JP2002100931A - Piezoelectric oscillator and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized piezoelectric oscillator that enables high-frequency oscillation to be performed stably and properly, using overtone oscillation, and is easy to modify the characteristics thereof and is superior in versatility and noise resistance. SOLUTION: The piezoelectric oscillator comprises a casing body 1, in which an upper cavity portion 5 and a lower cavity portion 10 are separated from each other by a diaphragm 8, a piezoelectric transducer 2 housed in the upper cavity portion 5, an IC chip 3 and electronic components 41 to 44 constituting an oscillation circuit housed in the lower cavity portion 10, and external terminal electrodes 11 to 14, which are formed on the periphery of the underside of the casing body 1 and are connected with the oscillation circuit. The oscillation circuit oscillates, utilizing overtones which are three or more times those of the waves of the piezoelectric transducer 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric oscillator in which a piezoelectric vibrator is accommodated in a cavity of a container used for, for example, a mobile communication control device, and more particularly to a piezoelectric oscillator suitable for high-frequency oscillation using overtone oscillation. The present invention relates to an oscillator and a method for manufacturing the same. Here, the piezoelectric vibrator includes a vibrator using a quartz plate, a piezoelectric ceramic substrate, or a single crystal piezoelectric substrate.

[0002]

2. Description of the Related Art As a piezoelectric oscillator, for example, a crystal oscillator is a very important component which is mounted in a mobile communication control device or a control device for controlling a LAN and generates an oscillation frequency for controlling its operation. For example, a crystal oscillator used in a mobile communication control device or the like must have a very small volume as the mobile communication control device becomes smaller.

For example, Japanese Patent Application Laid-Open No. 10-28024 discloses a surface mount type crystal oscillator that achieves such miniaturization, which comprises a rectangular single plate-shaped substrate and a frame-shaped leg, and a rectangular opening. Using a container body with a cavity part on the bottom,
A structure has been proposed in which a quartz oscillator is mounted on the surface of the container and an IC chip is mounted in the cavity of the container.

FIGS. 21 to 24 show such a conventional surface mount type crystal oscillator 150. FIG.

The crystal oscillator 150 comprises a container 151,
It is mainly composed of a rectangular crystal oscillator 152, an IC chip 153 constituting an oscillation control circuit, and a metal lid 154.

The quartz oscillator 150 uses a container 151 in which a rectangular single-plate ceramic substrate 155 and a frame-shaped leg 156 are integrated, and a cavity 157 is formed on the bottom surface of the container 151. I was

A via-hole conductor 158 is formed on a single-plate-shaped ceramic substrate 155 that separates the surface of the container 151 from the bottom surface of the cavity portion 157. I have. Also,
On the surface thereof, a sealing conductor pattern 159 for sealing the metal lid 154 is formed. A wiring pattern 160 including an IC electrode pad is formed on the bottom surface of the cavity 157. Further, the frame-shaped leg 156
External terminal electrodes 161 to 164 are formed at the four corners of the bottom surface of.

A rectangular quartz oscillator 152 is conductively bonded to the surface of the container body 151 via conductive supports 169 and 170 with conductive adhesives 171 and 172. In order to hermetically seal the vibrator 152, the dish-shaped metal lid 154 is integrally joined using the sealing conductor pattern 159. The cavity 157 accommodates an IC chip 153. The IC chip 153 is connected to an IC electrode pad as the wiring pattern 160 via a bump or a bonding wire. The quartz oscillator 152 mounted on the surface of the container 151 is connected to the crystal oscillator 152 via via-hole conductors 158 and 158.
The IC chip 153 is connected to the external terminal electrodes 161 to 164 via the wiring pattern 160. Further, the cavity 157 is filled with a filling resin 173 and cured. Thus, the IC chip 153 is completely covered with the filling resin 173, and has a structure with improved moisture resistance.

[0009]

However, the above-described conventional crystal oscillator has an oscillation frequency band of a fundamental wave level,
For example, it is a relatively low-frequency oscillator used in a frequency band of about 13 MHz to 28 MHz. For this reason, when assuming a LAN 90 constituting Gigabit Ethernet (registered trademark) as shown in FIG. 25 for performing high-speed communication processing of large-capacity communication information including data such as audio, still images, and moving images, this crystal is used. Communication control equipment using an oscillator has a problem in terms of communication capability.

[0010] Specifically, the network group A includes:
A plurality of information terminals 91 having a communication capability of 10 Mbps are connected via a hub 93 to a gigabit Ethernet switch 95.
It is connected to the. A plurality of information terminals 92 having a communication capability of 100 Mbps are connected to a gigabit Ethernet switch 95A via a 100M repeater 94. The Gigabit Ethernet switch 95A is connected to a server 96 having a communication capability of 1000 Mbps. The network groups B and C have the same configuration, and the Gigabit Ethernet switch 95B of the network group B is connected to the router 97.
The Gigabit Ethernet switch 95A of the network group C is connected to the Gigabit Ethernet switch 95A via the router 98.

In the LAN 90, a clock frequency of about 25 MHz is used for communication of a portion indicated by a circle.
A clock frequency of about 125 MHz is used for communication of the portion indicated by the mark. As described above, each communication control device that requires a crystal oscillator that oscillates at a high frequency of 125 MHz is required to process enormous communication information of the entire network at high speed and accurately. In addition, under the demand for higher speed in information communication, a crystal oscillator that performs further high-frequency oscillation of 125 MHz or more is required.

On the other hand, the characteristics of a crystal oscillator that performs high-frequency oscillation used in a high-speed communication control device include a jitter J characteristic, which is a phase variation of an oscillation waveform for each cycle t1 shown in FIG.
It is important in correctly processing information.

Here, the jitter J will be described in detail. As shown in FIG. 27, the jitter J is represented as a total jitter TJ including a jitter DJ which is a non-fluctuation component and a jitter RJ which is a fluctuation component. That is, it is known that the following expression (1) is satisfied: TJ = DJ + 14RJ (1)

Therefore, by suppressing the jitter RJ to be low, the total jitter TJ can be suppressed, and the high-frequency oscillation using the overtone oscillation can be stably performed well. Specifically, for example, at a clock frequency of 125 MHz, a standard deviation σ having a center value of 8 ns needs to be 10 ps or less.

Since the above-mentioned conventional crystal oscillator does not have such characteristics, it should be used, for example, in a communication control device for processing enormous communication information of the entire network at high speed and accurately as described above. Could not.

In the above-mentioned conventional crystal oscillator, FIG.
As shown in the figure, the oscillation circuit of the crystal unit 152 has one I
This is achieved with the C chip 153. Specifically, this I
The C chip 153 includes oscillation inverters 181, 182,
Drain capacitance capacitor Cd, gate capacitance capacitor C
g and the feedback resistor Rf are integrated into one chip. For this reason, when it is desired to change the oscillation characteristics of the crystal oscillator, it is necessary to newly design and replace the IC chip 153 itself.
There was a problem in terms of versatility.

