Method for manufacturing dense jointed board high-precision thin rigid-flexible combined board

Abstract

The invention discloses a method for manufacturing a dense jointed board high-precision thin rigid-flexible combined board, which comprises the following steps of: manufacturing an auxiliary cushion layer, laminating the auxiliary cushion layer with a flexible covering film, performing depth-controlled milling on the whole board, and reserving a part corresponding to a flexible area to integrally form a milling layer; a first window is manufactured on the milling layer corresponding to the rigid area, a groove body is formed in the edge of the flexible area, connecting positions are distributed on the groove body, and a punching layer is integrally formed; a flexible core plate is manufactured to be attached to the punching layer, then the connecting position is cut off, and a flexible plate is formed; manufacturing and forming a rigid core plate; a second window is manufactured in a flexible area corresponding to the high-flow glue prepreg, and a windowed prepreg is formed; stacking and pressing the plate layers, and removing the flexible auxiliary cushion layer after forming to form the rigid-flexible combined plate; the whole processing technology forms process, batch and industrial processing conditions, front and back procedures are matched with each other, and a front and back matched relevance technology is formed.

Description

Technical Field

[0001] The invention relates to the field of printed circuit board manufacturing, in particular to the field of rigid-flexible board manufacturing, and more particularly to a method for manufacturing a densely assembled, high-precision, thin rigid-flexible board. Background Art

[0002] In the field of digital video, in order to realize powerful but compact equipment, the circuit board, as a core component, needs to have the characteristics of flexible installation, ultra-thin design and high density. Therefore, the rigid-flexible board that has the characteristics of both rigid and flexible boards and can adapt to complex electronic component layouts and compact space constraints has become the first choice.

[0003] When this type of rigid-flex PCB is made using traditional processing methods, the following problems exist: (1) Due to the small size of the unit board, the density of the panels is relatively high. If the outer layer circuit pattern is made by opening windows first and then pressing, the semi-cured sheet is opened in the corresponding flexible area, and its glass fiber is cut into several shorter sizes. During pressing, the restraint force of the glass fiber cloth itself is reduced, and it is easy to flow with the flow of glue, but the glass fiber itself (relative to the resin) does not flow. Therefore, it is easy for the semi-cured sheet or glass fiber to overflow from the rigid-flexible joint, which not only affects the appearance quality but also increases the difficulty of cleaning. Furthermore, if a low-flow semi-cured sheet is selected to solve the above-mentioned glue overflow problem, the problem of poor interlayer bonding after pressing will occur. If the pressure is increased to increase the interlayer bonding strength, it is easy to deform too much, affecting the circuit accuracy. In addition, the surface layer is concave after pressing, making it difficult to make circuit patterns on the surface.

[0004] (2) Since the size of this type of rigid-flexible board is generally small, multiple units will be combined into a large panel in actual production to improve efficiency. However, since the covering film of the flexible board is only attached to the flexible area of ​​the rigid-flexible board, a large amount of covering film is required on a panel, and the shape and size of the covering film are not uniform, resulting in increased alignment and number of attachments, which increases processing costs.

[0005] Therefore, in order to solve the above-mentioned problems, it is necessary to provide a method for manufacturing a densely assembled, high-precision, thin rigid-flexible board. Summary of the invention

[0006] The present invention aims to solve the comprehensive problems of glue overflow at the rigid-flexible combination position or low lamination reliability in the processing of the rigid-flexible combination board in the prior art, and proposes a method for manufacturing a densely spliced ​​high-precision thin rigid-flexible combination board. The rigid-flexible combination board is designed and processed in a splicing manner during the processing process. The rigid-flexible combination board is designed with a molding line, and the area within the molding line is an effective area, and the other areas are invalid areas. The effective area includes a flexible area and a rigid area. The manufacturing method includes the following steps: S10: laminating the first cushion layer and the second cushion layer for the first time to form an auxiliary cushion layer, and laminating the flexible covering film and the auxiliary cushion layer for the second time to form a covering film cushion layer. S20: performing laser milling on the auxiliary cushion layer in the covering film cushion layer, retaining a portion corresponding to the flexible area to form a flexible auxiliary cushion layer, and the covering film cushion layer forms a milling layer; S30: Punching the milled layer, wherein the punching forms a first window corresponding to the rigid area and forms a groove at the edge of the flexible area, wherein the groove has connecting positions, and the milled layer forms a punched layer; S40: forming a flexible core board, roughening the surface, and attaching the core board to the punched layer to form a flexible board; S50: forming a rigid core board; and taking a high-flow prepreg to form a second window corresponding to the flexible area to form a window prepreg; S60: stacking the window prepreg and the rigid core board in order from the inside to the outside on the surface of the flexible board, and pressing them together, then uncovering and processing, removing the flexible auxiliary cushion layer, and forming the rigid-flexible board.

