A manufacturing method of a surface flexible layer rigid-flexible combination board for an intelligent video module

Abstract

The application discloses a manufacturing method of a rigid-flexible combined board with a surface flexible layer for an intelligent video module, takes a double-sided flexible copper-clad plate, opens a window on a first copper layer corresponding to a first through hole to form a flexible core plate; takes a first covering film and opens a window corresponding to the first through hole to form a window covering film; attaches the window covering film to one side of a second copper layer of the flexible core plate to form a covering film core plate; takes a semi-cured sheet and makes a glue-blocking film corresponding to a flexible area of the semi-cured sheet to form a glue-blocking semi-cured sheet and make a rigid core plate; stacks and presses each layer plate in sequence from top to bottom, with the glue-blocking film facing the covering film core plate, then makes a through hole on a rigid area, laser-ablates an insulating medium layer corresponding to a copper layer window pattern, electroplates, and then carries out uncovering processing, then removes the second copper layer at the bottom of a blind hole to form a first through hole, and finally forms a rigid-flexible combined board, and the metallization processes of the flexible area and the rigid area are combined into one electroplating process, so that the consistency of the copper layer thickness is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of rigid-flex printed circuit board manufacturing, and in particular to a manufacturing method of a rigid-flex printed circuit board with a surface flexible layer for an intelligent video module. BACKGROUND

[0002] For a rigid-flex printed circuit board applied to an intelligent visual feedback module, an intelligent camera, or a visual module of an intelligent networked vehicle, when the installation space requirement is high, or the conductive and signal transmission of the circuit layer have special requirements, a structure with a flexible layer arranged on the surface layer is used to distribute and adjust the transmission path and performance.

[0003] Such rigid-flex printed circuit boards generally require the ability to support intelligentization and multifunctionalization of the load, and thus generally require a large circuit density and hole density. Therefore, the design fully utilizes the flexible plate area space to set through-holes and soldering holes for plug-in welding components, forming a circuit board structure in which the rigid plate area and the flexible plate area are both allocated with through-holes or soldering holes.

[0004] For the above rigid-flex printed circuit board, the key steps of the existing manufacturing method are as follows:

[0005] (1) Take a double-sided flexible copper-clad plate, drill holes, electroplate, make a circuit pattern on the second surface, attach a cover film on the second surface, and paste a resist film on the flexible plate area to form a flexible plate;

[0006] (2) Make a rigid plate layer according to the existing technical process;

[0007] (3) Take a semi-cured sheet layer, align and stack it with the flexible plate layer and the rigid plate layer, press, drill holes, electroplate, make an outer circuit pattern, attach a cover film on the first surface, make a solder resist, control the depth of the milling cut on the rigid plate layer covering the flexible plate area, uncover, tear off the resist film, repair the residual glue, process through the subsequent processes, and form a rigid-flex printed circuit board through molding.

[0008] The existing manufacturing method has the following problems:

[0009] Since the through holes of the flexible plate area need to be drilled first, and then the resist film is attached to the surface of the corresponding flexible plate area of the flexible plate layer, and then the through holes are subjected to a large amount of chemical attack during the electroplating and outer circuit pattern making process (including etching process, solder resist process, etc.), the probability of the adhesive tape detaching increases, leading to the penetration of chemicals into the board, and the adhesive is prone to residual after being soaked and attacked by the chemicals. The repair of the residual adhesive is difficult and time-consuming and costly.

[0010] Due to one-time plating of through holes when making the flexible plate, and two-time plating of through holes of the flexible plate due to plating of through holes of the rigid plate area when making the rigid-flexible combination plate, the two-time plating leads to too large difference in thickness of the through holes of the flexible plate, the through holes of the rigid plate, and the surface copper, and causes processing quality problem, which further affects subsequent application.

