Multi-stage printed circuit board, processing method of multi-stage printed circuit board and signal shielding groove

Abstract

The invention relates to the technical field of multi-order printed circuit boards, in particular to a multi-order printed circuit board, a processing method of the multi-order printed circuit board and a signal shielding groove, and the processing method of the multi-order printed circuit board comprises the following steps: carrying out pressing operation on the printed circuit board after circuit pattern arrangement is completed, sequentially pressing the insulating substrate and the copper foil on the printed circuit board; high-speed signal holes are formed in target positions of the insulating substrate and the copper foil; a signal shielding groove is formed in the outer side of the high-speed signal hole around the high-speed signal hole; performing chemical copper deposition and hole blocking and copper coating operation on the signal shielding groove; performing circuit pattern arrangement on the copper foil to obtain a printed circuit board on which circuit pattern arrangement is completed; and repeating the steps to obtain the multi-stage printed circuit board. According to the multi-stage printed circuit board, the processing method of the multi-stage printed circuit board and the signal shielding groove, the shielding capability of the high-speed signal hole can be improved, the transmission requirement of a higher-speed signal is ensured, and the loss caused by the influence of the surrounding environment in the signal transmission process is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of multi-level HDI and PCB, and in particular to a multi-level printed circuit board, a processing method of the multi-level printed circuit board and a signal shielding groove. Background Art

[0002] This application involves designing a signal shielding groove around a high-speed signal hole in a multi-level HDI and PCB product to reduce the loss of high-speed signals caused by the surrounding environment when the signal is transmitted in the signal hole. Especially for multi-level HDI products with high-density interconnection, when the transmission signal requirement of the PCB product design reaches 112Gbps or even 224Gbps, the shielding requirement around the signal hole will become higher and higher.

[0003] The existing design method is to prepare high-speed signal holes through multi-step stacking lasers, and design several groups of multi-step stacking laser holes around the signal holes as shielding holes, but the shielding holes are not designed to extend to the bottom signal layer. The existing shielding hole design method can meet the design and transmission requirements for 28Gbps and 56Gbps, but it is difficult to fully meet the shielding requirements when the higher 112Gbps or even 224Gbps requirements are met.

[0004] The present invention provides a multi-stage HDI and PCB product, which can improve the shielding capability of high-speed signal holes on the basis of existing designs, ensure the demand for higher-speed signal transmission, and reduce the loss caused by the surrounding environment during signal transmission. Summary of the invention

[0005] The purpose of the present invention is to provide a multi-level printed circuit board, a processing method for a multi-level printed circuit board and a signal shielding groove, which can improve the shielding capability of high-speed signal holes, ensure the transmission requirements of higher-speed signals, and reduce the loss caused by the surrounding environment during signal transmission.

[0006] To achieve the above object, the present invention provides the following technical solutions: In a first aspect, the present invention provides a multi-stage printed circuit board processing method, comprising the following steps: The printed circuit board with the circuit pattern layout completed is pressed, and the insulating substrate and the copper foil are pressed on the printed circuit board in sequence; Opening high-speed signal holes at target locations of the insulating substrate and the copper foil; A signal shielding groove is provided around the high-speed signal hole on the outside of the high-speed signal hole; Perform chemical copper deposition and hole plugging and copper coating operations on the signal shielding slot; Arranging a circuit pattern on the copper foil to obtain a printed circuit board with a completed circuit pattern arrangement; Repeat the above steps to obtain a multi-level printed circuit board.

[0007] In combination with the first aspect, further, opening a signal shielding groove around the high-speed signal hole on the outside of the high-speed signal hole includes: The signal shielding groove is formed by laser through the method of burning and superimposed drilling. Several deep blind holes are made by laser so that adjacent deep blind holes partially overlap to form a signal shielding groove surrounding the high-speed signal hole.

[0008] In combination with the first aspect, further, the diameters of the high-speed signal hole and the deep blind hole are both A, 5mil≤A≤8mil; The center distance between two adjacent deep blind holes is between 1mil and 1 / 2A.

