JP2000013141A - Piezoelectric oscillator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small sized crystal oscillator with excellent quality of its crystal vibrator and an excellent production efficiency. SOLUTION: A ceramic package 1 has a recessed part to its upper part to mount a crystal vibrator element 3 and a recessed part to its lower part to contain an electronic circuit 102, is provided with terminals for electric connection to the crystal vibration element 3 in addition to the upper recessed part, and a configuration is adopted, where the electronic circuit 102 is mounted on a ceramic substrate 7 and the ceramic substrate 7 seals the opening of the lower recessed part to obtain a crystal oscillator consisting of an oscillator circuit and then the crystal vibrator and the electronic circuit are assembled in parallel and the characteristic of the crystal vibrating element 3 is confirmed before the ceramic substrate 7 connects to the ceramic package 1.

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 particular, it relates to a piezoelectric oscillator excellent in productivity and quality.

[0002]

2. Description of the Related Art In recent years, mobile communication devices such as mobile phones have been rapidly reduced in price and miniaturized. There is an increasing demand for price reduction and miniaturization. In response to such demands, an oscillator circuit including a frequency adjustment circuit and a frequency temperature compensation circuit has been integrated to reduce the number of components, and to enable automatic adjustment to improve productivity. .

Generally, in a crystal oscillator, a crystal oscillator used for the crystal oscillator is housed in a separate hermetically sealed container. After measuring electrical characteristics such as equivalent capacitance, impedance, and frequency, a good crystal is selected. It was built into the oscillator circuit. Therefore, the use of a separate crystal resonator has limited the size of the crystal oscillator. Therefore, a structure shown in FIG. 3 has been proposed to reduce the size. That is, FIG. 3 is a cross-sectional view showing the structure of a conventional crystal oscillator using an electronic circuit including an integrated circuit. The crystal oscillator shown in FIG. 1 has an electronic circuit 102 including an integrated circuit and the like mounted on a bottom surface in a concave portion of a ceramic container 101, and a quartz vibrating element 103 is disposed above the electronic circuit 102 using a step portion of the inner wall of the concave portion as a support. The upper opening of the ceramic container 101 is hermetically sealed with a metal lid 104. still,
Excitation electrodes (not shown) are provided on the front and back surfaces of the quartz vibrating element 103, and the electrodes are connected to the electronic circuit 102 via a wiring pattern provided inside the ceramic container 101. However, in a crystal oscillator having a structure as shown in FIG.
Since the crystal vibrating element 103 is mounted, an oscillation circuit is connected between its terminals when the crystal vibrating element 103 is mounted. Inspection of characteristics becomes impossible. Therefore, the device on which the defective crystal vibrating element 103 is mounted does not oscillate, and all components constituting the crystal oscillator may be wasted as defective products.

In view of the above, there has conventionally been a structure as shown in FIG. 4, which is capable of inspecting only the electric characteristics of the crystal vibrating element. FIG. 1A shows a side sectional view, and FIG. 1B shows the configuration of the lower surface. The ceramic container 201 shown in FIG. 2A has upper and lower concave portions, and the crystal vibrating element 103 is accommodated in the upper concave portion. After the crystal vibrating element 103 is mounted, the opening of the concave portion is closed. Metal lid 1
Sealing with 04 completes the crystal resonator. The lower recess of the ceramic container 201 is for accommodating the oscillation circuit 102. Before mounting the oscillation circuit, it is possible to measure the electrical characteristics of the crystal unit. If the oscillation circuit is mounted only on the measurement completed and determined to be good, the above-described problem can be solved. In addition, in order to prevent the electronic components from dropping and being damaged after the oscillation circuit 102 is mounted, the entire electronic components are covered with a potting agent 202 such as a resin. Further, as shown in FIG. 3B, a functional terminal of the crystal oscillator and a terminal 204 for inputting a setting signal of the electronic circuit 102 are provided on the outer peripheral frame surface 203 on the lower surface side of the ceramic container 201. .

