Circuit board manufacturing method and circuit board

Abstract

The invention relates to the field of circuit board processing and manufacturing, in particular to a circuit board manufacturing method and a circuit board. The method comprises the following steps: laminating a PCB inner-layer core board and a PCB isolation board according to a preset sequence to obtain a first pretreatment board; forming a through hole coaxial with the preset metalized through hole in the first pretreated plate to form a partition through hole, forming a through hole in a preset position in the first pretreated plate to form a communicating hole, and obtaining a second pretreated plate; anti-electroplating dry films are attached to the two sides of the second pretreatment plate, exposure and development treatment is conducted on the anti-electroplating dry films, and the portions, at the through hole partition positions, of the anti-electroplating dry films are reserved; carrying out whole plate electroplating treatment on the second pretreatment plate pasted with the anti-electroplating dry film, and removing the anti-electroplating dry film to obtain a third pretreatment plate; and performing circuit pattern processing on the third preprocessing board to form the circuit board. The through holes are cut off, so that the ineffective paths in the through holes of the obtained circuit board can be cut off, the transmission loss of signals is reduced, the transmission quality of the signals is improved, and the reliability is high.

Description

Technical Field

[0001] This application relates to the field of circuit board processing and manufacturing, and in particular to a method for manufacturing a circuit board and a circuit board. Background Technology

[0002] With the development of communication technology, the signal requirements of communication electronic products are becoming increasingly stringent. Each generation of product upgrades requires the technical support of Printed Circuit Board (PCB) processes, which in turn places higher demands on PCB technology. As signal frequencies increase, the impact of PCB design and manufacturing becomes more pronounced, leading to increased signal transmission loss. Through-hole designs often contain redundant paths that are ineffective for signal transmission, and these paths significantly impact signal loss. Currently, the industry primarily addresses this issue by back-drilling to remove the copper traces on these ineffective paths within the through-holes, thereby reducing signal transmission loss and improving signal integrity.

[0003] Although back-drilling technology has matured, it still has many drawbacks. For example, uneven board thickness makes processing difficult, precise depth control is challenging, and incomplete back-drilling can easily occur, leaving residual structures that still affect signal transmission quality; there is a problem of drilling through the conductive layer, which significantly impacts product yield; back-drilling creates a semi-destructive structure in the hole, causing uneven stress on the hole under thermal stress conditions such as reflow soldering, which can easily lead to reliability failures in localized areas. Summary of the Invention

[0004] Based on this, this application provides a method for manufacturing a circuit board and a circuit board to solve the problems of low signal transmission quality, low processing yield and poor reliability in back-drilling process.

[0005] On one hand, this application provides a method for manufacturing a circuit board, including:

[0006] A PCB inner layer core board is provided, which has a preset metallized through hole. The PCB inner layer core board and the PCB isolation board are pressed together in a preset order to obtain the first pre-processed board.

[0007] A through hole coaxially arranged with a preset metallized through hole in the inner core of the PCB is opened on the first pre-processing board to form a partition through hole. A through hole is opened at a preset position in the first pre-processing board to form a connecting hole, thereby obtaining a second pre-processing board.

[0008] Anti-electroplating dry film is applied to both sides of the second pretreatment plate, and the anti-electroplating dry film is exposed and developed to retain the anti-electroplating dry film at the location of the through hole.

[0009] The second pretreatment board with the anti-electroplating dry film is subjected to whole-board electroplating treatment, and the anti-electroplating dry film is removed to obtain the third pretreatment board;

[0010] The circuit pattern of the third preprocessing board is processed to form a circuit board.

[0011] In one possible implementation, an inner PCB core board is provided, comprising:

[0012] A PCB core board is provided, which has preset metallized through holes. The preset metallized through holes are filled to form an isolation block.

[0013] The circuit pattern of the PCB core board is processed to form the inner layer core board of the PCB.

[0014] In one possible implementation, a PCB core board is provided, comprising:

[0015] A substrate is provided, and a hole-opening process is performed at a preset position on the substrate to form a PCB substrate with a first through hole;

[0016] The PCB substrate with the first through hole is subjected to whole-board electroplating treatment to metallize the first through hole, forming a preset metallized through hole, and thus obtaining the PCB core board.

