CN108010841B - Method for manufacturing a diode and the resulting diode - Google Patents

Abstract

The invention discloses a method for manufacturing a diode and a diode obtained therefrom. The method of the invention includes the steps of diode crystal grain preparation, filling, welding, cleaning and packaging. The coefficient of thermal expansion and deformation, without aligning the grains in advance before welding, the grains can be automatically straightened after welding, the pore area is greatly reduced, and the welding quality is improved. Through the volume ratio of hydrofluoric acid: acetic acid: sulfuric acid: nitric acid = 8.8:13:5.6:9.2 The prepared mixed acid has a high yield rate of grain electrical properties after pickling.

Description

Method for manufacturing a diode and the resulting diode

technical field

The invention belongs to the field of high-voltage silicon stacks, and in particular relates to a method for manufacturing a diode and the diode produced therefrom.

Background technique

The current general method of grain manufacturing is to use the process of welding and stacking the whole silicon wafer and then cutting it. The welding fixture is bulky and complicated, and due to the deformation caused by the diffusion process of the whole silicon wafer before, the distribution of the large silicon wafer is not uniform after high temperature melting. , leading to a high breakage rate during the cutting process, and the small units after cutting have to be refilled with welding leads. The second welding causes secondary damage to the grains, and the more welding times, the more serious the damage. The above process is not only complicated in process and complex in equipment, but also high in cost and low in yield (about 80%).

General grain production can easily lead to polarity reversal and inconsistent polarity. Therefore, the polarity of grains needs to be selected and verified before welding, which brings great trouble to subsequent correct welding.

For conventional grain welding, no one has conducted detailed and serious research on the size ratio relationship between the solder piece and the grain, so it has not been able to contribute to the alignment problem of grain welding.

Moreover, the temperature of silicon surfacing welding generally used in the industry is greater than 350°C. When the temperature is less than 350°C, poor welding will occur. When the temperature reaches 350°C to 380°C, good welding can be achieved, but the high temperature leads to welding out. Silicon surfacing welding has large pores, the area of pores is generally 8-20%, the yield rate is low (less than 90%), and energy is wasted.

Pickling is a key step and process for soldered diodes before applying white glue. It is simple and effective to remove the roughness of the pn junction cut surface caused by grain cutting and avoid surface corrosion pits that may be caused by pickling. Removing copper, lead and other difficult-to-wash substances can improve the electrical yield and improve the quality of the pickling process.

Many diodes often work in an environment above 60°C, and the junction temperature of the chip often reaches above 125°C. Therefore, it is very meaningful to improve the high temperature reverse bias capability of the product. Produced by traditional technology, their high-temperature reverse-bias pass rate can only reach about 60%. In order to make the product more competitive, the product quality and reliability under high-temperature environment can be improved, and the high-temperature reverse-bias screening pass rate of the product can be improved. There has been no breakthrough in technology.

In the current conventional formula of mixed acid, the surface of some products is rough after pickling, and a considerable proportion of surface corrosion pits will be caused.

Contents of the invention

In view of the defects in the prior art, the present invention provides a method for manufacturing a diode and the resulting diode. The diode produced by the method of the present invention has a high reverse withstand voltage and a small forward voltage. The present invention only needs one Filling and welding can automatically align the grains through welding, and the area of welding pores is small, and the yield rate is high. The pickling process of the present invention can clean the roughness of the cutting surface to the greatest extent, effectively avoid surface corrosion pits that may be caused by pickling, and improve the electrical yield of products.

The technical scheme of the technical problem to be solved in the present invention is:

A method of manufacturing a diode, comprising the steps of:

Step 1: Preparation of Diode Die

1.1. Pre-cut in the thickness direction of the silicon wafer to form incompletely cut square diode crystal grains. The cutting depth of the silicon wafer is 3/5 to 4/5 of the total thickness of the silicon wafer.

1.2. Place the pre-cut silicon wafer in the thickness direction with the N side up on the grain cracking paper, with the cutting edge facing upwards, and press lightly to completely crack the incompletely cut diode grains.

Step 2: Filling

2.1. Put the lower lead into the lower welding boat.

2.2. Put the solder tab into the solder tab sucker and move it into the soldering boat. The solder tab falls on the lead wire; the diode die is placed in the solder boat and falls on the solder tab. Place the solder tab on the diode die and place it on the solder boat Spray flux evenly on the surface, and finally close the upper soldering boat carrying the upper lead.

