Preparation process of long-life diode

[0061]Example 1. A process of preparation of long life diodes, characterized in that:

[0062]Includes the following steps:

[0063]Step 1: Preparation of diode crystal grains

[0064]1.1: Pre-cutting in the thickness direction of the silicon wafer, forming an incompletely cut diode crystal grain, and the cutting depth of the silicon wafer is a total thickness of the silicon wafer.

[0065]1.2: The silicon wafer N pre-cut in the thickness direction is placed on the crystal granulating release paper, and the cutting the knife is cut towards up, light pressure, so that the diode crystal crystal crystal crystal crystal crystal crystal crystal crystal crystal crystals is completely cleaved.

[0066]Step 2: Solution to the copper lead electrode sprayed rosin isopropanol solution

[0067]In the rosin isopropyl alcohol solution, the mass ratio of rosin and isopropanol is 1:10;

[0068]Step 3: Filling

[0069]The two copper lead electrode 1, two solders 2, and wafer 3 are loaded into the clamp; each copper lead electrode includes a countertop 12, a lead 11; each copper lead electrode 1, a solder sheet 2, and the wafer 3 are circular. , Each copper lead electrode 1, solder sheet 2, wafer 3 coaxial setting Download Adobe Reader

[0070]Such asfigure 2 As shown, the size of the surface 12 of each copper lead electrode is equal to the size of the wafer 3, and the ratio of the diameter of the solder sheet 2 and the diameter of the wafer 3 is 1.02: 1; use this structure, the solder sheet 2 is dissolved in surface tension The lower surface 12 can be well bonded to the wafer 3; the average thickness of the solder sheet is 0.04-0.06mm, too thick to cause the solder material overflow weld area and short circuit.

[0071]Step 4: Welding

[0072]Filled in the welding boat, then put it in the tunnel furnace for welding, form diode welds;

[0073]The protective gas spray mouth of the tunnel furnace has five roads. The first spout is placed in the feed port of the tunnel furnace. The fifth junction is set in the tunnel furnace discharge port, the second junction, the third junction, respectively, set in the tunnel The bottom of the heating section of the furnace is disposed on the cooling section of the tunnel furnace;

[0074]Every time I started, I opened the second junction, the third spout, the fourth junction, spray the protective gas, maintain the second spout, the third junction, and the fourth junction of 4500 liters / hour. At this time, the first junction, the fifth spout is closed, and the air in the furnace is thoroughly rushed completely; then open the first jet, the fifth spout is sprayed, the first junction Traffic control is in 2000 liters / hour, the flow control of the fifth junction is 2500 liters / hour; reduce the flow rate of the second junction to 2500 liters / hour, reduce the third spout, the flow rate of the fourth jet to 3000 liters / hour;

[0075]Confirm that the flow is stable to start feed welding; the protective gas is nitrogen.

[0076]The welding temperature and time are: heating from the heating slope of 16.5 ° C / min, heating the boat to 330 ° C, welding temperature maintenance time: 8min; then send the welding boat to the cooling section of the tunnel furnace, at 5.0 ° C / min's cooling slope is lowered to 65 ° C, released, and finally fell to room temperature.

[0077]Step 5: Cleaning

[0078]Includes the following steps:

[0079]5.1: According to the concentration of> 68% nitric acid: concentration> 48% hydrofluoric acid: concentration> 99% ice acetic acid: concentration> 98% sulfuric acid volume ratio = 10: 95: 11: 2 mixed stirring production 1 Liquid; 1 lotus liquid is not exceeded 28 ° C; use mixed acid to wash the soldered diode welding for 130 seconds, then flush the diode welding with deionized water; in the process of flushing the diode welding, flush the nozzle back and forth The temperature of the deionized water is controlled at 15 ° C; the pickled temperature of the 1st solution must not exceed 28 ° C, and when the room temperature is higher than 28 degrees Celsius, cooling measures are used. The corrosion of mixed acid to silicon is a chemical process, the same as all chemical processes, and its reaction rate is strongly related to temperature. The higher the temperature, the faster reaction speed. More than 28 degrees Celsius, the corrosion speed causes a more obvious trench in the wafer acid erosion boundary, and the gallery appears on the trench, which is disadvantageous. The water temperature is less than 15 ° C, and the solubility of various devices decreases in water, difficult to clean, water temperature above 30 ° C, and the impurity of water container materials will dissolve into water, and contaminate the device. During the flushing diode welding, the flushing head is swinged back and forth; the flushing head is swinged back and forth, and the trench is easily cleaned.

