Heating device of continuous vacuum reflow soldering furnace

Abstract

The invention discloses a heating device of a continuous vacuum reflow soldering furnace, belongs to the field of semiconductor processing, aims to solve the problem of heat efficiency during soldering furnace heating, and adopts the technical scheme that the heating device comprises an upper heating furnace body assembly arranged on a rack and a lower heating plate assembly arranged on the rack, the lower heating plate assembly is located below the upper heating furnace body assembly, the upper heating furnace body assembly comprises a top base, a top cover is fixed to the bottom of the top base, a homogenizing impeller is rotationally connected into the top cover, a servo motor for driving the homogenizing impeller is fixed to the top base, the bottom of the top cover is connected with a bottom cover through two vertical covers, and the bottom cover is connected with a bottom cover. A top heating plate is arranged in the bottom cover, and a horizontal transverse flow restraining structure for restraining horizontal transverse airflow is arranged in the bottom cover. The heating device of the continuous vacuum reflow soldering furnace has a good transverse flow restraining effect, it can be guaranteed that hot air flow is kept in a vertical circulation state as much as possible, and the heating efficiency can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of welding, in particular to a heating device of a continuous vacuum reflow oven. Background Art

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

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

[0004] The heating device of the vacuum reflow furnace mostly adopts resistance airflow heating. The current heating method cannot well control the cross flow of the airflow, which affects the heating efficiency. Summary of the invention

[0005] In view of the problems mentioned in the background technology, the purpose of the present invention is to provide a heating device for a continuous vacuum reflow oven to solve the problems mentioned in the background technology.

[0006] The above technical objectives of the present invention are achieved through the following technical solutions:

[0007] The heating device of a continuous vacuum reflow soldering furnace comprises an upper heating furnace body assembly arranged on a frame and a lower heating plate assembly arranged on the frame, wherein the lower heating plate assembly is located below the upper heating furnace body assembly, and the upper heating furnace body assembly comprises 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 the bottom cover through two vertical covers, a top heating plate is arranged in the bottom cover, a densely distributed first air outlet is opened on the top heating plate, and a horizontal lateral flow suppression structure for suppressing horizontal lateral airflow is arranged in the bottom cover.

[0008] By adopting the above technical scheme, the heating device of the continuous vacuum reflow oven has a good effect of suppressing cross flow, can ensure that the hot air flow is kept in a vertical flow state as much as possible, and can improve the heating efficiency; the columnar jet of hot air resists the heat resistance layer on the surface of the substrate, 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 auxiliary heating makes up for the disadvantage of poor temperature uniformity of contact heating; when this equipment is applied, the servo motor on the top seat can drive the uniformizing impeller to rotate, and can inhale air flow from the middle bottom of the uniformizing impeller and blow air flow out from the outer ring of the uniformizing 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 pass through the horizontal cross flow suppression structure to suppress the cross flow of the air flow, so that the air flow can be blown out vertically as much as possible.

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

[0010] By adopting the above technical solution, the bottom plate, resistance heater and bottom heating plate in the lower heating plate can achieve specific wavelength heating. By adopting surface contact molecular heat transfer + IR assistance, the problem of poor temperature uniformity caused by the flatness of the fixture or bottom plate of the traditional heating plate can be solved. The actual temperature difference of the installed substrate can be as low as ±1 degree. Since the heat propagates from the bottom to the top, the solder paste melts slowly from the bottom to the top, which solves the factor of surface tension caused by the surface of the solder paste melting first and prevents the generation of a large number of voids.

[0011] Preferably, the horizontal lateral flow suppression structure includes a plurality of integrally formed diverter plate segments, each of the diverter plate segments includes a horizontal bottom, a horizontal top and an inclined edge, and a plurality of second air outlets are respectively provided on the horizontal bottom and the horizontal top, and the second air outlets correspond to the first air outlets.

