Method for processing via of ptfecollimated circuit board and circuit board

Abstract

The application relates to the field of printed wiring board manufacturing, and discloses a processing method of a PTFE laminated wiring board via hole and a wiring board. The processing method of the PTFE laminated wiring board via hole comprises the following steps: providing a substrate, the substrate comprising a wiring layer and a PTFE layer which are arranged in a stack, the substrate having a first side and a second side which are opposite to each other; processing a via hole on the substrate by using a mechanical drilling method from the first side, the via hole penetrating through the wiring layer and the PTFE layer; and performing a glue removing treatment on the via hole by using a CO2 laser from the second side, wherein the aperture of the CO2 laser is coaxially arranged with the via hole, and the diameter of the aperture is larger than that of the via hole. The processing method of the PTFE laminated wiring board via hole and the wiring board can solve the problem that, in the prior art, all the residues in the via holes cannot be removed completely, thereby causing that the wiring layers of the wiring board cannot be effectively connected after subsequent copper plating, and resulting in the functional open-circuit defect.

Description

Technical Field

[0001] This application relates to the field of printed circuit board manufacturing, and more particularly to a method for processing through holes in a PTFE laminated circuit board and the circuit board thereof. Background Technology

[0002] Some special-purpose circuit boards on the market, such as multilayer boards, require the use of PTFE (Polytetrafluoroethylene) laminates, and through-holes need to be machined on these PTFE laminated circuit boards. Generally, the conventional method for machining through-holes on PTFE laminated circuit boards is to first mechanically drill the holes, and then use processes such as adhesive removal, plasma washing, high-pressure water washing, and board grinding to further improve the problem of adhesive residue clogging the holes.

[0003] Because the PTFE laminate uses a composite PTFE structure, which is relatively soft and sticky, conventional processing methods can easily pull the connecting layer of the through-hole wall to the center of the hole, forming glue residue and causing glue residue blockage. Even with subsequent treatments such as plasma (or glue removal), high-pressure water washing, and grinding, it is impossible to guarantee that all glue residue in the through-hole is completely removed. Consequently, during the subsequent copper plating process, the glue residue in the through-hole prevents the black shadow and copper plating solution from properly and evenly soaking the hole wall. After copper plating, the circuit layers cannot be effectively connected, resulting in functional open circuit defects. Summary of the Invention

[0004] This application provides a method for processing through holes in a PTFE laminated circuit board and a circuit board in general. This method can improve the problem in related technologies where it is impossible to ensure that all slag in the through holes is completely removed, which leads to ineffective connection between the circuit layers after copper plating and causes functional open circuit defects.

[0005] In a first aspect, embodiments of this application provide a method for processing through-holes in a PTFE laminated circuit board, including:

[0006] A substrate is provided, the substrate comprising a circuit layer and a PTFE layer stacked together, the substrate having a first side and a second side opposite to each other;

[0007] A through-hole is machined on the substrate from the first side using mechanical drilling, and the through-hole penetrates the circuit layer and the PTFE layer;

[0008] The through hole is cleaned using a CO2 laser from the second side. The aperture of the CO2 laser is coaxially arranged with the through hole, and the diameter of the aperture is larger than the diameter of the through hole.

[0009] In some embodiments, when a through hole is machined on the substrate by mechanical drilling from the first side, a positioning hole is machined on the substrate; using the positioning hole as a positioning reference, the through hole is descaled by CO2 laser from the second side.

[0010] In some embodiments, the number of positioning holes is multiple, and the multiple positioning holes are distributed at intervals.

[0011] In some embodiments, the difference between the diameter of the aperture and the diameter of the through hole is 0.075mm-0.150mm.

[0012] In some embodiments, the CO2 laser uses a pulsed wave with a pulse width of 10μs-15μs, a main reference energy of 20mj-30mj, and a pulse number of 1Shot-3Shot.

[0013] In some embodiments, there are multiple circuit layers and multiple PTFE layers, and at least one circuit layer is disposed between two adjacent PTFE layers.

