JP2023111185A - Vibration device, and method for manufacturing vibration device - Google Patents

Abstract

To provide a vibration device in which stress is hardly transmitted to a vibration element, and a method for manufacturing a vibration device.SOLUTION: A vibration device has an outside package, an inside package accommodated in the outside package, a vibration element accommodated in the inside package, and a first joint member joining the vibration element and the inside package to each other. The first joint member includes an adhesive, and a bump group including at least one bump covered by the adhesive. The inside package has an inside base to which the vibration element is joined, and an inside lid joined to the inside base to accommodate the vibration element between the inside base and the inside lid, and the inside package is joined to the outside package with the inside lid therebetween.SELECTED DRAWING: Figure 4

Description

TECHNICAL FIELD The present invention relates to a vibrating device and a method for manufacturing the vibrating device.

For example, the oscillator described in Patent Document 1 has an outer container, an inner container housed in the outer container, and a vibration element and a circuit element housed in the inner container. Also, the vibrating element is mounted on the bottom surface of the recess of the inner container via an adhesive.

JP 2020-137025 A

However, in the oscillator disclosed in Patent Document 1, the vibrating element is fixed to the inner container via an adhesive. Therefore, it is difficult to secure the height of the vibrating element with respect to the bottom surface of the concave portion due to the spread and collapse of the adhesive when the vibrating element is mounted. Therefore, there is a problem that stress is easily transmitted from the inner container to the vibrating element, resulting in deterioration of vibration characteristics.

The vibration device of the present invention comprises an outer package,
an inner package housed in the outer package;
a vibrating element housed in the inner package;
a first joint member that joins the vibration element and the inner package;
The first bonding member includes an adhesive and a bump group including at least one bump covered with the adhesive.

A method of manufacturing a vibrating device according to the present invention includes a bump forming step of forming a bump group including at least one bump on an inner base;
an adhesive application step of applying an adhesive so as to cover the bump group to form a bonding member;
a vibrating element bonding step of bonding the vibrating element to the inner base via the bonding member;
an inner lid bonding step of bonding an inner lid to the inner base so as to accommodate the vibration element between the inner base and the inner lid to obtain an inner package;
an inner package housing step of housing the inner package in an outer package.

1 is a cross-sectional view showing a vibration device according to a first embodiment; FIG. 4 is a cross-sectional view showing the inside of the inner package; FIG. 4 is a plan view showing the inside of the inner package; FIG. FIG. 4 is a vertical cross-sectional view showing a joining member that joins the inner package and the vibrating element; FIG. 5 is a cross-sectional view of the joining member shown in FIG. 4; FIG. 11 is a cross-sectional view showing a modification of the joining member; FIG. 11 is a cross-sectional view showing a modification of the joining member; FIG. 11 is a cross-sectional view showing a modification of the joining member; FIG. 11 is a cross-sectional view showing a modification of the joining member; FIG. 11 is a cross-sectional view showing a modification of the joining member; It is a longitudinal section showing a modification of a joint member. 1 is a circuit diagram showing a PLL circuit; FIG. It is a flow chart which shows a manufacturing process of a vibrating device. It is sectional drawing explaining the manufacturing method of a vibration device. It is sectional drawing explaining the manufacturing method of a vibration device. It is sectional drawing explaining the manufacturing method of a vibration device. It is sectional drawing explaining the manufacturing method of a vibration device. It is sectional drawing explaining the manufacturing method of a vibration device. It is sectional drawing explaining the manufacturing method of a vibration device. It is sectional drawing explaining the manufacturing method of a vibration device. It is sectional drawing explaining the manufacturing method of a vibration device. FIG. 10 is a plan view showing the inside of the inner package according to the second embodiment; FIG. 4 is a vertical cross-sectional view showing a joining member that joins the inner package and the vibrating element; FIG. 11 is a plan view showing a modification of the vibrating element; FIG. 11 is a cross-sectional view showing the inside of an inner package according to a third embodiment; FIG. 11 is a cross-sectional view showing a vibration device according to a fourth embodiment; FIG. 11 is a cross-sectional view showing a vibrating device according to a fifth embodiment; FIG. 11 is a cross-sectional view showing a vibration device according to a sixth embodiment; FIG. 11 is a cross-sectional view showing a vibration device according to a seventh embodiment;

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a vibrating device and a method for manufacturing a vibrating device according to the present invention will now be described in detail with reference to the accompanying drawings.

<First Embodiment>
FIG. 1 is a cross-sectional view showing the vibration device according to the first embodiment. FIG. 2 is a cross-sectional view showing the inside of the inner package. FIG. 3 is a plan view showing the inside of the inner package. FIG. 4 is a longitudinal sectional view showing a joining member that joins the inner package and the vibrating element. 5 is a cross-sectional view of the joining member shown in FIG. 4. FIG. 6 to 10 are cross-sectional views showing modifications of the joining member. FIG. 11 is a vertical cross-sectional view showing a modification of the joining member. FIG. 12 is a circuit diagram showing a PLL circuit. FIG. 13 is a flow chart showing the manufacturing process of the vibrating device. 14 to 21 are cross-sectional views explaining the manufacturing method of the vibrating device.

For convenience of explanation, X-axis, Y-axis and Z-axis that are orthogonal to each other are illustrated in each figure except FIG. 12 and FIG. 13 . Further, hereinafter, the direction along the X-axis direction is also called the “X-axis direction”, the direction along the Y-axis direction is also called the “Y-axis direction”, and the direction along the Z-axis direction is also called the “Z-axis direction”. Also, the arrow side of each axis is called "plus side" and the opposite side is called "minus side". The positive side in the Z-axis direction is also called "upper", and the negative side in the Z-axis direction is also called "lower".