[0017] In one possible implementation, a through-hole coaxially arranged with a preset metallized through-hole in the inner core of the PCB is formed on the first pre-processing board to create a partition through-hole, and a through-hole is formed at a preset position in the first pre-processing board to create a connecting hole, thereby obtaining a second pre-processing board, including:

[0018] A through hole coaxially arranged with the isolation block in the inner core board of the PCB is opened on the first pre-processing board to form an isolation through hole, and a through hole is opened at a preset position in the first pre-processing board to form a connecting hole;

[0019] At the partition through-hole, the residual isolation block in the preset metallized through-hole of the PCB inner layer core board is dissolved and removed to obtain the second pre-processed board.

[0020] In one possible implementation, after performing whole-board electroplating on the second pretreatment board with the anti-electroplating dry film applied, and removing the anti-electroplating dry film to obtain the third pretreatment board, the method further includes:

[0021] For the partition through-hole, the residual isolation block in the pre-metallized through-hole is dissolved and removed.

[0022] In one possible implementation, the diameter of the partition hole is less than or equal to the diameter of the partition block.

[0023] In one possible implementation, the isolation block is formed by filling a pre-defined metallized through-hole with soluble resin ink or paint-like ink.

[0024] In one possible implementation, the isolation holes and connecting holes are formed by mechanical drilling.

[0025] In one possible implementation, the circuit patterning is performed as an etching process.

[0026] On the other hand, this application provides a circuit board, which is processed by the above-mentioned circuit board manufacturing method, and the circuit board is provided with a partition through hole coaxially disposed with a preset metallized through hole in the inner core board of the PCB.

[0027] This application provides a method for manufacturing a circuit board and the circuit board itself. A partitioned through-hole, coaxially aligned with a pre-set metallized through-hole, is formed on a first pre-processing board. This partitioned through-hole is then covered with an anti-plating dry film. A second pre-processing board is then electroplated. Finally, the anti-plating dry film is removed, and circuit pattern processing is performed to form the circuit board. The formed partitioned through-hole allows the obtained circuit board to block invalid paths within the through-hole. Compared with existing back-drilling techniques, this reduces signal transmission loss, improves transmission quality, and enhances signal integrity. Furthermore, this manufacturing method is convenient, has a higher yield and efficiency, and does not cause semi-destructive structures to the through-hole, thus eliminating the problem of uneven stress on the through-hole in environments with thermal stress, such as reflow soldering, which can lead to localized reliability failures. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic flowchart illustrating a method for manufacturing a circuit board according to Embodiment 1 of this application.

[0030] Figure 2 This is a schematic flowchart illustrating a method for manufacturing a circuit board according to Embodiment 2 of this application.

[0031] Figure 3 This is a schematic diagram of the structure of a PCB substrate provided in Embodiment 2 of this application;

[0032] Figure 4 This is a schematic diagram of the structure of a PCB core board provided in Embodiment 2 of this application;

[0033] Figure 5 This is a schematic diagram of the PCB core board obtained after step S203 in Embodiment 2 of this application;

[0034] Figure 6 This is a schematic diagram of the PCB inner layer core board provided in Embodiment 2 of this application;

[0035] Figure 7 This is a schematic diagram of the structure of the first pretreatment plate provided in Embodiment 2 of this application;

[0036] Figure 8 This is a schematic diagram of the structure of the first pretreatment plate obtained after step S206 in Embodiment 2 of this application;

[0037] Figure 9 This is a schematic diagram of the structure of the second pretreatment plate provided in Embodiment 2 of this application;

[0038] Figure 10 This is a schematic diagram of the structure of the second pretreatment plate after step S208 in Embodiment 2 of this application;

[0039] Figure 11 This is a schematic diagram of the structure of the third pretreatment plate provided in Embodiment 2 of this application.

[0040] Explanation of reference numerals in the attached figures:

[0041] 10-Substrate; 11-First base layer; 12-First through hole; 13-First copper layer; 131-First conductive circuit layer; 14-Preset metallized through hole; 15-Second copper layer; 151-Second conductive circuit layer; 17-Isolation block; 20-First pre-treatment board; 22-Isolation through hole; 24-Connecting hole; 26-Conductive hole; 30-PCB isolation board; 40-Second pre-treatment board; 50-Anti-plating dry film; 60-Third pre-treatment board; 70-Outer copper layer. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar components or components having the same or similar functions throughout. The described embodiments are some, but not all, of the embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0043] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an indirect connection through an intermediate medium, or the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0044] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0045] The terms “first,” “second,” and “third” (if any) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0046] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion, such that a process, method, system, product, or display that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or display.