[0014] In some embodiments, the circuit layer includes circuits and reinforcements, the circuits and reinforcements are spaced apart, and there are multiple through holes, some of which penetrate the circuits and the PTFE layer, and some of which penetrate the reinforcements and the PTFE layer.

[0015] In some embodiments, the substrate further includes a connection layer, a portion of which is located between two adjacent PTFE layers, and a portion of which is located between the circuit layer and the PTFE layer.

[0016] In some embodiments, after the through-hole is descaled using a CO2 laser from the second side, the substrate is subjected to grinding and / or plasma treatment.

[0017] Secondly, embodiments of this application provide a circuit board manufactured using the PTFE stacked circuit board through-hole processing method described in the first aspect.

[0018] The PTFE laminate circuit board through-hole processing method provided in this application has the following advantages: First, through-holes are processed on the substrate using mechanical drilling from the first side, penetrating the circuit layer and the PTFE layer. Then, the through-holes are cleaned using CO2 laser from the second side. The aperture of the CO2 laser is coaxially set with the through-hole, and the diameter of the aperture is larger than the diameter of the through-hole. Therefore, not only can all the adhesive residue inside the through-hole be completely vaporized, thus removing all the adhesive residue and preventing abnormal blockage of the through-hole by adhesive residue, but the circuit layers of the circuit board can be effectively connected after subsequent copper plating, ensuring the functionality of the circuit board. Furthermore, it can avoid the problem of poor copper breakage after subsequent copper plating caused by excessive concavity of the through-hole wall.

[0019] The advantages of the circuit board provided in this application compared to the prior art can be seen in the description of the advantages of the PTFE laminate circuit board through-hole processing method provided in this application compared to the prior art, which will not be repeated here. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application, 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 this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of a circuit board in the prior art;

[0022] Figure 2 Using existing processing methods Figure 1 The diagram shown is a schematic of the circuit board after cleaning and descaling.

[0023] Figure 3 This is a flowchart of a method for processing through-holes in a PTFE laminated circuit board according to one embodiment of this application;

[0024] Figure 4 This is a schematic diagram of the substrate structure in one embodiment of this application;

[0025] Figure 5 It is achieved by using mechanical drilling on the first side. Figure 4 A schematic diagram showing through-holes machined on a substrate;

[0026] Figure 6 It is done by using CO2 laser on the second side Figure 5 A schematic diagram showing the process of cleaning adhesive from the through-hole;

[0027] Figure 7It is done by using CO2 laser on the second side Figure 5 The diagram shows the through-hole after the adhesive removal process.

[0028] The markings in the diagram mean:

[0029] 1. Circuit board; 2. Through-hole; 3. Adhesive residue;

[0030] 100. Substrate;

[0031] 101. First side; 102. Second side; 10. Circuit layer; 11. Circuit; 12. Reinforcing section; 20. PTFE layer; 30. Connecting layer; 40. Through hole; 50. Adhesive residue;

[0032] 200. Drill bit;

[0033] 300. Laser head. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0035] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0036] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0037] In this specification, references to "one embodiment," "some embodiments," or simply "embodiment" mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. Furthermore, in one or more embodiments, specific features, structures, or characteristics may be combined in any suitable manner.

[0038] To illustrate the technical solution of this application, the following description is provided in conjunction with specific accompanying drawings and embodiments.

[0039] Some special-purpose circuit boards on the market, such as multilayer boards, require the use of PTFE laminates, and through-holes need to be machined on these PTFE laminate circuit boards. Generally, the conventional method for machining through-holes on PTFE laminate circuit boards is to first mechanically drill the holes, and then use processes such as adhesive removal, plasma washing, high-pressure water washing, and board grinding to further improve the problem of adhesive residue clogging the holes.

[0040] Please refer to Figure 1 and Figure 2 , Figure 1 This is a schematic diagram of the structure of circuit board 1 in the prior art. Figure 2 Using existing processing methods Figure 1 The diagram shown is a schematic of the circuit board 1 after cleaning and descaling.

