Circuit board and manufacturing method thereof, and electronic device

Abstract

The present application discloses a circuit board and a manufacturing method thereof, and an electronic device. The circuit board includes a base layer, a first isolation layer, and a first conductive circuit layer, which are stacked in sequence; the base layer includes a first insulating layer formed of a first insulating material and a second insulating layer formed of a second insulating material, the flexibility of the first insulating layer is greater than the flexibility of the second insulating layer, and the second insulating layer is connected to opposite sides of the first insulating layer; wherein the projections of the first insulating layer and the second insulating layer on a plane perpendicular to the stacking direction of the base layer, the first isolation layer, and the first conductive circuit layer do not intersect; the projections of the first conductive circuit layer and the first insulating layer on a plane perpendicular to the stacking direction of the base layer, the first isolation layer, and the first conductive circuit layer do not intersect. The present application can form a circuit board that combines rigidity and flexibility through the above scheme, so that the circuit board can be installed in installation spaces of different shapes as needed.

Description

Technical Field

[0001] The present application relates to the technical field of printed circuit boards, and in particular to a circuit board and a manufacturing method thereof, and an electronic device. Background Art

[0002] With the continuous advancement of communication technology, the requirements for signal transmission speed are getting higher and higher. At the same time, since electronic products usually need to be compact in structure, the circuit boards of electronic products need to adopt rigid-flexible circuit boards. By bending the flexible area of ​​the circuit board, the entire circuit board can be placed inside the electronic product. Existing rigid-flexible circuit boards are generally formed by connecting a rigid printed circuit board (PCB) and a flexible flexible circuit board (FPC) through male and female connectors.

[0003] However, the rigid-flexible circuit board obtained by this solution is usually complex in structure and requires additional installation operations. At the same time, the connection is formed by using male and female connectors, which may cause damage to the connectors during long-term use, thereby causing the printed circuit board and the flexible circuit board to be unable to be electrically connected normally. Summary of the invention

[0004] The present application provides a circuit board and a manufacturing method thereof, and an electronic device to solve the problem in the prior art that a rigid-flexible connection is formed by using male and female connectors, which may cause connector damage during long-term use, thereby causing the printed circuit board and the flexible circuit board to be unable to be electrically connected normally.

[0005] In order to solve the above technical problems, a technical solution adopted in the present application is: providing a circuit board, the circuit board comprising a first isolation layer, a base layer and a second isolation layer stacked in sequence;

[0006] The base layer includes a first insulating layer formed by a first insulating material and a second insulating layer formed by a second insulating material, wherein the second insulating layer is connected to opposite sides of the first insulating layer, wherein the flexibility of the first insulating layer is greater than the flexibility of the second insulating layer, and the first insulating layer is used to form a bendable area of ​​the circuit board.

[0007] In one embodiment,

[0008] A first conductive circuit layer is further disposed between the first isolation layer and the second isolation layer, the first conductive circuit layer is attached to a surface of one side of the first isolation layer or the second isolation layer, and the first insulating layer and the second insulating layer are filled between the first isolation layer and the second isolation layer and surround the first conductive circuit layer;

[0009] The first conductive circuit layer includes a first conductive circuit and a second conductive circuit that are electrically connected. The first conductive circuit is surrounded by the first insulating layer, and the second conductive circuit is surrounded by the second insulating layer.

[0010] In one embodiment,

[0011] A first shielding layer and a third isolation layer are also provided on the sides of the first isolation layer and the second isolation layer away from each other;

[0012] The third isolation layer is disposed on a side of the first shielding layer facing away from the first isolation layer and the second isolation layer.

[0013] In one embodiment,

[0014] The third isolation layer comprises a covering film and a third insulating layer, wherein the covering film and the third insulating layer are both attached to a surface of the first shielding layer that is opposite to the first isolation layer and the second isolation layer, and the covering film and the third insulating layer have the same thickness;

[0015] The projections of the third insulating layer and the second insulating layer on a plane perpendicular to the stacking direction of the base layer, the first isolation layer and the first conductive circuit layer at least partially overlap; the projections of the covering film and the first insulating layer on a plane perpendicular to the stacking direction of the base layer, the first isolation layer and the first conductive circuit layer at least partially overlap.

