A flexible circuit board with multiple reinforcement structures capable of three-dimensional installation and a manufacturing method thereof

Abstract

The present invention provides a flexible circuit board with multiple reinforcement structures that can be installed three-dimensionally and a manufacturing method, characterized in that: the flexible circuit board is formed by directly bonding polyimide and rolled copper foil; a part of the flexible circuit board is a rigid part, and a part of the flexible part is a flexible part that can be bent or curved; the rigid part is a reinforcement part, which is bonded to the area with circuit wiring of the flexible circuit board with a thermosetting adhesive layer. The present invention utilizes the flexibility and rigidity of the combination of the flexible circuit board and the reinforcement material to perform vertical installation in the housing of an electronic product with a complex structure, thereby reducing the volume of the electronic product and saving some connecting wires.

Description

Technical Field

[0001] The invention relates to a flexible circuit board, in particular to a flexible circuit board with multiple reinforcement structures capable of three-dimensional installation. Background Art

[0002] Some electronic products have special product structures, such as some payment terminals, which require the installation of circuit boards in limited spaces with complex structures. Flexible circuit boards are the best choice. The main feature of flexible circuit boards is their flexibility. Reinforcement materials are added to certain parts, which have a certain degree of hardness and rigidity. Components can be mounted and connected. If the flexibility and rigidity are used to perform three-dimensional installation on electronic products with complex shapes and structures, the volume of these electronic products will be reduced and some connecting wires will be saved. Summary of the invention

[0003] The present invention provides a flexible circuit board with multiple reinforcement structures that can be installed three-dimensionally, and its purpose is to solve the shortcomings of the prior art. By utilizing the combined flexibility and rigidity of the flexible circuit board and the reinforcement material, the flexible circuit board can be installed vertically in the casing of an electronic product with a complex structure, thereby reducing the volume of the electronic product and saving some connecting wires.

[0004] The technical solution adopted by the present invention to solve the technical problem is:

[0005] A flexible circuit board with multiple reinforcement structures capable of three-dimensional installation, characterized in that:

[0006] The flexible circuit board is formed by directly bonding polyimide and rolled copper foil;

[0007] A part of the flexible circuit board is a rigid part, and another part is a flexible part that can be bent or curved;

[0008] The rigid part is a reinforcement part, which is bonded to the area with line wiring of the flexible circuit board by a thermosetting adhesive layer.

[0009] The LED lamp mounting area and low-power device area are reinforced with aluminum alloy sheets, the IC and resistor and capacitor mounting areas are reinforced with FR4, and the connectors are reinforced with steel sheets.

[0010] After the flexible part is bent or curved, the reinforcement is installed on a horizontal surface, a vertical surface or an inclined surface.

[0011] A method for manufacturing a flexible circuit board with multiple reinforcement structures capable of three-dimensional installation, characterized in that:

[0012] Step 1:

[0013] After determining the circuit, reinforcement materials and shape of the flexible circuit board, the layout is carried out by panelization;

[0014] Step 2:

[0015] According to the layout of the panel, drilling, black hole copper plating, exposure, etching, film lamination, lamination, and electrical testing are carried out to make a semi-finished flexible circuit board. Then, a mold with designed slots and shapes is used for punching to obtain a semi-finished flexible circuit board with slots and shapes.

[0016] The slots designed around the single-piece shape of the flexible circuit board are hollowed out after punching, and the connection points support each product;

[0017] Step 3:

[0018] Making reinforcement, the reinforcement is glued to the micro-mucosal membrane with a thermosetting adhesive layer;

[0019] Step 4:

[0020] On the basis of completing step 2, the roll-shaped reinforcement produced in step 3 is installed on the reinforcement machine, and the adhesive surface of the reinforcement is respectively bonded to the corresponding bonding positions of the flexible circuit board. During bonding, the thermosetting adhesive on the reinforcement surface is bonded to the flexible circuit board, and then laminated and baked. The reinforcement bonding process is completed, and various finished panel products are obtained on the flexible circuit board.

