Method for producing and manufacturing PCB (Printed Circuit Board) depth-control milling groove

Abstract

The invention belongs to the field of PCB (printed circuit board) processing, and particularly relates to a PCB depth-control milling groove production and manufacturing method which comprises the following steps: S1, material pressing: a substrate, a prepreg and a copper foil material are formed into a whole by a pressing machine through a pressing process to manufacture a PCB substrate; s2, burr polishing is carried out, a polishing and brushing machine is used for carrying out burr polishing on the PCB substrate, and the polishing and brushing machine carries out polishing 2-3 times at the speed of 4.0 + / -0.5 m / min; s3, copper plating: the PCB substrate is subjected to copper plating treatment, and the copper plating process comprises PTH copper deposition and copper plating; s4, the paperboard is fixed to a bakelite plate of a CNC equipment table top, positioning drilling is conducted according to PCB product positioning data, and scraps and sundries in holes are cleaned, through the arrangement of the method, the production and quality problems can be effectively controlled, the production quality of the depth-control gong is improved, a leveling paperboard is designed before the gong plate is designed for the depth-control gong groove, and the production efficiency of the depth-control gong groove is improved. The board can be placed flatly, the depth can be controlled uniformly, the gong depths of all shafts are on the same level, and the quality of the gong with the depth controlled is improved.

Description

Technical Field

[0001] This invention relates to the field of PCB board processing, specifically a method for producing controlled-depth grooves on PCB boards. Background Technology

[0002] At present, electronic PCBs are developing and being laid out in a high-end, precise and advanced direction. Making full use of space and making products thin, light and small have become the research and development direction. How to fix the various components on the PCB board without wasting space has become a problem that must be solved. The design of PCB board control depth routing provides a solution for this design.

[0003] Controlled-depth slots are a precision machining process in PCB manufacturing achieved through CNC milling. Controlled-depth slots precisely remove part of the dielectric material, forming steps or local grooves. They often do not cut through the entire board, but remain at a specific depth to meet some special structural or functional requirements, such as in BGA step design, device embedding areas, and copper block heat dissipation areas.

[0004] However, in actual production, depth control routers may encounter problems such as copper adhesion, no copper in the hole, burrs, uneven bottom, copper shavings, copper blistering, insufficient depth control, and uneven depth control. Therefore, a method for manufacturing depth control router slots on PCB boards is proposed to address these issues. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies and solve at least one of the technical problems mentioned in the background art, this invention proposes a method for manufacturing controlled deep slots on PCB boards.

[0006] The technical solution adopted by this invention to solve its technical problem is: a method for manufacturing controlled-depth router slots on a PCB board, comprising the following steps:

[0007] S1: Pressing materials, using a press to press the substrate, prepreg and copper foil materials into a whole to make a PCB substrate;

[0008] S2: Snap polishing. Use a brush polisher to snap the PCB substrate. The brush polisher polishes 2-3 times at a speed of 4.0±0.5m / min.

[0009] S3: Copper plating, copper plating treatment of PCB substrate, the copper plating process includes PTH copper plating and copper plating.

[0010] S4: Fix the cardboard onto the bakelite board on the CNC machine table, drill positioning holes according to the PCB product positioning data, clean the debris and foreign matter in the holes, and then install the anti-foolproof pins for positioning.

[0011] S5: Depth control milling machine. Fix the PCB on the bakelite board, place cardboard at the bottom of the PCB substrate, and cover the surface of the PCB with another layer of cardboard. Use a flat-bottom milling cutter to process the depth control groove on the PCB.

[0012] S6: Clean the PCB substrate to remove residual powder and oil from the depth control tank, board surface and holes.

[0013] Preferably, in S5, when the depth control position intersects with the subsequent forming process, a CNC secondary forming process is added.

[0014] Preferably, in S3 and S4, the cardboard surface or local area needs to be precisely milled and leveled using CNC milling equipment to eliminate thickness deviations and unevenness on the cardboard surface, or to make specific areas reach a uniform target thickness. A 2.4mm milling cutter is used during processing.

[0015] Preferably, in step S4, before processing the PCB substrate, the PP powder and copper wire residue on the surface of the PCB substrate are cleaned to ensure that there are no impurities on the PCB substrate that affect the depth or thickness. After each PCB board is removed from the substrate and before it is installed, the impurities and PP powder on the cardboard are cleaned.

