Printed circuit boards and their manufacturing methods

Abstract

This invention relates to printed circuit boards and a method for manufacturing the same. The method includes: providing an inner layer laminate having a pressing region and an outer circuit region; the inner layer laminate having pressing holes and at least two vias in the pressing region, each via surrounding the pressing hole; stacking an insulating layer and an outer core board on at least one side of the inner layer laminate and pressing them together to obtain an outer layer laminate; the insulating layer having clearance windows covering the pressing holes and vias; fabricating an outer circuit layer on the surface of the outer core board; and removing the portion of the outer core board corresponding to the pressing region. By using the insulating layer and the outer core board to cover the pressing region, the etching solution used to fabricate the outer circuit layer is prevented from corroding the pressing holes and vias, thereby effectively protecting the pressing holes and vias. The vias located around the pressing holes can effectively absorb the flowing insulating material, thereby effectively preventing the pressing holes from being blocked.

Description

Technical Field

[0001] This invention relates to the field of printed circuit board manufacturing technology, and in particular to a printed circuit board and its manufacturing method. Background Technology

[0002] With the rapid development of electronic devices, printed circuit boards (PCBs) on these devices are becoming increasingly multifunctional. Therefore, PCBs in electronic devices need to accommodate more electronic components. To enable communication between these components, PCBs are evolving towards multi-layer designs while maintaining their existing footprint.

[0003] Multilayer circuit boards are made by laminating multiple core boards. Each core board has a circuit layer, and the circuit layers on each core board are connected by vias. This allows the circuit layers on the circuit board to extend from the plane to the vertical direction, thereby forming a larger circuit layer to meet the connection and functional requirements of electronic components.

[0004] Electrical components are mounted on multilayer circuit boards and can be connected by soldering, while some components are connected by insertion. Multilayer circuit boards have crimp holes with conductive copper sidewalls, allowing electrical connections between the component pins and the circuit layers. These crimp holes cannot be plugged with insulating material to accommodate the components. However, etching is required during the fabrication of the outer core circuit layers of the multilayer circuit board. If the etching solution flows into the crimp holes, it will damage them. Summary of the Invention

[0005] Therefore, it is necessary to provide a printed circuit board and a method for manufacturing the same.

[0006] A method for manufacturing a printed circuit board, comprising: An inner lamination plate is provided, the inner lamination plate having a lamination area and an outer circuit area, the inner lamination plate having a lamination hole and at least two through holes in the lamination area, each of the through holes being arranged around the lamination hole; An insulating layer and an outer core board are superimposed on at least one side of the inner laminate and pressed together to obtain an outer laminate. The insulating layer has a clearance window that covers the crimping hole and each of the through holes. An outer circuit layer is fabricated on the surface of the outer core board; Remove the portion of the outer core board corresponding to the pressing area.

[0007] In one embodiment, each of the vias is provided with a first insulating plugging material layer, and the first insulating plugging material layer does not cover the end face of the via.

[0008] In one embodiment, at least a portion of the insulating layer flows into the via under thermal pressure to form a second insulating plugging material layer.

[0009] In one embodiment, no pads are provided on the edge of the end face of each via.

[0010] In one embodiment, the metal sidewalls of each of the vias are provided with partition areas.

[0011] In one embodiment, the step of providing the inner laminate includes: An inner core board is provided, each of the inner core boards having a crimping area and an outer circuit area, and a drilling area is provided in the crimping area; Apply anti-plating ink to the drilled area of ​​at least one of the inner core boards; The inner core boards are stacked and pressed together in a preset order to form the inner pressed board. Drill holes in the pressing area to form pressing holes, and drill holes in the drilling area of ​​the inner layer pressing plate to form through holes; The inner lamination plate is subjected to copper plating and electroplating treatment to form a conductive metal layer on the sidewall of the crimping hole, and a conductive metal layer with a partition region is formed on the sidewall of each of the vias.

[0012] In one embodiment, the outer core board includes a core board body, a first circuit layer disposed on a first side of the core board body, and a conductor layer disposed on a second side of the core board body, wherein the first circuit layer does not completely cover the first side of the core board body; In the step of stacking an insulating layer and an outer core board on at least one side of the inner laminate and pressing them together, the first side of the core board body is attached to the insulating layer, and the projection of the first circuit layer on the surface of the inner laminate is offset from the pressing area. The step of fabricating an outer circuit layer on the surface of the outer core board includes: On the second side of the outer core board, a circuit pattern is fabricated on the conductor layer to form the outer circuit layer.

