SMT reflow soldering equipment and method for PCB circuit board soldering

Abstract

The present invention discloses an SMT reflow soldering device and method for PCB circuit board welding, which relates to the field of reflow soldering technology, including a bearing seat, an air guide heating element is arranged on the outer side of the bearing seat, and an alternating support piece is installed on the inner side of the bearing seat. The present invention sets an alternating support piece, and the sleeve plate drives the plug plate to move up and down reciprocatingly through the rotation of the motor. When the plug plate moves up, the U-shaped slider moves toward the first piston cylinder, and at this time, the second guide roller will move to the inside of the second inclined section. When the plug plate moves down, the second guide roller first enters the horizontal section. As the U-shaped slider continues to move away from the first piston cylinder, the second guide plug moves down, so that the first support plate and the second support plate can alternately support the pad, so that the bottom of the pad can be prevented from being heated unevenly, so that the solder paste on the pad is fully melted, and the stability of the connection between the components and the pad is further improved.

Description

Technical Field

[0001] The invention relates to the technical field of reflow soldering, and in particular to an SMT reflow soldering device and method for soldering a PCB circuit board. Background Art

[0002] Reflow soldering is a specific process in the SMT process. It means heating air or nitrogen to a high enough temperature and blowing it toward the circuit board with components already mounted on it, so that the solder paste melts (the solder paste is generally a mixture of metal tin powder, flux and other chemicals, and the small particles return to a flowing liquid state after heating). In this way, the solder paste on the pad covers both sides of the component, so that the component pins are bonded to the pad. Finally, it solidifies after cooling air, allowing the electronic components pre-mounted on the pad to connect to the pad on the PCB.

[0003] During the reflow soldering process, it is crucial to heat the bottom of the pad. This is because the solder paste needs to reach a certain temperature to melt and form a good electrical connection with the pad and component pins. If the bottom of the pad is not heated enough, the solder paste may not be completely melted, resulting in poor welding or insufficient welding strength. Generally, during the reflow soldering process, the pad with the component is directly placed on the carrier plate, and then the carrier plate is placed on the conveyor belt of the reflow soldering machine. The conveyor belt allows the carrier plate to drive the pad through the preheating zone, constant temperature zone, welding zone, and cooling zone in the reflow soldering machine. However, in this process, part of the bottom of the pad is in contact with the carrier plate. During the heating process, the heating effect is poor at the position where the pad contacts the carrier plate, which affects the stability of the connection between the component and the pad. Summary of the invention

[0004] The purpose of the present invention is to provide an SMT reflow soldering device and method for PCB circuit board soldering in order to solve the problem that the heating effect at the contact position between the solder pad and the carrier plate is poor, which affects the connection stability between the component and the solder pad.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: an SMT reflow soldering device for PCB circuit board welding, comprising a bearing seat, a placing plate is installed on the top of the bearing seat, a positioning groove is opened on the top of the placing plate, a first guide plug that penetrates to the inner side of the bearing seat is inserted on the top of the positioning groove, a first supporting pallet located on the inner side of the positioning groove is installed on the top of the first guide block, a second guide block extending to the inner side of the bearing seat is inserted on the side of the first guide block close to the center of the placing plate, a second supporting pallet is installed on the top of the second guide block, an air guide heating element is arranged on the outer side of the bearing seat, and an alternating supporting element is installed on the inner side of the bearing seat.

[0006] As a further solution of the present invention: the number of the first supporting pallet and the number of the second supporting pallet are both two, and the two first supporting pallets and the two second supporting pallets are both symmetrically arranged along the vertical center axis of the placement plate.

