Manufacturing method for realizing nondestructive glue blocking of blind slot of PCB (Printed Circuit Board) based on twice coating

Abstract

The invention belongs to the technical field of circuit board processing and manufacturing, and particularly discloses a manufacturing method for realizing nondestructive glue blocking of a blind slot of a PCB (Printed Circuit Board) based on twice coating. By means of the manufacturing method for achieving PCB blind groove lossless glue blocking based on two times of coating, the circuit surface is prevented from being cut and damaged, and the phenomenon of PP residual glue on the circuit surface of the blind groove is avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of circuit board processing and manufacturing, and in particular relates to a method for manufacturing a blind slot of a PCB board without loss of adhesive based on double lamination. Background Art

[0002] With the development of the PCB industry in recent years, PCB products are moving towards high density and high integration. In order to avoid spatial interference of devices on the surface of PCB boards and reduce signal transmission paths, blind slot structure design has become more and more widespread.

[0003] The traditional method of making blind slots is to first etch the circuit pattern at the bottom of the slot, then use PI or PTFE tape to apply the circuit at the bottom of the blind slot, then use laser cutting for lamination, and finally use a controlled depth blind fishing method to mill the slot to expose the blind slot surface. However, in this process, on the one hand, due to the step difference after etching the circuit at the bottom of the slot, PI or PTFE tape cannot completely fill the circuit gap, causing the PP glue to flow into the blind slot surface along the gap during lamination, resulting in residual glue. On the other hand, since the PI tape is directly applied to the circuit, it is easy to cut the circuit at the bottom of the slot when laser cutting is used later, resulting in the occurrence of open circuits in the subsequent circuits, affecting the reliability of product processing. Summary of the invention

[0004] The purpose of the present invention is to overcome the above problems existing in the prior art and provide a method for manufacturing a blind slot of a PCB board without loss of adhesive based on double lamination, so as to prevent the circuit surface from being damaged by cutting and solve the problem of PP adhesive residue on the circuit surface of the blind slot.

[0005] In order to achieve the above technical objectives and the above technical effects, the present invention is implemented through the following technical solutions:

[0006] A method for manufacturing a non-destructive adhesive barrier for blind slots of a PCB board based on double lamination, the manufacturing method comprising the following steps:

[0007] S1: Prepare the bottom core plate according to the design requirements;

[0008] S2: According to the design requirements, a pattern is produced on the groove bottom core board 1, and after scanning and detection using AOI, a dielectric board 1 with a blind groove is obtained;

[0009] S3: After performing a coating film treatment on the bottom area of ​​the blind groove on the dielectric plate 1, a coating film is formed on the bottom area of ​​the blind groove on the dielectric plate 1 to prepare a coated dielectric plate;

[0010] S4: Prepare the second slot top core plate according to design requirements;

[0011] S5: According to the design requirements, patterning is performed on the second slot top core plate, and AOI is used to perform scanning and detection to obtain the second dielectric plate;

[0012] S6: performing a secondary coating treatment on the position of the second dielectric plate adjacent to the bottom of the blind groove, forming a secondary coating film on the position of the second dielectric plate adjacent to the bottom of the blind groove, and preparing a secondary coating dielectric plate;

[0013] S7: laser cutting and opening windows according to the blind groove size for the dielectric plate 2 to which the secondary lamination film has been applied;

[0014] S8: preparing a prepreg;

[0015] S9: slotting the prepreg according to the size of the blind slot on the dielectric plate 1 to prepare a prepreg with slots;

[0016] S10: placing the secondary coating dielectric plate, the prepreg with the notch, and the primary coating dielectric plate in order from top to bottom to form a laminated structure plate, and pressing the laminated structure plate to prepare a semi-finished plate;

[0017] S11: After CNC drilling, hole metallization, resin plugging, and patterning of the semi-finished board according to the outer layer design requirements, a front board is prepared;

[0018] S12: After etching the outer pattern of the front plate, depth-controlled milling is performed to expose the primary coating film on the primary coating dielectric plate;

[0019] S13: removing the secondary coating film;

[0020] S14: Remove the primary laminating film and complete the non-destructive adhesive treatment of the blind groove of the PCB board.

[0021] Furthermore, the materials of the bottom core plate 1 and the top core plate 2 are any one or more of epoxy material, PTFE material, hydrocarbon material, and mixed pressure material mixed in any proportion;

[0022] The prepreg is high-flow PP, medium-flow PP or low-flow PP.