[0047] With the development of communication technology, the signal requirements of communication electronic products are becoming increasingly stringent. Each generation of product upgrades requires the technical support of Printed Circuit Board (PCB) processes, which in turn places higher demands on PCB technology. As signal frequencies increase, the impact of PCB design and manufacturing becomes more pronounced, leading to increased signal transmission loss. Through-hole designs often contain redundant paths that are ineffective for signal transmission, and these paths significantly impact signal loss. Currently, the industry primarily addresses this issue by back-drilling to remove the copper traces on these ineffective paths within the through-holes, thereby reducing signal transmission loss and improving signal integrity.

[0048] Although back-drilling technology has matured, it still has many drawbacks. For example, uneven board thickness makes processing difficult, precise depth control is challenging, and incomplete back-drilling can easily occur, leaving residual structures that still affect signal transmission quality; there is a problem of drilling through the conductive layer, which significantly impacts product yield; back-drilling creates a semi-destructive structure in the hole, causing uneven stress on the hole under thermal stress conditions such as reflow soldering, which can easily lead to reliability failures in localized areas.

[0049] After repeated consideration and verification, the inventors discovered a new method for processing and manufacturing circuit boards. The resulting through-holes can block invalid paths within the through-holes, reducing signal transmission loss, improving transmission quality, and enhancing signal integrity compared to existing back-drilling techniques. Furthermore, this manufacturing method is convenient, has a higher yield and efficiency, and does not cause semi-destructive structures to the through-holes. This eliminates the problem of uneven stress on through-holes in environments with thermal stress, such as reflow soldering, which can lead to localized reliability failures.

[0050] In view of this, this application provides a method for manufacturing a circuit board for processing metal hole partitions, comprising: providing a PCB inner layer core board, the PCB inner layer core board having preset metallized through holes; pressing the PCB inner layer core board and a PCB isolation board in a preset order to obtain a first pre-processed board; forming through holes coaxially arranged with the preset metallized through holes in the PCB inner layer core board to form partition through holes; forming through holes at preset positions in the first pre-processed board to form connecting holes to obtain a second pre-processed board; attaching anti-plating dry film to both sides of the second pre-processed board, and performing exposure and development treatment on the anti-plating dry film, retaining the anti-plating dry film at the position of the partition through holes; performing whole-board electroplating treatment on the second pre-processed board with the attached anti-plating dry film, and removing the anti-plating dry film to obtain a third pre-processed board; and performing circuit pattern processing on the third pre-processed board to form a circuit board.

[0051] This application involves creating partitioned through-holes coaxially with pre-set metallized through-holes on a first pre-processing plate, covering the partitioned through-holes with an anti-plating dry film, electroplating the second pre-processing plate, removing the anti-plating dry film, and then performing circuit pattern processing to form a circuit board. The formed partitioned through-holes block invalid paths within the through-holes, reducing signal transmission loss, improving transmission quality, and enhancing signal integrity compared to existing back-drilling techniques. Furthermore, this manufacturing method is convenient, yields higher efficiency, and avoids causing semi-destructive structures to the through-holes, thus eliminating the problem of uneven stress on the through-holes and localized reliability failures caused by thermal stress in environments such as reflow soldering.

[0052] The contents of this application will now be described in detail with reference to the accompanying drawings, so that those skilled in the art can have a clearer and more detailed understanding of the contents of this application.

[0053] Figure 1 This is a schematic flowchart illustrating a method for manufacturing a circuit board according to Embodiment 1 of this application.

[0054] The method for manufacturing the circuit board provided in this application includes the following steps:

[0055] Step S101: Provide a PCB inner layer core board with preset metallized through holes. Press the PCB inner layer core board and the PCB isolation board together in a preset order to obtain the first pre-processed board.

