CN114535734B - Laser welding method of LED - Google Patents
Laser welding method of LED Download PDFInfo
- Publication number
- CN114535734B CN114535734B CN202011342451.5A CN202011342451A CN114535734B CN 114535734 B CN114535734 B CN 114535734B CN 202011342451 A CN202011342451 A CN 202011342451A CN 114535734 B CN114535734 B CN 114535734B
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- electrode
- led
- laser
- welding
- substrate
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- 238000003466 welding Methods 0.000 title claims abstract description 52
- 238000000034 method Methods 0.000 title claims abstract description 30
- 239000000758 substrate Substances 0.000 claims abstract description 36
- 239000004065 semiconductor Substances 0.000 claims description 12
- 238000004519 manufacturing process Methods 0.000 abstract description 5
- 238000005476 soldering Methods 0.000 description 5
- 238000010521 absorption reaction Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000017525 heat dissipation Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000002834 transmittance Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K1/00—Soldering, e.g. brazing, or unsoldering
- B23K1/005—Soldering by means of radiant energy
- B23K1/0056—Soldering by means of radiant energy soldering by means of beams, e.g. lasers, E.B.
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K3/00—Apparatus or processes for manufacturing printed circuits
- H05K3/30—Assembling printed circuits with electric components, e.g. with resistor
- H05K3/32—Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits
- H05K3/34—Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits by soldering
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Mechanical Engineering (AREA)
- Laser Beam Processing (AREA)
- Led Devices (AREA)
Abstract
The invention discloses a laser welding method of an LED, which comprises the following steps: providing an LED and a substrate, wherein the LED comprises a first electrode, a second electrode and an ITO transparent conducting layer, the substrate comprises a third electrode and a fourth electrode, and the area of the third electrode is smaller than that of the fourth electrode; laser welding the first electrode and the third electrode, wherein in the welding process, laser irradiates the LED and the third electrode at a preset first incident angle; and welding the second electrode and the fourth electrode by laser, wherein in the welding process, the laser irradiates the LED and the fourth electrode at a preset second incident angle, and the first incident angle is larger than the second incident angle. Aiming at the substrate with the electrode asymmetric design, the invention irradiates the LED and the third electrode with smaller area than the fourth electrode with laser at a larger first incident angle, thereby fixing the LED on the substrate, and ensuring the welding yield and the production efficiency under the condition of keeping the laser power unchanged.
Description
Technical Field
The invention belongs to the technical field of LED welding, and particularly relates to a laser welding method of an LED.
Background
The continuous development of society and the vigorous advocation of the country make the LED industry become one of the most active industries nowadays, and LED display screen products gradually enter various fields of social life. Meanwhile, with the innovation and development of the technology of the LED display screen, the small-space seamless connection LED display screen with high resolution of unit area has become a main stream product of the LED display screen, and can display higher definition images and videos, display more videos and image pictures, and especially can realize seamless and arbitrary large-area splicing by application in the aspect of image splicing.
Currently, two welding modes exist for fixing an LED on a substrate: one is reflow soldering, the reflow soldering mode is a conventional soldering mode, but the module needs to be subjected to reflow soldering for a plurality of times when being repaired, and the yield of products is easily affected; the other is laser welding, fixed-point welding is adopted when the module is repaired, and other LEDs do not receive the influence of laser.
In the current substrate design, the anode and the cathode are in asymmetric design, so that the heat conducting capacities of the anode and the cathode are different. When the LEDs are laser welded, the actual welding temperatures at the positive and negative electrodes are not the same, which easily results in low welding yield.
Disclosure of Invention
The invention aims to provide a laser welding method of an LED so as to solve the technical problems.
To achieve the purpose, the invention adopts the following technical scheme:
a laser welding method of an LED, comprising the steps of:
providing an LED and a substrate, wherein the LED comprises a first electrode, a second electrode and an ITO transparent conducting layer, the substrate comprises a third electrode and a fourth electrode, and the area of the third electrode is smaller than that of the fourth electrode;
placing the LED on the substrate, the first electrode on the third electrode, and the second electrode on the fourth electrode;
laser welding the first electrode and the third electrode, wherein in the welding process, laser irradiates the LED and the third electrode at a preset first incident angle;
and welding the second electrode and the fourth electrode by laser, wherein in the welding process, the laser irradiates the LED and the fourth electrode at a preset second incidence angle, and the first incidence angle is larger than the second incidence angle.