[0023] Furthermore, in step S3, the processing flow of the primary coating film treatment is as follows: a primary coating material is coated in the bottom area of ​​the blind groove on the first dielectric plate, and after exposure and development, a primary coating film is formed in the bottom area of ​​the blind groove on the first dielectric plate.

[0024] Furthermore, the primary coating material is a photosensitive material.

[0025] Furthermore, the photosensitive material is liquid photosensitive ink or dry film.

[0026] Furthermore, during the exposure and development process, the size of the exposure area matches the size of the blind groove on the medium plate 1.

[0027] Furthermore, in step S6, the processing flow of the secondary coating film treatment is as follows: a secondary coating material is applied to the position adjacent to the bottom of the blind groove on the second dielectric plate, and pre-cured after affixing to form a secondary coating film on the position adjacent to the bottom of the blind groove on the second dielectric plate.

[0028] Furthermore, the secondary coating material is any one of PI covering film, PI reinforcing material and FR4 reinforcing material.

[0029] Furthermore, in step S9, when the prepreg is slotted, the width of the slot is not less than the width of the blind slot on the first dielectric plate, and the length of the slot is not less than the length of the blind slot on the first dielectric plate.

[0030] Furthermore, in step S14, removing the primary coating film specifically involves removing the primary coating film by soaking in a reagent.

[0031] Furthermore, the reagent is an alkali solution or an organic film removal solution; preferably, the alkali solution is a sodium hydroxide solution.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] In the present invention, by preparing the PCB board to be processed (i.e., the core board at the bottom of the groove one), the graphics are made according to the requirements, and after AOI scanning, the photosensitive material is coated on the bottom of the blind groove for exposure, and a coating film is formed at the bottom of the groove after development, and the circuit steps are filled to ensure that the circuit at the bottom of the groove and the medium are not directly contaminated by the PP glue during the subsequent pressing process. In addition, the core board / sub-board to be opened (i.e., the core board at the top of the groove two) is also graphic-made as required, and after AOI scanning, a secondary coating film is pasted on the surface of the core board / sub-board to be opened and the groove bottom and the corresponding area of ​​the groove bottom, and then a laser is used to cut according to the size of the blind groove. This method can fully fill the bottom of the groove through two coatings to fully fill the glue blocking area, avoid the problem of PP glue contamination and residual glue being difficult to remove due to the height difference between the bottom groove road surface and the medium surface caused by the inaccurate filling of the glue blocking material, and the pressing bulging and delamination problems. This method solves the problem of residual glue in the blind groove from the source, obtains a groove bottom with no damage to the glue blocking, fundamentally ensures product quality, and reduces processing difficulty. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0035] Figure 1 It is a schematic diagram of the process of the present invention;

[0036] Figure 2 It is a structural schematic diagram of a PCB board provided in Example 1 of the present invention.

[0037] The reference numerals in the drawings are: 1. dielectric plate 1; 2. dielectric plate 2; 3. prepreg with notches; 4. primary laminating film; 5. secondary laminating film. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] In the description of the present invention, it should be understood that the terms "opening", "upper", "lower", "thickness", "top", "middle", "length", "inside", "all around" and the like indicating orientation or positional relationship are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the components or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0040] like Figure 1 As shown, a method for manufacturing a blind slot of a PCB board without loss of adhesive based on double lamination is provided, and the manufacturing method comprises the following steps:

[0041] S1: Prepare the bottom core plate according to the design requirements;

[0042] S2: According to the design requirements, a pattern is produced on the groove bottom core board 1, and after scanning and detection using AOI, a dielectric board 1 with a blind groove is prepared;

[0043] S3: performing a coating film treatment on the bottom area of ​​the blind groove on the dielectric plate 1, thereby forming a coating film on the bottom area of ​​the blind groove on the dielectric plate 1, and preparing a coated dielectric plate;

[0044] In step S3, the process flow of the primary coating film treatment is as follows: a primary coating material is coated on the bottom area of ​​the blind groove on the dielectric plate 1, and after exposure and development, a primary coating film is formed on the bottom area of ​​the blind groove on the dielectric plate 1;

[0045] During the exposure and development process, the size of the exposure area matches the size of the blind groove on the medium plate 1; for example, the size of the exposure area can match the size of the blind groove on the medium plate 1, and specifically, the size and shape of the exposure area can be the same or substantially the same as the size and shape of the blind groove on the medium plate 1;

[0046] The exposure and development process refers to developing with a developer after exposure. Specifically, the developer may be a sodium carbonate solution. After development, the uncured primary coating film on the dielectric plate may be removed.

