High-density large-current LED module based on improved copper substrate circuit

Abstract

The invention discloses a high-density large-current LED (light-emitting diode) module based on an improved copper substrate circuit, which is characterized in that a traditional single'lane 'is widened into a plurality of'lanes' by additionally arranging a third bonding pad which is not electrically connected with an anode and a cathode at the bottom of a lamp bead and an auxiliary current path which is arranged on a copper substrate and corresponds to the third bonding pad; a low-resistance path is provided for current, and the current capacity, the packaging density, the heat dissipation performance and the welding yield are remarkably improved. Meanwhile, the adjacent welding bosses belonging to the same electrical network are connected through one or more solder paste flowing channels. The solder paste flowing channel is an exposed copper foil channel formed after etching. In the reflow soldering process, molten soldering tin can flow in the boss and the channel system which are communicated with each other to automatically compensate the tin quantity difference on each bonding pad, so that the uniformity of the welding height is realized, and the defects of tombstone standing, deviation, pseudo soldering and the like are effectively prevented.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor lighting, in particular to a high-density large-current LED module based on an improved copper substrate circuit, which is suitable for professional lighting equipment (such as stage lights, landscape lights, imaging lights, and photography lights) that require high-brightness output and high-density, large-current carrying capacity of LED module application scenarios. BACKGROUND

[0002] LEDs have been widely used in professional lighting fields due to their high brightness, energy saving, long service life, and other advantages. In these applications, in order to achieve extremely high brightness output, the LED module is usually required to carry very large driving current, and the light-emitting points (light sources) are required to be as small and dense as possible to achieve better optical design and sharper light output effect. Currently, common high-performance LED modules use copper substrates as heat sinks and circuit carriers. The traditional method is to form a circuit on the copper substrate by etching, and then solder the LED beads on the circuit pads. However, this traditional structure has the following main bottlenecks: 1. Current carrying capacity limitation: Current is mainly transmitted through the relatively thin copper foil circuit etched on the copper substrate. When a large current is required, the line width must be significantly increased, which greatly limits the flexibility of circuit design and forces the pad spacing to increase, making it impossible to achieve high-density layout.

[0003] 2. Heat management limitation: Large current generates a large amount of heat. Although the copper substrate itself has good heat dissipation, the heat is concentrated at the single pad below the LED chip, and the heat channel is relatively concentrated, which may cause local overheating in some high-power scenarios, affecting the light efficiency and service life.

[0004] 3. Packaging density limitation: In order to avoid current carrying capacity and heat dissipation problems, a large spacing must be maintained between the beads, resulting in a large light-emitting surface size, which is not conducive to the secondary light distribution of optical lenses, affecting the spot quality and system miniaturization.

[0005] 4. Soldering process defects: In the trend of high-density layout, the pads are designed to be very small and isolated from each other. In surface mount technology (SMT), small fluctuations in the amount of solder paste applied can easily cause uneven amounts of solder paste on different pads. During reflow soldering, pads with too much solder paste are prone to cause the beads to "float up" and stand or shift, while pads with too little solder paste may form a virtual weld, which seriously affects the production yield and long-term reliability of high-density LED modules.

[0006] Therefore, there is an urgent need in the art for a new solution to accommodate more LED beads in a limited board area, carry larger current, and at the same time ensure good heat dissipation and soldering process reliability. SUMMARY

[0007] The present application aims at overcoming the deficiencies of the prior art, and provides a high-density large-current LED module based on an improved copper substrate circuit, which significantly improves the current capacity, packaging density, heat dissipation performance and soldering yield by combining a unique copper substrate circuit design with a lamp bead bottom structure.

[0008] To achieve the above-mentioned purpose, the present application adopts the following technical solutions: The present application provides a high-density large-current LED module based on an improved copper substrate circuit, comprising a copper substrate (1) and a plurality of LED lamp beads (2), wherein the surface of the copper substrate (1) is provided with an insulating layer, and the insulating layer is etched with a conductive circuit composed of copper foil; the plurality of LED lamp beads (2) are array-soldered on the solder pads of the conductive circuit through soldering; The bottom soldering surface of the LED lamp bead (2) is provided with an anode pad (21), a cathode pad (22) and a third pad (23) which is electrically disconnected with the anode and the cathode inside the lamp bead; The conductive circuit comprises a first main circuit (11) and a second main circuit (12) for transmitting current, and an auxiliary current path (13); The auxiliary current path (13) is arranged on the copper substrate (1) and is electrically connected with the third pad (23) of at least one LED lamp bead (2) through soldering, so as to form an auxiliary current and heat conduction path parallel to the first main circuit (11) and / or the second main circuit (12).

