Method for detecting state of die bonding using air flow

Abstract

The present application provides a method for detecting the state of die bonding by airflow, comprising the following steps: a local block of a die is separated from a die bonding device and contacts a substrate to form a bonding wave; the bonding wave spreads from the local block of the die to other blocks of the die and has a spreading trend, so that the die gradually separates from the die bonding device and is fixed on the substrate; airflow flows along the surface of the die; the flow or pressure change degree of airflow at different positions is sensed and a plurality of sensing information is obtained; the distance change degree of the die from the die bonding device is determined according to the plurality of sensing information; the spreading trend of the bonding wave is determined according to the distance change degree of the die from the die bonding device; and whether the die is closely bonded to the substrate is determined according to the spreading trend of the bonding wave. The technical scheme of the present application can accurately identify whether the die is closely bonded to the substrate.

Description

Technical Field

[0001] This invention relates to a crystal-solidification method, and more particularly to a method for detecting the crystal-solidification state using airflow. Background Technology

[0002] Integrated circuits are fabricated on semiconductor wafers in large batches through multiple processes. The wafers are then further divided into multiple dies. In other words, a die is a small, unpackaged integrated circuit component made of semiconductor material. The divided dies are neatly attached to a carrier device, which is then transported by a carrier frame. Finally, a die bonding device sequentially transfers the dies to a substrate for subsequent processing.

[0003] Furthermore, during the process of transferring the die to the substrate, local blocks of the die detach from the die bonding device and contact the substrate to form a bond wave. The bond wave diffuses from the local blocks of the die towards other blocks of the die, causing the die to gradually detach from the die bonding device and be fixed to the substrate.

[0004] However, air bubbles may be trapped between the bottom surface of the die and the top surface of the substrate, forming a void, or particles may adhere to the bottom surface of the die, causing the bottom surface of the die to not be tightly bonded to the top surface of the substrate. Once the die is not tightly bonded to the substrate, subsequent processing procedures such as picking or identification of the die will be easily affected by air bubbles or particles, reducing the yield of the products produced by subsequent processing. Technicians in this field usually pick out the dies that are not tightly bonded to the substrate.

[0005] The substrate contains numerous and very small chips, making it difficult to accurately identify which chips are tightly bonded to the substrate and which are not. Therefore, those skilled in the art have virtually no way to remove chips that are not tightly bonded to the substrate. Summary of the Invention

[0006] The main objective of this invention is to provide a method for detecting the solidification state using airflow, which can accurately identify whether the grains are tightly bonded to the substrate.

[0007] To achieve the aforementioned objectives, the present invention provides a method for detecting die bonding status using airflow, comprising the following steps: a local block of a die detaches from a die bonding device and contacts a substrate to form a bonding wave; the bonding wave diffuses from the local block of the die towards other blocks of the die and has a diffusion trend, causing the die to gradually detach from the die bonding device and be fixed to the substrate; an airflow flows along the surface of the die; the degree of change in flow rate or pressure of the airflow at different locations is sensed and multiple sensing information is obtained; the degree of change in the distance between the die and the die bonding device is determined based on the multiple sensing information; the diffusion trend of the bonding wave is determined based on the degree of change in the distance between the die and the die bonding device; and the diffusion trend of the bonding wave is determined based on the diffusion trend of the bonding wave to determine whether the die is tightly bonded to the substrate.

[0008] In some embodiments, the step of forming the bonding wave further includes: the die bonding device generating an airflow through a positive pressure to blow a local block of the die, causing the local block of the die to detach from the die bonding device and flex and deform to contact the substrate; and wherein the step of the airflow flowing along the surface of the die further includes: the airflow generated by the positive pressure turning and flowing along the surface of the die after contacting the surface of the die.

[0009] In some embodiments, the step of the airflow flowing along the surface of the grain further includes: the airflow flowing along the surface of the grain in a gap between the die bonding device and the grain, and then the airflow entering multiple channels of the die bonding device; and wherein the step of sensing the degree of change in flow rate or pressure of the airflow at different locations further includes: multiple sensors sensing the degree of change in flow rate or pressure of the airflow through the multiple channels respectively, and obtaining multiple sensing information.

