Vacuum eutectic reflow soldering furnace

Abstract

The invention discloses a vacuum eutectic reflow soldering furnace which comprises a furnace body, a heating system, an air cooling system, a liquid cooling system and an external protection system. A sealing cavity is formed in the furnace body; the heating system at least comprises a heating plate, and the heating plate is arranged in the sealed cavity; the air cooling system comprises an air cooling passage which extends from the outside of the furnace body to be communicated with the sealing cavity; the liquid cooling system comprises a liquid cooling passage, the liquid cooling passage comprises a liquid inlet part, a liquid outlet part and a cooling part, the liquid inlet part and the liquid outlet part are located outside the furnace body, the cooling part is located in the furnace body, the liquid inlet part, the cooling part and the liquid outlet part are sequentially communicated, and the cooling part is attached to the heating plate; the external protection system comprises an external protection passage, and the external protection passage is located outside the furnace body, attached to the outer surface of the furnace body, and / or attached to the joint of the liquid outlet part and the furnace body, and / or attached to the area, close to the furnace body, of the liquid outlet part. According to the scheme, the air cooling mode and the liquid cooling mode can be switched, and the defect of a single cooling mode is overcome.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor packaging and microelectronic assembly, in particular to a vacuum eutectic reflow soldering equipment for high-reliability devices (such as power chips and optoelectronic devices), and especially to a vacuum eutectic reflow soldering furnace with a multi-mode cooling system. BACKGROUND

[0002] With the development of semiconductor technology towards smaller size and higher integration, the quality of chip packaging and soldering is required to be extremely high. The traditional soldering technology is prone to produce voids under normal pressure, which reduces the thermal / electrical conductivity; the cooling rate is uncontrollable: single air cooling is slow, and water cooling is easy to cause thermal shock, which affects the microstructure of the solder joint; the heating efficiency is low in a vacuum environment, and the temperature uniformity is poor; the oxidation risk is high in the cooling stage, which affects the solder wetting property. SUMMARY

[0003] The purpose of the present application is to provide a vacuum eutectic reflow soldering furnace, which can flexibly select the cooling mode according to the process requirements, so as to improve the cooling efficiency and reduce the influence of improper cooling on the quality of the soldered parts To achieve the above-mentioned purpose, the technical scheme provided by the present application is: a vacuum eutectic reflow soldering furnace, comprising a furnace body, a heating system, an air cooling system, a liquid cooling system and an external protection system; the furnace body is internally provided with a sealed cavity; the heating system at least comprises a heating plate, which is arranged in the sealed cavity; the air cooling system comprises an air cooling passage, which extends from the outside of the furnace body to communicate with the sealed cavity, and is used for flowing through a cooling gas; the liquid cooling system comprises a liquid cooling passage, which comprises an inlet liquid part and an outlet liquid part located outside the furnace body, and a cooling part located inside the furnace body, the inlet liquid part, the cooling part and the outlet liquid part are sequentially communicated, the cooling part abuts against the heating plate, and the liquid cooling passage is used for flowing through a first cooling liquid; the external protection system comprises an external protection passage, which is located outside the furnace body, abuts against the outer surface of the furnace body, and / or abuts against the connection between the outlet liquid part and the furnace body, and / or abuts against the region adjacent to the furnace body of the outlet liquid part, and the external protection passage is used for flowing through a second cooling liquid.

[0004] The vacuum eutectic reflow soldering furnace provided by the present application can switch between air cooling and liquid cooling modes according to process requirements, which makes up for the defects of slow single air cooling and easy thermal shock of single liquid cooling, and the external protection system can also cool the furnace body and high-temperature components outside the furnace body, maintain the constant temperature and normal work of the entire vacuum eutectic reflow soldering furnace, improve the stability and reliability of the equipment, and reduce the failure probability of the equipment caused by overheating and other problems.

[0005] The above description is only a summary of the technical solutions of the present application. In order to make the technical means of the present application more clear and understandable, and to make the above and other purposes, characteristics and advantages of the present application more obvious and easy to understand, the following will describe the specific embodiments of the present application in detail. BRIEF DESCRIPTION OF DRAWINGS

[0006] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings. Figure 1 is a schematic diagram of the three-dimensional structure of the vacuum eutectic reflow soldering furnace provided by the embodiments of the present application; Figure 2 is a schematic diagram of the three-dimensional structure of the vacuum eutectic reflow soldering furnace of Figure 1 after removing the upper furnace body; Figure 3 is a schematic diagram of the top view structure plane of Figure 2 after removing the heating plate; Figure 4 is a schematic diagram of the top view structure plane of the gas cooling passage in Figure 1 ; Figure 5 is a schematic diagram of the top view structure plane of the liquid cooling passage in Figure 1 ; Figure 6 is a schematic diagram of the structure of the liquid inlet part of the liquid cooling passage in Figure 5 ; Figure 7 is a schematic diagram of the structure of the cooling part of the liquid cooling passage in Figure 5 ; Figure 8 is a schematic diagram of the structure of the liquid outlet part of the liquid cooling passage in Figure 5 ; Figure 9 is a schematic diagram of the top view structure plane of the external protection passage in Figure 1 ; Figure 10 is a schematic diagram of the three-dimensional structure of the first liquid distribution block in Figure 3 and Figure 5 ; Figure 11 is a schematic diagram of the side view structure plane of the first protection pressing block / second protection pressing block in Figure 9 ; Figure 12 is a schematic diagram of the three-dimensional structure of the gas distribution block in Figure 4 ; Figure 13 isFigure 2 Vertical sectional view of the first protection block and the gas distribution block.

[0007] Legend of reference signs: Furnace body 10 Sealing cavity 101 Upper furnace body 11 Lower furnace body 12 Heating system 20 Heating plate 21 Heat source 22 First infrared quartz array lamp tube 221 Second infrared quartz array lamp tube 222 Air cooling system 30 Air cooling passage 31 Air cooling tube 301 Gas distribution block 302 First gas distribution block 302a Second gas distribution block 302b Gas distribution chamber 3020 Nozzle 3021 Liquid cooling system 40 Liquid cooling passage 41 Liquid inlet portion 41a Cooling portion 41b Liquid outlet portion 41c Cooling liquid inlet tube 401 Second switch 4011 One-way valve 4012 First liquid inlet sub-tube 402 Second liquid inlet sub-tube 403 First liquid distribution block 404 First internal liquid inlet passage 4041 First internal liquid outlet passage 4042 First internal protection passage 4043 Second liquid distribution block 405 Second internal liquid inlet passage 4051 Second internal liquid outlet passage 4052 Second internal protection passage 4053 First liquid cooling branch tube 406 Second liquid cooling branch tube 407 First liquid outlet sub-tube 408 Second liquid outlet sub-tube 409 Cooling liquid outlet tube 410 Purging water removal line 42 Third switch 420 External protection system 50 External protection passage 51 Protective liquid inlet pipe 501 First protective block 502 First protective channel 5020 Second protective block 503 Second protective channel 5030 Protective liquid outlet pipe 504 First connecting pipe 505 Second connecting pipe 506 Third connecting pipe 507 Transverse direction X Longitudinal direction Y Height direction Z DETAILED DESCRIPTION

[0008] The embodiments of the technical solutions of the present application will be described in detail below with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application, and therefore only serve as examples, and cannot limit the protection scope of the present application.

