Circuit board precision welding process and equipment thereof

Abstract

The invention relates to the technical field of welding, in particular to a circuit board precision welding process and equipment thereof.The welding equipment comprises a base, a conveying rail is fixedly installed at the top of the base, and a chip mounter is erected outside the conveying rail; the soldering paste printing part comprises a lifting assembly mounted at the top of the base, a correction assembly arranged at one end of the lifting assembly, a bearing assembly arranged at the top of the base and right opposite to the correction assembly, and an extrusion assembly arranged on the correction assembly; the reflow soldering part comprises a reflow soldering bin erected outside the conveying track, and a preheating bin, a heat preservation bin, a reflow bin and a cooling bin which are sequentially distributed on the inner side of the reflow soldering bin; the welding process comprises the following steps: feeding; printing soldering paste; pasting is conducted; the solder paste printing on the surface of the target circuit board is completed by adopting an extrusion type discharging mode to replace a traditional scraper scraping mode, air in a printing cavity can be discharged easily, and positioning operation is easy.

Description

Technical Field

[0001] The present invention relates to the field of welding technology, in particular to a circuit board precision welding process and equipment thereof. Background Art

[0002] Amidst the continuous innovation and development of the electronic information industry, electronic products continue to advance towards miniaturization and higher performance. As a key component of electronic products, technological innovation in printed circuit boards (PCBs) is particularly important. Furthermore, with the continuous advancement of miniaturization technology for assembling components, the wiring area and pattern design area of ​​PCBs are gradually shrinking, placing more stringent requirements on PCB soldering processes.

[0003] The prior art discloses a Chinese patent with publication number CN 112046134 B: A screen printing device for circuit boards, and discloses a screen printing mechanism and a lifting device. After the lifting device drives the positioning column to move upward to position the circuit board, the second drive component is started to drive the ink scraping component to move to print the solder paste on the screen onto the circuit board.

[0004] However, the above-mentioned existing technology still has certain defects. That is, during use, when the solder paste on the screen is scraped onto the circuit board with a scraper, the scraped solder paste moves horizontally and enters the cavity between the mesh of the screen and the circuit board. It is easy for the air inside the cavity to be not discharged in time to form a vacant area, thereby affecting the printing quality of the solder paste and the service life of the finished circuit board, and the positioning process is relatively complicated. Summary of the Invention

[0005] The object of the present invention is to provide a circuit board precision welding process and equipment thereof to solve the problems raised in the above background technology.

[0006] The purpose of the present invention can be achieved through the following technical solutions: A circuit board precision welding device, comprising: A base, a conveying track is fixedly installed on the top of the base, a placement machine is set up outside the conveying track, and a stopper is provided on the top of the base corresponding to the position of the placement machine for blocking the conveying of the circuit board; The solder paste printing unit includes a lifting assembly mounted on the top of the base, a correction assembly disposed at one end of the lifting assembly, a supporting assembly disposed on the top of the base opposite to the correction assembly, and an extrusion assembly disposed on the correction assembly; The reflow soldering part includes a reflow soldering chamber mounted on the outside of the conveying track, and a preheating chamber, a heat preservation chamber, a reflow chamber and a cooling chamber distributed sequentially inside the reflow soldering chamber along the conveying direction of the circuit board. Lifting parts for lifting the circuit board are provided at the positions of the preheating chamber, heat preservation chamber, reflow chamber and cooling chamber on the top of the base corresponding to the positions of the preheating chamber, heat preservation chamber, reflow chamber and cooling chamber.

[0007] As a preferred solution of the circuit board precision welding equipment described in the present invention, the lifting assembly includes a cylinder 1 and a guide plate fixed on the top of the base, a movable sleeve on the top of the guide plate is provided with a lifting plate, and the telescopic end of the cylinder 1 is fixedly connected to the lifting plate.

[0008] As a preferred solution of the circuit board precision welding equipment described in the present invention, the correction component includes an upper plate and a lower plate arranged from top to bottom, four support plates distributed in a rectangular array are fixedly connected between the upper plate and the lower plate, four correcting parts distributed in a rectangular array are installed on the lower plate, the correcting parts and the support plates are alternately and equidistantly distributed, and cylinder 2 is fixedly installed between the upper plate and the lifting plate, and the telescopic end of cylinder 2 movably passes through the upper plate.

[0009] As a preferred solution of the circuit board precision welding equipment described in the present invention, the correcting part includes a guide groove that is opened through the lower plate, a trapezoidal plate is slidably connected to the inside of the guide groove, a socket is opened on one side of the trapezoidal plate, and an insertion rod that is movably inserted into the inside of the socket is fixed at one end of the guide groove close to the center of the lower plate, and a top rod that movably passes through the corresponding guide groove is fixed on the other side of the trapezoidal plate, and a spring that is fixedly connected to the trapezoidal plate and the corresponding inner side of the guide groove is provided on the outer side of the insertion rod.

[0010] As a preferred solution of the circuit board precision welding equipment described in the present invention, the correction assembly further includes a ring plate sleeved on the outer side of the lower plate and an L-shaped rod fixed on the upper surface of the lower plate opposite to the support plate, four extrusion plates arranged horizontally and coplanarly with the top rod are fixed on the inner side of the ring plate, and four limiting grooves corresponding to the L-shaped rod are opened on the inner side of the ring plate, one end of the L-shaped rod is movably inserted into the corresponding limiting groove, a rack is fixed on the upper surface of the ring plate, a gear is engaged with the top of the rack, and a driving motor that rotates due to the driving gear is installed on the extrusion assembly.

