cross-sectional view. It is the schematic which showed the structure of the electronic device which concerns on one Embodiment of this invention, (a) is a top view, (b) is a longitudinal cross-sectional view. It is the schematic which showed the structure of the modification of the electronic device which concerns on one Embodiment of this invention, (a) is a longitudinal cross-sectional view of the modification 1, (b) is a longitudinal cross-sectional view of the modification 2. The perspective view which shows the structure of the mobile type (or notebook type) personal computer as an electronic device provided with the vibration element which concerns on one Embodiment of this invention. The perspective view which shows the structure of a mobile telephone (PHS is also included) as an electronic device provided with the vibration element which concerns on one Embodiment of this invention. The perspective view which shows the structure of the digital camera as an electronic device provided with the vibration element which concerns on one Embodiment of this invention. The perspective view which shows the structure of the motor vehicle as a moving body to which the vibrator provided with the vibration element which concerns on one Embodiment of this invention, or an electronic device is applied.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic diagram illustrating a configuration of a vibration element according to an embodiment of the present invention. FIG. 1 (a) is a plan view of the vibration element, and FIG. 1 (b) is a PP line of FIG. 1 (a). It is sectional drawing.

(Configuration of vibration element)
The vibration element 1 includes a substrate 10 having a vibration part 12, and a base electrode layer 29 as a lower conductive layer laminated so as to face both main surfaces (front and back surfaces in the ± Y ′ direction) of the substrate 10. And an electrode layer 28 as the uppermost conductive layer. In the present embodiment, a configuration in which two conductive layers are stacked will be described.
The vibration element 1 includes an excitation electrode 20 including a base electrode layer 29 and an electrode layer 28, a lead electrode 23, a pad electrode 24, and a connection electrode 26.
The excitation electrode 20 is an electrode that drives the vibration unit 12 and is formed so as to be opposed to the substantially central portions of both main surfaces (front and back surfaces in the ± Y ′ direction) of the vibration unit 12. The excitation electrode 20 includes a main electrode 21 which is a part of the electrode layer 28 and a main electrode base part 22 which is a part of the base electrode layer 29 so that the outer edge of the main electrode 21 is within the outer edge of the main electrode base part 22. Is formed.
The lead electrode 23 extends from the excitation electrode 20 and is conductively connected to a pad electrode 24 formed at the end of the substrate 10.
The pad electrode 24 is formed to face the end portions of both main surfaces of the substrate 10. The pad electrodes 24 on both main surfaces are conductively connected by connection electrodes 26 formed on the side surface portion 13 of the substrate 10.

In the embodiment shown in FIG. 1A, an example in which the shape of the excitation electrode 20 formed so as to face the main surface of the substantially central portion of the vibration unit 12 is rectangular has been shown, but it is necessary to limit to this. Alternatively, the shape of the excitation electrode may be circular or elliptical.
The excitation electrode 20, the lead electrode 23, the pad electrode 24, and the connection electrode 26 are formed by using, for example, a chromium (Cr) film as a lower layer and a gold ( Au) is stacked to form a film. As electrode materials, nickel (Ni), titanium (Ti), nickel chromium alloy (NiCr) instead of chromium (Cr) in the lower layer, and silver (Ag) instead of gold (Au) in the uppermost layer Platinum (Pt) may be used.
Furthermore, although the configuration in which two conductive layers are stacked has been described, the present invention is not limited to this. A configuration in which three or more layers are laminated may be used.

  When the substrate 10 is a piezoelectric material, the vibration element 1 generates an electric field in the vibration part 12 between the vibration electrode 1 and the excitation electrode 20 due to the excitation current input from the pad electrode 24, and the vibration part 12 vibrates due to the piezoelectric effect. When the substrate 10 is formed using a crystal belonging to a trigonal piezoelectric material, the substrate 10 has crystal axes X, Y, and Z orthogonal to each other as shown in FIG. The X-axis is an electrical axis, the Y-axis is a mechanical axis, and the Z-axis is an optical axis. The so-called rotation Y cut out along a plane obtained by rotating the XZ plane around the X axis by a predetermined angle θ. A flat plate made of a cut quartz substrate is used as the substrate 10.