[0013] In one embodiment, the number of crimp holes is plurality of, and the positions of each crimp hole and each through hole are set to one of the following: Each of the aforementioned vias is disposed on the outside of all the crimping holes and surrounds all the crimping holes; A plurality of through holes are provided around the outer side of each of the crimping holes.

[0014] In one embodiment, the insulating layer includes a first insulating layer and a second insulating layer, and the outer core plate includes a first core plate and a second core plate; The step of stacking an insulating layer and an outer core board on at least one side of the inner laminate and then laminating them includes: The first insulating layer is superimposed on the first side of the inner laminate, and the first core board is superimposed on the side of the first insulating layer facing away from the inner laminate. The second insulating layer is superimposed on the second side of the inner laminate, and the second core board is superimposed on the side of the second insulating layer facing away from the inner laminate; The first core board, the first insulating layer, the inner layer lamination board, the second insulating layer, and the second core board are laminated together.

[0015] A printed circuit board is manufactured using the printed circuit board manufacturing method described in any of the above embodiments.

[0016] The beneficial effects of this invention are as follows: Before fabricating the outer circuit layer on the surface of the outer core board, the crimping area is covered by the insulating layer and the outer core board, which prevents the etching solution used to fabricate the outer circuit layer from corroding the crimping holes and vias, thereby effectively protecting the crimping holes and vias. In addition, since the insulating layer has a clearance window, it can prevent the insulating layer from flowing due to heat and blocking the crimping holes. The vias located around the crimping holes can effectively absorb this flowing insulating material, thereby effectively preventing the crimping holes from being blocked. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic flowchart of a printed circuit board manufacturing method according to one embodiment; Figure 2 This is a partial cross-sectional view of the inner layer lamination of a printed circuit board according to one embodiment. Figure 3 This is a schematic diagram of the inner layer lamination of a printed circuit board according to one embodiment; Figure 4 This is a partial cross-sectional view of the outer lamination of a printed circuit board according to one embodiment. Figure 5 This is a partial cross-sectional view of a printed circuit board after a portion of the outer core board has been removed from the outer lamination. Figure 6 This is a partial cross-sectional view of the inner lamination of a printed circuit board according to another embodiment. Figures 7 to 10This is a partial cross-sectional structural diagram of the manufacturing process of the inner layer lamination board of a printed circuit board according to an embodiment. Figure 11 This is a partial cross-sectional view of the outer lamination of a printed circuit board according to another embodiment.

[0019] Explanation of reference numerals in the attached figures: 10. Outer laminate; 100. Inner laminate; 101. Press hole; 102. Through hole; 110. Press area; 120. Outer circuit area; 210. Insulating layer; 220. Outer core board; 221. Core board body; 222. First circuit layer; 223. Conductor layer on the second side of the core board body; 201. Clearance window; 220a. Outer circuit layer; 102a. Partition area; 310. Inner core board; 311. Drilling area; 312. Anti-plating ink layer; 221a. First board body; 221b. Second board body; 221c. V-groove; 102b. First insulating plugging material layer; 101a. First metal conductive layer; 102c. Second metal conductive layer. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] In the existing technology CN111565524A, an outer first insulating plate and a first core plate are used to protect the crimping hole. Furthermore, to prevent the prepreg, which serves as the first insulating plate, from flowing into and blocking the crimping hole due to heat, a window is provided on the first insulating plate. In this structure, if the window area is small, causing the window edge to be too close to the crimping hole, the prepreg, under heat and pressure, will diffuse outwards, flow into the crimping hole, and enter under pressure, thus blocking it. In this case, the blocked prepreg is difficult to clean, affecting the use of the crimping hole. If the window area is large, the uneven distribution of the prepreg will result in uneven stress on the insulating layer, affecting the connection stability of the outer core plate.

[0022] like Figure 1 As shown, this is a printed circuit board manufacturing method according to an embodiment of the present invention, comprising: Step 110: Provide an inner layer laminating plate, the inner layer laminating plate having a crimping area and an outer circuit area, the inner layer laminating plate having a crimping hole and at least two through holes in the crimping area, each of the through holes being arranged around the crimping hole.

[0023] In this embodiment, as Figure 2 and Figure 3 As shown, the inner lamination plate 100 has a crimping area 110 and an outer circuit area 120. The inner lamination plate 100 is provided with a crimping hole 101 and at least two through holes 102 in the crimping area 110, and each of the through holes 102 is arranged around the crimping hole 101.