[0009] In combination with the first aspect, further, opening a signal shielding groove around the high-speed signal hole on the outside of the high-speed signal hole also includes: At the connection between the high-speed signal line and the high-speed signal hole, the signal shielding groove is a closed ring surrounding the high-speed signal hole; At the connection between the high-speed signal line and the high-speed signal hole, the signal shielding groove is in a "U" shape surrounding the high-speed signal hole, and the high-speed signal line is electrically connected to the outside of the signal shielding groove through the opening of the "U" shape.

[0010] In combination with the first aspect, further, performing chemical copper deposition and hole plugging copper coating operations on the signal shielding slot includes: A copper plating layer is deposited at the signal shielding groove by a chemical copper deposition process; Filling the signal shielding slot with resin by vacuum plugging method; A layer of copper is plated on the signal shielding groove by electroplating.

[0011] In combination with the first aspect, further, the copper foil is subjected to circuit pattern arrangement to obtain a printed circuit board having completed circuit pattern arrangement, comprising: The copper foil is etched to form a circuit pattern, which includes a copper bar, a high-speed signal line, and a signal hole block PAD. The signal hole block PAD is arranged around the high-speed signal hole, and an isolation ring is arranged on the periphery of the signal hole block PAD. The high-speed signal line is electrically connected to the high-speed signal hole through the signal hole PAD. The copper bar is arranged on the outside of the isolation ring, and the copper bar is arranged in a "U" shape. The high-speed signal line is electrically connected to the outside of the copper bar through the "U" shaped opening.

[0012] In a second aspect, the present invention provides a multi-level printed circuit board, comprising a signal layer, a P / G layer and a plurality of high-speed signal holes, wherein the plurality of high-speed signal holes are used to connect different signal layers or P / G layers, and high-speed signal lines are electrically connected to the high-speed signal holes. Signal shielding grooves are correspondingly provided between each signal layer and P / G layer through which the high-speed signal hole passes, and a plurality of signal shielding grooves of adjacent layers are stacked to form signal shielding stacked grooves extending to both ends of the high-speed signal hole.

[0013] In combination with the second aspect, further, the signal shielding groove is circumferentially closed and arranged around the high-speed signal hole, and the signal shielding groove correspondingly opened on the signal layer provided with the high-speed signal line is provided with an opening for the high-speed signal line to pass through.

[0014] In a third aspect, the present invention provides a signal shielding slot for a multi-level printed circuit board, wherein a plurality of signal shielding slots located at corresponding positions and subjected to chemical copper deposition, hole plugging and copper coating operations are stacked up and down to form a signal shielding stacked slot extending to both ends of a high-speed signal hole.

[0015] In combination with the third aspect, further, the signal shielding stack groove is provided with an opening for the high-speed signal line to pass through.