[0080]5.2: The concentration of 84% phosphoric acid: concentration of 34% hydrogen oxygen: concentration> 48% hydrofluoric acid: 2-hydroxyphosphonic acid: pure water according to volume ratio = 10: 15: 2: 1: 30 mixed stir The temperature of the No. 2 liquid, the temperature of the No. 2 is not exceeded 30 ° C, and the diode weld is washed 50-60 seconds in this acid wash, and then rinsed with deionized water; the rinsing the diode welded back and forth. The reaction should appear white foam. After the reaction, the solution is light blue; too low temperature, its complex oxidation is significantly reduced. The temperature of deionized water is controlled at 15 ° C. The water temperature is less than 15 ° C, and the solubility of various devices decreases in water, difficult to clean, and the water temperature is higher than 30 ° C, and the impurity of the water container material is dissolved into the water, which causes contamination to the device. During the flushing diode welding, the flushing head is swinged back and forth; the flushing head is swinged back and forth, and the trench is easily cleaned.

[0081]5.3: The concentration of 25% by weight of the ammonia, the concentration of 35 ± 1% is mixed according to the volume ratio of 5: 1: 12-14, and the No. 3 solution is heated to 60 ° C, Diode welds were cleaned for 50 seconds using the No. 3 solution; then rinsed the diode welding with deionized water above 65 ° C. During the flushing diode welding, the flushing head is swinged back and forth. Alkaline substances are harmful to clean, usually with soap, washing and exotherm, there is always a kind of gliitive feeling, ammonia water is alkaline, and the material after the ammonia is treated with a temperature above 65 ° C, the cleaning effect is good. .

[0082]5.4: The cleaning diode welding is cleaned in deionized water ultrasound or mean, and then rinsing diode welds with deionized water above 60 ° C;

[0083]5.5: Diode welding is placed in methanol soaking. There are two: 1, using methanol, use the "dehydration" treatment of the material; 2. Since the surface of the water is large, the unstead of retaining in the fine slit may be difficult to escape, while the surface of methanol is small. It is easy to enter the fine gap to bring the unstead of the ware. 3. For "cost-effective", it is far better than isopropanol and ethanol.

[0084]5.6: Dry diode welding. Drying process: 200 ° C, drying time is not less than 0.5 hours;

[0085]Step 6: Plastic

[0086]After the wafer and the surface of the diode weld after cleaning, the diameter is solidified, and the diode package is formed by the diode package molding.

[0087]In step 6, the plastic seal is covered with the mold and press to cover the wafer portion of the soldered diode, and only the two leads are exposed to the diode package.

[0088]The plastic seal includes a binder and a filler, the binder is an epoxy resin, a quartz powder of the filler; the volume ratio of the binder and the filler is 4: 1.

[0089]The lead hardness is controlled at 0.9. The weight percentage of the solder sheet is: lead: 92.5%, tin: 5%, silver: 2.5%. The welding furnace is imported as the topow, the exit is the structure of the downhill. The thickness of the solder was 0.06 mm. The line has a diameter of 0.6 mm. The white gum is an epoxy-plastic seal. Before the glue, the epoxy molded material is not removed from the cold storage, and "wake up" is stored at room temperature for 14 hours, and then place another 0.5 hours after opening the sealing package. It is made consistent with the ambient temperature, then preheating, the preheating temperature is 80 ° C, and when the mold is transformed into a dark color, it is plastic in 5 seconds.

