Hollow printed circuit board and method for manufacturing the same

Abstract

The application discloses a kind of hollow type printed circuit board and its preparation method, wherein, the preparation method of hollow type printed circuit board includes: obtaining the carrying plate with target conductive layer on one side, forming hollow circuit on the preset area of target conductive layer;First release protection layer is covered on the side of the hollow circuit of preset area away from the carrying plate;At least one layer processing is carried out on the side of target conductive layer away from the carrying plate, and the carrying plate is removed to obtain the processing plate part;Based on the position of preset area, the processing plate part is controlled from the side of processing plate part away from target conductive layer Deep processing is carried out until the first release protection layer is exposed;Remove the first release protection layer to obtain the hollow type printed circuit board.By the above manner, the application can reduce the difficulty of depth control in the preparation process of hollow type printed circuit board, and then solve the problem of easy damage of hollow circuit and high requirement of depth control.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of printed circuit boards, and particularly relates to a hollow printed circuit board and a preparation method thereof. BACKGROUND

[0002] In a special type of printed circuit board, the conductor lines in the designated area need to be processed by "hollowing": the insulating medium layer between the conductor lines and the medium layer adhered on the hollow conductor lines need to be removed, that is, the hollow area only retains the conductor lines without any insulating medium layer.

[0003] The current solution is as follows: first, the conductor lines in the area to be "hollowed" are manufactured, then the insulating medium material between the conductor lines is removed by depth control, and finally, the medium layer adhered on the conductor lines is removed by a drill cleaning process.

[0004] However, the above method has the problems of easy damage to the conductor lines in the hollow area and high requirement for depth control, and if there is residual depth control, it will affect the stability of the board. SUMMARY

[0005] The application provides a hollow printed circuit board and a preparation method thereof to solve the problems mentioned in the background.

[0006] To solve the above technical problems, the application provides a preparation method of a hollow printed circuit board, which comprises the following steps: obtaining a carrier plate with a target conductive layer attached on one side, preparing a hollow line on a preset area of the target conductive layer; covering a first release protection layer on the side of the hollow line in the preset area away from the carrier plate; performing at least one layer increasing treatment on the side of the target conductive layer away from the carrier plate, and removing the carrier plate to obtain a processed board; based on the position of the preset area, performing a depth control treatment on the processed board from the side of the processed board away from the target conductive layer until the first release protection layer is exposed; and removing the first release protection layer to obtain a hollow printed circuit board.

[0007] In the application, a positioning mark is arranged on the target conductive layer; the step of preparing a hollow line on the preset area of the target conductive layer comprises the following steps: determining the position information of the preset area by using the positioning mark; and performing a depth control treatment on the preset area based on the position information to penetrate the target conductive layer to prepare the hollow line.

[0008] In the application, the step of preparing a hollow line on the preset area of the target conductive layer comprises the following steps: sequentially performing film pasting, exposure development, etching and film removal on the side of the preset area of the target conductive layer away from the carrier plate to prepare the hollow line.

[0009] The first release protective layer comprises a peelable ink; the step of covering the first release protective layer on the side of the hollowed-out circuit in the preset area away from the carrier plate comprises: attaching a second release protective layer on the side of the target conductive layer away from the carrier plate, and exposing the preset area; printing the peelable ink into the preset area until the peelable ink covers the surface of the second release protective layer and is solidified; wherein the peelable ink fills the gap between the hollowed-out circuits and covers the side of the hollowed-out circuit away from the carrier plate; and removing the second release protective layer.

[0010] The first release protective layer comprises a dry film; the step of covering the first release protective layer on the side of the hollowed-out circuit in the preset area away from the carrier plate comprises: attaching the dry film in the preset area to cover the side of the hollowed-out circuit away from the carrier plate.

[0011] The step of removing the carrier plate to obtain the processed plate part comprises: sequentially placing a first dielectric layer, a second dielectric layer and a conductive layer on the side of the target conductive layer away from the carrier plate, and pressing; removing the carrier plate; and sequentially performing film attaching, exposure and development, etching, film removing on the conductive layer and the target conductive layer to form a conductive circuit to obtain the processed plate part; wherein the first dielectric layer is hollowed out at a position corresponding to the preset area.