[0012] By adopting the above-mentioned technical solution, the horizontal bottom, horizontal top and inclined edge on the diverter plate section can achieve horizontal lateral flow suppression. After the wind blows out from the first air outlet to the second air outlet on the horizontal top, it enters the trapezoidal space formed by the two inclined edges. At this time, the lateral airflow will be corrected to vertical blowing when impacting the inclined edge, thereby achieving horizontal lateral flow suppression.

[0013] Preferably, an end cover is fixed to the bottom of the bottom cover, and a densely distributed third air outlet is opened on the end cover, and the second air outlet corresponds to the third air outlet; and a height control structure for controlling the blowing height of the airflow 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 airflow blowing position from the bottom welding circuit board, thereby adjusting the airflow blowing amount and wind force to regulate the welding process.

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

[0016] By adopting the above technical solution, when the micro electric cylinder is started, it can drive the adjustment plate to slide up and down, thereby driving several outer tubes to slide outside the inner tube, so as to adjust the height position of the airflow blowing out. Relying on the self-adjusting structure on the outer tube, automatic adjustment can be achieved when the airflow 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 guide 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 guide block is fixed at the bottom end of the outer tube, the guide block is an annular block, and the cross-section of the guide block is a streamlined arch 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, and the spring and the guide block can cooperate to self-adjust when the wind force blowing through the guide block is strong or weak. Since the guide block is arched in shape, the arched part forms wind pressure up and down, and the spring can be used to achieve self-expansion when there is a difference in wind pressure up and down.

[0019] Preferably, an infrared distance sensor and a controller are fixed to the bottom of the adjustment plate, the infrared distance sensor is electrically connected to a 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 adjustment plate from the workpiece, the controller can be used to control the micro electric cylinder to achieve adjustment.

[0021] Preferably, a guide slope is provided on the top of the bottom cover.

[0022] By adopting the above technical solution, the setting of the guide slope can promote wind flow.

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

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

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

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

[0027] Figure 3 This is one of the structural cross-sectional views of the upper heating furnace assembly in the present invention;

[0028] Figure 4 This is the second structural cross-sectional view of the upper heating furnace assembly in the present invention;

[0029] Figure 5 yes Figure 4 A in the enlarged view;

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

[0031] Figure 7 It is a structural cross-sectional view of the height control structure in the present invention.

[0032] : 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. diverter 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. adjustment plate; 54. micro electric cylinder; 55. self-adjusting structure; 551. first shaft shoulder; 552. second shaft shoulder; 553. spring; 554. guide block. DETAILED DESCRIPTION

[0033] 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.

[0034] refer to Figure 1-Figure 7The heating device of the 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 the bottom cover 26 through two vertical covers 25, a top heating plate 27 is arranged in the bottom cover 26, a densely distributed first air outlet 28 is opened on the top heating plate 27, and a horizontal lateral flow suppression structure 4 for suppressing horizontal lateral airflow is arranged in the bottom cover 26. The heating device of the continuous vacuum reflow oven 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 columnar jet of hot air resists the heat resistance layer on the surface of the substrate, and the strong convection nozzle design resists the occurrence of horizontal cross flow; high-pressure and high-density hot air heating greatly improves the heat uniformity effect; the bottom hot plate auxiliary heating makes up for the disadvantage of poor temperature uniformity of contact heating; when this equipment is used, the servo motor 24 on the top seat 21 can drive the uniformizing impeller 23 to rotate, and can inhale air flow from the middle bottom of the uniformizing impeller 23 and blow air flow out from the outer ring of the uniformizing 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, and the heated air flow can pass through the horizontal cross flow suppression structure 4 to suppress the cross flow of the air flow, so that the air flow can be blown out vertically as much as possible.

