A manufacturing method of a high-precision rigid-flex combined circuit board

Abstract

Said the application discloses a kind of high-precision load type rigid-flex circuit board manufacturing method, and processing process plate design has forming line, manufacturing method includes: the flexible plate including flexible area and rigid combination area is made, take rigid copper-clad plate, manufacturing circuit pattern, circuit pattern includes the auxiliary circuit pattern corresponding with flexible plate pad pattern, flexible area contour makes first slot body, first slot body is set with auxiliary area first connecting site, rigid combination area contour makes second slot body, second slot body is set with auxiliary area second connecting site, form rigid bearing plate, flexible plate and rigid bearing plate are pressed together, shaping, form high-precision load type rigid-flex circuit board;Flexible plate and rigid bearing plate are independently made, and rigid bearing plate is made according to forming line to form with slot body, then overall pressing, flexible plate is shaped using laser cutting, effectively avoid the flexible plate pulling, tearing and other problems generated by milling cutting shaping of overall plate body, improve processing quality and reliability.

Description

Technical Field

[0001] This invention relates to the field of flexible circuit board processing, and more particularly to a method for manufacturing a high-precision load-bearing rigid-flex circuit board. Background Technology

[0002] For electronic modules in some intelligent connected vehicles or testing equipment, high-precision rigid-flex circuit boards are required. The rigid board serves to support and weld electronic components, while the flexible board serves to provide three-dimensional mounting and conductive connections.

[0003] The design and fabrication of rigid-flex circuit boards are generally quite complex. When the precision requirements for rigid-flex circuit boards are high, but the circuit pattern design is relatively simple, the traditional rigid-flex circuit boards have little advantage in terms of design difficulty and fabrication cost.

[0004] Therefore, load-bearing rigid-flex circuit boards have emerged that manufacture flexible and rigid boards separately and then further fabricate the circuit patterns. These rigid-flex circuit boards can effectively ensure the processing accuracy of the flexible board and provide the load-bearing capacity of the rigid board for the flexible board.

[0005] Currently, for this type of high-precision load-bearing rigid-flex circuit board, the general method is to first fabricate the circuit patterns of the flexible board and the rigid board separately, then press them together with an adhesive layer, and finally mill them into shape. For areas where the rigid board is not needed, a controlled-depth milling method is used to remove it.

[0006] Since the insulating dielectric layer material of flexible circuit boards is generally polyimide, which has strong inertness and toughness, the milling cutter can easily cause problems such as pulling, tearing, and rolling of the polyimide material during the forming process of the above manufacturing method. This can lead to deformation of the flexible circuit board, affecting accuracy, or even tearing. Furthermore, depth-controlled milling requires high precision in the thickness of the board. If the board itself is uneven or warped, it is easy to cause problems such as insufficient or excessive depth control, making it difficult to remove the unnecessary rigid plate, or damaging the surface of the flexible board during milling.

[0007] Based on the above background and technology, there is a need to provide a method for manufacturing a high-precision load-bearing rigid-flex circuit board. Summary of the Invention

[0008] This invention aims to solve the problems of stretching, deformation, and even tearing of flexible boards during milling in the processing of high-precision load-bearing rigid-flex circuit boards, as well as the problems of insufficient or excessive depth control in depth-controlled milling. The invention provides a method for manufacturing a high-precision load-bearing rigid-flex circuit board, wherein the rigid-flex circuit board during processing includes a forming line referencing the outline of the finished rigid-flex circuit board; the board body within the forming line is the effective area, and the area outside the forming line is the auxiliary area.

[0009] The manufacturing method includes the following steps:

[0010] S10: Fabricate 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;

[0011] S20: Take a rigid copper-clad laminate and fabricate a circuit pattern, the circuit pattern including an auxiliary circuit pattern corresponding to the flexible board pad pattern;

[0012] A first groove is made according to the molding line at the contour position of the flexible area. The first groove is provided with a first connection position that is not part of the groove. The first connection position is located at a position other than the connection area between the flexible area and the rigid bonding area.