[0009] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion.

[0010] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise explicitly and specifically limited.

[0011] In this paper, the reference to "embodiments" means that the specific features, structures or properties described in conjunction with the embodiments can be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily mean the same embodiment, nor is it an independent or alternative embodiment to other embodiments. The skilled person in the art explicitly and implicitly understands that the embodiments described herein can be combined with other embodiments.

[0012] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship between the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " in this paper generally represents a "or" relationship between the front and rear associated objects.

[0013] In the description of the embodiments of the present application, the term "a plurality of" refers to two or more (including two), and similarly, "a plurality of groups" refers to two or more groups (including two groups), and "a plurality of pieces" refers to two or more pieces (including two pieces).

[0014] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the embodiments of the present application and simplifying the description, and does not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0015] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connection", "connection", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0016] The term "parallel" in the present application not only includes the case of absolute parallel, but also includes the case of approximate parallel which is generally recognized in engineering; at the same time, "perpendicular" also not only includes the case of absolute perpendicular, but also includes the case of approximate perpendicular which is generally recognized in engineering. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0017] In the field of electronic manufacturing and semiconductor packaging, the precision and reliability of the welding process directly determine the performance of the product.

[0018] Reflow soldering is a process that melts the solder paste (composed of solder alloy powder, flux and other components) pre-coated on the PCB (printed circuit board) pad and then reflows it to realize the welding of components and circuit boards. The core is to control the heating curve (preheating, holding, reflow, cooling four stages) to ensure uniform melting of the solder and form reliable solder joints.

[0019] Traditional reflow soldering is carried out in an air environment, which is prone to defects such as voids and false soldering due to oxidation. Vacuum reflow soldering eliminates the influence of oxygen on the solder by extracting the air in the cavity, significantly improving the welding quality, especially suitable for high-precision scenarios.

[0020] Eutectic reflow soldering is a subfield of reflow soldering, which refers to a soldering process using eutectic solder (such as Sn-Pb eutectic alloy, melting point 183℃; or lead-free Sn-Ag-Cu alloy, melting point 217℃). Eutectic solder has a constant temperature during solid-liquid phase transition, with no temperature difference between melting and solidification, and can achieve no over-melting phenomenon, resulting in a dense solder joint structure and extremely high reliability.

[0021] Eutectic reflow soldering has the following advantages: 1. Low defect rate: precise eutectic point temperature, reducing internal stress and voids in the solder joint; 2. High thermal conductivity: suitable for power device heat dissipation requirements (such as IGBT, LED chip); 3. Ultra-thin soldering: micron-level solder layer thickness can be achieved to meet advanced packaging (such as Flip Chip).

[0022] In general, in high-precision scenarios such as semiconductors, automotive electronics, military, etc., vacuum eutectic reflow soldering is chosen to ensure solder joint reliability and long-term stability.

[0023] As semiconductor technology develops towards smaller size and higher integration, the quality of chip packaging and soldering is extremely high. Traditional soldering techniques under normal pressure can easily produce voids, reducing thermal / electrical conductivity; cooling rate is not controllable: single air cooling is slow, and water cooling can cause thermal shock, affecting the microstructure of the solder joint; heating efficiency is low in a vacuum environment, and temperature uniformity is poor; oxidation risk is high during the cooling stage, affecting solder wetting.

[0024] To compensate for the shortcomings of single cooling mode, the present application provides a vacuum eutectic reflow soldering furnace, which innovatively integrates and realizes two physically distinct cooling channels of air cooling and liquid cooling, allowing flexible selection of cooling mode according to process requirements.

[0025] The structure and principle of the vacuum eutectic reflow soldering furnace provided by the embodiments of the present application are described in detail below in conjunction with the accompanying drawings.

[0026] Please refer to Figure 1 , Figure 1 is a schematic diagram of the three-dimensional structure of the vacuum eutectic reflow soldering furnace provided by the embodiments of the present application. In one specific embodiment, the vacuum eutectic reflow soldering furnace includes a furnace body 10, a heating system 20, an air cooling system 30, a liquid cooling system 40, and an external protection system 50.

[0027] The furnace body 10 is provided with a sealed cavity 101 for providing an oxidation-free welding environment. The workpiece to be welded is placed in the sealed cavity 101 and heated to realize welding. Exemplarily, the furnace body 10 can include an upper furnace body 11 and a lower furnace body 12, which are overlapped with each other to jointly form the sealed cavity 101. The furnace body 10 can be made of high-strength alloy material, which has good sealing performance and high-temperature resistance. The furnace body 10 is provided with an observation window for facilitating real-time observation of the welding condition.

[0028] To realize the oxidation-free welding environment, the vacuum eutectic reflow soldering furnace further includes a vacuum system (not shown in the figure), which is composed of a vacuum pump, a vacuum valve and a vacuum detection device. The vacuum pump is connected with the furnace body 10 through a pipeline and can control the vacuum degree in the furnace within a preset range. The vacuum valve is used to control the on-off of the vacuum passage. The vacuum detection device monitors the vacuum degree in the furnace in real time and feeds back the data to the control system.

[0029] Please refer to Figure 2 , Figure 2 is Figure 1 the perspective structural schematic diagram of the vacuum eutectic reflow soldering furnace after removing the upper furnace body 11, in combination with Figure 1 and Figure 2 , the heating system 20 at least includes a heating plate 21, please refer to Figure 3 , Figure 3 is Figure 2 the planar schematic diagram of the perspective structure after removing the heating plate 21. The heating plate 21 is arranged in the sealed cavity 101. The heating plate 21 is used to place the workpiece to be welded and transmits the absorbed heat to the workpiece to be welded placed thereon, so that the workpiece reaches the required temperature for eutectic welding. The heating plate 21 can be made of, but not limited to, high-temperature-resistant and excellent heat-conducting materials (such as graphite). The graphite heating plate is not easy to be oxidized and corroded at high temperature, has good chemical stability, excellent heat-conducting performance and thermal stability, can improve the temperature uniformity and stability during welding, and improve the reliability and consistency of the welding quality. In addition, the service life of the graphite heating plate is relatively long, which reduces the maintenance cost of the equipment.