The vibration device 1 shown in FIG. 1 is an oven-controlled crystal oscillator (OCXO), and accommodates a vibration element 6, a circuit element 8, a temperature control element 7, a vibration element 6, a circuit element 8, and a temperature control element 7. a circuit element 4; an outer package 2 housing the inner package 3 and the circuit element 4; and a voltage controlled crystal oscillator 5 disposed in the outer package 2. there is These units will be described in order below.

≪Outer package 2≫
As shown in FIG. 1, the outer package 2 has an outer base 21 and an outer lid 22 . The outer base 21 is box-shaped and has an upper concave portion 211 opening on the upper surface and a lower concave portion 212 opening on the lower surface.

The outer lid 22 has a plate shape and is joined to the upper surface of the outer base 21 via a sealing member 23 such as a seal ring or low-melting-point glass so as to block the opening of the upper concave portion 211 . As a result, the upper concave portion 211 is airtightly sealed, and the outer accommodation space A2 is formed in the outer package 2 . On the other hand, the opening of the lower concave portion 212 is not sealed and faces the outside of the outer package 2 . The inner package 3 and the circuit element 4 are accommodated in the outer accommodation space A2, and the voltage-controlled crystal oscillator 5 is arranged in the lower concave portion 212. As shown in FIG.

Materials for forming the outer base 21 and the outer lid 22 are not particularly limited. can be configured with As a result, the outer package 2 is durable and has excellent mechanical strength. Moreover, the coefficients of linear expansion of both can be made substantially equal, and the thermal stress generated in the outer package 2 can be reduced.

The outer housing space A2 will be described in detail. The upper recessed portion 211 has a first upper recessed portion 211a that opens to the upper surface of the outer base 21, and an opening that is smaller than the first upper recessed portion 211a that opens to the bottom surface of the first upper recessed portion 211a. It has a second upper recessed portion 211b and a third upper recessed portion 211c that opens to the bottom surface of the second upper recessed portion 211b and has a smaller opening than the second upper recessed portion 211b. The circuit element 4 is arranged on the bottom surface of the first upper concave portion 211a, and the inner package 3 is arranged on the bottom surface of the third upper concave portion 211c.

The outer housing space A2 is airtight and is in a decompressed state, preferably in a state closer to a vacuum. As a result, the heat insulation of the outer package 2 is enhanced, and the vibrating device 1 is less susceptible to external temperature. In addition, the heat of the temperature control element 7 becomes difficult to escape, and the heating efficiency of the vibrating element 6 increases. Therefore, the temperature of the vibrating element 6 is more stable, and power saving can be achieved. However, the atmosphere of the outer accommodation space A2 is not particularly limited.

Further, as shown in FIG. 1, a plurality of internal terminals 241 are arranged on the bottom surface of the first upper concave portion 211a, and a plurality of internal terminals 242 are arranged on the bottom surface of the second upper concave portion 211b. A plurality of internal terminals 243 are arranged on the bottom surface, and a plurality of external terminals 244 are arranged on the lower surface of the outer base 21 . Each internal terminal 241 is electrically connected to the circuit element 4 via a bonding wire BW1, each internal terminal 242 is electrically connected to the inner package 3 via a bonding wire BW2, and each internal terminal 243 is It is electrically connected to the voltage-controlled crystal oscillator 5 via a conductive joint member B1.

These terminals 241, 242, 243, and 244 are appropriately electrically connected via internal wiring (not shown) formed in the outer base 21, and the circuit element 4, the inner package 3, and the voltage-controlled crystal oscillator are connected. 5 and an external terminal 244 are electrically connected. In such a vibrating device 1 , connection with the external device 100 is made at the external terminal 244 .

≪Inner package 3≫
As shown in FIG. 1, the inner package 3 is housed in the outer housing space A2 of the outer package 2. As shown in FIG. As shown in FIG. 2, the inner package 3 has an inner base 31 and an inner lid 32 . The inner base 31 is box-shaped and has a recessed portion 311 that opens downward. The inner lid 32 has a plate shape and is joined to the lower surface of the inner base 31 via a sealing member 33 such as a seal ring or low-melting-point glass so as to block the opening of the recess 311 . As a result, the recessed portion 311 is airtightly sealed, and an inner accommodation space A3 is formed in the inner package 3 . The vibration element 6, the temperature control element 7 and the circuit element 8 are accommodated in the inner accommodation space A3.

Materials for forming the inner base 31 and the inner lid 32 are not particularly limited. can be configured with As a result, the inner package 3 is durable and has excellent mechanical strength. In addition, the coefficients of linear expansion of both can be made substantially equal, and the thermal stress generated in the inner package 3 can be reduced.

Describing the inner housing space A3 in detail, the recess 311 includes a first recess 311a that opens to the lower surface of the inner base 31, and a second recess 311b that opens to the bottom of the first recess 311a and has an opening smaller than that of the first recess 311a. and a third recess 311c that opens to the bottom surface of the second recess 311b and has an opening smaller than that of the second recess 311b. The vibrating element 6 is arranged on the bottom surface of the first recess 311a, and the temperature control element 7 and the circuit element 8 are arranged on the bottom surface of the third recess 311c.

Such inner accommodation space A3 is airtight and is in a decompressed state, preferably in a state closer to a vacuum. As a result, the viscous resistance of the inner accommodation space A3 is reduced, and the vibration characteristics of the vibration element 6 are improved. However, the atmosphere of the inner accommodation space A3 is not particularly limited.

A pair of internal terminals 341a and 341b are arranged on the bottom surface of the first recess 311a, a plurality of internal terminals 342 and 343 are arranged on the bottom surface of the second recess 311b, and a plurality of external terminals 342 and 343 are arranged on the top surface of the inner base 31. A terminal 344 is arranged. The internal terminal 341a is electrically connected to the vibrating element 6 via a bonding member 9 as a conductive first bonding member, and the internal terminal 341b is electrically connected to the vibrating element 6 via a bonding wire BW3. , each internal terminal 342 is electrically connected to the temperature control element 7 via a bonding wire BW4, and each internal terminal 343 is electrically connected to the circuit element 8 via a bonding wire BW5.