[0013] A second groove is made according to the molding line at the outline position of the rigid bonding area. The second groove is provided with a second connection position that is not part of the groove. The second connection position is located at a position other than the connection area between the flexible area and the rigid bonding area.

[0014] The widths of both the first and second grooves extend from the forming line toward the auxiliary area;

[0015] Forming a rigid load-bearing plate;

[0016] S30: Align and bond the flexible plate with the rigid bearing plate, and press them together to form a pressed plate. Then, form the plate according to the forming line to form the high-precision load-bearing rigid-flex circuit board.

[0017] Furthermore, the length of the connecting region is greater than or equal to the width of the second groove, the first groove and the second groove are connected in the connecting region, and the second groove is connected in the connecting region.

[0018] Furthermore, the forming process according to the forming line includes: using laser cutting to cut the flexible plate of the first groove, the connecting area, and the second groove along the forming line; and using milling to mill away the positions of the first connecting position and the second connecting position along the forming line.

[0019] Furthermore, the length of the connecting area is greater than or equal to the width of the second groove, and the connecting area is provided with a third connecting position, which is located between the second groove and the first groove.

[0020] Furthermore, the molding process according to the molding line includes: cutting the flexible plate of the first groove along the molding line using laser cutting; and milling off the positions of the first connecting position and the second connecting position and the third connecting position along the molding line using milling.

[0021] Further, the forming line from the first groove, the third connecting position to the second groove forms a zigzag line; the rigid bearing plate is milled from the first groove along the zigzag line to the second groove, partially cutting the third connecting position; the forming according to the forming line includes: using laser cutting to cut the first groove and the milled portion of the flexible plate of the third connecting position along the forming line; using milling to mill away the positions of the first connecting position and the second connecting position and the remaining unmilled portion of the third connecting position along the forming line.

[0022] Further, the pressing includes: taking an adhesive layer of the same size as the flexible plate, processing open windows at the positions of the flexible area, the first groove, the connecting area and the second groove corresponding to the adhesive layer, bonding the flexible plate and the rigid bearing plate together through the adhesive layer, and then performing the pressing.

[0023] Furthermore, after forming the press-fit plate, the process further includes: attaching a windowed cover film with a windowed pattern to one side of the flexible plate, the windowed pattern corresponding to the flexible plate plug circuit pattern and the flexible plate solder pad pattern, and covering the flexible plate plug circuit pattern with dry film or blue adhesive; forming a solder resist pattern layer with solder resist windows on one side of the rigid plate, the solder resist windows corresponding to the auxiliary circuit pattern; drilling through holes according to the auxiliary circuit pattern and electroplating to form through holes.

[0024] Optionally, forming the lamination plate further includes: the size of the flexible board pad pattern on the outer surface of the lamination plate is larger on one side than the size of the flexible board pad pattern of the finished high-precision load-bearing rigid-flex circuit board; the size of the auxiliary circuit pattern on the outer surface of the lamination plate is larger on one side than the size of the auxiliary circuit pattern of the finished high-precision load-bearing rigid-flex circuit board; attaching a windowed cover film with a windowed pattern to one side of the flexible board, the windowed pattern corresponding to the flexible board plug circuit pattern and the flexible board pad pattern, the windowed pattern being smaller on one side than the flexible board plug circuit pattern; covering the flexible board plug circuit pattern with dry film or blue glue; forming a solder resist pattern layer with solder resist windows on one side of the rigid board, the solder resist windows corresponding to and smaller on one side than the auxiliary circuit pattern; drilling through holes according to the auxiliary circuit pattern and electroplating to form through holes.

[0025] Furthermore, after the lamination plate is formed, the circuit pattern of the flexible board plug is electroplated with gold.