[0009] Further, the auxiliary current path (13) is an auxiliary current path copper foil which is designed as a continuous soldering boss, and a raised platform is formed on the soldering boss corresponding to the position of the third pad (23) of each connected LED lamp bead (2).

[0010] Further, the auxiliary current path (13) is composed of a series of discrete auxiliary pads, each of which is arranged corresponding to the third pad (23) of an LED lamp bead (2), and the discrete auxiliary pads are electrically connected through widened connecting bridges.

[0011] Further, the auxiliary current path (13) is composed of a metal block embedded in the insulating layer and partially exposed, the upper surface of the metal block is soldered with the third pad (23), and the lower surface and / or side surface of the metal block is connected with the metal base layer of the copper substrate (1) through a heat-conducting via.

[0012] Further, the conductive circuit is composed of multiple solder bumps and connecting wires; adjacent solder bumps belonging to the same electrical network are connected by one or more solder paste flow channels (14); the solder paste flow channel (14) is a bare copper foil channel formed by etching, with a surface level with the solder bump and covered with the same solderable coating.

[0013] Further, at least one flow barrier is arranged in the solder paste flow channel, which is a copper foil protrusion formed in the same process as the solder bump, with a height lower than that of the solder bump.

[0014] Further, the solderable coating on the surface of the solder paste flow channel is differentially treated, with a low-surface-energy coating in the middle region and a high-surface-energy coating in the edge region close to the solder bump.

[0015] Further, the copper substrate (1) is a double-sided copper substrate, with the conductive circuit etched on the front-side insulating layer and a back-side copper foil pattern etched on the back-side insulating layer; the front-side auxiliary current passage is electrically and thermally connected to the back-side copper foil pattern through a via.

[0016] Further, the back-side copper foil pattern includes a heat dissipation pad (41) arranged corresponding to the position of each LED lamp bead (2) and / or an auxiliary current strip (42) arranged in parallel with the front-side auxiliary current passage (13).

[0017] Further, the back-side copper foil pattern is composed of multiple solder bumps, with adjacent solder bumps belonging to the same electrical network connected by a solder paste flow channel.

[0018] Compared with the prior art, the present application has the following beneficial effects: The present application provides a low-resistance passage for current through the newly added third solder pad at the bottom of the lamp bead and the corresponding auxiliary current passage on the copper substrate. This is equivalent to widening the traditional single "lane" into a double "lane", significantly reducing the overall loop resistance and allowing the LED module to pass through a higher current than the traditional design without overheating.

[0019] The present application designs the auxiliary current passage as a continuous solder bump, with a raised platform formed corresponding to the position of the third solder pad of each LED lamp bead. These raised platforms are integrally connected by the solder paste flow channel, forming an auxiliary passage integrated structure. During the reflow soldering process, the molten solder will flow in the interconnected bump and channel system under the action of surface tension, automatically compensating for the tin amount difference on each solder pad, thereby achieving uniformity of the soldering height and effectively preventing defects such as tombstone, offset, and loose solder. After soldering is completed, the solder solidified in the solder paste flow channel also becomes an additional conductive and heat-conductive body, improving the system performance The application can effectively slow down the flow speed of the molten solder paste, prevent it from flowing out of a certain pad too fast and too much, make the solder paste balancing process more controllable, and further inhibit the component from standing by through the anchoring effect on the molten solder paste.

[0020] The application can make the solder paste more willing to stay in the edge area of the pad rather than accumulate in the center of the channel, which helps to form a more ideal solder joint shape, avoid the formation of a large tin bridge between solder joints, and still retain the ability to regulate the amount of tin between different pads. Further, the morphology of the final solder joint can be more accurately controlled by designing different surface energy patterns in different areas, thereby improving the consistency and reliability of soldering.