[0047] The primary coating material is a photosensitive material, specifically, the photosensitive material can be a liquid photosensitive ink or a dry film;

[0048] The primary laminating film is mainly used to protect the circuits and media on the dielectric plate to avoid direct contamination caused by the flow of PP glue;

[0049] S4: According to the design requirements, prepare the second trough top core plate, wherein the size of the second trough top core plate may be the same or substantially the same as the size of the first trough bottom core plate;

[0050] S5: According to the design requirements, the pattern is produced on the second slot top core board, and the second medium board is obtained after scanning and detection by AOI;

[0051] S6: performing a secondary coating treatment on the position of the second dielectric plate adjacent to the bottom of the blind groove, forming a secondary coating film on the position of the second dielectric plate adjacent to the bottom of the blind groove, and preparing a secondary coating dielectric plate;

[0052] In step S6, the processing flow of the secondary coating film treatment is as follows: a secondary coating material is applied to a position adjacent to the bottom of the blind groove on the dielectric plate 2, and pre-cured after application, so as to form a secondary coating film at a position adjacent to the bottom of the blind groove on the dielectric plate 2; specifically, during the secondary coating film treatment process, the position adjacent to the bottom of the blind groove on the dielectric plate 2 refers to a position on the dielectric plate 2 close to the blind groove on the dielectric plate 1 during the subsequent pressing of the dielectric plate 2 with the dielectric plate 1, that is, during the subsequent pressing of the dielectric plate 2 with the dielectric plate 1, the secondary coating film applied on the dielectric plate 2 is directly opposite to the blind groove on the dielectric plate 1;

[0053] The secondary coating material is any one of PI covering film, PI reinforcing material and FR4 reinforcing material;

[0054] S7: laser cutting and opening windows according to the blind groove size for the dielectric plate 2 to which the secondary lamination film has been applied;

[0055] Wherein, the size of the laser window is the same or substantially the same as the size of the blind groove on the dielectric plate 1;

[0056] During the laser cutting and window opening process, the laser is emitted by a laser, and the laser used is an ultraviolet laser. When laser cutting and window opening is performed, the cutting power is 33%, the frequency is 1000KHz, the marking speed is 1200mm / s, the marking delay is 500us, the jump speed is 3000mm / s, and the jump delay is 500us; when the laser is turned on / off, the cutting parameters can be adjusted accordingly as the laser energy fluctuates during cutting; the number of cutting times is 4-8 times, and the flatness of the laser table is checked during the cutting process to maintain a precise and consistent focal depth, ultimately ensuring the uniformity of the cutting;

[0057] The secondary lamination film is applied to the upper surface of the blind groove of the dielectric plate 2, and the graphic layer is located on the dielectric plate 1, so the circuit on the blind groove surface will not be damaged after laser cutting;

[0058] Among them, the secondary laminating film is used to fill the gap between layers, and at the same time, it uses its own alternating low fluidity to fill the height difference after the primary laminating film, so that the primary laminating film and the secondary laminating film can be seamlessly connected, thereby forming a glue barrier isolation, and finally achieving the purpose of non-destructive glue barrier;

[0059] Among them, the secondary coating film of the non-blind groove part can be removed after cutting;

[0060] S8: preparing a prepreg;

[0061] S9: slotting the prepreg according to the size of the blind slot on the dielectric plate 1 to prepare a prepreg with slots;

[0062] In step S9, when the prepreg is slotted, the width of the slot is not less than the width of the blind slot on the dielectric plate 1, and the length of the slot is not less than the length of the blind slot on the dielectric plate 1; specifically, when the prepreg is slotted, the width of the slot is 0.05-0.2 mm greater than the width of the blind slot on the dielectric plate 1, and the length of the slot is 0.05-0.2 mm greater than the length of the blind slot on the dielectric plate 1;

[0063] S10: placing the secondary coating dielectric plate, the prepreg with the notch, and the primary coating dielectric plate in order from top to bottom to form a laminated structure plate, and pressing the laminated structure plate to prepare a semi-finished plate;

[0064] S11: After CNC drilling, hole metallization, resin plugging, and patterning of the semi-finished board according to the outer layer design requirements, a front board is prepared;

[0065] S12: After the outer layer pattern of the front plate is etched, a controlled depth milling groove is performed to expose the primary coating film on the primary coating dielectric plate; during the controlled depth milling groove process, the secondary coating film is removed along with the cover opening operation;

