PCB welding device and process thereof

Abstract

The invention relates to the field of PCB welding, and discloses a PCB welding device and a process thereof.The device comprises a welding table and a controller, a heater is arranged in the welding table, an automatic mechanical arm is arranged on one side of the welding table, and the automatic mechanical arm is used for placing a PCB to be welded on the welding table. An element tinning mechanism is further arranged on one side of the welding table, the element tinning mechanism is used for tinning element pins to be welded on the PCB, the element tinning mechanism comprises a base provided with a soldering flux pool and a soldering tin pool, and heaters are arranged in the soldering flux pool and the soldering tin pool; the electric displacement platform is used for driving an element to move in parallel, a clamping assembly is further installed on the electric displacement platform, and the clamping assembly is used for clamping a body of the element and exposing an element pin to be tinned; and the subsequent welding quality is improved by tinning the element pins in advance.

Description

Technical Field

[0001] The invention relates to the field of PCB board welding, and in particular to a PCB board welding device and a process thereof. Background Art

[0002] PCB soldering plays an extremely important role in the field of electronic manufacturing. Through soldering, the pins of electronic components are connected to the pads on the PCB to form a reliable electrical path, ensuring that the current can be accurately transmitted in the circuit, so that each electronic component can work together to realize the function of the entire circuit; at the same time, it provides mechanical support for the electronic components so that they can be firmly installed on the PCB; during the use of electronic products, it can withstand certain external forces and vibrations to ensure that the connection between the electronic components and the PCB will not loosen easily, thereby improving the stability and reliability of the product; finally, a good soldering connection can reduce the loss, distortion and interference during signal transmission, which is particularly important for the transmission of high-frequency and high-speed signals, and helps to ensure that the performance indicators of electronic products meet the design requirements.

[0003] The principle of soldering is roughly as follows: when the heated solder wire contacts the copper foil pads and electronic component pins on the PCB board, due to the surface tension of the solder and its affinity for metal, the solder will spread on the metal surface to form a thin layer of liquid solder. This process is called wetting. Only when the solder can wet the metal surface well can a firm weld be achieved. Subsequently, on the basis of wetting, the metal atoms such as tin and lead in the solder diffuse with the metal atoms on the copper foil pads and the electronic component pins at high temperatures to form a layer of intermetallic compounds at the interface. This compound has good conductivity and mechanical strength and is the key to achieving welding connections. Finally, after wetting and the formation of intermetallic compounds, heating is stopped and the solder begins to cool and solidify. During the cooling process, the state of the solder changes from liquid to solid, firmly connecting the electronic component pins to the PCB pads to form a stable welded joint.

[0004] For components with thicker pins or more serious oxidation, the pins can be tinned first, that is, the pins are dipped in flux and then tinned on the soldering iron tip so that a thin layer of tin is evenly coated on the surface of the pins. This can improve the success rate and quality of welding. However, there are still some defects in the process of pin tinning. For example, due to the lack of accurate feeding monitoring and adjustment mechanism in the control of tin layer thickness, the tin layer is often too thick or too thin. If the tin layer is too thick, it will not only waste solder, but also may cause short circuit due to excessive solder flow during subsequent welding. If the tin layer is too thin, the tinning effect cannot be guaranteed. Summary of the invention

[0005] The object of the present invention is to provide a PCB board welding device and a process thereof, so as to solve the technical problem that the tin layer is often too thick or too thin due to the lack of accurate feeding monitoring and adjustment mechanism in the control of the tin layer thickness.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A PCB board welding device comprises a welding platform and a controller, wherein a heater is arranged inside the welding platform, and an automatic mechanical arm is arranged on one side of the welding platform;

[0008] A component tinning mechanism is also provided on one side of the soldering station, and the component tinning mechanism is used to tin the component pins waiting to be soldered on the PCB board, and the component tinning mechanism includes:

[0009] A base is provided with a flux pool and a solder pool, wherein the flux pool and the solder pool are both equipped with a built-in heater;

[0010] The electric displacement platform is used to drive the component to move in parallel. A mounting frame is arranged on the electric displacement platform. A clamping assembly is arranged below the mounting frame. The clamping assembly is used to clamp the body of the component and expose the component pins to be tinned.