[0056] Step S102: A through hole coaxially arranged with a preset metallized through hole in the inner core of the PCB is opened on the first pre-processing board to form a partition through hole. A through hole is opened at a preset position in the first pre-processing board to form a connecting hole, thereby obtaining the second pre-processing board.

[0057] In step S103, anti-electroplating dry film is applied to both sides of the second pretreatment plate, and the anti-electroplating dry film is exposed and developed to retain the anti-electroplating dry film at the location of the through hole.

[0058] Step S104: Perform whole-board electroplating on the second pretreatment board with the anti-electroplating dry film, and remove the anti-electroplating dry film to obtain the third pretreatment board.

[0059] Step S105: Perform circuit pattern processing on the third preprocessing board to form a circuit board.

[0060] In this embodiment, in order to manufacture the inner layer core board of the PCB, a PCB core board is provided, which has preset metallized through holes. The preset metallized through holes are filled to form an isolation block. The PCB core board is then subjected to circuit pattern processing to form the inner layer core board of the PCB.

[0061] A filler is filled into the pre-metallized through-holes to form a spacer block. The filler includes substances such as soluble resin ink or paint-like ink. Different filling methods can be used depending on the material. The main function of the spacer block is to prevent resin from flowing into the pre-metallized through-holes during pressing, thus ensuring the conductivity of the pre-metallized through-holes.

[0062] If the pre-metallized vias are not filled and covered by isolation blocks, the resin pressed into the pre-metallized vias after lamination may not be completely removed by drilling or other methods, which will cause contamination inside the pre-metallized vias and affect the realization of the functions of the pre-metallized vias on the circuit board, such as connecting external components and conducting with the components.

[0063] To manufacture the inner core board of a PCB, the PCB core board undergoes circuit pattern processing. It is known that circuit pattern processing can be achieved through etching, forming a conductive line layer on the surface of the PCB core board according to a pre-defined circuit pattern.

[0064] The PCB inner core board and the PCB isolation board are pressed together according to a preset sequence to obtain the first pre-processed board. It should be noted that the PCB isolation board is a glass plate containing resin. The preset sequence is determined according to the circuit board design requirements. Generally, circuit boards are multilayer boards, which can be composed of several PCB inner core boards and several PCB isolation boards. Their quantity and structure can be set by those skilled in the art.

[0065] A through-hole is formed on the first pre-processing board, coaxially aligned with a pre-set metallized through-hole in the inner core of the PCB, thus forming a partition through-hole. Specifically, since the position of the partition through-hole corresponds to the position of the isolation block in the pre-set metallized through-hole, the partition through-hole can be formed at a corresponding position on the first pre-processing board according to the position of the isolation block. The diameter of the partition through-hole is less than or equal to the diameter of the isolation block to prevent damage to the circuitry on the inner core of the PCB. Preferably, the diameter of the partition through-hole is equal to the diameter of the isolation block to remove as much of the isolation block as possible from the vicinity of the partition through-hole. Furthermore, in this step, the drilling parameters can be selected based on the high-temperature resistance characteristics of the material; this application does not impose any limitations on this.

[0066] An anti-plating dry film is applied to both sides of the second pretreatment board, and then exposed and developed. The anti-plating dry film is retained at the locations of the vias. Specifically, the anti-plating dry film includes either a dry film type solder resist or a photoresist dry film. In this step, the dry film type solder resist or photoresist dry film can be applied to both sides of the second pretreatment board by pressing, that is, the dry film material of the dry film type solder resist or photoresist dry film is directly pressed onto both sides of the second pretreatment board. The anti-plating dry film can be exposed and developed, retaining the anti-plating dry film only on both sides of the via locations to prevent the formation of an electroplated copper layer during subsequent electroplating.

[0067] The second pretreatment board with the anti-electroplating dry film is subjected to whole-board electroplating treatment, and the anti-electroplating dry film is removed to obtain the third pretreatment board. Specifically, the second pretreatment board with the anti-electroplating dry film is subjected to palladium activation treatment, so that ionic palladium is attached to the inner wall of the connecting hole and the areas on both sides of the second pretreatment board where the anti-electroplating dry film is not attached. Then, copper electroplating treatment is performed to plate copper on the connecting hole area and the surface of the second pretreatment board.

