Wide-temperature-range high-vacuum brazing equipment and using method thereof

Abstract

The invention discloses wide-temperature-range high-vacuum brazing equipment and a using method thereof, and relates to the technical field of brazing equipment, the wide-temperature-range high-vacuum brazing equipment comprises a vacuum heating tank body, a metal heating cylinder arranged in the vacuum heating tank body and a vacuum system used for enabling the interior of the vacuum heating tank body to be in a vacuum state, and the heating temperature of the metal heating cylinder is adjustable. The vacuum heating tank body is provided with a soft soldering working state and a hard soldering working state, and the water path subsystem is used for cooling the vacuum heating tank body, so that the vacuum heating tank body is switched from the hard soldering working state to the soft soldering working state. The wide-temperature-range high-vacuum brazing equipment is unique in design, and flexible switching of the equipment between a soft brazing working state and a hard brazing working state is achieved through the temperature-adjustable metal heating cylinder; and meanwhile, a water path subsystem arranged in the device effectively adjusts the temperature, the multifunctionality and the operation flexibility of the device are enhanced, and the device is suitable for various brazing requirements.

Description

Technical Field

[0001] The invention relates to the technical field of brazing equipment, and in particular to a wide temperature range high vacuum brazing equipment and a use method thereof. Background Art

[0002] Brazing is to put the brazing material into the position where the workpiece needs to be welded, and melt the brazing material by high temperature, that is, after the brazing material and the workpiece are heated to the melting temperature of the brazing material at a temperature lower than the melting point of the weldment, the capillary action between the liquid brazing material and the workpiece is used to fill the gap of the solid workpiece so that the workpiece adheres to each other, so as to achieve the effect of mutual connection. Brazing is widely used in electronic circuits, electrical connections, precision electronic components, metal workpiece connections (such as cemented carbide, catheters, containers), steel and copper alloy workpieces and tools, dissimilar metals, metals and non-metals, etc.

[0003] In addition to being widely used in the connection of metal workpieces, brazing technology is also used in the semiconductor industry. Ceramic substrate metallization (AMB, active metal brazing) is widely used in electronic device packaging mainly because ceramic substrates have the advantages of high thermal conductivity, high temperature resistance, low thermal expansion coefficient, high mechanical strength, corrosion resistance, good insulation and radiation resistance. In the production process of AMB ceramic substrates, the vacuum brazing of ceramic-metal only requires one heating process to complete, and the welding temperature is above 800°C. The performance of the vacuum brazing equipment will directly affect the quality of the final product.

[0004] Brazing is divided into soft soldering and hard soldering. The temperature of soft soldering needs to be kept below 450℃, and the temperature of hard soldering needs to be kept above 450℃. Existing brazing equipment can only be used for soft soldering connection or hard soldering connection, that is, it can be used for workpiece connection of low melting point solder paste or high melting point solder paste. Generally, enterprises will be equipped with two sets of brazing equipment and use systems to realize soft soldering and hard soldering respectively. However, this not only wastes equipment resources and increases the procurement cost of manufacturers, but also increases the subsequent maintenance and other work.

[0005] To this end, technicians have proposed a wide temperature range high vacuum brazing equipment to solve the above problems. Summary of the invention

[0006] The purpose of the present invention is to solve the problems in the prior art and to propose a high vacuum brazing equipment with a wide temperature range. The equipment can flexibly switch between soft soldering and hard soldering by adjusting the heating temperature of the metal heating tube, thereby meeting the brazing needs of different materials and process requirements.

[0007] To solve the above problems, the present invention provides the following technical solutions:

[0008] A high-vacuum brazing equipment with a wide temperature range comprises a vacuum heating tank body, a metal heating cylinder arranged in the vacuum heating tank body, and a vacuum system for making the interior of the vacuum heating tank body a vacuum state. The heating temperature of the metal heating cylinder is adjustable so that the vacuum heating tank body has a soft soldering working state and a hard soldering working state. The equipment also comprises a water circuit subsystem for cooling the vacuum heating tank body so that the vacuum heating tank body can be switched from the hard soldering working state to the soft soldering working state.

[0009] As a further solution of the present invention: the water circuit subsystem includes a water main circuit, a water inlet circuit, a water outlet circuit, and two groups of water distribution seats. The water main circuit is connected to the water inlet circuit, and the water inlet circuit and the water outlet circuit are respectively connected to the two groups of water distribution seats. Two interconnected connecting pipes are arranged on the vacuum heating tank body, and the ends of the two connecting pipes are respectively connected to the two groups of water distribution seats.

[0010] As a further solution of the present invention: the vacuum heating tank body is composed of an outer tank body and an inner tank body, and a gap is formed between the inner tank body and the outer tank body, and the connecting pipeline is inserted in the gap.

[0011] As a further solution of the present invention: three temperature-controlling thermocouples and power supply electrodes are inserted into the vacuum heating tank body, and a tank door is provided at the end of the vacuum heating tank body. Two interconnected connecting pipes are provided on the temperature-controlling thermocouple, the power supply electrode and the tank door, and the ends of the two connecting pipes are respectively connected to two groups of water distribution seats.

