TW201936025A - Bendable soft circuit board - Google Patents

Abstract

A bendable soft circuit board includes an insulating layer, an electrically conductive layer, a thin plating layer, a thick plating layer, a first protective layer and a second protective layer. The insulating layer includes at least one bending portion and at least two connection portions. The electrically conductive layer is formed on the bending portion and the connection portions, and is attached to a first face of the insulating layer. The thin plating layer is formed on the bending portion and the connection portions, and is attached to the electrically conductive layer. The thick plating layer is formed on the connection portions and is attached to the thin plating layer. The first protective layer is formed on the bending portion and attached to the thin plating layer. The first protective layer is formed on the bending portion and attached to the first protective layer.

Description

Flexible circuit board with bending resistance

The invention relates to a flexible circuit board with bending resistance, particularly a flexible circuit board with bending resistance that can withstand bending stress and protect the circuit board circuit.

General electronic products are composed of several electronic components arranged on a circuit board to form a complete circuit structure, so that all electronic components function to achieve product efficacy. However, the current development of electronic products tends to be light, thin, short, and more efficient, resulting in the miniaturization of various electronic components. For example, if the circuit board carrying various electronic components is changed from a rigid substrate to a flexible flexible substrate, the circuit board It can be bent and deformed according to the structure of the electronic product, so that the mounting circuit board only needs to use a limited narrow space, which is helpful to achieve the purpose of reducing the volume of the electronic product.

Please refer to FIG. 1, which is a conventional flexible circuit board 9. An electronic circuit layer 92 is carried by a substrate 91, and a part of the electronic circuit layer 92 is covered with a protective film 93 so that the electronic circuit layer The connection line in 92 is exposed, and an external circuit module can be electrically connected. When the flexible circuit board 9 is bent for mounting, the protective film 93 can prevent the electronic circuit layer 92 from being damaged by friction with external devices, and the substrate 91 and the protective film 93 jointly clamp the bend of the electronic circuit layer 92. Fold the part to avoid bending stress to break the line.

However, when the flexible circuit board 9 is applied to thin and light electronic products, when the flexible circuit board 9 is folded to enter a small installation space, the electronic circuit layer 92 is easily pulled or squeezed at the folded place, which will cause circuit electricity. Poor performance, and even the substrate 91 may be broken.

In view of this, the conventional flexible circuit board does still need to be improved.

In order to solve the above problems, an object of the present invention is to provide a flexible circuit board with bending resistance, which can improve the ability of bending resistance to avoid the bending stress from damaging the circuit board.

A secondary object of the present invention is to provide a flexible circuit board with bending resistance, which can be stacked in a staggered structure to prevent collision or corrosion from damaging the inner circuit.

The flexible circuit board with bending resistance of the present invention may include: an insulating layer including at least one bent portion and at least two connecting portions; and a conductive layer formed on the bent portion and the connecting portion and attached On a first surface of the insulating layer; a thin plating layer formed on the bent portion and the connecting portion and attached to the conductive layer; a thick plating layer formed on the connecting portion and attached to the thin plating layer; A first protective layer is formed on the bent portion and is attached to the thin plating layer; and a second protective layer is formed on the bent portion and is attached to the first protective layer.

The flexible circuit board with bending resistance of the present invention includes: an insulating layer including at least one bending portion and at least two connecting portions; and a conductive layer formed on the bending portion and the connecting portion and attached to the A first surface of an insulating layer; a thin plating layer formed on the connection portion and attached to the conductive layer; a thick plating layer formed on the connection portion and attached to the thin plating layer; a first protective layer formed on The bent portion is attached to the conductive layer; and a second protective layer is formed on the bent portion and is attached to the first protective layer.

According to this, the flexible circuit board with bending resistance of the present invention enhances the bending resistance of the first protective layer through the thin plating layer and the second protective layer, and protects the conductive layer as an electronic circuit. And the intersection of the conductive layer and the first protective layer can avoid the failure of the circuit of the circuit board due to fracture, collision or corrosion. In addition, the area and thickness of the thin plating layer, the first protective layer and the second protective layer And section changes in specifications, such as having the effect of selecting the best bending resistance according to the installation conditions such as bending range, angle and pitch.

The second protective layer is formed on a part of the bent portion. In this way, an additional increase in the thickness of the bent portion has the effect of improving the bending resistance of the concave folded portion.

The second protective layer is formed on the bent portion and a part of the connecting portion, and the second protective layer is attached to the first protective layer and the thin plating layer. In this way, it has the effect of enhancing the bonding between the first protective layer and the thin plating layer.

