A method for manufacturing a rigid-flex printed circuit board with a cross surface flexible layer

Abstract

The application discloses a manufacturing method of a rigid-flexible combined board of a cross type surface flexible layer, and comprises the following steps: taking a double-sided flexible copper-clad plate, forming a groove body on one of the copper layers and the insulating medium layer, forming an etching ablation groove, distributing the groove body corresponding to the edge of the flexible plate area, attaching a cover film in the groove body range, forming upper and lower flexible plates, manufacturing a rigid core plate layer and a prepreg, stacking and pressing to form a pressing plate, manufacturing an outer layer circuit pattern, and then forming a rigid-flexible combined board; optionally, manufacturing a windowed rigid core plate and a windowed prepreg, and stacking and pre-pressing one layer of flexible plates to form a groove body structure, setting a release pad in the groove body, and then stacking and pressing another layer of flexible plates to form a pressing plate; by setting the etching ablation groove on the flexible plate, it is ensured that the flexible plate will not cause a problem difficult to mill when being formed, and optionally, the setting of the release pad is used to replace the way of breaking off after depth control milling, so that the processing quality and precision of the plate body are effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of rigid-flex printed circuit board manufacturing, and particularly relates to a rigid-flex printed circuit board manufacturing method with cross surface flexible layers. BACKGROUND

[0002] For some complex electronic modules, it is required to realize more and stronger functions in a limited space, so the rigid-flex printed circuit board is generally used to meet the conditions of supporting and three-dimensional installation of electronic components.

[0003] For the control module such as intelligent light group of intelligent networked vehicle, it is required to have more complex functions, so more complex design and processing technology are required for the rigid-flex printed circuit board. Some rigid-flex printed circuit boards are designed to have flexible board layers arranged on the upper and lower surfaces of the board body, and the flexible boards are in a cross state.

[0004] At present, for this kind of rigid-flex printed circuit board, there is a great difficulty in the process of removing the intermediate layers that do not need to be reserved after laminating to form a laminated board, so as to form a flexible board area. Generally, a control depth groove is made at the rigid-flex joint position of the rigid board layer that needs to be removed, and then the rigid board layer at this position is broken after forming.

[0005] However, if the rigid board layer protrudes into the rigid board area due to expansion and contraction during lamination, or the control depth groove is filled with lamination resin, the rigid board layer is not easy to break, which affects the processing quality and efficiency, and may even cause the board to delaminate and be scrapped.

[0006] In view of the above background and problems, an effective manufacturing method for a rigid-flex printed circuit board with cross surface flexible layers is needed. SUMMARY

[0007] The present application aims to solve the problem that the intermediate layer of the rigid board is difficult to remove during the processing of the rigid-flex printed circuit board with cross surface flexible layers, and to provide a rigid-flex printed circuit board manufacturing method with cross surface flexible layers. The rigid-flex printed circuit board includes a rigid board area and a flexible board area. The combination position of the rigid board area and the flexible board area is a rigid-flex joint position. The flexible board area includes an upper flexible board area and a lower flexible board area. The upper and lower surface layers of the rigid board area are the combination layers of the upper flexible board area and the lower flexible board area and the rigid board area. The rigid-flex printed circuit board in the processing process is provided with a forming line. The forming line is an effective area, and the area outside the forming line is an auxiliary area.

[0008] The manufacturing method comprises the following steps:

[0009] S10: take a double-sided flexible copper-clad plate, make etching patterns on one of the copper layers, and laser ablate the exposed insulating medium layer corresponding to the etching patterns to form etching ablation grooves; the etching ablation grooves are distributed corresponding to the edges of the upper flexible plate area not combined with the rigid plate area and the rigid-flexible combination positions of the lower flexible plate area; cover the upper and lower surfaces of the double-sided flexible copper-clad plate in the range of the etching ablation grooves with cover films corresponding to the upper flexible plate area; and process the whole to form an upper flexible plate;

[0010] The lower flexible plate is made by the same method as the upper flexible plate.

[0011] S20: take a rigid copper-clad plate, make a rigid plate circuit pattern to form a rigid core plate; take a prepreg, and sequentially align and stack the upper flexible plate, the rigid core plate, and the lower flexible plate, with the prepreg arranged between the upper flexible plate and the rigid core plate and between the rigid core plate and the lower flexible plate; the etching ablation grooves of the upper flexible plate are arranged opposite to the etching ablation grooves of the lower flexible plate; and then press to form a press-bonded plate.

