Formic acid supply system and vacuum furnace

Abstract

The formic acid supply system comprises a first formic acid barrel, a formic acid conveying pipe, a second formic acid barrel, a first gas injection assembly, a plurality of sealing structures, a second gas injection assembly and a mixed gas outlet pipe, the inlet end of the formic acid conveying pipe is arranged at the bottom of the first formic acid barrel, the outlet end of the formic acid conveying pipe is arranged on the upper portion of the second formic acid barrel, the top of the second formic acid barrel is provided with the mixed gas outlet pipe, and the top of the second formic acid barrel is provided with the second gas injection assembly. The top of the first formic acid barrel is provided with the first gas injection assembly, and the part, in the first formic acid barrel, of the first gas injection assembly is higher than the formic acid height of the first formic acid barrel. The sealing structure is arranged at the joint of the first gas injection assembly and the first formic acid barrel, and the sealing structures are arranged at the joints of the second gas injection assembly and the second formic acid barrel and the joint of the mixed gas outlet pipe and the second formic acid barrel.

Description

Technical Field

[0001] The utility model relates to the technical field of vacuum sintering, in particular to a formic acid supply system and a vacuum furnace. Background Art

[0002] Formic acid, commonly known as formic acid, is a colorless, volatile liquid with a pungent odor. It is a weak electrolyte with a melting point of 8.6°C and a boiling point of 100.8°C. It is highly acidic and corrosive, causing skin irritation and blistering. It is an organic chemical raw material. Formic acid is a strong reducing agent. At high temperatures, formic acid gas itself can consume oxygen through a chemical reaction, resulting in oxygen-free welding. It can also reduce oxidized metal surfaces through a reduction reaction, leaving a clean metal surface. Therefore, in the semiconductor and other welding and packaging fields, the use of formic acid as a cleaning agent or reducing agent is increasing in equipment. However, existing formic acid supply systems are prone to air contamination, resulting in poor weld quality. Summary of the Invention

[0003] The utility model provides a formic acid supply system, which is used to solve the problem in the prior art that the formic acid supply system of a vacuum furnace is easily mixed with air, resulting in poor welding quality.

[0004] The utility model provides a formic acid supply system, comprising a first formic acid barrel, a formic acid delivery pipe, a second formic acid barrel, a first gas injection assembly, a plurality of sealing structures, a second gas injection assembly and a mixed gas outlet pipe; the inlet end of the formic acid delivery pipe is arranged at the bottom of the first formic acid barrel, the outlet end of the formic acid delivery pipe is arranged at the upper part of the second formic acid barrel, the mixed gas outlet pipe is arranged at the top of the second formic acid barrel, the second gas injection assembly is arranged at the top of the second formic acid barrel, the first gas injection assembly is arranged at the top of the first formic acid barrel, the portion of the first gas injection assembly in the first formic acid barrel is higher than the formic acid height of the first formic acid barrel, the sealing structure is arranged at the connection between the first gas injection assembly and the first formic acid barrel, and the sealing structures are arranged at the connections between the second gas injection assembly and the mixed gas outlet pipe and the second formic acid barrel respectively.

[0005] According to the formic acid supply system of the present invention, the pressure of the first formic acid tank is greater than the pressure of the second formic acid tank.

[0006] According to the formic acid supply system of the present invention, it also includes a first low liquid level sensor and a formic acid injection port; the first low liquid level sensor is provided at the lower part of the first formic acid barrel, and the formic acid injection port is provided at the top of the first formic acid barrel.

[0007] According to the formic acid supply system of the present invention, it also includes a second low liquid level sensor and a high liquid level sensor. The second low liquid level sensor is arranged at the bottom side of the second formic acid barrel, and the high liquid level sensor is arranged in the middle of the second formic acid barrel.

[0008] According to the formic acid supply system of the present invention, the second gas injection assembly includes a first one-way valve, a first switch valve, a connecting pipe and a circular pipe; the first one-way valve is connected to the first switch valve, the connecting pipe and the circular pipe in sequence, and the circular pipe is arranged at the inner bottom of the second formic acid barrel.

[0009] According to the formic acid supply system of the present invention, it further includes a second pressure sensor, and the second pressure sensor is arranged on the top of the second formic acid barrel.

[0010] According to the formic acid supply system of the present invention, it also includes a safety pressure relief valve, and the safety pressure relief valve is arranged on the top of the second formic acid barrel.

