Solder flux recovery device and vacuum soldering apparatus

Abstract

The application relates to the technical field of semiconductor chip welding, in particular to a flux recovery device and a vacuum welding device. The flux recovery device comprises a recovery cabin, a condensing mechanism, a filtering assembly and a safety pressure relief mechanism. The device mainly utilizes a vacuum pumping mechanism to pre-filter waste gas containing fog-shaped suspended flux and other oxides through the filtering assembly when the vacuum cavity is pumped, removes liquid and solid oxides in the waste gas, and prevents the cooling area from being affected by the heat exchange coefficient due to excessive dirt accumulation. Subsequently, the waste gas enters the cooling area, gaseous flux undergoes phase change condensation to form liquid flux, the liquid flux flows to the recovery area under the action of airflow and is accumulated, the waste gas after filtering and condensing out the flux is finally introduced into the vacuum pumping mechanism through the clean area, so that the waste gas cannot affect the vacuum pumping mechanism, and the service life of the device is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor chip welding, in particular to a flux recovery device, and further relates to a vacuum welding device comprising the flux recovery device. BACKGROUND

[0002] Vacuum eutectic welding, also known as vacuum reflow welding or vacuum controlled atmosphere eutectic furnace, has the characteristics of uniform temperature, ultra-low temperature safe welding, no temperature difference, no overheating, reliable and stable process parameters, no need for complex process test, environmental protection and low cost operation, and is widely used in semiconductor product production.

[0003] The main part of the vacuum eutectic welding is a vacuum cavity. During the welding process of the chip, the solder often contains flux. The flux is made of turpentine, tackifier, active agent, etc. and is adjusted with a solvent. It has strong viscosity and is corrosive. During the heating process of welding, it will volatilize into misty steam and suspend in the reducing gas protection body or the vacuum cavity. When the steam is not recovered in time, its concentration in the reflow soldering furnace exceeds a certain concentration. On the one hand, it will drip and adhere to the welding elements to form residues, thereby affecting the welding quality. On the other hand, when the misty steam cools down or meets a cold wall, it will adhere to the vacuum cavity wall or other parts in the cavity to form a liquid with strong viscosity, thereby corroding the vacuum cavity and other parts and affecting the vacuum degree of the vacuum cavity. In addition, the misty flux suspended in the reducing protection gas or the vacuum cabin will corrode the pipes and parts adhered to the vacuum pump during vacuumizing, thereby affecting the service life of the vacuum pump.

[0004] The prior art disclosed vacuum eutectic furnace does not have a flux recovery and treatment function, or the treatment effect is not ideal, which leads to corrosion of the vacuum cavity and various parts by the uncontrolled flux, affecting the welding quality of the product and the service life of the equipment.

[0005] Patent CN215145522U discloses a vacuum cabin with a flux recovery function, which comprises a cabin body. The inner side walls of the cabin body are provided with recovery devices. The recovery device comprises a mounting plate connected to the inner side wall of the cabin body. A recovery groove is formed in the top of the mounting plate. The recovery groove is connected with a flow guide plate. The flow guide plates are all arranged upwardly inclined. When the flux adheres to the inner wall of the vacuum cabin, it will flow downward. After flowing on the flow guide plate, it will automatically flow into the recovery groove to avoid flowing to the bottom of the vacuum cabin. This scheme can only recover the flux adhering to the inner wall of the vacuum cavity and cannot solve the corrosion problem of the flux to other parts. Moreover, the recovered flux is still in the recovery groove inside the cavity. When the flux in the recovery groove encounters high temperature, it will volatilize. Therefore, this scheme cannot fundamentally solve the problem.

[0006] The utility model provides a kind of flux recovery device for semiconductor soldering furnace, including cooling chamber and cooling water pipe, the cooling chamber upper portion is provided with air inlet, the air inlet is connected with welding device, the cooling chamber lower portion is provided with air outlet, the cooling chamber inside is provided with air deflector, the air deflector is alternately arranged on the opposite two side walls of the cooling chamber, the cooling water pipe is arranged between adjacent two air deflectors.The cooling water pipe is spiral, the cooling water pipe is provided with multiple, adjacent two cooling water pipes are arranged in parallel, to form the flux of vapor form in welding process and carry out recovery, prevent the formation of flux accumulation in soldering furnace inside, the scheme is mainly used in its online reflow soldering, gas circulation is realized in cavity by centrifugal fan, additional N2 is needed to be introduced, plus cooling water pipe is cooled to hot gas, N2 is introduced into cavity again under the action of centrifugal fan after cooling, residual flux in N2 There may be the risk of secondary pollution. SUMMARY

[0007] The technical problem to be solved by the present application is to prevent the flux from entering the vacuum pumping mechanism during the recovery process, which can cause corrosion of the vacuum pumping mechanism. To solve this problem, the present application provides a flux recovery device. In addition, the present application also relates to a vacuum welding equipment comprising the above-mentioned flux recovery device. The flux recovery device can timely recover and process the mist-suspended flux in the vacuum welding furnace, improve the welding quality of the product, protect the internal parts of the vacuum welding equipment and the vacuum pump from corrosion, and prolong the service life of the equipment.