Optionally, the step of laser welding between the first electrode and the second electrode further comprises the steps of:
the position of the laser is kept unchanged, and the incident angle of the laser is changed by adjusting the position of the substrate.
Optionally, the substrate includes a plurality of third electrodes, the fourth electrode is a common electrode, the third electrode is a dot, and the fourth electrode is a stripe.
Optionally, the LED is a blue, green or red LED.
Optionally, the LED includes an N-type semiconductor layer, a light emitting layer, and a P-type semiconductor layer sequentially disposed.
Optionally, the ITO transparent conductive layer is in contact with the N-type semiconductor layer.
Optionally, the ITO transparent conductive layer is in contact with the P-type semiconductor layer.
Optionally, the wavelength of the laser is greater than 1000nm.
Optionally, the laser is a pulsed laser.
Optionally, the first incident angle is greater than 5 ° and the second incident angle is 0 °.
Compared with the prior art, the embodiment of the invention has the following beneficial effects:
according to the laser welding method of the LED, provided by the embodiment of the invention, aiming at the substrate with the electrode asymmetric design, the LED and the third electrode with the area smaller than that of the fourth electrode are irradiated by laser at a larger first incident angle, so that the LED is fixed on the substrate, and the welding yield and the production efficiency are ensured under the condition that the laser power is kept unchanged.
Drawings
In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
The structures, proportions, sizes, etc. shown in the present specification are shown only for the purposes of illustration and description, and are not intended to limit the scope of the invention, which is defined by the claims, so that any structural modifications, changes in proportions, or adjustments of sizes, which do not affect the efficacy or the achievement of the present invention, should fall within the scope of the invention.
FIG. 1 is a top view of a substrate according to an embodiment of the present invention;
fig. 2 is a front view of a substrate according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of a laser welding method according to an embodiment of the present invention;
FIG. 4 is a schematic view of a laser welding method according to an embodiment of the present invention;
fig. 5 is a schematic diagram of oblique welding in a laser welding method according to an embodiment of the present invention.
Illustration of:
101. a substrate; 102. a third electrode; 103. a fourth electrode; 201. a first laser; 202. a second laser; 301. a first light spot; 302. a second light spot; 401. a first electrode; 402. and a second electrode.
Detailed Description
In order to make the objects, features and advantages of the present invention more obvious and understandable, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is apparent that the embodiments described below are only some embodiments of the present invention, not all embodiments of the present invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
As shown in fig. 1, a substrate 101 is provided, and fig. 2 is a front view thereof. The substrate 101 includes a third electrode 102 and a fourth electrode 103. Alternatively, the third electrode 102 is a positive electrode and the fourth electrode 103 is a negative electrode.
Specifically, the third electrode 102 and the fourth electrode 103 are of asymmetric design. Optionally, the third electrode 102 is dot-shaped, and the fourth electrode 103 is stripe-shaped. Therefore, the areas of the third electrode 102 and the fourth electrode 103 are not uniform, and the area of the third electrode 102 is smaller than the area of the fourth electrode 103.
When the laser with the same power is respectively irradiated to the positions of the third electrode 102 and the fourth electrode 103, the heat is rapidly dissipated on the fourth electrode 103 due to the large area of the fourth electrode 103, so that the actual temperature at the fourth electrode 103 is lower than that at the third electrode 102, and the welding effect at the two positions is inconsistent. One solution provided by the prior art is that the laser power is inconsistent when two welding, but the time is needed for stabilizing the laser power, and the production efficiency is affected.
In addition, the absorption of laser by the LED itself is also an important factor in the yield of the weld. Because the laser spot irradiates both the LED and the electrode of the substrate 101 during soldering. When laser light is irradiated, the following is liable to occur: the LED reflects more laser and heats up slower, but the electrode of the substrate 101 absorbs more laser and heats up faster, so that high-temperature material sputtering occurs at the electrode of the substrate 101, even the substrate 101 breaks down, and the temperature at the electrode of the LED fails to weld.
