A bimetallic circuit board and an LED lamp strip using the same
By employing a first and second circuit layer design on the circuit board, and utilizing a combination of inexpensive conductor materials and materials with good solderability, the problems of material cost and manufacturing process complexity in the prior art are solved, achieving the effects of cost reduction and process simplification.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- IHOME LIGHTING CO LTD OF ZHONGSHAN
- Filing Date
- 2025-05-21
- Publication Date
- 2026-06-26
AI Technical Summary
While existing copper-aluminum bimetallic circuit layers have reduced some material costs, the increased complexity of the manufacturing process means that the overall cost reduction is not significant.
The design employs a first circuit layer and a second circuit layer. The first circuit layer is made of inexpensive conductive material, while the second circuit layer is made of a material with good solderability. They are bonded together by upper and lower insulating layers. The second circuit layer is exposed in the pad area, and the two are in direct electrical contact or coated with conductive adhesive to improve reliability.
This approach reduces material costs, simplifies manufacturing processes, improves welding performance, and ensures that the production process is environmentally friendly and efficient.
Smart Images
Figure CN224418998U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a circuit board, specifically a bimetallic circuit board; this utility model also relates to an LED lamp, specifically an LED light strip using a bimetallic circuit board. Background Technology
[0002] Existing LED light strip circuit boards include a circuit layer, a lower insulating layer on the back of the circuit layer, and an upper insulating layer on the front of the circuit layer. The upper insulating layer has pads exposing portions of the circuit layer at locations where electronic components need to be soldered. LED beads or other electronic components can be soldered onto the circuit layer through these pads. The circuit layer is generally made of copper foil because copper adheres well to solder paste used for electronic components. However, copper is expensive. To reduce costs, the industry has developed copper-aluminum bimetallic circuit layers. These copper-aluminum bimetallic circuit layers have two structures: one involves completely wrapping aluminum foil with copper foil, then rolling it into copper-aluminum foil, and then creating circuit patterns on the copper-aluminum foil, forming a circuit layer with an aluminum core and a copper outer layer; the other involves first creating the circuit layer pattern using aluminum foil, then plating copper on the surface of the aluminum circuit layer pattern, forming a circuit layer with an aluminum bottom layer and a copper top layer. In this case, the exposed material in the pad area is copper, which can be used to solder electronic components, while the inner core or bottom circuit layer is made of cheaper aluminum, reducing the material cost of the circuit layer. While existing copper-aluminum circuit layers reduce some material costs, they increase the complexity of the manufacturing process, resulting in a less significant overall cost reduction. Utility Model Content
[0003] Therefore, it is necessary to provide a bimetallic circuit board that can reduce material costs and simplify the manufacturing process to address the existing technical problems.
[0004] To address the problems of existing technologies, this utility model discloses a bimetallic circuit board, comprising a circuit layer, a lower insulating layer disposed on the back of the circuit layer, and an upper insulating layer disposed on the front of the circuit layer. The circuit layer includes a main circuit and a connection circuit. The upper insulating layer has pads at the locations where electronic components need to be soldered. The circuit layer includes a first circuit layer and a second circuit layer. The second circuit layer is made of a conductor that has good adhesion to solder materials for electronic components. The first circuit layer is made of a conductor that is cheaper than the second circuit layer. The second circuit layer covers the pad area and is at least partially directly attached to the first circuit layer.
[0005] The beneficial effects of this utility model are as follows: Since the first circuit layer and the second circuit layer are prefabricated and pressed between the upper insulating layer and the insulating layer, and the second circuit layer is exposed at the pad position, this utility model can reduce material costs and simplify the manufacturing process, making it more environmentally friendly.
[0006] As a further improvement of this utility model: the first circuit layer forms the main circuit and the connection circuit, and the second circuit layer forms the same main circuit and connection circuit as the first circuit layer, with the second circuit layer completely overlapping and attached to the first circuit layer. The first circuit layer only forms the main circuit, and the second circuit layer only forms the connection circuit. The second circuit layer has connection portions at locations requiring electrical connection with the first circuit layer, and these connection portions are attached to the first circuit layer. The first circuit layer forms the main circuit and the connection circuit, and the second circuit layer only covers the pad area, directly attached to the first circuit layer. The attachment areas of the first and second circuit layers are coated with conductive adhesive. The material of the first circuit layer is aluminum, and the material of the second circuit layer is copper.
