Wafer automatic baking equipment

Abstract

The invention relates to the technical field of wafer baking equipment, in particular to automatic wafer baking equipment which comprises a feeding and discharging mechanism, a temporary storage mechanism, a turnover mechanism and a baking mechanism. The temporary storage mechanism is used for transferring and temporarily storing the cartridge; the turnover mechanism is used for transferring the cartridge; the baking mechanism is provided with a baking box body, a heating device and an air supply pipeline, and the baking box body is used for accommodating the cartridge, so that the heating device can bake a plurality of wafers in the cartridge at the same time; one end of the gas supply pipeline communicates with the baking box body, and the other end of the gas supply pipeline communicates with an external nitrogen gas source and is used for injecting nitrogen into the baking box body to form a nitrogen protection environment. In conclusion, efficient and accurate baking of the multiple wafers is achieved, the production efficiency and the product quality are remarkably improved, meanwhile, the production cost and the energy consumption are reduced, and wide application prospects and market values are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of wafer baking equipment, and in particular, to an automatic wafer baking equipment. Background Art

[0002] Silicon wafers and silicon solar cells are typical representatives of semiconductor materials and semiconductor devices respectively. Semiconductor characteristic parameters measure and characterize the performance of materials and their devices. With the rapid development of semiconductor technology, the requirements for accuracy and reliability in chip manufacturing processes have reached an unprecedented height. As a key material in the lithography process, the curing quality of photoresist PI (polyimide) directly affects the quality of lithography patterns and the performance of semiconductor devices. At the same time, semiconductor wafer baking plays an irreplaceable role in stabilizing the internal structure of wafers, removing moisture and impurities, relieving residual stress, and improving the stability of electrical properties, and is an essential key step in the chip manufacturing process.

[0003] Traditional wafer baking devices usually use baking trays to heat and cure or bake single wafers. This method has obvious limitations: only one wafer can be baked at a time, resulting in low production efficiency. Although enterprises can increase production capacity by operating multiple baking devices in parallel, it will significantly increase equipment procurement, maintenance, and comprehensive costs. In addition, existing baking devices also have deficiencies in nitrogen protection, making it difficult to ensure the stability of nitrogen concentration during baking, which easily leads to oxidation of the wafer surface and affects electrical properties.

[0004] As disclosed in the Chinese patent document with the publication number CN207320066U, a wafer baking device is disclosed. The wafer suction cup is lifted by a lifting mechanism and physically contacts the central area of the bottom surface of the wafer, and continues to lift to make the wafer close to the heating and baking surface of the upper heater to bake the wafer. It still uses a heater to bake single wafers, resulting in low efficiency.

[0005] Therefore, how to achieve simultaneous baking of multiple wafers and maintain a stable nitrogen protection environment during baking to improve production efficiency, reduce costs, and ensure product quality has become a technical problem to be solved urgently. Summary of the Invention

[0006] The present invention aims to provide a technical solution to overcome the above deficiencies.

[0007] The present invention provides an automatic wafer baking device, which includes a loading and unloading mechanism, a temporary storage mechanism, a turnover mechanism and a baking mechanism. The loading and unloading mechanism is used for loading or unloading a cassette loaded with multiple wafers; the temporary storage mechanism is arranged between the loading and unloading mechanism and the turnover mechanism, and is used for transferring and temporarily storing the cassette; the turnover mechanism is arranged between the temporary storage mechanism and the baking mechanism, and is used for transferring the cassette; the baking mechanism is provided with a baking chamber, a heating device and a gas supply pipeline. The baking chamber is used for accommodating the cassette, so that the heating device can bake multiple wafers in the cassette simultaneously; one end of the gas supply pipeline is connected to the baking chamber, and the other end is connected to an external nitrogen gas source, and is used for injecting nitrogen gas into the baking chamber to form a nitrogen gas protection environment.

[0008] Further: One side of the baking chamber facing the turnover mechanism is provided with a first window for putting in or taking out the cassette; one side of the baking chamber corresponding to the first window is equipped with a heat insulation device, and the heat insulation device is detachably covered on the first window to perform a sealing and heat insulation operation on the first window.

[0009] Further: The turnover mechanism is provided with a turnover chamber and a second robotic arm. One side of the turnover chamber is connected to the baking mechanism, and the other side is provided with a second window. The second robotic arm is installed inside the turnover chamber and picks up and places the cassette stored in the temporary storage mechanism through the second window, or picks up and places the cassette in the baking mechanism through the first window; one side of the turnover chamber corresponding to the second window is equipped with a heat insulation device, and the heat insulation device is detachably covered on the second window to perform a sealing operation on the second window.

[0010] Further: The heat insulation device is provided with a heat insulation bracket, a heat insulation door panel and a driving module. One end of the heat insulation bracket is provided with a strip-shaped base for installing the heat insulation device; the side plates on both sides thereof are respectively provided with bracket guide grooves, and the heat insulation door panel is respectively provided with door panel guide posts corresponding to the two sides of the bracket guide grooves. The door panel guide posts are embedded in the bracket guide grooves and slide along the bracket guide grooves; the driving module is installed on the heat insulation device through a rotating shaft, and its driving end is in transmission connection with the heat insulation door panel through a rotating shaft; one end of the bracket guide groove inclines towards the direction of the strip-shaped base, so as to drive the heat insulation door panel to move a certain distance towards the strip-shaped base.