[0011] Therefore, to solve the above-mentioned problems, realize efficient and high-quality manufacturing of the rigid-flexible combination plate with the flexible layer on the surface layer and the flexible layer having the through hole design, and provide a manufacturing method of the surface flexible layer rigid-flexible combination plate for the intelligent video module. SUMMARY

[0012] The present application aims to solve the comprehensive problems of the rigid-flexible combination plate manufactured by the prior art, such as easy glue residue at the through hole position, and uneven copper thickness caused by two-time plating, and proposes a manufacturing method of the surface flexible layer rigid-flexible combination plate for the intelligent video module, the rigid-flexible combination plate is processed according to design data, the design data is designed with a forming line, the area in the forming line is an effective area, the effective area includes a flexible area and a rigid area, the flexible area is designed with a first through hole, and the manufacturing method includes the following steps:

[0013] S10: taking a double-sided flexible copper-clad plate formed by stacking a first copper layer, an insulating medium layer, and a second copper layer in sequence, making a circuit pattern on the second copper layer; making an opening on the first copper layer corresponding to the first through hole to form a copper layer opening pattern; forming a flexible core plate; taking a first cover film, making an opening on the first cover film corresponding to the first through hole to form a cover film opening pattern, and forming an opening cover film as a whole; attaching the opening cover film to the second copper layer of the flexible core plate, and forming a cover film core plate as a whole;

[0014] S20: taking a prepreg and a blocking film, making the blocking film on the prepreg corresponding to the flexible area to form a blocking prepreg;

[0015] S30: taking a rigid copper-clad plate to form a rigid core plate;

[0016] Stacking the cover film core plate, the blocking prepreg, and the rigid core plate in sequence from top to bottom, with the blocking film facing the cover film core plate, to form a stacking structure, and then pressing to form a pressed plate;

[0017] S40: drilling a hole in the rigid area of the pressed plate to form a through hole, and laser ablation of the insulating medium layer corresponding to the copper layer opening pattern to form a blind hole to be plated, and then plating, the through hole forms a second through hole, and the blind hole to be plated forms a blind hole, and the whole plate forms a plated plate;

[0018] S50: the electroplated plate is subjected to uncovering processing to form an uncovering plate, then the second copper layer at the bottom of the blind hole is removed to form the first through hole, and post-processing is performed, then the whole plate is formed to form the rigid-flexible combination plate.

[0019] Further, the covering film windowing pattern is larger than the copper layer windowing pattern.

[0020] Further, the prepreg is a high-flow prepreg, and the glue content is 70% to 80%.

[0021] Further, forming the laminated plate includes arranging a first auxiliary laminating structure on one side of the rigid core plate of the laminated structure, and the first auxiliary laminating structure is composed of a first release film and a first steel plate laminated structure, and the release film faces the laminated structure.

[0022] Further, forming the laminated plate includes arranging a second auxiliary laminating structure on one side of the flexible core plate of the laminated structure, and the second auxiliary laminating structure is composed of a second release film and a second steel plate laminated structure, and the second release film faces the laminated structure.

[0023] Further, the glue blocking film is a PI adhesive tape or blue glue.

[0024] Further, after forming the electroplated plate, a surface circuit pattern is made on the electroplated plate, a second covering film is made on the flexible area of the first copper layer, a first solder resist layer is made on the rigid area of the first copper layer, and a second solder resist layer is made on the entire surface of the second copper layer.

[0025] Further, the uncovering processing includes controlled depth milling of the uncovering plate corresponding to the flexible area, and the depth of the controlled depth milling is from the second solder resist layer to the glue blocking film.

[0026] Further, forming the rigid-flexible combination plate includes sandblasting after removing the second copper layer at the bottom of the blind hole to form the first through hole.

[0027] Further, forming the electroplated plate includes drilling holes in the rigid area of the laminated plate, and then performing plasma treatment.

[0028] The technical scheme of the present application mainly has the following beneficial effects:

[0029] For the rigid-flex combination board with the flexible layer as the surface layer, a manufacturing method of "firstly manufacturing the copper layer opening window pattern of the flexible area hole site -> overall lamination -> synchronously manufacturing the rigid area through hole and the flexible area to-be-plated blind hole -> one-time plating" is adopted, compared with the twice plating process in the prior art, the metalization process of the flexible area and the rigid area is combined into one-time plating, the consistency of the copper plating layer thickness is ensured, and the positioning and calibration steps between the twice plating are also saved, the deviation risk caused by multiple alignment is reduced, the processing efficiency is improved, and the product yield is ensured.

[0030] By manufacturing the blind hole to form the bottom copper closed structure, the closed cavity structure is formed between the glue blocking film and the second copper layer, the problems of the existing technology of directly drilling the hole to cause the drug water to penetrate into the board body and the glue to be soaked and attacked by the drug water are avoided, and the subsequent repair of residual glue and other processes are avoided.

[0031] (3) The front and rear overall processing processes are cooperated: the copper layer opening window in the front process provides a precise target for the flexible area to-be-plated blind hole, and ensures the accuracy of the hole site when the laser ablation blind hole is ablated; the high flowability of the high flow glue semi-cured sheet is adapted to the requirement of the one-time plating on the interlayer bonding force; and the auxiliary lamination structure provides rigid support to offset the stress generated by the high flow glue flow, and ensures the flatness of the board after lamination; the differential selection processing of the rigid area mechanical drilling and the flexible area laser drilling finally realizes the high-precision processing of the high-density rigid-flex combination board with the flexible layer on the surface. BRIEF DESCRIPTION OF DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the drawings shown.

[0033] Figure 1 It is a process flow diagram of the embodiment of the present application;

[0034] Figure 2 It is a plane diagram of the core board of the cover film of the embodiment of the present application;

[0035] Figure 3 It is Figure 2 A-A sectional view of;

[0036] Figure 4 It is a sectional view of the lamination structure of the embodiment of the present application;

[0037] Figure 5 It is a sectional view of the lamination board of the embodiment of the present application;

[0038] Figure 6 A cross-sectional view of a plated board according to an embodiment of the present application;

[0039] Figure 7 A cross-sectional view of a plated board according to an embodiment of the present application;

[0040] Figure 8 A cross-sectional view of a plated board according to an embodiment of the present application;

[0041] Figure 9 A cross-sectional view of a plated board according to an embodiment of the present application;

[0042] Figure 10 A cross-sectional view of a plated board according to an embodiment of the present application;

[0043] Figure 11 A cross-sectional view of a plated board according to an embodiment of the present application; Figure 10 A top view of a plated board according to an embodiment of the present application.

[0044] BRIEF DESCRIPTION OF DRAWINGS: 100, forming line; 200, active area; 300, flexible area; 400, rigid area; 10, cover film core board; 110, flexible core board; 1010, first copper layer; 1020, insulating dielectric layer; 1030, second copper layer; 1040, copper layer opening pattern; 210, opening cover film; 2010, cover film opening pattern; 310, adhesive resist prepreg; 3020, adhesive resist film; 3010, prepreg; 410, rigid core board; 20, lamination structure; 20A, second auxiliary pressing structure; 2010A, second release film; 2020A, second steel plate; 20B, first auxiliary pressing structure; 2010B, first release film; 2020B, first steel plate; 30, pressing board; 320, cavity; 40, plated board; 4010, through hole; 4020, plated blind hole; 50, plated board; 5010, second via hole; 5020, blind hole; 60, protective layer board; 6010, surface circuit pattern; 6020, second cover film; 6030, first resist layer; 6040, second resist layer; 70, uncovering board; 80, rigid-flexible combination board; 500, first via hole.

[0045] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0046] The technical solutions in the embodiments of the present application will be apparently and completely described with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without any creative work belong to the protection scope of the present application.

[0047] It should be noted that all the direction indications (such as up, down, left, right, front, back, inside, outside, etc.) in the embodiments of the present application are only used to explain the relative position relationship, motion condition, etc. between the components in a certain specific posture (as shown in the drawings), and if the specific posture changes, the direction indications will also change accordingly.

[0048] In addition, the descriptions such as "first", "second" and the like in the present application are only for the purpose of description, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second" can be explicitly or implicitly included at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0049] In addition, the technical solutions of various embodiments of the present application can be combined with each other, but it must be based on the fact that a person skilled in the art can realize it, and when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist and is not within the protection scope required by the present application.

[0050] The rigid-flex combined board of the embodiment is processed according to the design data, the design data is designed with a forming line 100, the area in the forming line 100 is an effective area 200, the effective area 200 includes a flexible area 300 and a rigid area 400, the flexible area 300 is designed with a first through hole 500, and the manufacturing method includes the following steps:

[0051] Please refer to Figure 1 , Figure 2 and Figure 3 ; Figure 1 is a process flow diagram of the embodiment of the present application; Figure 2 is a plane schematic diagram of the cover film core board of the embodiment of the present application; Figure 3 is Figure 2 A-A cross-sectional schematic diagram.

