Manufacturing method of high-precision bearing type rigid-flexible combined circuit board

Abstract

The invention discloses a manufacturing method of a high-precision bearing type rigid-flexible combined circuit board, a forming line is designed in a processing process board, the manufacturing method comprises the following steps: manufacturing a flexible board comprising a flexible area and a rigid combined area, taking a rigid copper-clad plate, and manufacturing a circuit pattern, the circuit pattern comprises an auxiliary circuit pattern corresponding to a bonding pad pattern of the flexible board, a first groove body is manufactured on the outline of the flexible area, a first connecting position is arranged between the first groove body and the auxiliary area, a second groove body is manufactured on the outline of the rigid combination area, a second connecting position is arranged between the second groove body and the auxiliary area, a rigid bearing plate is formed, the flexible plate and the rigid bearing plate are pressed and formed, and the high-precision bearing type rigid-flexible combined circuit board is formed. The flexible plate and the rigid bearing plate are manufactured independently, the rigid bearing plate is manufactured according to the forming line to form the groove body, then overall pressing is conducted, the flexible plate is formed through laser cutting, the problems of pulling, tearing and the like of the flexible plate caused by milling forming of the overall plate body are effectively solved, and the machining quality and reliability are improved.

Description

Technical Field

[0001] The present invention relates to the field of flexible circuit board processing, and in particular to a method for manufacturing a high-precision load-bearing rigid-flexible circuit board. Background Art

[0002] For some electronic modules of smart connected cars or testing equipment, high-precision rigid-flex boards are required. The rigid board is used to carry and weld electronic components, while the flexible board is used for three-dimensional installation and conductive connection.

[0003] The design and processing of rigid-flex PCBs are generally more complicated. When the precision requirements for rigid-flex PCBs are high, but the circuit graphic design is relatively simple, the traditional rigid-flex PCBs have little advantages in terms of design difficulty and processing cost.

[0004] Therefore, a load-bearing rigid-flexible board has emerged, which is made by independently manufacturing the flexible board and the rigid board, and then further manufacturing the circuit graphics. This type of rigid-flexible board can effectively ensure the processing accuracy of the flexible board and provide the flexible board with the load-bearing performance of the rigid board.

[0005] At present, for this type of high-precision load-bearing rigid-flexible circuit board, the circuit graphics of the flexible board and the circuit graphics of the rigid board are generally produced separately, and then pressed together through a glue layer, and then milled and formed. For areas where the rigid board is not needed, controlled depth milling is used to remove them.

[0006] Since the insulating dielectric layer material of the flexible circuit board is generally a polyimide material, which has strong inertness and toughness, during the molding process of the above-mentioned manufacturing method, the milling cutter is likely to pull, tear, and roll the polyimide material, causing deformation in the processing of the flexible circuit board, affecting the accuracy, and even tearing. The controlled depth milling process has high requirements on the accuracy of the board thickness. If the board itself is uneven or warped or bowed, it is easy to have problems with insufficient or excessive depth control, making it difficult to remove the unnecessary rigid board, or damaging the surface of the flexible board by milling.

[0007] Based on the above background and technology, it is necessary to provide a method for manufacturing a high-precision load-bearing rigid-flexible circuit board. Summary of the invention

[0008] The present invention aims to solve the problem of pulling, deformation, and even tearing of flexible boards caused by milling during the processing of high-precision load-bearing rigid-flexible circuit boards, and the problem of insufficient or excessive depth control in depth-controlled milling. A method for manufacturing a high-precision load-bearing rigid-flexible circuit board is provided. The rigid-flexible board during the processing includes a molding line that refers to the contour line of the rigid-flexible board of the finished product; the board body within the molding line is an effective area, and the area outside the molding line is an auxiliary area.

