Heating device of continuous vacuum reflow soldering furnace

Abstract

The present invention discloses a heating device for a continuous vacuum reflow soldering furnace, belonging to the field of semiconductor processing, aiming to solve the problem of thermal efficiency during the heating of the soldering furnace. The key technical points of its technical solution are as follows: It includes an upper heating furnace body assembly arranged on a frame and a lower heating plate assembly arranged on the frame. The lower heating plate assembly is located below the upper heating furnace body assembly. The upper heating furnace body assembly includes a top seat, a top cover is fixed to the bottom of the top seat, a homogenizing impeller is rotatably connected in the top cover, a servo motor for driving the homogenizing impeller is fixed on the top seat. The bottom of the top cover is connected to a bottom cover through two vertical covers. A top heating plate is arranged in the bottom cover, and a horizontal cross-flow suppression structure for suppressing horizontal cross-flow is arranged in the bottom cover. The heating device of the continuous vacuum reflow soldering furnace has a good effect of suppressing cross-flow, can ensure that the hot air flow maintains a vertical flow state as much as possible, and can improve the heating efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of welding, and particularly to a heating device for a continuous vacuum reflow soldering furnace. Background Art

[0002] A vacuum reflow soldering furnace is a device used for soldering electronic components during the electronic manufacturing process. It heats the electronic components in a vacuum environment, causing them to melt and connect to the circuit board. This soldering method can improve the soldering quality, reduce soldering defects, and enhance the reliability of electronic products.

[0003] A vacuum reflow soldering furnace mainly consists of the following parts: The furnace body of the vacuum reflow soldering furnace: The furnace body is the main part of the vacuum reflow soldering furnace, which is used to accommodate electronic components and circuit boards and provide a heating function. The heater: The heater usually consists of a resistance wire or a heating tube and is used to heat the electronic components and circuit boards inside the furnace body. The control system: The control system is used to control the working process of the vacuum reflow soldering furnace, including parameters such as heating temperature, heating time, and vacuum degree. The cooling system: The cooling system is used to quickly cool the electronic components and circuit boards after soldering to improve the soldering strength and reliability. Vacuum reflow soldering furnaces are widely used in the field of electronic manufacturing, such as products like mobile phones, computers, and automotive electronics. It can solder various electronic components, such as chips, resistors, capacitors, transistors, etc. Using a vacuum reflow soldering furnace can improve the quality and reliability of electronic products and reduce production costs.

[0004] Most of the heating devices of vacuum reflow soldering furnaces use resistance air flow heating. The current heating method cannot well control the cross-flow of the air flow, which affects the heating efficiency. Summary of the Invention

[0005] Aiming at the problems mentioned in the background art, the purpose of the present invention is to provide a heating device for a continuous vacuum reflow soldering furnace to solve the problems mentioned in the background art.

[0006] The above technical purpose of the present invention is achieved through the following technical solutions:

[0007] A heating device for a continuous vacuum reflow soldering furnace includes an upper heating furnace body assembly arranged on a frame and a lower heating plate assembly arranged on the frame. The lower heating plate assembly is located below the upper heating furnace body assembly. The upper heating furnace body assembly includes a top seat. A top cover is fixed to the bottom of the top seat. A homogenizing impeller is rotatably connected in the top cover. A servo motor for driving the homogenizing impeller is fixed on the top seat. The bottom of the top cover is connected to a bottom cover through two vertical covers. A top heating plate is arranged in the bottom cover. A dense first air outlet is formed on the top heating plate. A horizontal cross-flow suppression structure for suppressing horizontal cross-flow of air is arranged in the bottom cover.