[0016] Compared with the prior art, the present invention has the following beneficial effects: it can improve the shielding capability of high-speed signal holes, ensure the transmission requirements of higher-speed signals, and reduce the loss caused by the surrounding environment during signal transmission; The multi-level printed circuit board, the processing method of the multi-level printed circuit board and the use method of the signal shielding groove provided by the present invention improve the shielding capability of the high-speed signal hole by setting a continuous signal shielding groove on the outside of the high-speed signal hole on the printed circuit board. Through multiple pressing operations, the upper and lower adjacent signal shielding grooves are superimposed to form a signal shielding stacking groove extending to both ends of the high-speed signal hole. The signal shielding groove is set into a "U" shape at the connection between the high-speed signal line and the high-speed signal hole, so that the high-speed signal line can be electrically connected to the outside of the signal shielding groove through the "U"-shaped opening. While improving the overall shielding capability of the signal shielding stacking groove on the high-speed signal hole, it does not affect the signal transmission of the high-speed signal hole. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of the structure of a high-speed signal hole and a signal shielding slot in a multi-stage printed circuit board provided by an embodiment of the present invention; Figure 2 A schematic diagram of a top view of a high-speed signal hole and a signal shielding slot in a multi-level printed circuit board provided by an embodiment of the present invention; Figure 3 A schematic diagram of a PCB stacking structure of a 5+12+5 HDI structure provided by an embodiment of the present invention; Figure 4 A schematic diagram of a circuit pattern structure in a method for processing a multi-stage printed circuit board provided by an embodiment of the present invention; Figure 5 A schematic diagram of a shielding stacking groove processing flow of a multi-stage printed circuit board provided in Example 3 of the present invention; Figure 6 A schematic diagram of a shielding stacking groove processing flow of a multi-stage printed circuit board provided in Embodiment 4 of the present invention; Figure 7 A schematic diagram of a shielding stacking groove processing flow of a multi-stage printed circuit board provided in Example 5 of the present invention; Figure 8 A schematic diagram of a shielding stacking groove processing flow of a multi-stage printed circuit board provided in Example 6 of the present invention; Fig. 9 A schematic diagram of a shielding stacking groove processing flow of a multi-stage printed circuit board provided in Example 7 of the present invention; Fig.10 A schematic diagram of a shielding stacking groove processing flow of a multi-stage printed circuit board provided in Example 8 of the present invention; Fig.11 A schematic structural diagram of an implementation method of winding, burning and superimposed punching of a method for processing a multi-stage printed circuit board provided in an embodiment of the present invention.

[0018] The markings in the attached figure are: 1. insulating substrate; 2. copper foil; 3. high-speed signal hole; 4. signal shielding groove; 5. deep blind hole; 6. high-speed signal line; 7. copper bar; 8. signal hole PAD; 9. isolation ring. DETAILED DESCRIPTION

[0019] The technical solution of the present application is further described in detail below in conjunction with specific implementation methods.

[0020] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and should not be construed as limitations on the present application. In the absence of conflict, the embodiments of the present application and the technical features in the embodiments may be combined with each other.

[0021] Embodiment 1: This embodiment provides a multi-stage printed circuit board processing method, such as Figure 1-Figure 11 As shown, the shielding capability of the high-speed signal hole 3 can be improved, the transmission requirements of higher-speed signals can be guaranteed, and the loss caused by the surrounding environment during signal transmission can be reduced. A multi-stage printed circuit board processing method includes the following steps: Step 1: laminating the printed circuit board with the circuit pattern arranged, and laminating the insulating substrate 1 and the copper foil 2 on the printed circuit board in sequence; Step 2: A high-speed signal hole 3 is opened at the target position of the insulating substrate 1 and the copper foil 2. In this embodiment, a laser is used to form a signal shielding groove 4 by a wrapping and superimposed punching method. A plurality of deep blind holes 5 are made by laser so that adjacent deep blind holes 5 partially overlap to form a signal shielding groove 4 surrounding the high-speed signal hole 3, wherein the diameters of the high-speed signal hole 3 and the deep blind hole 5 are both A, 5mil≤A≤8mil; and the center distance between two adjacent deep blind holes 5 is between 1mil and 1 / 2A.

[0022] Step 3: A signal shielding groove 4 is opened around the high-speed signal hole 3 on the outside of the high-speed signal hole 3. In this embodiment, at the place where there is no high-speed signal line 6 connected to the high-speed signal hole 3, the signal shielding groove 4 is a closed ring surrounding the high-speed signal hole 3; at the place where there is a high-speed signal line 6 connected to the high-speed signal hole 3, the signal shielding groove 4 is a "U" shape surrounding the high-speed signal hole 3, and the high-speed signal line 6 is electrically connected to the outside of the signal shielding groove 4 through the opening of the "U" shape, such as Figure 1 As shown, from left to right are a cross-sectional view of a high-speed signal hole 3 of a multi-stage printed circuit board, a cross-sectional view of a signal shielding slot 4 processed by a mechanical method, a cross-sectional view of a signal shielding slot 4 processed by a laser method, and a schematic diagram of a three-dimensional structure of the signal shielding slot 4; Step 4: Perform chemical copper plating and hole plugging and copper coating operations on the signal shielding groove 4. In this embodiment, a layer of copper plating is deposited on the signal shielding groove 4 by a chemical copper plating process; the signal shielding groove 4 is filled with resin by a vacuum plugging method; and a layer of copper is plated on the signal shielding groove 4 by electroplating.