[0009] The production method comprises the following steps: S10: manufacturing a flexible board including a flexible board plug circuit pattern, a flexible board circuit pattern, and a flexible board pad pattern; the flexible board is divided into a flexible area and a rigid bonding area; S20: Take a rigid copper clad laminate and make a circuit pattern, wherein the circuit pattern includes an auxiliary circuit pattern corresponding to the pad pattern of the flexible board; make a first slot body at the contour position of the flexible area according to the molding line, wherein the first slot body is provided with a first connection position that is not a slot body, and the first connection position is provided at a position other than the connection area between the flexible area and the rigid combination area; make a second slot body at the contour position of the rigid combination area according to the molding line, wherein the second slot body is provided with a second connection position that is not a slot body, and the second connection position is provided at a position other than the connection area between the flexible area and the rigid combination area; the width of the first slot body and the second slot body are both extended from the molding line to the auxiliary area; form a rigid bearing plate; S30: Aligning and laminating the flexible board and the rigid supporting board, and pressing them to form a pressed board, and then molding them according to the molding line to form the high-precision load-bearing rigid-flexible circuit board.

[0010] Furthermore, the length of the connection area is greater than or equal to the width of the second slot body, the first through slot and the second through slot penetrate the connection area, and the second slot body penetrates the connection area.

[0011] Furthermore, the molding according to the molding line includes: cutting the first through groove, the connection area and the second through groove of the flexible plate along the molding line by laser cutting; and milling the positions of the first connection position and the second connection position along the molding line by milling.

[0012] Optionally, the length of the connection area is greater than or equal to the width of the second slot body, and the connection area is provided with a third connection position, and the third connection position is located between the second slot body and the first slot body.

[0013] Optionally, the molding according to the molding line includes: cutting the flexible plate of the first slot body along the molding line by laser cutting; and milling off the positions of the first connection position, the second connection position and the third connection position along the molding line by milling.

[0014] Optionally, the molding line passing through the first through groove, the third connection position to the second through groove forms a fold line; the third connection position of the rigid supporting plate is milled from the first through groove along the fold line to the second through groove; the molding according to the molding line includes: cutting the first groove body and the flexible plate of the third connection position of the milled part along the molding line by laser cutting; milling off the positions of the first connection position and the second connection position and the remaining unmilled part of the third connection position along the molding line by milling.

[0015] Furthermore, the lamination includes: taking the adhesive layer with the same size as the flexible board, opening windows at the flexible area, the first through groove, the connection area and the second through groove corresponding to the adhesive layer, bonding the flexible board and the rigid supporting board through the adhesive layer, and then laminating.

[0016] Furthermore, after the forming of the pressed board, it also includes: attaching a window covering film with a window pattern to one side of the flexible board, the window pattern corresponds to the flexible board plug circuit pattern and the flexible board pad pattern, and covering the flexible board plug circuit pattern with a dry film or blue glue; making a solder resist pattern layer with a solder resist window on one side of the rigid board, the solder resist window corresponds to the auxiliary circuit pattern; drilling through holes according to the auxiliary circuit pattern, and electroplating to form conductive holes.

[0017] Optionally, the forming of the press plate also includes: the size of the flexible board pad pattern located on the outer surface of the press plate is larger on one side than the size of the flexible board pad pattern of the finished high-precision load-bearing rigid-flexible circuit board; the size of the auxiliary circuit pattern located on the outer surface of the press plate is larger on one side than the size of the auxiliary circuit pattern of the finished high-precision load-bearing rigid-flexible circuit board; a window covering film with a window pattern is attached to one side of the flexible board, the window pattern corresponds to the flexible board plug circuit pattern and the flexible board pad pattern, and the window pattern is smaller on one side than the flexible board plug circuit pattern; the flexible board plug circuit pattern is covered with a dry film or blue glue; a solder resist pattern layer with a solder resist window is made on one side of the rigid board, the solder resist window corresponds to and is smaller on one side than the auxiliary circuit pattern; through holes are drilled according to the auxiliary circuit pattern, and electroplated to form vias.

[0018] Furthermore, after the pressing plate is formed, the flexible board plug circuit pattern is subjected to gold electroplating.

