Wire bonding method for an LED device

Abstract

The present invention discloses a wire bonding method for an LED device. The LED device includes 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 includes: installing a welding wire on the capillary of a ball bonder and fixing the LED bracket in a wire bonding fixture; the LED chip is installed on the first surface of the LED bracket; the diameter of the capillary is D; sintering the end of the welding wire to form a first solder ball and welding the first solder ball to the electrode of the LED chip; after the capillary drives the welding wire to move along a set trajectory to the end point of the trajectory, sintering the end of the welding wire on the capillary to form a second solder ball and welding the second solder ball to the LED bracket to form a wire bond. The wire bond includes a first segment connecting the LED chip and a second segment connecting the LED bracket, and the second segment is in contact with the first surface of the LED bracket; the value range of the length L of the second segment is: L > D / 2. The technical solution of the present invention can prevent the occurrence of dead lights in the LED and improve the reliability of the LED device.

Description

Technical Field

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

[0002] With the continuous deterioration of the global climate, the conditions faced by LED outdoor displays are becoming increasingly harsh. In the Middle East region, when the module is lit, 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] The main failures of LEDs are caterpillar string lighting and dead lamp problems. The main reason for the dead lamp problem is the disconnection of the electrical connection between the LED chip and the LED bracket. For example, the gold wire breaks or the solder joint breaks, etc. 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 occurrence of dead lamps in LEDs, and improve the reliability of LED devices.

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

[0006] Install the welding wire on the capillary of the ball bonder, and fix the LED bracket in the wire bonding fixture; the LED chip is installed on the first surface of the LED bracket; the diameter of the capillary is D;

[0007] Sinter the end of the welding wire to form a first solder ball, and weld the first solder ball on the electrode of the LED chip;

[0008] After the capillary drives the welding wire to move along a set trajectory to the end point of the trajectory, sinter the end of the welding wire on the capillary to form a second solder ball, and weld the second solder ball on the LED bracket to form a wire bond; the wire bond includes a first segment connecting the LED chip, a second segment connecting the LED bracket, and an intermediate segment connecting the first segment and the second segment, the second segment is attached to the first surface of the LED bracket; the value range of the length L of the second segment is: L > D / 2.

[0009] Optionally, the included angle α between the intermediate 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: 50 mA ≤ I ≤ 80 mA, and the value range of the ball burning time t is: 0.55 ms ≤ t ≤ 0.65 ms.

[0011] Optionally, before sintering the end of the welding wire to form the first solder ball, the following steps are further included:

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

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

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

[0015] Weld the second solder ball at the virtual second welding position point to form a bonding wire.

[0016] In a second aspect, the present invention provides a bonding wire method for an LED device. 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:

[0017] Install the welding wire on the capillary of the ball bonder, and fix the LED bracket in the bonding wire fixture; the LED chip is installed on the first surface of the LED bracket;

[0018] Sinter the end of the welding wire to form the first solder ball, and weld the first solder ball on the electrode of the LED chip;

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

[0020] Optionally, the bonding wire includes 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. The diameter of the capillary is D; the included angle between the intermediate section and the second section is α; the value range of the thickness H of the second solder ball is: H > D / (2tanα).

[0021] Optionally, before sintering the end of the welding wire to form the first solder ball, the following steps are further included:

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

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

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

[0025] Welding the second solder ball at the virtual second welding position point to form a bonding wire.

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

[0027] Optionally, there is also an intermediate section between the first section and the second section, and the included 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 bonding wire method for an LED device, 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:

[0029] Install the welding wire on the capillary of the ball bonder, and fix the LED bracket in the bonding wire fixture; the LED chip is installed on the first surface of the LED bracket;

[0030] Sinter the end of the welding wire to form a first solder ball, and weld the first solder ball on the electrode of the LED chip;

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

[0032] When the second pad is deviated, take the actual position of the second pad as the second welding position area; and set a virtual second welding position point through image recognition, sinter the end of the welding wire on the capillary to form the second solder ball, and weld the second solder ball at the virtual second welding position point to form a bonding wire.

