Method for recycling sapphire substrate

Abstract

The present application relates to the technical field of LED chip, and particularly relates to a method for recycling sapphire substrate, which comprises the following steps: S1: removing etching glue on the upper surface of the LED chip through developing exposure; S2: starting etching process of the etching machine; S3: adding hydrogen peroxide and sodium hydroxide into the cleaning tank; and placing the LED chip into the cleaning tank. The present application has the beneficial effect that the etching process of the reaction cavity can quickly remove the gallium nitride structure on the LED chip. In the process of reacting with gallium nitride, sodium hydroxide also generates a large amount of gas with hydrogen peroxide, which increases the contact area of sodium hydroxide and gallium nitride and also increases the degree of confusion at the contact between sodium hydroxide and gallium nitride, thus improving the rate of sodium hydroxide removing gallium nitride and reducing the cost of recycling sapphire substrate.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of LED chip, and particularly relates to a method for recycling sapphire substrate. BACKGROUND

[0002] LED (Light Emitting Diode) is a kind of solid-state semiconductor device which converts electrical energy into light energy. As a new type of light-emitting device, LED has the advantages of high light efficiency, energy saving, long service life, short response time, environmental protection, etc., and is therefore called the most potential new generation light source.

[0003] The basic structure of the LED chip includes a substrate, an N-type gallium nitride layer, a quantum well layer and a P-type gallium nitride layer which are stacked in sequence. The substrate is usually made of sapphire material because the sapphire substrate has the advantages of excellent stability and mature production technology.

[0004] In order to reduce the production cost of LED chip, a sapphire substrate recycling method is disclosed in Chinese patent CN114373836A, which removes the gallium nitride structure on the sapphire substrate by multiple corrosion of alkaline solution and multiple high-temperature baking in the process of corrosion, so that the sapphire substrate can be recycled and reused.

[0005] However, the above-mentioned scheme has the following disadvantages: in order to remove the gallium nitride structure on the sapphire substrate as much as possible, multiple repeated steps are used, which consumes a large amount of power for high-temperature baking of the sapphire substrate and causes high time cost. SUMMARY

[0006] The technical problem to be solved by the present application is to provide a method for recycling sapphire substrate, which improves the efficiency of removing the gallium nitride structure on the sapphire substrate and reduces the cost of recycling sapphire substrate.

[0007] In order to solve the above technical problems, a technical solution adopted by the present application is as follows: a method for recycling sapphire substrate, comprising the following steps:

[0008] S1: coating etching glue on the surface of the LED chip, and removing the etching glue on the upper surface of the LED chip by developing exposure;

[0009] S2: placing the LED chip into the reaction cavity of the etching machine, and starting the etching process of the etching machine;

[0010] S3: adding 20%-40% concentration hydrogen peroxide solution and 60%-80% concentration sodium hydroxide solution into the cleaning tank of the cleaning machine; the volume ratio of the hydrogen peroxide solution and the sodium hydroxide solution added into the cleaning tank is 1:5; keeping the liquid temperature in the cleaning tank at 80-120 degrees, and placing the LED chip into the cleaning tank for 60-90 minutes;

[0011] S4: completing the recycling of the sapphire substrate.

[0012] The method for recycling the sapphire substrate provided by the application has the advantages that the etching glue is arranged to protect the outer surface of the LED chip which does not need to be etched, the etching glue on the upper surface of the LED chip is removed through development exposure, and the gallium nitride structure on the LED chip is exposed. The gallium nitride structure on the LED chip can be quickly removed through the etching process of the reaction cavity. After most of the gallium nitride is basically removed, the LED chip is placed into the mixed solution of sodium hydroxide and hydrogen peroxide. In the process of reacting with the gallium nitride, the sodium hydroxide also generates a large amount of gas with the hydrogen peroxide, which increases the contact area of the sodium hydroxide and the gallium nitride and also increases the degree of disorder at the contact position of the sodium hydroxide and the gallium nitride. The temperature of the solution in the cleaning tank is increased to accelerate the reaction rate, and therefore the rate of removing the gallium nitride by the sodium hydroxide is improved, and the cost of recycling the sapphire substrate is reduced. DETAILED DESCRIPTION

[0013] To make the technical contents, the purposes and the effects of the application clear, the following describes the application in combination with the embodiments.