[0011] As a further technical solution, the component tinning mechanism further includes: a tin layer thickness control component; the tin layer thickness control component includes:

[0012] The laser distance measuring sensor is installed above the mounting frame and perpendicular to the pins of the component to be tinned. It is used to measure the distance from the tin layer surface of the component pin to the sensor in real time during the tinning process.

[0013] The micro weight sensor is set at the contact point between the clamping assembly and the component body, and can measure the weight change of the component before and after tinning;

[0014] An adjustable tin scraper is installed on one side of the solder pool and is located on the moving path of the component pins after tinning; the adjustable tin scraper is connected through an electric push rod, the electric push rod is set on the base, and the electric push rod is electrically connected to the controller; when the controller determines that the tin layer is too thick according to the data of the laser ranging sensor or the micro weight sensor, a command is sent to the electric push rod, and the electric push rod pushes the adjustable tin scraper to move to the component pins to scrape off excess solder, thereby controlling the thickness of the tin layer.

[0015] As a further technical solution, the clamping assembly includes: a bracket, an electric telescopic column is arranged at the bottom of the bracket, a horizontal frame is fixed at the bottom end of the electric telescopic column, a displacement groove is opened at the bottom of the horizontal frame, a screw rod is rotatably installed in the displacement groove, the screw rod is provided with two sections of spiral grooves with opposite rotation directions, sliders with corresponding rotation directions are arranged at both ends of the screw rod, the sliders are slidably installed in the displacement groove, and the top ends of the sliders are fixedly connected with clamping pieces, and the opposite sides of the two clamping pieces are provided with inclined surfaces;

[0016] An elastic rough layer is arranged on the side surface of the slider and the groove wall of the displacement groove, and the position of the slider is maintained by the friction force between the slider and the displacement groove, thereby providing the initial clamping force of the clamping member.

[0017] As a further technical solution, a linkage component is arranged between the clamping component and the tin layer thickness control component, and the linkage component is used to drive the clamping member of the clamping component to adjust the clamping force on the component body when the tin layer thickness control component is running.

[0018] As a further technical solution, the linkage assembly includes a transmission gear, which is fixedly connected to one end of the screw rod extending out of the displacement slot, and a rack is provided at the end of one of the electric push rods, and the transmission gear is meshed with the rack through a selection assembly.

[0019] As a further technical solution, the selection component includes a shift fork, the middle part of which is hingedly mounted on the top surface of the transverse frame through a torsion spring, one end of the shift fork is fixed with a magnet No. 1, and an electromagnet is arranged on the transverse frame. The electromagnet and the magnet No. 1 are magnetically attracted to each other, and the rack includes a linkage rod and a tooth portion, one end of the linkage rod is fixedly mounted on the end of the electric push rod, and the other end is hingedly connected to the end of the tooth portion through a torsion spring, a limit plate is arranged at the end of the linkage rod, and the limit plate is used to limit the rack to be able to deflect upward only, and the rack is initially in a horizontal state under the action of the torsion spring, and the electromagnet is electrically connected to the controller.

[0020] As a further technical solution, a magnetic baffle is provided at the bottom of the flux pool, and the magnetic baffle is connected to the spiral sleeve through a spring. A spiral rod is provided at the bottom end of the magnetic baffle, and the spiral rod passes downward through the spiral sleeve and is connected to circumferentially distributed paddles. The outer wall of the spiral sleeve is set on the pool wall of the flux pool through a fixing rod, and the magnetic baffle is in a facing position with the electromagnet.

[0021] As a further technical solution, the adjustable tin scraping plate is matched with the component pins, and a tin scraping portion is nested inside the adjustable tin hanging plate, and the tin scraping surface of the tin scraping portion is made of flexible material.

