JP3125732B2 - Piezoelectric oscillator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric vibrator oscillator in which a piezoelectric vibrator and an IC chip including the piezoelectric vibrator and forming an oscillation circuit are housed in a closed container.

[0002]

2. Description of the Related Art Piezoelectric oscillators using piezoelectric oscillators such as quartz oscillators are widely used in various electronic devices such as communication devices such as mobile phones and personal computers. With the downsizing of electronic devices, as with other various electronic components, various measures have been taken to reduce the size of piezoelectric vibrator oscillators in order to increase the component mounting density on printed wiring boards. For example, in order to reduce the mounting area, a crystal resonator package is mounted on an IC package containing an oscillation circuit main body, or a crystal resonator and an oscillation circuit main body are housed in one package. (For example, JP-A-63-305604 and JP-A-03-019406).

When a crystal resonator and an oscillation circuit main body are housed in one package, it is more compact to arrange them vertically than to arrange them side by side in a package. Is more advantageous. FIG. 5 is a sectional side view showing the structure of such a conventional piezoelectric vibrator oscillator. The piezoelectric vibrator oscillator 102 shown in FIG. 5 includes a quartz oscillator 106 in a closed vessel 104 and a quartz oscillator 106
And an IC chip 108 that forms an oscillation circuit. The closed container 104 includes a base 110 and a metal cover plate 112. The base 110 is formed of a ceramic substrate 114, a ceramic frame 116 mounted thereon, and a metal seam mounted thereon. It is formed by a ring 117. And the substrate 11
The IC chip 108 is placed horizontally inside the frame body 116 on the upper side 4, and the plate-shaped quartz oscillator 106 is spaced apart therefrom.
Is arranged. In this state, the lid plate 112 is put on the seam ring 117, and the quartz oscillator 106 and the IC
The chip 108 is sealed inside.

An input / output electrode 118 connected to an excitation electrode is formed on the lower surface of the crystal unit 106.
An input / output terminal 124 connected to an input / output terminal 122 on a substrate 114 is disposed on an inner edge of the frame 116 facing the input / output electrode 118 via a through hole 120 penetrating the frame 116. ing. Then, the input / output electrode 118
The input and output terminals 124 are electrically connected to each other by a conductive adhesive 126, and the crystal plate is supported and fixed in the state shown in FIG. 5 by the conductive adhesive 126. IC
On the upper surface of the chip 108, the input / output terminals 12
8, 130 are arranged and they are bonding wire 1
32, the input / output terminals 122 and 134 on the substrate 114
It is connected to the. In addition, as described above, the crystal oscillator and the IC
A structure in which a chip is arranged vertically and a crystal unit is electrically connected and supported using a conductive adhesive is disclosed in
7-297666.

[0005]

However, in such a conventional piezoelectric resonator oscillator 102, in order to electrically connect the crystal resonator 106 and the IC chip 108 and to support the crystal resonator 106, I / O terminals 122, 124
And the through hole 120 must be provided, and the structure of the sealed container 104 is complicated and large, and as a result, there is a problem that the manufacturing cost is increased. In addition, there is a problem in that volatile gas is generated from the conductive adhesive 126 and adheres to the surface of the crystal unit 106, thereby lowering the reliability of the oscillator. The present invention has been made in order to solve such a problem, and an object of the present invention is to provide a closed container having a simple and compact structure, and as a result, a low manufacturing cost and a highly reliable piezoelectric device. An object of the present invention is to provide a resonator oscillator.