[0012] S30: make an outer layer circuit pattern of a surface layer on the press-bonded plate, the outer layer circuit pattern including etching patterns of the surface copper layer corresponding to the etching ablation grooves; and then perform forming processing according to the forming line to form a rigid-flexible combination plate of the cross-type surface flexible layer.

[0013] Further, the forming of the press-bonded plate includes:

[0014] S210: make a first through window on the rigid core plate to form an open-window rigid core plate; make a second through window on the prepreg to form an open-window prepreg; sequentially align and stack the upper flexible plate or the lower flexible plate with the open-window rigid core plate, with the open-window prepreg arranged between the upper flexible plate or the lower flexible plate and the open-window rigid core plate and on the surface of the open-window rigid core plate; the etching ablation grooves of the upper flexible plate or the lower flexible plate are arranged towards the open-window rigid core plate; the coverage range of the first through window and the second through window includes the range of the flexible plate area; and then perform pre-pressing to form a pre-pressing open-window groove.

[0015] S220: arrange a release pad in the pre-pressing open-window groove, and align and stack the lower flexible plate or the upper flexible plate on one side of the release pad; and then press to form the press-bonded plate.

[0016] Further, the edges of the release pad adjacent to the rigid-flexible combination positions are made with edge groove bodies, and the release agent is filled into the edge groove bodies after the release pad is arranged.

[0017] Further, the release agent is a PTFE type release agent, and the viscosity is 350 dPa·s to 900 dPa·s.

[0018] Further, the size of the release pad is less than or equal to the size of the pre-pressing window groove.

[0019] Further, the material of the release pad is PTFE, PI, TPX, ETFE or silica gel.

[0020] Further, the pre-pressing window groove has a groove body in the range of the flexible plate area; the pre-pressing window groove further has an auxiliary groove body extending from the groove body to the auxiliary area; the auxiliary groove body is a convex groove structure greater than or equal to a quadrilateral connected to the groove body; the release pad has an auxiliary fixed area corresponding to the auxiliary groove structure.

[0021] Further, the pre-pressing is performed at a temperature of 140°C to 180°C, using a pressure of 15 kg / cm² to 25 kg / cm², and for 2 minutes to 10 minutes.

[0022] Optionally, the forming of the press-bonded plate comprises:

[0023] S210A: The semi-cured sheet layer is arranged on the upper and lower surfaces of the rigid core plate, and pre-pressing is performed to form a pre-pressing core plate; according to the forming line, a through groove is made at the edge position of the rigid plate area corresponding to the rigid-flexible joint position of the pre-pressing core plate to form a pre-cut groove, and a pre-cut groove core plate is formed;

[0024] S220A: The upper flexible plate, the pre-cut groove core plate and the lower flexible plate are sequentially aligned and stacked, and then press-bonded to form the press-bonded plate.

[0025] Optionally, the through groove is made by milling or by laser ablation of the insulating dielectric layer combined with etching of the copper layer.

[0026] The technical solution of the present invention first makes an etching and ablation groove on the flexible board layer to form a flexible board opening effect during the final processing, and uses the windows of each layer of the rigid board layer to make a pre-pressed plate. Furthermore, a release pad is set, and an auxiliary fixing area and a filling release agent are set, which effectively improves the setting accuracy and processability of the release pad, replacing the existing technology of making a controlled depth groove at the position of the rigid-flexible combination position and then breaking the rigid board, making the processing process more operable, reducing the impact of errors in the processing process on the processing itself, and improving the quality and reliability of the processing; further, laser ablation is combined with etching of the copper layer to make a pre-cut groove on the edge of the rigid board at the rigid-flexible combination position, improving the processing accuracy of the pre-cut groove, facilitating the pre-cut groove to form a carbonized inert groove inner wall, preventing the pressing process from closing the groove body, and combined with the etching and ablation groove of the flexible board layer, the rigid board layer can be conveniently removed after subsequent molding; the overall manufacturing method forms a process of coordinated processing of the flexible board layer and the rigid board layer, forming an effective overall processing flow, which can effectively improve the processing quality and processing accuracy of the rigid-flexible combination board with a cross-surface flexible layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. 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 any creative work.