[0011] As a preferred solution of the circuit board precision welding equipment described in the present invention, the supporting assembly includes a bracket fixed on the top of the base, slots are provided on the outside of the bracket corresponding to the position of each trapezoidal plate, a carrier is fixed on the top of the bracket, and limiting members are installed at the four corners of the carrier.

[0012] As a preferred solution of the circuit board precision welding equipment described in the present invention, the limiting part includes a column fixed on the top of the lower plate, an inner sleeve is provided on the outer side of the top of the column, an outer sleeve is provided on the outer side of the top of the inner sleeve, a pressure plate is fixed on the bottom end of the outer side of the inner sleeve, a spring 2 is provided on the outer side of the inner sleeve for fixedly connecting the outer sleeve and the pressure plate, and a spring 3 is provided on the inner side of the inner sleeve for fixedly connecting the column and the inner sleeve.

[0013] As a preferred solution of the circuit board precision welding equipment described in the present invention, wherein: the extrusion assembly includes a material frame fixed in a through-type at the center position of the lower plate and a push plate fixed at the second telescopic end of the cylinder, the drive motor is fixed on the outside of the material frame, and the bottom end of the outer side of the material frame is movably connected with a U-shaped moving plate, and a cylinder three is fixedly installed between the inner end of the U-shaped moving plate and the material frame, and the area on the U-shaped moving plate located on the inner side of the material frame and the bottom end of the material frame are penetrated by material holes, and a scraper is fixed on the inside of the U-shaped moving plate.

[0014] As a preferred embodiment of the circuit board precision welding equipment of the present invention, an air curtain assembly is further provided inside the reflow soldering chamber, the air curtain assembly comprising strips fixed on both sides of the inner cavity of the preheating chamber, the insulation chamber, the reflow chamber, and the cooling chamber, and an air supply chamber fixed at one end of the reflow soldering chamber, and an air pump is installed on the top of the air supply chamber; Each of the strips is horizontally penetrated by an air slot, and the air slots on the multiple strips arranged in a collinear manner on the inner side of the reflow soldering chamber are sequentially connected, the air slots on both sides of the inner cavity of the reflow soldering chamber are staggered up and down, and one end of the air slot on the inner side of the cooling chamber is connected to the air supply chamber, and the preheating chamber, the insulation chamber and the two strips inside the reflow chamber are all provided with a through slot, and the two through slots are staggered up and down. A ventilation slot connected to the corresponding through slot is provided on the outer side of the reflow soldering chamber.

[0015] The present invention also provides a process for welding a circuit board using the above-mentioned circuit board precision welding equipment, which specifically includes the following steps: S1. Loading: The circuit board is placed on the top of the carrier by a robotic arm or manually, waiting for solder paste printing; S2. Printing solder paste: Cylinder 1 drives the lifting plate downward, thereby driving the correction component to move downward synchronously and mate with the supporting component to correct the position of the circuit board. After the correction is completed, the solder paste is printed on the designated area on the circuit board through the extrusion component; S3, patch: push the circuit board with solder paste printing to the conveyor track, and then convey the circuit board to the area where the patch machine is located to complete the patching of related components. S4, reflow soldering: The circuit board with completed patch is transported to the reflow soldering area through the conveyor track to complete the reflow soldering of related components.

[0016] Beneficial effects of the present invention: 1. The present invention adopts an extrusion-type discharging method to replace the traditional scraping method to complete the printing of solder paste on the surface of the target circuit board. This can help to expel the air inside the material cavity formed between the discharge port of the extrusion component and the upper surface of the target circuit board, thereby preventing the formation of cavities due to residual air during the process of printing the solder paste on the upper surface of the target circuit board, thereby affecting the subsequent reflow soldering quality and further affecting the quality of the finished circuit board; 2. The present invention provides a limiter so that after the solder paste is printed on the circuit board, the pressure plate can be used to limit the circuit board so that the discharge end of the extrusion assembly is completely separated from the circuit board. Only then will the pressure plate be separated from the circuit board under the action of the compression and restoring force of the corresponding spring 3, thereby preventing the circuit board from moving upward. 3. After the solder paste is printed, the present invention can use the through-holes on the U-shaped shift plate that are staggered with the bottom of the material frame to block the adhesion between the solder paste inside the material frame and the solder paste printed on the circuit board surface, thereby preventing the extrusion component that moves upward with the correction component from driving the solder paste printed on the target circuit board off the circuit board, thereby ensuring the printing quality of the solder paste; 4. The present invention sets an air curtain assembly on the inner side of the reflow soldering chamber, so as to form a double-layer air curtain structure at the feeding port of the preheating chamber, the insulation chamber and the reflow chamber, so as to reduce the heat overflow in the preheating chamber, the insulation chamber and the reflow chamber, and reduce the waste of heat energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, those skilled in the art can derive other drawings based on these drawings without inventive effort. Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic structural diagram of the solder paste printing unit of the present invention from a first perspective; Figure 3 This is a schematic structural diagram of the solder paste printing unit of the present invention from a second viewing angle; Figure 4 is a schematic diagram of the expansion of the correction component of the present invention; Figure 5 It is a schematic diagram of the partial structure of the correction component of the present invention; Figure 6 This invention Figure 5 Schematic diagram of the cross-section structure in ; Figure 7 It is a schematic structural diagram of the supporting assembly of the present invention; Figure 8 Schematic diagram of the structure of the position limiting member of the present invention; Figure 9 It is a schematic diagram of the conveyor track structure of the present invention; Figure 10 It is a schematic diagram of the partial cross-sectional structure of the conveying track of the present invention; Figure 11 It is a schematic diagram of the partial structure of the reflow soldering part of the present invention; Figure 12 This invention Figure 11 Schematic diagram of the cross-section structure in.