[0026] The technical solution of this invention first involves independently fabricating the shape of the flexible board. Then, based on the required load-bearing area shape of the flexible board, and considering the overall integrity of the processing and ease of subsequent forming, a first and second groove, as well as a first and second connecting position, are designed and fabricated on the rigid board. This independently forms a rigid load-bearing plate, creating a pre-milled effect. After lamination and pressing with adhesive layers, an integral structure is formed. Finally, laser cutting is used on the flexible board, and the first and second connecting positions are milled away. Since the rigid load-bearing plate corresponding to the forming line has already been fabricated with the first and second grooves, laser cutting can cut all of the flexible board except for the first and second connecting positions. The forming line effectively avoids problems such as stretching and tearing of the flexible board caused by milling the entire board. The adhesive layer is divided into areas where rigid support plates need to be combined with flexible plates, and areas where rigid support plates do not need to be combined with flexible plates, with open windows. Combined with the contours of the first and second grooves, the removal of rigid support plates that do not need rigid support does not require depth-controlled milling, further improving the processing accuracy of the board and protecting the quality of the flexible board. The overall processing forms a streamlined process of front and rear coordination, and no milling is used on the flexible board except for the first and second connection positions, ensuring the high precision characteristics of the flexible board and improving the processing quality and reliability of the overall board. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0028] Figure 1 This is a process flow diagram of the high-precision load-bearing rigid-flex circuit board according to an embodiment of the present invention.

[0029] Figure 2 This is a schematic diagram of the planar structure of the flexible plate according to an embodiment of the present invention;

[0030] Figure 3 for Figure 2 Schematic diagram of the AA section structure;

[0031] Figure 4 This is a schematic diagram of the planar structure of the rigid bearing plate according to an embodiment of the present invention;

[0032] Figure 5 A schematic diagram of the planar structure of another rigid bearing plate according to an embodiment of the present invention;

[0033] Figure 6 for Figure 5 Schematic diagram of the BB cross-section structure;

[0034] Figure 7 for Figure 5 Enlarged view of the XQ region;

[0035] Figure 8 This is a schematic diagram of the planar structure of the laminated plate according to an embodiment of the present invention;

[0036] Figure 9 for Figure 8 A schematic diagram of the CC section structure;

[0037] Figure 10 for Figure 8 Schematic diagram of the DD cross-section structure;

[0038] Figure 11 This is a schematic diagram of the planar structure of the high-precision load-bearing rigid-flex circuit board formed according to an embodiment of the present invention.

[0039] Figure 12 for Figure 11 Schematic diagram of the EE cross-section structure;

[0040] Figure 13 for Figure 11 A schematic diagram of the FF cross-section structure;

[0041] Figure 14 for Figure 11 A schematic diagram of another cross-sectional structure of F'-F'.

[0042] Explanation of icon numbers:

[0043]

[0044] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0045] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0046] It should be noted that all directional indications (such as up, down, left, right, front, back, inside, outside, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0047] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0048] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0049] Please see Figure 1 ; Figure 1 This is a process flow diagram of a high-precision load-bearing rigid-flex circuit board according to an embodiment of the present invention.

[0050] The present invention discloses a method for manufacturing a high-precision load-bearing rigid-flex circuit board. The rigid-flex circuit board during processing includes a forming line 10C referencing the outline of the finished rigid-flex circuit board. The board body within the forming line 10C is the effective area, and the area outside is the auxiliary area. The manufacturing method includes using… Figure 1 The implementation of each step in the process will be described below. Figure 1 The process of each step will be explained step by step.

[0051] Please see Figure 2 and Figure 3 ; Figure 2 This is a schematic diagram of the planar structure of the flexible plate according to an embodiment of the present invention; Figure 3 for Figure 2 A schematic diagram of the AA section structure.

[0052] Step S10:

[0053] A flexible board 10 is fabricated, comprising a flexible board plug circuit pattern 110, a flexible board circuit pattern 120, and a flexible board pad pattern 130; the flexible board 10 is divided into a flexible region 10R and a rigid bonding region 10G; the flexible board 10 includes a flexible board dielectric layer 140.

[0054] In this embodiment, the flexible plate 10 and the rigid plate (i.e., the rigid bearing plate 20) are designed and manufactured separately. The flexible plate 10 is manufactured separately to form a separate flexible plate 10. Separate manufacturing can effectively ensure the high precision characteristics of the flexible plate 10 and avoid the problems of high processing difficulty and limited precision caused by using the design and manufacturing method of rigid-flex circuit boards.