[0024] Specifically, the inner layer laminate 100 is formed by laminating multiple inner core boards 310. Each inner core board 310 has a circuit layer on one or both sides, and the circuit layers of each inner core board 310 are connected through vias 102. In this embodiment, the sidewall of the via 102 is provided with a conductive metal layer, i.e., a copper layer, thereby connecting the circuit layers of different inner core boards 310. The crimping hole 101 is either a through hole or a blind hole, and its sidewall is provided with a conductive metal layer, for example, a copper layer. The crimping hole 101 is used to connect external electrical components. It is worth noting that the circuit layers of the inner core boards 310 connected by the via 102 can be configured according to circuit design requirements. In this embodiment, the via 102 is an insulating plug, meaning that insulating material, such as resin, needs to be inserted into the via 102 to form an insulating plug.

[0025] Step 120: An insulating layer and an outer core board are stacked on at least one side of the inner laminate and pressed together to obtain an outer laminate. The insulating layer has a clearance window that covers the crimping hole and each of the through holes.

[0026] like Figure 4 As shown, an insulating layer 210 and an outer core board 220 are laminated together on the top surface of the inner laminate 100 to obtain the outer laminate 10. The insulating layer 210 has a clearance window 201, and the projection of the clearance window 201 on the surface of the inner laminate 100 covers the crimping hole 101 and each of the through holes 102.

[0027] In this embodiment, the insulating layer 210 is made of a prepreg. The insulating layer 210 has a clearance window 201, within which a prepreg is disposed, ensuring that the prepreg does not cover the crimping hole 101 and the through holes 102. Thus, during the pressing process, the surface of the inner layer pressing plate 100 surrounding the crimping hole 101 will not be contacted by the prepreg, preventing it from flowing into the crimping hole 101 under heat and pressure. Furthermore, when the prepreg flows close to the crimping hole 101, the through holes 102 on the outer side of the crimping hole 101 absorb the flowing prepreg material, thus blocking the prepreg from entering the crimping hole 101. Since the through holes 102 are resin plugs, the entering prepreg material does not affect the performance of the through holes 102. Since the via 102 can absorb the prepreg material, the clearance window 201 does not need to be set too large to avoid the crimping hole 101, thereby avoiding uneven stress on the insulating layer 210 and solving the problem of uneven stress on the outer core board 220.

[0028] It is worth mentioning that if the clearance window 201 is too large, it will cause the prepreg in the pressing area 110 and the surrounding prepreg to flow towards the clearance window 201, causing one side of the prepreg to tilt downwards, which in turn causes one side of the outer core board 220 to tilt downwards, resulting in uneven stress on the outer core board 220 and affecting the connection between the outer core board 220 and the outer circuit area 120 of the inner laminating plate 100. In this embodiment, the structure described above effectively avoids the clearance window 201 being too large, and makes the flow of the prepreg more uniform, resulting in a more uniform thickness of the prepreg and uniform stress on the outer core board 220, thus avoiding affecting the connection between the outer core board 220 and the outer circuit area 120 of the inner laminating plate 100.

[0029] Step 130: Fabricate an outer circuit layer on the surface of the outer core board.

[0030] In this embodiment, as Figure 4 As shown, the surface of the outer core board 220 has a conductor layer 223, for example, the conductor layer 223 is a copper foil layer. Photoresist or a dry film is coated onto the surface of the outer core board 220. The photoresist or dry film is patterned, exposed, and developed. Subsequently, the conductor layer is etched using a mask of the photoresist or dry film, such as... Figure 5 As shown, an outer circuit layer 220a is formed on the surface of the outer core board 220. It is worth mentioning that, since the surface of the inner lamination board 100 is covered by the insulating layer 210, the crimp holes 101 and vias 102 on the inner lamination board 100 can be effectively prevented from being etched.

[0031] Step 140: Remove the portion of the outer core board corresponding to the pressing area.

[0032] In this embodiment, laser cutting or mechanical cutting is used, such as... Figure 5 As shown, a portion of the outer core plate 220 on the crimping area 110 is cut off and eliminated, thereby exposing the crimping area 110.