  For example, when the rotated Y-cut quartz substrate is an AT-cut quartz substrate, the angle θ is 35.25 ° (35 ° 15 ′). Here, when the Y-axis and the Z-axis are rotated by an angle θ around the X-axis to make the Y′-axis and the Z′-axis, the AT-cut quartz substrate has crystal axes X, Y ′, and Z ′ that are orthogonal to each other. Therefore, the AT-cut quartz substrate has a Y ′ axis in the thickness direction, a surface including the X axis and the Z ′ axis orthogonal to the Y ′ axis is a main surface, and thickness shear vibration is excited as a main vibration on the main surface. . The substrate 10 is formed from the AT-cut quartz substrate thus formed. In addition, the board | substrate 10 which concerns on this embodiment is not limited to AT cut whose angle (theta) shown in FIG. 2 is 35.25 degrees, For example, board | substrates 10, such as BT cut which excites thickness shear vibration, may be sufficient.

(Manufacturing method of vibration element)
Next, a method for manufacturing a vibration element according to an embodiment of the present invention will be described with reference to the flowchart of FIG. In consideration of mass productivity and manufacturing cost, the vibration element 1 is generally manufactured from a large substrate by a batch processing method. Here, a schematic cross-sectional view of one vibration element 1 will be described. The manufacturing process includes an outer shape forming process for forming the outer shape of the vibrating element 1 and an electrode forming process for forming electrode patterns on both main surfaces of the substrate 10 of the vibrating element 1.
In the outer shape forming step, first, the substrate 10 is washed with pure water (ST11), and then a base film 34 is provided on the front and back surfaces of the substrate 10. This is provided in order to compensate for the fact that gold (Au) serving as the corrosion-resistant film 36 is weakly adherent to the substrate 10. As the base film 34, for example, chromium (Cr) is formed by sputtering or vapor deposition. Yes. On top of this, gold (Au) is formed as a corrosion-resistant film 36 by sputtering or vapor deposition (ST12).
Next, a resist 32 is applied to the entire surface of the corrosion-resistant film 36 (ST13), and exposure / development is performed to form a resonator element outer shape mask (ST14).

Subsequently, gold (Au), which is the corrosion-resistant film 36 exposed from the mask opening, is etched using, for example, a potassium iodide solution, and then chromium (Cr), which is the base film 34, using a ceric ammonium nitrate solution. Is etched (ST15).
Here, the potassium iodide solution that is an etching solution of gold (Au) that is the corrosion resistant film 36 selectively etches gold (Au) and does not etch chromium (Cr) that is the base film 34, or etching. Even so, the etching rate is 1/10 or less of gold (Au).
Also, for the ceric ammonium nitrate solution that is an etching solution of chromium (Cr) that is the base film 34, chromium (Cr) is selectively etched and gold (Au) that is the corrosion-resistant film 36 is not etched, or Even if it etches, an etching rate is 1/10 or less of chromium (Cr).
Accordingly, since the upper corrosion-resistant film 36 and the lower base film 34 can be selectively etched, a high dimensional accuracy outer mask can be formed, and the vibration element 1 having a high precision outer dimension can be obtained.
Next, the substrate 10 exposed from the mask opening is etched using, for example, an ammonium fluoride solution in the case of a quartz substrate (ST16). Thereby, as shown to Fig.1 (a), the external shape of the vibration element 1 is formed.
Subsequently, the resist 32 is peeled off, and the corrosion-resistant film 36 and the base film 34 are all removed using the two types of solutions (ST17).

Next, an electrode formation process will be described. In the electrode formation, as in the outer shape formation, gold (Au), which is the electrode layer 28 as the uppermost conductive layer, and chromium (Cr) for improving the adhesion of the substrate 10 are disposed on the front and back surfaces of the substrate 10. A base electrode layer 29 as a conductive layer is formed by sputtering or vapor deposition in the order of chromium (Cr) and gold (Au) (ST18).
Next, a resist 32 is applied to the entire surface of the electrode layer 28 (ST19), and exposed and developed to form an excitation electrode mask (ST20).
Subsequently, gold (Au) and chromium (Cr) for the excitation electrode 20 are also etched with the solution used in the outer shape forming process. First, gold (Au) to be the electrode layer 28 is etched (ST21), and then chromium (Cr) of the base electrode layer 29 is etched (ST22). At this time, since a gap 70 is generated between the electrode layer 28 and the substrate 10, next, gold (Au) that becomes the electrode layer 28 is etched again to remove the gap 70 (ST23). ).
Here, since an etching solution capable of selectively etching the electrode layer 28 and the base electrode layer 29 is used, the high-precision outer dimensions are obtained in the same manner as a vibration element having a high-precision outer dimension is obtained. It is possible to obtain the excitation electrode 20.
Thereafter, the resist 32 is peeled off (ST24), and the vibration element 1 is completed.