[0041] Because the PTFE laminate uses a composite PTFE structure, which is relatively soft and sticky, when the circuit board 1 is manufactured using conventional processing methods, the PTFE and other dielectric layers on the hole walls of the through-hole 2 are easily pulled to the center of the hole, forming glue residue 3. This causes glue residue blockage. Even if plasma (or glue removal), high-pressure water washing, and grinding processes are used for subsequent treatment, it is impossible to guarantee that all glue residue 3 in the through-hole 2 is completely removed. Consequently, during the subsequent copper plating process, due to the obstruction of glue residue 3 in the through-hole 2, the black shadow and copper plating solution cannot be properly and evenly soaked in the hole walls. After copper plating, the circuit layers of the circuit board 1 cannot be effectively connected, resulting in functional open circuit defects.

[0042] In view of this, this application provides a method for processing through-holes in a PTFE laminated circuit board and a circuit board in general. First, through-holes are machined on the substrate from a first side, penetrating both the circuit layer and the PTFE layer. Then, from a second side, CO2 laser is used to remove the adhesive residue from the through-holes. The aperture of the CO2 laser is coaxially set with the through-hole, and its diameter is larger than the diameter of the through-hole. Therefore, not only can all the adhesive residue inside the through-hole be completely vaporized, thus removing all the adhesive residue and preventing abnormal blockage, but the circuit layers can also be effectively connected after subsequent copper plating, ensuring the functionality of the circuit board. Furthermore, it avoids the problem of copper breakage after subsequent copper plating caused by excessive concavity in the through-hole wall.

[0043] Please refer to Figures 3 to 7 , Figure 3 This is a flowchart of a method for processing the through-hole 40 of a PTFE laminated circuit board in one embodiment of this application. Figure 4 This is a schematic diagram of the structure of the substrate 100 in one embodiment of this application. Figure 5It is made by mechanical drilling on the first side 101. Figure 4 A schematic diagram showing a through hole 40 machined on the substrate 100 is shown. Figure 6 It is done by using CO2 laser on the second side 102. Figure 5 The diagram shown illustrates the process of cleaning adhesive from the through-hole 40. Figure 7 It is done by using CO2 laser on the second side 102. Figure 5 The diagram shows the through hole 40 after the adhesive removal process.

[0044] In a first aspect, embodiments of this application provide a method for processing a through-hole 40 in a PTFE laminated circuit board, comprising:

[0045] S100: A substrate 100 is provided, the substrate 100 including a circuit layer 10 and a PTFE layer 20 stacked together, the substrate 100 having a first side 101 and a second side 102 opposite to each other.

[0046] Specifically, the substrate 100 can undergo processes such as material cutting, primary drilling, layer pattern circuit 11, inner layer AOI (Automated Optical Inspection), browning and lamination, punching, glue removal, copper reduction, and X-ray drilling.

[0047] Cutting: The material is cut into sheets and then transferred to the drilling process.

[0048] One-time drilling: Drilling positioning holes for stacked boards and inner layer pattern exposure positioning holes.

[0049] Inner layer pattern circuitry: Exposure, development, and etching to create the inner layer circuitry.

[0050] Inner layer AOI: Scanning to confirm the quality of the inner layer product.

[0051] Browning: Roughens the copper surface of the inner layer product to improve the bonding strength during lamination.

[0052] Laminate lamination: Use the pre-drilled lamination positioning holes to position the laminate, and then laminate it with the outer layer material and thermosetting adhesive.

[0053] Punching: Punching away the edges of the waste material to prevent it from contaminating the horizontal line and to facilitate subsequent operations.

[0054] Adhesive removal: Remove excess adhesive from the board surface and edges to prevent quality defects caused by residual adhesive during subsequent copper plating and patterning.

[0055] Copper reduction: The copper thickness of the outer layer material is reduced to prepare for subsequent pattern circuitry.

[0056] X-Ray drill target: Identifies inner layer PADs (pads) to drill positioning holes for mechanical drilling and classifies products by expansion and contraction.