[0014] A method for recycling a sapphire substrate, comprising the following steps:

[0015] S1: coating etching glue on the surface of the LED chip, and removing the etching glue on the upper surface of the LED chip through development exposure;

[0016] S2: placing the LED chip into the reaction cavity of the etching machine, and starting the etching process of the etching machine;

[0017] S3: adding 20%-40% concentration hydrogen peroxide solution and 60%-80% concentration sodium hydroxide solution into the cleaning tank of the cleaning machine; the volume ratio of the hydrogen peroxide solution and the sodium hydroxide solution added into the cleaning tank is 1:5; keeping the liquid temperature in the cleaning tank at 80-120 degrees, and placing the LED chip into the cleaning tank for 60-90 minutes;

[0018] S4: completing the recycling of the sapphire substrate.

[0019] From the above description, the beneficial effects of the present application are that: the method for recycling sapphire substrate provided by the present application sets etching glue to protect the outer surface of the LED chip which does not need to be etched, removes the etching glue on the upper surface of the LED chip through developing exposure, and exposes the gallium nitride structure on the LED chip. The etching process of the reaction cavity can quickly remove the gallium nitride structure on the LED chip. After most of the gallium nitride is removed, the LED chip is placed in a mixed solution of sodium hydroxide and hydrogen peroxide. In the process of reacting with gallium nitride, sodium hydroxide also generates a large amount of gas with hydrogen peroxide, which increases the contact area of sodium hydroxide and gallium nitride and also increases the degree of confusion at the contact between sodium hydroxide and gallium nitride, thereby increasing the temperature of the solution in the cleaning tank and accelerating the reaction rate. Therefore, the rate of removing gallium nitride by sodium hydroxide is improved, and the cost of recycling sapphire substrate is reduced.

[0020] Further, S2 is specifically:

[0021] The LED chip is placed in the reaction cavity of the etching machine, and the reaction cavity is kept at a flow rate of 50-100sccm of chlorine, 50-100sccm of boron trichloride, and 10-50sccm of argon. The etching process of the etching machine is started.

[0022] From the above description, the above setting provides a simple and efficient method for helping to etch gallium nitride. The removal rate of gallium nitride is improved.

[0023] Further, in the S3 step, the ultrasonic treatment process of the cleaning machine is kept started.

[0024] From the above description, the reaction rate of gallium nitride on the LED chip with sodium hydroxide is accelerated by ultrasonic cleaning of the LED chip at the same time, and the gallium nitride is more completely removed.

[0025] Further, S3 is specifically:

[0026] A 20%-40% hydrogen peroxide solution and a 60%-80% sodium hydroxide solution are added to the cleaning tank of the cleaning machine. The volume ratio of the hydrogen peroxide solution and the sodium hydroxide solution added to the cleaning tank is 1:5. The liquid temperature in the cleaning tank is kept at 80-120 degrees. The LED chip is placed in the cleaning tank, and the ultrasonic treatment process of the cleaning machine is started. The ultrasonic frequency of the cleaning machine is set to 70-150hz, and the process lasts for 60-90 minutes.

[0027] From the above description, the above setting provides a simple and efficient method for ultrasonic cleaning of the LED chip.

[0028] Further, it also includes a step S2.1 between S2 and S3;

[0029] S2.1: stripping the etching glue of the LED chip, setting a sodium hydroxide solution with a concentration of 60%-80% in the cleaning machine, keeping the temperature of the sodium hydroxide solution at 60-100 degrees, and placing the LED chip into the sodium hydroxide solution for 15-30 minutes.

[0030] As can be seen from the above description, the LED chip is cleaned with a common sodium hydroxide solution after the etching process, so that the gallium nitride which is more easily reacted is reacted; this step can reduce the cost of recycling the sapphire substrate and improve the reaction rate of the gallium nitride.

