Flexible circuit board easy to bend and reinforce and manufacturing method thereof

Abstract

The invention discloses a flexible circuit board easy to bend and reinforce and a manufacturing method of the flexible circuit board. The method comprises the following steps: respectively providing a thermoplastic reinforcing film and a flexible circuit substrate of which the circuit is manufactured; according to preset pre-pressing parameters, the thermoplastic reinforcing film is pre-pressed on the reinforcing area of the flexible circuit substrate, and a to-be-pressed reinforcing circuit board is obtained; according to preset pressing parameters, pressing the to-be-pressed reinforced circuit board to obtain a semi-finished circuit board; and heating the semi-finished circuit board by using a preset mold according to preset heating parameters, so that the reinforcing area of the semi-finished circuit board and the thermoplastic reinforcing film on the reinforcing area form a bent structure together, and the target circuit board is obtained. Based on the thermoplastic reinforcing film, the effect that the reinforcing area of the flexible circuit board can be bent into any required angle and does not rebound can be achieved, and the problem that due to a traditional reinforcing material, the reinforcing area is not prone to being bent and formed or the angle is difficult to maintain after forming, and the delamination risk exists is solved.

Description

Technical Field

[0001] The present invention relates to the field of flexible circuit board manufacturing, and in particular to a flexible circuit board with easy bending and reinforcement and a manufacturing method thereof. Background Art

[0002] Flexible Printed Circuit (FPC), also known as soft circuit board or flexible circuit board, is a highly reliable and excellent flexible printed circuit board made of polyimide or polyester film as the base material. FPC has the characteristics of high wiring density, light weight, thin thickness and good bendability.

[0003] While FPC is thin and soft, it also loses its rigidity. Therefore, in order to increase the thickness and rigidity of the designated parts of the product for subsequent installation or assembly, a rigid plate needs to be attached to these locations, i.e. reinforcement. FR4 (Flame Resistant 4, whose main materials are glass fiber cloth and resin) is one of the common reinforcement methods for flexible circuit boards. It is generally used on the back of patch components with low flatness requirements, or around the pins of plug-in soldered components, to support components or increase the local thickness of FPC for easy assembly.

[0004] Due to the rigidity of FR4, it is impossible to achieve the reinforcement requirements for areas that need to be bent and formed. Steel sheet reinforcement is another reinforcement method. Although it can achieve the purpose of bending and forming, the steel sheet needs to be glued when it is attached. It is difficult to maintain the angle between the steel sheet and the glue in a high temperature environment or there is a risk of delamination. With the increase in the demand for FPC and the sophistication of production design, the application scenarios of bendable and easy-to-form reinforcement are gradually increasing. Therefore, there is an urgent need for a subsequent high-reliability bendable and easy-to-form reinforcement production method to produce a flexible circuit board that meets the requirements of easy-to-bend reinforcement. Summary of the invention

[0005] In view of this, an embodiment of the present invention provides a flexible circuit board with easy-to-bend reinforcement and a manufacturing method thereof to solve the problem that the reinforcement in the existing flexible circuit board is difficult to bend into shape or the angle is difficult to maintain after forming, resulting in the risk of delamination.

[0006] The present invention provides a method for manufacturing a flexible circuit board with easy-to-bend reinforcement, the method comprising:

[0007] A thermoplastic reinforcement film and a flexible circuit substrate with completed circuit production are provided respectively; wherein the flexible circuit substrate is provided with a reinforcement area;

[0008] Pre-pressing the thermoplastic reinforcement film onto the reinforcement area of ​​the flexible circuit substrate according to preset pre-pressing parameters to obtain a reinforced circuit board to be pressed;

[0009] According to preset pressing parameters, the reinforced circuit board to be pressed is pressed to obtain a semi-finished circuit board;

[0010] According to preset heating parameters, the semi-finished circuit board is heated using a preset mold, so that the pasting reinforcement area of ​​the semi-finished circuit board and the thermoplastic reinforcement film on the pasting reinforcement area form a bending structure together to obtain a target circuit board.

[0011] Optionally, the thermoplastic reinforcing film includes a thermoplastic material layer, and the thermoplastic material layer is made of any one thermoplastic material selected from the group consisting of polyphenylene sulfide, polyetheretherketone and liquid crystal polymer.