[0030] To realize the heating of the heating plate 21, the heating system 20 can further comprise a heat source 22, which can be an infrared quartz array lamp tube that can directly radiate heat to the heating plate 21, realize high-efficiency energy conversion, accurately control the heating temperature (±0.5℃ precision) by adjusting the lamp tube power and radiation intensity, ensure the stability of the process curve, and when the heating plate 21 and the infrared quartz array lamp tube work together, the infrared quartz array lamp tube provides a stable heat source, the heating plate 21 realizes uniform heat transfer, and together guarantees high-precision welding quality. The infrared quartz array lamp tube of the embodiment of the application cooperates with auxiliary processes such as nitrogen filling and vacuumizing to realize an oxidation-free welding environment and improve the surface activation and wettability of the workpiece to be welded. Specifically, the infrared quartz array lamp tube can comprise a first infrared quartz array lamp tube 221 and a second infrared quartz array lamp tube 222 located on the upper and lower sides of the heating plate 21, respectively, to realize more uniform heating of the heating plate 21. The first infrared quartz array lamp tube 221 can be installed on the upper furnace body 11, and the second infrared quartz array lamp tube 222 can be installed on the lower furnace body 12, and the first infrared quartz array lamp tube 221 and the second infrared quartz array lamp tube 222 are located on different side walls of the furnace body 10, respectively.

[0031] The gas cooling system 30 comprises a gas cooling passage 31, please refer to Figure 4 , Figure 4 is Figure 1 a top view structural plane structure diagram of the gas cooling passage 31 in the embodiment, Figure 4 The gray part represents the furnace body 10 to more clearly show the relative position relationship between the gas cooling passage 31 and the furnace body 10. The gas cooling passage 31 extends from the outside of the furnace body 10 to the communication sealing cavity 101, and the gas cooling passage 31 is used for flowing through the cooling gas. Exemplarily, the cooling gas can be an inert gas such as nitrogen. Generally, to realize the supply of the cooling gas, the gas cooling system 30 further comprises a high-pressure gas cylinder that can provide high-pressure cooling gas. The gas enters the gas cooling passage 31 after being reduced by a pressure reducing valve, and the cooling gas in the gas cooling passage 31 enters the furnace body 10 from the outside of the furnace body 10, absorbs heat in the sealing cavity 101, thereby cooling the components such as the heating plate 21 inside the sealing cavity 101. The cooling gas after heat absorption can be discharged out of the furnace body 10 through the exhaust port on the furnace body 10.

[0032] The liquid cooling system 40 comprises a liquid cooling passage 41, please refer to Figure 5 , Figure 5 is Figure 1 a top view structural plane structure diagram of the liquid cooling passage 41 in the embodiment, Figure 5The gray area represents the furnace body 10, to more clearly illustrate the relative position of the liquid cooling passage 41 to the furnace body 10. The liquid cooling passage 41 is used for the flow of a first cooling liquid, which, exemplarily, may be, but is not limited to, cooling water. The liquid cooling passage 41 extends through the furnace body 10 and includes an inlet and an outlet portion located outside the furnace body 10, as well as a cooling portion located inside the furnace body 10. Please refer to [link / reference]. Figures 6 to 8 , Figure 6 yes Figure 5 A schematic diagram of the liquid inlet section 41a of the liquid cooling passage 41. Figure 7 yes Figure 5 A schematic diagram of the structure of the cooling section 41b of the liquid cooling passage 41. Figure 8 yes Figure 5 A schematic diagram of the liquid outlet section 41c of the liquid cooling passage 41. Figures 6-8 The gray area represents the furnace body 10, to more clearly show the relative positions of the liquid inlet section 41a, cooling section 41b, and liquid outlet section 41c of the liquid cooling passage 41 with respect to the furnace body 10. The liquid inlet section 41a, cooling section 41b, and liquid outlet section 41c are connected in sequence, with the cooling section 41b attached to the heating plate 21. Thus, when the first cooling liquid flows through the liquid cooling passage 41, it enters the cooling section 41b inside the furnace body 10 from the liquid inlet section 41a. Since the cooling section 41b is attached to the heating plate 21, the first cooling liquid inside the cooling section 41b can conduct heat exchange with the heating plate 21. The heat is conducted to the cooling section 41b, thereby cooling the heating plate 21. The first cooling liquid, after absorbing heat, flows from the cooling section 41b inside the furnace body 10 to the liquid outlet section 41c outside the furnace body 10, carrying the heat out of the furnace body 10.

[0033] Typically, to supply the first cooling liquid, the liquid cooling system 40 also includes a water supply component (not shown in the figure), specifically including a water tank, a water pump and a cooler. The water tank stores cooling water, and the water pump delivers the cooling water to the liquid cooling passage 41. After absorbing heat, the water enters the cooler to cool down and then flows back to the water tank, forming a cycle.

[0034] External protection system 50 includes external protection path 51, please refer to Figure 9 , Figure 9 yes Figure 1 The diagram shows a top view of the external protection passage 51, located outside the furnace body 10. The external protection passage 51 allows the flow of a second cooling liquid, which can be, but is not limited to, cooling water. The second cooling liquid flowing through the external protection passage 51 cools the high-temperature components outside the furnace body 10, thereby protecting the sealing connection between the liquid cooling passage 41 and the furnace body 10, ensuring sealing reliability, and preventing excessively high temperatures outside the sealed cavity 101.

[0035] In some embodiments, the external protection passage 51 is attached to the connection between the liquid outlet portion 41c and the furnace body 10. Generally, the second cooling liquid after absorbing heat has a higher temperature. The second cooling liquid with a higher temperature flows from the cooling portion 41b to the liquid outlet portion 41c. Thus, the second cooling liquid flowing through the external protection passage 51 can cool the connection between the liquid outlet portion 41c and the furnace body 10, reducing the risk of sealing leakage at the connection between the liquid outlet portion 41c and the furnace body 10. For example, when a sealing ring or other sealing member is arranged at the connection between the liquid outlet portion 41c and the furnace body 10 to improve the sealing performance of the connection between the liquid outlet portion 41c and the furnace body 10, the sealing ring can be deformed and damaged due to the high temperature of the furnace body 10. The second cooling liquid flowing through the external protection passage 51 can cool the sealing ring, so that the temperature at the sealing ring is not too high, ensuring the long service life and low maintenance requirement of the equipment, and also cooling the first cooling liquid with a higher temperature after absorbing heat inside the liquid outlet portion 41c, avoiding the temperature of the liquid outlet portion 41c outside the sealing cavity 101 being too high.

[0036] In some embodiments, the external protection passage 51 is attached to the area of the liquid outlet portion 41c adjacent to the furnace body 10. Thus, the second cooling liquid flowing through the external protection passage 51 can cool the area of the liquid outlet portion 41c adjacent to the furnace body 10 outside the furnace body 10, so that the temperature outside the sealing cavity 101 is not too high.

[0037] In some embodiments, the external protection passage 51 is attached to the outer surface of the furnace body 10. Thus, the second cooling liquid flowing through the external protection passage 51 can exchange heat with the furnace body 10, thereby cooling the outer surface of the furnace body 10.