[0022] A PCB board welding process comprises the following steps:

[0023] S1, initially clamping the component through the clamping assembly;

[0024] S2. The electric displacement platform drives the clamping assembly and the component to move parallel to the top of the flux pool, and the electric telescopic column descends to immerse the component pins in the flux pool so that the pins are evenly coated with flux. After the coating is completed, the electric telescopic column rises, and the electric displacement platform drives the component to move toward the solder pool;

[0025] S3, the electric displacement platform moves the component to the top of the solder pool, and the electric telescopic column descends again, so that the component pins are immersed in the molten solder for tinning operation; during the tinning process, the laser ranging sensor continuously emits a laser beam and receives reflected light, measures the distance from the tin layer surface of the component pin to the sensor in real time, and transmits the data to the controller;

[0026] At the same time, the micro weight sensor measures the weight change of the component in real time and feeds back the weight data to the controller; the controller determines in real time whether the tin layer thickness meets the requirements based on the preset corresponding relationship between the tin layer thickness and the component weight, combined with the data of the laser ranging sensor and the micro weight sensor. If the controller determines that the tin layer is too thick, it enters S4, otherwise it enters S5;

[0027] S4, sending a command to the electric push rod controlling the adjustable tin scraper, the electric push rod pushes the adjustable tin scraper to move to the component pin, scrapes off the excess solder, and after the scraping is completed, the electric push rod retreats;

[0028] S5. The electric displacement platform moves the tinned component to the corresponding welding position of the PCB on the welding table. The electric telescopic column descends, aligns the component pins with the welding points on the PCB, and performs the welding operation. After the welding is completed, the electric telescopic column rises, the clamp releases the component, and the automatic robot arm removes the welded PCB to complete the welding.

[0029] Beneficial effects of the present invention:

[0030] (1) The present invention monitors the thickness of the tin layer in real time through a laser rangefinder sensor and a micro weight sensor, and uses an adjustable tin scraper to perform precise tin scraping, thereby effectively ensuring the consistency and accuracy of the tin thickness of the component pins, improving the welding quality, and reducing the occurrence of welding defects such as cold solder joints and short circuits.

[0031] (2) The clamping assembly in the present invention utilizes the elastic rough layer to provide a stable initial clamping force, and when the tin layer thickness control assembly is in operation, the clamping force is automatically adjusted through the linkage assembly to ensure that the position of the component is stable during the tinning and scraping process, thereby avoiding the tinning and welding effects affected by the shaking of the component, and improving the stability and reliability of the entire welding process. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The present invention will be further described below in conjunction with the accompanying drawings.

[0033] Figure 1 It is a partial three-dimensional schematic diagram of the component tinning mechanism in the present invention;

[0034] Figure 2 for Figure 1 A three-dimensional schematic diagram from another angle;

[0035] Figure 3 for Figure 2 A partial enlarged view of the middle part;

[0036] Figure 4 It is a bottom view structural schematic diagram of the clamping assembly in the present invention;

[0037] Figure 5 It is a structural schematic diagram of the linkage component in the present invention;

[0038] Figure 6 It is a schematic diagram of the structure in the flux pool of the present invention.

[0039] Description of the drawings: 1. Component tinning mechanism; 11. Flux pool; 12. Solder pool; 13. Base; 14. Mounting frame; 15. Clamping assembly; 151. Bracket; 152. Electric telescopic column; 153. Horizontal frame; 154. Displacement slot; 155. Screw rod; 156. Clamping piece; 157. Inclined surface; 16. Tin layer thickness control assembly; 161. Laser ranging sensor; 162. Adjustable tin scraper; 163. Electric push rod; 17. Linkage assembly; 171. Transmission gear; 172. Rack; 1721. Linkage rod; 1722. Tooth; 173. Selection assembly; 1731. Fork; 1732. Magnet No. 1; 1733. Electromagnet; 18. Magnetic baffle; 19. Spring; 20. Spiral sleeve; 21. Spiral rod; 22. Pick; 23. Fixed rod. DETAILED DESCRIPTION

[0040] 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.

