Flexible circuit board based on ultrasonic welding conduction

Abstract

The application discloses a flexible circuit board based on ultrasonic welding conduction, which comprises a main circuit layer, a power circuit layer, a first solder resist layer and a second solder resist layer, the main circuit layer is composed of a plurality of circuit units, a single circuit unit comprises a positive metal foil, a negative metal foil and a plurality of connecting metal foils, the opposite sides of the positive metal foil and the negative metal foil are respectively provided with welding ears, and two straight line circuits of the power circuit layer are respectively connected with two welding ears of each circuit unit through ultrasonic welding to realize conduction; the first solder resist layer is arranged on the outer side of the main circuit layer, and a plurality of pad windows are arranged on the first solder resist layer; and the second solder resist layer is arranged on the outer side of the power circuit layer. Through ultrasonic welding, the two welding ears of each circuit unit of the main circuit layer and the two straight line circuits of the power circuit layer are welded and conducted, the problem that different conductors are difficult to be welded and conducted can be overcome, the welding is firm, and the reliability of the welding can be fully ensured.

Description

Technical Field

[0001] This invention relates to the field of LED light strip technology, and more specifically to a flexible circuit board based on ultrasonic welding for conduction. Background Technology

[0002] In recent years, flexible printed circuit boards have been used more and more widely, especially in the manufacture of LED light strips. LED light strips generally require a long length, tens of meters or even hundreds of meters, thus requiring a certain current load capacity.

[0003] The front side of a continuous circuit board has several pads for soldering LED chips. To improve the current load capacity of the flexible printed circuit board, positive and negative lines are often set on the back side of the board, making the board a double-layer circuit board. Existing products have an insulating film with mesh openings between the two layers of lines. Soldering is used to conduct the circuits on both sides at predetermined positions on the continuous circuit board. Soldering conduction is not stable enough, and the yield rate cannot be guaranteed. The insulating film also requires a process of opening mesh openings, which also results in greater wear on the cutting tools.

[0004] Furthermore, the use of soldering for conduction has significant limitations on the conductors of the two layers of circuits. In existing products with soldering for conduction, the pad lines on the front side and the positive and negative lines on the back side mostly use copper-clad aluminum conductors. From the perspective of saving costs, the positive and negative lines on the back side can be replaced with cheaper aluminum foil conductors. However, it is difficult to solder the copper-clad aluminum conductor on the front side and the aluminum foil conductor on the back side. Summary of the Invention

[0005] The main objective of this invention is to provide a flexible circuit board based on ultrasonic welding to solve the problems of poor conductivity of soldering in existing double-layer circuit board products due to the mesh structure of the insulating film and the difficulty in welding the positive and negative circuits using different conductors.

[0006] To address the aforementioned technical problems, this invention proposes a flexible circuit board based on ultrasonic welding conductivity, comprising: The system comprises a main circuit layer and a power circuit layer. The main circuit layer consists of several circuit units. Each circuit unit includes a positive metal foil, a negative metal foil, and multiple connecting metal foils disposed between the positive and negative metal foils for connecting components in series. The opposite sides of the positive and negative metal foils are respectively provided with welding ears. The power circuit layer consists of two parallel straight lines. The two straight lines of the power circuit layer are connected to the two welding ears of each circuit unit by ultrasonic welding to achieve conductivity. A first solder mask layer is disposed on the outside of the main circuit layer. The first solder mask layer has a plurality of evenly distributed solder pad windows. The position where the main circuit layer is connected to the component is exposed through the solder pad windows. A second solder mask layer is disposed on the outside of the power line layer.

[0007] Furthermore, it also includes an insulating layer disposed between the main circuit layer and the power circuit layer, wherein the two welding lugs of a single circuit unit are connected to the two straight lines of the power circuit layer by ultrasonic welding through the insulating layer.

[0008] Furthermore, a welding hole is provided on the insulating layer at a preset position for ultrasonic welding.

[0009] Furthermore, the main circuit layer is made of any one of copper, aluminum, copper-aluminum alloy, foil, or nickel.

[0010] Furthermore, the power line layer is made of any one of copper, aluminum, copper-aluminum alloy, foil, or nickel.

[0011] Furthermore, the two parallel straight lines of the power line layer are flat lines or round lines.

[0012] Furthermore, the insulating layer is a PET film or a PI film.

[0013] Compared with the prior art, the advantages of the present invention are as follows: This invention uses ultrasonic welding to weld the two welding lugs of each circuit unit in the main circuit layer to the two straight lines in the power circuit layer for conduction. Furthermore, even in structures with an insulating layer, ultrasonic welding can directly penetrate the insulating layer to achieve conduction, overcoming the problem of difficulty in welding different conductors to conduction. The weld is strong and can fully guarantee the reliability of the weld. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a three-dimensional structural diagram of the present invention. Figure 2 for Figure 1 Explosion diagram, Figure 3 A schematic diagram of the structure of the present invention after removing the first solder mask layer 3. Figure 4 This is an exploded view of the structure of the six embodiments with insulating layers. The attached figures are labeled as follows: Main circuit layer 1, positive electrode metal foil 11, negative electrode metal foil 12, connecting metal foil 13, solder lug 14, power circuit layer 2, first solder resist layer 3, solder pad window 4, second solder resist layer 5, insulating layer 6. Detailed Implementation

[0016] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be described in detail below with reference to the accompanying drawings. The description in this part is only exemplary and explanatory, and should not be used to limit the scope of protection of the present invention in any way.