[0007] Furthermore, the punching includes punching to form a plurality of compensating windows at the position of the ineffective area, and the plurality of compensating windows are separated from the effective area.

[0008] Furthermore, the first opening is larger than the rigid area.

[0009] Furthermore, the surface roughening treatment is: firstly performing plasma treatment on the flexible core board, and then performing micro-etching treatment on the flexible core board.

[0010] Furthermore, the size of the flexible core board is larger on one side than the punching layer.

[0011] Furthermore, the pressure of the first pressing is greater than the pressure of the second pressing, and the time of the first pressing is greater than the time of the second pressing.

[0012] Furthermore, the first pressing is performed by using a pressure of 18kg / cm² to 25kg / cm², at a temperature of 120°C to 160°C, for 20 seconds to 26 seconds.

[0013] Furthermore, the second pressing is: using a pressure of 12kg / cm² to 15kg / cm², at a temperature of 120°C to 160°C, and pressing for 12 seconds to 20 seconds.

[0014] Furthermore, the hardness of the first cushion layer is greater than the hardness of the second cushion layer.

[0015] Furthermore, the hardness of the first cushion layer is HRC70 to HRC85, and the hardness of the second cushion layer is HRC40 to HRC50.

[0016] The technical solution of the present invention first makes a covering film cushion layer through the whole plate, and then punches the whole plate in the later process, replacing the existing manual or machine single-piece covering film attachment process, realizing batch and industrial production and processing, greatly improving production efficiency, reducing labor costs, and also reducing errors and defective rates caused by manual operation, solving the problems of large-scale attachment of covering films in the prior art that easily cause alignment of attachments, increased number of attachments, and increased processing costs; by first pressing the first cushion layer and the second cushion layer with different hardness, and then pressing them with the flexible covering film, the consistency and stability of the entire structure can be ensured; and by using the difference in the parameters of the two pressings, different bonding strengths between the layers can be achieved, which, on the one hand, ensures the close bonding between the layers, and avoids surface defects caused by the use of rapid pressing, provides a flatter working surface, and solves the problem of the surface layer being concave after pressing in the prior art, making it difficult to make circuit patterns on the surface; on the other hand, it can also remove the flexible auxiliary cushion layer in the subsequent processing process to provide a smooth The peeling effect; by opening windows in the high-flow semi-cured sheet, a greater depth control tolerance is provided for the later use of controlled depth milling, which solves the depth control problem in the depth control milling process due to the thin plate body in the existing technology processing; by designing and manufacturing the windowed semi-cured sheet, and stacking and pressing it together with the flexible auxiliary cushion layer with differentiated hardness, the harder first cushion layer provides overall support for the subsequent process and the punching layer attachment, and in the subsequent pressing process, it can effectively prevent the position of the windowed semi-cured sheet from excessive deformation; the second cushion layer uses its soft properties to play a major buffering and covering role in the pressing process; and due to the slight flow of glue of the second cushion layer itself, it can offset the excess flow of glue generated by the windowed semi-cured sheet during the pressing process, solving the problem that the semi-cured sheet or glass fiber is easy to overflow from the rigid-flexible combination position during the pressing of the existing technology, affecting the appearance quality and increasing the difficulty of cleaning; the overall processing technology forms a process-based, batch, and industrialized processing condition, and the front and rear processes cooperate with each other to form a related technology that matches the front and rear. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0018] Figure 1 Schematic diagram of the process flow of an embodiment of the present invention; Figure 2 A schematic plan view of a densely packed panel according to an embodiment of the present invention Figure 3 is a cross-sectional schematic diagram of an auxiliary cushion layer according to an embodiment of the present invention; Figure 4 is a cross-sectional schematic diagram of a milling layer according to an embodiment of the present invention; Figure 5 A schematic plan view of a punching layer according to an embodiment of the present invention; Figure 6 for Figure 5 AA cross-sectional diagram of ; Figure 7 is a schematic cross-sectional view of a flexible board according to an embodiment of the present invention; Figure 8 for Figure 7 Schematic diagram of the plane; Fig. 9 is a schematic cross-sectional view of a stacked structure according to an embodiment of the present invention; Fig.10 is a schematic cross-sectional view of a pressed plate according to an embodiment of the present invention; Fig.11 A sliced ​​physical picture of the rigid-flex joint position of the pressed plate according to the embodiment of the present invention; Fig.12 It is a schematic plan view of a rigid-flex board according to an embodiment of the present invention.