Diode chips can be put in at any angle, and there is no need to deliberately adjust the angle of the chips, and there is no need to deliberately adjust the position when the solder piece is put in.

2.3. The size of the solder tab and the size of the square grain follow a strict size ratio relationship. If the solder tab is too large, the square grain cannot be straightened. If the solder tab is too small, the contact between the square grains is poor. 47, 55, 90, 134mil The dimensions of the square grains corresponding to the solder pieces are: Φ1.30mm, thickness 0.05mm; Φ1.70mm, thickness 0.05mm; Φ2.80mm, thickness 0.05mm; Φ3.56mm, thickness 0.10mm.

Step 3: Soldering

The loaded welding boat is put into the welding furnace for welding to form a diode welding piece. The welding temperature and time are:

At room temperature, heat the welding temperature to 310~320℃ with a heating slope of 16.5±0.5℃/min, and maintain the welding temperature for 5~10min; then cool down to 70±5℃ with a cooling slope of 7.0±0.5℃/min. Finally, let it cool down to room temperature naturally.

Step 4: Cleaning

Including the following steps:

4.1: Use a mixed acid to pickle the diode welded parts after welding at room temperature for 150 seconds, and then rinse the diode welded parts with deionized water for 60 seconds.

4.2: Mix phosphoric acid with a concentration of 85±1%: hydrogen peroxide with a concentration of 35±1%: pure water according to the volume ratio of 1:1:3 and stir for 8 to 10 minutes to obtain a pickling solution. Heating to 60°C, cleaning the diode soldering parts in this pickling solution for 60 seconds, and then rinsing the diode soldering parts with deionized water for 60 seconds.

4.3: Mix ammonia water with a concentration of 25% to 28%, hydrogen peroxide with a concentration of 35±1%, and pure water in a volume ratio of 9:1:9 to prepare a pickling solution. Use this pickling solution at room temperature to clean the diode The weldment was rinsed for 60 seconds, and then the diode weldment was rinsed with deionized water for 60 seconds.

4.4: Clean the diode welded parts in deionized water ultrasonically or megasonically for 3 minutes, and then rinse the diode welded parts with 50-60°C deionized water for 60 seconds.

4.5: Soak the diode welding parts in isopropanol for 5-8 minutes.

4.6: Dry the diode weldment at 170-210°C for one hour.

Step 5: Apply white glue to the cleaned and dried diode welding parts, and then cure, and the diode is packaged and formed.

More preferably, the components of the solder sheet in step 3 are: lead: 92.5%, tin: 5%, silver: 2.5%.

More preferably, in the step 3, the crystal grains are protected by nitrogen or hydrogen during heating and welding in a welding furnace, the welding temperature is 315° C., and the welding temperature is maintained for 7 minutes.

Better, the mixed acid in the step 4 is composed of hydrofluoric acid, acetic acid, sulfuric acid and nitric acid, the volume ratio of hydrofluoric acid: acetic acid: sulfuric acid: nitric acid=8.8:13:5.6:9.2, the hydrogen The concentration of hydrofluoric acid is 48.5-49.5%, the concentration of acetic acid is 99.6-99.9%, the concentration of sulfuric acid is 97.6-98.6%, and the concentration of nitric acid is 67.5-68.5%.

Better, the mixed acid is prepared in the following steps:

When the temperature is 25±5℃, add raw materials in the following order

Step 1: Add acetic acid with a concentration of 99.6-99.9% into the container, then add hydrofluoric acid with a concentration of 49±0.05%, and stir for 10-15 minutes.

Step 2: Add nitric acid with a concentration of 68±0.5%, and stir for 15 minutes.

Step 3: Finally add sulfuric acid with a concentration of 98.1±0.5%, mix and stir for 2-3 hours.

More preferably, in the steps 4.2 and 4.3, the temperature of the deionized water used is 50-60 degrees.

More preferably, the preparation of the diode grain in step 1 also includes the following steps:

First, place the transparent anti-reflection cover under the chip cracking paper, buckle the opening side of the suction cup on the diode crystal of the chip cracking paper, and then place the transparent anti-reflection cover, chip cracking paper, square crystal grains, and the suction cup as a whole The horizontal direction is reversed, and the anti-reverse cover and the die suction cup are properly clamped to prevent the relative movement of the die during the reversal, so that the diode die is moved into the suction cup as a whole; the suction cup is below, and the diode die, die Cracked paper and transparent anti-reflection cover.