[0031] Further, S2.1 specifically refers to: stripping the etching glue of the LED chip, setting a sodium hydroxide solution with a concentration of 60%-80% in the cleaning machine, keeping the temperature of the sodium hydroxide solution at 60-100 degrees, and placing the LED chip into the sodium hydroxide solution for 15-30 minutes, then starting the ultrasonic treatment process of the cleaning machine, with an ultrasonic frequency of 70-150 hz, and the ultrasonic treatment process lasting for 30-60 minutes.

[0032] As can be seen from the above description, the LED chip is cleaned with an ultrasonic cleaning while the sodium hydroxide reacts with the gallium nitride, which improves the reaction rate of the gallium nitride.

[0033] Further, it further includes a step S3.1 between S3 and S4;

[0034] S3.1: setting deionized water in the cleaning machine, placing the LED chip into the deionized water, and starting the ultrasonic treatment process of the cleaning machine, lasting for 60-90 minutes.

[0035] As can be seen from the above description, the deionized water can clearly remove the substrate on the sapphire substrate, improving the quality of the recycled sapphire substrate.

[0036] Further, S3.1 specifically refers to: setting deionized water in the cleaning machine, keeping the temperature of the deionized water at 60-100 degrees, placing the LED chip into the deionized water, and starting the ultrasonic treatment process of the cleaning machine, with an ultrasonic frequency of 70-150 hz, and lasting for 60-90 minutes.

[0037] As can be seen from the above description, the above setting provides a simple and efficient method for cleaning the sapphire substrate with deionized water.

[0038] Further, it further includes a step S3.2 between S3 and S4;

[0039] S3.2: placing the LED chip into the spin dryer, with a spin-drying time of 10-20 minutes and a spin-drying rate of 500-1000 revolutions per minute.

[0040] As can be seen from the above description, the above setting provides a simple and efficient method for drying the sapphire substrate.

[0041] Further, the step S3.3 between S3 and S4 is further included;

[0042] S3.3: drying the LED chip in the drying machine, and the drying temperature is 80-90 degrees.

[0043] From the above description, it can be seen that the above setting provides a simple and efficient method for drying the sapphire substrate.

[0044] Embodiment one

[0045] The method for recycling the sapphire substrate provided by the embodiment includes the following steps:

[0046] S1: applying the etching glue on the surface of the LED chip, and removing the etching glue on the upper surface of the LED chip by developing and exposing;

[0047] S2: placing the LED chip into the reaction cavity of the etching machine, maintaining the input of 50sccm of chlorine gas, 50sccm of boron trichloride and 10-50sccm of argon gas in the reaction cavity, and starting the etching process of the etching machine;

[0048] S3: peeling off the etching glue of the LED chip, setting the sodium hydroxide solution with a concentration of 60%-80% in the cleaning machine, maintaining the temperature of the sodium hydroxide solution at 60 degrees, placing the LED chip into the sodium hydroxide solution for 15-30 minutes, and then starting the ultrasonic treatment process of the cleaning machine, with an ultrasonic frequency of 70hz, and the ultrasonic treatment process lasting for 30-60 minutes;

[0049] S4: adding the hydrogen peroxide solution with a concentration of 20%-40% and the sodium hydroxide solution with a concentration of 60%-80% into the cleaning tank of the cleaning machine; the volume ratio of the hydrogen peroxide solution to the sodium hydroxide solution added into the cleaning tank is 1:5; maintaining the temperature of the liquid in the cleaning tank at 80 degrees, placing the LED chip into the cleaning tank, starting the ultrasonic treatment process of the cleaning machine, setting the ultrasonic frequency of the cleaning machine to 70-150hz, and lasting for 60-90 minutes;

[0050] S5: setting the deionized water in the cleaning machine, maintaining the temperature of the deionized water at 60-100 degrees, placing the LED chip into the deionized water, starting the ultrasonic treatment process of the cleaning machine, with an ultrasonic frequency of 70hz, and lasting for 60-90 minutes;

[0051] S6: placing the LED chip into the spin-drying machine, and the spin-drying time is 10-20 minutes, and the spin-drying rate is 500 revolutions per minute;

[0052] S7: placing the LED chip into the drying machine for drying, and the drying temperature is 80 degrees; and the recycling of the sapphire substrate is completed.