Further, it is very difficult to achieve a stable operation of the crystal oscillator with only one IC chip 153. That is, the external terminal electrode 161 serving as the Vcc supply terminal
It is necessary to cut off high-frequency noise superimposed on the power supply voltage Vcc supplied to the oscillation inverter integrated in the IC chip 153 from the above. To deal with this, for example, an electronic component such as a large-capacity bypass capacitor Cb is used. 1
83 are used. However, this capacitor 18
Since it is difficult to integrate the crystal oscillator 3 into the IC chip 153, it is usually arranged on a printed wiring board on which a crystal oscillator is mounted. In that case, Vcc on the printed wiring board
Assuming that the connection between the line and the capacitor 183 is P and the electrode pad for supplying Vcc of the IC chip 153 (the pad connected to the external terminal electrode 161 for Vcc) is Q, the physical connection between the connection P and the pad Q The distance becomes longer, and high-frequency noise is more likely to be superimposed. In addition, there is a problem in that the external circuit of the printed wiring board becomes complicated, and the trouble of mounting the capacitor 183 on the printed wiring board increases.

The present invention solves such problems of the prior art, and can stably and satisfactorily perform high-frequency oscillation using overtone oscillation, and can easily change the characteristics, and can achieve versatility and versatility. An object of the present invention is to provide a small-sized piezoelectric oscillator excellent in noise resistance and a method for manufacturing the same.

[0019]

According to the present invention, there is provided a piezoelectric oscillator comprising:
A container body in which an upper cavity portion and a lower cavity portion are separated by a partition, a piezoelectric vibrator accommodated in the upper cavity portion, and an IC constituting an oscillation circuit accommodated in the lower cavity portion A chip and an electronic component, and an external terminal formed around the lower surface of the container and connected to the oscillation circuit, wherein the oscillation circuit oscillates using an overtone of a third harmonic or more of the piezoelectric vibrator. Configuration.

According to this configuration, stable and good high-frequency oscillation can be performed even if an overtone of a third harmonic or more of the piezoelectric vibrator is used by the oscillation circuit.

Here, if overtone oscillation is used,
The fact that stable and good high-frequency oscillation can be performed will be described in detail.

In an oscillation circuit in which a capacitance is added in series to a piezoelectric vibrator, the oscillation frequency f is expressed by the following equations (2) and (3): f = f0 (1 + 1 / {2γ (1 + CL / C0)}) ( 2) It is known that γ = C0 / C1 (3) is satisfied.

Here, f0: series resonance frequency of the piezoelectric vibrator, C0: parallel equivalent capacitance of the piezoelectric vibrator, C1: series equivalent capacitance of the piezoelectric vibrator, γ: capacitance ratio, and CL: load capacitance of the piezoelectric vibrator. Represent.

Further, the frequency change amount Δf satisfies the following expression (4) which is a modification of the above expression (1): Δf = f−f0 = f0 / {2γ (1 + CL / C0)} (4)

The relationship between the frequency change Δf and the load capacitance CL shows a characteristic in the case of the fundamental wave, as shown in FIG. 17, that the slope of the frequency change Δf increases as the load capacitance CL decreases.

On the other hand, in the overtone oscillation of the third harmonic or more, as shown in FIG. 18, the frequency change amount Δf becomes substantially constant even if the load capacitance CL changes.

That is, in the overtone oscillation of the third harmonic or more, the capacitance ratio γ becomes large (γ> 1000), and the frequency fluctuation due to the load is small.

Therefore, when the overtone oscillation of the third harmonic or more is used, stable and good high-frequency oscillation can be performed.

Further, in the piezoelectric oscillator of the present invention, the electronic components constituting the oscillation circuit are not integrated into one IC chip,
Since the configuration is such that the C chip and the electronic component are independent, it is easy to appropriately select the electronic component, change the characteristics, set the piezoelectric oscillator to desired characteristics, and improve the versatility of the piezoelectric oscillator. .

Further, since a piezoelectric vibrator is accommodated in an upper cavity portion of a container body separated by a partition, and an IC chip and an electronic component constituting an oscillation circuit are accommodated in a lower cavity portion, each element is formed. Can be condensed and placed in a narrow space, and the oscillation circuit composed of IC chips can be protected from noise, making it possible to make the piezoelectric oscillator highly reliable, small, and small in mounting area. Become.

In the method of manufacturing a piezoelectric oscillator according to the present invention, there is provided a piezoelectric vibrator mounting step of mounting the piezoelectric vibrator in an upper cavity portion of the container, and a step of mounting the IC chip and the IC chip in a lower cavity portion of the container. And a component mounting step of mounting an electronic component, wherein the piezoelectric vibrator mounting step is performed before the component mounting step.

According to this manufacturing method, the piezoelectric vibrator mounting process can be performed with respect to high frequency oscillation using overtone oscillation which is susceptible to the influence of foreign matter because the crystal impedance value which is the resonance resistance value of the piezoelectric vibrator increases. Since the process is performed before the component mounting process, after the piezoelectric vibrator is mounted in the upper cavity portion of the container and the container is sealed, the IC chip and the electronic component are placed under the container using a conductive resin paste or the like. Since it is mounted in the cavity, it is possible to prevent foreign substances and outgas generated from the conductive resin paste from adhering to the piezoelectric vibrator at that time. As a result, high-frequency oscillation using overtone oscillation, which is easily affected by foreign matter, can be stably improved.

[0033] In the above manufacturing method, a thermal aging step of thermally aging the piezoelectric vibrator for stabilizing the frequency of the piezoelectric vibrator is provided between the piezoelectric vibrator mounting step and the component mounting step. Configuration.

According to this manufacturing method, since the heat aging step of the piezoelectric vibrator can be performed before the components such as the IC chip are mounted, unnecessary heat is not applied to the IC chip.
The operation reliability of the oscillation circuit composed of a C chip or the like can be improved, and stable oscillation output can be achieved.

When mounting an IC chip,
An Au bump is formed using an Au wire or the like on the aluminum electrode of each electrode on the non-mounting surface of the C chip. When a high heat is applied in a state where the Au bump is formed on the aluminum electrode, Al Due to the difference in the diffusion speed of Au, the Cargendall void phenomenon occurs, which causes a problem that the connection strength at the bonding interface between Al and Au is reduced.

On the other hand, in the above manufacturing method, components such as IC chips are mounted after the heat aging step,
Since the occurrence of the Cargendall void phenomenon that occurs at the joint surface between the electrode of the chip and the connecting member (bump or wire) can be effectively suppressed, the joining state is also stabilized, and thus, the IC chip is also stabilized. Operation becomes possible.

[0037]

Embodiments of the present invention will be specifically described below with reference to the drawings.

(First Embodiment) FIGS. 1 to 11 show a configuration example of a surface mount type crystal oscillator 100 which is a piezoelectric oscillator according to a first embodiment of the present invention. The oscillation circuit will be described by taking an overtone oscillation circuit of a third harmonic or more, for example, a third harmonic as an example.