Second, pick up the transparent anti-reflective cover, remove the transparent anti-reflective cover and chip cracking paper, and then re-fasten the transparent anti-reflective cover on the square die, the distance between the transparent anti-reflective cover and the chip sucker is smaller than the diode The side of the crystal grain is long to prevent it from turning over when the plate is shaken.

Third, shake the suction cup, the suction cup starts to absorb the diode crystal grains, ensure that each suction hole of the suction cup absorbs the diode crystal grains, and the direction of the diode crystal grains in the suction holes of the suction cup is consistent without reversal.

Fourth, turn on the vacuum switch, suck the diode crystal grains in the suction cup hole, and pour out a small amount of square crystal grains for other use.

The invention also discloses a diode produced by the above steps. The diode includes lead wires at both ends and diode crystal grains located between the lead wires at both ends. The diode crystal grains are electrically connected to the lead wires at both ends through welding. The outer periphery of the final diode crystal grain is provided with a protective white glue, and the outer periphery of the white glue is provided with a plastic sealing epoxy resin layer, and the diode crystal grain is manufactured according to any one of claims 1-7.

Excellent effect of the present invention:

1. The polarity of the crystal grains is consistent during the production process, so there is no need to select and verify the polarity of the grains before welding, which improves production efficiency and ensures product quality.

2. The present invention utilizes the different thermal expansion coefficients and deformations of crystal grains and solder tabs at high temperatures. It is not necessary to align the crystal grains in advance before welding, and it is loaded in the order of lead-solder tab-grain-solder tab-lead wire, which can realize post-soldering The grains are automatically straightened. The invention realizes that at a relatively low temperature of 310°C to 320°C, the pore area is greatly reduced (the pore area is less than 10%), and the good product rate is 95% to 100%, effectively avoiding the problem of not dense and firm welding, and saving energy.

3. Using the mixed acid of the present invention for the pickling step of the diode production process can realize high-performance pickling, improve the reliability of the product at high temperature by improving the electrical yield of pn, and especially effectively improve the high-temperature reflection of the diode. Bias and high temperature storage are two reliability indicators, and the product has a more competitive advantage.

Detailed ways

The technical content of the present invention is described below through specific specific embodiments, and those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various modifications and changes can be made to the details in this specification based on different viewpoints and applications without departing from the spirit of the present invention.

A method of manufacturing a diode, comprising the steps of:

Step 1: Preparation of Diode Die

1.1. Pre-cut in the thickness direction of the silicon wafer to form incompletely cut square diode crystal grains. The cutting depth of the silicon wafer is 3/5 to 4/5 of the total thickness of the silicon wafer.

1.2. Place the pre-cut silicon wafer in the thickness direction with the N side up on the grain cracking paper, with the cutting edge facing upwards, and press lightly to completely crack the incompletely cut diode grains.

Step 2: Filling

2.1. Put the lower lead into the lower welding boat.

2.2. Put the solder tab into the solder tab sucker and move it into the soldering boat. The solder tab falls on the lead wire; the diode die is placed in the solder boat and falls on the solder tab. Place the solder tab on the diode die and place it on the solder boat Spray flux evenly on the surface, and finally close the upper soldering boat carrying the upper lead.

Diode chips can be put in at any angle, and there is no need to deliberately adjust the angle of the chips, and there is no need to deliberately adjust the position when the solder piece is put in.

2.3. The size of the solder tab and the size of the square grain follow a strict size ratio relationship. If the solder tab is too large, the square grain cannot be straightened. If the solder tab is too small, the contact between the square grains is poor. 47, 55, 90, 134mil The dimensions of the square grains corresponding to the solder pieces are: Φ1.30mm, thickness 0.05mm; Φ1.70mm, thickness 0.05mm; Φ2.80mm, thickness 0.05mm; Φ3.56mm, thickness 0.10mm.

Step 3: Soldering

The loaded welding boat is put into the welding furnace for welding to form a diode welding piece. The welding temperature and time are:

At room temperature, heat the welding temperature to 310~320℃ with a heating slope of 16.5±0.5℃/min, and maintain the welding temperature for 5~10min; then cool down to 70±5℃ with a cooling slope of 7.0±0.5℃/min. Finally, let it cool down to room temperature naturally.

A preferred embodiment is that in the step 4, the crystal grains are protected by nitrogen or hydrogen during the heating and welding process of the welding furnace. key. Preferably, the length of the optional welding furnace is 11m, the length of the heating zone is 3.4m, the length of the buffer zone is 1m, and the rest is the cooling zone. Moreover, the two ends of the welding furnace are provided with nitrogen air curtains corresponding to the upper and lower sides, the nitrogen flow rate is 1.2 cubic meters/h, and the nitrogen flow rate in the heating zone is 4 cubic meters/h.