[0021] The present invention is beneficial in that:

[0022] The present invention is suitable for flexible circuit boards required by some electronic products with small volume and complex structure. According to the needs of the structure and function of the electronic products, the production process adopts a paneling method. In some parts of the flexible circuit board, different materials are reinforced by etching, CNC milling and other different processing methods to obtain a single reinforcement, which is pasted on a roll-type micro-mucosa to obtain a roll reinforcement. The reinforcement materials of different types, shapes and thicknesses are pasted on the corresponding positions of the flexible circuit board by an automatic pasting and reinforcement machine, and are pressed and baked at one time to obtain a flexible circuit board finished product with soft parts and hard parts. Some parts have a certain hardness and rigidity, and devices can be mounted and easily installed and fixed. The softness of some parts can be bent or curved. Some rigid parts of the flexible circuit board can be installed on the plane of the casing. By bending or bending the flexible part, some rigid parts can be installed on the facade or inclined surface of the casing, and some can be plugged in at any angle. The three-dimensional installation of the flexible circuit board is realized. The volume of the electronic product is reduced and some connecting wires are saved, making the product neat and beautiful. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0024] Figure 1 This is the appearance structure diagram of the flexible circuit board;

[0025] Figure 2 It is the appearance diagram of the glue layer;

[0026] Figure 3 For various reinforcement appearance drawings;

[0027] Figure 4 This is the finished product structure diagram;

[0028] Figure 5 This is a schematic diagram of a three-dimensional installation;

[0029] Figure 6 Design drawings for typography;

[0030] Figure 7 Design drawings of positioning holes and outer slots after typesetting;

[0031] Figure 8 To fix the reinforcement position and the reinforcement diagram after the panels are assembled. DETAILED DESCRIPTION

[0032] In order to more clearly illustrate the technical solution of the present invention, the following will briefly introduce the drawings required for the description. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other embodiments can be obtained based on these drawings without creative work. In order to facilitate the understanding of the present invention, the present invention is described in more detail below in combination with the drawings and specific embodiments.

[0033] It should be noted that when an element is described as being "fixed to" another element, it may be directly on the other element, or one or more centered elements may exist therebetween. When an element is described as being "connected" to another element, it may be directly connected to the other element, or one or more centered elements may exist therebetween. The terms "upper", "lower", "inner", "outer", "bottom", etc. used in this specification indicate an orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", "third", etc., etc. are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0034] According to the product structure and functional requirements, flexible circuit boards use glue-free rolled copper. This material uses polyimide (PI for short) to directly bond with rolled copper foil (no need for a layer of glue between PI and copper foil), so it is more resistant to bending and folding, and the copper foil is not easy to crack.

[0035] Structural design such as Figure 1 As shown, the flexible circuit board has an outer shape 1 and some mounting holes AK, and the circuit wiring is performed according to the outer shape and the location of the components.

[0036] Figure 2 It is a layer of thermosetting adhesive layer between the flexible circuit board and the reinforcement, used to reinforce the adhesion with the flexible circuit board; the shapes and sizes of the adhesive layers 20, 30, 40, 50 and 60 are respectively Figure 3 The reinforcement parts 2, 3, 4 and 5 are the same, and corresponding mounting holes AK are provided on the adhesive layer.

[0037] Figure 3 It is the shape of various reinforcing materials. According to the functional requirements, different reinforcing materials are selected. Figure 1 Based on the design, the reinforcement shape of each part is designed. Reinforcement part 2 is the LED lamp mounting area, and reinforcement part 3 is the low-power device area. 0.5mm thick aluminum alloy sheets with certain hardness and good heat dissipation are used for reinforcement. Reinforcement part 4 and reinforcement part 5 are IC and resistor and capacitor mounting areas, and 0.4mm thick FR4 is used for reinforcement. Reinforcement part 6 is the connector reinforced with 0.2 steel sheet.

[0038] Figure 4 It is a monolithic finished product structure. The reinforcements of various parts are bonded to the flexible circuit board with a thermosetting adhesive layer. The reinforcement part 2 made of aluminum alloy is installed horizontally on the casing of the electronic product. After the flexible part 101 of the flexible circuit board is bent, the reinforcement part 3 made of aluminum alloy is installed vertically on the casing of the electronic product. After the flexible part 102 of the flexible circuit board is bent, the reinforcement part 4 made of FR4 is installed horizontally on the casing of the electronic product. After the flexible part 103 of the flexible circuit board is bent at a certain angle, the reinforcement part 5 made of FR4 is leaned against the casing of the electronic product in the oblique direction. The flexible part 104 of the flexible circuit board can be flexibly bent at a certain angle, and the connector socket of the reinforcement part 6 made of steel sheet material is connected to other circuits.

