Packaging process of temperature sensor chip

Abstract

A packaging process of a temperature sensor chip comprises the following steps: selecting an aluminum nitride ceramic substrate, and selecting a gold-tin solder sheet with a corresponding size according to the size of the chip; cleaning the aluminum nitride ceramic substrate; manufacturing a double-sided metallization layer of the aluminum nitride ceramic substrate; cutting up the aluminum nitride ceramic substrate on which the metallization layer is deposited according to the size of the chip, then placing a metal tube shell on a sintering mold, placing a gold-tin solder piece on the metal tube shell, placing the cut aluminum nitride ceramic substrate on the gold-tin solder piece, placing the gold-tin solder piece on the aluminum nitride ceramic substrate again, and then placing the gold-tin solder piece on the aluminum nitride ceramic substrate again; and finally placing a chip. Putting the raw materials into an eutectic welding furnace for sintering; and a programmable vacuum eutectic welding furnace is selected for eutectic sintering, after welding is completed, after the temperature is reduced to 70 DEG C or below, a cavity door is opened, and the device is taken out. The beneficial effects are that the temperature sensing performance is high, the insulation effect is good, the technology is reasonable, the operation is simple, the production efficiency is high, and the method is suitable for industrial production.

Description

Technical Field

[0001] The invention relates to a packaging process, in particular to a packaging process for a temperature sensor chip. Background Art

[0002] As we all know, the temperature sensor chip is a chip with high temperature accuracy and very fast response speed. Since the main function of the temperature sensor chip is temperature sensing, the chip and the shell must have a good temperature transmission channel during packaging. The eutectic welding method will greatly reduce the thermal resistance between the chip and the shell, but the nature of the chip itself determines that the chip cannot be directly connected to the metal shell. At present, the temperature sensor chip is usually bonded with insulating glue, that is, the chip and the shell are bonded with insulating glue, which greatly reduces the thermal conductivity and temperature transfer performance. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a packaging process for a temperature sensor chip, which not only has high temperature sensing performance and good insulation effect, but also has reasonable process, simple operation, high production efficiency and is suitable for industrial production.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A packaging process for a temperature sensor chip comprises the following steps:

[0006] 1. Select aluminum nitride ceramic substrate and choose gold-tin solder sheet of corresponding size according to the size of chip;

[0007] 2. Cleaning of aluminum nitride ceramic substrates;

[0008] 3. Make the metallization layer of aluminum nitride ceramic substrate;

[0009] 3.1. Select a magnetron sputtering table with four target positions and deposit the composite metal layer by sputtering; put the aluminum nitride ceramic substrate into the tray and send it into the sputtering chamber of the magnetron sputtering table, and heat the substrate to a temperature of 160°C ± 10°C;

[0010] 3.2. Then, the aluminum nitride ceramic substrate is reversely sputtered, bombarding the aluminum nitride ceramic substrate at a power of 150W±10W for 300s±10s to remove the contamination layer on the substrate surface, activate the substrate surface, and improve the adhesion of the sputtered film layer on the substrate surface;

[0011] 3.3. Sputtering CrSi-NiCr-Au composite film on the substrate surface, first sputtering CrSi layer, power set at 100W±10W, time 500s±10s, argon flow rate of 13sccm±2sccm; during sputtering, first cut off the high valve flow, control the vacuum channel to be partially closed, then turn on the oxygen flow meter switch, and introduce a certain amount of oxygen for reactive sputtering, oxygen flow rate 3sccm±1sccm; immediately after sputtering the CrSi layer, sputtering NiCr film, power set at 300W±10W, time 300s±10s; finally sputtering Au layer, power set at 200W±10W, time 300s±10s; after sputtering, take out the aluminum nitride ceramic substrate, and use the same method to sputter and deposit the other side, so that CrSi-NiCr-Au composite film metallization layer is formed on both sides of the substrate;

[0012] 4. Cut the aluminum nitride ceramic substrate with the metallized layer deposited according to the size of the chip, then place the metal shell on the sintering mold, then place the gold-tin solder sheet on the metal shell, place the cut aluminum nitride ceramic substrate on the gold-tin solder sheet, place the gold-tin solder sheet on the aluminum nitride ceramic substrate again, and finally place the chip; and put them together in a eutectic soldering furnace for sintering;

[0013] 5. Use a programmable vacuum eutectic welding furnace for eutectic sintering. After welding is completed, wait for the temperature to drop below 70°C, open the chamber door and take out the device.

