Manufacturing method of high-expansion flexible circuit board for new energy automobile

Abstract

The invention discloses a manufacturing method of a high-expansion flexible circuit board for a new energy automobile, and the method comprises the steps: manufacturing a double-sided copper-clad plate which is provided with a first region and a second region and has different expansion and shrinkage rates, arranging a PI layer corresponding to the junction of the first region and the second region, and enabling the PI layer to be located in the middle of a glue layer of the double-sided copper-clad plate; the PI layer extends into the first region and the second region; the expansion and shrinkage rate of the first region is greater than that of the PI layer, and the expansion and shrinkage rate of the PI layer is greater than that of the second region; electroplating the double-sided copper-clad plate, manufacturing a snake-shaped circuit in the first region, manufacturing a plug-in circuit in the second region, and integrally forming a pattern plate; the snakelike line is connected with the plugging line; the supporting plate is manufactured and pasted to the edge of the pattern plate, the circuit board is formed through post-process machining, the limitation of a traditional single-material flexible circuit board on the expansion and shrinkage performance is broken through, and accurate performance application of different areas of the circuit board is achieved by combining materials with different expansion and shrinkage performance on the same plane.

Description

Technical Field

[0001] The present invention relates to the field of flexible circuit board manufacturing, and in particular to a manufacturing method for a high expansion and contraction flexible circuit board for new energy vehicles. Background Art

[0002] The application environments of products such as new energy vehicles and low-altitude aircraft are relatively complex. Currently, for relatively large-sized flexible circuit boards applied to such products, a relatively large size pre-value for summer high-temperature expansion or winter cold contraction is usually reserved to adapt to the expansion and contraction effects of the external environment and form a dynamic size effect.

[0003] However, this method has problems: on the one hand, it will require a larger actual layout space. For complex layout space structures, more precise calculations and applications are needed; on the other hand, under certain conditions, the expansion of the product will cause wear of the flexible circuit board, and it is not flexible enough to adapt to different environments.

[0004] In addition, generally, flexible circuit boards are processed with materials having a single expansion and contraction performance, and the entire board has the same expansion and contraction. For flexible circuit boards with two electrical connection methods of welding and plugging, plugging requires high stability to prevent electrical connection problems caused by dimensional changes, and welding is easier to fix and control; and during the processing and welding of the board body, due to the large and soft board body, after being completely formed, welding is prone to problems such as inaccurate alignment, poor welding, or even difficult welding.

[0005] Therefore, to solve the above-mentioned problems, a manufacturing method for a high expansion and contraction flexible circuit board for new energy vehicles is needed. Summary of the Invention

[0006] The present invention aims to solve the comprehensive problems existing in the prior art of large-sized flexible circuit boards, such as large expansion and contraction rates and high welding difficulty due to the softness of the board body. A manufacturing method for a high expansion and contraction flexible circuit board for new energy vehicles is proposed. The circuit board is designed with a forming line. The area within the range of the forming line is the effective area, and the area outside is the tool area. The manufacturing method includes the following steps:

[0007] S10: Manufacture a double-sided copper clad laminate with different expansion and contraction rates in the first area and the second area. A PI layer (i.e., a polyimide material layer) is provided at the junction corresponding to the first area and the second area. The PI layer is located in the adhesive layer of the double-sided copper clad laminate; the PI layer extends into the first area and the second area; the expansion and contraction rate of the first area is greater than that of the PI layer, and the expansion and contraction rate of the PI layer is greater than that of the second area;

[0008] S20: Electroplate the double-sided copper clad laminate, and then manufacture a surface circuit pattern, including manufacturing serpentine lines in the first area and plugging lines in the second area to form a graphic board as a whole; the serpentine lines are connected to the plugging lines;

[0009] S30: Manufacture a support board and paste it to the tool area of the graphic board. After post - process machining, the flexible circuit board is formed.

[0010] Furthermore, the manufacturing method of the double - sided copper - clad laminate is as follows: Take the first single - sided copper - clad laminate, the second single - sided copper - clad laminate and the PI layer. Lay the first single - sided copper - clad laminate and the second single - sided copper - clad laminate adjacent to each other to form a partitioned single - sided copper - clad laminate. Stack the PI layer between the two relatively stacked partitioned single - sided copper - clad laminates and perform lamination to form the double - sided copper - clad laminate; the first single - sided copper - clad laminate corresponds to the first region, and the second single - sided copper - clad laminate corresponds to the second region.