[0019] Explanation of the accompanying numbers: PB-close-packed panel; FD-local enlarged position; 10-auxiliary cushion layer; 100-first cushion layer; 100a-PI layer of the first cushion layer; 100b-glue layer of the first cushion layer; 200-second cushion layer; 200a-PI layer of the second cushion layer; 200b-glue layer of the second cushion layer; 20-milling layer; 2010-flexible covering film; 2020-flexible auxiliary cushion layer; 30-punching layer; 3010-first window; 3020-groove; 3030-connecting position; 3040-compensating window; 40-flexible core board; 50-flexible board; 60-rigid core board; 70-window semi-cured sheet; 7010-second window; 80-stacked structure; 80A-pressed board; 90-rigid-flexible board.

[0020] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0021] 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.

[0022] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, inside, outside...) are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0023] In addition, in the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0024] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0025] See also Figure 1 , Figure 1 Schematic diagram of the process flow of an embodiment of the present invention.

[0026] The manufacturing process of the embodiment of the present invention includes using Figure 1 The following will implement the various steps in the process Figure 1 Each step in the process is further explained step by step.

[0027] The rigid-flex board of this embodiment is designed and processed by a panelization method during the processing, and is designed with a molding line. The area within the molding line is the effective area, and the other area is the invalid area. The effective area includes the flexible area and the rigid area.

[0028] See also Figure 2 , Figure 2 It is a plan view schematic diagram of a dense puzzle board according to an embodiment of the present invention.

[0029] This embodiment aims at the case where a rigid-flexible board with a smaller unit size is formed into a densely packed board PB, and solves the process and technical problems in the processing.

[0030] In order to more clearly illustrate the technical process of this embodiment, the following figures are all Figure 2 A partial enlarged view of the panel structure at position FD is provided for illustration.

[0031] Please refer to Figure 3 , Figure 3 Schematic cross-sectional view of an auxiliary cushion layer according to an embodiment of the present invention.

[0032] Step S10: The first cushion layer 100 and the second cushion layer 200 are pressed together for the first time to form the auxiliary cushion layer 10 , and then the flexible covering film 2010 and the auxiliary cushion layer 10 are pressed together for the second time to form the covering film cushion layer.

[0033] The first cushion layer 100 is composed of a first cushion layer PI layer 100a and a first cushion layer glue layer 100b stacked together; the second cushion layer 200 is composed of a second cushion layer PI layer 200a and a second cushion layer glue layer 200b stacked together.

[0034] The auxiliary pad layer 10 is designed mainly to compensate for the height difference caused by the window semi-cured sheet 70 in the subsequent stacking and pressing process, so that the board surface after pressing is smoother, providing ideal plane conditions for the subsequent production of surface circuit patterns, and the auxiliary pad layer 10 is formed by pressing the first pad layer 100 and the second pad layer 200 with different hardness, rather than selecting an integrally formed pad layer, in order to give full play to the characteristics of different hardness of the first pad layer 100 and the second pad layer 200 to provide different functions in the processing process.