[0008] The technical solution adopted by the present application to solve the technical problem is a flux recovery device, comprising:

[0009] a recovery cabin having an inner cavity;

[0010] a condensing mechanism arranged in the inner cavity, which divides the inner cavity into at least a cooling zone, a recovery zone and a clean zone, and is used to provide cold energy to the cooling zone to condense the gaseous flux contained in the gas in the cooling zone into liquid flux, and the recovery zone is used to collect the liquid flux;

[0011] a filter assembly in communication with the air inlet of the recovery cabin for filtering the gas, the outlet end of the filter assembly is in communication with the cooling zone, the cooling zone is in communication with the recovery zone and the clean zone, and the clean zone is in communication with the vacuum pumping mechanism;

[0012] and a safety pressure relief mechanism in communication with the inner cavity, which is in an open state when the pressure in the inner cavity exceeds a threshold value to release the pressure in the inner cavity.

[0013] In the scheme, when the vacuumizing mechanism is pumping the vacuum chamber, the waste gas containing fog-shaped suspended flux and other oxides is filtered by the filtering assembly in advance to remove the liquid and solid oxides in the waste gas and prevent the cooling area from being affected by too much dirt accumulation to affect the heat exchange coefficient; then the waste gas enters the cooling area, the gaseous flux undergoes phase change and condenses into liquid flux, the liquid flux flows to the recovery area under the action of the airflow and gathers in the recovery area to prevent the cooling area from being affected by too much liquid flux to affect the heat exchange efficiency, the waste gas after filtering and condensing out the flux finally passes through the clean area and enters the vacuumizing mechanism, so that the waste gas does not affect the vacuumizing mechanism and the service life of the equipment is improved.

[0014] The safety pressure relief mechanism can effectively avoid the problems of safety hazards caused by excessive pressure of the recovery cabin and overloading of the vacuumizing mechanism.

[0015] Further, the cooling area is arranged outside the clean area, and the cross-sectional area of the cooling area and the cross-sectional area of the clean area are both smaller than the cross-sectional area of the recovery area.

[0016] One end of the cooling area is in communication with the outlet end of the filtering assembly, and the other end is in communication with the recovery area; one end of the clean area is in communication with the recovery area, and the other end is in communication with the vacuumizing mechanism, and when the vacuumizing mechanism is pumping, the gas flow direction of the cooling area is opposite to the gas flow direction of the recovery area.

[0017] The above layout has the following advantages:

[0018] First, when the waste gas flows from the cooling area to the recovery area, the cross-sectional area of the waste gas flow path increases, the flow rate of the waste gas is reduced in the recovery area, and the tiny droplets entrained in the waste gas are easily deposited at the bottom of the recovery area, thereby increasing the recovery rate of the flux and improving the flux removal rate of the waste gas;

[0019] Second, when the waste gas flows from the cooling area to the recovery area, it will impact the inner wall of the recovery area and produce reverse flow, and in the process of impact, the tiny droplets entrained in the waste gas are easily attached to the inner wall of the recovery area, thereby further increasing the recovery rate of the flux and further improving the flux removal rate of the waste gas;

[0020] Third, the cooling area is arranged outside the clean area, which has the advantages of compact structure and the cold energy of the cooling area can be transferred to the clean area, so that the clean area also has the ability to condense the flux in the waste gas, and the waste gas after condensation in the cooling area and deposition of liquid flux in the recovery area can be condensed again in the clean area, ensuring the cleanliness of the waste gas.

[0021] In order to facilitate manufacturing and assembly, further, the condensing mechanism comprises a fixed tube and a condensing tube arranged outside the fixed tube.

[0022] The first end of the fixed tube is sealingly and fixedly connected with the recovery cabin, and the tail end of the fixed tube is inserted into the inner cavity, a cooling zone is formed between the inner circumferential wall of the inner cavity and the outer circumferential wall of the fixed tube, and the end of the inner cavity where the tail end of the fixed tube is located is a recovery zone, and the inner circumferential wall of the fixed tube is a clean zone.

[0023] The condensing tube is arranged in the cooling zone.