These terminals 341a, 341b, 342, 343, and 344 are appropriately electrically connected via internal wiring (not shown) formed in the inner package 3, and the vibrating element 6, temperature control element 7, It electrically connects the circuit element 8 and the external terminal 344 . In such an inner package 3 , the inside and the outside are electrically connected through the external terminals 344 .

The inner package 3 as described above is fixed to the bottom surface of the third upper concave portion 211c in the inner lid 32 via the joining member B3 as a second joining member having sufficiently low thermal conductivity. The sufficiently low thermal conductivity means that the thermal conductivity is at least lower than the thermal conductivity of the outer base 21 and the inner lid 32 which are the connection partners. Such a bonding member B3 is not particularly limited, and various insulating resin materials such as silicone resin and epoxy resin can be used, for example. By using an insulating material, the thermal conductivity of the joining member B3 can be sufficiently lowered with a simple configuration.

According to such a configuration, since the inner package 3 and the outer package 2 are insulated by the bonding member B3, the heat of the temperature control element 7 is less likely to escape to the outside through the outer package 2. FIG. Therefore, the vibration element 6 can be heated stably and efficiently by the temperature control element 7 . In particular, in this embodiment, a plurality of bonding members B3 are scattered like islands. As a result, the inner package 3 can be joined to the outer package 2 in a stable posture, and the heat transfer path connecting the inner package 3 and the outer package 2 can be narrowed. Therefore, the heat of the temperature control element 7 becomes more difficult to escape. Furthermore, in this embodiment, the inner lid 32 is fixed to the bottom surface of the third upper concave portion 211c. Therefore, a long heat transfer path can be ensured between the outer base 21 and the temperature control element 7, and the heat of the temperature control element 7 becomes more difficult to escape. However, the method of fixing the inner package 3 to the outer package 2 is not particularly limited.

<<Vibration element 6>>
As shown in FIG. 3 , the vibration element 6 has a piezoelectric substrate 61 and electrode patterns arranged on the surface of the piezoelectric substrate 61 . The piezoelectric substrate 61 has a plate-like shape and has an upper surface and a lower surface that are opposite to each other. Further, the piezoelectric substrate 61 has a substantially rectangular shape with the X-axis direction as the longitudinal direction and the Y-axis direction as the lateral direction in plan view from the Z-axis direction. In addition, the piezoelectric substrate 61 includes a substantially rectangular vibrating portion 611 in plan view.

The electrode pattern consists of a first excitation electrode 621 and a first connection electrode 622 arranged on the upper surface, a first extraction electrode 623 connecting them, a second excitation electrode 631 arranged on the lower surface, and a second connection electrode 622 . It has an electrode 632 and a second extraction electrode 633 connecting them. In addition, the first and second excitation electrodes 621 and 631 are arranged overlapping in the Z-axis direction in the central portion of the piezoelectric substrate 61, and the first and second connection electrodes 622 and 632 are arranged at one end portion of the piezoelectric substrate 61 (hereinafter referred to as , also referred to as a base end) are arranged to overlap in the Z-axis direction.

The first excitation electrode 621 and the second excitation electrode 631 are arranged with the vibrating portion 611 interposed therebetween. In other words, the vibrating portion 611 is provided at a position overlapping both the first excitation electrode 621 and the second excitation electrode 631 in plan view. The vibrating portion 611 performs thickness-shear vibration due to a voltage applied between the first excitation electrode 621 and the second excitation electrode 631 .

Although the vibration element 6 has been described above, its configuration is not particularly limited. For example, the planar shape of the piezoelectric substrate 61 is not limited to a rectangle, and may be a circle, an ellipse, a semicircle, or other polygons. In addition, the piezoelectric substrate 61 may be subjected to bevel processing for grinding the outer edge thereof, or convex processing for forming the upper and lower surfaces of the piezoelectric substrate 61 into convex curved surfaces. As the vibration element 6, instead of the SC cut crystal vibration element, an AT cut crystal vibration element, a BT cut crystal vibration element, a tuning fork crystal vibration element, a surface acoustic wave resonator, other piezoelectric vibration elements, a MEMS resonance element, or the like may be used. may be used.

Such a vibrating element 6 is fixed to the bottom surface of the first concave portion 311a at the base end via a joint member 9 as a first joint member. Also, the first connection electrode 622 and the internal terminal 341a are electrically connected via the bonding member 9, and the second connection electrode 632 and the internal terminal 341b are electrically connected via the bonding wire BW3. there is

In addition, as shown in FIG. 4, the joint member 9 is located between the internal terminal 341a and the first connection electrode 622. As shown in FIG. Also, the bonding member 9 has an adhesive 91 and a group of bumps 92 covered with the adhesive 91 . Also, the bump group 92 includes a plurality of bumps 921 . The adhesive 91 has electrical conductivity, mechanically joins the internal terminal 341a and the first connection electrode 622, and electrically connects them. By using the conductive adhesive 91 in this way, the inner base 31 and the vibrating element 6 can be easily electrically connected.

Such an adhesive 91 is not particularly limited as long as it has electrical conductivity. material can be used. This simplifies the configuration of the adhesive 91 .

Each bump 921 is embedded in the adhesive 91 . Each of these bumps 921 is rigid and functions as a spacer that secures a predetermined distance D between the inner base 31 and the vibrating element 6 . Therefore, the clearance between the inner base 31 and the vibrating element 6, that is, the height of the adhesive 91 can be stably secured. As a result, the adhesive 91 can be easily elastically deformed, and the adhesive 91 can function as a buffer layer that absorbs and relaxes stress caused by expansion, deformation, etc. of the inner package 3 . . Therefore, the stress applied to the vibrating element 6 is reduced, and deterioration of vibration characteristics such as hysteresis can be effectively suppressed.