[0012] Optionally, the thermoplastic reinforcing film comprises a thermoplastic material layer and a backing adhesive attached to one side of the thermoplastic material layer, and the thermoplastic material layer is made of any one thermoplastic material selected from polyphenylene sulfide, polyetheretherketone and liquid crystal polymer.

[0013] Optionally, when the thermoplastic reinforcing film comprises a thermoplastic material layer and a backing adhesive bonded to one side of the thermoplastic material layer, the pre-pressing of the thermoplastic reinforcing film onto the bonding and reinforcing area of ​​the flexible circuit substrate according to a preset pre-pressing parameter comprises:

[0014] According to the preset pre-pressing parameters, the side of the thermoplastic reinforcement film having the back adhesive is pre-pressed onto the reinforcement area of ​​the flexible circuit substrate.

[0015] Optionally, the glass transition temperature of the thermoplastic material layer is 60-210°C, and the melting point of the thermoplastic material layer is less than 350°C.

[0016] Optionally, the preset pre-pressing parameters include pre-pressing temperature and pre-pressing pressure.

[0017] Optionally, the pre-pressing temperature ranges from 80 to 170° C.; and / or the pre-pressing pressure ranges from 0.4 to 0.8 MPa.

[0018] Optionally, the preset heating parameters include heating temperature, heating time and mold bending angle.

[0019] Optionally, the heating temperature ranges from 25 to 230° C.; and / or the heating time ranges from 5 to 30 s; and / or the bending angle of the mold ranges from 30 to 180°.

[0020] Optionally, the preset pressing parameters include preheating parameters and fast pressing parameters;

[0021] The method of laminating the reinforced circuit board to be laminated according to preset laminating parameters to obtain a semi-finished circuit board comprises:

[0022] Preheating the reinforced circuit board to be pressed according to the preheating parameters; wherein the preheating parameters include preheating temperature, preheating pressure and preheating time;

[0023] According to the fast pressing parameters, the preheated reinforced circuit board to be pressed is fast pressed to obtain the semi-finished circuit board; wherein the fast pressing parameters include fast pressing temperature, fast pressing pressure and fast pressing time.

[0024] Optionally, the preheating temperature ranges from 80 to 90°C; and / or the preheating pressure is 0 MPa; and / or the preheating time ranges from 5 to 15 s; and / or the fast pressing temperature ranges from 110 to 220°C; and / or the fast pressing pressure ranges from 2 to 5 MPa; and / or the fast pressing time ranges from 30 to 180 s.

[0025] Optionally, before the semi-finished circuit board is heated using a preset mold according to preset heating parameters, the method further includes:

[0026] The semi-finished circuit board is cured using a hot air oven according to first preset curing parameters; wherein the first preset curing parameters include a first curing temperature and a first curing time.

[0027] Optionally, the first curing temperature ranges from 150 to 250° C.; and / or the first curing time ranges from 30 to 120 min.

[0028] Optionally, before the semi-finished circuit board is heated using a preset mold according to preset heating parameters, the method further includes:

[0029] The semi-finished circuit board is cured using a tunnel oven according to second preset curing parameters; wherein the second preset curing parameters include a second curing temperature and a second curing time.

[0030] Optionally, the second curing temperature is in the range of 170-280° C.; and / or the second curing time is in the range of 10-20 min.

[0031] In addition, the present invention also provides a flexible circuit board with easy-to-bend reinforcement, which is manufactured using the aforementioned manufacturing method.

[0032] The beneficial effects of the present invention are as follows: a thermoplastic reinforcing film is used as a reinforcing material, and firstly, it is pre-pressed onto a pasting and reinforcing area of ​​a flexible circuit substrate on which circuit manufacturing has been completed. The pasting and reinforcing area is required to support electronic products such as components to be subsequently pasted, and also needs to have a bending area. By pre-pressing the reinforcing material of the material, the thermoplastic reinforcing film can be better positioned, and the subsequent pressing accuracy can be conveniently improved; and then, pressing is performed according to preset pressing parameters, so that the thermoplastic reinforcing film and the flexible circuit substrate can be better and tightly fitted without falling off; and finally, a preset mold is used for heating treatment, so that the pasting and reinforcing area and the thermoplastic reinforcing film thereon form a bending structure together, and a flexible circuit board with easy-to-bend reinforcement that meets the requirements is obtained;