[0007] As a further solution of the present invention: the alternating supporting member includes a first piston cylinder installed on the top of the inner wall of the bearing seat, a piston rod extending to the outside of the first piston cylinder is inserted into the interior of the first piston cylinder, a transition block is installed at the end of the piston rod away from the first piston cylinder, both sides of the transition block are rotatably connected with push-position transfer plates through a rotating shaft, the end of the push-position transfer plate away from the transition block is rotatably connected with a positioning block through a rotating shaft, one side of the positioning block is provided with a U-shaped slider slidably connected to the inner wall of the bearing seat, a U-shaped guide frame is provided on the top of the U-shaped slider, the U-shaped guide frame includes a first inclined section, a second inclined section, and a horizontal section, the bottom end of the first guide block is provided with a A second guide roller is installed on the inner side of the seat, and the first guide roller is installed on the bottom end of the second guide plug block. Both ends of the first guide roller and the second guide roller are slidably connected to the inner side of the U-shaped guide frame. A telescopic rod located on one side of the first piston cylinder is installed on the top of the inner wall of the bearing seat, and a second piston cylinder is installed on the bottom end of the telescopic rod. A motor is installed on the outer wall of the second piston cylinder, and a reciprocating screw is connected to the output end of the motor. A sleeve plate is sleeved on the reciprocating screw, and a rectangular guide block extending to the inner side of the second piston cylinder is installed on the top of the sleeve plate. A plug plate located on the inner side of the second piston cylinder is installed on the top of the rectangular guide block, and a hose connected to the first piston cylinder is provided on the top of the second piston cylinder.

[0008] As a further solution of the present invention: a buffer spring is arranged on the inner side of the telescopic rod.

[0009] As a further solution of the present invention: the air-conducting heating element includes an air storage bin installed on one side of the inner wall of the bearing seat, a push plug extending to the inner side of the air storage bin is installed on the side of the U-shaped slider away from the positioning block, an air intake check valve located on the outside of the bearing seat is installed on the air storage bin, an exhaust check valve located below the air intake check valve is installed on the air storage bin, a second ring connecting pipe is installed at one end of the air intake check valve, a first ring connecting pipe located on the outside of the bearing seat is installed at one end of the exhaust check valve, a vertical through pipe is installed on the top of the first ring connecting pipe, an exhaust frame is installed on the top of the vertical through pipe, the second ring connecting pipe is located above the exhaust frame, and an air intake hole is opened at the top of the second ring connecting pipe.

[0010] As a further solution of the present invention: the exhaust rack and the positioning slot are at the same horizontal height, and the length of the exhaust rack is equal to the length of the positioning slot.

[0011] As a further solution of the present invention: the length and width of the inner side of the second ring-connecting tube are greater than the length and width of the outer wall of the bearing seat, and there are multiple air suction holes, which are equidistantly distributed along the edge of the second ring-connecting tube.

[0012] As a further solution of the present invention: the width of the inner side of the U-shaped guide frame is equal to the diameter of the first guide roller and the second guide roller.

[0013] As a further solution of the present invention: a battery is installed on the inner wall of the supporting seat, and the battery is electrically connected to the motor through a wire.

[0014] The present invention also discloses a SMT reflow soldering method for PCB circuit board welding, which adopts the above-mentioned SMT reflow soldering device for PCB circuit board welding, and comprises the following steps:

[0015] S1: First, a steel mesh is opened according to the PCB board, and the mesh holes on the steel mesh correspond to the pads of the board. Then, solder paste is applied to make the pads evenly coated with solder paste. Then, components are placed on the pads. After placement, the pads with components are placed on the inner side of the positioning slots. At this time, the pads are supported by the cooperation between the first supporting plate, the second supporting plate and the alternating supporting member;

[0016] S2: placing the carrier on the conveyor belt in the reflow soldering machine;

[0017] S3: Start the alternating support member inside the bearing seat, and move the second support plate downward through the operation of the alternating support member. At this time, only the first support plate supports the pad. As the alternating support member continues to operate, the second support plate supports the pad again, and at the same time, the first support plate moves downward, so that the first support plate and the second support plate are alternately separated from the pad, so as to prevent a part of the bottom of the pad from being blocked;

