JP2001332933A - Piezoelectric oscillator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-cost, miniaturized quartz oscillator, having improved frequency stability and frequency purity. SOLUTION: Concerning the piezoelectric oscillator, composed of a piezoelectric resonator and an electronic circuit, the electronic circuit is composed of a plurality of IC substrates, at least one of IC substrates is provided with connecting terminals on the upper and lower surfaces thereof, and the other IC substrates are connected to the connecting terminal on the upper surface of the IC substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric oscillation circuit, and more particularly to a low-cost high-frequency output type piezoelectric oscillator.

[0002]

2. Description of the Related Art In recent years, a small crystal oscillator as shown in FIG. That is, FIG. 4 is a side sectional configuration view of a conventional so-called single seal type crystal oscillator 100. In this example, a ceramic package 10 is used.
After mounting an IC chip 102 in which electronic circuits such as an oscillation circuit and a temperature compensation circuit are integrated on a single chip at the bottom of the recessed portion, a quartz vibrating piece 103 is made of silicone conductive so as to cover the upper surface of the IC chip 102. By fixing the package at a predetermined position of the package 101 using an adhesive 104, the crystal resonator element 103 and the IC chip 102 are electrically connected to each other through wiring in the package 101, though not shown. is there.

[0005] By arranging the electronic components constituting the crystal oscillator 100 in cascade, the component mounting area can be suppressed to a narrow range, so that the crystal oscillator 100 can be downsized.

[0004]

However, a bipolar type circuit is generally used as a variable capacitance element included in an oscillator circuit other than the crystal unit 103, and a C-MOS type circuit is generally used as an amplifier circuit. However, in order to form a one-chip IC by mixing such heterogeneous semiconductor circuits, a complicated and advanced manufacturing technique is required, so that an increase in the cost of the IC 102 is unavoidable. He couldn't expect price.

Further, a crystal oscillator circuit composed of an AC circuit typified by an oscillation amplifier circuit and a series circuit typified by a frequency temperature compensation voltage generating circuit is formed into a one-chip IC so that the AC circuit and the DC circuit can be separated. Proximity arrangement is unavoidable, so that particularly high frequency output type crystal oscillator 10
In the case of 0, the oscillation condition of the crystal oscillator 100 changes due to the coupling of an electric signal using a semiconductor material as a transmission medium between the DC circuit and the AC circuit, so that a required oscillation frequency is not output. Inevitably, the problem of abnormal oscillation and the deterioration of phase noise characteristics due to the superposition of noise from the DC circuit in the oscillation loop have been unavoidable.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a small-sized piezoelectric oscillator which is low in cost by solving the above-mentioned problems of the piezoelectric oscillator and which is excellent in frequency stability and frequency purity even in a high-frequency output type. I have.

[0007]

According to a first aspect of the present invention, there is provided a piezoelectric oscillator comprising a piezoelectric vibrator and an electronic circuit, wherein the electronic circuit comprises a plurality of ICs. The IC substrate is characterized in that at least one of the IC substrates has connection terminals on upper and lower surfaces thereof and is configured to connect another IC substrate to connection terminals on the upper surface of the IC substrate.

According to a second aspect of the present invention, in a piezoelectric oscillator comprising a piezoelectric vibrator and an electronic circuit, the electronic circuit comprises a plurality of IC substrates, and at least some of the IC substrates are connected to upper and lower surfaces thereof. It is characterized by having terminals and being configured to be connected to each other in an overlapping manner.

According to a third aspect of the present invention, in addition to the first or second aspect, the electronic circuit includes a DC circuit and an AC circuit, and the DC circuit and the AC circuit are connected to separate I / O circuits.
It is characterized by comprising a C substrate.

A fourth aspect of the present invention is characterized in that, in addition to the first to third aspects, the IC substrates are flip-chip connected to each other.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on illustrated embodiments. FIG. 1 is a side sectional configuration view of an embodiment of a crystal oscillator according to the present invention.
In the crystal oscillator 1 shown in FIG. 1, an IC substrate 4 having connection terminals 2 and 3 on the upper and lower surfaces is provided in a concave portion of a ceramic package 5 and on a bottom surface of the package 5 by connecting a terminal 6 and a connection terminal 2 to, for example, gold bumps. 7 and a connection terminal 9 provided on one surface of another IC substrate 8 through a flip-chip mounting method. Mounted, and furthermore, a quartz oscillator 11 so as to cover the upper surface of the IC substrate 8.
Is fixed to an appropriate position of the package 5 with the silicone conductive adhesive 12.

That is, the crystal oscillator 1 has the following two features. The first point is that an electronic circuit which is a crystal oscillator circuit portion other than the crystal oscillator 11 is configured by a plurality of IC substrates, and for example, a portion of the oscillator circuit configured by a bipolar type semiconductor is formed by an IC. Substrate 4
In this case, the portion made of a MOS type semiconductor can be formed as an IC substrate 8 in an individual manufacturing process.

Second, as shown in FIG. 2A, an IC in which connection terminals 2 are provided on the lower surface and connection terminals 3 are provided on the upper surface.
The substrate 4 and the IC substrate 8 provided with the connection terminals 9 on the lower surface are cascaded using the gold bumps 7 and 10 as described above, and are disposed below the crystal unit 11.