[0033] In the above embodiments, before fabricating the outer circuit layer 220a on the surface of the outer core board 220, the crimping area 110 is covered by the insulating layer 210 and the outer core board 220 to prevent the etching solution used to fabricate the outer circuit layer 220a from corroding the crimping hole 101 and the via 102, thereby effectively protecting the crimping hole 101 and the via 102. In addition, since the insulating layer 210 has a clearance window 201, it can prevent the insulating layer 210 from flowing due to heat and blocking the crimping hole 101. The via 102 located around the crimping hole 101 can effectively absorb this part of the flowing insulating material, thereby effectively preventing the crimping hole 101 from being blocked.

[0034] Furthermore, since the through hole 102 located outside the crimp hole 101 can absorb the fluid of the prepreg, the clearance window 201 does not need to be set too large, thereby effectively avoiding uneven stress on the insulating layer 210 and solving the problem of uneven stress on the outer core board 220.

[0035] It is worth mentioning that the via 102 not only absorbs the prepreg material but also hinders its flow. Traditional resin plugging uses modified epoxy resin, while the prepreg is an epoxy resin containing fiberglass cloth. Therefore, compared to traditional resin plugging, the prepreg is more resilient, has slightly less flowability, and provides stronger overall support. Once the prepreg material enters the via 102, its strong toughness and viscosity create resistance to subsequent and adjacent prepreg material, effectively preventing the remaining prepreg material from flowing into the crimping hole 101. Furthermore, the prepreg material, capable of plugging the via 102, provides sufficient sealing and heat resistance compared to traditional resin plugging.

[0036] In one embodiment, such as Figure 6 As shown, each of the vias 102 is provided with a first insulating plugging material layer 102b, and the first insulating plugging material layer 102b does not cover the end face of the via 102.

[0037] In one embodiment, at least a portion of the insulating layer 210 flows into the via 102 under thermal pressure to form a second insulating plugging material layer.

[0038] In this embodiment, an insulating plugging material is pre-injected into the through-hole 102 to form a first insulating plugging material layer 102b, thereby blocking the middle of the through-hole 102 that extends through both ends, and reserving space for the through-hole 102 so that prepreg material can still flow into the opening of the through-hole 102. In this embodiment, the insulating plugging material is used to block the middle of the through-hole 102, thereby blocking the flow of prepreg material, causing the entering prepreg material to be squeezed under pressure, thereby forming a dense second insulating plugging material layer.

[0039] In one embodiment, the step of removing the portion of the outer core board corresponding to the pressing area further includes: A via-filling resin is injected into the via, and after the resin cures, a third insulating via-filling material layer is formed. After the via-filling resin cures to form the third insulating via-filling material layer, the surface of the via is polished. or The second insulating plugging material layer on the via surface is polished.

[0040] In this embodiment, after the prepreg material fills the through-hole 102, the plugging material on the surface of the through-hole 102 is polished according to the filling situation to keep the surface of the through-hole 102 flat. Specifically, when the prepreg material completely fills the through-hole 102, there is no need to fill it with plugging resin again, and the second insulating plugging material layer can be polished directly. When the prepreg material does not completely fill the through-hole 102, plugging resin needs to be injected into the through-hole 102 to form a third insulating plugging material layer, so that the through-hole 102 is completely sealed, making the insulating plugging structure more stable. Subsequently, the third insulating plugging material layer on the surface of the through-hole 102 is polished to keep the surface of the through-hole 102 flat.

[0041] It is worth mentioning that, in order to minimize the size of the clearance window 201, the via 102 needs to be closer to the crimp hole 101. However, if the via 102 is too close to the crimp hole 101, parasitic capacitance will be generated between the via 102 and the crimp hole 101. To reduce the parasitic capacitance between the via 102 and the crimp hole 101, in one embodiment, no pads are provided on the edge of the end face of each via 102. In this embodiment, since the inner lamination plate 100 does not provide pads on the outer surface of the via 102, on the one hand, the distance between the via 102 and the crimp hole 101 can be reduced, and on the other hand, the parasitic capacitance between them can also be reduced.

[0042] To reduce the parasitic capacitance between via 102 and crimp hole 101, in one embodiment, the metal sidewall of each via 102 is provided with a partition region 102a. In this embodiment, the metal sidewall of the via 102 is provided with a discontinuity, i.e., a partition region 102a, making the metal sidewall of the via 102 discontinuous. This metal sidewall of the via 102 is connected to the circuit layer of the corresponding inner core board 310 according to circuit design requirements. Because the metal sidewall of the via 102 is provided with a partition region 102a, the metal sidewall of the via 102 forms a discontinuous shape, thus effectively reducing the parasitic capacitance between it and the crimp hole 101.

