CN113411950B

CN113411950B - Circuit board and manufacturing method thereof

Info

Publication number: CN113411950B
Application number: CN202110508989.7A
Authority: CN
Inventors: 张志强; 曾向伟
Original assignee: Shenzhen Kinwong Electronic Co Ltd
Current assignee: Shenzhen Kinwong Electronic Co Ltd
Priority date: 2021-05-11
Filing date: 2021-05-11
Publication date: 2023-02-17
Anticipated expiration: 2041-05-11
Also published as: CN113411950A

Abstract

The invention is suitable for the field of circuit boards, and provides a circuit board which comprises a first circuit board unit and a second circuit board unit which are connected; a cutting seam and a connecting position are arranged between the first circuit board unit and the second circuit board unit, the cutting seam extends along the edge of the first circuit board unit and is arranged on two opposite sides of the connecting position, and the first circuit board unit and the second circuit board unit are connected through the connecting position; the thickness of the connecting position is smaller than the thickness of the first circuit board unit and the second circuit board unit. The invention also provides a manufacturing method of the circuit board. The circuit board and the manufacturing method thereof improve the flexibility of the sub-board.

Description

Circuit board and manufacturing method thereof

Technical Field

The invention relates to the field of circuit boards, in particular to a circuit board and a manufacturing method thereof.

Background

The rigid-flex board is divided into a hard board area and a soft board area, wherein the hard board area and the soft board area are usually respectively provided with a connecting position, the circuit board units and the process frame are connected together through the connecting positions, and the circuit board units and the process frame are delivered to an SMT (Surface Mounted Technology) manufacturer in a multi-unit connection mode so as to improve the Surface mounting efficiency. After the SMT process is completed, the circuit board units are separated from the process frame, and a simple and quick method is needed to achieve this board splitting operation, especially at the sample stage.

The connecting position of the hard board area is usually designed as a stamp hole, and after the SMT procedure is finished, the connecting position of the stamp hole can be manually broken to separate the hard board area from the process frame; the connection position in the soft board area is made of soft materials and has certain toughness, the soft board connection position cannot be torn off manually under normal conditions, even if the connection position is torn off manually, the torn path is not controllable, the tearing opening can be expanded into the soft board area unit, the circuit area in the unit is damaged, and the product is scrapped. Therefore, at present, the manual board dividing action of the whole soft and hard combined board unit cannot be realized by an SMT factory, the connection position of the soft board needs to be cut off by adopting a laser cutting or die punching method, and the flexibility of board dividing operation is not high.

Disclosure of Invention

In view of this, the present invention provides a circuit board and a method for manufacturing the same to improve flexibility of board separation operation.

The embodiment of the invention provides a circuit board, which comprises a first circuit board unit and a second circuit board unit which are connected with each other; a cutting seam and a connecting position are arranged between the first circuit board unit and the second circuit board unit, the cutting seam extends along the edge of the first circuit board unit and is arranged on two opposite sides of the connecting position, and the first circuit board unit and the second circuit board unit are connected through the connecting position; the thickness of the connecting position is smaller than the thickness of the first circuit board unit and the second circuit board unit.

In an embodiment, the first circuit board unit is a flexible circuit board unit, the second circuit board unit is a frame unit, the first circuit board unit and the second circuit board unit both include a flexible substrate layer and a cover layer disposed above the flexible substrate layer, and the first circuit board unit further includes a circuit layer disposed between the flexible substrate layer and the cover layer; the covering layer is provided with a window at the connecting position, and the connecting position is only provided with the flexible base material layer.

In one embodiment, at least one end of the cutting slot extends into the connection location.

In an embodiment, two ends of the cutting seam extend into the connecting position from two opposite sides respectively and have a preset distance.

In an embodiment, an extension length of the connection position along the first circuit board unit is set to be L, a length of each end of the cutting seam extending into the connection position is 1/4L to 1/3L, and a distance between two ends of the cutting seam in the connection position is 1/3L to 1/2L.

In one embodiment, the extension length of the connection position is 1mm-2mm, and the extension width of the connection position is 0.5mm-1.0mm.

In one embodiment, one end of the connection position is located in the first circuit board unit, and the extension width of the connection position in the first circuit board unit is 0.05mm-0.1mm.

In one embodiment, the covering layer is windowed by flat plate cutting forming, punching forming or laser cutting forming; the cutting seam is a laser cutting line.

In an embodiment, the circuit board further includes a hard board circuit board unit, and a plurality of sequentially arranged circular holes are formed between the hard board circuit board unit and the adjacent second circuit board unit.