[0028] Figure 1 A key process flow chart of an embodiment of the present invention;

[0029] Figure 2 This is a schematic diagram of the planar structure of the upper flexible board formed in this embodiment;

[0030] Figure 3 for Figure 2 AA cross-sectional structural diagram;

[0031] Figure 4 A key process flow chart for forming a pressed plate according to an embodiment of the present invention;

[0032] Figure 5 This is a schematic diagram of a cross-sectional structure of a stacked structure formed in accordance with an embodiment of the present invention;

[0033] Figure 6 This is a schematic diagram of the cross-sectional structure of a pre-pressed plate formed in accordance with an embodiment of the present invention;

[0034] Figure 7 This is a schematic diagram of the cross-sectional structure of a release pad pre-pressing plate produced according to an embodiment of the present invention;

[0035] Figure 8 Figure 1 is a schematic view of a B-B cross-sectional structure of the present application; Figure 7

[0036] Figure 9 Figure 2 is a schematic view of a cross-sectional structure of a pre-pressing plate with auxiliary fixing area made by the embodiment of the present application;

[0037] Figure 10 Figure 3 is a schematic view of a cross-sectional structure of a pressing plate made by the embodiment of the present application;

[0038] Figure 11 Figure 4 is a key process flow chart of making another pressing plate by the embodiment of the present application;

[0039] Figure 12 Figure 5 is a schematic view of a planar structure of a pre-cut slot core plate made by the embodiment of the present application;

[0040] Figure 13 Figure 6 is a schematic view of a C-C cross-sectional structure of the present application; Figure 12

[0041] Figure 7 is a schematic view of a cross-sectional structure of another pressing plate made by the embodiment of the present application; Figure 14

[0042] Figure 8 is a schematic view of a planar structure of a rigid-flex combined plate with cross-type surface flexible layer made by the embodiment of the present application; Figure 15

[0043] Figure 9 is a schematic view of a D-D cross-sectional structure of the present application; Figure 16 Figure 15 Figure 10 is a schematic view of an E-E cross-sectional structure of the present application.

[0044] Figure 17 Brief Description of the Drawings: Figure 15

[0045]

[0046] 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

[0047] The technical solutions in the embodiments of the present application will be clearly 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, but not all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application. DETAILED DESCRIPTION

[0048] The technical solutions in the embodiments of the present application will be clearly 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, but not all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0049] ​​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, movement condition, etc. between components in a certain specific posture (as shown in the drawings), and if the specific posture changes, the direction indications will also change accordingly.

[0050] 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.

[0051] 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.

[0052] Please refer to Figure 1 , Figure 1 for the key process flow of the embodiment of the present application.

[0053] The manufacturing method of the rigid-flex combined board of the embodiment of the present application comprises Figure 1 the key manufacturing process flow, which is described in detail in the following steps.

[0054] Please refer to Figure 2 and Figure 3 ; Figure 2 for the schematic diagram of the planar structure of the flexible plate formed by the embodiment of the present application; Figure 3 for the schematic diagram of the A-A cross-sectional structure of Figure 2 .

[0055] The manufacturing method of the cross-type surface flexible layer rigid-flex combined board 60 provided by the embodiment of the present application comprises a rigid plate area 10G and a flexible plate area 10R, the combination position of the rigid plate area 10G and the flexible plate area 10R is a rigid-flex combination position, the flexible plate area 10R comprises an upper flexible plate area 10RS and a lower flexible plate area 10RX, the upper and lower surface layers of the rigid plate area 10G are respectively the combination layers of the upper flexible plate area 10RS and the lower flexible plate area 10RX and the rigid plate area 10G; the rigid-flex combined board is provided with a forming line 10C in the processing process, the effective area is within the forming line 10C, and the auxiliary area is outside the forming line 10C.

[0056] The manufacturing method comprises the following steps:

[0057] Step S10:

[0058] Take a double-sided flexible copper-clad plate, make etching patterns on one side of the copper layer, and laser ablate the exposed insulating medium layer corresponding to the etching patterns to form etching ablation grooves 110; the etching ablation grooves 110 are distributed corresponding to the edges of the upper flexible plate area 10RS that are not combined with the rigid plate area 10G, and are distributed corresponding to the rigid-flexible combination sites of the lower flexible plate area 10RX; the upper and lower surfaces of the double-sided flexible copper-clad plate corresponding to the upper flexible plate area 10RS within the range of the etching ablation grooves 110 are attached with a cover film 120; and the whole is processed to form an upper flexible plate 10 (as shown in Figure 2 and Figure 3 The cover film is a first cover film 120, and preferably, the cover film extends into the rigid plate area by a distance of 20 μm to 200 μm, which can ensure that the cover film is firmly pressed into the interior of the rigid plate area to form an effective rigid-flexible combination effect.