[0012] As a further solution of the present invention: a cylindrical tank reflective screen and a heating element are fixedly arranged inside the metal heating cylinder. The heating element is a cage-type structure and is coaxially arranged inside the tank reflective screen, so that when the heating element is working, the heat generated is gathered by the tank reflective screen to the working area inside the heating element.

[0013] As a further solution of the present invention: the vacuum system includes a mechanical pump, two groups of molecular pumps, a first branch and a second branch. The output end of the mechanical pump can be connected to the first branch and one end of the second branch, and its output end is selectively connected to the first branch and the second branch. The other end of the first branch is inserted into the interior of the inner tank body. The two groups of molecular pumps are connected to the second branch. The output ends of the two groups of molecular pumps are provided with flanges, and the flanges are adapted to be connected to the flanges on the vacuum heating tank body to achieve communication with the interior of the inner tank body.

[0014] As a further solution of the present invention: the equipment also includes a pneumatic subsystem, which includes a control air pipe, a pneumatic triplet, a solenoid valve connected to the pneumatic triplet, and a conducting pipe for connecting the solenoid valve to the vacuum heating tank body; valves are provided on the first branch, the second branch and the molecular pump, and the control air pipe is connected to the valve and is used to open and close the valve.

[0015] As a further solution of the present invention: the equipment also includes an electrical control system, which includes a touch screen, a PLC, a heating control system, a vacuum action system and an alarm system, and the heating control system includes a temperature controller, a power voltage regulator, a circuit breaker and the temperature-control thermocouple.

[0016] As a further solution of the present invention: a workpiece support frame is provided inside the heating element and arranged along the length direction of the heating element, a carrier is provided on the workpiece support frame, and a carrier plate for carrying the workpiece to be welded is provided inside the carrier for movable drawing.

[0017] The present invention also proposes a method for using a wide temperature range high vacuum brazing device, comprising the following steps:

[0018] Step 1: During the brazing operation, the workpiece to be welded is placed on the carrier, the heating element is operated, and three sets of temperature-controlled thermocouples are controlled to monitor the temperature of the inner tank body, so that the internal temperature of the inner tank body is maintained between 800℃ and 1000℃;

[0019] Step 2: Open the valve on the first branch, close the corresponding valve on the second branch and the molecular pump, start the mechanical pump to roughly pump the inner tank body, and pump the inner tank body pressure to 10Pa;

[0020] Step 3: Then close the valve on the first branch, open the second branch and the corresponding valve on the molecular pump, and use the mechanical pump and molecular pump to evacuate the inner tank at the same time, so that the vacuum degree inside the inner tank is lower than 5.0*10 -3 Pa;

[0021] Step 4: Maintain the aforementioned temperature and vacuum degree in the inner tank for a period of time until the brazing of the workpiece to be welded is completed;

[0022] Step 5: When it is necessary to switch from the hard soldering working state to the soft soldering working state, the main water pipe in the water circuit subsystem is used to supply cooling water to the water inlet pipe, and the cooling water will flow to the water distribution seat connected to the water inlet pipe. The water distribution seat will guide the cooling water to a connecting pipe and return it to the water outlet pipe through another connecting pipe. In this process, the cooling water contacts and exchanges heat with the vacuum heating tank body, tank door, power supply electrode, molecular pump and sealing ring on the corresponding connecting pipe, so that the temperature of the vacuum heating tank body reaches the standard for soft soldering;

[0023] Step 6: During the soldering operation, the heating element works and controls one set of temperature-control thermocouples to monitor the temperature of the inner tank body, so that the internal temperature of the inner tank body is maintained between 300°C and 500°C;

[0024] Step 7: Open the valve on the first branch, close the corresponding valve on the second branch and the molecular pump, start the mechanical pump to roughly pump the inner tank body, and pump the pressure inside the inner tank body to 50Pa;

[0025] Step 8: Then close the valve on the first branch, open the second branch and the corresponding valve on the molecular pump, and use the mechanical pump and molecular pump to evacuate the inner tank at the same time, so that the vacuum degree inside the inner tank is lower than 3.0*10 -2 Pa;

[0026] Step 9: Maintain the aforementioned temperature and vacuum degree in the inner tank for a period of time until the brazing of the workpieces to be welded is completed.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The wide temperature range high vacuum brazing equipment has a unique design. Through the adjustable temperature metal heating cylinder, the equipment can flexibly switch between soft soldering and hard soldering. At the same time, the built-in water subsystem of the equipment effectively adjusts the temperature, enhances the versatility and operational flexibility of the equipment, and is suitable for a variety of brazing needs.

[0029] 2. The water subsystem realizes the effective circulation and distribution of cooling water through the reasonable layout of the water main pipeline, water inlet pipeline, water outlet pipeline and two sets of water distribution seats, ensures the uniform cooling of the vacuum heating tank, and improves the stability and efficiency of the equipment.