[0057] The number of circuit layers 10 and the number of PTFE layers 20 can be multiple. The PTFE layers 20 are located between two adjacent circuit layers 10. The circuit layers 10 can be copper layers. A connecting layer 30, such as an AD (adhesive) layer, can also be provided to connect two adjacent PTFE layers 20 and adjacent circuit layers 10 and PTFE layers 20. The PTFE layers 20 and the connecting layer 30 can form a dielectric layer.

[0058] S200: A through hole 40 is machined on the substrate 100 by mechanical drilling from the first side 101. The through hole 40 penetrates the circuit layer 10 and the PTFE layer 20.

[0059] Specifically, a drill bit 200 of a drilling machine can be used to process through-holes 40 on the substrate 100. One or more through-holes 40 can be provided, and drilling can be performed from the first layer to the Nth layer of the substrate 100. When there are multiple circuit layers 10 and multiple PTFE layers 20, the through-holes 40 can penetrate all circuit layers 10 and all PTFE layers 20. The through-holes 40 can also penetrate the connection layer 30.

[0060] For example, the diameter of the through hole 40 can be 0.15mm-0.25mm. A matching drill bit 200 with a target hole diameter of 0.15mm-0.25mm can be used with a mechanical drilling machine, and the corresponding expansion and contraction drill tape can be selected to machine the through hole 40. The size of the drill bit 200 used for mechanical drilling can be selected according to the conventional production design requirements without special treatment. The rotation speed is generally set to 160krpm-180krpm, the cutting speed is generally set to 1.8m / min-2.0m / min, the retraction speed is generally set to 18m / min-20m / min, and the life is 600Hits-1000Hits.

[0061] The purpose of machine drilling through holes 40 is to first drill out the hole shape of through holes 40. Because this type of circuit board has thick copper and many layers, it is not practical to directly use laser drilling for through holes 40. Due to the large number of layers and thick copper, laser drilling requires repeated laser ablation, which can easily lead to the hole shape of through holes 40 being trumpet-shaped, the hole shape being not perpendicular enough, and the hole wall roughness being poor. This is not only inefficient, but the hole shape also does not meet the product requirements.

[0062] It is understandable that after the through hole 40 is machined on the substrate 100 by mechanical drilling from the first side 101, because the PTFE layer 20 material is relatively soft and sticky, the PTFE layer 20 and the connecting layer 30 of the hole wall of the through hole 40 are easily pulled to the center of the hole during the mechanical drilling process, thus forming adhesive residue 50 and causing the hole to be blocked.

[0063] S300: The through hole 40 is cleaned by CO2 laser using the second side 102. The aperture of the CO2 laser is set coaxially with the through hole 40, and the diameter of the aperture is larger than the diameter of the through hole 40.

[0064] Specifically, the laser head 300 of the CO2 laser equipment can be used to select the corresponding expansion and contraction drill tape to perform adhesive removal treatment on the through hole 40. The through hole 40 can be treated by CO2 laser in the direction from the Nth layer to the 1st layer.

[0065] Because the aperture of the CO2 laser is coaxially set with the through hole 40, and the diameter of the aperture is larger than the diameter of the through hole 40, when the CO2 laser is used to remove the adhesive from the through hole 40 by the second side 102, the outer ring of the laser cross section covers the through hole 40 that needs to be removed. Therefore, all the adhesive residue 50 inside the through hole 40 can be completely vaporized, thereby removing all the adhesive residue 50 inside the through hole 40 and preventing the abnormal blockage of the hole by adhesive residue. After subsequent copper plating, the circuit layers 10 of the circuit board can be effectively connected, ensuring the functionality of the circuit board.

[0066] Understandably, the first side 101 can be placed facing upwards first. After the through hole 40 is machined on the substrate 100 using mechanical drilling on the first side 101, the second side 102 can be placed facing upwards, and then the through hole 40 can be cleaned using CO2 laser on the second side 102.

[0067] It is also understandable that CO2 laser is different from UV (Ultraviolet Rays) laser. CO2 laser cannot act on the circuit layer 10 (copper layer) that has not been browned or blackened. It will not damage the hole wall and hole surface due to energy greater than the hole diameter. It can ensure the hole diameter and hole shape while cleaning the adhesive residue 50 inside the through hole 40. It can avoid the problem of incomplete adhesive removal caused by the difference in precision between two drillings.