[0018] S4: The conveyor belt of the reflow soldering machine is operated to make the soldering pad pass through the preheating zone, constant temperature zone, welding zone and cooling zone of the reflow soldering machine. In this process, the support parts and the air-conducting heating parts are alternately coordinated to make the hot air and cold air around the soldering pad flow quickly.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. By setting an alternating support piece, the sleeve plate drives the plug plate to move up and down reciprocatingly through the rotation of the motor. When the plug plate moves up, the U-shaped slider moves toward the first piston cylinder. At this time, the second guide roller will move to the inside of the second inclined section. At this time, only the second support plate supports the pad. When the plug plate moves down, the second guide roller first enters the horizontal section. At this time, the first support plate contacts the bottom of the pad again. As the U-shaped slider continues to move away from the first piston cylinder, the first guide roller will drive the second guide block to move down under the extrusion guide of the first inclined section. In this way, the first support plate and the second support plate can alternately support the pad, so as to prevent uneven heating at the bottom of the pad, so as to fully melt the solder paste on the pad, and further improve the stability of the connection between the components and the pad.

[0021] 2. By setting an air-conducting heating element, when the U-shaped slider moves toward the first piston cylinder, the push plug moves in the direction away from the exhaust one-way valve. At this time, the hot air or cold air around the bearing seat will enter the air storage chamber through the suction hole, the second ring connecting pipe, and the air intake one-way valve. When the U-shaped slider moves in the direction away from the first piston cylinder, the push plug will let the air in the air storage chamber pass through the exhaust one-way valve, the first ring connecting pipe, and the vertical through pipe into the exhaust rack, and then be discharged through the exhaust rack, so as to increase the fluidity of the air around the pad, and further improve the melting and cooling efficiency of the solder paste on the pad. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0023] Figure 2 It is a schematic diagram of the internal structure of the bearing seat of the present invention;

[0024] Figure 3 It is a schematic diagram of the connection between the transition block and the second piston connecting cylinder of the present invention;

[0025] Figure 4 It is a schematic diagram of the connection between the first piston cylinder and the second piston cylinder of the present invention;

[0026] Figure 5 It is a schematic diagram of the structure of the air-conducting heating element of the present invention;

[0027] Figure 6 This is a schematic diagram of the internal structure of the gas storage warehouse of the present invention;

[0028] Figure 7 It is a schematic diagram of the connection between the first supporting plate and the U-shaped sliding block of the present invention;

[0029] Figure 8 It is a schematic diagram of the internal structure of the second piston connecting cylinder and the telescopic rod of the present invention.

[0030] In the figure: 1, bearing seat; 2, placement plate; 3, positioning groove; 4, first support plate; 5, first guide plug; 6, second support plate; 7, second guide plug; 801, vertical through pipe; 802, exhaust frame; 803, first piston cylinder; 804, buffer spring; 805, push plug; 806, gas storage chamber; 807, transition block; 808, first ring tube; 809, second ring tube; 810, suction hole; 811, second piston cylinder; 812, U-shaped slide Block; 813, sleeve plate; 814, piston rod; 815, push-position transfer plate; 816, positioning block; 817, U-shaped guide frame; 8171, first inclined section; 8172, second inclined section; 8173, horizontal section; 818, first guide roller; 819, second guide roller; 820, hose; 821, telescopic rod; 822, motor; 823, plug plate; 824, rectangular guide block; 825, exhaust check valve; 826, intake check valve; 827, reciprocating screw. DETAILED DESCRIPTION

[0031] 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.

[0032] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "set" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal connection of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. The following is an explanation of an embodiment of the present invention based on the overall structure of the present invention.