[0030] 3. The sleeve design of the outer tank body and the inner tank body not only enhances the structural strength of the equipment, but also forms a gap between the two, which is convenient for the insertion of connecting pipes and the circulation of cooling water, further improving the cooling effect and temperature control accuracy of the equipment.

[0031] 4. Three temperature-controlled thermocouples and power supply electrodes are set on the vacuum heating tank body, and a tank door is equipped. At the same time, these components are provided with two interconnecting connecting pipes, which ensures the temperature uniformity and stability of the equipment during the heating and cooling process and improves the brazing quality.

[0032] 5. The tank reflective screen and cage-type heating element fixed inside the metal heating cylinder effectively gather heat and improve heating efficiency, ensuring the temperature uniformity and stability in the working area, providing a strong guarantee for high-quality brazing.

[0033] 6. The vacuum system adopts a combination design of mechanical pump and molecular pump. Through the flexible switching of the first branch and the second branch, rough and fine pumping of the inner tank body is realized, ensuring the high vacuum requirement of the equipment during the brazing process.

[0034] 7. The addition of the pneumatic subsystem realizes the effective control of the valves in the vacuum system, improves the automation level and operation convenience of the equipment, and ensures the stability and reliability of the brazing process.

[0035] 8. The workpiece support frame and carrier design set inside the heating element facilitate the placement and removal of the workpiece to be welded. At the same time, the movable pull-out carrier design inside the carrier further improves the operational flexibility and work efficiency of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The present invention will be further described below in conjunction with the accompanying drawings.

[0037] Figure 1 It is a schematic diagram of the three-dimensional structure of the vacuum heating tank and the water circuit subsystem in the present invention;

[0038] Figure 2 The three-dimensional structure of the vacuum heating tank in the present invention is shown in FIG. Figure 1 ;

[0039] Figure 3 The three-dimensional structure of the vacuum heating tank in the present invention is shown in FIG. Figure 2 ;

[0040] Figure 4 It is a schematic diagram of the cross-sectional structure of the vacuum heating tank in the present invention;

[0041] Figure 5 yes Figure 4 A is an enlarged structural diagram;

[0042] Figure 6 It is a schematic diagram of the three-dimensional structure of the vacuum heating tank body of the present invention without the tank door installed;

[0043] Figure 7 It is a schematic diagram of the three-dimensional structure of the metal heating tube in the present invention;

[0044] Figure 8 It is a schematic diagram of the three-dimensional structure of the heating element in the present invention;

[0045] Fig. 9 is a schematic diagram of the three-dimensional structure of the carrier in the present invention;

[0046] Fig.10 It is a schematic diagram of the three-dimensional structure of the vacuum system in the present invention;

[0047] Fig.11 The three-dimensional structure of the tank door in the present invention is shown in FIG. Figure 1 ;

[0048] Fig.12 The three-dimensional structure of the tank door in the present invention is shown in FIG. Figure 2 ;

[0049] Fig.13 It is a schematic diagram of the three-dimensional structure of the bearing frame in the present invention;

[0050] Fig.14 It is a three-dimensional structural schematic diagram of the present invention.

[0051] In the figure: 1. Vacuum heating tank; 101. Outer tank; 102. Inner tank; 1021. Metal heating cylinder; 1022. Heating element; 1023. Tank reflector; 1024. Insulating porcelain; 1025. Workpiece support; 103. Tank door; 103. Tank door reflector; 104. Temperature control thermocouple; 105. Power supply electrode 105; 106. Safety valve; 2. Vacuum system; 201. Machine Mechanical pump; 202, molecular pump; 203, first branch; 204, second branch; 3, carrier; 401, water main line; 402, water inlet line; 403, water outlet line; 404, water distribution seat; 405, connecting line; 406, water flow switch; 407, manual ball valve; 5, carrying frame; 501, pneumatic triplet; 502, solenoid valve; 503, conduction pipeline; 504, control air pipe. DETAILED DESCRIPTION

[0052] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0053] Embodiment 1:

[0054] like Figure 1-Figure 14 As shown, a wide temperature range high vacuum brazing equipment includes a vacuum heating tank 1 with a heating component inside, a vacuum system 2 for converting the inside of the vacuum heating tank 1 into a vacuum state, a water and gas system, a carrier 3 for supporting the workpiece to be welded, a bearing frame 5 for providing installation support for the vacuum heating tank 1 and other components, and an electrical control system for making the above components work in sequence. The above components are described in sequence as follows:

[0055] (1) Vacuum heating tank body 1. The vacuum heating tank body 1 provides a vacuum environment and thermal working layout for vacuum brazing. The vacuum heating tank body 1 is composed of an outer tank body 101 and an inner tank body 102, and a gap is formed between the inner tank body 102 and the outer tank body 101, that is, the overall structure of the vacuum heating tank body 1 is a double-layer jacket type, and there is a gap between the two layers, and cooling water can be passed into the gap. A metal heating cylinder 1021 for placing workpieces is arranged inside the inner tank body 102. The temperature of the metal heating cylinder 1021 is adjustable so that the vacuum heating tank body 1 has a soft soldering working state and a hard soldering working state; a tank door 103 for opening or closing the vacuum heating tank body 1 is arranged at the end of the vacuum heating tank body 1. The vacuum heating tank body 1 and the tank door 103 are both welded from metal plates. The weld is formed by a protective anti-oxidation welding method, which meets the vacuum container manufacturing standards. Three temperature-controlled thermocouples 104 and a power supply electrode 105 are inserted into the vacuum heating tank body 1. At the same time, a safety valve 106 is also provided on the vacuum heating tank body. The temperature-controlled thermocouple 104 is used to monitor the temperature inside the metal heating tube 1021 in the vacuum heating tank body 1 and feed back to the electrical control system. The power supply electrode 105 is used to provide a power connector to the heating element 1022 on the metal heating tube 1021. The safety valve 106 is used to ensure the safe use of the vacuum heating tank body 1.

[0056] Preferably, the temperature-controlling thermocouple 104 is configured as a double-core thermocouple, one core for temperature control and the other core for temperature measurement, which has a unique design; at the same time, the depth of the double-core thermocouple inserted into the metal heating tube 1021 can be adjusted, so that it can better monitor the temperature inside the metal heating tube 1021. Figure 3 Although the figure shows the situation that three sets of double-core thermocouples are inserted into the vacuum heating tank body 1, the article does not limit the number of double-core thermocouples. When in use, a corresponding number of double-core thermocouples can be set according to the actual situation.

[0057] Further, based on Figure 3 The three groups of dual-core thermocouples shown in the figure can also be provided with three groups of independent control systems corresponding thereto respectively. The three groups of independent control systems work independently without interfering with each other. When in use, the dual-core thermocouples at the corresponding positions can be turned on according to the actual application situation.

[0058] The flange material of the inner tank body 102 and the vacuum heating tank body 1 can be SUS304 stainless steel, with an inner surface roughness of ≤1.6μm, and the outer wall 100 is made of SUS304 stainless steel or Q235A high-quality carbon steel. At the same time, a zinc block is welded in the gap formed between the outer tank body 101 and the inner tank body 102, and the setting of the zinc block can greatly improve the service life of the furnace body.

[0059] The structural material used in the metal heating cylinder 1021 will not have a harmful effect on the vacuum brazing process of the workpiece to be welded. Specifically, the interior of the metal heating cylinder 1021 is provided with a heating element 1022, a tank reflective screen 1023, an insulating porcelain piece 1024 and a workpiece support frame 1025. The tank reflective screen 1023 is arranged in a cylindrical shape inside the metal heating cylinder 1021, and the material of the tank reflective screen 1023 is metal. The reflective screen made of metal has a small thermal inertia and a small heat capacity, which can achieve rapid heating and cooling of the workpiece to be welded. The heating element 1022 uses a metal high-temperature molybdenum strip (i.e., molybdenum-lanthanum alloy). The heating element 1022 adopts a modular design, and the design style is a squirrel cage type, and is arranged inside the metal heating cylinder 1021 by relying on multiple insulating porcelain pieces 1024; at the same time, the heating element 1022 has sufficient installation margin inside the metal heating cylinder 1021 to ensure that the heating element 1022 can be freely expanded and contracted to prevent the heating element 1022 from being deformed or damaged due to thermal expansion or contraction. The insulating porcelain part 1024 is insulated by alumina ceramic parts, which can be disassembled separately and easily replaced when damaged. The tank body reflective screen 1023 is a 5-6 layer all-metal cylindrical sleeve structure: the inner 2-3 layers are made of molybdenum, and the outer 3-4 layers are made of stainless steel. There is a certain interval between each layer of the tank body reflective screen 1023. When heated, the thermal expansion of the heating element 1022 and the tank body reflective screen 1023 is released through its own structure. The workpiece support frame 1025 is arranged inside the heating element 1022. It has sufficient strength to ensure that there is no obvious deformation when it is subjected to the maximum load for a long time at the highest design temperature of 1100℃. The workpiece support frame 1025 adopts a detachable structure.

[0060] In some possible embodiments, the tank door 103 is installed at the end of the vacuum heating tank body 1 by means of a metal hinge. The tank door 103 and the end of the vacuum heating tank body 1 are sealed by a sealing ring. The sealing ring is made of fluororubber and is installed in the sealing groove at the end of the vacuum heating tank body 1. The vacuum seal is achieved by pressing the cover tightly. A plurality of door locks for locking with the vacuum heating tank body 1 are arranged in a circumferential array on the tank door 103. A tank door reflective screen 1031 is arranged on the side of the tank door 103 facing the end of the vacuum heating tank body 1. The design method, number of layers and thickness of the tank door reflective screen 1031 are consistent with those of the tank body reflective screen 1023. The tank door 103 is a double-layer elliptical head structure. The side of the tank door 103 facing the end of the vacuum heating tank body 1 is made of SUS304 stainless steel, and the side of the tank door 103 away from the end of the vacuum heating tank body 1 is made of Q235A high-quality carbon steel or SUS304 stainless steel.