[0033] Optionally, the diameter of the capillary is D; the bonding wire includes 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; the second section is attached to the first surface of the LED bracket;

[0034] The value range of the length L of the second section is: L > D / 2.

[0035] Optionally, the included angle α between the middle section and the second section ranges as follows: α ≤ 5°.

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

[0037] In the technical solution of the present invention, an 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 LED chip is installed on the first surface of the LED bracket. By installing a welding wire on the capillary of a ball bonder and fixing the LED bracket in a bonding wire fixture, the end of the welding wire is sintered to form a first solder ball, and the first solder ball is welded to the electrode of the LED chip. After the capillary 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 capillary is sintered to form a second solder ball, and the second solder ball is welded to the LED bracket to form a bonding wire. The bonding wire includes a first section connecting the LED chip, a second section connecting the LED bracket, and a middle section connecting the first section and the second section, such that the second section connecting the LED bracket fits the first surface of the LED bracket, and the length L of the second section > D / 2, so that when the second solder ball is welded to the LED bracket, the capillary will not press on the bonding wire, thereby avoiding damage to the bonding wire and further reducing the problem of dead lights caused by the fracture of the bonding wire under the action of stress during subsequent use.

[0038] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present invention, nor is it used 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 will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0040] Figure 1 It is a flowchart of a bonding wire method for an LED device provided in Embodiment 1 of the present invention;

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

[0042] Figure 3 It is a flowchart of a bonding wire method for an LED device provided in Embodiment 2 of the present invention;

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

[0044] Figure 5 Flowchart of a wire bonding method of an LED device provided in the third embodiment of the present invention;

[0045] Figure 6 Partial structural schematic diagram of an LED bracket provided in the third embodiment of the present invention. Detailed implementation manners

[0046] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope 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 do not necessarily need to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention described herein can be implemented in an order different from those illustrated or described herein.

[0048] Embodiment 1

[0049] Figure 1 Flowchart of a wire bonding method of an LED device provided in the first embodiment of the present invention, Figure 2 Partial schematic diagram of a wire bonding structure of an LED device provided in the first embodiment of the present invention. Refer to Figure 1 and Figure 2 As shown, this embodiment provides a wire bonding method for an LED device. The LED device includes an LED chip 1, an LED bracket 2, and at least one wire bond 3 electrically connecting the LED chip 1 and the LED bracket 2. The method includes the following steps:

[0050] S110. Install the welding wire on the capillary of the ball bonder and fix the LED bracket in the wire bonding fixture.

[0051] Among them, the LED chip 1 is installed 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, the surface on the side where the working area is formed.

[0052] The capillary of the ball bonder is hollow, and one end of the wire passes through the hollow capillary to reach the tip of the capillary. The wire clamping fixture is used to fix the LED bracket so that the LED bracket does not move during wire bonding, thus ensuring the accuracy of wire bonding.

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

[0054] Among them, the wire can be, but is not limited to, a conductive material such as gold wire. The end of the wire can be understood as the end of the wire fixed on the capillary. High voltage is generated by the ball bonder to discharge the end of the wire to generate an electric spark, and then the end of the wire is instantaneously melted at high temperature. Under the action of surface tension, the melted end of the wire solidifies into the first solder ball 4. Then, control the capillary to descend above the electrode of the LED chip 1, and weld the first solder ball 4 to the electrode of the LED chip 1 under a certain pressure and energy to complete the welding of the first solder joint (the wire and the electrode of the LED chip 1).

[0055] S130. After the capillary drives the wire to move along the set trajectory to the end point of the trajectory, sinter the end of the wire on the capillary to form a second solder ball, and weld the second solder ball to the LED bracket to form a wire bond.

[0056] Among them, the set trajectory is the set movement trajectory of the capillary, that is, the position of the wire bond 3. The end point of the trajectory can be understood as the position near the second solder pad on the LED bracket 2. After the capillary drives the wire to move along the set trajectory to the end point of the trajectory, sinter the end of the wire on the capillary to form the second solder ball 5, and then press and weld the second solder ball 5 to the LED bracket 2. In this way, the wire bond 3 that electrically connects 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 to the LED bracket 2 is similar to the process of welding the first solder ball 4 to the LED chip 1. The specific process parameters can be set according to actual requirements.