[0033] See also Figures 1 to 8In an embodiment of the present invention, an SMT reflow soldering device for PCB circuit board welding includes a bearing seat 1, a placement plate 2 is installed on the top of the bearing seat 1, a positioning groove 3 is opened on the top of the placement plate 2, a first guide plug 5 that penetrates the inner side of the bearing seat 1 is inserted at the top of the positioning groove 3, a first supporting pallet 4 located on the inner side of the positioning groove 3 is installed on the top of the first guide plug 5, a second guide plug 7 extending to the inner side of the bearing seat 1 is inserted on the side of the first guide plug 5 close to the center of the placement plate 2, a second supporting pallet 6 is installed on the top of the second guide plug 7, an air guide heating element is arranged on the outer side of the bearing seat 1, and an alternating supporting element is installed on the inner side of the bearing seat 1.

[0034] In this embodiment: first, a steel mesh is opened according to the PCB board, and the mesh holes on the steel mesh are made to correspond to the pads of the board. Then, solder paste is brushed on the pads so that the pads are evenly coated with solder paste. Then, components are placed on the pads. After placement, the pads with components are placed on the inner side of the positioning slots 3. At this time, the pads are supported by the cooperation between the first supporting pallet 4, the second supporting pallet 6 and the alternating supporting parts. Then, the bearing seat 1 is placed on the conveyor belt in the reflow soldering machine, and the alternating supporting parts on the inner side of the bearing seat 1 are started at the same time. The second supporting pallet 6 is moved downward by the operation of the alternating supporting parts. At this time, only the first supporting pallet 4, the second supporting pallet 6 and the alternating supporting parts are supported. The plate 4 supports the soldering pad, and with the continuous operation of the alternating support member, the second support plate 6 supports the soldering pad again, and at the same time, the first support plate 4 moves downward, so that the first support plate 4 and the second support plate 6 are alternately separated from the soldering pad, so as to prevent part of the bottom of the soldering pad from being blocked, and the soldering pad passes through the preheating zone, constant temperature zone, welding zone, and cooling zone of the reflow soldering machine through the operation of the reflow soldering machine conveyor belt. In this process, the alternating support member and the air-conducting heating member cooperate to increase the fluidity of hot air and cold air around the soldering pad, so as to improve the melting and cooling efficiency of the solder paste on the soldering pad.

[0035] Please refer to Figure 1 , Figure 3 There are two first supporting plates 4 and two second supporting plates 6 , and the two first supporting plates 4 and the two second supporting plates 6 are symmetrically arranged along the vertical center axis of the placement plate 2 .

[0036] In this embodiment: by providing this structure, the first supporting plate 4 and the second supporting plate 6 support both ends of the pad, thereby improving the stability of the pad.

[0037] Please refer to Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 7The alternating supporting member includes a first piston cylinder 803 installed on the top of the inner wall of the bearing seat 1, a piston rod 814 extending to the outside of the first piston cylinder 803 is inserted inside the first piston cylinder 803, a transition block 807 is installed at the end of the piston rod 814 away from the first piston cylinder 803, both sides of the transition block 807 are rotatably connected with push-position transfer plates 815 through a rotating shaft, and the end of the push-position transfer plate 815 away from the transition block 807 is rotatably connected with a positioning block 816 through a rotating shaft, and a U-shaped slider 812 slidably connected to the inner wall of the bearing seat 1 is provided on one side of the positioning block 816, and a U-shaped guide frame 817 is provided on the top of the U-shaped slider 812. The U-shaped guide frame 817 includes a first inclined section 8171, a second inclined section 8172, and a horizontal section 8173, and the bottom end of the first guide plug block 5 is installed with a second guide roller located on the inner side of the bearing seat 1 819, a first guide roller 818 is installed at the bottom end of the second guide plug block 7, and both ends of the first guide roller 818 and the second guide roller 819 are slidably connected to the inner side of the U-shaped guide frame 817, a telescopic rod 821 located on one side of the first piston cylinder 803 is installed at the top of the inner wall of the bearing seat 1, a second piston cylinder 811 is installed at the bottom end of the telescopic rod 821, a motor 822 is installed on the outer wall of the second piston cylinder 811, a reciprocating screw 827 is connected to the output end of the motor 822, a sleeve 813 is sleeved on the reciprocating screw 827, a rectangular guide block 824 extending to the inner side of the second piston cylinder 811 is installed at the top of the sleeve 813, a plug plate 823 located on the inner side of the second piston cylinder 811 is installed at the top of the rectangular guide block 824, and a hose 820 connected to the first piston cylinder 803 is provided at the top of the second piston cylinder 811.