In the conventional manufacturing method, after etching chromium (Cr) of the base electrode layer 29, the resist 32 is peeled off (corresponding to ST24), and the vibration element 1 is completed. Therefore, the resonator element 1 has the gap 70 between the electrode layer 28 and the substrate 10.
In the manufacturing method of the above-described embodiment, after the chromium (Cr) etching of the base electrode layer 29 (ST22), the gold (Au) that becomes the electrode layer 28 is etched again (ST23).
Thereby, after the chromium (Cr) of the base electrode layer 29 is etched, the gap portion 70 formed between the electrode layer 28 and the substrate 10 can be eliminated. Next, the elimination of the gap 70 will be described.

FIG. 4 is an enlarged cross-sectional view illustrating the configuration of the electrodes of the vibration element according to the embodiment of the present invention. FIG. 4A is a cross-sectional view of the vibration element manufactured by the manufacturing method according to the embodiment. (B) is sectional drawing of the vibration element manufactured by the conventional manufacturing method.
In the resonator element 200 manufactured by the conventional manufacturing method shown in FIG. 4B, the gap portion 270 is provided between the main electrode 221 and the substrate 210, whereas the embodiment shown in FIG. In the resonator element 1 in such a manufacturing method, the gap 70 shown in FIG. 3 (ST22) is not generated. The reason why the gap 270 is generated between the main electrode 221 and the substrate 210 in the conventional manufacturing method is that the deposited metal material is isotropic, and not only the direction perpendicular to the substrate surface during etching but also the substrate Side etching, which is a phenomenon in which the side wall surface of the main electrode base portion 222 also progresses by etching in a direction parallel to the surface, and undercut, which is a corrosion phenomenon in which an etching solution wraps under the mask. Because it happens. Accordingly, the main electrode base portion 222 which is a part of the base electrode layer 29 has a smaller outer shape (outer edge) than the main electrode 221 serving as a mask in the chromium (Cr) etching, and generates a void portion 270. It has been found from the researches, experiments, and analysis by the inventors of the present application that the void portion 270 significantly deteriorates the DLD characteristics and significantly reduces the manufacturing yield.

Therefore, in the manufacturing method according to the present embodiment, after the chromium (Cr) etching of the main electrode base portion 22 (ST22 shown in FIG. 3), the region protruding outside from the outer shape of the main electrode base portion 22 by the gap 70 is formed. A step of etching gold (Au) as the main electrode 21 again (ST23 shown in FIG. 3) was added. By this etching (ST23) again, at least the gold (Au) in the protruding region is removed, so that the gap 70 is eliminated. As a result, the outer edge of the main electrode 21 is located inside the outer edge of the main electrode base 22, and the main electrode 21 is in the entire region of the interface between the main electrode 21 and the main electrode base 22. It was realized to form the excitation electrode 20 in close contact with the electrode.
Here, although the excitation electrode 20 shown in FIG. 1 has been described as an example, the other electrodes (the lead electrode 23, the pad electrode 24, and the connection electrode 26) preferably have the same electrode configuration.

5A and 5B show DLD characteristics of the resonator element manufactured by the manufacturing method according to the embodiment of the present invention. FIG. 5A shows the frequency change amount and FIG. 5B shows the CI change amount.
FIG. 6 shows the DLD characteristics of the vibration element manufactured by the conventional manufacturing method. FIG. 6A shows the frequency change amount, and FIG. 6B shows the CI change amount.
5 and 6, the DLD characteristics of the resonator element 1 produced by the manufacturing method according to the present embodiment are stable with less variation in both frequency and CI than those of the conventional manufacturing method.
Until now, it has been said that the deterioration of the DLD characteristics is caused by the occurrence of residual stress or contamination on the substrate that occurs during processing of the vibration element 1. Residual stress is considered to be as small as possible because it has been processed by photolithographic technology. Contamination is also caused by metal film pieces and substrate pieces by overdrive (strong excitation drive) during work and assembly in a clean room. It is thought that the influence is small because the process of removing the slag is performed.
However, the present inventors have studied that the cause of the large variation in the DLD characteristics of the resonator element 200 manufactured by the conventional manufacturing method is that the gap portion 270 generated between the main electrode 221 and the substrate 210 is large. It has become clear by. That is, a part of the main electrode 221 around the gap 270 from which the main electrode base portion 222 has been removed is in a state similar to a state in which a foreign object such as a metal piece or metal powder adheres, and vibration energy leaks during excitation. However, it is considered that the frequency change and the CI change were caused.
Therefore, the manufacturing method according to the present embodiment in which the step of etching gold (Au) to be the main electrode 21 again (ST23) is added after the etching of the chromium (Cr) of the main electrode base portion 22 (ST22) has the DLD characteristics. The main electrode 21 that is not in close contact with the main electrode base portion 22 that is expected to deteriorate is not produced, so that the yield of the DLD characteristic inspection of the vibration element 1 can be improved, and a vibration element having excellent DLD characteristics can be manufactured. Demonstrate great effect.