[0038] To supply the second cooling liquid, the external protection system 50 further comprises a water supply assembly (not shown in the figure), specifically including a water tank, a water pump and a cooler. The water tank stores cooling water. The water pump delivers the cooling water to the external protection passage 51. The water after absorbing heat flows back to the water tank after being cooled in the cooler, forming a circulation. The water supply assembly of the external protection system 50 and the water supply assembly of the liquid cooling system 40 can be shared to simplify the structure of the entire system. Thus, the cooling water flowing out of the water tank of the same water supply assembly can enter the liquid cooling passage 41 and the external protection passage 51 respectively, thereby realizing the cooling of the heating plate 21 by the cooling water flowing through the liquid cooling passage 41 and the liquid cooling protection of the external protection passage 51. The water supply assembly of the external protection system 50 and the water supply assembly of the liquid cooling system 40 can also be different water supply assemblies, so as to adjust the flow and cooling temperature of the first cooling liquid and the second cooling liquid respectively.

[0039] The vacuum eutectic reflow soldering furnace provided by the above scheme of the embodiment of the application comprises a furnace body 10, a heating system 20, a gas cooling system 30, a liquid cooling system 40 and an external protection system 50. The heating system 20 at least comprises a heating plate 21. The gas cooling system 30 comprises a gas cooling passage 31 for flowing through cooling gas. The cooling gas in the gas cooling passage 31 enters the furnace body 10 from outside the furnace body 10, absorbs heat in the sealed cavity 101, and thus cools the heating plate 21 and other components inside the sealed cavity 101, realizing the gas cooling mode of the vacuum eutectic reflow soldering furnace of the embodiment of the application. The liquid cooling system 40 comprises a liquid cooling passage 41 for flowing through a first cooling liquid. When the first cooling liquid flows through the liquid cooling passage 41, the first cooling liquid enters a cooling portion 41b in the furnace body 10 from a liquid inlet portion 41a. Since the cooling portion 41b abuts against the heating plate 21, the first cooling liquid in the cooling portion 41b can conductively exchange heat with the heating plate 21. The heat of the heating plate 21 is conducted to the cooling portion 41b, thus cooling the heating plate 21. The first cooling liquid after absorbing heat flows from the cooling portion 41b in the furnace body 10 to a liquid outlet portion 41c outside the furnace body 10, and takes out heat from the furnace body 10.

[0040] The vacuum eutectic reflow soldering furnace of the embodiment of the application integrates the gas cooling passage 31 and the liquid cooling passage 41, thus having the gas cooling mode and the liquid cooling mode, making up for the defects of slow cooling in the single gas cooling mode and easy heat shock in the single liquid cooling mode. The external protection system 50 can also cool the furnace body 10 and high-temperature components outside the furnace body 10, maintain the constant temperature and normal work of the entire vacuum eutectic reflow soldering furnace, improve the stability and reliability of the equipment, and reduce the failure probability of the equipment due to overheating and other problems.

[0041] The application can separately execute the gas cooling mode, separately execute the liquid cooling mode, and also can adopt the cooling mode of alternately cooling by gas and liquid. For example, when the temperature of the heating plate 21 is too high, the gas cooling mode can be switched to first. The cooling gas flowing through the gas cooling passage 31 enters the sealed cavity 101, and cools the heating plate 21. When the temperature of the heating plate 21 is reduced to a certain extent, the liquid cooling mode is switched to, the first cooling liquid flows through the liquid cooling passage 41, and the heating plate 21 is quickly cooled. By reasonably combining the alternately cooling by gas and liquid, the problem that the liquid cannot pass through the cooling portion 41b in a short time and is slowly cooled when the liquid contacts the cooling portion 41b abutting against the heating plate 21 and instantaneously vaporizes is avoided, and the problems of large waste of cooling gas, high cooling cost and slow cooling speed in the single gas cooling mode are also avoided, thus ensuring a better cooling effect and improving the quality of the soldered parts.

[0042] In some embodiments, referring again toFigure 3 and Figure 5 The liquid cooling passage 41 comprises a cooling inlet pipe 401, a first inlet sub-pipe 402, a second inlet sub-pipe 403, a first sub-pipe block 404, a second sub-pipe block 405, a first liquid cooling branch pipe 406, a second liquid cooling branch pipe 407, a first outlet sub-pipe 408, a second outlet sub-pipe 409, and a cooling outlet pipe 410.

[0043] The cooling inlet pipe 401 is located outside the furnace body 10 and is connected to a water tank of the liquid cooling system 40. The cooling inlet pipe 401 serves as an inlet pipe for cooling water. The cooling water in the water tank enters the cooling inlet pipe 401 through the inlet of the cooling inlet pipe 401.

[0044] The first inlet sub-pipe 402 and the second inlet sub-pipe 403 are respectively located outside the furnace body 10 and are respectively connected to the cooling inlet pipe 401. In this way, the cooling water in the cooling inlet pipe 401 can be divided and respectively enter the first inlet sub-pipe 402 and the second inlet sub-pipe 403, so as to realize the cooling of the heating plate 21 from different sides of the furnace body 10, thereby improving the uniformity of the overall cooling of the heating plate 21.

[0045] The first sub-pipe block 404 and the second sub-pipe block 405 are respectively located on opposite sides of the furnace body 10. The first sub-pipe block 404 and the second sub-pipe block 405 are similar in structure and are combined together as follows: Figure 10 , Figure 10 is Figure 3 and Figure 5 The first sub-pipe block 404 is provided with a first internal inlet passage 4041 and a first internal outlet passage 4042 which are isolated from each other. The second sub-pipe block 405 is provided with a second internal inlet passage 4051 and a second internal outlet passage 4052 which are isolated from each other. The first internal inlet passage 4041 is connected to the first inlet sub-pipe 402, and the second internal inlet passage 4051 is connected to the second inlet sub-pipe 403. In this way, the cooling water in the first inlet sub-pipe 402 can enter the first internal inlet passage 4041, and the cooling water in the second inlet sub-pipe 403 can enter the second internal inlet passage 4051.

[0046] The first liquid cooling branch pipe 406 is at least one. For example, there can be one, two, three or more, Figure 3 and Figure 5The first liquid cooling branch pipes 406 are shown in three cases, the first liquid cooling branch pipes 406 are arranged in the furnace body 10 and abut against the heating plates 21, the inlets of the first liquid cooling branch pipes 406 are respectively communicated with the first internal liquid inlet channels 4041, and the outlets of the first liquid cooling branch pipes 406 are respectively communicated with the second internal liquid outlet channels 4052. In this way, the cooling water in the first internal liquid inlet channels 4041 can enter the first liquid cooling branch pipes 406 respectively, and the parts of the first liquid cooling branch pipes 406 abutting against the heating plates 21 exchange heat with the heating plates 21, so as to cool the heating plates 21, and the cooling water after absorbing heat is gathered to the second internal liquid outlet channels 4052.

[0047] The second liquid cooling branch pipes 407 are at least one, and exemplarily can be one, two, three or more in number, Figure 3 and Figure 5 The second liquid cooling branch pipes 407 are shown in three cases, the second liquid cooling branch pipes 407 are arranged in the furnace body 10 and abut against the heating plates 21, the inlets of the second liquid cooling branch pipes 407 are respectively communicated with the second internal liquid inlet channels 4051, and the outlets of the second liquid cooling branch pipes 407 are respectively communicated with the first internal liquid outlet channels 4042. In this way, the cooling water in the second internal liquid inlet channels 4051 can enter the second liquid cooling branch pipes 407 respectively, and the parts of the second liquid cooling branch pipes 407 abutting against the heating plates 21 exchange heat with the heating plates 21, so as to cool the heating plates 21, and the cooling water after absorbing heat is gathered to the first internal liquid outlet channels 4042.

