JPH0634437B2 - Board connection structure - Google Patents

Description

The present invention relates to a connecting structure between substrates in an electronic device.

[Conventional technology]

FIG. 2 is a perspective view showing an example of a conventional connection structure. The wiring 4 of the flexible substrate 5 in which the wiring 4 is formed with the same width and pitch as the external wiring connection terminal 3 on the substrate 1 which is the base of the external connection portion of various electronic devices is positioned over the connection terminal 3 portion. They were aligned and connected by soldering or pressure welding.

[Problems to be solved by the invention]

However, in recent years, electronic devices have become smaller and higher in density, and the connection pitch and the connection area have become extremely small. Therefore, in the above-described connection configuration, there is a problem in that the area required for connection (connection area) becomes relatively large and the alignment becomes difficult as the pitch decreases.

The present invention eliminates the above-mentioned problems that the area for connection is large and that it is difficult to perform the alignment with a fine pitch, and the connection can be performed in a small area, and a highly reliable connection structure can be provided. The purpose is to provide.

[Means for solving problems]

The board connection structure of the present invention includes a first board having a wiring conductor on a first surface, a second board having a wiring conductor on first and second surfaces, and a wiring conductor on the first board. And the second above
Connecting means for connecting to a wiring conductor on the substrate of the first substrate, the first substrate and the second substrate having overlapping regions in the vicinity of respective end portions of the first substrate and the second substrate.
The wiring conductors of the substrate are parallel to each other in the vicinity of the overlapping region, every other wiring conductor extends into the overlapping region, and the other wiring conductor has an end portion in the vicinity of the overlapping region. Among the first wiring conductors of the second substrate, the first wiring conductors located in the overlapping region extend in parallel with each other, and each of them is bonded to each of the first wiring conductors of the first substrate in the overlapping region. And the wiring conductors on the second surface of the second substrate located in the overlapping area are parallel to each other and the wiring conductors on the first surface are located in the overlapping area. The connecting means are provided in parallel with each other, and the connecting means includes a tape connector having wiring conductors parallel to each other, and one end of the wiring conductor of the tape connector is near an end of the other wiring of the first substrate. Connected and the other end Those that are connected to the wiring of the serial the second surface of the second substrate.

[Work]

In the above configuration, only every other one of the wiring conductors of the first substrate exists in the overlapping region where the first substrate and the second substrate overlap, which is the first of the second substrate. Is bonded to the wiring conductor on the surface by an anisotropic conductive adhesive or the like. on the other hand,
The conductors (“other wiring conductors”) located between every other wiring conductors (“other wiring conductors”) are connected to the wiring conductors on the second surface of the second substrate by a tape connector. Therefore, the number of wiring conductors connected to each other in the overlapping region is approximately one half of the total number of wiring conductors on the first substrate. Therefore, if the distance between adjacent conductors when they are contacted with each other in the overlapping area to make a connection is the same as the conventional one, the pitch of the wiring conductors is halved from the conventional one outside the overlapping area, and the width of the overlapping area ( The dimension in the direction orthogonal to the extending direction of the wiring conductor) can be halved. Therefore, the area required for connection is significantly reduced.

〔Example〕

1 and 3 to 5 show one embodiment of the present invention. Of these, FIG. 1 shows the connection state,
3 to 5 show each board and tape connector before connection. As shown in the figure, the connection structure includes an electronic component (not shown) such as a thermal head, the substrate 1 having its leads connected to an external connection wiring conductor 2, and an external electronic circuit such as a thermal head drive circuit. For connecting to the flexible substrate 5 having the wiring conductors 4a and 4b for connecting to.

The wiring conductor 2 of the substrate 1 is provided on the first surface (upward surface in the drawing) 1 a of the substrate 1. Flexible board 5
Wiring conductor 4a is provided on the first surface (downward surface in the drawing) 5a of the flexible substrate 5, and the wiring conductor 4b is second surface (upward surface in the drawing) 5 of the flexible substrate 5.
It is provided in b. That is, the wiring conductors 4a and 4b are arranged in a zigzag manner in the vertical sectional shape orthogonal to the extending direction of these conductors.

The substrate 1 and the substrate 5 have overlapping regions 7 in the vicinity of the respective end portions 1c and 5c, which overlap each other. As shown in FIG. 3, the wiring conductors of the substrate 1 are parallel to each other at least in the vicinity of the overlapping region, and every other wiring conductor 2a extends in the overlapping region 7 and reaches the end 1c. On the other hand, the other wiring conductor (wiring conductor interposed between every other wiring conductors) 2b has an end portion in the vicinity of the overlapping region 7. The wiring conductors 4a on the first surface 5a of the flexible substrate 5 also extend parallel to each other in at least the overlapping region 7.