[0014] 6. Finally, the eutectic sintered product is bonded and capped to complete the packaging.

[0015] As a further preference, the aluminum nitride ceramic substrate has a thickness of 0.3±0.02 mm and a thermal conductivity of ≥170 W / m·k.

[0016] As a further preference, when cleaning the aluminum nitride ceramic substrate, firstly, ultrasonic cleaning is performed with acetone for 15 minutes, then rinsing with deionized water, and finally, dehydrating with anhydrous ethanol, drying with nitrogen, and drying with a drying lamp for later use.

[0017] As a further preferred embodiment, when eutectic sintering is performed, the steps are as follows:

[0018] (1) First, evacuate the vacuum chamber and fill it with nitrogen to purify the atmosphere in the vacuum chamber; then start to heat up until the temperature in the furnace reaches 180°C ± 10°C, then introduce formic acid with a flow rate controlled at a maximum of 8s lm to 10s lm; formic acid decomposes under heat to produce hydrogen, which neutralizes the oxygen in the vacuum chamber and provides the reducing gas required for welding; preheat the mold and tube shell;

[0019] (2) Continue to heat up to 280℃±10℃, and keep the temperature constant for 200s~300s to fully preheat the mold and tube shell to prepare for the solder melting eutectic below;

[0020] (3) After the constant temperature is completed, the temperature is quickly raised to 350℃±10℃ within 100s±10s, and the temperature is kept constant for 50s±10s to melt the gold-tin solder sheet and end the eutectic;

[0021] (4) Turn off the formic acid flow, evacuate the chamber, and remove the remaining formic acid in the vacuum chamber; then turn off the heating and fill with nitrogen to cool down.

[0022] The beneficial effects of the present invention are:

[0023] 1. Reasonable process and simple operation; by selecting aluminum nitride ceramic substrate with high thermal conductivity, using sputtering process to perform ceramic metallization treatment on it, selecting CrSi-NiCr-Au composite film metallization layer, and introducing oxygen when sputtering the first CrSi layer, oxygen combines with the incident deposition atoms to generate an oxide intermediate layer, which can enhance the adhesion of the film.

[0024] 2. During eutectic sintering, a programmable vacuum eutectic soldering furnace is selected, and a double-layer gold-tin solder sheet is used for eutectic sintering; the eutectic sintering process is cleverly and reasonably modified, the eutectic curve is edited, and the constant temperature time of the preheating section is increased, so that the double-layer gold-tin solder sheet completes eutectic sintering; this temperature sensor chip packaging process not only has high temperature sensing performance and good insulation effect, but also has high production efficiency, is suitable for industrial production, and can improve product quality reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the structure of the aluminum nitride ceramic substrate after metallization of the present invention.

[0026] Figure 2 It is a cross-sectional schematic diagram of the chip, aluminum nitride ceramic substrate and tube shell after eutectic sintering of the present invention.

[0027] Figure 3 It is a top view schematic diagram of the chip, aluminum nitride ceramic substrate and tube shell after eutectic sintering of the present invention.

[0028] In the figure: aluminum nitride ceramic substrate 1, metallization layer 2, chip 3, gold-tin solder sheet 4, tube shell 5. DETAILED DESCRIPTION

[0029] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0030] Example 1

[0031] Reference Figures 1 to 3 As shown, the present invention relates to a packaging process of a temperature sensor chip, comprising the following steps:

[0032] 1. Select an aluminum nitride ceramic substrate 1, and select a gold-tin solder sheet 4 of corresponding size according to the size of the chip; the thickness of the aluminum nitride ceramic substrate 1 is 0.3±0.02 mm, and the thermal conductivity is ≥170 W / m·k.