[0023] Step 5: Arrange the circuit pattern on the copper foil 2 to obtain a printed circuit board with the circuit pattern arranged. In this embodiment, the copper foil 2 is etched to form a circuit pattern, such as Figure 2 As shown, Figure 2From left to right, they are: a schematic diagram of the signal layer circuit pattern, the signal shielding slot 4, and the position structure of the high-speed signal hole 3; a schematic diagram of the P / G layer circuit pattern, the signal shielding slot 4, and the position structure of the high-speed signal hole 3; a schematic diagram of the inner signal transmission layer where the high-speed signal line 6 and the high-speed signal hole 3 are connected; the circuit pattern includes a copper bar 7, a high-speed signal line 6, and a signal hole pad PAD 8. The signal hole pad PAD 8 is arranged around the high-speed signal hole 3. An isolation ring 9 is arranged on the periphery of the signal hole pad PAD 8. The high-speed signal line 6 passes through the signal hole PAD and the high-speed The signal hole 3 is electrically connected, the stopper copper bar 7 is arranged on the outside of the isolation ring 9, the stopper copper bar 7 is arranged in a "U" shape, and the high-speed signal line 6 is electrically connected to the outside of the stopper copper bar 7 through the "U"-shaped opening. In this embodiment, the diameter of the high-speed signal hole 3 is A, 5mil≤A≤8mil, the diameter of the signal hole stop PAD8 is between A+5mil and A+9mil, the width of the stopper copper bar 7 is between A+6mil and A+10mil, the distance between the stopper copper bar 7 and the high-speed signal line 6 is between 3mil and 6mil, and the distance between the stopper copper bar 7 and the signal hole stop PAD8 is between 5mil and 8mil.

[0024] Repeat the above steps to obtain a multi-order printed circuit board, perform the above steps once to obtain a first-order printed circuit board, perform the above steps twice to obtain a second-order printed circuit board, perform the above steps three times to obtain a third-order printed circuit board, and so on; by setting a continuous signal shielding groove on the outside of the high-speed signal hole on the printed circuit board, the shielding capability of the high-speed signal hole is improved, and through multiple pressing operations, the upper and lower adjacent signal shielding grooves are superimposed to form a signal shielding stacking groove extending to both ends of the high-speed signal hole, and the signal shielding groove is set in a "U" shape at the connection between the high-speed signal line and the high-speed signal hole, so that the high-speed signal line can be electrically connected to the outside of the signal shielding groove through the "U"-shaped opening, while improving the shielding capability of the signal shielding stacking groove on the whole high-speed signal hole without affecting the signal transmission of the high-speed signal hole.

[0025] like Figure 3 It is a 5+12+5 HDI structure PCB board stack. From this HDI structure, we can see that the specific lamination preparation sequence is the first lamination, the second lamination, the third lamination, the fourth lamination, the fifth lamination, and the sixth lamination. It can be seen that the second to the sixth lamination are all HDI layer laminations, that is, only the outer layer PP and copper foil 2 are pressed.

[0026] like Figure 4As shown, it is an example to illustrate the graphic data of the inner signal transmission layer L7 during the first lamination, which includes the copper strip 7, the high-speed signal line 6, and the signal hole PAD8. At this time, the L6 layer is the copper foil 2, and the graphic data has not been prepared yet; it is an example to illustrate the graphic data L5 of the upper-order HDI layer during the HDI layer lamination, which includes the signal hole PAD8 and the insulating layer after etching. At this time, the L4 layer is the copper foil 2, and the graphic data has not been prepared.