Although such a configuration requires the thickness of the gold bump 11 for connecting the IC substrate 4 and the IC substrate 8 which is not required in the configuration of the conventional crystal oscillator, the gold bump 11 after bonding is generally required. Has a small value of about 20 μm or less, and the configuration of the IC substrate classified by circuit type is simpler than that of the one-chip IC used in the conventional crystal oscillator. Therefore, it is possible to reduce the thickness of each IC board. Therefore, the total thickness of the stacked IC boards and the thickness of the one-chip IC should be substantially equal if the circuit functions are equal. Can be.

As a result, although the crystal oscillator 1 uses a plurality of IC substrates, its height is higher than that of a conventional crystal oscillator using a one-chip IC.
It can be suppressed to almost the same value. Further, although the above description has been made using IC substrates classified according to the type of semiconductor, other than that, for example, an AC circuit such as an oscillation amplifier circuit may be used as the IC substrate 4 and a DC compensation circuit such as a temperature compensation voltage generation circuit may be used. The circuit may be configured as an IC substrate 8. In this way, by configuring the DC circuit and the AC circuit as separate IC substrates, an electric signal between the DC circuit and the AC circuit, which has been a problem in the past, via a semiconductor. Unnecessary coupling can be prevented.

Further, in the above description, the present invention has been described by taking as an example a configuration using two IC boards, but the present invention is not limited to this, and two or more IC boards are connected in cascade. It may be something.

FIG. 3 is a side sectional view of a crystal oscillator using three IC substrates as another embodiment of the crystal oscillator according to the present invention. The feature of the crystal oscillator 1 shown in the figure is that, in addition to the IC substrate 6, an IC substrate 15 having connection terminals 13 and 14 on the upper and lower surfaces is provided.
The connection terminals 3 on the upper surface of the IC substrate 6 and the connection terminals 13 on the lower surface of the IC substrate 15 are connected by gold bumps 10, and the IC
The connection terminals 14 on the upper surface of the substrate 15 and the connection terminals 9 on the lower surface of the IC substrate 8 are connected by gold bumps 16 to form three ICs.
This is where the board is cascaded.

With such a configuration, for example, the IC substrate 6
Is an AC circuit composed of a bipolar type semiconductor, an IC substrate 15 is an AC circuit composed of a MOS type semiconductor, and furthermore, if the IC substrate 8 is a DC circuit, an oscillator circuit is composed of semiconductors of different types. Even in this case, there is no need for complicated IC manufacturing processes,
Further, unnecessary coupling of an electric signal does not occur between the DC circuit and the AC circuit.

In the above description, the present invention has been described using gold bumps in flip chip mounting. However, the present invention is not limited to this, and bumps made of a material other than gold, such as solder bumps, are used. Even in such a case, the present invention can be applied. Furthermore, although the present invention has been described using a quartz oscillator as a vibration source, the present invention can be applied to any piezoelectric oscillator using a piezoelectric oscillator other than a quartz oscillator as a vibration source.

[0020]

As described above, the crystal oscillator according to the present invention is a piezoelectric oscillator comprising a piezoelectric vibrator and an electronic circuit, wherein the electronic circuit comprises a plurality of IC substrates, and at least one of the IC substrates is provided. Is equipped with connection terminals on the upper and lower surfaces, and is configured to connect another IC substrate to the connection terminals on the upper surface of the IC substrate, so that it is possible to use an inexpensive electronic circuit using a heterogeneous semiconductor without impairing the compact shape of the crystal oscillator. And the occurrence of electric signal coupling between the DC and AC circuits of the electronic circuit can be suppressed. There is an effect that a piezoelectric oscillator is possible.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing one embodiment of a crystal oscillator according to the present invention.

FIG. 2 is a top view and a bottom view of an IC substrate used for a crystal oscillator according to the present invention.

FIG. 3 is a side sectional view showing another embodiment of the crystal oscillator according to the present invention.

FIG. 4 is a side cross-sectional configuration diagram of a conventional crystal oscillator.

[Explanation of symbols]

1,100 crystal oscillator, 2, 3, 9, 13, 14 connection terminals, 4, 8, 15 IC substrate, 5, 101 package, 6
Terminals, 7, 10, 16 gold bumps, 11, 103 crystal oscillator, 12, 104 silicone conductive adhesive, 1021 chip IC,

Claims (4)

[Claims] 1. A piezoelectric oscillator comprising a piezoelectric vibrator and an electronic circuit, wherein the electronic circuit comprises a plurality of IC substrates,
At least one of the IC substrates has connection terminals on upper and lower surfaces thereof, and another connection terminal is provided on the upper surface connection terminal of the IC substrate.
A piezoelectric oscillator configured to connect a C substrate. 2. A piezoelectric oscillator comprising a piezoelectric vibrator and an electronic circuit, wherein said electronic circuit comprises a plurality of IC substrates,
A piezoelectric oscillator, wherein at least some of the IC substrates have connection terminals on upper and lower surfaces thereof and are configured to be connected to each other in an overlapping manner. 3. The piezoelectric device according to claim 1, wherein the electronic circuit comprises a DC circuit and an AC circuit, and the DC circuit and the AC circuit are formed on separate IC boards. Oscillator. 4. The piezoelectric oscillator according to claim 1, wherein said IC substrates are flip-chip connected to each other.