[0061] (2) A vacuum system 2, which is used to make the vacuum heating tank body 1 in a vacuum environment. On the basis of configuring the vacuum heating tank body 1 as an outer tank body 101 and an inner tank body 102, the vacuum system 2 is used to make the interior of the inner tank body 102 in a vacuum environment. The vacuum system 2 includes a mechanical pump 201, two groups of molecular pumps 202, a first branch 203 and a second branch 204. The output end of the mechanical pump 201 can be connected to one end of the first branch 203 or the second branch 204, and its output end is connected to one of the first branch 203 and the second branch 204. The other end of the first branch 203 is inserted into the interior of the inner tank body 102. The two groups of molecular pumps 202 are connected to the second branch 204. The output ends of the two groups of molecular pumps 202 are provided with flanges, which are adapted to be connected with the flanges on the vacuum heating tank body 1 to achieve communication with the interior of the inner tank body 102. At the same time, corresponding valves are provided on the first branch 203, the second branch 204 and the molecular pump 202 to cooperate with the vacuum pumping work in sequence. When in use, the vacuum stage can be divided into two stages: low vacuum and high vacuum. First, the mechanical pump 201 is turned on, and the first branch 203 and the mechanical pump 201 are in a conducting state. Then, the inner tank body 102 can be evacuated by relying on the mechanical pump 201. At this time, the vacuum degree in the inner tank body 102 will be higher than 10Pa to 50Pa; then the mechanical pump 201 continues to work, and the second branch 204 and the mechanical pump 201 are in a conducting state, and the two groups of molecular pumps 202 are working at the same time. Then, under the joint action of the mechanical pump 201 and the two groups of molecular pumps 202, the vacuum degree in the inner tank body 102 can be made lower than 10Pa to 50Pa. It should be noted that the first branch 203, the second branch 204 and the corresponding valves on the molecular pump 202 can all be made of stainless steel, which has high cleanliness and improves the pumping speed, and the multiple valves are all pneumatically controlled (the pneumatic control can be achieved by the pneumatic subsystem described below) and interlocked, so that the vacuum state in the inner tank 102 can still be maintained when the power is off.

[0062] Furthermore, the two groups of molecular pumps 202 in the vacuum system 2 serve as main pumps, the vacuum system 2 uses a right-angle pneumatic high vacuum baffle valve as the main valve, the front-stage pump is a two-stage oil vane pump as a roughing pump and a maintaining pump, plus a vacuum baffle valve, an air source (as the power source for the operation of the vacuum baffle valve), a main pump filter, a vacuum detection system consisting of an ionization gauge, a resistance gauge and a compound vacuum gauge, a vacuum solenoid valve connected to the outer wall of the vacuum heating tank 1 (used for venting and pressure relief) and connecting pipes, etc., constitute a complete vacuum working system.

[0063] (3) Water and gas system, which includes a water subsystem and a gas subsystem.

[0064] 1) The water circuit subsystem is used to cool the vacuum heating tank body 1, the tank door 103, the power supply electrode 105, the molecular pump 202 and the sealing ring, so that the vacuum heating tank body 1 can quickly switch from the hard soldering working state to the soft soldering working state. The water circuit subsystem includes a main water circuit 401, a water inlet circuit 402, a water outlet circuit 403, and two groups of water distribution seats 404. The main water circuit 401 is connected to the water inlet circuit 402, and the water inlet circuit 402 and the water outlet circuit 403 are respectively connected to the two groups of water distribution seats 404. The temperature-controlling thermocouple 104, the power supply electrode 105, the tank door 103, and the vacuum heating tank body 1 (the gap between the outer tank body 101 and the inner tank body 102) are all provided with two interconnected connecting pipes 405, and the ends of the two connecting pipes 405 are respectively connected to the two groups of water distribution seats 404. Then, the water inlet circuit 402 can deliver cooling water to the gap between the temperature-controlling thermocouple 104, the power supply electrode 105, the tank door 103, and the outer tank body 101 and the inner tank body 102, and the cooling water that absorbs heat is diverted away through the water outlet circuit 403, thereby forming a circulating cooling passage. In order to accurately control the flow rate and flow rate of cooling water, an electric contact water pressure gauge is installed on the main water pipe 401, and the electric contact water pressure gauge has a low water pressure alarm function; a water flow switch 406 for monitoring the connecting pipe 405 is provided on the water distribution seat 404 connected to the outlet water pipe 403; manual ball valves 407 are provided on the main water pipe 401, the water inlet pipe 402, and the outlet water pipe 403 to close the corresponding pipes for maintenance. At the same time, each group of connecting pipes 405 are selected as black rubber hoses.