[0055] The fabricated flexible board 10 includes a flexible board plug pattern 110 for welding or plugging in subsequent applications, a flexible board circuit pattern 120 for conduction, and a flexible board pad pattern 130 corresponding to the rigid support plate 20 in the subsequent process.

[0056] Please see Figures 4 to 7 ; Figure 4 This is a schematic diagram of the planar structure of the rigid bearing plate according to an embodiment of the present invention; Figure 5 A schematic diagram of the planar structure of another rigid bearing plate according to an embodiment of the present invention; Figure 6 for Figure 5 Schematic diagram of the BB cross-section structure; Figure 7 for Figure 5 A magnified view of the XQ region.

[0057] Step S20:

[0058] A rigid copper-clad laminate is used to fabricate a circuit pattern, which includes an auxiliary circuit pattern 210 corresponding to the flexible board pad pattern 130. A first groove 220 is fabricated according to the outline position of the forming line 10C in the flexible region 10R. The first groove 220 is provided with a non-groove first connection position 2210, which is located outside the connection area 20L between the flexible region 10R and the rigid bonding region 10G. A second groove 230 is fabricated according to the outline position of the forming line 10C in the rigid bonding region 10G. The second groove 230 is provided with a non-groove second connection position 2310, which is located outside the connection area 20L between the flexible region 10R and the rigid bonding region 10G. The widths of the first groove 220 and the second groove 230 both extend from the forming line 10C to the auxiliary region. A rigid support plate 20 is formed. The rigid support plate 20 includes a rigid board dielectric layer 240.

[0059] Similarly, the rigid plate is also made separately, and in this embodiment, the rigid plate acts as a support plate for the flexible plate 10, thus becoming a rigid support plate 20.

[0060] To ensure that the precision of the flexible board 10 is not affected by the processing in subsequent processes, the rigid bearing plate 20 must not only ensure high-precision dimensional matching and auxiliary circuit pattern matching with the flexible board 10 during subsequent bonding processing and load-bearing processes, but also avoid the impact of rigid plate forming on the dimensional regeneration of the flexible board 10 and the application of board edge smoothness. In particular, the forming of the rigid plate requires milling, which can cause significant pulling, tearing, and substrate rolling problems to the flexible board 10, thus affecting its expansion and contraction and board edge smoothness. Therefore, high-precision flexible board 10 is generally formed by laser cutting, which can effectively ensure the forming effect.

[0061] Therefore, in this embodiment, the rigid bearing plate 20 is fabricated with a first groove 220 and a second groove 230, which ensures that each area of ​​the rigid bearing plate 20 forms a bearing function. At the same time, it ensures that during subsequent molding, only laser cutting is needed to cut the flexible plate 10 from the first groove 220 and the second groove 230, which effectively improves the processing accuracy of the flexible plate 10. The width of the first groove 220 and the second groove 230 is generally 0.2mm to 2.0mm. The width should not be too wide, otherwise it is easy to cause problems such as excessive compression and concavity, and concavity, squeezing and pulling of the flexible plate 10.

[0062] However, it is also necessary to ensure that the shapes of the rigid bearing plates 20 within the range of the first groove 220 and the second groove 230 are connected to the rigid bearing plates 20 themselves to form an integral structure. Therefore, it is necessary to retain the first connection position 2210 and the second connection position 2310. The width of the first connection position 2210 and the second connection position 2310 is generally 0.5mm to 2mm. The width should not be too large, otherwise it will affect the flexible plate 10 during subsequent milling.

[0063] In one embodiment, the length of the connecting region 20L is greater than or equal to the width of the second groove 230, the first groove 220 and the second groove 230 are connected in the connecting region 20L, and the second groove 230 is connected in the connecting region 20L.

[0064] In this embodiment, the entire connection area 20L is covered by the flexible plate 10. That is, after the high-precision load-bearing rigid-flex circuit board is finally formed, the rigid load-bearing plate 20 of the connection area 20L is completely removed, leaving only the flexible plate 10. Therefore, the first groove and the second groove of this embodiment are connected to meet the structural and processing requirements.

