Silver nano soldering paste low-temperature sintering device of semiconductor chip

Abstract

The invention discloses a silver nano soldering paste low-temperature sintering device of a semiconductor chip, which belongs to the technical field of semiconductor chip processing and comprises a box body, a heating table, a sucking pump, a box door, a first gas transmission mechanism, a second gas transmission mechanism and a gas circulation mechanism. According to the silver nano soldering paste low-temperature sintering device of the semiconductor chip, the first gas transmission mechanism and the second gas transmission mechanism are arranged, in the sintering process, nitrogen serves as a protective atmosphere, silver nano particles can be prevented from being oxidized, poor compounds such as silver oxide are prevented from being formed on the surface of the soldering paste, and the conductivity and the bonding force of a welding contact surface can be reduced due to oxidation; therefore, the welding quality is influenced; the hydrogen has a reduction effect at high temperature, can reduce existing oxides on the surface of the silver nano soldering paste, helps welding and fusion of silver particles, and ensures better welding quality.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor chip processing, and in particular relates to a low-temperature sintering device for silver nano solder paste of semiconductor chips. Background Art

[0002] With the rapid development of semiconductor technology, the application fields of semiconductor chips are becoming increasingly extensive, and higher requirements are also placed on the manufacturing quality and efficiency of semiconductor chips. In the manufacturing process of semiconductor chips, welding is a crucial link, which is directly related to the performance and reliability of the chip. Traditional welding methods often use high-temperature sintering, but this method not only has high energy consumption, but also easily causes thermal damage to semiconductor chips, thereby affecting their performance. In recent years, silver nano solder paste, as a new type of welding material, has been widely used in the welding of semiconductor chips due to its good electrical conductivity, thermal conductivity and solderability. Compared with traditional welding materials, silver nano solder paste has a lower sintering temperature and higher welding quality.

[0003] However, silver nano solder paste is also susceptible to oxygen during the sintering process, which causes the silver nanoparticles to oxidize and form undesirable compounds such as silver oxide, thereby reducing the conductivity and adhesion of the welding contact surface and affecting the welding quality. Summary of the invention

[0004] The purpose of the present invention is to provide a low-temperature sintering device for silver nano solder paste of semiconductor chips, which is used to solve the technical problem that the silver nano solder paste in the prior art is also easily affected by oxygen during the sintering process, resulting in oxidation of silver nano particles to form undesirable compounds such as silver oxide, thereby reducing the conductivity and adhesion of the welding contact surface and affecting the welding quality.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The invention discloses a low-temperature sintering device for silver nano solder paste of semiconductor chips, comprising: a box; a heating platform installed in the box; an air pump installed on the top surface of the box, and its air pumping pipe extends into the box; a box door hinged with the box; a first gas delivery mechanism for delivering nitrogen into the box; a second gas delivery mechanism for delivering hydrogen into the box; and a gas circulation mechanism for making the temperature distribution in the box uniform.

[0007] Preferably, the silver nano solder paste low-temperature sintering device for semiconductor chips also includes: an observation window installed on the box; two mounting plates installed on the two sides of the box respectively; a barometer installed on the top surface of the box; a handle installed on the box door; and a locking assembly.

[0008] Preferably, the locking assembly includes: a box body, mounted on the box body; a slide groove, opened on the box body; a stopper, slidably connected to the box body; and a handle, mounted on the stopper, passing through the slide groove and slidably connected to the slide groove.

[0009] Preferably, the first gas delivery mechanism includes: a first gas storage box, installed on the top surface of the mounting plate, and filled with nitrogen; a first gas delivery pipe, one end of which is connected to the first gas storage box and the other end of which extends into the box body; a first valve, installed on the first gas delivery pipe; and a first flow meter, installed on the first gas delivery pipe.

[0010] Preferably, the second gas delivery mechanism includes: a second gas storage box, installed on the top surface of the mounting plate, and filled with hydrogen; a second gas delivery pipe, one end of which is connected to the second gas storage box and the other end of which extends into the box body; a second valve, installed on the second gas delivery pipe; and a second flow meter, installed on the second gas delivery pipe.

[0011] Preferably, the gas circulation mechanism includes: two mounting tubes, both mounted on the inner wall of the box; two mounting blocks, respectively mounted in the two mounting tubes; two shafts, rotatably connected to the mounting blocks and the box; and two groups of fan blades, respectively mounted on the two shafts.