[0019] The technical solution of the present invention first independently patterns the flexible board, and designs and manufactures the first trough body and the second trough body and the first connection position and the second connection position of the rigid board according to the pattern of the load-bearing title area required by the flexible board, combined with the integrity in the processing process and the property that is convenient for subsequent molding processing, and independently manufactures a rigid bearing plate to form a pre-milling effect, and then forms an overall structure through lamination and lamination of the adhesive layer. Thereafter, laser cutting is used for the flexible board, and the first connection position and the second connection position are milled off by milling. Since the rigid bearing plate corresponding to the molding line has been manufactured to form the first trough body and the second trough body, laser cutting can cut all the flexible boards except the first connection position and the second connection position. The molding line effectively avoids the problems of pulling and tearing of the flexible board caused by milling the entire board, and the adhesive layer is divided into areas according to the areas where the rigid carrier board and the flexible board need to be combined, and the areas where the rigid carrier board and the flexible board do not need to be combined to make opening windows. Combined with the contours of the first trough body and the second trough body, when removing the rigid carrier board that does not need the support of the rigid board, there is no need to use controlled depth milling processing, which further improves the processing accuracy of the board and protects the quality of the flexible board. The overall processing process forms a streamlined process of front and back coordination, and no milling processing is used for the flexible board except for the first connection position and the second connection position, ensuring the high-precision characteristics of the flexible board and improving the processing quality and reliability of the entire board. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] 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.

[0021] Figure 1 This is a process flow chart of a high-precision load-bearing rigid-flexible circuit board according to an embodiment of the present invention; Figure 2 is a schematic diagram of a planar structure of a flexible board according to an embodiment of the present invention; Figure 3 for Figure 2 AA cross-sectional structure schematic diagram; Figure 4 It is a schematic diagram of the planar structure of a rigid load-bearing plate according to an embodiment of the present invention; Figure 5 A schematic diagram of a planar structure of another rigid load-bearing plate according to an embodiment of the present invention; Figure 6 for Figure 5 Schematic diagram of BB cross-section structure; Figure 7 for Figure 5Enlarged view of the middle XQ region; Figure 8 A schematic diagram of a planar structure of a laminated plate formed according to an embodiment of the present invention; Fig. 9 for Figure 8 Schematic diagram of CC cross-section structure; Fig.10 for Figure 8 Schematic diagram of DD cross-section structure; Fig.11 A schematic diagram of the planar structure of a high-precision load-bearing rigid-flexible circuit board formed in an embodiment of the present invention; Fig.12 for Fig.11 Schematic diagram of EE cross-sectional structure; Fig.13 for Fig.11 Schematic diagram of FF cross-sectional structure; Fig.14 for Fig.11 Schematic diagram of another cross-sectional structure of F'-F'.

[0022] Description of Figure Numbers:

[0023] 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

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] See also Figure 1 ; Figure 1 The figure is a process flow chart of a high-precision load-bearing rigid-flexible circuit board according to an embodiment of the present invention.

[0029] The method for manufacturing a high-precision load-bearing rigid-flexible circuit board in an embodiment of the present invention comprises: the rigid-flexible circuit board in the processing process comprises a molding line 10C referring to the contour line of the finished rigid-flexible circuit board; the board body within the molding line 10C is an effective area, and the area outside the molding line 10C is an auxiliary area; the manufacturing method comprises 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.

[0030] See also Figure 2 and Figure 3 ; Figure 2 is a schematic diagram of a planar structure of a flexible board according to an embodiment of the present invention; Figure 3 for Figure 2 Schematic diagram of the AA cross-section structure.

[0031] Step S10: A flexible board 10 including a flexible board plug circuit pattern 110 , a flexible board circuit pattern 120 , and a flexible board pad pattern 130 is manufactured; the flexible board 10 is divided into a flexible area 10R and a rigid bonding area 10G; and the flexible board 10 includes a flexible board dielectric layer 140 .

[0032] The flexible board 10 and the rigid board (i.e., the rigid supporting board 20) of the present embodiment are designed and manufactured separately. The flexible board 10 is manufactured separately to form a separate flexible board 10. The separate manufacturing can effectively ensure the high-precision characteristics of the flexible board 10, and avoid the design and manufacturing method of the rigid-flexible board, which causes the problems of high processing difficulty and limited precision.