[0018] The accompanying drawings are numeraled as follows: 1. base; 2. solder paste printing unit; 21. lifting assembly; 211. guide plate; 212. cylinder 1; 213. lifting plate; 22. correction assembly; 221. cylinder 2; 222. upper plate; 223. lower plate; 224. guide groove; 225. ejector rod; 226. trapezoidal plate; 227. L-shaped rod; 228. ring plate; 229. extrusion plate; 2210. limiting groove; 2211. rack; 2212. gear; 23. supporting assembly; 231. bracket; 232. notch; 233. carrier; 234. position limiting member; 2341. column; 2342. inner sleeve; 234 3. Press plate; 2344. Outer sleeve; 24. Extrusion assembly; 241. Material frame; 242. Push plate; 243. U-shaped shift plate; 244. Cylinder three; 245. Scraper; 3. Mounter; 4. Reflow soldering unit; 5. Conveyor track; 51. Track frame; 52. Conveyor roller; 53. Notch; 54. Limiting bar; 55. Rotary column; 56. Drive wheel; 57. Guide wheel; 6. Electric push rod one; 7. Baffle; 8. Electric push rod two; 9. L-shaped support plate; 10. Air curtain assembly; 101. Air trough; 102. Through slot; 103. Ventilation slot; 11. Air supply bin; 12. Air pump; 13. Vertical plate; 14. Disc. DETAILED DESCRIPTION

[0019] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making any creative efforts shall fall within the scope of protection of the present invention.

[0020] The circuit board welding equipment of the present invention belongs to the intelligent manufacturing equipment industry, is a part of the welding equipment, and is mainly used for precise printing of solder paste, patch and reflow soldering on rectangular circuit boards.

[0021] Example 1: Refer to the attached instructions Figure 1-Figure 2 and Figure 9, which is the first embodiment of the present invention, the present invention provides a circuit board precision welding equipment, including a base 1, a conveying track 5 fixedly installed on the top of the base 1, a placement machine 3 mounted on the outside of the conveying track 5, and a stopper for blocking the conveying of the circuit board is provided at the position of the top of the base 1 corresponding to the placement machine 3, wherein the stopper is composed of an electric push rod 1 6 fixedly installed on the top of the base 1 and a baffle 7 fixed at the telescopic end of the electric push rod 1 6. When the circuit board is conveyed to the placement station, the electric push rod 1 6 can be used to lift the baffle 7 to intercept the circuit board in the placement station to complete the placement of related components. After the placement is completed, the electric push rod 1 6 is used to drive the baffle 7 to descend to release the blocking state of the circuit board, and then the conveying track 5 is used to convey the circuit board with the placement completed to the reflow soldering station; The lifting assembly 21 is mounted on the top of the base 1, the correction assembly 22 is disposed at one end of the lifting assembly 21, the supporting assembly 23 is disposed on the top of the base 1 opposite the correction assembly 22, and the extrusion assembly 24 is disposed on the correction assembly 22. The lifting assembly 21, the correction assembly 22, the supporting assembly 23, and the extrusion assembly 24 are connected to the solder paste printing unit 2. The reflow soldering chamber is set up on the outside of the conveying track 5, and the preheating chamber, insulation chamber, reflow chamber and cooling chamber are distributed in sequence on the inside of the reflow soldering chamber along the conveying direction of the circuit board. The preheating chamber, insulation chamber, reflow chamber and cooling chamber together constitute the reflow soldering part 4. The top of the base 1 is provided with lifting parts for lifting the circuit board at the positions corresponding to the preheating chamber, insulation chamber, reflow chamber and cooling chamber. Each lifting part consists of an electric push rod 2 8 fixedly installed on the top of the base 1 and an L-shaped support plate 9 fixed at the telescopic end of the electric push rod 2 8. When the circuit board is conveyed to the preheating station, insulation station, reflow station and cooling station, the corresponding electric push rod 2 8 can be used to lift the L-shaped support plate 9 to lift the circuit board to the corresponding station for processing.

[0022] Furthermore, photoelectric sensors are installed on the conveyor track 5 at the positions corresponding to the placement machine 3, preheating chamber, insulation chamber, reflow chamber and cooling chamber, which are used to accurately detect whether the circuit board conveyed on the conveyor track 5 enters the designated processing station and control the corresponding electric push rod 1 6 or electric push rod 2 8 to move. Among them, the photoelectric sensor uses a micro photoelectric sensor with model EE-SG3, and the electric push rod 1 6 and the electric push rod 2 8 both use HB-DJ801 electric push rods.