[0017] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0018] It should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use. They are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0019] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0020] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0021] Please refer to Figures 1 to 4 This invention provides a flexible circuit board based on ultrasonic welding for conductive circuitry, comprising a main circuit layer 1, a power circuit layer 2, a first solder resist layer 3, and a second solder resist layer 5, wherein: The main circuit layer 1 is formed by etching or die cutting and is used to solder LEDs and other electronic components. Under the premise of meeting the current carrying requirements, its material can be any one of copper, aluminum, copper-aluminum alloy, foil, or nickel. The thickness is determined according to the actual current carrying capacity and cost control requirements. like Figure 2 The main circuit layer 1 is composed of several circuit units. Each circuit unit includes a positive metal foil 11, a negative metal foil 12, and multiple connecting metal foils 13 disposed between the positive metal foil 11 and the negative metal foil 12 for realizing the series connection of components. The opposite sides of the positive metal foil 11 and the negative metal foil 12 are respectively provided with welding ears 14. The two welding ears 14 of each circuit unit are connected to the power circuit layer 2 by ultrasonic welding. The power line layer 2 consists of two parallel straight lines, which can be flat or round wires, used for external power supply. It is manufactured using a back-wire process and is made using the applicant's existing equipment. The patent application with publication number CN216017456U describes this equipment. After several flat copper wires are straightened by a wire-arranging roller, they are adjusted to the same plane by a perforated baffle. The back wires of the double-sided board are then laminated with an adhesive insulating film to form the required power line layer. The adhesive insulating film here forms the second solder resist layer 5, located on the outside of the power line layer 2. Under the premise of meeting the current carrying requirements, its material can be any one of copper, aluminum, copper-aluminum alloy, foil, or nickel. Because the power line layer 2 is to be connected to an external power supply, its current carrying requirements are relatively high. Therefore, the thickness of the power line layer 2 is greater than that of the main line layer 1. The two straight lines of the power line layer 2 are connected to the two welding lugs 14 of each line unit by ultrasonic welding to achieve conductivity. The first solder mask layer 3 is disposed on the outside of the main circuit layer 1. Several evenly distributed solder pad windows 4 are provided on the first solder mask layer 3. Part of the main circuit layer 1 (the position where the main circuit layer 1 is connected to the components) is exposed in the solder pad windows 4 to form solder pads for soldering components such as LED lights.

[0022] As another implementation, an insulating layer 6 can be provided between the main circuit layer 1 and the power circuit layer 2, such as... Figure 4The main circuit layer 1 and the power circuit layer 2 can be directly connected by ultrasonic welding through the insulation layer 6. Ultrasonic welding is a relatively mature technology that can directly weld through the insulation layer 6 to achieve the connection between the main circuit layer 1 and the power circuit layer 2. In order to ensure better welding effect, multiple welding holes are opened on the insulation layer 6 at the preset welding position. Compared with the original mesh insulation film, there is no need to open the mesh or fewer holes, which greatly reduces the consumption of the hole opening tool. Moreover, the stability of ultrasonic welding is very reliable. It also overcomes the technical problem of difficult welding between the main circuit layer 1 and the power circuit layer 2 using different conductors. The insulation layer 6 of the present invention is made of PET film or PI film material.

[0023] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A flexible circuit board based on ultrasonic welding conductivity, characterized in that, include: The main circuit layer (1) and the power circuit layer (2) are composed of several circuit units. Each circuit unit includes a positive metal foil (11), a negative metal foil (12) and multiple connecting metal foils (13) disposed between the positive metal foil (11) and the negative metal foil (12) for realizing the series connection of components. The positive metal foil (11) and the negative metal foil (12) are respectively provided with welding ears (14). The power circuit layer (2) consists of two parallel straight lines. The two straight lines of the power circuit layer (2) are respectively connected to the two welding ears (14) of each circuit unit by ultrasonic welding. A first solder mask layer (3) is provided on the outside of the main circuit layer (1). The first solder mask layer (3) has a plurality of evenly distributed pad windows (4). The position where the main circuit layer (1) is connected to the component is exposed through the pad windows (4). The second solder mask layer (5) is disposed on the outside of the power line layer (2).

2. The flexible circuit board based on ultrasonic welding conductivity according to claim 1, characterized in that, It also includes an insulation layer (6) disposed between the main circuit layer (1) and the power circuit layer (2), wherein the two welding lugs (14) of a single circuit unit are connected to the two straight lines of the power circuit layer (2) by ultrasonic welding through the insulation layer (6).

3. The flexible circuit board based on ultrasonic welding conductivity according to claim 2, characterized in that, A welding hole is provided on the insulating layer (6) at the preset position for ultrasonic welding.

4. The flexible circuit board based on ultrasonic welding conductivity according to claim 1, characterized in that, The material of the main circuit layer (1) is any one of copper, aluminum, copper-aluminum alloy, foil, and nickel.

5. The flexible circuit board based on ultrasonic welding conductivity according to claim 2, characterized in that, The power line layer (2) is made of any one of copper, aluminum, copper-aluminum alloy, foil, or nickel.

6. The flexible circuit board based on ultrasonic welding conductivity according to claim 1, characterized in that: The two parallel straight lines of the power line layer (2) are flat lines or round lines.

7. The flexible circuit board based on ultrasonic welding conductivity according to claim 2, characterized in that: The insulating layer (6) is a PET film or a PI film.

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