[0008] By adopting the above technical solutions, the heating device of the continuous vacuum reflow soldering furnace has a good effect of suppressing cross flow, can ensure that the hot air flow keeps a vertical flow state as much as possible, and can improve the heating efficiency; the hot air form of columnar jet resists the thermal resistance layer on the substrate surface, and the strong convection nozzle design resists the occurrence of horizontal cross flow; the high-pressure and high-density hot air heating greatly improves the heat uniformity effect; the bottom hot plate is used for auxiliary heating, which makes up for the disadvantage of poor temperature uniformity in contact heating; when this equipment is applied, the servo motor on the top seat can drive the homogenizing impeller to rotate, which can suck air flow from the middle bottom of the homogenizing impeller and blow out the air flow from the outer ring of the homogenizing impeller. After the air flow enters the top cover, it enters the bottom cover through the vertical cover. The top heating plate in the bottom cover can heat the air flow, and the heated air flow can suppress the horizontally flowing air flow through the horizontal cross flow suppression structure, so that the air flow can be blown out vertically as much as possible.

[0009] Preferably, the lower heating plate assembly includes a bottom plate, a resistance heater and a bottom heating plate, and the resistance heater is located between the bottom plate and the bottom heating plate.

[0010] By adopting the above technical solutions, the bottom plate, the resistance heater and the bottom heating plate in the lower heating plate can achieve heating at a specific wavelength. By adopting surface contact molecular heat transfer + IR assistance, the problem of poor temperature uniformity caused by fixture or flatness problems of the bottom plate in the traditional heating plate can be solved, and the measured temperature difference of the mounted substrate can be as low as ±1 degree at the lowest. Since the heat propagates from the bottom upwards, the solder paste melts slowly from the bottom upwards, solving the factor of surface tension caused by the prior melting of the solder paste surface and preventing the generation of a large number of voids.

[0011] Preferably, the horizontal cross flow suppression structure includes a plurality of integrally formed flow dividing plate segments. Each of the plurality of flow dividing plate segments includes a horizontal bottom, a horizontal top and an inclined side portion. A plurality of second air outlets are respectively formed on the horizontal bottom and the horizontal top, and the second air outlets correspond to the first air outlets.

[0012] By adopting the above technical solutions, the horizontal bottom, the horizontal top and the inclined side portion on the flow dividing plate segment can achieve horizontal cross flow suppression. After the wind blows from the first air outlet to the second air outlet on the horizontal top, it enters the trapezoidal space formed by the two inclined side portions. At this time, the horizontal air flow will be corrected to vertical blowing when impacting the inclined side portion, so as to achieve horizontal cross flow suppression.

[0013] Preferably, an end cover is fixed to the bottom of the bottom cover. A dense number of third air outlets are formed on the end cover, and the second air outlets correspond to the third air outlets; a height control structure for controlling the blowing height of the air flow is arranged at the bottom of the end cover.

[0014] By adopting the above technical solution, the height control structure at the bottom of the end cover can control the height of the air flow blowing position from the bottom welding circuit board, so as to adjust the air flow blowing volume and wind force, and regulate the welding process.

[0015] Preferably, the height control structure includes a plurality of inner tubes, a plurality of outer tubes, an adjusting plate, a micro electric cylinder and a self-adjusting structure. The plurality of inner tubes are respectively fixed at the third air outlet on the end cover. The plurality of outer tubes are respectively slidably connected to the outside of the inner tubes. The plurality of outer tubes are respectively installed on the adjusting plate through the self-adjusting structure. The cylinder body of the micro electric cylinder is fixed on the end cover, and the end of the piston rod of the micro electric cylinder is fixed on the adjusting plate.

[0016] By adopting the above technical solution, when the micro electric cylinder is started, it can drive the adjusting plate to slide up and down, so as to drive the plurality of outer tubes to slide outside the inner tubes, so as to adjust the height position of the air flow blowing. Depending on the self-adjusting structure on the outer tube, automatic adjustment can be realized when the air flow passing through the outer tube is large or small.

[0017] Preferably, the self-adjusting structure includes a first shoulder, a second shoulder, a spring and a flow guiding block. The first shoulder is located at the bottom end of the inner tube, the second shoulder is located at the top end of the outer tube, the spring is connected between the first shoulder and the second shoulder, the flow guiding block is fixed at the bottom end of the outer tube, the flow guiding block is an annular block, and the cross section of the flow guiding block is a streamline arched shape.