[0011] Further: A lower support is arranged inside the baking chamber. One end of the lower support is fixedly connected to the inner side wall of the baking chamber, and the other end forms a baking station for supporting the cassette, so that the cassette is supported at the central part of the baking chamber.

[0012] Further: The baking mechanism is further provided with a circulation pipeline. The air inlet end and the air outlet end of the circulation pipeline are respectively connected to the baking chamber for circulating the gas in the chamber.

[0013] Furthermore: The baking chamber is provided with an inner chamber and an outer chamber. There is a heat-insulating door frame between the outer chamber and the inner chamber, and the inner chamber is suspended and installed at the central part of the outer chamber through the heat-insulating door frame.

[0014] Furthermore: The baking mechanism is also provided with a plurality of temperature sensors respectively installed on the walls of the chamber, which are used to detect the air temperature at different positions in the baking chamber; and a plurality of nitrogen sensors respectively installed on the walls of the chamber, which are used to detect the nitrogen content at different positions in the baking chamber.

[0015] Furthermore: The temporary storage mechanism is provided with a temporary storage shelf and a first robotic arm. There are a plurality of temporary storage stations on the temporary storage shelf for temporarily storing cassettes. Among them, a transfer station is provided at a position close to the turnover mechanism for assisting the turnover mechanism to transfer the cassettes; the first robotic arm is installed on the temporary storage shelf for shifting the cassettes among the temporary storage stations, the transfer station and the loading / unloading mechanism.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: Significantly improve the baking efficiency: The present invention creatively sets up a cassette, which can load multiple wafers at the same time, and uses the baking chamber as an overall baking container to realize the synchronous baking of multiple wafers in the cassette. Compared with the traditional method of baking only one wafer at a time, the baking efficiency is greatly improved, effectively meeting the urgent need of the semiconductor manufacturing industry for high-efficiency production.

[0017] Optimize the baking environment: By filling the baking chamber with high-purity inert gas (such as nitrogen) to create an oxygen-free environment and form a nitrogen protection environment, it can effectively prevent the surface of the wafer from being oxidized during high-temperature baking, effectively protect the metal layer and semiconductor material on the surface of the wafer, and strongly ensure the stability of the electrical performance of the wafer, improving the quality and reliability of chip manufacturing.

[0018] Intelligently maintain the nitrogen environment: After the first window of the baking chamber is opened to take and place the cassette, the nitrogen sensor will detect the nitrogen concentration in real time and feed the data back to the automatic control system to control the gas supply pipeline to inject nitrogen, accurately increasing the nitrogen concentration to ensure the continuous existence of a stable nitrogen protection environment, providing a reliable environmental guarantee for wafer baking.

[0019] Reduce temperature fluctuations: A gas heating device is set in the gas supply pipeline to preheat the injected nitrogen so that its temperature is the same as the internal gas temperature of the baking chamber before injection, effectively avoiding the problem of the temperature in the chamber decreasing due to nitrogen injection, ensuring the stability of the temperature during the baking process, and being beneficial to improving the consistency of wafer baking quality.

[0020] Heat insulation and sealing design: Heat insulation devices are installed at the first window of the baking box facing the turnover mechanism and the second window of the turnover box. The device is openably covered on the corresponding window, opened when taking and placing the cassette, and closed at other times to form a sealed state, which can effectively prevent the heat dissipation and gas leakage inside the baking box, and can also preheat the wafers using the remaining temperature of nitrogen during the turnover process, expel oxygen, reduce the oxygen concentration, and avoid the wafers being affected by oxygen.

[0021] Flexible and efficient turnover mechanism: The turnover mechanism is equipped with a turnover box and a second robotic arm, and is provided with a vertical movement module and a horizontal movement module. The second robotic arm is installed at the driving end of the horizontal movement module, and through the cooperation of the two, flexible picking and placing operations of multiple cassettes of the baking box can be realized. In addition, the turnover mechanism is also provided with an exhaust pipeline, which can extract and recycle the remaining nitrogen inside the turnover box, reduce production costs, and at the same time, a vacuum pump is set in the exhaust pipeline to evacuate the inside of the box when extracting nitrogen, further reducing the heat dissipation of the baking box.

[0022] Gas circulation and temperature control: The baking mechanism is provided with a circulation pipeline, whose inlet end and outlet end are respectively connected to the relative parts of the baking box, and the gas is circulated by an external air pump to make the temperature inside the box more uniform. At the same time, a gas heating device can be set in the external gas path to heat the circulating gas to form a high-temperature gas flow, which is directly used for the baking operation of the wafers. In addition, the outlet end of the circulation pipeline can also discharge the mixed air as needed, and high-concentration nitrogen is input through the inlet end to maintain the nitrogen protection environment inside the baking box.