[0057] The formed wire bond 3 includes a first segment 31 connecting the LED chip 1, a second segment 32 connecting the LED bracket, and an intermediate segment 33 connecting the first segment 31 and the second segment 32. One end of the first segment 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 segment 31 and the second segment 32 are connected through the intermediate segment.

[0058] When welding the second solder ball onto the LED bracket 2, it is necessary to control the capillary to descend to the second welding position of the LED bracket 2 and, under a certain pressure and energy, weld the second solder ball at the second welding position of the LED bracket 2. By fitting the second segment 32 to the first surface of the LED bracket 2, with the length L of the second segment 32 > D / 2, when controlling the capillary to descend to the second welding position of the LED bracket 2 and applying pressure and energy to the second solder ball, due to the length L of the second segment 32 > D / 2, the capillary will not press on the wire, thereby avoiding damage to the bonding wire 3. Here, D is the diameter of the capillary.

[0059] In this embodiment, 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 LED chip is installed on the first surface of the LED bracket. By installing the wire on the capillary of the ball bonder and fixing the LED bracket in the bonding wire fixture, the end of the wire is sintered to form the first solder ball, and the first solder ball is welded to the electrode of the LED chip. After the capillary drives the wire to move along the set trajectory to the end point of the trajectory, the end of the wire on the capillary is sintered to form the second solder ball, and the second solder ball is welded to the LED bracket to form a bonding wire. The bonding wire includes a first segment 31 connecting the LED chip, a second segment connecting the LED bracket, and an intermediate segment connecting the first segment and the second segment. The second segment connecting the LED bracket is fitted to the first surface of the LED bracket, and the length L of the second segment > D / 2, so that when the second solder ball is welded to the LED bracket, the capillary will not press on the bonding wire, thereby avoiding damage to the bonding wire and further reducing the problem of dead lamps caused by the fracture of the bonding wire under the action of stress during subsequent use.

[0060] In an alternative embodiment, the value range of the angle α between the intermediate segment and the second segment 32 is: α ≤ 5°.

[0061] Specifically, the smaller the angle α between the intermediate segment 33 and the second segment 32, the smaller the pulling force of the bonding wire of the intermediate segment 33 on the bonding wire of the second segment 32, and the more it can ensure that the second segment 32 is completely fitted to the first surface of the LED bracket 2, thereby further avoiding the capillary pressing on the bonding wire. Therefore, by limiting the angle α between the intermediate segment 33 and the second segment 32 to α ≤ 5°, the pulling force of the bonding wire of the intermediate segment 33 on the bonding wire of the second segment 32 is small enough to ensure that the second segment 32 is completely fitted to the first surface of the LED bracket 2, thereby avoiding the capillary pressing on the bonding wire and making the bonding wire 3 easily damaged, and preventing the problem of dead lamps caused by the fracture of the bonding wire 3 under the action of stress during subsequent use.

[0062] Embodiment 2

[0063] Figure 3 It is a flowchart of a bonding wire method for an LED device provided in Embodiment 2 of the present invention. Figure 4Partial schematic diagram of a wire bonding structure of an LED device provided in the second embodiment of the present invention. With reference to Figure 3 and Figure 4 shown, this embodiment provides a wire bonding method for an LED device. The LED device includes an LED chip 1, an LED bracket 2, and at least one wire bond 3 electrically connecting the LED chip 1 and the LED bracket 2. The method includes the following steps:

[0064] S210: Install the welding wire on the capillary of the ball bonder, and fix the LED bracket in the wire bonding fixture.

[0065] Among them, the LED chip 1 is installed on the first surface S1 of the LED bracket 2.

[0066] S220: Sinter the end of the welding wire to form a first solder ball, and weld the first solder ball to the electrode of the LED chip.