[0043] In order to form a partition region 102a on the via 102, in one embodiment, the step of providing the inner laminate includes: An inner core board is provided, each of the inner core boards having a crimping area and an outer circuit area, and a drilling area is provided in the crimping area; Apply anti-plating ink to the drilled area of ​​at least one of the inner core boards; The inner core boards are stacked and pressed together in a preset order to form the inner pressed board. Drill holes in the pressing area to form pressing holes, and drill holes in the drilling area of ​​the inner layer pressing plate to form through holes; The inner lamination plate is subjected to copper plating and electroplating treatment to form a conductive metal layer on the sidewall of the crimping hole, and a conductive metal layer with a partition region is formed on the sidewall of each of the vias.

[0044] In this embodiment, as Figure 7 As shown, firstly, inner core boards 310 are provided. A circuit layer is fabricated on the surface of the inner core board 310. Then, an anti-plating ink is applied to the drilled areas 311 of the core board where the isolation area 102a needs to be formed, forming an anti-plating ink layer 312. The area of ​​this anti-plating ink layer 312 is larger than the area of ​​the via 102, and this anti-plating ink has the characteristic of not allowing copper to pass through. Subsequently, as... Figure 8 As shown, the inner core boards 310 are stacked and pressed together to form an inner laminate 100, as follows. Figure 9 As shown, a hole is drilled in the crimping area 110 to form a crimping hole 101. A hole is drilled in the drilling area 311 of the inner laminate 100 to form a through hole 102. Because the area of ​​the anti-plating ink layer 312 is larger than the area of ​​the through hole 102, after drilling, the anti-plating ink layer 312 can surround the outer side of one or more sections of the sidewall of the through hole 102. Subsequently, as... Figure 10As shown, the inner laminate 100 undergoes copper plating and electroplating processes to form a first conductive metal layer 101a on the sidewall of the crimp hole 101 and a second conductive metal layer 102c on the sidewall of the via 102. Both the first conductive metal layer 101a and the second conductive metal layer 102c are copper layers. Since one or more sections of the sidewall of the via 102 are partition regions 102a, the second conductive metal layer 102c on the metal sidewall of the via 102 is discontinuous, thereby effectively reducing the parasitic capacitance between the via and the crimp hole 101.

[0045] It is worth mentioning that, in each embodiment, the structure between the circuit board and each core board layer is only a schematic diagram, representing the structure corresponding to the embodiment, and is not used to represent the entire structure and actual proportions of the circuit board and each core board layer.

[0046] In order to form the partition region 102a on the via 102, in other embodiments, the partition region 102a is formed on the metal sidewall by back drilling.

[0047] In one embodiment, such as Figure 3 As shown, there are multiple crimping holes 101, and each through hole 102 is disposed on the outside of all the crimping holes 101 and surrounds all the crimping holes 101.

[0048] In this embodiment, as Figure 3 As shown, there are multiple crimping holes 101, and each of the vias 102 is disposed on the outside of all the crimping holes 101 and surrounds all the crimping holes 101. In this way, each via 102 surrounds each crimping hole 101, allowing the crimping hole 101 to absorb and block the prepreg material. It is worth mentioning that, since the vias 102 form a surrounding ring, they can better block the prepreg material and prevent the crimping holes 101 from being blocked by the prepreg material.

[0049] In one embodiment, the number of crimping holes is multiple, and multiple through holes are arranged around the outside of each crimping hole.

[0050] In this embodiment, there are multiple crimping holes, and multiple through holes are arranged around the outer side of each crimping hole. In this embodiment, there are also multiple corresponding clearance windows. A group of holes consists of one crimping hole and multiple through holes surrounding it, with each clearance window corresponding to one group of holes, and each clearance window covering the crimping hole and through holes of its corresponding group. This allows for smaller areas of each clearance window and a more uniform distribution of the prepreg, resulting in more uniform flow and thickness of the prepreg. Furthermore, the multiple through holes in each group of holes surrounding a crimping hole effectively absorb and block prepreg material from the crimping hole, preventing it from being blocked by the prepreg material.

