Method for improving coating property of LED chip electrode

Abstract

The invention relates to the technical field of LED chip electrode cladding, in particular to a method for improving LED chip electrode cladding, which comprises the following steps of: 1, mounting a servo motor and a linear guide rail on a platform at the bottom of a cavity, and mounting a crucible assembly on a pre-designed fixed seat on the linear guide rail; and 2, controlling the servo motor to rotate to drive the fixed seat and the crucible to move on the platform by an external controller connected with the servo motor. Wherein the moving distance and the moving speed are both accurately controlled by a PLC, and the specific numerical values are set in a coating program; and step 3, active metal in a common electrode material uses the crucible, the incident angle is gradually reduced along with the lengthening of the moving distance of the crucible, and the coverage area of the corresponding film layer on the substrate is increased, so that the coating property is realized. The abnormal risk is small, the thickness of a metal material does not need to be changed, the influence on electrode metal stress is small, and therefore peeling and other yield abnormities do not need to be worried about.

Description

Technical Field

[0001] The present invention relates to the technical field of LED chip electrode covering properties, and in particular to a method for improving the electrode covering properties of an LED chip. Background Art

[0002] Today, semiconductor LED lighting is widely used in various industries, including indoor and outdoor lighting, display devices, and industrial and mining applications. Due to its energy-saving and environmentally friendly advantages, it enjoys strong national support and holds enormous development prospects. Competition in the LED industry is becoming increasingly fierce, and the performance and reliability of LED chips are of paramount importance. During LED chip manufacturing, electrode coating significantly impacts product reliability, so improving electrode coating and enhancing product reliability is a major focus in the industry.

[0003] The current technical solutions in the industry to improve electrode coating properties are: 1. Change the photoresist morphology by adjusting the photoresist composition, coating parameters, etc. 2. Match different electrode materials and improve coating properties through stress adjustment; 3. Adjust the angle of the coating pot and the height of the guide rail to match the heating coating method.

[0004] In the LED chip manufacturing process, improving electrode coverage is a key step in ensuring device performance, reliability, and lifespan. Currently, common electrode structural materials in the industry include metal materials that are easily oxidized and corroded. Therefore, these metals need to be fully covered and protected to avoid corrosion damage during subsequent chip manufacturing processes. In order to improve the electrode coating, the existing technology has the following shortcomings: 1. The stability of photoresist components is affected by batch-to-batch differences, which can easily lead to poor morphology consistency and poor coating properties; 2. Increasing stress usually narrows the process window, and excessive stress can easily cause electrode peeling and fall off, affecting product yield; 3. The plating pot angle and guide rail height are generally fixed, making it difficult to freely adjust different layers of metal. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for improving the electrode coverage of LED chips, which has a low risk of abnormalities, does not require changing the thickness of the metal material, and has little effect on the electrode metal stress. Therefore, there is no need to worry about yield abnormalities such as peeling, so as to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solution: a method for improving the electrode coverage of an LED chip, comprising the following steps: Step 1: Install the servo motor and linear guide rail on the bottom platform of the chamber, and install the crucible assembly on the pre-designed fixed seat on the linear guide rail; Step 2: The controller connected to the servo motor controls the servo motor to rotate and move the fixed seat and crucible on the platform. The moving distance and speed are precisely controlled by the PLC, and the specific values ​​are set in the coating program. Step 3: This crucible is used for active metals in general electrode materials. As the crucible moves longer, the incident angle gradually decreases, and the corresponding film layer covers an increased area on the substrate, thereby achieving coverage.

[0007] Preferably, the travel distance of each metal can be set independently, with the more active metal having a smaller distance. This can generally be set according to the following formula: x = d / D, L = a * 50cm, where d is the thickness of the metal being protected, D is the thickness of the coating metal, and L is the travel distance of the coating metal crucible.

[0008] Preferably, when x≤1, a=x / 5; when x>1, a=x / 2, and L does not exceed 50 cm at most.

[0009] Preferably, if the electrode coating is metal A, metal B, and metal C from bottom to top, the crucible position is set to 0 cm when plating metal A, 15 cm when plating metal B, and 30 cm when plating metal C.

[0010] Preferably, the metal A is the metal to be protected, the metal B is the protective metal, and the metal C is the protective metal.

[0011] Preferably, when coating metal A, the crucible group is at position 1, and the evaporation source incident angle is the largest; when coating B, the crucible group is at position 2; and when coating C, the crucible group is at position 3, and the evaporation angle gradually decreases, so that metal A can be better coated and protected.

[0012] Compared with the prior art, the present invention has the following beneficial effects: 1. The risk of abnormality is small, there is no need to change the thickness of the metal material, and the impact on the electrode metal stress is small, so there is no need to worry about yield abnormalities such as peeling.