[0010] In some embodiments, the step of the airflow flowing along the surface of the grain further includes: a vacuum device guiding the airflow through the plurality of channels by a negative pressure.

[0011] In some embodiments, the adsorption force generated by negative pressure is insufficient to adsorb crystal grains.

[0012] In some embodiments, a vacuum device is disposed on top of the die bonding device. The vacuum device has an air extraction port, a chamber, and multiple perforations. The air extraction port communicates with the chamber, the multiple perforations communicate with the chamber, the multiple perforations communicate with the multiple channels, and the multiple sensors are disposed in the multiple perforations without blocking the openings of the multiple channels.

[0013] In some embodiments, the plurality of sensors are respectively disposed outside the openings of the plurality of channels, and do not block the openings of the plurality of channels.

[0014] In some embodiments, the step of determining the degree of change in the distance between the die and the die bonding device further includes: a processing unit receiving the plurality of sensing information and determining the degree of change in the flow rate or pressure of the airflow at different locations based on the plurality of sensing information; the processing unit further determining the degree of change in the distance between the die and the die bonding device based on the degree of change in the flow rate or pressure of the airflow at different locations; wherein, the step of determining the diffusion trend of the bonding wave further includes: the processing unit determining the diffusion trend of the bonding wave based on the degree of change in the distance between the die and the die bonding device; and wherein, the step of determining whether the die is tightly bonded to the substrate further includes: the processing unit determining whether the die is tightly bonded to the substrate based on the diffusion trend of the bonding wave.

[0015] The beneficial effect of the above-mentioned technical solution of the present invention is that the method of the present invention can use airflow to detect the solidification state and accurately identify which grains are tightly attached to the substrate and which grains are not tightly attached to the substrate. Attached Figure Description

[0016] Figure 1A This is one of the flowcharts for a method of detecting solidification state using airflow provided in an embodiment of the present invention.

[0017] Figure 1B This is a second flowchart of a method for detecting the solidification state using airflow, provided in an embodiment of the present invention.

[0018] Figure 2A A schematic diagram of the die bonding device and sensor is shown.

[0019] Figure 2B A top view of the die bonding device and sensor is shown.

[0020] Figure 3 A schematic diagram showing the connection relationship between the vent and the first vacuum device and the gas supply device is provided.

[0021] Figure 4 A schematic diagram showing the connection relationship between the sensor and the processing unit is provided.

[0022] Figure 5 The diagram shows a crystal bonding device that uses negative pressure to generate adsorption force to adsorb crystal grains.

[0023] Figure 6 A schematic diagram showing the airflow, the degree of change in airflow volume or pressure, and the diffusion trend of the bonding wave in a first embodiment of the method of the present invention is shown.

[0024] Figure 7 This diagram illustrates how the raised portion of the grain affects the degree of change in airflow or pressure and the diffusion trend of the bonding wave.

[0025] Figure 8This diagram illustrates the diffusion trend of bonding waves when there are no voids or particles between the grain and the substrate.

[0026] Figure 9 This diagram illustrates the diffusion trend of bonding waves when there are voids or particles between the grain and the substrate.

[0027] Figure 10 A schematic diagram of the die bonding device, sensor, and second vacuum device is shown.

[0028] Figure 11 This is a schematic diagram illustrating the airflow, the degree of change in airflow volume or pressure, and the diffusion trend of the bonding wave in a second embodiment of the method of the present invention.

[0029] Explanation of reference numerals in the attached figures:

[0030] 10: Die bonding device; 101-104: Corner; 11-14: Pore; 15, 16: Side; 17: Channel; 20: Grain; 21: Raised portion; 30: First vacuum device; 31: Negative pressure; 40: Gas supply device; 41: Positive pressure; 50: Substrate; 60: Diffusion trend of bonding wave; 61: Airflow; 70: Gap; 71: Void; 80: Sensor; 81: Sensing information; 90: Processing unit; 100: Second vacuum device; 110: Evacuation port; 120: Chamber; 130: Perforation; 140: Negative pressure; D1-D3, D1A-D3A: Direction; F1-F6: Airflow rate change; P1-P6: Airflow pressure change; S100-S800: Step. Detailed Implementation

[0031] The following description, in conjunction with the accompanying drawings and component symbols, provides a more detailed account of the embodiments of the present invention, so that those skilled in the art can implement them after studying this specification.