[0067] S230: After the capillary drives the welding wire to move along the set trajectory to the end point of the trajectory, sinter the end of the welding wire on the capillary to form a second solder ball, and weld the second solder ball to the LED bracket to form a wire bond.

[0068] Among them, when forming the second solder ball, the value range of the ball burning current I is: 50 mA ≤ I ≤ 80 mA, and the value range of the ball burning time t is: 0.55 ms ≤ t ≤ 0.65 ms, so that the formed second solder ball is relatively large. After welding the second solder ball to the LED bracket 2, the thickness H of the second solder ball > D / (2tanα), so as to prevent the tip of the capillary from pressing on the welding wire when welding the second solder ball to the LED bracket 2, and further avoid damage to the wire bond 3.

[0069] In this embodiment, the LED device includes an LED chip, an LED bracket, and at least one wire bond electrically connecting the LED chip and the LED bracket, and the LED chip is installed on the first surface of the LED bracket. By installing the welding wire on the capillary of the ball bonder and fixing the LED bracket in the wire bonding fixture, sinter the end of the welding wire to form a first solder ball, and weld the first solder ball to the electrode of the LED chip. After the capillary drives the welding wire to move along the set trajectory to the end point of the trajectory, sinter the end of the welding wire on the capillary to form a second solder ball, and weld the second solder ball to the LED bracket to form a wire bond. By making the thickness H of the second solder ball > D / (2tanα), the capillary will not press on the wire bond, so as to avoid damage to the wire bond, and further reduce the problem of dead lamps caused by wire bond breakage under the action of stress during subsequent use.

[0070] Embodiment Three

[0071] Figure 5 Flowchart of a wire bonding method for an LED device provided in the third embodiment of the present invention,Figure 6 This is a partial structural schematic diagram of an LED bracket provided in Embodiment 3 of the present invention. With reference to Figure 4 、 Figure 5 and Figure 6 shown, this embodiment provides a wire bonding method for an LED device. The LED device includes an LED chip 1, an LED bracket 2, and at least one wire 3 electrically connecting the LED chip 1 and the LED bracket 2. The method includes the following steps:

[0072] S310: Install the welding wire on the capillary of the ball bonder and fix the LED bracket in the wire bonding fixture.

[0073] Among them, the LED chip 1 is installed on the first surface S1 of the LED bracket 2;

[0074] S320: Determine whether there is a deviation in the position of the second pad on the LED bracket.

[0075] S330: When the second pad is deviated, use the actual position of the second pad as the second welding position area, and set a virtual second welding position point through image recognition.

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

[0077] S350: After the capillary drives the welding wire to move along the set trajectory to the end point of the trajectory, sinter the end of the welding wire on the capillary to form a second welding ball, and weld the second welding ball to the virtual second welding position point to form a wire bond.

[0078] Among them, the second pad on the LED bracket 2 is the electrical connection point between the second welding ball 5 and the LED bracket 2, that is, the second welding ball 5 is electrically connected to the LED bracket 2 through the second pad 6. The deviation of the second pad 6 can be understood as the situation where there is a deviation on the left and right of the second pad 6, resulting in a difference between the second pad 6 and the second pad 6 in the design drawing.

[0079] It can be understood that the bowl cup of the LED bracket 2 is formed by an injection molding process. When forming the bowl cup of the LED bracket 2, injection molding offset may occur, resulting in a deviation in the size of the second pad, that is, the left pad is large and the right pad is small, or the left pad is small and the right pad is large. When there is injection molding offset and the size of the second pad 6 shrinks, when the second solder ball 5 is welded to the position of the second pad 6 of the LED bracket 2, part of the second solder ball 5 is welded to the second pad 6, and part of the second solder ball 5 is welded to the track 61 around the second pad 6, or on the edge of the track 61; due to the height difference between the second pad 6 and the track 61 around the second pad 6, during the subsequent use of the LED device, a pulling force is generated due to the height difference at the connection between the second solder ball 5 and the LED bracket 2, which further leads to the electrical connection failure between the second solder ball 5 and the second pad 6, and the problem of dead lights in the LED device occurs.

