CN100584147C - Soft circuit board and its making method - Google Patents

Abstract

The invention discloses a flexible circuit board which comprises a flexible substrate, a plurality of metal lead wires, a position mark and a bracing structure, wherein, the plurality of metal lead wires are positioned on the flexible substrate; the position mark is arranged between a lead wire in the most outside and a corner of the flexible substrate; the bracing structure can be arranged between the position mark and the corner and reduce the warping of the corner of the flexible substrate.

Description

Flexible printed circuit board and its manufacturing method

technical field

The present invention relates to a flexible circuit board, and in particular to a flexible circuit board which needs image detection processing.

Background technique

As the name implies, a flexible circuit board is a flexible circuit board. Because of its flexibility, it can be called a flexible printed circuit board. A flexible circuit board is composed of an insulating substrate, an adhesive and a copper conductor. composed of. The advantage of flexible printed circuit boards is that it can perform three-dimensional wiring operations, and can be embedded in conductors in various shapes to meet the needs of equipment. Compared with general rigid base boards, flexible printed circuit boards are flexible, light and thin, and their types can be roughly divided into single-sided boards, double-sided boards, hybrid (multi-layer) boards, and soft-rigid boards.

In order to inspect the appearance of the flexible circuit board, as a basis for judging whether the flexible circuit board can operate normally, an image inspection system is generally used for appearance inspection to speed up the quality control process and improve the pass rate.

FIG. 1 is a schematic diagram of a conventional flexible circuit board. The flexible circuit board 10 includes a flexible substrate 11 and a positioning mark 12 . However, due to the flexible characteristic of the flexible circuit board 10 , corner warping sometimes occurs, as shown in FIG. 1 .

When the corners are warped, the positioning marks 12 arranged on the flexible circuit board 10 will warp accordingly, so that the level of the positioning marks 12 is inconsistent with the level of the circuit pattern of the flexible circuit board. At this time, the image detection system The captured images of the positioning markers are blurred, so that the image detection system cannot correctly identify the images of the positioning markers.

On the other hand, when the flexible printed circuit board 10 with warped corners is used for image inspection, the warped corners will block the positioning marks 12 , making it impossible for the image detection system to capture a complete image of the positioning marks. However, the image detection operation needs to use the positioning marks to compare the captured FPC images. When the images of the positioning marks are blurred, the recognition of the FPC will be reduced, which will easily cause errors in the image detection system. Classify it as defective. In this case, the amount of discarded materials increases with the increase of defective products, thus causing a problem of cost increase.

In view of this, in order to avoid the misjudgment of the image detection system caused by the warping of the corners of the flexible circuit board, resulting in an increase in the amount of discarded materials, it is necessary to design a flexible circuit board that can overcome the aforementioned problems, which can Improving the image recognition of the image detection system, and at the same time reducing the amount of materials thrown away has the effect of reducing costs.

Contents of the invention

The technical problem to be solved by the present invention is to provide a flexible circuit board to avoid misjudgment of the image detection system caused by warpage of the corners of the flexible circuit board.

With regard to the flexible circuit board provided by the present invention, the misjudgment of the image detection system caused by the warping of the corners of the flexible circuit board can indeed be avoided.

Moreover, the present invention also proposes a manufacturing method of the flexible circuit board for the provided flexible circuit board, so as to avoid misjudgment by the image detection system caused by warpage of the corner of the flexible circuit board.

To achieve the aforementioned purpose, the present invention provides a flexible circuit board, which includes: a flexible substrate, a plurality of metal wires, positioning marks and a supporting structure. A plurality of metal wires are located on the flexible substrate, and the positioning marks are arranged between the outermost metal wires and a corner of the flexible substrate. The support structure can be arranged between the positioning mark and the corner, and the support structure can reduce the warping of the corner of the flexible substrate.

The present invention further provides a flexible circuit board, which includes: a flexible substrate, a plurality of metal wires, a first support structure and a second support structure. A plurality of metal wires are located on the flexible substrate. The first support structure is disposed between the outermost metal wires and a corner of the flexible substrate, and the first support structure can reduce warpage of the corner of the flexible substrate. The second support structure is disposed on part of the first support structure, the light reflectance of the second support structure may be lower than that of the first support structure, and an exposed area of the first support structure is defined by the second support structure as a positioning mark.

The present invention also provides a method for manufacturing a flexible circuit board, comprising the following steps: forming a positioning mark adjacent to the outer corner of the flexible circuit board; and forming a supporting structure between the positioning mark and the corner . Moreover, the supporting structure can reduce the warping of the corners of the flexible substrate.