[0068] The third preprocessing board is subjected to circuit pattern processing to form a circuit board. It is known that the circuit pattern processing can be carried out by etching, forming a conductive line layer on the surface of the third preprocessing board according to the preset circuit pattern, thus forming the circuit board.

[0069] The circuit board manufacturing method provided in this application involves providing a PCB inner core board with preset metallized through holes, laminating the PCB inner core board and a PCB isolation board in a preset order to obtain a first pre-processed board; forming isolation through holes by opening through holes coaxially with the preset metallized through holes in the PCB inner core board on the first pre-processed board, and forming connecting holes by opening through holes at preset positions in the first pre-processed board to obtain a second pre-processed board; attaching anti-plating dry film to both sides of the second pre-processed board and performing exposure and development treatment on the anti-plating dry film, retaining the anti-plating dry film at the isolation through hole positions; performing whole-board electroplating treatment on the second pre-processed board with the attached anti-plating dry film, and removing the anti-plating dry film to obtain a third pre-processed board; and performing circuit pattern processing on the third pre-processed board to form a circuit board. This application involves filling pre-formed metallized through-holes with isolation blocks, creating isolation through-holes on a first pre-processing board, covering the isolation through-holes with an anti-plating dry film, and then performing full-board electroplating on a second pre-processing board. Finally, the anti-plating dry film is removed, and circuit pattern processing is performed to form a circuit board. The formed isolation through-holes can block invalid paths within the through-holes in the obtained circuit board. Compared with existing back-drilling technology, this reduces signal transmission loss, improves transmission quality, and enhances signal integrity. Furthermore, this manufacturing method is convenient, has a higher yield and efficiency, and does not cause semi-destructive structures to the through-holes. This eliminates the problem of uneven stress on the through-holes and localized reliability failures caused by thermal stress in environments such as reflow soldering.

[0070] Based on the above embodiment one, Figure 2 This is a schematic flowchart illustrating a method for manufacturing a circuit board according to Embodiment 2 of this application. Figure 2 As shown, the manufacturing method includes the following steps:

[0071] Step S201: A substrate is provided, and an opening process is performed at a preset position on the substrate to form a PCB substrate with a first through hole.

[0072] Step S202: Perform whole-board electroplating on the PCB substrate with the first through hole to metallize the first through hole, forming a preset metallized through hole, and obtain the PCB core board.

[0073] Step S203: Fill the pre-defined metallized through holes in the PCB core board with isolation blocks.

[0074] Step S204: Perform circuit pattern processing on the PCB core board to form the inner layer core board of the PCB.

[0075] Step S205: Press the PCB inner core board and the PCB isolation board together in a preset order to obtain the first pre-processed board.

[0076] Step S206: A through hole coaxially disposed with the isolation block in the inner core board of the PCB is opened on the first pre-processing board to form an isolation through hole, and a through hole is opened at a preset position in the first pre-processing board to form a connecting hole.

[0077] The diameter of the partition hole is less than or equal to the diameter of the partition block.

[0078] Step S207: At the partition through-hole, the residual isolation block in the preset metallized through-hole of the PCB inner layer core board is dissolved and removed to obtain the second pre-processed board.

[0079] In step S208, anti-plating dry film is applied to both sides of the second pretreatment plate, and the anti-plating dry film is exposed and developed to retain the anti-plating dry film at the location of the through hole.

[0080] Step S209: Perform whole-board electroplating treatment on the second pretreatment board with the anti-electroplating dry film, and remove the anti-electroplating dry film to obtain the third pretreatment board.

[0081] Step S210: Perform circuit pattern processing on the third preprocessing board to form a circuit board.

[0082] This second embodiment is a method for manufacturing a circuit board based on the first embodiment. In this embodiment, in order to manufacture the circuit board, the single-sided copper-clad board or the double-sided copper-clad board can first be drilled and the whole board can be electroplated.

[0083] Figure 3 This is a schematic diagram of the structure of a PCB substrate provided in Embodiment 2 of this application.

[0084] The substrate 10 includes a flexible first base layer 11 and a first copper layer 13 and a second copper layer 15 respectively formed on two opposite surfaces of the first base layer 11.