[0090]Example 2. A process of preparation of long life diodes, characterized in that:

[0091]Includes the following steps:

[0092]Step 1: Preparation of diode crystal grains

[0093]1.1: Pre-cutting in the thickness direction of the silicon wafer, forming an incomplete cut diode crystal grain, the cutting depth of the silicon wafer is 3/4 of the total thickness of the silicon wafer;

[0094]1.2: The silicon wafer N pre-cut in the thickness direction is placed on the crystal granulating release paper, and the cutting the knife is cut towards up, light pressure, so that the diode crystal crystal crystal crystal crystal crystal crystal crystal crystal crystal crystals is completely cleaved.

[0095]Step 2: Solution to the copper lead electrode sprayed rosin isopropanol solution

[0096]In the rosin isopropyl alcohol solution, rosin and isopropanol mass ratio is 1: 10-15;

[0097]Step 3: Filling

[0098]The two copper lead electrode 1, two solders 2, and wafer 3 are loaded into the clamp; each copper lead electrode includes a countertop 12, a lead 11; each copper lead electrode 1, a solder sheet 2, and the wafer 3 are circular. , Each copper lead electrode 1, solder sheet 2, wafer 3 coaxial setting Download Adobe Reader

[0099]Such asfigure 2 As shown, the size of the surface 12 of each copper lead electrode is equal to the size of the wafer 3, the ratio of the diameter of the solder sheet 2 and the diameter of the wafer 3 is 1.01: 1; use this structure, the solder sheet 2 is dissolved in surface tension The next to the wafer 3, the table 12 can be well bonded. The thickness of the solder was 0.04 mm.

[0100]Step 4: Welding

[0101]Filled in the welding boat, then put it in the tunnel furnace for welding, form diode welds;

[0102]The protective gas spray mouth of the tunnel furnace has five roads. The first spout is placed in the feed port of the tunnel furnace. The fifth junction is set in the tunnel furnace discharge port, the second junction, the third junction, respectively, set in the tunnel The bottom of the heating section of the furnace is disposed on the cooling section of the tunnel furnace;

[0103]Each time you open the furnace, you will first open the second jet, the third junction, the fourth junction, spray the protective gas, keep the second junction, the third spout, the fourth spout is 5,500 liters / hour At this time, the first junction, the fifth spout is closed, and the air in the furnace is thoroughly rushed completely; then open the first jet, the fifth spout is sprayed, the first junction Flow control at 2500 liters / hour, the flow control of the fifth junction is 2500 liters / hour; reduce the flow rate of the second spout to 2500 liters / hour, reduce the third spout, the fourth-channel spout flow to 3000 liters / hour;

[0104]Confirm that the flow is stable to start feed welding; the protective gas is nitrogen.

[0105]The welding temperature and time are: heated by heating slope at 16 ° C / min, heating the boat to 330 ° C; welding temperature maintenance time: 8min; then send the welding boat to the cooling section of the tunnel furnace, at 4.5 ° C / min's cooling slope is lowered to 65 ° C, released, and finally fell to room temperature.

[0106]Step 5: Cleaning

[0107]Includes the following steps:

[0108]5.1: Follow concentration of> 48% of the nitric acid: concentration> 48% hydrofluoric acid: concentration> 99% glacial acid: concentration> 98% sulfuric acid volume ratio = 10: 105: 11: 2 Mixed stirring production 1 Liquid; 1 lotus liquid is not exceeded 28 ° C; use mixed acid to wash the soldered diode welding for 130 seconds, then flush the diode welding with deionized water; in the process of flushing the diode welding, flush the nozzle back and forth The temperature of the deionized water is controlled at 15 ° C; the pickled temperature of the 1st solution must not exceed 28 ° C, and when the room temperature is higher than 28 degrees Celsius, cooling measures are used. The corrosion of mixed acid to silicon is a chemical process, the same as all chemical processes, and its reaction rate is strongly related to temperature. The higher the temperature, the faster reaction speed. More than 28 degrees Celsius, the corrosion speed causes a more obvious trench in the wafer acid erosion boundary, and the gallery appears on the trench, which is disadvantageous. The water temperature is less than 15 ° C, and the solubility of various devices decreases in water, difficult to clean, water temperature above 30 ° C, and the impurity of water container materials will dissolve into water, and contaminate the device. During the flushing diode welding, the flushing head is swinged back and forth; the flushing head is swinged back and forth, and the trench is easily cleaned.