[0006]

According to the present invention, a plate-shaped piezoelectric vibrator and an IC chip including the piezoelectric vibrator and forming an oscillation circuit are housed in a closed container. In the piezoelectric vibrator oscillator, the IC chip has first and second input / output terminals on an upper surface, and is disposed on the bottom of the closed container, and the piezoelectric vibrator is connected to an excitation electrode. A first and a second input / output electrode are provided on a lower surface, and the first and second input / output electrodes are respectively opposed to first and second input / output terminals of the IC chip. The first and second IC chips are arranged at a distance from the IC chip.
A conductive substance is interposed between the input / output terminal of the piezoelectric vibrator and the first and second input / output electrodes of the piezoelectric vibrator,
The piezoelectric vibrator is supported and fixed above the IC chip by the conductive material, and the first and second input / output electrodes of the piezoelectric vibrator are connected to the IC chip by the conductive material. The IC chip is further electrically connected to an output terminal, and the IC chip further has first and second auxiliary terminals electrically independent from other circuit elements on an upper surface, and the piezoelectric vibrator is electrically connected to the excitation electrode on a lower surface. Electrically independent
The semiconductor device further includes first and second auxiliary electrodes facing the first and second auxiliary terminals of the C chip, respectively.
A conductive material is interposed between the first and second auxiliary terminals of the C chip and the first and second auxiliary electrodes of the piezoelectric vibrator, respectively, and the piezoelectric vibrator is made of the same conductive material. And is supported and fixed above the IC chip.

In the piezoelectric vibrator oscillator of the present invention, the piezoelectric vibrator is supported and fixed above the IC chip by a conductive material, and the first and second input / output electrodes of the piezoelectric vibrator are formed of a conductive material. Is electrically connected to the first and second input / output terminals of the IC chip, so that the piezoelectric vibrator and the IC chip are electrically connected and the piezoelectric vibrator is supported as in the related art. There is no need to provide input / output terminals and through holes at the locations of the members that make up the sealed container itself, and further, since no conductive adhesive is used, no gas is generated.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described based on embodiments with reference to the drawings. FIG. 1 is a sectional side view showing an example of the piezoelectric vibrator according to the present invention, FIG. 2 is a plan view showing a main part of the piezoelectric vibrator shown in FIG. 1, and FIG.
4 is an equivalent circuit diagram of the piezoelectric vibrator oscillator of the present embodiment. The piezoelectric vibrator oscillator 2 of the present embodiment includes:
The sealed container 4 contains a quartz crystal plate 6 as a piezoelectric vibrator and an IC chip 8 including the quartz crystal plate 6 to form an oscillation circuit. The closed container 4 includes a base 10 and a metal cover plate 12. The base 10 is formed of a ceramic substrate 14 and a ceramic frame 16 mounted thereon.
And a metal seam ring 17 loaded thereon.
Are formed. The IC chip 8 is horizontally mounted on the substrate 14 inside the frame 16, and the plate-shaped quartz crystal plate 6 is arranged above the central portion of the IC chip 8 with a space therebetween. In this state, the cover plate 12 is put on the seam ring 17, and the quartz crystal plate 6 and the IC chip 8 are sealed inside.

The quartz plate 6 is formed in a rectangular shape in this embodiment, excitation electrodes 18 and 20 are formed on the upper and lower surfaces, respectively, and first and second input / output electrodes 22 and 24 are formed on the lower surface. And first and second auxiliary electrodes 2
6, 28 are formed. The first and second input / output electrodes 22 and 24 are disposed in the vicinity of two adjacent corners of the quartz crystal plate 6, and the excitation electrode 18 on the upper surface is connected to the first input / output electrode 22 via the lead 30. On the other hand, the lower excitation electrodes 20 are connected to the second input / output electrodes 24, respectively. Further, the first and second auxiliary electrodes 26 and 28 are arranged near other corners. First and second auxiliary electrodes 26,
Reference numeral 28 is provided for supporting the quartz crystal plate 6 and is electrically independent from the excitation electrodes 18 and 20. A quartz oscillator 42 is formed by the quartz plate 6 and various electrodes.

On the other hand, the IC chip 8 has first and second input / output terminals 23 and 25 and first and second auxiliary terminals 27 and 29 on the upper surface.
Reference numerals 3 and 25 denote first and second auxiliary terminals 27 and 24, respectively, on the first and second input / output electrodes 22 and 24 of the crystal plate 6.
Reference numeral 29 denotes the first and second auxiliary electrodes 26, 2 of the quartz crystal plate 6.
8. Further, two input / output terminals 32 electrically connected to circuit elements on the IC chip 8 are provided on opposite sides of the upper surface of the IC chip 8.