[0005]

However, in the structure as shown in the figure, it is possible to confirm the operation as a quartz oscillator after mounting the quartz oscillator 103, but after the confirmation, A series of manufacturing steps of mounting electronic components on the back surface of the ceramic container 201 are required. That is, as long as the incorporation and measurement of the quartz oscillator are not completed, the oscillation circuit 10
It was not possible to start assembling the two parts, and even if all the components of the oscillation circuit were available, if the availability of the crystal oscillator was delayed, the completion of the oscillator would be delayed. In particular, for industrial crystal oscillators, after customer specifications such as frequency are determined, product design and order production related to assembly are common, and it takes a certain amount of time to complete the product, It was important to supply users with crystal oscillators in a short delivery time.

[0006]

According to a first aspect of the present invention, there is provided a piezoelectric vibrating device having an excitation electrode in one of the concave portions of a package having upper and lower concave portions. The element is mounted, the opening is sealed with a lid, and the other concave part is mounted on a plate-shaped printed board that seals the opening with the electronic components necessary to configure the oscillation circuit. It is characterized by. According to a second aspect of the present invention, in addition to the first aspect, a terminal electrically connected to an excitation electrode of a piezoelectric vibration element housed in the one concave portion is provided in the one concave portion. An external terminal electrically connected to the terminal is provided on the outer peripheral surface of the package or in the other concave portion. The invention according to claim 3 according to the present invention is the same as the above-described claims 1 and 2,
The printed circuit board is provided with circuit wiring electrically connected to electronic components mounted on the printed circuit board, and a part of the circuit wiring provided on the package is exposed in the other concave portion, When the other recessed portion is sealed with a printed board, the exposed circuit wiring and the circuit wiring provided on the printed board are electrically connected.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on illustrated embodiments. FIG. 1 shows a configuration diagram of an embodiment of a crystal oscillator according to the present invention. FIG. 2A shows a ceramic container 1 having an H-shaped cross section and a quartz resonator element 3 mounted in an upper concave portion 2 having upper and lower concave portions, and an opening of the concave portion formed by a metal lid 104. It is sectional drawing which shows the state which sealed. FIG. 2B shows a structural view as viewed from below (back side) of the ceramic container 1. As shown in FIG. 1B, a mounting terminal 4 for an oscillator is provided on the outer peripheral frame surface of the ceramic container 1. Further, the terminals 5 provided on the shelf-like surface located one step above the lowermost surface are electrically connected to a later-described ceramic substrate for mounting electronic components. Further, the terminal 6 formed on the bottom surface inside the lower concave portion is connected to the upper concave portion 2.
It is electrically connected to the crystal resonator element 3 mounted inside. FIG. 3C is a side view of the ceramic printed wiring board 7 having the electronic circuit 102 mounted on the main surface, and FIG. 4D is a view of the ceramic substrate 7 as viewed from above.
The oscillation circuit 102 is electrically connected to a terminal 8 provided on the surface of the ceramic substrate 7 via a wiring pattern. FIG. 7E is an external view showing the state of the back surface of the ceramic substrate 7, and land patterns 9 are provided at four corners. In this way, the functional portion as a crystal oscillator as shown in FIG. 1A is separated from the electronic circuit 102 as shown in FIG. 1C, and further, the terminal 6 is connected to the ceramic container. By using the terminal 6, it is possible to use the terminal 6 to measure the electrical characteristics of the quartz oscillator alone, and to assemble and adjust the functional part as the quartz oscillator and to adjust the electronic circuit The work of mounting the substrate 10 on the ceramic substrate 7 can also be performed. FIG. 2A shows FIG.
FIG. 6A is a sectional view of a completed oscillator in which the ceramic substrate 7 is fitted in the recess at the lower portion of the ceramic container 1 shown in FIG. 7A so that the electronic circuit 102 is housed in the recess; The terminal 5 and the terminal 8 provided in 1 are connected by a conductive substance such as solder or a conductive adhesive. Thereby, the crystal vibrating element 3 and the electronic circuit 102 are electrically connected to each other to form an oscillator circuit. FIG. 2 (g) is a view of FIG. 2 (f) viewed from below, and the terminal 4 provided on the ceramic container 1 and the terminal 9 provided on the ceramic substrate 7 are configured to be adjacent to each other, so that It is possible to sufficiently secure the area of the mounting terminal.