[0018] By adopting the above technical solution, the first shoulder and the second shoulder can be used to limit the separation of the inner tube and the outer tube. The cooperation of the spring and the flow guiding block can perform self-adjustment when the wind force passing through the flow guiding block is large or small. Since the flow guiding block is in an arched shape, wind pressure is formed above and below its arched part, and the spring can be used to realize self-expansion and contraction when there is a difference in wind pressure above and below.

[0019] Preferably, an infrared distance sensor and a controller are fixed at the bottom of the adjusting plate. The infrared distance sensor is electrically connected to the control input end of the controller, and the control output end of the controller is electrically connected to the micro electric cylinder.

[0020] By adopting the above technical solution, when the infrared distance sensor senses the height of the adjusting plate from the workpiece, the controller can be used to control the micro electric cylinder, so as to realize the adjustment.

[0021] Preferably, a flow guiding inclined surface is arranged at the top of the bottom cover.

[0022] By adopting the above technical solution, the arrangement of the flow guiding inclined surface can promote the flow of wind force.

[0023] In summary, the present invention mainly has the following beneficial effects:

[0024] The heating device of the continuous vacuum reflow soldering furnace has a good effect of suppressing cross flow, can ensure that the hot air flow maintains a vertical flow state as much as possible, and can improve the heating efficiency; the hot air form of columnar jet suppresses the thermal resistance layer on the surface of the substrate, and the strong convection nozzle design suppresses the occurrence of horizontal cross flow; the high-pressure and high-density hot air heating greatly improves the heat uniformity effect; the bottom hot plate is used for auxiliary heating to make up for the disadvantage of poor temperature uniformity in contact heating; when this equipment is applied, the servo motor on the top seat can drive the homogenizing impeller to rotate, which can suck in air flow from the middle bottom of the homogenizing impeller and blow out air flow from the outer ring of the homogenizing impeller. The air flow enters the top cover and then enters the bottom cover through the vertical cover. The top heating plate in the bottom cover can heat the air flow, and the heated air flow can suppress the horizontally flowing air flow through the horizontal cross flow suppression structure, so that the air flow can be vertically blown out as much as possible. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is one of the structural schematic diagrams of the upper heating furnace body assembly of the present invention;

[0026] Figure 2 is the second structural schematic diagram of the upper heating furnace body assembly of the present invention;

[0027] Figure 3 is one of the structural sectional views of the upper heating furnace body assembly of the present invention;

[0028] Figure 4 is the second structural sectional view of the upper heating furnace body assembly of the present invention;

[0029] Figure 5 is Figure 4 the enlarged view at A in

[0030] Figure 6 is the structural schematic diagram of the lower heating plate assembly of the present invention;

[0031] Figure 7 is the structural sectional view of the height control structure of the present invention.

[0032] Reference numerals: 1, frame; 2, upper heating furnace body assembly; 3, lower heating plate assembly; 21, top seat; 22, top cover; 23, homogenizing impeller; 24, servo motor; 25, vertical cover; 26, bottom cover; 27, top heating plate; 28, first air outlet; 4, horizontal cross-flow suppression structure; 31, bottom plate; 32, resistance heater; 33, bottom heating plate; 40, shunt plate section; 401, horizontal bottom; 402, horizontal top; 403, inclined edge; 404, second air outlet; 29, end cover; 291, third air outlet; 5, height control structure; 51, inner tube; 52, outer tube; 53, adjusting plate; 54, micro electric cylinder; 55, self-adjusting structure; 551, first shoulder; 552, second shoulder; 553, spring; 554, guide block. Detailed implementation manners