The first and second input / output electrodes 22 and 24 and the first and second auxiliary electrodes 26 and 28 of the quartz crystal plate 6 and the first and second input / output terminals 23 of the IC chip 8 , 25 and first and second auxiliary terminals 2
Conductive substances are respectively interposed between 7, 7 and 29,
In this embodiment, the metal bump 34 is used as a conductive substance. Each electrode and metal bump, and each terminal and metal bump are welded, respectively. The quartz crystal plate 6 is supported and fixed on the IC chip 8 by these metal bumps 34, and the first and second input / output electrodes 22 and 24 of the quartz crystal plate 6 and the first and second The input / output terminals 23 and 25 are electrically connected to each other.

On the upper surface of the inner edge of the frame 16 constituting the closed container 4, four input / output terminals 36 are provided (only two input / output terminals 36 are shown in FIG. 1). Is a through hole 19 penetrating the frame 16 and the substrate 14.
External input / output terminal 3 formed on the lower surface of substrate 14
8 are electrically connected to each other. The input / output terminals 36 are electrically connected to the input / output terminals 32 provided on the IC chip 8 by bonding wires 40, respectively.

An oscillation circuit composed of the crystal plate 6 and the IC chip 8 is equivalent to that shown in FIG. In FIG. 4, the portion surrounded by the dotted line is I
This is a circuit formed by circuit elements on the C chip 8.
This circuit includes a quartz crystal unit 42 including a quartz crystal plate 6 and the above-mentioned electrodes formed thereon, an inverter 44, a buffer amplifier 46, resistors 48 and 50, a capacitor 52,
54. Both ends of the quartz oscillator 42,
That is, the excitation electrodes 18 and 20 are connected to the ground via capacitors 52 and 54, respectively, and a series circuit of resistors 48 and 50 is connected in parallel to both ends of the crystal unit 42. An output terminal of the inverter 44 and an input terminal of the buffer amplifier 46 are connected to a common connection point of the resistors 48 and 50, and the other end of the resistor 48 is connected to an input terminal of the inverter 44. The control terminal 56 of the inverter 44 and the buffer amplifier 46 and the output terminal of the buffer amplifier 46 are connected to different external input / output terminals 38, respectively.

In such a configuration, the inverter 44 and the buffer amplifier 46 are connected through the external input / output terminal 38.
When a predetermined bias voltage is applied to the control terminal 56, the inverter 44 and the buffer amplifier 46 are in the operating state, and the inverter 44 is in the operating state, so that the reactance component of the crystal unit 42 itself and the crystal unit 42
The frequency component in which the reactance on the IC chip 8 side looking out from the side cancels out is amplified, and the circuit oscillates. The oscillation signal is amplified by the buffer amplifier 46 and output from one of the external input / output terminals 38.

As described above, in the piezoelectric vibrator 2 of the present embodiment, the crystal plate 6 is supported and fixed above the IC chip 8 by the metal bumps 34, and the first
And the second input / output electrodes 22 and 24 are connected to the first and second input / output terminals 23 of the IC chip 8 by metal bumps 34.
25 is electrically connected. Therefore, the crystal plate 6 and the IC chip 8 are electrically connected as in the related art,
Further, it is not necessary to provide input / output terminals and through holes for supporting the quartz crystal plate 6 at the positions of the members constituting the closed container itself. As a result, the structure of the closed container can be simplified and downsized. As a result, a reduction in manufacturing cost can be realized. Further, since there is no need to use a conductive adhesive, no gas is generated in the closed container 4, and therefore,
Reliability can be improved.

[0016]

As described above, in the piezoelectric vibrator oscillator of the present invention, the piezoelectric vibrator is supported and fixed above the IC chip by a conductive substance, and the first and second input terminals of the piezoelectric vibrator are fixed. The output electrode is electrically connected to the first and second input / output terminals of the IC chip by a conductive material.

Therefore, as in the prior art, the piezoelectric vibrator and the IC chip are electrically connected, and the input / output terminals and through holes for supporting the piezoelectric vibrator are provided at the locations of the members constituting the sealed container itself. As a result, the structure of the closed container can be simplified and downsized, and as a result, the manufacturing cost can be reduced.