[0065] Please continue reading. Figures 4 to 7 Please see also Figures 8 to 10 ; Figure 8 This is a schematic diagram of the planar structure of the laminated plate according to an embodiment of the present invention; Figure 9 for Figure 8 A schematic diagram of the CC section structure; Figure 10 for Figure 8 A schematic diagram of the DD cross-section structure.

[0066] In one embodiment, the pressing process includes: taking an adhesive layer 310 with the same size as the flexible plate 10, processing open windows at the positions of the flexible area 10R, the first groove, the connecting area 20L, and the second groove corresponding to the adhesive layer 310, bonding the flexible plate 10 and the rigid bearing plate together through the adhesive layer 310, and then pressing them together to form a pressed plate 30.

[0067] Based on the above design and structure, the pressing in this embodiment is performed by pressing with an adhesive layer 310. The adhesive layer 310 is a room temperature solid adhesive, specifically acrylic adhesive, epoxy resin adhesive, polyolefin adhesive, etc. Since the area of ​​the flexible plate 10 and the rigid bearing plate 20 of the connecting 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 open window.

[0068] It is worth noting that the adhesive layer 310 can be taken out and then open windows can be made only in the area of ​​the flexible board 10 and the connection area 20L. After that, it can be attached to the rigid copper-clad board after the circuit pattern is made, and then the first groove and the second groove can be made. This allows the adhesive layer 310 and the rigid copper-clad board to be processed together to form a rigid bearing board 20, which improves the processing accuracy of the adhesive layer 310 and facilitates its subsequent integration with the flexible board 10.

[0069] In one embodiment, forming is performed along the forming line 10C, including: cutting the flexible plate 10 of the first groove, the connecting area 20L and the second groove along the forming line 10C by laser cutting; and milling off the positions of the first connecting position 2210 and the second connecting position 2310 along the forming line 10C by milling.

[0070] Based on the above design and structure, the molding process of this embodiment first involves laser cutting the flexible plate 10 along the molding line 10C according to the contours of the first groove, the connecting area 20L, and the second groove. Then, the positions of the first connecting position 2210 and the second connecting position 2310 are milled off by mechanical milling. As a result, the rigid bearing plate 20 corresponding to the open window area of ​​the adhesive layer 310 falls off, that is, the area forms the flexible plate 10. In the area where the adhesive layer 310 is bonded, the rigid bearing plate 20 and the flexible plate 10 are bonded together to form a whole, that is, a rigid plate is formed. The whole plate forms a high-precision load-bearing rigid-flex circuit board 40.

[0071] During the processing, the forming process after pressing did not use milling to form the flexible plate 10, thus ensuring the high precision of the flexible plate 10.

[0072] Please continue reading. Figure 5 and Figure 7 In another embodiment, the length of the connecting region 20L is greater than or equal to the width of the second groove 230, and the connecting region 20L is provided with a third connecting position 250, which is located between the second groove 230 and the first groove 220.

[0073] In this embodiment, to ensure that the rigid-flex joint (the junction of the flexible plate 10 and the rigid support plate 20) of the high-precision load-bearing rigid-flex circuit board is located in the middle of the connection area 20L, so that the rigid-flex circuit board has better bending performance and improves the tear resistance of the flexible plate 10, the rigid support plate 20 is set to partially "extend" towards the flexible plate 10 within the connection area 20L. That is, after the high-precision load-bearing rigid-flex circuit board is formed, about half of the connection area 20L has the rigid support plate 20 and the other part has the flexible plate 10.

[0074] To ensure the accuracy of the "extended" part during the pressing process and to prevent the pressing position from shifting or displacing, a third connection position 250 is provided in this area to improve the overall machinability and high precision characteristics of the rigid bearing plate 20.