As shown in FIG. 2, the crystal oscillator 100 includes a substantially rectangular parallelepiped container body 1 in which an upper cavity portion 5 and a lower cavity portion 10 are separated by a partition 8, and an upper cavity portion 5. A rectangular crystal oscillator 2 to be housed,
It mainly comprises an IC chip 3 and four electronic components 41 to 44 constituting an oscillation circuit housed in the lower cavity section 10, a metal lid 6 and a filling resin 7.

The container body 1 has a plurality of substantially rectangular ceramic insulating layers 1a and 1b, a ceramic insulating layer 1c having a central portion and rectangular openings at the upper, lower, left and right sides thereof, and a frame shape having a central portion opened in a cross shape. Of ceramic insulating layers 1d are integrally laminated.

The ceramic insulating layers 1a and 1b serve as partition walls 8 for separating the crystal unit 2 from the IC chip 3 and the electronic components 41 to 44, and the ceramic insulating layers 1c and 1d.
Thus, the frame-shaped leg 9 is formed. The concave portion surrounded by the inner wall surface of the frame-shaped leg portion 9 and the lower surface of the partition wall 8 becomes the cavity portion 10. External terminal electrodes 11 to 14 are formed at four corners on the lower surface of the container 1.

More specifically, on the upper surface of the container 1, that is, on the upper surface of the ceramic insulating layer 1a, a sealing conductor film 19 is formed so as to surround the outer periphery thereof, as shown in FIG. Electrode pads 20 and 21 for the crystal unit for connecting to the crystal unit 2 are arranged in parallel near one end of the surface of the container 1 in the longitudinal direction. On the upper surface, connection bumps 22 and 23 for forming a predetermined interval on the lower surface of the crystal unit 2 are formed.

As shown in FIG. 7, on the lower surface of the ceramic insulating layer 1a, the electrode pad 20 for the crystal unit,
An island-shaped connection pattern 113 including via-hole conductors 25 and 26 for connecting to the wiring 21 and via-hole conductors 27 and 28 for connecting to a wiring pattern 31 of the ceramic insulating layer 1b described later is formed. On the lower surface, a Vcc pattern 112 for supplying power to the IC chip 3 and connecting to the electronic component 44 serving as the bypass capacitor Cb is formed. A ground pattern 111 is formed on substantially the entire surface so as to substantially surround the Vcc pattern 112. Via hole conductors 131 to 131 formed in this ground pattern 111
138 is for forming a conductor path for grounding the IC chip 3 and the oscillation circuit. Also, the via-hole conductors 12 formed in the ground pattern 111
Reference numerals 5 and 126 are used to connect the sealing conductor film 19 formed on the upper surface of the ceramic insulating layer 1a and the ground pattern 111. Then, the metal lid 6 is joined to the sealing conductor film 19 to cause the metal lid 6 to have a shielding effect. Vcc pattern 11
The via-hole conductors 121 to 124 formed in 2 are used to connect to the electronic component 44 serving as the bypass capacitor Cb of the oscillation circuit and to form a conductor path for supplying power to the IC chip 3.

As shown in FIG. 8, a mounting portion 114 of the IC chip 3 is formed substantially at the center on the lower surface of the ceramic insulating layer 1b, and the oscillation characteristics of the crystal unit 2 are measured around the mounting portion 114 alone. Monitor electrode pads 34 and 35 and a plurality of element electrode pads 33 are formed. Furthermore, IC
Chip 3, electronic components 41 to 44 and external terminal electrodes 11 to
A wiring pattern 31 for forming an oscillating circuit by connecting the circuit 14 is formed. Via-hole conductors 121 to 124, 131 to 139 formed in this wiring pattern 31
121 'and 136' are ceramic insulating layers 1c to be described later.
To form a conductor path for connection to the IC chip 3 and the oscillation circuit. The mounting portion 114, the via-hole conductors 121, 1
21 ′, 122, 123, and 124 become a part of the conductor path of the above-mentioned Vcc potential, and the via-hole conductors 131 to 13
5, 137 to 139 become the ground potential.

As shown in FIG. 9, a substantially rectangular IC cavity 101 is formed substantially at the center of the ceramic insulating layer 1c, and substantially rectangular electronic component cavities 102 to 105 are formed on the upper, lower, left, and right sides thereof. Is formed. On the lower surface of the ceramic insulating layer 1c, IC electrode pads 32 and 32a for connection with the IC chip 3 and a wiring pattern 30 for forming an oscillation circuit are formed. Also, via-hole conductors 121, 124, 131-1
39, 121 'and 136' are connected to the wiring pattern 30 of the ceramic insulating layer 1c and the external terminal electrodes formed on the lower surface of the ceramic insulating layer 1d, and form conductor paths for connecting to the IC chip 3 and the oscillation circuit. It is for forming. The via-hole conductors 121 and 124 and the IC
The electrode pad 32a forms a part of a conductor path of the Vcc potential.

On the lower surface of the ceramic insulating layer 1d, FIG.
As shown in the figure, a GND terminal 11 for grounding at four corners as an external terminal electrode, a control terminal 12 for controlling the crystal oscillator 100, and a V for supplying power
An cc terminal 13 and an output terminal 14 for performing oscillation output are formed.

As described above, in the container body 1 formed by laminating the ceramic insulating layers 1a to 1d, the electrode pads and the wiring patterns 30, 31 of the ceramic insulating layers 1a to 1d have via hole conductors. Each conductive path is formed through the oscillating circuit, and an oscillation circuit including the IC chip 3 and the electronic components 41 to 44 is connected to the crystal resonator 2.

According to the above configuration, the IC chip 3 is protected from noise by the jitter reduction structure formed on the partition wall 8 of the container 1 separating the crystal unit 2 and the IC chip 3, and the output terminal 14 of the external terminal electrode is provided. The jitter component of the oscillation waveform output from the device can be reduced. As a result, stable and good high-frequency oscillation using overtone oscillation can be performed.

The electronic components 41 to 41 constituting the oscillation circuit
Since the IC chip 3 and the electronic components 41 to 44 are configured independently of each other without forming the IC chip 3 into one IC chip 3, the characteristics are changed by appropriately selecting the electronic components 41 to 44 and the crystal oscillator 100 is changed. Is easily set to a desired characteristic, and the versatility of the crystal oscillator 100 is improved.

The crystal resonator 2 is housed in the upper cavity 5 of the container 1 separated by the partition 8, and the IC chip 3 and the electronic components 41 to 44 constituting the oscillation circuit are accommodated in the lower cavity 10. Since the device is housed, each element can be condensed and arranged in a narrow space.
00 can be reduced in size and mounting area.