[0027] Embodiment 2: The embodiment of the present invention provides a multi-level printed circuit board, such as Figure 1-Figure 4 As shown, it can be manufactured based on the processing method described in Example 1.

[0028] The present embodiment provides a multi-level printed circuit board, which can improve the shielding ability of the high-speed signal hole 3, ensure the transmission demand of higher-speed signals, and reduce the loss caused by the surrounding environment during signal transmission. The multi-level printed circuit board includes a signal layer, a P / G layer and a plurality of high-speed signal holes 3. The plurality of high-speed signal holes 3 are used to connect different signal layers or P / G layers. The high-speed signal holes 3 are electrically connected to high-speed signal lines 6. Signal shielding grooves 4 are correspondingly opened between each signal layer and P / G layer passed by the high-speed signal hole 3. The plurality of signal shielding grooves 4 of adjacent layers are stacked to form signal shielding stacked grooves extending to both ends of the high-speed signal hole 3.

[0029] In this embodiment, the signal shielding groove 4 is circumferentially closed and arranged outside the high-speed signal hole 3 , and the signal shielding groove 4 correspondingly opened on the signal layer with the high-speed signal line 6 is provided with an opening for the high-speed signal line 6 to pass through.

[0030] Embodiment 3: The present embodiment provides a signal shielding groove of a multi-level printed circuit board, which can improve the shielding ability of the high-speed signal hole 3, ensure the transmission demand of higher-speed signals, and reduce the loss caused by the surrounding environment during signal transmission. A signal shielding groove of a multi-level printed circuit board can be made based on the processing method described in Example 1. Several signal shielding grooves 4 located at corresponding positions and subjected to chemical copper plating and hole plugging and copper coating operations are stacked up and down to form a signal shielding stacked groove extending to both ends of the high-speed signal hole 3. In this embodiment, the signal shielding stacked groove is provided with an opening for the high-speed signal line 6 to pass through.

[0031] like Figure 1-Figure 5 as well as Fig.11As shown, a signal shielding groove of a multi-level printed circuit board can be made by the following method. In this embodiment, after the pressing operation, a heat-absorbing film is deposited on the copper foil 2 by a chemical deposition process. The main component of the heat-absorbing film is copper oxide, which is obtained by copper black oxidation treatment. The heat-absorbing film is used in combination with a carbon dioxide laser to make a deep blind hole 5. The diameter of the deep blind hole 5 is A. By means of partially overlapping and punching in sequence by burning, the center distance of adjacent deep blind holes 5 is controlled between 1 mil and 1 / 2 A, so that the deep blind holes 5 form a signal shielding groove 4 around the high-speed signal hole 3. After the signal shielding groove 4 is formed, the black copper oxide heat-absorbing film on the surface of the copper foil 2 is removed by 5% dilute sulfuric acid to expose a fresh bright copper surface. Then, a layer of copper with a thickness of 1 mil to 2 mil is deposited on the inner wall of the signal shielding groove 4 and the surface of the copper foil 2 by a chemical copper deposition process. Then, a plugging resin is plugged into the signal shielding groove 4 by a vacuum plugging method. The plugging resin includes but is not limited to PHP900IR 10FE, PHP900IR IR6P, etc. After the plugging is completed and the long-bake curing is performed, the residual resin on the outer copper surface is ground off by a grinder, and the resin surface of the 4 ports of the signal shielding groove is leveled. Finally, a layer of copper with a thickness of between 0.8 mil and 1.5 mil is plated on the outer copper surface and the resin surface of the 4 ports of the signal shielding groove by electroplating. Then, the above process is repeated after the next pressing operation to finally obtain the signal shielding stacked groove of the multi-level printed circuit board.