[0033] The manufactured flexible board 10 includes a flexible board plug circuit pattern 110 for welding or plugging in the subsequent application process, a flexible board circuit pattern 120 for conducting function, and a flexible board pad pattern 130 corresponding to the rigid carrier board 20 in the subsequent process.

[0034] See also Figures 4 to 7 ; Figure 4 It is a schematic diagram of the planar structure of a rigid load-bearing plate according to an embodiment of the present invention; Figure 5A schematic diagram of a planar structure of another rigid load-bearing plate according to an embodiment of the present invention; Figure 6 for Figure 5 Schematic diagram of BB cross-section structure; Figure 7 for Figure 5 Magnified view of the XQ region.

[0035] Step S20: A rigid copper clad laminate is used to make a circuit pattern, wherein the circuit pattern includes an auxiliary circuit pattern 210 corresponding to the flexible board pad pattern 130; a first slot body 220 is made according to the contour position of the forming line 10C in the flexible area 10R, and the first slot body 220 is provided with a first connection position 2210 that is not a slot body, and the first connection position 2210 is set at a position other than the connection area 20L between the flexible area 10R and the rigid bonding area 10G; a second slot body 230 is made according to the contour position of the forming line 10C in the rigid bonding area 10G, and the second slot body 230 is provided with a second connection position 2310 that is not a slot body, and the second connection position 2310 is set at a position other than the connection area 20L between the flexible area 10R and the rigid bonding area 10G; the width of the first slot body 220 and the second slot body 230 are both extended from the forming line 10C to the auxiliary area; a rigid carrier board 20 is formed; the rigid carrier board 20 includes a rigid board dielectric layer 240.

[0036] Likewise, the rigid board is also manufactured separately, and the rigid board of this embodiment functions as a supporting board for the flexible board 10 , thus becoming a rigid supporting board 20 .

[0037] In order to ensure that the accuracy of the flexible board 10 in the post-processing process is not affected by the processing process to the greatest extent, the rigid carrier board 20 must not only ensure high-precision size matching and auxiliary circuit pattern matching with the flexible board 10 in the subsequent combined processing with the flexible board 10 and in the load-bearing process, but also avoid the influence of rigid board molding on the regenerated size of the flexible board 10 and the smoothness of the board edge. In particular, the molding of the rigid board requires milling molding, which will cause greater pulling, tearing, and rolling of the substrate on the flexible board 10, thereby affecting its expansion and contraction and the smoothness of the board edge. Therefore, the molding of high-precision flexible boards 10 generally adopts laser cutting, which can effectively ensure the molding effect.

[0038] Therefore, this embodiment manufactures the first groove body 220 and the second groove body 230 for the rigid supporting plate 20, which can ensure that each area of ​​the rigid supporting plate 20 forms a bearing function, and at the same time ensure that during subsequent molding, it is only necessary to use laser cutting to cut the flexible board 10 from the first groove body 220 and the second groove body 230 and other positions, thereby effectively improving the processing accuracy of the flexible board 10; the width of the first groove body 220 and the second groove body 230 is generally 0.2mm to 2.0mm, and the width should not be too wide, otherwise it is easy to cause subsequent excessive depressions in the pressing, and the depressions squeeze and pull the flexible board 10 and other problems.

[0039] However, it is necessary to ensure that the patterns of the rigid carrier plate 20 within the first trough body 220 and the second trough body 230 are connected to the rigid carrier plate 20 itself to form an integral structure. Therefore, the first connection position 2210 and the second connection position 2310 need to be retained. The width of the first connection position 2210 and the second connection position 2310 are generally 0.5 mm to 2 mm, and the width should not be too large, otherwise it will affect the flexible board 10 during subsequent milling and forming.

[0040] In one embodiment, the length of the connection area 20L is greater than or equal to the width of the second slot body 230 , the first through slot 220 and the second through slot 230 penetrate the connection area 20L, and the second slot body 230 penetrates the connection area 20L.

[0041] The connection area 20L of this embodiment is completely covered by the flexible board 10, that is, after the high-precision load-bearing rigid-flexible circuit board is finally formed, the rigid load-bearing board 20 of the connection area 20L is completely removed, and only the flexible board 10 is retained; therefore, the first through groove and the second through groove of this embodiment are connected to meet the structural and processing requirements.