[0012] Preferably, the gas circulation mechanism also includes: two sprockets, both located below the box body and fixedly mounted on the two shafts respectively; a mounting frame mounted on the bottom surface of the box body; a motor mounted on the mounting frame, and a power output shaft thereof is fixedly connected to the lower end of any one of the shafts; and a chain mounted on the two sprockets.

[0013] Preferably, the silver nano solder paste low-temperature sintering device for semiconductor chips also includes a control system, which includes: a data acquisition and entry module for acquiring comprehensive data information of the low-temperature sintering device, wherein the comprehensive data information includes particle size data of the silver nano solder paste, viscosity data of the silver nano solder paste, thermal conductivity data of the substrate material, and temperature difference data in the box; a data analysis module for generating a sintering temperature influence coefficient based on the comprehensive data information, and generating a corresponding sintering temperature level based on the sintering temperature influence coefficient; a data acquisition module for acquiring a historical training data set of the low-temperature sintering device, wherein the historical training data set includes heating comprehensive influence data and nitrogen-hydrogen ratio; wherein the heating comprehensive influence data includes comprehensive data information and heating temperature data of the heating table; a nitrogen-hydrogen ratio prediction module for training a machine learning model for predicting the nitrogen-hydrogen ratio based on the historical training data set, acquiring real-time heating comprehensive influence data, and inputting the data into the trained machine learning model to predict the nitrogen-hydrogen ratio.

[0014] Preferably, the sintering temperature influence coefficient is generated as follows:

[0015]

[0016] In the formula, Wd is the sintering temperature influence coefficient, Kl is the particle size data of the silver nano solder paste, Nd is the viscosity data of the silver nano solder paste, Dr is the thermal conductivity data of the substrate material, and Wc is the temperature difference data inside the box body (100).

[0017] Preferably, the sintering temperature level is generated as follows: The sintering temperature level includes a primary sintering temperature, a secondary sintering temperature, and a tertiary sintering temperature, where the primary sintering temperature, the secondary sintering temperature, and the tertiary sintering temperature increase in sequence; the threshold range of the preset sintering temperature influence coefficient is Wd1, Wd2, and Wd1 < Wd2; if Wd ≤ Wd1, at this time, the data analysis module generates the primary sintering temperature; if Wd2 ≥ Wd > Wd1, at this time, the data analysis module generates the secondary sintering temperature; if Wd > Wd2, at this time, the data analysis module generates the tertiary sintering temperature.

[0018] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are as follows:

[0019] 1. The silver nano solder paste low-temperature sintering device for semiconductor chips in the present invention is provided with a first air delivery mechanism and a second air delivery mechanism. During the sintering process, nitrogen serves as a protective atmosphere, which can prevent the oxidation of silver nanoparticles and prevent the formation of bad compounds such as silver oxide on the surface of the solder paste. Oxidation will reduce the conductivity and adhesion of the welding contact surface, thereby affecting the welding quality; hydrogen has a reducing effect at high temperatures and can reduce the existing oxides on the surface of the silver nano solder paste to help the welding and fusion of silver particles, ensuring better welding quality.

[0020] 2. The gas circulation mechanism in the present invention is provided with an installation cylinder, a shaft rod, a fan blade, a sprocket, an installation frame, a motor, and a chain. When the motor operates, the power output shaft of the motor will drive a shaft rod to rotate, and then drive another shaft rod to rotate through the chain and the sprocket. When the shaft rod rotates, it will drive the fan blade to rotate. The rotating fan blade will send the air below the installation cylinder upward, thereby accelerating the air flow inside the box body, facilitating the uniformity of the temperature inside the box body, and being beneficial to the progress of the sintering process.

[0021] 3. The control system in the present invention is equipped with a data collection and entry module, a data analysis module, a data acquisition module and a nitrogen-hydrogen ratio prediction module. The control system can generate a sintering temperature influence coefficient through the data analysis module based on the comprehensive data information collected by the data collection and entry module, and judge and generate a corresponding sintering temperature level, so as to optimize the sintering parameters, improve the sintering efficiency and quality, avoid unnecessary energy waste, and reduce production costs; the nitrogen-hydrogen ratio prediction module in the control system can train and predict a machine learning model for the nitrogen-hydrogen ratio based on a historical training data set, thereby realizing accurate prediction and control of the nitrogen-hydrogen ratio, further ensuring the stability and reliability of the sintering process, and ensuring better welding quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 The three-dimensional low-temperature sintering device of the silver nano solder paste for the semiconductor chip of the present invention is Figure 1 ;