[0024] In order to improve the compactness of the structure, further, the filter assembly comprises a filter screen and a filter screen plate, the filter screen plate is sleeved on the outer circumferential wall of the fixed tube and is fixedly connected with the fixed tube, and the filter screen plate divides the space between the inner circumferential wall of the inner cavity and the outer circumferential wall of the fixed tube into a filter zone located at the first end of the fixed tube and a cooling zone located at the tail end of the fixed tube, the filter screen plate is provided with a plurality of through holes, the filter zone and the cooling zone are communicated through the through holes, and the filter screen is filled in the filter zone; by embedding the filter assembly in the recovery cabin, compared with the external filter assembly, the compactness of the structure can be improved, and the sealing difficulty is reduced.

[0025] Further, the filter screen is a gas-liquid filter screen or a wire mesh demister.

[0026] In order to facilitate the replacement, disassembly and maintenance of the filter screen and the condensing tube, further, the first end of the fixed tube is fixedly provided with a flange plate, the flange plate is sealingly and fixedly connected with the recovery cabin in a detachable manner, and is provided with a gas outlet for being communicated with a vacuumizing mechanism, the gas outlet is communicated with the clean zone; the flange plate is further provided with a cooling liquid inlet joint and a cooling liquid outlet joint, the cooling liquid outlet joint and the cooling liquid inlet joint are respectively communicated with the inlet and the outlet of the condensing tube, and the condensing tube is fixedly installed on the fixed tube or the flange plate.

[0027] In order to improve the reliability of pressure relief and reduce the processing and manufacturing cost, a gravity type safety pressure relief mechanism is adopted, specifically, the safety pressure relief mechanism comprises a sliding block and a pressure relief port, the pressure relief port is communicated with the inner cavity, the sliding block is arranged to block the pressure relief port under its own gravity, and when the pressure in the inner cavity exceeds a threshold value, the sliding block generates displacement to overcome its own gravity to open the pressure relief port to release the pressure in the inner cavity.

[0028] In order to facilitate manufacturing and assembly, further, the safety pressure relief mechanism further comprises a gas permeable structure and a base body having a sliding cavity inside, the base body is sealingly and fixedly connected with the recovery cabin, the sliding block is slidingly installed in the sliding cavity, the pressure relief port is located at the bottom of the sliding cavity, the sliding block is located above the pressure relief port and completely covers the pressure relief port, and when the sliding block moves upward, the pressure relief port is communicated with the gas permeable structure.

[0029] In order to improve the flexibility of the sliding block, prevent the sliding block from swinging left and right, and prevent the sliding block from being stuck, the outer peripheral wall of the sliding block is in clearance fit with the inner peripheral wall of the sliding cavity; a plurality of grooves are formed in the outer peripheral wall of the sliding block, and a sliding wear-resistant ring is embedded in the grooves, and the outer peripheral wall of the sliding wear-resistant ring is tightly combined with the sliding cavity.

[0030] Further, the sliding wear-resistant ring is an elastic member with elasticity, the sliding wear-resistant ring has a notch, and two free ends separated from each other are formed at the notch; on the one hand, the sliding wear-resistant ring with the notch is convenient to install, and on the other hand, the sliding wear-resistant ring is tightly combined with the inner wall of the sliding cavity body, and the elastic deformation plays a tensioning and buffering role; even if the sliding block is not completely vertically lifted, the outer circle of the sliding wear-resistant ring can be guaranteed to be always tightly combined with the inner wall of the sliding cavity body.

[0031] Further, the air permeable structure is an air permeable groove formed in the outer peripheral wall of the sliding block or an air permeable hole formed in the sliding block, and the space above the sliding block and the space below the sliding block in the sliding cavity are communicated through the air permeable structure.

[0032] The lower end surface of the sliding block or the cavity bottom of the sliding cavity is provided with a sealing ring, and when the sliding block presses the sealing ring on the cavity bottom of the sliding cavity, the communication path between the air permeable structure and the pressure relief port is blocked by the sealing ring.

[0033] Further, the cooling area and the clean area are gradually inclined downward from the clean area to the recovery area, the lower part of the recovery area is communicated with a sewage outlet, and the sewage outlet is used for communication with a collection mechanism; so as to realize that the liquid flux in the cooling area and the clean area converges to the recovery area under the action of gravity, and is collected through the collection mechanism.

[0034] The application also provides a vacuum welding device comprising the flux recovery device.