[0035] Furthermore, the hardness of the first cushion layer 100 is greater than that of the second cushion layer 200. The first cushion layer 100 provides overall support for the subsequent process and the punching layer 30, and can effectively prevent excessive deformation of the position of the window semi-cured sheet 70 during the subsequent lamination process. The second cushion layer 200 uses its soft properties to play a major buffering and coating role during the lamination process. Moreover, due to the slight glue flow characteristics of the second cushion layer 200 itself, it can offset the excess glue flow generated by the window semi-cured sheet 70 during the lamination process, and at the same time guide the glass fiber to avoid the window position, thereby avoiding the glass fiber overflow that may occur after the subsequent cover is removed.

[0036] It is worth mentioning that since the auxiliary pad layer 10 formed by pressing the first pad layer 100 and the second pad layer 200 together has a height difference with the windowed semi-cured sheet 70 in the stacked structure 80 of the subsequent process, the number of layers of the first pad layer 100 and the second pad layer 200 can be appropriately increased during processing according to the height of the windowed semi-cured sheet 70. For example, two layers of the first pad layer 100 and two layers of the second pad layer 200 are pressed together to form the auxiliary pad layer 10.

[0037] Optionally, the hardness of the first cushion layer 100 is HRC70 to HRC85, and the hardness of the second cushion layer 200 is HRC40 to HRC50.

[0038] This embodiment adopts a step-by-step pressing process, in particular, the pressure of the first pressing is greater than the pressure of the second pressing, and the time of the first pressing is greater than the time of the second pressing, in order to ensure a good bond between the first cushion layer 100 and the second cushion layer 200, thereby enhancing the interlayer bonding force. In addition, the pressure and time of the first pressing are both greater than the pressure of the second pressing, so that the bonding force between the first cushion layer 100 and the second cushion layer 200 is greater than the bonding force between the flexible covering film 2010 and the auxiliary cushion layer 10, thereby providing a processing basis for removing the flexible auxiliary cushion layer 2020 after molding.

[0039] Optionally, the first pressing is: using a pressure of 18kg / cm² to 25kg / cm², at a temperature of 120℃ to 160℃, pressing for 20 seconds to 26 seconds; the second pressing is: using a pressure of 12kg / cm² to 15kg / cm², at a temperature of 120℃ to 160℃, pressing for 12 seconds to 20 seconds.

[0040] Please refer to Figure 4 , Figure 4 Schematic cross-sectional view of a milled layer according to an embodiment of the present invention.

[0041] Step S20: The auxiliary cushion layer 10 in the covering film cushion layer is laser milled to retain the portion corresponding to the flexible area to form a flexible auxiliary cushion layer 2020 , and the covering film cushion layer forms a milled layer 20 .

[0042] In this embodiment, part of the auxiliary cushion layer 10 in the covering film cushion layer is selectively removed by milling, and the part corresponding to the flexible area is retained, thereby forming a flexible auxiliary cushion layer 2020, which provides support for the flexible area during lamination and also provides a processing basis for subsequent processing steps; this process requires high precision to ensure that the surrounding structures or materials are not damaged, and because the thickness of the covering film cushion layer is relatively small, laser-controlled depth milling is used to achieve high-precision cutting.

[0043] Please refer to Figure 5 and Figure 6 , Figure 5 A schematic plan view of a punching layer according to an embodiment of the present invention; Figure 6 for Figure 5 Schematic diagram of the AA section.

[0044] Step S30: The milling layer 20 is punched to form a first window 3010 in the corresponding rigid area and a groove 3020 is formed at the edge of the flexible area. The groove 3020 is provided with connecting positions 3030 . The milling layer 20 is formed into a punching layer 30 .