Wherein, the thick plating layer is formed on a part of the connecting portion, and the thick plating layer does not overlap the second protective layer. In this way, the conductive layer can be electrically connected to an external circuit through the thickness layer, and has the functions of soldering and conducting.

Wherein, the second protective layer covers an interface between the thin plating layer and the first protective layer. In this way, the system has the effect of avoiding the expansion of the erosion range caused by the dissociation of the potential difference at the junction.

The flexible circuit board with bending resistance according to the present invention may further include a conductive layer, a thin plating layer, a thick plating layer, a first protective layer and a second protective layer, and stacked on the insulating layer opposite to the A second surface of the first surface. In this way, it has the effect of double-sided connection circuit and bidirectional strengthening of bending resistance.

〔this invention〕

1‧‧‧ insulation

2,2a‧‧‧ conductive layer

3,3a‧‧‧thin coating

4,4a‧‧‧thick plating

5,5a‧‧‧First protective layer

6,6a‧‧‧Second protective layer

S1‧‧‧First surface

S2‧‧‧Second surface

B‧‧‧ Bending section

C‧‧‧Connection Department

〔Usually〕

9‧‧‧ flexible circuit board

91‧‧‧ substrate

92‧‧‧Electronic circuit layer

93‧‧‧ protective film

Figure 1: Device diagram of a conventional flexible circuit board.

Fig. 2: A cross-sectional view of the structure of the first embodiment of the present invention.

FIG. 3 is a sectional view showing a structure of a second embodiment of the present invention.

FIG. 4 is a cross-sectional view of a structure of a third embodiment of the present invention.

Fig. 5 is a cross-sectional view showing a structure of a fourth embodiment of the present invention.

Fig. 6 is a cross-sectional view showing a structure of a fifth embodiment of the present invention.

Fig. 7 is a sectional view showing a structure of a sixth embodiment of the present invention.

Fig. 8 is a sectional view showing a structural change of a sixth embodiment of the present invention.

In order to make the above and other objects, features, and advantages of the present invention more comprehensible, the following describes the preferred embodiments of the present invention and the accompanying drawings in detail, as follows: Please refer to FIG. 2, which is a first embodiment of a flexible circuit board having bending resistance according to the present invention, which includes an insulating layer 1, a conductive layer 2, a thin plating layer 3, a thick plating layer 4, The first protective layer 5 and a second protective layer 6. The insulating layer 1 is used as a substrate, and the conductive layer 2, the thin plating layer 3, the thick plating layer 4, the first protective layer 5 and the second protective layer 6 are stacked one by one to form one of the insulating layers 1. First surface S1.

The insulating layer 1 can be divided into at least one bent portion B and at least two connecting portions C along the first surface S1. The insulating layer 1 can be flexibly deformed by the bent portion B, and various electronic components or circuit molds A group can be installed in this connection part C. The area, position, and number of the bent portion B and the connecting portion C are not limited to this embodiment. In addition, the insulating layer 1 preferably has characteristics such as high ductility, large tensile strength, wide application temperature, and chemical resistance. The insulating layer 1 may be made of materials such as polyimide.

The conductive layer 2 can be attached to the first surface S1 of the insulating layer 1 by sputtering or printing, and the conductive layer 2 is processed to form an electronic circuit. It can electrically connect various electronic components or circuit modules. The conductive layer 2 preferably has high conductivity, and the conductive layer 2 preferably has high ductility, so that the conductive layer 2 can be bent with the insulating layer 1 without breaking. The conductive layer 2 may be a metal coating, and a common metal material is copper or tin.

The thin plating layer 3 can be used to partially or fully cover the conductive layer 2 by electroplating, so that the thin plating layer 3 and the insulating layer 1 cover the conductive layer 2, and the thin plating layer 3 has a function of protecting the conductive layer 2 from corrosion. And maintain electrical conductivity. The thin plating layer 3 may be made of a material such as tin or gold.

The thick plating layer 4 can be attached to a part of the thin plating layer 3 in the connection portion C by electroplating, and has the effect of improving the bonding between the connection portion C and various electronic components or circuit modules. The plating layer 4 has conductivity, and the conductive layer 2 can be used to electrically connect various electronic components or circuit modules through the thin plating layer 3 and the thick plating layer 4. The thick plating layer 4 may be made of materials such as nickel, tin, or gold. The thickness of the thick plating layer 4 is preferably greater than the thickness of the thin plating layer 3.