An embodiment of the second aspect of the present invention provides a method for manufacturing a circuit board, which is used for manufacturing the circuit board according to any one of the embodiments of the first aspect, and the method for manufacturing the circuit board includes:

manufacturing a first circuit board unit and a second circuit board unit, and manufacturing a connecting position between the first circuit board unit and the second circuit board unit, wherein the thickness of the connecting position is smaller than that of the first circuit board unit and that of the second circuit board unit;

and manufacturing cutting seams along the edges of the first circuit board units, wherein the cutting seams are arranged on two opposite sides of the connecting position.

The circuit board comprises a first circuit board unit and a second circuit board unit which are connected through a connecting position, a cutting seam is arranged between the first circuit board unit and the second circuit board unit, and when the first circuit board unit and the second circuit board unit need to be separated, the connecting position is manually torn along the cutting seam, so that the first circuit board unit and the second circuit board unit can be separated; meanwhile, the thickness of the connecting position is smaller than that of the first circuit board unit and that of the second circuit board unit, so that when the connecting position is torn manually, the tearing area is limited in the connecting position, and the first circuit board unit and the second circuit board unit are prevented from being damaged. Therefore, the circuit board can be manually separated, the tearing path is controllable, the circuit board unit is not easy to tear or damage, the flexible circuit board unit is particularly suitable for the flexible circuit board unit, and the problem that products are scrapped due to board separation is solved; after the SMT process, the circuit board is not required to be separated in a laser cutting or die cutting mode, flexibility and efficiency of board separation operation are improved, and manufacturing cost is reduced.

The manufacturing method of the circuit board achieves the aim of manually tearing off the connecting position by changing the manufacturing method of the connecting position; the circuit board manufactured by the manufacturing method is convenient for manual board separation, and the board separation is performed without adopting a laser cutting or die cutting mode, so that the production efficiency and the production flexibility are improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

FIG. 1 is a partial schematic view of a circuit board provided by an embodiment of the invention;

FIG. 2 is a schematic diagram of a portion II of the circuit board according to an embodiment of the invention;

FIG. 3 is a cross-sectional view of the circuit board shown in FIG. 2;

FIG. 4 is a partial schematic view of a circuit board provided in accordance with another embodiment of the present invention;

fig. 5 is a flowchart of a method for manufacturing a circuit board according to an embodiment of the invention;

FIG. 6 is a flow chart of a method for manufacturing a circuit board according to another embodiment of the present invention;

fig. 7 is a schematic structural diagram of a circuit board according to another embodiment of the present invention.

The designations in the figures mean:

100. a circuit board; 10. a first circuit board unit; 20. a second circuit board unit; 30. cutting a seam; 40. a connection bit; 50. a hard board circuit board unit; 51. a circular hole; 101. a flexible substrate layer; 102. a circuit layer; 103. a cover layer; 104. a hard board substrate layer; 105. a prepreg.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail below with reference to the accompanying drawings, which are examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly or indirectly secured to the other element. When an element is referred to as being "connected to" another element, it can be directly or indirectly connected to the other element. The terms "upper", "lower", "left", "right", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description, and do not indicate or imply that the referred devices or elements must have a specific orientation, be constructed and operated in a specific orientation, and thus, are not to be construed as limiting the patent. The terms "first", "second" and "first" are used merely for descriptive purposes and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features. The meaning of "plurality" is two or more unless specifically limited otherwise.

To illustrate the technical solution of the present invention, the following description is made with reference to the specific drawings and examples.

Embodiments of a first aspect of the invention provide a circuit board. Referring to fig. 1 and 2, a circuit board 100 includes a first circuit board unit 10 and a second circuit board unit 20 connected to each other; a cutting slit 30 and a connecting position 40 are arranged between the first circuit board unit 10 and the second circuit board unit 20, the cutting slit 30 extends along the edge of the first circuit board unit 10 and is arranged at two opposite sides of the connecting position 40, and the first circuit board unit 10 and the second circuit board unit 20 are connected through the connecting position 40.

Fig. 3 is a sectional view taken along the first circuit board unit 10, the cutting slit 30, the connection site 40, and the second circuit board unit 20. Referring to fig. 3, the thickness of the connection site 40 is smaller than the thickness of the first circuit board unit 10 and the second circuit board unit 20.