[0032] Please see Figures 1A to 9 , Figure 1A This is one of the flowcharts for a method of detecting the solidification state using airflow provided in an embodiment of the present invention. Figure 1B This is the second flowchart of a method for detecting the solidification state using airflow provided in an embodiment of the present invention. Figure 2A A schematic diagram of the die bonding device 10 and the sensor 80 is shown. Figure 2B A top view of the die bonding device 10 and the sensor 80 is shown. Figure 3 A schematic diagram showing the connection relationship between vents 11-14, the first vacuum device 30, and the gas supply device 40 is provided. Figure 4 A schematic diagram showing the connection relationship between sensor 80 and processing unit 90 is provided. Figure 5 The diagram shows a crystal bonding device 10 adsorbing crystal grains 20 by generating an adsorption force through a negative pressure 31. Figure 6This diagram illustrates the flow of airflow 61, the degree of change in flow rate or pressure of airflow 61, and the diffusion trend 60 of the bonding wave according to a first embodiment of the method of the present invention. Figure 7 This diagram illustrates how the raised portion 21 of grain 20 affects the flow rate or pressure change of airflow 61 and the diffusion trend 60 of the bonding wave. Figure 8 This diagram illustrates the diffusion trend 60 of the bonding wave when there are no voids or particles between the grain 20 and the substrate 50. Figure 9 A schematic diagram showing the diffusion trend 60 of the bonding wave when there are voids 71 ​​or particles between the grain 20 and the substrate 50 is displayed. This invention provides a method for detecting the solidification state using airflow, comprising the following steps:

[0033] Step S100, as follows Figure 1A and Figure 5 As shown, a crystal bonding device 10 uses a negative pressure 31 to generate an adsorption force to adsorb a crystal grain 20. More specifically, as Figure 2A and Figure 2B As shown, the die bonding device 10 has four pores 11-14, and the plurality of pores 11-14 are distributed at the four corners 101-104 of the die bonding device 10; as Figure 3 As shown, the plurality of air holes 11-14 are connected to a first vacuum device 30 and a gas supply device 40; as Figure 2B , Figure 3 and Figure 5 As shown, the first vacuum device 30 evacuates air from the plurality of vents 11-14 to generate a negative pressure 31. The die-bonding device 10 uses the negative pressure 31 to generate an adsorption force to adsorb the four corners 101-104 of the crystal grain 20, so that the crystal grain 20 is tightly attached to the periphery of the bottom surface of the die-bonding device 10. Because the periphery of the crystal grain 20 can be tightly attached to the periphery of the bottom surface of the die-bonding device 10, there are no gaps between the periphery of the crystal grain 20 and the periphery of the bottom surface of the die-bonding device 10, preventing external air from entering and affecting the adsorption effect of the negative pressure 31 on the crystal grain 20.

[0034] Step S200, as follows Figure 1A , Figure 6 and Figure 7 As shown, the die bonding device 10 generates an airflow 61 through a positive pressure 41 to blow on a local area of ​​the die 20, causing the local area of ​​the die 20 to detach from the die bonding device 10 and flex and deform to contact a substrate 50. After the local area of ​​the die 20 contacts the substrate 50, a bond wave is formed. Step S200 of the first embodiment can be further divided into the following two implementation methods.