[0023] It should be noted that in the process of soldering the circuit board, the circuit board with the relevant components to be soldered (referred to as the target circuit board, the same below) is placed in the solder paste printing part 2 for solder paste printing, and then the circuit board with the solder paste printing is pushed onto the conveying track 5. The conveying track 5 is used to sequentially convey it to the patch station, preheating station, insulation station, reflow station and cooling station to complete the corresponding processing, so as to achieve precise soldering of the components to the designated area on the circuit board.

[0024] Furthermore, if Figure 2-Figure 3 As shown, the lifting assembly 21 includes a cylinder 212 and a guide plate 211 fixed on the top of the base 1. The top of the guide plate 211 is movably sleeved with a lifting plate 213. The telescopic end of the cylinder 212 is fixedly connected to the lifting plate 213. The correction assembly 22 is installed at the bottom of one end of the lifting plate 213.

[0025] It should be noted that the present invention uses the control end to control the cylinder 1 212 to drive the lifting plate 213 equipped with the correction component 22 to move toward the supporting component 23, and uses the interlocking process of the two to complete the placement position correction of the target circuit board placed on the supporting component 23, so as to achieve accurate and smooth solder paste printing process.

[0026] Furthermore, if Figure 2 and Figure 4-Figure 6 As shown, the correction assembly 22 includes an upper plate 222 and a lower plate 223 arranged from top to bottom. Four support plates distributed in a rectangular array are fixedly connected between the upper plate 222 and the lower plate 223. Four correcting members distributed in a rectangular array are installed on the lower plate 223. The correcting members and the support plates are alternately and equidistantly distributed. A second cylinder 221 is fixedly installed between the upper plate 222 and the lifting plate 213. The telescopic end of the second cylinder 221 movably passes through the upper plate 222. The correcting member includes a cross-shaped guide groove 224 that passes through the lower plate 223, and a trapezoidal plate 226 is slidably connected inside the guide groove 224. The trapezoidal plate 226 is set to a right-angled trapezoidal structure. The cross-shaped structure of the guide groove 224 can ensure that the trapezoidal plate 226 undergoes stable linear translation movement inside the guide groove 224. A socket is provided on one side of the trapezoidal plate 226, and an end of the guide groove 224 near the center of the lower plate 223 is fixed with a plug rod that is movably inserted into the socket. The other side of the trapezoidal plate 226 is fixed with a top rod 225 that movably passes through the corresponding guide groove 224. A spring 1 is provided on the outside of the plug rod to fix the connection between the trapezoidal plate 226 and the corresponding inner side of the guide groove 224. When the trapezoidal plate 226 is in the position as shown in the figure, Figure 6 When in the position shown, the spring 1 is still in a compressed state, and the insertion rod is still kept inserted into the corresponding insertion hole.

[0027] Furthermore, the correction assembly 22 also includes a ring plate 228 sleeved on the outside of the lower plate 223 and an L-shaped rod 227 fixed on the upper surface of the lower plate 223 and facing the support plate. Four extrusion plates 229 are fixed on the inner side of the ring plate 228 and are arranged horizontally and coplanarly with the top rod 225. The inner side of the ring plate 228 is provided with four limiting grooves 2210 corresponding to the L-shaped rod 227. One end of the L-shaped rod 227 is movably inserted into the corresponding limiting groove 2210. The four L-shaped rods 227 distributed in a rectangular array can be used to support the ring plate. 228, ensure that the squeezing plate 229 and the ejector pin 225 maintain a horizontal and coplanar state, and realize that the squeezing plate 229 rotates with the ring plate 228 to squeeze the ejector pin 225, thereby adjusting the distance between the two trapezoidal plates 226 that are arranged opposite to each other, so as to adapt to target circuit boards of different sizes for correction, shaping, and clamping. A rack 2211 is fixedly provided on the upper surface of the ring plate 228, and a gear 2212 is meshed on the top of the rack 2211. A driving motor that rotates due to the driving gear 2212 is installed on the squeezing assembly 24; Specifically, one end of the squeezing plate 229 along the rotation direction of the ring plate 228 and close to the center point of the ring plate 228 is set as an inclined surface, and the inclined surface and the end of the squeezing plate 229 close to the corresponding push rod 2225 have a smooth transition.

[0028] It should be noted that, in the process of using the correction component 22 to correct and position the target circuit board placed on the supporting component 23, it is first necessary to adjust the size of the cavity surrounded by the four correction components according to the size of the target circuit board, that is, the drive motor installed on the extrusion component 24 drives the gear 2212 to rotate, and the engagement between the rotating gear 2212 and the rack 2211 on the upper surface of the ring plate 228 is used to allow the rotating gear 2212 to drive the ring plate 228 to rotate. In the process of the rotation of the ring plate 228, the extrusion plate 229 that rotates with it will gradually squeeze the ejector rod 225 at the corresponding position, thereby pushing the corresponding trapezoidal plate 226 along the guide groove 224 to compress the spring 1 at the position, so as to achieve the purpose of adjusting the size of the cavity surrounded by the four trapezoidal plates 226; Secondly, after completing the relative position adjustment of the four trapezoidal plates 226, the lifting plate 213 is pushed downward along the guide plate 211 by controlling the cylinder 1 212, thereby driving the upper plate 222 to move downward, and driving the correcting member on the lower plate 223 to move downward synchronously. When the trapezoidal plate 226 on the correcting member comes into contact with the target circuit board placed on the supporting assembly 23 during the downward movement, as the trapezoidal plate 226 continues to move downward, the oblique edge of the downward trapezoidal plate 226 will be used to squeeze the deviated target circuit board. After the discharge end of the downward extrusion assembly 24 contacts the upper surface of the target circuit board on the supporting assembly 23, the four trapezoidal plates 226 also descend to a state where the vertical short straight edges thereon are in contact with the corresponding sides of the target circuit board, thereby completing the correction and positioning of the target circuit board.