The circuit board comprises a first circuit board unit 10 and a second circuit board unit 20 which are connected through a connecting position 40, a cutting seam 30 is arranged between the first circuit board unit 10 and the second circuit board unit 20, and when the first circuit board unit 10 and the second circuit board unit 20 need to be separated, the connecting position 40 is manually torn along the cutting seam 30, so that the first circuit board unit 10 and the second circuit board unit 20 can be separated; meanwhile, since the thickness of the connecting position 40 is smaller than the thickness of the first circuit board unit 10 and the second circuit board unit 20, that is, the thickness of the connecting position 40 is thinner than the area of the periphery thereof, which is equivalent to that the periphery of the connecting position 40 is covered with a circle of fence, when the connecting position 40 is torn manually, the torn area is limited to the thinner part in the fence, and cannot go deep into the first circuit board unit 10 and the second circuit board unit 20, thereby avoiding damage to the first circuit board unit 10 and the second circuit board unit 20. Therefore, the circuit board can realize manual board separation, the tearing path is controllable, the circuit board unit is not easy to tear or damage, the flexible circuit board unit is particularly suitable for the flexible circuit board unit, and the problem of product scrapping caused by board separation is avoided; after the SMT process, the circuit board is not required to be separated in a laser cutting or die cutting mode, the flexibility and efficiency of plate separation operation are improved, the circuit board is particularly suitable for the condition of small number of samples, and the manufacturing cost is reduced.

As shown in fig. 1 to fig. 3, in an embodiment, the first circuit board unit 10 is a flexible circuit board unit, the second circuit board unit 20 is a frame unit, each of the first circuit board unit 10 and the second circuit board unit 20 includes a flexible substrate layer 101 and a cover layer 103 disposed above the flexible substrate layer 101, and the first circuit board unit 10 further includes a circuit layer 102 disposed between the flexible substrate layer 101 and the cover layer 103; the cover layer 103 is windowed at the connection site 40 and only the flexible substrate layer 101 is present at the connection site 40, i.e. there is no copper layer and cover layer 103 at the connection site 40. It will be appreciated that the cover layer 103 includes a cover film and a glue layer disposed beneath the cover film.

In this embodiment, the covering layer 103 is windowed at the connection position 40, so that the purpose that the thickness of the connection position 40 is smaller than that of the first circuit board unit 10 and the second circuit board unit 20 can be achieved, and the manufacturing is simple and easy to implement; through setting up cutting seam 30 and connection position 40 in advance, conveniently separate flexible circuit board unit and frame unit through manual mode, need not to adopt laser cutting again or utilize the mould die-cut, the flexibility ratio of operation is higher, and the cost is lower.

In this embodiment, the first circuit board unit 10 is provided with one circuit layer 102 on both sides of the flexible substrate layer 101, and it can be understood that the circuit layer 102 in the first circuit board unit 10 may be one or more layers; in other embodiments, the first circuit board unit 10 and the second circuit board unit 20 may be both flexible circuit board units.

It is understood that the area shown in fig. 1 is only one partition of the circuit board 100, and the circuit board 100 may include a plurality of arrays of partitions, each of which may have the first circuit board unit 10, the second circuit board unit 20, and the hard board circuit board unit 50 disposed therein.

It is understood that the circuit board 100 may be a single-sided flexible board, a double-sided flexible board, and a rigid-flex board including a single-sided flexible board and a double-sided flexible board, and the number of rigid board layers in the rigid-flex board is not limited. In an embodiment, the circuit board 100 is a rigid-flex board, the circuit board 100 further includes a rigid circuit board unit 50, a plurality of sequentially arranged circular holes 51 are disposed between the rigid circuit board unit 50 and the adjacent second circuit board unit 20, the plurality of circular holes 51 form a "stamp hole" shape, and when separating the boards, the connection positions at the plurality of circular holes are manually broken, so that the rigid circuit board unit 50 can be separated.

As shown in fig. 2 and 3, at least one end of the cut 30 extends into the connection location 40. By extending the cutting slit 30 into the connecting position 40, the connecting position 40 can be torn along the cutting slit 30, so that the tearing direction can be controlled conveniently, and the circuit board unit is further prevented from being damaged.

Further, in an embodiment, two ends of the cutting slit 30 respectively extend into the connecting position 40 from two opposite sides and have a predetermined distance. In this way, the cutting seam 30 extends along the edge of the first circuit board unit 10, and two ends of the cutting seam 30 respectively extend into the connecting positions 40 from two opposite sides, so that the tearing direction can be better controlled; and, there is a gap between the two ends of the cutting slit 30 to leave a section of connecting rib in the connecting position 40, which functions to connect the first circuit board unit 10 and the second circuit board unit 20.