[0041] See also Figure 1-Figure 6 As shown, the present invention is a PCB board welding device, comprising a welding platform and a controller, wherein a heater is arranged inside the welding platform, and an automatic mechanical arm is arranged on one side of the welding platform;

[0042] A component tinning mechanism 1 is also provided on one side of the soldering station, and the component tinning mechanism 1 is used to tin the component pins waiting to be soldered on the PCB board, and the component tinning mechanism 1 includes:

[0043] A base 13 is provided with a flux pool 11 and a solder pool 12, wherein the flux pool and the solder pool 12 are both equipped with a built-in heater;

[0044] The electric displacement platform is used to drive the component to move in parallel. A mounting frame 14 is arranged on the electric displacement platform. A clamping assembly 15 is arranged below the mounting frame 14. The clamping assembly 15 is used to clamp the body of the component and expose the component pins to be tinned.

[0045] In the present invention, the setting of the component tinning mechanism 1 provides a special working unit for tinning the component pins. The built-in heaters in the flux pool 11 and the solder pool 12 can keep the flux and solder at a suitable working temperature. The electric displacement platform drives the component to move in parallel, which is convenient for the conversion of components between different processes. The clamping assembly 15 can stably clamp the component body and expose the pins, which is convenient for the tinning operation.

[0046] The component tinning mechanism 1 further includes: a tin layer thickness control component 16; the tin layer thickness control component 16 includes:

[0047] The laser ranging sensor 161 is installed above the mounting frame 14 and is perpendicular to the pins of the component to be tinned. It is used to measure in real time the distance from the surface of the tin layer of the component pins to the sensor during the tinning process. When the component pins are immersed in the solder pool 12 for tinning, the laser ranging sensor 161 continuously emits a laser beam and receives reflected light, and obtains the tin layer thickness data by calculating the propagation time of the light, and transmits the data to the controller in real time.

[0048] The micro weight sensor is arranged at the contact part between the clamping assembly 15 and the component body, and can measure the weight change of the component before and after tinning; before tinning, the micro weight sensor records the initial weight of the component; during the tinning process, as the tin layer increases, the weight of the component gradually increases, and the weight change data is fed back to the controller in real time; the controller determines whether the tin layer thickness meets the requirements according to the preset corresponding relationship between the tin layer thickness and the component weight;

[0049] The adjustable tin scraper 162 is installed on one side of the solder pool 12 and is located on the moving path of the component pins after tinning; the adjustable tin scraper 162 is connected through an electric push rod 163, the electric push rod 163 is set on the base 13, and the electric push rod 163 is electrically connected to the controller; when the controller determines that the tin layer is too thick according to the data of the laser ranging sensor 161 or the micro weight sensor, it sends an instruction to the electric push rod 163, and the electric push rod 163 pushes the adjustable tin scraper 162 to move to the component pins to scrape off excess solder, thereby controlling the thickness of the tin layer.

[0050] In the present invention, by setting up the tin layer thickness control component 16, on the one hand, the laser ranging sensor 161 and the micro weight sensor jointly monitor the tin layer thickness of the component pins during the tinning process in real time, and obtain data from different angles, thereby improving the accuracy and reliability of the tin layer thickness monitoring; on the other hand, the adjustable tin scraper plate 162 cooperates with the controller and the electric push rod 163, and when it is detected that the tin layer is too thick, the excess solder can be scraped off in time, thereby realizing precise control of the tin layer thickness and ensuring the tinning quality of the component pins.

[0051] The clamping assembly 15 comprises: a bracket 151, an electric telescopic column 152 is arranged at the bottom of the bracket 151, a horizontal frame 153 is fixed to the bottom end of the electric telescopic column 152, a displacement groove 154 is provided at the bottom of the horizontal frame 153, a screw rod 155 is rotatably installed in the displacement groove 154, the screw rod 155 is provided with two sections of spiral grooves with opposite rotation directions, sliders with corresponding rotation directions are arranged at both ends of the screw rod 155, the sliders are slidably installed in the displacement groove 154, and the top ends of the sliders are fixedly connected with clamping members 156, and the opposite sides of the two clamping members 156 are provided with inclined surfaces 157;

[0052] An elastic rough layer is provided on the side of the slider and the groove wall of the displacement groove 154, and the friction between the slider and the displacement groove 154 is used to maintain the position of the slider, thereby providing the initial clamping force of the clamping member 156; it should be noted that: one end of the screw rod 155 is driven by a driving motor installed on the horizontal frame 153, and the other end is connected to the transmission gear 171. Under normal circumstances, the clamping assembly 15 is driven by the driving motor to clamp the component body, and the drive is stopped after completion. Then, under the action of the linkage assembly 17, the transmission gear 171 is selectively driven to increase the clamping force of the supporting assembly.

