JPS641678Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a structure for connecting multiple circuit boards having steps, for example, a contact member for electrically connecting electronic circuits of modules housed separately in two cases. The present invention relates to a connection structure between two circuit boards having a step used in electronic wristwatches and the like.

Traditionally, watches have had batteries, ICs, crystals, train wheels, liquid crystal display devices, etc. all housed in one case, but as they have become more multi-functional, especially in digital watches, the content displayed on the liquid crystal display device has changed. As a solution to this problem, widening the liquid crystal display area,
We have adopted methods such as configuring the information into layers and switching the display.

However, the display area of a watch case is narrow and it is impossible to expand it any further, and there is a demand for larger batteries due to increased power consumption, but it is difficult to increase the display area of conventional watch structures. The use of batteries is disadvantageous in terms of design.

In other words, the above-mentioned space problem could be solved by making the wristwatch thicker and larger, but this would have many drawbacks in terms of design and portability, making it difficult to realize under the current circumstances. As a means of solving this problem, it has been proposed to house the analog module and the digital module in separate cases, as shown in Figure 1.

The purpose of this invention is to electrically connect the electronic circuits of the above-mentioned analog module and digital module with high reliability and at low cost. This provides an inexpensive and highly reliable connection structure.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a connection structure for an electronic wristwatch according to the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view and a side view of a typical electronic wristwatch, in which an analog case 10 and a digital case 20 are jointed by a hinge joint (not shown).

FIG. 2 is a cross-sectional view of the main parts of the connection part of the electronic wristwatch shown in FIG. 1 with a conventional structure, showing the analog module 11 housing the analog display, wheel train, power supply motor, etc. (not shown), and the digital display. This figure shows a digital module 21 housing a digital module 21, and a circuit board 31 for electrically connecting the electronic circuits of each module.

Reference numeral 12 denotes an IC which is a drive circuit for the analog module 11 and the digital module 21, and is mounted on the circuit board 13 on the analog module 11 side. A digital display device 22 is electrically connected to the circuit board 31 through a conductive rubber connector 23. The circuit board 31 is arranged to partially overlap the circuit board 13 on the analog module 11 side, so that the wiring pattern 13a of the circuit board 13 and the wiring pattern 3 of the circuit board 31
1a is electrically connected by a conductive rubber connector 15 having an L-shaped cross section and housed in a connector housing 14a provided in a part of the connector pusher member 14 on the analog module 11 side.

FIG. 3 shows the cross-sectional shape of the conductive rubber connector 15 shown in FIG. The conductive rubber connector 15 having an L-shaped cross section is used when two circuit boards having wiring patterns on the same side are arranged partially overlapping each other, and the two circuit boards are connected. It is something that exists. Even connectors with such irregular shapes can be manufactured relatively easily and at low cost if they are large in size, but for microelectronic components such as wristwatches, processing methods are limited. In addition, the yield is poor in terms of precision and the product becomes very expensive.

FIG. 4 is a cross-sectional view showing another example of a conventional conductive rubber connector, in which the cross-sectional L-shaped conductive rubber connector 1
This is a conductive rubber connector devised for the purpose of cost reduction as a replacement for 5, and is made of insulating rubber 16a.
A thin conductive rubber connector 16b is glued to the base, and is often used for large-sized connectors, but when it comes to ultra-small connectors, it becomes 7 to 10 times more expensive than conductive rubber with a rectangular cross section. It is.

FIG. 5 is a cross-sectional view of a main part of the connecting portion in the present invention, and the same numbers as in FIG. 2 indicate the same members.

Circuit board 13 on the analog module 11 side
and a circuit board 31 that connects the digital module and the analog module have wiring patterns 13a, 13a on their upper surfaces, and are arranged partially overlapping each other. Connector pressing member 3
When a conductive rubber connector with a rectangular cross-section, which will be described later, is placed in the connector storage section 34a of No. 4 at a step position where the two circuit boards 13 and 31 are overlapped,
A conductive rubber connector 17 having a rectangular cross section is mounted at the step position between the circuit boards, and is provided with a slope portion 34b corresponding to the slope caused in the conductive rubber connector having a resolutely rectangular shape due to the step. the inclined portion 34 of the connector pressing member 34;
By press deforming and fixing at b, the wiring pattern 13 on the two circuit boards 13 and 31 is
This is a connection structure that electrically connects a and 31a.

FIG. 6 is a perspective view showing the shape of the conductive rubber connector used in the present invention. It is an inexpensive conductive rubber connector 17 with a rectangular cross section, which is conventionally often used in digital watches, etc., and 17a is an insulating part, 17b is a conductive part.

As described above, in the present invention, a conventional inexpensive conductive rubber having a rectangular cross section is used as a connection structure between circuit boards having wiring patterns on their upper surfaces, and the slope of the steps of the stacked circuit boards is used. By providing an inclined portion corresponding to the direction in the connector pressing member and pressing the conductive rubber connector with the inclined portion, a highly reliable and extremely inexpensive connection structure can be provided, and it will be useful in the future. This contributes to the development of electronic watches as a circuit board connection structure that supports various variations of electronic watches.

[Brief explanation of the drawing]

Figure 1 shows a general electronic wristwatch with an analog module and a digital module housed in separate cases, with Figure 1a being a plan view and Figure 1b being a top view.
is a side view, FIG. 2 is a cross-sectional view of main parts showing the conventional structure of the connection part of the electronic wristwatch shown in FIG. 1, FIG. 3 is a conventional example in FIG. 2, and FIG. Cross-sectional view of a conventional L-shaped conductive rubber connector, No. 5
The figure is a cross-sectional view of a main part showing the connection between circuit boards in the electronic wristwatch of the present invention, and FIG. 6 is a perspective view of a conductive rubber connector with a rectangular cross section used in the present invention. 10... Analog case, 20... Digital case, 14, 34... Connector pressing member,
15... L-shaped conductive rubber connector, 22... Digital display device, 17... Conductive rubber connector.

Claims (1)

[Scope of utility model registration request] In an inter-board connection structure in which two circuit boards each having a wiring pattern on the upper surface are partially overlapped and the patterns between the two circuit boards are connected, a conductive rubber having a rectangular cross section is used. connector and
and a connector pressing member provided with an inclined portion corresponding to an inclination that occurs on the conductive rubber connector due to the step when the conductive rubber connector is placed at a step position where the two circuit boards are overlapped, The step is characterized in that the wiring patterns on the two circuit boards are connected by pressing and fixing a conductive rubber connector placed at the step between the circuit boards with the inclined part of the connector pressing member. A connection structure between boards with