[0016] In one embodiment,

[0017] A second conductive circuit layer is further disposed on a side of the third insulating layer facing away from the first isolation layer and the second isolation layer. The second conductive circuit layer is electrically connected to the first conductive circuit layer via a conductive through hole, and the conductive through hole does not intersect with the first insulating layer.

[0018] In one embodiment,

[0019] The dielectric constants of the first insulating material and the second insulating material are both less than 3.5 and the dielectric losses are both less than 0.002.

[0020] In one embodiment,

[0021] The first insulating material includes insulating glue, and the first insulating layer is formed by curing the insulating glue.

[0022] In order to solve the above technical problems, another technical solution adopted by the present application is: to provide a method for manufacturing a circuit board, the method for manufacturing a circuit board comprising:

[0023] preparing a core board, the core board comprising an isolation layer and conductive metal layers disposed on opposite sides of the isolation layer;

[0024] Forming a preset first conductive circuit layer on the conductive metal layer on one side of the first isolation layer of the first core board, wherein the first conductive circuit layer includes a first conductive circuit and a second conductive circuit that are electrically connected, and the second conductive circuit is arranged on two opposite sides of the first conductive circuit;

[0025] A first insulating material is covered on a first preset area of ​​the first core plate from one side of the first conductive circuit to form a first insulating layer, and the first insulating layer surrounds the first conductive circuit; a second insulating material is covered on other areas of the first core plate outside the first preset area from one side of the first conductive circuit to form a second insulating layer, and the second insulating layer surrounds the second conductive circuit; wherein the surfaces of the first insulating layer and the second insulating layer facing away from the first isolation layer are located on the same plane, and the flexibility of the first insulating layer is greater than the flexibility of the second insulating layer;

[0026] The conductive metal layer on one side of the second isolation layer of the second core board is removed, and the second isolation layer exposed after the conductive metal layer is removed is bonded to the first insulating layer and the surface of the second insulating layer on the side facing away from the first isolation layer.

[0027] In one embodiment, the method for manufacturing the circuit board further includes:

[0028] A third insulating layer is provided on at least one side of the first core plate and the second core plate facing away from each other;

[0029] A third core board is arranged on a side of the third isolation layer facing away from the first core board and the second core board, wherein the third core board includes a second conductive circuit layer;

[0030] A conductive through hole is opened on a side of the third core board facing away from the first core board and the second core board, and the conductive through hole is used to electrically connect the second conductive line with the second conductive line layer, wherein the conductive through hole does not intersect with the first insulating layer.

[0031] In order to solve the above technical problems, another technical solution adopted in the present application is: to provide an electronic device, which includes the circuit board as described above, or includes a circuit board manufactured by the manufacturing method of the circuit board as described above.

[0032] The beneficial effects of the present application are as follows: Different from the prior art, the present application provides a circuit board and a manufacturing method thereof, and an electronic device. By using a first insulating material with better flexibility to form a base layer of a bendable area, the formed circuit board can change the spatial shape of the entire circuit board through the bending of its bendable area, so that the circuit board can be installed in installation spaces of different shapes as needed. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a structural schematic diagram of a circuit board provided in an embodiment of the present application;

[0034] Figure 2 is a schematic diagram of the structure of another circuit board provided in an embodiment of the present application;

[0035] Figure 3 It is a schematic diagram of a process of manufacturing a circuit board provided in an embodiment of the present application;

[0036] Figure 4 It is a flow chart of another method for manufacturing a circuit board provided in an embodiment of the present application. DETAILED DESCRIPTION

[0037] The present application is described in detail below with reference to the accompanying drawings and embodiments.