At present, in the semiconductor manufacturing industry, most of the semiconductor materials and lead wires are welded using tunnel-type welding furnaces. During the welding process, the welding temperature range and the temperature change rate and accuracy in the cooling stage will cause irreparable damage to the quality of subsequent products. influences. In the existing process, the welding temperature is generally controlled at 350-380°C, and the cooling rate is not controlled accurately, or there are some out-of-control phenomena in the cooling rate at the initial stage of furnace opening, which will directly affect the quality of the finished product. In addition, the high temperature leads to large pores in the welded silicon surfacing, and the pore area is generally 8-20%, the yield rate is low (less than 90%), and energy is wasted. If the temperature is lower than 350°C in the prior art, poor welding will occur.

Using the temperature control curve as described in the present invention, welding can be realized at a relatively low temperature of 310°C to 320°C, the pore area is greatly reduced (the pore area is less than 10%), and the good product rate is 95% to 100%, effectively avoiding welding failure. Intensive solid problem, but also saves energy. Preferably, the welding temperature is 315° C., and the holding time of the welding temperature is 7 minutes.

Step 4: Cleaning

Including the following steps:

4.1: Use a mixed acid to pickle the diode welded parts after welding at room temperature for 150 seconds, and then rinse the diode welded parts with deionized water for 60 seconds.

4.2: Mix phosphoric acid with a concentration of 85±1%: hydrogen peroxide with a concentration of 35±1%: pure water according to the volume ratio of 1:1:3 and stir for 8 to 10 minutes to obtain a pickling solution. Heating to 60°C, cleaning the diode soldering parts in this pickling solution for 60 seconds, and then rinsing the diode soldering parts with deionized water for 60 seconds. More preferably, the temperature of the deionized water used is 50-60 degrees.

4.3: Mix ammonia water with a concentration of 25% to 28%, hydrogen peroxide with a concentration of 35±1%, and pure water in a volume ratio of 9:1:9 to prepare a pickling solution. Use this pickling solution at room temperature to clean the diode The weldment was rinsed for 60 seconds, and then the diode weldment was rinsed with deionized water for 60 seconds. More preferably, the temperature of the deionized water used is 50-60 degrees.

4.4: Clean the diode welded parts in deionized water ultrasonically or megasonically for 3 minutes, and then rinse the diode welded parts with 50-60°C deionized water for 60 seconds.

4.5: Soak the diode welding parts in isopropanol for 5-8 minutes.

4.6: Dry the diode weldment at 170-210°C for 1 hour.

The cleaning standard is that the pollutant particles do not affect the diode electrical properties.

After the above-mentioned acid-washed diode welded parts, the periphery of the pn junction is smooth and has texture, which can improve the index of electrical yield. In addition, using the mixed acid of the present invention and the diode cleaning method based on the mixed acid, 77 diodes are used A high-temperature reverse bias experiment was carried out, and 77 diodes produced by using the mixed acid of the present invention and the diode cleaning method based on the mixed acid were measured, and no failure occurred.

Step 5: Apply white glue to the cleaned and dried diode welding parts, and then cure, and the diode is packaged and formed.

The mixed acid in described step 5 is made up of hydrofluoric acid, acetic acid, sulfuric acid and nitric acid, described hydrofluoric acid: acetic acid: sulfuric acid: the volume ratio of nitric acid=8.8:13:5.6:9.2, the concentration of described hydrofluoric acid 48.5-49.5%, the concentration of acetic acid is 99.6-99.9%, the concentration of sulfuric acid is 97.6-98.6%, and the concentration of nitric acid is 67.5-68.5%.

The above-mentioned mixed acid used for pickling the diode welded parts has excellent effect, and the mixed acid of the present invention is used in the pickling step of the diode production process, which can realize high-performance pickling, by improving the electrical yield of pn , thereby improving product quality and saving labor costs. At the same time, the diode welded parts pickled by mixed acid can improve the reliability of diode welded parts at high temperature, especially the two reliability indicators of high temperature reverse bias and high temperature storage of diodes can be effectively improved, and the product has more competitive advantages.

The proportioning and preparation steps of the above-mentioned mixed acid are described in detail below.

When the temperature is 25±5℃, add raw materials in the following order

Step 1: Add acetic acid with a concentration of 99.6-99.9% into the container, then add hydrofluoric acid with a concentration of 49±0.05%, and stir for 10-15 minutes.