[0048] The first liquid outlet branch pipe 408 and the second liquid outlet branch pipe 409 are respectively located outside the furnace body 10, the inlet of the first liquid outlet branch pipe 408 is communicated with the first internal liquid outlet channels 4042, and the inlet of the second liquid outlet branch pipe 409 is communicated with the second internal liquid outlet channels 4052. In this way, the cooling water after absorbing heat in the first internal liquid outlet channels 4042 can enter the first liquid outlet branch pipe 408, and the cooling water after absorbing heat in the second internal liquid outlet channels 4052 can enter the second liquid outlet branch pipe 409.

[0049] The cooling liquid outlet pipe 410 is located outside the furnace body 10, and the outlets of the first liquid outlet branch pipe 408 and the second liquid outlet branch pipe 409 are respectively communicated with the cooling liquid outlet pipe 410. In this way, the cooling water after absorbing heat in the first liquid outlet branch pipe 408 and the second liquid outlet branch pipe 409 can enter the cooling liquid outlet pipe 410 and be discharged from the outlet of the cooling liquid outlet pipe 410.

[0050] In some embodiments, the furnace body 10 defines a transverse direction X and a longitudinal direction Y which are perpendicular to a height direction Z of the furnace body 10; the first liquid distribution block 404 and the second liquid distribution block 405 are respectively located on opposite sides of the furnace body 10 in the transverse direction X and respectively extend along the longitudinal direction Y; each first liquid cooling branch pipe 406 and each second liquid cooling branch pipe 407 are arranged in parallel and spaced apart along the longitudinal direction Y and respectively extend along the transverse direction X; each first liquid cooling branch pipe 406 and each second liquid cooling branch pipe 407 respectively abut one side of the heating plate 21 in the height direction Z, and the other side of the heating plate 21 in the height direction Z is used for placing a workpiece to be welded.

[0051] In the present embodiment, cooling water can enter the furnace body 10 from opposite sides outside the furnace body 10 to cool the heating plate 21, which can further improve the uniformity of cooling of the heating plate 21. It can be understood that if the cooling water in each pipe flows from one side to the other side of the side edge of the heating plate 21, the temperature of the heating plate 21 will be high on one side and low on the other side, resulting in poor uniformity of cooling temperature of the heating plate 21. However, the present embodiment uses a cooling method from the two side edges of the heating plate 21 to the inside, which can improve the uniformity of cooling of the heating plate 21 to some extent.

[0052] Each first liquid cooling branch pipe 406 and each second liquid cooling branch pipe 407 can be a straight pipe, and the parallel and spaced arrangement of each first liquid cooling branch pipe 406 and each second liquid cooling branch pipe 407 further improves the uniformity of cooling of the entire surface of the heating plate 21. In other embodiments, the shape of each first liquid cooling branch pipe 406 and each second liquid cooling branch pipe 407 can be various, for example, it can be a meandering and bending type such as S-shaped or M-shaped.

[0053] In some embodiments, one side of the heating plate 21 in the height direction Z is provided with a plurality of spaced grooves (not shown in the figure), and each first liquid cooling branch pipe 406 and each second liquid cooling branch pipe 407 are respectively embedded in a groove.

[0054] The shape of each first liquid cooling branch pipe 406 and each second liquid cooling branch pipe 407 can match the shape of the corresponding groove, for example, each first liquid cooling branch pipe 406 and each second liquid cooling branch pipe 407 can be a circular pipe, and the groove can be a semicircular groove, so that the shape of each first liquid cooling branch pipe 406 and each second liquid cooling branch pipe 407 can better match the corresponding groove, the matching area is larger, the heat conduction effect is better, and the cooling efficiency of the heating plate 21 is higher.

[0055] In some embodiments, referring again to Figures 1 to 3The liquid cooling system 40 further comprises a purge water-removing pipeline 42, which is in communication with the cooling water inlet pipeline 401 and is used for the flow of a water-removing gas, so that the water-removing gas flows through the liquid cooling passage 41 to remove the moisture in the liquid cooling passage 41. The water-removing gas can be a normal-temperature gas or a low-temperature gas.

[0056] Since the liquid cooling passage 41 is used for flowing through the cooling water, moisture may be left in the liquid cooling passage 41, which affects the heating efficiency of the heating plate 21 in the heating stage and the cooling efficiency of the heating plate 21 in the cooling stage (before the liquid cooling mode is performed to cool the heating plate 21, the temperature of the residual water is usually not low enough to reach the required cooling temperature, and if the cooling water is directly introduced for cooling, the cooling water will also absorb the heat of the residual water, thereby causing the cooling efficiency of the cooling water on the heating plate 21 to decrease), so the water-removing gas can be introduced into the liquid cooling passage 41 before the heating plate 21 is heated and before the cooling process, to remove the moisture in the liquid cooling passage 41.

[0057] Again referring to Figure 9 In some embodiments, the external protection passage 51 comprises a protection water inlet pipeline 501, a first protection block 502, a second protection block 503, and a protection water outlet pipeline 504.

[0058] The protection water inlet pipeline 501 is located outside the furnace body 10, and the cooling water can enter the protection water inlet pipeline 501 from the inlet of the protection water inlet pipeline 501.

[0059] The first protection block 502 and the second protection block 503 are respectively attached to different positions of the outer surface of the furnace body 10, the first protection block 502 is sleeved on the first liquid cooling branch pipeline 406, and the second protection block 503 is sleeved on the second liquid cooling branch pipeline 407, which is described in detail in Figure 11 , Figure 11 is Figure 9 a side view and a plan view of the first protection block 502 / second protection block 503, the first protection block 502 is provided with a first protection channel 5020, the second protection block 503 is provided with a second protection channel 5030, the first liquid cooling branch pipeline 406 is arranged in the first protection channel 5020, and the second liquid cooling branch pipeline 407 is arranged in the second protection channel 5030. The inlet of the first protection channel 5020 is in communication with the outlet of the protection water inlet pipeline 501, and the outlet of the first protection channel 5020 is in communication with the inlet of the second protection channel 5030.

[0060] The cooling water in the protection inlet pipe 501 can enter the first protection channel 5020 in the first protection block 502. Since the first protection channel 5020 and the second protection channel 5030 are in series, the cooling water in the first protection channel 5020 can enter the second protection channel 5030 in the second protection block 503. Since the first protection block 502 and the second protection block 503 respectively adhere to different positions of the outer surface of the furnace body 10, the cooling water in the first protection channel 5020 and the cooling water in the second protection channel 5030 can cool different areas of the outer surface of the furnace body 10, so as to avoid that the temperature of the outer surface of the furnace body 10 is too high. At the same time, since the first liquid cooling branch pipe 406 is arranged in the first protection channel 5020 and the second liquid cooling branch pipe 407 is arranged in the second protection channel 5030, the cooling water in the first protection channel 5020 can cool the area of the furnace body 10 where the first liquid cooling branch pipe 406 is arranged, so as to cool the cooling water in the first liquid cooling branch pipe 406 after absorbing heat, and the cooling water in the second protection channel 5030 can cool the area of the furnace body 10 where the second liquid cooling branch pipe 407 is arranged, so as to cool the cooling water in the second liquid cooling branch pipe 407 after absorbing heat, so as to avoid that the temperature of the pipeline outside the furnace body 10 is too high.