[0051] In one embodiment, such as Figure 4 As shown, the outer core board 220 includes a core board body 221, a first circuit layer 222 disposed on a first side of the core board body 221, and a conductor layer 223 disposed on a second side of the core board body 221. The first circuit layer 222 does not completely cover the first side of the core board body 221. In the step of stacking an insulating layer and an outer core board on at least one side of the inner laminate and pressing them together, the first side of the core board body 221 is attached to the insulating layer 210, and the projection of the first circuit layer 222 on the surface of the inner laminate 100 is offset from the pressing area 110. The step of fabricating an outer circuit layer on the surface of the outer core board includes: On the second side of the outer core board 220, the conductor layer is patterned to form the outer circuit layer 220a.

[0052] In this embodiment, as Figure 4 As shown, an insulating layer 210 is bonded to the first surface of the core board body 221. The core board body 221 has a first region corresponding to the pressing area 110 of the inner layer laminating plate 100 and a second region corresponding to the outer circuit area 120 of the inner layer laminating plate 100. During stacking, the first region of the core board body 221 is aligned with the pressing area 110 of the inner layer laminating plate 100, and the second region of the core board body 221 is aligned with the outer circuit area 120 of the inner layer laminating plate 100. The circuit layer 222 is disposed in the second region of the core board body 221, such that the first circuit layer 222 is offset from the pressing region 110 of the inner laminating plate 100. This avoids contact between the first circuit layer 222 on the core board body 221 and the circuit parts such as the pressing holes 101, vias 102, pads, and circuit layers of the pressing region 110 during the pressing process due to the avoidance window 201 provided in the insulating layer 210, thereby preventing damage to the circuit parts of the pressing region 110. In this embodiment, the second surface of the outer core board 220 is used as the surface of the outer core board 220. The conductor layer on the second surface of the outer core board 220 is coated, exposed, developed, and etched to form the outer circuit layer 220a.

[0053] In one embodiment, the insulating layer includes a first insulating layer and a second insulating layer, and the outer core plate includes a first core plate and a second core plate; The step of stacking an insulating layer and an outer core board on at least one side of the inner laminate and then laminating them includes: The first insulating layer is superimposed on the first side of the inner laminate, and the first core board is superimposed on the side of the first insulating layer facing away from the inner laminate. The second insulating layer is superimposed on the second side of the inner laminate, and the second core board is superimposed on the side of the second insulating layer facing away from the inner laminate; The first core board, the first insulating layer, the inner layer lamination board, the second insulating layer, and the second core board are laminated together.

[0054] In this embodiment, the first core board and the second core board each include a core board body, a first circuit layer disposed on a first surface of the core board body, and a conductor layer disposed on a second surface of the core board body.

[0055] In this embodiment, both sides of the inner layer laminating plate are provided with crimping holes and through holes. In this way, by providing a first insulating layer and a second insulating layer, as well as a first core board and a second core board on both sides of the inner layer laminating plate, the crimping holes on both sides can be effectively prevented from being etched during the process of making the circuit layer on the surface of the outer core board.

[0056] In this embodiment, the step of fabricating an outer circuit layer a on the surface of the outer core board includes: fabricating an outer circuit layer a on the second surface of the first core board and the second surface of the second core board respectively.

[0057] The step of removing the portion of the outer core board corresponding to the pressing area includes: removing the portions of the first core board and the second core board corresponding to the pressing area.

[0058] To further avoid the problem of unstable connection between the outer core board 220 and the outer circuit area 120 of the inner laminate 100 caused by uneven stress in the outer core board 220, in one embodiment, such as Figure 11 As shown, the core board body 221 includes a first plate 221a and a second plate 221b, wherein a first region is located in the first plate 221a and a second region is located in the second plate 221b, and the first plate 221a and the second plate 221b are connected by a pre-cut structure.

[0059] In this embodiment, the pre-cut structure refers to V-cutting. Specifically, a V-shaped groove 221c is formed between the first plate 221a and the second plate 221b through pre-cutting. Both sides of the first plate 221a and the second plate 221b are cut to form V-shaped grooves 221c, so that the first plate 221a and the second plate 221b are still connected, but the connection between the first plate 221a and the second plate 221b is a weak connection, not a rigid connection. The first plate 221a and the second plate 221b do not completely transmit the force. In this way, the uneven force caused by the flow of the semi-cured sheet material under the first plate 221a will not affect the second plate 221b, thereby avoiding affecting the connection between the second plate 221b and the outer circuit area 120 of the inner laminate 100.

[0060] In one embodiment, a printed circuit board is provided, which is manufactured using the printed circuit board manufacturing method described in any of the above embodiments.