[0033] The flexible circuit board with easy-to-bend reinforcement and the manufacturing method thereof of the present invention are based on a thermoplastic reinforcement film, and can achieve the effect that the reinforcement area of ​​the flexible circuit board can be bent into any desired angle without rebounding, thereby overcoming the problem that the reinforcement of traditional reinforcement materials is difficult to bend and form or the angle is difficult to maintain after forming, resulting in the risk of delamination. The angle is easy to maintain after forming, the risk of delamination is low, and the yield is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The features and advantages of the present invention will be more clearly understood by referring to the accompanying drawings, which are schematic and should not be construed as limiting the present invention in any way. In the accompanying drawings:

[0035] Figure 1 A flow chart of a method for manufacturing a flexible circuit board with easy-to-bend reinforcement in Embodiment 1 of the present invention is shown;

[0036] Figure 2 A cross-sectional structural diagram of a first semi-finished circuit board in Embodiment 1 of the present invention is shown;

[0037] Figure 3 A cross-sectional structural diagram of a second semi-finished circuit board in the first embodiment of the present invention is shown;

[0038] Figure 4 A cross-sectional structural diagram of a first target circuit board in Embodiment 1 of the present invention is shown;

[0039] Figure 5 The cross-sectional structure diagram of the second target circuit board in the first embodiment of the present invention is shown.

[0040] The description of each reference numeral is as follows:

[0041] 101. Thermoplastic material layer, 102. Adhesive backing, 103. Flexible circuit substrate, 104. Bending structure. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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 those skilled in the art without creative work are within the scope of protection of the present invention.

[0043] Embodiment 1

[0044] This embodiment provides a method for manufacturing a flexible circuit board with easy bending and reinforcement, such as Figure 1 As shown, including:

[0045] S1: providing a thermoplastic reinforcement film and a flexible circuit substrate on which circuits have been fabricated, respectively; wherein the flexible circuit substrate is provided with a reinforcement region;

[0046] S2: pre-pressing the thermoplastic reinforcement film onto the reinforcement area of ​​the flexible circuit substrate according to preset pre-pressing parameters to obtain a reinforced circuit board to be pressed;

[0047] S3: laminating the reinforced circuit board to be laminated according to preset laminating parameters to obtain a semi-finished circuit board;

[0048] S4: heating the semi-finished circuit board using a preset mold according to preset heating parameters, so that the pasting reinforcement area of ​​the semi-finished circuit board and the thermoplastic reinforcement film on the pasting reinforcement area form a bending structure together to obtain a target circuit board.

[0049] In this embodiment, a thermoplastic reinforcing film is used as a reinforcing material. First, it is pre-pressed onto the pasting reinforcement area of ​​the flexible circuit substrate where the circuit has been completed. The pasting reinforcement area is required to support the electronic products such as the components to be subsequently pasted, and also needs to have a bending area. Through the pre-pressing of the reinforcing material of this material, the thermoplastic reinforcing film can be better positioned, which is convenient for improving the subsequent pressing accuracy; then, pressing is performed according to the preset pressing parameters, so that the thermoplastic reinforcing film and the flexible circuit substrate can be better and tightly fitted without falling off; finally, a heat treatment is performed through a preset mold, so that the pasting reinforcement area and the thermoplastic reinforcing film thereon form a bending structure together, and a flexible circuit board with easy-to-bend reinforcement that meets the requirements is obtained.

[0050] The method for manufacturing a flexible circuit board with easy-to-bend reinforcement in this embodiment is based on a thermoplastic reinforcement film, which can achieve the effect that the reinforced area of ​​the flexible circuit board can be bent into any desired angle without rebounding, overcoming the problem that the reinforcement brought by traditional reinforcement materials is difficult to bend and form or the angle is difficult to maintain after forming, resulting in the risk of delamination. The angle is easy to maintain after forming, the risk of delamination is low, and the yield is high.

[0051] The following describes in detail each step of the manufacturing method of this embodiment.

[0052] In a first optional embodiment, the thermoplastic reinforcing film in S1 includes a thermoplastic material layer, and the thermoplastic material layer is made of any one thermoplastic material selected from the group consisting of polyphenylene sulfide, polyetheretherketone and liquid crystal polymer.

