Wire welding method of LED device

Abstract

The invention discloses a wire bonding method of an LED device. The LED device comprises an LED chip, an LED support and at least one bonding wire electrically connected with the LED chip and the LED support. The wire welding method comprises the following steps: mounting a welding wire on a chopper of a ball bonding machine, and fixing an LED bracket in a wire welding clamp; the LED chip is mounted on the first surface of the LED bracket; the diameter of the chopper is D; sintering the end part of the welding wire to form a first welding ball, and welding the first welding ball on the electrode of the LED chip; after the chopper drives the welding wire to move to the end point of the track along the set track, sintering the end part of the welding wire on the chopper to form a second welding ball, and welding the second welding ball on the LED bracket to form a welding wire; the bonding wire comprises a first section connected with the LED chip and a second section connected with the LED support, and the second section is attached to the first surface of the LED support; and the value range of the length L of the second section is L > D / 2. According to the technical scheme, the problem of dead light of the LED can be prevented, and the reliability of the LED device is improved.

Description

Technical Field

[0001] The invention relates to the technical field of LED devices, and in particular to a wire bonding method for LED devices. Background Art

[0002] As the global climate continues to deteriorate, the conditions faced by outdoor LED displays are becoming more and more harsh. When the modules are lit in the Middle East, the temperature of the LED display may be above 80 degrees Celsius. Therefore, the requirements for the reliability of LED lamp beads are getting higher and higher.

[0003] LED failures are mainly caterpillar string lighting and dead light problems. The main cause of the dead light problem is the disconnection of the electrical connection between the LED chip and the LED bracket, for example, the breakage of the gold wire or the breakage of the solder joint. Summary of the invention

[0004] The present invention provides a wire bonding method for an LED device to solve the problems existing in the prior art, prevent the LED from having a dead light problem, and improve the reliability of the LED device.

[0005] In a first aspect, the present invention provides a wire bonding method for an LED device, wherein the LED device comprises an LED chip, an LED bracket, and at least one wire bonding electrically connecting the LED chip and the LED bracket; the wire bonding method comprises:

[0006] The welding wire is mounted on the splitter of the ball welding machine, and the LED bracket is fixed in the welding wire fixture; the LED chip is mounted on the first surface of the LED bracket; the diameter of the splitter is D;

[0007] Sintering the end of the welding wire to form a first welding ball, and welding the first welding ball to the electrode of the LED chip;

[0008] After the splitting knife drives the welding wire to move along the set trajectory to the end point of the trajectory, the end of the welding wire on the splitting knife is sintered to form a second solder ball, and the second solder ball is welded to the LED bracket to form a welding wire; the welding wire includes a first section connected to the LED chip, a second section connected to the LED bracket, and an intermediate section connecting the first section and the second section, and the second section is in contact with the first surface of the LED bracket; the length L of the second section has a value range of: L>D / 2.

[0009] Optionally, the angle α between the middle segment and the second segment has a value range of: α≤5°.

[0010] Optionally, when forming the second solder ball, the value range of the ball burning current I is: 50mA≤I≤80mA, and the value range of the ball burning time t is: 0.55ms≤t≤0.65ms.

[0011] Optionally, before sintering the end of the welding wire to form the first welding ball, the method further includes:

[0012] Determine whether there is a deviation in the position of the second soldering pad on the LED bracket;

[0013] When the second pad deviates, the actual position of the second pad is used as the second welding position area; and a virtual second welding position point is set through image recognition;

[0014] Soldering the second solder ball on the LED bracket includes:

[0015] The second solder ball is welded to the virtual second welding position point to form a welding line.

[0016] In a second aspect, the present invention provides a wire bonding method for an LED device, wherein the LED device comprises an LED chip, an LED bracket, and at least one wire bonding electrically connecting the LED chip and the LED bracket; the wire bonding method comprises:

[0017] The welding wire is mounted on the splitter of the ball welding machine, and the LED bracket is fixed in the welding wire fixture; the LED chip is mounted on the first surface of the LED bracket;

[0018] Sintering the end of the welding wire to form a first welding ball, and welding the first welding ball to the electrode of the LED chip;

[0019] After the splitting knife drives the welding wire to move along the set trajectory to the end point of the trajectory, the end of the welding wire on the splitting knife is sintered to form a second solder ball, and the second solder ball is welded to the LED bracket to form a welding wire; wherein, when forming the second solder ball, the value range of the burning ball current I is: 50mA≤I≤80mA, and the value range of the burning ball time t is: 0.55ms≤t≤0.65ms.