[0013] 2. High flexibility: the metal source movement distance can be set according to the metal properties of different electrode materials to achieve layered coating function.

[0014] 3. Good stability, low requirements on photoresist performance, and the entire coverage protection can be completed in a single coating process. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0016] Figure 1 This is a diagram of the movement direction of the crucible table of the present invention on the platform at the bottom of the cavity; Figure 2 This is a diagram showing the incident angle position of the light source of the present invention; Figure 3 The electrode morphology of the conventional coating method of the present invention Figure 1 ; Figure 4 The electrode morphology of the conventional coating method of the present invention Figure 2 ; Figure 5 This is the morphology of the movable crucible coating electrode of the present invention. DETAILED DESCRIPTION

[0017] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0018] See also Figures 1 to 5 , the present invention provides a technical solution: A method for improving the electrode coverage of an LED chip, comprising the following steps: Step 1: Install the servo motor and linear guide rail on the bottom platform of the chamber, and install the crucible assembly on the pre-designed fixed seat on the linear guide rail; Step 2: The controller connected to the servo motor controls the servo motor to rotate and move the fixed seat and crucible on the platform. The moving distance and speed are precisely controlled by the PLC, and the specific values ​​are set in the coating program. Step 3: Figure 2 As shown: This figure shows the corresponding source incident angle when the metal material is evaporated. The incident angle at position 1 (the crucible is in the center) is the largest. Generally, active metals in electrode materials use the crucible at this position. As the crucible moves longer, the incident angle gradually decreases, and the corresponding film layer covers an increased area on the substrate, thereby achieving coverage.

[0019] Figure 1As shown: The crucible table moves horizontally within the red area, with a moving range of 0~50cm and a moving speed of 1~5cm / s The travel distance can be set independently for each metal, with more reactive metals having smaller distances. This can generally be set according to the following formula: x = d / D, L = a * 50cm, where d is the thickness of the metal being protected, D is the thickness of the coating metal, and L is the crucible travel distance for the coating metal.

[0020] When x≤1, a=x / 5; when x>1, a=x / 2, and L does not exceed 50cm.

[0021] like Figure 4 As shown, if the electrode coating from bottom to top is metal A (metal to be protected), metal B (protective metal), metal C (protective metal)... the crucible position can be set to 0cm when plating metal A, 15cm when plating metal B, and 30cm when plating metal C. Figure 2 As shown in the figure, when coating metal A, the crucible group is at position 1, where the evaporation source incident angle is the largest. When coating metal B, the crucible group is at position 2, and when coating metal C, the crucible group is at position 3. In this way, the evaporation angle gradually decreases, thereby better coating and protecting metal A. Similar multiple metal layer structures can achieve single-layer variable coating.

[0022] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for improving the electrode coverage of an LED chip, characterized by: The steps include: Step 1: Install the servo motor and linear guide rail on the bottom platform of the chamber, and install the crucible assembly on the pre-designed fixed seat on the linear guide rail; Step 2: The controller connected to the servo motor controls the servo motor to rotate and move the fixed seat and crucible on the platform. The moving distance and speed are precisely controlled by the PLC, and the specific values ​​are set in the coating program. Step 3: This crucible is used for active metals in general electrode materials. As the crucible moves longer, the incident angle gradually decreases, and the corresponding film layer covers an increased area on the substrate, thereby achieving coverage.

2. The method for improving the electrode coverage of an LED chip according to claim 1, wherein: The travel distance can be set independently for each metal, with more reactive metals having smaller distances. This can generally be set according to the following formula: x = d / D, L = a * 50cm, where d is the thickness of the metal being protected, D is the thickness of the coating metal, and L is the crucible travel distance for the coating metal.

3. The method for improving the electrode coverage of an LED chip according to claim 2, wherein: When x≤1, a=x / 5; when x>1, a=x / 2, and L does not exceed 50cm.

4. The method for improving the electrode coverage of an LED chip according to claim 3, wherein: If the electrode coating from bottom to top is metal A, metal B, and metal C, set the crucible position to 0 cm when plating metal A, 15 cm when plating metal B, and 30 cm when plating metal C.

5. The method for improving the electrode coverage of an LED chip according to claim 4, wherein: The metal A is the metal that needs to be protected, the metal B is the protective metal, and the metal C is the protective metal.

6. The method for improving the electrode coverage of an LED chip according to claim 5, wherein: When coating metal A, the crucible group is at position 1, and the evaporation source incident angle is the largest; when coating B, the crucible group is at position 2; and when coating C, the crucible group is at position 3. The evaporation angle gradually decreases, so that metal A can be better coated and protected.

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