To this end, the present embodiment provides a laser welding method of an LED, including the steps of:
step one, providing an LED and a substrate 101, wherein the LED comprises a first electrode 401, a second electrode 402 and an ITO transparent conductive layer, the substrate 101 comprises a third electrode 102 and a fourth electrode 103, and the area of the third electrode 102 is smaller than that of the fourth electrode 103;
step two, placing the LED on the substrate 101, placing the first electrode 401 on the third electrode 102, and placing the second electrode 402 on the fourth electrode 103;
step three, the first electrode 401 and the third electrode 102 are welded by laser, and in the welding process, the laser irradiates the LED and the third electrode 102 at a preset first incident angle;
fourth, the second electrode 402 and the fourth electrode 103 are welded by laser, and during welding, the laser irradiates the LED and the fourth electrode 103 at a preset second incident angle, and the first incident angle is larger than the second incident angle.
It should be understood that the order between the third step and the fourth step is not limited, and the fourth step may be performed before the third step.
The ITO transparent conductive layer has a high transmittance in the visible light band and a high absorptivity in the infrared band.
Referring to fig. 3, in step three, the laser is a first laser 201, the first laser 201 irradiates the LED and the third electrode 102 at a first incident angle, an effective welding spot irradiated by the first laser 201 is a first spot 301, and a width of the first spot 301 is W1. In the fourth step, the laser is the second laser 202, the second laser 202 irradiates the LED and the fourth electrode 103 at the second incident angle, the effective welding spot irradiated by the second laser 202 is the second spot 302, and the width of the second spot 302 is W2. The power of the first laser 201 and the second laser 202 are the same.
It is apparent that the width W1 of the first spot 301 is greater than the width W2 of the second spot 302. Therefore, the energy density of the first laser 201 irradiated on the LED and the third electrode 102 is lower than that of the second laser 202, so that the defect of the excessively high welding temperature caused by the low heat dissipation speed of the third electrode 102 can be overcome. Meanwhile, the first laser 201 is obliquely irradiated so that the laser is irradiated to the side wall of the LED. Since the side wall of the LED is generally a rough surface, the absorption of the side wall to the first laser 201 is strong, and the laser power can be further reduced.
Specifically, as one form of the asymmetric design of the third electrode 102 and the fourth electrode 103, the area of the third electrode 102 is smaller than the area of the fourth electrode 103, and the first incident angle is larger than the second incident angle. Optionally, the first angle of incidence is greater than 5 ° and the second angle of incidence is 0 °.
It should be appreciated that as another form of asymmetric design, the area of the third electrode 102 may also be larger than the area of the fourth electrode 103, and accordingly the first angle of incidence is set smaller than the second angle of incidence. Optionally, the second angle of incidence is greater than 5 ° and the first angle of incidence is 0 °.
It should be noted that, as an alternative manner of this embodiment, the first laser 201 and the second laser 202 may be understood as the same light source, and thus, fig. 3 may be understood as adjusting the position of the laser to adjust the incident angle of the laser, so as to meet the requirement of the incident angle of the third step and the fourth step, respectively.
As an alternative to this embodiment, as shown in fig. 4 and 5, the incident angle of the laser is changed by adjusting the position of the substrate 101 to improve the production efficiency. Specifically, between the third step and the fourth step, the method further comprises the following steps:
the position of the laser is kept unchanged, and the incident angle of the laser is changed by adjusting the position of the substrate 101, so that the incident angle requirements of the third step and the fourth step are respectively met.
As an alternative to this embodiment, the substrate 101 includes a plurality of third electrodes 102, and the fourth electrode 103 is a common electrode.
As an alternative to this embodiment, the LEDs are blue, green or red LEDs.
As an alternative way of this embodiment, the LED includes an N-type semiconductor layer, a light emitting layer, and a P-type semiconductor layer, which are disposed in this order. Optionally, the ITO transparent conductive layer is in contact with the N-type semiconductor layer. Optionally, the ITO transparent conductive layer is in contact with the P-type semiconductor layer.
As an alternative to this embodiment, the wavelength of the laser is greater than 1000nm.
As an alternative to this embodiment, the laser is a pulsed laser.
In summary, according to the laser welding method for the LED provided by the embodiment, for the substrate 101 with the electrode asymmetric design, the laser can be respectively irradiated on the electrodes with different areas on the substrate 101 at different incident angles, so that the LED is fixed on the substrate 101, and the welding yield is ensured and the production efficiency is also ensured under the condition of keeping the laser power unchanged.