As the above-mentioned jitter reducing structure, a ground pattern 111 for grounding the oscillation circuit is arranged between the layers of the laminate constituting the partition 8. That is, the IC chip 3 and the electronic component 41 that constitute the oscillation circuit with the crystal unit 2
By forming the ground pattern 111 on the partition wall 8 that separates the ground pattern 111 from the substrate 44, the ground pattern 111 having a large area can be formed, so that the ground potential is stabilized and the stray capacitance between the oscillation circuit and the crystal unit 2 is increased. Is reduced, whereby the jitter component of the oscillation waveform output from the output terminal 14 of the external terminal electrode can be significantly reduced. Therefore, stable and good high-frequency oscillation using overtone oscillation can be performed more reliably.

The Vcc pattern 112 connected to the electronic component 44 serving as the bypass capacitor Cb and supplying power to the IC chip 3 is formed so as to be substantially surrounded by the ground pattern 111. Vcc pattern 1 by 111
By protecting the IC chip 3 from noise generated from the output terminal 12, the jitter component of the oscillation waveform output from the output terminal 14 of the external terminal electrode can be further reduced. Therefore,
Stable and good high-frequency oscillation using overtone oscillation can be performed more reliably. The term “substantially surrounded” includes a form in which the periphery is completely surrounded and a form in which a part thereof is exposed from the open portion of the ground pattern 111, as shown in FIG.

An electronic component 44 serving as a large-capacity bypass capacitor Cb connected between the Vcc pattern 112 and the ground pattern 111 is arranged in the lower cavity portion 10, and the bypass capacitor Cb in the Vcc conductor path is provided. The distance from the connection portion P of the electronic component 44 to the IC electrode pad 32a at which the IC chip 3 has the Vcc potential is minimized. That is, since the connection is set by the short path, the influence of the external noise is reduced because the path is the short path, so that the high frequency noise superimposed on the power supply voltage supplied to the external terminal electrode is reliably removed. Can be. Thus, the jitter component of the oscillation waveform output from the output terminal 14 can be further reduced. Therefore, stable and good high-frequency oscillation using overtone oscillation can be performed more reliably. Furthermore, since the electronic component 44 serving as the bypass capacitor Cb is disposed in the lower cavity portion 10, the number of components of the external circuit mounted on the printed wiring board is reduced, and the wiring is simplified. A crystal oscillator 100 will be achieved.

Further, since the oscillation circuit accommodated in the lower cavity portion 10 of the container body 1 opened is covered with resin, the oscillation circuit is protected and the moisture resistance is improved.
The heat radiation effect of the C chip 3 can be improved.

Furthermore, if the crystal oscillator 100 is provided with frequency dividing means and is configured to be able to divide the oscillation output, it is possible to divide the oscillation output and obtain one or more outputs at a desired frequency. The frequency dividing means includes a flip-flop and a logic circuit, and can be integrated in the IC chip 3.

Next, a method of manufacturing the above-described container 1 will be described.

The container 1 has ceramic insulating layers 1a to 1a.
It is formed using a ceramic green sheet to be 1d. Specifically, for example, via-hole conductors 25 to 28, 1
Forming through holes 21 to 126, 131 to 138,
These through holes are filled with a high melting point metal paste such as molybdenum or tungsten. At the same time, a conductor film to be the electrode pads 20 and 21 for the crystal unit, a conductor film to be the connection bumps 22 and 23, and a conductor film to be the conductor film 19 for sealing are printed on the upper surface of the green sheet with a high melting point metal paste. Is formed.

Further, via-hole conductors 27, 28, 121-21 are formed on rectangular ceramic green sheets serving as insulating layers 1 b.
Through holes 124, 127, 128, 131 to 139 are formed, and these through holes are filled with a high melting point metal paste. At the same time, on the lower surface of the green sheet, a conductor film to be the element electrode pad 33, the monitor electrode pads 34 and 35, and the wiring pattern 31 constituting the oscillation circuit is formed.

An island-shaped connection pattern 113 for connecting via-hole conductors 25 to 28, a Vcc pattern 112, and a pattern 112 are formed on one of the green sheets to be the ceramic insulating layer 1 a and the ceramic insulating layer 1 b. Is formed by printing the above-mentioned refractory metal paste on the entire surface to become the ground pattern 111 formed substantially on the entire surface.

A via hole conductor 1 is formed in a ceramic green sheet in which a substantially rectangular opening 101 to 105 is formed in a central portion to be a ceramic insulating layer 1c and in upper, lower, left and right sides thereof.
21, 121 ', 124, 127, 128, 131-1
33, 136 to 139 are formed, and these through holes are filled with a high melting point metal paste. At the same time, IC
Conductive films that become the electrode pads 32 and 32a and the wiring patterns 30 that constitute the oscillation circuit are formed.

Further, via-hole conductors 121, 121 ′, 127, and 12 are provided on a frame-shaped ceramic green sheet having a cross-shaped opening in the center portion serving as the ceramic insulating layer 1 d.
8, 131, 132, 136, 136 'are formed, and these through holes are filled with a high melting point metal paste. At the same time, a conductor film to be each of the substantially rectangular terminals 11 to 14 is formed at four corners around an opening serving as a mounting bottom surface of the green sheet.

Next, after laminating and press-bonding such green sheets, a baking treatment is performed. In particular, since the crystal resonator 2 is mounted on the upper surface of the container 1 and the IC chip 3 is mounted on the cavity 10, flatness of both surfaces is important. In the crimping step, pressing is performed using the upper surface of the container body 1 as a reference surface. In order to perform pressing at a uniform pressure on the bottom surface region of the cavity portion 10, for example, the cavity portion 10 is pressed.
To fill the auxiliary filling member, or press with a jig with a flat top tip with a convex upper punch,
The insulating layers 1a and 1b and the insulating layers 1c and 1d are separately pressed, and then both are pressed by pressing.

Next, in the container 1, the terminals 11 to 14 exposed on the surface, the sealing conductor film 19, the crystal oscillator electrode pads 20 and 21, the IC electrode pads 32 and 32 a, the element electrode pads 33, and the monitor The container body 1 is completed by applying Ni plating, flash gold plating, etc. on the electrode pads 34, 35 and the various wiring patterns 30, 31.

Thus, the via-hole conductors and the wiring patterns 30 and 31 formed inside the container 1 are made of a high-melting metal conductor such as molybdenum or tungsten, and each terminal 11 exposed on the outer surface of the container 1 is formed. To 14, the sealing conductor film 19, the respective electrode pads 20, 21, 32, 32a,
33, 34, 35 and the wiring patterns 30, 31 are composed of a Ni layer, an A
The multilayer structure has u layers.

On the upper surface of the container 1, the connection bumps 22 and 23 are formed on the crystal oscillator electrode pads 20 and 21 by a multi-layer structure of a Ni layer and an Au layer on the surface using a high melting point metal as a base conductor. Alternatively, it may be formed by printing and baking a silver conductive paste or applying and curing a resin paste containing Ag powder. Further, in order to make the height of the connection bumps 22 and 23 equal to or higher than a predetermined value, printing and application may be performed a plurality of times. The height from the upper surface of the container 1 to the top of the connection bumps 22 and 23 is, for example, 15 μm.
２０20 μm.