[0033] 2. Cleaning the aluminum nitride ceramic substrate 1; when cleaning the aluminum nitride ceramic substrate 1, first use acetone ultrasonic cleaning for 15 minutes, then rinse with deionized water, and finally dehydrate with anhydrous ethanol, blow dry with nitrogen, and dry with a drying lamp for use.

[0034] 3. Making a metallization layer of the aluminum nitride ceramic substrate 1;

[0035] 3.1. Select a magnetron sputtering table with four target positions, and deposit the composite metal layer by sputtering; put the aluminum nitride ceramic substrate 1 into a tray and send it into the sputtering chamber of the magnetron sputtering table, and heat the substrate to a temperature of 160°C ± 10°C;

[0036] 3.2. Then, the aluminum nitride ceramic substrate 1 is reversely sputtered, and the aluminum nitride ceramic substrate 1 is bombarded at a power of 150W±10W for 300s±10s to remove the contamination layer on the substrate surface, activate the substrate surface, and improve the adhesion of the sputtered film layer on the substrate surface;

[0037] 3.3. Sputtering a CrSi-NiCr-Au composite film on the surface of the aluminum nitride ceramic substrate 1, first sputtering the CrSi layer, the power is set at 100W±10W, the time is 500s±10s, the argon flow rate is 13sccm±2sccm, and argon is introduced; during sputtering, the high valve is first cut off, the vacuum channel is partially closed, and then the oxygen flow meter switch is turned on, and a certain amount of oxygen is introduced for reactive sputtering, the oxygen flow rate is 3sccm±1sccm, and the oxygen and the incident The deposited atoms are combined to form an oxide intermediate layer, which can enhance the adhesion of the film; after sputtering the CrSi layer, the NiCr film is sputtered immediately, with the power set at 300W±10W and the time at 300s±10s; finally, the Au layer is sputtered, with the power set at 200W±10W and the time at 300s±10s; after the sputtering is completed, the aluminum nitride ceramic substrate 1 is taken out, and the other side is sputtered and deposited in the same way, so that the CrSi-NiCr-Au composite film metallization layer 2 is formed on both sides of the substrate, such as Figure 1 shown.

[0038] 4. Cut the aluminum nitride ceramic substrate 1 with the metallization layer 2 deposited according to the size of the temperature sensing chip 3 to be packaged, then place the metal tube shell 5 on the sintering mold, and then place the gold-tin solder sheet 4 on the metal tube shell 5, place the cut aluminum nitride ceramic substrate 1 on the gold-tin solder sheet 4, place the gold-tin solder sheet 4 on the aluminum nitride ceramic substrate 1 again, and finally place the chip 3; and put them together in the eutectic soldering furnace for sintering.

[0039] 5. Use a programmable vacuum eutectic welding furnace for eutectic sintering. After welding is completed, wait for the temperature to drop below 70°C, open the chamber door, and take out the eutectic devices, such as Figure 2 and Figure 3 Observe under a 30-60 times microscope, the solder of the eutectic product is well infiltrated, and there are no holes around the chip 3, so the eutectic sintering of the temperature sensing chip 3, the aluminum nitride ceramic metallized substrate, and the tube shell 5 can be completed, that is, the temperature sensor chip packaging process is completed.