[0012] The step of sequentially performing film attaching, exposure and development, etching, film removing on the conductive layer and the target conductive layer to form a conductive circuit to obtain the processed plate part further comprises: providing a solder resist layer on opposite sides of the processed plate part; wherein the projection of the solder resist layer on the target conductive layer does not overlap with the preset area.

[0013] The step of removing the first release protective layer to obtain the hollowed-out printed circuit board comprises: etching the first release protective layer by alkaline medicine to remove the first release protective layer to obtain the hollowed-out printed circuit board.

[0014] The depth control process comprises: UV laser cutting, CO2 laser cutting, water jet cutting or mechanical depth control.

[0015] To solve the above technical problems, the present application provides a hollowed-out printed circuit board, which is prepared by the preparation method of the hollowed-out printed circuit board according to any one of the above.

[0016] To solve the above technical problems, the preparation method of the hollow printed circuit board provided by the present application forms a hollow circuit on the preset area of the target conductive layer on the carrier plate, covers the first release protective layer on the side of the hollow circuit in the preset area away from the carrier plate, and then exposes the first release protective layer by controlling the depth after the circuit board build-up is completed, and then removes the first release protective layer by using the release characteristics, so as to obtain the hollow printed circuit board. Thus, the step of filling the hollow circuit with a dielectric layer and directly controlling the depth of the hollow circuit is avoided. During the depth control, only the first release protective layer needs to be controlled, which reduces the difficulty of depth control, solves the problems of easy damage of the hollow circuit and high requirement of depth control, reduces the risk of board preparation, improves the accuracy of the depth-controlled circuit, and even if there is residual depth control, the residual can be removed with the removal of the first release protective layer, thereby ensuring the stability of the board. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 FIG. 1 is a flowchart of an embodiment of the preparation method of the hollow printed circuit board provided by the present application;

[0018] Figure 2 FIG. 2 is a flowchart of another embodiment of the preparation method of the hollow printed circuit board provided by the present application;

[0019] Figure 3 FIG. 3 is a structure diagram of the hollow printed circuit board provided by the present application; Figure 2 FIG. 4 is a structure diagram of the preparation process of the hollow printed circuit board in the embodiment;

[0020] Figure 4 FIG. 5 is a structure diagram of an embodiment of the hollow printed circuit board provided by the present application. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0022] It should be noted that if the present application involves directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative positional relationship, movement condition, etc. between the components in a certain posture (as shown in the drawings). If the certain posture changes, the directional indications will also change accordingly.

[0023] In addition, if the description of "first", "second" and the like is involved in the embodiments of the present application, the description of "first", "second" and the like is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can be explicitly or implicitly included at least one of the features. In addition, the technical solutions of various embodiments can be combined with each other, but it must be based on the realization of ordinary skilled in the art, when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, nor in the protection scope required by the present application.

[0024] Please refer to Figure 1 , Figure 1 is a flowchart of an embodiment of the preparation method of the present application.

[0025] Step S11: a carrier plate with a target conductive layer attached on one side is obtained, and a hollow line is prepared on the preset area of the target conductive layer.

[0026] The target conductive layer is the conductive layer on which the hollow line needs to be made. The target conductive layer is arranged on one side of the carrier plate, wherein the length and width dimensions of the target conductive layer can be equal to or greater than the length and width dimensions of the carrier plate. Specifically, the length and width dimensions of the carrier plate need to meet the condition of completely coinciding with the preset area, so as to facilitate the subsequent setting of the first release protective layer on the preset area.

[0027] The carrier plate can include any rigid material to provide sufficient support for the preparation of the printed circuit board.

[0028] In a specific application scenario, the carrier plate can be a release carrier plate, and the target conductive layer is fixedly arranged on one side of the carrier plate, and then the release carrier plate is peeled off. In another specific application scenario, the target conductive layer can be placed on one side of the carrier plate, which is convenient for the removal of the carrier plate later.

[0029] A hollow line is prepared on the preset area of the target conductive layer. The preset area is the position corresponding to the hollow line on the printed circuit board.

[0030] In a specific application scenario, the hollow line can be prepared on the preset area of the target conductive layer by mechanical depth control, laser depth control or water jet cutting and other physical methods. In another specific application scenario, the hollow line can also be prepared on the preset area of the target conductive layer by chemical methods such as chemical etching. The specific preparation method is not limited here.

[0031] Step S12: the first release protective layer is covered on the side of the hollow line of the preset area away from the carrier plate.