[0061] The protection outlet pipe 504 is located outside the furnace body 10, and the outlet of the second protection channel 5030 is communicated with the inlet of the protection outlet pipe 504. In this way, the cooling water in the second protection channel 5030 can enter the protection outlet pipe 504, so that the cooling water after absorbing heat is discharged.

[0062] The outlet of the first protection channel 5020 can be communicated with the inlet of the second protection channel 5030 through the third connecting pipe 507.

[0063] In some embodiments, the furnace body 10 has a first side wall and a second side wall along the transverse direction X, the first side wall is provided with a first through hole and a second through hole, the second side wall is provided with a third through hole and a fourth through hole, the first liquid cooling branch pipe 406 is arranged in the first through hole on the first side wall, the sealing cavity 101 and the third through hole on the second side wall in sequence, and the second liquid cooling branch pipe 407 is arranged in the second through hole on the first side wall, the sealing cavity 101 and the fourth through hole on the second side wall in sequence. The first through hole, the second through hole, the third through hole and the fourth through hole are respectively provided with sealing members.

[0064] In the embodiment, the cooling water in the first protection channel 5020 and the cooling water in the second protection channel 5030 can cool the sealing members on each first liquid cooling branch pipe 406 and each second liquid cooling branch pipe 407, so as to protect each sealing member. The sealing member can be but is not limited to a sealing ring made of rubber, silica gel or the like.

[0065] The first protection channel 5020 in the first protection block 502 can be a groove structure with an opening facing the outer surface of the furnace body 10, and the first protection block 502 is fixedly attached to the outer surface of the furnace body 10 in a sealing manner, so that the sealing ring on each first liquid cooling branch pipe 406 can be located in the first protection channel 5020 and be wrapped by the cooling water in the first protection channel 5020.

[0066] The second protection channel 5030 in the second protection block 503 can be a groove structure with an opening facing the outer surface of the furnace body 10, and the second protection block 503 is fixedly attached to the outer surface of the furnace body 10 in a sealing manner, so that the sealing ring on each second liquid cooling branch pipe 407 can be located in the second protection channel 5030 and be wrapped by the cooling water in the second protection channel 5030.

[0067] In some embodiments, the external protection passage 51 further includes a first internal protection channel 4043, a first connecting pipe 505, a second internal protection channel 4053, and a second connecting pipe 506.

[0068] The first internal protection channel 4043 is arranged in the first distribution block 404, and the first internal protection channel 4043 is isolated from the first internal liquid inlet channel 4041 and the first internal liquid outlet channel 4042, respectively. The first internal protection channel 4043 can be located between the first internal liquid inlet channel 4041 and the first internal liquid outlet channel 4042, and the inlet of the first internal protection channel 4043 is in communication with the outlet of the protection liquid inlet pipe 501.

[0069] The first connecting pipe 505 is located outside the furnace body 10 and connects the outlet of the first internal protection channel 4043 and the inlet of the first protection channel 5020.

[0070] The second internal protection channel 4053 is arranged in the second distribution block 405, and the second internal protection channel 4053 is isolated from the second internal liquid inlet channel 4051 and the second internal liquid outlet channel 4052, respectively. The second internal protection channel 4053 can be located between the second internal liquid inlet channel 4051 and the second internal liquid outlet channel 4052, and the outlet of the second internal protection channel 4053 is in communication with the inlet of the protection liquid outlet pipe 504.

[0071] The second connecting pipe 506 is located outside the furnace body 10 and connects the inlet of the second internal protection channel 4053 and the outlet of the second protection channel 5030. In this way, the cooling water in the second protection channel 5030 can first enter the second internal protection channel 4053 in the second distribution block 405 through the second connecting pipe 506, and then flow into the protection liquid outlet pipe 504 and be discharged after being cooled.

[0072] Thus, the cooling water in the liquid inlet pipe 501 can first enter the first internal protection passage 4043 in the first distribution block 404 to cool the cooling water with a higher temperature in the first distribution block 404 and the first internal liquid outlet passage 4042 therein. The cooling water in the first internal protection passage 4043 can enter the first protection passage 5020 in the first protection compression block 502 via the first connecting pipe 505. The cooling water in the first protection passage 5020 can enter the second protection passage 5030 via the third connecting pipe 507. The cooling water in the second protection passage 5030 can enter the second internal protection passage 4053 in the second distribution block 405 via the second connecting pipe 506 to cool the cooling water in the second distribution block 405 and the second internal liquid outlet passage 4052 therein. The cooling water in the second internal protection passage 4053 can then be discharged after entering the liquid outlet pipe 504.

[0073] The present embodiment can take full advantage of the cold energy of the cooling water in the external protection passage 51 to cool the interiors of the first distribution block 404 and the second distribution block 405, thereby further reducing the temperature of the liquid cooling passage 41 outside the furnace body 10.

[0074] In other embodiments, the liquid inlet pipe 501 can be directly connected to the first protection passage 5020 in the first protection compression block 502 without the first distribution block 404. The second protection passage 5030 in the second protection compression block 503 can be directly connected to the liquid outlet pipe 504 without the second distribution block 405.

[0075] Again referring to Figure 4 In some embodiments, the gas cooling passage 31 includes a gas cooling pipe 301 and a gas distribution block 302. Referring to Figure 12 and Figure 13 , Figure 12 is Figure 4 a perspective view of the gas distribution block 302 in the gas cooling passage 31 of the gas cooling device 30 in the second embodiment, Figure 13 is Figure 2 a vertical sectional view of the first protection compression block 502 and the gas distribution block 302 in the gas cooling passage 31 of the gas cooling device 30 in the second embodiment, the gas cooling pipe 301 being located outside the furnace body 10. The gas distribution block 302 is connected to the outer surface of the furnace body 10. The gas distribution block 302 is provided with a gas distribution chamber 3020 in communication with the gas cooling pipe 301. The gas distribution block 302 is provided with a plurality of nozzles 3021 in communication with the gas distribution chamber 3020. The outlets of the nozzles 3021 are located in the sealed cavity 101 and face the heating plate 21. The nozzles 3021 and the cooling part 41b are located on the same side of the heating plate 21 in the height direction Z of the furnace body 10 and avoid each other.

[0076] Thus, after the cooling gas enters the air-cooling pipe 301, it can enter the air distribution chamber 3020 of the air distribution block 302, and then be sprayed out by each nozzle 3021. The cooling gas sprayed out by each nozzle 3021 can be blown to the bottom of the heating plate 21 or a specific area to cool the heating plate 21 through convection heat transfer.