[0016] Preferably, in S1, the process of pressing the material includes the following steps:

[0017] A1: Inspect the appearance of each substrate, PP sheet, and copper foil material, and remove materials with wrinkles, damage, or impurities;

[0018] A2: Cut the substrate, prepreg, and copper foil materials to the corresponding size according to the PCB board design, and clean the surface of the materials to remove oil and dust;

[0019] A3: Pre-stack the materials in the order of substrate - prepreg - copper foil - prepreg - substrate, and align each layer;

[0020] A4: Place the pre-stacked materials into the pressing mold, lay a high-temperature resistant release film inside the mold, and vacuum the inside of the mold.

[0021] A5: Heat the mold and start the press to apply pressure. The pressure and temperature need to be increased at a constant rate to press the material under high temperature and high pressure.

[0022] A6: After pressing, the mold is allowed to cool naturally to below 50°C before demolding to obtain the PCB substrate.

[0023] Preferably, in A6, after the PCB substrate is demolded, a CNC milling machine is used to trim the edges to remove excess PP sheet adhesive from the substrate edges. The trimming tolerance is ±0.2mm. During the CNC milling process, a vacuum dust removal system is used to remove resin powder and adhesive residue generated during the trimming process in real time.

[0024] Preferably, in step S5, the controlled depth milling process stacking is performed at 1PNL / stack or 1SET / stack.

[0025] Preferably, in S6, the cleaning process for the PCB substrate includes the following steps:

[0026] B1: Use a vacuum gun to aim at the depth control tank and the board surface, and slowly move it along the tank wall to remove the resin powder and copper powder from the tank and the board surface;

[0027] B2: Use a lint-free cloth dampened with isopropyl alcohol to wipe the surface of the depth control tank to remove surface oil and residual powder stains;

[0028] B3: Use an ultrasonic cleaner and cleaning agent to perform ultrasonic cleaning on the PCB substrate for 3-5 minutes;

[0029] B4: Transfer the PCB substrate to a deionized water bath and ultrasonically rinse twice, 2-3 minutes each time, to remove residual cleaning agent from the PCB substrate.

[0030] B5: Place the rinsed PCB board into the drying oven with the depth control groove of the PCB board facing upwards, and dry for 15-20 minutes at 60-80℃.

[0031] B6: Use a metallographic microscope to observe the walls and bottom of the depth control tank to confirm that there is no residue of powder, slag, or oil; at the same time, check whether there are micro-cracks on the tank wall caused by ultrasonic cleaning.

[0032] The advantages of this invention are:

[0033] 1. By setting the above method, the present invention can effectively control production and quality issues, improve the production quality of depth control mills, and design a leveling cardboard in front of the milling plate to ensure that the plate is placed flat and the depth control depth is uniform, so that the milling depth of each axis is at the same level, thereby improving the quality of depth control mills.

[0034] 2. This invention establishes a post-deep-tuning cleaning process for PCB substrates. Through this cleaning process, the cleaning effect within the depth-tuning tank of the PCB substrate can be guaranteed, removing residual powder, slag, and oil from the depth-tuning tank, board surface, and holes. This ensures the quality of the PCB substrate and prevents bubbles and pinholes in subsequent solder mask and gold plating processes. Simultaneously, the walls and bottom of the depth-tuning tank are inspected under a microscope to determine the cleaning effect, ensuring processing quality. The tank walls are also checked for microcracks caused by ultrasonic cleaning, allowing for timely adjustment of ultrasonic parameters. Attached Figure Description

[0035] 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.

[0036] Figure 1 This is a flowchart of the method of the present invention;

[0037] Figure 2 This is a flowchart of the method for pressing materials according to the present invention;

[0038] Figure 3 This is a flowchart of the PCB substrate cleaning method of the present invention; Detailed Implementation

[0039] 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.

[0040] Specific implementation examples are given below.

[0041] Please see Figure 1 As shown, a method for manufacturing controlled-depth router slots on a PCB board includes the following steps:

[0042] S1: Pressing materials, using a press to press the substrate, prepreg and copper foil materials into a whole to make a PCB substrate;

[0043] S2: Snap polishing. Use a brush polisher to snap the PCB substrate. The brush polisher polishes 2-3 times at a speed of 4.0±0.5m / min.