[0024] Figure 2 The three-dimensional low-temperature sintering device of the silver nano solder paste for the semiconductor chip of the present invention is Figure 2 ;

[0025] Figure 3 The three-dimensional low-temperature sintering device of the silver nano solder paste for the semiconductor chip of the present invention is Figure 3 ;

[0026] Figure 4 For the present invention Figure 3 A magnified schematic diagram of part A;

[0027] Figure 5 It is a schematic diagram of the internal structure of the box body in the present invention;

[0028] Figure 6 The three-dimensional low-temperature sintering device of the silver nano solder paste for the semiconductor chip of the present invention is Figure 4 ;

[0029] Figure 7 An exploded view of the mounting cylinder, mounting block, shaft rod and fan blades in the present invention;

[0030] Figure 8 It is a module diagram of the control system in the present invention;

[0031] Figure numerals: 100, box body; 101, observation window; 103, heating table; 104, mounting plate; 1041, support column; 105, vacuum pump; 106, barometer; 107, box door; 108, handle; 109, locking assembly; 1091, box body; 1092, slide; 1093, stopper; 1094, handle; 110, first gas delivery mechanism; 111, first gas storage box; 112, first Gas pipe; 113, first valve; 114, first flow meter; 120, second gas delivery mechanism; 121, second gas storage box; 122, second gas pipe; 123, second valve; 124, second flow meter; 130, gas circulation mechanism; 131, mounting cylinder; 132, mounting block; 133, shaft; 134, fan blade; 135, sprocket; 136, mounting frame; 137, motor; 138, chain. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Example 1: Figure 1-Figure 3 As shown, the low-temperature sintering device of silver nano solder paste for semiconductor chips includes a box body 100, a heating platform 103, an air pump 105, a box door 107, a first gas delivery mechanism 110, a second gas delivery mechanism 120 and a gas circulation mechanism 130.

[0034] The heating platform 103 is installed in the box 100, and the heating platform has a temperature adjustment function; the vacuum pump 105 is installed on the top surface of the box 100, and the vacuum pipe of the vacuum pump 105 extends into the box 100; the box door 107 is hinged to the box 100; the first gas delivery mechanism 110 is used to deliver nitrogen into the box 100; the second gas delivery mechanism 120 is used to deliver hydrogen into the box 100; the gas circulation mechanism 130 is used to make the temperature in the box 100 uniform.

[0035] Specifically, when in use, first apply a certain thickness of nano silver solder paste on the bare copper substrate, then place the semiconductor chip on the nano silver solder paste to obtain the circuit board to be sintered; then, open the box door 107, put the circuit board to be sintered into the box body 100, place the circuit board to be sintered on the heating table 103, and then close the box door 107.

[0036] Then, the air in the box 100 is extracted by starting the vacuum pump 105, and then, nitrogen is transported into the box 100 through the first gas delivery mechanism 110, and hydrogen is transported into the box 100 through the second gas delivery mechanism 120. After the transportation is completed, the heating table 103 is started to heat the circuit board to be sintered, so that the circuit board is sintered.

[0037] During the sintering process, the air circulation mechanism 130 is activated to speed up the flow of air inside the box 100, thereby facilitating a uniform temperature inside the box 100. During the sintering process, the servo cylinder (not shown) can also be used to drive the pressure plate (not shown) to move downward, so that the semiconductor chip and the nano silver solder paste are sintered under mechanical pressure, and the pressure of the servo cylinder is precisely adjustable.

[0038] By adding nitrogen into the box 100, during the sintering process, nitrogen acts as a protective atmosphere to avoid oxidation of silver nanoparticles and prevent the formation of undesirable compounds such as silver oxide on the surface of the solder paste. Oxidation will reduce the conductivity and adhesion of the welding contact surface, thereby affecting the welding quality.

[0039] Hydrogen has a reducing effect at high temperatures and can reduce existing oxides on the surface of silver nano solder paste. For silver nano solder paste, hydrogen can reduce silver oxides to silver metal, helping the welding and fusion of silver particles to ensure better welding quality. In addition, the reducing effect of hydrogen can promote the sintering of silver nano solder paste and improve its adhesion and conductivity.

[0040] like Figure 1 As shown, the low-temperature sintering device for silver nano solder paste of semiconductor chips also includes an observation window 101, two mounting plates 104, a barometer 106, a handle 108 and a locking assembly 109. The observation window 101 is mounted on the box body 100; the two mounting plates 104 are respectively mounted on the two side surfaces of the box body 100; the barometer 106 is mounted on the top surface of the box body 100; and the handle 108 is mounted on the box door 107.