[0011] Furthermore, the electroplating is as follows: First, perform pulse electroplating, and then perform ordinary electroplating.

[0012] Furthermore, manufacturing the surface circuit pattern includes manufacturing the surface circuit pattern at the junction to form a buffer circuit.

[0013] Furthermore, a number of through - slots are made at the edge of the forming line. A connection bridge is formed between adjacent through - slots, and the connection bridge connects the effective area and the tool area.

[0014] Furthermore, the connection bridge is pasted to the support board.

[0015] Furthermore, a window is opened at the position of the support board corresponding to the connection bridge. The connection direction of the connection bridge is the long direction, the dimension in the long direction is the length, and the direction perpendicular to the long direction is the width direction, and the dimension in the width direction is the width; the window is larger than the width of the connection bridge and smaller than the length of the connection bridge.

[0016] Furthermore, through - slots are made between adjacent serpentine lines.

[0017] Furthermore, manufacturing the surface circuit pattern includes manufacturing a pad pattern and a shrinkage and expansion guiding pattern in the first region. The pad pattern is located at one end of the serpentine line, and the shrinkage and expansion guiding pattern is located on both sides of the pad pattern.

[0018] Furthermore, a window is made in the area of the support board corresponding to the pad pattern.

[0019] The main beneficial effects of the technical solution of the present invention include:

[0020] (1) By fabricating a double-sided copper clad laminate with different expansion and contraction rates in different regions, an overall board structure is formed where one part has low expansion and contraction performance and the other part has high expansion and contraction performance in the planar direction. Subsequently, by fabricating plug-in circuits at one end of the second region, it can be ensured that it is not easily deformed. By fabricating high-elasticity circuits at one end of the first region with a high expansion and contraction rate, it can be made to match the high-expansion and contraction performance region, meeting the application requirements of high-elasticity expansion and contraction, breaking the limitations of traditional single-material flexible circuit boards in terms of expansion and contraction performance. By combining materials with different expansion and contraction performances on the same plane, precise performance applications for different functional regions of the circuit board are achieved.

[0021] (2) By setting up connection bridges on the pattern board to form a suspended connection between the effective area and the tool area, which only needs to be cut off by means of laser cutting, manual cutting, or other cutting methods, effectively avoiding the use of complex and destructive processing methods such as milling or punching to remove the tool area, making the processing of the circuit board easier to achieve, thereby improving the processing quality of the circuit board.

[0022] (3) By pasting a support board to the pattern board to provide support force for the board body, and then opening windows for the corresponding pad patterns to provide a processing basis for subsequent soldering processing; and the effect of opening windows at the positions corresponding to the connection bridges, and the width of the opened window is greater than the width of the connection bridge, serving as a cutting operation space, while the opened window is smaller than the length of the connection bridge, ensuring that the connection bridge can continue to play its connection and support roles and maintain the stability of the board body before the connection bridge is cut off.

[0023] (4) Further, by fabricating hollow slots between the serpentine circuits, the serpentine circuits form an independent or independent form board structure in groups of several, providing space for the deformation of the circuits. On the one hand, the hollow slots reduce the material amount of the board body, greatly improving the flexibility and softness of the flexible board. On the other hand, the independent wavy line structure enables each circuit to respond more freely to the expansion and contraction caused by temperature changes. When the temperature changes, the wavy lines can expand and contract more flexibly and will not be overly restricted by the surrounding circuits, thus greatly enhancing the expansion and contraction performance and better adapting to the board body expansion and contraction changes brought about by condition changes.

[0024] (5) The entire technical solution realizes the high-quality processing effect of the high-expansion and contraction flexible circuit board through the above-mentioned fabrication of double-sided copper clad laminates with different expansion and contraction rates in different regions, fabricating different serpentine circuits, buffer circuits, and connection bridges in different regions, then fabricating a support board and pasting it, and the coordinated action of opening windows corresponding to the connection bridges and pad patterns and the process processing, forming overall relevance and coordination. Description of the Drawings

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0026] Figure 1 Schematic process flow diagram of an embodiment of the present invention;

[0027] Figure 2 Cross-sectional schematic diagram of the stacked structure of an embodiment of the present invention;

[0028] Figure 3 Cross-sectional schematic diagram of the double-sided copper clad laminate of an embodiment of the present invention;

[0029] Figure 4 Cross-sectional structure schematic diagram of the electroplated board of an embodiment of the present invention;