[0035] The flux recovery device of the application utilizes the vacuum pumping mechanism to pre-filter the waste gas containing the mist-shaped suspended flux and other oxides when pumping the vacuum cavity, remove the liquid and solid oxides in the waste gas, prevent the cooling area from affecting the heat exchange coefficient due to accumulation of too much dirt, and then the waste gas enters the cooling area, the gaseous flux undergoes phase change and condensation to form liquid flux, the liquid flux flows to the recovery area under the action of airflow and accumulates, the waste gas after filtration and condensation of the flux finally passes through the clean area and enters the vacuum pumping mechanism, so as to ensure that the waste gas does not affect the vacuum pumping mechanism and improve the service life of the device. BRIEF DESCRIPTION OF DRAWINGS

[0036] The application will be further described below in combination with the drawings and examples.

[0037] Figure 1is a three-dimensional schematic diagram of the flux recovery device of the present application;

[0038] Figure 2 is a sectional view schematic diagram of the flux recovery device of the present application;

[0039] Figure 3 is Figure 2 is a partial enlarged schematic diagram of A in the figure;

[0040] Figure 4 is Figure 2 is a partial enlarged schematic diagram of B in the figure;

[0041] Figure 5 is a three-dimensional schematic diagram of the condensing filter module in the present application;

[0042] Figure 6 is a three-dimensional schematic diagram of the filter screen in the present application;

[0043] Figure 7 is a three-dimensional schematic diagram of the sliding block with sliding wear-resistant ring in the present application;

[0044] Figure 8 is a three-dimensional schematic diagram of the sliding wear-resistant ring in the present application;

[0045] Figure 9 is a three-dimensional schematic diagram of the flux recovery device of the present application connected with the vacuum pumping mechanism.

[0046] In the figure: 1, recovery cabin, 11, filtration zone, 111, air inlet, 12, cooling zone, 13, recovery zone, 131, sewage outlet, 14, clean zone;

[0047] 2, condensing mechanism, 21, flange, 211, air outlet, 212, cooling liquid inlet joint, 213, cooling liquid outlet joint, 214, handle, 22, fixed tube, 23, condensing tube;

[0048] 3, filter assembly, 31, filter screen, 32, filter screen plate, 321, through hole;

[0049] 4, safety pressure relief mechanism, 41, base body, 411, sliding cavity, 412, pressure relief port, 42, sliding block, 421, groove, 422, air permeable structure, 423, avoidance groove, 43, sliding wear-resistant ring, 431, notch, 44, sealing ring;

[0050] 5, collection mechanism, 51, valve;

[0051] 6, vacuum pumping mechanism, 61, vacuum pump. DETAILED DESCRIPTION

[0052] The invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the invention in a schematic manner. Therefore, they only show the components relevant to the invention, and the orientations and references (e.g., up, down, left, right, etc.) are only used to aid in the description of the features in the drawings. Therefore, the following specific embodiments are not intended to be limiting, and the scope of the claimed insulation subject matter is defined only by the appended claims and their equivalents.

[0053] like Figures 1-9 As shown, a flux recovery device includes:

[0054] Recovery capsule 1 has an internal cavity;

[0055] The condensation mechanism 2 is configured in the inner cavity, which divides the inner cavity into at least a cooling zone 12, a recovery zone 13 and a clean zone 14, and is used to provide cooling to at least the cooling zone 12 so that the gaseous flux contained in the gas in the cooling zone 12 condenses into liquid flux. The recovery zone 13 is used to collect the liquid flux.

[0056] The filter assembly 3 is connected to the air inlet 111 of the recovery chamber 1 and is used to filter the gas. The outlet end of the filter assembly 3 is connected to the cooling zone 12. The cooling zone 12 is connected to the clean zone 14 through the recovery zone 13. The clean zone 14 is used to connect to the vacuum mechanism 6.

[0057] And a safety pressure relief mechanism 4, which is connected to the inner cavity, is used to open when the pressure in the inner cavity exceeds a threshold, so as to relieve pressure in the inner cavity.

[0058] like Figure 2 As shown, in this embodiment, the cooling zone 12 is arranged around the outside of the clean zone 14, and the cross-sectional area of ​​both the cooling zone 12 and the clean zone 14 is smaller than the cross-sectional area of ​​the recovery zone 13.

[0059] One end of the cooling zone 12 is connected to the outlet end of the filter assembly 3, and the other end is connected to the recovery zone 13; one end of the clean zone 14 is connected to the recovery zone 13, and the other end is connected to the vacuuming mechanism 6. When the vacuuming mechanism 6 evacuates, the gas flow direction of the cooling zone 12 is opposite to the gas flow direction of the recovery zone 13.