[0040] When eutectic sintering is performed, the steps are as follows:

[0041] (1) First, the vacuum chamber is evacuated and filled with nitrogen, each lasting for more than 80 seconds, and this cycle is repeated twice to purify the atmosphere in the vacuum chamber; then the temperature is raised to 180°C ± 10°C, and formic acid is introduced at a maximum flow rate of 8s lm to 10s lm; formic acid is decomposed by heat to produce hydrogen, which neutralizes the oxygen in the vacuum chamber and provides the reducing gas required for welding - hydrogen; the mold and the tube shell 5 are preheated;

[0042] (2) Continue to raise the temperature to 280°C ± 10°C and keep the temperature constant for 200s to 300s to fully preheat the mold and the tube shell 5 to prepare for the solder melting eutectic below;

[0043] (3) After the constant temperature is completed, the temperature is quickly heated to 350°C±10°C within 100s±10s, and the temperature is kept constant for 50s±10s to melt the gold-tin solder sheet 4 and complete the eutectic;

[0044] (4) Turn off the formic acid flow, evacuate the chamber, and remove the remaining formic acid in the vacuum chamber; then turn off the heating and fill with nitrogen to cool down.

[0045] 6. Finally, use a gold wire ball welder to perform gold wire bonding on the product after eutectic sintering, and then use an energy storage welder to perform energy storage welding and sealing to complete the packaging of the temperature sensor chip.

[0046] Example 2

[0047] Reference Figures 1 to 3 As shown, the present invention relates to a packaging process of a temperature sensor chip, comprising the following steps:

[0048] 1. Select an aluminum nitride ceramic substrate 1, and select a gold-tin solder sheet 4 of corresponding size according to the size of the chip 3; the thickness of the aluminum nitride ceramic substrate 1 is 0.3±0.02 mm, and the thermal conductivity is ≥170 W / m·k.

[0049] 2. Cleaning the aluminum nitride ceramic substrate 1; when cleaning the aluminum nitride ceramic substrate 1, first use acetone ultrasonic cleaning for 15 minutes, then rinse with deionized water, and finally dehydrate with anhydrous ethanol, blow dry with nitrogen, and dry with a drying lamp for use.

[0050] 3. Making a metallization layer of the aluminum nitride ceramic substrate 1;

[0051] 3.1. Select a magnetron sputtering table with four target positions and deposit the composite metal layer by sputtering; put the aluminum nitride ceramic substrate 1 into a tray and send it into the sputtering chamber of the magnetron sputtering table, and heat the substrate to a temperature of 150° C.;

[0052] 3.2. Then, the aluminum nitride ceramic substrate 1 is reversely sputtered, and the aluminum nitride ceramic substrate 1 is bombarded at a power of 140 W for 290 seconds to remove the contamination layer on the substrate surface, activate the substrate surface, and improve the adhesion of the sputtered film layer on the substrate surface;

[0053] 3.3. Sputtering a CrSi-NiCr-Au composite film on the surface of the aluminum nitride ceramic substrate 1, first sputtering the CrSi layer, setting the power at 90W, the time at 490s, the argon flow rate at 11sccm, and introducing argon; during sputtering, first cut off the high valve flow, control the vacuum channel to be partially closed, then turn on the oxygen flow meter switch, introduce a certain amount of oxygen for reactive sputtering, the oxygen flow rate is 2sccm, and the oxygen combines with the incident deposition atoms to form an oxide intermediate layer, which can enhance the adhesion of the film; immediately after sputtering the CrSi layer, sputtering the NiCr film, setting the power at 290W, the time at 290s; finally sputtering the Au layer, setting the power at 190W, the time at 290s; after sputtering, taking out the aluminum nitride ceramic substrate 1, and using the same method to sputter and deposit the other side, so that a CrSi-NiCr-Au composite film metallization layer 2 is formed on both sides of the substrate, as shown in FIG. Figure 1 shown.

[0054] 4. Cut the aluminum nitride ceramic substrate 1 with the metallization layer 2 deposited according to the size of the temperature sensing chip to be packaged, then place the metal tube shell 5 on the sintering mold, and then place the gold-tin solder sheet 4 on the metal tube shell 5, place the cut aluminum nitride ceramic substrate 1 on the gold-tin solder sheet 4, place the gold-tin solder sheet 4 on the aluminum nitride ceramic substrate 1 again, and finally place the chip 3; and put them together in the eutectic soldering furnace for sintering.