[0007] This utility model also discloses an LED light strip using the above-mentioned circuit board, including the circuit board and LED beads, wherein the lamp base of the LED beads is soldered to the second circuit layer through the solder pad. Attached Figure Description
[0008] Figure 1.1 This is a schematic diagram of the structure of the first circuit layer in Embodiment 1 of this utility model.
[0009] Figure 1.2 This is a schematic diagram of the structure of the second circuit layer in Embodiment 1 of this utility model.
[0010] Figure 1.3 This is a schematic diagram of the structure after the first circuit layer and the second circuit layer of Embodiment 1 of this utility model are bonded together.
[0011] Figure 1.4 for Figure 1.3 A schematic diagram of the structure of section AA.
[0012] Figure 2.1 This is a schematic diagram of the structure of the first circuit layer in Embodiment 2 of this utility model.
[0013] Figure 2.2 This is a schematic diagram of the structure of the second circuit layer in Embodiment 2 of this utility model.
[0014] Figure 2.3 This is a schematic diagram of the structure after the first circuit layer and the second circuit layer of Embodiment 2 of this utility model are bonded together.
[0015] Figure 2.4 for Figure 2.3 A schematic diagram of the structure of the BB section.
[0016] Figure 3.1 This is a schematic diagram of the structure of the first circuit layer in Embodiment 3 of this utility model.
[0017] Figure 3.2This is a schematic diagram of the structure of the second circuit layer in Embodiment 3 of this utility model.
[0018] Figure 3.3 This is a schematic diagram of the structure after the first circuit layer and the second circuit layer are bonded together in Embodiment 3 of this utility model.
[0019] Figure 3.4 for Figure 3.3 A schematic diagram of the CC section.
[0020] Figure 4 This is a schematic diagram of the manufacturing method of Embodiment 1 of this utility model.
[0021] Figure 5 This is a schematic diagram of the manufacturing method of Embodiment 2 of this utility model.
[0022] Figure 6 This is one of the schematic diagrams of the manufacturing method of Embodiment 3 of this utility model.
[0023] Figure 7 This is the second schematic diagram of the manufacturing method of Embodiment 3 of this utility model.
[0024] Figure 8 This is a schematic diagram of the planar structure of an LED light strip using the circuit board of this utility model.
[0025] Figure 9 for Figure 8 A schematic diagram of the DD section. Detailed Implementation
[0026] To further understand the features, technical means, specific purposes, and functions of this utility model, a more detailed description of the utility model is provided below in conjunction with the accompanying drawings and specific embodiments. The descriptions of the positions of the components themselves and between components in this application (including but not limited to upper, lower, inner, outer, left, right, top, and bottom, etc.) are relative relationships with reference only to the positions of the relevant components shown in the accompanying drawings of this application, and do not represent an absolute limitation on the scope of protection of this utility model. Those skilled in the art should understand that if the view orientation of the components changes, the above description of the positional relationships may change, but the essential mechanical structure remains unchanged.
