JP2001077627A - Temperature-compensating piezoelectric oscillator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a direct type temperature-compensating piezoelectric crystal oscillator small-sized by printing a thick film of a thermistor or resistance, constituting a temperature compensating circuit on a rear surface of a package of a piezoelectric oscillator. SOLUTION: A recessed internal bottom surface is formed by stacking ceramic layers, a step part for mounting a piezoelectric vibrator is provided in a corner, and a conductor part electrically connecting the step part and an external terminal is formed by burning to obtain a ceramic package 1. In addition to input terminals 4 and 6 and terminal electrodes 5 and 7 for the piezoelectric vibrator, terminal electrodes 8 to 11 are provided, and thermistors 12 and 13 for low temperature and high temperature are formed by a thick-film forming method between the terminal electrodes 8 and 9 and terminal electrodes 10 and 11. Thus, the thermistor is formed by thick-film printing on the bottom surface substrate of the ceramic package containing the piezoelectric vibrator to eliminate area on a printed board that two thermistors occupy, thereby making the oscillator small-sized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature-compensated piezoelectric oscillator, and more particularly to a temperature-compensated piezoelectric oscillator in which temperature-compensating circuit components are integrated and miniaturized.

[0002]

2. Description of the Related Art Piezoelectric oscillators, particularly crystal oscillators, have excellent frequency accuracy, frequency temperature characteristics, and frequency aging characteristics, and are widely used in portable telephone terminals and the like. Temperature-compensated crystal oscillator shown in Fig. 6 (compensation circuit exists in the oscillation loop and high-frequency current flows, so direct TC
XO) is an AT-cut crystal unit X and an amplifier AMP
And two temperature compensation circuits (for low-temperature part compensation: L, for high-temperature part compensation: H) and an adjustment capacitor (C + Cv) in series to form an oscillation loop. FIG. 6A shows an example in which the temperature compensation circuit is formed in a series type (L + H), and FIG.
Is an example formed in a parallel type (L // H).

The above-described piezoelectric vibrator X has a frequency-temperature characteristic of 3
This is an AT-cut quartz resonator that exhibits a quadratic curve, and the amplifier AM
In general, a module having a built-in transistor is used as P, and the adjusting capacitor is generally a fixed capacitor and a trimmer capacitor connected in parallel. Here, as for the temperature compensation circuit, the temperature compensation for the low temperature compensation and the high temperature compensation can be basically performed by the parallel circuit of the thermistor Th and the capacitor Cp shown in FIG. 7A.

FIG. 7B shows an example of a low-temperature side compensation circuit in which a resistor R1 is connected in parallel to a parallel circuit of a thermistor Th1 and a capacitor C1 so that temperature compensation can be finely adjusted. Also,
FIG. 7C shows an example of a high temperature side compensation circuit in which a resistor R2 is inserted in series with the thermistor Th2 of a parallel circuit of the thermistor Th2 and the capacitor C2 so that temperature compensation can be finely adjusted.
With respect to the direct TCXO having the above-described configuration, each element value may be determined based on, for example, the disclosure of JP-A-56-68002.

[0005]

However, in the conventional direct TCXO, the compensation circuits on the low-temperature side and the high-temperature side are each composed of separate electronic components, that is, thermistors Th1 and Th2, resistors R1 and R2.
In addition, since the oscillator is configured using the capacitors C1 and C2, the size of the oscillator becomes large, and there has been a problem that it is not possible to meet the recent demand for miniaturization of mobile phone terminals. The present invention has been made to solve the above-mentioned problem, and has a small direct type.
The purpose is to provide TCXO.

[0006]