[0039] Figure 5The figure is a three-dimensional installation diagram. The reinforcement part 2 of the single-piece finished flexible circuit board after the components are mounted is first installed on the plane inside the housing, and fixed to the housing through the mounting hole AK; then the flexible part 101 is bent, and the reinforcement part 3 of the flexible circuit board is installed on the vertical surface (vertical surface) inside the housing, and fixed to the housing through the mounting hole AK; then the flexible part 102 is bent, and the reinforcement part 4 of the flexible circuit board is installed on the plane inside the housing, and fixed to the housing through the mounting hole AK; then the reinforcement part 6 of the flexible circuit board is connected to other circuit boards through connectors. Since the flexible part 103 and the flexible part 104 are bendable, it is easy to take the flexible part 103, the reinforcement part 5, the flexible part 104, and the reinforcement part 6 as a whole, and plug them with other circuit boards. After plugging, 103 and the reinforcement part 5 are placed on the inclined surface inside the housing, and then the flexible part 104 is bent downward so that the flexible part 104 and the reinforcement part 6 face downward. Through the above installation, the entire flexible circuit board is installed in a complex casing, making the interior of the casing neat and clear, reducing some connecting wires, reducing costs, and being very suitable for use in small-volume products.

[0040] Production part:

[0041] Step 1:

[0042] After determining the circuit, reinforcement materials and shape of the flexible circuit board, since these products are small in size, they need to be laid out according to the size and shape of the single piece and produced in a panelized manner.

[0043] Figure 6 To layout the drawing, first, according to the shape of the flexible circuit board, in order to improve the material utilization rate, the flexible circuit board 1-1 and the flexible circuit board 1'-1' are reversed and spliced, and then the layout is performed according to the width of the flexible circuit board substrate of 250mm, such as Figure 6 As shown, from flexible circuit board 1-1 and flexible circuit board 1'-1' to flexible circuit board 1-8 and flexible circuit board 1'-8', there are 16 pieces in one line. Considering the production suitability, flexible circuit board 1-9 and flexible circuit board 1'-9' to flexible circuit board 1-16 and flexible circuit board 1'-16' are arranged into two lines of 32 pieces as one panel.

[0044] Step 2:

[0045] According to production needs, positioning holes DK and frames need to be added after layout. At the same time, according to the needs of part support, some slots of different shapes are designed around the single-piece shape of the flexible circuit board, such as C 1 Small slot and C 2 Large slots, and design 0.8-1.0mm connection points between each slot according to support needs, such as L 1 , L 2 , L 3For a small connection point of 0.8 mm, L 4 The connection point is 1.0mm.

[0046] According to the layout of the panel, drilling, black hole copper plating, exposure, etching, film lamination, lamination, and electrical testing are carried out to make a semi-finished flexible circuit board. Then, a mold with designed slots and shapes is used for punching to obtain a semi-finished flexible circuit board with slots and shapes.

[0047] These slots are hollowed out after punching, leaving only the connection points to support each product, ensuring the integrity of the panel. Figure 7 shown.

[0048] Step 3:

[0049] Various reinforcements are made, such as aluminum alloy and steel sheet reinforcements, which are obtained by sticking dry film or coating photosensitive adhesive in sheet form, and then exposing, developing, etching and stripping the film according to the designed outer dimensions and aperture.

[0050] FR4 epoxy glass fiber cloth reinforcement is obtained by CNC milling according to the designed outer dimensions and aperture.

[0051] In order to reinforce the various processed single pieces and use the automatic reinforcement machine to stick them together, the reinforcement stickers must be glued to the tape first:

[0052] The semi-cured thermosetting adhesive is applied to the micro-mucosa in a roll-to-roll manner. According to the design layout, the roll-type knife die is used for kiss cutting, and then the waste material is torn off, leaving the adhesive of a single reinforcement shape on the micro-mucosa, so as to obtain a roll of semi-cured thermosetting adhesive with a specified shape on the micro-mucosa. Then, the corresponding single reinforcement is manually aligned according to the shape, and the reinforcement is pasted on the position of the corresponding shape, pasted and moved again, until the whole roll is pasted. The reinforcement can also be folded according to the shape direction, and another type of reinforcement machine is used to paste the reinforcement on the corresponding position of the roll. Then, the strips are divided into single reinforcements of the same shape to form a narrower strip of reinforcement rolls.