[0029] Furthermore, if Figure 2 and Figure 7-Figure 8 As shown, the supporting assembly 23 includes a bracket 231 fixed to the top of the base 1. A slot 232 is provided on the outer side of the bracket 231 at a position corresponding to each trapezoidal plate 226. The depth of the slot 232 is greater than the length of the guide groove 224 to ensure that the trapezoidal plate 226 can always pass through the corresponding slot 232 smoothly during the adjustment process. A carrier 233 is fixed to the top of the bracket 231. The target circuit board is overlapped on the upper surface of the carrier 233. Limiting members 234 are installed at the four corners of the carrier 233. The limiting member 234 includes a column 2341 fixed to the top of the lower plate 223, an inner sleeve 2342 is movably sleeved on the outer side of the top of the column 2341, an outer sleeve 2344 is movably sleeved on the outer side of the top of the inner sleeve 2342, the top of the outer sleeve 2344 is set as a hemispherical structure, a pressure plate 2343 is fixedly sleeved on the bottom end of the outer side of the inner sleeve 2342, a spring 2 is fixedly sleeved on the outer side of the inner sleeve 2342 for fixing the connection between the outer sleeve 2344 and the pressure plate 2343, and a spring 2342 is fixedly sleeved on the inner side of the inner sleeve 2342 for fixing the connection between the column 2341 and the outer side of the column 2341. The column 2341 and the spring three of the inner sleeve 2342, wherein the elastic coefficient of the spring two is greater than the elastic coefficient of the spring three, enable the correction component 22 to correct the target circuit board during the downward process, while the downward pressure plate 2343 will be used to press the target circuit board first, and then continue to press down to make the pressing port of the extrusion component 24 fit with the surface of the target circuit board. The design of the limiter 234 can effectively prevent the upward extrusion component 24 from sticking to the circuit board under the action of solder paste and moving upward synchronously.

[0030] Furthermore, a vertical plate 13 is fixed on the top of the bracket 231, and a rotating shaft that runs through the carrier 233 is rotatably installed on the vertical plate 13. A motor for driving the rotating shaft to rotate is fixedly installed on one side of the vertical plate 13. Discs 14 are fixedly sleeved on the outer sides of the rotating shaft at positions on both sides of the carrier 233. The circumferential side surface of the disc 14 is fixedly covered with a friction pad, wherein the outer side of the friction pad fits into the lower surface of the circuit board overlapped on the top of the carrier 233. The friction pad can be used to increase the contact static friction between the disc 14 and the circuit board, so that after the printing of the solder paste is completed, the rotating disc 14 can be used to drive the circuit board to accurately enter the interior of the conveying track 5. It should be noted that, in the process of using the correction component 22 to correct and position the target circuit board placed on the supporting component 23, when using the follow-down correcting member to correct and position the target circuit board placed on the carrier 233, the follow-down lower plate 223 will first contact the outer sleeve 2344. Since the elastic coefficient of spring two is greater than the elastic coefficient of spring three, the descending lower plate 223 will push the inner sleeve 2342 that descends synchronously with the outer sleeve 2344 to squeeze the spring three first, and the pressing plate 2343 will also descend synchronously with the inner sleeve 2342. Before the pressing plate 2343 moves downward and contacts the target circuit board, the trapezoidal plate in the downward process will complete the correction and positioning of the target circuit board. After the pressing plate 2343 moves downward and contacts the upper surface of the target circuit board, as the lower plate 223 continues to move downward, the bottom end of the trapezoidal plate 226 will be inserted into the corresponding notch 232 and continue to move downward along the notch 232. The descending pressing plate 2343 will push the corresponding outer sleeve 2344 downward to compress the spring 2 until the discharge end of the extrusion assembly 24 installed on the correction assembly 22 contacts the upper surface of the target circuit board. On the contrary, after the extrusion component 24 is used to complete the solder paste printing on the target circuit board, as the correction component 22 moves upward, the circuit board with the solder paste printing completed will be completely separated from the discharge end on the extrusion component 24 under the restriction of the pressure plate 2343, and then the pressure plate 2343 will be separated from the circuit board under the action of the compression restoring force of the corresponding spring three, and then the rotating disc 14 is used to push the circuit board with the solder paste printing completed to the conveying track 5, and the conveying track 5 is used to convey it to other processes for processing in sequence.