The first protective layer 5 can be fixed to the bent portion B by means of adhesive bonding or printing. The first protective layer 5 can be directly attached to the conductive layer 2 or the thin plating layer 3. The first protective layer 5 has the effect of protecting the conductive layer 2 from corrosion, collision or scratching. Moreover, the first protective layer 5 can reduce the impact of the bent portion B on the conductive layer 2. The thickness of the first protective layer 5 is preferably larger than the thickness of the thin plating layer 3. The first protective layer 5 may be a cover film (CL), or may include materials such as a solder resist component.

The second protective layer 6 can be fixed to a portion of the bent portion B or an interface between the bent portion B and the connecting portion C by means of adhesion, compression, or printing. The second protective layer 6 can cover the first portion. A protective layer 5 or a part or all of the thin plating layer 3, but the second protective layer 6 does not cover the thick plating layer 4, the second protective layer 6 has the effect of enhancing the first protective layer 5, and the first protective layer 5 The second protective layer 6 can cover and limit the boundary between the thin plating layer 3 and the first protective layer 5 to avoid the expansion of the erosion range caused by the potential difference dissociation at the interface. The second protective layer 6 may be the same as the first protective layer 5, and is a cover film and a material including a solder resist component.

As described above, in the first embodiment, the conductive layer 2 and the thin plating layer 3 are sequentially superimposed on the first surface S1 of the insulating layer 1 and are divided into the bent portion B and the bent portion B. The two connecting portions C on the two sides of the portion B; the first protective layer 5 is formed on the bent portion B and is directly attached to the thin plating layer 3 so that the first protective layer 5 covers the thin plating layer of the bent portion B 3, without covering the thin plating layer 3 of the two connecting portions C; the second protective layer 6 is formed on part of the bent portion B and part of the two connecting portions C, and covers part of the first protective layer 5, and part of the The thin plated layer 3 and the boundary between the first protective layer 5 and the thin plated layer 3; the thick plated layer 4 is formed at a portion of the two connecting portions C, and covers the uncovered portion of the second protective layer 6 of the thin plated layer 3. In this way, the second protective layer 6 can strengthen the bending strength of the two ends of the bent portion B.

Please refer to FIG. 3, which is the second embodiment of the present invention. Compared with the first embodiment, the main difference is that in the second embodiment, the first protective layer 5 is directly attached to the conductive layer. 2; the thin plating layer 3 is formed on the two connecting portions C and is directly attached to the conductive layer 2, The thin plating layer 3 covers the conductive layer 2 of the two connecting portions C, but does not cover the conductive layer 2 of the bent portion B; the second protective layer 6 is formed on part of the bent portion B and the bent portion The connection portion C on one side of B, and the connection portion C on the other side of the bent portion B do not form the second protective layer 6. In this way, the second protective layer 6 can strengthen the bending strength of one end of the bent portion B.

Please refer to FIG. 4, which is a third embodiment of the present invention. Compared with the first embodiment, the main difference is that in the third embodiment, the second protective layer 6 is formed on a part of the bend. The second protective layer 6 is not formed on the connecting portion C on one side of the portion B and the bent portion B, and on the other side of the bent portion B. In this way, the second protective layer 6 can strengthen the bending strength of one end of the bent portion B, and the thin plating layer 3 can prevent the conductive layer 2 from being corroded due to exposure.

Please refer to FIG. 5, which is the fourth embodiment of the present invention. The main difference from the first embodiment is that in the fourth embodiment, the second protective layer 6 is formed on part of the bent portion B. , So that the second protective layer 6 covers a part of the first protective layer 5 and does not cover the thin plating layer 3 of the two connecting portions C. In this way, the second protective layer 6 can strengthen the bending resistance of the middle portion of the bent portion B.

Please refer to FIG. 6, which is a fifth embodiment of the present invention. Compared with the first embodiment, the main difference is that in the fifth embodiment, the second protective layer 6 is formed on the bent portion. B and part of the two connecting parts C cover the first protective layer 5, part of the thin plating layer 3 and the boundary between the first protective layer 5 and the thin plating layer 3. In this way, the second protective layer 6 can evenly improve the bending strength of each section of the bending portion B.

