JPH077888B2 - Piezoelectric oscillator and manufacturing method thereof - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a piezoelectric oscillator in which a piezoelectric resonator and an oscillation circuit are housed in the same case and a method for manufacturing the same, and particularly to a step of setting a compensation characteristic of a temperature compensation circuit. Regarding improvement.

(Technical background of the invention) Recently, a large number of piezoelectric oscillators using a piezoelectric vibrator are used in a wide field of electronic technology.

In particular, a crystal oscillator using a crystal piece as a piezoelectric body has a very high Q value at resonance and is stable, so that it is widely used as a time and frequency reference source for communication equipment, digital control equipment and the like.

In addition, for the purpose of increasing frequency stability with this type of oscillator, for example, a capacitor is connected in series with a crystal unit, and a temperature detection element such as a thermistor is connected in parallel with this capacitor to change the frequency due to temperature changes. There is also the one to cancel.

FIG. 5 is a circuit diagram showing an example of such a temperature compensation circuit.
Crystal unit 2 between the base of transistor 1 and the reference potential
The first and second temperature sensitive elements, for example, the first and second thermistors 3 and 4, are connected in series on the reference potential side of the crystal oscillator. A resistor 5 for low temperature compensation is connected in parallel to the first thermistor 3 and a resistor 6 for high temperature compensation is connected in series to the second thermistor 4 so as to obtain a desired temperature compensation characteristic. The oscillation output of the transistor 1 is given to the transistor 8 via the capacitor 7 so as to be amplified and output.

The electronic components such as the resistors and the transistors are mounted on a substrate made of an insulating material such as ceramic having a conductive pattern formed on a plate surface to form an oscillation circuit and a temperature compensation circuit.

(Problems of the prior art) However, in such a case, when setting the temperature compensation characteristic, the resistance is temporarily attached and the temperature characteristic is confirmed, and according to this result, the resistance is changed to a different resistance value, etc. It is difficult to attach and detach, especially with a chip type resistor.

Therefore, there is a problem that the conductive pattern to which the resistor is attached is damaged, the reliability is lowered, and the number of steps for adjustment is increased.

(Object of the Invention) The present invention has been made in view of the above circumstances, and it is easy to set the compensation characteristics of the temperature compensation circuit without damaging the conductive pattern, thereby improving reliability and production. It is an object of the present invention to provide a piezoelectric oscillator that can improve the characteristics.

(Summary of the Invention) According to the present invention, an oscillator circuit is assembled on a circuit board that can be divided into a main body portion and a separation portion by a break line, and the resistance is adjusted by a resistance for confirmation of a compensation characteristic attached to the separation portion. Is equivalently mounted on the main body.

(Embodiment) Hereinafter, one embodiment of the present invention will be described in detail with reference to a perspective view shown in FIG. 1, a plan view shown in FIG. 2, a side view shown in FIG. 3 and a circuit diagram shown in FIG. To do.

The same parts as those in FIG. 5 are designated by the same reference numerals and the description thereof will be omitted. In the figure, reference numeral 11 denotes a ceramic substrate, for example. This substrate 11 is composed of a main body portion 11B and a separating portion 11C which can be divided by a break line 11A.

The oscillator circuit 12 and the oscillator circuit 12 are provided on the plate surface of the substrate 11.
A conductive pattern for mounting the components of the temperature compensation circuit 13 for compensating the temperature characteristic of is formed, and the pin 14 for electrical connection to the outside and mechanical holding is fixed.

Then, circuit components such as chip-type resistors, capacitors, and transistors and semi-fixed capacitors are mounted on this conductive pattern to form an oscillation circuit 12 and a temperature compensation circuit 13 for compensating the temperature characteristics of the oscillation circuit 12.

Then, the main body portion 11B is provided with a mounting pattern 17 of a resistor 15 for low temperature compensation that sets the compensation characteristic on the low temperature side of the temperature compensation circuit 13 and a resistor 16 for high temperature compensation that sets the compensation characteristic on the high temperature side, The mounting pattern 17 is led out to the separating portion 11C so that the resistors 18 and 19 for confirming the characteristics can be mounted.

Then, the resistors 18 and 19 for confirming each characteristic are attached to the attachment pattern 17 of the separation portion 11C.

Then, the oscillator is operated to measure the temperature characteristic, and if necessary, the resistors 18 and 19 are replaced to set the desired temperature characteristic.

In this way, the resistor 18 to obtain the desired temperature characteristics,
If the value of 19 is found, electrically equivalent, for example, chip-shaped compensation resistors 15 and 16 are mounted on the mounting pattern 17 of the main body 1 and the substrate 11 is divided from the break line 11A,
Separate to the disconnecting section 11C.

In this way, the mounting pattern 17 of the main body 11B has a resistance of 1
Since only 5 and 16 are attached once, the reliability can be improved without causing damage to the pattern.

Also, the selection of resistors 18 and 19 for confirming the characteristics is done by disconnecting 11C.
In addition, since it is possible to use a resistor having a lead wire which can be easily replaced, the workability is good and the productivity can be remarkably improved.

The present invention is not limited to the above embodiment,
For example, the present invention can be applied to a temperature compensation circuit in which a varicap is connected in series or in parallel with the piezoelectric vibrator and the voltage applied to the varicap is controlled.

(Effect of the Invention) As described in detail above, according to the present invention, it is possible to provide a piezoelectric oscillator in which the compensation characteristics of the temperature compensation circuit can be easily set and the productivity can be improved.

[Brief description of drawings]

1 to 4 are views showing an embodiment of the present invention. FIG. 1 is a perspective view, FIG. 2 is a plan view, FIG. 3 is a sectional view, and FIG. 4 is a circuit diagram. FIG. 5 is a circuit diagram showing an example of a conventional piezoelectric oscillator. 11 …… Board 11A …… Breakline 11B …… Main body 11C …… Disconnection 12 …… Oscillation circuit 13 …… Temperature compensation circuit 15,16 …… Compensation characteristic setting resistor 17 …… Conductive pattern 18,19 …… Characteristics Confirmation resistance

Claims (2)

[Claims] 1. A circuit board which has a conductive pattern formed on a plate surface and can be divided into a main body portion and a separation portion by a break line, an oscillation circuit having a piezoelectric vibrator provided in the main body portion of the circuit board, and an oscillation circuit of the oscillation circuit. The temperature compensation circuit that compensates the temperature characteristic and the compensation characteristic setting resistor of the temperature compensation circuit of the circuit board are attached in parallel to the mounting pattern of the resistor and are separated from the break line after confirming the temperature characteristic. A piezoelectric oscillator, comprising: a resistor for confirming characteristics, and a compensation characteristic setting resistor attached to a mounting pattern of the compensation characteristic setting resistor of the main body portion instead of the resistor for confirming characteristics. 2. An oscillating circuit having a piezoelectric vibrator on a main body of a circuit board which has a conductive pattern formed on a plate surface and can be divided into a main body and a separating portion by a break line, and temperature compensation for compensating temperature characteristics of the oscillating circuit. The process of assembling the circuit, the process of attaching the resistor for characteristic confirmation to the pattern derived to the disconnection part in parallel with the mounting pattern of the compensation characteristic setting resistor of the temperature compensation circuit of the circuit board, and the temperature by the resistor for characteristic confirmation A step of confirming a compensation characteristic, a step of attaching a resistance electrically equivalent to the characteristic confirmation resistance to the pattern of the main body, and a step of separating the separation part from the break line of the substrate. A method of manufacturing a piezoelectric oscillator, comprising: