A method for fabricating an outer flexible layer rigid-flex plate for an intelligent vision module

Abstract

A method for manufacturing a flexible outer layer rigid-flex plate for an intelligent vision module involves fabricating a flexible core board and a rigid core board with a release layer attached to the corresponding uncovered area, followed by the removal of a semi-cured sheet and a copper layer. The aforementioned boards are then stacked and pressed together to form a press-fit plate, with the release layer facing the flexible core board. The outer layer of the press-fit plate is a flexible layer. A first and second through-hole are drilled into the press-fit plate, followed by electroplating. The second through-hole undergoes controlled-depth drilling, transforming the first through-hole into a through-hole and the second through-hole into a controlled-depth hole, forming a controlled-depth hole plate. The controlled-depth holes are then filled with resin to form solid through-holes. Surface treatment and uncovering processes are then performed sequentially, followed by molding, resulting in a rigid-flex plate. This method significantly simplifies the processing flow and improves processing accuracy. The overall thickness and rigidity of the pressed plate are enhanced, thereby improving the stability of the polishing process and effectively avoiding problems such as over-polishing, excessive expansion and contraction, or cracking of the flexible layer.

Description

Technical Field

[0001] This invention relates to the field of circuit board processing, and in particular to a method for manufacturing an outer flexible layer rigid-flex board for an intelligent vision module. Background Technology

[0002] For some intelligent vision sensing modules, due to their limited installation space, high-density interconnect rigid-flex boards are usually used to achieve the structural effect of small-space three-dimensional assembly and high-density integration.

[0003] Furthermore, in order to meet the requirements of current or signal transmission in a specific layer and easy one-time bending installation, this type of board has a flexible board layer designed on the outermost layer. Its circuit pattern is interconnected with the rigid board layer in a high-density manner, and the surface of the flexible board layer is also provided with welding pads, thereby improving surface utilization and current and signal transmission efficiency. Finally, the overall board body forms a rigid-flex board with a high-density interconnect structure, where the flexible layer is located on the outer layer.

[0004] However, existing technologies for processing this type of circuit board have the following drawbacks:

[0005] (1) If high-density interconnection is achieved by making buried vias, the layers containing buried vias in the rigid board layer need to be laminated together to form the first core board. Then, the board goes through drilling, electroplating, resin plugging, baking and polishing processes, and then laminated with other layers to form the overall board. However, since the flexible board layer is soft and the copper layer is thin, the overall thickness of the first core board is also thin. During the polishing process, the board is prone to cracking, excessive expansion and contraction or uneven expansion and contraction, which can easily lead to the scrapping of the board or the misalignment of the subsequent circuit fabrication.

[0006] (2) If the stacked blind hole form is used instead, it is necessary to perform layer-by-layer pressing, layer-by-layer laser drilling and layer-by-layer filling electroplating, which not only greatly increases the processing accuracy requirements, but also significantly increases the complexity and cost of the processing process.

[0007] Based on the above background and problems, there is a need to provide a novel method for manufacturing an outer flexible rigid-flex plate for intelligent vision modules. Summary of the Invention

[0008] This invention aims to solve the comprehensive problems of existing rigid-flex PCBs with high-density interconnect structures and flexible layers located on the outer layer, such as poor processing accuracy. It provides a method for manufacturing a rigid-flex PCB with an outer flexible layer for intelligent vision modules. The rigid-flex PCB is processed according to design data, which includes forming lines. The area within the forming lines is the effective area, and other areas are ineffective areas. The effective area includes a covered area and a non-covered area. The non-covered area is designed with vias and pads. The manufacturing method includes the following steps:

[0009] S10: A flexible core board is fabricated according to the design data, and a rigid core board with a release layer attached to the corresponding uncovering area is fabricated. Then, a prepreg layer and a copper layer are taken. The flexible core board, the rigid core board, the prepreg layer and the copper layer are stacked in sequence and pressed together to form a press-fit plate. The release layer faces the flexible core board. The outer layer of the press-fit plate is a flexible layer.

[0010] S20: Drill a first through hole and a second through hole into the press plate, then electroplate, and perform controlled-depth drilling on the second through hole. The first through hole forms the through hole, and the second through hole forms the controlled-depth hole. The whole plate is formed into a controlled-depth hole plate.

[0011] S30: The controlled depth hole is resin plugged to form a solid through hole, and then surface treatment and capping are performed in sequence. After that, it is formed into the rigid-flexible plate. The capping process is controlled depth milling from the flexible core board to the release layer.

[0012] Furthermore, the flexible core board is fabricated by taking a double-sided flexible copper-clad laminate, fabricating a first circuit pattern on one side to form a single-sided patterned copper-clad laminate, and taking a first flexible insulating dielectric layer and pressing it with the single-sided patterned copper-clad laminate to form the flexible core board; the first circuit pattern faces the first flexible insulating dielectric layer; the stacking is such that the first flexible insulating dielectric layer of the flexible core board faces the rigid core board.

[0013] Furthermore, the flexible core board is fabricated by taking a first single-sided flexible copper-clad laminate and a second single-sided flexible copper-clad laminate; fabricating a second circuit pattern on the second single-sided flexible copper-clad laminate to form a second single-sided patterned copper-clad laminate; and pressing the first single-sided flexible copper-clad laminate and the second single-sided patterned copper-clad laminate together to form the flexible core board; the second circuit pattern faces the insulating dielectric layer of the first single-sided flexible copper-clad laminate.

[0014] Furthermore, a reinforcing sheet is attached to the side of the flexible core board facing the rigid core board; the reinforcing sheet corresponds to the area of ​​the solder pad.

[0015] Furthermore, the diameter of the depth-controlled hole is larger on one side than the diameter of the second through hole.

[0016] Furthermore, the stacking includes providing a prepreg between the first single-sided flexible copper-clad laminate and the second single-sided flexible copper-clad laminate, wherein the prepreg has an opening corresponding to the uncovering area, and a second flexible board insulating dielectric layer is formed in the area of ​​the opening.

[0017] Furthermore, the size of the insulating dielectric layer of the second flexible board is larger on one side than the uncovered area.

[0018] Furthermore, the invalid region adjacent to the solid through hole is provided with a plurality of compensation holes identical to the solid through hole.

[0019] Furthermore, the spacing between adjacent compensation holes increases sequentially from the effective region to the ineffective region.

[0020] Furthermore, the overall number of compensation holes is greater than the number of adjacent overall solid through holes, and the width of the distribution area of ​​the overall compensation holes is greater than the width of the distribution area of ​​adjacent overall solid through holes.

[0021] The main beneficial effects of this technical solution include the following:

[0022] (1) By using the processing flow of “direct integral pressing → drilling the second through hole → drilling the deep hole → resin plugging the hole → grinding → post-processing” to replace the existing technology’s multiple stacking and pressing process, the processing flow is greatly simplified. It can also avoid the accumulation of interlayer positioning deviation caused by multiple pressing and improve the processing accuracy. At the same time, the thickness and rigidity of the plate after integral pressing are enhanced, thereby improving the stability of the grinding process and effectively avoiding problems such as excessive grinding of the flexible layer, excessive expansion and contraction or cracking, thus improving product quality and pass rate.

[0023] (2) By adding a prepreg to the flexible board layer, the prepreg is used to make a window in the corresponding uncovered area. A second flexible board insulating dielectric layer is added to the windowed area to achieve directional reinforcement of the non-covered area while retaining the flexible characteristics of the uncovered area. On the one hand, the thickness of the flexible board layer can be increased to enhance the board support force; on the other hand, the strength of the flexible board layer can be enhanced to improve the resistance to grinding impact and tension, ensure the stability of the board size after grinding, and optimize the grinding flatness.

[0024] (3) By setting up a compensation plugging area, the compensation holes have the same structure as the solid through holes. The distance between adjacent compensation holes increases sequentially from the effective area to the ineffective area. The number and distribution width of the compensation holes are greater than those of the adjacent solid through holes. This achieves a steady increase and pre-stabilization of the grinding pressure, effectively avoiding problems such as plate pulling and damage caused by instantaneous changes in the pressure during grinding in dense hole areas, and ensuring grinding uniformity. Attached Figure Description

[0025] 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 the structures shown in these drawings without creative effort.

[0026] Figure 1 This is a process flow diagram of an embodiment of the present invention;

[0027] Figure 2 This is a cross-sectional schematic diagram of the first stacked structure according to an embodiment of the present invention;

[0028] Figure 3 This is a cross-sectional schematic diagram of the second stacked structure according to an embodiment of the present invention;

[0029] Figure 4 This is a cross-sectional schematic diagram of the third stacked structure according to an embodiment of the present invention;

[0030] Figure 5 This is a cross-sectional schematic diagram of the pressing plate according to an embodiment of the present invention;

[0031] Figure 6 This is a cross-sectional schematic diagram of the through-hole plate according to an embodiment of the present invention;

[0032] Figure 7 This is a cross-sectional schematic diagram of the depth-controlled hole plate according to an embodiment of the present invention;

[0033] Figure 8 This is a cross-sectional schematic diagram of a solid plate according to an embodiment of the present invention;

[0034] Figure 9 This is a schematic diagram of the distribution of grinding holes in the belt to be sanded according to an embodiment of the present invention;

[0035] Figure 10 This is a cross-sectional schematic diagram of the rigid-flexible plate according to an embodiment of the present invention.

[0036] Explanation of reference numerals: 100, forming line; 200, effective area; 210, uncovered area; 220, non-covered area; 300, ineffective area; 400, controlled-depth milling line; 500, reinforcing sheet; 600, compensation hole; 700, solid through-hole area; 800, compensation plugging hole area; 10, first type of stacked structure; 1010, flexible core board; 1010L, another type of flexible core board; 1010a, first circuit pattern; 1010b, copper foil; 1010c, first insulating dielectric layer; 1020, first flexible board insulating dielectric layer; 1030, rigid core board; 1030a, release layer; 1030d, rigid core board copper layer; 1030c, rigid core board insulating dielectric layer; 1040, prepreg layer; 1050, copper foil layer; 10A, second type of stacked structure Structure; 1060, First single-sided flexible copper-clad laminate; 1060a, First copper layer; 1060b, Second insulating dielectric layer; 1070, Second single-sided flexible copper-clad laminate; 1070a, Second circuit pattern; 1070b, Third insulating dielectric layer; 10B, Third stacked structure; 1080, Prepreg; 1080a, Second flexible board insulating dielectric layer; 20, Press-fit plate; 2010, First through hole; 2020, Second through hole; 30, Through-hole plate; 3010, First through-hole; 3020, Second through-hole; 40, Depth control hole plate; 4010, Depth control hole; 50, Solid plate; 5010, Solid through-hole; FX, Travel direction; 60, Rigid-flex plate; 6010, Solder resist layer; 6020, Cover film; 6030, Surface treatment layer.

[0037] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0038] 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 a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0039] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0040] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0041] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0042] To better understand the above technical solution, the following detailed explanation is provided in conjunction with the accompanying drawings.

[0043] Please see Figure 1 , Figure 1 This is a process flow diagram of an embodiment of the present invention.

[0044] A method for manufacturing an outer flexible rigid-flex plate for an intelligent vision module, wherein the rigid-flex plate 60 is processed according to design data, the design data includes a forming line 100, the area within the forming line 100 is the effective area 200, and the other areas are ineffective areas 300. The effective area 200 includes a covered area 210 and a uncovered area 220, the uncovered area 220 is designed with vias and pads, and a controlled-depth milling line 400 is used. The manufacturing method includes... Figure 1 The process flow shown is explained in detail below.

[0045] Please see Figure 2 , Figure 3 , Figure 4 and Figure 5 , Figure 2 This is a cross-sectional schematic diagram of the first stacked structure according to an embodiment of the present invention; Figure 3 This is a cross-sectional schematic diagram of the second stacked structure according to an embodiment of the present invention; Figure 4 This is a cross-sectional schematic diagram of the third stacked structure according to an embodiment of the present invention; Figure 5 This is a cross-sectional schematic diagram of the pressing plate according to an embodiment of the present invention.

[0046] Step S10:

[0047] A flexible core board 1010 is fabricated according to the design data, and a rigid core board 1030 (including a rigid core board insulating dielectric layer 1030c and a rigid core board copper layer 1030d) with a release layer 1030a attached to the corresponding uncovering area 210 is also fabricated. Then, a semi-cured sheet layer 1040 and a copper layer (i.e., the copper foil layer 1050 in the attached figure) are taken. The flexible core board 1010, the rigid core board 1030, the semi-cured sheet layer 1040 and the copper foil layer 1050 are then stacked in sequence to form a stacked structure 10 and pressed together to form a press plate 20. The release layer 1030a faces the flexible core board 1010. The outer layer of the press plate 20 is a flexible layer.

[0048] By using a one-time stacking and pressing process, interlayer misalignment caused by multiple pressings is reduced, significantly improving the alignment accuracy between plate layers and providing processing conditions for subsequent drilling and deep hole 4010 machining.

[0049] Please refer to it again. Figure 2 .

[0050] Optionally, the flexible core board 1010 is fabricated by taking a double-sided flexible copper-clad laminate (including a first insulating dielectric layer 1010c), fabricating a first circuit pattern 1010a on one side and a copper foil 1010b on the other side to form a single-sided patterned copper-clad laminate 110, and taking a first flexible insulating dielectric layer 1020 and pressing it with the single-sided patterned copper-clad laminate 110 to form the flexible core board 1010; the first circuit pattern 1010a faces the first flexible insulating dielectric layer 1020; the stacking is such that the first flexible insulating dielectric layer 1020 of the flexible core board 1010 faces the rigid core board 1030, forming the first type of stacking structure 10.

[0051] It is worth noting that the double-sided flexible copper clad laminate must first have a first circuit pattern 1010a made on one side, and the remaining copper foil 1010b is located on the outermost layer of the first stacking structure 10, and then it is stacked and pressed together with other layers as a whole, which reduces the risk of alignment deviation and simplifies the processing procedure.

[0052] Please refer to it again. Figure 3 .

[0053] Optionally, another flexible core board 1010L is fabricated by taking a first single-sided flexible copper-clad laminate 1060 (including a first copper layer 1060a and a second insulating dielectric layer 1060b) and a second single-sided flexible copper-clad laminate 1070 (including a second copper layer and a third insulating dielectric layer 1070b); fabricating a second circuit pattern 1070a on the second copper layer of the second single-sided flexible copper-clad laminate 1070 to form a second single-sided patterned copper-clad laminate 1070; pressing the first single-sided flexible copper-clad laminate 1060 and the second single-sided patterned copper-clad laminate 1070 together to form another flexible core board 1010L; the second circuit pattern 1070a faces the second insulating dielectric layer 1060b of the first single-sided flexible copper-clad laminate 1060, forming a second type of stacked structure 10A.

[0054] First, the first single-sided flexible copper-clad laminate 1060 and the second single-sided flexible copper-clad laminate 1070 are pressed together to ensure high-precision processing of the second circuit pattern 1070a. Then, they are stacked and pressed together with other layers to effectively avoid the alignment deviation problem when multiple substrates are stacked at the same time. Furthermore, the second circuit pattern 1070a is tightly wrapped by the second insulating dielectric layer 1060b of the first single-sided flexible copper-clad laminate 1060. In the subsequent two hot pressing processes of pre-pressing and overall pressing, the scrapping of the board due to circuit damage is reduced.

[0055] Optionally, a reinforcing sheet 500 is attached to the side of the flexible core board 1010 facing the rigid core board 1030; the reinforcing sheet 500 corresponds to the area of ​​the pad.

[0056] By attaching reinforcing pads 500, the support for the pads can be increased, preventing the pads from sinking or deforming during soldering, thus ensuring the reliability and structural integrity of the solder joints.

[0057] It is worth noting that the reinforcing sheet 500 in this embodiment is pre-pressed into the board body, rather than being attached separately in the process before welding. By attaching it in batches as a whole, the attachment accuracy of the reinforcing sheet 500 can be effectively increased, and the precise alignment of the reinforcing sheet 500 with the pad can be achieved, avoiding problems such as alignment shift caused by manual operation or reference deviation when attaching it separately in the future.

[0058] Please refer to it again. Figure 4 .

[0059] Optionally, the stacking includes setting a prepreg 1080 between the first single-sided flexible copper clad laminate 1060 and the second single-sided flexible copper clad laminate 1070. The prepreg 1080 has an opening corresponding to the cover area 210. The area with the opening is provided with a second flexible board insulating dielectric layer 1080a, forming a third stacking structure 10B.

[0060] Since the flexible copper clad laminate formed by laminating the first single-sided flexible copper clad laminate 1060 and the second single-sided flexible copper clad laminate 1070 is a double-layer structure and relatively thin, its flexibility will be further enhanced after subsequent resin plugging and baking treatment. During the grinding process, the board body lacks sufficient rigid support, which can easily lead to problems such as excessive grinding and stretching, excessive expansion and contraction of the flexible board layer, or uneven expansion and contraction.

[0061] Therefore, by setting a prepreg 1080 between the first single-sided flexible copper clad laminate 1060 and the second single-sided flexible copper clad laminate 1070, and specifically making a window at the position corresponding to the uncovered area 210 of the prepreg 1080, and adding a second flexible board insulating dielectric layer 1080a in the windowed area, the functional partitioning of the flexible layer is formed, and the rigid area (non-covered area 220) that needs to withstand grinding stress is strengthened, so that the flexible core board 1010 can resist the pulling force and pressure of the sanding belt during grinding, effectively avoiding the problems of excessive grinding, excessive expansion and contraction, or unevenness of the flexible board layer.

[0062] Optionally, the dimensions of the second flexible plate insulating dielectric layer 1080a are larger on one side than the uncovered area 210.

[0063] This structure, equivalent to the second flexible board insulating dielectric layer 1080a extending into the board body, can effectively prevent the exposure of circuit patterns due to insufficient size of the flexible board's cover film layer after subsequent processing.

[0064] Please see Figure 6 and Figure 7 , Figure 6 This is a cross-sectional schematic diagram of the through-hole plate according to an embodiment of the present invention; Figure 7 This is a cross-sectional schematic diagram of the depth control plate according to an embodiment of the present invention.

[0065] Step S20:

[0066] Drill a first through hole 2010 and a second through hole 2020 into the press plate 20, and then electroplate it. The first through hole 2010 forms a first through hole 3010, and the second through hole 2020 forms a second through hole 3020, forming a through hole plate 30. Drill a controlled depth hole into the second through hole 3020, forming a controlled depth hole 4010, and the whole thing forms a controlled depth hole plate 40.

[0067] By completing the processing steps of through holes, electroplating and controlled depth drilling (i.e., back drilling) in one go on the laminating plate 20, the circuit conduction between specific layers is formed. This eliminates the traditional blind hole process of layer-by-layer laser drilling and hole filling electroplating, and then layer-by-layer lamination, which effectively shortens the processing cycle.

[0068] Furthermore, because the overall pressed board is thicker and more stable, drilling and depth control processing at this stage are less likely to cause board deformation or cracking compared to traditional thin core board processing in stages, thus effectively improving processing accuracy.

[0069] Optionally, the diameter of the depth control hole 4010 is larger on one side than the diameter of the second through hole 2020.

[0070] The diameter of the controlled-depth drill hole 4010 is larger than the diameter of the second through hole 2020, which effectively cooperates with the controlled-depth drilling process to remove the deep hole copper that does not need to be connected in the second through hole 3020, thereby realizing the connection between specific copper layers.

[0071] It is worth noting that the diameter difference between the two and the chamfer formed by drilling need to be controlled within a reasonable size range. If the difference on one side is too large, a large step difference will be formed at the junction of the depth control hole 4010 and the second through hole 3020. When filling with resin, it is easy to form a flow dead corner at the step corner, resulting in air bubbles being hidden or incomplete filling. If the difference is too small, it will not meet the cutting requirements of the copper hole that does not need to be conductive.

[0072] Therefore, preferably, the diameter of the control hole 4010 is 10μm to 50μm larger on each side than the diameter of the second through hole 2020, following the principle that the smaller the value, the better, to ensure copper stripping and guarantee the accuracy of copper layer interconnection.

[0073] Please see Figure 8 , Figure 9 and Figure 10 , Figure 8 This is a cross-sectional schematic diagram of a solid plate according to an embodiment of the present invention; Figure 9 This is a schematic diagram of the distribution of grinding holes in the belt to be sanded according to an embodiment of the present invention; Figure 10 This is a cross-sectional schematic diagram of the rigid-flexible plate according to an embodiment of the present invention.

[0074] Step S30:

[0075] The controlled depth hole 4010 is filled with resin to form a solid through hole 5010, and the whole board is formed into a solid board 50. Then, surface treatment and capping are performed in sequence, and then the board is formed into a rigid-flexible board 60 (including a solder resist layer 6010, a cover film 6020 and a surface treatment layer 6030, wherein the surface treatment layer 6030 is located as a solder pad). The capping process is to perform controlled depth milling from the flexible core board 1010 to the release layer 1030a along the controlled depth milling line 400.

[0076] The controlled depth hole 4010 is filled with resin, forming a solid through hole 5010, which is equivalent to a blind hole. Combined with the previous processing, the entire technical solution uses the method of "full lamination + making through holes + drilling controlled depth holes 4010 (back drilling) + resin filling" to replace the buried hole processing of the existing technology, reducing the processing difficulty, improving the processing accuracy, and increasing the thickness of the board after full lamination, which makes the subsequent resin filling and grinding easier and can effectively prevent problems such as grinding cracks and excessive expansion and contraction.

[0077] Please refer to it again. Figure 9 During the grinding process, the solid plate 50 moves forward along the direction of travel FX.

[0078] Optionally, the invalid region 300 adjacent to the solid through hole 5010 is provided with a plurality of compensation holes 600 identical to the solid through hole 5010.

[0079] If the controlled depth holes 4010 are densely distributed, and the protruding resin after plugging and baking is too dense, grinding with a belt abrasive can be used. Since the grinding process involves adjusting the downward pressure as needed, the grinding pressure is relatively low when grinding areas without solid through holes 5010, but increases when grinding areas with solid through holes 700. If the protruding resin is too dense, the downward pressure will increase instantaneously, generating a large grinding force on other areas 700 of the board without solid through holes, which can easily cause grinding damage, over-grinding, or unevenness. Although multiple grinding sessions can improve this problem, it can easily lead to excessive stretching of the board, increased probability of grinding damage, and increased costs.

[0080] Therefore, a compensation plugging area 800 is provided in the ineffective area 300 of the solid through hole area 700 of the resin plugging hole, which is composed of a number of compensation holes 600. Specifically, during grinding, the compensation plugging area 800 first enters the grinding belt position, at which point the grinding pressure begins to increase. This pressure is maintained and the grinding enters the solid through hole area 700 of the resin plugging hole for grinding.

[0081] On the one hand, it solves the problem of grinding damage. The pre-pressure adjustment of the compensation plugging area 800 ensures that the solid through-hole area 700 is subjected to uniform force during grinding, avoiding defects such as excessive grinding of the board, cracking of the flexible layer, or uneven expansion and contraction caused by the instantaneous increase of downward pressure. This greatly improves the flatness and structural integrity of the board surface and reduces the product scrap rate. On the other hand, it also simplifies the grinding process. Uniform processing can be achieved in one grinding, which avoids excessive stretching of the board caused by multiple grindings and improves production efficiency.

[0082] Optionally, the spacing between adjacent compensation holes 600 increases sequentially from the effective region 200 to the ineffective region 300.

[0083] With the spacing of the compensation holes 600, the plate enters the sanding belt position, and the downward pressure gradually increases until it reaches a stable force.

[0084] On the one hand, the gradient spacing design of the compensation holes 600 allows the grinding belt to gradually adjust the pressure according to the hole density, ensuring that the pressure smoothly transitions from the initial value to a stable value. This effectively avoids problems such as plate pulling, twisting, or flexible layer cracking caused by a sudden increase in force. On the other hand, the smooth increase in pressure also increases the uniformity of grinding, ensuring that the grinding force state remains consistent before and after the plate enters the solid through hole area 700, thus guaranteeing the overall flatness of the plate surface.

[0085] Optionally, the number of overall compensation holes 600 is greater than the number of adjacent overall solid through holes 5010, the width of the distribution area of ​​the overall compensation holes 600 is greater than the width of the distribution area of ​​the adjacent overall solid through holes 5010, and the adjacent compensation holes 600 are evenly distributed in the length direction, with the width being perpendicular to the line connecting the invalid area 300 and the effective area 200.

[0086] By increasing the number of compensation holes 600 and the wider distribution area, the sanding belt can fully adjust and stabilize its downward pressure before entering the solid through hole area 700, avoiding uneven sanding in the hole area due to unstable pressure, forming a uniform and continuous sanding effect, and greatly improving the flatness of the board surface.

[0087] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made under the inventive concept of the present invention using the description and drawings of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A method for manufacturing an outer flexible rigid-flex board for an intelligent vision module, wherein the rigid-flex board is processed according to design data, the design data includes forming lines, the area within the forming lines is an effective area, and other areas are ineffective areas, the effective area includes a covered area and a non-covered area, the non-covered area is designed with vias and pads, characterized in that, The manufacturing method includes the following steps: S10: A flexible core board is formed according to the design data, and a rigid core board with a release layer attached to the corresponding uncovering area is formed. Then, a semi-cured sheet and a copper layer are taken. The flexible core board, the rigid core board, the semi-cured sheet, and the copper layer are then stacked and pressed together to form a laminated board. The release layer faces the flexible core board; the outer layer of the press-fit plate is a flexible layer; The flexible core board is fabricated by taking a double-sided flexible copper-clad laminate, fabricating a first circuit pattern on one side to form a single-sided patterned copper-clad laminate, and taking a first flexible board insulating dielectric layer and pressing it with the single-sided patterned copper-clad laminate to form the flexible core board; the first circuit pattern faces the first flexible board insulating dielectric layer. The stacking arrangement is such that the first flexible insulating dielectric layer of the flexible core board faces the rigid core board; or, The flexible core board is fabricated by taking a first single-sided flexible copper-clad laminate and a second single-sided flexible copper-clad laminate. A second circuit pattern is fabricated on the second single-sided flexible copper-clad laminate to form a second single-sided patterned copper-clad laminate; The first single-sided flexible copper-clad laminate and the second single-sided patterned copper-clad laminate are pressed together to form the flexible core board; the second circuit pattern faces the insulating dielectric layer of the first single-sided flexible copper-clad laminate. The stacking includes a prepreg set between the first single-sided flexible copper-clad laminate and the second single-sided flexible copper-clad laminate, wherein the prepreg has a window corresponding to the uncovered area, and the area of ​​the window has a second flexible board insulating dielectric layer. S20: Drill a first through hole and a second through hole into the press plate, then electroplate, and perform controlled-depth drilling on the second through hole. The first through hole forms the through hole, and the second through hole forms the controlled-depth hole. The whole plate is formed into a controlled-depth hole plate. S30: The depth control hole is resin plugged to form a solid through hole. Then, surface treatment and capping are performed in sequence, and then the whole plate is formed into the rigid-flexible plate. The peeling process involves controlled-depth milling from the flexible core board to the release layer.

2. The method for manufacturing an outer flexible layer rigid-flex plate for an intelligent vision module as described in claim 1, characterized in that, A reinforcing sheet is attached to the side of the flexible core board facing the rigid core board; the reinforcing sheet corresponds to the area of ​​the solder pad.

3. The method for manufacturing an outer flexible layer rigid-flex plate for an intelligent vision module as described in claim 1, characterized in that, The diameter of the depth control hole is larger on one side than the diameter of the second through hole.

4. The method for manufacturing an outer flexible layer rigid-flex plate for an intelligent vision module as described in claim 1, characterized in that, The size of the insulating dielectric layer of the second flexible board is larger on one side than the uncovered area.

5. The method for manufacturing an outer flexible layer rigid-flex plate for an intelligent vision module as described in claim 1, characterized in that, The invalid region adjacent to the solid through hole is provided with a plurality of compensation holes identical to the solid through hole.

6. The method for manufacturing an outer flexible layer rigid-flex plate for an intelligent vision module as described in claim 5, characterized in that, The spacing between adjacent compensation holes increases sequentially from the effective region to the ineffective region.

7. The method for manufacturing an outer flexible layer rigid-flex plate for an intelligent vision module as described in claim 6, characterized in that, The overall number of compensation holes is greater than the number of adjacent overall solid through holes, and the width of the distribution area of ​​the overall compensation holes is greater than the width of the distribution area of ​​adjacent overall solid through holes.

Images