[0023] Precise monitoring and control: A plurality of temperature sensors and nitrogen sensors are respectively installed on the walls of the baking box, which can comprehensively detect the air temperature and nitrogen content at different positions inside the box. The automatic control system accurately controls the heating device, circulation pipeline, and gas supply pipeline, etc. according to the sensor feedback data, realizes precise regulation of the heating rate, heat preservation time, cooling rate, and nitrogen concentration, ensures that multiple wafers are evenly heated, prevents wafer deformation or internal structure damage, and effectively improves the wafer yield.

[0024] In summary, the present invention innovatively sets the combination of the baking mechanism and the turnover mechanism, and makes the spaces of the two communicate with each other, so as to better utilize the high-temperature nitrogen discharged when the baking box is opened, which can not only assist in cooling but also preheat the wafers. By optimizing the wafer baking process flow, efficient and precise baking of multiple wafers is realized, significantly improving the production efficiency and product quality, while reducing the production cost and energy consumption, and having broad application prospects and market value.

[0025] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be understood through the practice of the present invention. Description of the Drawings

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0027] Figure 1 is a schematic structural diagram of the overall device of the present invention; Figure 2 is a schematic structural diagram of the temporary storage mechanism, the turnover mechanism and the baking mechanism of the present invention; Figure 3 is a schematic structural diagram of the temporary storage station and the turnover station of the present invention; Figure 4 is a schematic structural diagram of the state where the turnover mechanism and the baking mechanism of the present invention are separated from each other; Figure 5 is a schematic structural diagram of the baking box body and the heat insulation device of the present invention; Figure 6 is a schematic structural diagram of the first window and the heat insulation door frame of the present invention; Figure 7 is a schematic structural diagram of the gas supply pipeline and the circulation pipeline of the present invention; Figure 8 is a schematic structural diagram of the outer box body and the heat insulation device of the present invention; Figure 9 is a schematic diagram of the movement path of the cassette of the present invention.

[0028] The reference numerals and names in the drawings are as follows: 10 Equipment frame; 11 Loading mechanism; 12 Unloading mechanism; 13 Cassette; 20 Temporary storage mechanism; 21 Temporary storage shelf; 22 Temporary storage station; 23 Turnover station; 24 First robotic arm; 30 Turnover mechanism; 31 Turnover box body; 32 Open end; 33 Second window; 34 Second robotic arm; 35 Vertical movement module; 36 Horizontal movement module; 37 Exhaust gas pipeline; 40 Baking mechanism; 41 Baking bracket; 42 Gas supply pipeline; 43 Circulation pipeline; 44 Intake end; 45 Outlet end; 46 Temperature sensor; 47 Nitrogen sensor; 50 Baking box body; 51 Inner box body; 52 Outer box body; 53 Heat insulation door frame; 54 First window; 55 Lower bracket; 60 Heat insulation device; 61 Heat insulation bracket; 62 Strip-shaped base; 63 Bracket guide groove; 64 Heat insulation door panel; 65 Door panel guide post; 66 Driving module. Detailed implementation manners

[0029] The technical solutions in the embodiments of the present invention will be described clearly and completely below. Apparently, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0030] Please refer to Figures 1 to 9 , in the embodiment of the present invention, a wafer automatic baking device includes a loading and unloading mechanism 12, a temporary storage mechanism 20, a transfer mechanism 30, and a baking mechanism 40. The loading and unloading mechanism 12 is used to perform loading or unloading operations on a cassette 13 loaded with multiple wafer sheets; the temporary storage mechanism 20 is arranged between the loading and unloading mechanism 12 and the transfer mechanism 30 and is used to transfer and temporarily store the cassette 13; the transfer mechanism 30 is arranged between the temporary storage mechanism 20 and the baking mechanism 40 and is used to transfer the cassette 13; the baking mechanism 40 is provided with a baking box body 50, a heating device (not shown in the figure), and a gas supply pipeline 42. The baking box body 50 is used to accommodate the cassette 13 so that the heating device can bake multiple wafer sheets in the cassette 13 simultaneously; one end of the gas supply pipeline 42 is connected to the baking box body 50, and the other end is connected to an external nitrogen gas source and is used to inject nitrogen gas into the baking box body 50 to form a nitrogen gas protection environment.

[0031] Specifically, with the continuous development of semiconductor technology, the requirements for the accuracy and reliability of chip manufacturing processes are increasing day by day. As an important lithography material, the curing process of photoresist PI (polyimide) directly affects the quality of lithography patterns and the performance of semiconductor devices. And semiconductor wafer baking is a key step to ensure the stability of the internal structure of the wafer, remove moisture and impurities, relieve residual stress in the wafer, and improve the stability of electrical performance. The wafer automatic baking device in the present invention is designed according to semiconductor manufacturing processes and provides an accurate and efficient solution for the curing of photoresist PI and the baking of semiconductor wafers.

[0032] Existing baking devices heat and cure wafers through baking trays, and can only bake one wafer at a time, which has a greater impact on the wafer baking yield. Although semiconductor enterprises can start multiple such wafer baking devices simultaneously for multi-line operations of wafers, it will greatly increase the device procurement, maintenance, and other comprehensive costs. Therefore, how to heat and cure or bake multiple wafers simultaneously is a technical problem that needs to be solved.