[0053] The above-mentioned thermoplastic materials have excellent mechanical properties and high temperature resistance, and can be easily processed and formed under certain high temperature conditions. The thermoplastic reinforcement film made of these thermoplastic materials and pressed onto the flexible circuit substrate can achieve a good pressing effect, thereby ensuring that the reinforced area of ​​the flexible circuit board can be bent into any desired angle without rebounding, with a low risk of delamination and high subsequent reliability; and since there is no use of backing glue, on the one hand, the process flow can be simplified and the material cost can be reduced, and on the other hand, the risk of delamination between the reinforcement and the flexible circuit board can be further reduced, thereby improving the product yield.

[0054] In a second optional embodiment, the thermoplastic reinforcing film in S1 includes a thermoplastic material layer and a backing adhesive attached to one side of the thermoplastic material layer, and the thermoplastic material layer is made of any one thermoplastic material of polyphenylene sulfide, polyetheretherketone and liquid crystal polymer.

[0055] Similarly, the above-mentioned thermoplastic materials have excellent mechanical properties and high temperature resistance, and can be easily processed and formed under certain high temperature conditions. The thermoplastic reinforcement layer and back adhesive made of these thermoplastic materials are combined to form a thermoplastic reinforcement film, and it is pressed onto the flexible circuit substrate. A good pressing effect can be achieved, thereby ensuring that the reinforced area of ​​the flexible circuit board can be bent into any desired angle without rebounding, with low delamination risk and high subsequent reliability.

[0056] Preferably, the glass transition temperature of the thermoplastic material layer is 60-210°C, and the melting point of the thermoplastic material layer is less than 350°C.

[0057] The thermoplastic material layer with the above-mentioned glass transition temperature can be deformed when heated and maintain a certain shape after cooling. Its glass transition temperature is higher than room temperature, so that it can maintain a stable shape at room temperature. When heated to the glass transition temperature, the intermolecular stress is reduced, and it can be used for molding processing, which is convenient for the subsequent formation of a bending structure and meets the requirements of easy bending reinforcement. The thermoplastic material with the above-mentioned melting point can ensure that it is better attached to the flexible circuit board after it is heated and melted, which is convenient for the subsequent use of pre-pressing and pressing, ensuring a good bonding effect between the thermoplastic reinforcement film and the flexible circuit substrate and reducing the risk of faults.

[0058] Wherein, when the thermoplastic reinforcing film comprises a thermoplastic material layer and a back adhesive bonded to one side of the thermoplastic material layer, a thermoplastic reinforcing film is provided, comprising:

[0059] The back adhesive is adhered to one side of the thermoplastic material layer by rolling, quick pressing or laminating.

[0060] By combining the thermoplastic material layer and the backing adhesive together through the above method, the bonding effect between the two can be effectively improved, the delamination risk between the thermoplastic material layer and the backing adhesive can be reduced, and the subsequent delamination risk between the entire thermoplastic reinforcement film and the flexible circuit substrate can be reduced.

[0061] Preferably, before S2, the method further includes:

[0062] The thermoplastic reinforcing film is processed into an outer shape, and the processed thermoplastic reinforcing film is positioned on the reinforcing region of the flexible circuit substrate.

[0063] Through the shape processing of the thermoplastic reinforcement film, its installation space and functional requirements can be matched, and at the same time, the stress distribution can be optimized and unnecessary material waste can be reduced. Before pre-pressing, the thermoplastic reinforcement film after shape processing is positioned and attached to the reinforcement area to ensure the subsequent pressing accuracy between the two.

[0064] Specifically, the outer shape of the thermoplastic reinforcing film can be processed by punching or laser processing, and the positioning of the thermoplastic reinforcing film after outer shape processing can be achieved by an automatic laminating machine or a clamp to achieve alignment between the thermoplastic reinforcing film and the laminating reinforcement area.

[0065] Preferably, when the thermoplastic reinforcing film comprises a thermoplastic material layer and a back adhesive bonded to one side of the thermoplastic material layer, S2 comprises:

[0066] According to the preset pre-pressing parameters, the side of the thermoplastic reinforcement film having the back adhesive is pre-pressed onto the reinforcement area of ​​the flexible circuit substrate.

[0067] When the thermoplastic reinforcing film includes a thermoplastic material layer and a backing adhesive bonded to one side of the thermoplastic material layer, pre-pressing the backing adhesive side of the thermoplastic reinforcing film to the reinforcing area can ensure better bonding between the thermoplastic material layer and the flexible circuit substrate based on the characteristics of the backing adhesive, and make the thermoplastic material layer remain stable on the flexible circuit substrate.