In addition, the surface tension between the bumps 921 suppresses the wetting and spreading of the adhesive 91, and the diameter of the adhesive 91 can be further reduced. In other words, each bump 921 has a function as an anchor that suppresses wetting and spreading of the adhesive 91 in addition to the function as the spacer described above. As a result, the contact area between the adhesive 91 and the inner base 31 can be reduced, so that the adhesive 91 can absorb and relax the stress caused by the expansion, deformation, etc. of the inner package 3 with a small amount of elastic deformation. can be done. Therefore, it becomes difficult for the stress from the inner package 3 to be transmitted to the vibrating element 6 .

The number of bumps 921 included in the bump group 92 is not particularly limited, but is preferably two or more. Thereby, the strength of the bump group 92 can be increased, and the function as the spacer described above can be exhibited more reliably. Although the upper limit of the number of bumps 921 is not particularly limited, it is preferably 10 or less, more preferably 5 or less. As a result, excessive increase in the diameter of the joining member 9 can be suppressed.

In this embodiment, as shown in FIG. 5, four bumps 921 are arranged in a substantially square shape. As a result, the number and arrangement of the bumps 921 are optimized, and while the diameter of the bonding member 9 is suppressed to a sufficiently small diameter, the functions as the spacer, the anchor, and the buffer layer described above can be fully exhibited. can.

However, the number and arrangement of the bumps 921 are not particularly limited, and can be appropriately set according to the dimensions, mass, etc. of the vibrating element 6 . For example, one bump 921 may be added to the center as shown in FIG. 8, two may be arranged side by side in the X-axis direction, as shown in FIG. 9, two may be arranged side by side in the Y-axis direction, or as shown in FIG. , only one may be placed.

Each bump 921 is harder than the adhesive 91 . That is, each bump 921 has a higher Young's modulus than the adhesive 91 . In particular, in this embodiment, each bump 921 is composed of a metal bump. As a result, each bump 921 becomes sufficiently hard, and can more reliably perform the function as the spacer described above. Each bump 921 is composed of, for example, a stud bump using wire bonding technology, a plated bump, or the like. However, the constituent material and formation method of each bump 921 are not particularly limited.

Further, as shown in FIG. 4, each bump 921 is configured by stacking a plurality of unit bumps 921a. With such a configuration, the height of the bumps 921 can be easily controlled by the number of stacked unit bumps 921a. Therefore, it becomes easier to control the interval D. Furthermore, by stacking a plurality of unit bumps 921a, the surface area of the bumps 921 can be increased and the surface of the bumps 921 can be uneven. Therefore, the above-described anchor effect is further improved. However, the configuration of the bump 921 is not particularly limited, and may be composed of, for example, one unit bump 921a.

Further, in this embodiment, the bump group 92 , that is, each bump 921 is separated from the second connection electrode 632 . In other words, each bump 921 and the second connection electrode 632 are non-contact. As a result, the contact area between the adhesive 91 and the second connection electrode 632 can be suppressed from decreasing, and the bonding strength between them can be increased.

However, the present invention is not limited to this, and the bump group 92 may be in contact with the second connection electrode 632 as shown in FIG. 11, for example. Thereby, the internal terminal 341 a and the second connection electrode 632 can be electrically connected via the bump group 92 . Therefore, it is possible to use an insulating adhesive as the adhesive 91, increasing the options for the material.

<<Temperature control element 7>>
As shown in FIG. 2, the temperature control element 7 has a temperature sensor 71 and a heating circuit 72 . The temperature sensor 71 functions as a temperature detection section that detects the ambient temperature, particularly the temperature of the vibrating element 6 , and the heat generating circuit 72 functions as a heat generating section that heats the vibrating element 6 . The heating circuit 72 is controlled based on the detection result of the temperature sensor 71 so that the vibrating element 6 is maintained at a desired temperature. Such a temperature control element 7 is arranged on the bottom surface of the third recess 311c and electrically connected to the plurality of internal terminals 342 via bonding wires BW4. In this embodiment, since the vibrating element 6 and the temperature control element 7 are housed in the same space, the difference between the detection result of the temperature sensor 71 and the actual temperature of the vibrating element 6 is small, resulting in excellent frequency temperature characteristics. Vibration device 1 is obtained.

<<Circuit element 8>>
As shown in FIG. 2, the circuit element 8 has an oscillation circuit 81 that causes the vibration element 6 to oscillate. The oscillation circuit 81 is a circuit for amplifying the signal output from the vibration element 6 and feeding it back to the vibration element 6 to cause the vibration element 6 to oscillate and generate an oscillation signal. Such a circuit element 8 is arranged on the bottom surface of the third recess 311c and electrically connected to the plurality of internal terminals 343 via bonding wires BW5.

<<Voltage-controlled crystal oscillator 5>>
The voltage controlled crystal oscillator 5 is an oscillator included in a PLL circuit 42 which will be described later. As shown in FIG. 1, the voltage-controlled crystal oscillator 5 has a package 51 and a vibrating element 55 and a circuit element 59 housed in the package 51 . Such a voltage-controlled crystal oscillator 5 is fixed to the bottom surface of the lower concave portion 212 via a conductive bonding member B1 and electrically connected to the internal terminal 243. As shown in FIG.

<<Circuit element 4>>
As shown in FIG. 1, the circuit element 4 includes a temperature control circuit 41 that controls driving of the temperature control element 7, part of the PLL circuit 42, and an output buffer circuit 43. FIG.

The temperature control circuit 41 is a circuit for controlling the amount of current flowing through the resistance of the heating circuit 72 based on the output signal of the temperature sensor 71 and keeping the vibration element 6 at a constant temperature.