[0038] See also Figure 1 The circuit board 10 includes a first isolation layer 110, a base layer 120 and a second isolation layer 130 which are stacked in sequence;

[0039] The base layer 120 includes a first insulating layer 121 formed of a first insulating material and a second insulating layer 122 formed of a second insulating material, wherein the second insulating layer 122 is connected to opposite sides of the first insulating layer 121 , wherein the flexibility of the first insulating layer 121 is greater than that of the second insulating layer 122 .

[0040] Among them, a first conductive circuit layer 140 is also arranged between the first isolation layer 110 and the second isolation layer 130. The first conductive circuit layer 140 is attached to the surface of one side of the first isolation layer 110 or the second isolation layer 130. The first insulating layer 121 and the second insulating layer 122 are filled between the first isolation layer 110 and the second isolation layer 130 and surround the first conductive circuit layer 140.

[0041] The first conductive circuit layer 140 includes a first conductive circuit 141 and a second conductive circuit 142 which are electrically connected. The first conductive circuit 141 is surrounded by the first insulating layer 121 , and the second conductive circuit 142 is surrounded by the second insulating layer 122 .

[0042] In this embodiment, the first conductive circuit layer 140 may further include a third conductive circuit (not shown in the figure), and the two ends of the third conductive circuit may be respectively connected to the first conductive circuit 141 and the second conductive circuit 142, so that the first conductive circuit 141 and the second conductive circuit 142 are electrically connected through the third conductive circuit.

[0043] In this embodiment, the number of the first conductive circuit 141 and the number of the second conductive circuit 142 are both at least one; the second conductive circuit 142 is arranged on both sides of the first conductive circuit 141, and the first conductive circuit 141 and the second conductive circuits 142 arranged on both sides thereof can be electrically connected by the third conductive circuit as described above, so that the first conductive circuit layer 140 as a whole can form a conductive circuit for signal transmission.

[0044] In this embodiment, the flexibility of the first insulating layer 121 is greater than the flexibility of the second insulating layer 122, so the area where the first insulating layer 121 is located can be used to form a bendable area of ​​the circuit board 10. When the installation space of the circuit board 10 is insufficient, the area where the first insulating layer 121 is located can be bent to change the overall shape of the circuit board 10, so that the circuit board 10 can be installed in the space. At the same time, the second insulating layer 122 on the opposite sides of the first insulating layer 121 can be used to form a non-bending area of ​​the circuit board 10, wherein electronic components or other conductive circuits (not shown in the figure) can be arranged in the non-bending area, so that the entire circuit board 10 can form a preset functional circuit.

[0045] In this embodiment, the second insulating layer 122 is connected to the opposite sides of the first insulating layer 121, that is, a second insulating layer 122 can be provided on the opposite sides of the first insulating layer 121, and the two second insulating layers 122 on the opposite sides of the first insulating layer 121 can correspond to the non-bending areas of the circuit board 10. That is, the circuit board 10 in the present application is formed by a bendable area and two non-bending areas connecting the opposite sides of the bendable area.

[0046] Among them, the two non-bending areas can also be used to set other conductor circuit layers, or to set electronic components. Among them, the other conductor circuit layers or electronic components on the two non-bending areas can be electrically connected to the first conductive circuit 141 and the second conductive circuit 142 respectively, so that the non-bending areas on both sides of the entire circuit board 10 can be electrically connected through the first conductive circuit layer 140.

[0047] Furthermore, in this embodiment, both the first insulating material and the second insulating material may be high-speed low-loss materials, wherein the high-speed low-loss materials here may refer to materials with a dielectric constant (Dk) < 3.5 and a dielectric loss (Df) < 0.002. For example, the first insulating material may include insulating glue, such as high-speed insulating glue, and the first insulating layer 121 may be formed by curing the insulating glue; the second insulating material may include materials with good ion migration resistance such as PP (polypropylene) material.