Please refer to FIG. 7, which is a sixth embodiment of the present invention. Compared with the first embodiment, the main difference is that in this sixth embodiment, one of the second surfaces S2 of the insulating layer 1 is in order. A conductive layer 2a, a thin plating layer 3a, and a first protective layer 5a are stacked. The first protective layer 5a is formed on the bent portion B and a portion of the two connecting portions C, and covers a portion of the thin plating layer 3a; 4a is formed on part of the two connecting portions C, and covers the first protective layer 5a of the thin plating layer 3a. Cover part. In this way, the present invention can connect circuits on both sides through the conductive layer 2 and the conductive layer 2a, and the thin plating layer 3a and the first protective layer 5a can protect the conductive layer 2a and provide bending resistance in the direction of the second surface S2 Fold strength.

In addition, in the foregoing first to fifth embodiments, the second surface S2 of the insulating layer 1 may also have the conductive layer 2a, the thin plating layer 3a, the thick plating layer 4a, and the first protective layer 5a of the sixth embodiment. Stack structure.

In addition, the second surface S2 of the insulating layer 1 may further have another second protective layer 6a. As shown in FIG. 8, the conductive layer 2a, the thin plating layer 3a, the thick plating layer 4a, and the first protection are combined. The layer 5a and the second protective layer 6a can form the conductive layer 2, the thin plating layer 3, the thick plating layer 4, the first protective layer 5 and the second protective layer 6 in the first to fifth embodiments. The stacking structure, therefore, the first surface S1 and the second surface S2 may have any of the aforementioned stacking structures of the first to sixth embodiments, which can be applied to various devices and can strengthen the bending resistance of a specific position .

In summary, the flexible circuit board with bending resistance of the present invention can improve the bending resistance of the first protective layer by using the thin plating layer and the second protective layer, and protect the electronic circuit. The conductive layer and the interface between the conductive layer and the first protective layer can avoid the failure of the circuit of the circuit board due to fracture, collision, or corrosion. In addition, the thin plating layer, the first protective layer, and the second protective layer The area, thickness, and segmented position and other specifications change according to the installation conditions such as bending range, angle and spacing, and the effect of selecting the best bending resistance.

Although the present invention has been disclosed using the above-mentioned preferred embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make various changes and modifications to the above embodiments without departing from the spirit and scope of the present invention. The technical scope protected by the invention, so the scope of protection of the present invention shall be determined by the scope of the appended patent application.

Claims (10)

A flexible circuit board with bending resistance includes: an insulating layer including at least one bent portion and at least two connecting portions; a conductive layer formed on the bent portion and the connecting portion and attached to the insulating layer A first surface; a thin plating layer formed on the bent portion and the connecting portion and attached to the conductive layer; a thick plating layer formed on the connecting portion and attached to the thin plating layer; a first protective layer Is formed on the bent portion and is attached to the thin plating layer; and a second protective layer is formed on the bent portion and is attached to the first protective layer. The flexible circuit board with bending resistance according to item 1 of the scope of the patent application, wherein the second protective layer is formed on a part of the bending portion. The flexible circuit board with bending resistance according to item 1 of the scope of patent application, wherein the second protective layer is formed on the bent portion and a part of the connecting portion, and the second protective layer is attached to the first A protective layer and the thin plating layer. The flexible circuit board with bending resistance according to item 3 of the scope of the patent application, wherein the thick plating layer is formed at a part of the connecting portion, and the thick plating layer does not overlap the second protective layer. A flexible circuit board with bending resistance includes: an insulating layer including at least one bent portion and at least two connecting portions; a conductive layer formed on the bent portion and the connecting portion and attached to the insulating layer A first surface; a thin plating layer formed on the connection portion and attached to the conductive layer; a thick plating layer formed on the connection portion and attached to the thin plating layer; a first protective layer formed on the bend A folded portion is attached to the conductive layer; and a second protective layer is formed on the folded portion and is attached to the first protective layer. The flexible circuit board with bending resistance as described in item 5 of the scope of patent application, wherein the second A protective layer is formed in part of the bent portion. The flexible circuit board having bending resistance according to item 5 of the scope of patent application, wherein the second protective layer is formed on the bent portion and a part of the connecting portion, and the second protective layer is attached to the first A protective layer and the thin plating layer. The flexible circuit board with bending resistance according to item 7 of the scope of the patent application, wherein the thick plating layer is formed at a part of the connecting portion, and the thick plating layer does not overlap the second protective layer. The flexible circuit board with bending resistance according to item 7 of the scope of the patent application, wherein the second protective layer covers a boundary between the thin plating layer and the first protective layer. The flexible circuit board having bending resistance as described in any one of claims 1 to 9 of the scope of patent application, further comprising a conductive layer, a thin plating layer, a thick plating layer, a first protective layer and a second protective layer. Layers and stacked on a second surface of the insulating layer opposite to the first surface.