[0041] Specifically, by providing an observation window 101, it is convenient for the staff to observe the conditions in the box 100. By providing a barometer 106, it is convenient to judge the air pressure in the box 100; by providing a handle 108, it is convenient to move the box door 107; by providing a locking assembly 109, it is convenient to fix the box door 107 on the box 100 to prevent the box door 107 from opening automatically.

[0042] like Figure 3 and Figure 4As shown, the locking assembly 109 includes a box body 1091, a slide groove 1092, a stopper 1093 and a handle 1094. The box body 1091 is mounted on the box body 100; the slide groove 1092 is provided on the box body 1091; the stopper 1093 is slidably connected to the box body 1091; the handle 1094 is mounted on the stopper 1093, and the handle 1094 passes through the slide groove 1092 and is slidably connected to the slide groove 1092.

[0043] Specifically, when the box door 107 needs to be locked, the box door 107 is closed and then the handle 1094 is moved to drive the block 1093 to move toward the box door 107, so that the block 1093 contacts the box door 107, making the box door 107 unable to rotate, thereby preventing the box door 107 from opening by itself during sintering.

[0044] like Figure 1 , Figure 2 and Figure 5 As shown, the first gas delivery mechanism 110 includes a first gas storage box 111 , a first gas delivery pipe 112 , a first valve 113 and a first flow meter 114 .

[0045] The first gas storage box 111 is installed on the top surface of the mounting plate 104, and nitrogen is contained in the first gas storage box 111; one end of the first gas pipe 112 is connected to the first gas storage box 111, and the other end of the first gas pipe 112 extends into the box body 100; the first valve 113 is installed on the first gas pipe 112; and the first flow meter 114 is installed on the first gas pipe 112.

[0046] Specifically, by starting the first valve 113 , the nitrogen in the first gas storage box 111 enters the box body 100 through the first gas pipe 112 . When the nitrogen passes through the first gas pipe 112 , the first flow meter 114 measures the flowing nitrogen.

[0047] like Figure 1 and Figure 5 As shown, the second gas delivery mechanism 120 includes a second gas storage box 121, a second gas delivery pipe 122, a second valve 123 and a second flow meter 124. The second gas storage box 121 is mounted on the top surface of the mounting plate 104, and the second gas storage box 121 contains hydrogen; one end of the second gas delivery pipe 122 is connected to the second gas storage box 121, and the other end of the second gas delivery pipe 122 extends into the box body 100; the second valve 123 is mounted on the second gas delivery pipe 122; and the second flow meter 124 is mounted on the second gas delivery pipe 122.

[0048] Specifically, by starting the second valve 123 , the hydrogen in the second gas storage box 121 enters the box body 100 through the second gas pipe 122 . When the nitrogen passes through the second gas pipe 122 , the second flow meter 124 measures the flowing hydrogen.

[0049] like Figure 6 and Figure 7 As shown, the gas circulation mechanism 130 includes two mounting cylinders 131 , two mounting blocks 132 , two shafts 133 , two sets of fan blades 134 , two sprockets 135 , a mounting frame 136 , a motor 137 and a chain 138 .

[0050] The two mounting tubes 131 are mounted on the inner wall of the box 100; the two mounting blocks 132 are respectively mounted in the two mounting tubes 131; the two shafts 133 are rotatably connected with the mounting blocks 132 and the box 100; the two sets of fan blades 134 are respectively mounted on the two shafts 133. The two sprocket wheels 135 are both located below the box 100, and the two sprocket wheels 135 are respectively fixedly sleeved on the two shafts 133; the mounting frame 136 is mounted on the bottom surface of the box 100; the motor 137 is mounted on the mounting frame 136, and the power output shaft of the motor 137 is fixedly connected to the lower end of any shaft 133; the chain 138 is sleeved on the two sprocket wheels 135.

[0051] Specifically, when the motor 137 is running, the power output shaft of the motor 137 will drive a shaft 133 to rotate, and then drive another shaft 133 to rotate through the chain 138 and the sprocket 135. When the shaft 133 rotates, it will drive the fan blades 134 to rotate. The rotating fan blades 134 will transport the air under the mounting tube 131 upward, thereby accelerating the flow of air in the box 100, thereby facilitating the uniformity of the temperature in the box 100.