[0044] S3: Copper plating, copper plating treatment of PCB substrate, the copper plating process includes PTH copper plating and copper plating.

[0045] S4: Fix the cardboard onto the bakelite board on the CNC machine table, drill positioning holes according to the PCB product positioning data, clean the debris and foreign matter in the holes, and then install the anti-foolproof pins for positioning.

[0046] S5: Depth control milling machine. Fix the PCB on the bakelite board, place cardboard at the bottom of the PCB substrate, and cover the surface of the PCB with another layer of cardboard. Use a flat-bottom milling cutter to process the depth control groove on the PCB.

[0047] S6: Clean the PCB substrate to remove residual powder, slag, and oil from the control groove, board surface, and holes. During processing, placing cardboard on the PCB board prevents scratches on the back. The back of the PCB often has silkscreen printing, solder mask, or exposed copper foil. Slight displacement during milling can cause wear on the back. The cardboard is soft and flat, isolating the PCB from the worktable and preventing physical scratches. Additionally, covering the PCB with cardboard prevents burrs from forming at the edges when the milling cutter cuts the PCB substrate due to material stress release. The cardboard provides "holding force" to the milling area, suppressing material edge deformation and resulting in a smoother groove wall. To suppress burr formation, drilling and keying pins are used for positioning, thereby improving the repeatability of batch processing and preventing the depth control area from shifting due to PCB placement errors. Simultaneously, the PCB is cleaned after depth control milling to remove residual powder, slag, and oil from the depth control groove, board surface, and holes, ensuring PCB substrate quality and preventing bubbles and pinholes in subsequent solder mask and gold plating processes. These methods effectively control production and quality issues, improving the quality of depth control milling. A leveling board is designed before milling the depth control groove to ensure the board is placed flat and the depth control depth is uniform, ensuring that the milling depth of each axis is at the same level, thus improving the quality of depth control milling.

[0048] Furthermore, in S5, when the depth control position intersects with the subsequent forming process, a CNC secondary forming process is added. During processing, the addition of the CNC secondary forming process solves the problems of burrs, rough edges, and copper foil curling during subsequent forming.

[0049] Furthermore, in S3 and S4, the cardboard surface or local areas need to be precisely milled and leveled using CNC milling equipment to eliminate thickness deviations, unevenness, or to achieve a uniform target thickness in specific areas. A 2.4mm milling cutter is used during processing. In use, some thick cardboard surfaces may have fiber protrusions or local depressions. CNC milling equipment is used to precisely mill and level the cardboard surface or local areas to provide a flat reference surface for the subsequent PCB substrate depth control routing process, ensuring processing accuracy. After the cardboard is leveled, compressed air is used to blow away residual paper dust from the routing surface.

[0050] Furthermore, in step S4, before processing the PCB substrate, the PP powder and copper wire residue on the surface of the PCB substrate are cleaned to ensure that there are no impurities on the PCB substrate that could affect the depth or thickness. Each time the PCB board is removed from the substrate and before it is installed, the impurities and PP powder on the cardboard are cleaned. During processing, the PCB substrate and cardboard are cleaned to remove PP powder, copper wire residue and impurities from the surface, thereby reducing the impact on the processing depth or thickness during subsequent depth control machining.

[0051] Furthermore, such as Figure 2As shown, in S1, the process of pressing materials includes the following steps:

[0052] A1: Inspect the appearance of each substrate, PP sheet, and copper foil material, and remove materials with wrinkles, damage, or impurities;

[0053] A2: Cut the substrate, prepreg, and copper foil materials to the corresponding size according to the PCB board design, and clean the surface of the materials to remove oil and dust;

[0054] A3: Pre-stack the materials in the order of substrate - prepreg - copper foil - prepreg - substrate, and align each layer;

[0055] A4: Place the pre-stacked materials into the pressing mold, lay a high-temperature resistant release film inside the mold, and vacuum the inside of the mold.

[0056] A5: Heat the mold and start the press to apply pressure. The pressure and temperature need to be increased at a constant rate to press the material under high temperature and high pressure.

[0057] A6: After pressing, the mold is allowed to cool naturally to below 50°C before demolding to obtain the PCB substrate.