It will be appreciated that one or more connection sites 40 may be provided between the first circuit board unit 10 and the second circuit board unit 20, and that depending on the length of the first circuit board unit 10, for example, one connection site 40 may be provided every 30 mm.

In an embodiment, the extending length of the connecting position 40 along the first circuit board unit 10 is set to be L, the length L1 of each end of the cutting slit 30 extending into the connecting position 40 is set to be 1/4L to 1/3L, and the distance between two ends of the cutting slit 30 in the connecting position 40 is set to be 1/3L to 1/2L. By controlling the extension length of the cutting seam 30 at the connecting position 40, the connecting ribs of the connecting position 40 can be retained, and the connecting position 40 can be torn by hand conveniently.

In one embodiment, the extension length L of the connection site 40 is 1mm-2mm, and the extension width of the connection site 40 is 0.5mm-1.0mm. The connection sites 40 correspond to the fenestrated areas of the cover layer 103, i.e., the fenestrated areas of the cover layer 103 have a length of 1mm to 2mm and a width of 0.5mm to 1.0mm. As shown in fig. 2 and 3, the extending length direction of the connecting position 40 is the X direction, and is consistent with the extending direction of the first circuit board unit 10; the extending width direction is the Y direction. For example, the connection site 40 has an extension length of 1.6mm and an extension width of 0.8mm; the length of each end of the cutting seam 30 extending into the connecting position 40 is 0.4mm, and the distance between the two ends of the cutting seam 30 is 0.8mm, and the cutting seam serves as a connecting rib.

In one embodiment, most of the connection sites 40 are located in the second circuit board unit 20, one end of the connection sites 40 is located in the first circuit board unit 10, and the extension width D of the connection sites 40 in the first circuit board unit 10 is 0.05mm-0.1mm. By arranging the connecting position 40 in the first circuit board unit 10, the cutting seam 30 can be prevented from deviating from the windowing region of the covering layer 103 after the laser cutting and the windowing alignment of the covering layer 103 are deviated.

In one embodiment, the connection sites 40 are fabricated by cutting windows into the cover layer 103 by flat-plate cutting, die-cutting or laser cutting.

Referring to fig. 4, in an embodiment of the invention, the cutting slit 30 is a laser cutting line and extends along the periphery of the first circuit board unit 10. Alternatively, the cutting slit 30 is a narrow slit cut by laser, and the width is almost zero, and only needs to be cut once along the outer shape of the first circuit board unit 10. In this way, when the connection site 40 is manually torn, stress is concentrated on the root of the cut line 30, and the connection site 40 is easily torn. In the prior art, it is generally required to provide a closed cutting path at the outer circumference of the first circuit board unit 10 to form a cutting groove having a certain width; this embodiment is through setting up laser cutting seam 30, need not to form closed cutting route, has reduced the at least half length in laser route compared with prior art, has reduced the time of laser cutting, has improved the production efficiency of laser cutting soft board appearance. It is understood that the cut 30 may be formed by die cutting or the like.

A second aspect of the present invention provides a method for manufacturing a circuit board, which is used for manufacturing the circuit board according to any one of the embodiments of the first aspect. Referring to fig. 1 to 5, the method for manufacturing the circuit board includes the following steps.

Step S1: the first circuit board unit 10 and the second circuit board unit 20 are manufactured, and the connection sites 40 are manufactured between the first circuit board unit 10 and the second circuit board unit 20.

In an embodiment, the first circuit board unit 10 is a flexible circuit board unit, and the second circuit board unit 20 is a frame unit, and when the first circuit board unit 10 is manufactured, the second circuit board unit 20 is manufactured.

The step of fabricating the first circuit board unit 10 may include: cutting, manufacturing a circuit layer on the flexible base material layer 101, and attaching the cover layer 103 on the flexible base material layer 101 and the circuit layer.

Optionally, the covering layer 103 is cut, then a window is formed in the area corresponding to the connection position 40, and then the windowed covering layer 103 is attached to the flexible base material layer 101 and the circuit layer. Optionally, the cover layer 103 is windowed by flat cutting, die cutting or laser cutting; optionally, the pads within the first circuit board unit 10 are simultaneously windowed. In the present embodiment, the connection site 40 is manufactured by windowing the covering layer 103, so that the thickness of the connection site 40 is smaller than the thickness of the first circuit board unit 10 and the second circuit board unit 20.