7A and 7B are schematic diagrams illustrating a configuration of a vibration element according to an embodiment of the present invention. FIG. 7A is a plan view of the vibration element, and FIG. 7B is a PP line in FIG. It is sectional drawing.
The vibration element 2 includes a substrate 10 having a vibration part 12, and a base electrode layer 29 as a lower conductive layer laminated so as to face both main surfaces (front and back surfaces in the ± Y ′ direction) of the substrate 10, respectively. And an electrode layer 28 as the uppermost conductive layer.
The vibration element 2 includes a substrate 10, an excitation electrode 20 including a base electrode layer 29 and an electrode layer 28, a lead electrode 23, a pad electrode 24, and a connection electrode 26.
The substrate 10 includes a vibrating portion 12 and a thin-walled portion 14 that is thinner than the vibrating portion 12.
The excitation electrode 20 is an electrode that drives the vibration unit 12 and is formed so as to be opposed to the substantially central portions of both main surfaces (front and back surfaces in the ± Y ′ direction) of the vibration unit 12. The excitation electrode 20 includes a main electrode 21 which is a part of the electrode layer 28 and a main electrode base part 22 which is a part of the base electrode layer 29 so that the outer edge of the main electrode 21 is within the outer edge of the main electrode base part 22. Is formed.
The lead electrode 23 extends from the excitation electrode 20 and is conductively connected to a pad electrode 24 formed at the end of the substrate 10.
The pad electrode 24 is formed to face the end portions of both main surfaces of the thin portion 14 of the substrate 10. The pad electrodes 24 on both main surfaces are conductively connected by connection electrodes 26 formed on the side surface portion 13 of the substrate 10.

In the embodiment shown in FIG. 7A, an example is shown in which the shape of the excitation electrode 20 formed so as to be opposed to the main surface of the substantially central portion of the vibration portion 12 is rectangular, but it is necessary to limit to this. Alternatively, the shape of the excitation electrode 20 may be circular or elliptical.
In addition, the example of the mesa portion 16 having one step on the front and back main surfaces of the substrate 10 has been shown, but the present invention is not limited to this. Alternatively, one of the back main surfaces may have a mesa shape with one to multiple stages. Furthermore, although the example in which the shape of the mesa portion 16 is rectangular is shown, it is not necessary to be limited to this, and the shape of the mesa portion 16 may be circular or elliptical.
As shown in FIG. 7, when the substrate 10 has a mesa structure having the mesa portion 16 in the vibration portion 12, it is possible to avoid the coupling with the contour system spurious and confine the vibration energy of only the main vibration. There is an effect that a small vibration element 2 with suppressed spurious near the resonance frequency can be obtained.

8A and 8B are schematic views showing another structure of the resonator element according to the embodiment of the invention. FIG. 8A is a plan view of the first modification, and FIG. 8B is a plan view of the second modification. FIG. 8C is a plan view of the third modification.
FIG. 8A shows a first modification of the present embodiment shown in FIG. 7, in which the excitation electrode 20 formed on both the front and back main surfaces of the substrate 10 and the X-axis direction of the mesa unit 16 are shown. This is a case where the excitation electrode 20 is longer than the mesa portion 16 in both the lengths in the Z′-axis direction. FIG. 8B shows a second modification, in which the excitation electrode 20 and the mesa portion 16 have substantially the same length in the Z′-axis direction, and the length in the X-axis direction is longer in the excitation electrode 20. FIG. 8C shows a third modification, in which the excitation electrode 20 and the mesa portion 16 have substantially the same length in the X-axis direction, and the length in the Z′-axis direction is longer in the excitation electrode 20.
8A to 8C, the area of the excitation electrode 20 can be increased as compared with FIG. 7, so that the capacitance ratio of the vibrator can be reduced. Therefore, when used for an oscillator, there is an effect that the frequency adjustment amount and the frequency variable amount can be expanded.