Step 2: Add nitric acid with a concentration of 68±0.5%, and stir for 15 minutes.

Step 3: Finally add sulfuric acid with a concentration of 98.1±0.5%, mix and stir for 2-3 hours.

In the conventional manufacturing process of diode crystal grains, the diode crystal grains may be mixed together, which is inconvenient to distinguish the polarity of the crystal grains, which may affect product quality and reduce production efficiency. Therefore, the invention also discloses the innovativeness of the preparation of diode crystal grains A step of. In the above steps, it is a rough overview of the preparation of the diode crystal grains. The more detailed steps include the following steps, and the preferred several detailed steps are as follows:

More preferably, the preparation of the diode grain in step 1 also includes the following steps:

1. Place the transparent anti-reflection cover under the crystal cracking paper, buckle the opening side of the suction cup on the diode crystal of the crystal cracking paper, and then place the transparent anti-reflection cover, crystal cracking paper, square crystal grains, and suction cups in an overall level The direction is reversed, and the anti-reverse cover and the die sucker are properly clamped to prevent the relative movement of the die during the reversal, so that the diode die is moved into the sucker as a whole; paper and transparent anti-reflective cover,

2. Pick up the transparent anti-reflective cover, remove the transparent anti-reflective cover and chip cracking paper, and then re-fasten the transparent anti-reflective cover on the square die. The distance between the transparent anti-reflective cover and the die sucker is smaller than that of the diode crystal The side of the grain is long to prevent turning over when the plate is shaken,

3. Shake the suction cup, the suction cup starts to absorb the diode crystal grains, ensure that each suction hole of the suction cup absorbs the diode crystal grains, and the direction of the diode crystal grains in the suction holes of the suction cup is consistent without reversal;

4. Turn on the vacuum switch, suck the diode grains in the suction cup hole, and pour out a small amount of square grains for other use.

Using the above perfect steps can ensure that the production polarity of the grains is consistent, reduce unnecessary troubles in the follow-up, and save labor costs and improve the accuracy rate of grain production.

The invention also discloses a diode produced by the above steps. The diode includes lead wires at both ends and diode crystal grains located between the lead wires at both ends. The diode crystal grains are electrically connected to the lead wires at both ends by welding. The outer periphery of the final diode crystal grain is provided with a protective white glue, and the outer periphery of the white glue is provided with a plastic sealing epoxy resin layer, and the diode crystal grain is manufactured according to any one of claims 1-7.

Although the embodiments of the present invention have been shown and described, those skilled in the art can understand that various changes, modifications, substitutions and modifications can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the invention is defined by the claims and their equivalents.

Claims (7)