[0055] 5. Use a programmable vacuum eutectic welding furnace for eutectic sintering. After welding is completed, wait for the temperature to drop below 70°C, open the chamber door, and take out the eutectic devices, such as Figure 2 and Figure 3 Observe under a 30-60 times microscope, the solder of the eutectic product is well infiltrated, and there are no holes around the chip 3, so the eutectic sintering of the temperature sensing chip 3, the aluminum nitride ceramic metallized substrate, and the tube shell 5 can be completed, that is, the temperature sensor chip packaging process is completed.

[0056] When eutectic sintering is performed, the steps are as follows:

[0057] (1) First, the vacuum chamber is evacuated and filled with nitrogen, each lasting for more than 80 seconds, and this cycle is repeated twice to purify the atmosphere in the vacuum chamber; then the temperature is raised to 170°C, and formic acid is introduced at this time, with the flow rate controlled at a maximum of 8s lm; formic acid is decomposed by heat to produce hydrogen, which neutralizes the oxygen in the vacuum chamber and provides the reducing gas required for welding - hydrogen; the mold and the tube shell 5 are preheated;

[0058] (2) Continue to raise the temperature to 270° C. and keep the temperature constant for 300 seconds to fully preheat the mold and the tube shell 5 to prepare for the solder melting eutectic below;

[0059] (3) After the constant temperature is completed, the temperature is quickly heated to 340°C within 90 seconds and the temperature is kept constant for 60 seconds to melt the gold-tin solder sheet 4 and the eutectic is completed;

[0060] (4) Turn off the formic acid flow, evacuate the chamber, and remove the remaining formic acid in the vacuum chamber; then turn off the heating and fill with nitrogen to cool down.

[0061] 6. Finally, use a gold wire ball welder to perform gold wire bonding on the product after eutectic sintering, and then use an energy storage welder to perform energy storage welding and sealing to complete the packaging of the temperature sensor chip.

[0062] Example 3

[0063] Reference Figures 1 to 3 As shown, the present invention relates to a packaging process of a temperature sensor chip, comprising the following steps:

[0064] 1. Select an aluminum nitride ceramic substrate 1, and select a gold-tin solder sheet 4 of corresponding size according to the size of the chip 3; the thickness of the aluminum nitride ceramic substrate 1 is 0.3±0.02 mm, and the thermal conductivity is ≥170 W / m·k.

[0065] 2. Cleaning the aluminum nitride ceramic substrate 1; when cleaning the aluminum nitride ceramic substrate 1, first use acetone ultrasonic cleaning for 15 minutes, then rinse with deionized water, and finally dehydrate with anhydrous ethanol, blow dry with nitrogen, and dry with a drying lamp for use.

[0066] 3. Making a metallization layer of the aluminum nitride ceramic substrate 1;

[0067] 3.1. Select a magnetron sputtering table with four target positions and deposit the composite metal layer by sputtering; put the aluminum nitride ceramic substrate 1 into a tray and send it into the sputtering chamber of the magnetron sputtering table, and heat the substrate to a temperature of 170° C.;

[0068] 3.2. Then, the aluminum nitride ceramic substrate 1 is reversely sputtered, and the aluminum nitride ceramic substrate 1 is bombarded at a power of 160 W for 310 seconds to remove the contamination layer on the substrate surface, activate the substrate surface, and improve the adhesion of the sputtered film layer on the substrate surface;