[0035] In the first embodiment, a local area of ​​the die 20 is a corner of the die 20. The die bonding device 10 generates an airflow 61 through positive pressure 41 to blow on the corner of the die 20, causing the corner of the die 20 to detach from the die bonding device 10 and bend to contact the substrate 50. After the corner of the die 20 contacts the substrate 50, a bonding wave is formed. More specifically, the first vacuum device 30 stops evacuating air from the vents 11 at the corner 101 of the die bonding device 10, and the vents 11 stop adsorbing the corner of the die 20 through the suction force generated by the negative pressure 31. At the same time, the gas supply device 40 starts blowing air into the vents 11 at the corner 101 of the die bonding device 10 to generate positive pressure 41. The vents 11 start generating an airflow 61 through the positive pressure 41 to blow on the corner of the die 20. The first vacuum device 30 continues to evacuate air from the vents 12-14 at the other corners 102-104 of the die bonding device 10, ensuring that the vents 12-14 at the other corners 102-104 of the die bonding device 10 maintain the adsorption force generated by the negative pressure 31 to hold the other corners of the die 20. Therefore, the die 20 is not only kept fixed in the die bonding device 10, but also ensures that only its corners are flexed and deformed and most prominent, allowing the corners of the die 20 to contact the substrate 50 in a point-contact manner. Because the corners of the die 20 contact the substrate 50 in a point-contact manner, bonding forces are generated at the corners of the die 20 and in their vicinity, and these bonding forces further form adhesion waves. More specifically, the first vacuum device 30 sequentially stops evacuating air from the vents 12-14 at the other corners 102-104 of the die bonding device 10, and the vents 12-14 sequentially stop providing negative pressure 31 along the diagonal direction. The gas supply device 40 sequentially starts blowing air from the vents 12-14 at the other corners 102-104 of the die bonding device 10, and the vents 12-14 sequentially start providing positive pressure 41 along the diagonal direction to generate airflow 61 to blow on the other corners of the die 20, so that the other corners of the die 20 are sequentially blown by airflow 61 along the diagonal direction to generate a pressure difference fluctuation. The pressure difference fluctuation can further enable the corners of the die 20 to form a bonding wave after contacting the substrate 50.

[0036] In the second embodiment, a localized area of ​​the die 20 is one side of the die 20. The die bonding device 10 generates an airflow 61 through positive pressure 41 to blow on the side of the die 20, causing the side of the die 20 to detach from the die bonding device 10 and flex and deform to contact the substrate 50. After the side of the die 20 contacts the substrate 50, a bonding wave is formed. More specifically, the first vacuum device 30 stops evacuating air from the vents 11 and 12 at the two corners 101 and 102 of the side 15 of the die bonding device 10. The vents 11 and 12 stop adsorbing the two corners of the side of the die 20 through the suction force generated by the negative pressure 31. At the same time, the gas supply device 40 starts blowing air into the vents 11 and 12 at the two corners 101 and 102 of the side 15 of the die bonding device 10 to generate positive pressure 41. The vents 11 and 12 start to generate an airflow 61 through the positive pressure 41 to blow on the two corners of the side of the die 20. The first vacuum device 30 continues to evacuate air from the vents 13 and 14 at the two corners 103 and 104 of the other side 16 of the die bonding device 10, so that the vents 13 and 14 continue to maintain the adsorption force generated by the negative pressure 31 to hold the two corners of the other side of the die 20. Therefore, the die 20 can not only remain fixed in the die bonding device 10, but also ensure that only its side is flexed and deformed and most prominent, so that the side of the die 20 can contact the substrate 50 in a line contact manner. Because the side of the die 20 contacts the substrate 50 in a line contact manner, bonding forces are generated on the side of the die 20 and its vicinity, and these bonding forces will further form a bonding wave. More specifically, the first vacuum device 30 stops evacuating air from the vents 13 and 14 at the two corners 103 and 104 of the other side 16 of the die bonding device 10, and the vents 13 and 14 stop providing negative pressure 31. The gas supply device 40 sequentially starts blowing air into the vents 13 and 14 at the two corners 103 and 104 of the other side 16 of the die bonding device 10. The vents 13 and 14 begin to provide positive pressure 41 to generate airflow 61 to blow on the other side of the die 20, so that the die 20 is sequentially blown by the airflow 61 from one side to the other to generate a pressure difference fluctuation. The pressure difference fluctuation can further enable the side of the die 20 to form a bonding wave after contacting the substrate 50.