[0059] The lower flexible plate 20 is made by the same method as the upper flexible plate; that is, another double-sided flexible copper-clad plate is taken, etching patterns are made on one side of the copper layer, and laser ablation is performed on the exposed insulating medium layer corresponding to the etching patterns to form another etching ablation groove 210 (not labeled in the figure); the other etching ablation groove 210 is distributed corresponding to the edges of the lower flexible plate area 10RS that are not combined with the rigid plate area 10G; another cover film 220 (as shown in Figure 5 ) is attached to the upper and lower surfaces of the other double-sided flexible copper-clad plate corresponding to the lower flexible plate area 10RS within the range of the other etching ablation groove 210; and the whole is processed to form a lower flexible plate 20.

[0060] In this embodiment, etching ablation grooves are first made on one side of the copper layer and the insulating medium layer of the flexible plate (i.e., the upper flexible plate and the lower flexible plate), and the groove body position only retains one side of the copper layer. Since the groove body position corresponds to the outline of the flexible plate area 10R and the rigid-flexible combination site of the opposite flexible plate, during pressing, the position of the etching ablation groove does not form a pressing structure with other layers. On the other hand, when the flexible plate at the position of the etching ablation groove is subsequently formed, only the copper layer on the surface needs to be etched off, without the need for laser ablation, controlled depth milling, and other processing methods, thereby effectively improving the processing efficiency and processing precision.

[0061] Since the flexible plate is on the surface layer, and the rigid-flexible combination site of the opposite flexible plate needs to be "cut off" at the end to take out the internal rigid plate layer, the flexible plate layer of the rigid-flexible combination site of the opposite flexible plate also needs to be made with an etching ablation groove in advance.

[0062] Step S20:

[0063] A rigid copper-clad laminate is taken, and a rigid board circuit pattern is made to form a rigid core board; and a prepreg is taken; the upper flexible board 10, the rigid core board, and the lower flexible board 20 are aligned and stacked in sequence, and the prepreg is set between the upper flexible board 10 and the rigid core board, and between the rigid core board and the lower flexible board 20; the etching and ablation grooves 110 of the upper flexible board 10 and the etching and ablation grooves 210 of the lower flexible board 20 are set opposite to each other; and then pressed together to form a pressed board.

[0064] See also Figure 4 ; Figure 4 The key process flow chart for forming a pressed plate according to an embodiment of the present invention is shown.

[0065] In one embodiment, a method of forming a laminate comprises: Figure 4 The key production process.

[0066] See also Figure 5 to Figure 10 ; Figure 5 This is a schematic diagram of a cross-sectional structure of a stacked structure formed in accordance with an embodiment of the present invention; Figure 6 This is a schematic diagram of the cross-sectional structure of a pre-pressed plate formed in accordance with an embodiment of the present invention; Figure 7 This is a schematic diagram of the cross-sectional structure of a release pad pre-pressing plate produced according to an embodiment of the present invention; Figure 8 for Figure 7 BB cross-sectional structure diagram; Figure 9 This is a schematic cross-sectional view of a release pad pre-pressing plate having an auxiliary fixing area manufactured in accordance with an embodiment of the present invention; Figure 10 This is a schematic diagram of the cross-sectional structure of a pressed plate produced according to an embodiment of the present invention.

[0067] Forming a laminate includes:

[0068] Step S210:

[0069] A first through window 3110 is made on the rigid core board to form a windowed rigid core board 310; a second through window 3210 is made on the prepreg to form a windowed prepreg 320; the upper flexible board 10 or the lower flexible board 20 and the windowed rigid core board 310 are aligned and stacked in sequence, and the windowed prepreg 320 is set between the upper flexible board 10 or the lower flexible board 20 and the windowed rigid core board 310, and on the surface of the windowed rigid core board 310; the core layer stacking structure 30 (such as Figure 5 As shown); the etching and ablation groove 110 (or another etching and ablation groove 210) of the upper flexible board 10 or the lower flexible board 20 is arranged toward the windowed rigid core board 310; the coverage of the first through window 3110 and the second through window 3210 includes the range of the flexible board area 10R. Then pre-pressing is performed to form a pre-pressed board 40 (as shownFigure 6 The first window 3110 and the second window 3210 form a pre-pressing window groove 410.