[0066] In step S12, during the depth-controlled milling process, a CCD depth-controlled milling machine may be used for depth-controlled milling, and the depth of the controlled depth is based on the exposure of the primary coating film;

[0067] S13: removing the secondary coating film;

[0068] In step S13, the secondary coating film has good bonding force with the dielectric layer (i.e., dielectric plate 2) at the top of the blind groove, and the secondary coating film can be removed by removing the dielectric layer at the top of the blind groove after controlled depth milling;

[0069] S14: Remove the primary laminating film and complete the non-destructive adhesive treatment of the blind slot of the PCB board;

[0070] In step S14, the primary coating film is removed by soaking the primary coating film with a reagent, and the reagent used is a sodium hydroxide solution or an organic film removal liquid;

[0071] In the preparation method, the materials of the dielectric plate 1 and the dielectric plate 2 are any one or more of epoxy material, PTFE material, hydrocarbon material, and mixed pressure material mixed in any proportion;

[0072] The prepreg is high-flow PP, medium-flow PP or low-flow PP.

[0073] The following are specific examples. In the following examples, unless otherwise specified, all raw materials can be obtained from commercial sources.

[0074] Example 1

[0075] like Figure 2 As shown, this embodiment provides a method for manufacturing a lossless adhesive for a PCB board, wherein the PCB board comprises an epoxy material, a PTFE material, a hydrocarbon material and a mixed pressure material; the method is performed in the following steps in sequence:

[0076] Step 1: Select the dielectric plate 1 of Rogers RT6002, with the size of 305×457mm and the dielectric thickness of 0.254mm;

[0077] Step 2: Graphically produce the medium plate 1 according to the design requirements and scan it using AOI;

[0078] Step 3: After AOI scanning, a primary coating film is made on the dielectric plate 1, baked at 75 degrees for half an hour, and then exposed using LDI equipment. The exposure data and the slot size are made in a 1:1 ratio. After exposure, a 1% sodium carbonate solution is used for development to remove the uncured primary coating film on the dielectric plate surface; thereby forming a primary coating film 4 in the bottom area of ​​the blind slot on the dielectric plate 1;

[0079] Step 4: Prepare another layer of Rogers RT6002 dielectric plate 2, whose size is 305×457mm and dielectric thickness is 0.254mm;

[0080] Step 5: Also, the medium plate 2 is patterned according to the design requirements and scanned using AOI;

[0081] Step 6: After AOI scanning, a secondary laminating film is applied to the dielectric plate 2, with a film thickness of 0.1 mm. After application, a fast press is used for pre-curing to make the secondary laminating film 5 more closely bonded to the dielectric plate surface;

[0082] Step 7: Use laser to cut the secondary coating film. The laser cutting power is 33%, the frequency is 1000KHz, the marking speed is 1200mm / s, the marking delay is 500us, the jump speed is 3000mm / s, and the jump delay is 500us. When the laser is switched on and off, the cutting parameters should be adjusted accordingly as the laser energy fluctuates. The number of cuts is 4. During the cutting process, the flatness of the laser table is checked to maintain a precise and consistent focal depth, ultimately ensuring the uniformity of the cutting. After cutting, remove the secondary coating film of the non-blind groove part.

[0083] Step 8: The prepreg is mainly pressed, and the prepreg is a prepreg 3 with a notch, and the prepreg is Fastrise-28-0040-50 produced by TACONIC;

[0084] Step 9: CNC milling grooves on the prepreg, the milling groove size is 0.2mm smaller than the blind groove size on one side;

[0085] Step 10: Use two RT6002 and Fastrise-28-0040-50 prepreg sheets to press together according to the stacking structure;

[0086] Step 11: After lamination, carry out conventional processes such as outer layer CNC drilling, hole metallization, resin plugging, and pattern production according to design requirements;

[0087] Step 12: After the outer layer pattern is etched, use a CCD mechanical milling machine to control the depth of the milling groove according to the set depth of 0.3mm, and increase the depth by 0.01mm each time until the laminating film is exposed once. The purpose of using the CCD milling machine here is to capture the expansion and contraction of the outer layer and prevent milling groove deviation;

[0088] Step 13: Use tweezers or a surgical blade to remove the secondary coating;

[0089] Step 14: Use 8% sodium hydroxide solution, heat to 80°C, soak for 12 minutes, remove the coating film once, and complete the non-destructive adhesive.