[0052] Working principle: In specific use, first apply a certain thickness of nano silver solder paste on the bare copper substrate, then place the semiconductor chip on the nano silver solder paste to obtain a circuit board to be sintered; then, open the box door 107, put the circuit board to be sintered into the box body 100, put the circuit board to be sintered on the heating table 103, and then close the box door 107. Then, by moving the handle 1094, the stopper 1093 is driven to move in the direction close to the box door 107, and then the stopper 1093 contacts the box door 107, so that the box door 107 cannot rotate, and the box door 107 is prevented from opening automatically during sintering.

[0053] Then, the air in the box 100 is extracted by starting the air pump 105, and then, the first valve 113 and the second valve 123 are opened to allow the nitrogen in the first air storage tank 111 to enter the box 100 through the first delivery pipe, and the hydrogen in the second air storage tank 121 to enter the box 100 through the second delivery pipe.

[0054] After the gas delivery is completed, the heating stage 103 is started to heat the circuit board to be sintered, thereby sintering the circuit board.

[0055] During the sintering process, by starting the motor 137, the power output shaft of the motor 137 will drive one shaft 133 to rotate, and then drive another shaft 133 to rotate through the chain 138 and the sprocket 135. When the shaft 133 rotates, it will drive the fan blade 134 to rotate. The rotating fan blade 134 will transport the air below the mounting cylinder 131 upward, thereby accelerating the flow of air in the box 100, so as to make the temperature in the box 100 uniform. During the sintering process, the pressure plate (not shown) can also be driven downward by the servo cylinder (not shown) to sinter the semiconductor chip and the nano silver solder paste under mechanical pressure, and the pressure of the servo cylinder is precisely adjustable.

[0056] Then the state of the circuit board in the box body 100 is observed through the observation window 101 .

[0057] Among them, by adding nitrogen into the box 100, during the sintering process, nitrogen acts as a protective atmosphere to avoid oxidation of silver nanoparticles and prevent the formation of undesirable compounds such as silver oxide on the surface of the solder paste. Oxidation will reduce the conductivity and adhesion of the welding contact surface, thereby affecting the welding quality.

[0058] Hydrogen has a reducing effect at high temperatures and can reduce existing oxides on the surface of silver nano solder paste. For silver nano solder paste, hydrogen can reduce silver oxides to silver metal, helping the welding and fusion of silver particles to ensure better welding quality. In addition, the reducing effect of hydrogen can promote the sintering of silver nano solder paste and improve its adhesion and conductivity.

[0059] Example 2: Figure 1-Figure 8 As shown, when other parts are the same as those of Example 1, the difference between this embodiment and Example 1 is that: the silver nano solder paste low-temperature sintering device for semiconductor chips also includes a control system;

[0060] The control system includes: a data collection and entry module, a data analysis module, a data acquisition module and a nitrogen-hydrogen ratio prediction module. The modules are connected by wired / wireless means to realize data transmission.

[0061] The data collection and input module is used to collect comprehensive data information of the low-temperature sintering device, wherein the comprehensive data information includes the particle size data of the silver nano solder paste, the viscosity data of the silver nano solder paste, the thermal conductivity data of the base material and the temperature difference data in the box 100.

[0062] Specifically, the particle size data of the silver nano solder paste is data pre-entered by the user, and the particle size of the silver nano solder paste can be measured by a scanning electron microscope (SEM) or dynamic light scattering (DLS).

[0063] The viscosity data of the silver nano solder paste is the data pre-entered by the user, and the viscosity data of the silver nano solder paste can be measured by a viscometer;

[0064] The thermal conductivity data of the base material is data pre-entered by the user. In this embodiment, the base material is a bare copper substrate, and the thermal conductivity of the base material can be measured by a thermal conductivity tester.

[0065] The temperature difference data in the box 100 is obtained by installing a plurality of temperature sensors in the box 100 . The difference between the highest temperature and the lowest temperature measured by the plurality of temperature sensors is the temperature difference in the box 100 .

[0066] The data analysis module generates the sintering temperature influence coefficient according to the comprehensive data information, and generates the corresponding sintering temperature level according to the sintering temperature influence coefficient;

[0067] The sintering temperature influence coefficient is generated as follows:

[0068]

[0069] Wherein, Wd is the sintering temperature influence coefficient, Kl is the particle size data of the silver nano solder paste, Nd is the viscosity data of the silver nano solder paste, Dr is the thermal conductivity data of the base material, and Wc is the temperature difference data in the box 100. and are all weight coefficients, which are determined by technicians in this field according to specific application requirements. and All are greater than 0;

[0070] Among them, the particle size of silver nano solder paste will affect its sintering characteristics. Smaller particles are easy to aggregate and sinter at lower temperatures due to their larger surface energy. Therefore, smaller silver nanoparticles require a lower sintering temperature. In the case of larger particles, the sintering temperature needs to be increased to ensure effective connection between the particles.