[0045] The first window 3010 is formed by punching the rigid area, so as to provide sufficient adhesion space for the rigid board layer in the subsequent lamination process, thereby ensuring a good lamination effect; at the same time, a plurality of grooves 3020 are punched at the edge of the corresponding flexible area to form an effect in which a plurality of connection positions 3030 are distributed in the middle of the through groove. On the one hand, the grooves 3020 can be used as the design basis of the connection positions 3030, so as to maintain the integrity of the overall structure in the subsequent process, so that the flexible covering film 2010 in the flexible board area and the flexible covering film 2010 in the invalid area form a whole, which is convenient for batch processing. The entire processing is completed as a whole to realize batch and industrialized processing. The groove body 3020 is punched out as a whole so that the flexible covering film 2010 will not hinder the pressing process and effect of the board body itself, and provides sufficient space for the rigid board pressing and glue flow to prevent the glue flow from causing excessive squeezing of the flexible board area. At the same time, it provides a processing basis for removing the flexible auxiliary cushion layer 2020 in the subsequent process. Different areas are punched out together, and the flexible covering film 2010 in the invalid area is retained, so that the milling layer 20 can form an effect that can be processed in batches, and the function of setting the connection position 3030 is achieved.

[0046] Furthermore, the first window 3010 is larger than the rigid area, which provides sufficient glue flow space for the subsequent pressing process, ensures the adhesion between the rigid board layers, and helps to solve the problem of insufficient interlayer bonding that may occur in traditional methods.

[0047] Optionally, the first opening 3010 is larger than the rigid region by 50 μm to 2.0 mm.

[0048] Since the flexible covering film 2010 of the invalid area is retained, and the flexible covering film 2010 may cause problems such as weak interlayer bonding in the rigid board area, the punching also includes punching a number of compensating windows 3040 at the invalid area, and the several compensating windows 3040 are separated from the effective area, so that the resin glue layer in the lamination process can flow and fill in the gaps between different layers to ensure good interlayer adhesion, effectively improve the adhesion between layers, and effectively avoid problems such as insufficient space for glue flow between layers and uneven distribution of the resin glue layer, which lead to insufficient interlayer bonding.

[0049] In addition, it is worth mentioning that after the subsequent pressing, a compensating window 3040 is also made at the position of the tool hole, which can ensure that the tool hole will not be made in the covering film area within the layer after pressing, thereby preventing the tool hole from seeping chemicals through the covering film layer into the interior of the circuit board when the board body is processed with chemicals in the subsequent process.

[0050] Optionally, the distance between the plurality of compensation windows 3040 and the effective area is greater than 20 μm.

[0051] Please refer to Figure 7 , Figure 7 is a schematic cross-sectional view of a flexible board according to an embodiment of the present invention; Figure 8 for Figure 7 Schematic diagram of the floor plan.

[0052] Step S40: The flexible core board 40 is manufactured, the surface of which is roughened, and attached to the punched layer 30 to form a flexible board 50 .

[0053] In this embodiment, the surface roughening treatment is: firstly plasma treatment is performed on the flexible core board 40, and then micro-etching treatment is performed.

[0054] That is, plasma treatment changes the roughness of the surface of the insulating dielectric layer of the flexible core board 40, and then micro-etching (or super-roughening) treatment increases the roughness of the surface of the circuit pattern on the surface of the flexible core board 40, so that the bonding between the punching layer 30 and the flexible core board 40 can be stronger, and the bonding force formed between the two is greater than the bonding force between the second cushion layer 200 and the surface of the flexible covering film 2010, which provides a processing basis for the subsequent removal of the flexible auxiliary cushion layer 2020 after the cover is uncovered, and utilizes the difference in bonding force to effectively prevent the flexible covering film 2010 from being pulled and bubbled when the flexible auxiliary cushion layer 2020 is removed.

[0055] In this embodiment, since the flexible covering film 2010 of the invalid area is retained, multiple and small unit covering films can form a batch processing effect, thereby improving production efficiency and consistency; but it also brings potential problems, that is, when the rigid-flexible composite board 90 is pressed as a whole, the flexible covering film 2010 may affect the bonding strength between the pressed layers. If the size of the flexible covering film 2010 extends to the edge of the board, especially the interlayer bonding strength at the edge of the board, the size of the flexible core board 40 is set to be larger than the punching layer 30 on one side. On the one hand, it can effectively increase the effective adhesion area of ​​the edge of the board, improve the bonding strength between the flexible core board 40 and other layers, and make the entire board body more secure during the processing process. On the other hand, it can serve as a barrier, especially the part beyond the edge of the board, to prevent the chemical solution used in the subsequent processing process from penetrating from the edge of the board body into the interior, causing damage to internal components or performance degradation.