[0030] Figure 5 Planar structure schematic diagram of the pattern board of an embodiment of the present invention;

[0031] Figure 6 For Figure 5 A-A cross-sectional structure schematic diagram;

[0032] Figure 7 Planar structure schematic diagram of the pattern board with a hollow groove of an embodiment of the present invention;

[0033] Figure 8 For Figure 7 Design data diagram;

[0034] Figure 9 Planar structure schematic diagram of the paste board of an embodiment of the present invention;

[0035] Figure 10 For Figure 9 B-B cross-sectional structure schematic diagram;

[0036] Figure 11 Planar structure schematic diagram of another paste board of an embodiment of the present invention;

[0037] Figure 12 For Figure 11 C-C cross-sectional structure schematic diagram;

[0038] Figure 13 Partial physical plan view of the paste board of an embodiment of the present invention;

[0039] Figure 14 Is Figure 13 FD partial enlarged area diagram;

[0040] Figure 15 Schematic plan view of the flexible circuit board according to an embodiment of the present invention;

[0041] Figure 16 is Figure 15 Schematic D-D cross-sectional view of

[0042] Explanation of the reference numerals in the drawings: 100, forming line; 100A, effective area; 100B, tool area; 10, double-sided copper clad laminate; 1010, first area; 1020, second area; 1030, PI layer; 200, stacked structure; 10A, partitioned single-sided copper clad laminate; 20, electroplated board; 2010, electroplated copper layer; 30, pattern board; 30A, another pattern board; 3010, serpentine circuit; 3020, plug-in circuit; 3030, buffer circuit; 3040, hollow groove; 3050, pad pattern; 3060, shrinkage and expansion guiding pattern; 3070, through groove; 3080, connection bridge; 3080A, through hole; 3090, alignment pattern; 40, support plate; 4010, first opening; 4020, second opening; 50, adhesive plate; 5010, adhesive layer; 50A, another adhesive plate; FD, locally enlarged area; 60, flexible circuit board; 6010, component.

[0043] The realization, functional features and advantages of the object of the present invention will be further described in conjunction with the embodiments with reference to the accompanying drawings. Specific embodiments

[0044] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0045] 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 conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0046] In addition, the descriptions such as "first" and "second" in the present invention are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0047] 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 ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0048] Please refer to Figure 1 , Figure 1 , which is a schematic process flow diagram of an embodiment of the present invention.

[0049] The circuit board of the embodiment of the present invention is designed with a forming line 100. The area within the range of the forming line 100 is the effective area 100A, and the area outside is the tool area 100B; the manufacturing process includes using Figure 1 in each step process to achieve, and the following will further illustrate each step process in Figure 1 step by step.

[0050] Please refer to Figure 2 and Figure 3 , Figure 2 , which is a schematic cross-sectional view of the stacked structure of the embodiment of the present invention; Figure 3 , which is a schematic cross-sectional view of the double-sided copper clad laminate of the embodiment of the present invention.

[0051] S10: Manufacture a double-sided copper clad laminate 10 with different expansion and contraction rates in the first region 1010 and the second region 1020 respectively. A PI layer 1030 (i.e., a polyimide material layer) is provided at the junction corresponding to the first region 1010 and the second region 1020. The PI layer 1030 is located in the middle of the adhesive layer of the double-sided copper clad laminate 10; the PI layer 1030 extends into the first region 1010 and the second region 1020; the expansion and contraction rate of the first region 1010 is greater than that of the PI layer 1030, and the expansion and contraction rate of the PI layer 1030 is greater than that of the second region 1020.

[0052] Form an overall plate structure with low expansion and contraction performance in a part in the plane direction and high expansion and contraction performance in another part. Subsequently, a plug-in circuit 3020 is manufactured at one end of the second region 1020 with a low expansion and contraction rate to ensure that it is not easily deformed, and a highly elastic circuit (such as a wavy line) is manufactured at one end of the first region 1010 with a high expansion and contraction rate, thereby endowing the circuit with high elasticity so that it can perfectly match the first region 1010 with high expansion and contraction performance and meet the application requirements of high elastic expansion and contraction.

[0053] By optimizing the performance of the double-sided copper clad laminate 10 as a whole, the limitations of the traditional single-material flexible circuit board in terms of expansion and contraction performance are broken, and materials with different expansion and contraction performances are combined on the same plane, realizing the precise performance application of different functional regions of the circuit board.