[0052] Step S10:

[0053] Take the double-sided flexible copper-clad plate formed by the first copper layer 1010, the insulating dielectric layer 1020 and the second copper layer 1030 stacked in sequence, and make a circuit pattern on the second copper layer 1030; make a window on the first copper layer 1010 corresponding to the first through hole 500 to form a copper layer window pattern 1040; form a flexible core board 110; take the first cover film, make a window on the first cover film corresponding to the first through hole 500 to form a cover film window pattern 2010, and form a windowed cover film 210 as a whole; attach the windowed cover film 210 to the second copper layer 1030 of the flexible core board 110, and form a cover film core board 10 as a whole.

[0054] In the process of manufacturing the circuit pattern, the copper layer opening pattern 1040 is formed by etching the first copper layer 1010 corresponding to the first via hole 500, which provides a precise ablation range boundary for the subsequent laser ablation of the insulating medium layer 1020. The laser only needs to ablate the insulating medium layer 1020 corresponding to the copper layer opening pattern 1040, without ablation of the first copper layer 1010. This avoids excessive ablation of the insulating medium layer 1020 due to excessive energy or heat conduction when the laser directly acts on the first copper layer 1010, and provides a good processing substrate for the subsequent process.

[0055] Meanwhile, the position of the second copper layer 1030 corresponding to the first via hole 500 is not etched, so that the region forms a bottom copper closed structure. On the one hand, it provides a bottom copper basis for preventing burning through during the subsequent laser ablation of the insulating medium layer 1020 corresponding to the copper layer opening pattern 1040. On the other hand, the second copper layer 1030 at this position and the insulating medium layer 1020 can effectively prevent the etching drug from penetrating into the press plate 30, thereby preventing the generation of defects such as interlayer peeling and air bubbles, and ensuring the stability of the plate structure.

[0056] The manufacture of the opening cover film 210 also provides a basis for subsequent processes. The cover film opening pattern 2010 is pressed and combined with the resist film 3020 in the subsequent process, and the two can form a closed cavity 320 (in actual processing, since the thickness of each layer is relatively thin, all are in the order of tens of microns or dozens of microns, and the cavity 320 is actually only a separated layer structure), which effectively prevents the overflow of the glue of the high-flow prepreg to the flexible area 300.

[0057] Further, the cover film opening pattern 2010 is larger than the copper layer opening pattern 1040 on one side.

[0058] Since the subsequent process needs to form the to-be-plated blind hole 4020 by laser ablation of the insulating medium layer 1020, and then convert the to-be-plated blind hole 4020 into the first via hole 500 through electroplating, the area where the cover film opening pattern 2010 is larger than the copper layer opening pattern 1040 can provide space for the electroplated copper layer, and after electroplating, a complete hole ring is formed. The design of this size difference can also effectively avoid the hole ring processing defects caused by the alignment deviation during the lamination and pressing, and provides a pre-protection for the electrical connection reliability of the first via hole 500.

[0059] Step S20:

[0060] Take the prepreg 3010 and the resist film 3020, and make the resist film 3020 on the prepreg 3010 corresponding to the flexible area 300 to form the resist prepreg 310.

[0061] Further, the prepreg 3010 is a high-flow prepreg, and the glue content is 70% to 80%.

[0062] The high flow glue property enables the glue-resistant prepreg 310 to flow sufficiently and fill the line gap during the pressing process, ensures the interlayer bonding force between the cover film core board 10 and the rigid core board 410, and the process adopts the flow of “overall pressing first and then one-time electroplating”, so that the high flow glue prepreg can realize complete interlayer filling through one-time pressing, thereby avoiding problems such as delamination or drug penetration in subsequent processes caused by insufficient glue filling, and ensuring the structural integrity of the board.

[0063] Further, the glue-resistant film 3020 is a PI adhesive tape or blue glue.

[0064] Both materials have high-precision processing properties and excellent dimensional stability under high-temperature and high-pressure pressing environment, can precisely prevent the glue of the prepreg 3010 from overflowing to the flexible area 300, prevent glue overflow, and ensure that the glue of the rigid area 400 is filled sufficiently, thereby realizing high-precision processing.

