JPH0627979Y2 - Printed wiring board structure - Google Patents

Description

TECHNICAL FIELD The present invention relates to a structure of a printed wiring board.

Conventional technology Conventionally, in order to mount a large number of electric parts on a small device,
A configuration in which a flexible substrate is bent and incorporated is proposed in, for example, Japanese Utility Model Publication No. 55-1255.

Problems to be Solved by the Invention In FIG. 3 of the above-mentioned prior art, there is one in which one flexible substrate is divided into four parts, bent at each boundary, and installed along the pentaprism of a single-lens reflex camera. It is disclosed.

According to the folding method disclosed in this prior art, both end portions of a horizontally long substrate are folded inwardly to be superposed in a double manner, and further, the central portion is bent into a chevron shape.

In the case of such a bending method, since both end portions of the board are folded inward, the connection terminal portion that is usually provided at the end portion of the board goes inside, and this board and other circuit boards Has the drawback that it is difficult to connect.

The applicant of the present invention bends and overlaps the flexible substrate along the first folding curve, and further bends the overlapped portion along the second folding curve intersecting with the first folding curve so that the end portion of the substrate can be obtained. It has been found that the flexible substrate can be incorporated without being folded inward, and the above-mentioned drawbacks are eliminated.

However, when bent like this, there is a further problem that the flexible substrate becomes sharp at the intersection of each folding curve, and the substrate is easily folded at this portion.

An object of the present invention is to obtain a printed wiring board which can be easily folded with another circuit board and which is not broken and damaged.

Means for Solving the Problems In order to achieve the above object, the present invention provides a flexible substrate that is folded and overlapped along a first folding curve, and the overlapped portion intersects the first folding curve. It is configured so that the end portion of the substrate is not folded inward by further bending along the two-fold curve, and further, the intersection of the first folding curve and the second folding curve formed by each bending of the substrate. A feature is that a cutout portion is provided in the flexible substrate.

Function In the present invention, as described above, the end portion of the board is positioned so that it can be easily connected to another board without being folded inward, and is bent so that the folding curves intersect at the cutout portion. To be

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a plan view of a flexible printed wiring board according to an embodiment of the present invention before bending. In FIG. 1, (2) is a flexible board and (4) is a slit formed on the flexible board (2). This is to facilitate folding of the substrate (2). (6a), (6b), (6c), and (6d) are first, second, third, and fourth regions (I) (II) partitioned from each other by folding curves (A) and (B) of the flexible substrate (2). ) (III) (IV) is an IC mounted on. The flexible board (2) has each I
Although many wirings such as those for connecting between C are printed, they are omitted in this figure, and a description thereof will be given later.

Such a flexible substrate (2) is first bent about 180 ° along the folding curve (A), and then about 45 ° along the folding curve (B) so that the lower side of the figure is the inner surface. , A single-lens reflex camera with a shape that conforms to the upper surface of the pendant prism. When bending along the folding curve (B), it is easy to bend when the slit (4) is formed on the inner surface side.

Further, when bent in this manner, the flexible substrate becomes sharp at the intersection of the bending curves and is easily broken, but such a disadvantage does not occur when the slit is formed as described above. Furthermore, if there is no slit, the flexible board can be bent with a curve with a certain radius so that it will not be sharp at the bent part, so it is difficult to align the angle of the upper and lower surfaces that are overlapped, However, if bent at the slit portion, the angles with respect to the upper surface of the pentaprism can be made uniform, and the elements can be efficiently arranged.

The flexible substrate (2) bent in this way has the shape shown in the perspective view of FIG. 2, and the upper surface of the pentaprism (8) of the single-lens reflex camera as shown in the front view of FIG. Is arranged along the line. 2 and 3
In the figure, (10) and (12) are ceramic substrates, and both ends of the flexible substrate (2) are the ceramic substrates.
Fixed to (10) and (12), the corresponding connection terminals of the flexible substrate (2) and the ceramic substrates (10) and (12) are electrically connected to each other. As is clear from FIGS. 2 and 3, one IC is provided on each surface formed by bending the flexible substrate (2), and wiring for connecting the ICs is also provided. It is bent. The bent portion of this wiring is shown in FIG.