[0027] Example 1, Reference Figures 1.1 to 1.4A bimetallic circuit board includes a circuit layer 1, a lower insulating layer 2 disposed on the back of the circuit layer 1, and an upper insulating layer 3 disposed on the front of the circuit layer. The lower insulating layer 2 is made of PI film or PET film, and the upper insulating layer 3 is made of PI film, PET film, or solder resist ink. Pads 30 are provided on the upper insulating layer 3 at locations where electronic components need to be soldered, exposing partial circuit layers. The circuit layer 1, in terms of material, includes a first circuit layer 11 made of aluminum foil and a second circuit layer 12 made of copper foil; in terms of function, it includes a main circuit 1a and a connecting circuit 1b. The main circuit 1a is used to conduct the total current of the circuit board, and the connecting circuit 1b is used to connect the main circuit 1a and each pad 31, i.e., each electronic component. The first circuit layer 11 is adhered to the lower insulating layer 2 and includes the main circuit 1a and the connecting circuit 1b. The second circuit layer 12 also includes the same main circuit 1a and connecting circuit 1b as the first circuit layer 11. The second circuit layer 12 is directly attached to the first circuit layer 11, completely overlapping it. The upper insulating layer 3 is adhered to the second circuit layer 12. Thus, the circuit layer exposed in the pads 30 of the upper insulating layer 3 is the second circuit layer 12. This direct attachment means that there is no insulating barrier between the two circuit layers; they make direct electrical contact through the adhesive force of the upper and lower insulating layers. As a more preferred solution, conductive adhesive can also be applied between them for bonding. The first circuit layer 11 can also be made of iron or other materials cheaper than the second conductive layer 12, and the second circuit layer 12 can be made of gold or silver, materials that have good adhesion to solder paste for electronic components.
[0028] The beneficial effects of this utility model are as follows: since the second circuit layer is exposed in the pad area and is made of materials such as copper that have good adhesion to solder paste for electronic components, it can provide good soldering performance. The first conductive layer is made of a conductor that is cheaper than the second conductive layer, which can reduce the material cost of the circuit layer. At the same time, since the first circuit layer and the second circuit layer are directly attached by the adhesion of the upper and lower insulating layers, the manufacturing process is simple and environmentally friendly compared with the prior art.
[0029] Example 2, Reference Figures 2.1 to 2.4 As a further improvement to Embodiment 1, the first circuit layer 11 includes only the main circuit 1a, and the second circuit layer 12 includes only the connecting circuit 1b. The connecting circuit 1b has a connecting portion 1c that overlaps with the main circuit 1a at the point where electrical connection with the main circuit 1a is required. The connecting portion 1c is directly attached to the main circuit 1a. Since the main circuit 1a is used to transmit a large total current, a large cross-section, i.e., a thicker thickness, is usually required to reduce resistance. Using only inexpensive aluminum to manufacture the main circuit 1a further reduces material costs.
[0030] Example 3, Reference Figures 3.1 to 3.4As a further improvement of this utility model, the first circuit layer 11 includes a main circuit 1a and a connection circuit 1b, and the second circuit layer 12 only covers the pad 30 area at the bottom of the upper insulating layer. In this way, the main circuit 1a and the connection circuit 1b are made of lower-cost aluminum, and only the pad 30 area uses higher-cost copper. The second circuit layer 12 uses the least amount of material, which can maximize the saving of material costs.
[0031] The manufacturing method of Example 1 is referred to Figures 1.1 to 1.4 as well as Figure 4 A method for manufacturing a bimetallic circuit board: First, a first circuit layer 11 and a second circuit layer 12 are fabricated. The first circuit layer 11 uses aluminum foil with a lower insulating layer 2 attached as a first substrate 110. A first roller cutter A1 is used to die-cut the main circuit 1a and connecting circuit 1b patterns onto the aluminum foil of the first substrate 110. The cutting waste is recycled through a first recycling bin A10. The second circuit layer 12 uses copper foil with an upper insulating layer 3 attached as a second substrate 120. A second roller cutter A2 is used to die-cut solder pads 30 onto the upper insulating layer 3 of the second substrate 120. The die-cutting waste is recycled through a second recycling bin A20. Then, a third roller cutter A3 is used to die-cut the same main circuit 1a and connecting circuit 1b patterns as the first circuit layer 11 onto the copper foil of the second substrate 120. The die-cutting waste is recycled through a third recycling bin A30. In the second step, the aluminum foil of the first circuit layer 11, made in the first step, is placed upwards and the copper foil of the second circuit layer 12 is placed downwards. The layers are then pressed together in a hot press R1. Under the action of hot pressing, the upper and lower insulating layers fill the areas cut out from the circuit pattern and adhere to each other, allowing the first circuit layer 11 and the second circuit layer 12 to be directly attached and electrically contacted. To improve the reliability of the electrical contact between the first circuit layer 11 and the second circuit layer 12, conductive adhesive can be applied before die-cutting the two circuit layers. This way, when the two insulating layers are bonded, the two circuit layers are bonded together through the conductive adhesive, resulting in a more reliable electrical connection. Of course, the first circuit layer 11 and the second circuit layer 12 can also form the circuit pattern through etching. This invention prefers the die-cutting method, which offers higher production efficiency and a more environmentally friendly production process.