[0033] By setting up the cassette 13, multiple wafers can be loaded simultaneously, and the baking chamber 50 can be used as an integral baking container to bake multiple wafers in the cassette 13 simultaneously, improving the baking efficiency. The heating device (not shown in the figure) can be set outside the equipment. By heating the gas in the circulation pipeline 43, the internal temperature of the baking chamber 50 is raised to achieve the baking operation. The heating device can also be directly set between the inner chamber 51 and the outer chamber 52 of the baking chamber 50, so as to directly heat the inner chamber 51 and improve the heating efficiency. Either of the two heating methods can be selected, or both can be set simultaneously.

[0034] Secondly, in order to perform the baking operation better, high-purity inert gas, such as nitrogen, can also be filled into the baking chamber 50 to create an oxygen-free environment. When nitrogen is injected into the baking chamber 50, a nitrogen protection environment can be formed to prevent the surface of the wafer from being oxidized at high temperatures, protect the metal layer and semiconductor material on the surface of the wafer, and ensure that the electrical properties of the wafer are not affected.

[0035] Again, when the first window 54 of the baking chamber 50 is opened, the nitrogen inside the chamber will overflow into the transfer chamber 31, and when the cassette 13 is taken in and out, the air in the transfer chamber 31 may also diffuse into the baking chamber 50, resulting in a decrease in the nitrogen concentration in the baking chamber 50. Therefore, after the first window 54 is opened to take in and out the cassette 13, the nitrogen sensor 47 can detect the nitrogen concentration and then feedback it to the automatic control system, which controls the gas supply pipeline 42 to inject nitrogen to increase the nitrogen concentration and ensure the formation of a stable nitrogen protection environment.

[0036] In addition, in order to avoid reducing the temperature inside the baking chamber 50 when nitrogen is discharged into the baking chamber 50, a gas heating device can be set in the gas supply pipeline 42 to perform preheating operation on the nitrogen to be injected, so that it is preheated in advance and the temperature rises to close to the temperature of the gas inside the baking chamber 50 before being injected into the baking chamber 50.

[0037] As Figure 5 and Figure 6 shown, preferably, a first window 54 is provided on one side of the baking chamber 50 facing the transfer mechanism 30 for putting in or taking out the cassette 13; a heat insulation device 60 is installed on one side of the baking chamber 50 corresponding to the first window 54, and the heat insulation device 60 can be opened to cover the first window 54, so as to perform sealing and heat insulation operations on the first window 54.

[0038] Specifically, in order to seal the baking chamber 50 to prevent the internal heat from dissipating or gas from leaking, a heat insulation device 60 can also be installed at the position of the first window 54, so that the first window 54 can be opened when the cassette 13 needs to be taken in and out, and can be closed at other times to form a sealed state. In addition, asFigure 6 As shown, a heat insulation sealing ring with a certain width can also be set at the edge of the first window 54; as Figure 7 shown, a heat insulation sealing ring can also be set at the part of the heat insulation door panel 64 corresponding to the window, and the heat insulation sealing rings of the two cooperate with each other to form an enhanced heat insulation sealing effect.

[0039] Secondly, the baking mechanism 40 is also provided with a baking bracket 41. The baking bracket 41 is fixedly connected to the equipment frame 10 of the automatic baking equipment. A plurality of baking boxes 50 are respectively installed on the baking bracket 41, and a plurality of heat insulation devices 60 are also synchronously installed on the baking bracket 41 and cover the first window 54 of the corresponding baking box 50. In addition, the turnover box 31 is installed on the equipment frame 10, and its opening 32 faces the baking bracket 41 and forms a fixed connection with the baking bracket 41.

[0040] As Figures 2 to 4 shown, preferably, the turnover mechanism 30 is provided with a turnover box 31 and a second robotic arm 34. One side of the turnover box 31 communicates with the baking mechanism 40, and the other side is provided with a second window 33. The second robotic arm 34 is installed inside the turnover box 31 and picks up and places the cassette 13 stored in the temporary storage mechanism 20 through the second window 33, or picks up and places the cassette 13 in the baking mechanism 40 through the first window 54; a heat insulation device 60 is installed on one side of the turnover box 31 corresponding to the second window 33, and the heat insulation device 60 can be opened to cover the second window 33, so as to perform a sealing operation on the second window 33.

[0041] Specifically, on the side of the turnover mechanism 30 facing the baking mechanism 40, an opening 32 with a larger opening can be set, and the opening 32 is fixedly connected to the baking bracket 41, and the connection part forms a sealed state, so that the baking box 50 and the turnover box 31 form a relatively closed overall space that communicates with each other. When the first window 54 of the baking box 50 is opened, the nitrogen gas inside it will overflow into the turnover box 31, forming a turnover space with a certain temperature and nitrogen concentration. When the wafer in the cassette 13 is transferred from the temporary storage mechanism 20 to the baking box 50 by the second robotic arm 34, it can first pass through the turnover space, and the residual heat of the nitrogen gas can be used to preheat the wafer, and at the same time, the higher-concentration nitrogen gas can be used to expel oxygen to avoid the wafer being affected by oxygen.

[0042] Secondly, the second robotic arm 34 can extend into the first window 54 of the baking box 50 through the opening 32 to send in or take out the cassette 13; the second robotic arm 34 can also pick up and place the cassette 13 at the turnover station 23 through the second window 33. In order to close the second window 33, preferably, a heat insulation device 60 is also installed at the corresponding part to perform an openable sealing operation on the second window 33.