[0038] In this embodiment: when the carrier 1 is placed on the conveyor belt of the reflow soldering machine, the motor 822 is started, and the rotation of the motor 822 drives the sleeve plate 813 to drive the plug plate 823 to move up and down. When the plug plate 823 moves up, the aqueous solution inside the second piston cylinder 811 will enter the first piston cylinder 803 through the hose 820, so that the piston rod 814 drives the transition block 807 to move. At this time, the transition block 807 will drive the U-shaped slider 812 to move toward the first piston cylinder 803 through the push-position transfer plate 815 and the positioning block 816. At this time, the second guide roller 819 will move to the inside of the second inclined section 8172, so that the second guide roller 819 drives the first guide plug block 5 and the first support plate 4 to move downward under the extrusion and guidance of the second inclined section 8172, so as to separate the first support plate 4 from the welding pad. At this time, only the second The support plate 6 supports the pad, and when the plug plate 823 moves downward, the aqueous solution inside the first piston cylinder 803 will enter the second piston cylinder 811, so that the U-shaped slider 812 moves in the direction away from the first piston cylinder 803. During this process, the second guide roller 819 first enters the horizontal section 8173. At this time, the first support plate 4 contacts the bottom of the pad again. As the U-shaped slider 812 continues to move away from the first piston cylinder 803, the first guide roller 818 will drive the second guide plug 7 to move downward under the extrusion guidance of the first inclined section 8171, so as to separate the second support plate 6 from the pad, so that the first support plate 4 and the second support plate 6 can alternately support the pad, so as to prevent uneven heating of the bottom of the pad, so that the solder paste on the pad can be fully melted, further improving the stability of the connection between the component and the pad.

[0039] Please refer to Figure 8 A buffer spring 804 is arranged on the inner side of the telescopic rod 821 .

[0040] In this embodiment: this structure is provided to prevent the vibration generated by the motor 822 during operation from being transmitted to the support base 1, thereby further improving the stability of the pad placement, thereby preventing the components and pads from being misaligned due to the shaking of the motor 822 during operation.

[0041] Please refer to Figure 1 , Figure 2 , Figure 5 , Figure 6 , Figure 8The air-conducting heating element includes an air storage chamber 806 installed on one side of the inner wall of the bearing seat 1, a push plug 805 extending to the inner side of the air storage chamber 806 is installed on the side of the U-shaped slider 812 away from the positioning block 816, an air intake check valve 826 located on the outside of the bearing seat 1 is installed on the air storage chamber 806, an exhaust check valve 825 located below the air intake check valve 826 is installed on the air storage chamber 806, a second ring connecting pipe 809 is installed at one end of the air intake check valve 826, a first ring connecting pipe 808 located on the outside of the bearing seat 1 is installed at one end of the exhaust check valve 825, a vertical through pipe 801 is installed on the top of the first ring connecting pipe 808, an exhaust frame 802 is installed on the top of the vertical through pipe 801, the second ring connecting pipe 809 is located above the exhaust frame 802, and an air suction hole 810 is opened on the top of the second ring connecting pipe 809.

[0042] In this embodiment: when the U-shaped slider 812 moves toward the first piston cylinder 803, the push plug 805 moves in the direction away from the exhaust check valve 825. At this time, the hot air or cold air around the support seat 1 will enter the air storage chamber 806 through the suction hole 810, the second ring connecting pipe 809, and the air intake check valve 826. When the U-shaped slider 812 moves in the direction away from the first piston cylinder 803, the push plug 805 will allow the air in the air storage chamber 806 to enter the exhaust rack 802 through the exhaust check valve 825, the first ring connecting pipe 808, and the vertical through pipe 801, and then be discharged through the exhaust rack 802, so as to increase the fluidity of the air around the pad, and further improve the melting and cooling efficiency of the solder paste on the pad.