FIG. 9 is a schematic view showing the structure of a modification 4 of the resonator element according to the embodiment of the invention. FIG. 9A is a plan view of the resonator element, and FIG. 9B is FIG. It is PP sectional drawing.
The vibration element 3 includes a substrate 10 having a vibration part 12, and a base electrode layer 29 as a lower conductive layer laminated so as to face both main surfaces (front and back surfaces in the ± Y ′ direction) of the substrate 10. And an electrode layer 28 as the uppermost conductive layer.
The vibration element 3 includes a substrate 10, an excitation electrode 20 including a base electrode layer 29 and an electrode layer 28, a lead electrode 23, a pad electrode 24, and a connection electrode 26.
The substrate 10 includes a vibrating portion 12 and a thick portion 15 that is thicker than the vibrating portion 12.
The excitation electrode 20 is an electrode that drives the vibration unit 12 and is formed so as to be opposed to the substantially central portions of both main surfaces (front and back surfaces in the ± Y ′ direction) of the vibration unit 12. The excitation electrode 20 includes a main electrode 21 which is a part of the electrode layer 28 and a main electrode base part 22 which is a part of the base electrode layer 29 so that the outer edge of the main electrode 21 is within the outer edge of the main electrode base part 22. Is formed.
The lead electrode 23 extends from the excitation electrode 20 and is conductively connected to a pad electrode 24 formed at the end of the substrate 10.
The pad electrodes 24 are formed to face the ends of both main surfaces of the thick portion 15 of the substrate 10. The pad electrodes 24 on both main surfaces are conductively connected by connection electrodes 26 formed on the side surface portion 13 of the substrate 10.

In the embodiment shown in FIG. 9A, an example of a rectangular shape having the same shape and area of the excitation electrode 20 formed so as to be opposed to the main surface of the substantially central portion of the vibrating portion 12 is shown. The shape and area of the excitation electrode 20 are different in the upper and lower sides, and the shape may be circular or elliptical.
In addition, the concave portion 17 formed in the approximate center of the substrate 10 is formed by etching from one side of the substrate 10, but etching may be performed from both sides of the substrate 10 to form the concave portion 17 so as to face each other. Good.
As shown in FIG. 9, by using a substrate 10 having an inverted mesa structure in which the recessed portion 17 serves as the vibration portion 12, the vibration portion 12 can be made very thin, so that the resonance frequency can be increased. Therefore, it is possible to obtain a highly reliable high-frequency vibration element 3 excellent in impact resistance and vibration resistance.

FIG. 10 is a schematic view showing a configuration of a vibrator according to an embodiment of the present invention, FIG. 10 (a) is a plan view in which a lid member is omitted, and FIG. 10 (b) is a longitudinal sectional view. The vibrator 5 includes the vibration element 1, a package main body 40 formed in a rectangular box shape for housing the vibration element 1, a lid member 49 made of metal, ceramic, glass, or the like. Yes.
As shown in FIG. 10, the package body 40 is formed by laminating a first substrate 41, a second substrate 42, a third substrate 43, a seal ring 44, and mounting terminals 45. Yes. A plurality of mounting terminals 45 are formed on the outer bottom surface of the first substrate 41. The third substrate 43 is an annular body from which the central portion is removed, and a seal ring 44 such as Kovar is formed on the upper peripheral edge of the third substrate 43.
The third substrate 43 and the second substrate 42 form a cavity 84 that houses the vibration element 1. A plurality of element mounting pads 47 that are electrically connected to the mounting terminals 45 by conductors 46 are provided at predetermined positions on the upper surface of the second substrate 42. The element mounting pad 47 is disposed so as to correspond to the pad electrode 24 formed at the end of the substrate 10 when the vibration element 1 is mounted.