[0043] Again, the turnover mechanism 30 is further provided with a vertical movement module 35 and a horizontal movement module 36. Vertical movement modules 35 are respectively installed on both sides of the turnover box body 31 where there are no openings 32 and second windows 33. Both ends of the horizontal movement module 36 are respectively drivingly connected to the driving ends of the vertical movement modules 35, so that the vertical movement modules 35 can drive the horizontal movement module 36 to move vertically. The second robotic arm 34 is installed at the driving end of the horizontal movement module 36, and thus can move horizontally under the drive of the horizontal movement module 36. Preferably, the second robotic arm 34 is a three-axis robotic arm. Cooperating with the horizontal movement module 36 and the vertical movement module 35, it can realize the picking and placing operations of the cartridges 13 of multiple baking box bodies 50.

[0044] In addition, the turnover mechanism 30 is further provided with an exhaust pipeline 37 for discharging the remaining nitrogen gas inside the turnover box body 31. In order to reduce production costs, the remaining nitrogen gas can also be discharged into a preset container for recycling. Since it is mixed with a part of other gases, it cannot be directly reused. It can be recycled and returned to the manufacturer that supplies nitrogen gas to reduce the cost of nitrogen purification. In order to further reduce the heat dissipation of the baking box body 50, a vacuum pump can also be provided in the exhaust pipeline 37. When it extracts the nitrogen gas inside the turnover box body 31, it can also perform a vacuum pumping operation on the inside of the box body to make the internal air pressure reach the preset standard.

[0045] As Figures 6 to 8 shown, preferably, the heat insulation device 60 is provided with a heat insulation bracket 61, a heat insulation door panel 64 and a driving module 66. One end of the heat insulation bracket 61 is provided with a strip-shaped base 62 for installing the heat insulation device 60; the side plates on both sides thereof are respectively provided with bracket guide grooves 63. The heat insulation door panel 64 is respectively provided with door panel guide posts 65 corresponding to both sides of the bracket guide grooves 63. The door panel guide posts 65 are embedded in the bracket guide grooves 63 and slide along the bracket guide grooves 63; the driving module 66 is installed on the heat insulation device 60 through a rotating shaft, and its driving end is drivingly connected to the heat insulation door panel 64 through a rotating shaft; one end of the bracket guide groove 63 inclines towards the direction where the strip-shaped base 62 is located, so as to drive the heat insulation door panel 64 to move a certain distance towards the strip-shaped base 62.

[0046] Specifically, when the driving module 66 operates, it can drive the heat insulation door panel 64 to move along the bracket guide groove 63, thereby opening or closing the heat insulation door panel 64. Since one end of the bracket guide groove 63 has an inclined guide groove part, it can guide the heat insulation door panel 64 to move a certain distance towards the strip-shaped base 62, and finally cover the window corresponding to the strip-shaped base 62 to be covered, realizing the heat insulation and sealing operation of the window.

[0047] Secondly, preferably, the driving module 66 is an electric push rod, also known as a linear actuator, which is a power-driven device that converts the rotational motion of a motor into the linear reciprocating motion of a push rod, so that it can drive the heat insulation door panel 64 to move along the bracket guide groove 63.

[0048] As Figure 6 shown, preferably, a lower bracket 55 is provided inside the baking box body 50. One end of the lower bracket 55 is fixedly connected to the inner side wall of the baking box body 50, and the other end forms a baking station for supporting the cassette 13, so that the cassette 13 is supported at the central part of the baking box body 50.

[0049] Specifically, in order to perform a more uniform baking operation on the wafers in the cassette 13, it is preferable to provide the lower bracket 55 and suspend and fix the cassette 13 at the central part of the box body, so that the distances from the cassette 13 to the top wall, bottom wall or inner side wall of the box body are approximately the same, avoiding the influence of the box body itself on the temperature of the wafers, thereby making the overall baking temperature of the wafers loaded therein more uniform and stable.

[0050] As Figure 4 and Figure 6 shown, preferably, the baking mechanism 40 is further provided with a circulation pipeline 43. The air inlet end 44 and the air outlet end 45 of the circulation pipeline 43 are respectively communicated with the baking box body 50 for circulating the gas in the box body.

[0051] Specifically, the air inlet end 44 and the air outlet end 45 of the circulation pipeline 43 are respectively communicated with opposite parts of the baking box body 50. For example, if the air inlet end 44 is arranged on the left side wall, the air outlet end 45 is arranged on the right side wall; or if the air inlet end 44 is arranged on the top wall, the air outlet end 45 is arranged on the bottom wall, so that the inflow and outflow of the air can cover the entire interior of the box body, realizing a larger range of gas circulation.

[0052] Secondly, in order to realize the circulation of the air flow, the air inlet end 44 and the air outlet end 45 are also respectively communicated with an external air pump, so that the external air pump can drive the gas to circulate, thereby making the temperature in the box body more uniform. Since the gas in the box body has a high temperature, the external air pump and the connecting air path need to be set to be heat-resistant. In another embodiment, in order to perform high-temperature baking on the wafers, a gas heating device can also be arranged in the external air path to heat the circulating gas, thereby forming a high-temperature air flow and directly discharging it into the baking box body 50 to perform a baking operation on the wafers.