[0060] The above layout method has the following advantages:

[0061] First, when the exhaust gas flows from the cooling zone 12 to the recovery zone 13, the cross-sectional area of ​​the exhaust gas flow path increases, and the flow velocity of the exhaust gas is reduced in the recovery zone 13. The tiny droplets entrained in the exhaust gas are easily deposited at the bottom of the recovery zone 13, thereby increasing the flux recovery rate and improving the flux removal rate of the exhaust gas.

[0062] Secondly, when the exhaust gas flows from the cooling zone 12 to the recovery zone 13, it will impact the inner wall of the recovery zone 13, generating a reverse flow, and in the process of impact, the tiny liquid droplets entrained in the exhaust gas are easy to adhere to the inner wall of the recovery zone 13, thereby further increasing the recovery rate of the flux and further improving the flux removal rate of the exhaust gas;

[0063] Thirdly, the cooling zone 12 is arranged outside the clean zone 14, which has the advantages of compact structure on the one hand, and the cold energy of the cooling zone 12 can be transferred to the clean zone 14, so that the clean zone 14 also has the ability to condense the flux in the exhaust gas, so that the exhaust gas after condensation in the cooling zone 12 and deposition of liquid flux in the recovery zone 13 can be condensed again in the clean zone 14, ensuring the cleanliness of the exhaust gas.

[0064] As shown in Figure 2 and 5 , the condensing mechanism 2 in the embodiment includes a fixed tube 22 and a condensing tube 23 arranged outside the fixed tube 22;

[0065] The leading end of the fixed tube 22 is sealingly and fixedly connected with the recovery cabin 1, and the trailing end of the fixed tube 22 is inserted into the inner cavity, and the inner circumferential wall of the inner cavity and the outer circumferential wall of the fixed tube 22 form the cooling zone 12, and the fixed tube 22 can be coaxially arranged with the inner cavity, and the shape of the cross section of the fixed tube 22 and the inner cavity can be circular or polygonal, etc., which is not limited herein, and in the embodiment, the shape of the cross section of the fixed tube 22 and the inner cavity is circular, and the end of the inner cavity located at the trailing end of the fixed tube 22 has an interval as the recovery zone 13, for example, there is a gap between the trailing end of the fixed tube 22 and the inner wall of the inner cavity, so as to form the recovery zone 13; and the inner circumferential wall of the fixed tube 22 constitutes the clean zone 14;

[0066] As shown in Figure 2 and 5 , the condensing tube 23 is arranged in the cooling zone 12, and the condensing tube 23 can be a single-layer spiral condensing tube 23 or a multi-layer spiral condensing tube 23 with more than two sides, and it is worth noting that the multi-layer spiral tube has multiple spiral tube segments, and each spiral tube segment is coaxially sleeved from outside to inside.

[0067] As shown in Figure 2 , 3As shown in Figures 5 and 6, the filter assembly 3 includes a filter screen 31 and a filter screen plate 32. The filter screen plate 32 is sleeved on the outside of the fixed tube 22 and is fixedly connected to the fixed tube 22. The filter screen plate 32 divides the space between the inner peripheral wall of the inner cavity and the outer peripheral wall of the fixed tube 22 into a filter zone 11 located at the beginning of the fixed tube 22 and a cooling zone 12 located at the end of the fixed tube 22. The filter screen plate 32 has several through holes 321. The filter zone 11 and the cooling zone 12 are connected through the through holes 321. The filter screen 31 fills the filter zone 11. In this embodiment, the filter screen 31 can be a gas-liquid filter screen or a wire mesh demister. The filter screen 31 fills the entire filter zone 11. The material of the filter screen 31 is preferably a corrosion-resistant metal or non-metal, such as stainless steel, nickel wire, titanium wire or polytetrafluoroethylene.

[0068] It is worth noting that in this embodiment, the filter assembly 3 can be installed inside the recovery chamber 1 or outside the recovery chamber 1. By installing the filter assembly 3 inside the recovery chamber 1, the compactness of the structure can be improved and the sealing difficulty can be reduced compared to the external filter assembly 3.