[0043] Please refer to Figure 1 The exhaust rack 802 and the positioning slot 3 are at the same horizontal height, and the length of the exhaust rack 802 is equal to the length of the positioning slot 3.

[0044] In this embodiment: by setting this structure, the air sprayed from the exhaust frame 802 is allowed to fully contact the bottom of the pad, thereby improving the uniformity of heating and cooling of the solder paste on the pad.

[0045] Please refer to Figure 1 The length and width of the inner side of the second ring connecting tube 809 are greater than the length and width of the outer wall of the supporting seat 1. There are multiple air suction holes 810, and the multiple air suction holes 810 are equidistantly distributed along the edge of the second ring connecting tube 809.

[0046] In this embodiment: this structure is provided to prevent the second ring connecting tube 809 from obstructing the placement of the soldering pad.

[0047] Please refer to Figure 7 The width of the inner side of the U-shaped guide frame 817 is equal to the diameter of the first guide roller 818 and the second guide roller 819.

[0048] In this embodiment: by setting this structure, when the U-shaped guide frame 817 moves horizontally, the second guide roller 819 and the first guide roller 818 only move back and forth upward or downward, thereby improving the stability of the movement of the first support plate 4 and the second support plate 6.

[0049] Please refer to Figure 1 , Figure 2 A battery is installed on the inner wall of the supporting base 1, and the battery is electrically connected to the motor 822 through a wire.

[0050] In this embodiment: this structure is provided to provide power to the motor 822, and at the same time facilitates the removal of the support base 1 from the conveyor belt in the reflow soldering machine.

[0051] In combination with the above-mentioned SMT reflow soldering equipment for PCB circuit board soldering, a SMT reflow soldering method for PCB circuit board soldering is provided, which specifically includes the following steps:

[0052] S1: First, a steel mesh is opened according to the PCB board, and the mesh holes on the steel mesh correspond to the pads of the board. Then, solder paste is applied to make the pads evenly coated with solder paste. Then, components are placed on the pads. After placement, the pads with components are placed on the inner side of the positioning slot 3. At this time, the pads are supported by the cooperation between the first supporting plate 4, the second supporting plate 6 and the alternating supporting member;

[0053] S2: placing the carrier 1 on a conveyor belt in a reflow soldering machine;

[0054] S3: Start the motor 822, and the rotation of the motor 822 drives the sleeve plate 813 to drive the plug plate 823 to move up and down. When the plug plate 823 moves up, the aqueous solution inside the second piston cylinder 811 will enter the first piston cylinder 803 through the hose 820, so that the piston rod 814 drives the transition block 807 to move. At this time, the transition block 807 will drive the U-shaped slider 812 to move toward the first piston cylinder 803 through the push-position transfer plate 815 and the positioning block 816. At this time, the second guide roller 819 will move to the inside of the second inclined section 8172, so that the second guide roller 819 drives the first guide plug block 5 and the first support plate 4 to move downward under the extrusion guide of the second inclined section 8172, so as to separate the first support plate 4 from the welding pad. At this time, only the second support plate 6 supports the welding pad. When the plug plate 823 moves downward, the aqueous solution inside the first piston cylinder 803 will enter the second piston cylinder 811, so that the U-shaped slider 812 moves in the direction away from the first piston cylinder 803. During this process, the second guide roller 819 first enters the horizontal section 8173. At this time, the first support plate 4 contacts the bottom of the pad again. As the U-shaped slider 812 continues to move away from the first piston cylinder 803, the first guide roller 818 will drive the second guide plug 7 to move downward under the extrusion and guidance of the first inclined section 8171, so as to separate the second support plate 6 from the pad. In this way, the first support plate 4 and the second support plate 6 can alternately support the pad, so as to prevent the bottom of the pad from being heated unevenly, so as to fully melt the solder paste on the pad, and further improve the stability of the connection between the components and the pad.