[0021] The application also provides a wider low-resistance path for current through the double-sided copper substrate design and via connection, which is equivalent to widening the traditional single "lane" into multiple "lanes", and increasing the vertical current and heat dissipation capacity. This significantly reduces the overall circuit resistance and thermal resistance, allowing the LED module to pass through higher current without overheating, especially suitable for super high power density applications. BRIEF DESCRIPTION OF DRAWINGS

[0022] The accompanying drawings, which are incorporated into and form part of the specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the application.

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the accompanying drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, for those skilled in the art, other drawings can also be obtained based on these drawings without creative labor.

[0024] Figure 1 The accompanying drawings, which are incorporated into and form part of the specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the application.

[0025] Figure 2 The accompanying drawings, which are incorporated into and form part of the specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the application.

[0026] Figure 3 The accompanying drawings, which are incorporated into and form part of the specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the application.

[0027] Figure 4 The accompanying drawings, which are incorporated into and form part of the specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the application. Figure 3 The accompanying drawings, which are incorporated into and form part of the specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the application.

[0028] Figure 5 The accompanying drawings, which are incorporated into and form part of the specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the application.

[0029] Figure 6This is a schematic diagram of the copper foil pattern on the back of the copper substrate in Embodiment 2 of the present invention.

[0030] In the diagram: 1-Copper substrate, 2-LED chip, 11-First main circuit, 12-Second main circuit, 13-Auxiliary current path, 21-Anode pad, 22-Cathode pad and 23-Third pad, 111-First pad, 121-Second pad, 131-Raised platform, 14-Solder paste flow channel, 3-Solder, 4-Double-sided copper substrate, 41-Heat pad, 42-Auxiliary current strip, 5-Via Detailed Implementation The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0031] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0032] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" and "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0033] Example 1 like Figures 1-5 As shown, the present invention provides a high-density, high-current LED module based on an improved copper substrate circuit, which mainly includes a copper substrate 1 and multiple LED beads 2.

[0034] The copper substrate 1 has an insulating layer on its surface, and conductive lines made of copper foil are etched on the insulating layer (see...). Figure 3 , Figure 4 ).

[0035] Multiple LED beads 2 are soldered in an array onto the pads of the conductive lines on the copper substrate 1. The bottom of the LED bead 2 (see)Figure 2 ) There are three pads: anode pad 21, cathode pad 22 and third pad 23. The third pad 23 is electrically isolated inside the lamp bead, that is, the third pad has no electrical connection with the anode pad and the cathode pad inside the lamp bead, and its main function is to provide an external electrical connection and a heat dissipation interface.

[0036] The conductive circuit includes a first main circuit 11 (e.g. positive) and a second main circuit 12 (e.g. negative) for transmitting current, and an auxiliary current path 13. The auxiliary current path 13 is arranged in a meandering manner in the lamp bead array, and its position is designed to be just below the third pad 23 of the middle lamp bead of every adjacent three LED lamp beads. Through soldering 3, the third pad 23 and the auxiliary current path 13 below it are electrically and mechanically connected, thereby forming an auxiliary current path and a heat conduction path parallel to the main circuit.

[0037] In this embodiment, through the newly added third pad 23 at the bottom of the lamp bead and the corresponding auxiliary current path 13 on the copper substrate, a low-resistance path is provided for the current. This is equivalent to widening the traditional single "lane" into a double "lane", significantly reducing the overall loop resistance and allowing the LED module to pass through higher current than the traditional design without overheating.

[0038] In actual production, the conductive circuit is formed by the pads on the first main circuit 11 (e.g. positive) and the second main circuit 12 (e.g. negative) and the auxiliary current path 13, and a plurality of soldering bosses and connecting wires are formed. At the same time, the soldering bosses that are adjacent and belong to the same electrical network are connected through one or more solder paste flow channels 14. The solder paste flow channel is a bare copper foil channel formed after etching, whose surface is flush with the soldering boss and covered with the same solderable coating (such as gold plating, silver plating or OSP oxidation prevention layer).

[0039] Specifically, all soldering bosses, including the first pad 111 and the second pad 121 on the first main circuit 11 (e.g. positive) and the second main circuit 12 (e.g. negative), and the raised platform 131 on the auxiliary current path 13, are connected through the solder paste flow channel 14 if they belong to the same electrical network (e.g. both positive network). The solder paste flow channel 14 is formed in the same etching process as the soldering boss, with a flush surface and the same solderable coating.