[0053] In the present invention, the lead screw 155 is initially driven to rotate by a driving motor, and the slider and the clamping member 156 are simultaneously driven to move toward each other, and the friction force of the elastic rough layer between the slider and the displacement groove 154 is used to provide a stable initial clamping force, so as to firmly clamp the component body and expose the pins, so as to prepare for the subsequent tinning operation; then, after applying the solder flux, it reaches above the solder pool 12, at which time the electric telescopic column 152 repeats the action to realize the tinning action of the component pins, and the component pins return to the initial position after tinning, and the tin layer thickness of the component pins during the tinning process is monitored in real time by the laser ranging sensor 161 and the micro weight sensor. Once it is determined that there is a problem with the tinning thickness, when the thickness is too thick, the tin layer thickness control component 16 is started, and when the thickness is too thin, the above-mentioned action is repeated until the tin layer thickness meets the requirements; when the tinning thickness is too thick, the electric push rod 163 pushes the adjustable scraper plate 162 to extend to the specified position, so that the excess solder is scraped off by rotation during the movement of the component pins, thereby improving the uniformity of the tin layer of the tinning;

[0054] Moreover, during the tinning process, the laser ranging sensor 161 continuously emits a laser beam and receives reflected light, and the micro weight sensor measures the weight change of the component in real time. The two sensors monitor the tin layer thickness of the component pins in real time from different angles, which greatly improves the accuracy and reliability of tin layer thickness monitoring. The controller makes a real-time judgment on the tin layer thickness based on the preset correspondence between the tin layer thickness and the component weight, providing an accurate basis for the subsequent tin layer thickness adjustment.

[0055] A linkage assembly 17 is provided between the clamping assembly 15 and the tin layer thickness control assembly 16 , and the linkage assembly 17 is used to drive the clamping member 156 of the clamping assembly 15 to adjust the clamping force on the component body when the tin layer thickness control assembly 16 is in operation.

[0056] The linkage assembly 17 includes a transmission gear 171, which is fixedly connected to one end of the screw rod 155 extending out of the displacement slot 154, and a rack 172 is provided at the end of one of the electric push rods 163. The transmission gear 171 is meshed with the rack 172 through a selection assembly 173.

[0057] The selection component 173 includes a fork 1731, the middle part of which is hingedly mounted on the top surface of the transverse frame 153 through a torsion spring, one end of the fork 1731 is fixed with a magnet No. 1732, and an electromagnet 1733 is arranged on the transverse frame 153. The electromagnet 1733 and the magnet No. 1 are magnetically attracted to each other, and the rack 172 includes a linkage rod 1721 and a tooth portion 1722, one end of the linkage rod 1721 is fixedly arranged on the end of the electric push rod 163, and the other end is hingedly connected to the end of the tooth portion 1722 through a torsion spring, and a limiting plate is arranged at the end of the linkage rod 1721, and the limiting plate is used to limit the rack 172 to only be able to deflect upward, and the rack 172 is initially in a horizontal state under the action of the torsion spring, and the electromagnet 1733 is electrically connected to the controller.

[0058] In the present invention, if the controller determines that the tin layer is too thick, it will immediately send instructions to the electric push rod 163 and the electromagnet 1733 that control the adjustable tin scraping plate 162; the electromagnet 1733 plays a role again, on the one hand, it rotates the fork 1731, so that the transmission gear 171 and the rack 172 are meshed. The rack 172 is relatively wide and is in a meshing state before the adjustable tin scraping plate 162 has completely scraped the tin of the component pins, so as to maintain the stability of the force of the clamping component body. When the scraping is completed, the electric push rod 163 quickly drives the rack 172 to withdraw, so as to stagger with the electric telescopic column 152 in time to prevent damage caused by the collision between the two. The linear motion of the electric push rod 163 can be converted into the rotation of the screw rod 155 through the transmission gear 171 through the linkage component 17;