[0011] According to the formic acid supply system of the present invention, the first gas injection assembly further includes a second one-way valve, and the gas is injected into the first formic acid barrel through the second one-way valve.

[0012] A vacuum furnace comprises the formic acid supply system described above.

[0013] The inlet end of the formic acid delivery pipe of the utility model is arranged at the bottom of the first formic acid barrel, and the outlet end of the formic acid delivery pipe is arranged in the second formic acid barrel. The first gas injection assembly injects gas, and the formic acid is transmitted to the second formic acid barrel through the formic acid delivery pipe by the pressure of the gas, thereby preventing the formic acid directly injected into the second formic acid barrel from mixing with air, reducing the oxygen content of the formic acid-nitrogen mixed gas, and improving the welding quality of the vacuum furnace. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0015] Figure 1 This is a schematic diagram of the main structure of the formic acid supply system;

[0016] Figure 2 It is a schematic diagram of the three-dimensional structure of the formic acid supply system;

[0017] Figure 3 This is a cross-sectional structural diagram of the formic acid supply system;

[0018] Figure 4 It is a schematic diagram of the three-dimensional structure of the gas injection assembly;

[0019] Figure numerals: 1. first formic acid barrel; 2. formic acid delivery pipe; 3. second formic acid barrel; 11. first low liquid level sensor; 12. formic acid injection port; 13. first pressure sensor; 14. first gas injection assembly; 15. formic acid area; 16. sealing structure; 31. high liquid level sensor; 32. second low liquid level sensor; 33. second gas injection assembly; 34. second pressure sensor; 35. safety valve; 36. mixed gas outlet pipe; 331. first one-way valve; 332. connecting pipe; 333. circular pipe; 334. first switch valve; 361. second switch valve. DETAILED DESCRIPTION

[0020] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0021] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0022] In the description of the embodiments of the present invention, it should be noted that, unless otherwise specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present invention based on specific circumstances.

[0023] In the embodiments of the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, a first feature being "above," "above," or "above" a second feature may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below," "below," or "below" a second feature may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is lower in level than the second feature.

[0024] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0025] The following combination Figure 1-4 A formic acid supply system is described, comprising a first formic acid tank 1, a formic acid delivery pipe 2, a second formic acid tank 3, a first gas injection assembly 14, multiple sealing structures 16, a second gas injection assembly 33, and a mixed gas outlet pipe 36. The inlet end of the formic acid delivery pipe 2 is located at the bottom of the first formic acid tank 1, the outlet end of the formic acid delivery pipe 2 is located above the second formic acid tank 3, the mixed gas outlet pipe 36 is located at the top of the second formic acid tank 3, and the second gas injection assembly 33 is located at the top of the second formic acid tank 3. The first gas injection assembly 14 is located at the top of the first formic acid tank 1. The portion of the first gas injection assembly 14 within the first formic acid tank 1 is above the formic acid level in the first formic acid tank 1, i.e., the formic acid region 15. Seal structures 16 are located at the connection between the first gas injection assembly 14 and the first formic acid tank 1, and seal structures 16 are located at the connection between the second gas injection assembly 33 and the mixed gas outlet pipe 36 and the second formic acid tank 3, respectively. The mixed gas outlet pipe 36 is provided with a third one-way valve and a second on-off valve 361. The second on-off valve 361 is preferably a mini ball valve. The first gas injection assembly 14 and the second gas injection assembly 33 preferably inject inert gas, preferably nitrogen. Before injecting formic acid into the second formic acid barrel 3, the second formic acid barrel 3 is evacuated to prevent residual air.

[0026] In some embodiments, the pressure in the first formic acid tank 1 is greater than the pressure in the second formic acid tank 3. This pressure differential allows the formic acid in the first formic acid tank 1 to be pressed into the second formic acid tank 3. This prevents the incorporation of air into the formic acid when it is injected into the second formic acid tank 3. Air incorporation can compromise vacuum furnace welding quality. The pressure in the first formic acid tank 1 is measured by a first pressure sensor 13, while the pressure in the second formic acid tank 3 is measured by a second pressure sensor 34.

[0027] In some embodiments, the system further includes a first low liquid level sensor 11 and a formic acid injection port 12 . The first low liquid level sensor 11 is disposed at the bottom of the first formic acid tank 1 , and the formic acid injection port 12 is disposed at the top of the first formic acid tank 1 . When the first low liquid level sensor 11 sounds an alarm, the injection of formic acid into the second formic acid tank 3 is stopped, preventing air in the first formic acid tank 1 from entering the second formic acid tank 3 .