[0054] Optionally, the method for manufacturing the double-sided copper clad laminate 10 is as follows: Take the first single-sided copper clad laminate, the second single-sided copper clad laminate, and the PI layer 1030. Adjacent lay the first single-sided copper clad laminate and the second single-sided copper clad laminate to form a partitioned single-sided copper clad laminate 10A. Stack the PI layer 1030 between two relatively stacked partitioned single-sided copper clad laminates 10A to form a stacked structure 200, and then perform pressing to form the double-sided copper clad laminate 10. The first single-sided copper clad laminate corresponds to the first region 1010, and the second single-sided copper clad laminate corresponds to the second region 1020.

[0055] Furthermore, when laying, a spacing of about 20 μm to 100 μm is reserved between the first single-sided copper clad laminate and the second single-sided copper clad laminate to avoid mutual extrusion during pressing, which may cause problems such as protrusions and unevenness on the board surface, ensuring the quality of the double-sided copper clad laminate 10 and providing a good foundation for subsequent circuit board manufacturing processes. After pressing, this spacing forms a gap with a certain width.

[0056] It should be noted that the PI layer 1030, as a transition auxiliary layer between different expansion and contraction rates, should not have too large a size. Therefore, the size of the PI layer 1030 is set corresponding to the position of the above-mentioned gap. It extends into the first region 1010 and the second region 1020, enhancing the overall structural strength of the board body while not affecting the expansion and contraction performance of the two regions.

[0057] Optionally, the PI layer 1030 extends 50 μm to 5.0 mm both into the high expansion and contraction region and the low expansion and contraction region. Specifically, it is determined according to the overall board size, the bonding force between materials, and the wiring space size.

[0058] If the size of the PI layer 1030 is equal to the size of a whole panel, it is evenly distributed on the entire circuit board, just like covering the circuit board with a material with a single property. This makes the originally divided high expansion and contraction region and low expansion and contraction region tend to be the same in actual performance. The high expansion and contraction region cannot expand and contract significantly as expected, and the low expansion and contraction region is also difficult to maintain a stable size, resulting in the entire circuit board being unable to perform the functions that different regions should have.

[0059] Furthermore, since the PI layer 1030 participates in pressing as an intermediate layer, it needs to be subjected to plasma treatment to form a roughened and activated surface to achieve tight bonding with the upper and lower partitioned single-sided copper clad laminates 10A to ensure the stability of the entire board body.

[0060] Furthermore, the copper layer thickness of both the first single-sided copper clad laminate and the second single-sided copper clad laminate is controlled at about 5 μm to 10 μm. On the one hand, the low expansion and contraction characteristics of the copper layer are used to provide an effective expansion and contraction constraint effect for the board body during the pressing process. On the other hand, the thinner copper layer also provides good basic copper conditions for subsequent electroplating to thicken the copper.

[0061] Please refer to Figures 4 to 6 ,Figure 4 Schematic cross-sectional structure diagram of the electroplated board according to an embodiment of the present invention; Figure 5 Schematic plan structure diagram of the graphic board according to an embodiment of the present invention; Figure 6 is Figure 5 Schematic cross-sectional structure diagram of A-A of

[0062] S20: Electroplate the double-sided copper clad laminate 10 to form an electroplated board 20. Then, make a serpentine circuit 3010 in the first region 1010 and a plug-in circuit 3020 in the second region 1020 to form a surface circuit pattern, and integrally form a graphic board 30; the serpentine circuit 3010 is connected to the plug-in circuit 3020.

[0063] Since the plug-in circuit 3020 relies on plug-in connection, it is necessary to ensure low expansion and contraction of the plug-in to ensure stability. Therefore, the plug-in circuit 3020 is made in the second region 1020 with low expansion and contraction performance, avoiding large changes in the size of the plug-in part due to large expansion and contraction in the second region 1020 under the influence of factors such as temperature change, resulting in problems such as loosening and poor contact.

[0064] At the same time, make a serpentine circuit 3010 (for example: wavy circuit) in the first region 1010 with high expansion and contraction performance, and make full use of the high elasticity characteristics of the serpentine structure. When the temperature of the circuit board changes, the first region 1010 will have a large expansion or contraction. Due to its special shape, the serpentine circuit can adapt to size changes through its own deformation when being stretched or compressed, without damaging the electrical conductivity and structural integrity of the circuit, and still maintaining good electrical performance in an environment of high elastic expansion and contraction, meeting the special requirements of new energy vehicles for circuit boards in complex application scenarios.