[0032] The first release protective layer can include a dry film, a curable liquid, or a release plate piece, etc.

[0033] In one specific application scenario, the dry film type protective layer or the release plate piece type protective layer can be directly covered on the side of the hollowed-out circuit in the preset area away from the carrier plate. In another specific application scenario, the curable liquid can be filled into the preset area until it is cured after covering the side of the hollowed-out circuit in the preset area away from the carrier plate. The specific way of covering the first release protective layer is not limited here. Preferably, the curable liquid can coat the hollowed-out circuit to protect it in all directions.

[0034] Step S13: At least one layering treatment is performed on the side of the target conductive layer away from the carrier plate, and the carrier plate is removed to obtain a processed plate piece.

[0035] The layering treatment can be to sequentially place a dielectric layer and a conductive layer on the side of the target conductive layer away from the carrier plate, and then perform compression; then the conductive circuit and the conductive hole are prepared on the conductive layer on the plate piece after compression.

[0036] The number of layering treatments can be set based on the number of layers required for the printed circuit board, for example, it can be 1, 2, 3, 5, 10 times, etc., which is not limited here.

[0037] After the layering treatment is completed, the carrier plate is removed to obtain a processed plate piece.

[0038] After the carrier plate is removed, the side of the hollowed-out circuit originally attached to the carrier plate is exposed.

[0039] Step S14: Based on the position of the preset area, a depth control treatment is performed on the processed plate piece from the side of the processed plate piece away from the target conductive layer until the first release protective layer is exposed.

[0040] The depth control treatment is performed on the processed plate piece to remove the dielectric layer and the conductive layer on the first release protective layer to expose the first release protective layer.

[0041] The depth control can include physical depth control methods such as UV laser cutting, CO2 laser cutting, water jet cutting, or mechanical depth control, etc.

[0042] The depth control of this step only needs to expose the first release protective layer, and does not need to be finely controlled along the edge of the hollowed-out circuit, thereby reducing the difficulty and time of depth control and improving the accuracy of the depth control circuit.

[0043] Step S15: The first release protective layer is removed to obtain a hollowed-out printed circuit board.

[0044] Since the first release protection layer is a release piece such as a dry film, a curable liquid, or a release plate piece, after the first release protection layer is exposed from the side of the processed plate piece away from the target conductive layer, the first release protection layer can be naturally removed without residue by using its release characteristics, thereby exposing the other side of the hollowed-out circuit, completing the exposure of the hollowed-out circuit on the opposite sides, and obtaining a hollowed-out printed circuit board.

[0045] The hollowed-out circuit is also called a "suspended wire" circuit or a "flying wire", which has no specific shape and is determined according to requirements.

[0046] Through the above steps, the preparation method of the hollowed-out printed circuit board of the embodiment can obtain a hollowed-out printed circuit board by covering the first release protection layer on the side of the hollowed-out circuit in the preset area away from the carrier plate after the hollowed-out circuit is prepared on the target conductive layer in the preset area on the carrier plate, and then removing the first release protection layer by using the release characteristics after the circuit board build-up is completed. Therefore, the steps of filling the dielectric layer into the hollowed-out circuit and directly controlling the depth of the hollowed-out circuit are avoided. During the depth control, only the first release protection layer needs to be controlled, which reduces the difficulty of depth control, solves the problems of easy damage of the hollowed-out circuit and high requirement of depth control, reduces the risk of plate preparation, improves the precision of the controlled depth circuit, and ensures the stability of the plate by removing the residual first release protection layer even if there is residual depth control. The above preparation method has a simple process and does not need to be processed multiple times, which can improve the preparation efficiency of the hollowed-out printed circuit board.

[0047] Please refer to Figures 2-3 , Figure 2 is a flowchart of another embodiment of the preparation method of the hollowed-out printed circuit board provided by the present application. Figure 3 is Figure 2 is a structural schematic diagram of the preparation process of the hollowed-out printed circuit board in the embodiment.

[0048] Step S21: Obtain a carrier plate with a target conductive layer attached to one side, determine the position information of the preset area by using the positioning mark, and control the depth of the preset area based on the position information to penetrate the target conductive layer, thereby preparing a hollowed-out circuit.

[0049] Please refer to Figure 3 a, obtain a carrier plate 12 with a target conductive layer 11 attached to one side.