[0020] Optionally, the welding wire includes a first section connected to the LED chip, a second section connected to the LED bracket, and a middle section connecting the first section and the second section. The diameter of the chopper is D; the angle between the middle section and the second section is α; the thickness H of the second solder ball has a value range of: H>D / 2tanα.

[0021] Optionally, before sintering the end of the welding wire to form the first welding ball, the method further includes:

[0022] Determine whether there is a deviation in the position of the second soldering pad on the LED bracket;

[0023] When the second pad deviates, the actual position of the second pad is used as the second welding position area; and a virtual second welding position point is set through image recognition;

[0024] Soldering the second solder ball on the LED bracket includes:

[0025] The second solder ball is welded to the virtual second welding position point to form a welding line.

[0026] Optionally, the diameter of the chopping knife is D; the welding wire includes a first section connecting the LED chip and a second section connecting the LED bracket and connecting the first section and the second section, and the second section is attached to the first surface of the LED bracket; the length L of the second section has a value range of: L>D / 2.

[0027] Optionally, an intermediate section is included between the first section and the second section, and the angle α between the intermediate section and the second section has a value range of: α≤5°.

[0028] In a third aspect, the present invention provides a wire bonding method for an LED device, wherein the LED device comprises an LED chip, an LED bracket, and at least one wire bonding electrically connecting the LED chip and the LED bracket; the wire bonding method comprises:

[0029] The welding wire is mounted on the splitter of the ball welding machine, and the LED bracket is fixed in the welding wire fixture; the LED chip is mounted on the first surface of the LED bracket;

[0030] Sintering the end of the welding wire to form a first welding ball, and welding the first welding ball to the electrode of the LED chip;

[0031] After the splitting knife drives the welding wire to move along the set trajectory to the end point of the trajectory, it is determined whether there is a deviation in the position of the second welding pad on the LED bracket;

[0032] When the second welding pad deviates, the actual position of the second welding pad is used as the second welding position area; and a virtual second welding position point is set through image recognition, the end of the welding wire on the splitting knife is sintered to form the second welding ball, and the second welding ball is welded to the virtual second welding position point to form a welding line.

[0033] Optionally, the diameter of the chopping knife is D; the welding wire includes a first section connected to the LED chip, a second section connected to the LED bracket, and a middle section connecting the first section and the second section; the second section is attached to the first surface of the LED bracket;

[0034] The length L of the second segment has a value range of: L>D / 2.

[0035] Optionally, the angle α between the middle segment and the second segment has a value range of: α≤5°.

[0036] Optionally, when forming the second solder ball, the value range of the ball burning current I is: 50mA≤I≤80mA, and the value range of the ball burning time t is: 0.55ms≤t≤0.65ms.

[0037] According to the technical solution of the present invention, the LED device comprises an LED chip, an LED bracket, and at least one welding wire electrically connecting the LED chip and the LED bracket, and the LED chip is mounted on the first surface of the LED bracket, by mounting the welding wire on the chopper of the ball welding machine, and fixing the LED bracket in the welding wire fixture, the end of the welding wire is sintered to form a first welding ball, and the first welding ball is welded to the electrode of the LED chip, after the chopper drives the welding wire to move along a set trajectory to the end point of the trajectory, the end of the welding wire on the chopper is sintered to form a second welding ball, and the second welding ball is welded to the LED bracket to form a welding wire, the welding wire comprises a first section connecting the LED chip, a second section connecting the LED bracket, and an intermediate section connecting the first section and the second section, so that the second section connecting the LED bracket is fitted with the first surface of the LED bracket, and the length L of the second end is greater than D / 2, so that when the second welding ball is welded to the LED bracket, the chopper will not press the welding wire, thereby avoiding damage to the welding wire, thereby reducing the problem of dead light caused by the welding wire breaking under the action of stress during subsequent use.