Further, on the sealing conductor film 19, a seal ring 36, which is a substantially rectangular metal frame, is joined by means of Ag brazing or the like. The seal ring 36 is made of 42 alloy, which is an alloy of Fe-Ni, Kovar, which is an alloy of Fe-Ni-Co, phosphor bronze, or the like, and has a structure corresponding to the shape of the sealing conductor film 19. Therefore, a region surrounded by the upper surface of the container body 1 and the seam ring 36 becomes a housing region (upper cavity portion 5) of the crystal resonator 2.

A quartz oscillator 2 is arranged on the upper surface of the container 1. The quartz oscillator 2 includes excitation electrodes 2b and 2c formed on both main surfaces of a rectangular quartz plate 2a having a predetermined cut, for example, an AT cut, and the excitation electrodes 2b and 2c.
Island-shaped extraction electrode portions 2d, 2
e. In FIG. 4, the excitation electrode 2c and the extraction electrode 2e on the lower surface are indicated by dotted lines. The extraction electrodes 2d and 2e are connected to the crystal oscillator electrode pads 20 and 21 via conductive adhesives 2f and 2g. Also,
The excitation electrodes 2b and 2e and the extraction electrodes 2d and 2e are composed of Cr and Ni as underlayers on both sides of the quartz plate 2a and A as surface layers.
g, Au, or the like is deposited by a thin film technique such as evaporation or sputtering.

The quartz oscillator 2 mounted on the upper surface side of the container 1 is hermetically sealed by a metal lid 6.
The metal lid 6 is made of a metal material such as Kovar or 42 alloy, has a thickness of, for example, 0.1 mm, and has a seam ring 36 brazed to the sealing conductor film 19 on the surface of the container 1. Welded and joined. It is desirable that Ni, aluminum, or the like be adhered to the outer surface-side main surface of the metal lid 6. Thereby, it is possible to prevent the brazing material from wrapping around to the front surface side of the lid 6 at the time of welding, and to perform stable and strong joining.

As shown in FIG. 5, an IC chip 3 and electronic components 41 to 44 constituting an oscillation circuit are accommodated in a cavity 10 of a container 1. This IC chip 3 includes oscillation inverters 51 and 52 constituting an oscillation circuit.
(See FIG. 11), and Vc to which the power supply voltage is supplied.
It has a c-electrode, a GND electrode to which a ground potential is connected, a crystal connection electrode to be connected to the crystal resonator 2, an output electrode for performing oscillation output, and a control terminal for enabling external frequency adjustment. The electronic component 41 is a drain capacitor Cd, the electronic component 42 is a gate capacitor Cg, the electronic component 43 is a feedback resistor Rf, and the electronic component 44 is a bypass capacitor Cb having a large capacity (for example, a capacity of 103 pF). .

As shown in the circuit diagram of FIG. 11, an electronic component 42 that is a gate capacitance capacitor Cg and an electronic component 41 that is a drain capacitance capacitor Cd are input / output capacitances of an oscillation circuit. The electronic component 43, which is the feedback resistor Rf, is connected between the output and the input of the oscillation inverters 51 and 52, which are the oscillation portion of the oscillation circuit, and adjusts the level of the feedback signal. The electronic component 44, which is a large-capacity bypass capacitor Cb, is for removing high-frequency noise superimposed on the power supply voltage supplied to the external terminal electrode 13 of Vcc.

The Vcc electrode of the IC chip 3 is
It is led to the Vcc terminal 13 via the electrode pad 32a and the wiring pattern 30 forming the oscillation circuit. Also,
The output electrode is led to the output electrode 14 via a predetermined IC electrode pad 32 and a wiring pattern 30 forming an oscillation circuit. The GND electrode is led out to the external terminal electrode 11 via a predetermined IC electrode pad 32 and a wiring pattern 30 forming an oscillation circuit. The control terminal is led out to the external terminal electrode 12 via a predetermined IC electrode pad 32 and a wiring pattern 30 forming an oscillation circuit. The two crystal connection electrodes are provided with a predetermined IC electrode pad 32 and a wiring pattern 30 forming an oscillation circuit.
31 and the monitor electrodes 34 and 35, and is electrically connected to the electrode pads 20 and 21 on the upper surface of the container body 1 via conductive paths.

Each of these electrodes forms an aluminum electrode 3a on the non-mounting surface side of the IC chip 3 and is connected to predetermined IC electrode pads 32, 32a via bonding wires 4. The mounting surface of the IC chip 3 is connected to the Vcc pattern of the insulating layer 1a via via hole conductors 122 and 123 formed in the insulating layer 1b.

Each of the electronic components 41 to 44 is a chip-shaped component, and each of the electronic components 41 to 44 is a pair of element electrode pads 3.
3 and 33 are joined via a conductive resin adhesive containing Ag powder.

The IC chip 3 and the four electronic components 41 to 44 are arranged in the cavity 10 so as to minimize the mounting space according to the planar shape of the cavity 10. I have.

The cavity portion 10 is filled with a filling resin 7 in order to firmly join the IC chip 3 and the electronic components 41 to 44 and to improve the moisture resistance reliability. The filling resin layer 7 is filled and cured so as to completely cover at least the upper surfaces of the IC chip 3 and the electronic components 41 to 44. Note that the filling resin 7 does not protrude from the opening surface of the cavity 10. this is,
This is for stably disposing the surface-mounted crystal oscillator 100 on the printed wiring board.

In the crystal oscillator 100 described above, as shown in FIG. 5, the IC chip 3 and the four electronic components 41 to 44
Is mounted in the cavity portion 10, a component having a large planar shape such as the IC chip 3 is disposed at the center, and electronic components 41 to 44 having a small outer shape are disposed around the component, thereby saving space. The arrangement structure and the bottom structure of the container body 1 are considered. Specifically, the IC chip 3 is disposed in the IC cavity 101 provided substantially at the center of the bottom surface of the container body 1, and the electronic components 41 to 44 are placed in the electronic component cavities 102 to 105 provided on the upper, lower, left, and right sides thereof. Each is arranged. The external terminal electrodes 11 to 14 are arranged in four corner regions on the bottom surface of the container 1. With such an arrangement, no wasteful space exists on the entire bottom surface of the container 1 and the crystal oscillator 100
The mounting area of the container body 1 on the printed wiring board can be extremely reduced.

As shown in the circuit diagram of the crystal oscillator 100 in FIG. 11, the IC chip 3 is composed of only the oscillation inverters 51 and 52 constituting the oscillation circuit. An electronic component 41 which is a drain capacitance Cd as an input / output capacitance of an oscillation circuit above and below the IC chip 3,
An electronic component 42 that is a gate capacitance capacitor Cg is arranged, and an electronic component 43 that is a feedback resistor Rf and an electronic component 44 that is a large-capacity bypass capacitor Cb are arranged on the left and right sides of the IC chip 3.