[0058] Furthermore, in A6, after the PCB substrate is demolded, a CNC milling machine is used to trim the edges, removing excess PP sheet adhesive from the substrate edges. The trimming tolerance is ±0.2mm. During the CNC milling trimming process, a vacuum dust removal system is used to remove resin powder and adhesive residue generated during the trimming process in real time.

[0059] Furthermore, in S5, the controlled depth milling process stacking is carried out at 1PNL / stack or 1SET / stack.

[0060] For further details, please refer to Figure 3 As shown, in S6, the cleaning process for the PCB substrate includes the following steps:

[0061] B1: Use a vacuum gun to aim at the depth control tank and the board surface, and slowly move it along the tank wall to remove the resin powder and copper powder from the tank and the board surface;

[0062] B2: Use a lint-free cloth dampened with isopropyl alcohol to wipe the surface of the depth control tank to remove surface oil and residual powder stains;

[0063] B3: Use an ultrasonic cleaner and cleaning agent to perform ultrasonic cleaning on the PCB substrate for 3-5 minutes;

[0064] B4: Transfer the PCB substrate to a deionized water bath and ultrasonically rinse twice, 2-3 minutes each time, to remove residual cleaning agent from the PCB substrate.

[0065] B5: Place the rinsed PCB board into the drying oven with the depth control groove of the PCB board facing upwards, and dry for 15-20 minutes at 60-80℃.

[0066] B6: Use a metallographic microscope to observe the walls and bottom of the depth control tank to confirm that there is no residue of powder, slag, or oil; at the same time, check whether there are micro-cracks on the tank wall caused by ultrasonic cleaning.

[0067] The working principle is as follows: During processing, cardboard is placed on the PCB board to prevent scratches on the back of the PCB. The back of the PCB often has silkscreen printing, solder mask, or exposed copper foil. Slight displacement during milling can cause wear on the back. The cardboard is soft and flat, which can isolate the PCB from the worktable and avoid physical scratches. At the same time, when the milling cutter cuts the PCB substrate, the edges are prone to burrs due to the release of material stress. The cardboard cover can form a "holding force" on the milling area, suppressing the deformation of the material edges, making the groove wall flatter, and suppressing the generation of burrs. By drilling and using anti-foolproof pins for positioning, the repeatability accuracy of batch processing is improved, and the position of the depth control area is avoided due to PCB placement deviation. At the same time, the PCB board is cleaned after the depth control milling to remove residual powder and oil in the depth control groove, board surface and holes, ensuring the quality of the PCB substrate and preventing bubbles and pinholes in subsequent solder mask and gold plating processes.

[0068] During processing, a secondary CNC forming process is added to address defects such as burrs, rough edges, and copper foil curling that may occur during subsequent forming. In use, some thick cardboard surfaces may have fiber protrusions or localized depressions. CNC milling equipment is used to precisely mill and level the cardboard surface or specific areas, providing a flat reference surface for subsequent PCB substrate depth control router processes and ensuring processing accuracy. After leveling, residual paper dust on the router surface is blown away with compressed air. During processing, the PCB substrate and cardboard are cleaned to remove PP powder, copper wire residue, and other debris from the surfaces. This reduces the impact of these impurities on the processing depth or thickness allowance during subsequent depth control router processes.

[0069] During use, the above cleaning process ensures the cleaning effect in the controlled depth tank of the PCB substrate, removing residual powder, slag and oil stains in the controlled depth tank, board surface and holes, ensuring the quality of the PCB substrate, and preventing bubbles and pinholes in subsequent solder mask and gold plating processes. At the same time, the walls and bottom of the controlled depth tank are inspected under a microscope to determine the cleaning effect, ensure the quality of processing, and check whether there are micro-cracks in the tank wall caused by ultrasonic cleaning, so as to adjust the ultrasonic parameters in time.