The above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims (10)
1. A method of laser welding an LED comprising the steps of:
providing an LED and a substrate, wherein the LED comprises a first electrode, a second electrode and an ITO transparent conducting layer, the substrate comprises a third electrode and a fourth electrode, and the area of the third electrode is smaller than that of the fourth electrode;
placing the LED on the substrate, the first electrode on the third electrode, and the second electrode on the fourth electrode;
the first electrode and the third electrode are welded by laser, in the welding process, the LED and the third electrode are irradiated by the laser at a preset first incident angle, an effective welding light spot of the first electrode and the third electrode is used as a first light spot in the laser welding, and the width of the first light spot is W1;
the second electrode and the fourth electrode are welded by laser, in the welding process, the laser irradiates the LED and the fourth electrode at a preset second incident angle, the first incident angle is larger than the second incident angle, an effective light spot of the second electrode and the fourth electrode is a second light spot, the width of the second light spot is W2, and the width W1 of the first light spot is larger than the width W2 of the second light spot.
2. The method of laser welding an LED of claim 1, wherein said step of laser welding said first electrode and said step of laser welding said second electrode further comprises the steps of:
the position of the laser is kept unchanged, and the incident angle of the laser is changed by adjusting the position of the substrate.
3. The method of claim 1, wherein the substrate comprises a plurality of third electrodes, the fourth electrode is a common electrode, the third electrode is a dot, and the fourth electrode is a stripe.
4. The method of laser welding an LED of claim 1, wherein said LED is a blue, green or red LED.
5. The method of laser welding an LED of claim 1, wherein said LED comprises an N-type semiconductor layer, a light emitting layer, and a P-type semiconductor layer disposed in that order.
6. The method of laser welding an LED of claim 5, wherein said ITO transparent conductive layer is in contact with said N-type semiconductor layer.
7. The method of claim 5, wherein the ITO transparent conductive layer is in contact with the P-type semiconductor layer.
8. The method of laser welding an LED of claim 1, wherein the wavelength of said laser is greater than 1000nm.
9. The method of laser welding an LED of claim 1, wherein said laser is a pulsed laser.
10. The method of laser welding an LED of claim 1, wherein said first angle of incidence is greater than 5 ° and said second angle of incidence is 0 °.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011342451.5A CN114535734B (en) | 2020-11-25 | 2020-11-25 | Laser welding method of LED |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011342451.5A CN114535734B (en) | 2020-11-25 | 2020-11-25 | Laser welding method of LED |
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| Publication Number | Publication Date |
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| CN114535734A CN114535734A (en) | 2022-05-27 |
| CN114535734B true CN114535734B (en) | 2024-01-26 |
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| CN202011342451.5A Active CN114535734B (en) | 2020-11-25 | 2020-11-25 | Laser welding method of LED |
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Citations (8)
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|---|---|---|---|---|
| JPH0529759A (en) * | 1991-07-18 | 1993-02-05 | Mitsubishi Electric Corp | Laser-soldering method |
| JPH11250806A (en) * | 1998-03-02 | 1999-09-17 | Matsushita Electric Ind Co Ltd | Assembly method and device for electrode of discharge lamp |
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Family Cites Families (3)
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| TWI514635B (en) * | 2011-12-29 | 2015-12-21 | Hon Hai Prec Ind Co Ltd | Led light bar and manufacturing method of the same |
| JP6264568B2 (en) * | 2013-08-06 | 2018-01-24 | パナソニックＩｐマネジメント株式会社 | Light emitting device and display device |
| US11145795B2 (en) * | 2016-05-31 | 2021-10-12 | Citizen Electronics Co., Ltd. | Light emitting apparatus and method for manufacturing same |
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2020
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| JPH0529759A (en) * | 1991-07-18 | 1993-02-05 | Mitsubishi Electric Corp | Laser-soldering method |
| JPH11250806A (en) * | 1998-03-02 | 1999-09-17 | Matsushita Electric Ind Co Ltd | Assembly method and device for electrode of discharge lamp |
| JP2016076552A (en) * | 2014-10-03 | 2016-05-12 | 三菱電機株式会社 | Light-emitting device mounting substrate |
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| JP6384937B1 (en) * | 2017-08-18 | 2018-09-05 | ルーメンス カンパニー リミテッド | Light emitting device and manufacturing method thereof |
| CN212011026U (en) * | 2019-05-29 | 2020-11-24 | 首尔伟傲世有限公司 | Light emitting element with cantilever electrode, display panel with light emitting element and display device |
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| CN114535734A (en) | 2022-05-27 |
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