In FIG. 4, (14) are flexible substrates (2), respectively.
Shown on the wiring printed above, each wire (14) is a fold
It is arranged so as to be orthogonal to (A), the bent portion has a wide width, and at least one slit is formed in the wide portion. With this slit, the bent portion of each wiring is divided into a plurality of divided wirings. Of FIG.
Explaining (a), the bent portion of the wiring (14) is wider than the other portions, and is formed in the center of the bent portion (A) in a direction perpendicular to the folding line (A), that is, the wiring (14) extends. Two slits of the same width are provided by the slits (16) extending in the direction
It is divided into (14a) and (14b). With this configuration, even if a crack is generated in one of the divided wirings at the time of bending, and the divided wiring is cut due to the progress of the crack, the slit (16) causes the crack in the other divided wiring. Since it is prevented from progressing to, the other divided wiring is not cut off,
It is possible to reduce the occurrence rate of disconnection as one wiring (14). Further, the bent portion of the wiring (14) is easier to bend than in the case where the entire bent portion is wide, and the energy loss is small because the area of the wiring (14) is small.

As shown in FIG. 4 (b), still another wiring has a wide bent portion, and three slits are formed in this wide portion, and four slits are divided by the three slits. The divided wirings have different widths. In this way, when the widths of the plurality of divided wirings are made different from each other, the durability against cutting at the time of bending of each divided wiring is different, so that it is possible to prevent all of the plurality of divided wirings from being cut at the time of bending, It is possible to reduce the occurrence rate of disconnection as one wiring (14). Furthermore, by increasing the number of divided wirings, it is possible to reduce the rate of disconnection of the wirings (14) as a whole due to the progress of cracks.

Further wirings are configured as shown in (c) (d) (e) (f) (g) of FIG. 4, respectively. What is shown in (C) is
The slits inclined with respect to the direction in which the wiring (14) extends, that is, the direction perpendicular to the folding curve (A), are formed in the wide portion of the wiring (14), and by configuring in this manner,
Since the widths of the two divided wirings divided by the slits are changed in inverse proportion to each other and one of them becomes wider than the width in the folding curve (A), the bending is performed deviating from the folding curve (A). In this case, the disconnection can be better prevented. What is shown in (d) is a modification of (a), in which a wide portion is provided on one side of the straight wiring (14) to form a slit, and what is shown in (e) is a modification of (b). Then, as shown in (18), one of the plurality of slits is a triangular slit in which the width of the divided wiring divided by it changes in direct proportion, and (f) is the slit. The shape of each slit is set so that each split wiring has a constant width in the extending direction of the wiring in accordance with the outer shape of the wide portion. As described above, the slit according to the present invention can have various shapes. Further, if the width is sufficient to form the slit, the bent portion of the wiring does not need to be particularly wide. The configuration of the present invention does not necessarily have to be applied to the bent portions of all the wirings, but may be applied appropriately to those that are prone to breakage.

Effects As described above, according to the present invention, since the flexible substrate is efficiently bent, the end portion is not folded inward, so that the connection with other substrates is not hindered and the bending curve Since the board is not broken and damaged at the intersection of, it is possible to obtain a very practical printed circuit board.

[Brief description of drawings]

FIG. 1 is a development view of a flexible substrate according to an embodiment of the present invention,
FIG. 2 is a perspective view showing the bent state, FIG. 3 is a front view of essential parts of the single-lens reflex camera showing the arrangement state, and FIG.
The figure is a diagram showing the shapes of various printed wirings on the substrate. 2 ... flexible substrate, 4 ... opening, A ... first fold curve, B ... second fold curve, I ... first area, II ... second area, III ... third area, IV ...... The fourth area.

Claims (1)

[Scope of utility model registration request] 1. A flexible substrate having a conductive pattern formed thereon is bent and overlapped along a first folding curve, and the overlapped portion is further bent along a second folding curve intersecting with the first folding curve. The first folding curve and the second folding curve which are formed by bending each of the substrates.
A printed wiring board structure, characterized in that a cutout is provided in the flexible board at the intersection of a folding curve.