[0069] like Figure 5 As shown, a flange 21 is fixed to the first end of the fixed pipe 22. The flange 21 is detachably and sealedly connected to the recovery chamber 1. For example, the end face of the flange 21 and the end face of the recovery chamber 1 face each other, and a seal is provided between them. The flange 21 and the recovery chamber 1 are fixed by bolt assembly components. After the seal is pressed, a seal is formed. The flange 21 has an outlet 211 for communicating with the vacuum mechanism 6. The outlet 211 is connected to the clean area 14. For example, the vacuum mechanism 6 includes a vacuum pump 61. One end of the vacuum bellows is sealedly connected to the inlet 111 of the vacuum pump 61, and the other end is connected to the outlet 211. 1. Sealed connection; The flange 21 is also equipped with a coolant inlet connector 212 and a coolant outlet connector 213. The coolant outlet connector 213 and the coolant outlet connector 213 are respectively connected to the inlet and outlet of the condenser pipe 23. The condenser pipe 23 is fixedly installed on the fixed pipe 22 or the flange 21, so that the flange 21, the fixed pipe 22, the condenser pipe 23 and the filter assembly 3 form an integrated condenser filter module, which facilitates installation, removal and subsequent maintenance, and improves the convenience of use; At the same time, a handle 214 can also be installed on the flange 21 to remove the condenser filter module when installing or replacing the filter screen 31.

[0070] The cooling area 12 and the clean area 14 are both inclined downward from the clean area 14 to the recovery area 13 in the embodiment, and the recovery area 13 is communicated with a pollution outlet 131 below, which is used to communicate with the collecting mechanism 5; so that the liquid flux in the cooling area 12 and the clean area 14 can gather in the recovery area 13 under the action of gravity, and then be collected by the collecting mechanism 5, for example, the collecting mechanism 5 includes a valve 51 and a collecting box, the collecting box is arranged below the pollution outlet 131, and the valve 51 is in series with the pollution outlet 131; when the valve 51 is opened, the liquid flux in the recovery area 13 flows into the collecting box from the pollution outlet 131 under the action of gravity;

[0071] In order to improve the reliability of pressure relief and reduce the processing manufacturing cost, the gravity type safety pressure relief mechanism 4 is adopted, specifically, the safety pressure relief mechanism 4 includes a sliding block 42 and a pressure relief port 412, the pressure relief port 412 is communicated with the inner cavity, and in the embodiment, the connection point of the pressure relief port 412 and the inner cavity is located in the recovery area 13 and above the recovery area 13, so that the liquid flux can be prevented from entering the safety pressure relief mechanism 4; the sliding block 42 is arranged to block the pressure relief port 412 under its own gravity, and when the pressure of the inner cavity exceeds the threshold value, the sliding block 42 overcomes its own gravity to produce displacement, so as to open the pressure relief port 412 to release the pressure of the inner cavity;

[0072] As shown in Figure 2 and 4 The safety pressure relief mechanism 4 further includes a gas permeable structure 422 and a base body 41 with a sliding cavity 411 inside, the base body 41 is sealingly and fixedly connected with the recovery cabin 1, the sliding block 42 is slidingly installed in the sliding cavity 411, the pressure relief port 412 is located at the bottom of the sliding cavity 411, the sliding block 42 is above the pressure relief port 412 and completely covers the pressure relief port 412, and when the sliding block 42 moves upward, the pressure relief port 412 is communicated with the gas permeable structure 422;

[0073] As shown in Figure 7As shown, the outer peripheral wall of the sliding block 42 is in clearance fit with the inner peripheral wall of the sliding cavity 411; a plurality of grooves 421 are formed on the outer peripheral wall of the sliding block 42, and a sliding wear-resistant ring 43 is embedded in the grooves 421; the outer peripheral wall of the sliding wear-resistant ring 43 is in close contact with the sliding cavity 411; in this embodiment, the cross section of the sliding block 42 and the cross section of the sliding cavity 411 are both circular; the sliding wear-resistant ring 43 is a circular ring structure; the sliding block 42, the sliding cavity 411 and the sliding wear-resistant ring 43 are coaxially arranged; preferably, the sliding wear-resistant ring 43 is an elastic member with elasticity; the sliding wear-resistant ring 43 has a notch 431, and two free ends separated from each other are formed at the notch 431; on the one hand, the sliding wear-resistant ring 43 with the notch 431 is convenient to install; on the other hand, the sliding wear-resistant ring 43 can keep close contact with the inner wall of the sliding cavity 411, and the elastic deformation plays a role of tensioning and buffering; even if the sliding block 42 is not completely vertically lifted, the outer circle of the sliding wear-resistant ring 43 can always be in close contact with the inner wall of the sliding cavity 411.

[0074] As shown in the figure, Figure 7 The air permeable structure 422 is an air permeable groove formed on the outer peripheral wall of the sliding block 42 or an air permeable hole formed on the sliding block 42; the space above the sliding block 42 and the space below the sliding block 42 in the sliding cavity 411 are communicated through the air permeable structure 422; in this embodiment, the air permeable groove is used as the air permeable structure 422, and the depth of the air permeable groove is greater than the depth of the groove 421, so that the gas in the air permeable groove is not blocked by the sliding wear-resistant ring 43 when pressure relief; or an avoidance groove 423 is arranged at the intersection of the air permeable groove bottom and the arc-shaped groove 421, and the length of the avoidance groove 423 is greater than the width of the groove 421.