[0070] Step S220:

[0071] A release pad 420 is arranged in the pre-pressing window groove 410 to form a release pad pre-pressing plate 40A (as shown in Figure 7 and Figure 8 The lower flexible plate 10RX or the upper flexible plate 10RS is aligned and stacked on one side of the release pad 420, and then is pressed to form the pressed plate 50.

[0072] In this embodiment, the method is used to first open windows in each layer of the rigid core plate layer, then pre-press one layer of the flexible plate, and then arrange the release pad 420 in the pre-pressing window groove 410. The release pad 420 is used as a filling and releasing role of the groove during the plate pressing process. The release pad 420 has good covering and processing capabilities after processing, and can form an effective auxiliary working role. Compared with the processing method of first controlling the depth of the rigid core plate and then breaking off, the method has better operability, and prevents the broken-off part from being pressed into the rigid plate, which causes the problem of being difficult to break off or damaging the plate.

[0073] Further, the size of the release pad 420 is less than or equal to the size of the pre-pressing window groove 410. Further, the material of the release pad 420 is PTFE, PI, TPX, ETFE or silicone.

[0074] Because the rigid plate material and the flexible plate material have certain expansion and contraction performance during the pressing process, the size of the release pad 420 needs to be relatively small compared to the size of the pre-pressing window groove 410, so as to give the material sufficient glue flow and filling space.

[0075] Further, the edge of the release pad adjacent to the rigid-flexible combination position is made to have an edge groove. After the release pad 420 is arranged, glue is applied to the edge groove. The glue is a filling release agent 430 (as shown in Figure 7 and Figure 8 Further, the release agent 430 is a PTFE type release agent, and the viscosity is 350 dPa·s to 900 dPa·s.

[0076] Since the flexible plate layer of the rigid-flexible combination plate prepared in the embodiment is located on the surface layer, another key processing position is the rigid-flexible combination position. Since the release pad has certain rigidity, there is a certain alignment error in the process of arranging the release pad, which may cause recesses, protrusions and other problems in the rigid-flexible combination position due to glue flow and glue filling during pressing, thereby causing processing difficulties in subsequent processes. Therefore, in this embodiment, the release pad is arranged at the rigid-flexible combination position, and the release agent 430 is filled into the edge groove formed by the arrangement. The release agent 430 has the properties of being softer, more flexible and more plastic than the release pad 420, thereby improving the buffering performance of the rigid-flexible combination position to glue flow and glue filling during pressing, and improving the flatness of the pressed plate surface.

[0077] Further, the pre-pressing window groove 410 has a groove body in the range of the flexible plate area; the pre-pressing window groove 410 further has an auxiliary groove extending from the groove body to the auxiliary area; the auxiliary groove is a convex groove structure greater than or equal to a quadrilateral connected to the groove body; and the release pad 420 has an auxiliary fixing area 420F corresponding to the auxiliary groove structure (as shown in Figure 9 ).

[0078] To further improve the alignment setting accuracy of the release pad 420, the pre-pressing window groove 410 and the corresponding release pad 420 are both extended to the auxiliary area. Since the auxiliary area will be cut off during the final molding process, the size of the extended release pad 420 can be the same as that of the extended pre-pressing window groove 410, that is, the release pad 420 at the extended position is “locked” in the pre-pressing window groove 410 to form an effective fixing effect. However, after pressing, the plate surface will be raised, so the auxiliary fixing area 420F should not be too close to the rigid plate area and the flexible plate area, and the distance therebetween is generally more than 200 μm to ensure that the plate surface protrusion generated during pressing in this area will not affect the processing effect of the effective area.

[0079] It is worth noting that, to further improve the alignment setting accuracy of the release pad 420, an adhesive layer can be arranged on the auxiliary area outside the effective area (i.e., the rigid plate area and the flexible plate area) of the release pad 420, which can be epoxy resin glue or acrylic glue, for firmly adhering the release pad 420 to the bottom of the pre-pressing window groove 410, thereby further ensuring the accuracy of the release pad 420 during alignment setting and preventing slippage and deviation during pressing.

[0080] Further, the pre-pressing is performed at a temperature of 140°C to 180°C, using a pressure of 15 kg / cm² to 25 kg / cm², and pressing for 2 minutes to 10 minutes.