[0032] Embodiment 4: The present embodiment provides a shielding stacking groove of a multi-level printed circuit board. The difference from the embodiment 3 is that the shielding stacking groove of the multi-level printed circuit board can be manufactured by the following method: Figure 6 and Fig.11 As shown, in this embodiment, after the lamination operation, a layer of heat-absorbing film is deposited on the copper foil 2 by a chemical deposition process. The main component of the heat-absorbing film is copper oxide, which is obtained by copper black oxidation treatment. The heat-absorbing film is used in combination with a carbon dioxide laser to make a deep blind hole 5. The diameter of the deep blind hole 5 is A. The center distance of adjacent deep blind holes 5 is controlled between 1 mil and 1 / 2 A by partially overlapping and punching in sequence by burning, so that the deep blind hole 5 forms a signal shielding groove 4 around the high-speed signal hole 3. After the signal shielding groove 4 is formed, the black copper oxide heat-absorbing film on the surface of the copper foil 2 is removed by 5% dilute sulfuric acid to expose a fresh bright copper surface. The prepared signal shielding groove 4 is filled with solid copper by a pulse electroplating hole filling process. Then, the above process flow is repeated after the next lamination operation to finally obtain a signal shielding stacked groove of a multi-stage printed circuit board.

[0033] Embodiment 5: The present embodiment provides a shielding stacking groove of a multi-level printed circuit board. The difference from the embodiment 3 is that the shielding stacking groove of the multi-level printed circuit board can be manufactured by the following method: Figure 7 and Fig.11As shown, in this embodiment, after the lamination operation, a deep blind hole 5 is made by mechanical methods such as controlled depth drilling or controlled fishing, and the depth is between 40% and 80% of the interlayer depth. The diameter of the deep blind hole 5 is A, so that the deep blind hole 5 forms a signal shielding groove 4 around the high-speed signal hole 3, and then the residual resin at the bottom of the deep blind groove is cleaned by carbon dioxide laser. The diameter of the laser hole is A. By burning and partially overlapping the punching in sequence, the center distance between adjacent laser holes is controlled between 1 mil and 1 / 2 A. Burning is carried out along the signal shielding groove 4 to remove the residual resin at the bottom. Then, a layer of copper with a thickness of between 1 mil and 2 mil is deposited on the inner wall of the signal shielding groove 4 and the surface of the copper foil 2 through a chemical copper deposition process. Then, the plugging resin is plugged into the signal shielding groove 4 through a vacuum plugging method. The plugging resin includes but is not limited to PHP900IR 10FE, PHP900IR IR6P, etc. After the plugging is completed and the long-bake curing is performed, the residual resin on the outer copper surface is ground off by a grinder, and the resin surface of the 4 ports of the signal shielding groove is leveled. Finally, a layer of copper with a thickness of between 0.8 mil and 1.5 mil is plated on the outer copper surface and the resin surface of the 4 ports of the signal shielding groove by electroplating. Then, the above process is repeated after the next pressing operation to finally obtain the signal shielding stacked groove of the multi-level printed circuit board.

[0034] Embodiment 6: The present embodiment provides a shielding stacking groove of a multi-level printed circuit board. The difference from the embodiment 5 is that the shielding stacking groove of a multi-level printed circuit board can be manufactured by the following method: Figure 8 and Fig.11 As shown, in this embodiment, after the lamination operation, a deep blind hole 5 is made by mechanical methods such as controlled depth drilling or controlled fishing, and the depth is between 40% and 80% of the interlayer depth. The diameter of the deep blind hole 5 is A, so that the deep blind hole 5 forms a signal shielding groove 4 around the high-speed signal hole 3, and then the residual resin at the bottom of the deep blind groove is cleaned by carbon dioxide laser. The diameter of the laser hole is A. By burning and partially overlapping the holes in sequence, the center distance between adjacent laser holes is controlled between 1 mil and 1 / 2 A. Burning is carried out along the signal shielding groove 4 to clean the residual resin at the bottom. The prepared signal shielding groove 4 is filled with solid copper through a pulse electroplating hole filling process. Then, the above process flow is repeated after the next lamination operation to finally obtain a signal shielding stacked groove of a multi-stage printed circuit board.