[0032] The manufacturing method of Example 2 is referred to Figures 2.1 to 2.4 as well as Figure 5A method for manufacturing a bimetallic circuit board: First, a first circuit layer 11 and a second circuit layer 12 are fabricated. The first circuit layer 11 uses aluminum strips 111 arranged at certain intervals. The aluminum strips 111 are then adhered to a lower insulating layer 2 using a first hot press R1. The aluminum strips 111 constitute the main circuit 1a of the first circuit layer. The second circuit layer 12 uses copper foil with an adhered upper insulating layer 3 as a second substrate 120. A second roller cutter A2 is used to die-cut solder pads 30 from the upper insulating layer 3 of the second substrate 120. The die-cutting waste is collected through a second recycling cylinder A20. Then, a third roller cutter A3 is used to die-cut the pattern of the connecting circuit 1b onto the copper foil of the second substrate 120. The die-cutting waste is collected through a third recycling cylinder A30. The connecting circuit 1b, where it needs to be electrically connected to the main circuit 1a, has a connection portion 1c that overlaps with the main circuit 1a. In the second step, the aluminum foil of the first circuit layer 11, made in the first step, faces upwards, and the copper foil of the second circuit layer 12 faces downwards. They are then fed into a second hot press R2 for pressing. Under the action of hot pressing, the upper and lower insulating layers fill the areas of the conductor material that have been removed from the circuit pattern and adhere to each other, so that the connecting part 1c of the second circuit layer 12 is attached to the first circuit layer 1a for electrical contact. Similarly, to improve the reliability of the electrical contact between the connecting part and the first circuit layer, conductive adhesive can be applied before they are bonded together. Likewise, the first and second circuit layers can also form the circuit pattern by etching. This invention prefers a die-cutting method, which is more efficient and environmentally friendly. The first conductive layer in this embodiment can also be manufactured using the method in Embodiment 1, but the manufacturing process in this embodiment is simpler.
[0033] The manufacturing method of Example 3 is referred to Figures 3.1 to 3.4 and Figure 6A method for manufacturing a bimetallic circuit board: First, a first circuit layer 11 and a second circuit layer 12 are fabricated. The first circuit layer 11 uses aluminum foil with a lower insulating layer as the first substrate 110. A first roller cutter A1 is used to die-cut the main circuit 1a and the connecting circuit 1b onto the aluminum foil of the first substrate 110. The cutting waste is recycled through a first recycling bin A10. The second circuit layer uses copper foil with an upper insulating layer as the second substrate 120. A second roller cutter A2 is used to die-cut the second circuit layer 12 onto the copper foil of the second substrate 120. The second circuit layer 12 only covers the area where the solder pads 30 will be die-cut later. Then, a third roller cutter A3 is used to die-cut the solder pads 30 onto the upper insulating layer 3 corresponding to the position of the second circuit layer 12. The area of the solder pads 30 is slightly smaller than that of the second circuit layer 12 so that the copper foil can adhere to the back side of the upper insulating layer 3. The die-cutting waste is recycled through a third recycling bin A30. In the second step, the aluminum foil of the first circuit layer 11, made in the first step, is placed upwards and the copper foil of the second circuit layer 12 is placed downwards. The two layers are then pressed together in a hot press R. Under the action of hot pressing, the upper and lower insulating layers fill the areas on the two circuit layers where the conductor material has been removed and adhere to each other, allowing the second circuit layer 12 to directly attach to and make electrical contact with the first circuit layer 11. Similarly, to improve the reliability of the electrical contact between the second circuit layer 12 and the first circuit layer 11, conductive adhesive can be applied before they are bonded together. Likewise, the first circuit layer 11 and the second circuit layer 12 can also be formed by etching to create the circuit pattern. This invention preferably uses a die-cutting method, which results in higher production efficiency and a more environmentally friendly production process.