[0085] The material of the first base layer 11 can be selected from one of the following: polyimide (PI), liquid crystal polymer (LCP), polyetheretherketone (PEEK), polyethylene terephthalate (PET), and polyethylene naphthalate (PEN).

[0086] By performing an opening process on the substrate, at least one first through hole 12 is opened at a predetermined position on the substrate 10 along the stacking direction of the first copper layer 13, the first base layer 11 and the second copper layer 15 to form a PCB substrate.

[0087] In this embodiment, the first through hole 12 is formed by mechanical drilling. In other embodiments, the first through hole 12 can be formed by other methods, such as laser engraving, stamping, etc.

[0088] Figure 4 This is a schematic diagram of the structure of a PCB core board provided in Embodiment 2 of this application.

[0089] The PCB substrate is electroplated to metallize the first through hole 12, forming a preset metallized through hole 14, and the first copper layer 13 and the second copper layer 15 are electrically connected through the preset metallized through hole 14 to obtain the PCB core board.

[0090] Figure 5 This is a schematic diagram of the PCB core board obtained after step S203 in Embodiment 2 of this application.

[0091] Filler is filled into the preset metallized through-hole 14 of the PCB core board to form an isolation block 17 that fills the preset metallized through-hole 14.

[0092] The spacer block 17 can be a soluble resin ink or paint-like ink, and different filling methods can be used depending on the material. The main function of the spacer block 17 is to prevent resin from flowing into the pre-metallized through-hole 14 during the pressing process.

[0093] Figure 6 This is a schematic diagram of the PCB inner core board provided in Embodiment 2 of this application.

[0094] By etching the first copper layer 13 and the second copper layer 15, a first conductive line layer 131 and a second conductive line layer 151 are formed on both sides of the first base layer 11 according to the preset circuit pattern, thus forming the inner core board of the PCB.

[0095] Figure 7 This is a schematic diagram of the structure of the first pretreatment plate provided in Embodiment 2 of this application.

[0096] The PCB inner core board and PCB isolation board 30 are pressed together according to a preset sequence to obtain the first pre-processed board 20. It should be noted that the PCB inner core board can be... Figure 6 The PCB inner core board shown is shown, and the PCB isolation board 30 is a glass plate containing resin. The preset order is determined according to the circuit board design requirements. Generally, circuit boards are multi-layer board structures, which can be composed of several PCB inner core boards and several PCB isolation boards. Their quantity and structure can be set by those skilled in the art.

[0097] Figure 8 This is a schematic diagram of the structure of the first pretreatment plate obtained after step S206 in Embodiment 2 of this application.

[0098] A through hole coaxially disposed with the isolation block 17 in the inner core board of the PCB is opened on the first pre-processing board 20 to form an isolation through hole 22, and a through hole is opened at a preset position in the first pre-processing board to form a connecting hole 24.

[0099] Specifically, since the position of the isolation via 22 corresponds to the position of the isolation block 17, the isolation via 22 can be opened at the corresponding position on the first pre-processing board 20 according to the position of the isolation block 17. The diameter of the isolation via 22 is less than or equal to the diameter of the isolation block 17 to prevent damage to the conductive circuit layer on the inner core board of the PCB. Preferably, the diameter of the isolation via 22 is equal to the diameter of the isolation block 17 to remove as much of the isolation block 17 as possible near the position of the isolation via 22. Furthermore, in this step, the drilling parameters can be selected according to the high-temperature resistance characteristics of the material, and this application does not impose any limitations on this.

[0100] In this embodiment, the partition hole 22 and the connecting hole 24 are formed by mechanical drilling. In other embodiments, the partition hole 22 and the connecting hole 24 can be formed by other methods, such as laser engraving, stamping, etc.

[0101] Figure 9 This is a schematic diagram of the structure of the second pretreatment plate provided in Embodiment 2 of this application.

[0102] After step S206, the position of the pre-metallized through hole 14 of the first pre-processing plate 20 filled with the isolation block 17 has been drilled through, but there are still remnants of the filled isolation block 17 attached to the hole wall of the pre-metallized through hole 14.

[0103] At the partition through-hole 22, the residual isolation block 17 in the preset metallized through-hole 14 of the PCB inner core board is dissolved and removed to obtain the second pre-processed board 40.