[0053] Embodiment two

[0054] The method for recycling the sapphire substrate provided by the embodiment comprises the following steps:

[0055] S1: coating etching glue on the surface of the LED chip, removing the etching glue on the upper surface of the LED chip by developing exposure;

[0056] S2: placing the LED chip into the reaction cavity of the etching machine, keeping the reaction cavity to pass through 75sccm of chlorine, 75sccm of boron trichloride and 30sccm of argon, starting the etching process of the etching machine;

[0057] S3: peeling off the etching glue of the LED chip, setting a sodium hydroxide solution with a concentration of 70% in the cleaning machine, keeping the temperature of the sodium hydroxide solution at 80 degrees, placing the LED chip into the sodium hydroxide solution for 23 minutes, starting the ultrasonic treatment process of the cleaning machine, setting the ultrasonic frequency at 110hz, and continuing the ultrasonic treatment process for 45 minutes;

[0058] S4: adding a hydrogen peroxide solution with a concentration of 30% and a sodium hydroxide solution with a concentration of 70% into the cleaning tank of the cleaning machine; the volume ratio of the hydrogen peroxide solution and the sodium hydroxide solution added into the cleaning tank is 1:5; keeping the liquid temperature in the cleaning tank at 100 degrees, placing the LED chip into the cleaning tank, starting the ultrasonic treatment process of the cleaning machine, setting the ultrasonic frequency of the cleaning machine at 110hz, and continuing for 75 minutes;

[0059] S5: setting deionized water in the cleaning machine, keeping the temperature of the deionized water at 80 degrees, placing the LED chip into the deionized water, starting the ultrasonic treatment process of the cleaning machine, setting the ultrasonic frequency at 110hz, and continuing for 75 minutes;

[0060] S6: placing the LED chip into the spin dryer, spinning for 15 minutes at a speed of 750 revolutions per minute;

[0061] S7: placing the LED chip into the drying machine for drying, and setting the drying temperature at 85 degrees; and completing the recycling of the sapphire substrate.

[0062] Embodiment three

[0063] The method for recycling the sapphire substrate provided by the embodiment comprises the following steps:

[0064] S1: coating etching glue on the surface of the LED chip, removing the etching glue on the upper surface of the LED chip by developing exposure;

[0065] S2: placing the LED chip into the reaction cavity of the etching machine, keeping the reaction cavity to pass through 75sccm of chlorine, 75sccm of boron trichloride and 30sccm of argon, starting the etching process of the etching machine;

[0066] S3: stripping the etching glue of the LED chip, setting a concentration of 80% sodium hydroxide solution in the cleaning machine, keeping the temperature of the sodium hydroxide solution at 60-100 degrees, placing the LED chip into the sodium hydroxide solution for 15-30 minutes, then starting the ultrasonic treatment process of the cleaning machine, the ultrasonic frequency being 150hz, and the ultrasonic treatment process lasting for 30-60 minutes;

[0067] S4: adding a concentration of 40% hydrogen peroxide solution and a concentration of 80% sodium hydroxide solution into the cleaning tank of the cleaning machine; the volume ratio of the hydrogen peroxide solution and the sodium hydroxide solution added into the cleaning tank being 1:5; keeping the liquid temperature in the cleaning tank at 80-120 degrees, placing the LED chip into the cleaning tank, starting the ultrasonic treatment process of the cleaning machine, setting the ultrasonic frequency of the cleaning machine at 150hz, and lasting for 60-90 minutes;

[0068] S5: setting deionized water in the cleaning machine, keeping the temperature of the deionized water at 100 degrees, placing the LED chip into the deionized water, starting the ultrasonic treatment process of the cleaning machine, the ultrasonic frequency being 150hz, and lasting for 60-90 minutes;

[0069] S6: placing the LED chip into the spin-dryer, the spin-dry time being 10-20 minutes, and the spin-dry rate being 1000 revolutions per minute;

[0070] S7: placing the LED chip into the drying machine for drying, the drying temperature being 90 degrees; and completing the recycling of the sapphire substrate.