[0038] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0040] Figure 1 A flow chart of a wire bonding method for an LED device provided in Embodiment 1 of the present invention;

[0041] Figure 2 A partial schematic diagram of a bonding wire structure of an LED device provided in Embodiment 1 of the present invention;

[0042] Figure 3 A flow chart of a wire bonding method for an LED device provided in Embodiment 2 of the present invention;

[0043] Figure 4 A partial schematic diagram of a bonding wire structure of an LED device provided in the second embodiment of the present invention;

[0044] Figure 5 A flow chart of a wire bonding method for an LED device provided in Embodiment 3 of the present invention;

[0045] Figure 6 This is a partial structural schematic diagram of an LED bracket provided in Embodiment 3 of the present invention. DETAILED DESCRIPTION

[0046] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0047] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein.

[0048] Embodiment 1

[0049] Figure 1 This is a flow chart of a wire bonding method for an LED device provided in Embodiment 1 of the present invention. Figure 2 This is a partial schematic diagram of a bonding wire structure of an LED device provided in the first embodiment of the present invention. Figure 1 and Figure 2 As shown, this embodiment provides a wire bonding method for an LED device, wherein the LED device comprises an LED chip 1, an LED bracket 2, and at least one bonding wire 3 electrically connecting the LED chip 1 and the LED bracket 2, and the method comprises the following steps:

[0050] S110, install the welding wire on the splitter of the ball welding machine, and fix the LED bracket in the welding wire fixture.

[0051] The LED chip 1 is mounted on the first surface S1 of the LED bracket 2; the first surface S1 can be understood as the working surface of the LED bracket 2, that is, a side surface forming a working area.

[0052] The chopper of the ball welding machine is hollow, and one end of the welding wire passes through the hollow chopper to reach the tip of the chopper. The wire welding fixture is used to fix the LED bracket so that the LED bracket does not move during wire welding, thereby ensuring the accuracy of the wire welding.

[0053] S120, sintering the end of the solder wire to form a first solder ball, and soldering the first solder ball to the electrode of the LED chip.

[0054] The welding wire may be, but is not limited to, a conductive material such as a gold wire. The end of the welding wire can be understood as the end of the welding wire fixed on the splitter. The ball welding machine generates high voltage to discharge the end of the welding wire to generate electric sparks, and then the high temperature instantly melts the end of the welding wire. Under the action of surface tension, the melted end of the welding wire solidifies into a first welding ball 4. Then the splitter is controlled to descend to the top of the electrode of the LED chip 1, and the first welding ball 4 is welded to the electrode of the LED chip 1 under a certain pressure and energy, completing the welding of the first welding point (the welding wire and the electrode of the LED chip 1).

[0055] S130, after the splitting knife drives the welding wire to move along the set trajectory to the end point of the trajectory, the end of the welding wire on the splitting knife is sintered to form a second welding ball, and the second welding ball is welded to the LED bracket to form a welding wire.

[0056] Among them, the set trajectory is the set movement trajectory of the splitting knife, that is, the position of the welding wire 3. The end point of the trajectory can be understood as being near the position of the second welding pad on the LED bracket 2. After the splitting knife drives the welding wire to move along the set trajectory to the end point of the trajectory, the end of the welding wire on the splitting knife is sintered to form a second solder ball 5, and then the second solder ball 5 is pressed down and welded on the LED bracket 2, so that the welding wire 3 electrically connecting the LED chip 1 and the LED bracket 2 is formed. Among them, the process of forming the second solder ball 5 is similar to the process of forming the first solder ball 4, and the process of welding the second solder ball 5 on the LED bracket 2 is similar to the process of welding the first solder ball 4 on the LED chip 1. The specific process parameters can be set according to actual needs.

[0057] The formed welding wire 3 includes a first section 31 connected to the LED chip 1, a second section 32 connected to the LED bracket, and a middle section 33 connecting the first section 31 and the second section 32. One end of the first section 31 is connected to the LED chip 1, one end of the second end is connected to the LED bracket 2, and the other ends of the first section 31 and the second section 32 are connected through the middle section.