[0037] Step S300, as follows Figure 1A , Figure 6 and Figure 7 As shown, the bonding wave diffuses from a local block of the die 20 to other blocks of the die 20 and has a diffusion trend 60, causing the die 20 to gradually detach from the die bonding device 10 and be fixed to the substrate 50. Step S300 of the first embodiment can be further divided into the following two implementation methods.

[0038] In the first embodiment, the pressure difference fluctuation guides the bonding wave to diffuse along a diagonal line of the grain 20. In the second embodiment, the pressure difference fluctuation guides the bonding wave to diffuse from one side of the grain 20 to the other.

[0039] In some embodiments, the number and distribution of the plurality of pores can be varied. For example, there may be six pores, with four pores located at the four corners of the die bonding device 10 and the other two pores located on opposite sides of the die bonding device 10. Alternatively, there may be nine pores, with four pores located at the four corners of the die bonding device 10 and the other four pores located on the four sides of the die bonding device 10, respectively located between the corners. For example, there may be only two pores, located at opposite corners or opposite sides of the die bonding device 10. For example, the die bonding device 10 may have only one pore, located at the axis of the die bonding device 10. Regardless of the variation in the number and distribution of the pores, steps S200 and S300 in these embodiments are essentially quite similar, both capable of forming bonding waves and diffuse bonding waves. The above examples are merely illustrative of the diversity in the number and distribution of pores and are not intended to limit the scope of the invention.

[0040] Step S400, as follows Figure 1A , Figure 6 and Figure 7 As shown, the airflow 61 flows along the surface of the grain 20. Specifically, as... Figure 2A and Figure 2B As shown, the die bonding device 10 has multiple channels 17, which are uniformly distributed throughout the die bonding device 10; as Figure 6 and Figure 7 As shown, the airflow 61 generated by the positive pressure 41 turns after contacting the surface of the grain 20 and flows along the surface of the grain 20 in a gap 70 between the die bonding device 10 and the grain 20. Then the airflow 61 enters the plurality of channels 17 of the die bonding device 10.

[0041] Step S500, as follows Figure 1A , Figure 4 , Figure 6 and Figure 7 As shown, the flow rate or pressure change of airflow 61 at different locations is sensed and multiple sensing information 81 is obtained. Specifically, as... Figure 2A and Figure 2B As shown, multiple sensors 80 are respectively disposed outside the openings of the multiple channels 17, without blocking the openings of the multiple channels 17, to ensure that the multiple channels 17 maintain ventilation. Figure 6As shown, when there are no voids or particles between the grain 20 and the substrate 50, the gap 70 gradually increases along the diffusion trend 60 of the bonding wave. The larger the gap 70, the greater the change in flow rate or pressure of the airflow 61. Therefore, the change in flow rate of the airflow 61 through different channels 17 is F1>F2>F3>F4>F5, and the change in pressure of the airflow 61 through different channels 17 is P1>P2>P3>P4>P5. Figure 7 As shown, when the grain 20 and the substrate 50 together enclose a bubble to form a void 71, or when some particles (not shown) adhere to the bottom surface of the grain 20, the grain 20 will bulge upwards. The bulging portion 21 of the grain 20 blocks or approaches one of the channels 17, preventing the airflow 61 from entering one of the channels 17, resulting in changes in flow rate or pressure. Therefore, the degree of change in flow rate of the airflow 61 through different channels 17 is F1>F3>F4>F5 and F2=0, and the degree of change in pressure of the airflow 61 through different channels 17 is P1>P3>P4>P5 and P2=0. Figure 4 As shown, the plurality of sensors 80 respectively sense the degree of change in flow rate or pressure of the airflow 61 passing through the plurality of channels 17, and obtain a plurality of sensing information 81. Among them, the sensor 80 used to sense the degree of change in flow rate of airflow 61 is a flow sensor, and the sensor 80 used to sense the degree of change in pressure of airflow 61 is a pressure sensor.