Step S2: the cutting slits 30 are formed along the edge of the first circuit board unit 10, and the cutting slits 30 are disposed at opposite sides of the connection sites 40.

Cutting a cutting seam 30 along the shape of the first circuit board unit 10 by using laser according to a preset path, so that two ends of the cutting seam 30 are respectively arranged at two opposite sides of the connecting position 40; optionally, the two ends of the cutting seam 30 are respectively extended into the connecting positions 40, and a section of the connecting position 40 is reserved as a connecting rib, so that the tearing direction can be controlled conveniently, and the connecting position 40 can be torn conveniently.

The circuit board convenient to divide can be manufactured by the manufacturing method, the tearing path can be controlled by manufacturing the connecting position 40 with the thickness smaller than that of the first circuit board unit 10 and the second circuit board unit 20, and the circuit board units are not easy to tear or damage; the manufacturing method has simple flow, does not need additional manufacturing process, can manufacture the connecting position 40 while windowing the covering layer 103, and has higher production efficiency and lower cost.

Referring to fig. 6 and 7, the method for manufacturing the 4-layer rigid-flex circuit board is described in detail below.

S11, a first circuit board unit 10, a hard board unit 50, and a second circuit board unit (not shown) are manufactured, and a connection site 40 between the first circuit board unit 10 and the second circuit board unit is manufactured.

The first circuit board unit 10 is a flexible circuit board unit and is located in the flexible board area a; the second circuit board unit is a frame unit. The substrate layer in the flexible circuit board unit is a flexible substrate layer, and the flexible circuit board unit is used for assembling, bending and mounting a finished product; the hard board circuit board unit 50 further includes a hard board base material layer 104 located in the hard board region B.

Specifically, the advanced inter-layer manufacturing process includes the following steps.

(1) And manufacturing L2 and L3 circuit layers. Specifically, cutting, performing a pattern etching process, manufacturing a circuit of the L2-L3 layer, performing browning, roughening the copper layer on the surface, simultaneously attaching the covering layer 103 to the flexible board area of the L2-L3 layer, pressing and fixing the covering layer 103, then curing, punching out the riveting hole of the board edge for soft and hard combined riveting, and performing press fitting after the surface of the flexible substrate is roughened by plasma.

The manufacturing of the covering layer 103 comprises material cutting and windowing, wherein the windowing comprises windowing at a pad in the flexible circuit board unit and windowing at a position corresponding to the connection position 40, and then attaching the flexible circuit board unit with the windowing to form the connection position 40.

(2) The L1, L4 wiring layers in the hard board circuit board unit 50 are fabricated. Specifically, two double-sided copper-clad plate core plates with consistent sizes are obtained by cutting materials, wherein each double-sided copper-clad plate core plate comprises a hard plate base material layer 104; and respectively etching copper on one side of the inner layer of the double-sided copper-clad plate core plate, punching a riveting hole, milling a blind slot, and turning to soft-hard combination pressing. The blind groove is positioned at the soft board area except the soft and hard junction.

(3) And (4) cutting the prepreg 105 without flowing, drilling riveting positioning holes and milling windows. The window milling is to correspondingly mill off the prepregs 105 in the flexible circuit board units, so that the flexible substrate layer 101 and the hard board substrate layer 104 are prevented from being adhered during lamination, and the cover cannot be uncovered subsequently; the windowing single edges at the two sides intersected with the hard board area are retracted 0.4mm-0.6mm inwards the hard board area, and the windowing single edges at the two sides of the soft board area are 1.0mm-2.0mm larger than the windowing single edge of the covering layer 103 at the connecting position 40, so that glue is prevented from flowing to the connecting position 40.

(4) And (4) sequentially stacking the plates, riveting and fixing the stacked plates, and feeding the riveted rigid-flexible printed circuit boards into a high-temperature press for pressing.

Then, an outer layer manufacturing process is carried out, which comprises the following steps: drilling, copper plate plating, outer layer circuit plating, pattern electroplating, etching, AOI, welding prevention, plate milling for the first time, depth control milling of an L1 surface, depth control milling of an L4 surface, cover uncovering, surface treatment, PI reinforcement pasting, laser soft plate appearance engraving, plate milling for the second time and electrical measurement.

The first plate milling is an area except for depth control milling in the milling unit, a through groove is milled, and all layers are milled through, so that subsequent uncovering is facilitated. The positions of the through grooves are two sides of the soft and hard intersection area, and the purpose is to form a closed path with a subsequent depth control mill so as to remove the rigid base material corresponding to the soft plate area. The through groove position does not include the peripheral position of the soft board area.