When the vibration element 1 is supported and fixed, first, the pad electrode 24 of the vibration element 1 is placed on the element mounting pad 47 coated with the conductive adhesive 30 and a load is applied.
Next, in order to cure the conductive adhesive 30, it is placed in a high temperature furnace at a predetermined temperature for a predetermined time. After the conductive adhesive 30 is cured, an annealing process is performed, and the frequency is adjusted by adding mass to the excitation electrode 20 or reducing the mass. Thereafter, the lid member 49 is placed on the seal ring 44 formed on the upper surface of the third substrate 43 of the package body 40, and the lid member 49 is seam welded and sealed in a vacuum or in an atmosphere of nitrogen gas. The vibrator 5 is completed.
Alternatively, there is also a method in which the lid member 49 is placed on the low melting point glass applied to the upper surface of the package body 40 and melted and adhered. Also in this case, the cavity of the package is evacuated or filled with an inert gas such as nitrogen gas, and the vibrator 5 is completed.
In the above-described embodiment of the vibrator 5, an example in which a laminated plate is used for the package body 40 has been described. However, a vibrator using a single-layer ceramic plate for the package body 40 and a cap that has been drawn on the lid body. 5 may be configured.

FIG. 11 is a schematic view showing a configuration of an electronic device according to an embodiment of the present invention. FIG. 11 (a) is a plan view in which a lid member is omitted, and FIG. 11 (b) is a longitudinal sectional view. .
The electronic device 7 includes a package body 50, a lid member 49, the vibration element 1, an IC component 51 on which an oscillation circuit for exciting the vibration element 1 is mounted, a variable capacitance element whose capacitance varies with voltage, and a resistance depending on temperature. And at least one electronic component 52 such as a changing thermistor or inductor.
As shown in FIG. 11, the package main body 50 is formed by stacking a first substrate 61, a second substrate 62, and a third substrate 63. A plurality of mounting terminals 45 are formed on the outer bottom surface of the first substrate 61. The 2nd board | substrate 62 and the 3rd board | substrate 63 are formed with the annular body from which the center part was removed.
The first substrate 61, the second substrate 62, and the third substrate 63 form a cavity 84 that accommodates the vibration element 1, the IC component 51, the electronic component 52, and the like. A plurality of element mounting pads 47 that are electrically connected to the mounting terminals 45 by conductors 46 are provided at predetermined positions on the upper surface of the second substrate 62. The position of the element mounting pad 47 is arranged so as to correspond to the pad electrode 24 formed at the end of the substrate 10 when the vibration element 1 is placed.

The pad electrode 24 of the vibration element 1 is placed on the element mounting pad 47 of the package body 50 to which the conductive adhesive 30 is applied, and the conductive adhesive 30 is cured at a predetermined temperature. Conduction with the mounting pad 47 is intended. The IC component 51 is fixed at a predetermined position of the package body 50, and the terminal of the IC component 51 and the electrode terminal 55 of the package body 50 are connected by the bonding wire BW. Further, the electronic component 52 is placed at a predetermined position of the package body 50 and connected to the conductor 46 using a metal bump or the like. The package body 50 is filled with an inert gas such as vacuum or nitrogen, and the package body 50 is sealed with a lid member 49 to complete the electronic device 7.
As shown in FIG. 11, since the vibration element 1 having a good DLD characteristic is used, a small electronic device 7 having an excellent starting characteristic can be obtained.
As the electronic device 7, a small oscillator, a temperature compensation oscillator, a voltage control oscillator, or the like can be configured.

Next, another electronic device according to the present embodiment will be described with reference to the drawings.
FIG. 12A is a cross-sectional view of an electronic device 8 according to a modification of FIG. The electronic device 8 roughly includes the vibration element 1 of the present invention, a thermistor 53 that is a temperature-sensitive element, and a package 82 that houses the vibration element 1 and the thermistor 53. The package 82 includes a package body 80 and a lid member 49. The package body 80 has a cavity 84 for accommodating the vibration element 1 on the upper surface side and a recess 86 for accommodating the thermistor 53 on the lower surface side. A plurality of element mounting pads 47 are provided at the end of the inner bottom surface of the cavity 84, and each element mounting pad 47 is conductively connected to the plurality of mounting terminals 45 by a conductor 46. The conductive adhesive 30 is applied to the element mounting pad 47, the vibration element 1 is placed on the conductive adhesive 30, and the pad electrode 24 and each element mounting pad 47 are connected to the conductive adhesive 30. Electrically connected and fixed through. A seal ring 44 is baked on the upper portion of the package body 80, and a lid member 49 is placed on the seal ring 44 and welded using a resistance welder to hermetically seal the cavity 84. The cavity 84 may be evacuated or filled with an inert gas.
On the other hand, a recess 86 is formed in the approximate center of the lower surface side of the package body 80, and the electronic component mounting pad 48 is baked on the upper surface of the recess 86. The thermistor 53 is mounted on the electronic component mounting pad 48 and is electrically connected using solder or the like to form the electronic device 8. The electronic component mounting pad 48 is conductively connected to the plurality of mounting terminals 45 by the conductor 46.