[0042] Please continue reading Figures 4 to 7 ; and see Figures 8 to 10 ; Figure 8 A schematic diagram of a planar structure of a laminated plate formed according to an embodiment of the present invention; Fig. 9 for Figure 8 Schematic diagram of CC cross-section structure; Fig.10 for Figure 8 Schematic diagram of the DD cross-section structure.

[0043] In one embodiment, the lamination includes: taking an adhesive layer 310 of the same size as the flexible board 10, opening windows at the flexible area 10R, the first through groove, the connection area 20L and the second through groove corresponding to the adhesive layer 310, bonding the flexible board 10 and the rigid carrier board through the adhesive layer 310, and then laminating them to form a laminated board 30.

[0044] Based on the above design and structure, the lamination of this embodiment is performed by using the adhesive layer 310. The adhesive layer 310 is made of room temperature solid adhesive, and specifically acrylic adhesive, epoxy resin adhesive, polyolefin adhesive, etc. are selected. Since the area of ​​the flexible board 10 and the rigid supporting board 20 of the connection area 20L need to be removed, the adhesive layer 310 cannot be attached to this area, that is, the adhesive layer 310 in this area needs to be made into an opening window.

[0045] It is worth mentioning that the adhesive layer 310 can be taken, and then opening windows can be made only in the area of ​​the flexible board 10 and the connection area 20L, and then attached to the rigid copper clad board with the circuit pattern made, and then the first through groove and the second through groove can be made. The adhesive layer 310 and the rigid copper clad board can be processed together to form a rigid carrier board 20, thereby improving the processing accuracy of the adhesive layer 310 and facilitating the subsequent combination with the flexible board 10.

[0046] In one embodiment, molding is performed according to the molding line 10C, including: cutting the first through groove, the connection area 20L and the second through groove of the flexible board 10 along the molding line 10C by laser cutting; and milling off the positions of the first connection position 2210 and the second connection position 2310 along the molding line 10C by milling.

[0047] Based on the above design and structure, the molding of this embodiment firstly laser cuts the flexible board 10 according to the contours of the first through groove, the connection area 20L and the second through groove along the molding line 10C, and then mechanically mills the positions of the first connection position 2210 and the second connection position 2310. Then, the rigid carrier board 20 corresponding to the opening window area of ​​the adhesive layer 310 falls off, that is, the flexible board 10 is formed in this area, and the rigid carrier board 20 and the flexible board 10 are bonded to each other in the area bonded by the adhesive layer 310 to form a whole, that is, a rigid board is formed, and the overall board body forms a high-precision load-bearing rigid-flexible circuit board 40.

[0048] During the processing, in the molding process after lamination, the flexible board 10 is not formed and milled by a milling method, thereby ensuring the high precision of the flexible board 10.

[0049] Please continue reading Figure 5 and Figure 7 In another embodiment, the length of the connection area 20L is greater than or equal to the width of the second slot body 230 , and the connection area 20L is provided with a third connection position 250 , and the third connection position 250 is located between the second slot body 230 and the first slot body 220 .

[0050] In this embodiment, in order to ensure that the rigid-flexible junction (the junction of the flexible board 10 and the rigid carrier board 20) of the high-precision load-bearing rigid-flexible circuit board is located in the middle position of the connection area 20L, so that the rigid-flexible circuit board has better bending performance and improves the tear resistance of the flexible board 10, a rigid carrier board 20 is provided within the range of the connection area 20L, partially "extending toward" the flexible board 10, that is, after the high-precision load-bearing rigid-flexible circuit board is manufactured, about half of the connection area 20L has the rigid carrier board 20 and the rest is the flexible board 10.

[0051] In order to ensure the accuracy of the "extended" part during the pressing process and to ensure that the pressing at this position will not be offset or shifted, a third connecting position 250 is set in this area to improve the overall processability and high-precision characteristics of the rigid supporting plate 20.