[0040] In another embodiment of the present application, at least one flow barrier can be provided in the solder paste flow channel 14. The flow barrier is a copper foil protrusion formed in the same process as the solder bumps, but its height is lower than that of the solder bumps, preferably 1 / 3 to 2 / 3 of the height of the solder bumps, and the top is also covered with a solderable coating. The flow barrier does not completely block the solder paste, but slows down its flow speed and disrupts the flow path. This can prevent the solder paste from flowing excessively and rapidly from one pad to another at the beginning of reflow, causing new imbalance. At the same time, when the molten solder flows through the flow barrier, it will partially wrap it, generating additional anchoring force, which helps to further suppress the drift of the component in the liquid solder, further enhancing the anti-monument effect. That is, the embodiment of the present application provides a flow barrier in the solder paste flow channel 14, which can effectively slow down the flow speed of the molten solder paste, prevent it from flowing too fast and too much from a certain pad, make the solder paste balancing process more gentle and controllable, and further suppress the monument of the component through the anchoring effect of the molten solder paste.

[0041] In another embodiment of the present application, the solderable coating on the surface of the solder paste flow channel 14 is differentially treated to form a differentially surface energy channel. For example, but not limited to, a coating with relatively low surface energy (such as a certain OSP treatment agent) is used in the middle region of the solder paste flow channel 14, and a coating with relatively high surface energy (such as silver plating) is used in the region near the solder bumps. In actual production, the molten solder paste tends to spread to the region with higher surface energy during reflow. The differentially surface energy channel of the present embodiment will encourage the solder paste to stay in the edge region of the pad rather than accumulate in the center of the channel, which helps to form a more ideal solder joint shape and avoid the formation of a large solder bridge between solder joints, while still retaining the ability to adjust the amount of solder between different pads. Further, by designing different surface energy patterns in different regions, the shape of the final solder joint can be more accurately controlled, improving the consistency and reliability of the soldering.

[0042] In this embodiment, the auxiliary current path itself is designed as a continuous solder bump, and a raised platform corresponding to the position of the third pad of each LED lamp bead is formed on it. These raised platforms are integrally connected by the solder paste flow channel to form an auxiliary path integrated structure.

[0043] In another embodiment of the present application, the auxiliary current path 13 is no longer a continuous copper foil, but is composed of a series of discrete auxiliary pads. Each discrete auxiliary pad corresponds to the third pad 23 of an LED lamp bead 2 arranged directly below it. At the same time, these discrete auxiliary pads are electrically connected through a widened connecting bridge, the width of which is designed to be greater than the width of a conventional signal conductor, for example, its width is 1 / 5 to 1 / 2 of the width of the main line. The discrete auxiliary pad structure has a wider process window during etching than the continuous boss, reducing the risk of short circuit or open circuit due to uneven etching, and improving the adaptability of the etching process and the process yield; the widened connecting bridge has a certain deformation ability, which can effectively absorb the thermal stress generated due to the mismatch of the thermal expansion coefficient (CTE) between the copper substrate 1 and the LED lamp bead 2 while ensuring low resistance, reducing the risk of fatigue cracking of the solder joint under long-term thermal cycling, and maintaining the shunt and heat conduction effect of the auxiliary current path, while improving product reliability.

[0044] In another embodiment of the present application, the auxiliary current path is composed of a metal block embedded in the insulating layer and partially exposed. The material of the metal block is copper, aluminum alloy or high thermal conductivity composite material. The upper surface of the metal block serves as a soldering boss and is connected to the third pad 23 of the LED lamp bead through solder 3; its side or bottom is connected to the metal base layer of the copper substrate 1 through a thermally conductive via to achieve close thermal and electrical connection. The auxiliary current path composed of the metal block provides a super-low thermal resistance vertical path from the third pad of the LED lamp bead to the metal base layer of the copper substrate, greatly improving the heat dissipation efficiency of the core heat generating area, and is particularly suitable for application scenarios that pursue extreme power density and thermal management. At the same time, the metal block provides a more solid support platform for the LED lamp bead, enhancing the module's ability to resist mechanical vibration and impact.