[0071] The viscosity of silver nano solder paste determines its fluidity and fusion during the sintering process. Higher viscosity will make it difficult for the solder paste to flow fully at low temperatures, so a higher temperature is required to promote the sintering process; lower viscosity can complete sintering at a lower temperature.

[0072] The thermal conductivity of the base material affects the speed of heat transfer, thereby affecting the sintering temperature of the silver nano solder paste. Base materials with higher thermal conductivity (such as copper) can disperse heat more quickly, reduce local temperature, and make the sintering of silver nanoparticles more efficient. On the contrary, base materials with lower thermal conductivity (such as ceramics) require higher temperatures.

[0073] The temperature difference in the box 100 can indicate the temperature uniformity in the box 100. The larger the temperature difference, the worse the temperature uniformity; the smaller the temperature difference, the better the temperature uniformity. The temperature uniformity in the box 100 will affect the temperature distribution of the silver nano solder paste during the entire sintering process. If the temperature distribution is uneven, the temperature in some areas may be too high or too low, thereby affecting the sintering efficiency and temperature requirements. Conversely, if the temperature uniformity in the box 100 is good, the sintering temperature can be reduced.

[0074] It should be noted that the formulas involved in the above-mentioned are all calculated by removing dimensions and taking numerical values. They are a formula that is closest to the actual situation obtained by collecting a large amount of data and performing software simulation. The weight coefficients in the formulas and the various preset thresholds in the analysis process are set by technical personnel in this field according to actual conditions or obtained by simulating a large amount of data; the size of the weight coefficient is to quantify each parameter to obtain a specific value for subsequent comparison. The size of the weight coefficient depends on the amount of sample data and the corresponding processing coefficients initially set by technical personnel in this field for each group of sample data; as long as it does not affect the proportional relationship between the parameters and the quantized values.

[0075] The sintering temperature grades are generated as follows:

[0076] The sintering temperature levels include a primary sintering temperature, a secondary sintering temperature and a tertiary sintering temperature, wherein the primary sintering temperature, the secondary sintering temperature and the tertiary sintering temperature increase in sequence, and the primary sintering temperature, the secondary sintering temperature and the tertiary sintering temperature are all the temperatures of the heating stage 103;

[0077] The threshold range of the preset sintering temperature influence coefficient is Wd1, Wd2, Wd1 <Wd2;

[0078] If Wd≤Wd1, at this time, the data analysis module generates the primary sintering temperature;

[0079] If Wd2≥Wd>Wd1, at this time, the data analysis module generates the secondary sintering temperature;

[0080] If Wd>Wd2, at this time, the data analysis module generates three-level sintering temperature.

[0081] Wherein, Wd1 and Wd2 are determined by those skilled in the art according to specific application requirements.

[0082] Exemplarily, the heating temperatures of the heating stage 103 corresponding to the primary sintering temperature, the secondary sintering temperature and the tertiary sintering temperature are 180° C., 230° C. and 280° C. respectively; the heating temperature of the heating stage 103 may also be customized according to specific circumstances.

[0083] According to the corresponding sintering temperature level, the data analysis module generates a corresponding sintering temperature level control signal. For example, when the sintering temperature level is the first-level sintering temperature, the data analysis module generates a first-level sintering temperature control signal, and then sends the first-level sintering temperature control signal to the controller of the heating platform 103, thereby controlling and adjusting the heating temperature of the heating platform 103.

[0084] The data acquisition module is used to collect a historical training data set of the low-temperature sintering device, and the historical training data set includes heating comprehensive influence data and nitrogen-hydrogen ratio; wherein the heating comprehensive influence data includes comprehensive data information and heating temperature data of the heating stage 103, and the heating temperature data of the heating stage 103 can be measured and obtained by a temperature sensor;

[0085] The nitrogen-hydrogen ratio refers to the ratio of nitrogen to hydrogen in the box 100 , and the nitrogen-hydrogen ratio can be measured and calculated by the first flowmeter 114 and the second flowmeter 124 .