[0065] Optionally, the width of the serpentine line is 25 μm to 1.0 mm, and the radian of a single bending position of the serpentine line is 5° to 150°; different serpentine line effects can be formed for different application scenarios.

[0066] Furthermore, the electroplating is carried out by first performing pulse electroplating and then ordinary electroplating. Since there may be a gap between the first single-sided copper clad laminate and the second single-sided copper clad laminate during the lamination process, if a single electroplating method is used, it is difficult to ensure that the gap and the entire board surface are evenly plated with a copper layer. Therefore, the method of first pulse electroplating and then ordinary electroplating is adopted. After the gap electroplating is completed by pulse electroplating, the whole board is processed by ordinary electroplating to form a uniform and continuous copper layer on the entire board surface, further increasing the thickness of the copper layer, making the entire board surface form a complete and smooth copper surface, providing a copper layer foundation with sufficient thickness for subsequent circuit production, and ensuring the electrical conductivity and stability of the circuit.

[0067] Optionally, before electroplating, laser ablation is performed on the gap position to remove the overflow glue and trim the gap, so that the gap forms a smooth surface microscopically, which is more conducive to electroplating copper.

[0068] Optionally, the thickness of the electroplated copper layer 2010 is 10 μm to 105 μm, which forms an effective cooperation with the thinner copper layer used in the previous process. In the previous process, the low expansion and contraction characteristics of the thin copper layer are first utilized to provide expansion and contraction constraints for the board body during the lamination process, and then the copper layer thickness is increased to 10 μm to 105 μm in the electroplating process, effectively making up for the deficiencies of the thin copper layer and meeting the electrical performance requirements of the circuit board.

[0069] Further, a surface circuit pattern is made, including making the surface circuit pattern at the junction to form a buffer circuit 3030.

[0070] Optionally, the length of the buffer circuit 3030 is equal to the length of the PI layer 1030, or is 50 μm to 10.0 mm.

[0071] Since materials with different expansion and contraction rates will form a stress concentration phenomenon at the junction, making the buffer circuit 3030 at the junction can effectively restrain the stress change caused by the expansion and contraction difference between different expansion and contraction regions, thereby protecting the overall structure of the circuit and the circuit board.

[0072] Further, the width of the buffer circuit 3030 is greater than the width of the serpentine circuit 3010, further alleviating the stress concentration at the junction and increasing the overall structural stability of the circuit board.

[0073] Please refer to Figure 7 and Figure 8 , Figure 7 which is a schematic plan view of a graphic board with a hollow groove according to an embodiment of the present invention; Figure 8 is Figure 7 the design data diagram of

[0074] Further, a hollow groove 3040 is made between adjacent serpentine circuits 3010, that is, after the serpentine circuit 3010 is made, the hollow groove 3040 is made on the graphic board 30 to form another graphic board 30A.

[0075] When the circuit gap is wide enough (width ≥ 100 μm to less than the width of the board body), the hollow groove 3040 is made along the edge of the serpentine circuit 3010, so that the serpentine circuit 3010 forms an independent or several independent form board body structures in a group. The existence of the hollow groove 3040 provides space for the deformation of the circuit, avoids damage or deformation caused by mutual extrusion between circuits, and ensures the integrity and electrical performance of the circuit.

[0076] On the one hand, the hollow groove 3040 reduces the material amount of the plate body, lowers the stiffness of the plate body, and thus greatly improves the flexibility and softness of the flexible plate. On the other hand, the independent wavy line structure enables each circuit to respond more freely to the expansion and contraction caused by temperature changes. When the temperature changes, the wavy line can expand and contract more flexibly and will not be overly restricted by the surrounding circuits, thereby greatly enhancing the expansion and contraction performance and better adapting to the expansion and contraction changes of the plate body brought about by condition changes.

[0077] Optionally, the width of the hollow groove 3040 is ≥30 μm and does not exceed the maximum width of the plate body; the distance between the edge of the hollow groove 3040 and the adjacent serpentine circuit 3010 is 20 μm to 5.0 mm.

[0078] Furthermore, fabricating the surface circuit pattern includes fabricating a pad pattern 3050 and an expansion and contraction guiding pattern 3060 in the first region 1010. The pad pattern 3050 is located at one end of the serpentine circuit 3010, and the expansion and contraction guiding pattern 3060 is located on both sides of the pad pattern 3050.