[0077] The gas distribution block 302 can extend along the longitudinal direction Y of the furnace body 10 to facilitate the arrangement of multiple nozzles 3021.

[0078] There can be one or more gas distribution blocks 302. For example, there can be two gas distribution blocks 302, namely a first gas distribution block 302a and a second gas distribution block 302b. The first gas distribution block 302a and the second gas distribution block 302b are located on both sides of the furnace body 10 in the horizontal direction X. The first gas distribution block 302a and the second gas distribution block 302b are respectively connected to the air cooling pipe 301. Therefore, the cooling gas in the air cooling pipe 301 can be diverted and enter the first gas distribution block 302a and the second gas distribution block 302b respectively, and be sprayed out through the nozzles 3021 in the first gas distribution block 302a and the second gas distribution block 302b, so as to improve the cooling efficiency and cooling uniformity of the heating plate 21.

[0079] like Figure 13 As shown, the first protective pressure block and the gas distribution block 302 are arranged along the height direction Z of the furnace body 10.

[0080] In some embodiments, the vacuum eutectic reflow oven further includes a first switch (not shown), a second switch 4011, and a control system (not shown); the first switch is located on the inlet side of the gas cooling passage 31; the second switch 4011 is located on the inlet side of the liquid cooling passage 41; and the control system is electrically connected to the first switch and the second switch 4011. The first switch and the second switch 4011 may be electric valves such as solenoid valves.

[0081] The control system includes a memory and a processor. The memory stores switching operation instructions, and the processor executes the switching operation instructions to implement the following method steps: When the air-cooling mode is executed, the first switch is opened, the second switch 4011 is closed, and the cooling gas is controlled to enter the inlet of the air-cooling passage 31; When executing liquid cooling mode, the first switch is closed, the second switch 4011 is opened, and the inlet of the first cooling liquid into the liquid cooling passage 41 and the inlet of the second cooling liquid into the external protection liquid cooling passage 41 are controlled.

[0082] In the embodiment, the vacuum eutectic reflow soldering furnace is provided with a control system, which can automatically control the switching of the air cooling mode and the liquid cooling mode. The switching condition of the cooling mode can be a manually input switching instruction, or the control system can automatically switch the cooling mode by automatically detecting various parameters in the furnace body 10. For example, the control system stores a plurality of welding process templates in the memory, which are suitable for welding different types of workpieces, and supports user-defined process parameters and saves specific welding process templates. The furnace body 10 performs the welding process according to the set welding process template, and the memory also stores a plurality of user-defined welding process parameters, such as heating temperature, temperature rising rate, holding time, cooling mode switching temperature, etc. The processor switches the appropriate cooling mode according to the automatically detected parameters in the furnace body 10.

[0083] When the liquid cooling system 40 comprises the purge water removal pipeline 42 in the above embodiment, the purge water removal pipeline 42 can be provided with a third switch 420 electrically connected to the control system, and the third switch 420 can be an electromagnetic valve. When it is necessary to purge the residual moisture in the liquid cooling passage 41, the control system controls the first switch (electromagnetic valve) on the liquid inlet pipe to be in a closed state and controls the third switch 420 on the purge water removal pipeline 42 to be in an open state, so that the cooling gas can enter the liquid cooling passage 41 through the purge water removal pipeline 42 to purge the residual moisture in the liquid cooling passage 41. After the purging process is completed, when it is necessary to cool the heating plate 21, the control system controls the first switch (electromagnetic valve) on the liquid inlet pipe to be in an open state and controls the third switch 420 on the purge water removal pipeline 42 to be in a closed state, so that the first cooling liquid can enter the liquid cooling passage 41 to cool the heating plate 21.

[0084] The liquid cooling system 40 can further comprise a one-way valve 4012 provided on the cooling liquid inlet pipe 401, which can prevent high-temperature gas in the sealed cavity 101 from damaging the second switch 4011 and the third switch 420 when the temperature rises.

[0085] In summary, the vacuum reflow soldering furnace with a multi-mode cooling system provided by the embodiment has the following advantages: First, the cooling efficiency is high: the cooling mode can be flexibly selected according to the temperature of the heating plate 21. If the temperature is too high, the air cooling mode is used to quickly reduce the temperature to avoid problems caused by sudden temperature changes. When the temperature drops to a certain extent, the liquid cooling mode is switched to further quickly cool the heating plate 21 by using the high specific heat capacity of the liquid, which can effectively shorten the cooling time and improve the production efficiency.

[0086] Second, the welding quality is good: the reasonable combination of gas cooling and liquid cooling alternating cooling mode can avoid the problem that the liquid gasification in the moment of contacting the cooling part 41b of the heating plate 21, resulting in water vapor resistance, and then the liquid cooling is slow, which ensures the cooling effect, reduces the influence of improper cooling on the welding quality, helps to improve the strength and reliability of the welded joint, and reduces the welding defect rate.

[0087] Third, the production cost is low: the traditional gas cooling method needs to consume a large amount of inert gas such as nitrogen, and the cost is high. The liquid and gas cooling switchable design of the present application can use liquid cooling mode when gas cooling is not needed, which reduces the consumption of inert gas and reduces the production cost. At the same time, the liquid cooling method helps to prolong the service life of the equipment, reduce the equipment maintenance frequency and maintenance cost.

[0088] Fourth, the device stability is high: the external protection system 50 can ensure that the structure of the furnace body 10 and other components is not deformed and damaged under the condition of vacuum high heat, maintain the constant temperature and normal work of the whole vacuum eutectic reflow soldering furnace system, improve the stability and reliability of the equipment, and reduce the failure probability of the equipment caused by overheating and other problems.

[0089] Fifth, the process adaptability is strong: different welding processes may have different requirements for cooling speed and mode. The welding furnace can switch the cooling mode, which can better meet the needs of various welding processes. For some materials or devices sensitive to the cooling process, the cooling mode can be adjusted flexibly to achieve the best welding effect, which expands the application range of the equipment.

[0090] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description simple, all possible combinations of the technical features in the above-mentioned embodiments are not described, however, as long as the combination of the technical features does not exist contradictory, it should be considered as the scope of the present application. The above-mentioned embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it should not be understood as limiting the scope of the patent application. It should be noted that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the protection scope of the present application patent should be subject to the appended claims.

Claims

1. A vacuum eutectic reflow oven, characterized in that, include: The furnace body has a sealed cavity inside; A heating system, including at least a heating plate disposed within the sealed cavity; An air-cooling system includes an air-cooling passage extending from the furnace body to a sealed cavity, the air-cooling passage being used for the flow of cooling gas. A liquid cooling system includes a liquid cooling passage that extends through the furnace body. The liquid cooling passage includes an inlet portion and an outlet portion located outside the furnace body, and a cooling portion located inside the furnace body. The inlet portion, the cooling portion, and the outlet portion are connected in sequence. The cooling portion is attached to the heating plate. The liquid cooling passage is used for the flow of a first cooling liquid. An external protection system includes an external protection passage located outside the furnace body, abutting the connection between the liquid outlet portion and the furnace body, and / or abutting the area of ​​the liquid outlet portion adjacent to the furnace body, and / or abutting the outer surface of the furnace body, the external protection passage being used to flow through a second cooling liquid.