[0081] Since the entire board needs to be pressed later, a pre-pressing method is adopted here, that is, under the condition that the Tg value temperature of the rigid board insulating medium layer and the semi-cured sheet is reached, a relatively small pressure is used and the pressing time is relatively short to make the pre-pressed board form a preliminary pressed state, which meets the prerequisite of the overall structure of subsequent processing, prevents excessive glue flow caused by excessive pressing, causes deformation of the pre-pressed window groove 410, and prevents excessive expansion and contraction during subsequent secondary pressing.

[0082] See also Figure 11 ; Figure 11 A key process flow chart for forming another type of pressed board according to an embodiment of the present invention.

[0083] In another embodiment, a method of forming another pressboard comprises: Figure 10 The key production process.

[0084] See also Figure 12 to Figure 14 ; Figure 12 This is a schematic diagram of the planar structure of a pre-grooved core plate produced in accordance with an embodiment of the present invention; Figure 13 for Figure 12 Schematic diagram of CC cross-section structure; Figure 14 This is a schematic diagram of the cross-sectional structure of another pressed plate produced according to an embodiment of the present invention.

[0085] Another method of forming a laminate includes:

[0086] Step S210A:

[0087] The semi-cured sheet layer is set on the upper and lower surfaces of the rigid core board, and pre-pressed to form a pre-pressed core board; according to the molding line 10C, a through groove is made at the edge position of the rigid plate area 10G of the pre-pressed core board corresponding to the rigid-flexible combination position to form a pre-cut groove 410X; the pre-pressed core board is processed to form a pre-cut groove core board 40X (such as Figure 12 and Figure 13 shown).

[0088] Step S220A:

[0089] The upper flexible board 10RX, the pre-grooved core board 40X, and the lower flexible board 10RS are aligned and stacked in sequence, and then pressed together to form another pressed board 50X (such as Figure 14 shown).

[0090] In this embodiment, a rigid core board without a flexible board is pre-pressed to form an integral rigid core board, and then a pre-cut groove 410X structure is made at the rigid-flexible junction position with reference to the rigid board area, and then pressed together with the upper flexible board 10 and the lower flexible board 20 to form a whole; this processing method is simpler and can form an effective removable rigid core board layer, but compared with the processing method of setting a release pad 420, this method has lower processing accuracy, because the production of the pre-cut groove 410X needs to ensure that the groove body has a certain width so that the groove body will not be pressed closed during the pressing process, resulting in problems of pressing into the rigid board area or subsequent difficulty in peeling off, and the width of the pre-cut groove 410X can easily cause the board surface to be pressed and depressed, making the subsequent surface circuit production more difficult; therefore, this method is generally suitable for processing conditions with relatively low precision requirements (for example: the circuit width is large, the circuit gap is wide, and the flexible board layer thickness is thick).

[0091] Furthermore, the through groove is produced by milling, or by laser ablation of the insulating dielectric layer combined with etching of the copper layer.

[0092] The manufacturing method is to combine laser ablation of the insulating dielectric layer with etching of the copper layer. The laser ablation has higher precision, and after ablation, a highly inert carbon black layer is formed on the edge of the slot, which helps to prevent the slot from being pressed and closed.

[0093] See also Figure 15 to Figure 17 ; Figure 15 A schematic diagram of the planar structure of a rigid-flex board with a cross-type surface flexible layer manufactured in accordance with an embodiment of the present invention; Figure 16 for Figure 15 DD cross-sectional structure diagram; Figure 17 for Figure 15 Schematic diagram of the EE cross-sectional structure.

[0094] After the above processing, the pressed plate 50 or another pressed plate 50X is manufactured, and further processing is performed using the following processing steps; taking the pressed plate 50 as an example.

[0095] Step S30:

[0096] The outer layer circuit pattern of the surface layer of the laminate 50 is formed, and the outer layer circuit pattern includes the etching pattern of the surface copper layer corresponding to the etching and ablation groove 110; then the molding process is performed according to the molding line 10C to form the cross-type surface flexible layer rigid-flexible board 60 (such as Figure 15 to Figure 17 shown).

[0097] Since only the copper layer remains on the surfaces of the etched and ablated grooves of the upper flexible board 10 and the lower flexible board 20 , the copper layer can be removed by etching, thereby improving the processing accuracy of the board body.