[0068] Specifically, polyphenylene sulfide (PPS) has a high glass transition temperature, usually exceeding 100°C; high mechanical strength, excellent wear resistance and chemical corrosion resistance; excellent high temperature resistance, and can be used for a long time in a high temperature environment without deformation or degradation.

[0069] Polyetheretherketone (PEEK) has a glass transition temperature of 143°C and is a high melting point thermoplastic. It has excellent high temperature resistance, with a continuous use temperature of up to 240°C and a short-term use temperature of over 300°C. It has excellent mechanical properties, high strength and modulus, and excellent impact resistance and toughness. It has strong chemical corrosion resistance and can withstand erosion by a variety of corrosive media and steam.

[0070] Liquid crystal polymer (LCP), whose glass transition temperature is usually in the range of 150-190℃, depends on the type of material and manufacturer. It has good high temperature resistance, high heat deformation temperature, and can maintain stable mechanical properties in high temperature environment; it has high mechanical strength, excellent rigidity and toughness; it has good processing performance and is easy to form and process.

[0071] In S2, the preset pre-pressing parameters include pre-pressing temperature and pre-pressing pressure.

[0072] Specifically, the pre-pressing temperature ranges from 80 to 170°C.

[0073] Specifically, the pre-compression pressure ranges from 0.4 to 0.8 MPa.

[0074] By means of the above-mentioned pre-pressing temperature and pre-pressing pressure, the thermoplastic reinforcing film can be better fixed to the to-be-laminated area of ​​the flexible circuit substrate.

[0075] Specifically, during pre-pressing, a dot matrix pre-pressing machine is used to implement the pre-pressing.

[0076] Preferably, in S3, the preset pressing parameters include preheating parameters and fast pressing parameters;

[0077] Then S3 includes:

[0078] S31: preheating the reinforced circuit board to be pressed according to the preheating parameters; wherein the preheating parameters include preheating temperature, preheating pressure and preheating time;

[0079] S32: According to the fast pressing parameters, the preheated reinforced circuit board to be pressed is fast pressed to obtain the semi-finished circuit board; wherein the fast pressing parameters include fast pressing temperature, fast pressing pressure and fast pressing time.

[0080] The lamination process is divided into two stages, namely preheating and fast pressing. Preheating can evacuate the air between the thermoplastic reinforcement film and the flexible circuit substrate, and fast pressing can quickly ensure that the thermoplastic reinforcement film is fully adhered to the to-be-laminated area of ​​the flexible circuit substrate, thereby effectively improving the lamination effect. By improving the lamination effect between the thermoplastic reinforcement film and the flexible circuit substrate, it can effectively ensure that the reinforced area of ​​the flexible circuit board (i.e., the laminated reinforcement area) can be bent into any desired angle without rebounding, and reduce the risk of delamination.

[0081] Specifically, in S31, the preheating temperature is in the range of 80-90°C; and / or, the preheating pressure is 0 MPa; and / or, the preheating time is in the range of 5-15s.

[0082] Through the above preheating parameters, the air between the thermoplastic reinforcement film and the flexible circuit substrate can be efficiently evacuated, which is convenient for subsequent rapid pressing.

[0083] Specifically, in S32, the rapid pressing temperature is in the range of 110 to 220°C; and / or, the rapid pressing pressure is in the range of 2 to 5 MPa; and / or, the rapid pressing time is in the range of 30 to 180 s.

[0084] Through the above-mentioned fast pressing parameters, the full bonding between the plastic reinforcing film and the flexible circuit substrate can be effectively achieved, with high efficiency and good effect.

[0085] When the thermoplastic reinforcing film of this embodiment only includes a thermoplastic material layer, after the lamination is completed, the cross-sectional structure of the semi-finished circuit board obtained is as follows: Figure 2 As shown, in Figure 2 In the figure, 101 is a thermoplastic material layer, and 103 is a flexible circuit substrate; when the thermoplastic reinforcing film of this embodiment includes a thermoplastic material layer and a backing adhesive, after the lamination is completed, the cross-sectional structure of the semi-finished circuit board obtained is as follows Figure 3 As shown, in Figure 3 In the figure, 102 is adhesive backing.