[0065] 2) The pneumatic subsystem has two functions. One is that when the first branch 203 and the second branch 204 are selected, the valve on the corresponding branch can be opened or closed. The second is that when the inner tank body 102 is in a vacuum state, the inner tank body 102 is inflated to break the vacuum. The pneumatic subsystem includes a control air pipe 504, a pneumatic triplet 501 (the pneumatic triplet 501 includes a filter, a pressure gauge, and an oil mist separator), a solenoid valve 502 connected to the pneumatic triplet 501, and a conducting pipe 503 for connecting the solenoid valve 502 to the vacuum heating tank body 1. The solenoid valve 502 is electric and in a normally closed state. The conducting pipe 503 is made of stainless steel, preferably SUS304. When the inner tank body 102 is in a vacuum state and needs to be broken, the pneumatic triplet 501 and the solenoid valve 502 can be used to transport gas to the inner tank body 102 to break the vacuum. When the first branch 203 and the second branch 204 are selected, the control air pipe 504 can be used to perform corresponding opening and closing control processing on the valves on the first branch 203, the second branch 204 and the molecular pump 202.

[0066] (4) Carrier 3, carrier 3 is used to be placed on the workpiece support frame 1025, and the carrier 3 is provided with a carrier plate inside the carrier 3. The workpiece to be welded is placed on the carrier plate for vacuum brazing, and the carrier plate 3 is used to transfer the workpiece to be welded; the carrier 3 and the carrier plate can both be set as a hollow structure, the advantage of which is that the workpiece to be welded can receive more radiant heat. The carrier 3 and the carrier plate are both made of high-temperature resistant alloy steel, which can be SUS310S or Inconel 601 alloy. When in use, the carrier 3 is placed on the workpiece support frame 1025 and the workpiece to be welded is placed on the carrier plate. At this time, the workpiece to be welded will be located inside the heating element 1022. Under the action of the tank body reflection screen 1023 and the vacuuming action of the inner tank body 102, the workpiece to be welded can be provided with the required temperature and vacuum degree.

[0067] (5) The supporting frame 5 provides installation support for the vacuum heating tank body 1 and other components, and the supporting frame 5 also wraps the vacuum heating tank body 1 and other components to make the overall appearance simple. Fig.14 Specifically, the entire surface of the supporting frame 5 is sprayed with plastic or painted, and is provided with mounting holes and chambers for fixing the vacuum heating tank 1, the mechanical pump 201, the water and gas system and other components.

[0068] (6) Electrical control system. The electrical control system can be designed according to the equipment control requirements and instrument configuration requirements. It can include a touch screen, PLC, heating control system, vacuum action system and alarm system. The touch screen and PLC in the electrical control system are the control core. The two cooperate with each other and work together to realize the control and communication of components such as the heating element 1022 and the water and gas system. The heating control system is composed of control devices such as a temperature controller, a temperature control thermocouple 104, an electric voltage regulator and a circuit breaker. The temperature control thermocouple 104 is installed in the inner tank 102 to detect the real-time temperature and feed it back to the temperature controller. The PID algorithm inside the instrument calculates a reasonable output rate and controls the electric voltage regulator to adjust the heating power to achieve the temperature control effect. The temperature is increased according to the process curve. The temperature control system can achieve a stable temperature increase process and strong followability.

[0069] Based on the main structure design of the above equipment, this application also includes the following improvements:

[0070] The contact surface between the tank door 103 and the vacuum heating tank body 1 is the main sealing surface, and a dovetail groove O-type sealing ring is used for sealing, and the sealing ring material is fluororubber. The power supply electrode 105 and the temperature control thermocouple 104 are both sealed with rectangular groove O-type sealing rings, and the sealing ring material is also fluororubber.

[0071] Furthermore, in order to ensure reliable vacuum sealing performance, the sealing surface accuracy and assembly must meet certain requirements. The upper and lower surfaces of the dovetail groove are the main sealing surfaces, and the surface roughness must reach Ra1.6 or above. The left and right surfaces are auxiliary sealing surfaces, and the surface roughness must reach Ra3.2 or above. Taking into account the processing difficulty and processability, the surface roughness of the upper and lower surfaces of the dovetail groove and rectangular groove sealing surfaces is stipulated to be Ra1.6, and the surface roughness of the left and right surfaces is Ra3.2.

[0072] Embodiment 2:

[0073] The present application also proposes a method for using a wide temperature range high vacuum brazing device, comprising the following steps:

[0074] Step 1: During the brazing operation, the workpiece to be welded is placed on the carrier, the heating element 1022 is operated, and the three sets of temperature-controlled thermocouples 104 are controlled to operate to monitor the temperature of the inner tank body 102, so that the internal temperature of the inner tank body 102 is maintained between 800°C and 1000°C;

[0075] Step 2: Open the valve on the first branch 203, close the corresponding valves on the second branch 204 and the molecular pump 202, start the mechanical pump 201 to roughly pump the inner tank body 102, and pump the pressure of the inner tank body 102 to 10Pa;

[0076] Step 3: Then close the valve on the first branch 203, open the corresponding valves on the second branch 204 and the molecular pump 202, and use the mechanical pump 201 and the molecular pump 202 to evacuate the inner tank 102 at the same time, so that the vacuum degree inside the inner tank 102 is lower than 5.0*10 -3 Pa;

[0077] Step 4: Maintain the aforementioned temperature and vacuum degree in the inner tank 102 for a period of time until the brazing of the workpieces to be welded is completed;