As shown in FIG. 12, the PLL circuit 42 includes a first phase comparator 421 to which a reference frequency signal as an oscillation signal output from the oscillation circuit 81 is input, a first low-pass filter 422, and a first low-pass filter 422. and a first frequency divider 424 to which the frequency signal output from the voltage controlled oscillator 423 is input. The frequency signal divided by the first frequency divider 424 is input to the first phase comparator 421 . The first phase comparator 421 detects the phase difference between the reference frequency signal and the frequency signal and outputs it to the first low-pass filter 422 . First low-pass filter 422 removes the high-frequency component from the output signal from first phase comparator 421 , converts it into a voltage, and outputs it as a DC signal for controlling voltage-controlled oscillator 423 .

It should be noted that the first frequency divider 424 can set a decimal frequency division ratio, for example, by switching the integer frequency division ratio to an average decimal frequency division ratio. As a result, the front-stage PLL circuit portion composed of the first phase comparator 421, the first low-pass filter 422, the voltage-controlled oscillator 423, and the first frequency divider 424 can be used as a fractional frequency dividing PLL circuit (fractional PLL circuit). Function. As a result, the fractional frequency division PLL circuit can output a signal of any frequency.

The PLL circuit 42 includes a second phase comparator 425 to which the frequency signal output from the voltage-controlled oscillator 423 is input, a second low-pass filter 426, a voltage-controlled crystal oscillator 5, and a voltage-controlled crystal oscillator. and a second frequency divider 427 to which the frequency signal output from 5 is input. Then, the frequency signal divided by the second frequency divider 427 is input to the second phase comparator 425 . The second phase comparator 425 detects the phase difference between the frequency signal output from the voltage-controlled oscillator 423 and the frequency signal divided by the second frequency divider 427, and outputs it to the second low-pass filter 426. do. The second low-pass filter 426 removes high-frequency components from the output signal from the second phase comparator 425 , converts it to voltage, and outputs it as a DC signal (frequency control signal) for controlling the voltage-controlled crystal oscillator 5 .

The second frequency divider 427 is, for example, an integer frequency divider that divides the input signal by an integer. As a result, the latter stage PLL circuit portion composed of the second phase comparator 425, the second low-pass filter 426, the voltage-controlled crystal oscillator 5, and the second frequency divider 427 is an integer frequency division PLL circuit (integer PLL circuit). ). The integer frequency division PLL circuit has relatively little phase noise and can have a relatively simple circuit configuration.

Then, the voltage-controlled crystal oscillator 5 outputs a frequency signal corresponding to the voltage of the DC signal to the output buffer circuit 43 . That is, the oscillation frequency of the voltage-controlled crystal oscillator 5 is controlled based on the reference frequency signal output from the oscillation circuit 81 .

Among the circuit elements that make up the PLL circuit 42, the voltage-controlled crystal oscillator 5 is configured separately from the circuit element 4, and the other elements are also configured separately from the circuit element 4. may For example, the first and second low-pass filters 422 and 426 may be configured separately from the circuit element 4 and arranged side by side with the voltage-controlled crystal oscillator 5 on the bottom surface of the lower concave portion 212 .

Next, a method for manufacturing the vibration device 1 will be described. As shown in FIG. 13, the method of manufacturing the vibrating device 1 includes a bump forming step S1, an adhesive applying step S2, a vibrating element bonding step S3, an inner lid bonding step S4, and an inner package housing step S5. contains.

<<Bump forming step S1>>
First, as shown in FIG. 14, the inner base 31 is prepared. Note that the circuit element 8 and the temperature control element 7 are already mounted on the inner base 31 . Next, as shown in FIG. 15, a plurality of bumps 921 are formed on the inner base 31 to obtain a bump group 92. Next, as shown in FIG. The bumps 921 can be formed of stud bumps or plated bumps using wire bonding technology.

<<Adhesive application step S2>>
Next, as shown in FIG. 16, an uncured adhesive 91 is applied over the bump group 92 . As a result, the bonding member 9 in which the bump group 92 is covered with the adhesive 91 is obtained.

<<Vibration element bonding step S3>>
Next, the vibrating element 6 is prepared. Next, as shown in FIG. 17, the vibrating element 6 is placed on the bonding member 9 so as to be pressed against the bump group 92 . As described above, at this time, the bump group 92 functions as a spacer for ensuring the predetermined distance D between the inner base 31 and the vibrating element 6 . Therefore, crushing of the adhesive material 91 more than expected can be suppressed. Therefore, the function as the buffer layer described above can be reliably exhibited. Next, the adhesive 91 is cured. As a result, the vibrating element 6 is joined to the inner base 31 via the joining member 9 .

<<Inner lid joining step S4>>
Next, the inner lid 32 is prepared, and as shown in FIG. 18, the inner lid 32 and the inner base 31 are joined via the sealing member 33 . As described above, the inner package 3 is obtained.

<<Inner package accommodation step S5>>
Next, as shown in FIG. 19, the outer base 21 is prepared, the inner package 3 is bonded to the bottom surface of the third upper concave portion 211c of the outer base 21 via the bonding member B3, and these are electrically connected. A bonding wire BW2 is formed. Next, as shown in FIG. 20, the circuit element 4 is bonded to the bottom surface of the first upper concave portion 211a of the outer base 21, bonding wires BW1 for electrically connecting them are formed, and bonding members B1 are formed. The voltage-controlled crystal oscillator 5 is joined to the lower recessed portion 212 via the . Next, as shown in FIG. 21 , the outer lid 22 is prepared and joined to the upper surface of the outer base 21 via the sealing member 23 . As described above, the vibrating device 1 is obtained.

