JPS585390B2 - Denshiki Udedokei - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronic wristwatch with a ceramic trimmer capacitor for capacitively correcting the frequency of a standard source.

An object of the present invention is to miniaturize an electronic wristwatch and to make it easier to install additional mechanisms that have hitherto been difficult to install due to dimensional constraints.

Another object of the present invention is to reduce the cost of electronic watches using ceramic trimmer capacitors.

Generally, a standard oscillation circuit for a piezoelectric resonator, such as a crystal resonator, includes a crystal resonator 1, capacitors 2, 3,
It consists of a resistor 4, an impark 5 formed into a CMO8-IC, a frequency dividing circuit, and the like.

At this time, the frequency f of the crystal resonator exhibits an f-C characteristic as shown in FIG. 2 by changing the capacitance C of the capacitor 2 incorporated in the crystal resonator 1.

Therefore, in crystal oscillation wristwatches that use piezoelectric resonators, such as crystal resonators, as the standard source, a trimmer capacitor that can continuously adjust the capacitance is incorporated, making use of the f-C characteristics shown in Figure 2. Adjustments are being made.

Conventionally, the structure of the ceramic trimmer capacitor generally used for adjusting the speed of electronic wristwatches is as shown in FIGS. 3 and 4, and its manufacturing process includes vapor deposition, adhesion, coating, welding, A rotor 8 made of high dielectric ceramic, for example, mainly made of barium titanate, with an upper surface electrode 7 formed by a method such as spraying, a lower surface electrode 9 formed by the same method as described above, and stator fixed terminals 13, 14. When soldering or welding metal,
For installation, which can be soldered or welded, pass the stator 11 made of a low insulating material such as alumina, steatite, zirconia, etc., which also forms part 10, and the metal fixing spring 12, which also serves as a take-out of the upper electrode, and then attach the tip of the stator 11 to the top electrode. After tightening, rotor 8
Solder 17 or the like is applied to fix the metal rivet 6 and the metal rivet 6.

Next, the stake fixing terminals 13 and 14 are attached to the stake 11 by soldering, welding, gluing, or the like.

Thereafter, the trimmer capacitor was assembled into the part 16 of the watch body to which the lead wire 15 was attached by screwing, soldering, welding, etc.

However, in order to assemble the trimmer capacitor into the watch body after completing it in this way, it is necessary to form a capacitor-embedding part on the watch body, and in addition, titanic acid for the trimmer capacitor with a dielectric constant of 200 to 500 is used as the material of Roku 8. If barium-based porcelain is used and the capacitance is to have a large change of about 5 to 60 PF, the maximum planar dimension of the Ikioi trimmer capacitor will be 8 to 12 mm.

As a result, the area ratio of the trimmer capacitor fitted into the watch body has become extremely large, making it difficult to miniaturize electronic wristwatches and to attach various additional mechanisms comparable to mechanical watches.

The present invention eliminates such drawbacks, and one embodiment of the present invention will be described in detail below with reference to FIGS. 4 and 5.

First, in an electronic wristwatch using a crystal oscillator, after drilling a center hole in a ceramic substrate 18 for mounting a MOS-IC for the watch, a bottom electrode 19 is placed on the front surface, and a top electrode extraction portion 20 is placed on the back surface. At the same time, a conductive silver paste is baked at 800°C.

Next, the dielectric constant is 300~350° and the external dimensions are 5φXO, 6m.
On the surface of the rotor 21 mainly made of barium titanate, an upper surface electrode 22 is formed by baking at 800° C. with conductive silver paste.

Next, the rotor 21 and the ceramic substrate 18 are passed through a metal rivet 23 made of gold-plated brass.

Furthermore, after a fixing spring 24 made of phosphor bronze is passed through, the tip of the metal rivet 20 is caulked, and the rotor 21 and the metal rivet 23 are fixed with solder 25.

Thereafter, a MOS-IC was attached to the free space of the ceramic substrate 18 and assembled into a watch body.

The ceramic trimmer capacitor made in this way can change the capacitance from 4.8 to 59PF, and can fully fulfill its role as a trimmer capacitor for adjusting the speed of crystal oscillation wristwatches. By increasing the length of the ceramic substrate used to mount the MOS-IC by 15%, there is no longer any need for the trimmer capacitor to take up as much space as before.

Furthermore, there is no longer any need for work such as soldering or screwing to incorporate the trimmer capacitor into the watch body.

In this way, the present invention makes it possible to miniaturize electronic wristwatches using trimmer capacitors and reduce costs by using part of the parts that make up the watch body as stators for trimmer capacitors. be.

Although the embodiment of the present invention uses an example in which a ceramic substrate for mounting a MOS-IC is used as a stator of a trimmer capacitor, other insulating parts, such as a printed circuit board used for wiring, can also be used. I can,
Furthermore, other conductive parts can also be used as stators for trimmer capacitors by coating them with insulating resin or the like.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a standard oscillation circuit for an electronic watch, in which 1 is a crystal oscillator, 2 and 3 are capacitors, 4 is a resistor, and 5 is an impark. FIG. 2 shows the f-C characteristics. 3 and 4 are schematic diagrams of conventionally used trimmer capacitors, and Figures 5 and 6 are schematic diagrams showing the structure according to the present invention, in which 6 and 23 are metal rivets, and T and 22 are upper surface electrodes. , 8 and 21 are low gears, 9 and 19 are bottom electrodes, 10 is a terminal mounting part, 11 is a stator, 12 and 24 are fixed springs, 13 and 14 are stator fixed terminals, 15 and 20 are wiring, 16 is a clock Body parts 17 and 25 are solder, and 18 is a ceramic substrate.

Claims (1)

[Claims] 1. In an electronic watch having a standard source using a piezoelectric vibrator and a trimmer capacitor for correcting the frequency of the standard source using a capacitance, a bottom electrode is formed on a circuit board made of an insulating member that constitutes a watch body in the electronic watch. At the same time, a hole through which a metal rivet passes is provided in a part, an upper surface electrode is formed on the upper surface of the rotor made of a dielectric material, a hole through which a metal rivet passes is provided in a part, and the hole in the circuit board and the rotor are formed. An electronic wristwatch characterized in that a metal rivet is passed through the hole and the metal rivet is engaged with a fixing spring on the back surface of the circuit board.