[0053] In addition, the air outlet end 45 of the circulation pipeline 43 can also directly discharge the gas, such as discharging it into the external air, or extracting it into a preset container for recycling. For example, when the nitrogen concentration in the baking box body 50 is insufficient, which means that the oxygen concentration in the mixed air is relatively high, a part of the mixed air can be discharged through the air outlet end 45, and then the automatic control system can control the gas supply pipeline 42 to input nitrogen with a higher concentration, thereby increasing the nitrogen concentration inside the baking box body 50 and maintaining the nitrogen protection environment.

[0054] As Figure 7 and Figure 8As shown, preferably, the baking box body 50 is provided with an inner box body 51 and an outer box body 52. A heat-insulating door frame 53 is arranged between the outer box body 52 and the inner box body 51. The inner box body 51 is suspended and installed at the central part of the outer box body 52 through the heat-insulating door frame 53.

[0055] Specifically, in order to reduce heat transfer and loss, preferably, the inner box body 51 and the outer box body 52 are also provided, so that the inner box body 51 is suspended and installed at the central part of the outer box body 52, that is, a certain distance is maintained between the outer wall surface of the inner box body 51 and the inner wall surface of the outer box body 52 to form a heat-insulating space. Heat-insulating materials such as heat-insulating cotton can be filled in the heat-insulating space, or the heat-insulating space can be evacuated to form a vacuum heat-insulating effect. The heat-insulating door frame 53 is preferably also made of heat-insulating materials to further reduce the heat transfer from the inner box body 51 to the outer box body 52.

[0056] Secondly, in another embodiment, in order to achieve high-temperature baking of the wafer, the heating device can also be directly arranged between the inner box body 51 and the outer box body 52. For example, heating components such as heating wires are arranged, and the inner box body 51 is directly heated by the heating device, and then the heat is transferred to the internal gas through the inner box body 51, and then the wafer is subjected to high-temperature baking.

[0057] As Figures 5 to 7 shown, preferably, the baking mechanism 40 is also provided with a plurality of temperature sensors 46 respectively installed on the walls of the box body for detecting the air temperature at different positions in the baking box body 50; and a plurality of nitrogen sensors 47 respectively installed on the walls of the box body for detecting the nitrogen content at different positions in the baking box body 50.

[0058] Specifically, sensors can be installed one by one at the top wall, bottom wall and side walls of the box body to achieve a comprehensive perception of each part of the box body, ensure that the temperature of each part is relatively uniform, and the nitrogen distribution is also relatively uniform. A plurality of temperature sensors 46 can be arranged and installed in the baking box body 50, and the detected temperature data is transmitted to the automatic control system, so that the automatic control system can control the heating device in the circulation pipeline 43 or the heating device installed at the baking box body 50 according to the corresponding temperature data, and can accurately control the heating rate, holding time and cooling rate according to the preset temperature curve.

[0059] Precise temperature control can ensure that multiple wafers are evenly heated, prevent the wafers from deforming or the internal structure from being damaged due to local overheating or overcooling, thereby improving the yield of the wafers. Similarly, the nitrogen sensor 47 can detect the nitrogen concentration of each part in real time and feedback it to the automatic control system, so that it controls the gas supply pipeline 42 to inject nitrogen into the box body to ensure the stable existence of the nitrogen protection environment; or controls the air outlet 45 to discharge a part of the air to reduce the oxygen content in the box body.

[0060] AsFigure 2 and Figure 3 As shown in Figure 3 , preferably, the temporary storage mechanism 20 is provided with a temporary storage shelf 21 and a first robotic arm 24. The temporary storage shelf 21 is provided with a plurality of temporary storage stations 22 for temporarily storing the cartridge 13. A turnover station 23 is provided at a position close to the turnover mechanism 30 for assisting the turnover mechanism 30 in transferring the cartridge 13. The first robotic arm 24 is installed on the temporary storage shelf 21 for shifting the cartridge 13 among the temporary storage station 22, the turnover station 23 and the loading and unloading mechanism 12.

[0061] Specifically, grippers or suction cups are respectively installed at the finger ends of the first robotic arm 24 and the second robotic arm 34 to grab or suck the cartridge 13, and then corresponding transfer operations are performed. The first robotic arm 24 is preferably set as a six-axis robotic arm, which can transfer the cartridge 13 from the loading mechanism 11 to the temporary storage station 22 for temporary storage operation, or transfer the cartridge 13 from the temporary storage station 22 to the unloading mechanism 12 for unloading operation; it can also transfer the cartridge 13 from the temporary storage station 22 or the loading station to the turnover station 23 for the second robotic arm 34 to pick up; it can also transfer the cartridge 13 from the turnover station 23 to the temporary storage station 22 or the unloading mechanism 12.

[0062] The specific working process of the present invention includes the following steps: Loading preparation: MAS sends a signal, and the loading mechanism 11 extends and waits. The external AGV places the cartridge 13 into the loading station. MAS (Manufacturing Automation System), that is, the manufacturing automation system, includes an automatic control system, electronic switches, etc., which can control the components in the equipment to operate automatically.