FIG. 12B shows an electronic device 9 according to a modification of FIG. 12A, which is different from the electronic device 8 in that a recess 86 is formed on the bottom surface of the cavity 84 of the package body 80. The thermistor 53 is connected to the electronic component mounting pad 48 fired on the bottom surface of the recess 86 through a metal bump or the like. The electronic component mounting pad 48 is electrically connected to the mounting terminal 45. That is, the vibration element 1 and the thermistor 53 of the temperature sensitive element are accommodated in the cavity 84 and hermetically sealed.
The example in which the vibration element 1 and the thermistor 53 are accommodated in the package 82 has been described above, but at least one of the thermistor, the capacitor, the reactance element, and the semiconductor element is accommodated as the electronic component accommodated in the package 82. It is desirable that the electronic device 9 is configured.
Since the vibration element can be manufactured as described above, the delivery time of the electronic device can be greatly shortened. Further, by combining the vibration element with the thermistor, the capacitor, the reactance element, the semiconductor element, etc., there is an effect that it is possible to quickly meet the requirements of various specifications.

Next, an electronic device (an electronic device of the present invention) to which the vibration element according to an embodiment of the present invention is applied will be described in detail with reference to FIGS.
FIG. 13 is a perspective view illustrating a configuration of a mobile (or notebook) personal computer as an electronic apparatus including the resonator element according to the embodiment of the invention. In this figure, a personal computer 1100 includes a main body portion 1104 provided with a keyboard 1102 and a display unit 1106 provided with a display portion 100. The display unit 1106 is rotated with respect to the main body portion 1104 via a hinge structure portion. It is supported movably. Such a personal computer 1100 incorporates a vibration element 1 that functions as at least one of a filter, a resonator, a reference clock, and the like.

  FIG. 14 is a perspective view illustrating a configuration of a mobile phone (including PHS) as an electronic apparatus including the resonator element according to the embodiment of the invention. In this figure, a cellular phone 1200 includes a plurality of operation buttons 1202, an earpiece 1204, and a mouthpiece 1206, and the display unit 100 is disposed between the operation buttons 1202 and the earpiece 1204. Such a cellular phone 1200 incorporates the vibration element 1 that functions as a filter, a resonator, or the like.

FIG. 15 is a perspective view illustrating a configuration of a digital camera as an electronic apparatus including the vibration element according to the embodiment of the invention. In this figure, connection with an external device is also simply shown. Here, a normal camera sensitizes a silver salt photographic film with a light image of a subject, whereas a digital camera 1300 captures a light image of a subject by photoelectrically converting it with an image sensor such as a CCD (Charge Coupled Device). A signal (image signal) is generated.
A display unit 100 is provided on the back surface of a case (body) 1302 in the digital camera 1300, and is configured to perform display based on an imaging signal from the CCD. The display unit 100 displays a subject as an electronic image. Function as. A light receiving unit 1304 including an optical lens (imaging optical system), a CCD, and the like is provided on the front side (the back side in the drawing) of the case 1302.
When the photographer confirms the subject image displayed on the display unit 100 and presses the shutter button 1306, the CCD image pickup signal at that time is transferred and stored in the memory 1308. In the digital camera 1300, a video signal output terminal 1312 and an input / output terminal 1314 for data communication are provided on the side surface of the case 1302. As shown in the figure, a television monitor 1430 is connected to the video signal output terminal 1312 and a personal computer 1440 is connected to the input / output terminal 1314 for data communication as necessary. Further, the imaging signal stored in the memory 1308 is output to the television monitor 1430 or the personal computer 1440 by a predetermined operation. Such a digital camera 1300 incorporates a vibration element 1 that functions as a filter, a resonator, or the like.

  Note that the electronic apparatus including the resonator element according to the embodiment of the invention includes, for example, an ink jet type in addition to the personal computer (mobile personal computer) in FIG. 13, the mobile phone in FIG. 14, and the digital camera in FIG. 15. Discharge device (for example, inkjet printer), laptop personal computer, TV, video camera, video tape recorder, car navigation device, pager, electronic notebook (including communication function), electronic dictionary, calculator, electronic game device, word processor, Workstations, videophones, crime prevention TV monitors, electronic binoculars, POS terminals, medical equipment (for example, electronic thermometers, blood pressure monitors, blood glucose meters, electrocardiogram measuring devices, ultrasonic diagnostic devices, electronic endoscopes), fish detectors, various types Measuring equipment, instruments (eg cars , Aircraft, gauges of a ship), can be applied to a flight simulator or the like.