[0050] The target conductive layer 11 is a conductive layer on which a hollowed-out circuit needs to be made. The length and width dimensions of the target conductive layer 11 can be equal to or greater than the length and width dimensions of the carrier plate 12. Specifically, the length and width dimensions of the carrier plate 12 need to meet the condition of completely coinciding with the preset area, so as to facilitate the subsequent setting of the first release protection layer on the preset area.

[0051] Please further refer to Figure 3 b and Figure 3 c, wherein, Figure 3 c is Figure 3 The top view of the b structure is provided with positioning marks 111 on the target conductive layer 11, wherein the number of the positioning marks 111 can be one or more, and the positioning marks 111 can be arranged at the four corners of the plate or any free area. The positioning marks 111 can include pads, positioning holes or other prominent structures to be recognized by a depth control machine or a positioning system.

[0052] The target conductive layer 11 is positioned by using the positioning marks 111 to determine the position information of the preset area 14, that is, the coordinates of the preset area 14, and then the preset area 14 is subjected to a depth control process based on the position information to penetrate the target conductive layer 11, thereby obtaining the hollow circuit 13.

[0053] The number and position of the preset area 14 on the target conductive layer 11 can be set based on actual needs.

[0054] The depth control process can include UV (ultraviolet) laser cutting, CO2 (carbon dioxide) laser cutting, water jet cutting or mechanical depth control.

[0055] In other embodiments, the method for preparing the hollow circuit 13 can further include sequentially performing film pasting, exposure and development, etching and film removal on the preset area 14 of the target conductive layer 11 to obtain the hollow circuit 13.

[0056] Step S22: A second release protection layer is attached on the side of the target conductive layer away from the carrier plate, and the preset area is exposed; and a strippable ink is printed into the preset area until the strippable ink covers the surface of the second release protection layer and then solidified.

[0057] In this embodiment, the first release protection layer is taken as an example of the strippable ink, which is a kind of solder resist ink and can be quickly stripped.

[0058] Please further refer to Figure 3 d, a second release protection layer 16 is attached on the side of the target conductive layer 11 away from the carrier plate 12, and the preset area 14 is exposed.

[0059] The second release protection layer 16 can be slotted at a position corresponding to the preset area 14 to expose the preset area 14, thereby facilitating the filling of the strippable ink 15 in the subsequent process.

[0060] The length L1 and the width W1 of the through slot in the second release protective layer 16 correspond to the length L2 and the width W2 of the preset area 14 as follows: L2-200 μm≤L1≤L2+800 μm, W2-200 μm≤W1≤W2+800 μm, and 15 μm≤the thickness C of the second release protective layer 16≤500 μm. The through slot in this range can facilitate the printing and filling of the strippable ink 15.

[0061] The second release protective layer 16 can include a jig plate, a dry film, and the like.

[0062] The strippable ink 15 is printed into the preset area 14. Since the strippable ink 15 is a liquid at this time, the strippable ink 15 can naturally fill the gaps between the hollowed-out lines 13 when the strippable ink 15 is printed. The strippable ink 15 is printed until the strippable ink 15 covers the surface of the second release protective layer 16, and the strippable ink 15 that protrudes from the surface of the second release protective layer 16 is scraped off and then solidified. At this time, the strippable ink 15 fills the gaps between the hollowed-out lines 13 and covers the side of the hollowed-out lines 13 away from the carrier plate 12.

[0063] After the printing is completed, the second release protective layer 16 is removed.

[0064] In other embodiments, when the first release protective layer is a dry film or a release plate, the method of arranging the first release protective layer can further include: pasting the dry film in the preset area to cover the side of the hollowed-out lines away from the carrier plate.

[0065] Step S23: sequentially placing the first dielectric layer, the second dielectric layer, and the conductive layer on the side of the target conductive layer away from the carrier plate, and performing compression; removing the carrier plate; and sequentially performing film pasting, exposure and development, etching, and film removal on the conductive layer and the target conductive layer to form a conductive line, thereby obtaining a processed plate.

[0066] For further reference Figure 3 e, sequentially placing the first dielectric layer 17, the second dielectric layer 18, and the conductive layer 19 on the side of the target conductive layer 11 away from the carrier plate 12, and performing compression. After compression, the carrier plate 12 can be removed, and after the carrier plate 12 is removed, the side of the hollowed-out lines 13 is exposed.