[0031] Furthermore, if Figure 2 and Figure 4-Figure 6The cam 243 is fixed to the bottom of the frame 241 and is secured to the bottom of the frame 241. The cam 243 is secured to the bottom of the frame 241 and is secured to the bottom of the frame 241. Figure 6 As shown), it can be used to scrape off the solder paste remaining on the surface of the U-shaped moving plate 243 that has slipped. In addition, a mechanical seal can be set at the position where the U-shaped moving plate 243 passes through the material frame 241 to avoid material leakage at the position where the U-shaped moving plate 243 passes through during the process of squeezing the solder paste through the push plate 242.

[0032] It should be noted that, in the initial state, the through-holes on the U-shaped shift plate 243 located in the inner area of ​​the material frame 241 and the through-holes at the bottom end of the material frame 241 maintain a one-to-one correspondence and a through-state, wherein, during the period of the downward movement of the correction component 22 and the buckling of the supporting component 23, when the deviation correction and positioning of the target circuit board are completed and the discharge end of the extrusion component 24 is brought into contact with the upper surface of the target circuit board, the correction component 22 stops descending, and then the push plate 242 is pushed downward by controlling the second cylinder 221, and the downward movement of the push plate 24 is utilized. 2 to squeeze the solder paste inside the material frame 241, allowing the solder paste to pass through the material hole and fall onto the upper surface of the target circuit board. In this process, the extrusion-type discharging method can help to discharge the air inside the material cavity formed between the discharge port of the extrusion component 24 and the upper surface of the target circuit board compared to the traditional scraper scraping method for printing solder paste, thereby avoiding the formation of cavities due to residual air during the process of printing the solder paste onto the upper surface of the target circuit board, thereby affecting the subsequent reflow soldering quality and further affecting the quality of the finished circuit board; After the printing of the solder paste is completed, the U-shaped moving plate 243 can be pushed to move by the cylinder three 244, so that the material holes on the U-shaped moving plate 243 located in the inner area of ​​the material frame 241 are completely offset from the material holes at the bottom of the material frame 241, thereby blocking the adhesion between the solder paste inside the material frame 2241 and the solder paste printed on the surface of the circuit board, and preventing the extrusion component 24 that moves upward with the correction component 22 from driving the solder paste printed on the target circuit board off the circuit board, thereby ensuring the printing quality of the solder paste.

[0033] Example 2: Refer to the attached instructions Figure 11-12 This embodiment is the second embodiment of the present invention. The difference between this embodiment and the first embodiment is that an air curtain assembly 10 is further provided on the inside of the reflow soldering chamber. The air curtain assembly 10 includes strips fixed on both sides of the inner cavity of the preheating chamber, the insulation chamber, the reflow chamber and the cooling chamber, and an air supply chamber 11 fixed at one end of the reflow soldering chamber. An air pump 12 is installed on the top of the air supply chamber 11.

[0034] Furthermore, each bar is provided with a wind slot 101 running through it horizontally, and the wind slots 101 on multiple bars arranged in a collinear manner on the inner side of the reflow soldering chamber are connected in sequence, and the wind slots 101 on both sides of the inner cavity of the reflow soldering chamber are staggered up and down, and one end of the wind slot 101 located on the inner side of the cooling chamber is connected to the air supply chamber 11, wherein the air outlets of the wind slots 101 located on the inner side of the preheating chamber, the insulation chamber and the reflow chamber are arranged in a constricted shape towards the direction of the air outlet, and the two bars on the inner side of the preheating chamber, the insulation chamber and the reflow chamber are provided with a through slot 102, and the two through slots 102 are staggered up and down, and a ventilation slot 103 connected to the corresponding through slot 102 is provided on the outer side of the reflow soldering chamber.

[0035] It should be noted that, in the process of sending the target circuit board with completed solder paste printing and related component placement into the reflow soldering chamber for preheating, heat preservation, reflow and cooling, the air can be continuously supplied to the air supply chamber 11 through the air pump 12, and the air inside the air supply chamber 11 will pass through the through air slots 101 into the areas where the preheating chamber, heat preservation chamber and reflow chamber are located. Under the pressure of continuous air supply, the air entering the air slots 101 will be discharged from the air outlets in the areas where the preheating chamber, heat preservation chamber and reflow chamber are located, and then pass through the corresponding through slots 102 and ventilation slots 103 in turn and be discharged to the outside of the reflow soldering chamber, thereby forming a double-layer air curtain structure at the material inlet ports in the areas where the preheating chamber, heat preservation chamber and reflow chamber are located, so as to reduce heat overflow in the areas where the preheating chamber, heat preservation chamber and reflow chamber are located, and reduce heat energy waste.

[0036] Example 3: Refer to the attached instructions Figure 9-10 This embodiment is the third embodiment of the present invention. What is different from the second embodiment is that the conveying track 5 includes two parallel track frames 51. The top ends of the opposite sides of the two track frames 51 are provided with a running groove. A plurality of conveying rollers 53 distributed at equal distances are rotatably installed inside the two running grooves. A transmission box is provided on the top ends of the opposite sides of the two track frames 51. A plurality of dynamic shafts fixedly connected to the corresponding conveying rollers 53 are rotatably installed inside the transmission box. A plurality of fixed shafts distributed at equal distances are also fixed inside the transmission box. Each dynamic shaft is arranged at a position between two adjacent fixed shafts. A transmission wheel 56 is fixedly sleeved on the outer side of each dynamic shaft. A guide wheel 57 is fixedly sleeved on the outer side of each fixed shaft. A transmission belt is wound between the transmission wheel 56 and the guide wheel 57 (see Figure 10), and one of the moving shafts is rotated by a motor installed on the outside of the corresponding track frame 51, wherein the positions corresponding to the preheating chamber, the insulation chamber, the reflow chamber and the cooling chamber on the track frame 51 are provided with through slots connected to the travel slots, so that the circuit board transported to the designated work station can be smoothly pushed into the corresponding processing area for corresponding processing.