[0065] Please refer to Figure 4 and Figure 5 , Figure 4 is a cross-sectional schematic view of the lamination pressing structure of the embodiment of the present application; Figure 5 is a cross-sectional schematic view of the pressed board of the embodiment of the present application.

[0066] Step S30:

[0067] Take the rigid copper-clad plate to form the rigid core board 410; stack the cover film core board 10, the glue-resistant prepreg 310 and the rigid core board 410 from top to bottom in sequence, with the glue-resistant film 3020 facing the cover film core board 10, to form a stacking structure 20, and press to form a pressed board 30.

[0068] The glue-resistant film 3020 in the stacking structure 20 faces the cover film core board 10 and precisely corresponds to the area of the cover film windowing pattern 2010 on the cover film core board 10, and after pressing, a cavity 320 not filled with glue is formed at the position of the cover film windowing pattern 2010, the physical gap formed by the cavity 320 provides space for separation during the uncovering process, makes it easier to control the processing precision when removing the excess material on the surface of the flexible area 300, and provides a key precondition for the uncovering process in the subsequent step S50.

[0069] Further, forming the pressed board 30 includes providing a first auxiliary pressing structure 20B on one side of the rigid core board 410 of the stacking structure 20, the first auxiliary pressing structure 20B is composed of a first release film 2010B and a first steel plate 2020B stacked together, and the first release film 2010B faces the stacking structure 20.

[0070] Furthermore, a laminated plate 30 is formed, including setting a second auxiliary laminated structure 20A on one side of the flexible core plate 110 of the stacked structure 20, the second auxiliary laminated structure 20A being composed of a second release film 2010A and a second steel plate 2020A stacked together, and the second release film 2010A facing the stacked structure 20.

[0071] It is worth noting that the conventional auxiliary pressing structure includes a coating film for compensating for thickness differences and transmitting uniform pressure. However, since this embodiment uses a high-flow glue semi-cured sheet, its higher fluidity can form a synergistic effect with the rigid support of the first steel plate 2020B and the second steel plate 2020A. The upper and lower hard steel plates are directly used, which can not only ensure the glue flow filling performance during pressing, but also form self-compensation for the thickness differences in different areas. Moreover, since the flexible layer is located on the surface layer, it can also improve the flatness of the surface layer after pressing, and prevent the problem of uneven surface of the plate (especially the side of the flexible layer) caused by excessive buffering caused by the setting of the coating film. Therefore, the coating film is cancelled in the first auxiliary pressing structure 20B and the second auxiliary pressing structure 20A.

[0072] In summary, since the overall process adopts the method of "first opening a window on the flexible board, and then laser ablation to form the blind hole 4020 to be plated", the previous process uses a high-flow adhesive semi-cured sheet to ensure that the line gap of the flexible area 300 is fully filled, laying the foundation for the subsequent electroplating reliability of the blind hole 4020 to be plated. However, although the high-flow adhesive semi-cured sheet can be efficiently filled during pressing, the flow of the colloid may cause local uneven pressure, which in turn causes board warping or colloid contamination. The first auxiliary pressing structure 20B and the second auxiliary pressing structure 20A provide rigid support to evenly transfer the pressure to the entire stacked structure 20, offsetting the stress difference caused by the colloid flow.

[0073] The high-flow adhesive prepreg cooperates with the first auxiliary pressing structure 20B and the second auxiliary pressing structure 20A to form a front-to-back fit, ultimately enabling the pressing plate 30 to achieve a firm combination of flexibility and rigidity while accurately retaining the preformed space of the blind hole 4020 to be electroplated, providing a structurally complete and dimensionally stable circuit board foundation for the electroplating and uncovering processing of the blind hole 4020 to be electroplated in subsequent steps.

[0074] See also Figure 6 and Figure 7 , Figure 6 is a schematic cross-sectional view of a plate to be electroplated according to an embodiment of the present invention; Figure 7 Schematic cross-sectional view of an electroplating plate according to an embodiment of the present invention.

[0075] Step S40:

[0076] The rigid area 400 of the laminated board 30 is drilled to form a through hole 4010, and the laser ablation windowing pattern 1040 of the copper layer is used to ablate the insulating medium layer 1020 to form a blind hole 4020 to be electroplated. The whole board forms an electroplating board 40, and then electroplating is performed. The through hole 4010 forms a second through hole 5010, and the blind hole 4020 to be electroplated forms a blind hole 5020. The whole board forms an electroplating board 50.