[0075] As shown in the figure, Figure 4 The lower end surface of the sliding block 42 or the cavity bottom of the sliding cavity 411 can be provided with a sealing groove, and a sealing ring 44 is embedded in the sealing groove; when the sliding block 42 presses the sealing ring 44 on the cavity bottom of the sliding cavity 411, the communication path between the air permeable structure 422 and the pressure relief port 412 is blocked by the sealing ring 44.

[0076] Under the normal state, the gas in the inner cavity is not enough to overcome the gravity of the sliding block 42, so the sliding block 42 covers the pressure relief port 412 under the action of gravity, forming a seal; once the pressure in the inner cavity exceeds the threshold value, the sliding block 42 is lifted, and the gas in the recovery cabin 1 is quickly discharged through the air permeable structure 422, so as to ensure that the pressure in the recovery cabin 1 is always below the predetermined pressure; after the inner cavity is relieved, the sliding block 42 is automatically reset under the action of its own gravity.

[0077] The working principle of this embodiment is as follows:

[0078] The inside of the recovery cabin 1 is divided into a filtering area 11, a cooling area 12, a recovery area 13 and a clean area 14 by the condensing mechanism 2 and the filtering assembly 3. During operation, the gas and gas-liquid mixture inside the vacuum cavity of the vacuum soldering equipment are extracted out of the vacuum cavity by the vacuum pump 61. The hot gas or gas-liquid mixture is first filtered in the filtering area 11 by the wire mesh filter. The liquid and solid oxide in the hot gas are filtered, and then the hot gas enters the cooling area 12 and is in full contact with the multi-layer spiral condensing tube 23 in the cooling area 12 to exchange heat, so that the temperature of the hot gas is reduced. The residual flux adheres to the inside of the recovery cabin 1 due to the cooling. Since the recovery cabin 1 is installed obliquely, the accumulated flux flows to the recovery area 13 under the action of gravity. In combination with the design that the horizontal area of the recovery area 13 is increased and the arrangement of the cooling area 12, the recovery area 13 and the clean area 14, the gas flow rate is reduced and the reverse flow is generated, so that the liquid drops mixed in the gas are deposited in the recovery area 13. The liquid drops are collected and treated by the collecting mechanism 5 regularly. The filtered and cooled gas is finally extracted out of the equipment by the vacuum pump 61 from the clean area 14.

[0079] Embodiment 2

[0080] A vacuum soldering equipment comprising the flux recovery device in the above embodiment 1. The vacuum cavity of the vacuum soldering equipment and the gas inlet 111 of the recovery cabin 1 are in communication. The upper end of the sliding cavity 411 is in sealing connection with the exhaust mechanism of the vacuum soldering equipment.

[0081] The above ideal embodiments according to the present application are for illustration. Through the above description, relevant personnel can make various changes and modifications without deviating from the technical idea of the present application. The technical scope of the present application is not limited to the content in the specification, and must be determined according to the scope of claims.