[0058] When the second solder ball is welded on the LED bracket 2, it is necessary to control the chopper to descend to the second welding position of the LED bracket 2, and weld the second solder ball to the second welding position of the LED bracket 2 under a certain pressure and energy. By fitting the second section 32 to the first surface of the LED bracket 2, the length L of the second section 32 is greater than D / 2, so that when the chopper is controlled to descend to the second welding position of the LED bracket 2 and pressure and energy are applied to the second solder ball, the length L of the second section 32 is greater than D / 2, so that the chopper will not press the welding wire, thereby avoiding damage to the welding wire 3. Wherein, D is the diameter of the chopper.

[0059] In this embodiment, the LED device includes an LED chip, an LED bracket, and at least one welding wire electrically connecting the LED chip and the LED bracket, and the LED chip is mounted on the first surface of the LED bracket. The welding wire is mounted on the chopper of the ball welding machine, and the LED bracket is fixed in the welding wire fixture, and the end of the welding wire is sintered to form a first welding ball, and the first welding ball is welded to the electrode of the LED chip. After the chopper drives the welding wire to move along a set trajectory to the end point of the trajectory, the end of the welding wire on the chopper is sintered to form a second welding ball, and the second welding ball is welded to the LED bracket to form a welding wire. The welding wire includes a first section 31 connected to the LED chip, a second section connected to the LED bracket, and an intermediate section connecting the first section and the second section, so that the second section connected to the LED bracket is fitted with the first surface of the LED bracket, and the length L of the second end is greater than D / 2, so that when the second welding ball is welded to the LED bracket, the chopper will not press the welding wire, thereby avoiding damage to the welding wire, thereby reducing the problem of dead light caused by the welding wire breaking under the action of stress during subsequent use.

[0060] In an optional embodiment, the angle α between the middle section and the second section 32 has a value range of: α≤5°.

[0061] Specifically, the smaller the angle α between the middle section 33 and the second section 32, the smaller the pulling force of the welding wire of the middle section 33 on the welding wire of the second section 32, and the more it can ensure that the second section 32 is completely in contact with the first surface of the LED bracket 2, thereby further preventing the splitter from pressing the welding wire. Therefore, by limiting the angle α between the middle section 33 and the second section 32 to ≤ 5°, the pulling force of the welding wire of the middle section 33 on the welding wire of the second section 32 is small enough to ensure that the second section 32 is completely in contact with the first surface of the LED bracket 2, thereby preventing the splitter from pressing the welding wire and making the welding wire 3 easily damaged, and preventing the welding wire 3 from breaking under the action of stress during subsequent use, thereby preventing the problem of dead light.

[0062] Embodiment 2

[0063] Figure 3 This is a flow chart of a wire bonding method for an LED device provided in Embodiment 2 of the present invention. Figure 4This is a partial schematic diagram of a wire bonding structure of an LED device provided in the second embodiment of the present invention. Figure 3 and Figure 4 As shown, this embodiment provides a wire bonding method for an LED device, wherein the LED device comprises an LED chip 1, an LED bracket 2, and at least one bonding wire 3 electrically connecting the LED chip 1 and the LED bracket 2, and the method comprises the following steps:

[0064] S210, install the welding wire on the splitter of the ball welding machine, and fix the LED bracket in the welding wire fixture.

[0065] The LED chip 1 is mounted on the first surface S1 of the LED bracket 2 .

[0066] S220, sintering the end of the solder wire to form a first solder ball, and soldering the first solder ball to the electrode of the LED chip.

[0067] S230, after the splitting knife drives the welding wire to move along the set trajectory to the end point of the trajectory, the end of the welding wire on the splitting knife is sintered to form a second welding ball, and the second welding ball is welded to the LED bracket to form a welding wire.

[0068] Among them, when forming the second solder ball, the value range of the burning current I is: 50mA≤I≤80mA, and the value range of the burning time t is: 0.55ms≤t≤0.65ms, so that the formed second solder ball is larger. After the second solder ball is welded to the LED bracket 2, the thickness of the second solder ball H>D / 2tanα, thereby preventing the tip of the splitter from pressing on the welding wire when the second solder ball is welded to the LED bracket 2, thereby avoiding damage to the welding wire 3.