[0035] Embodiment 7: The present embodiment provides a shielding stacking groove of a multi-level printed circuit board. The difference from the embodiment 3 is that the shielding stacking groove of the multi-level printed circuit board can be manufactured by the following method: Fig. 9 and Fig.11As shown, in this embodiment, after the lamination operation, a layer of dry film is laminated on the copper foil 2, and after exposure and development by LDI or traditional film method, the annular or "U"-shaped annular copper surface shown in the figure is exposed and etched away, and the ring width is A. A deep blind hole 5 is made by carbon dioxide laser, and the diameter of the deep blind hole 5 is A. By burning and partially overlapping the punching in sequence, the center distance of adjacent deep blind holes 5 is controlled between 1mil and 1 / 2A, so that the deep blind holes 5 form a signal shielding groove 4 around the high-speed signal hole 3, and then a layer of copper with a thickness of 1mil to 2mil is deposited on the inner wall of the signal shielding groove 4 and the surface of the copper foil 2 by chemical copper deposition process, and then a plugging resin is plugged into the signal shielding groove 4 by vacuum plugging method. The plugging resin includes but is not limited to PHP900IR 10FE, PHP900IR IR6P, etc. After the plugging is completed and the long-bake curing is performed, the residual resin on the outer copper surface is ground off by a grinder, and the resin surface of the 4 ports of the signal shielding groove is leveled. Finally, a layer of copper with a thickness of between 0.8 mil and 1.5 mil is plated on the outer copper surface and the resin surface of the 4 ports of the signal shielding groove by electroplating. Then, the above process is repeated after the next pressing operation to finally obtain the signal shielding stacked groove of the multi-level printed circuit board.

[0036] Embodiment 8: The present embodiment provides a shielding stacking groove of a multi-level printed circuit board. The difference from the embodiment 7 is that the shielding stacking groove of a multi-level printed circuit board can be manufactured by the following method: Figure 10-11 As shown, in this embodiment, after the lamination operation, a layer of dry film is laminated on the copper foil 2, and after exposure and development through LDI or traditional film method, the annular or "U"-shaped annular copper surface shown in the figure is exposed and etched away, and the ring width is A. A deep blind hole 5 is made by carbon dioxide laser, and the diameter of the deep blind hole 5 is A. By burning and partially overlapping the punching in sequence, the center distance of adjacent deep blind holes 5 is controlled between 1mil and 1 / 2A, so that the deep blind hole 5 forms a signal shielding groove 4 around the high-speed signal hole 3, and the prepared signal shielding groove 4 is filled with solid copper through the pulse electroplating filling process, and then the above process flow is repeated after the next lamination operation, and finally the signal shielding stacked groove of the multi-stage printed circuit board is obtained.

[0037] The above are only preferred embodiments of the present invention. It should be pointed out that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention. These should also be regarded as the protection scope of the present invention. These will not affect the effect of the implementation of the present invention and the practicality of the patent.

Claims

1. A multi-stage printed circuit board processing method, characterized in that: The steps include: Performing a lamination operation on the printed circuit board on which the circuit pattern is arranged, laminating the insulating substrate (1) and the copper foil (2) on the printed circuit board in sequence; Opening high-speed signal holes (3) at target positions of the insulating substrate (1) and the copper foil (2); A signal shielding groove (4) is provided on the outer side of the high-speed signal hole (3) and surrounds the high-speed signal hole (3); Performing chemical copper deposition and hole plugging copper coating operations on the signal shielding slot (4); Arranging a circuit pattern on the copper foil (2) to obtain the printed circuit board with the circuit pattern arranged; Repeat the above steps to obtain a multi-level printed circuit board.