[0063] Loading identification and verification: The loading mechanism 11 scans and identifies the information of the cartridge 13 and transmits it to MAS, and MAS performs data verification. If the data is incorrect, the equipment waits for instructions in place and issues an alarm; if it is correct, the loading mechanism 11 retracts into the equipment and waits for further instructions.

[0064] Transfer of the cartridge 13 to the turnover station 23: MAS issues a baking instruction or a temporary storage instruction. The first robotic arm 24 places the cartridge 13 in the temporary storage station 22 to wait, or the first robotic arm 24 picks up the cartridge 13 and places it in the turnover station 23. The heat-insulating door panel 64 of the second window 33 of the turnover box 31 is opened, and the cartridge 13 is picked up by the second robotic arm 34 and sent into the turnover box 31, and then the second window 33 is closed.

[0065] The cassette 13 enters the oven: the heat-insulating door panel 64 of the first window 54 of the baking box 50 is opened, and the nitrogen with a relatively high temperature in the baking box 50 enters the turnover box 31. After the heat-insulating door panel 64 is opened in place, the second robot arm 34 in the turnover box 31 puts the cassette 13 on the lower bracket 55 in the inner box 51. After the cassette 13 is in place, the second robot arm 34 retreats and closes the heat-insulating door panel 64. Before closing the heat-insulating door panel 64 of the first window 54, the gas supply pipeline 42 also releases nitrogen into the baking box 50, thereby discharging oxygen, so that the nitrogen concentration inside the baking box 50 reaches a preset value. Since the gas supply port of the gas supply pipeline 42 is set at the innermost side away from the first window 54, when it releases nitrogen, it can push the oxygen on the outside out of the first window 54, thereby achieving the effect of discharging oxygen.

[0066] Gas extraction operation: extract and recover the nitrogen remaining inside the turnover box 31 to reduce the internal gas pressure to a preset standard.

[0067] Baking and cooling: MAS controls the operation of the heating device to automatically heat up the interior of the baking box 50 and stabilize it at a preset temperature for baking until the set baking time is reached. During the baking process, the circulation pipeline 43 continues to operate to circulate the gas inside the baking box 50, making the temperature inside the box more uniform, which is conducive to the simultaneous baking of multiple wafers.

[0068] After baking is completed, the heating is stopped, and the heat-insulating door plate 64 of the first window 54 of the baking box 50 is opened, so that the high-temperature and high-pressure nitrogen in the box is discharged into the turnover box 31. Since the volume of the turnover box 31 is much larger than the baking box 50, it is equivalent to releasing the pressure and cooling the nitrogen, so that the discharged nitrogen forms a relatively low-temperature normal-pressure nitrogen, which is convenient for the transfer and transportation of the wafers. A temperature sensor 46 and a nitrogen sensor 47 can also be set in the turnover box 31. When the temperature and concentration of the nitrogen in the turnover box 31 reach the preset index, the second robot arm 34 takes out the cassette 13 from the baking box 50 and closes the heat-insulating door plate 64 of the first window 54. The pressure release and cooling operation of the turnover box 31 can avoid directly taking out the cassette 13, cooling too quickly, causing quality problems of the wafers, and even causing the wafers to crack.

[0069] Discharging preparation: MAS issues instructions based on the data fed back from the baking box 50 and the turnover box 31, so that the heat-insulating door plate 64 of the second window 33 of the turnover box 31 is opened, and the baked cassette 13 taken out from the baking box 50 is re-output to the turnover station 23 by the second robot arm 34, and then the second window 33 is closed. The inside of the turnover box 31 can be evacuated again to extract and recycle nitrogen, thereby maintaining a lower air pressure standard inside the turnover box 31.

[0070] The first robotic arm 24 picks up the cassette 13 after baking from the turnover station 23, transfers it to the temporary storage station 22, or directly transfers it to the unloading mechanism 12. After the transfer is completed, the first robotic arm 24 can pick up the cassette 13 to be baked again from the temporary storage station 22 or the loading mechanism 11, send it to the turnover station 23, and wait for the second robotic arm 34 to pick up a new cassette 13, and repeat the above process.

[0071] Therefore, when the turnover mechanism 30 needs to immediately perform the turnover operation of the next cassette 13, the nitrogen in the turnover box 31 can be not extracted first. After the newly arrived cassette 13 to be baked is placed in the baking box 50 and the corresponding first window 54 is closed, the nitrogen in the turnover box 31 is extracted and recycled. By operating in this way, the process can be optimized and the efficiency can be improved, and the subsequent incoming cassette 13 can be transferred and conveyed in a nitrogen protection environment with the same temperature and concentration. In addition, the turnover box 31 can also concentrate a certain amount of heat, shorten the heating time of the baking box 50, and make its effective constant temperature time longer, thus saving energy.

[0072] Unloading operation: The unloading mechanism 12 scans and verifies the data and uploads it to the MAS, and then controls the external AGV to carry away the cassette 13 from the unloading mechanism 12. If the handling is not carried out immediately, the first robotic arm 24 places the cassette 13 at the temporary storage station 22. The temporary storage station 22 feeds back the corresponding placement parameters. After waiting for the MAS to issue a pick-up command, the first robotic arm 24 places the cassette 13 at the temporary storage station 22 on the unloading mechanism 12 again. After repeated scanning and verification, the handling process is carried out.