[0077] The copper layer windowing pattern 1040 formed by the previous process is formed at a predetermined position. In this step, the laser ablation is directly used to ablate the insulating medium layer 1020 to form the blind hole 4020 to be electroplated, which is adapted to the subsequent electroplating requirement. Then, the whole board is electroplated to metalize the through hole 4010 of the rigid area 400 and the blind hole 4020 to be electroplated of the flexible area 300 at one time. This not only simplifies the processing flow, but also avoids the thickness difference of the copper layer caused by multiple electroplating.

[0078] Further, the electroplating board 50 is formed by drilling the rigid area 400 of the laminated board 30 and then performing plasma treatment.

[0079] The plasma treatment increases the roughness of the hole wall, improves the activation degree of the hole wall, and forms a hole wall surface with uniform and fine roughness. The binding force between the copper layer and the hole wall during the subsequent electroplating is improved, and a reliable substrate condition is provided for the subsequent formation of a stable second through hole 5010 of the through hole 4010.

[0080] Please refer to Figure 8 , Figure 8 for the cross-sectional view of the protective board according to an embodiment of the present application.

[0081] Further, after the electroplating board 50 is formed, a surface circuit pattern 6010 is made on the electroplating board 50; a second cover film 6020 is made on the flexible area 300 of the first copper layer 1010; a first solder resist layer 6030 is made on the rigid area 400 of the first copper layer 1010; and a second solder resist layer 6040 is made on the whole surface of the second copper layer 1030 to form a protective board 60.

[0082] After the surface circuit pattern 6010 is made, the protective layer is made according to the area difference. The second cover film 6020 is attached to the flexible area 300 and is windowed according to the cover film windowing pattern 2010 to form a hole ring structure corresponding to the upper and lower parts. For the remaining area, only a solder resist layer is needed as a protective layer.

[0083] Please refer to Figure 9 , Figure 10 and Figure 11 , Figure 9 for the cross-sectional view of the uncovering board according to an embodiment of the present application. Figure 10 for the cross-sectional view of the rigid-flexible combination board according to an embodiment of the present application. Figure 11 for Figure 10 the top view.

[0084] Step S50: Covering processing is performed on the electroplated plate 50 to form a covering plate 70, then the second copper layer 1030 at the bottom of the blind hole 5020 is removed to form a first through hole 500, and post-process processing is performed, then the whole plate is formed to form a rigid-flexible combined plate 80.

[0085] Further, the covering processing includes controlled depth milling of the covering plate 70 corresponding to the flexible area 300, and the depth of the controlled depth milling is from the second solder resist layer 6040 to the resist film 3020.

[0086] Further, forming the rigid-flexible combined plate 80 includes performing sand blasting treatment after removing the second copper layer 1030 at the bottom of the blind hole 5020 to form the first through hole 500.

[0087] Since burrs and burrs are easily left at the bottom edge of the hole after the second copper layer 1030 is removed, the sand blasting treatment can polish the hole wall by non-contact cleaning of high-speed abrasive spraying, so that the copper layer of the hole wall reaches a smooth state, providing an ideal substrate for subsequent gold plating and other surface treatment processes, and ensuring the uniformity of the plated layer.

[0088] And since the first through hole 500 is located in the flexible area 300, traditional abrasive belt polishing, abrasive brush polishing and other contact processes will exert pressure on the plate surface, which may cause deformation of the flexible area 300 and damage to the circuit; and the sand blasting adopts a non-contact operation, and the abrasive is acted on the hole site by airflow, only the burrs in the hole are cleaned, and no mechanical stress is generated on the plate body, effectively avoiding the structural damage of the flexible area 300 caused by stress, and protecting the bending performance of the flexible area 300.

[0089] Optionally, the way to remove the second copper layer 1030 at the bottom of the blind hole 5020 is laser ablation or mechanical drilling, if the precision requirement is high, laser ablation processing can be used, and if the processing efficiency requirement is high, mechanical drilling processing can be used.

[0090] The above only describes the preferred embodiments of the present application, and does not limit the patent scope of the present application, and any equivalent structural transformation made under the inventive concept of the present application, or direct / indirect application in other related technical fields is included in the patent protection scope of the present application.