[0098] It is worth mentioning that, due to the fact that the circuit board in the actual design and processing process is more precise, the actual structure diagram and the thickness between layers, the line width and other sizes are micron level, for example, the thickness of each layer is generally 5-50 μm, if the attached drawings of the specification are made according to the actual proportion, there is a problem of unclear illustration, therefore, in order to more clearly represent the implementation process of the manufacturing method, the drawings of the embodiment are schematic diagrams of the technical features, which do not represent the size of the actual structure diagram, nor represent the enlarged diagram of the actual structure diagram in proportion.

[0099] The above is only the preferred embodiment 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, using the content of the specification and drawings, or directly / indirectly applied in other related technical fields is included in the patent protection scope of the present application.

Claims

1. A manufacturing method of a rigid-flexible combined board of a cross-type surface flexible layer, characterized in that, the rigid-flexible combined board comprises a rigid plate area and a flexible plate area, a combined position of the rigid plate area and the flexible plate area is a rigid-flexible combined position, the flexible plate area comprises an upper flexible plate area and a lower flexible plate area, and upper and lower surface layers of the rigid plate area are combined layers of the upper flexible plate area and the lower flexible plate area with the rigid plate area respectively; the rigid-flexible combined board is provided with a forming line in a processing process, a range of the forming line is an effective area, and a range outside the effective area is an auxiliary area; the manufacturing method comprises the following steps: S10: taking a double-sided flexible copper-clad plate, manufacturing an etching pattern on one copper layer, and performing laser ablation on an exposed insulating medium layer corresponding to the etching pattern to form an etching ablation groove; the etching ablation groove is distributed corresponding to an edge of the upper flexible plate area which is not combined with the rigid plate area, and is distributed corresponding to the rigid-flexible combined position of the lower flexible plate area; an upper and lower surface of the double-sided flexible copper-clad plate corresponding to the upper flexible plate area in a range of the etching ablation groove is attached with a cover film; an upper flexible plate is formed through overall processing; another double-sided flexible copper-clad plate is taken, another etching pattern is manufactured on one copper layer, and another etching ablation groove is formed through laser ablation on an exposed insulating medium layer corresponding to the other etching pattern; the other etching ablation groove is distributed corresponding to an edge of the lower flexible plate area which is not combined with the rigid plate area; an upper and lower surface of the other double-sided flexible copper-clad plate corresponding to the lower flexible plate area in a range of the other etching ablation groove is attached with another cover film; and the lower flexible plate is formed through overall processing; S20: taking a rigid copper-clad plate, manufacturing a rigid plate circuit pattern to form a rigid core plate; and taking a prepreg, and sequentially aligning and stacking the upper flexible plate, the rigid core plate and the lower flexible plate, and the prepreg is arranged between the upper flexible plate and the rigid core plate and between the rigid core plate and the lower flexible plate; the etching ablation groove of the upper flexible plate is arranged opposite to the etching ablation groove of the lower flexible plate; then, the prepreg is pressed to form a pressed plate; the pressed plate is formed through the following steps: S210: manufacturing a first through window on the rigid core plate to form an open-window rigid core plate; manufacturing a second through window on the prepreg to form an open-window prepreg; sequentially aligning and stacking the upper flexible plate or the lower flexible plate and the open-window rigid core plate, and the open-window prepreg is arranged between the upper flexible plate or the lower flexible plate and the open-window rigid core plate and on a surface of the open-window rigid core plate; the etching ablation groove of the upper flexible plate or the lower flexible plate is arranged towards the open-window rigid core plate; a coverage range of the first through window and the second through window comprises a range of the flexible plate area; then, pre-pressing is performed, and the first through window and the second through window form a pre-pressing open-window groove; S220: arranging a release pad in the pre-pressing open-window groove, and aligning and stacking the lower flexible plate or the upper flexible plate on one side of the release pad, and then pressing to form the pressed plate. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ An edge groove is made at the edge of the release pad adjacent to the rigid-flexible combination position. After the release pad is arranged, adhesive is applied into the edge groove. The adhesive is a release agent. S30: An outer layer circuit pattern is made on the surface layer of the laminated board. The outer layer circuit pattern includes an etching pattern of the surface copper layer corresponding to the etching and ablation groove. Then, the cross-type surface flexible layer rigid-flexible combination board is formed by forming processing according to the forming line.