[0048] Therefore, the first conductive circuit layer 140 in this embodiment can be used to transmit high-frequency signals in high-speed circuits. Among them, when the frequency of the digital logic circuit reaches or exceeds 45MHZ-50MHZ, and the circuit or signal operating at this frequency accounts for a certain proportion of the entire circuit system, such as more than 1 / 3, then the circuit is called a high-speed circuit and the related signal is a high-speed signal.

[0049] Therefore, in order to prevent the high-frequency signal from being lost due to external interference during transmission, a shielding layer may be provided inside the circuit board 10 .

[0050] See also Figure 2 A first shielding layer 150 and a third isolation layer 160 are also provided on the side of the first isolation layer 110 and the second isolation layer 130 away from each other; wherein the third isolation layer 160 is provided on the side of the first shielding layer 150 facing away from the first isolation layer 110 and the second isolation layer 130 .

[0051] In this embodiment, a first shielding layer 150 and a third isolation layer 160 are provided on the side of the first isolation layer 110 facing away from the second isolation layer 130; similarly, a first shielding layer 150 and a third isolation layer 160 are also provided on the side of the second isolation layer 130 facing away from the first isolation layer 110. The first shielding layer 150 can be made of conductive metal.

[0052] Take the first shielding layer 150 and the third isolation layer 160 on the side of the first isolation layer 110 facing away from the second isolation layer 130 as an example. The first shielding layer 150 is disposed on the surface of the first isolation layer 110 facing away from the second isolation layer 130, and the third isolation layer 160 is disposed on the surface of the first shielding layer 150 facing away from the first isolation layer 110.

[0053] Among them, the third isolation layer 160 may include a covering film 161 and a third insulating layer 162. In this embodiment, the opposite sides of the covering film 161 may be connected to a third insulating layer 162 respectively, and the covering film 161 and the third insulating layer 162 are both attached to the surface of the first shielding layer 150 facing away from the first isolation layer 110, and the thickness of the covering film 161 and the third insulating layer 162 are the same.

[0054] In this embodiment, the cover film 161 can be arranged in the bendable area as described above, and the cover film 161 can also be made of insulating material, so as to protect the first shielding layer 150. The third insulating layer 162 can be arranged in the non-bending area corresponding to the second insulating layer. The third insulating layer 162 can be formed of the same material as the second insulating material.

[0055] Furthermore, as mentioned above, the two non-bending areas in the circuit board 10 in this embodiment can also be used to set other conductive circuit layers or set electronic components.

[0056] Please read further Figure 2 Among them, the other conductive line layer may be the second conductive line layer 170 .

[0057] The second conductive line layer 170 is disposed on a side of the third insulating layer 162 facing away from the first isolation layer 110 and the second isolation layer 130 .

[0058] In this embodiment, a third isolation layer 160 is disposed on the side of the first isolation layer 110 and the second isolation layer 130 facing away from each other. The third insulating layer 162 of each third isolation layer 160 is disposed on the opposite sides of its cover film 1611, that is, the second wire layer 170 can be disposed on the side of the third insulating layer 162 of each third isolation layer 160 facing away from the first isolation layer 110 and the second isolation layer 130.

[0059] Please read further Figure 2 In this embodiment, a second shielding layer 180 may be disposed between the second conductor layer 170 and the third insulating layer 162 , wherein the second shielding layer 180 may be formed of a conductive metal. Therefore, a fourth isolation layer 190 may be disposed between the second conductor layer 170 and the second shielding layer 180 .

[0060] That is to say, the second shielding layer 180 can be arranged on the surface of the third insulating layer 162 facing away from the first isolation layer 110, the fourth isolation layer 190 is arranged on the surface of the second shielding layer 180 facing away from the third insulating layer 162, and the second wire layer 170 is arranged on the surface of the fourth isolation layer 190 facing away from the second shielding layer 180.

[0061] Therefore, the third insulating layer 162 , the second shielding layer 180 , the fourth isolation layer 190 and the second wire layer 170 are stacked in sequence.