[0068] It should be noted that since the through hole 40 is first machined on the substrate 100 by mechanical drilling from the first side 101, the drilling bit 200 will take a relatively long time to act on the PTFE layer 20 and the connecting layer 30 corresponding to the first side 101 (upper layer). Therefore, the inward shrinkage at the PTFE layer 20 and the connecting layer 30 corresponding to the through hole 40 will also be relatively large. If the through hole 40 is then cleaned by CO2 laser from the first side 101, that is, when the direction of machining the through hole 40 on the substrate 100 by mechanical drilling is the same as the direction of cleaning the through hole 40 by CO2 laser, the inward shrinkage at the PTFE layer 20 and the connecting layer 30 corresponding to the through hole 40 will be further increased. This can easily cause the hole wall of the through hole 40 to be too concave, resulting in poor copper breakage after subsequent copper plating. Therefore, reverse cleaning is required when cleaning the through hole 40.

[0069] As can be seen from the above, the PTFE stacked circuit board through-hole 40 processing method provided in this application embodiment is used to process the through-hole 40 on the substrate 100 by mechanical drilling from the first side 101. The through-hole 40 penetrates the circuit layer 10 and the PTFE layer 20. Then, the through-hole 40 is cleaned by CO2 laser from the second side 102. The aperture of the CO2 laser is coaxially set with the through-hole 40, and the diameter of the aperture is larger than the diameter of the through-hole 40. Therefore, not only can all the adhesive residue 50 inside the through-hole 40 be completely vaporized, thereby removing all the adhesive residue 50 inside the through-hole 40 and preventing the abnormal blockage of the hole by adhesive residue, but also the circuit layers 10 of the circuit board can be effectively connected after subsequent copper plating, ensuring the functionality of the circuit board. Furthermore, it can avoid the problem of poor copper breakage after subsequent copper plating caused by excessive concavity of the hole wall of the through-hole 40.

[0070] In order to improve the alignment between the aperture used by the CO2 laser and the through hole 40 when the through hole 40 is cleaned by the second side 102 using a CO2 laser, in this embodiment, when the through hole 40 is machined on the substrate 100 by the first side 101 using a mechanical drilling method, a positioning hole is machined on the substrate 100; the through hole 40 is cleaned by the second side 102 using a CO2 laser with the positioning hole as the positioning reference.

[0071] By adopting the above solution, the aperture used by the CO2 laser can be well matched with the position of the through hole 40, which can ensure effective removal of adhesive for each through hole 40 and avoid the problem of poor interlayer conductivity caused by adhesive residue blocking.

[0072] Optionally, there may be multiple positioning holes, and these positioning holes may be spaced apart.

[0073] This setup allows for better cleaning of the through hole 40 using a CO2 laser from the second side 102, with the positioning hole serving as the positioning reference.

[0074] For example, four positioning holes with a diameter of 0.5mm can be set, and these four positioning holes can be designed on the four corner process edges of the circuit board panel.

[0075] It should be noted that when the through hole 40 is machined on the substrate 100 by mechanical drilling on the first side 101, a tool hole is machined on the substrate 100. The tool hole is mainly used for positioning in the subsequent process. The requirements for the hole wall quality of this type of hole are not high, and the internal multilayer board parameters can be used.

[0076] Optionally, the difference between the diameter of the aperture and the diameter of the through hole 40 is 0.075mm-0.150mm, such as 0.075mm, 0.100mm, 0.125mm or 0.150mm.

[0077] This design allows all adhesive residue 50 inside the through-hole 40 to be completely vaporized, thus removing all adhesive residue 50 from the through-hole 40 and preventing adhesive residue from clogging the hole. This ensures effective connection between the circuit layers 10 of the circuit board after subsequent copper plating, guaranteeing the functionality of the circuit board.

[0078] For example, the aperture of the through hole 40 is 0.15mm, and an aperture (mask) with a matching aperture of 0.225mm-0.3mm is selected when performing CO2 laser engraving.