[0079] Optionally, the length by which the expansion and contraction guiding pattern 3060 extends outward is 50 μm to 10.0 mm, and the width is 30 μm to the same as the length of the pad pattern 3050, or 1.2 times to 2.0 times the length of the pad pattern 3050.

[0080] When the temperature rises or falls, the plate body material will tend to deform due to thermal expansion and contraction. The expansion and contraction guiding pattern 3060 guides this deformation tendency to the longitudinal direction through interaction with the surrounding materials, effectively preventing the chaotic expansion and contraction direction of the plate body, ensuring the connection accuracy between the circuit board and other components 6010, and avoiding connection failure problems caused by expansion and contraction.

[0081] Furthermore, a number of through grooves 3070 are fabricated at the edge of the forming line 100, and connection bridges 3080 are formed between adjacent through grooves 3070. The connection bridges 3080 connect the effective area 100A and the tool area 100B.

[0082] Optionally, the width of the through groove 3070 is 30 μm to 3.0 mm.

[0083] The connection bridges 3080 connect the effective area 100A and the tool area 100B into a whole, providing stable support for the effective area 100A during the welding process. At the same time, the suspended connection method of the connection bridges 3080 forms an indirect connection between the tool area 100B and the effective area 100A, facilitating subsequent separation operations.

[0084] More importantly, after the components 6010 are soldered in the subsequent process, it is not convenient to remove the tool area 100B by milling or punching. Therefore, for the suspended connection of the connection bridge 3080, it only needs to be cut off by laser cutting, manual cutting or other cutting methods, and methods such as laser cutting are relatively simple and have relatively low technical requirements for operators, thus reducing the processing threshold, making the processing of the circuit board easier to achieve, effectively avoiding the use of complex and destructive processing methods such as milling or punching to remove the tool area 100B, which is likely to cause vibration and wear impact on the board body, reducing the risk of damage to the board body and the components 6010, and thus improving the processing quality of the circuit board.

[0085] It is worth noting that the tool area 100B is made with alignment patterns 3090 for subsequent soldering alignment. On the one hand, it leaves more space for distributing circuits on the flexible circuit board. On the other hand, it is convenient to form an overall alignment effect during soldering processing. After soldering is completed, the alignment patterns 3090 will be removed together with the tool area 100B, which will not cause adverse effects on the graphic design of the entire circuit board and also avoids having too many useless graphics distributed on the board body, increasing the simplicity and beauty of the board body.

[0086] Please refer to Figure 9 and Figure 10 , Figure 9 which is a schematic plan view of the paste board according to the embodiment of the present invention; Figure 10 is Figure 9 the schematic cross-sectional structure view of B-B of

[0087] S30: Fabricate the support board 40 and paste it on the edge of the graphic board 30 to form the paste board 50, and through subsequent process machining, form the flexible circuit board 60.

[0088] Since the board body is large and soft, it is not easy to handle and operate during soldering. Therefore, by fabricating the support board 40 to provide a supporting role for it, and bonding the area corresponding to the tool area 100B to form the bonding layer 5010, ensuring that the overall board body has stronger support, and transmitting the supporting force of the support board 40 to the graphic board 30, avoiding the graphic board 30 from shaking or deforming during the soldering process, thus ensuring the accuracy and quality of soldering.

[0089] For the un-soldered and un-bonded areas, the support board 40 is set for support, and the support board 40 and the graphic board 30 are only laminated without bonding. The support board 40 can share the weight of the graphic board 30, reducing the deformation of the board body caused by its own gravity. Moreover, this structural setting will not form a permanent connection between the graphic board 30 and the support board 40. After soldering is completed, the board body can be easily separated from the support board 40, avoiding the problems of board body damage or difficult separation caused by too strong bonding.

[0090] Furthermore, by providing the support plate 40, it also plays an important role in restricting expansion and contraction, has a certain restraint on the expansion or contraction of the circuit board, and further improves the processing accuracy during the soldering process.

[0091] Optionally, the pattern board 30 is adhered to the support plate 40 at the tool area 100B by attaching an acrylic adhesive layer or an epoxy resin adhesive layer on the surface of the board body or the surface of the support plate 40 and using the film laminating and hot pressing method.

[0092] Optionally, the thickness of the support plate 40 is 0.5 mm to 3.0 mm.

[0093] Optionally, the material of the support plate 40 is a rigid plate, preferably an FR-4 board, an epoxy resin board, a PP board, a PVC board, or a rigid waste board with a flat surface during the processing can also be used to achieve material recycling and resource conservation.