[0059] On the other hand, the sliders at both ends of the screw rod 155 move toward each other in the displacement groove 154, driving the clamping piece 156 to increase the clamping force on the component body; thereby reflecting the close linkage effect between multiple mechanisms, enhancing the stability of the component during the tin scraping operation, and avoiding the problem of uneven tin scraping caused by component shaking; at the same time, the adjustable tin scraping plate 162 is pushed by the electric push rod 163, and the scraping part made of flexible and wear-resistant silicone material nested inside it can accurately fit the component pins, while effectively scraping off excess solder, protecting the component pins from damage, thereby ensuring the quality of tinning.

[0060] A magnetic baffle 18 is provided at the bottom of the flux pool 11, and the magnetic baffle 18 is connected to the spiral sleeve 20 through a spring 19. A spiral rod 21 is provided at the bottom of the magnetic baffle 18. The spiral rod 21 passes downward through the spiral sleeve 20 and is connected to a circumferentially distributed paddle 22. The outer wall of the spiral sleeve 20 is set on the pool wall of the flux pool 11 through a fixing rod 23, and the magnetic baffle 18 is in a facing position with the electromagnet 1733.

[0061] In the present invention, a stirring mechanism is added. When the electric displacement platform drives the component to move above the flux pool 11, when the flux coating operation is required, the controller energizes the electromagnet 1733. On the one hand, the electromagnet 1733 attracts the No. 1 magnet 1732 on the fork 1731 to rotate the fork 1731. At this time, the fork 1731 forms an inclined posture, thereby exposing part of the transmission gear 171. Under the current posture, the transmission gear 171 and the rack 172 can be meshed and transmitted at the specified position; if the electromagnet 1733 is powered off, the fork 1731 is in the initial position, and the transmission gear 171 is partially blocked. Even if the electric push rod 163 malfunctions, during the process in which the fork 1731 contacts the hinged tooth portion 1722 and forcibly pushes the tooth portion 1722 to deflect upward, It also prevents the transmission gear 171 and the rack 172 from meshing and transmitting, thereby preventing the tin layer thickness control component 16 from interfering with the clamping component 15; on the other hand, the electromagnet 1733 attracts the magnetic baffle 18 at the bottom of the flux pool 11, and the magnetic baffle 18 overcomes the pulling force of the spring 19 and moves upward, and the spiral rod 21 at its bottom end rotates in the spiral sleeve 20, driving the paddle 22 to rotate and stir the flux, and the existing power source of the electromagnet 1733 in the linkage component 17 is used to stir the flux, thereby ensuring the uniformity of the flux and improving the use effect of the flux, while avoiding the need for an additional power device, simplifying the device structure and reducing the cost; then, the electric telescopic column 152 descends and then rises to its original position, thereby achieving the purpose of immersing the component pins in the flux pool 11 and evenly applying the flux, and then performing the tinning action.

[0062] The adjustable tin scraping plate 162 is adapted to the component pins, and a tin scraping portion is nested inside the adjustable tin hanging plate, and the tin scraping surface of the tin scraping portion is made of flexible material.

[0063] The scraping surface of the scraping part is made of flexible and wear-resistant material, such as silicone, which can effectively scrape off excess solder without damaging component pins.

[0064] A PCB board welding process comprises the following steps:

[0065] S1, initially clamping the component by the clamping assembly 15;

[0066] S2, the electric displacement platform drives the clamping assembly 15 and the component to move parallel to the top of the flux pool 11, and the electric telescopic column 152 descends to immerse the component pins in the flux pool 11 so that the pins are evenly coated with flux; after the coating is completed, the electric telescopic column 152 rises, and the electric displacement platform drives the component to move to the solder pool 12;

[0067] S3, the electric displacement platform moves the component to the top of the solder pool 12, and the electric telescopic column 152 descends again, so that the component pins are immersed in the molten solder for tinning operation; during the tinning process, the laser ranging sensor 161 continuously emits a laser beam and receives reflected light, measures the distance from the surface of the tin layer of the component pin to the sensor in real time, and transmits the data to the controller;