[0037] Furthermore, if Figure 9 As shown, a limiting bar 54 is further provided inside the passage groove on the track frame 51, and a stud that movably passes through the corresponding track frame 51 and two guide columns are fixed on the opposite sides of the two limiting bars 54. The stud is threadedly connected to the track frame 51, and the part of the stud located on the outside of the track frame 51 is fixedly connected with a rotary column 55 for adjusting the distance between the two limiting bars 54. The spacing adjustment is carried out based on the result measured before printing solder paste on the circuit board. In addition, ball bearings are rollingly embedded on the opposite sides of the two limiting bars 54, so that the limiting bars 54 can be used to limit the circuit board in transportation while reducing the friction resistance from the limiting bars 54 during the transportation of the circuit board, thereby ensuring smooth transportation.

[0038] It should be noted that in the process of transporting the circuit boards using the conveyor track 5, the relative positions of the circuit boards are detected by photoelectric sensors installed at the positions of the placement machine 3, preheating bin, insulation bin, reflow bin and cooling bin, and the electric push rod 1 6 is controlled according to the data fed back by the photoelectric sensor to push the corresponding baffle 7 to block the circuit board, or the corresponding electric push rod 2 8 is controlled to push the corresponding L-shaped pallet 9 to block the circuit board, and the circuit board is lifted to the corresponding position for processing. Since the processing time of the circuit board in each position is different, the lifting action of each position is independently controlled.

[0039] In the above technical solution, each of the cylinders mentioned uses a single-acting cylinder with model DSA25N200; the air pump 12 mentioned uses a micro air pump with model PCF5015N; and the placement machine 3 mentioned uses a four-head flying placement machine with model BV-F452L.

[0040] Based on the above embodiment, the present invention further provides a circuit board precision welding process, which specifically includes the following steps: S1. Loading: The circuit board is placed on top of the carrier 233 by a robotic arm or manually, waiting for solder paste printing; S2. Printing solder paste: Cylinder 1 212 drives the lifting plate 213 downward, thereby driving the correction component 22 to move downward synchronously and mate with the supporting component 23 to correct the position of the circuit board. After the correction is completed, the solder paste is printed on the designated area on the circuit board by the extrusion component 24; S3, patch: push the circuit board with solder paste printed on it onto the conveyor track 5, and convey it to the area where the patch machine 3 is located to complete the patching of related components. S4, reflow soldering: the circuit board with the patch completed is transported to the reflow soldering area through the conveyor track 5 to complete the reflow soldering of the relevant components.

[0041] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention, and such changes and modifications fall within the scope of the invention as claimed.

Claims

1. A circuit board precision welding device, characterized in that: include: A base (1), wherein a conveying track (5) is fixedly mounted on the top of the base (1), a placement machine (3) is mounted outside the conveying track (5), and a stopper for blocking the conveying of a circuit board is provided at a position on the top of the base (1) corresponding to the placement machine (3); The solder paste printing unit (2) comprises a lifting assembly (21) mounted on the top of the base (1), a correction assembly (22) arranged at one end of the lifting assembly (21), a supporting assembly (23) arranged on the top of the base (1) and facing the correction assembly (22), and an extrusion assembly (24) arranged on the correction assembly (22); The reflow soldering section (4) comprises a reflow soldering chamber mounted on the outside of a conveying track (5), a preheating chamber, a heat preservation chamber, a reflow chamber and a cooling chamber sequentially distributed inside the reflow soldering chamber along the conveying direction of the circuit board, and a lifting member for lifting the circuit board is provided at positions on the top of the base (1) corresponding to the preheating chamber, the heat preservation chamber, the reflow chamber and the cooling chamber.

2. A circuit board precision welding device according to claim 1, characterized in that: The lifting assembly (21) comprises a cylinder 1 (212) and a guide plate (211) fixed on the top of the base (1); a lifting plate (213) is movably sleeved on the top of the guide plate (211); and a telescopic end of the cylinder 1 (212) is fixedly connected to the lifting plate (213).

3. The circuit board precision welding equipment according to claim 2, characterized in that: The correction assembly (22) includes an upper plate (222) and a lower plate (223) arranged from top to bottom. Four support plates distributed in a rectangular array are fixedly connected between the upper plate (222) and the lower plate (223). Four correction members distributed in a rectangular array are installed on the lower plate (223). The correction members and the support plates are alternately and equidistantly distributed. A second cylinder (221) is fixedly installed between the upper plate (222) and the lifting plate (213). The telescopic end of the second cylinder (221) movably passes through the upper plate (222).