[0071] The above description is only an embodiment of the present application, and does not limit the patent scope of the present application, and any equivalent transformation or direct or indirect application in the related technical field based on the content of the present application is also included in the patent protection scope of the present application.

Claims

1. A method for recycling and reusing sapphire substrates, characterized in that, Includes the following steps: S1: Apply the etching resin to the surface of the LED chip, and remove the etching resin from the upper surface of the LED chip by developing and exposing it. S2: Place the LED chip into the reaction chamber of the etching machine and start the etching process of the etching machine; S3: Add a 20%-40% hydrogen peroxide solution and a 60%-80% sodium hydroxide solution to the cleaning tank of the cleaning machine; the volume ratio of the hydrogen peroxide solution to the sodium hydroxide solution added to the cleaning tank is 1:5; maintain the liquid temperature in the cleaning tank at 80-120 degrees Celsius, place the LED chip into the cleaning tank, and continue for 60-90 minutes. S4: Complete the recycling of the sapphire substrate.

2. The method for recycling and reusing sapphire substrates according to claim 1, characterized in that, Specifically, S2 is: Place the LED chip into the reaction chamber of the etching machine, maintain the flow of chlorine gas at 50-100 sccm, boron trichloride gas at 50-100 sccm, and argon gas at 10-50 sccm in the reaction chamber, and start the etching process of the etching machine.

3. The method for recycling and reusing sapphire substrates according to claim 1, characterized in that, In step S3, keep the ultrasonic treatment process of the cleaning machine running.

4. The method for recycling and reusing sapphire substrates according to claim 3, characterized in that, Specifically, S3 is: Add a 20%-40% hydrogen peroxide solution and a 60%-80% sodium hydroxide solution to the cleaning tank of the cleaning machine; the volume ratio of the hydrogen peroxide solution to the sodium hydroxide solution in the cleaning tank is 1:5; maintain the liquid temperature in the cleaning tank at 80-120 degrees Celsius, place the LED chip into the cleaning tank, start the ultrasonic treatment process of the cleaning machine, set the ultrasonic frequency of the cleaning machine to 70-150 Hz, and continue for 60-90 minutes.

5. The method for recycling and reusing sapphire substrates according to claim 1, characterized in that, It also includes step S2.1 between S2 and S3; S2.1: Remove the etchant from the LED chip, prepare a 60%-80% sodium hydroxide solution in the cleaning machine, maintain the sodium hydroxide solution temperature at 60-100 degrees Celsius, and immerse the LED chip in the sodium hydroxide solution for 15-30 minutes.

6. The method for recycling and reusing sapphire substrates according to claim 5, characterized in that, S2.1 specifically involves: stripping the etchant from the LED chip, setting a 60%-80% sodium hydroxide solution in a cleaning machine, maintaining the sodium hydroxide solution temperature at 60-100 degrees Celsius, immersing the LED chip in the sodium hydroxide solution for 15-30 minutes, and then starting the ultrasonic treatment process of the cleaning machine at an ultrasonic frequency of 70-150 Hz for 30-60 minutes.

7. The method for recycling and reusing sapphire substrates according to claim 1, characterized in that, It also includes step S3.1 between S3 and S4; S3.1: Set the cleaning machine with deionized water, place the LED chip in the deionized water, and start the ultrasonic treatment process of the cleaning machine for 60-90 minutes.

8. The method for recycling and reusing sapphire substrates according to claim 7, characterized in that, S3.1 specifically involves: setting deionized water in the cleaning machine, maintaining the deionized water temperature at 60-100 degrees Celsius, placing the LED chip in the deionized water, and starting the ultrasonic treatment process of the cleaning machine at an ultrasonic frequency of 70-150 Hz for 60-90 minutes.

9. The method for recycling and reusing sapphire substrates according to claim 1, characterized in that, It also includes step S3.2 between S3 and S4; S3.2: Place the LED chip into the spin dryer and spin dry for 10-20 minutes at a speed of 500-1000 revolutions per minute.

10. The method for recycling and reusing sapphire substrates according to claim 1, characterized in that, It also includes step S3.3 between S3 and S4; S3.3: Place the LED chip in a dryer and dry it at a temperature of 80-90 degrees Celsius.