[0068] At the same time, the micro weight sensor measures the weight change of the component in real time and feeds back the weight data to the controller; the controller determines in real time whether the tin layer thickness meets the requirement based on the preset correspondence between the tin layer thickness and the component weight, combined with the data of the laser ranging sensor 161 and the micro weight sensor. If the controller determines that the tin layer is too thick, it enters S4, otherwise it enters S5;

[0069] S4, sending a command to the electric push rod 163 controlling the adjustable tin scraping plate 162, the electric push rod 163 pushes the adjustable tin scraping plate 162 to move to the component pin, scrapes off the excess solder, and after the scraping is completed, the electric push rod 163 retreats;

[0070] S5. The electric displacement platform moves the tinned component to the corresponding welding position of the PCB board on the welding table, and the electric telescopic column 152 descends to align the component pins with the welding points on the PCB board to perform the welding operation; after the welding is completed, the electric telescopic column 152 rises, the clamping member 156 releases the component, and the automatic robot arm removes the welded PCB board to complete the welding.

[0071] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A PCB board welding device, comprising a welding platform and a controller, wherein a heater is arranged inside the welding platform, and an automatic mechanical arm is arranged on one side of the welding platform; It is characterized in that A component tinning mechanism (1) is also provided on one side of the soldering station. The component tinning mechanism (1) is used to tin component pins waiting to be soldered on the PCB board. The component tinning mechanism (1) comprises: A base (13) is installed with a flux pool (11) and a solder pool (12), wherein the flux pool (11) and the solder pool (12) are both equipped with a built-in heater; An electric displacement platform is used to drive a component to move in parallel. A mounting frame (14) is arranged on the electric displacement platform. A clamping assembly (15) is arranged below the mounting frame (14). The clamping assembly (15) is used to clamp the body of the component and expose the component pins to be tinned.

2. The PCB board welding device according to claim 1, characterized in that: The component tinning mechanism (1) further comprises: a tin layer thickness control component (16); the tin layer thickness control component (16) comprises: A laser distance measuring sensor (161) is installed above the mounting frame (14) and is perpendicular to the pins of the component to be tinned, and is used to measure in real time the distance from the surface of the tin layer of the pins of the component to the sensor during the tinning process; A micro weight sensor is arranged at the contact position between the clamping assembly (15) and the component body, and is capable of measuring the weight change of the component before and after tinning; An adjustable tin scraper (162) is installed on one side of the solder pool (12) and is located on the moving path of the component pin after tinning; the adjustable tin scraper (162) is connected via an electric push rod (163), the electric push rod (163) is arranged on the base (13), and the electric push rod (163) is electrically connected to a controller; when the controller determines that the tin layer is too thick based on data from a laser distance sensor (161) or a micro weight sensor, an instruction is sent to the electric push rod (163), and the electric push rod (163) pushes the adjustable tin scraper (162) to move to the component pin to scrape off excess solder, thereby controlling the thickness of the tin layer.

3. The PCB board welding device according to claim 2, characterized in that: The clamping assembly (15) comprises: a bracket (151), an electric telescopic column (152) is arranged at the bottom of the bracket (151), a horizontal frame (153) is fixed at the bottom end of the electric telescopic column (152), a displacement groove (154) is provided at the bottom of the horizontal frame (153), a screw rod (155) is rotatably installed in the displacement groove (154), the screw rod (155) is provided with two sections of spiral grooves with opposite rotation directions, sliders with corresponding rotation directions are arranged at both ends of the screw rod (155), the sliders are slidably installed in the displacement groove (154), and the top ends of the sliders are fixedly connected with clamping members (156), and the opposite sides of the two clamping members (156) are provided with inclined surfaces (157); An elastic rough layer is provided on the side surface of the slider and the groove wall of the displacement groove (154), and the position of the slider is maintained by utilizing the friction force between the slider and the displacement groove (154), thereby providing the initial clamping force of the clamping member (156).

4. The PCB board welding device according to claim 3, characterized in that: A linkage assembly (17) is provided between the clamping assembly (15) and the tin layer thickness control assembly (16), and the linkage assembly (17) is used to drive the clamping member (156) of the clamping assembly (15) to adjust the clamping force on the component body when the tin layer thickness control assembly (16) is in operation.