[0078] Step 5: When it is necessary to switch from the hard soldering working state to the soft soldering working state, the main water pipe 401 in the water circuit subsystem is used to supply cooling water to the water inlet pipe 402, and the cooling water will flow to the water distribution seat 404 connected to the water inlet pipe 402. The water distribution seat 404 will guide the cooling water to a connecting pipe 405, and return to the water outlet pipe 403 through another connecting pipe 405. In this process, the cooling water contacts and exchanges heat with the vacuum heating tank body 1, the tank door 103, the power supply electrode 105, the molecular pump 202 and the sealing ring on the corresponding connecting pipe 405, so that the temperature of the vacuum heating tank body 1 reaches the standard for soft soldering;

[0079] Step 6: In the soldering working state, the heating element 1022 works, and independently controls one set of temperature-controlling thermocouples 104 to work to monitor the temperature of the inner tank body 102, so that the internal temperature of the inner tank body 102 is maintained between 300°C and 500°C;

[0080] Step 7: Open the valve on the first branch 203, close the corresponding valves on the second branch 204 and the molecular pump 202, start the mechanical pump 201 to roughly pump the inner tank body 102, and pump the pressure inside the inner tank body 102 to 50Pa;

[0081] Step 8: Then close the valve on the first branch 203, open the corresponding valves on the second branch 204 and the molecular pump 202, and use the mechanical pump 201 and the molecular pump 202 to evacuate the inner tank 102 at the same time, so that the vacuum degree inside the inner tank 102 is lower than 3.0*10 -2 Pa;

[0082] Step 9: Maintain the aforementioned temperature and vacuum degree in the inner tank 102 for a period of time until the brazing of the workpieces to be welded is completed.

[0083] The wide temperature range high vacuum brazing equipment provided by the present invention has the following beneficial effects: the present invention is compatible with both soft soldering and hard soldering processes, saving equipment investment; it meets the soft soldering process, the use temperature is 300-500℃, the temperature uniformity is better than ±3℃, and the vacuum degree is lower than 3.0*10 -2 Pa; meet the brazing process, use temperature 800-1000℃, temperature uniformity better than ±5℃, vacuum degree less than 5.0*10 -3 Pa, stable and reliable to use.

[0084] The following table shows the performance test results after vacuum brazing of the AMB ceramic substrate as the workpiece to be welded:

[0085] Serial number Test items Require Single-sided welding Double-sided welding in conclusion 1 Peel strength >8N / mm 13.7N / mm 14.0N / mm qualified 2 Insulation resistance >20GN 80GN 177GN qualified 3 Grain size ≤3mm 0.8mm 1.2mm qualified 4 Appearance - - - qualified 5 Solderability ≥95％ ≥95％ ≥95％ qualified 6 Solder Residue none none none qualified

[0086] It can be seen from the above table that no matter single-sided welding or double-sided welding is performed on the AMB ceramic substrate, the corresponding test items can meet the requirements and are qualified products.

[0087] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A wide temperature range high vacuum brazing equipment, characterized in that: The invention comprises a vacuum heating tank body (1), a metal heating cylinder (1021) arranged in the vacuum heating tank body (1), and a vacuum system (2) for making the interior of the vacuum heating tank body (1) in a vacuum state. The heating temperature of the metal heating cylinder (1021) is adjustable so that the vacuum heating tank body (1) has a soft soldering working state and a hard soldering working state. The device also comprises a water circuit subsystem for cooling the vacuum heating tank body (1) so that the vacuum heating tank body (1) switches from the hard soldering working state to the soft soldering working state.

2. A wide temperature range high vacuum brazing equipment according to claim 1, characterized in that: The water circuit subsystem comprises a main water circuit (401), a water inlet circuit (402), a water outlet circuit (403), and two groups of water distribution seats (404); the main water circuit (401) is connected to the water inlet circuit (402); the water inlet circuit (402) and the water outlet circuit (403) are respectively connected to the two groups of water distribution seats (404); and two interconnected connecting circuits (405) are provided on the vacuum heating tank body (1), and the ends of the two connecting circuits (405) are respectively connected to the two groups of water distribution seats (404).

3. A wide temperature range high vacuum brazing equipment according to claim 2, characterized in that: The vacuum heating tank body (1) is composed of an outer tank body (101) and an inner tank body (102) which are nested together, and a gap is formed between the inner tank body (102) and the outer tank body (101), and the connecting pipeline (405) is inserted into the gap.

4. The wide temperature range high vacuum brazing equipment according to claim 3, characterized in that: The vacuum heating tank body (1) is provided with three temperature-controlling thermocouples (104) and power supply electrodes (105), and a tank door (103) is provided at the end of the vacuum heating tank body (1). Two interconnecting connecting pipes (405) are provided on the temperature-controlling thermocouples (104), the power supply electrodes (105), and the tank door (103), and the ends of the two connecting pipes (405) are respectively connected to the two groups of water distribution seats (404).