[0067] The dielectric layer includes epoxy resin, polyimide, BT, ABF, ceramic base, and the like, and plays an insulating role in a printed circuit board.

[0068] The first dielectric layer 17 is hollowed out at a position corresponding to the preset area 14, so as to accommodate the corresponding peelable ink 15. The length L3, width W3 and thickness H3 of the hollowed-out area on the first dielectric layer 17 correspond to the length L1, width W1 and thickness C of the through groove on the second release layer 16 as follows: L1-500 μm≤L3≤L1+300 μm, W1-500 μm≤W3≤W1+300 μm, C-15 μm≤H3≤C+30 μm.

[0069] In the actual application, the number of times of the build-up treatment can include multiple times, which is determined based on the preparation requirements of the printed circuit board. The subsequent build-up treatment steps can include sequentially placing a new dielectric layer and a new conductive layer, and pressing; sequentially performing film pasting, exposure development, etching and film removal on the new conductive layer to form a conductive circuit. The board can also be drilled and plated to prepare a conductive hole that communicates between the conductive layers.

[0070] For further reference Figure 3 f. The conductive layer 19 and the target conductive layer 11 are sequentially subjected to film pasting, exposure development, etching and film removal to form a conductive circuit, thereby obtaining a processed board 20.

[0071] A solder resist layer 21 is arranged on opposite sides of the processed board 20; wherein the projection of the solder resist layer 21 on the target conductive layer 11 does not overlap the preset area 14, so as to prevent affecting the hollow state of the hollow circuit 13.

[0072] Step S24: Based on the position of the preset area, the depth control treatment is performed on the processed board from the side of the processed board away from the target conductive layer until the peelable ink is exposed.

[0073] For further reference Figure 4 g. Based on the position of the preset area 14, the depth control treatment is performed on the processed board 20 from the side of the processed board 20 away from the target conductive layer 11 until the peelable ink 15 is exposed.

[0074] During the depth control process, the peelable ink 15 can protect the hollow circuit 13, which can buffer the depth control allowance and reduce the depth control vibration.

[0075] The depth control treatment includes one or more of UV laser cutting, CO2 laser cutting, water jet cutting or mechanical depth control.

[0076] The depth control treatment of the present embodiment only needs to expose the hollow circuit 13, without the need for fine depth control along the shape of the hollow circuit 13, thereby reducing the difficulty of depth control and reducing the risk of laser carbonization and delamination.

[0077] Step S25: removing the peelable ink to obtain the hollow printed circuit board.

[0078] The peelable ink 15 is etched by alkaline chemical solution to remove the peelable ink 15, expose the other side of the hollow circuit 13, complete the exposure of the opposite sides of the hollow circuit 13, and obtain the hollow printed circuit board.

[0079] The alkaline chemical solution does not affect the structure of the hollow circuit 13, thereby ensuring the structural integrity of the hollow circuit 13.

[0080] In other embodiments, when the first release protection layer is a dry film or a release carrier plate, the dry film or the release carrier plate can be directly torn off to obtain the hollow printed circuit board.

[0081] The preparation method of the hollow printed circuit board of the embodiment can be applied to various types of printed circuit boards and various hollow circuit manufacturing, which is not limited here.

[0082] Through the above steps, the preparation method of the hollow printed circuit board of the embodiment forms a hollow circuit on the target conductive layer on the predetermined area of the carrier plate, covers the peelable ink on the side of the hollow circuit away from the carrier plate on the predetermined area, fills the gap between the hollow circuits, and after the circuit board is layered, the peelable ink is first exposed, and then etched to remove the peelable ink to obtain the hollow printed circuit board. Thus, the step of filling the dielectric layer on the hollow circuit and directly controlling the depth of the hollow circuit is avoided. During the depth control, only the peelable ink needs to be controlled, which reduces the difficulty of depth control, solves the problem of easy damage and high requirement of depth control of the hollow circuit, reduces the risk of board preparation, improves the precision of the depth controlled circuit, and even if there is residual depth control, the peelable ink can be removed to remove the residual and ensure the stability of the board.

[0083] Please refer to Figure 4 , ​ is a structural schematic diagram of an embodiment of the hollow printed circuit board provided by the application.

[0084] The hollow printed circuit board 300 of the embodiment includes a conductive layer 311 and a dielectric layer 318 which are sequentially crossed, laminated and attached.