[0034] refer to Figures 3.1 to 3.4 and Figure 7 In embodiment 3, the second circuit layer 12 can also be implemented in another way. The copper foil and the upper insulating layer 3 do not need to be pre-attached. First, the second roller cutter A2 is used to die-cut the pads 30 on the upper insulating layer 3. Then, the roller cutter or punch is used to cut copper foil sheets that can cover the pads 30. Then, the roller T is used to attach the copper foil sheets to the predetermined position on the first circuit layer 11 or to the pad 30 area on the back of the insulating layer 3. Finally, the first circuit layer 11 and the upper insulating layer 3 are sent into the hot press R. The hot press R attaches the upper insulating layer to the first circuit layer 11 and places the pads 30 on the copper foil sheets, i.e., the second circuit layer 12.
[0035] This invention saves material costs and simplifies the manufacturing process by pre-fabricating the first and second circuit layers using a die-cutting machine and then bonding them between the upper insulating layer and the insulating layer using a hot press, with the second circuit layer exposed in the pad area.
[0036] refer to Figure 8 and Figure 9An LED light strip using the aforementioned bimetallic circuit board includes a circuit board comprising a circuit layer 1, a lower insulating layer 2 disposed on the back of the circuit layer 1, and an upper insulating layer 3 disposed on the front of the circuit layer 1. The circuit layer 1, in terms of material, includes a first circuit layer 11 made of aluminum foil and a second circuit layer 12 made of copper foil; in terms of function, it includes a main circuit 1a and a connection circuit 1b. The second circuit layer 12 at least covers the area of the pads 30 and is at least partially directly attached to the first circuit layer 11. Pads 30 are formed on the upper insulating layer 3. The strip also includes LED beads 4, each comprising at least a first lamp lead 41 and a second lamp lead 42, which are soldered to the second circuit layer 12 via the pads 30.
[0037] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.
Claims
1. A bimetallic circuit board, comprising a circuit layer, a lower insulating layer disposed on the back side of the circuit layer and an upper insulating layer disposed on the front side of the circuit layer, the circuit layer comprising a main circuit and a connection circuit, and pads being provided on the upper insulating layer at locations where electronic components need to be soldered, characterized in that: The circuit layer includes a first circuit layer and a second circuit layer. The second circuit layer is made of a conductor that adheres well to electronic component solder. The first circuit layer is made of a conductor that is cheaper than the second circuit layer. The second circuit layer covers the pad area and is at least partially directly attached to the first circuit layer.
2. The bimetallic circuit board according to claim 1, characterized in that: The first circuit layer forms the main circuit and the connection circuit, and the second circuit layer forms the same main circuit and connection circuit as the first circuit layer. The second circuit layer is completely overlapped with the first circuit layer.
3. A bimetallic circuit board according to claim 1, characterized in that: The first circuit layer forms only the main circuit, and the second circuit layer forms only the connection circuit. The second circuit layer has a connection part at the position where it needs to be electrically connected to the first circuit layer, and the connection part is attached to the first circuit layer.
4. A bimetallic circuit board according to claim 1, characterized in that: The first circuit layer forms the main circuit and the connection circuit, and the second circuit layer only covers the pad area. The second circuit layer is directly attached to the first circuit layer.
5. A bimetallic circuit board according to claim 1, characterized in that: The areas where the first and second circuit layers are attached are coated with conductive adhesive.
6. A bimetallic circuit board according to claim 1, characterized in that: The first circuit layer is made of aluminum, and the second circuit layer is made of copper.
7. An LED light strip using the circuit board described in claim 1, 2, 3, 4, 5, or 6, characterized in that: It includes the circuit board and LED beads, with the LED beads' leads soldered to the second circuit layer via the pads.