[0086] The nitrogen-hydrogen ratio prediction module trains a machine learning model for predicting the nitrogen-hydrogen ratio based on a historical training data set, collects real-time heating comprehensive impact data, and inputs it into the trained machine learning model to predict the nitrogen-hydrogen ratio;

[0087] The training method of the machine learning model for predicting the nitrogen-hydrogen ratio includes:

[0088] Convert the collected comprehensive heating impact data into a corresponding set of feature vectors;

[0089] Each group of feature vectors is used as the input of the machine learning model. The machine learning model takes the nitrogen-hydrogen ratio corresponding to each group of comprehensive heating impact data as output, takes the nitrogen-hydrogen ratio actually corresponding to each group of comprehensive heating impact data as the prediction target, and takes minimizing the loss function value of the machine learning model as the training target; training stops when the loss function value of the machine learning model is less than or equal to the preset target loss value.

[0090] The machine learning model can be one of the models such as SVM regression, random forest regression or neural network regression.

[0091] The loss function value of the machine learning model is the mean square error;

[0092] Mean square error is one of the commonly used loss functions. Minimization is used as the goal to train the model so that the machine learning model better fits the data, thereby improving the performance and accuracy of the model;

[0093] In the loss function, MSE is the loss function value of the machine learning model, x is the feature vector group number; m is the number of feature vector groups; y is the number of feature vector groups; xis the nitrogen-hydrogen ratio predicted by the xth group of feature vectors, is the nitrogen-hydrogen ratio actually corresponding to the xth group of eigenvectors;

[0094] Other model parameters of the machine learning model, target loss value, optimization algorithm, training set test set validation set ratio, and loss function optimization are all achieved through actual engineering implementation and continuous experimental tuning.

[0095] The opening time of the first valve 113 and the second valve 123 are controlled according to the predicted nitrogen-hydrogen ratio, so as to adjust the ratio of nitrogen and hydrogen in the box 100 .

[0096] Hydrogen can lower the formation temperature of silver oxide and promote direct bonding between silver particles. This reduction process can start at a lower temperature, reducing the need for sintering of silver nanoparticles at high temperatures, thereby reducing the overall sintering temperature.

[0097] It can also be said that at low temperatures (e.g., 180°C-230°C), the driving force for the diffusion and sintering of silver nanoparticles is weak, and the reduction effect of hydrogen becomes more critical. Therefore, at lower temperatures (e.g., 180°C-230°C), a higher proportion of hydrogen (e.g., 40% to 50%) is required to ensure that the reduction and sintering of the oxide are fully carried out.

[0098] At higher temperatures (e.g. 230°C-280°C), silver particles have higher diffusion capacity and the sintering driving force is strong enough to reduce the dependence on hydrogen. At this time, the nitrogen ratio can be increased (e.g., the hydrogen ratio can be reduced to 10%-30%). High temperature enhances the thermal decomposition ability of oxides on the particle surface, so too much hydrogen is not needed to reduce the oxides.

[0099] To sum up, the control system can generate the sintering temperature influence coefficient through the data analysis module based on the comprehensive data information collected by the data acquisition and entry module, and judge and generate the corresponding sintering temperature level, so as to optimize the sintering parameters, improve the sintering efficiency and quality, avoid unnecessary energy waste, and reduce production costs.

[0100] The nitrogen-hydrogen ratio prediction module in the control system can train a machine learning model to predict the nitrogen-hydrogen ratio based on a historical training data set, thereby achieving accurate prediction and control of the nitrogen-hydrogen ratio, further ensuring the stability and reliability of the sintering process and ensuring better welding quality.

[0101] 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.

[0102] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A low-temperature sintering device for silver nano solder paste of semiconductor chips, characterized in that: include: Box (100); A heating table (103) is installed in the box (100); An air extraction pump (105) is installed on the top surface of the box (100), and its air extraction pipe extends into the box (100); A box door (107) is hinged to the box body (100); A first gas delivery mechanism (110) for delivering nitrogen into the box (100); A second gas delivery mechanism (120) for delivering hydrogen into the box (100); The gas circulation mechanism (130) is used to make the temperature distribution in the box (100) uniform.

2. The low-temperature sintering device for silver nano solder paste of semiconductor chips according to claim 1, characterized in that: Also includes: An observation window (101) is installed on the box (100); Two mounting plates (104) are respectively mounted on two side surfaces of the box body (100); A barometer (106) mounted on the top surface of the box (100); A handle (108) mounted on the door (107); Locking assembly (109).