[0075] Similarly, in this embodiment, the pressing includes: taking an adhesive layer 310 with the same size as the flexible plate 10, processing open windows at the positions of the flexible area 10R, the first groove, the connecting area 20L and the second groove corresponding to the adhesive layer 310, bonding the flexible plate 10 and the rigid bearing plate 20 through the adhesive layer 310, and then pressing them together to form a pressed plate 30.

[0076] In another embodiment, forming is performed along the forming line 10C, including: cutting the flexible plate 10 of the first groove 220 along the forming line 10C by laser cutting; and milling off the positions of the first connecting position 2210 and the second connecting position 2310 and the third connecting position 250 along the forming line 10C by milling.

[0077] Similar to the above processing method, the flexible plate 10 is processed by laser cutting, and the connecting parts are processed by mechanical milling, which will not be described in detail here.

[0078] In another embodiment, the forming line 10C from the first groove, the third connecting position 250 to the second groove forms a zigzag line; the rigid bearing plate is milled from the first groove along the zigzag line to the second groove, with the third connecting position 250 being milled; forming is performed according to the forming line 10C, including: using laser cutting to cut the first groove 220 and the milled portion of the third connecting position 250 along the forming line 10C of the flexible plate 10; using milling to mill off the positions of the first connecting position 2210 and the second connecting position 2310 and the remaining unmilled portion of the third connecting position 250 along the forming line 10C, see Figure 5 Another type of rigid load-bearing plate, 20A.

[0079] When the "extended" part is trapezoidal, inverted trapezoidal, planar bent, or other shapes, the forming line 10C at that location forms a fold line. Generally, during subsequent forming, this location is machined along the fold line path. However, for the fold line location, on the one hand, the rigid bearing plate 20 has already undergone the first milling process to form the first groove. After alignment and pressing, a second milling is performed. The first and second milling processes will have certain errors, leading to problems such as milling deformation or incomplete milling at the fold line location. On the other hand, the fold... Compared to straight-line milling, wire milling is more prone to problems such as pulling, tearing, and blade curling of the flexible plate 10, and is more likely to cause burrs on the edge of the flexible plate 10, leading to poor processing. Therefore, this embodiment adopts a processing method in which, during the first milling of the rigid bearing plate 20, at one end of the fold line forming line 10C at the third connection position 250, a groove is first milled at a partial milling position 260, and then during subsequent forming, a straight-line milling is performed from the rear milling position 270 at the other end (see [link to documentation]). Figure 7 For the already milled groove, the flexible plate 10 can be processed by laser cutting. This method forms the third connection position 250 by non-broken line milling, which avoids problems such as the stretching of the flexible plate 10 caused by milling broken lines, and reduces the width of the third connection position 250, making subsequent processing easier and effectively improving processing accuracy.

[0080] Please continue reading. Figures 8 to 10 Please see also Figures 11 to 14 ; Figure 11 This is a schematic diagram of the planar structure of the high-precision load-bearing rigid-flex circuit board formed according to an embodiment of the present invention. Figure 12 for Figure 11 Schematic diagram of the EE cross-section structure; Figure 13 for Figure 11 A schematic diagram of the FF cross-section structure; Figure 14 for Figure 11 A schematic diagram of another cross-sectional structure of F'-F'.

[0081] Step S30:

[0082] The flexible plate 10 and the rigid bearing plate 20 are aligned and bonded together to form a press plate 30. Then, it is formed according to the forming line 10C to form a high-precision load-bearing rigid-flex circuit board 40.

[0083] In one embodiment, after forming the lamination plate 30, the method further includes: attaching a window cover film 410 with a window pattern 4110 to one side of the flexible plate 10, the window pattern 4110 corresponding to the flexible plate plug circuit pattern 110 and the flexible plate solder pad pattern 130, and covering the flexible plate plug circuit pattern 110 with dry film or blue glue; forming a solder resist pattern layer 420 with solder resist windows on one side of the rigid plate, the solder resist windows corresponding to auxiliary circuit patterns; drilling through holes according to the auxiliary circuit patterns and electroplating to form through holes 430.