[0045] In this embodiment, the newly added solder joint (the solder joint between the third pad and the auxiliary current path) is not only an electrical connection point, but also an additional heat conduction path. Heat can be conducted from the lamp bead to the copper substrate through more solder joints, improving heat management and increasing the reliability and life of the module.

[0046] During production, the SMT steel mesh opening covers the soldering boss and the channel. During the reflow soldering process, the molten solder 3 will flow in the interconnected boss and channel system under the action of surface tension, automatically compensating for the tin amount difference on each pad, thereby achieving uniformity of the soldering height and effectively preventing defects such as tombstone, offset, and loose solder. After soldering is completed, the solder solidified in the solder paste flow channel 14 also becomes an additional conductor and heat conductor, improving system performance.

[0047] In this embodiment, the LED module structure is fully compatible with the existing surface mounting process, without the need to add additional production steps, just using the designed LED lamp beads and the corresponding copper substrate light drawing file, easy to realize industrialization.

[0048] Embodiment two The embodiment provides a high-density large-current LED module based on an improved copper substrate circuit, which is mainly different from the embodiment one in that the copper substrate 1 is a double-sided copper substrate 4, and the front surface structure of the copper substrate is the same as that of the embodiment one, which will not be repeated here. The technical scheme of the embodiment two will be described in detail in combination with the main difference.

[0049] The double-sided copper substrate includes a front surface and a back surface, and the front surface and the back surface are both provided with an insulating layer, the front surface insulating layer is etched with a conductive circuit composed of a copper foil, and the back surface insulating layer is etched with a heat dissipation and auxiliary current path composed of a copper foil. The conductive circuit on the front surface includes a first main circuit 11 (positive electrode) and a second main circuit 12 (negative electrode) for transmitting current, and an auxiliary current path copper foil 13. Figures 3-4 As shown in the figure, the copper foil on the back surface of the copper substrate is patterned into a plurality of heat dissipation pads 41 and auxiliary current strips 42, the heat dissipation pads 41 correspond to the positions of each LED lamp bead 2, and the auxiliary current strips 42 are arranged in parallel with the auxiliary current path copper foil 13 on the front surface. Figure 6 As shown in the figure, the copper foil on the back surface of the copper substrate is patterned into a plurality of heat dissipation pads 41 and auxiliary current strips 42, the heat dissipation pads 41 correspond to the positions of each LED lamp bead 2, and the auxiliary current strips 42 are arranged in parallel with the auxiliary current path copper foil 13 on the front surface.

[0050] A plurality of LED lamp beads 2 are welded on the pads of the conductive circuit on the front surface of the double-sided copper substrate 4 through a soldering tin array. The auxiliary current path copper foil 13 on the front surface is electrically and thermally connected with the auxiliary current strips 42 and the heat dissipation pads 41 on the back surface through a plurality of vias. The vias are filled with conductive materials (such as copper or soldering tin) to form a low-resistance path. In this way, the auxiliary current path copper foil 13 is not only connected with the third pad 23, but also connected with the back surface copper foil in parallel through the via 5, forming an auxiliary current path and a heat conduction path across the front and back surfaces.

[0051] In this embodiment, through the design of the double-sided copper substrate and the connection of the via, a wider low-resistance path is provided for the current, which is equivalent to widening the traditional single "lane" into multiple "lanes", and increasing the vertical current and heat diffusion capacity. This significantly reduces the overall loop resistance and thermal resistance, allowing the LED module to pass through higher current without overheating, especially suitable for super high power density applications.

[0052] In actual production, the backside thermal pads 41 and auxiliary current bars 42 are also connected through similar solder paste flow channels, ensuring uniform solder flow during reflow soldering. In the SMT process, the steel mesh openings cover the solder bumps and channels on the front side, and part of the thermal pads on the back side. During reflow soldering, the molten solder flows in the front and back channel systems, automatically compensating for the tin amount difference and achieving uniform solder height. At the same time, the conductive material in the via further enhances electrical and thermal conductivity.

[0053] In this embodiment, the newly added via structure and backside copper foil not only provide additional electrical connection points, but also greatly improve heat management. Heat can be conducted away from the lamp beads through the third solder pad and the front side auxiliary copper foil, while being rapidly conducted to the backside copper foil through the via, reducing hot spot temperature and improving module reliability and lifespan.