As described above, the electronic component 41 serving as the drain capacitance capacitor Cd, the electronic component 42 serving as the gate capacitance capacitor Cg, and the electronic component 43 serving as the feedback resistor Rf constituting the oscillation circuit are not integrated into one chip. Therefore, it becomes easy to appropriately select these electronic components 41 to 43 and set the crystal oscillator to desired characteristics.

The electronic component 44, which is a large-capacity bypass capacitor Cb, is for removing high-frequency noise superimposed on the power supply voltage supplied to the external terminal electrode 13 of Vcc. 3 was difficult to integrate, so it was arranged on a printed circuit board on which a crystal oscillator was mounted. On the other hand, in the present invention, the electronic component 44 is also mounted in the cavity 10 of the container 1 as a chip-like element. As a result, the number of electronic components mounted on the printed wiring board is reduced, wiring is simplified, and it is possible to greatly contribute to miniaturization required for mobile communication devices and the like. Type crystal oscillator 100
Becomes

Next, a method of assembling the above-described crystal oscillator 100 will be described with reference to the process chart shown in FIG.

First, the container 1 is formed (step S1).
The detailed structure and the method for forming the same are as described above.

At the same time, a step of selecting the crystal unit 2 is performed (step S2). That is, since the frequency characteristic of the crystal unit 2 changes greatly due to a minute change in the cut angle, ranking is performed based on frequency variation.

Then, the container 1, the crystal unit 2, the IC chip 3, the electronic components 41 to 44 such as capacitors and resistors, and the metal lid 6 are prepared. In addition, on the surface of the container 1,
The seam ring 36 is joined by brazing or the like, and the bumps 24 are formed.
Bumps 22 and 23 are formed on 0 and 21. Furthermore, on the aluminum electrode of each electrode on the surface side of the IC chip 3,
Gold bumps are formed in advance.

Next, the crystal resonator 2 having the predetermined characteristics is mounted (step S3). Specifically, the connection bumps 22 and 23 formed on the crystal resonator electrode pads 20 and 21 on the surface of the container 1 and the extraction electrode 2 of the crystal resonator 2
The extraction electrode portions 2d and 2e and the electrode pads 20 and 21 are joined together by using conductive adhesives 2f and 2g such as Ag.

Thus, the excitation electrode 2 of the crystal unit 2
b, 2c are the electrode pads 20, 21, the via hole conductor 2
Conduction is made to predetermined electrode pads 32 and monitor electrode pads 34 and 35 formed on the bottom surface of the cavity 10 via the wiring patterns 30 and 31 and the wiring patterns 30 and 31.

Next, the frequency of the crystal unit 2 is measured (step S4). Specifically, the monitor electrode pads 34 and 35
Is brought into contact with a measuring terminal (probe) of the frequency measuring device, and the crystal oscillator 2 is oscillated at a predetermined frequency to measure the frequency.

Next, the frequency of the crystal unit 2 is adjusted (step S5). Specifically, based on the above measurement results,
An inert gas such as Ar is hit on the excitation electrode 31 using an ion gun or the like on the excitation electrode 2b on the upper surface side of the crystal unit 2 joined to the container body 1 to cut the excitation electrode 2b or to remove metal such as Ag. And the oscillation frequency is adjusted by changing the mass of the excitation electrode 2b.

Next, the adjusted frequency of the crystal unit 2 is stabilized (step S6). Specifically, the entire container 1 to which the crystal unit 2 is bonded is subjected to a heat treatment at 150 to 250 ° C. This heat treatment is generally called thermal aging. This thermal aging stabilizes the deposited material for frequency adjustment deposited on the excitation electrode 2b and volatilizes impurities such as a solvent contained in the conductive paste and the like.

Next, the container 1 containing the crystal unit 2 is sealed with the metal lid 6 (step S7). Specifically, the metal lid 6 is placed on the seal ring 36, and the periphery of the metal lid 6 is contact-moved with a roller electrode (not shown) for seam welding while applying a welding current. And weld them together.

Next, the IC chip 3 and the electronic components 41 to 4
4 is mounted in the cavity 10 (step S8).

Specifically, the electronic components 41 to 44 are joined by applying a conductive resin paste containing Ag powder or the like between a pair of device electrode pads 33 and 33, and attaching the electronic components 41 to 44 thereto. Place and cure the conductive resin paste by curing.

The IC chip 3 is mounted by positioning and mounting the IC chip 3 and die-bonding, and then performing plasma cleaning. Thereafter, each electrode made of an aluminum electrode formed on the non-mounting surface side of the IC chip 3 is removed. Then, it is connected to a predetermined IC electrode pad 32 via a bonding wire 4.

In order to prevent heat from curing of the conductive paste from being applied to the IC chip 3, it is preferable to mount the electronic components 41 to 44 first, and then mount the IC chip 3.

When mounting the IC chip 3,
An Au bump is formed on the aluminum electrode of each electrode portion on the non-mounting surface side of the IC chip 3 using an Au wire or the like.
When high heat is applied in a state where an Au bump is formed on the aluminum electrode, a Cargendall void phenomenon occurs due to a difference in diffusion speed between Al and Au, and the connection strength at a bonding interface between Al and Au is reduced. Problem arises.

On the other hand, in the above manufacturing method, since the IC chip 3 is mounted after the heat aging step (step S6), the electrodes of the IC chip 3 and the connecting members (bumps and wires) are mounted.
Since the occurrence of the Cargendall void phenomenon that occurs at the bonding surface such as that described above can be effectively suppressed, the bonding state is also stabilized, which also enables the IC chip to operate stably.

Next, the cavity 10 is filled and covered with the filling resin 7 so as to cover the IC chip 3 and the electronic components 41 to 44 (step S9). Specifically, the IC chip 3 and the electronic component 4 placed in the cavity 10
An epoxy resin having excellent moisture resistance is filled and cured in all of Nos. 1 to 44.

As described above, the assembly of the crystal oscillator 100 is completed, and thereafter, a predetermined electrical test is performed.

According to the above-described manufacturing method, since the step of mounting the crystal resonator 2 is performed before the step of mounting the IC chip 3 and the electronic components 41 to 44, the crystal resonator 2 is mounted on the upper cavity portion of the container 1. 5 and after the container 1 is sealed,
Since the IC chip 3 and the electronic components 41 to 44 are mounted in the lower cavity portion 10 of the container body 1 using a conductive resin paste or the like, foreign matter and outgas generated from the conductive resin paste at that time are reduced. It can be prevented from adhering to the crystal unit 2.

As a result, the crystal impedance value which is the resonance resistance value of the crystal unit 2 increases, and the high frequency oscillation using the overtone oscillation which is easily affected by the foreign matter is removed, and the influence of the foreign matter is eliminated. And stable high-frequency oscillation can be achieved.