According to the manufacturing method as described above, the bump group 92 functions as a spacer that secures the predetermined distance D between the inner base 31 and the vibration element 6 . Therefore, the clearance between the inner base 31 and the vibrating element 6, that is, the height of the adhesive 91 can be stably secured. As a result, the adhesive 91 can be easily elastically deformed, and the adhesive 91 can function as a buffer layer that absorbs and relaxes stress caused by expansion, deformation, etc. of the inner package 3 . . Therefore, the stress applied to the vibrating element 6 is reduced, and deterioration of vibration characteristics such as hysteresis can be effectively suppressed.

The vibration device 1 and the method for manufacturing the vibration device 1 have been described above. As described above, the vibrating device 1 includes the outer package 2, the inner package 3 housed in the outer package 2, the vibrating element 6 housed in the inner package 3, and the vibrating element 6 and the inner package. and a joining member 9 as a first joining member that joins the . The bonding member 9 includes an adhesive 91 and a bump group 92 including at least one bump 921 covered with the adhesive 91 . With such a configuration, the bump group 92 functions as a spacer that secures a predetermined distance D between the inner base 31 and the vibration element 6 . Therefore, the clearance between the inner base 31 and the vibrating element 6, that is, the height of the adhesive 91 can be stably secured. As a result, the adhesive 91 can be easily elastically deformed, and the adhesive 91 can function as a buffer layer that absorbs and relaxes stress caused by expansion, deformation, etc. of the inner package 3 . . Therefore, the stress applied to the vibrating element 6 is reduced, and deterioration of vibration characteristics such as hysteresis can be effectively suppressed.

Further, as described above, the inner package 3 includes an inner base 31 to which the vibrating element 6 is bonded and an inner lid bonded to the inner base 31 so as to accommodate the vibrating element 6 between the inner base 31 and the inner base 31 . 32 and . The inner package 3 is joined to the outer package 2 via the inner lid 32 . Thereby, a long heat transfer path can be secured between the vibrating element 6 and the outer package 2 . Therefore, the vibrating element 6 is less likely to be affected by the external temperature, and the temperature of the vibrating element 6 is stabilized.

Further, as described above, the vibration device 1 has the joint member B3 as a second joint member that joins the outer package 2 and the inner package 3 together. A plurality of bonding members B3 are arranged between the outer package 2 and the inner package 3 so as to be scattered like islands. Thereby, the heat transfer path connecting the inner package 3 and the outer package 2 can be narrowed. Therefore, the vibrating element 6 is less likely to be affected by the external temperature, and the temperature of the vibrating element 6 is stabilized.

In addition, as described above, the bonding member B3 has a lower thermal conductivity than the outer package 2 and the inner package 3 . According to such a configuration, the inner package 3 and the outer package 2 are insulated by the joining member B3. Therefore, the vibrating element 6 is less likely to be affected by the external temperature, and the temperature of the vibrating element 6 is stabilized.

Also, as described above, the bump group 92 includes a plurality of bumps 921 . Thereby, the strength of the bump group 92 can be increased, and the function as the spacer described above can be exhibited more reliably.

Moreover, as described above, the bump 921 is configured by stacking a plurality of unit bumps 921a. Thereby, the height of the bumps 921 can be easily controlled by the number of stacked unit bumps 921a. Therefore, it becomes easier to control the interval D. Furthermore, by stacking a plurality of unit bumps 921a, the surface area of the bumps 921 can be increased and the surface of the bumps 921 can be uneven. Therefore, the above-described anchor effect is further improved.

Further, as described above, the adhesive 91 has conductivity. This facilitates electrical connection between the inner package 3 and the vibrating element 6 .

Also, as described above, the bumps 921 are separated from the vibrating element 6 . As a result, the contact area between the adhesive 91 and the vibrating element 6 can be suppressed from decreasing, and the bonding strength between them can be increased.

Further, as described above, the method of manufacturing the vibrating device 1 includes the bump forming step S1 of forming the bump group 92 including at least one bump 921 on the inner base 31, and applying the adhesive 91 so as to cover the bump group 92. a bonding material application step S2 for forming the bonding member 9 by using the bonding member 9; a vibration element bonding step S3 for bonding the vibration element 6 to the inner base 31 via the bonding member 9; An inner lid bonding step S4 of bonding the inner lid 32 to the inner base 31 to obtain the inner package 3 and an inner package housing step S5 of housing the inner package 3 in the outer package 2 are included. According to such a manufacturing method, the bump group 92 functions as a spacer that secures the predetermined distance D between the inner base 31 and the vibration element 6 . Therefore, the clearance between the inner base 31 and the vibrating element 6, that is, the height of the adhesive 91 can be stably secured. As a result, the adhesive 91 can be easily elastically deformed, and the adhesive 91 can function as a buffer layer that absorbs and relaxes stress caused by expansion, deformation, etc. of the inner package 3 . . Therefore, the stress applied to the vibrating element 6 is reduced, and deterioration of vibration characteristics such as hysteresis can be effectively suppressed.

<Second embodiment>
22 is a plan view showing the inside of the inner package according to the second embodiment. FIG. FIG. 23 is a longitudinal sectional view showing a joining member that joins the inner package and the vibrating element. FIG. 24 is a plan view showing a modification of the vibrating element.

The vibrating device 1 of this embodiment is the same as the above-described first embodiment except that the configuration of the vibrating element 6 and the method of joining the vibrating element 6 and the inner base 31 are different. Therefore, in the following description, regarding this embodiment, the differences from the first embodiment described above will be mainly described, and the description of the same matters will be omitted. Moreover, in each figure in this embodiment, the same code|symbol is attached|subjected about the structure similar to embodiment mentioned above.

