Improved double-cavity tin drop spraying device

Abstract

The invention provides an improved double-cavity tin drop jetting device, and relates to the technical field of integrated circuit manufacturing photoetching equipment. Comprising a tin drop body, the tin drop body comprises a heating cavity and a spraying cavity suitable for being communicated with the heating cavity, and a communication valve assembly is arranged between the heating cavity and the spraying cavity to automatically control connection and disconnection of the heating cavity and the spraying cavity. By adopting the two-cavity design, the heating part and the spraying part are separated, so that the large capacity of the whole liquid metal and the high heating speed are guaranteed, the size of the spraying part is further reduced, the distance between magnets is reduced, and the magnetic force is enhanced.

Description

Technical Field

[0001] The invention relates to the technical field of integrated circuit manufacturing photolithography equipment, and in particular to an improved double-cavity tin droplet injection device. Background Art

[0002] The current liquid metal jetting uses a piezoelectric driven diaphragm method to achieve the on-demand jetting function of low-temperature liquid metal (47°C). The piezoelectric liquid metal micro-jet method is also used in the research of three-dimensional functional gradient materials. The pressure-driven diaphragm micro-jet structure is suitable for low-temperature liquid metals, and its potential jetting frequency is relatively high. However, since piezoelectric ceramics are sensitive to temperature, this micro-jet method is not suitable for the jetting of medium- and high-temperature liquid metals.

[0003] Invention patent CN112540512A discloses a tin droplet generating device, comprising: an inverted tin droplet generator body; a tin pool is arranged above the nozzle of the tin droplet generator body, and the tin pool is connected to the nozzle; a heating coil is arranged on the tin pool to heat the tin in the tin pool to keep it in a molten state. However, the tin pool is connected to the nozzle, and the unmelted solid tin easily enters the inner cavity of the nozzle, and the inverted manner is not convenient for feeding. Summary of the invention

[0004] The present invention discloses an improved dual-chamber tin droplet injection device, which divides the heating, melting and injection of metal droplets into two cavities, which can not only meet the needs of large-capacity and rapid melting of metal materials, but also reduce the size of the injection valve to increase the electric field and magnetic field strength, thereby improving the success rate and yield rate of metal droplet injection.

[0005] The present invention adopts the following scheme:

[0006] An improved dual-chamber tin droplet injection device comprises a tin droplet body, wherein the tin droplet body comprises a heating chamber and an injection chamber suitable for communicating with the heating chamber, and a connecting valve assembly is arranged between the heating chamber and the injection chamber to automatically control the connection and disconnection of the heating chamber and the injection chamber;

[0007] The connecting valve assembly includes a pressure-regulating spring, a valve body, and a valve core, wherein the valve body is suitable for connecting the heating chamber and the injection chamber; the valve core is movably arranged in the valve body; the pressure-regulating spring is connected above the valve core to provide an upward elastic force to the valve core; the valve core is configured to move upward to cut off the connection between the injection chamber and the heating chamber when the sum of the elastic force provided by the pressure-regulating spring and the buoyancy provided in the injection chamber is greater than the pressure of the tin liquid in the heating chamber, and to move downward to connect the injection chamber with the heating chamber when the sum of the elastic force provided by the pressure-regulating spring and the buoyancy provided in the injection chamber is less than the pressure of the tin liquid in the heating chamber.

[0008] Furthermore, the valve core includes a closing portion arranged at the top, a flow channel arranged on the periphery of the closing portion, and a float body arranged at the bottom. The closing portion is suitable for cutting off the connection between the injection chamber and the heating chamber when the valve core moves upward to a dead point, the flow channel is suitable for connecting the injection chamber with the heating chamber when the valve core is away from the dead point, and the float body is suitable for enhancing the buoyancy of the valve core.

[0009] Furthermore, a plurality of heating blocks are evenly distributed on the periphery of the heating chamber to heat the interior of the heating chamber.

[0010] Furthermore, the cross-section of the inner cavity of the spray chamber is set to be rectangular, and two electrodes are set on the inner wall of the spray chamber to pass pulse current to the liquid tin droplets in the wall.

[0011] Furthermore, an inverted trapezoidal convergence groove is provided at one end of the injection chamber away from the heating chamber to facilitate the convergence of the tin droplets to the nozzle module.