[0052] Similarly, in this embodiment, the lamination includes: taking an adhesive layer 310 of the same size as the flexible board 10, opening windows at the flexible area 10R, the first through groove, the connection area 20L and the second through groove corresponding to the adhesive layer 310, bonding the flexible board 10 and the rigid carrier board 20 through the adhesive layer 310, and then laminating them to form a laminated board 30.

[0053] In another embodiment, molding is performed according to the molding line 10C, including: cutting the flexible board 10 of the first trough body 220 along the molding line 10C by laser cutting; and milling off the first connection position 2210, the second connection position 2310 and the third connection position 250 along the molding line 10C by milling.

[0054] Similar to the above processing method, the flexible board 10 is processed by laser cutting, and the connection position is processed by mechanical milling, which will not be described in detail here.

[0055] In another embodiment, a forming line 10C passing through the first through slot, the third connection position 250 to the second through slot forms a fold line; the rigid carrier plate is milled from the first through slot along the fold line to the second through slot, and part of the third connection position 250 is milled; and forming is performed according to the forming line 10C, including: cutting the first slot body 220 and the flexible board 10 of the milled third connection position 250 along the forming line 10C by laser cutting; milling away the positions of the first connection position 2210 and the second connection position 2310 and the remaining unmilled third connection position 250 along the forming line 10C by milling, see Figure 5 Another rigid carrier plate 20A.

[0056] When the "extended" part is in a trapezoidal, inverted trapezoidal, flat bending or other shapes, the molding line 10C at this position forms a fold line. Generally, in the subsequent molding, this position is milled by mechanical milling according to the fold line path. However, for the fold line position, on the one hand, the rigid carrier plate 20 has been milled for the first time to form the first through groove, and after alignment and pressing, the second milling is performed. There will be a certain error between the first milling and the second milling, resulting in problems such as milling deformation or continuous milling at the fold line position. On the other hand, Compared with linear milling, line milling itself is more likely to cause problems such as pulling, tearing, and rolling of the flexible board 10, and is more likely to cause problems such as burrs on the edge of the flexible board 10, which is easy to cause poor processing. Therefore, this embodiment adopts a processing method in which a through groove is milled according to the partial milling position 260 at one end of the fold line forming line 10C at the third connection position 250 of the rigid carrier board 20 during the first milling, and then a linear milling is performed from the rear milling position 270 at the other end during subsequent molding (see Figure 7 ), and the position where the through groove has been milled can be processed by laser cutting of the flexible board 10. This method forms a non-folding line milling process of the third connection position 250. On the one hand, it avoids the problem of pulling the flexible board 10 caused by the milling folding line. On the other hand, it reduces the width of the third connection position 250, making subsequent processing easier to achieve and effectively improving the processing accuracy.

[0057] Please continue reading Figures 8 to 10 ; and see Figures 11 to 14 ; Fig.11 A schematic diagram of the planar structure of a high-precision load-bearing rigid-flexible circuit board formed in an embodiment of the present invention; Fig.12 for Fig.11 Schematic diagram of EE cross-sectional structure; Fig.13 for Fig.11 Schematic diagram of FF cross-sectional structure; Fig.14 for Fig.11 Schematic diagram of another cross-sectional structure of F'-F'.

[0058] Step S30: The flexible board 10 and the rigid supporting board 20 are aligned and laminated to form a laminated board 30 , and then molded according to a molding line 10C to form a high-precision load-bearing rigid-flexible circuit board 40 .

[0059] In one embodiment, after the pressing plate 30 is formed, it also includes: attaching a window covering film 410 with a window pattern 4110 to one side of the flexible board 10, the window pattern 4110 corresponds to the flexible board plug circuit pattern 110 and the flexible board pad pattern 130, and covering the flexible board plug circuit pattern 110 with a dry film or blue glue; making a solder resist pattern layer 420 with a solder resist window on one side of the rigid board, and the solder resist window corresponds to the auxiliary circuit pattern; drilling through holes according to the auxiliary circuit pattern, and electroplating to form a conductive hole 430.