[0069] 3.3. Sputtering a CrSi-NiCr-Au composite film on the surface of the aluminum nitride ceramic substrate 1, first sputtering the CrSi layer, setting the power at 110W, the time for 510s, the argon flow rate of 15sccm, and introducing argon; during sputtering, first cut off the high valve flow, control the vacuum channel to be partially closed, then turn on the oxygen flow meter switch, and introduce a certain amount of oxygen for reactive sputtering, the oxygen flow rate is 4sccm, and the oxygen combines with the incident deposition atoms to form an oxide intermediate layer, which can enhance the adhesion of the film; immediately after sputtering the CrSi layer, sputtering the Ni Cr film, setting the power at 310W, the time for 310s; finally, sputtering the Au layer, setting the power at 210W, the time for 310s; after sputtering, take out the aluminum nitride ceramic substrate 1, and use the same method to sputter and deposit the other side, so that the CrSi-NiCr-Au composite film metallization layer 2 is formed on both sides of the substrate, as shown Figure 1 shown.

[0070] 4. Cut the aluminum nitride ceramic substrate 1 with the metallization layer 2 deposited according to the size of the temperature sensing chip 3 to be packaged, then place the metal tube shell 5 on the sintering mold, and then place the gold-tin solder sheet 4 on the metal tube shell 5, place the cut aluminum nitride ceramic substrate 1 on the gold-tin solder sheet 4, place the gold-tin solder sheet 4 on the aluminum nitride ceramic substrate 1 again, and finally place the chip 3; and put them together in the eutectic soldering furnace for sintering.

[0071] 5. Use a programmable vacuum eutectic welding furnace for eutectic sintering. After welding is completed, wait for the temperature to drop below 70°C, open the chamber door, and take out the eutectic devices, such as Figure 2 and Figure 3 Observe under a 30-60 times microscope, the solder of the eutectic product is well infiltrated, and there are no holes around the chip 3, so the eutectic sintering of the temperature sensing chip 3, the aluminum nitride ceramic metallized substrate, and the tube shell 5 can be completed, that is, the temperature sensor chip packaging process is completed.

[0072] When eutectic sintering is performed, the steps are as follows:

[0073] (1) First, the vacuum chamber is evacuated and filled with nitrogen, each lasting for more than 80 seconds, and this cycle is repeated twice to purify the atmosphere in the vacuum chamber; then the temperature is raised to 190°C, and formic acid is introduced at this time, with the flow rate controlled at a maximum of 10s lm; formic acid is decomposed by heat to produce hydrogen, which neutralizes the oxygen in the vacuum chamber and provides the reducing gas required for welding - hydrogen; the mold and the tube shell 5 are preheated;

[0074] (2) Continue to raise the temperature to 290° C. and keep the temperature constant for 200 seconds to fully preheat the mold and the tube shell 5 to prepare for the solder melting eutectic below;

[0075] (3) After the constant temperature is completed, the temperature is quickly heated to 360°C within 110 seconds and the temperature is kept constant for 40 seconds to melt the gold-tin solder sheet 4 and the eutectic is completed;

[0076] (4) Turn off the formic acid flow, evacuate the chamber, and remove the remaining formic acid in the vacuum chamber; then turn off the heating and fill with nitrogen to cool down.

[0077] 6. Finally, use a gold wire ball welder to perform gold wire bonding on the product after eutectic sintering, and then use an energy storage welder to perform energy storage welding and sealing to complete the packaging of the temperature sensor chip.

[0078] In order to detect the bonding strength between the aluminum nitride ceramic substrate and the metal tube shell of the eutectic sintered product, 10 eutectic sintered products were selected from the above embodiments for shear force test. Since the bonding strength of gold-tin solder is large, a non-destructive shear strength test was set when performing the shear strength test, and the test data was completely qualified. The test data is shown in Table 1.

[0079]

[0080]

[0081] Table 1

[0082] It can be seen from Table 1 that the temperature sensor chip packaged by the embodiment of the present invention fully complies with the standard requirements of GJB548C-2021 "Test Methods and Procedures for Microelectronic Devices".