[0012] Furthermore, two installation slots are provided on the outside of the injection chamber for installing the neodymium magnet group, and the two installation slots are distributed on two opposite sides of the injection chamber.

[0013] Furthermore, the injection chamber and the connecting valve assembly are made of high-temperature resistant glass fiber to prevent current leakage and high temperature from causing demagnetization of the neodymium magnet.

[0014] Furthermore, the injection chamber and the heating chamber are separate and the two are detachably connected.

[0015] Furthermore, the valve body is connected to the bottom of the heating chamber by bolts, and the upper end of the valve body is connected to the heating chamber, and the lower end is connected to the injection chamber, an installation space suitable for installing the connecting valve assembly is formed on the injection chamber, and a sealing gasket is arranged between the injection chamber and the bottom of the valve body.

[0016] Furthermore, a spring frame is provided above the heating chamber for connecting the other end of the pressure regulating spring.

[0017] Beneficial effects:

[0018] This solution divides the heating, melting and spraying of metal droplets into two chambers, which can not only meet the needs of large-capacity and rapid melting of metal materials, but also reduce the size of the spray valve to increase the electric and magnetic field strengths, thereby improving the success rate and yield rate of metal droplet spraying. A mechanical structure is used to control the downstream flow of droplets to prevent the use of too many sensors from causing overall structural redundancy, resulting in an excessively large volume of the spray valve and affecting the ability to spray droplets. The mechanical structure is simple, reliable and stable. A pressure-adjusting spring is used, and the elastic force can be freely adjusted to cope with different types of metals and different capacities, making the system more robust. This solution can be used to heat and spray other types of metals, such as bismuth, gallium, metallic mercury, etc., and the product has high applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a partial cross-sectional structural schematic diagram of an improved dual-chamber tin droplet injection device according to an embodiment of the present invention;

[0020] Figure 2 It is a schematic diagram of the overall structure of an improved dual-chamber tin droplet injection device according to an embodiment of the present invention;

[0021] Figure 3 It is a schematic diagram of the valve body structure of a communication valve assembly of an improved dual-chamber tin droplet injection device according to an embodiment of the present invention;

[0022] Figure 4 It is a schematic diagram of the valve core structure of a communication valve assembly of an improved dual-chamber tin droplet injection device according to an embodiment of the present invention;

[0023] Figure 5 It is a structural schematic diagram of a valve core of a communication valve assembly of an improved dual-chamber tin droplet ejection device according to an embodiment of the present invention from another perspective;

[0024] Figure 6 It is a schematic cross-sectional structure diagram of a spray chamber of an improved dual-chamber tin droplet spraying device according to an embodiment of the present invention;

[0025] Figure 7 It is a schematic cross-sectional structure diagram of another viewing angle of a spray chamber of an improved dual-chamber tin droplet spraying device according to an embodiment of the present invention;

[0026] Figure 8 It is a structural schematic diagram of an improved dual-chamber tin droplet injection device according to an embodiment of the present invention when a connecting valve assembly is in a blocked state;

[0027] Fig. 9 It is a structural schematic diagram of an improved dual-chamber tin droplet injection device according to an embodiment of the present invention when a connecting valve assembly is in an open state;

[0028] Fig.10 It is a schematic diagram of the exploded structure of an improved dual-chamber tin droplet injection device according to an embodiment of the present invention;

[0029] Icons: Heating chamber outer cavity 1, spring frame 2, heating chamber inner cavity 3, heating block 4, injection chamber 5, neodymium magnet group 6, electrode 7, nozzle module 8, sealing gasket 9, connecting valve assembly 10, valve core 11, float body 11-1, flow channel 11-2, pressure regulating spring 12, installation point 13, wiring channel 14, convergence groove 15, installation slot 16, injection chamber inner cavity 17. DETAILED DESCRIPTION