[0008]

As described above, according to the first aspect of the present invention, since the portion functioning as the quartz oscillator and the other oscillator circuit portion are separated from each other, It is possible to manufacture the other oscillator circuit portions in parallel, so that it is possible to realize the manufacturing in a short period of time and to quickly supply products by order production.

According to the second aspect of the present invention, in addition to the effect of the first aspect of the present invention, a terminal for electrically connecting to the piezoelectric vibrating element is provided outside the recess in which the piezoelectric vibrating element is housed. With this configuration, it is possible to accurately inspect the electrical characteristics of a single functional part as a piezoelectric vibrating element. The effect that it becomes possible to ensure the stability of this is achieved. Further, since only the piezoelectric vibrating element having poor characteristics can be discarded, there is an effect that the cost of the oscillator can be reduced as the production cost decreases. Further, since it is possible to measure the electric characteristics of the piezoelectric vibrator in a state where the wiring pattern of the electronic circuit is not connected to the piezoelectric vibrating element, the electric characteristics are caused by the stray capacitance generated between the wiring patterns. An accurate result can be obtained without being affected, which also has the effect that the stability of the characteristics of the oscillator can be reliably estimated.

The effect of the third aspect of the invention is the same as that of the first or second aspect of the invention, except that a portion functioning as a crystal oscillator and a portion of another oscillator circuit are separated. After the configuration, by electrically connecting both to form a piezoelectric oscillator, the piezoelectric vibrator portion,
This makes it possible to achieve a production process in which the other oscillator circuit portions are balanced, thereby achieving an effect that the cost of the oscillator can be reduced with the improvement in productivity and can be realized.

[0011]

[Brief description of the drawings]

FIG. 1 shows a configuration diagram of an embodiment of a crystal oscillator according to the present invention. (A) It is a figure which shows the cross-section structural diagram of the ceramic container used for one Example of the crystal oscillator based on this invention. (B) It is a figure which shows the lower surface side structural drawing of the ceramic container of (a). (C) is a sectional view of a ceramic substrate used in an embodiment of the crystal oscillator according to the present invention. (D) It is a figure which shows the upper surface side structural drawing of the ceramic substrate of (c). (E) It is a figure which shows the lower surface side structural drawing of the ceramic substrate of (c).

FIG. 2 shows a configuration diagram of a crystal oscillator based on the present invention. (F) is a side sectional structural view of the crystal oscillator according to the present invention. (G) shows a lower structural view of the crystal oscillator according to the present invention.

FIG. 3 is a side sectional structural view of a conventional crystal oscillator.

FIG. 4 is a side sectional structural view of a conventional crystal oscillator.

[Explanation of symbols]

1, 101, 201 ceramic container, 2 upper concave portion,
3, 103 crystal vibrating element, 4 mounting terminals 5, 6, 8 terminals,
7 ceramic substrate, 9 land pattern, 102 electronic circuit, 104 metal cover, 202 potting agent, outer frame 20
3, terminal 204

Claims (3)

[Claims] 1. A package having an upper and lower concave portion, a piezoelectric vibrating element having an excitation electrode is mounted on one of the concave portions, an opening thereof is sealed with a lid, and the other A piezoelectric oscillator characterized in that electronic components necessary for forming an oscillation circuit are mounted on a plate-shaped printed board that seals an opening. 2. A terminal which is electrically connected to an excitation electrode of a piezoelectric vibrating element housed in the concave portion, and an external terminal which is electrically connected to the terminal is provided in the one concave portion. 2. The piezoelectric oscillator according to claim 1, wherein the piezoelectric oscillator is provided in an outer peripheral surface of the package or in the other concave portion. 3. The printed circuit board is provided with circuit wiring electrically connected to electronic components mounted on the printed circuit board.
A part of the circuit wiring provided on the package is exposed in the other recess, and the circuit wiring and the exposed circuit wiring are provided on the printed board when the other recess is sealed with the printed board. 3. The piezoelectric oscillator according to claim 1, wherein the piezoelectric oscillator is electrically connected to a circuit wiring.