[0109]5.2: The concentration of 84% phosphoric acid: concentration of 34% hydrogen oxygen: concentration> 48% hydrofluoric acid: 2-hydroxyphosphonic acid: pure water according to volume ratio = 10: 18: 2.5: 1.5: 30 mixed stir The temperature of the No. 2 liquid, the temperature of the No. 2 is not exceeded 30 ° C, and the diode weld is washed 50-60 seconds in this acid wash, and then rinsed with deionized water; the rinsing the diode welded back and forth. The reaction should appear white foam. After the reaction, the solution is light blue; too low temperature, its complex oxidation is significantly reduced. The temperature of deionized water is controlled at 15 ° C. The water temperature is less than 15 ° C, and the solubility of various devices decreases in water, difficult to clean, and the water temperature is higher than 30 ° C, and the impurity of the water container material is dissolved into the water, which causes contamination to the device. During the flushing diode welding, the flushing head is swinged back and forth; the flushing head is swinged back and forth, and the trench is easily cleaned.

[0110]5.3: The concentration of 25 %% of the ammonia, the concentration of 34% is mixed with a volume ratio of 6: 1: 12 ratio, and the No. 3 solution is heated to 60 ° C, using the No. 3 solution. The diode weld is washed 50 seconds; then the diode welding is then rinsed with deionized water above 65 ° C.

[0111]5.4: The cleaning diode welding is cleaned in deionized water ultrasound or mean, and then rinsing diode welds with deionized water above 60 ° C;

[0112]5.5: Diode welding is placed in methanol soaking.

[0113]5.6: Dry diode welding. Drying process: 205 ° C, drying time is not less than 0.5 hours;

[0114]Step 6: Plastic

[0115]After the wafer and the surface of the diode weld after cleaning, the diameter is solidified, and the diode package is formed by the diode package molding.

[0116]When the air in the furnace is accepted thoroughly, the second jet, the third junction, the fourth jet spouting gas time is not less than 40 minutes. The white gum is an epoxy-plastic seal. Before the glue, the epoxy molding is not removed from the cold storage, and "wake up" is stored in 16 hours at room temperature. After opening the block package, you need to place another hour. Letting it match the temperature and the ambient temperature, then preheating, the preheating temperature is 90 ° C, and when the mold is transformed into a dark color, it is plastic in 5 seconds.

[0117]The rest is the first embodiment.

[0118]Example 3. A process of preparation of long life diodes, characterized in that:

[0119]Includes the following steps:

[0120]Step 1: Preparation of diode crystal grains

[0121]1.1: Pre-cutting in the thickness direction of the silicon wafer, forming an incompletely cut diode crystal grain, and the cutting depth of the silicon wafer is 2/3 of the total thickness of the silicon wafer;

[0122]1.2: The silicon wafer N pre-cut in the thickness direction is placed on the crystal granulating release paper, and the cutting the knife is cut towards up, light pressure, so that the diode crystal crystal crystal crystal crystal crystal crystal crystal crystal crystal crystals is completely cleaved.