The depth-controlled milling of the L1 surface (or the L4 surface) is to control the depth to mill the position of the periphery of the shape of the soft and hard combined area and the L1 surface (or the L4) soft board area. The depth can be connected with the milling blind groove to ensure that the L1 surface (or L4) hard board layer is milled through, and meanwhile, the soft board layer below the hard board layer cannot be damaged.

And uncovering is to manually remove the hard board material corresponding to the soft board area after the first board milling and the depth control milling of the L1 surface and the L4 surface are completed.

Step S12, a dicing line 30 is formed along the edge of the first circuit board unit 10.

According to predetermine the route, use laser to cut out a cutting joint 30 along the appearance of first circuit board unit 10, make the relative both sides of hookup location 40 be located respectively at the both ends of cutting joint 30, extend into hookup location 40 respectively with the both ends of cutting joint 30 in, and reserve one section hookup location 40 and regard as the splice bar to do benefit to control and tear the direction, conveniently tear hookup location 40. The number of the connection sites 40 is determined according to the length of the flexible board area, and for example, one connection site 40 is arranged every 30mm or so.

The manufacturing method achieves the aim of manually tearing off the connecting position 40 by changing the manufacturing method of the connecting position 40 so as to complete the board splitting of the flexible circuit board unit; in addition, the hard board area can be divided by manually tearing the stamp hole connecting position 40, so that the circuit board manufactured by the manufacturing method is convenient to be divided manually after the SMT process, the circuit board is not required to be divided by adopting a laser cutting or die cutting mode, and the production efficiency and the production flexibility are improved; the circuit board 100 manufactured by the above manufacturing method is convenient to control the tearing path of the connecting position 40 when the circuit board is separated, and the circuit board unit is not easy to be damaged or torn.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the embodiments of the present invention, and they should be construed as being included therein.

Claims

1. A circuit board, characterized by: the circuit board comprises a first circuit board unit and a second circuit board unit which are connected; a cutting seam and a connecting position are arranged between the first circuit board unit and the second circuit board unit, the cutting seam extends along the edge of the first circuit board unit and is arranged on two opposite sides of the connecting position, the extending width of the connecting position is 0.5mm-1.0mm, the cutting seam is a laser cutting line, two ends of the cutting seam respectively extend into the connecting position from two opposite sides and have a preset distance so as to leave a section of connecting rib in the connecting position, and the first circuit board unit is connected with the second circuit board unit through the connecting position; the thickness of the connecting position is smaller than the thicknesses of the first circuit board unit and the second circuit board unit, and the thickness of the connecting position is thinner than the thickness of the area around the connecting position.

2. The circuit board of claim 1, wherein the first circuit board unit is a flexible circuit board unit, the second circuit board unit is a bezel unit, the first circuit board unit and the second circuit board unit each include a flexible substrate layer and a cover layer disposed over the flexible substrate layer, the first circuit board unit further includes a circuit layer disposed between the flexible substrate layer and the cover layer; the covering layer is provided with a window at the connecting position, and the connecting position is only provided with the flexible base material layer.

3. The circuit board of claim 1, wherein an extension length of the connection position along the first circuit board unit is set to be L, a length of each end of the cutting seam extending into the connection position is set to be 1/4L to 1/3L, and a distance between two ends of the cutting seam in the connection position is set to be 1/3L to 1/2L.

4. The circuit board of claim 3, wherein the connection sites extend from 1mm to 2mm in length.

5. The circuit board of claim 3, wherein one end of the connection site is located in the first circuit board unit, and the connection site has an extension width of 0.05mm to 0.1mm in the first circuit board unit.

6. The circuit board of claim 2, wherein the cover layer is windowed by flat-cut, die-cut, or laser-cut.

7. The circuit board of claim 2, further comprising a hard board unit, wherein a plurality of circular holes are sequentially arranged between the hard board unit and the adjacent second circuit board unit.

8. A method for manufacturing a circuit board, which is used for manufacturing the circuit board according to any one of claims 1 to 7, wherein the method for manufacturing the circuit board comprises the following steps:

utilize laser edge the edge preparation cutting joint of first circuit board unit, cutting joint locates the relative both sides of splice location, cutting joint's both ends extend to respectively from relative both sides just have predetermined interval in the splice location, with leave one section splice bar in the splice location.