Claims

1. A manufacturing method of a rigid-flex printed circuit board for an intelligent video module, the rigid-flex printed circuit board being processed according to design data, the design data being designed with a forming line, an area within the forming line being an effective area, the effective area including a flexible area and a rigid area, the flexible area being designed with a first via, characterized in that, The manufacturing method comprises the following steps: S10: taking a double-sided flexible copper-clad plate formed by stacking a first copper layer, an insulating medium layer and a second copper layer in sequence, manufacturing a circuit pattern on the second copper layer; manufacturing an opening on the first copper layer corresponding to the first through hole to form a copper layer opening pattern; and forming a flexible core plate; taking a first cover film, manufacturing an opening on the first cover film corresponding to the first through hole to form a cover film opening pattern, and forming an opening cover film as a whole; attaching the opening cover film to the second copper layer of the flexible core plate, and forming a cover film core plate as a whole; S20: taking a prepreg and a resist film, manufacturing the resist film on the flexible area of the prepreg to form a resist prepreg; S30: taking a rigid copper-clad plate to form a rigid core plate; stacking the cover film core plate, the resist prepreg and the rigid core plate in sequence from top to bottom, with the resist film facing the cover film core plate, to form a stacking structure, and pressing to form a pressed plate; S40: drilling a hole in the rigid area of the pressed plate to form a through hole, and laser ablation of the insulating medium layer corresponding to the copper layer opening pattern to form a to-be-plated blind hole, and then electroplating, so that the through hole forms a second through hole and the to-be-plated blind hole forms a blind hole, and a whole electroplated plate is formed; S50: performing uncovering processing on the electroplated plate to form an uncovering plate, then removing the second copper layer at the bottom of the blind hole to form the first through hole, and then performing post-process processing and whole plate forming to form the rigid-flexible combination plate.

2. The method for manufacturing a rigid-flex board with a surface flexible layer for an intelligent video module according to claim 1, wherein: The cover film opening pattern is larger than the copper layer opening pattern on one side.

3. The method for manufacturing a rigid-flex board with a surface flexible layer for an intelligent video module according to claim 1, wherein: The prepreg is a high-flow prepreg, and the glue content is 70% to 80%.

4. The method of claim 3, wherein the surface flexible layer rigid-flex board is used for an intelligent video module. 3 The formation of the pressed plate comprises arranging a first auxiliary pressing structure on one side of the rigid core plate of the stacking structure, the first auxiliary pressing structure being composed of a first release film and a first steel plate stacked together, and the first release film facing the stacking structure.

5. The method for manufacturing a rigid-flex board with a surface flexible layer for an intelligent video module according to claim 3 or 4, wherein: The formation of the pressed plate comprises arranging a second auxiliary pressing structure on one side of the flexible core plate of the stacking structure, the second auxiliary pressing structure being composed of a second release film and a second steel plate stacked together, and the second release film facing the stacking structure.

6. The method for manufacturing a rigid-flex board with a surface flexible layer for an intelligent video module according to claim 1, wherein: The resist film is a PI tape or blue glue.

7. The method for manufacturing a rigid-flex board with a surface flexible layer for an intelligent video module according to claim 1, wherein: After the formation of the electroplated plate, a surface circuit pattern is manufactured on the electroplated plate, a second cover film is manufactured on the flexible area of the first copper layer, a first solder resist layer is manufactured on the rigid area of the first copper layer, and a second solder resist layer is manufactured on the whole surface of the second copper layer.

8. The method for manufacturing a rigid-flex board with a surface flexible layer for an intelligent video module according to claim 7, wherein: The uncovering processing comprises controlled depth milling of the uncovering plate corresponding to the flexible area, and the depth of the controlled depth milling is from the second solder resist layer to the resist film.

9. The method for manufacturing a rigid-flex board with a surface flexible layer for an intelligent video module according to claim 1, wherein: The formation of the rigid-flexible combination plate comprises sandblasting after removing the second copper layer at the bottom of the blind hole to form the first through hole.

10. The method for manufacturing a rigid-flex board with a surface flexible layer for an intelligent video module according to claim 1, wherein: The formation of the electroplated plate comprises drilling a hole in the rigid area of the pressed plate, and then performing plasma treatment.

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