[0053] Step 4:

[0054] On the basis of completing step 2, the tape-shaped reinforcement produced in step 3 is installed on the reinforcement machine, and the automatic reinforcement machine identifies the bonding position according to the shape, bonding position 2', bonding position 3', bonding position 4', bonding position 5', bonding position 6', and accurately bonds the various reinforced adhesive surfaces to the corresponding bonding positions 2', bonding position 3', bonding position 4', bonding position 5', and bonding position 6' of the flexible circuit board. Since the reinforcement machine platform has a temperature, the thermosetting adhesive of the reinforcement surface can be bonded to the flexible circuit board during bonding, and then one-time lamination and baking are performed to complete the reinforcement bonding process (for example: the lamination method of reinforcements of different thicknesses of flexible circuit boards, the method of 202310052668.X), such as Figure 8 As shown, the flexible circuit board is provided with various reinforcements at the positions of reinforcement part 2, reinforcement part 3, reinforcement part 4, reinforcement part 5, and reinforcement part 6.

[0055] The finished flexible circuit board is assembled, and after the whole board is mounted with components and reflowed, the connection points are torn off (because the polyimide of the flexible circuit board is very thin, the connection points are very small, and the connection points can be easily torn off by hand), and a complete single-piece flexible circuit board that can be three-dimensionally installed is obtained. Figure 4 shown.

[0056] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the embodiments can be referred to each other. The above description of the disclosed embodiments enables professionals and technicians in this field to implement or use the present invention. Various modifications to these embodiments will be obvious to professionals and technicians in this field, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown in this article, but will comply with the widest range consistent with the principles and novel features disclosed herein.

Claims

1. A flexible circuit board with multiple reinforcement structures that can be installed three-dimensionally, characterized in that: The flexible circuit board is formed by directly bonding polyimide and rolled copper foil; A flexible circuit board has a rigid part and a flexible part that can be bent or curved. The rigid part is a reinforcement part, which is bonded to the area with line wiring of the flexible circuit board by a thermosetting adhesive layer.

2. A three-dimensionally mountable flexible circuit board with multiple reinforcement structures as claimed in claim 1, characterized in that: The LED lamp mounting area and low-power device area are reinforced with aluminum alloy sheets, the IC and resistor and capacitor mounting areas are reinforced with FR4, and the connectors are reinforced with steel sheets.

3. A three-dimensionally mountable flexible circuit board with multiple reinforcement structures as claimed in claim 1, characterized in that: After the flexible part is bent or curved, the reinforcement is installed on a horizontal surface, a vertical surface or an inclined surface.

4. The method for manufacturing a flexible circuit board with multiple reinforcement structures capable of three-dimensional installation as claimed in claim 1, characterized in that: Step 1: After determining the circuit, reinforcement materials and shape of the flexible circuit board, the layout is carried out by panelization; Step 2: According to the layout of the panel, drilling, black hole copper plating, exposure, etching, film lamination, lamination, and electrical testing are carried out to make a semi-finished flexible circuit board. Then, a mold with designed slots and shapes is used for punching to obtain a semi-finished flexible circuit board with slots and shapes. The slots designed around the single-piece shape of the flexible circuit board are hollowed out after punching, and the connection points support each product; Step 3: Making reinforcement, the reinforcement is glued to the micro-mucosal membrane with a thermosetting adhesive layer; Step 4: On the basis of completing step 2, the roll-shaped reinforcement produced in step 3 is installed on the reinforcement machine, and the adhesive surface of the reinforcement is respectively bonded to the corresponding bonding positions of the flexible circuit board. During bonding, the thermosetting adhesive on the reinforcement surface is bonded to the flexible circuit board, and then laminated and baked. The reinforcement bonding process is completed, and various finished panel products are obtained on the flexible circuit board.

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