[0070] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0071] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A method for manufacturing controlled-depth router slots on a PCB board, characterized in that: Includes the following steps: S1: Pressing materials, using a press to press the substrate, prepreg and copper foil materials into a whole to make a PCB substrate; S2: Snap polishing. Use a brush polisher to snap the PCB substrate. The brush polisher polishes 2-3 times at a speed of 4.0±0.5m / min. S3: Copper plating, copper plating treatment of PCB substrate, the copper plating process includes PTH copper plating and copper plating. S4: Fix the cardboard onto the bakelite board on the CNC machine table, drill positioning holes according to the PCB product positioning data, clean the debris and foreign matter in the holes, and then install the anti-foolproof pins for positioning. S5: Depth control milling machine. Fix the PCB on the bakelite board, place cardboard at the bottom of the PCB substrate, and cover the surface of the PCB with another layer of cardboard. Use a flat-bottom milling cutter to process the depth control groove on the PCB. S6: Clean the PCB substrate to remove residual powder and oil from the depth control tank, board surface and holes.

2. The method for manufacturing a controlled-depth router slot on a PCB board according to claim 1, characterized in that: In S5, when the depth control position intersects with the subsequent forming process, a CNC secondary forming process is added.

3. The method for manufacturing a controlled-depth router slot on a PCB board according to claim 2, characterized in that: In S3 and S4, the cardboard needs to be precisely milled and leveled using CNC milling equipment to eliminate thickness deviations, unevenness, or other defects on the cardboard surface, or to achieve a uniform target thickness in a specific area. A 2.4mm milling cutter is used during processing.

4. The method for manufacturing a PCB board controlled-depth router groove according to claim 3, characterized in that: In step S4, before processing the PCB substrate, the surface of the PCB substrate is cleaned of PP powder and copper wire residue to ensure that there are no impurities on the PCB substrate that may affect the depth or thickness. After each PCB board is removed from the substrate and before it is installed, the impurities and PP powder on the cardboard are cleaned.

5. The method for manufacturing a PCB board controlled-depth router slot according to claim 1, characterized in that: In S1, the process of pressing materials includes the following steps: A1: Inspect the appearance of each substrate, PP sheet, and copper foil material, and remove materials with wrinkles, damage, or impurities; A2: Cut the substrate, prepreg, and copper foil materials to the corresponding size according to the PCB board design, and clean the surface of the materials to remove oil and dust; A3: Pre-stack the materials in the order of substrate - prepreg - copper foil - prepreg - substrate, and align each layer; A4: Place the pre-stacked materials into the pressing mold, lay a high-temperature resistant release film inside the mold, and vacuum the inside of the mold. A5: Heat the mold and start the press to apply pressure. The pressure and temperature need to be increased at a constant rate to press the material under high temperature and high pressure. A6: After pressing, the mold is allowed to cool naturally to below 50°C before demolding to obtain the PCB substrate.

6. The method for manufacturing a controlled-depth router slot on a PCB board according to claim 5, characterized in that: In A6, after the PCB substrate is demolded, a CNC milling machine is used to trim the edges, removing excess PP sheet adhesive from the substrate edges. The trimming tolerance is ±0.2mm. During the CNC milling process, a vacuum dust removal system is used to remove resin powder and adhesive residue generated during the trimming process in real time.

7. The method for manufacturing a controlled-depth router slot on a PCB board according to claim 1, characterized in that: In S5, the controlled depth milling process stacking is carried out at 1PNL / stack or 1SET / stack.

8. The method for manufacturing a controlled-depth router slot on a PCB board according to claim 1, characterized in that: In S6, the cleaning process for the PCB substrate includes the following steps: B1: Use a vacuum gun to aim at the depth control tank and the board surface, and slowly move it along the tank wall to remove the resin powder and copper powder from the tank and the board surface; B2: Use a lint-free cloth dampened with isopropyl alcohol to wipe the surface of the depth control tank to remove surface oil and residual powder stains; B3: Use an ultrasonic cleaner and cleaning agent to perform ultrasonic cleaning on the PCB substrate for 3-5 minutes; B4: Transfer the PCB substrate to a deionized water bath and ultrasonically rinse twice, 2-3 minutes each time, to remove residual cleaning agent from the PCB substrate. B5: Place the rinsed PCB board into the drying oven with the depth control groove of the PCB board facing upwards, and dry for 15-20 minutes at 60-80℃. B6: Use a metallographic microscope to observe the walls and bottom of the depth control tank to confirm that there is no residue of powder, slag, or oil; at the same time, check whether there are micro-cracks on the tank wall caused by ultrasonic cleaning.

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