[0062] In this embodiment, on a plane perpendicular to the stacking direction of the third insulating layer 162, the second shielding layer 180, the fourth isolation layer 190 and the second conductive wire layer 170, the projections of the second shielding layer 180, the fourth isolation layer 190 and the second conductive wire layer 170 overlap with the projection of the third insulating layer 162, and the projections of the second shielding layer 180, the fourth isolation layer 190 and the second conductive wire layer 170 do not exceed the range of the projection of the third insulating layer 162.

[0063] Furthermore, the second conductive wire layer 170 may be electrically connected to the first conductive circuit layer 140 through the conductive via 101. The conductive via 101 may sequentially penetrate the second conductive wire layer 170, the fourth isolation layer 190, the second shielding layer 180, the third insulating layer 162, the first shielding layer 150 and the first isolation layer 110 (or the second isolation layer 130) and then be electrically connected to the first conductive circuit layer 140.

[0064] The conductive through hole 101 does not electrically connect to the first shielding layer 150 and the second shielding layer 180 at a position penetrating the first shielding layer 150 and the second shielding layer 180 .

[0065] In this embodiment, the conductive via 101 does not pass through the first insulating layer 121 .

[0066] Furthermore, in other embodiments, the second conductor layer 170 may also be directly disposed on the surface of the third insulating layer 162 facing away from the first isolation layer 110 , that is, the second shielding layer 180 and the fourth isolation layer 190 are not disposed.

[0067] See also Figure 3 The present application also provides a method for manufacturing a circuit board. The method is used to manufacture the circuit board 10 as described above.

[0068] The manufacturing method of the circuit board specifically includes the following steps:

[0069] S110: preparing a core board, wherein the core board includes an isolation layer and conductive metal layers arranged on opposite sides of the isolation layer.

[0070] In this embodiment, the core board includes an isolation layer and a conductive metal layer disposed on opposite sides of the isolation layer. The isolation layer of the core board can be made of PP material and PI (polyimide) material, wherein the core board isolation layer can be formed of the same material as the first isolation layer 110 and the second isolation layer 130 described above. The conductive metal layer can be made of a conductive metal film, such as copper foil.

[0071] The core board in this step can be formed by hot-pressing a conductive metal film onto opposite sides of the isolation layer.

[0072] S120: forming a preset first conductive circuit layer on the conductive metal layer on one side of the first isolation layer of the first core board, wherein the first conductive circuit layer includes a first conductive circuit and a second conductive circuit that are electrically connected, and the second conductive circuit is arranged on opposite sides of the first conductive circuit.

[0073] A core board is taken out from the prepared core boards, and the core board can be referred to as a first core board. The isolation layer of the first core board can be referred to as a first isolation layer. The conductive metal layer on one side of the first isolation layer forms a preset first conductive circuit layer.

[0074] The first conductive circuit layer may include electrically connected first and second conductive circuits, the number of the second conductive circuits may be two, and the two second conductive circuits are respectively arranged on opposite sides of the first conductive circuit, and the two second conductive circuits may be electrically connected to the first conductive circuit.

[0075] In this step, the conductive metal layer on one side of the first isolation layer can be etched through a photodevelopment process to form the desired first conductive circuit layer, wherein the first conductive circuit layer in this step can be the same as the first conductive circuit layer 140 described above, and similarly, the first isolation layer in this step can also be the same as the first isolation layer 110 described above.

[0076] S130: Cover the first insulating material from one side of the first conductive circuit on the first preset area of ​​the first core board to form a first insulating layer, and the first insulating layer surrounds the first conductive circuit; cover the second insulating material from one side of the first conductive circuit on other areas outside the first preset area of ​​the first core board to form a second insulating layer, and the second insulating layer surrounds the second conductive circuit; wherein the surfaces of the first insulating layer and the second insulating layer facing away from the first isolation layer are located on the same plane, and the flexibility of the first insulating layer is greater than the flexibility of the second insulating layer.