[0084] The rigid plate portion of this type of high-precision load-bearing rigid-flex circuit board 40 not only serves a load-bearing function, but also forms electrical connection characteristics or auxiliary welding characteristics due to the adhesive layer 310 being set and pressed into a whole. That is, through holes are made into the flexible board pad pattern 130 corresponding to the auxiliary circuit pattern, and metallized holes are formed by electroplating, forming a support for electrical connection or welding, giving the flexible board 10 stronger auxiliary support, welding, and conductivity performance.

[0085] In this embodiment, the flexible board 10 uses a window pattern 4110 of the same size as the flexible board pad pattern 130 to make a cover film. After processing such as drilling and electroplating, a through hole 430 is formed.

[0086] In another embodiment, forming the lamination plate further includes: a flexible board pad pattern 130 located on the outer surface of the lamination plate having a size larger on one side than the size of the flexible board pad pattern 130 of the finished high-precision load-bearing rigid-flex circuit board 40; an auxiliary circuit pattern located on the outer surface of the lamination plate having a size larger on one side than the size of the auxiliary circuit pattern of the finished high-precision load-bearing rigid-flex circuit board 40; attaching a window cover film 410 with a window pattern 4110 to one side of the flexible board 10, the window pattern 4110 corresponding to the flexible board plug circuit pattern 110 and the flexible board pad pattern 130, the window pattern 4110 being smaller on one side than the flexible board plug circuit pattern 110; covering the flexible board plug circuit pattern 110 with dry film or blue glue; forming a solder resist pattern layer 420 with solder resist windows on one side of the rigid board, the solder resist windows corresponding to and being smaller on one side than the auxiliary circuit pattern; drilling through holes according to the auxiliary circuit pattern and electroplating to form through holes 430.

[0087] Please continue reading. Figure 14In another embodiment, if the cover film is directly made with an opening pattern 4110 the same size as the flexible board pad pattern 130, it is difficult to achieve precise alignment between the opening pattern 4110 and the flexible board pad pattern 130 when the cover film is aligned and pressed, which affects the processing accuracy of the via 430. Therefore, when the size and wiring space are sufficient, the size of the flexible board pad pattern 130 and the auxiliary circuit pattern are pre-designed and made larger. Then, when the opening cover film 410 is pressed, the opening pattern 4110 is smaller than the flexible board pad pattern 130. This allows the flexible board pad pattern 130 with the exposed opening pattern 4110 to more accurately form the pad for making the via 430. The manufacturing principle of the auxiliary circuit pattern is similar and will not be described again.

[0088] In one embodiment, after the lamination plate is formed, the flexible board plug circuit pattern 110 is electroplated with gold.

[0089] If the via 430 needs to be gold-plated, then the via 430 is electroplated with gold. If the via 430 does not need to be gold-plated, then it needs to be covered by means of dry film, and the flexible board plug circuit pattern 110 is electroplated with gold separately.

[0090] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural transformations made using the contents of the specification and drawings of the present invention under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the scope of patent protection of the present invention.

Claims

1. A method for manufacturing a high-precision load-bearing rigid-flex circuit board, wherein the rigid-flex circuit board during the manufacturing process includes a forming line referencing the outline of the finished rigid-flex circuit board; the board body within the forming line is the effective area, and the area outside the forming line is the auxiliary area. Its features are, The manufacturing method includes the following steps: S10: Fabricate 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 fabricate a circuit pattern, the circuit pattern including an auxiliary circuit pattern corresponding to the flexible board pad pattern; A first groove is made according to the molding line at the contour position of the flexible area. The first groove is provided with a first connection position that is not part of the groove. The first connection position is located at a position other than the connection area between the flexible area and the rigid bonding area. A second groove is made according to the molding line at the outline position of the rigid bonding area. The second groove is provided with a second connection position that is not part of the groove. The second connection position is located at a position other than the connection area between the flexible area and the rigid bonding area. The widths of both the first and second grooves extend from the forming line toward the auxiliary area; Forming a rigid load-bearing plate; S30: Align and bond the flexible plate with the rigid bearing plate, and press them together to form a pressed plate. Then, form the plate according to the forming line to form the high-precision load-bearing rigid-flex circuit board.