[0079] Please refer to Figure 6 In this embodiment, the CO2 laser uses a pulsed wave with a pulse width of 10μs-15μs, a main reference energy of 20mj-30mj, and a pulse number of 1Shot-3Shot.

[0080] By adopting the above solution, it can be ensured that the adhesive residue 50 inside the through hole 40 is cleaned up without damaging the hole wall or surface of the through hole 40.

[0081] There are multiple line layers 10 and multiple PTFE layers 20, and at least one line layer 10 is provided between two adjacent PTFE layers 20.

[0082] With this configuration, the PTFE stacked circuit board through-hole 40 processing method provided in this application embodiment can be used to fabricate multi-layer circuit boards.

[0083] For example, the circuit board manufactured by the processing method of the PTFE stacked circuit board through-hole 40 provided in the embodiments of this application can be a high-frequency high-speed FPC (Flexible Printed Circuit) thick copper multilayer board.

[0084] Optionally, the circuit layer 10 includes a circuit 11 and a reinforcing part 12, with the circuit 11 and the reinforcing part 12 spaced apart. There are multiple through holes 40, some of which penetrate the circuit 11 and the PTFE layer 20, and some of which penetrate the reinforcing part 12 and the PTFE layer 20.

[0085] With this configuration, the reinforcing part 12 can provide stable support for the PTFE layer 20, and when the through hole 40 is machined on the substrate 100 by mechanical drilling from the first side 101, the problem of hole blockage caused by the pulling of the drill bit 200 on the PTFE layer 20 can be avoided.

[0086] For example, the reinforcement 12 can be a dummy copper pad.

[0087] Optionally, the substrate 100 further includes a connection layer 30, a portion of which is located between two adjacent PTFE layers 20, and a portion of which is located between the circuit layer 10 and the PTFE layer 20.

[0088] With this configuration, the PTFE stacked circuit board through-hole 40 processing method provided in this application embodiment can be used to manufacture multi-layer circuit boards, and the two PTFE layers 20 and the adjacent circuit layer 10 and PTFE layer 20 are tightly connected.

[0089] For example, the bonding layer 30 may be an AD adhesive, etc.

[0090] Optionally, after the through hole 40 is cleaned by CO2 laser treatment on the second side 102, the substrate 100 is subjected to grinding and / or plasma treatment.

[0091] This configuration allows for the removal of burrs on the circuit layer 10 that may be generated when the via 40 is machined on the substrate 100 by mechanical drilling from the first side 101 through grinding. It also allows for the removal of carbon powder inside the via 40 through plasma treatment of the substrate 100, roughening the hole walls of the via 40, and facilitating subsequent shading and copper plating.

[0092] The substrate 100 provided in this application embodiment can be a multilayer board. In one embodiment, the substrate 100 sequentially includes a circuit layer 10 (12 μm thick), a PTFE layer 20 (100 μm thick), an AD adhesive (25 μm thick), a circuit layer 10 (18 μm thick), a PTFE layer 20 (100 μm thick), a circuit layer 10 (18 μm thick), an AD adhesive (25 μm thick), a PTFE layer 20 (100 μm thick), and a circuit layer 10 (12 μm thick). In another embodiment, the substrate 100 sequentially includes a circuit layer 10 (12 μm thick), a PTFE layer 20 (100 μm thick), an AD adhesive (25 μm thick), a PTFE layer 20 (100 μm thick), an AD adhesive (25 μm thick), a PTFE layer 20 (100 μm thick), and a circuit layer 10 (12 μm thick).

[0093] The diameter of the through hole 40 is 0.15mm-0.25mm. The speed of the drill bit 200 used for mechanical drilling is set to 160krpm-180krpm. The cutting speed is generally set to 1.8m / min-2.0m / min, the retraction speed is generally set to 18m / min-20m / min, and the lifespan is 600Hits-1000Hits.