[0077] After the first conductive circuit layer is formed on the first core board, the first insulating material is covered on the first preset area of ​​the first core board from one side of the first conductive circuit to form a first insulating layer, so that the first insulating material and the first isolation layer can cover the first conductive circuit. The first insulating layer in this step can be the same as the first insulating layer 121 described above.

[0078] After the first insulating layer is set, the second insulating material is then covered from one side of the first conductive circuit to other areas outside the first preset area of ​​the first core board, thereby forming a second insulating layer. The second insulating layer formed in this step can form a containing space with the first isolation layer, thereby covering the second conductive circuit. Similarly, the second insulating layer in this step can be the same as the second insulating layer 122 described above.

[0079] In this step, the surfaces of the first insulating layer and the second insulating layer facing away from the first isolation layer are located on the same plane, that is, the first insulating layer and the second insulating layer have the same thickness. The first insulating layer and the second insulating layer can form the base layer 120 as described above.

[0080] Moreover, the flexibility of the first insulating layer is greater than that of the second insulating layer. Therefore, the area corresponding to the first insulating layer can be set as a bendable area, and the area corresponding to the second insulating layer can be set as a non-bending area.

[0081] S140: removing the conductive metal layer on one side of the second isolation layer of the second core board, and attaching the second isolation layer exposed after removing the conductive metal layer to the first insulation layer and the surface of the second insulation layer facing away from the first isolation layer.

[0082] Another core board is taken out from the prepared core boards, and the core board can be referred to as a second core board. The isolation layer of the second core board can be referred to as a second isolation layer, and the second isolation layer in this step can be the same as the second isolation layer 130 described above, which will not be described in detail here.

[0083] The conductive metal layer on one side of the second isolation layer of the second core plate is removed, so that the surface of the second isolation layer covered by the conductive metal layer is exposed. Then, the surface of the second core plate on the side where the conductive metal layer is removed is attached to the surface of the first insulation layer and the second insulation layer facing away from the first isolation layer, so that the second core plate is fixedly connected to the first core plate through the first insulation layer and the second insulation layer.

[0084] In this step, the first isolation layer of the first core board and the second isolation layer of the second core board are away from the conductive metal layer on one side of each other, so the first shielding layer 150 as described above can be formed.

[0085] In this step, the first core board, the base layer (formed by the first insulating layer and the second insulating layer) and the second core board can be fixed and bonded by heat pressing to form a circuit board.

[0086] For further information, see Figure 4 The manufacturing method of the circuit board in this embodiment also includes the steps S110 to S140 as described above. The difference between the manufacturing method of the circuit board in this embodiment and the manufacturing method of the circuit board described above is that after step S140, the specific steps of the manufacturing method of the circuit board in this embodiment also include:

[0087] S150: Disposing a third isolation layer on at least one side of the first core plate and the second core plate facing away from each other.

[0088] The third isolation layer in this step is the same as the third isolation layer 160 described above, and both include a covering film and a third insulating layer. The covering film and the third insulating layer in this step are the same as the covering film 161 and the third insulating layer 162 described above.

[0089] In this step, a third isolation layer may be provided on the side of the first core plate or the second core plate facing away from each other, or a third isolation layer may be provided on the side of the first core plate and the second core plate facing away from each other.

[0090] Here, an example is taken in which the third isolation layer is arranged on the side of the first core plate facing away from the second core plate.

[0091] First, a covering film can be covered on the conductive metal layer on the side of the first isolation layer facing away from the second isolation layer. Moreover, the covering film can be located in the bendable area as described above. Then, a third insulating layer is arranged in the non-bending areas on opposite sides of the covering film. The third insulating layer and the covering film have the same thickness, and the third insulating layer and the covering film are both arranged on the surface of one side of the same conductive metal layer.

[0092] S160: Arrange a third core board on a side of the third isolation layer facing away from the first core board and the second core board, wherein the third core board includes a second conductive circuit layer.