[0104] Specifically, the method for dissolving and removing the residual isolation block 17 is selected based on the material properties of the isolation block 17. For example, an alkaline decomposition solution can be used to vibrate the through hole 22 to remove the isolation block 17. The alkaline decomposition solution can be sodium hydroxide decomposition solution, and the vibration treatment can include ultrasonic waves, rocking, or vibrating.

[0105] Figure 10 This is a schematic diagram of the structure of the second pretreatment plate after step S208 in Embodiment 2 of this application.

[0106] Anti-plating dry film 50 is applied to both sides of the second pretreatment board 40, and the anti-plating dry film 50 is exposed and developed, retaining the anti-plating dry film 50 at the location of the via 22. Specifically, the anti-plating dry film 50 includes one of the following materials: dry film type solder resist or photoresist dry film. In this step, the dry film type solder resist or photoresist dry film can be applied to both sides of the second pretreatment board 40 by pressing, that is, the dry film material of the dry film type solder resist or photoresist dry film is directly pressed to both sides of the second pretreatment board 40. The anti-plating dry film 50 can be exposed and developed, retaining the anti-plating dry film 50 only on both sides of the location of the via 22 to prevent the formation of an electroplated copper layer at the location of the via 22 in the subsequent electroplating process.

[0107] Figure 11 This is a schematic diagram of the structure of the third pretreatment plate provided in Embodiment 2 of this application.

[0108] The second pretreatment board 40, to which the anti-electroplating dry film 50 is applied, undergoes a full-board electroplating process to metallize the connecting holes 24, forming vias 26, and electrically connecting the conductive circuit layers in the third pretreatment board 60 through the vias 26. The anti-electroplating dry film 50 is then removed to obtain the third pretreatment board 60. Specifically, the second pretreatment board 40 to which the anti-electroplating dry film 50 is applied undergoes palladium activation treatment, causing ionic palladium to adhere to the inner walls of the connecting holes 24 and the areas on both sides of the second pretreatment board 40 where the anti-electroplating dry film 50 is not applied. Then, copper electroplating is performed to plate copper onto the locations of the connecting holes 24 and the surface of the second pretreatment board 40, forming vias 26 and an outer copper layer 70.

[0109] In some embodiments, step S207 may be located after step S209, that is, the second pre-processed plate is obtained directly in step S206 and before step S210, the isolation block 17 remaining in the preset metallized through hole 14 at the partition through hole 22 is dissolved and removed.

[0110] Finally, the outer layer circuit pattern of the third preprocessing board is processed to form the circuit board.

[0111] Specifically, by etching the outer copper layer 70, an outer conductive circuit layer is formed according to a preset circuit pattern, thus obtaining a circuit board.

[0112] The circuit board manufacturing method provided in this application involves performing an opening process at a predetermined position on a substrate to form a PCB substrate with a first through-hole; performing a full-board electroplating process on the PCB substrate with the first through-hole to metallize the first through-hole, forming a predetermined metallized through-hole, thus obtaining a PCB core board; filling the predetermined metallized through-hole of the PCB core board with isolation blocks; performing circuit pattern processing on the PCB core board to form an inner PCB core board; laminating the inner PCB core board and the PCB isolation board in a predetermined sequence to obtain a first pre-processed board; and forming an isolation block on the first pre-processed board that is isolated from the inner PCB core board. A through-hole is coaxially arranged to form a partition through-hole. A through-hole is opened at a preset position in the first pre-processing board to form a connecting hole. At the partition through-hole, the isolation block remaining in the preset metallized through-hole of the PCB inner layer core board is dissolved and removed to obtain a second pre-processing board. Anti-plating dry film is applied to both sides of the second pre-processing board, and the anti-plating dry film is exposed and developed, retaining the anti-plating dry film at the position of the partition through-hole. The second pre-processing board with the anti-plating dry film is subjected to whole-board electroplating treatment, and the anti-plating dry film is removed to obtain a third pre-processing board. The third pre-processing board is processed for circuit patterning to form a circuit board.