[0094] When the through-hole 40 is cleaned using a CO2 laser from the second side 102, it includes three laser cutting sequences: Rool 1 has a pulse width of 10μs-15μs, a master reference energy of 20mJ-30mJ, and a pulse count of 1-3 shots, corresponding to an aperture diameter of 0.225mm-0.3mm; Rool 2 has a pulse width of 10μs-15μs, a pulse count of 1-3 shots, and a corresponding aperture diameter of 0.225mm-0.3mm; Rool 3 has a pulse width of 10μs-15μs, a pulse count of 1-3 shots, and a corresponding aperture diameter of 0.225mm-0.3mm.

[0095] It should be noted that when the material stacking of the substrate 100 to be processed and the diameter of the through hole 40 are different, the processing parameters can be adjusted appropriately.

[0096] Secondly, embodiments of this application provide a circuit board manufactured by the processing method of PTFE stacked circuit board through-hole 40 as described in the first aspect.

[0097] The circuit board provided in this application embodiment first uses mechanical drilling to process through-holes 40 on the substrate 100 from the first side 101. The through-holes 40 penetrate the circuit layer 10 and the PTFE layer 20. Then, the through-holes 40 are cleaned by CO2 laser from the second side 102. The aperture of the CO2 laser is coaxially set with the through-holes 40, and the diameter of the aperture is larger than the diameter of the through-holes 40. Therefore, not only can all the adhesive residue 50 inside the through-holes 40 be completely vaporized, thereby removing all the adhesive residue 50 inside the through-holes 40 and preventing abnormal blockage of the holes by adhesive residue, but also the circuit layers 10 of the circuit board can be effectively connected after subsequent copper plating, ensuring the functionality of the circuit board. Furthermore, it can avoid the problem of poor copper breakage after subsequent copper plating caused by excessive concavity of the hole wall of the through-holes 40.

[0098] 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 of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A method for processing through holes in a PTFE laminated circuit board, characterized in that, include: A substrate is provided, the substrate comprising a circuit layer and a PTFE layer stacked together, the substrate having a first side and a second side opposite to each other; One or more through holes are formed on the substrate by mechanical drilling from the first side, and the through holes penetrate the circuit layer and the PTFE layer. The through hole is cleaned using a CO2 laser from the second side. The aperture of the CO2 laser is coaxially arranged with the through hole, and the diameter of the aperture is larger than the diameter of the through hole.

2. The method for processing through holes in a PTFE laminated circuit board according to claim 1, characterized in that, When a through hole is machined on the substrate by mechanical drilling from the first side, a positioning hole is machined on the substrate; using the positioning hole as a positioning reference, the through hole is descaled by CO2 laser from the second side.

3. The method for processing through holes in a PTFE laminated circuit board according to claim 2, characterized in that, The number of positioning holes is multiple, and the multiple positioning holes are distributed at intervals.

4. The method for processing through holes in a PTFE laminated circuit board according to claim 1, characterized in that, The difference between the diameter of the aperture and the diameter of the through hole is 0.075mm-0.150mm.

5. The method for processing through holes in a PTFE laminated circuit board according to claim 1, characterized in that, The CO2 laser uses pulsed waves with a pulse width of 10μs-15μs, a main reference energy of 20mj-30mj, and a pulse number of 1Shot-3Shot.

6. The method for processing through-holes in a PTFE laminated circuit board according to any one of claims 1 to 5, characterized in that, The number of the circuit layers and the number of the PTFE layers are both multiple, and at least one circuit layer is provided between two adjacent PTFE layers.

7. The method for processing through holes in a PTFE laminated circuit board according to claim 6, characterized in that, The circuit layer includes circuits and reinforcing parts, with the circuits and reinforcing parts spaced apart. There are multiple through holes, some of which penetrate the circuits and the PTFE layer, and some of which penetrate the reinforcing parts and the PTFE layer.

8. The method for processing through holes in a PTFE laminated circuit board according to claim 6, characterized in that, The substrate further includes a connection layer, part of which is located between two adjacent PTFE layers, and part of which is located between the circuit layer and the PTFE layer.

9. The method for processing through-holes in a PTFE laminated circuit board according to any one of claims 1 to 5, characterized in that, After the through-hole is cleaned by CO2 laser from the second side, the substrate is then subjected to grinding and / or plasma treatment.

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