Claims

1. A flux recovery device characterized by: The application relates to a recovery cabin (1) with an inner cavity, a condensing mechanism (2) arranged in the inner cavity and used for providing cold energy to at least a cooling area (12) to condense gaseous flux-cored wire flux contained in gas in the cooling area (12) to form liquid flux, a recovery area (13) used for collecting the liquid flux, a filtering assembly (3) in communication with an air inlet (111) of the recovery cabin (1) and used for filtering the gas, an outlet end of the filtering assembly (3) in communication with the cooling area (12), the cooling area (12) in communication with the recovery area (13) and the clean area (14), the clean area (14) in communication with a vacuumizing mechanism (6), and a safety pressure relief mechanism (4) in communication with the inner cavity and used for relieving pressure of the inner cavity when the pressure exceeds a threshold value. The cooling area (12) surrounds the outside of the clean area (14), and the cross-sectional area of the cooling area (12) and the cross-sectional area of the clean area (14) are both smaller than the cross-sectional area of the recovery area (13). One end of the cooling area (12) is in communication with the outlet end of the filtering assembly (3), and the other end is in communication with the recovery area (13); one end of the clean area (14) is in communication with the recovery area (13), and the other end is in communication with the vacuumizing mechanism (6), and the gas flow direction of the cooling area (12) is opposite to the gas flow direction of the recovery area (13) when the vacuumizing mechanism (6) is vacuumizing. The condensing mechanism (2) comprises a fixed tube (22) and a condensing tube (23) arranged outside the fixed tube (22). The first end of the fixed tube (22) is fixedly connected with the recovery cabin (1), the tail end of the fixed tube (22) is inserted into the inner cavity, the inner circumferential wall of the inner cavity and the outer circumferential wall of the fixed tube (22) form the cooling area (12), the end of the inner cavity located at the tail end of the fixed tube (22) has an interval as the recovery area (13), and the inner circumferential wall of the fixed tube (22) forms the clean area (14). The filtering assembly (3) comprises a filtering screen (31) and a filtering screen plate (32), the filtering screen plate (32) is sleeved outside the fixed tube (22) and fixedly connected with the fixed tube (22), the filtering screen plate (32) divides the space between the inner circumferential wall of the inner cavity and the outer circumferential wall of the fixed tube (22) into a filtering area (11) located at the first end of the fixed tube (22) and the cooling area (12) located at the tail end of the fixed tube (22), the filtering screen plate (32) is penetrated by a plurality of through holes (321), the filtering area (11) and the cooling area (12) are in communication through the through holes (321), and the filtering screen (31) is filled in the filtering area (11). ​ ​ ​ ​ 2. The flux recovery device of claim 1, wherein: ​ 3. The flux recovery device of claim 1, wherein: The first end of the fixed pipe (22) is fixed with a flange plate (21), the flange plate (21) is detachably and sealingly fixedly connected with the recovery cabin (1), and is provided with a gas outlet (211) for communicating with the vacuumizing mechanism (6), the gas outlet (211) communicates with the clean area (14); the flange plate (21) is further provided with a cooling liquid inlet joint (212) and a cooling liquid outlet joint (213), the cooling liquid outlet joint (213) and the cooling liquid outlet joint (213) respectively communicate with the inlet and outlet of the condenser pipe (23); the condenser pipe (23) is fixedly installed on the fixed pipe (22) or the flange plate (21).

4. The flux recovery device of claim 1, wherein: The safety pressure relief mechanism (4) comprises a sliding block (42) and a pressure relief port (412), the pressure relief port (412) communicates with the inner cavity, the sliding block (42) is arranged to block the pressure relief port (412) under its own gravity, and when the pressure of the inner cavity exceeds a threshold value, the sliding block (42) overcomes its own gravity to produce displacement to open the pressure relief port (412) to release the pressure of the inner cavity.

5. The flux recovery device of claim 4, wherein: The safety pressure relief mechanism (4) further comprises a gas permeable structure (422) and a base body (41) having a sliding cavity (411) inside, the base body (41) is sealingly and fixedly connected with the recovery cabin (1), the sliding block (42) is slidingly installed in the sliding cavity (411) in an up-down direction, the pressure relief port (412) is located at the bottom of the sliding cavity (411), the sliding block (42) is located above the pressure relief port (412) and completely covers the pressure relief port (412), when the sliding block (42) moves upward, the pressure relief port (412) communicates with the gas permeable structure (422).

6. The flux recovery device of claim 5, wherein: The outer peripheral wall of the sliding block (42) is gap-fitted with the inner peripheral wall of the sliding cavity (411); a plurality of grooves (421) are formed in the outer peripheral wall of the sliding block (42), a sliding wear-resistant ring (43) is embedded in each groove (421), and the outer peripheral wall of the sliding wear-resistant ring (43) is tightly fitted with the sliding cavity (411).

7. The flux recovery device of claim 6, wherein: The sliding wear-resistant ring (43) is an elastic member with elasticity, the sliding wear-resistant ring (43) has a notch (431) and forms two free ends separated from each other at the notch (431).

8. The flux recovery device of claim 5, wherein: The gas permeable structure (422) is a gas permeable groove formed in the outer peripheral wall of the sliding block (42) or a gas permeable hole formed in the sliding block (42), and the space above the sliding block (42) and the space below the sliding block (42) in the sliding cavity (411) communicate through the gas permeable structure (422). A sealing ring (44) is arranged on the lower end surface of the sliding block (42) or the bottom of the sliding cavity (411), when the sliding block (42) presses the sealing ring (44) against the bottom of the sliding cavity (411), the communication path between the gas permeable structure (422) and the pressure relief port (412) is blocked by the sealing ring (44).

9. The flux recovery device of claim 1, wherein: The cooling area (12) and the clean area (14) are gradually inclined downward from the clean area (14) to the recovery area (13), the recovery area (13) is communicated with a sewage outlet (131) below, and the sewage outlet (131) is used for communicating with the collecting mechanism (5).

10. A vacuum brazing apparatus characterized by: A flux recovery device comprising the flux recovery device according to any one of claims 1 to 9.

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