FIG. 16 schematically shows an automobile 106 as a specific example of a moving object. The automobile 106 is equipped with a vibrator or an electronic device having the vibration element according to the present invention.
For example, keyless entry, immobilizer, car navigation system, car air conditioner, antilock brake system (ABS), airbag, tire pressure monitoring system (TPMS), engine control, hybrid car and electric car The present invention can be widely applied to electronic control units (ECUs) 108 such as battery monitors and vehicle attitude control systems.

  1, 2, 3, 101, 102, 103, 200 ... vibration element, 5 ... vibrator, 7, 8, 9 ... electronic device, 10, 210 ... substrate, 12, 212 ... vibration part, 13 ... side part, 14 ... Thin part, 15 ... Thick part, 16 ... Mesa part, 17 ... Recessed part, 20 ... Excitation electrode, 21 221 ... Main electrode, 22, 222 ... Main electrode base part, 23 ... Lead electrode, 24 ... Pad electrode , 26 ... connection electrode, 28 ... electrode layer, 29 ... base electrode layer, 30 ... conductive adhesive, 32 ... resist, 34 ... base film, 36 ... corrosion resistant film, 40, 50, 80 ... package body, 41 ... first 1 substrate 42 ... second substrate 43 ... third substrate 44 ... seal ring 45 ... mounting terminal 46 ... conductor 47 ... element mounting pad 48 ... electronic component mounting pad 49 ... lid member 50 ... Package body, 51 ... IC parts, 52 ... Electronic part 53 ... Thermistor, 55 ... Electrode terminal, 61 ... First substrate, 62 ... Second substrate, 63 ... Third substrate, 70,270 ... Gap, 82 ... Package, 84 ... Cavity, 86 ... Recessed part, 100 ... Display part, 106 ... Automobile, 107 ... Car body, 108 ... Electronic control unit, 109 ... Tire, 1100 ... Personal computer, 1102 ... Keyboard, 1104 ... Main body part, 1106 ... Display unit, 1200 ... Mobile phone, 1202 ... operation buttons, 1204 ... earpiece, 1206 ... mouthpiece, 1300 ... digital camera, 1302 ... case, 1304 ... light receiving unit, 1306 ... shutter button, 1308 ... memory, 1312 ... video signal output terminal, 1314 ... input / output terminal 1430 ... TV monitor, 1440 ... personal computer.

Claims (10)

A vibration part that vibrates in thickness, and a substrate that is disposed around the vibration part and has an outer edge part that is thinner than the thickness of the vibration part;
When viewed from the direction orthogonal to the surface of the substrate, the lower conductive layer provided on the surface, and the shape provided on the surface of the lower conductive layer and within the outer edge of the lower conductive layer An excitation electrode having an upper conductive layer,
Including
Area of the excitation electrode is much larger than the area of the vibrating portion,
When viewed from the direction, an outer edge of the upper conductive layer is located closer to the outer edge than an outer edge of the vibration part . In claim 1,
When viewed from the front Symbol Direction,
The resonator element, wherein an outer shape of the upper conductive layer is smaller than an outer shape of the lower conductive layer. In claim 1 or claim 2,
The material of the upper conductive layer is any one of Au, Ag, and Pt,
The vibration element, wherein a material of the lower conductive layer is Cr, Ni, Ti, or a NiCr alloy. The vibration element according to any one of claims 1 to 3 ,
A package containing the vibration element;
A vibrator characterized by comprising: The vibration element according to any one of claims 1 to 3 ,
An electronic element;
A container for mounting the vibration element and the electronic element;
An electronic device comprising: In claim 5 ,
An electronic device, wherein the electronic element is at least one of a thermistor, a capacitor, a reactance element, and a semiconductor element. An electronic apparatus comprising the vibration element according to any one of claims 1 to 3 . An electronic apparatus comprising the vibrator according to claim 4 . An electronic apparatus characterized by comprising an electronic device according to claim 5 or 6. A moving body comprising the vibration element according to any one of claims 1 to 3 .

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