[0069] In this embodiment, the LED device includes an LED chip, an LED bracket, and at least one welding wire electrically connecting the LED chip and the LED bracket, and the LED chip is mounted on the first surface of the LED bracket. The welding wire is mounted on the chopper of the ball welding machine, and the LED bracket is fixed in a welding wire fixture, and the end of the welding wire is sintered to form a first welding ball, and the first welding ball is welded to the electrode of the LED chip. After the chopper drives the welding wire to move along a set trajectory to the end point of the trajectory, the end of the welding wire on the chopper is sintered to form a second welding ball, and the second welding ball is welded to the LED bracket to form a welding wire. By making the thickness of the second welding ball H>D / 2tanα, the chopper will not press the welding wire, thereby avoiding damage to the welding wire, and further reducing the problem of dead light caused by breaking of the welding wire under the action of stress during subsequent use.

[0070] Embodiment 3

[0071] Figure 5 This is a flow chart of a wire bonding method for an LED device provided in Embodiment 3 of the present invention. Figure 6 This is a partial structural diagram of an LED bracket provided by Embodiment 3 of the present invention. Figure 4 , Figure 5 and Figure 6 As shown, this embodiment provides a wire bonding method for an LED device, wherein the LED device comprises an LED chip 1, an LED bracket 2, and at least one bonding wire 3 electrically connecting the LED chip 1 and the LED bracket 2, and the method comprises the following steps:

[0072] S310, install the welding wire on the splitter of the ball welding machine, and fix the LED bracket in the welding wire fixture.

[0073] Wherein, the LED chip 1 is mounted on the first surface S1 of the LED bracket 2;

[0074] S320, determine whether there is a deviation in the position of the second soldering pad on the LED bracket.

[0075] S330, when the second pad deviates, the actual position of the second pad is used as the second welding position area, and a virtual second welding position point is set through image recognition.

[0076] S340, sintering the end of the welding wire to form a first welding ball, and welding the first welding ball to the electrode of the LED chip.

[0077] S350, after the splitting knife drives the welding wire to move along the set trajectory to the end point of the trajectory, the end of the welding wire on the splitting knife is sintered to form a second welding ball, and the second welding ball is welded to the virtual second welding position point to form a welding line.

[0078] The second solder pad on the LED bracket 2 is the electrical connection point between the second solder ball 5 and the LED bracket 2, that is, the second solder ball 5 is electrically connected to the LED bracket 2 through the second solder pad 6. The deviation of the second solder pad 6 can be understood as the deviation of the second solder pad 6, which causes the second solder pad 6 to be different from the second solder pad 6 in the design drawing.

[0079] It is understandable that the bowl of the LED bracket 2 is formed by an injection molding process. When forming the bowl of the LED bracket 2, there may be an injection molding deviation, resulting in a deviation in the size of the second pad, that is, the pad on the left is larger and the pad on the right is smaller, or the pad on the left is smaller and the pad on the right is larger. When the injection molding is offset, the size of the second pad 6 is reduced, resulting in the second solder ball 5 being welded to the position of the second pad 6 of the LED bracket 2. Part of the second solder ball 5 is welded on the second pad 6, and part of the second solder ball 5 is welded on the path 61 around the second pad 6, or on the edge of the path 61; due to the height difference between the second pad 6 and the path 61 around the second pad 6, the LED device is pulled during subsequent use due to the height difference at the connection between the second solder ball 5 and the LED bracket 2, which in turn causes the electrical connection between the second solder ball 5 and the second pad 6 to fail, resulting in the problem of LED device dead light.

[0080] Among them, the second solder pad 6 is the second solder pad area, and a virtual second solder position point is set through image recognition as the actual second solder position, so as to realize the repositioning of the actual position of the second solder ball 5, and by welding the second solder ball 5 at the virtual second solder position point, when the second solder ball 5 is welded, the second solder ball 5 can accurately fall into the actual second solder position of the second solder pad 6, thereby improving the connection reliability between the second solder ball 5 and the second solder pad 6, and preventing the LED device from having a dead light problem.