[0033] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0034] Refer to Figures 1 - 7, The heating device of a continuous vacuum reflow soldering furnace includes an upper heating furnace body assembly 2 arranged on a frame 1 and a lower heating plate assembly 3 arranged on the frame 1. The lower heating plate assembly 3 is located below the upper heating furnace body assembly 2. The upper heating furnace body assembly 2 includes a top seat 21. A top cover 22 is fixed to the bottom of the top seat 21. A homogenizing impeller 23 is rotatably connected in the top cover 22. A servo motor 24 for driving the homogenizing impeller 23 is fixed on the top seat 21. The bottom of the top cover 22 is connected to a bottom cover 26 through two vertical covers 25. A top heating plate 27 is arranged in the bottom cover 26. A dense first air outlet 28 is formed on the top heating plate 27. A horizontal cross-flow suppression structure 4 for suppressing horizontal cross-flow is arranged in the bottom cover 26. The heating device of the continuous vacuum reflow soldering furnace has a good effect of suppressing cross-flow, can ensure that the hot air flow maintains a vertical flow state as much as possible, and can improve the heating efficiency; the hot air form of columnar jet suppresses the thermal resistance layer on the substrate surface, and the nozzle design of strong convection suppresses the occurrence of horizontal cross-flow; the hot air heating of high pressure and high density greatly improves the heat uniformity effect; the bottom hot plate is used for auxiliary heating to make up for the disadvantage of poor temperature uniformity of contact heating; when this equipment is applied, the servo motor 24 on the top seat 21 can drive the homogenizing impeller 23 to rotate, can suck air flow from the middle bottom of the homogenizing impeller 23 and blow out the air flow from the outer ring of the homogenizing impeller 23. The air flow enters the bottom cover 26 through the vertical cover 25 after entering the top cover 22. The top heating plate 27 in the bottom cover 26 can heat the air flow. The heated air flow can suppress the horizontally flowing air flow through the horizontal cross-flow suppression structure 4, so that the air flow can be vertically blown out as much as possible.

[0035] Reference Figures 1 - 7 , wherein the lower heating plate assembly 3 includes a bottom plate 31, a resistance heater 32 and a bottom heating plate 33. The resistance heater 32 is located between the bottom plate 31 and the bottom heating plate 33. The bottom plate 31, the resistance heater 32 and the bottom heating plate 33 in the lower heating plate can achieve heating at a specific wavelength. By adopting surface contact molecular heat transfer + IR assistance, the problem of poor temperature uniformity caused by the flatness problem of the jig or the bottom plate 31 of the traditional heating plate can be solved. The measured temperature difference of the mounted substrate can be as low as ±1 degree at the lowest. Since the heat propagates from the bottom upwards, the solder paste melts slowly from the bottom upwards, solving the factor of surface tension generated due to the prior melting of the surface of the solder paste and preventing the generation of a large number of voids.

[0036] Reference Figures 1 - 7, wherein the horizontal cross-flow suppression structure 4 includes a plurality of integrally formed flow splitting plate segments 40. The plurality of flow splitting plate segments 40 respectively include a horizontal bottom 401, a horizontal top 402, and an inclined side 403. A plurality of second air outlets 404 are respectively formed on the horizontal bottom 401 and the horizontal top 402, and the second air outlets 404 correspond to the first air outlet 28. The horizontal bottom 401, the horizontal top 402, and the inclined side 403 on the flow splitting plate segment 40 can achieve horizontal cross-flow suppression. After the wind blows out from the first air outlet 28 to the second air outlet 404 on the horizontal top 402, it enters the trapezoidal space formed by the two inclined sides 403. At this time, the horizontal airflow will be corrected to vertical blowing when it impacts the inclined side 403, thereby achieving horizontal cross-flow suppression.

[0037] Reference Figures 1 - 7 , wherein an end cover 29 is fixed to the bottom of the bottom cover 26. A dense array of third air outlets 291 is formed on the end cover 29, and the second air outlets 404 correspond to the third air outlets 291; a height control structure 5 for controlling the height of the airflow blowing out is provided at the bottom of the end cover 29. The height control structure 5 at the bottom of the end cover 29 can control the height of the airflow blowing position from the bottom welding circuit board, so as to adjust the airflow blowing amount and the wind force, and regulate the welding process. The height control structure 5 includes a plurality of inner tubes 51, a plurality of outer tubes 52, an adjustment plate 53, a micro electric cylinder 54, and a self-adjusting structure 55. The plurality of inner tubes 51 are respectively fixed at the third air outlets 291 on the end cover 29. The plurality of outer tubes 52 are respectively slidably connected to the outside of the inner tubes 51. The plurality of outer tubes 52 are respectively installed on the adjustment plate 53 through the self-adjusting structure 55. The cylinder body of the micro electric cylinder 54 is fixed on the end cover 29, and the end of the piston rod of the micro electric cylinder 54 is fixed on the adjustment plate 53. When the micro electric cylinder 54 is started, it can drive the adjustment plate 53 to slide up and down, so as to drive the plurality of outer tubes 52 to slide outside the inner tubes 51, thereby adjusting the height position of the airflow blowing out. Depending on the self-adjusting structure 55 on the outer tubes 52, automatic adjustment can be achieved when the airflow flowing through the outer tubes 52 is large or small.