[0056] Optionally, the size of the flexible core board 40 is larger than that of the punched layer 30 by a distance of 30 μm to 20 mm.

[0057] Alternatively, if the size of the ineffective area at the edge of the flexible core board itself is small, the edge of the flexible core board 40 can be unilaterally extended relative to the size of the covering film.

[0058] Optionally, the connection position 3030 at the edge of the flexible area is then cut by laser; the punching layer 30 is attached to the surface of the flexible core board 40, and after the attachment is completed, the connection position 3030 is cut off, preferably by laser cutting, to provide a prerequisite for easier processing for the subsequent uncovering and molding processing of the flexible area, and to prevent the molding processing from causing problems such as pulling on the connection position 3030, thereby causing problems such as deformation of the flexible area.

[0059] Please refer to Fig. 9 and Fig.10 , Fig. 9 Schematic cross-sectional view of a stacked structure according to an embodiment of the present invention.

[0060] Step S50: A rigid core board 60 is manufactured; and a second window 7010 is manufactured in the corresponding flexible area of ​​the high-flow adhesive prepreg, so as to form a window prepreg 70 .

[0061] In the subsequent stacking and pressing process, since the flexible auxiliary pad 2020 is capable of preventing the overflow of glass fiber, the high-flow adhesive semi-cured sheet is used here to improve the interlayer bonding strength, thereby improving the reliability of the board body. By utilizing its good fluidity, the gap between the rigid core board 60 and the flexible board 50 can be effectively filled during the pressing process, while avoiding the problem of insufficient interlayer bonding strength caused by low fluidity in traditional methods.

[0062] It is worth mentioning that during the lamination process, the high-flow glue semi-cured sheet will have the problem of glue overflow or glass fiber overflow (the existing technology will also have this problem). The glue overflow is due to the excessive flow of the colloid under high temperature and high pressure lamination, which overflows from the rigid area to the flexible area. The glass fiber overflow is due to the fact that several unit boards are assembled into a puzzle board, and the resulting puzzle board density is relatively large. The high-flow glue semi-cured sheet needs to have more window areas corresponding to the flexible board area, and its glass fiber is cut into several shorter sizes. During lamination, the restraining force of the glass fiber cloth itself is reduced, and it is easy to flow with the flow of glue, but the glass fiber itself (relative to the resin) does not flow. Therefore, the glass fiber will flow from one window area to another (that is, from the larger area of ​​the uncut piece to the cut scattered area), resulting in the squeezing of the glass fiber and thus overflowing into the flexible board area.

[0063] The second cushion layer 200 with lower hardness is mainly used for the purpose of forming a certain degree of conformability and fluidity during pressing, so as to offset the overflow of the high-flow adhesive semi-cured sheet and keep the overflow within a controllable range (for example, less than 20 μm). At the same time, the combination of the first cushion layer 100 and the second cushion layer 200 can move the glass fiber toward the second cushion layer 200, thereby preventing the problem of excessive overflow due to the glass fiber extending into the flexible area and adhering to the resin, and preventing the problem of excessive overflow due to the glass fiber pressing the second cushion layer 200.

[0064] Optionally, the high-flow adhesive prepreg has an adhesive content of 55% to 68%.

[0065] It is worth mentioning that in order to ensure sufficient glue flow space, the window size on the high-flow glue semi-cured sheet is designed to be 20μm to 70μm larger than the size of the flexible auxiliary pad 2020 on one side, which helps to control the direction and range of the flow of the resin glue layer, reduce or prevent the resin glue layer from overflowing to unnecessary places, thereby solving the glue overflow problem that is prone to occur in the traditional method of opening a window first and then pressing.