[0093] In this step, a third core plate is arranged on the side of the third isolation layer facing away from the first core plate and the second core plate. The third core plate is arranged on the side of the third insulating layer of the third isolation layer facing away from the first core plate and the second core plate. Moreover, the third core plate may not exceed the range of the non-bending area.

[0094] The third core board in this step may also include an isolation layer and a conductive metal layer arranged on both sides of the isolation layer. Among them, the isolation layer of the third core board may be the same as the fourth isolation layer 190 described above. And the two conductive metal layers on the opposite sides of the isolation layer may form a second conductive circuit layer and a second shielding layer, respectively. Similarly, the second conductive circuit layer and the second shielding layer in this step are the same as the second conductive circuit layer 170 and the second shielding layer 180 described above, and are not described in detail here.

[0095] Likewise, in this step, the third core board can also be attached to the surface of the third insulating layer on the side facing away from the first core board and the second core board by means of heat pressing.

[0096] S170: Opening a conductive through hole from a side of the third core board facing away from the first core board and the second core board, wherein the conductive through hole is used to connect the second conductive circuit to the second conductive circuit layer, wherein the conductive through hole does not intersect with the first insulating layer.

[0097] After completing step S160, a conductive through hole can be opened from the side of the third core board facing away from the first core board and the second core board, and the conductive through hole is used to connect the second conductive circuit to the second conductive circuit layer, wherein the conductive through hole does not intersect the first insulating layer.

[0098] The conductive through hole may be the same as the conductive through hole 101 described above, and will not be described in detail here.

[0099] Furthermore, the present application also provides an electronic device, wherein the electronic device may include the circuit board 10 as described above, which will not be described in detail herein. The electronic device may include a high-frequency signal transmission device.

[0100] In summary, the present application provides a circuit board and a manufacturing method thereof, and an electronic device. By using a first insulating material with better flexibility to form a base layer of a bendable area, the formed circuit board can change the spatial shape of the entire circuit board through the bending of its bendable area, so that the circuit board can be installed in installation spaces of different shapes as needed.

[0101] The above description is only an implementation method of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A manufacturing method of a circuit board, characterized in that, the manufacturing method includes: preparing a plurality of core boards, the core boards including an isolation layer and conductive metal layers provided on opposite sides of the isolation layer; the plurality of core boards including a first core board and a second core board; forming a preset first conductive circuit layer on the conductive metal layer on one side of the first isolation layer of the first core board, the first conductive circuit layer including an electrically connected first conductive circuit and a second conductive circuit, the second conductive circuit being provided on opposite sides of the first conductive circuit; covering the first core board with a first insulating material from one side of the first conductive circuit in a first preset area of the first core board, thereby forming a first insulating layer, the first insulating layer surrounding the first conductive circuit; covering the first core board with a second insulating material from one side of the first conductive circuit in other areas outside the first preset area of the first core board, thereby forming a second insulating layer, the second insulating layer surrounding the second conductive circuit; wherein, the surfaces of the first insulating layer and the second insulating layer on the side opposite to the first isolation layer are located on the same plane, and the flexibility of the first insulating layer is greater than that of the second insulating layer; removing the conductive metal layer on one side of the second isolation layer of the second core board, and attaching the exposed second isolation layer after removing the conductive metal layer to the surfaces of the first insulating layer and the second insulating layer on the side opposite to the first isolation layer.

2. The manufacturing method of the circuit board according to claim 1, characterized in that, the plurality of core boards further include a third core board, and the manufacturing method further includes: providing a third isolation layer on at least one side of the first core board and the second core board facing away from each other; providing a third core board on the side of the third isolation layer facing away from the first core board and the second core board, the third core board including a second conductive circuit layer; drilling a conductive through hole from the side of the third core board facing away from the first core board and the second core board, the conductive through hole being used to electrically connect the second conductive circuit and the second conductive circuit layer, wherein the conductive through hole does not intersect with the first insulating layer.

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