[0083] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A packaging process for a temperature sensor chip, characterized in that The steps include: (1) Select an aluminum nitride ceramic substrate and select a gold-tin solder sheet of corresponding size according to the size of the chip; (2) Cleaning of aluminum nitride ceramic substrates; (3) Making a metallization layer of an aluminum nitride ceramic substrate; 3.

1. Select a magnetron sputtering table with four target positions and deposit the composite metal layer by sputtering; put the aluminum nitride ceramic substrate into the tray and send it into the sputtering chamber of the magnetron sputtering table, and heat the substrate to a temperature of 160°C ± 10°C; 3.

2. Then, the aluminum nitride ceramic substrate is reversely sputtered, bombarding the aluminum nitride ceramic substrate at a power of 150W±10W for 300s±10s to remove the contamination layer on the substrate surface, activate the substrate surface, and improve the adhesion of the sputtered film layer on the substrate surface; 3.

3. Sputtering CrSi-NiCr-Au composite film on the substrate surface, first sputtering CrSi layer, power set at 100W±10W, time 500s±10s, argon flow rate of 13sccm±2sccm; during sputtering, first cut off the high valve, control the vacuum channel to be partially closed, then turn on the oxygen flow meter switch, and introduce a certain amount of oxygen for reactive sputtering, oxygen flow rate 3sccm±1sccm; immediately after sputtering CrSi layer, sputter NiCr film, power set at 300W±10W, time 300s±10s; finally sputtering Au layer, power set at 200W±10W, time 300s±10s; After the sputtering is completed, the aluminum nitride ceramic substrate is taken out and the other side is sputtered and deposited in the same way, so that a CrSi-NiCr-Au composite film metallization layer is formed on both sides of the substrate; (4) Cutting the aluminum nitride ceramic substrate with the metallization layer deposited thereon according to the size of the chip, then placing the metal tube shell on the sintering mold, placing a gold-tin solder sheet on the metal tube shell, placing the cut aluminum nitride ceramic substrate on the gold-tin solder sheet, placing a gold-tin solder sheet on the aluminum nitride ceramic substrate again, and finally placing the chip; and placing them together in a eutectic soldering furnace for sintering; (5) Use a programmable vacuum eutectic welding furnace for eutectic sintering. After welding, wait until the temperature drops below 70°C, open the chamber door, and take out the device; (6) Finally, the eutectic sintered product is bonded and capped to complete the packaging.

2. The packaging process of a temperature sensor chip according to claim 1, characterized in that: The thickness of the aluminum nitride ceramic substrate is 0.3±0.02 mm, and the thermal conductivity is ≥170 W / m·k.

3. The packaging process of a temperature sensor chip according to claim 1, characterized in that: When the aluminum nitride ceramic substrate is cleaned, it is firstly ultrasonically cleaned with acetone for 15 minutes, then rinsed with deionized water, and finally dehydrated with anhydrous ethanol, dried with nitrogen, and dried with a drying lamp for use.

4. The packaging process of a temperature sensor chip according to claim 1, characterized in that: When eutectic sintering is performed, the steps are as follows: (1) First, evacuate the vacuum chamber and fill it with nitrogen to purify the atmosphere in the vacuum chamber; then start to heat up until the temperature in the furnace reaches 180°C ± 10°C, then introduce formic acid with a flow rate controlled at a maximum of 8slm to 10slm; formic acid decomposes under heat to produce hydrogen, which neutralizes the oxygen in the vacuum chamber and provides the reducing gas required for welding; preheat the mold and tube shell; (2) Continue to heat up to 280℃±10℃, and keep the temperature constant for 200s~300s to fully preheat the mold and tube shell to prepare for the solder melting eutectic below; (3) After the constant temperature is completed, the temperature is quickly raised to 350℃±10℃ within 100s±10s, and the temperature is kept constant for 50s±10s to melt the gold-tin solder sheet and end the eutectic; (4) Turn off the formic acid flow, evacuate the chamber, and remove the remaining formic acid in the vacuum chamber; then turn off the heating and fill with nitrogen to cool down.

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