[0055] S4: The operation of the reflow soldering machine conveyor belt allows the soldering pad to pass through the preheating zone, constant temperature zone, welding zone, and cooling zone in the reflow soldering machine. When the U-shaped slider 812 moves toward the first piston cylinder 803, the push plug 805 moves in the direction away from the exhaust check valve 825. At this time, the hot air or cold air around the support seat 1 will enter the air storage chamber 806 through the suction hole 810, the second ring connecting pipe 809, and the air intake check valve 826. When the U-shaped slider 812 moves in the direction away from the first piston cylinder 803, the push plug 805 will allow the air in the air storage chamber 806 to enter the exhaust rack 802 through the exhaust check valve 825, the first ring connecting pipe 808, and the vertical through pipe 801, and then be discharged through the exhaust rack 802, thereby increasing the fluidity of the air around the soldering pad and further improving the melting and cooling efficiency of the solder paste on the soldering pad.

[0056] What is described above is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A SMT reflow soldering device for PCB circuit board soldering, comprising a carrier (1), characterized in that: A placement plate (2) is installed on the top of the bearing seat (1), a positioning groove (3) is opened on the top of the placement plate (2), a first guide plug (5) penetrating to the inner side of the bearing seat (1) is inserted at the top of the positioning groove (3), a first support plate (4) located on the inner side of the positioning groove (3) is installed on the top of the first guide plug (5), a second guide plug (7) extending to the inner side of the bearing seat (1) is inserted on the side of the first guide plug (5) close to the center of the placement plate (2), a second support plate (6) is installed on the top of the second guide plug (7), an air guide heating element is arranged on the outer side of the bearing seat (1), and an alternating support element is installed on the inner side of the bearing seat (1); The alternating support member comprises a first piston connecting cylinder (803) mounted on the top of the inner wall of the bearing seat (1); a piston rod (814) extending to the outside of the first piston connecting cylinder (803) is inserted into the interior of the first piston connecting cylinder (803); a transition block (807) is mounted on one end of the piston rod (814) away from the first piston connecting cylinder (803); two sides of the transition block (807) are rotatably connected to push-position transfer plates (815) via a rotating shaft; the push-position transfer plates (815) are away from the transition block (807). One end of the first guide block (5) is rotatably connected to a positioning block (816) via a rotating shaft, one side of the positioning block (816) is provided with a U-shaped slider (812) slidably connected to the inner wall of the bearing seat (1), the top of the U-shaped slider (812) is provided with a U-shaped guide frame (817), the U-shaped guide frame (817) comprises a first inclined section (8171), a second inclined section (8172), and a horizontal section (8173), the bottom end of the first guide plug block (5) is provided with a second guide roller (8171) located inside the bearing seat (1). 19), a first guide roller (818) is installed at the bottom end of the second guide plug (7), both ends of the first guide roller (818) and the second guide roller (819) are slidably connected to the inner side of the U-shaped guide frame (817), a telescopic rod (821) located on one side of the first piston cylinder (803) is installed at the top of the inner wall of the bearing seat (1), a second piston cylinder (811) is installed at the bottom end of the telescopic rod (821), and a motor (822) is installed on the outer wall of the second piston cylinder (811), The output end of the motor (822) is connected to a reciprocating screw (827), a sleeve plate (813) is sleeved on the reciprocating screw (827), a rectangular guide block (824) extending to the inside of the second piston cylinder (811) is installed on the top of the sleeve plate (813), a plug plate (823) located on the inside of the second piston cylinder (811) is installed on the top of the rectangular guide block (824), and a hose (820) connected to the first piston cylinder (803) is provided on the top of the second piston cylinder (811).