In the above-described manufacturing method, a thermal aging step for stabilizing the frequency of the crystal unit 2 is performed between the mounting step of the crystal unit 2 and the mounting steps of the IC chip 3 and the electronic components 41 to 44. Provided. That is, since the heat aging process of the crystal unit 2 can be performed before the IC chip 3 and the like are mounted, unnecessary heat is not applied to the IC chip 3.
The operation reliability of the oscillation circuit composed of the chip 3 and the like can be improved, and high-frequency oscillation using overtone oscillation can be stably improved.

FIG. 19 shows that the crystal oscillator 100 is
(A) reflowed at 250 ° C .; and (b) 125
106.250M for those heat aged at <RTIgt;
The change in characteristics when oscillating at Hz is performed, in which time is plotted on the horizontal axis and frequency fluctuation rate is plotted on the vertical axis. FIG. 20 shows similar test results for a conventional oscillator having a structure in which a crystal resonator and an oscillation circuit IC are arranged in one cavity.

As is apparent from the results, the crystal oscillator 100 according to the present invention hardly changes the frequency characteristics due to heat, whereas the conventional oscillator greatly changes the frequency characteristics due to heat.

(Second Embodiment) FIGS. 13 to 16 show examples of the configuration of a surface-mounted crystal oscillator 300 which is a piezoelectric oscillator according to a second embodiment of the present invention.

As shown in FIG. 13, the crystal oscillator 300 has a lower cavity portion 340d for accommodating an IC chip 303 on the lower side of the whole container, and a crystal resonator 302 on the upper side. Upper cavity 35
0 is formed. The lower cavity portion 340d that accommodates the IC chip 303 is a surface-mounted crystal oscillator that is open on the upper surface side.

That is, the container body 301 is
And a second container 340. And
The first container 310 includes a flat ceramic layer 310a serving as a partition and a ring-shaped ceramic layer 310b, and a seam ring 336 is disposed on the surface of the ring-shaped ceramic layer 310b. The quartz oscillator 302 is disposed in the upper cavity 350 defined by the ceramic layer 310a, the ceramic layer 310b, and the seam ring 336, and the quartz oscillator 302 is hermetically sealed by the metal cover 306. Has been stopped. The ceramic layer 310a has a laminated structure (not shown) as in the above-described first embodiment, and a ground pattern 111a is arranged between the layers and is connected to a via-hole conductor 326 having a GND potential. .

In the second container 340, a flat ceramic layer 340a, a substantially rectangular IC cavity 401 is formed substantially at the center, and a substantially rectangular electronic component cavity 402 is formed on the upper, lower, left and right sides. To 405 are formed, and a ring-shaped ceramic layer 340c. This ceramic layer 34
As shown in FIG. 15, an IC chip 3 and electronic components 41 to 44 are arranged in a lower cavity portion 340d defined by Oa and ceramic layers 340b and 340c. The bottom surface of the cavity 340d has an I
An electrode pad on which the C chip 303 and the electronic components 341 to 344 are arranged and a predetermined wiring pattern are formed.

As shown in FIG. 14, bonding terminal electrodes 351 to 351 are provided at the four corners on the lower surface of the first container 310.
354 are formed. Of these, the joining terminal electrode 35
1, 352 are electrically connected to the crystal resonator electrode pad 320 via the via-hole conductor 325. Then, the joining terminal electrodes 353 and 354 have the GND potential, and are electrically connected to the seam ring 336 via the via-hole conductor 326.

As shown in FIG. 15, the second container 340 has a cavity 340d opened on the upper surface. Then, bonding terminal electrodes 361 to 364 are formed around the opening of the cavity portion 340d.
The joining terminal electrodes 361 and 362 are connected to the first container 31.
0 are connection terminal electrodes 353 and 354 connected to the connection terminal electrodes 353 and 354 on the lower surface of the first container 310.
2 is a terminal electrode for connection to be connected to 2. The bonding terminal electrodes 361 to 364 are connected to the ceramic layers 340 c and 34.
Ob is conducted to a predetermined wiring pattern via a via-hole conductor (not shown) penetrating through Ob.

As shown in FIG. 16, external terminals 311 to 314 are provided at four corners on the lower surface of the second container 340.
Are formed. The external terminals 311 to 314 are connected to a predetermined wiring pattern via via-hole conductors (not shown) of the ceramic layer 340a.

For example, the external terminal 311 is a Vcc terminal electrode, the external terminal 312 is an output terminal for performing oscillation output, the external terminal 313 is a GND terminal, and the external terminal 31
Reference numeral 4 denotes a control terminal used for adjusting a frequency.

The first container 310 and the second container 340 are connected to each other via a conductive joining member 360 made of a conductive resin paste containing a metal powder such as solder or Ag. And the joining terminal electrodes 361 to 364 of the second container 340 are joined and integrated. That is, 34 of the second container
The lower cavity portion 340d opened upward from 0 is covered and laminated by the first container 310.

The lower cavity portion 340 is arranged so that electronic components 41 to 44 having a small shape are arranged around a component having a large planar shape such as the IC chip 3.
d to constitute the above-described oscillation circuit shown in FIG. Specifically, the IC chip 3 is arranged in the IC cavity 401 provided substantially at the center of the upper surface of the second container 340, and the electronic component cavities 4 provided on the upper, lower, left, and right sides thereof.
Electronic components 41 to 44 are arranged at 02 to 405, respectively. External terminals 311 to 314 are arranged at four corners on the bottom surface of the second container 340.

As described above, the piezoelectric oscillator and the method of manufacturing the same according to the present invention are not limited to the specific configurations and steps of each of the above-described embodiments, but may be modified or added or deleted as needed. Needless to say, this may be done.

[0114]

As described above, according to the piezoelectric oscillator of the present invention, stable and good high-frequency oscillation can be performed even if an overtone of a third harmonic or more of the piezoelectric vibrator is used.

Further, the electronic components constituting the oscillation circuit may be replaced with an IC.
Since the IC chip and the electronic component are independent from each other without being integrated into a single chip, it is easy to appropriately select the electronic component, change the characteristics, and set the piezoelectric oscillator to desired characteristics. The versatility of the piezoelectric oscillator is improved.

Further, since the piezoelectric vibrator is accommodated in the upper cavity portion of the container body separated by the partition, and the lower cavity portion accommodates the IC chip and the electronic component constituting the oscillation circuit, each element is formed. Can be condensed and arranged in a narrow space, and the oscillation circuit composed of an IC chip or the like can be protected from noise, so that the piezoelectric oscillator can be made highly reliable, small, and small in mounting area.

In the method for manufacturing a piezoelectric oscillator according to the present invention, the piezoelectric vibrator mounting step is performed before the component mounting step, so that the piezoelectric vibrator is mounted in the upper cavity portion of the container and the container is sealed. Later, since the IC chip and the electronic component are mounted in the lower cavity portion of the container body using a conductive resin paste or the like, foreign substances generated from the conductive resin paste adhere to the piezoelectric vibrator at that time. Therefore, high-frequency oscillation using an overtone that is easily affected by foreign matter can be stably and excellently performed.