2. The method for manufacturing a high-precision load-bearing rigid-flex circuit board as described in claim 1, characterized in that, The length of the connecting area is greater than or equal to the width of the second groove, the first groove and the second groove are connected in the connecting area, and the second groove is connected in the connecting area.

3. The method for manufacturing a high-precision load-bearing rigid-flex circuit board as described in claim 2, characterized in that, The forming process according to the forming line includes: The flexible plate, comprising the first groove, the connecting area, and the second groove, is cut along the forming line using laser cutting. The positions of the first connecting position and the second connecting position are milled off along the forming line using a milling method.

4. The method for manufacturing a high-precision load-bearing rigid-flex circuit board as described in claim 1, characterized in that, The length of the connecting area is greater than or equal to the width of the second groove, and the connecting area is provided with a third connecting position, which is located between the second groove and the first groove.

5. The method for manufacturing a high-precision load-bearing rigid-flex circuit board as described in claim 4, characterized in that, The forming process according to the forming line includes: The flexible plate of the first groove is cut along the forming line using laser cutting. The positions of the first connecting position, the second connecting position, and the third connecting position are milled off along the forming line using a milling method.

6. The method for manufacturing a high-precision load-bearing rigid-flex circuit board as described in claim 5, characterized in that, The forming line passing through the first groove, the third connecting position to the second groove forms a zigzag line; The rigid bearing plate is milled from the first groove along the broken line towards the second groove, with the third connecting position partially cut. The forming process according to the forming line includes: The flexible plate at the third connecting position of the first groove and the milled portion is cut along the forming line using laser cutting. The positions of the first and second connecting positions, as well as the remaining unmilled portion of the third connecting position, are milled off along the forming line using a milling method.

7. A method for manufacturing a high-precision load-bearing rigid-flex circuit board as described in claim 2 or 4, characterized in that, The pressing includes: Take an adhesive layer of the same size as the flexible plate, and process openings in the flexible area, the first groove, the connecting area and the second groove corresponding to the adhesive layer. Then, bond the flexible plate and the rigid support plate together through the adhesive layer and press them together.

8. The method for manufacturing a high-precision load-bearing rigid-flex circuit board as described in claim 1, characterized in that, After forming the pressed plate, the process also includes: A windowed cover film with a windowed pattern is attached to one side of the flexible board. The windowed pattern corresponds to the plug circuit pattern and the pad pattern of the flexible board. The plug circuit pattern of the flexible board is covered with dry film or blue glue. A solder resist pattern layer with solder resist openings is formed on one side of the rigid bearing plate, and the solder resist openings correspond to the auxiliary circuit pattern. Drill through holes according to the auxiliary circuit pattern and electroplate them to form through holes.

9. The method for manufacturing a high-precision load-bearing rigid-flex circuit board as described in claim 1, characterized in that, The process of forming the press plate also includes: The size of the flexible board pad pattern located on the outer surface of the laminating plate is larger on one side than the size of the flexible board pad pattern of the finished high-precision load-bearing rigid-flex circuit board. The auxiliary circuit pattern located on the outer surface of the laminating plate has a size on one side that is larger than the size of the auxiliary circuit pattern on the finished high-precision load-bearing rigid-flex circuit board. A windowed cover film with a windowed pattern is attached to one side of the flexible board. The windowed pattern corresponds to the plug circuit pattern and the pad pattern of the flexible board. One side of the windowed pattern is smaller than the plug circuit pattern of the flexible board. The flexible board plug circuit pattern is covered with dry film or blue adhesive. A solder resist pattern layer with a solder resist opening is formed on one side of the rigid bearing plate, and the solder resist opening corresponds to and is smaller on one side than the auxiliary circuit pattern. Drill through holes according to the auxiliary circuit pattern and electroplate them to form through holes.

10. A method for manufacturing a high-precision load-bearing rigid-flex circuit board as described in claim 1, characterized in that, After the lamination plate is formed, the circuit pattern of the flexible board plug is electroplated with gold.

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