[0042] Step S600, as follows Figure 1A , Figure 4 , Figure 6 and Figure 7 As shown, the degree of change in the distance between the die 20 and the die bonding device 10 is determined based on the multiple sensing information 81. More specifically, the multiple sensors 80 are electrically connected to a processing unit 90. Figure 4 and Figure 6 As shown, when there are no voids or particles between the die 20 and the substrate 50, the processing unit 90 receives the plurality of sensing information 81 and determines, based on the plurality of sensing information 81, the degree of change in flow rate of the airflow 61 through different channels 17 as F1>F2>F3>F4>F5 or the degree of change in pressure as P1>P2>P3>P4>P5. The processing unit 90 further determines, based on the degree of change in flow rate of the airflow 61 through different channels 17 as F1>F2>F3>F4>F5 or the degree of change in pressure as P1>P2>P3>P4>P5, the degree of change in the distance between the die 20 and the die bonding device 10. Figure 4 and Figure 7As shown, when there are voids 71 ​​or particles between the die 20 and the substrate 50, the processing unit 90 receives the plurality of sensing information 81 and determines the degree of change in the flow rate of the airflow 61 through different channels 17 as F1>F3>F4>F5 and F2=0 or the degree of change in pressure as P1>P3>P4>P5 and P2=0, and determines the degree of change in the distance between the die 20 and the die bonding device 10.

[0043] Step S700, as follows Figure 1A , Figure 4 , Figure 6 and Figure 7 As shown, the processing unit 90 determines the diffusion trend 60 of the bonding wave based on the degree of change in the distance between the grain 20 and the die bonding device 10.

[0044] Step S800, as follows Figure 1B , Figure 4 and Figures 6 to 9 As shown, the processing unit 90 determines whether the die 20 is tightly bonded to the substrate 50 based on the diffusion trend 60 of the bonding wave. Figure 8 As shown, when there are no voids or particles between the grain 20 and the substrate 50, the diffusion trend 60 of the bonding wave extends approximately along the diagonal direction D1 of the grain 20 or from one side of the grain 20 to the other direction D2, D3, thus indicating that the grain 20 and the substrate 50 are tightly bonded. Figure 9 As shown, when there are voids 71 ​​or particles between the grain 20 and the substrate 50, the diffusion trend 60 of the bonding wave generally extends around the raised portion 21 along the diagonal direction D1A of the grain 20 or from one side of the grain 20 to the other side in the directions D2A and D3A, thereby determining that the grain 20 is not tightly bonded to the substrate 50.

[0045] Figure 10 A schematic diagram of the die bonding device 10, the sensor 80, and the second vacuum device 100 is shown. (As shown) Figure 10 As shown, in terms of structure, the difference between the second embodiment and the first embodiment is that: a second vacuum device 100 is disposed on the top of the die bonding device 10. The second vacuum device 100 has an air extraction port 110, a chamber 120 and a plurality of perforations 130. The air extraction port 110 communicates with the chamber 120. The plurality of perforations 130 communicate with the chamber 120 and the plurality of perforations 130 communicate with the plurality of channels 17. The plurality of sensors 80 are disposed in the plurality of perforations 130.

[0046] Figure 11 A schematic diagram showing the flow of airflow 61, the degree of change in flow rate or pressure of airflow 61, and the diffusion trend 60 of the adhering wave according to a first embodiment of the method of the present invention is provided. Figure 11As shown, in terms of method, the difference between the second embodiment and the first embodiment is that step S400 further includes: the second vacuum device 100 guides the airflow 61 through the plurality of channels 17 through a negative pressure 140. Specifically, a vacuum pump (not shown) evacuates the chamber 120 through the vacuum port 110 to generate a negative pressure 140; the negative pressure 140 can guide the airflow 61 to enter the chamber 120 through the plurality of channels 17 and the plurality of perforations 130 with a larger flow rate and pressure, and then discharge it outward through the vacuum port 110. Because the flow rate and pressure of the airflow 61 through the plurality of channels 17 are larger, the flow rate or pressure of the airflow 61 measured by the plurality of sensors 80 is more significant, improving the sensing accuracy. Therefore, the processing unit 90 can accurately determine the relative relationship of the flow rate or pressure of the airflow 61 through different channels 17 based on the plurality of sensing information 81. Importantly, the adsorption force generated by the negative pressure 140 is insufficient to adsorb the crystal grains 20. In other words, the negative pressure 140 is actually less than the negative pressure 31 to prevent the crystal grains 20 from being adsorbed and fixed by the crystal fixing device 10 again.