3. The low-temperature sintering device for silver nano solder paste of semiconductor chips according to claim 2, characterized in that: The locking assembly (109) comprises: A box body (1091) is mounted on the box body (100); A slide groove (1092) is provided on the box body (1091); A stopper (1093) slidably connected to the box body (1091); The handle (1094) is mounted on the stopper (1093), passes through the slide groove (1092) and is slidably connected to the slide groove (1092).

4. The low-temperature sintering device for silver nano solder paste of semiconductor chips according to claim 2, characterized in that: The first gas delivery mechanism (110) comprises: A first gas storage box (111), mounted on the top surface of the mounting plate (104), containing nitrogen; A first air delivery pipe (112), one end of which is connected to the first air storage box (111), and the other end of which extends into the box body (100); A first valve (113) installed on the first gas transmission pipe (112); A first flow meter (114) is installed on the first gas transmission pipe (112).

5. The low-temperature sintering device for silver nano solder paste of semiconductor chips according to claim 4, characterized in that: The second gas delivery mechanism (120) comprises: A second gas storage box (121), mounted on the top surface of the mounting plate (104), containing hydrogen; A second air delivery pipe (122), one end of which is connected to the second air storage box (121), and the other end of which extends into the box body (100); A second valve (123) installed on the second gas transmission pipe (122); A second flow meter (124) is installed on the second gas transmission pipe (122).

6. The low-temperature sintering device for silver nano solder paste of semiconductor chips according to claim 5, characterized in that: The gas circulation mechanism (130) comprises: Two installation cylinders (131), both installed on the inner wall of the box body (100); Two mounting blocks (132) are respectively mounted in the two mounting tubes (131); Two shafts (133) rotatably connected to the mounting block (132) and the box body (100); Two groups of fan blades (134) are respectively mounted on the two shaft rods (133).

7. The low-temperature sintering device for silver nano solder paste of semiconductor chips according to claim 6, characterized in that: The gas circulation mechanism (130) further comprises: Two sprocket wheels (135) are both located below the box body (100) and are respectively fixedly sleeved on the two shaft rods (133); A mounting frame (136) mounted on the bottom surface of the box (100); A motor (137) is mounted on the mounting frame (136), and its power output shaft is fixedly connected to the lower end of any one of the shafts (133); The chain (138) is sleeved on the two sprocket wheels (135).

8. The low-temperature sintering device for silver nano solder paste of semiconductor chips according to claim 7, characterized in that: Also included is a control system, the control system comprising: The data collection and input module is used to collect comprehensive data information of the low-temperature sintering device, wherein the comprehensive data information includes particle size data of the silver nano solder paste, viscosity data of the silver nano solder paste, thermal conductivity data of the base material, and temperature difference data in the box (100); The data analysis module generates the sintering temperature influence coefficient according to the comprehensive data information, and generates the corresponding sintering temperature level according to the sintering temperature influence coefficient; The data acquisition module is used to collect a historical training data set of the low-temperature sintering device, the historical training data set including heating comprehensive influence data and nitrogen-hydrogen ratio; wherein the heating comprehensive influence data includes comprehensive data information and heating temperature data of the heating table (103); The nitrogen-hydrogen ratio prediction module trains a machine learning model for predicting the nitrogen-hydrogen ratio based on a historical training data set, collects real-time heating comprehensive impact data, and inputs it into the trained machine learning model to predict the nitrogen-hydrogen ratio.

9. The low-temperature sintering device for silver nano solder paste of semiconductor chips according to claim 8, characterized in that: The sintering temperature influence coefficient is generated as follows: Wherein, Wd is the sintering temperature influence coefficient, Kl is the particle size data of the silver nano solder paste, Nd is the viscosity data of the silver nano solder paste, Dr is the thermal conductivity data of the base material, and Wc is the temperature difference data in the box (100).

10. The low-temperature sintering device for silver nano solder paste of semiconductor chips according to claim 9, characterized in that: The sintering temperature levels are generated as follows: The sintering temperature grades include primary sintering temperature, secondary sintering temperature and tertiary sintering temperature, wherein the primary sintering temperature, the secondary sintering temperature and the tertiary sintering temperature increase in sequence; The threshold range of the preset sintering temperature influence coefficient is Wd1, Wd2, Wd1 <Wd2; If Wd≤Wd1, at this time, the data analysis module generates the primary sintering temperature; If Wd2≥Wd>Wd1, at this time, the data analysis module generates the secondary sintering temperature; If Wd>Wd2, at this time, the data analysis module generates three-level sintering temperature.

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