[0123]Step 2: Solution to the copper lead electrode sprayed rosin isopropanol solution

[0124]In the rosin isopropyl alcohol solution, rosin and isopropanol mass ratio is 1:12;

[0125]Step 3: Filling

[0126]The two copper lead electrode 1, two solders 2, and wafer 3 are loaded into the clamp; each copper lead electrode includes a countertop 12, a lead 11; each copper lead electrode 1, a solder sheet 2, and the wafer 3 are circular. , Each copper lead electrode 1, solder sheet 2, wafer 3 coaxial setting Download Adobe Reader

[0127]Such asfigure 2 As shown, the size of the surface 12 of each copper lead electrode is equal to the size of the wafer 3, the ratio of the diameter of the solder sheet 2 and 1.008: 1; uses this structure, the solder sheet 2 is dissolved in surface tension Under the wafer 3, the table 12 can be well bonded;

[0128]Step 4: Welding

[0129]Filled in the welding boat, then put it in the tunnel furnace for welding, form diode welds;

[0130]The protective gas spray mouth of the tunnel furnace has five roads. The first spout is placed in the feed port of the tunnel furnace. The fifth junction is set in the tunnel furnace discharge port, the second junction, the third junction, respectively, set in the tunnel The bottom of the heating section of the furnace is disposed on the cooling section of the tunnel furnace;

[0131]Each time you open the furnace, you will first open the second jet, the third junction, the fourth junction, spray the protective gas, keep the second junction, the third spout, the fourth spout is 5,500 liters / hour At this time, the first junction, the fifth spout is closed, and the air in the furnace is thoroughly rushed completely; then open the first jet, the fifth spout is sprayed, the first junction The flow control is 2500 liters / hour, the flow control of the fifth junction is 3000 liters / hour; the flow rate of the second junction is reduced to 3000 liters / hour, lower the third spout, the flow rate of the fourth road spout to 3,500 liters / hour;

[0132]Confirm that the flow is stable to start feed welding; the protective gas is nitrogen.

[0133]The welding temperature and time are: heating the heated slope of 17 ° C / min to heat the welding of the tunnel furnace to 340 ° C, welding temperature maintenance time: 10 min; then send the welding boat to the cooling section of the tunnel furnace, 5. The cooling slope of. 5 ° C / min was cooled to 75 ° C, released, and finally fell to room temperature.

[0134]Step 5: Cleaning

[0135]Includes the following steps:

[0136]5.1: According to the concentration of> 68% nitric acid: concentration> 99% glycetic acid: concentration> 98% sulfuric acid volume ratio = 10: 105: 11: 3 mixed stirring production 1 Liquid; 1st liquid is not exceeded 28 ° C; use mixed acid to wash the soldered diode welding for 150 seconds, then rinse the diode welding with deionized water; in the process of flushing the diode welding, flush the spray back and forth The temperature of the deionized water was controlled at 30 ° C; the pickling temperature of the 1st liquid should not exceed 28 ° C. .

[0137]5.2: The concentration of 85 ± 1% of the phosphoric acid: concentration of 36% hydrogen oxygen: concentration> 48% hydrofluoric acid: 2-hydroxyphosphonic acid: pure water according to volume ratio = 10: 20: 3: 2: 30 mixed After stirring, No. 2 liquid, the temperature of the No. 2 liquid should not exceed 30 ° C, the diode weld is washed 60 seconds in this acid washing solution, and then rinsed with deionized water; rinse the diode welding process, flushing the shot back and forth.

[0138]5.3: The concentration of 28% ammonia, the concentration of 36% is mixed with a volume ratio of 6: 1: 14 ratio, and the No. 3 solution is heated to 65 ° C, and the No. 3 solution will be used. Diode welds are cleaned for 60 seconds; then the diode weld is then rinsed with deionized water above 65 ° C.

[0139]5.4: The cleaning diode welding is cleaned in deionized water ultrasound or mean, and then rinsing diode welds with deionized water above 60 ° C;

[0140]5.5: Diode welding is placed in methanol soaking.

[0141]5.6: Dry diode welding. Drying process: 210 ° C, drying time is not less than 0.5 hours.

[0142]Step 6: Plastic

[0143]After the wafer and the surface of the diode weld after cleaning, the diameter is solidified, and the diode package is formed by the diode package molding.

[0144]The rest is the first embodiment.