[0080] Among them, the second pad 6 is the second soldering pad area. A virtual second soldering position point is set through image recognition as the actual second soldering position, so as to reposition the actual position of the second solder ball 5. By welding the second solder ball 5 at this virtual second soldering position point, when the second solder ball 5 is welded, the second solder ball 5 can accurately fall into the actual second soldering position of the second pad 6, thereby improving the connection reliability between the second solder ball 5 and the second pad 6 and preventing the problem of dead lights in the LED device.

[0081] In an optional embodiment, the distance between the set virtual second soldering position point and the edge of the bowl cup should be greater than about (D / 2 + 1μm) to (D / 2 + 2μm) as the actual second soldering position, so as to further avoid that when the second solder ball 5 is welded, part of the second solder ball 5 is welded to the second pad 6 and part of the second solder ball 5 is welded to the bowl cup around the second pad 6, so that when the second pad 6 is small, it is farthest from the position of the track 61 to the greatest extent, and further prevent the electrical connection failure between the second solder ball 5 and the second pad 6.

[0082] In this embodiment, 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 LED chip is installed on the first surface of the LED bracket. By installing the welding wire on the capillary of the ball bonder and fixing the LED bracket in the wire bonding fixture, it is determined whether there is a deviation in the position of the second pad on the LED bracket. When there is a deviation in the second pad, the actual position of the second pad is used as the second bonding position area, and a virtual second bonding position point is set through image recognition. The end of the welding wire is sintered to form a first solder ball, and the first solder ball is welded to the electrode of the LED chip. After the capillary 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 capillary is sintered to form a second solder ball, and the second solder ball is welded to the virtual second bonding position point to form a bonding wire, so that when the second solder ball is welded, the second solder ball can completely fall into the actual second bonding position of the second pad, avoiding the situation where part of the second solder ball is welded on the second pad and part of the second solder ball is welded on the track around the second pad, thereby improving the connection reliability between the second solder ball and the second pad and preventing the dead lamp problem of the LED device.

[0083] It should be noted that the wire bonding methods of the LED devices provided in Embodiments 1, 2, and 3 can be implemented independently, or combined in pairs or all three, and all are within the protection scope of this embodiment.

[0084] Table 1. Thermal shock test data

[0085] The following provides the thermal shock test results of the LED lamp beads prepared by using the wire bonding method of the LED device provided in this embodiment and the LED lamp beads prepared by using the wire bonding method of the LED device provided in the prior art (the test conditions are: a low-temperature - high-temperature cycle of -50°C to 150°C is carried out every 30 minutes). As shown in Table 1, the number of failures of the LED lamp beads prepared by using the wire bonding method of the LED device provided in this embodiment is lower than that of the LED lamp beads prepared by using the wire bonding method of the LED device provided in the prior art in each thermal shock test round; and for the LED lamp beads prepared by combining the three wire bonding methods of Embodiments 1, 2, and 3, the number of failures in each round of the thermal shock test is 0, that is, zero failures can be achieved in the thermal shock test of 500 rounds.

[0086] The above specific embodiments do not constitute a limitation to the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principle of the present invention shall be included within 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; the angle between the intermediate section and the second section is α, and after the second solder ball is welded to the LED bracket, the thickness H of the second solder ball is>D / 2tanα.

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 current I is: 50mA≤I≤80mA, and the value range of the burning time t is: 0.55ms≤t≤0.65ms; 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 splitting knife is D; the angle between the middle section and the second section is α; the value range of the thickness H of the second solder ball is: H>D / 2tanα.

6. 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.

7. 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.

8. The wire bonding method of an LED device according to claim 7, 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°.

9. 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 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; the welding line 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 splitting knife is D; the angle between the middle section and the second section is α; the value range of the thickness H of the second welding ball is: H>D / 2tanα.

10. The wire bonding method of an LED device according to claim 9, 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.

11. The wire bonding method of an LED device according to claim 10, characterized in that: The value range of the angle α between the middle section and the second section is: α≤5°.

12. The wire bonding method of an LED device according to claim 9, 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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