[0060] The rigid board portion of this type of high-precision load-bearing rigid-flexible circuit board 40 not only plays a load-bearing role, but also can form electrical connection characteristics or auxiliary welding characteristics due to the provision of a glue layer 310 and lamination to form a whole, that is, a through hole is made to the flexible board pad pattern 130 corresponding to the auxiliary circuit pattern, and a metallized hole is formed by electroplating to form an electrical connection or welding support, thereby giving the flexible board 10 stronger auxiliary support, welding, and conduction performance.

[0061] In this embodiment, the flexible board 10 uses a cover film to make a window pattern 4110 that is as large as the flexible board pad pattern 130, and after drilling, electroplating and other processes, a conductive hole 430 is formed.

[0062] In another embodiment, a laminate is formed, further comprising: a flexible board pad pattern 130 located on the outer surface of the laminate is larger on one side than the flexible board pad pattern 130 of the finished high-precision load-bearing rigid-flexible circuit board 40; an auxiliary circuit pattern located on the outer surface of the laminate is larger on one side than the auxiliary circuit pattern of the finished high-precision load-bearing rigid-flexible circuit board 40; a window covering film 410 having a window pattern 4110 is attached to one side of the flexible board 10, the window pattern 4110 corresponds to the flexible board plug circuit pattern 110 and the flexible board pad pattern 130, and the window pattern 4110 is smaller on one side than the flexible board plug circuit pattern 110; the flexible board plug circuit pattern 110 is covered with a dry film or blue glue; a solder resist pattern layer 420 having a solder resist window is made on one side of the rigid board, the solder resist window corresponds to and is smaller on one side than the auxiliary circuit pattern; through holes are drilled according to the auxiliary circuit pattern, and electroplated to form vias 430.

[0063] Please continue reading Fig.14In another embodiment, if a window pattern 4110 of the same size as the flexible board pad pattern 130 is directly made on the covering film, it is difficult to accurately align the window pattern 4110 with the flexible board pad pattern 130 when the covering film is aligned and pressed, which affects the processing accuracy of the via 430. Therefore, when the size and wiring space conditions are sufficient, the sizes of the flexible board pad pattern 130 and the auxiliary circuit pattern are pre-designed and manufactured. When the window covering film 410 is then pressed, the window pattern 4110 is smaller than the flexible board pad pattern 130. In this way, the flexible board pad pattern 130 that exposes the window pattern 4110 can more accurately form the pad for making the via 430. The production principle of the auxiliary circuit pattern is similar and will not be repeated.

[0064] In one embodiment, after forming the laminate, the flexible board plug circuit pattern 110 is subjected to gold electroplating.

[0065] If the via hole 430 needs to be gold-plated, the via hole 430 is electroplated with gold. If the via hole 430 does not need to be gold-plated, it needs to be covered with a dry film or the like, and the flexible board plug circuit pattern 110 is electroplated with gold separately.

[0066] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, 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 high-precision load-bearing rigid-flexible circuit board, wherein the rigid-flexible circuit board during processing comprises a molding line referring to the contour line of the finished rigid-flexible circuit board; the board body within the molding line is an effective area, and the area outside the molding line is an auxiliary area; It is characterized in that The production method comprises the following steps: S10: manufacturing a flexible board including a flexible board plug circuit pattern, a flexible board circuit pattern, and a flexible board pad pattern; the flexible board is divided into a flexible area and a rigid bonding area; S20: Take a rigid copper-clad board and make a circuit pattern, wherein the circuit pattern includes an auxiliary circuit pattern corresponding to the pad pattern of the flexible board; A first slot body is manufactured at the contour position of the flexible zone according to the molding line, wherein the first slot body is provided with a first connection position which is not a slot body, and the first connection position is provided at a position other than the connection area between the flexible zone and the rigid combination zone; A second slot body is manufactured at the contour position of the rigid combination area according to the molding line, the second slot body is provided with a second connection position which is not a slot body, and the second connection position is provided at a position other than the connection area between the flexible area and the rigid combination area; The width of the first trough body and the second trough body both extend from the forming line to the auxiliary area; forming a rigid load-bearing plate; S30: Aligning and laminating the flexible board and the rigid supporting board, and pressing them to form a pressed board, and then molding them according to the molding line to form the high-precision load-bearing rigid-flexible circuit board.