2. The multi-stage printed circuit board processing method according to claim 1, characterized in that: A signal shielding groove (4) is provided on the outer side of the high-speed signal hole (3) and around the high-speed signal hole (3), comprising: The signal shielding groove (4) is formed by a laser through a circumferential burning and superimposed punching method, and a plurality of deep blind holes (5) are made by laser so that adjacent deep blind holes (5) partially overlap, thereby forming the signal shielding groove (4) surrounding the high-speed signal hole (3).

3. The multi-stage printed circuit board processing method according to claim 2, characterized in that: The diameters of the high-speed signal hole (3) and the deep blind hole (5) are both A, 5mil≤A≤8mil; The center distance between two adjacent deep blind holes (5) is between 1 mil and 1 / 2A.

4. The multi-stage printed circuit board processing method according to claim 1, characterized in that: A signal shielding groove (4) is provided on the outer side of the high-speed signal hole (3) and surrounds the high-speed signal hole (3), and further comprises: At the connection between the non-high-speed signal line (6) and the high-speed signal hole (3), the signal shielding groove (4) is a closed ring surrounding the high-speed signal hole (3); At a location where a high-speed signal line (6) is connected to the high-speed signal hole (3), the signal shielding groove (4) is in a "U" shape surrounding the high-speed signal hole (3), and the high-speed signal line (6) is electrically connected to the outside of the signal shielding groove (4) through an opening of the "U" shape.

5. The multi-stage printed circuit board processing method according to claim 1, characterized in that: The chemical copper deposition and hole plugging copper coating operations on the signal shielding slot (4) include: Depositing a copper plating layer at the signal shielding groove (4) by a chemical copper plating process; Filling the signal shielding groove (4) with resin by vacuum plugging; A layer of copper is plated on the signal shielding groove (4) by electroplating.

6. The multi-stage printed circuit board processing method according to claim 1, characterized in that: Arranging a circuit pattern on the copper foil (2) to obtain the printed circuit board having the circuit pattern arranged comprises: The copper foil (2) is etched to form a circuit pattern, the circuit pattern comprising a copper bar (7), a high-speed signal line (6), and a signal hole pad (8), the signal hole pad (8) being arranged around the high-speed signal hole (3), an isolation ring (9) being arranged on the periphery of the signal hole pad (8), the high-speed signal line (6) being electrically connected to the high-speed signal hole (3) through the signal hole pad (9), the copper bar (7) being arranged on the outside of the isolation ring (9), the copper bar (7) being arranged in a "U" shape, and the high-speed signal line (6) being electrically connected to the outside of the copper bar (7) through the opening of the "U" shape.

7. A multi-level printed circuit board as claimed in any one of claims 1 to 6, comprising a signal layer, a P / G layer and a plurality of high-speed signal holes (3), characterized in that: A plurality of the high-speed signal holes (3) are used to connect different signal layers or the P / G layers. A high-speed signal line (6) is electrically connected to the high-speed signal hole (3). Signal shielding grooves (4) are correspondingly provided between each of the signal layers and the P / G layers through which the high-speed signal hole (3) passes. A plurality of the signal shielding grooves (4) in adjacent layers are stacked to form signal shielding stacked grooves extending to both ends of the high-speed signal hole (3).

8. The multi-level printed circuit board according to claim 7, characterized in that: The signal shielding groove (4) is circumferentially closed and arranged outside the high-speed signal hole (3); the signal shielding groove (4) correspondingly opened on the signal layer provided with the high-speed signal line (6) is provided with an opening for the high-speed signal line (6) to pass through.

9. A signal shielding slot of a multi-stage printed circuit board as claimed in any one of claims 1 to 6, characterized in that: A plurality of signal shielding slots (4) located at corresponding positions and having undergone chemical copper deposition, hole plugging and copper coating operations are stacked up and down to form signal shielding stacked slots extending to both ends of the high-speed signal hole (3).

10. A signal shielding slot for a multi-level printed circuit board as claimed in claim 9, characterized in that: The signal shielding stack groove is provided with an opening for the high-speed signal line (6) to pass through.

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