4. The circuit board precision welding equipment according to claim 3, characterized in that: The correcting member comprises a guide groove (224) extending through the lower plate (223), a trapezoidal plate (226) being slidably connected to the inside of the guide groove (224), a socket being provided on one side of the trapezoidal plate (226), a plug rod being fixedly provided at one end of the guide groove (224) near the center of the lower plate (223) and being movably plugged into the socket, a top rod (225) being fixedly provided at the other side of the trapezoidal plate (226) and being movably inserted into the corresponding guide groove (224), and a spring being sleeved on the outer side of the plug rod for fixedly connecting the trapezoidal plate (226) and the inner side of the guide groove (224) corresponding thereto.

5. The circuit board precision welding equipment according to claim 4, characterized in that: The correction assembly (22) further comprises a ring plate (228) sleeved on the outside of the lower plate (223) and an L-shaped rod (227) fixed on the upper surface of the lower plate (223) and facing the support plate. Four extrusion plates (229) arranged in a horizontal and coplanar manner with the top rod (225) are fixedly provided on the inner side of the ring plate (228), and four limiting grooves (2210) corresponding to the L-shaped rods (227) are opened on the inner side of the ring plate (228). One end of the L-shaped rod (227) is movably inserted into the corresponding limiting groove (2210). A rack (2211) is fixed on the upper surface of the ring plate (228), and a gear (2212) is meshed at the top of the rack (2211). A driving motor that rotates due to the driving gear (2212) is installed on the extrusion assembly (24).

6. The circuit board precision welding equipment according to claim 4, characterized in that: The supporting assembly (23) includes a bracket (231) fixed to the top of the base (1), a slot (232) is provided on the outside of the bracket (231) at a position corresponding to each trapezoidal plate (226), a platform (233) is fixed on the top of the bracket (231), and limiting members (234) are installed at the four corners of the platform (233).

7. The circuit board precision welding equipment according to claim 6, characterized in that: The limiting member (234) includes a column (2341) fixed on the top of the lower plate (223); an inner sleeve (2342) is movably sleeved on the outer side of the top of the column (2341); an outer sleeve (2344) is movably sleeved on the outer side of the top of the inner sleeve (2342); a pressure plate (2343) is fixedly sleeved on the outer bottom end of the outer sleeve (2342); a second spring for fixedly connecting the outer sleeve (2344) and the pressure plate (2343) is sleeved on the outer side of the inner sleeve (2342); and a third spring for fixedly connecting the column (2341) and the inner sleeve (2342) is sleeved on the inner side of the inner sleeve (2342).

8. The circuit board precision welding equipment according to claim 5, characterized in that: The extrusion assembly (24) includes a material frame (241) fixed in a through-type manner at the center of the lower plate (223) and a push plate (242) fixed at the telescopic end of the second cylinder (221). The drive motor is fixed on the outside of the material frame (241). The bottom end of the outer side of the material frame (241) is movably connected with a U-shaped moving plate (243). The third cylinder (244) is fixedly installed between the inner end of the U-shaped moving plate (243) and the material frame (241). The area of ​​the U-shaped moving plate (243) located on the inner side of the material frame (241) and the bottom end of the material frame (241) are both penetrated by material holes. A scraper (245) is fixedly provided on the inner side of the U-shaped moving plate (243).

9. The circuit board precision welding equipment according to claim 1, characterized in that: An air curtain assembly (10) is further provided inside the reflow soldering chamber. The air curtain assembly (10) comprises strips fixed on both sides of the inner cavity of the preheating chamber, the heat preservation chamber, the reflow chamber, and the cooling chamber, and an air supply chamber (11) fixed at one end of the reflow soldering chamber. An air pump (12) is installed on the top of the air supply chamber (11); Each of the strips is provided with an air slot (101) running through it horizontally, and the air slots (101) on the multiple strips arranged in a collinear manner on the inner side of the reflow soldering chamber are sequentially connected, the air slots (101) on both sides of the inner cavity of the reflow soldering chamber are arranged in an up-down staggered manner, and one end of the air slot (101) located on the inner side of the cooling chamber is connected to the air supply chamber (11), and the preheating chamber, the insulation chamber and the two strips on the inner side of the reflow chamber are provided with a through slot (102), and the two through slots (102) are arranged in an up-down staggered manner. A ventilation slot (103) connected to the corresponding through slot (102) is provided on the outer side of the reflow soldering chamber.

10. A circuit board precision welding process, using a circuit board precision welding device as described in any one of Figures 1-9 to weld a circuit board, characterized in that: The specific steps are as follows: S1, loading: the circuit board is placed on the top of the carrier (233) by a robotic arm or manually, waiting for the printing of solder paste; S2. Printing solder paste: using the cylinder 1 (212) to drive the lifting plate (213) to move downward, thereby driving the correction component (22) to move downward synchronously and to complete the buckling with the supporting component (23), so as to achieve the correction of the position of the circuit board. After the correction is completed, the solder paste is printed on the designated area on the circuit board through the extrusion component (24); S3, patch: push the circuit board with the solder paste printed on it onto the conveyor track (5), and convey the circuit board to the area where the patch machine (3) is located under the conveyor track (5) to complete the patching of related components; S4, reflow soldering: the circuit board with the patch completed is transported to the reflow soldering area through the conveyor track (5) to complete the reflow soldering of the relevant components.

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