[0028] In some embodiments, a second low liquid level sensor 32 and a high liquid level sensor 31 are further included. The second low liquid level sensor 32 is set at the bottom of the side of the second formic acid barrel 3, and the high liquid level sensor 31 is set in the middle of the second formic acid barrel 3.

[0029] In some embodiments, the second gas injection assembly 33 includes a first one-way valve 331, a first on-off valve 334, a connecting pipe 332, and a circular pipe 333. The first one-way valve 331 is sequentially connected to the first on-off valve 334, the connecting pipe 332, and the circular pipe 333. The circular pipe 333 is disposed at the bottom of the second formic acid barrel 3. The first on-off valve 334 is preferably a mini ball valve.

[0030] In some embodiments, a second pressure sensor 34 is further included, and the second pressure sensor 34 is disposed on the top of the second formic acid barrel 3. A first pressure sensor 13 is disposed on the top of the first formic acid barrel 1.

[0031] In some embodiments, a safety valve 35 , i.e., a safety pressure relief valve 35 , is further included. The safety pressure relief valve 35 is disposed on the top of the second formic acid barrel 3 .

[0032] In some embodiments, an electronic scale is further included and is disposed below the second formic acid barrel 3. The electronic scale is used to weigh the weight of the second formic acid barrel before and after use. The difference between the two is the used weight, which is used for automatic replenishment, thereby achieving quantitative automatic replenishment.

[0033] In some embodiments, the first gas injection assembly 14 further includes a second one-way valve, through which the gas is injected into the first formic acid barrel 1 .

[0034] A vacuum furnace includes the formic acid supply system. The vacuum furnace is connected to the formic acid supply system via a mixed gas outlet pipe 36. The mixed gas includes a mixture of formic acid and nitrogen, and the mixed gas is filled into the vacuum furnace through the mixed gas outlet pipe 36.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A formic acid supply system, characterized in that: The invention comprises a first formic acid barrel, a formic acid delivery pipe, a second formic acid barrel, a first gas injection assembly, a plurality of sealing structures, a second gas injection assembly and a mixed gas outlet pipe; the inlet end of the formic acid delivery pipe is arranged at the bottom of the first formic acid barrel, the outlet end of the formic acid delivery pipe is arranged at the upper part of the second formic acid barrel, the mixed gas outlet pipe is arranged at the top of the second formic acid barrel, the second gas injection assembly is arranged at the top of the second formic acid barrel, the first gas injection assembly is arranged at the top of the first formic acid barrel, the part of the first gas injection assembly in the first formic acid barrel is higher than the formic acid height of the first formic acid barrel, the sealing structure is arranged at the connection between the first gas injection assembly and the first formic acid barrel, and the sealing structure is arranged at the connection between the second gas injection assembly and the mixed gas outlet pipe and the second formic acid barrel respectively.

2. The formic acid supply system according to claim 1, characterized in that: The pressure of the first formic acid tank is greater than the pressure of the second formic acid tank.

3. The formic acid supply system according to claim 1, characterized in that: It also includes a first low liquid level sensor and a formic acid injection port; the first low liquid level sensor is arranged at the lower part of the first formic acid barrel, and the formic acid injection port is arranged at the top of the first formic acid barrel.

4. The formic acid supply system according to claim 1, characterized in that: It also includes a second low liquid level sensor and a high liquid level sensor. The second low liquid level sensor is set at the bottom of the side of the second formic acid barrel, and the high liquid level sensor is set in the middle of the second formic acid barrel.

5. The formic acid supply system according to claim 1, characterized in that: The second gas injection assembly includes a first one-way valve, a first switch valve, a connecting pipe and a circular pipe; the first one-way valve is connected to the first switch valve, the connecting pipe and the circular pipe in sequence, and the circular pipe is arranged at the inner bottom of the second formic acid barrel.

6. The formic acid supply system according to claim 1, characterized in that: The system further includes a second pressure sensor, which is disposed on the top of the second formic acid barrel.

7. The formic acid supply system according to claim 1, characterized in that: It also includes a safety pressure relief valve, which is arranged on the top of the second formic acid barrel.

8. The formic acid supply system according to claim 1, characterized in that: The first gas injection assembly further includes a second one-way valve, through which gas is injected into the first formic acid barrel.

9. A vacuum furnace, characterized in that: The formic acid supply system comprises the formic acid supply system according to any one of claims 1 to 8.

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