Description of drawings

In order to make the above and other objects, features, advantages and embodiments of the present invention more obvious and understandable, the detailed description of the accompanying drawings is as follows:

FIG. 1 is a schematic diagram of an existing flexible circuit board;

FIG. 2a shows a partial schematic diagram of a flexible circuit board according to an embodiment of the present invention;

FIG. 2b shows a schematic diagram of a flexible circuit board according to an embodiment of the present invention;

FIG. 3 shows a schematic diagram of a flexible circuit board according to another embodiment of the present invention;

4a to 4f are schematic diagrams illustrating a plurality of flexible printed circuit boards according to some embodiments of the present invention;

FIG. 5 shows a schematic diagram of a flexible circuit board according to yet another embodiment of the present invention;

FIG. 6 shows a schematic diagram of a flexible circuit board according to another embodiment of the present invention;

FIG. 7 shows a schematic diagram of another flexible circuit board according to an embodiment of the present invention;

FIG. 8 is a flow chart of a method for manufacturing a flexible circuit board according to an embodiment of the invention.

Wherein, reference sign is:

10, 20, 30, 50, 60, 70: flexible circuit board

11, 21, 31, 43, 51, 61, 71: flexible substrate

12, 23, 33, 41, 47, 53, 63, 75: positioning marks

22, 32, 52, 62, 72: metal wire

24, 34, 42, 44, 45, 46, 48, 49, 54, 64, 73, 74: Support structure

211, 213: side

d: distance

Detailed ways

Image inspection systems are widely used in the pass rate inspection of circuit boards. The image inspection system compares the images of standard circuit boards with the captured images of multiple circuit boards to be tested to determine the number of circuit boards to be tested. Whether it is a defective product. During the detection process, the positioning marks are set on the circuit board to be tested, and the positioning marks are the calibration basis for the image detection system to compare the image of the standard circuit board with the image of the circuit board to be tested.

In order to solve the problem of warping of the corners of the flexible circuit board, the embodiment of the present invention provides a supporting structure around the positioning marks of the flexible circuit board, because the supporting structure can prevent the positioning marks from being affected by the warping of the corners of the flexible circuit board. The impact of the image detection system reduces the recognition, so it can effectively reduce unnecessary throwing.

In the following embodiments, except for some special considerations in some embodiments, copper foil is used as an example for the materials of the positioning marks and supporting structures. After the exposure and development processes, the positioning marks and supporting structures can be integrated with the wiring pattern And it is formed on a flexible circuit board, so the process steps can be reduced and the cost can be reduced at the same time.

FIG. 2a is a partial schematic diagram of a flexible circuit board according to an embodiment of the present invention. The flexible circuit board 20 includes a flexible substrate 21, a positioning mark 23 and a supporting structure 24. The flexible substrate 21 also includes sides 211 and 213. The corners of the flexible substrate 21 are located at the intersection of the two sides 211 and 213, and part of the supporting structure 24 is arranged between the positioning mark 23 and the corner. For example, the supporting structure 24 disposed parallel to the side 211 or 213 can reduce the corner warping of the flexible substrate 21 . The following will take the supporting structure parallel to the side 213 as an example to illustrate the embodiment of the present invention.

FIG. 2b is a schematic diagram of a flexible circuit board according to an embodiment of the present invention. Please refer to FIG. 2 b , in this embodiment, the flexible circuit board 20 includes: a flexible substrate 21 , a plurality of metal wires 22 , positioning marks 23 and a supporting structure 24 . A plurality of metal wires 22 are disposed above the flexible substrate 21 , and the positioning mark 23 is disposed between the outermost metal wires 22 of the flexible substrate 21 and a corner of the flexible substrate 21 . Moreover, the support structure 24 is a long rectangle, which is arranged between the positioning mark 23 and the corner, and the support structure 24 can reduce the warping of the corner of the flexible substrate 21 .