[0094] Furthermore, a window is made in the area of the support plate 40 corresponding to the pad pattern 3050 to form the first window 4010, exposing the pad pattern 3050 completely, providing a processing basis for the soldering process.

[0095] Optionally, another kind of hollow groove is made on the board body of the flexible circuit board 60 corresponding to the adjacent serpentine lines 3010.

[0096] Another kind of hollow groove can be made on the formed flexible circuit board 60. Its groove structure is the same as the above-mentioned hollow groove 3040, so that when the finished flexible circuit board 60 is applied, it has a thinner and lighter board body and more flexible expansion and contraction (the function is similar to that of the above-mentioned hollow groove 3040); that is, the above-mentioned hollow groove 3040 is made by making a hollow in the pattern board 30 on the inner layer of the flexible circuit board 60, and the cover film attached to the surface of the pattern board 30 is not made hollow, while another kind of hollow groove is made on the flexible circuit board 60 of the overall structure after the cover film is attached.

[0097] Please refer to Figure 11 and Figure 12 , Figure 11 which is a schematic plan view of another paste board according to an embodiment of the present invention; Figure 12 is Figure 11 a schematic cross-sectional structure view of C-C of

[0098] If the circuit board is designed for single-sided soldering, at this time the support plate 40 is located on the other side of the pattern board 30 to form another paste board 50A. This pasting method will not hinder the soldering operation, so the process of making the first window 4010 corresponding to the pad pattern 3050 can be omitted, reducing the process steps.

[0099] Further, a window is formed at the position of the support plate 40 corresponding to the connection bridge 3080, forming a second window 4020. The connection direction of the connection bridge 3080 is the long direction, the dimension in the long direction is the length, and the direction perpendicular to the long direction is the width direction, and the dimension in the width direction is the width; the second window 4020 is larger than the width of the connection bridge 3080 and smaller than the length of the connection bridge 3080.

[0100] The connection bridge 3080 plays an important role in connecting the effective area 100A and the tool area 100B during the circuit board processing, ensuring the integrity and stability of the board body during the soldering process. After the soldering is completed, the connection bridge 3080 needs to be cut off to separate the effective area 100A and the tool area 100B. If no window is made at the position of the support plate 40 corresponding to the connection bridge 3080, when cutting off the connection bridge 3080 subsequently, due to the obstruction of the support plate 40, whether it is laser cutting, manual cutting or other cutting methods, great difficulties will be faced, and during the cutting process, it may cause adverse effects such as vibration and wear to the already soldered circuit board, reducing the product quality.

[0101] The second window 4020 of the support plate 40 is larger than the width of the connection bridge 3080, which can fully expose the part of the connection bridge 3080 that needs to be cut off, providing enough operating space for the cutting tool. And the second window 4020 is smaller than the length of the connection bridge 3080, which ensures that before cutting off the connection bridge 3080, the connection bridge 3080 can continue to play its connection and support role, maintaining the stability of the board body.

[0102] Please refer to Figure 13 and Figure 14 , Figure 13 which is a partial physical plan view of the sticker board according to the embodiment of the present invention, Figure 14 is Figure 13 the FD partial enlarged area view of

[0103] Optionally, a plurality of through holes 3080A are made at one end of the connection bridge 3080 close to the forming line 100, which is convenient for manually removing the board body after the components 6010 are soldered.

[0104] Further, the connection bridge 3080 is pasted to the support plate 40, so that the positions of the first window 4010 of the connection bridge 3080 and the support plate 40 adhere to each other, strengthening the adhesion effect of the graphic board 30, avoiding the phenomenon that a large area of the board body is easily separated and suspended from the support plate 40 due to factors such as the self-weight of the graphic board 30 and slight external vibrations, and the adhesive layer cannot extend into the effective area 100A, reserving good board surface conditions for subsequent processing operations.

[0105] After cutting off the connection bridge 3080, the flexible circuit board 60 in the left blank area can be easily removed from the support board 40, just like untying the "bond" between the connection effective area 100A and the tool area 100B. Since the corresponding connection bridge 3080 has not been cut off and is still in a supported state, it further reflects the structural design of the cooperation between the connection bridge 3080 and the support board 40.