Each of these wiring conductors 4 a is connected to each of the wiring conductors 2 a in the overlapping region 7 among the wiring conductors of the first substrate 1. This connection is for the wiring conductor 4 of the flexible substrate 5.
The anisotropic conductive adhesive 9c is applied on the surface a, and the first substrate 1 is heated and pressed. The wiring conductors 4b on the second surface 5b of the flexible substrate 5 are also parallel to each other at least in the overlapping region 7 and extend parallel to the wiring conductors on the first surface 5a. Then, it is connected to the wiring conductor 2b of the substrate 1 by the tape connector 8. The tape connector 8 is one in which wiring conductors 11 parallel to each other are provided on one surface of a synthetic resin film 10, and one end portion 11a thereof is provided.
Is connected to the wiring 2b of the substrate 1, and the other end 11b is connected to the wiring conductor of the second surface 5b of the substrate 5. The anisotropic conductive adhesives 9a and 9b are used for the connection.

The wiring conductors 2a, 2 in the vicinity of the overlapping region 7 of the substrate 1
The pitch of the wiring conductors 2a in the overlapping area 7 of the substrate 1, the pitch of the wiring conductors 4a and 4b on each of the surfaces 5a and 5b of the substrate 5 and the pitch of the wiring conductors 11 of the tape connector 8 are 2 with respect to the pitch of b. Double.

In assembling the above-mentioned connection structure, first, the wiring conductor 4a of the substrate 5 is aligned with the wiring conductor 2a of the substrate 1, and the wiring conductor 2a and the wiring conductor 4a are bonded by the anisotropic conductive adhesive 9c.
And are connected to each other.

Next, the anisotropic conductive adhesives 9a and 9b are attached to the tape connector 8
Of the wiring conductor 2b of the substrate 1 and the wiring conductor 4b of the flexible substrate 5 are made to face the wiring conductor 2b of the substrate 1 and the portions coated with the anisotropic conductive adhesives 9a and 9b, respectively. , The wiring conductors are aligned with each other and connected by heating pressure welding. In this case, the anisotropic conductive adhesive becomes conductive only in the thickness direction when pressure is applied.

In the above embodiment, the substrate 1 is for mounting electronic components and the substrate 5 is for wiring, but the present invention can be applied to substrates for any purpose.

〔The invention's effect〕

As described above, according to the present invention, the area required for connection can be reduced, and the alignment can be facilitated during assembly.

[Brief description of drawings]

FIG. 1 is a perspective view showing a connection structure of an embodiment of the present invention, FIG. 2 is a perspective view showing a conventional connection structure, FIG. 3 is a perspective view showing a part of a board on which electronic components are mounted, and FIG. FIG. 5 is a perspective view showing a part of a wiring flexible substrate coated with an anisotropic conductive adhesive, and FIG. 5 is a perspective view showing a tape connector. 1 ... Board, 2, 2a, 2b, 4a, 4b, 11 ... Wiring conductor, 5 ... Flexible board, 7 ... Overlap area,
8 ... Tape connector, 9a, 9b, 9c ... Anisotropic conductive adhesive.

Claims (3)

[Claims] 1. A first substrate having a wiring conductor on a first surface, a second substrate having wiring conductors on the first and second surfaces, a wiring conductor on the first substrate, and the first substrate. Connection means for connecting the wiring conductors on the second substrate, the first substrate and the second substrate have overlapping regions in the vicinity of their respective ends to be overlapped with each other, and the first substrate Of the wiring conductors are parallel to each other in the vicinity of the overlapping region, every other wiring conductor extends into the overlapping region, and the other wiring conductor has an end portion in the vicinity of the overlapping region. Among the wiring conductors on the first surface of the substrate, the wiring conductors located in the overlapping region extend parallel to each other,
Each of them is joined to each of the wiring conductors of the first substrate in the overlapping area, and the wiring conductors of the second surface of the second substrate located in the overlapping area are mutually Parallel and extending parallel to one of the wiring conductors on the first surface located in the overlapping region, the connecting means comprises a tape connector having wiring conductors parallel to each other, One end of the wiring conductor is connected to the vicinity of the end of the other wiring of the first substrate, and the other end is connected to the wiring of the second surface of the second substrate. Board connection structure. 2. The structure according to claim 1, wherein the tape connector is bonded to the first substrate and the second substrate with an anisotropic conductive adhesive. 3. The structure according to claim 1, wherein the second substrate is bonded to the first substrate with an anisotropic conductive adhesive.