CN101448358A - Flexible printed circuit board bending region structure design - Google Patents

Abstract

A flexible printed circuit board bending region structural design, the flexible printed circuit board has a base plate, at least a printed circuit and a bending region, the bending region is staggered with the at least a printed circuit, and form at least a recess in the bending region of the printed circuit, the thickness of the recess is smaller than or equal to the thickness of the printed circuit, and the recess does not cut off the printed circuit; by the design of the grooves, the stress position can be effectively controlled in the bending area of the flexible printed circuit board, and the purpose of accurate bending angle of the flexible printed circuit board is achieved.

Description

Structural Design of Bending Area of Flexible Printed Circuit Board

technical field

The invention relates to a structural design of a flexible printed circuit board, in particular to a structural design in which grooves are provided in the bending area of the flexible printed circuit board to form bending stress lines.

Background technique

The main characteristics and advantages of flexible printed circuit boards (FPC) are easy to bend and flexibility. Therefore, flexible printed circuit boards are often used in design structures that need to be flexed during assembly. It is very important that the location is accurate.

Please refer to FIG. 1 and FIG. 2 , in the prior art, a white paint line 11 is generally added at the bending position of the flexible printed circuit board 10 so that the operator can identify the bending position. However, in this conventional bending method, due to the printing tolerance of the white paint line 11 and the tolerance caused by the operator's manual bending, it is often impossible for the flexible printed circuit board 10 to achieve a completely accurate bending angle.

In addition, some manufacturers have partially hollowed out the bending area of the flexible printed circuit board in order to improve the above-mentioned lack of control over the bending accuracy. However, such methods must destroy the flexible printed circuit board, which reduces the strength of the flexible printed circuit board, and even causes the flexible printed circuit board to break.

Contents of the invention

In view of the lack of conventional technology, the purpose of the present invention is to propose a flexible printed circuit board bending area structure design, the printed circuit of the flexible printed circuit board is designed as a special stress line, which can be used in flexible printed circuit boards. When the plate is bent, the position where the stress is generated is controlled, so as to achieve the effect of precise bending angle.

In order to achieve the above object, the present invention proposes a structural design of a bending area of a flexible printed circuit board. The flexible printed circuit board has at least one printed circuit and a bending area, and the bending area intersects with the at least one printed circuit. And at least one groove is formed in the bending area of the printed circuit, and the groove does not cut off the printed circuit; through the design of these grooves, the stress position can be effectively controlled in the bending area of the flexible printed circuit board .

In order to have a further understanding and recognition of the structure, purpose and effect of the present invention, a detailed description is given below with the help of diagrams.

Description of drawings

FIG. 1 is a schematic structural diagram of a conventional flexible printed circuit board.

FIG. 2 is a schematic diagram of a conventional flexible printed circuit board after being bent.

Fig. 3 is a schematic structural diagram of an embodiment of the present invention.

Fig. 4 is a schematic diagram of a partially enlarged structure of the present invention after bending.

FIG. 5 is a schematic structural view of the embodiment of FIG. 3 after being bent.

6 to 11 are structural schematic diagrams of different embodiments of the present invention.

Explanation of main component symbols

1. Previous technology:

10-Flexible printed circuit board

11-White paint wire

Two, the present invention:

2, 12, 22, 32, 42, 52, 62-flexible printed circuit board

20, 120, 220, 320, 420, 520, 620-substrate

21, 121, 221, 321, 421, 521, 621, 22, 122, 222, 322, 422, 522, 622 - printed circuit

1211-wide area

23, 123, 223, 323, 423, 523, 623-Bending area

24, 124, 224, 324, 424, 524a, 524b, 624a, 624b - groove

After g-flexible printed circuit board is bent, the gap between its opposite sides

L - the length of the groove

t-thickness of flexible printed circuit board

W - the width of the groove

W1 Width of printed circuit

θ-bending angle

π-pi

Detailed ways

The technical means and effects used by the present invention to achieve the purpose will be described below with reference to the attached drawings, and the embodiments listed in the following drawings are only for auxiliary description, to facilitate understanding, but the technical means of the present invention are not limited The diagrams listed.

Please refer to FIG. 3 , a specific embodiment of the flexible printed circuit board bending area structure design provided by the present invention, the flexible printed circuit board 2 has a substrate 20, at least one printed circuit and a bending area 23, As shown in the figure, there are two printed circuits 21, 22, and the bending area 23 intersects with the printed circuits 21, 22. Usually, the bending area 23 and the substrate 20 form a bending angle θ of 45 degrees; by etching In other processing methods, a groove 24 is formed at the bending area 23 of the printed circuit 21 .

Since the groove 24 etches the printed circuit 21 completely, the depth of the groove 24 must be less than or equal to the thickness of the printed circuit 21; the length L of the groove 24 is not limited, as long as the printed circuit 21 is not completely cut off , as shown in this embodiment, the width W1 of the printed circuit 21 provided with the groove 24 is increased, so that the length L of the groove 24 can cover most of the area of the flexible printed circuit board 2 , and the printed circuit 21 can still maintain the state of circuit connection; moreover, please refer to FIG. 4, the width W of the groove 24 is designed according to the following formula:

W≧(g/2+t)*π;

Wherein, W is the width of the groove 24; g is the gap between the two opposite sides of the flexible printed circuit board 2 after it is bent; t is the thickness of the flexible printed circuit board 2; π is the circumference ratio.