[0066] See also Fig.10 , Fig.11 and Fig.12 , Fig.10 is a schematic cross-sectional view of a pressed plate according to an embodiment of the present invention, Fig.11 This is a sliced ​​physical picture of the rigid-flex joint position of the pressed plate according to the embodiment of the present invention. Fig.12 It is a schematic plan view of a rigid-flex board according to an embodiment of the present invention.

[0067] Step S60: On the surface of the flexible board 50, the windowed semi-cured sheet 70 and the rigid core board 60 are stacked in sequence from the inside to the outside to form a stacked structure 80, and pressed together to form a pressed board 80A, which is then uncovered and processed, and the flexible auxiliary pad layer 2020 is removed, and after molding, a rigid-flexible composite board 90 is formed.

[0068] The cover-lifting process can use laser controlled depth cutting or mechanical controlled depth milling. Since the groove body 3020 and the flexible auxiliary cushion layer 2020 are set in the early stage, the accuracy of the cover-lifting process is relatively improved, and the adhesion strength of the flexible auxiliary cushion layer 2020 to the covering film is relatively low, and it can be removed together with the cover-lifting process, thereby exposing the flexible covering film 2010 in the flexible area.

[0069] If the thickness of the board is thinner and the thickness of the cover is thinner, the "front cover" processing method can be used, that is, all windows are opened in the positions of the rigid board layer corresponding to the flexible area before lamination, and then the lamination gasket (release film, coating film) is used as a buffer layer for lamination, and then the rigid-flexible joint is trimmed.

[0070] Depend on Fig.11It can be seen that after the flexible auxiliary pad 2020 is provided, the glue flow of the high-flow glue semi-cured sheet toward the window area is effectively suppressed, and the glass fibers extend toward the top of the flexible covering film 2010, that is, the glass fibers are effectively suppressed outside the second window 7010, avoiding the problem of glass fiber overflow.

[0071] In summary, in this embodiment, the covering film cushion layer is first manufactured on the whole board, and then the whole board is punched in the post-process, which replaces the covering film attachment process, realizes batch and industrialized production and processing, greatly improves production efficiency, reduces labor costs, and also reduces errors and defective rates caused by manual operations, solving the problems of large-scale attachment of covering films in the prior art, resulting in increased alignment and number of attachments, and increased processing costs; by first pressing the first cushion layer 100 and the second cushion layer 200 with different hardness, and then pressing them with the flexible covering film 2010, the consistency and stability of the entire structure can be ensured; and by using the difference in the two pressing parameters, different bonding strengths between the layers can be achieved, which, on the one hand, ensures the close bonding between the layers, and also avoids the surface defects caused by the use of rapid pressing, provides a flatter working surface, and solves the problems of the surface layer being concave after pressing in the prior art, making it difficult to make circuit patterns on the surface; on the other hand, the flexible auxiliary cushion layer 2020 can be removed in the subsequent processing process to provide a smooth peeling effect; Opening windows in the semi-cured sheet with high glue flow provides a greater depth control tolerance for the subsequent controlled depth milling, solving the problem of depth control in the controlled depth milling process due to the thin plate body in the prior art processing; by designing and manufacturing the semi-cured sheet with windows 70, and stacking and pressing it together with the flexible auxiliary cushion layer 2020 with differentiated hardness, the harder first cushion layer 100 provides overall support for the subsequent process and the punching layer 30, and in the subsequent pressing process, it can effectively prevent the position of the semi-cured sheet with windows 70 from excessive deformation; the second cushion layer 200 uses its soft properties to play a major buffering and covering role in the pressing process; and due to the slight glue flow characteristics of the second cushion layer 200 itself, it can offset the excess glue flow generated by the semi-cured sheet with windows 70 during the pressing process, solving the problem that the semi-cured sheet or glass fiber easily overflows from the rigid-flexible combination position during pressing in the prior art, affecting the appearance quality and increasing the difficulty of cleaning; the overall processing technology forms a process-oriented, batch-based, and industrialized processing condition, and the front and rear processes cooperate with each other to form a related technology that matches the front and rear.