According to a first aspect of the present invention, there is provided a temperature-compensated piezoelectric oscillator according to the present invention, comprising a piezoelectric vibrator, an amplifier, and a thermistor, a capacitor, and a resistor constituting a temperature compensation circuit. Wherein the thermistor or the resistor is formed by thick-film printing on the back surface side of the package of the piezoelectric oscillator. According to a second aspect of the present invention, there is provided a temperature-compensated piezoelectric oscillator including a piezoelectric vibrator, an amplifier, and a thermistor, a chip capacitor, and a resistor constituting a temperature compensation circuit, wherein the thermistor or the resistor is formed by thick-film printing on the surface of the chip capacitor. A temperature-compensated piezoelectric oscillator is formed and connected in parallel with the capacitance of a chip capacitor. According to a third aspect of the present invention, there is provided a temperature-compensated piezoelectric oscillator including a piezoelectric vibrator, an amplifier, and a thermistor, a chip capacitor, and a resistor that constitute a temperature compensation circuit. Are connected in parallel with the capacitance of a chip capacitor. According to a fourth aspect of the present invention, there is provided a temperature compensated piezoelectric oscillator including a piezoelectric vibrator, an amplifier, and a thermistor, a chip capacitor, and a resistor constituting a temperature compensation circuit, wherein the thermistor, the resistor and the resistor are formed by thick-film printing on the surface of the chip capacitor. And a series connection circuit of a thermistor and a resistor, and these are connected in parallel with the capacitance of a chip capacitor.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on an embodiment shown in the drawings. FIG. 1 is a diagram showing an example in which two thermistors constituting a temperature compensation circuit of a direct TCXO according to the present invention are formed by thick-film printing on the bottom surface of a piezoelectric vibrator package. FIG. (B) is a right side view, (c) is a bottom view, (d)
Is an electrical equivalent circuit. A feature of the first embodiment of the present invention is that a thermistor is formed by thick-film printing on a bottom substrate of a ceramic package containing a piezoelectric vibrator. As is well known, a ceramic package is formed by laminating several layers of ceramics, forming a concave inner bottom surface, providing a step portion on which a piezoelectric vibration element is mounted at a corner thereof, and electrically connecting the step portion and a package external terminal. The conductor is formed by firing. As shown in the bottom view of FIG. 1C, the package of the thermistor integrated piezoelectric vibrator X according to the present invention has four terminal electrodes other than the input / output terminals 4 and 6 and the ground terminals 5 and 7 for the piezoelectric vibrator. 8, 9, 10, 11 are provided, between terminals 8 and 9 and terminal 10
Thermistors 12, 13 are formed by thick film formation between
One is for low temperature and the other is for high temperature.

[0008] A piezoelectric vibrating element (not shown) is mounted on the step portion of the inner bottom of the package 1 formed as described above, and is conductively fixed using a conductive adhesive. The metallized portion and the metal lid 2 are hermetically welded by means of resistance welding or the like to form a thermistor integrated piezoelectric vibrator. By using the thermistor integrated piezoelectric vibrator of the first embodiment of the present invention, the area on the printed circuit board conventionally occupied by two separate thermistors can be omitted, which contributes to the downsizing of the direct TCXO. .

2 (a), 2 (b) and 2 (c) are a front perspective view, a rear perspective view and an electrical equivalent showing the configuration of a compensation circuit integrated block 20 according to a second embodiment of the present invention. It is a figure showing a circuit. The compensation circuit integrated block 20 is a thermistor arranged in parallel between the electrodes 22 and 23 on the surface which is a good insulating material of the ceramic chip capacitor 21 by a thick film firing method.
The compensation circuit integrated block 20 is formed by forming the resistors 24 and 25 and the parallel resistors 26 and 27 between the electrodes 22 and 23 on the back surface in the same manner. As shown in FIG. 2C, the electric circuit of the block 20 includes the thermistors Th1 and Th2 and the resistances R1 and R2 as the capacitance C of the ceramic chip capacitor 21 itself.
Are circuits connected in parallel. Where the thermistor Th
The electrical constant of 1 and the resistance R1 is set for low temperature, and that of the thermistor Th2 and the resistance R2 is set for high temperature. In this way, the chip components of the thermistor and the resistor can be omitted by thick film printing, and downsizing can be achieved. It is also possible to reduce one capacitor as compared with the case of connecting in series.

FIGS. 3A and 3B are a front perspective view and a rear perspective view, respectively, showing the configuration of a low-temperature compensation circuit 30 according to a third embodiment of the present invention. As shown in FIG. 3A, a thermistor 34 is formed between the electrodes 32 and 33 on the front surface of the chip capacitor 31 by a thick film firing method, and a resistor 35 is formed between the electrodes 32 and 33 on the back surface by the same method. . An electrical equivalent circuit of the low-temperature side compensation circuit 30 is a circuit shown in FIG. Since the resistor R1 is connected in parallel to the thermistor Th1, there is a feature that low-temperature compensation can be performed more minutely.

FIG. 4 is a perspective view showing a configuration of a high temperature side compensation circuit 30 according to a fourth embodiment of the present invention. A thermistor 44 is formed on the left end of the chip capacitor 41 shown in FIG. 4 from the electrode 42 to the electrode 43 by a thick film firing method, and a resistor 45 is formed on the right end of the chip capacitor 41 from the electrode 43 to the electrode 42.
Then, the ends of the thermistor 44 and the resistor 45 that are not connected to the electrodes 42 and 43 are connected using a conductive thick film material 46, and a chip capacitor is connected to a series connection circuit of the thermistor 44 and the resistor 45.
A circuit corresponding to FIG. 7C is obtained by connecting 41 capacitors C in parallel. As described above, since the resistor R2 is connected in series to the thermistor Th2, there is a feature that the compensation on the high temperature side can be performed more minutely.