[0090] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0091] The above shows and describes 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, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A method for manufacturing a lossless adhesive barrier for a blind slot of a PCB board based on double lamination, characterized in that: The preparation method comprises the following steps: S1: Prepare the bottom core plate according to the design requirements; S2: According to the design requirements, a pattern is produced on the groove bottom core board 1, and after scanning and detection using AOI, a dielectric board 1 with a blind groove is obtained; S3: After performing a coating film treatment on the bottom area of ​​the blind groove on the dielectric plate 1, a coating film is formed on the bottom area of ​​the blind groove on the dielectric plate 1 to prepare a coated dielectric plate; S4: Prepare the second slot top core plate according to design requirements; S5: According to the design requirements, patterning is performed on the second slot top core plate, and AOI is used to perform scanning and detection to obtain the second dielectric plate; S6: performing a secondary coating treatment on the position of the second dielectric plate adjacent to the bottom of the blind groove, forming a secondary coating film on the position of the second dielectric plate adjacent to the bottom of the blind groove, and preparing a secondary coating dielectric plate; S7: laser cutting and opening windows according to the blind groove size for the dielectric plate 2 to which the secondary lamination film has been applied; S8: Preparing a prepreg; S9: slotting the prepreg according to the size of the blind slot on the dielectric plate 1 to prepare a prepreg with slots; S10: placing the secondary coating dielectric plate, the prepreg with the notch, and the primary coating dielectric plate in order from top to bottom to form a laminated structure plate, and pressing the laminated structure plate to prepare a semi-finished plate; S11: After CNC drilling, hole metallization, resin plugging, and patterning of the semi-finished board according to the outer layer design requirements, a front board is prepared; S12: After etching the outer pattern of the front plate, depth-controlled milling is performed to expose the primary coating film on the primary coating dielectric plate; S13: removing the secondary coating film; S14: Remove the primary laminating film and complete the non-destructive adhesive treatment of the blind groove of the PCB board.

2. According to claim 1, a method for manufacturing a lossless adhesive barrier for a blind slot of a PCB board based on double conformation, characterized in that: The materials of the bottom core plate 1 and the top core plate 2 are any one or more of epoxy material, PTFE material, hydrocarbon material, and mixed pressure material mixed in any proportion; The prepreg is high-flow PP, medium-flow PP or low-flow PP.

3. The method for manufacturing a lossless adhesive tape for blind slots of PCB boards based on double lamination according to claim 1 is characterized in that: In step S3, the process flow of the primary coating film treatment is as follows: a primary coating material is coated in the bottom area of ​​the blind groove on the first dielectric plate, and after exposure and development, a primary coating film is formed in the bottom area of ​​the blind groove on the first dielectric plate.

4. The method for manufacturing a lossless adhesive tape for blind slots of PCB boards based on double conformation according to claim 3 is characterized in that: The primary coating material is a photosensitive material.

5. The method for manufacturing a lossless adhesive tape for blind slots of PCB boards based on double lamination according to claim 4 is characterized in that: The photosensitive material is liquid photosensitive ink or dry film.

6. The method for manufacturing a lossless adhesive tape for blind slots of PCB boards based on double lamination according to claim 3 is characterized in that: During the exposure and development process, the size of the exposure area matches the size of the blind groove on the medium plate.

7. The method for manufacturing a lossless adhesive tape for blind slots of PCB boards based on double lamination according to claim 1 is characterized in that: In step S6, the processing flow of the secondary lamination film treatment is as follows: a secondary lamination material is applied to the position adjacent to the bottom of the blind groove on the second dielectric plate, and pre-cured after application to form a secondary lamination film on the position adjacent to the bottom of the blind groove on the second dielectric plate.

8. The method for manufacturing a lossless adhesive barrier for a blind slot of a PCB board based on double lamination according to claim 7 is characterized in that: The secondary coating material is any one of a PI covering film, a PI reinforcing material, and a FR4 reinforcing material.

9. The method for manufacturing a lossless adhesive tape for blind slots of PCB boards based on double lamination according to claim 1, characterized in that: In step S9, when the prepreg is slotted, the width of the slot is not less than the width of the blind slot on the dielectric plate 1, and the length of the slot is not less than the length of the blind slot on the dielectric plate 1.

10. The method for manufacturing a lossless adhesive tape for blind slots of PCB boards based on double conformation according to claim 1, characterized in that: In step S14, the primary coating film is removed by soaking the primary coating film with a reagent.

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