[0030] Combination Figures 1 to 10 As shown, this embodiment provides an improved dual-chamber tin droplet injection device, including a tin droplet body, the tin droplet body including a heating chamber and an injection chamber 5 suitable for communicating with the heating chamber, a connecting valve assembly 10 is arranged between the heating chamber and the injection chamber 5 to automatically control the connection and disconnection of the heating chamber and the injection chamber 5; the connecting valve assembly 10 includes a pressure regulating spring 12, a valve body, and a valve core 11, wherein the valve body is suitable for connecting the heating chamber and the injection chamber 5; the valve core 11 is movably arranged in the valve body; the pressure regulating spring 12 is connected above the valve core 11 to provide an upward elastic force to the valve core 11; the valve core 11 is configured to move upward to cut off the connection between the injection chamber 5 and the heating chamber when the sum of the elastic force provided by the pressure regulating spring 12 and the buoyancy provided in the injection chamber 5 is greater than the pressure of the tin liquid in the heating chamber, and move downward to connect the injection chamber 5 with the heating chamber when the sum of the elastic force provided by the pressure regulating spring 12 and the buoyancy provided in the injection chamber 5 is less than the pressure of the tin liquid in the heating chamber.

[0031] Combination Figure 1 and Fig.10 As shown, in this embodiment, the improved dual-chamber tin droplet injection device includes a heating chamber, a spring frame 2, a heating chamber, a heating block 4, an injection chamber 5, a neodymium magnet group 6, an electrode 7, a nozzle module 8, a sealing gasket 9, a valve body, a valve core 11, a pressure regulating spring 12, etc. Specifically, the heating chamber includes a heating chamber outer chamber 1 and a heating chamber inner chamber 3, wherein the heating chamber inner chamber 3 is used to hold metal droplets, such as tin liquid, metal mercury, etc.; the heating chamber outer chamber 1 is arranged outside the heating chamber inner chamber 3, and an installation chamber suitable for installing a heating block 4 is formed between the heating chamber outer chamber 1 and the heating chamber inner chamber 3, and the heating blocks are evenly distributed on the outside of the heating chamber inner chamber 3 to heat the inside of the heating chamber. Tin metal is placed in the heating chamber inner chamber 3, and the solid tin inside is heated by four heating blocks 4 distributed in the reserved holes of the heating chamber outer chamber 1 (the melting point of tin is 231.89°C) to heat the tin to 250°C to ensure that the solid tin inside is fully melted. The spring frame 2 is arranged at the top of the heating chamber to connect one end of the voltage regulating spring.

[0032] Combination Figures 1 to 10As shown, the injection chamber 5 and the heating chamber are in a split and detachable connection, and the injection chamber 5 can be fixed to the heating chamber by bolts and other fasteners, which is convenient for disassembly; the injection chamber 5 is formed with an installation space suitable for installing the connecting valve assembly 10, and the connecting valve assembly 10 is installed in the installation space, the valve body is connected to the bottom of the heating chamber by bolts, and the upper end of the valve body is connected to the heating chamber, and the lower end is connected to the injection chamber 5, and a sealing gasket 9 is arranged between the injection chamber 5 and the bottom of the valve body to prevent leakage. It should be noted that a connecting portion protruding outward is arranged at the lower end of the heating chamber inner cavity 3 of the heating chamber, and the valve body is sleeved on the outside of the connecting portion, which can improve the sealing effect between the valve body and the heating chamber on the one hand, and limit the valve body on the other hand. The valve body is sealed and connected to the injection chamber 5 by a sealing gasket 9, and the channel inside the valve body is provided with a stop to limit the highest position of the upward movement of the valve core 11.

[0033] Combination Figure 1 , 3 As shown in , 4, 7, and 8, the valve core 11 includes a closing portion arranged at the top, a flow channel 11-2 arranged around the closing portion, and a float body 11-1 arranged at the bottom. The closing portion is suitable for cutting off the connection between the injection chamber 5 and the heating chamber when the valve core 11 moves upward to the stop point, the flow channel 11-2 is suitable for connecting the injection chamber 5 with the heating chamber when the valve core 11 is away from the stop point, and the float body 11-1 is suitable for enhancing the buoyancy of the valve core 11. Here, the closing portion is set in a truncated cone shape, and when the side of the truncated cone is clamped at the stop mouth, the passage of the valve body can be blocked to prevent metal droplets from passing through. The flow channel 11-2 is distributed at the lower part of the truncated cone. When the valve core 11 moves downward and disengages from the stop mouth, the flow channel 11-2 can connect the heating chamber and the injection chamber 5, so that the tin liquid flows from the heating chamber into the injection chamber 5. One end of the pressure regulating spring 12 is connected to the closing portion, and always applies a vertical upward pulling force to the valve core 11 to balance the pressure generated by the melted tin liquid above the valve core 11 .