When the width W is closer to (g/2+t)*π, the bending angle will be more accurate.

By designing the depth, length L, width W and other dimensions of the groove 24, as shown in FIG. The purpose of the bending angle of plate 2 is precise.

Please refer to the embodiment shown in FIG. 6, which is based on the embodiment in FIG. The wide area 1211 of width W1, which covers the bending area 123, can be used to set the groove 124. The feature of this embodiment is that the width of the two ends of the wide area 1211 away from the bending area 123 is tapered to be the same as the other The width of the printed circuit 122 is equivalent; the tapered portion 1212 should have a proper distance from the bending area 123 to avoid forming another stress line at the tapered portion 1212 .

Please refer to the structural schematic diagrams of other different embodiments of the present invention shown in FIG. 7 to FIG. 11 .

As shown in Figure 7, the flexible printed circuit board 22 has a substrate 220, a wider printed circuit 221, a narrower printed circuit 222 and a bending area 223, in the bending area 223 of the printed circuit 221 A groove 224 is disposed at the position. The characteristic of this embodiment is that the groove 224 is disposed on the edge of the printed circuit 221 close to the printed circuit 222 .

As shown in Figure 8 again, the flexible printed circuit board 32 has a substrate 320, a wider printed circuit 321, a narrower printed circuit 322 and a bending area 323, in the bending area of the printed circuit 321 A groove 324 is provided at the position 323 . The characteristic of this embodiment is that the groove 324 is arranged at about the center of the printed circuit 321 and does not penetrate through the two sides of the printed circuit 321 .

As shown in Figure 9 again, the flexible printed circuit board 42 has a substrate 420, a wider printed circuit 421, a narrower printed circuit 422 and a bending area 423, the feature of this embodiment is that the printed circuit The bending area 423 of 421 is provided with a plurality of grooves 424, and the shape of the grooves 424 is not limited to the circle shown in the figure, and can be any combination of geometric shapes.

As shown in Figure 10, the flexible printed circuit board 52 has a substrate 520, two printed circuits 521, 522 with the same width, and a bending area 523. The feature of this embodiment is that the printed circuits 521, 522 are bent The area 523 is respectively provided with a groove 524a, 524b, and the grooves 524a, 524b are respectively arranged on the edges of the printed circuits 521, 522 away from each other.

As shown in Figure 11, the flexible printed circuit board 62 has a substrate 620, two printed circuits 621, 622 with the same width and a bending area 623, this embodiment is based on the embodiment in Figure 10, and is unique to this The bending regions 623 of the printed circuits 621 and 622 are respectively provided with grooves 624 a and 624 b , and the characteristic of this embodiment is that the grooves 624 a and 624 b are arranged on adjacent edges of the printed circuits 621 and 622 .

In summary, the structural design of the bending area of the flexible printed circuit board provided by the present invention is characterized in that the bending area of the printed circuit forms a groove stress line, which can effectively control the stress position on the bending area of the flexible printed circuit board. The bending area achieves the purpose of precise bending angle of the flexible printed circuit board; it must be noted that the shape, quantity and position of the groove are not limited to the above-mentioned embodiment, and the key point of the design is to reduce the thickness of the bending area of the printed circuit, Or fully etch without cutting the printed circuit.

The foregoing descriptions are merely examples of the present invention, and should not be used to limit the implementation scope of the present invention. That is, all equivalent changes and modifications made according to the scope of the patent application of the present invention should still fall within the scope covered by the patent of the present invention.

Claims (10)

1. A flexible printed circuit board bending area structure design, characterized in that it includes: A flexible printed circuit board, the flexible printed circuit board has at least one printed circuit and a bending area, and the bending area is interlaced with the at least one printed circuit; At least one groove is recessed in the printed circuit, and the groove is located in the bending area. 2. The structural design of the bending area of the flexible printed circuit board as claimed in claim 1, wherein the depth of the groove is less than or equal to the thickness of the printed circuit, so that the printed circuit forms at least one gap. 3. The structural design of the bending area of the flexible printed circuit board as claimed in claim 2, wherein the notch of the printed circuit does not cut off the printed circuit. 4. The structural design of the bending area of the flexible printed circuit board as claimed in claim 3, wherein a plurality of notches are provided, and the total length of the plurality of notches does not cut off the printed circuit. 5. The structural design of the bending area of the flexible printed circuit board according to claim 1, characterized in that: the groove is designed according to the following formula: W≧(g/2+t)*π; where, W is the groove width; g is the gap between the opposite sides of the flexible printed circuit board after it is bent; t is the thickness of the flexible printed circuit board; π is the circumference ratio. 6. The structural design of the bending area of the flexible printed circuit board according to claim 1, wherein the flexible printed circuit board has two printed circuits, and one of the printed circuits has a wide area, and the wide area covers The bending area is provided with grooves. 7. The structural design of the bending area of the flexible printed circuit board as claimed in claim 6, wherein the groove is arranged on the edge of the wider printed circuit. 8. The structural design of the bending area of the flexible printed circuit board according to claim 6, wherein the groove is arranged at about the center of the wider printed circuit, and does not penetrate the two sides of the printed circuit edge. 9. The structural design of the bending area of the flexible printed circuit board according to claim 1, wherein the shape of the groove can be a circle or any combination of geometric shapes. 10. The structural design of the bending area of the flexible printed circuit board according to claim 1, wherein the widths of the two printed circuits are about the same, and the two printed circuits are each provided with at least one groove.

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