5. The PCB board welding device according to claim 4, characterized in that: The linkage assembly (17) comprises a transmission gear (171), the transmission gear (171) being fixedly connected to one end of the lead screw (155) extending out of the displacement slot (154), a rack (172) being provided at the end of one of the electric push rods (163), and the transmission gear (171) being meshed with the rack (172) via a selection assembly (173).

6. The PCB board welding device according to claim 5, characterized in that: The selection assembly (173) comprises a shift fork (1731), the middle part of which is hingedly mounted on the top surface of the transverse frame (153) via a torsion spring, one end of the shift fork (1731) is fixed with a first magnet (1732), an electromagnet (1733) is arranged on the transverse frame (153), the electromagnet (1733) and the first magnet are magnetically attracted to each other, and the rack (172) comprises a linkage rod (1721) and a tooth portion (1722), one end of the linkage rod (1721) is fixedly arranged on the end of the electric push rod (163), and the other end is hingedly connected to the end of the tooth portion (1722) through a torsion spring. A limit plate is arranged at the end of the linkage rod (1721), and the limit plate is used to limit the rack (172) to only be able to deflect upward. The rack (172) is initially in a horizontal state under the action of the torsion spring, and the electromagnet (1733) is electrically connected to the controller.

7. The PCB board welding device according to claim 6, characterized in that: A magnetic baffle (18) is arranged at the bottom of the flux pool (11), and the magnetic baffle (18) is connected to the spiral sleeve (20) via a spring (19). A spiral rod (21) is arranged at the bottom end of the magnetic baffle (18), and the spiral rod (21) passes downward through the spiral sleeve (20) and is connected to a circumferentially distributed paddle (22). The outer wall of the spiral sleeve (20) is arranged on the pool wall of the flux pool (11) via a fixing rod (23), and the magnetic baffle (18) is in a facing position with the electromagnet (1733).

8. The PCB board welding device according to claim 7, characterized in that: The adjustable tin scraping plate (162) is adapted to the component pins, and a tin scraping portion is nested inside the adjustable tin hanging plate, and the tin scraping surface of the tin scraping portion is made of flexible material.

9. A PCB board welding process, the process is applicable to the PCB board welding device according to any one of claims 1 to 8, characterized in that: The steps include: S1, initially clamping the component by means of a clamping assembly (15); S2, the electric displacement platform drives the clamping assembly (15) and the component to move parallel to the top of the flux pool (11), the electric telescopic column (152) descends, and the component pins are immersed in the flux pool (11) so that the pins are evenly coated with flux; after the coating is completed, the electric telescopic column (152) rises, and the electric displacement platform drives the component to move toward the solder pool (12); S3, the electric displacement platform moves the component to the top of the solder pool (12), and the electric telescopic column (152) descends again, so that the component pins are immersed in the molten solder for tinning operation; during the tinning process, the laser distance sensor (161) continuously emits a laser beam and receives reflected light, measures the distance from the surface of the tin layer of the component pin to the sensor in real time, and transmits the data to the controller; At the same time, the micro weight sensor measures the weight change of the component in real time and feeds back the weight data to the controller; the controller determines in real time whether the tin layer thickness meets the requirement based on the preset corresponding relationship between the tin layer thickness and the component weight, combined with the data of the laser distance sensor (161) and the micro weight sensor; if the controller determines that the tin layer is too thick, it enters S4, otherwise it enters S5; S4, sending a command to the electric push rod (163) controlling the adjustable tin scraping plate (162), the electric push rod (163) pushes the adjustable tin scraping plate (162) to move to the component pin, scrapes off the excess solder, and after the scraping is completed, the electric push rod (163) retreats; S5, the electric displacement platform moves the tinned component to the top of the corresponding welding position of the PCB board on the welding table, and the electric telescopic column (152) descends to align the component pins with the welding points on the PCB board to perform the welding operation; after the welding is completed, the electric telescopic column (152) rises, the clamping member (156) releases the component, and the automatic mechanical arm removes the welded PCB board to complete the welding.

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