Further, since there is no need to use a conductive adhesive, no gas is generated in the closed container, and therefore, the reliability of the piezoelectric vibrator oscillator can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional side view showing an example of a piezoelectric vibrator oscillator according to the present invention.

FIG. 2 is a plan view showing a main part of the piezoelectric vibrator oscillator of FIG.

FIG. 3 is a sectional view taken along line AA ′ of FIG. 1;

FIG. 4 is an equivalent circuit diagram of the piezoelectric vibrator oscillator of the present embodiment.

FIG. 5 is a sectional side view showing a structure of a conventional piezoelectric vibrator oscillator.

[Explanation of symbols]

2 ... Piezoelectric oscillator, 4 ... Closed container, 6 ... Crystal plate, 8 ... IC chip, 10 ... Base, 12 ... Cover plate, 14 ... Substrate, 16 ... Frame, 18 , 20 ... excitation electrode, 22 ... first input / output electrode, 23 ... first input / output terminal, 24 ... second input / output electrode, 25 ... second input / output terminal, 26 ... First auxiliary electrode, 27 first auxiliary terminal, 28 second auxiliary electrode, 29 second auxiliary terminal, 34 metal bump, 40 bonding wire, 42 crystal vibration Child, 44 ... inverter, 46 ...
... buffer amplifiers, 48, 50 ... resistors, 52, 54 ...
... capacitors.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H03B 5/30-5/42 H03H 9/00

Claims (6)

(57) [Claims] 1. A piezoelectric vibrator oscillator comprising a plate-shaped piezoelectric vibrator and an IC chip including the piezoelectric vibrator and forming an oscillation circuit in a closed container, wherein the IC chip is provided on an upper surface thereof. A piezoelectric vibrator having a first input / output terminal and a second input / output terminal, the piezoelectric vibrator being disposed at a bottom of the closed container;
And a second input / output electrode on the lower surface. The first and second input / output electrodes are respectively opposed to the first and second input / output terminals of the IC chip. And a conductive material disposed between the first and second input / output terminals of the IC chip and the first and second input / output electrodes of the piezoelectric vibrator. A substance is interposed, the piezoelectric vibrator is supported and fixed above the IC chip by the conductive substance, and the first and second input / output electrodes of the piezoelectric vibrator are formed by the conductive substance. The IC chip is electrically connected to an input / output terminal of the IC chip , and the IC chip is electrically independent from other circuit elements on an upper surface.
First and second auxiliary terminals, wherein the piezoelectric vibrator is electrically isolated from the excitation electrode on the lower surface.
To the first and second auxiliary terminals of the IC chip
A first auxiliary electrode and a second auxiliary electrode;
And the first and second auxiliary terminals of the IC chip and the
The piezoelectric vibrator is located between the first and second auxiliary electrodes.
A conductive material is interposed therebetween, and the piezoelectric vibrator is made of the same conductive material as the IC chip.
Characterized by being supported and fixed above the piezoelectric vibrator. 2. The piezoelectric vibrator is formed in a rectangular shape in a plan view, and the first and second input / output electrodes are arranged near two adjacent corners of the piezoelectric vibrator, respectively. 2. The piezoelectric vibrator oscillator according to claim 1, wherein the second auxiliary electrodes are arranged near other corners. 3. The airtight container according to claim 1, wherein the airtight container includes a base having a recess for accommodating the piezoelectric vibrator and the IC chip, and a lid plate for sealing the recess. 2. The piezoelectric oscillator according to claim 1. 4. The base comprises a ceramic substrate, a ceramic frame mounted on the substrate, and a metal seam ring mounted on the frame, wherein the IC chip is mounted on the frame. The piezoelectric vibrator oscillator according to claim 3, wherein the piezoelectric vibrator is arranged inside a body. 5. The oscillator according to claim 1, wherein the piezoelectric oscillator is a quartz oscillator. 6. The oscillator according to claim 1, wherein the conductive material is a metal bump.