[0106] Please refer to Figure 15 and Figure 16 , Figure 15 is a plan view of the flexible circuit board according to an embodiment of the present invention; Figure 16 is Figure 15 a schematic cross-sectional view taken along line D-D of

[0107] The support board 40 makes a window corresponding to the pad pattern 3050 to completely expose the pad pattern 3050, providing a basis for welding, so that the component 6010 is welded on the flexible circuit board 60 and then disconnected from the support board 40. Through the above technology, the smooth progress of the welding operation is ensured, the welding quality and efficiency are improved, and at the same time, the post-treatment of the flexible circuit board 60 is facilitated, ensuring the good application of the flexible circuit board 60.

[0108] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention. Any equivalent structural transformation made under the inventive concept of the present invention by using the content of the specification and drawings of the present invention, or directly / indirectly applied in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A manufacturing method of a high-expansion and contraction flexible circuit board for a new energy vehicle. The circuit board is designed with a forming line. The area within the range of the forming line is the effective area, and the area outside is the tool area. It is characterized in that, The manufacturing method includes the following steps: S10: Fabricate a double-sided copper clad laminate with different shrinkage and expansion rates in the first area and the second area respectively. A PI layer is provided corresponding to the junction of the first area and the second area, and the PI layer is located in the adhesive layer of the double-sided copper clad laminate; the PI layer extends into the first area and the second area; The shrinkage and expansion rate of the first area is greater than that of the PI layer, and the shrinkage and expansion rate of the PI layer is greater than that of the second area; S20: Electroplate the double-sided copper clad laminate, and then fabricate a surface circuit pattern, including fabricating a serpentine circuit in the first area and a plug-in circuit in the second area to form a pattern board as a whole; The serpentine circuit is connected to the plug-in circuit; S30: Fabricate a support plate and paste it to the tool area of the pattern board, and through subsequent process processing, form the flexible circuit board.

2. The manufacturing method of a high-expansion and contraction flexible circuit board for a new energy vehicle according to claim 1, characterized in that The manufacturing method of the double-sided copper clad laminate is as follows: Take a first single-sided copper clad laminate, a second single-sided copper clad laminate, and the PI layer. Lay the first single-sided copper clad laminate and the second single-sided copper clad laminate adjacent to each other to form a partitioned single-sided copper clad laminate, stack the PI layer between the two relatively laminated partitioned single-sided copper clad laminates, and perform lamination to form the double-sided copper clad laminate; The first single-sided copper clad laminate corresponds to the first area, and the second single-sided copper clad laminate corresponds to the second area.

3. The manufacturing method of a high-expansion and contraction flexible circuit board for a new energy vehicle as described in claim 1, characterized in that, The electroplating is as follows: First, perform pulse electroplating, and then perform ordinary electroplating.

4. The manufacturing method of a high-expansion and contraction flexible circuit board for a new energy vehicle according to claim 1, characterized in that, Fabricating the surface circuit pattern includes fabricating the surface circuit pattern at the junction to form a buffer circuit.

5. The manufacturing method of a high-expansion and contraction flexible circuit board for a new energy vehicle according to claim 1, characterized in that, A number of through slots are made at the edge of the forming line, and a connection bridge is formed between adjacent through slots, and the connection bridge connects the effective area and the tool area.

6. The manufacturing method of a high-expansion and contraction flexible circuit board for a new energy vehicle according to claim 5, characterized in that The connection bridge is pasted to the support plate.

7. The manufacturing method of a high-expansion and contraction flexible circuit board for a new energy vehicle according to claim 5 or 6, characterized in that, A window is opened at the position of the support plate corresponding to the connection bridge. The connection direction of the connection bridge is the long direction, the dimension in the long direction is the length, and the direction perpendicular to the long direction is the width direction, and the dimension in the width direction is the width; the window is larger than the width of the connection bridge and smaller than the length of the connection bridge.

8. The manufacturing method of a high-expansion and contraction flexible circuit board for a new energy vehicle as described in claim 1, characterized in that, Through slots are made between adjacent serpentine circuits, or through slots are made in the board body of the flexible circuit board corresponding to the positions between adjacent serpentine circuits.

9. The manufacturing method of a high-expansion and contraction flexible circuit board for a new energy vehicle according to claim 1, characterized in that, Fabricating the surface circuit pattern includes fabricating a pad pattern and a shrinkage and expansion guiding pattern in the first area. The pad pattern is located at one end of the serpentine circuit, and the shrinkage and expansion guiding pattern is located on both sides of the pad pattern.

10. The manufacturing method of a high-expansion and contraction flexible circuit board for a new energy vehicle according to claim 9, characterized in that, A window is opened in the area of the support plate corresponding to the pad pattern.

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