2. The method of claim 1, wherein the rigid-flex board is a cross-surface flexible layer rigid-flex board. The release agent is a PTFE type release agent with a viscosity of 350 dPa·s to 900 dPa·s.

3. The method of claim 1, wherein the rigid-flex board is a cross-surface flexible layer rigid-flex board. The size of the release pad is equal to or less than the size of the pre-pressing window groove.

4. The method of claim 1, wherein the rigid-flex board is a cross-surface flexible layer rigid-flex board. The material of the release pad is PTFE, PI, TPX, ETFE or silicone.

5. The method of claim 1, wherein the rigid-flex board is a cross-surface flexible layer rigid-flex board. The groove in the range of the flexible board area of the pre-pressing window groove is a groove body. The pre-pressing window groove further comprises an auxiliary groove extending from the groove body to the auxiliary area. The auxiliary groove is a convex groove structure connected to the groove body and equal to or greater than a quadrilateral. The release pad is provided with an auxiliary fixing area corresponding to the auxiliary groove structure.

6. The method of claim 1, wherein the rigid-flex board is a cross-surface flexible layer rigid-flex board. The pre-pressing is performed at a temperature of 140°C to 180°C, a pressure of 15 kg / cm² to 25 kg / cm², and for 2 minutes to 10 minutes.

7. A cross-type surface flexible layer rigid-flexible combination board manufacturing method, characterized in that, The rigid-flexible combination board comprises a rigid board area and a flexible board area. The combination position of the rigid board area and the flexible board area is a rigid-flexible combination position. The flexible board area comprises an upper flexible board area and a lower flexible board area. The upper and lower surface layers of the rigid board area are the combination layers of the upper and lower flexible board areas and the rigid board area, respectively. The rigid-flexible combination board in the processing process is provided with a forming line. The range of the forming line is an effective area, and the range outside the forming line is an auxiliary area. The manufacturing method comprises the following steps: S10: Take a double-sided flexible copper-clad plate. An etching pattern is made on one side of the copper layer. The insulating medium layer exposed by the etching pattern is ablated by laser to form an etching and ablation groove. The etching and ablation groove is distributed corresponding to the edge of the upper flexible board area which is not combined with the rigid board area, and corresponding to the rigid-flexible combination position of the lower flexible board area. The upper and lower surfaces of the double-sided flexible copper-clad plate in the range of the etching and ablation groove corresponding to the upper flexible board area are attached with a cover film. The whole is processed to form an upper flexible board. Take another double-sided flexible copper-clad plate. Another etching pattern is made on one side of the copper layer. The insulating medium layer exposed by the other etching pattern is ablated by laser to form another etching and ablation groove. The other etching and ablation groove is distributed corresponding to the edge of the lower flexible board area which is not combined with the rigid board area. The upper and lower surfaces of the other double-sided flexible copper-clad plate in the range of the other etching and ablation groove corresponding to the lower flexible board area are attached with another cover film. The whole is processed to form the lower flexible board. S20: Take a rigid copper-clad plate. A rigid board circuit pattern is made to form a rigid core board. And take prepreg, the upper flexible plate, the rigid core plate, the lower flexible plate in turn alignment stacking, in the upper flexible plate and the rigid core plate, and the rigid core plate and the lower flexible plate, both set the prepreg between them; The etching ablation slot of the upper flexible plate is arranged opposite to the etching ablation slot of the lower flexible plate; Then press together, form the press together plate; The forming press together plate includes: S210A: set the prepreg layer to the upper and lower surface of the rigid core plate, and pre-press together, form the pre-press core plate; According to the forming line, the edge position of the rigid plate area corresponding to the rigid-flexible combination position of the pre-press core plate is made into a through slot, and a pre-cut slot is formed; The pre-press core plate is processed to form a pre-cut slot core plate; S220A: the upper flexible plate, the pre-cut slot core plate, the lower flexible plate are stacked in turn, and then press together to form the press together plate; S30: make the outer layer circuit pattern of the surface layer on the press together plate, and the outer layer circuit pattern includes the etching pattern of the surface copper layer corresponding to the etching ablation slot; Then according to the forming line, the rigid-flexible combination plate of the cross type surface flexible layer is formed by forming processing.

8. The method of claim 7, wherein the rigid-flex board is a cross-surface flexible layer rigid-flex board. The through slot is made by milling or by laser ablation of the insulating dielectric layer combined with etching of the copper layer.

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