FIG. 3 is a schematic diagram of a flexible circuit board according to another embodiment of the present invention. The flexible circuit board 30 includes: a flexible substrate 31 , a plurality of metal wires 32 , positioning marks 33 and a supporting structure 34 . Compared with FIG. 2b, the difference between the flexible circuit board 30 of this embodiment and the flexible circuit board 20 is that the positioning marks 33 and the support structure 34 are both offset inward by a distance d, so as to avoid the warping of the corners from affecting the positioning. The legibility of the mark 33. In this embodiment, the flexible circuit board 30 is installed in mobile devices such as mobile phones. For this flexible circuit board 30, the degree of recognition will not be affected due to the width of the deflection at the corners of 1-1.5 mm. , and if the distance d exceeds 5 mm, the wiring space of the metal wire 32 will be affected. Therefore, based on the above considerations, the range of the distance d may be 1.5-5 mm.

According to the concepts adopted in the above embodiments, the following will describe multiple embodiments of different types derived from the concepts.

4a to 4f are schematic diagrams illustrating a plurality of flexible printed circuit boards according to some embodiments of the present invention. Please refer to FIG. 4 a , the support structure 42 can be obliquely disposed between the corner of the flexible circuit board and the positioning mark 41 to prevent the influence of the deflection of the corner on the positioning mark 41 , thus achieving the effect of improving the recognition degree. In addition, please refer to FIG. 4b. According to the aspect of this embodiment, the support structure 44 can be located on the corner of the flexible circuit board and extend obliquely around the part of the positioning mark, which can also prevent the deflection of the corner from affecting the positioning. The influence of the mark, and achieve the effect of improving the image recognition.

Please refer to FIG. 4c and FIG. 4d , the supporting structure 45 and the supporting structure 46 are respectively L-shaped or V-shaped, and the supporting structures 45 and 46 are disposed on both sides of the positioning mark 41 . The difference between the two lies in that the angles between the two wires constituting the support structures 45 and 46 are different, and part of the support structure 45 is disposed on the corner and part of the support structure 46 is disposed obliquely between the positioning mark 41 and the corner.

In addition, please refer to FIG. 4e and FIG. 4f. In these two embodiments, the positioning mark 47 has a T-shaped structure, for example, but the present invention is not limited thereto. Any shape that can be used as a positioning mark of the image detection system can be used in the present invention. The anchor tag is used. In FIG. 4 e , the supporting structure 48 has a groove, which roughly accommodates part of the positioning mark 47 . In FIG. 4f , the support structure 49 is a long rectangle, and the positioning mark 47 is adjacent to but not coupled to the support structure 49 .

FIG. 5 is a schematic diagram of a flexible circuit board according to yet another embodiment of the present invention. The flexible circuit board 50 includes: a flexible substrate 51 , a plurality of metal wires 52 , positioning marks 53 and a supporting structure 54 . The difference between the flexible circuit board 50 of this embodiment and the flexible circuit board 20 is that the supporting structure 54 is a quadrilateral, which is directly formed around the positioning mark 53, and the supporting structure 54 can reduce the corner warping of the flexible substrate 51. song. In addition, an electroplating process can be used to form an electroplating layer on the supporting structure 54 , and the light reflectivity of the electroplating layer is lower than that of the positioning mark 53 , which will help the image detection system to recognize the image of the positioning mark 53 . That is, when the flexible circuit board is performing image detection operations, the image detection system projects light onto the flexible circuit board 50 and receives light reflected by the flexible circuit board 50 to obtain an image of the flexible circuit board 50 . Compared with the support structure 54, the positioning mark 53 can reflect more light to facilitate the image detection system to identify the positioning mark 53, thereby improving the accuracy of the subsequent detection process.

FIG. 6 is a schematic diagram of a flexible circuit board according to another embodiment of the present invention. The flexible circuit board 60 includes: a flexible substrate 61 , a plurality of metal wires 62 , positioning marks 63 and a supporting structure 64 . The difference between the flexible circuit board 60 of this embodiment and the flexible circuit board 50 is that the support structure 54 is circular and is directly formed around the positioning mark 53 . Likewise, an electroplating layer can be formed on the supporting structure 64 by electroplating process, and the light reflectance of the electroplating layer is lower than that of the positioning marks 63, so as to achieve the effect of improving the accuracy of the subsequent detection process.

FIG. 7 is a schematic diagram of another flexible circuit board according to an embodiment of the present invention. In this embodiment, the flexible circuit board 70 includes: a flexible substrate 71 , a plurality of metal wires 72 , and supporting structures 73 and 74 . A plurality of metal wires 72 are located on the flexible substrate 71 , and a supporting structure 73 is disposed between the outermost metal wires 72 and a corner of the flexible substrate 71 . The supporting structure 73 can reduce warping of the corners of the flexible substrate 71 . The support structure 74 is disposed on a part of the support structure 73 , the light reflectance of the support structure 74 is lower than that of the support structure 73 and the support structure 74 defines an exposed area on the support structure 73 , and the exposed area serves as a positioning mark 75 . In addition, an electroplating process may be used to form an electroplating layer on the supporting structure 74 , and the light reflectivity of the electroplating layer is lower than that of the positioning marks 75 .