2. The vacuum eutectic reflow oven according to claim 1, characterized in that, The liquid cooling path includes: The cooling inlet pipe is located outside the furnace body; The first liquid inlet pipe and the second liquid inlet pipe are located outside the furnace body and are respectively connected to the cooling liquid inlet pipe; The first liquid distribution block and the second liquid distribution block are located on opposite sides of the furnace body, respectively. The first liquid distribution block is provided with a first internal liquid inlet channel and a first internal liquid outlet channel that are isolated from each other. The second liquid distribution block is provided with a second internal liquid inlet channel and a second internal liquid outlet channel that are isolated from each other. The first internal liquid inlet channel is connected to the first liquid inlet pipe, and the second internal liquid inlet channel is connected to the second liquid inlet pipe. At least one first liquid-cooled branch pipe is inserted through the furnace body and attached to the heating plate. The inlet of each first liquid-cooled branch pipe is connected to the first internal liquid inlet channel, and the outlet of each first liquid-cooled branch pipe is connected to the second internal liquid outlet channel. At least one second liquid-cooled branch pipe is installed through the furnace body and attached to the heating plate. The inlet of each second liquid-cooled branch pipe is connected to the second internal liquid inlet channel, and the outlet of each second liquid-cooled branch pipe is connected to the first internal liquid outlet channel. The first liquid outlet pipe and the second liquid outlet pipe are located outside the furnace body, respectively. The inlet of the first liquid outlet pipe is connected to the first internal liquid outlet channel, and the inlet of the second liquid outlet pipe is connected to the second internal liquid outlet channel. A cooling liquid outlet pipe is located outside the furnace body, and the outlets of the first liquid outlet branch pipe and the second liquid outlet branch pipe are respectively connected to the cooling liquid outlet pipe.

3. The vacuum eutectic reflow oven according to claim 2, characterized in that, The furnace body is defined with perpendicular horizontal and vertical directions, the horizontal and vertical directions being perpendicular to the height direction of the furnace body, respectively; The first liquid distribution block and the second liquid distribution block are respectively located on opposite sides of the furnace body in the transverse direction and extend along the longitudinal direction. Each of the first liquid cooling branch pipes and each of the second liquid cooling branch pipes are arranged at intervals along the longitudinal direction and extend along the transverse direction. Each of the first liquid-cooled branch pipes and each of the second liquid-cooled branch pipes is attached to one side of the heating plate in the height direction, and the other side of the heating plate in the height direction is used to place the workpiece to be welded.

4. The vacuum eutectic reflow oven according to claim 3, characterized in that, The heating plate has multiple spaced grooves on one side in the height direction, and each of the first liquid cooling branch pipes and each of the second liquid cooling branch pipes is respectively embedded in one of the grooves.

5. The vacuum eutectic reflow oven according to claim 2, characterized in that, The liquid cooling system also includes: The purging and dewatering pipeline is connected to the cooling liquid inlet pipeline. The purging and dewatering pipeline is used for the flow of dewatering gas, which in turn allows the dewatering gas to flow through the liquid cooling passage to remove moisture from the liquid cooling passage.

6. The vacuum eutectic reflow oven according to claim 3, characterized in that, The external protection pathway includes: The liquid inlet pipe is protected and located outside the furnace body; The first protective block and the second protective block are respectively attached to different positions on the outer surface of the furnace body. The first protective block is sleeved on the first liquid cooling branch pipe, and the second protective block is sleeved on the second liquid cooling branch pipe. The first protective block is provided with a first protective channel, and the second protective block is provided with a second protective channel. The first liquid cooling branch pipe passes through the first protective channel, and the second liquid cooling branch pipe passes through the second protective channel. The inlet of the first protective channel is connected to the outlet of the protective liquid inlet pipe, and the outlet of the first protective channel is connected to the inlet of the second protective channel. The protective outlet pipe is located outside the furnace body, and the outlet of the second protective channel is connected to the inlet of the protective outlet pipe.

7. The vacuum eutectic reflow oven according to claim 6, characterized in that, The furnace body has a first sidewall and a second sidewall along the transverse direction. The first sidewall has a first through hole and a second through hole, and the second sidewall has a third through hole and a fourth through hole. The first liquid cooling branch pipe passes through the first through hole on the first sidewall, the sealing cavity, and the third through hole on the second sidewall in sequence. The second liquid cooling branch pipe passes through the second through hole on the first sidewall, the sealing cavity, and the fourth through hole on the second sidewall in sequence. A sealing element is provided in the first through hole, the second through hole, the third through hole and the fourth through hole respectively.

8. The vacuum eutectic reflow oven according to claim 6, characterized in that, The external protection pathway also includes: A first internal protection channel is provided within the first liquid distribution block. The first internal protection channel is isolated from the first internal liquid inlet channel and the first internal liquid outlet channel, respectively. The inlet of the first internal protection channel is connected to the outlet of the protection liquid inlet pipe. The first connecting pipe is located outside the furnace body and connects the outlet of the first internal protection channel to the inlet of the first protection channel; The second internal protection channel is provided in the second liquid distribution block. The second internal protection channel is isolated from the second internal liquid inlet channel and the second internal liquid outlet channel respectively. The outlet of the second internal protection channel is connected to the inlet of the protection outlet pipe. The second connecting pipe is located outside the furnace body and connects the inlet of the second internal protection channel to the outlet of the second protection channel.

9. The vacuum eutectic reflow oven according to claim 2, characterized in that, The air-cooling passage includes: The air-cooled pipe is located outside the furnace body; A gas distribution block is connected to the outer surface of the furnace body. The gas distribution block has a gas distribution chamber that communicates with the air cooling pipe. The gas distribution chamber is connected to the air cooling pipe. The gas distribution block has multiple nozzles that communicate with the gas distribution chamber. The outlet of the nozzle is located in the sealed cavity and faces the heating plate. The nozzle and the cooling part are located on the same side of the heating plate in the height direction of the furnace body and avoid each other.

10. The vacuum eutectic reflow oven according to claim 1, characterized in that, The vacuum eutectic reflow oven also includes: The first switch is located on the inlet side of the air-cooling passage; The second switch is located on the inlet side of the liquid cooling passage; The control system is electrically connected to the first switch and the second switch; The control system includes a memory and a processor. The memory stores switching operation instructions, and the processor executes the switching operation instructions to implement the following method steps: In air-cooling mode, the first switch is opened and the second switch is closed, and the cooling gas is controlled to enter the inlet of the air-cooling passage; in liquid-cooling mode, the first switch is closed and the second switch is opened, and the first cooling liquid is controlled to enter the inlet of the liquid-cooling passage and the second cooling liquid is controlled to enter the inlet of the external protective liquid-cooling passage.

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