[0034] Combination Figure 1 , 7As shown in Figure 8, in this embodiment, the injection chamber 5 is provided with an injection chamber inner cavity 17 with a rectangular cross-section, and two electrodes 7 are arranged on the inner wall of the injection chamber inner cavity 17 to pass pulse current to the liquid tin droplets in the wall. The injection chamber 5 is made into a relatively compact shape. For example, the cross-section of the heating chamber inner cavity 3 is set to a rectangle, which can ensure that the Lorentz force on the tin droplets is strong. Placing two electrodes 7, one positive and one negative, at the inner wall installation position 13 of the injection chamber inner cavity 17 can not only pass pulse current to the liquid tin droplets in the cavity, but also serve as part of the wall of the injection chamber inner cavity 17. A wiring channel 14 for the electrode 7 is also reserved in the injection chamber 5. An inverted trapezoidal convergence groove 15 is arranged at one end of the injection chamber inner cavity 17 away from the heating chamber to facilitate the convergence of the tin droplets to the nozzle module 8 below, thereby producing a better injection effect. The outer side of the injection cavity 5 also reserves a mounting slot 16 for the neodymium magnet group 6. The two mounting slots 16 are distributed on opposite sides of the injection cavity 5 to facilitate the position determination of the neodymium magnet group 6 on the YZ plane, and also prevent the uneven force phenomenon caused by the deviation of the magnet position. The nozzle module 8 described in this embodiment is a prior art and will not be described here.

[0035] Combination Figure 7 , 8 As shown, when working, when there is not enough melted tin in the heating chamber cavity 3 of the heating chamber or there is enough tin liquid in the lower injection chamber 5, the valve core 11 moves upward to the upper dead point because the sum of the elastic force provided by the pressure regulating spring 12 and the buoyancy provided by the lower tin liquid is greater than the tin liquid pressure above the valve core 11. At this time, the closing part of the valve core 11 closes the passage of the valve body and cuts off the upper and lower passages. At this time, it prevents the unmelted solid tin above from entering the lower injection chamber 5, and also prevents the lower tin liquid from excessively communicating with the tin liquid in the upper heating chamber cavity 3, causing the current generated by the electrode 7 to spread to the upper heating area, so that the tin liquid in the lower injection chamber 5 cannot be subjected to sufficient Lorentz force. When there is sufficient molten tin in the heating chamber cavity 3 of the heating chamber and there is insufficient tin liquid in the lower injection chamber 5, the valve core 11 moves downward because the sum of the elastic force provided by the pressure regulating spring 12 and the buoyancy provided by the lower tin liquid is less than the tin liquid pressure above the valve core 11, and the molten tin liquid above flows along the flow channel 11-2 of the valve core 11 into the tin droplet injection below. The tin liquid is passed through a high-frequency current through the electrode 7. Since the free electrons inside the energized metal liquid move in a directional manner under the drive of the electric field, when it is placed in a magnetic field, the free electrons will move due to the Lorentz force, and the free electrons cannot escape from the metal liquid, so they can only continuously collide with one end of the metal liquid to drive the metal liquid to flow in this direction, forming a Lorentz force field. Based on this principle, a pulse current can be passed through the two electrodes 7 in a magnetic field environment to the liquid metal, so that the liquid metal obtains a pulsed Lorentz force toward the outside of the nozzle, and the metal liquid obtains instantaneous kinetic energy, forcing the liquid metal to be ejected from the tiny nozzle to obtain tiny metal droplets.

[0036] In this embodiment, the injection chamber 5, nozzle module 8, sealing gasket 9, and connecting valve assembly 10 can all be made of high-temperature resistant insulating materials such as glass fiber to prevent current leakage and high temperature from causing demagnetization of the neodymium magnet.

