JPS6112230B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronic wristwatch using LSI (large scale integrated circuit) elements.

With the development of CMOS LSI and liquid crystal display devices, the technological development of electronic digital watches has progressed rapidly, and has even reached the field of wristwatches. Generally, such completely electronic digital watches are constructed by appropriately assembling parts such as a crystal oscillator, CMOS-LSI, display section, and step-up DC-DC converter. In particular, this assembly structure has great significance for miniaturization, which is an essential condition for electronic wristwatches, and is the key to successful commercialization.

The present invention has been made in view of this point, and particularly provides an electronic wristwatch with a novel structure characterized by the assembly structure of CMOS-LSI elements.

In general, conventional electronic wristwatches use CMOS-LSI.
The element is configured to be inserted into a predetermined package and then attached to the board of this device, and thus
This requires a very troublesome process for attaching a large number (30 to 50) of leads of an LSI element to a printed circuit board, which becomes a factor in complicating the element manufacturing process and lowering reliability.

In contrast, the invention of the present application eliminates the above drawbacks by attaching the LSI element directly to the circuit board.

EMBODIMENT OF THE INVENTION Below, the electronic wristwatch according to the present invention will be described in detail by way of examples.

FIG. 1 is a diagram illustrating a main part of an apparatus according to an embodiment of the present invention before a liquid crystal display means is attached. Now, the configuration of the above device will be explained with reference to FIG.
A recessed portion 4 is formed by cutting out the central portion.
Further, metallization 5, 5, . . . is formed on the front and back surfaces of the insulating substrates 2, 3 according to a predetermined wiring pattern. Now, the metallization 5a is provided on the bottom surface of the recess 4 of the substrate 1, and the metallization 5b is the first metallization 5b.
It is assumed that the metallization 5c is provided on the upper surface of the second insulating substrate 2, and the metallization 5c is provided on the lower surface of the second insulating substrate 3.

In the device of the present invention, the metallization 5a is formed on the bottom surface of the recess 4 of the circuit board 1 having the above structure.
The structure is such that a CMOS-LSI element 6 is directly die-bonded as shown in the figure, and each electrode terminal of the LSI element 6 has a wire 7 connected to metallization 5b, 5b, . . . formed in advance on the first insulating substrate 2. It is wire bonded. Furthermore, this CMOS-LSI
The element 6 is sealed from the outside by a sealing member 8 provided on the first insulating substrate 2 so as to surround the periphery of the recess 4 and a plate-shaped cap 9. 2 and 3 are plan views of the device shown in FIG. 1, and in particular, FIG. 2 is a drawing to facilitate understanding of the shape of the sealing member 8, and FIG. 3 is a plan view of the shape of the plate-shaped cap 9. It is. Now this seal member 8 and plate-shaped cap 9
is made of Au-plated Kovar, and the two are bonded together by soldering or welding. The device of the present invention has a structure in which the CMOS-LSI element 6 is directly attached to the circuit board 1 in this manner, and then packaged.

In addition, in this device, a crystal oscillator, a silver battery, a DC-
Various parts such as a DC converter are assembled, and together with the CMOS-LSI element 6, it constitutes the drive circuit section of the electronic wristwatch. FIG. 4 is a plan view of the bottom surface of the substrate 1, with metallization 5c, 5c...
In order to show the shape of the device, the drawing is shown before parts such as the crystal oscillator and silver battery are attached.
Incidentally, electrical connections on the surface of the substrate 1 are made by through holes 10 formed in the substrate 1.

In this device, the display section for displaying the time includes:
A liquid crystal display element 11 with extremely low power consumption is used, and the element 11 is mounted on the cap 9 as shown in the cross-sectional view of FIG. Electrical connections are made by connecting the liquid crystal electrodes led out to the bottom surface of the ends of the liquid crystal display element 11 and the metallized layers 5b, 5b, . . . using sockets 12 made of conductive rubber or the like.

The device of the present invention has the above configuration, for example,
Since the LSI element is directly attached to the circuit board without being packaged in advance, the process of packaging the LSI element in advance can be omitted.Moreover, the package is attached to the board and its leads are connected to the wiring conductor on the board. No process is required. Therefore, the electronic wristwatch according to the present invention has low cost and high reliability. Furthermore, in this device, the LSI elements are mounted directly on the board, so unnecessary space is not required, and the thickness of the device itself can be made extremely thin.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of main parts of a device according to an embodiment of the present invention, Figs. 2, 3, and 4 are plan views for explaining the configuration of the device shown in Fig. 1, and Fig. 5 is a diagram showing an embodiment of the present invention. FIG. 2 is a cross-sectional view of an example device. 1 is a circuit board, 6 is an LSI element, 9 is a cap,
11 indicates a liquid crystal display element.

Claims (1)

[Claims] 1. A circuit board consisting of first and second insulating boards on which wiring patterns are formed on the front and back sides via through holes, and die bonding directly to the bottom of the recess of the circuit board by cutting out the center of the first insulating board. an LSI element assembled on the circuit board and electrically connected to the wiring pattern and having a bonding part and a connecting part of the wiring pattern sealed from the outside; An electronic wristwatch comprising a display section and other electronic components that constitute a drive circuit section together with the LSI element.