[0072] It is worth noting that due to the precise design and processing of the rigid-flex board 90, the structure of the actual processing process and the thickness of each layer, line width and other dimensions are all at the micron level. If the drawings are made according to the enlarged ratio of the actual structure, the drawings will be unclear. Therefore, in order to more clearly and intuitively represent the implementation process of the manufacturing method of this embodiment, the drawings of this embodiment are all schematic diagrams that enlarge the technical features, which do not represent the size of the actual structure, nor are they enlarged views of the actual structure in proportion.

[0073] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A method for manufacturing a densely spliced ​​high-precision thin rigid-flexible board, wherein the rigid-flexible board is designed and processed by splicing during processing, and the rigid-flexible board is designed with a molding line, the area within the molding line is an effective area, and the other areas are invalid areas, the effective area includes a flexible area and a rigid area, and is characterized in that: The production method comprises the following steps: S10: laminating the first cushion layer and the second cushion layer for the first time to form an auxiliary cushion layer, and laminating the flexible covering film and the auxiliary cushion layer for the second time to form a covering film cushion layer; S20: performing laser milling on the auxiliary cushion layer in the covering film cushion layer, retaining a portion corresponding to the flexible area to form a flexible auxiliary cushion layer, and the covering film cushion layer forms a milling layer; S30: Punching the milled layer, wherein the punching forms a first window corresponding to the rigid area and forms a groove at the edge of the flexible area, wherein the groove has connecting positions, and the milled layer forms a punched layer; S40: forming a flexible core board, roughening the surface, and attaching the core board to the punched layer to form a flexible board; S50: forming a rigid core board; and taking a high-flow prepreg to form a second window corresponding to the flexible area to form a window prepreg; S60: stacking the window prepreg and the rigid core board in order from the inside to the outside on the surface of the flexible board, and pressing them together, then uncovering and processing, removing the flexible auxiliary cushion layer, and forming the rigid-flexible board.

2. The method for manufacturing a densely assembled high-precision thin rigid-flexible board as claimed in claim 1, characterized in that: The punching includes punching to form a plurality of compensation windows at the position of the ineffective area, and the plurality of compensation windows are separated from the effective area.

3. The method for manufacturing a densely assembled high-precision thin rigid-flexible board as claimed in claim 1, characterized in that: The first opening is larger than the rigid region.

4. The method for manufacturing a densely assembled high-precision thin rigid-flexible board according to claim 1, characterized in that: The surface roughening treatment is: firstly performing plasma treatment on the flexible core board, and then performing micro-etching treatment on the flexible core board.

5. The method for manufacturing a densely assembled high-precision thin rigid-flexible board as claimed in claim 1, characterized in that: The flexible core panel has a single side dimension larger than the punched layer.

6. The method for manufacturing a densely assembled high-precision thin rigid-flexible board according to claim 1, characterized in that: The pressure of the first pressing is greater than the pressure of the second pressing, and the time of the first pressing is greater than the time of the second pressing.

7. A method for manufacturing a densely assembled high-precision thin rigid-flexible board as claimed in claim 1 or 6, characterized in that: The first pressing is performed by using a pressure of 18kg / cm² to 25kg / cm², at a temperature of 120°C to 160°C, for 20 seconds to 26 seconds.

8. A method for manufacturing a densely assembled high-precision thin rigid-flexible board as claimed in claim 1 or 6, characterized in that: The second pressing is performed by using a pressure of 12kg / cm² to 15kg / cm², at a temperature of 120°C to 160°C, for 12 seconds to 20 seconds.

9. The method for manufacturing a densely assembled high-precision thin rigid-flexible board as claimed in claim 1, characterized in that: The hardness of the first cushion layer is greater than the hardness of the second cushion layer.

10. A method for manufacturing a densely assembled high-precision thin rigid-flexible board as claimed in claim 1 or 9, characterized in that: The hardness of the first cushion layer is HRC70 to HRC85, and the hardness of the second cushion layer is HRC40 to HRC50.

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