As shown in FIG. 22, in the vibration element 6 of this embodiment, the first and second connection electrodes 622 and 632 are both arranged on the upper surface of the piezoelectric substrate 61 in the Y-axis direction. The vibrating element 6 is joined to the inner base 31 via a pair of joining members 9 . The pair of joint members 9 are arranged side by side in the Y-axis direction. One joining member 9 is positioned between the internal terminal 341a and the first connection electrode 622 to mechanically and electrically connect them. The other joint member 9 is located between the internal terminal 341b and the second connection electrode 632 and mechanically and electrically connects them.

Also, as shown in FIG. 23, the width of the first excitation electrode 621 along the direction in which the pair of bonding members 9 are arranged, that is, the Y-axis direction is L1, and the bumps 921 included in one bonding member 9 and the other bonding member 9 satisfies the relationship of L1≧L2, where L2 is the maximum separation distance from the bump 921 included in 9 . Thereby, the separation distance L3 between the pair of joint members 9 can be reduced, and the thermal stress applied to the vibration element 6 due to the difference in linear expansion coefficient between the vibration element 6 and the inner base 31 can be reduced. Therefore, for example, it is possible to effectively suppress deterioration of vibration characteristics of the vibrating element 6 such as hysteresis. Note that the maximum separation distance L2 is the separation distance along the Y-axis direction between the bumps 921 that are farthest apart in the Y-axis direction from the other joint member 9 among the plurality of bumps 921 included in each joint member 9. say. Also, as shown in FIG. 23, the distance includes the width of the bump 921 itself.

As described above, it is sufficient to satisfy the relationship of L1≧L2, but it is preferable to satisfy the relationship of 0.9L1≧L2, and more preferably to satisfy the relationship of 0.8L1≧L2. Thereby, the separation distance L3 can be further reduced, and deterioration of the vibration characteristics of the vibrating element 6 can be suppressed more effectively.

In this embodiment, since the first and second excitation electrodes 621 and 631 have the same shape, the width L1 may be the width of the first excitation electrode 621 or the width of the second excitation electrode 631. . On the other hand, for example, as shown in FIG. 24, when the first and second excitation electrodes 621 and 631 have different shapes, the smaller one of the first and second excitation electrodes 621 and 631, that is, in the illustrated case , the width of the first excitation electrode 621 should be the width L1.

In addition, in the present embodiment, the joint member 9 is arranged so as to be within the range of the vibrating portion 611 in the Y-axis direction. All you have to do is In addition, the planar shape of the first excitation electrode 621, the second excitation electrode 631, and the vibrating portion 611 is not limited to a rectangle, and may be a circle, an ellipse, an oval, a semicircle, or other polygons. In that case, the maximum value of the width of the vibrating portion 611 in the Y-axis direction should be L1.

Such a second embodiment can also exhibit the same effect as the first embodiment described above.

<Third Embodiment>
FIG. 25 is a cross-sectional view showing the inside of the inner package according to the third embodiment.

The vibrating device 1 of this embodiment is the same as the vibrating device 1 of the second embodiment described above, except that the joint members 9 have different configurations. Therefore, in the following description, the differences between this embodiment and the above-described second embodiment will be mainly described, and the description of the same matters will be omitted. In addition, in the drawings of this embodiment, the same reference numerals are given to the same configurations as in the above-described embodiment.

As shown in FIG. 25, in the present embodiment, among the four bumps 921 included in each bonding member 9, two bumps 921 located on the base end side of the vibrating element 6 have a height of two bumps 921 located on the tip side. lower than the height of one bump 921 . By adopting such a configuration, the vibrating element 6 can be arranged on the inner base 31 in an inclined posture with its distal end facing downward. Thereby, contact between the vibrating element 6 and the inner base 31 can be suppressed.

Note that the height and arrangement of each bump 921 can be appropriately set depending on the attitude in which the vibrating element 6 is mounted.

Such a third embodiment can also exhibit the same effect as the first embodiment described above.

<Fourth Embodiment>
FIG. 26 is a cross-sectional view showing a vibration device according to a fourth embodiment;

The vibrating device 1 of this embodiment is the same as the vibrating device 1 of the first embodiment described above, except that the configuration of the outer package 2 is different. Therefore, in the following description, regarding this embodiment, the differences from the first embodiment described above will be mainly described, and the description of the same matters will be omitted. In addition, in the drawings of this embodiment, the same reference numerals are given to the same configurations as in the above-described embodiment.

As shown in FIG. 26, in the vibrating device 1 of this embodiment, the lower concave portion 212 is omitted from the outer package 2 . Instead, the upper recessed portion 211 is additionally provided with a fourth upper recessed portion 211d that opens to the bottom surface of the third upper recessed portion 211c and has an opening smaller than that of the third upper recessed portion 211c. A voltage-controlled crystal oscillator 5 is arranged on the bottom surface of the fourth upper concave portion 211d.

Such a fourth embodiment can also exhibit the same effect as the first embodiment described above.

<Fifth Embodiment>
FIG. 27 is a cross-sectional view showing the vibration device according to the fifth embodiment.

The vibrating device 1 of this embodiment is the same as the vibrating device 1 of the first embodiment described above, except that the structure of the outer package 2 is different and the arrangement of each part in the outer package 2 is different. Therefore, in the following description, regarding this embodiment, the differences from the first embodiment described above will be mainly described, and the description of the same matters will be omitted. In addition, in the drawings of this embodiment, the same reference numerals are given to the same configurations as in the above-described embodiment.

As shown in FIG. 27, in the vibrating device 1 of this embodiment, the lower concave portion 212 is omitted from the outer package 2 . The circuit element 4 is arranged on the bottom surface of the second upper concave portion 211b, the inner package 3 is arranged on the bottom surface of the circuit element 4, and the voltage-controlled crystal oscillator 5 is arranged on the top surface of the circuit element 4. In other words, the circuit element 4 serves as a relay substrate, and the inner package 3 and the voltage-controlled crystal oscillator 5 are supported by the outer base 21 via the circuit element 4 .