[0113] This application involves filling pre-formed metallized through-holes with isolation blocks, creating isolation through-holes on a first pre-processing board, covering the isolation through-holes with an anti-plating dry film, and then performing full-board electroplating on a second pre-processing board. Finally, the anti-plating dry film is removed, and circuit pattern processing is performed to form a circuit board. The formed isolation through-holes can block invalid paths within the through-holes in the obtained circuit board. Compared with existing back-drilling technology, this reduces signal transmission loss, improves transmission quality, and enhances signal integrity. Furthermore, this manufacturing method is convenient, has a higher yield and efficiency, and does not cause semi-destructive structures to the through-holes. This eliminates the problem of uneven stress on the through-holes and localized reliability failures caused by thermal stress in environments such as reflow soldering.

[0114] This application also provides a circuit board, which is manufactured using any of the circuit board manufacturing methods in Embodiment 1 or Embodiment 2. The circuit board has a partition through hole that is coaxially arranged with a preset metallized through hole in the inner core board of the PCB.

[0115] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method for manufacturing a circuit board, characterized in that, include: A PCB inner layer core board is provided, the PCB inner layer core board is provided with preset metallized through holes, and the PCB inner layer core board and PCB isolation board are pressed together in a preset order to obtain a first pre-processed board; A through hole is formed on the first pre-processing board, which is coaxially arranged with the preset metallized through hole in the inner core board of the PCB to form a partition through hole. A through hole is formed at a preset position in the first pre-processing board to form a connecting hole, thereby obtaining a second pre-processing board. An anti-electroplating dry film is attached to both sides of the second pretreatment plate, and the anti-electroplating dry film is exposed and developed to retain the anti-electroplating dry film at the location of the partition through hole. The second pretreatment board with the anti-electroplating dry film is subjected to whole-board electroplating treatment, and the anti-electroplating dry film is removed to obtain the third pretreatment board; The third preprocessing board is subjected to circuit pattern processing to form a circuit board.

2. The method for manufacturing a circuit board according to claim 1, characterized in that, The PCB inner layer core board provided includes: A PCB core board is provided, wherein the PCB core board has the preset metallized through holes, and the preset metallized through holes are filled to form an isolation block; The PCB core board is processed to form the inner layer core board of the PCB.

3. The method for manufacturing a circuit board according to claim 2, characterized in that, The provided PCB core board includes: A substrate is provided, and an opening process is performed at a predetermined position on the substrate to form a PCB substrate with a first through hole; The PCB substrate with the first through hole is subjected to whole-board electroplating to metallize the first through hole, forming the preset metallized through hole, and thus obtaining the PCB core board.

4. The method for manufacturing a circuit board according to claim 2, characterized in that, A through hole is formed on the first pre-processing board, coaxially arranged with the preset metallized through hole in the inner core board of the PCB, forming a partition through hole. A through hole is formed at a preset position in the first pre-processing board, forming a connecting hole, to obtain a second pre-processing board, including: A through hole is formed on the first pre-processing board, which is coaxially arranged with the isolation block in the inner core board of the PCB, to form the isolation through hole; and a through hole is formed at a preset position in the first pre-processing board to form the connecting hole. At the isolation through-hole, the residual isolation block in the preset metallized through-hole of the PCB inner core board is dissolved and removed to obtain the second pre-treated board.

5. The method for manufacturing a circuit board according to claim 2, characterized in that, After the step of performing whole-board electroplating on the second pretreatment board with the anti-electroplating dry film attached, and removing the anti-electroplating dry film to obtain the third pretreatment board, the method further includes: The isolation block remaining in the preset metallized through hole at the partition is dissolved and removed.

6. The method for manufacturing a circuit board according to any one of claims 2-5, characterized in that, The diameter of the partition hole is less than or equal to the diameter of the isolation block.

7. The method for manufacturing a circuit board according to any one of claims 2-5, characterized in that, The isolation block is formed by filling the pre-designed metallized through-holes with soluble resin ink or paint-like ink.

8. The method for manufacturing a circuit board according to claim 1, characterized in that, The partition hole and the connecting hole are formed by mechanical drilling.

9. The method for manufacturing a circuit board according to claim 1, characterized in that, The circuit pattern processing is an etching process.

10. A circuit board, characterized in that, The circuit board is manufactured using the circuit board manufacturing method as described in any one of claims 1-9, and the circuit board is provided with a partition through hole coaxially disposed with the preset metallized through hole in the inner core board of the PCB.

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