[0038] Reference Figures 1 - 7, wherein the self-adjusting structure 55 includes a first shoulder 551, a second shoulder 552, a spring 553 and a flow guide block 554. The first shoulder 551 is located at the bottom end of the inner tube 51, the second shoulder 552 is located at the top end of the outer tube 52, the spring 553 is connected between the first shoulder 551 and the second shoulder 552, and the flow guide block 554 is fixed at the bottom end of the outer tube 52. The flow guide block 554 is an annular block, and the cross section of the flow guide block 554 is a streamlined arch shape. The first shoulder 551 and the second shoulder 552 can be used to limit the separation of the inner tube 51 and the outer tube 52. The cooperation of the spring 553 and the flow guide block 554 can perform self-adjustment when the wind blowing through the flow guide block 554 is large or small. Since the flow guide block 554 is in an arch shape, wind pressure is formed above and below its arch part, and the spring 553 can be used to achieve self-expansion and contraction when there is a difference in wind pressure above and below.

[0039] Reference Figures 1 - 7 , wherein an infrared distance sensor and a controller are fixed at the bottom of the adjusting plate 53. The infrared distance sensor is electrically connected to the control input end of the controller, and the control output end of the controller is electrically connected to the micro-electric cylinder 54. When the infrared distance sensor senses the height of the adjusting plate 53 from the workpiece, the controller can be used to control the micro-electric cylinder 54, thereby realizing adjustment. A flow guiding slope is arranged at the top of the bottom cover 26, and the arrangement of the flow guiding slope can promote the flow of wind.

[0040] Reference Figures 1 - 7 , the use principle and method of the present invention are as follows:

[0041] When applying this device, the servo motor 24 on the top seat 21 can drive the homogenizing impeller 23 to rotate, which can suck in air flow from the middle bottom of the homogenizing impeller 23 and blow out the air flow from the outer ring of the homogenizing impeller 23. After the air flow enters the top cover 22, it enters the bottom cover 26 through the vertical cover 25. The top heating plate 27 in the bottom cover 26 can heat the air flow. The heated air flow can pass through the horizontal cross-flow suppression structure 4 to suppress the laterally flowing air flow. The horizontal bottom 401, horizontal top 402 and inclined edges 403 on the shunt plate section 40 can achieve horizontal cross-flow suppression. After the wind blows out from the first air outlet 28 to the second air outlet 404 on the horizontal top 402, it enters the trapezoidal space formed by the two inclined edges 403. At this time, the lateral air flow will be corrected to vertical blowing when impacting the inclined edges 403, so as to achieve horizontal cross-flow suppression and make the air flow blow out vertically as much as possible. When it is necessary to adjust the air flow blowing height, the height control structure 5 at the bottom of the end cover 29 can control the height of the air flow blowing position from the bottom welding circuit board, so as to adjust the air flow blowing volume and wind force size and regulate the welding process. When the micro electric cylinder 54 is started, it can drive the adjusting plate 53 to slide up and down, so as to drive several outer tubes 52 to slide outside the inner tube 51, so as to adjust the height position of the air flow blowing. Depending on the self-adjusting structure 55 on the outer tube 52, it can be automatically adjusted when the air flow passing through the outer tube 52 is large or small. The first shoulder 551 and the second shoulder 552 can limit the separation of the inner tube 51 and the outer tube 52. The cooperation of the spring 553 and the guide block 554 can be self-adjusted when the wind force passing through the guide block 554 is large or small. Since the guide block 554 is in an arched shape, wind pressure is formed above and below its arched part. It can achieve self-expansion and contraction by using the spring 553 when there is a difference in wind pressure above and below. When the wind force below is large, an upward thrust is generated to make the outer tube 52 rise. When the wind force below is small, a downward pressing thrust is generated to make the outer tube 52 descend.