In the above-described manufacturing method, there is provided a manufacturing method having a thermal aging step of thermally aging a piezoelectric vibrator between the piezoelectric vibrator mounting step and the component mounting step in order to stabilize the frequency of the piezoelectric vibrator. Then, since the heat aging process of the piezoelectric vibrator can be performed before the IC chip or the like is mounted, unnecessary heat is not applied to the IC chip, so that the operation reliability of the oscillation circuit including the IC chip or the like can be improved. As a result, high-frequency oscillation using the overtone can be stably made favorable.

Furthermore, since components such as an IC chip are mounted after the heat aging step, the occurrence of the Cargendall void phenomenon which occurs at the joint surface between the electrode of the IC chip and the connecting member (bump or wire) is effectively suppressed. Therefore, the bonding state is also stabilized, and this also enables the IC chip to operate stably.

[Brief description of the drawings]

FIG. 1 is an external perspective view illustrating a configuration example of a surface-mounted crystal oscillator that is a piezoelectric oscillator according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a configuration example of a surface-mounted crystal oscillator which is a piezoelectric oscillator according to the first embodiment of the present invention.

FIG. 3 is a side view showing a configuration example of a surface mount type crystal oscillator which is a piezoelectric oscillator according to the first embodiment of the present invention.

FIG. 4 is a top view illustrating a configuration example of a surface-mounted crystal oscillator, which is a piezoelectric oscillator according to the first embodiment of the present invention, with a lid omitted.

FIG. 5 is a lower view showing a configuration example of a surface mount type crystal oscillator which is a piezoelectric oscillator according to the first embodiment of the present invention, omitting a filling resin.

FIG. 6 is a top view showing a configuration example of a ceramic insulating layer 1a constituting a container of a surface-mounted crystal oscillator which is a piezoelectric oscillator according to the first embodiment of the present invention.

FIG. 7 is a lower view showing a configuration example of a ceramic insulating layer 1a constituting a container body of the surface mount type crystal oscillator which is the piezoelectric oscillator according to the first embodiment of the present invention.

FIG. 8 is a lower view showing a configuration example of a ceramic insulating layer 1b constituting a container body of the surface-mounted crystal oscillator which is the piezoelectric oscillator according to the first embodiment of the present invention.

FIG. 9 is a bottom view showing a configuration example of a ceramic insulating layer 1c constituting a container body of the surface-mounted crystal oscillator which is the piezoelectric oscillator according to the first embodiment of the present invention.

FIG. 10 is a bottom view showing a configuration example of a ceramic insulating layer 1d constituting a container body of a surface-mounted crystal oscillator which is a piezoelectric oscillator according to the first embodiment of the present invention.

FIG. 11 is a diagram showing an oscillation circuit of a surface-mounted crystal oscillator which is a piezoelectric oscillator of the present invention.

FIG. 12 is a process diagram showing a manufacturing process of a surface-mounted crystal oscillator which is a piezoelectric oscillator of the present invention.

FIG. 13 is a cross-sectional view illustrating a configuration example of a surface-mounted crystal oscillator that is a piezoelectric oscillator according to a second embodiment of the present invention.

FIG. 14 is a bottom view showing a configuration example of a first container constituting a container body of a surface-mounted crystal oscillator which is a piezoelectric oscillator according to a second embodiment of the present invention.

FIG. 15 is a top view showing a configuration example of a second container constituting a container body of a surface-mounted crystal oscillator which is a piezoelectric oscillator according to a second embodiment of the present invention.

FIG. 16 is a bottom view showing a configuration example of a second container constituting a container body of a surface-mounted crystal oscillator which is a piezoelectric oscillator according to a second embodiment of the present invention.

FIG. 17 is a graph showing a relationship between a frequency change Δf during oscillation by a fundamental wave and a load capacitance CL.

FIG. 18 is a graph showing a relationship between a frequency change Δf during oscillation due to overtone and a load capacitance CL.

19A and 19B are graphs showing changes in frequency characteristics due to heat in a surface-mounted crystal oscillator which is a piezoelectric oscillator according to the present invention, wherein FIG.
Represents heat aged at 125 ° C., respectively.

FIG. 20 is a graph showing a change in frequency characteristics due to heat in a conventional surface mount type crystal oscillator, where (a) is 2
(B) represents a sample reflowed at 50 ° C., and (b) represents a sample subjected to heat aging at 125 ° C.

FIG. 21 is a cross-sectional view showing a configuration example of a conventional surface mount type crystal oscillator.

FIG. 22 is a top view showing a configuration example of a conventional surface mount type crystal oscillator without a lid.

FIG. 23 is a bottom view showing a configuration example of a conventional surface mount type crystal oscillator without a filling resin.

FIG. 24 is a diagram showing an oscillation circuit of a conventional surface mount type crystal oscillator.

FIG. 25 is a diagram illustrating a configuration example of a LAN configuring a gigabit Ethernet using a high-speed communication control device using a piezoelectric oscillator.

FIG. 26 is an explanatory diagram for explaining jitter.

FIG. 27 is an explanatory diagram for explaining jitter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Container body 2 Crystal oscillator (piezoelectric oscillator) 3 IC chip 5 Upper cavity part 8,310a Partition wall (jitter reduction structure) 10 Lower cavity part 11 GND terminal 13 Vcc terminal 14 Output terminal 41-44 Electronic component (44) 100,300 Crystal oscillator (piezoelectric oscillator) S3 Piezoelectric vibrator mounting process S6 Thermal aging process S8 Component mounting process

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) H03H 3/02 H03H 9/02 L 9/02 H01L 41/08 U 41/22 Z

Claims (3)

[Claims] 1. A container body in which an upper cavity portion and a lower cavity portion are separated by a partition, a piezoelectric vibrator accommodated in the upper cavity portion, and an oscillation accommodated in the lower cavity portion. An IC chip and an electronic component constituting a circuit; and an external terminal formed around the lower surface of the container and connected to the oscillation circuit, wherein the oscillation circuit has an overtone of a third harmonic or more of the piezoelectric vibrator. A piezoelectric oscillator characterized in that it oscillates using a piezoelectric element. 2. The method for manufacturing a piezoelectric oscillator according to claim 1, wherein: a piezoelectric vibrator mounting step of mounting the piezoelectric vibrator in an upper cavity portion of the container; and a lower cavity portion of the container. And a component mounting step of mounting the IC chip and the electronic component, wherein the piezoelectric vibrator mounting step is performed before the component mounting step. 3. The method according to claim 1, further comprising a step of thermally aging the piezoelectric vibrator between the piezoelectric vibrator mounting step and the component mounting step to stabilize the frequency of the piezoelectric vibrator. The method for manufacturing a piezoelectric oscillator according to claim 2.