5. A wide temperature range high vacuum brazing equipment according to claim 3 or 4, characterized in that: A cylindrical tank body reflection screen (1023) and a heating element (1022) are fixedly arranged inside the metal heating cylinder (1021); the heating element (1022) is a cage-type structure and is coaxially arranged inside the tank body reflection screen (1023), so that when the heating element (1022) is working, the heat generated is gathered by the tank body reflection screen (1023) to the working area inside the heating element (1022).

6. A wide temperature range high vacuum brazing equipment according to any one of claims 1 to 4, characterized in that: The vacuum system (2) comprises a mechanical pump (201), two groups of molecular pumps (202), a first branch (203) and a second branch (204); the output end of the mechanical pump (201) can be connected to one end of the first branch (203) or the second branch (204), and the output end is connected to one of the first branch (203) and the second branch (204); the other end of the first branch (203) is inserted into the interior of the inner tank body (102); the two groups of molecular pumps (202) are connected to the second branch (204); the output ends of the two groups of molecular pumps (202) are provided with flanges, and the flanges are adapted to be connected to the flanges on the vacuum heating tank body (1) to achieve communication with the interior of the inner tank body (102).

7. The wide temperature range high vacuum brazing equipment according to claim 6, characterized in that: The device further comprises a pneumatic subsystem, the pneumatic subsystem comprising a control air pipe (504), a pneumatic triplet (501), a solenoid valve (502) connected to the pneumatic triplet (501), and a conducting pipe (503) used to connect the solenoid valve (502) to the vacuum heating tank body (1); valves are arranged on the first branch (203), the second branch (204) and the molecular pump (202), and the control air pipe (504) is connected to the valve and is used to open and close the valve.

8. The wide temperature range high vacuum brazing equipment according to claim 4, characterized in that: The device also includes an electrical control system, which includes a touch screen, a PLC, a heating control system, a vacuum action system and an alarm system. The heating control system includes a temperature controller, a power voltage regulator, a circuit breaker and the temperature control thermocouple (104).

9. The wide temperature range high vacuum brazing equipment according to claim 5, characterized in that: A workpiece support frame (1025) is arranged inside the heating element (1022), and the workpiece support frame (1025) is arranged along the length direction of the heating element (1022). A carrier (3) is arranged on the workpiece support frame (1025), and a carrier plate for carrying a workpiece to be welded is movably drawn inside the carrier (3).

10. A method for using the wide temperature range high vacuum brazing equipment according to claim 1, characterized in that: The following steps are involved: Step 1: During the brazing operation, the workpiece to be welded is placed on the carrier plate, the heating element (1022) is operated, and the three sets of temperature-controlling thermocouples (104) are controlled to operate simultaneously to monitor the temperature of the inner tank body (102), so that the internal temperature of the inner tank body (102) is maintained between 800° C. and 1000° C.; Step 2: Open the valve on the first branch (203), close the corresponding valves on the second branch (204) and the molecular pump (202), start the mechanical pump (201) to roughly pump the inner tank body (102), and pump the pressure of the inner tank body (102) to 10Pa; Step 3: Then close the valve on the first branch (203), open the corresponding valves on the second branch (204) and the molecular pump (202), and use the mechanical pump (201) and the molecular pump (202) to evacuate the inner tank (102) at the same time, so that the vacuum degree inside the inner tank (102) is lower than 5.0*10 -3 Pa; Step 4: maintaining the aforementioned temperature and vacuum degree in the inner tank (102) for a period of time until the brazing of the workpieces to be welded is completed; Step 5: When it is necessary to switch from the hard soldering working state to the soft soldering working state, the main water pipe (401) in the water circuit subsystem is used to supply cooling water to the water inlet pipe (402), and the cooling water will flow to the water distribution seat (404) connected to the water inlet pipe (402). The water distribution seat (404) will guide the cooling water to a connecting pipe (405) and return to the water outlet pipe (403) through another connecting pipe (405). During this process, the cooling water contacts and exchanges heat with the vacuum heating tank body (1), the tank door (103), the power supply electrode (105), the molecular pump (202) and the sealing ring on the corresponding connecting pipe (405), so that the temperature of the vacuum heating tank body (1) reaches the standard for soft soldering; Step 6: In the soldering working state, the heating element (1022) works, and independently controls one set of temperature-controlling thermocouples (104) to work so as to monitor the temperature of the inner tank body (102), so that the internal temperature of the inner tank body (102) is maintained between 300° C. and 500° C.; Step 7: Open the valve on the first branch (203), close the corresponding valves on the second branch (204) and the molecular pump (202), start the mechanical pump (201) to roughly pump the inner tank body (102), and pump the pressure inside the inner tank body (102) to 50 Pa; Step 8: Then close the valve on the first branch (203), open the corresponding valves on the second branch (204) and the molecular pump (202), and use the mechanical pump (201) and the molecular pump (202) to evacuate the inner tank (102) at the same time, so that the vacuum degree inside the inner tank (102) is lower than 3.0*10 -2 Pa; Step 9: Maintain the aforementioned temperature and vacuum degree in the inner tank body (102) for a period of time until the brazing of the workpieces to be welded is completed.

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