[0047] In summary, the method of the present invention can use airflow 61 to detect the die-bonding state and accurately identify which grains 20 are tightly bonded to the substrate 50 and which grains 20 are not tightly bonded to the substrate 50. Those skilled in the art can perform subsequent processing on the grains 20 that are tightly bonded to the substrate 50 and pick out the grains 20 that are not tightly bonded to the substrate 50.

[0048] The above description is merely for explaining preferred embodiments of the present invention and is not intended to limit the present invention in any way. Therefore, any modifications or changes made to the present invention under the same inventive spirit should still be included within the scope of protection intended by the present invention.

Claims

1. A method for detecting the solidification state using airflow, characterized in that, Includes the following steps: A localized block of a grain detaches from a die bonding device and contacts a substrate to form a bonding wave; The bonding wave diffuses from a local block of the grain toward other blocks of the grain and has a diffusion trend, causing the grain to gradually detach from the die bonding device and be fixed to the substrate. An airflow flows along the surface of the grain; The flow rate or pressure change of the airflow at different locations is sensed and multiple sensing information is obtained; The degree of change in the distance between the grain and the die-bonding device is determined based on the multiple sensing information. The diffusion trend of the bonding wave is determined based on the degree of change in the distance between the grain and the die-bonding device; and Whether the grain is tightly bonded to the substrate is determined based on the diffusion trend of the bonding wave.

2. The method for detecting solidification state using airflow according to claim 1, characterized in that, The step of forming the bonding wave further includes: The die bonding device generates the airflow through a positive pressure to blow on local blocks of the grain, causing the local blocks of the grain to detach from the die bonding device and flex and deform to contact the substrate. The step of the airflow flowing along the surface of the grain further includes: the airflow generated by the positive pressure turns and flows along the surface of the grain after contacting the surface of the grain.

3. The method for detecting solidification state using airflow according to claim 2, characterized in that, The step of the airflow flowing along the surface of the grain further includes: The airflow flows along the surface of the grain in a gap between the die bonding device and the grain, and then the airflow enters multiple channels of the die bonding device; The step of sensing the degree of change in flow rate or pressure of the airflow at different locations further includes: multiple sensors respectively sensing the degree of change in flow rate or pressure of the airflow through the multiple channels, and obtaining multiple sensing information.

4. The method for detecting solidification state using airflow according to claim 3, characterized in that, The step of the airflow flowing along the surface of the grain further includes: A vacuum device guides the airflow through the plurality of channels by a negative pressure.

5. The method for detecting solidification state using airflow according to claim 4, characterized in that, The adsorption force generated by the negative pressure is insufficient to adsorb the crystal grains.

6. The method for detecting solidification state using airflow according to claim 4, characterized in that, The vacuum device is located on top of the die bonding device. The vacuum device has an air extraction port, a chamber, and multiple perforations. The air extraction port communicates with the chamber, the multiple perforations communicate with the chamber, and the multiple perforations communicate with multiple channels. The multiple sensors are located in the multiple perforations and do not block the openings of the multiple channels.

7. The method for detecting solidification state using airflow according to claim 3, characterized in that, The plurality of sensors are respectively disposed outside the openings of the plurality of channels, and do not block the openings of the plurality of channels.

8. The method for detecting solidification state using airflow according to claim 1, characterized in that, The step of determining the degree of change in the distance between the grain and the die-bonding device further includes: A processing unit receives the plurality of sensing information and determines the degree of change in the flow rate or pressure of the airflow at different locations based on the plurality of sensing information. The processing unit also determines the degree of change in the distance between the grain and the die bonding device based on the degree of change in the flow rate or pressure of the airflow at different locations. The step of determining the diffusion trend of the bonding wave further includes: the processing unit determining the diffusion trend of the bonding wave based on the degree of change in the distance between the grain and the die bonding device; and The step of determining whether the grain is tightly bonded to the substrate further includes: the processing unit determining whether the grain is tightly bonded to the substrate based on the diffusion trend of the bonding wave.

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