2. The SMT reflow soldering equipment for PCB circuit board soldering according to claim 1, characterized in that: The number of the first supporting pallet (4) and the second supporting pallet (6) is two, and the two first supporting pallets (4) and the two second supporting pallets (6) are symmetrically arranged along the vertical center axis of the placement plate (2).

3. The SMT reflow soldering equipment for PCB circuit board soldering according to claim 1, characterized in that: A buffer spring (804) is provided on the inner side of the telescopic rod (821).

4. The SMT reflow soldering equipment for PCB circuit board soldering according to claim 3, characterized in that: The air-conducting heating element comprises an air storage chamber (806) mounted on one side of the inner wall of the bearing seat (1); a push-in plug (805) extending to the inner side of the air storage chamber (806) is mounted on the side of the U-shaped sliding block (812) away from the positioning block (816); an air intake check valve (826) located outside the bearing seat (1) is mounted on the air storage chamber (806); an exhaust check valve (825) located below the air intake check valve (826) is mounted on the air storage chamber (806); A second ring connecting pipe (809) is installed at one end of the one-way valve (826); a first ring connecting pipe (808) located outside the support seat (1) is installed at one end of the exhaust one-way valve (825); a vertical through pipe (801) is installed at the top of the first ring connecting pipe (808); an exhaust frame (802) is installed at the top of the vertical through pipe (801); the second ring connecting pipe (809) is located above the exhaust frame (802); and an air intake hole (810) is opened at the top of the second ring connecting pipe (809).

5. The SMT reflow soldering equipment for PCB circuit board soldering according to claim 4, characterized in that: The exhaust rack (802) and the positioning slot (3) are at the same horizontal height, and the length of the exhaust rack (802) is equal to the length of the positioning slot (3).

6. The SMT reflow soldering equipment for PCB circuit board soldering according to claim 5, characterized in that: The length and width of the inner side of the second ring connecting tube (809) are both greater than the length and width of the outer wall of the bearing seat (1); a plurality of the air suction holes (810) are provided, and the plurality of air suction holes (810) are distributed at equal distances along the edge of the second ring connecting tube (809).

7. The SMT reflow soldering equipment for PCB circuit board soldering according to claim 1, characterized in that: The width of the inner side of the U-shaped guide frame (817) is equal to the diameter of the first guide roller (818) and the second guide roller (819).

8. The SMT reflow soldering equipment for PCB circuit board soldering according to claim 3, characterized in that: A storage battery is installed on the inner wall of the support seat (1), and the storage battery is electrically connected to the motor (822) via a wire.

9. A SMT reflow soldering method for PCB circuit board soldering, characterized in that: The SMT reflow soldering equipment for soldering a PCB circuit board according to any one of claims 1 to 8 comprises the following steps: S1: First, a steel mesh is opened according to the PCB board, and the mesh holes on the steel mesh correspond to the pads of the board. Then, solder paste is applied so that the pads are evenly coated with solder paste. Then, components are placed on the pads. After placement, the pads with components are placed on the inner side of the positioning groove (3). At this time, the pads are supported by the cooperation between the first supporting plate (4), the second supporting plate (6) and the alternating supporting member; S2: placing the carrier (1) on a conveyor belt in a reflow soldering machine; S3: activating the alternating support member inside the bearing seat (1), and moving the second support plate (6) downward through the operation of the alternating support member, at which time only the first support plate (4) supports the soldering pad, and as the alternating support member continues to operate, the second support plate (6) supports the soldering pad again, and at the same time, the first support plate (4) moves downward, so that the first support plate (4) and the second support plate (6) are alternately separated from the soldering pad, so as to prevent a part of the bottom of the soldering pad from being blocked; S4: The conveyor belt of the reflow soldering machine is operated to make the soldering pad pass through the preheating zone, constant temperature zone, welding zone and cooling zone of the reflow soldering machine. In this process, the support parts and the air-conducting heating parts are alternately coordinated to make the hot air and cold air around the soldering pad flow quickly.

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