[0086] in, Figure 2 and Figure 3 The flexible circuit substrate can be a combination of a flexible copper-clad board and a protective film, or a combination of a flexible copper-clad board and an electromagnetic shielding film, or a flexible circuit substrate with other structural forms that has completed circuit production, depending on the specific situation. Flexible copper-clad boards include any of single-sided boards, double-sided boards, and multi-layer boards.

[0087] In a first optional embodiment, after S3 and before S4, the method further includes:

[0088] The semi-finished circuit board is cured using a hot air oven according to first preset curing parameters; wherein the first preset curing parameters include a first curing temperature and a first curing time.

[0089] The hot air oven can provide a uniform hot air environment, the temperature and wind speed of which can be precisely controlled, and has a large capacity and heating area. Therefore, the above method is used to cure the semi-finished circuit board with the thermoplastic reinforcement film pressed together, which can improve the curing efficiency and ensure the curing quality, thereby further ensuring the bonding effect between the thermoplastic reinforcement film and the flexible circuit substrate, and effectively ensuring the stability of the semi-finished circuit board.

[0090] Specifically, the first curing temperature ranges from 150 to 250° C.; and / or the first curing time ranges from 30 to 120 min.

[0091] By using the first preset curing parameter within the above range, a good curing effect of the hot air oven on the semi-finished circuit board can be achieved.

[0092] In a second optional embodiment, after S3 and before S4, the method further includes:

[0093] The semi-finished circuit board is cured using a tunnel oven according to second preset curing parameters; wherein the second preset curing parameters include a second curing temperature and a second curing time.

[0094] The tunnel furnace can provide a stable and uniform heat source, has a precise temperature and time control system, is suitable for FPC products of different sizes and shapes, and does not produce harmful substances during operation. Therefore, the above method is used to cure the semi-finished circuit board laminated with a thermoplastic reinforcement film, which can have a high curing effect and wide adaptability, and is environmentally friendly and energy-saving.

[0095] Specifically, the second curing temperature is in the range of 170-280° C.; and / or the second curing time is in the range of 10-20 min.

[0096] By using the second preset curing parameter within the above range, a good curing effect of the semi-finished circuit board in the tunnel furnace can be achieved.

[0097] Preferably, in S4, the preset heating parameters include heating temperature, heating time and mold bending angle.

[0098] Specifically, the heating temperature ranges from 25 to 230° C.; and / or the heating time ranges from 5 to 30 seconds; and / or the bending angle of the mold ranges from 30 to 180°.

[0099] Through the above-mentioned preset heating parameters, it can be effectively ensured that the semi-finished circuit board forms a bending structure that meets the design requirements and meets the reinforcement requirements of the bending and forming area of ​​the flexible circuit board, so that the bending and forming area of ​​the flexible circuit board can also play a role in supporting components or increasing the local thickness of the FPC.

[0100] In S4, the preset mold is usually designed according to the required bending structure, and when the preset mold is heated, the required bending structure can be formed. The required bending structure depends on the specific product design and is not limited in this embodiment.

[0101] When the thermoplastic reinforcing film of this embodiment only includes a thermoplastic material layer, after heating to form a bending structure, the cross-sectional structure of the target circuit board is obtained as follows: Figure 4 When the thermoplastic reinforcing film of this embodiment includes a thermoplastic material layer and a backing adhesive, after heating to form a bent structure, the cross-sectional structure of the target circuit board is obtained as shown Figure 5 As shown, in Figure 4 and Figure 5 In the figure, 104 is a bent structure.

[0102] This embodiment lists the following three specific production examples:

[0103] Specific production example 1:

[0104] The thermoplastic reinforcing film includes a thermoplastic material layer made of polyphenylene sulfide and a backing adhesive. The backing adhesive is bonded to the thermoplastic material layer made of polyphenylene sulfide at 100°C using a hot roller press to form a thermoplastic reinforcing film. According to the pre-pressing temperature of 80°C and the pre-pressing pressure of 0.4MPa, the pre-pressing of the thermoplastic reinforcing film and the flexible circuit substrate is completed to obtain a reinforced circuit board to be pressed. According to the preheating temperature of 110°C, the preheating pressure of 0MPa and the preheating time of 5s, the first stage of the pressing process (i.e. preheating) is completed. According to the fast pressing temperature of 180°C, the fast pressing pressure of 2MPa and the fast pressing time of 180s, the second stage of the pressing process (i.e. fast pressing) is completed. The semi-finished circuit board is cured by using a hot air oven, the first curing temperature is 160°C, the first curing time is 120min, and the curing of the semi-finished circuit board is completed. By heating the semi-finished circuit board at a mold bending angle of 40°, a heating time of 10s and a heating temperature of 180°C, a flexible circuit board with easy-to-bend reinforcement can be obtained. The reinforced area of ​​the flexible circuit board can be bent to any desired angle without rebounding, and the risk of delamination is low.

[0105] Specific production example 2:

[0106] The thermoplastic reinforcing film includes a thermoplastic material layer made of liquid crystal polymer. The thermoplastic reinforcing film and the flexible circuit substrate are pre-pressed at a pre-pressing temperature of 100°C and a pre-pressing pressure of 0.5MPa to obtain a reinforced circuit board to be pressed. The first stage of the pressing process (i.e., preheating) is completed at a preheating temperature of 120°C, a preheating pressure of 0MPa and a preheating time of 10s. The second stage of the pressing process (i.e., fast pressing) is completed at a fast pressing temperature of 180°C, a fast pressing pressure of 5MPa and a fast pressing time of 90s. The semi-finished circuit board is cured by hot air oven with a first curing temperature of 180°C and a first curing time of 90min. The semi-finished circuit board is heated at a mold bending angle of 60°, a heating time of 8s and a heating temperature of 150°C to obtain a flexible circuit board with easy-to-bend reinforcement, so that the reinforced area of ​​the flexible circuit board can be bent to any desired angle without rebounding, and the risk of delamination is low.

[0107] Specific production example three:

[0108] The thermoplastic reinforcing film includes a thermoplastic material layer made of polyetheretherketone. The pre-pressing temperature is 170°C and the pre-pressing pressure is 0.8MPa. The pre-pressing of the thermoplastic reinforcing film and the flexible circuit substrate is completed to obtain a reinforced circuit board to be pressed. The first stage of the pressing process (i.e., preheating) is completed according to the preheating temperature of 190°C, the preheating pressure of 0MPa and the preheating time of 15s. The second stage of the pressing process (i.e., fast pressing) is completed according to the fast pressing temperature of 210°C, the fast pressing pressure of 5MPa and the fast pressing time of 180s. The semi-finished circuit board is cured by a tunnel furnace, the second curing temperature is 200°C, and the second curing time is 20min. The heating of the semi-finished circuit board is completed according to the mold bending angle of 90°, the heating time of 30s and the heating temperature of 170°C, and a flexible circuit board with easy-to-bend reinforcement can be obtained, so that the reinforced area of ​​the flexible circuit board can be bent to any desired angle without rebounding, and the risk of delamination is low.

[0109] Embodiment 2

[0110] This embodiment provides a flexible circuit board with easy-to-bend reinforcement, which is manufactured by the manufacturing method of the flexible circuit board with easy-to-bend reinforcement described in the first embodiment.

[0111] This embodiment is based on a thermoplastic reinforcement film, which can achieve the effect that the reinforced area of ​​the flexible circuit board can be bent into any desired angle without rebounding, overcoming the problem that the reinforcement brought by traditional reinforcement materials is difficult to bend into shape or the angle is difficult to maintain after forming, resulting in the risk of delamination. The angle is easy to maintain after forming, the risk of delamination is low, and the yield is high.

[0112] The manufacturing method of the flexible circuit board with easy bend reinforcement in this embodiment is the same as the method steps described in the first embodiment. Therefore, for details not provided in this embodiment, please refer to the first embodiment and the second embodiment. Figure 1 to Figure 5 The specific description of this embodiment will not be repeated in detail.

[0113] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A method for manufacturing a flexible circuit board with easy bending and reinforcement, characterized in that: The method comprises: A thermoplastic reinforcement film and a flexible circuit substrate with completed circuit production are provided respectively; wherein the flexible circuit substrate is provided with a reinforcement area; Pre-pressing the thermoplastic reinforcement film onto the reinforcement area of ​​the flexible circuit substrate according to preset pre-pressing parameters to obtain a reinforced circuit board to be pressed; According to preset pressing parameters, the reinforced circuit board to be pressed is pressed to obtain a semi-finished circuit board; According to preset heating parameters, the semi-finished circuit board is heated using a preset mold, so that the pasting reinforcement area of ​​the semi-finished circuit board and the thermoplastic reinforcement film on the pasting reinforcement area form a bending structure together to obtain a target circuit board.