[0042] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. Heating device of a continuous vacuum reflow soldering furnace, characterized in that: It includes an upper heating furnace body assembly (2) arranged on a frame (1) and a lower heating plate assembly (3) arranged on the frame (1). The lower heating plate assembly (3) is located below the upper heating furnace body assembly (2). The upper heating furnace body assembly (2) includes a top seat (21). A top cover (22) is fixed to the bottom of the top seat (21). A homogenizing impeller (23) is rotatably connected in the top cover (22). A servo motor (24) for driving the homogenizing impeller (23) is fixed on the top seat (21). The bottom of the top cover (22) is connected to a bottom cover (26) through two vertical covers (25). A top heating plate (27) is arranged in the bottom cover (26). A dense first air outlet (28) is formed on the top heating plate (27). A horizontal cross-flow suppression structure (4) for suppressing horizontal cross-flow is arranged in the bottom cover (26). The horizontal cross-flow suppression structure (4) includes a plurality of integrally formed flow dividing plate segments (40). Each of the plurality of flow dividing plate segments (40) includes a horizontal bottom (401), a horizontal top (402), and an inclined side (403). A plurality of second air outlets (404) are respectively formed on the horizontal bottom (401) and the horizontal top (402). The second air outlets (404) correspond to the first air outlet (28). An end cover (29) is fixed to the bottom of the bottom cover (26). A dense third air outlet (291) is formed on the end cover (29). The second air outlets (404) correspond to the third air outlet (291). A height control structure (5) for controlling the blowing height of the air flow is arranged at the bottom of the end cover (29). The height control structure (5) includes a plurality of inner tubes (51), a plurality of outer tubes (52), an adjusting plate (53), a micro electric cylinder (54), and a self-adjusting structure (55). Each of the plurality of inner tubes (51) is fixed at the third air outlet (291) on the end cover (29). Each of the plurality of outer tubes (52) is slidably connected to the outside of the inner tube (51). Each of the plurality of outer tubes (52) is installed on the adjusting plate (53) through the self-adjusting structure (55). The cylinder body of the micro electric cylinder (54) is fixed on the end cover (29). The piston rod end of the micro electric cylinder (54) is fixed on the adjusting plate (53).

2. The heating device of the continuous vacuum reflow soldering furnace according to claim 1, characterized in that: The lower heating plate assembly (3) includes a bottom plate (31), a resistance heater (32), and a bottom heating plate (33). The resistance heater (32) is located between the bottom plate (31) and the bottom heating plate (33).

3. The heating device of the continuous vacuum reflow soldering furnace according to claim 1, characterized in that: The self-adjusting structure (55) includes a first shoulder (551), a second shoulder (552), a spring (553), and a flow guide block (554). The first shoulder (551) is located at the bottom end of the inner tube (51), the second shoulder (552) is located at the top end of the outer tube (52), the spring (553) is connected between the first shoulder (551) and the second shoulder (552), the flow guide block (554) is fixed at the bottom end of the outer tube (52), the flow guide block (554) is an annular block, and the cross section of the flow guide block (554) is a streamlined arched shape.

4. The heating device of the continuous vacuum reflow soldering furnace according to claim 3, wherein: An infrared distance sensor and a controller are fixed at the bottom of the adjusting plate (53). The infrared distance sensor is electrically connected to the control input end of the controller, and the control output end of the controller is electrically connected to the micro electric cylinder (54).

5. The heating device of the continuous vacuum reflow soldering furnace according to claim 1, wherein: A flow guide inclined surface is provided at the top of the bottom cover (26).

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