FIG. 8 is a manufacturing method of a flexible circuit board according to an embodiment of the present invention. This manufacturing method includes the following steps: first, in step S81, a positioning mark is formed on a corner adjacent to the outer side of the flexible circuit board, and, in step S83, a supporting structure is formed between the positioning mark and the corner, This support structure reduces corner warpage on flexible substrates. Similarly, taking the flexible circuit board 30 mounted on a mobile device such as a mobile phone as an example, considering factors such as corner warpage and wiring space for metal wires, the distance between the positioning mark and the corner can be 1.5-5mm. In addition, the distance between the support structure and the corner can be in the range of 1.5-5 mm. In addition, the support structure can be selectively formed around the part of the positioning mark. In this case, the manufacturing method can further include step S85. In step S85, an electroplating layer is formed on the support structure by using an electroplating process, and electroplating The light reflectivity of the layer is lower than the light reflectivity of the alignment marks. In this way, compared with the support structure, the positioning mark can reflect more light to the image detection system, so that the image of the positioning mark can be easily recognized by the image detection system, thereby improving the degree of recognition.

From the above-mentioned embodiments of the present invention, it can be seen that the application of the present invention can reduce the warpage of the corners of the flexible substrate through the support structure, so that the image inspection system can normally recognize the influence of the positioning marks, so as to perform image comparison operations on the circuit board . Therefore, the flexible circuit board of the embodiment of the present invention can substantially reduce the misjudgment of the image detection system caused by the warpage of the corner of the flexible circuit board, and can reduce the amount of material thrown away caused by the misjudgment, thereby reducing the cost. advantage.

Although the present invention has been disclosed above with a preferred embodiment, it is not intended to limit the present invention. Those skilled in the art can make various corresponding modifications according to the present invention without departing from the spirit and essence of the present invention. Changes and modifications, but these corresponding changes and modifications should belong to the scope of protection of the appended claims of the present invention.

Claims (8)

1, a kind of flexible circuit board is characterized in that, this flexible circuit board comprises:

One flexible base plate;

Many strip metals lead is positioned on this flexible base plate;

One location mark is arranged between the corner of outermost those plain conductors and this flexible base plate;

One supporting construction is arranged between this telltale mark and this corner to this supporting construction of small part, and this supporting construction reduces this corner warpage of this flexible base plate; And

One electrodeposited coating is formed on this supporting construction, and wherein the light reflectivity of this electrodeposited coating is lower than this specifically labelled light reflectivity.

2, flexible circuit board as claimed in claim 1 is characterized in that, the distance range of this telltale mark and this corner is 1.5～5mm.

3, flexible circuit board as claimed in claim 1 is characterized in that, the distance range of this supporting construction and this corner is 1.5～5mm.

4, flexible circuit board as claimed in claim 1 is characterized in that, this supporting construction is formed at around this specifically labelled part.

5, flexible circuit board as claimed in claim 1 is characterized in that, this supporting construction is arranged at this specifically labelled both sides.

6, a kind of flexible circuit board is characterized in that, this flexible circuit board comprises:

One flexible base plate;

Many strip metals lead is positioned on this flexible base plate;

One first supporting construction is arranged between the corner of outermost those plain conductors and this flexible base plate, and this first supporting construction reduces this corner warpage of this flexible base plate; And

One second supporting construction is arranged on this first supporting construction of part, and the light reflectivity of this second supporting construction is lower than the exposed region that this first supporting construction and this this second supporting construction define this first supporting construction, locatees mark as one.

7, a kind of manufacture method of flexible circuit board is characterized in that, comprises:

Form a location mark, a corner in the outside that is close to this flexible circuit board;

Form a supporting construction, between this telltale mark and this corner; And

Form an electrodeposited coating on this supporting construction, wherein the light reflectivity of this electrodeposited coating is lower than this specifically labelled light reflectivity,

Wherein, this supporting construction reduces this corner warpage of this flexible base plate.

8, method as claimed in claim 7 is characterized in that, the distance range of this telltale mark and this corner is 1.5～5mm, and the distance range of this supporting construction and this corner is 1.5～5mm.

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