[0081] In an optional embodiment, the distance between the set virtual second welding position point and the edge of the bowl cup should be greater than (D / 2+1μm) to (D / 2+2um) or so as to be used as the actual second welding position, so as to further avoid the situation that when the second solder ball 5 is welded, part of the second solder ball 5 is welded to the second solder pad 6, and part of the second solder ball 5 is welded to the bowl cup around the second solder pad 6, so that when the second solder pad 6 appears to be smaller, it is as far away from the path 61 as possible, thereby further preventing the electrical connection between the second solder ball 5 and the second solder pad 6 from failing.

[0082] In the present embodiment, the LED device includes an LED chip, an LED bracket, and at least one welding wire electrically connecting the LED chip and the LED bracket, and the LED chip is mounted on the first surface of the LED bracket. By mounting the welding wire on the chopper of the ball welding machine and fixing the LED bracket in the welding wire clamp, it is determined whether there is a deviation in the position of the second welding pad on the LED bracket. When the second welding pad deviates, the actual position of the second welding pad is used as the second welding position area, and a virtual second welding position point is set through image recognition, the end of the welding wire is sintered to form a first welding ball, and the first welding ball is welded to the electrode of the LED chip. After the chopper drives the welding wire to move along the set trajectory to the end point of the trajectory, the end of the welding wire on the chopper is sintered to form a second welding ball, and the second welding ball is welded to the virtual second welding position point to form a welding wire, so that when the second welding ball is welded, the second welding ball can completely fall into the actual second welding position of the second welding pad, avoiding the situation where part of the second welding ball is welded on the second welding pad and part of the second welding ball is welded on the path around the second welding pad, thereby improving the connection reliability between the second welding ball and the second welding pad, and preventing the LED device from having a dead light problem.

[0083] It should be noted that the wire bonding methods for LED devices provided in embodiments 1, 2 and 3 may be implemented individually, or in combination of two or three, and all are within the protection scope of this embodiment.

[0084] Table 1. Thermal shock test data

[0085] Provided below are the results of hot and cold shock tests on LED lamp beads prepared by the wire welding method for LED devices provided in the present embodiment and LED lamp beads prepared by the wire welding method for LED devices provided in the prior art (the experimental conditions are: a low temperature-high temperature cycle of -50°C to 150°C is performed every 30 minutes). As shown in Table 1, the number of failures of the LED lamp beads prepared by the wire welding method for LED devices provided in the present embodiment under each number of hot and cold shock test rounds is lower than that of the LED lamp beads prepared by the wire welding method for LED devices provided in the prior art; and the LED lamp beads prepared by the combination of the three wire welding methods for LED devices provided in Embodiments 1, 2 and 3 have a failure number of 0 under each number of rounds in the hot and cold shock test, that is, zero failure can be achieved in 500 rounds of hot and cold shock tests.

[0086] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A wire bonding method for an LED device, characterized in that: The LED device includes an LED chip, an LED bracket, and at least one bonding wire electrically connecting the LED chip and the LED bracket; the bonding wire method includes: The welding wire is mounted on the splitter of the ball welding machine, and the LED bracket is fixed in the welding wire fixture; the LED chip is mounted on the first surface of the LED bracket; the diameter of the splitter is D; Sintering the end of the welding wire to form a first welding ball, and welding the first welding ball to the electrode of the LED chip; After the splitting knife drives the welding wire to move along the set trajectory to the end point of the trajectory, the end of the welding wire on the splitting knife is sintered to form a second solder ball, and the second solder ball is welded to the LED bracket to form a welding wire; the welding wire includes a first section connected to the LED chip, a second section connected to the LED bracket, and an intermediate section connecting the first section and the second section, and the second section is in contact with the first surface of the LED bracket; the length L of the second section has a value range of: L>D / 2.

2. The wire bonding method of an LED device according to claim 1, characterized in that: The value range of the angle α between the middle section and the second section is: α≤5°.

3. The wire bonding method of an LED device according to claim 1, characterized in that: When forming the second solder ball, the value range of the ball burning current I is: 50mA≤I≤80mA, and the value range of the ball burning time t is: 0.55ms≤t≤0.65ms.

