JPS6039831Y2 - Terminal structure for rate adjustment of electronic clocks - Google Patents

Description

[Detailed Description of the Invention] The present invention provides an electronic timepiece configured to provide a rate adjustment pattern on a circuit board that matches a variable frequency dividing rate adjustment circuit, and to perform rate adjustment by cutting the pattern. This invention relates to a terminal structure for rate adjustment.

Conventional pointer display type electronic watches have a circuit block structure in which electronic parts such as an IC chip and a crystal resonator are mounted on a circuit board with a wiring pattern, and a trimmer capacitor for rate adjustment is also mounted. was commonly used.

However, electronic watches using the above-mentioned conventional structure require a large planar space for the circuit block itself due to the mounting of the trimmer capacitor for rate adjustment.
This has the disadvantage that it is extremely difficult to miniaturize the watch module.

Furthermore, the cross section also affects the arrangement of other watch parts, making it difficult to reduce the thickness.

Moreover, trimmer capacitors are generally attached to the circuit board with solder, but soldering is difficult to automate among circuit mounting tasks and requires a high number of man-hours, considering the price of the trimmer capacitor itself. , the cost of circuit blocks for watches using trimmer capacitors has become very high.

The purpose of the present invention is to provide a rate adjustment terminal structure that eliminates the drawbacks of the prior art described above, makes it possible to realize a smaller and thinner watch module, reduces costs, and is easy to handle. .

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a plan view of a circuit block according to an embodiment of the present invention;
FIG. 2 is a sectional view taken along the line BB in FIG. 1, showing the part incorporated into the base plate.

In this embodiment, four rate adjustment patterns 4a made of thin metal plates such as copper foil are provided, and a variable frequency division type frequency adjustment method is adopted in which the rate is adjusted by combining the cutting of each pattern.

The four wiring patterns 4a have a constricted shape so that they can be easily cut when adjusting the rate, and the wiring patterns 4a are electrically connected to the positive power supply potential VDD. On the other hand, they are connected at one end.

Further, the rate adjustment wiring pattern 4a has a frequency division ratio adjustment terminal portion D provided on the IC chip 1 at the other end side.
f1. Df2. Df3. Df, and is connected via a solder bump.

Further, the circuit board 2 is made of a flexible sheet made of polyimide or the like in order to be thinner, and a hole 2a is formed in a part of the circuit board 2 to facilitate cutting of the rate adjustment pattern 4a. .

That is, the rate adjustment pattern is provided so as to be bridged over the hole 2a.

After mounting the IC chip 1, insert mold sealing is performed with resin to protect the IC chip 1, and the shape of the insert mold part 3 is changed to a second shape in consideration of impact resistance.
As shown in the figure, the shape 3a is such that it touches the base plate 5.

Furthermore, when cutting the rate adjustment pattern 4a with a cutting jig when adjusting the rate, the circuit board 2 may bend and be difficult to cut, and the circuit board may be deformed during cutting. Insert mold part 3 around the periphery
By forming b, the circuit board 2 is stabilized and stabilized, and deformation of the circuit board 2 is prevented.

Furthermore, even if the curvature of 4a' at the time of cutting hangs down on the outer periphery of the hole 2a, the insert mold part 3 is placed around the hole 2a.
Due to the presence of a and 3b, there is no electrical short circuit,
A stable circuit structure can be achieved.

As described above, the mounting structure that uses the variable frequency division type frequency adjustment method instead of the trimmer capacitor and protects the periphery of the rate adjustment pattern with a non-conductive material provides a circuit block that is inexpensive. In addition, the present invention provides a rate adjustment terminal structure that has a great effect on a small and thin structure and is easy to adjust when adjusting the rate.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an embodiment of the present invention, and FIG. 2 is a partial sectional view taken along line BB in FIG. 1...IC chip, 2...circuit board,
2a... Hole, 3, 3b... Insert mold part, 4a... Rate adjustment pattern, D
fl, Df2. Df3. Df, ... Division ratio adjustment terminal.

Claims (1)

[Scope of utility model registration request] A rate adjustment wiring pattern connected to the division ratio adjustment terminal of the IC chip is provided on a circuit board cut out from a flexible sheet, and by cutting the rate adjustment wiring pattern, the rate of the clock can be adjusted. In the configured electronic timepiece, the rate adjustment pattern is made of a thin metal plate such as copper foil, and the rate adjustment pattern is arranged so as to bridge over a hole formed in a part of the circuit board. A terminal structure for rate adjustment of an electronic timepiece, characterized in that an extended portion of a resin member protecting an IC chip is disposed on the lower surface side of the circuit board so as to surround the hole.