[0054] This embodiment is fully compatible with existing surface mounting processes, requiring only the use of double-sided copper substrate light and designed LED lamp beads, without the need to add production steps and easy to industrialize. Embodiment Two further improves current capacity and heat dissipation efficiency based on Embodiment One, suitable for more demanding application environments.

[0055] In the description of the specification, the description of the terms "one embodiment", "example", "specific example" and the like means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0056] The above is only a specific embodiment of the present application, enabling those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features applied herein.

Claims

1. A high-density, high-current LED module based on an improved copper substrate circuit, comprising a copper substrate (1) and a plurality of LED beads (2), wherein an insulating layer is disposed on the surface of the copper substrate (1), and conductive lines composed of copper foil are etched on the insulating layer; the plurality of LED beads (2) are soldered in an array onto the pads of the conductive lines; characterized in that: The bottom welding surface of the LED bead (2) is provided with an anode pad (21), a cathode pad (22), and a third pad (23) that is electrically connected to the anode and cathode inside the bead. The conductive circuit includes a first main line (11), a second main line (12), and an auxiliary current path (13) for transmitting current. The auxiliary current path (13) is disposed on the copper substrate (1) and is electrically connected to the third pad (23) of at least one of the LED beads (2) by solder to form an auxiliary current and heat conduction path parallel to the first main line (11) and / or the second main line (12).

2. The high-density, high-current LED module based on an improved copper substrate circuit according to claim 1, characterized in that, The auxiliary current path (13) is an auxiliary current path copper foil, which is designed as a continuous welding boss, and a raised platform is formed on the welding boss corresponding to the third pad (23) position of each connected LED bead (2).

3. A high-density, high-current LED module based on an improved copper substrate circuit according to claim 1, characterized in that, The auxiliary current path (13) consists of a series of discrete auxiliary pads, each discrete auxiliary pad corresponding to the third pad (23) of an LED bead (2), and the discrete auxiliary pads are electrically connected to each other by a widened connecting bridge.

4. A high-density, high-current LED module based on an improved copper substrate circuit according to claim 1, characterized in that, The auxiliary current path (13) is composed of a metal block embedded in the insulating layer and partially exposed. The upper surface of the metal block is welded to the third pad (23), and its lower surface and / or side surface are connected to the metal base layer of the copper substrate (1) through thermally conductive vias.

5. A high-density, high-current LED module based on an improved copper substrate circuit according to any one of claims 1 to 4, characterized in that, The conductive line consists of multiple soldering bosses and connecting wires; adjacent soldering bosses belonging to the same electrical network are connected by one or more solder paste flow channels (14); the solder paste flow channel (14) is an exposed copper foil channel formed after etching, with a surface flush with the soldering boss and covered with the same solderable coating.

6. A high-density, high-current LED module based on an improved copper substrate circuit according to claim 5, characterized in that, At least one flow barrier is provided in the solder paste flow channel. The flow barrier is a copper foil protrusion formed in the same process as the soldering boss, and its height is lower than that of the soldering boss.

7. A high-density, high-current LED module based on an improved copper substrate circuit according to claim 5, characterized in that, The solderable coating on the surface of the solder paste flow channel is differentiated, with a low surface energy coating in the central area and a high surface energy coating in the edge area near the solder boss.

8. A high-density, high-current LED module based on an improved copper substrate circuit according to claim 1, characterized in that, The copper substrate (1) is a double-sided copper substrate, with the conductive lines etched on the front insulating layer and the back copper foil pattern etched on the back insulating layer; the auxiliary current path on the front side is electrically and thermally connected to the back copper foil pattern on the back side through vias.

9. A high-density, high-current LED module based on an improved copper substrate circuit according to claim 8, characterized in that, The back copper foil pattern includes a heat dissipation pad (41) provided at the position of each LED bead (2) and / or an auxiliary current strip (42) arranged parallel to the front auxiliary current path (13).

10. A high-density, high-current LED module based on an improved copper substrate circuit according to claim 8 or 9, characterized in that, The copper foil pattern on the back is composed of multiple soldering bosses, and adjacent soldering bosses belonging to the same electrical network are connected by solder paste flow channels.

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