2. A method for manufacturing a high-precision load-bearing rigid-flexible circuit board according to claim 1, characterized in that: The length of the connection area is greater than or equal to the width of the second slot body, the first through slot and the second through slot penetrate the connection area, and the second slot body penetrates the connection area.

3. A method for manufacturing a high-precision load-bearing rigid-flexible circuit board as claimed in claim 2, characterized in that: The molding according to the molding line comprises: Cutting the first through groove, the connection area and the flexible plate of the second through groove along the molding line by laser cutting; The positions of the first connection position and the second connection position are cut off along the forming line by milling.

4. The method for manufacturing a high-precision load-bearing rigid-flexible circuit board according to claim 1, characterized in that: The length of the connection area is greater than or equal to the width of the second slot body, and the connection area is provided with a third connection position. The third connecting position is located between the second slot body and the first slot body.

5. A method for manufacturing a high-precision load-bearing rigid-flexible circuit board as claimed in claim 4, characterized in that: The molding according to the molding line comprises: Cutting the flexible plate of the first trough body along the forming line by laser cutting; The first connection position, the second connection position and the third connection position are milled off along the molding line by milling.

6. A method for manufacturing a high-precision load-bearing rigid-flexible circuit board as claimed in claim 5, characterized in that: The forming line passing through the first through slot, the third connecting position and the second through slot forms a fold line; Milling a portion of the third connection position of the rigid bearing plate from the first through groove along the fold line toward the second through groove; The molding according to the molding line comprises: Cutting the first slot body and the flexible board at the third connection position of the milled portion along the molding line by laser cutting; The positions of the first connection position and the second connection position and the remaining unmilled portion of the third connection position are milled off along the molding line by milling.

7. A method for manufacturing a high-precision load-bearing rigid-flexible circuit board as claimed in claim 2 or 4, characterized in that: The pressing comprises: Take the adhesive layer that is equal to the size of the flexible board, open windows at the flexible area, the first through groove, the connection area and the second through groove corresponding to the adhesive layer, bond the flexible board and the rigid carrier board through the adhesive layer, and then perform the pressing.

8. The method for manufacturing a high-precision load-bearing rigid-flexible circuit board according to claim 1, characterized in that: After forming the pressed plate, the method further comprises: A window covering film having a window pattern is attached to one side of the flexible board, wherein the window pattern corresponds to the flexible board plug circuit pattern and the flexible board pad pattern, and the flexible board plug circuit pattern is covered with a dry film or a blue glue; A solder resist pattern layer having a solder resist window is formed on one side of the rigid board, wherein the solder resist window corresponds to the auxiliary circuit pattern; Through holes are drilled according to the auxiliary circuit pattern and electroplated to form conducting holes.

9. The method for manufacturing a high-precision load-bearing rigid-flexible circuit board according to claim 1, characterized in that: The forming of the pressed plate further comprises: The size of the flexible board pad pattern located on the outer surface of the pressing plate is larger than the size of the flexible board pad pattern of the finished high-precision load-bearing rigid-flexible circuit board on one side; The size of the auxiliary circuit pattern located on the outer surface of the pressing plate is larger than the size of the auxiliary circuit pattern of the finished high-precision load-bearing rigid-flexible circuit board on one side; A window covering film having a window pattern is attached to one side of the flexible board, wherein the window pattern corresponds to the flexible board plug circuit pattern and the flexible board pad pattern, and a single side of the window pattern is smaller than the flexible board plug circuit pattern; Using dry film or blue glue to cover the flexible board plug circuit pattern; A solder resist pattern layer with a solder resist window is formed on one side of the rigid board, wherein the solder resist window corresponds to and is smaller than the auxiliary circuit pattern on one side; Through holes are drilled according to the auxiliary circuit pattern and electroplated to form conducting holes.

10. The method for manufacturing a high-precision load-bearing rigid-flexible circuit board according to claim 1, characterized in that: After the pressing plate is formed, the flexible board plug circuit pattern is subjected to gold electroplating.

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