[0035] refer to Figure 1-Figure 7 , wherein the lower heating plate assembly 3 includes a bottom plate 31, a resistance heater 32 and a bottom heating plate 33, wherein the resistance heater 32 is located between the bottom plate 31 and the bottom heating plate 33, and the bottom plate 31, the resistance heater 32 and the bottom heating plate 33 in the lower heating plate can realize heating at a specific wavelength, and by adopting surface contact molecular heat transfer + IR assistance, the problem of poor temperature uniformity caused by the flatness of the fixture or the bottom plate 31 of the traditional heating plate can be solved, and the actual temperature difference of the installed substrate can be as low as ±1 degree. Since the heat propagates from the bottom to the top, the solder paste melts slowly from the bottom to the top, which solves the factor of surface tension caused by the solder paste surface melting first, and prevents the generation of a large number of voids.

[0036] refer to Figure 1-Figure 7, wherein the horizontal transverse flow suppression structure 4 includes a plurality of integrally formed splitter plate sections 40, and the plurality of splitter plate sections 40 respectively include a horizontal bottom 401, a horizontal top 402 and an inclined edge 403, and a plurality of second air outlets 404 are respectively provided 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 edge 403 on the splitter plate section 40 can achieve horizontal transverse flow suppression, and 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, and at this time, the transverse airflow will be corrected to be blown vertically when impacting the inclined edge 403, thereby achieving horizontal transverse flow suppression.

[0037] refer to Figure 1-Figure 7 , wherein an end cover 29 is fixed at the bottom of the bottom cover 26, and a densely distributed third air outlet 291 is opened on the end cover 29, and the second air outlet 404 corresponds to the third air outlet 291; a height control structure 5 for controlling the airflow blowing height is arranged 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 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, wherein the plurality of inner tubes 51 are respectively fixed at the third air outlet 291 on the end cover 29, the plurality of outer tubes 52 are respectively slidably connected to the outside of the inner tube 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 piston rod end 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, thereby driving a plurality of outer tubes 52 to slide outside the inner tube 51, so as to adjust the height position of the airflow. The self-adjusting structure 55 on the outer tube 52 can realize automatic adjustment when the airflow passing through the outer tube 52 is large or small.

[0038] refer to Figure 1-Figure 7, wherein the self-adjusting structure 55 includes a first shoulder 551, a second shoulder 552, a spring 553 and a guide block 554, wherein 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 guide block 554 is fixed at the bottom end of the outer tube 52, the guide block 554 is an annular block, and the cross section of the 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 spring 553 and the guide block 554 can cooperate to self-adjust when the wind force blowing through the guide block 554 is large or small, and since the guide block 554 is in an arch shape, its arched part forms wind pressure up and down, and the spring 553 can be used to achieve self-expansion when there is a difference in wind pressure up and down.

[0039] refer to Figure 1-Figure 7 , wherein an infrared distance sensor and a controller are fixed at the bottom of the adjustment 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 adjustment plate 53 from the workpiece, the controller can be used to control the micro-electric cylinder 54 to achieve adjustment. The top of the bottom cover 26 is provided with a guide slope, and the setting of the guide slope can promote wind flow.

[0040] refer to Figure 1-Figure 7 The use principle and method of the present invention are as follows:

[0041] When the device is used, the servo motor 24 on the top seat 21 can drive the homogenizing impeller 23 to rotate, so that the airflow can be sucked in from the middle bottom of the homogenizing impeller 23 and blown out from the outer ring of the homogenizing impeller 23. After the airflow 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 airflow. The heated airflow can pass through the horizontal transverse flow suppression structure 4 to suppress the transverse flow of the airflow. The horizontal bottom 401, the horizontal top 402 and the inclined edge 403 on the diverter plate section 40 can achieve horizontal transverse 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 transverse airflow will be corrected to vertical blowing when impacting the inclined edge 403, thereby realizing horizontal transverse flow suppression, so that the airflow can be blown out vertically as much as possible; when it is necessary to adjust the airflow blowing height, the height control structure at the bottom of the end cover 29 5 can control the height of the airflow blowing position from the bottom welding circuit board, so as to adjust the airflow blowing amount and wind force, and regulate the welding process. When the micro electric cylinder 54 is started, it can drive the adjustment plate 53 to slide up and down, so as to drive a plurality of outer tubes 52 to slide outside the inner tube 51, so as to adjust the height position of the airflow blowing. By relying on the self-adjusting structure 55 on the outer tube 52, automatic adjustment can be achieved when the airflow flowing through the outer tube 52 is large or small. 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 spring 553 and the guide block 554 can cooperate to self-adjust when the wind force blowing through the guide block 554 is large or small. Since the guide block 554 is in an arched shape, the arched part forms wind pressure up and down. When the wind pressure difference between the upper and lower parts is large, the spring 553 can be used to realize self-expansion. When the wind force is large at the bottom, an upward thrust is generated, so that the outer tube 52 rises. When the wind force is small at the bottom, a downward thrust is generated, so that the outer tube 52 falls.

[0042] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A heating device for a continuous vacuum reflow oven, characterized in that: The invention comprises an upper heating furnace body assembly (2) arranged on a frame (1) and a lower heating plate assembly (3) arranged on the frame (1), wherein the lower heating plate assembly (3) is located below the upper heating furnace body assembly (2), the upper heating furnace body assembly (2) comprises a top seat (21), a top cover (22) is fixed at 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 the bottom cover (26) through two vertical covers (25), a top heating plate (27) is arranged in the bottom cover (26), a densely distributed first air outlet (28) is opened on the top heating plate (27), and a horizontal transverse flow suppression structure (4) for suppressing horizontal transverse airflow is arranged in the bottom cover (26).

2. The heating device of the continuous vacuum reflow oven according to claim 1, characterized in that: The lower heating plate assembly (3) comprises a bottom plate (31), a resistance heater (32) and a bottom heating plate (33), wherein 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 oven according to claim 1, characterized in that: The horizontal lateral flow suppression structure (4) comprises a plurality of integrally formed splitter plate sections (40), wherein the plurality of splitter plate sections (40) respectively comprise a horizontal bottom (401), a horizontal top (402) and an inclined edge (403), and the horizontal bottom (401) and the horizontal top (402) are respectively provided with a plurality of second air outlets (404), wherein the second air outlets (404) correspond to the first air outlets (28).

4. The heating device of the continuous vacuum reflow oven according to claim 3, characterized in that: An end cover (29) is fixed to the bottom of the bottom cover (26); the end cover (29) is provided with densely distributed third air outlets (291); the second air outlets (404) correspond to the third air outlets (291); and a height control structure (5) for controlling the height of airflow is provided at the bottom of the end cover (29).

5. The heating device of the continuous vacuum reflow oven according to claim 4, characterized in that: The height control structure (5) comprises 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 outlet (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 mounted on the adjustment plate (53) via 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).

6. The heating device of the continuous vacuum reflow oven according to claim 5, characterized in that: The self-adjusting structure (55) comprises a first shaft shoulder (551), a second shaft shoulder (552), a spring (553) and a guide block (554); the first shaft shoulder (551) is located at the bottom end of the inner tube (51); the second shaft shoulder (552) is located at the top end of the outer tube (52); the spring (553) is connected between the first shaft shoulder (551) and the second shaft shoulder (552); the guide block (554) is fixed at the bottom end of the outer tube (52); the guide block (554) is an annular block; and the cross-section of the guide block (554) is a streamlined arch shape.

7. The heating device of the continuous vacuum reflow oven according to claim 6, characterized in that: An infrared distance sensor and a controller are fixed to the bottom of the adjustment plate (53); the infrared distance sensor is electrically connected to a control input end of the controller, and the control output end of the controller is electrically connected to the micro electric cylinder (54).

8. The heating device of the continuous vacuum reflow oven according to claim 1, characterized in that: The top of the bottom cover (26) is provided with a flow guide slope.

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