Such a fifth embodiment can also exhibit the same effect as the first embodiment described above.

<Sixth embodiment>
FIG. 28 is a cross-sectional view showing the vibration device according to the sixth embodiment.

The vibrating device 1 of this embodiment is the same as the vibrating device 1 of the fifth embodiment described above, except that the posture of the circuit element 4 is reversed. Therefore, in the following description, the differences between this embodiment and the fifth embodiment will be mainly described, and the description of the same items will be omitted. In addition, in the drawings of this embodiment, the same reference numerals are given to the same configurations as in the above-described embodiment.

As shown in FIG. 28, in the vibrating device 1 of this embodiment, the arrangement of the inner package 3 and the voltage-controlled crystal oscillator 5 is reversed compared to the fifth embodiment described above, and the upper surface of the circuit element 4 is reversed. An inner package 3 is arranged in the inner package 3 , and a voltage-controlled crystal oscillator 5 is arranged on the lower surface of the circuit element 4 .

Such a sixth embodiment can also exhibit the same effect as the first embodiment described above.

<Seventh embodiment>
FIG. 29 is a cross-sectional view showing a vibration device according to the seventh embodiment.

The vibration device 1 of this embodiment is the same as the vibration device 1 of the sixth embodiment described above, except that the orientation of the inner package 3 is reversed. Therefore, in the following description, the differences between this embodiment and the sixth embodiment will be mainly described, and the description of the same items will be omitted. In addition, in the drawings of this embodiment, the same reference numerals are given to the same configurations as in the above-described embodiment.

As shown in FIG. 29, in the vibrating device 1 of this embodiment, the posture of the inner package 3 is reversed, and the inner base 31 is joined to the circuit element 4, as compared with the sixth embodiment.

Such a seventh embodiment can also exhibit the same effect as the first embodiment described above.

Although the vibrating device and the method for manufacturing the vibrating device of the present invention have been described above based on the illustrated embodiments, the present invention is not limited to this, and the configuration of each part may be any one having similar functions. It can be replaced with a configuration. Also, other optional components may be added to the present invention. Further, each of the embodiments described above may be combined as appropriate.

Further, in each of the above-described embodiments, the oscillatory device is applied to the oven-controlled crystal oscillator (OCXO), but is not limited to this. etc., may be applied to any oscillator.

Reference Signs List 1 Vibration device 100 External device 2 Outer package 21 Outer base 211 Upper recess 211a First upper recess 211b Second upper recess 211c Third upper recess 211d Fourth Upper concave portion 212 Lower concave portion 22 Outer lid 23 Sealing member 241 Internal terminal 242 Internal terminal 243 Internal terminal 244 External terminal 3 Inner package 31 Inner base 311... recess 311a...first recess 311b...second recess 311c...third recess 32...inner lid 33...sealing member 341a...internal terminal 341b...internal terminal 342...internal terminal 343... Internal terminals 344 External terminals 4 Circuit elements 41 Temperature control circuit 42 PLL circuit 421 First phase comparator 422 First low-pass filter 423 Voltage controlled oscillator 424 Second 1 frequency divider 425 second phase comparator 426 second low pass filter 427 second frequency divider 43 output buffer circuit 5 voltage controlled crystal oscillator 51 package 55 vibration element , 59... Circuit element 6... Vibration element 61... Piezoelectric substrate 611... Vibration part 621... First excitation electrode 622... First connection electrode 623... First extraction electrode 631... Second excitation electrode 632 Second connection electrode 633 Second extraction electrode 7 Temperature control element 71 Temperature sensor 72 Heat generation circuit 8 Circuit element 81 Oscillation circuit 9 Joining member 91 Adhesive 92 Bump group 921 Bump 921a Unit bump A2 Outside accommodation space A3 Inside accommodation space B1 Joining member B3 Joining member BW1 Bonding wire BW2 Bonding wire BW3 Bonding wire BW4: Bonding wire, BW5: Bonding wire, D: Spacing, L1: Width, L2: Maximum distance, L3: Distance, S1: Bump forming step, S2: Adhesive application step, S3: Vibration element bonding step, S4 ... Inner lid bonding step, S5 ... Inner package housing step

Claims (9)

an outer package;
an inner package housed in the outer package;
a vibrating element housed in the inner package;
a first joint member that joins the vibration element and the inner package;
The vibrating device, wherein the first bonding member includes an adhesive and a bump group including at least one bump covered with the adhesive. The inner package has an inner base to which the vibrating element is bonded, and an inner lid which is bonded to the inner base so as to accommodate the vibrating element between the inner base and the inner lid. 2. The vibration device according to claim 1, wherein the vibration device is joined to the outer package via a lid. a second joining member joining the outer package and the inner package;
3. The vibrating device according to claim 1, wherein a plurality of said second joint members are interspersed between said outer package and said inner package. 4. The vibrating device according to claim 2, wherein the second joint member has lower thermal conductivity than the outer package and the inner package. 5. The vibrating device according to claim 1, wherein said bump group includes a plurality of said bumps. 6. The vibrating device according to claim 5, wherein the bump is configured by stacking a plurality of unit bumps. The vibration device according to any one of claims 1 to 6, wherein the adhesive has conductivity. 8. The vibrating device according to any one of claims 1 to 7, wherein the bumps are spaced apart from the vibrating element. a bump forming step of forming a bump group including at least one bump on the inner base;
an adhesive application step of applying an adhesive so as to cover the bump group to form a bonding member;
a vibrating element bonding step of bonding the vibrating element to the inner base via the bonding member;
an inner lid bonding step of bonding an inner lid to the inner base so as to accommodate the vibration element between the inner base and the inner lid to obtain an inner package;
and an inner package housing step of housing the inner package in the outer package.

Images