4. The wire bonding method of an LED device according to claim 1, characterized in that: Before sintering the end of the welding wire to form the first welding ball, the method further includes: Determine whether there is a deviation in the position of the second soldering pad on the LED bracket; When the second pad deviates, the actual position of the second pad is used as the second welding position area, and a virtual second welding position point is set through image recognition; Soldering the second solder ball on the LED bracket includes: The second solder ball is welded to the virtual second welding position point to form a welding line.

5. A wire bonding method for an LED device, characterized in that: The LED device includes an LED chip, an LED bracket, and at least one bonding wire electrically connecting the LED chip and the LED bracket; the bonding wire method includes: The welding wire is mounted on the splitter of the ball welding machine, and the LED bracket is fixed in the welding wire fixture; the LED chip is mounted on the first surface of the LED bracket; Sintering the end of the welding wire to form a first welding ball, and welding the first welding ball to the electrode of the LED chip; After the splitting knife drives the welding wire to move along the set trajectory to the end point of the trajectory, the end of the welding wire on the splitting knife is sintered to form a second solder ball, and the second solder ball is welded to the LED bracket to form a welding wire; wherein, when forming the second solder ball, the value range of the burning ball current I is: 50mA≤I≤80mA, and the value range of the burning ball time t is: 0.55ms≤t≤0.65ms.

6. The wire bonding method of an LED device according to claim 5, characterized in that: The welding wire includes a first section connected to the LED chip, a second section connected to the LED bracket, and a middle section connecting the first section and the second section. The diameter of the chopper is D; the angle between the middle section and the second section is α; the thickness H of the second solder ball has a value range of: H>D / 2tanα.

7. The wire bonding method of an LED device according to claim 5, characterized in that: Before sintering the end of the welding wire to form the first welding ball, the method further includes: Determine whether there is a deviation in the position of the second soldering pad on the LED bracket; When the second pad deviates, the actual position of the second pad is used as the second welding position area, and a virtual second welding position point is set through image recognition; Soldering the second solder ball on the LED bracket includes: The second solder ball is welded to the virtual second welding position point to form a welding line.

8. The wire bonding method of an LED device according to claim 5, characterized in that: The diameter of the chopping knife is D; the welding wire includes a first section connecting the LED chip and a second section connecting the LED bracket and connecting the first section and the second section, and the second section is in contact with the first surface of the LED bracket; the length L of the second section has a value range of: L>D / 2.

9. The wire bonding method of an LED device according to claim 8, characterized in that: There is also an intermediate section between the first section and the second section, and the angle α between the intermediate section and the second section has a value range of α≤5°.

10. A wire bonding method for an LED device, characterized in that: The LED device includes an LED chip, an LED bracket, and at least one bonding wire electrically connecting the LED chip and the LED bracket; the bonding wire method includes: The welding wire is mounted on the splitter of the ball welding machine, and the LED bracket is fixed in the welding wire fixture; the LED chip is mounted on the first surface of the LED bracket; Determine whether there is a deviation in the position of the second soldering pad on the LED bracket; When the second pad deviates, the actual position of the second pad is used as the second welding position area, and a virtual second welding position point is set through image recognition; Sintering the end of the welding wire to form a first welding ball, and welding the first welding ball to the electrode of the LED chip; After the splitting knife drives the welding wire to move along the set trajectory to the trajectory end point, the end of the welding wire on the splitting knife is sintered to form a second welding ball, and the second welding ball is welded to the virtual second welding position point to form a welding line.

11. The wire bonding method of an LED device according to claim 10, characterized in that: The diameter of the splitting knife is D; the welding wire includes a first section connected to the LED chip, a second section connected to the LED bracket, and a middle section connecting the first section and the second section; The second section is in contact with the first surface of the LED bracket; The length L of the second segment has a value range of: L>D / 2.

12. The wire bonding method of an LED device according to claim 11, characterized in that: The value range of the angle α between the middle section and the second section is: α≤5°.

13. The wire bonding method of an LED device according to claim 10, characterized in that: When forming the second solder ball, the value range of the ball burning current I is: 50mA≤I≤80mA, and the value range of the ball burning time t is: 0.55ms≤t≤0.65ms.

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