[0061] In the above embodiments, before fabricating the outer circuit layer 220a on the surface of the outer core board 220, the crimping area 110 is covered by the insulating layer 210 and the outer core board 220. This prevents the etching solution used to fabricate the outer circuit layer 220a from corroding the crimping holes 101 and vias 102, thus effectively protecting the crimping holes 101 and vias 102. Furthermore, since the insulating layer 210 has a clearance window 201, it can prevent the insulating layer 210 from flowing due to heat and blocking the crimping holes 101. The vias 102 located around the crimping holes 101 can effectively absorb this flowing insulating material, thereby effectively preventing the crimping holes 101 from being blocked. This effectively improves the quality and yield of the printed circuit board.

[0062] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0063] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for manufacturing a printed circuit board, characterized in that, include: An inner lamination plate is provided, the inner lamination plate having a lamination area and an outer circuit area, the inner lamination plate having a lamination hole and at least two through holes in the lamination area, each of the through holes being arranged around the lamination hole; An insulating layer and an outer core board are superimposed on at least one side of the inner laminate and pressed together to obtain an outer laminate. The insulating layer has a clearance window that covers the crimping hole and each of the through holes. An outer circuit layer is fabricated on the surface of the outer core board; Remove the portion of the outer core board corresponding to the pressing area.

2. The printed circuit board manufacturing method according to claim 1, characterized in that, Each of the vias is provided with a first insulating plugging material layer, and the first insulating plugging material layer does not cover the end face of the via.

3. The printed circuit board manufacturing method according to claim 1, characterized in that, At least a portion of the insulating layer flows into the via under thermal pressure, forming a second insulating plugging material layer.

4. The printed circuit board manufacturing method according to claim 1, characterized in that, No pads are provided on the edge of the end face of each via.

5. The printed circuit board manufacturing method according to claim 1, characterized in that, Each of the vias has a partitioned area on its metal sidewall.

6. The printed circuit board manufacturing method according to claim 5, characterized in that, The step of providing the inner laminate includes: An inner core board is provided, each of the inner core boards having a crimping area and an outer circuit area, and a drilling area is provided in the crimping area; Apply anti-plating ink to the drilled area of ​​at least one of the inner core boards; The inner core boards are stacked and pressed together in a preset order to form the inner pressed board. Drill holes in the pressing area to form pressing holes, and drill holes in the drilling area of ​​the inner layer pressing plate to form through holes; The inner lamination plate is subjected to copper plating and electroplating treatment to form a conductive metal layer on the sidewall of the crimping hole, and a conductive metal layer with a partition region is formed on the sidewall of each of the vias.

7. The method for manufacturing a printed circuit board according to any one of claims 1-6, characterized in that, The outer core board includes a core board body, a first circuit layer disposed on a first side of the core board body, and a conductor layer disposed on a second side of the core board body, wherein the first circuit layer does not completely cover the first side of the core board body; In the step of stacking an insulating layer and an outer core board on at least one side of the inner laminate and pressing them together, the first side of the core board body is attached to the insulating layer, and the projection of the first circuit layer on the surface of the inner laminate is offset from the pressing area. The step of fabricating an outer circuit layer on the surface of the outer core board includes: On the second side of the outer core board, a circuit pattern is fabricated on the conductor layer to form the outer circuit layer.

8. The method for manufacturing a printed circuit board according to any one of claims 1-6, characterized in that, The number of crimping holes is plurality of, and the positions of each crimping hole and each through hole are set to one of the following: Each of the aforementioned vias is disposed on the outside of all the crimping holes and surrounds all the crimping holes; A plurality of through holes are provided around the outer side of each of the crimping holes.

9. The method for manufacturing a printed circuit board according to any one of claims 1-6, characterized in that, The insulating layer includes a first insulating layer and a second insulating layer, and the outer core board includes a first core board and a second core board; The step of stacking an insulating layer and an outer core board on at least one side of the inner laminate and then laminating them includes: The first insulating layer is superimposed on the first side of the inner laminate, and the first core board is superimposed on the side of the first insulating layer facing away from the inner laminate. The second insulating layer is superimposed on the second side of the inner laminate, and the second core board is superimposed on the side of the second insulating layer facing away from the inner laminate; The first core board, the first insulating layer, the inner layer lamination board, the second insulating layer, and the second core board are laminated together.

10. A printed circuit board, characterized in that, It is manufactured using the printed circuit board manufacturing method described in any one of claims 1-9.

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