[0037] The scheme of this embodiment has a reasonable structure, which is not only simple to process, but also easy to disassemble and assemble, and has parts that are not easy to wear. For example, the heating chamber and the injection chamber 5 adopt a split design, which is easy to replace and maintain, reduces maintenance costs, and improves the economy and practicality of the product; and the two-chamber design is adopted to separate the heating part from the injection part, which not only ensures that the overall liquid metal capacity is large and the heating speed is fast, but also further reduces the volume of the injection part, reduces the distance between the magnets, enhances the magnetic force, and then increases the Lorentz force on the metal droplets, and increases the initial velocity of the injection droplets. This scheme also uses a connecting valve assembly 10 to compare the pressure of the metal liquid in the heating chamber with the buoyancy generated by the metal droplets in the injection chamber 5 to automatically control the fall of the metal droplets. While isolating the liquid metal connection between the upper and lower chambers, it prevents the current from being conducted away, causing injection failure. In addition, the mechanical structure is simple and reliable, which improves the service life of the electromagnetic injection valve.

[0038] It should be understood that the above are only preferred implementations of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention.

[0039] The above description of the drawings used in the implementation manner only illustrates certain embodiments of the present invention and should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

Claims

1. An improved dual-chamber tin droplet injection device, comprising a tin droplet body, characterized in that: The tin droplet body comprises a heating chamber and an injection chamber suitable for communicating with the heating chamber, and a communication valve assembly is provided between the heating chamber and the injection chamber to automatically control the connection and disconnection of the heating chamber and the injection chamber; The connecting valve assembly includes a pressure-regulating spring, a valve body, and a valve core, wherein the valve body is suitable for connecting the heating chamber and the injection chamber; the valve core is movably arranged in the valve body; the pressure-regulating spring is connected above the valve core to provide an upward elastic force to the valve core; the valve core is configured to move upward to cut off the connection between the injection chamber and the heating chamber when the sum of the elastic force provided by the pressure-regulating spring and the buoyancy provided in the injection chamber is greater than the pressure of the tin liquid in the heating chamber, and to move downward to connect the injection chamber with the heating chamber when the sum of the elastic force provided by the pressure-regulating spring and the buoyancy provided in the injection chamber is less than the pressure of the tin liquid in the heating chamber.

2. The improved dual-chamber tin droplet injection device according to claim 1, characterized in that: The valve core includes a closing portion arranged at the top, a flow channel arranged on the periphery of the closing portion, and a float body arranged at the bottom. The closing portion is suitable for cutting off the connection between the injection chamber and the heating chamber when the valve core moves upward to a dead point, the flow channel is suitable for connecting the injection chamber with the heating chamber when the valve core is away from the dead point, and the float body is suitable for enhancing the buoyancy of the valve core.

3. The improved dual-chamber tin droplet injection device according to claim 1, characterized in that: A plurality of heating blocks are evenly distributed on the periphery of the heating chamber to heat the interior of the heating chamber.

4. The improved dual-chamber tin droplet injection device according to claim 1, characterized in that: The cross section of the inner cavity of the spray chamber is set to be rectangular, and two electrodes are set on the inner wall of the spray chamber to pass pulse current to the liquid tin droplets in the wall.

5. The improved dual-chamber tin droplet injection device according to claim 4, characterized in that: An inverted trapezoidal convergence groove is arranged at one end of the injection cavity away from the heating cavity so as to facilitate the tin droplets to converge to the nozzle module.

6. The improved dual-chamber tin droplet injection device according to claim 4, characterized in that: Two installation slots are arranged outside the injection cavity for installing the neodymium magnet group, and the two installation slots are distributed on two opposite sides of the injection cavity.

7. The improved dual-chamber tin droplet injection device according to claim 6, characterized in that: The injection chamber and the connecting valve assembly are made of high-temperature resistant glass fiber to prevent current leakage and high temperature from causing demagnetization of the neodymium magnet.

8. The improved dual-chamber tin droplet injection device according to claim 1, characterized in that: The injection chamber and the heating chamber are separate and can be detachably connected.

9. The improved dual-chamber tin droplet injection device according to claim 8, characterized in that: The valve body is connected to the bottom of the heating chamber by bolts, and the upper end of the valve body is connected to the heating chamber, and the lower end is connected to the injection chamber. An installation space suitable for installing the connecting valve assembly is formed on the injection chamber, and a sealing gasket is arranged between the injection chamber and the bottom of the valve body.

10. The improved dual-chamber tin droplet ejection device according to claim 1, characterized in that: A spring frame is arranged above the heating chamber to connect the other end of the pressure regulating spring.

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