FIGS. 5 (a) and 5 (b) are front and rear perspective views showing the structure of a fifth embodiment according to the present invention. As shown in FIG. 5A, the low- and high-temperature compensating element integrated block 50 is formed by thick-film firing of a thermistor 54 at the left end in the figure and a resistor 55 at the right end in the figure between the electrodes 52 and 53 on the surface of the chip capacitor 21. It is formed by a method. Further, as shown in FIG. 5B, a series connection circuit of a thermistor 56 and a resistor 57 is formed between the electrodes 52 and 53 on the back surface of the chip capacitor 51 by a thick film firing method as shown in FIG. I do. By forming the compensating element on the front and back of the chip capacitor in this way, the electric circuit can be configured on the chip capacitor by connecting the circuits of FIGS. 7B and 7C in parallel. It is possible to reduce the size significantly.

[0013]

According to the present invention, as described above, the compensation circuit of the series TCXO can be reduced, and as a result, the shape and dimensions of the series TCXO can be significantly reduced. . If the series TCXO according to the present invention is used for a mobile phone terminal or the like, an excellent effect that the external shape of the device can be significantly reduced in thickness and size as compared with the conventional device can be obtained.

[Brief description of the drawings]

1 (a), 1 (b) and 1 (c) are a plan view, a right side view and a bottom view of a thermistor integrated piezoelectric vibrator of the present invention, respectively, and FIG. 1 (d) is an electrical equivalent circuit thereof.

FIGS. 2A and 2B are perspective views of the front and back surfaces of a low and high temperature compensation integrated block, respectively, and FIG. 2C is an electric equivalent circuit thereof.

FIGS. 3A and 3B are perspective views of a front surface and a back surface of a low-temperature compensation integrated block, respectively.

FIG. 4 is a perspective view of a high-temperature compensation integrated block.

FIGS. 5A and 5B are perspective views of a front surface and a back surface of a low and high temperature compensation integrated block, respectively.

6A and 6B are diagrams showing a circuit configuration of a conventional series TCXO.

FIG. 7A is a circuit as a basic form of a temperature compensation circuit,
(B) is a low-temperature compensation circuit, and (c) is a high-temperature compensation circuit.

[Explanation of symbols]

1. Ceramic package 2. Metallized part 3. Metal cover 4, 5, 6, 7, 8, 9, 10, 11, 22, 23, 3
2, 33, 42, 43, 52, 53, terminal electrode 56, thermistor 57, resistor 20, 30, 40, 50 temperature compensation integrated block 21, 31, 41, 51 chip capacitor 58 -Conductor Th1, Th2-Thermistor R1, R2-Resistance C-Capacitance

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5J079 AA04 BA02 BA44 CB02 DA12 FA14 FA21 FA24 FB01 HA22 HA23 5J081 AA02 CC17 CC42 EE05 FF23 JJ02 JJ18 LL01 MM01 MM06

Claims (4)

[Claims] 1. A temperature compensated piezoelectric oscillator comprising a piezoelectric vibrator, an amplifier, and a thermistor, a capacitor, and a resistor constituting a temperature compensating circuit, wherein the thermistor or the thermistor is formed by thick-film printing on a back surface side of a package of the piezoelectric vibrator. A temperature-compensated piezoelectric oscillator characterized by forming a resistor. 2. A temperature-compensated piezoelectric oscillator comprising a piezoelectric vibrator, an amplifier, and a thermistor, a chip capacitor, and a resistor constituting a temperature compensation circuit, wherein the thermistor or the resistor is formed by thick-film printing on the surface of the chip capacitor. A temperature-compensated piezoelectric oscillator, wherein said thermistor or resistor is connected in parallel with said chip capacitor. 3. A temperature-compensated piezoelectric oscillator comprising a piezoelectric vibrator, an amplifier, and a thermistor, a chip capacitor, and a resistor constituting a temperature compensation circuit, wherein the thermistor and the resistor are connected in series by thick-film printing on the surface of the chip capacitor. A temperature-compensated piezoelectric oscillator, wherein a circuit is formed and the series-connected circuit and the chip capacitor are connected in parallel. 4. A temperature-compensated piezoelectric oscillator comprising a piezoelectric vibrator, an amplifier, and a thermistor, a chip capacitor, and a resistor constituting a temperature compensation circuit, wherein a first thermistor is formed by thick-film printing on the surface of the chip capacitor; A temperature-compensated piezoelectric oscillator comprising a resistor, a second thermistor, and a series-connected circuit of a second resistor, which are connected in parallel with the chip capacitor.