1. A method for manufacturing a diode, characterized in that: Including the following steps: Step 1: Preparation of Diode Die 1.1. Pre-cut in the thickness direction of the silicon wafer to form incompletely cut square diode grains. The cutting depth of the silicon wafer is 3/5 to 4/5 of the total thickness of the silicon wafer; 1.2. Place the pre-cut silicon wafer in the thickness direction with the N side up on the crystal cracking paper, with the cutting edge facing upwards, and press lightly to completely crack the incompletely cut diode crystals; Step 2: Filling 2.1. Put the lower lead into the lower welding boat, 2.2. Put the solder tab into the solder tab sucker and move it into the soldering boat. The solder tab falls on the lead wire; the diode die is placed in the solder boat and falls on the solder tab. Place the solder tab on the diode die and place it on the solder boat Spray the flux evenly on the surface, and finally close the upper soldering boat with the upper lead; Diode chips can be put in at any angle, and there is no need to deliberately adjust the angle of the chips, and there is no need to deliberately adjust the position when the solder is put in; 2.3. The size of the solder tab and the size of the square grain follow a strict size ratio relationship. If the solder tab is too large, the square grain cannot be straightened. If the solder tab is too small, the contact between the square grains is poor. 47, 55, 90, 134mil The dimensions of the square grains corresponding to the solder pieces are: Φ1.30mm, thickness 0.05mm; Φ1.70mm, thickness 0.05mm; Φ2.80mm, thickness 0.05mm; Φ3.56mm, thickness 0.10mm; Step 3: Soldering The loaded welding boat is put into the welding furnace for welding to form a diode welding piece. The welding temperature and time are: At room temperature, heat the welding temperature to 310~320℃ with a heating slope of 16.5±0.5℃/min, and maintain the welding temperature for 5~10min; then cool down to 70±5℃ with a cooling slope of 7.0±0.5℃/min. Finally, it was naturally cooled to room temperature, Step 4: Cleaning Including the following steps: 4.1: Use mixed acid to pickle the diode welded parts after welding at room temperature for 150 seconds, and then rinse the diode welded parts with deionized water for 60 seconds; 4.2: Mix phosphoric acid with a concentration of 85±1%: hydrogen peroxide with a concentration of 35±1%: pure water according to the volume ratio of 1:1:3 and stir for 8 to 10 minutes to obtain a pickling solution. Heating to 60°C, cleaning the diode soldering parts in this pickling solution for 60 seconds, and then rinsing the diode soldering parts with deionized water for 60 seconds; 4.3: Mix ammonia water with a concentration of 25% to 28%, hydrogen peroxide with a concentration of 35±1%, and pure water in a volume ratio of 9:1:9 to prepare a pickling solution. Use this pickling solution at room temperature to wash the diode Clean the weldment for 60 seconds, then rinse the diode weldment with deionized water for 60 seconds; 4.4: Clean the diode welded parts in deionized water ultrasonically or megasonically for 3 minutes, and then rinse the diode welded parts with 50-60°C deionized water for 60 seconds; 4.5: Soak the diode welding parts in isopropanol for 5-8 minutes; 4.6: Dry the diode weldment at 170-210°C for one hour, Step 5: Apply white glue to the cleaned and dried diode welding parts, and then cure, and the diode is packaged and formed. 2. The manufacturing method of a kind of diode according to claim 1, characterized in that: The composition of solder sheet in described step 3 is: Lead: 92.5%, Tin: 5%, Silver: 2.5%. 3. The manufacturing method of a kind of diode according to claim 1, characterized in that: In the step 3, the crystal grains are protected by nitrogen or hydrogen gas during the heating and welding process of the welding furnace, the welding temperature is 315° C., and the welding temperature is maintained for 7 minutes. 4. The manufacturing method of a kind of diode according to claim 1, characterized in that: The mixed acid in described step 4 is made up of hydrofluoric acid, acetic acid, sulfuric acid and nitric acid, described hydrofluoric acid: acetic acid: sulfuric acid: the volume ratio of nitric acid=8.8:13:5.6:9.2, the concentration of described hydrofluoric acid 48.5-49.5%, the concentration of acetic acid is 99.6-99.9%, the concentration of sulfuric acid is 97.6-98.6%, and the concentration of nitric acid is 67.5-68.5%. 5. A method for manufacturing a diode according to any one of claims 1 or 4, characterized in that: Described mixed acid is prepared as follows: When the temperature is 25±5℃, add raw materials in the following order Step 1: Add acetic acid with a concentration of 99.6 to 99.9% in the container, then add hydrofluoric acid with a concentration of 49±0.05%, and stir for 10 to 15 minutes. Step 2: add nitric acid with a concentration of 68±0.5%, stir for 15 minutes, Step 3: Finally add sulfuric acid with a concentration of 98.1±0.5%, mix and stir for 2-3 hours. 6. The manufacturing method of a kind of diode according to claim 1, characterized in that: In the steps 4.2 and 4.3, the temperature of the deionized water used is 50-60 degrees. 7. The manufacturing method of a kind of diode according to claim 1, characterized in that: The preparation of the step 1 diode grain also includes the following steps: 7.1. Place the transparent anti-reflection cover under the crystal cracking paper, buckle the opening side of the suction cup on the diode crystal of the crystal cracking paper, and then place the transparent anti-reflection cover, crystal cracking paper, square crystal grains, and suction cups as a whole horizontally The direction is reversed, and the anti-reverse cover and the die sucker are properly clamped to prevent the relative movement of the die during the reversal, so that the diode die is moved into the sucker as a whole; paper and transparent anti-reflective cover, 7.2. Pick up the transparent anti-reflective cover, remove the transparent anti-reflective cover and chip cracking paper, and then re-fasten the transparent anti-reflective cover on the square die. The distance between the transparent anti-reflective cover and the die sucker is smaller than that of the diode The side of the grain is long to prevent turning over when the plate is shaken, 7.3. Shake the suction cup, the suction cup starts to absorb the diode crystal grains, ensure that each suction hole of the suction cup absorbs the diode crystal grains, and the direction of the diode crystal grains in the suction holes of the suction cup is consistent without reversal. 7.4. Turn on the vacuum switch, suck the diode grains in the hole of the suction cup, pour out a small amount of excess square grains for other use.