[0085] The conductive layer 311 on the outer side of the hollow printed circuit board 300 is also attached with a solder mask layer 321.

[0086] The conductive layer 311 on the outer side of the hollow printed circuit board 300 is formed with hollow lines 313, the hollow lines 313 are arranged at intervals, and the positions corresponding to the hollow lines 313 on the hollow printed circuit board 300 are hollow.

[0087] The hollow printed circuit board 300 of the embodiment is prepared from the hollow printed circuit board of any one of the above embodiments, thereby avoiding the steps of filling the hollow lines with the dielectric layer and directly controlling the depth of the hollow lines, further solving the problems of easy damage of the hollow lines and high control depth requirement, and guaranteeing the stability of the board.

[0088] The above is only the embodiment of the present application, and does not limit the patent scope of the present application, any equivalent structure or equivalent process transformation using the content of the present application specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method of manufacturing a printed circuit board of the type having a plurality of openings, characterized in that, The preparation method of the hollow printed circuit board comprises the following steps: A carrier plate with a target conductive layer attached on one side is obtained, and a hollow circuit is prepared on a preset area of the target conductive layer; A first release protection layer is covered on the side of the hollow circuit in the preset area away from the carrier plate; At least one build-up process is performed on the side of the target conductive layer away from the carrier plate, and the carrier plate is removed to obtain a processed board; wherein, the first dielectric layer, the second dielectric layer and the conductive layer are sequentially placed on the side of the target conductive layer away from the carrier plate, and are pressed; wherein, the first dielectric layer is hollow in the position corresponding to the preset area; the carrier plate is removed; the conductive layer and the target conductive layer are sequentially subjected to film pasting, exposure and development, etching, film removal to form a conductive circuit, thereby obtaining the processed board; wherein, a solder resist layer is arranged on opposite sides of the processed board; the projection of the solder resist layer on the target conductive layer does not overlap with the preset area; Based on the position of the preset area, the depth control process is performed on the processed board from the side of the processed board away from the target conductive layer until the first release protection layer is exposed; The first release protection layer is removed to obtain a hollow printed circuit board.

2. The method of claim 1, wherein the method is a method of manufacturing a hollow printed circuit board. The target conductive layer is provided with a positioning mark; The step of preparing a hollow circuit on the preset area of the target conductive layer comprises: The position information of the preset area is determined by using the positioning mark; Based on the position information, the depth control process is performed on the preset area to penetrate the target conductive layer, thereby obtaining the hollow circuit.

3. The method of claim 1, wherein the method is a method of manufacturing a hollow printed circuit board. The step of preparing a hollow circuit on the preset area of the target conductive layer comprises: On the side of the preset area of the target conductive layer away from the carrier plate, film pasting, exposure and development, etching, film removal are sequentially performed to obtain the hollow circuit.

4. The method of claim 1, wherein the method is a method of manufacturing a hollow printed circuit board. The first release protection layer comprises a peelable ink; The step of covering the first release protection layer on the side of the hollow circuit in the preset area away from the carrier plate comprises: A second release protection layer is attached on the side of the target conductive layer away from the carrier plate, and the preset area is exposed; The peelable ink is printed into the preset area until the peelable ink is cured after covering the surface of the second release protection layer; wherein, the peelable ink fills the gap between the hollow circuits and covers the side of the hollow circuits away from the carrier plate; The second release protection layer is removed.

5. The method of claim 1, wherein the method is a method of manufacturing a hollow printed circuit board. The first release protection layer comprises a dry film; The step of covering the first release protection layer on the side of the hollow circuit in the preset area away from the carrier plate comprises: The dry film is attached on the side of the hollow circuit in the preset area away from the carrier plate.

6. The method of claim 1, wherein the method is a method of manufacturing a hollow printed circuit board. The step of removing the first release protection layer to obtain a hollow printed circuit board comprises: The first release protection layer is etched by alkaline chemical solution to remove the first release protection layer, thereby obtaining a hollow printed circuit board.

7. The method of claim 1 or 2, wherein the method is a method of manufacturing a hollow printed circuit board. The depth control processing includes UV laser cutting, CO2 laser cutting, water jet cutting or mechanical depth control.

8. A printed circuit board of the type having a plurality of holes, characterized in that, The hollow printed circuit board is prepared by the method of any one of claims 1-7.

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