2. The method according to claim 1, characterized in that: The thermoplastic reinforcing film includes a thermoplastic material layer, and the thermoplastic material layer is made of any one thermoplastic material of polyphenylene sulfide, polyetheretherketone and liquid crystal polymer.

3. The method according to claim 1, characterized in that: The thermoplastic reinforcing film comprises a thermoplastic material layer and a back glue attached to one side of the thermoplastic material layer, and the thermoplastic material layer is made of any one thermoplastic material of polyphenylene sulfide, polyetheretherketone and liquid crystal polymer.

4. The method according to claim 3, characterized in that: When the thermoplastic reinforcement film includes a thermoplastic material layer and a backing adhesive bonded to one side of the thermoplastic material layer, the pre-pressing of the thermoplastic reinforcement film onto the reinforcement area of ​​the flexible circuit substrate according to a preset pre-pressing parameter includes: According to the preset pre-pressing parameters, the side of the thermoplastic reinforcement film having the back adhesive is pre-pressed onto the reinforcement area of ​​the flexible circuit substrate.

5. The production method according to claim 2 or 3, characterized in that: The glass transition temperature of the thermoplastic material layer is 60-210°C, and the melting point of the thermoplastic material layer is less than 350°C.

6. The method according to claim 1, characterized in that: The preset pre-pressing parameters include pre-pressing temperature and pre-pressing pressure.

7. The manufacturing method according to claim 6, characterized in that: The pre-pressing temperature ranges from 80 to 170° C.; and / or the pre-pressing pressure ranges from 0.4 to 0.8 MPa.

8. The manufacturing method according to claim 1, characterized in that: The preset heating parameters include heating temperature, heating time and mold bending angle.

9. The manufacturing method according to claim 8, characterized in that: The heating temperature ranges from 25 to 230° C.; and / or the heating time ranges from 5 to 30 seconds; and / or the mold bending angle ranges from 30 to 180°.

10. The manufacturing method according to claim 1, characterized in that: The preset pressing parameters include preheating parameters and fast pressing parameters; The method of laminating the reinforced circuit board to be laminated according to preset laminating parameters to obtain a semi-finished circuit board comprises: Preheating the reinforced circuit board to be pressed according to the preheating parameters; wherein the preheating parameters include preheating temperature, preheating pressure and preheating time; According to the fast pressing parameters, the preheated reinforced circuit board to be pressed is fast pressed to obtain the semi-finished circuit board; wherein the fast pressing parameters include fast pressing temperature, fast pressing pressure and fast pressing time.

11. The manufacturing method according to claim 10, characterized in that: The preheating temperature ranges from 80 to 90°C; and / or the preheating pressure is 0 MPa; and / or the preheating time ranges from 5 to 15 s; and / or the rapid pressing temperature ranges from 110 to 220°C; and / or the rapid pressing pressure ranges from 2 to 5 MPa; and / or the rapid pressing time ranges from 30 to 180 s.

12. The manufacturing method according to claim 1, characterized in that: Before the semi-finished circuit board is heated using a preset mold according to preset heating parameters, the method further includes: The semi-finished circuit board is cured using a hot air oven according to first preset curing parameters; wherein the first preset curing parameters include a first curing temperature and a first curing time.

13. The manufacturing method according to claim 12, characterized in that: The first curing temperature ranges from 150 to 250° C.; and / or the first curing time ranges from 30 to 120 min.

14. The manufacturing method according to claim 1, characterized in that: Before the semi-finished circuit board is heated using a preset mold according to preset heating parameters, the method further includes: The semi-finished circuit board is cured using a tunnel oven according to second preset curing parameters; wherein the second preset curing parameters include a second curing temperature and a second curing time.

15. The manufacturing method according to claim 14, characterized in that: The second curing temperature is in the range of 170-280° C.; and / or the second curing time is in the range of 10-20 min.

16. A flexible circuit board with easy-to-bend reinforcement, characterized in that: The method is produced according to any one of claims 1 to 15.

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