[0073] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention.

Claims

1. A wafer automatic baking device, characterized in that: The invention comprises a loading and unloading mechanism (12), a temporary storage mechanism (20), a turnover mechanism (30) and a baking mechanism (40); the loading and unloading mechanism (12) is used for loading or unloading a cassette (13) loaded with a plurality of wafers; the temporary storage mechanism (20) is arranged between the loading and unloading mechanism (12) and the turnover mechanism (30) and is used for transferring and temporarily storing the cassette (13); the turnover mechanism (30) is arranged between the temporary storage mechanism (20) and the baking mechanism (40) , used for transferring the cassette (13); the baking mechanism (40) is provided with a baking box (50), a heating device and an air supply pipeline (42); the baking box (50) is used for accommodating the cassette (13), so that the heating device can bake a plurality of wafers in the cassette (13) at the same time; one end of the air supply pipeline (42) is connected to the baking box (50), and the other end thereof is connected to an external nitrogen gas source, so as to inject nitrogen into the baking box (50) to form a nitrogen protective environment.

2. The automatic wafer baking equipment according to claim 1, characterized in that: A first window (54) is provided on a side of the baking box (50) facing the turnover mechanism (30) for placing or removing the cartridge (13); a heat insulating device (60) is installed on a side of the baking box (50) corresponding to the first window (54); the heat insulating device (60) can be opened to cover the first window (54), thereby performing a sealing and heat insulating operation on the first window (54).

3. The automatic wafer baking equipment according to claim 2, characterized in that: The turnover mechanism (30) is provided with a turnover box (31) and a second mechanical arm (34); one side of the turnover box (31) is connected to the baking mechanism (40), and the other side thereof is provided with a second window (33); the second mechanical arm (34) is installed inside the turnover box (31) and takes in and places a cassette (13) stored in the temporary storage mechanism (20) through the second window (33), or takes in and places a cassette (13) in the baking mechanism (40) through the first window (54); a heat insulating device (60) is installed on a side of the turnover box (31) corresponding to the second window (33); the heat insulating device (60) can be opened to cover the second window (33), thereby performing a sealing operation on the second window (33).

4. The automatic wafer baking equipment according to claim 3, characterized in that: The heat insulation device (60) is provided with a heat insulation bracket (61), a heat insulation door panel (64) and a driving module (66); one end of the heat insulation bracket (61) is provided with a strip base (62) for mounting the heat insulation device (60); side panels on both sides thereof are respectively provided with bracket guide grooves (63); the heat insulation door panel (64) is respectively provided with door panel guide pillars (65) on both sides corresponding to the bracket guide grooves (63); the door panel guide pillars (65) are embedded in the bracket guide grooves (63) and slide along the bracket guide grooves (63); the driving module (66) is installed on the heat insulation device (60) via a rotating shaft, and a driving end thereof is connected to the heat insulation door panel (64) via the rotating shaft to form a transmission connection; one end of the bracket guide groove (63) is inclined in the direction of the strip base (62), thereby driving the heat insulation door panel (64) to move a certain distance in the direction of the strip base (62).

5. The wafer automatic baking equipment according to claim 1, characterized in that: A lower bracket (55) is provided in the baking box (50), one end of which is fixedly connected to the inner wall of the baking box (50), and the other end of which forms a baking station for supporting the cassette (13), so that the cassette (13) is supported at the center of the baking box (50).

6. The wafer automatic baking equipment according to claim 1, characterized in that: The baking mechanism (40) is further provided with a circulation pipeline (43), and the air inlet end (44) and the air outlet end (45) of the circulation pipeline (43) are respectively connected to the baking box (50) for circulating the gas in the box.

7. The wafer automatic baking equipment according to claim 1, characterized in that: The baking box (50) is provided with an inner box (51) and an outer box (52); an insulating door frame (53) is provided between the outer box (52) and the inner box (51); and the inner box (51) is suspended and mounted at the center of the outer box (52) via the insulating door frame (53).

8. The wafer automatic baking equipment according to claim 1, characterized in that: The baking mechanism (40) is further provided with a plurality of temperature sensors (46) respectively mounted on the walls of the box body, for detecting the air temperature at different positions in the baking box body (50); and a plurality of nitrogen sensors (47) respectively mounted on the walls of the box body, for detecting the nitrogen content at different positions in the baking box body (50).

9. The wafer automatic baking equipment according to claim 1, characterized in that: The temporary storage mechanism (20) is provided with a temporary storage shelf (21) and a first robotic arm (24); the temporary storage shelf (21) is provided with a plurality of temporary storage stations (22) for temporarily storing the cartridges (13); a turnover station (23) is provided at a position close to the turnover mechanism (30) for assisting the turnover mechanism (30) in transferring the cartridges (13); the first robotic arm (24) is installed on the temporary storage shelf (21) for performing a shifting operation on the cartridges (13) between the temporary storage stations (22), the turnover stations (23) and the loading and unloading mechanism (12).

Images