Laser heating soft soldering equipment

Abstract

The present invention relates to the field of welding technology, and specifically to a laser heating soft soldering equipment. It includes a mounting frame, a Z-axis sliding mechanism is mounted on the mounting frame, a tin ball separation mechanism and an optical path system are mounted on the Z-axis sliding mechanism, the tin ball separation mechanism is connected to the optical path system, and a calibration system is mounted on the mounting frame corresponding to the optical path system; the optical path system includes a transmission optical fiber connected to a laser, and the output end of the transmission optical fiber is sequentially connected to a collimating lens and a focusing lens, and the tin ball separation mechanism can separate multiple tin balls one by one to the focal point under the focusing lens in the optical path system. The laser heating soft soldering method adopted in the present application not only does not need to contact the product during the welding process and has no stress on the product, but can also be used for miniaturized pads that are difficult to achieve with traditional methods, and has high energy utilization, is environmentally friendly and energy-saving.

Description

Technical Field

[0001] The invention relates to the technical field of welding, and in particular to a laser heating type soft soldering welding device. Background Art

[0002] Microelectronic welding technology mainly refers to the connection technology in the miniaturization design and manufacturing process of electronic components and circuits. Microelectronic welding technology has two purposes when connecting two materials. One is to obtain good conductivity, and the other is to obtain lasting and reliable mechanical connection strength. Soft soldering technology is mainly used in microelectronic welding technology. In the fields of electronic manufacturing and precision machining, soft soldering is a commonly used connection technology. The soft soldering method usually uses soldering iron welding and wave soldering.

[0003] Soldering with a soldering iron tip is done by using a soldering iron tip with an automatic tin wire feeder. The soldering iron tip can be heated by electricity, and there is a coating on the tip surface of the soldering iron tip. The coating contacts the tin wire, causing the tin wire to melt and flow to the pad, thus forming a weld. During the soldering process, the soldering iron tip needs to actually contact the pad, so stress and strain will inevitably be generated on the product. At the same time, since the soldering iron tip has a certain size, it is impossible to achieve welding on micro pads with a high density. In addition, the coating on the tip of the soldering iron tip will age with continuous use, and the aging of the coating will cause the effect to gradually deteriorate. Therefore, it is difficult to ensure the consistency of the soldering effect when the soldering iron tip is used in mass production.

[0004] The basic principle of wave soldering is to melt the tin alloy into liquid, and then pass through an electric pump or electromagnetic pump to form a wave crest shape. The high-temperature liquid tin maintains an inclined surface, and then the soldering surface of the plug-in board pre-coated with flux is directly contacted with the high-temperature liquid tin to achieve the purpose of soldering. During the wave soldering process, a large amount of tin contacts the product, which is very likely to cause a short circuit. Therefore, effective soldering cannot be achieved when the pad is miniaturized.

[0005] Therefore, how to achieve stable and reliable welding under the condition of miniaturization of the pad is an urgent problem to be solved by those skilled in the art. Summary of the invention

[0006] In order to achieve stable and reliable welding with miniaturized pads, the present application provides a laser heating soft soldering device.

[0007] The laser heating soldering equipment provided in this application adopts the following technical solution:

[0008] A laser heating type soft soldering equipment comprises a mounting frame, on which a Z-axis sliding mechanism is mounted, on which a solder ball separation mechanism and an optical path system are mounted, the solder ball separation mechanism is connected to the optical path system, and a calibration system is mounted on the mounting frame corresponding to the optical path system; the optical path system comprises a transmission optical fiber, the input end of the transmission optical fiber is connected to a laser, the output end of the transmission optical fiber is connected to a collimating lens barrel, a collimating lens is mounted inside the collimating lens barrel, a focusing lens is mounted on one end of the collimating lens barrel away from the transmission optical fiber, a first protective lens is fixedly and sealedly connected to the upper end of the focusing lens barrel, a focusing lens is sealed and slidably connected to the inside of the focusing lens barrel, the solder ball separation mechanism can separate a plurality of solder balls one by one to the focus under the focusing lens in the optical path system, the focusing lens barrel is connected to the solder ball separation mechanism with an adjustment component, and the adjustment component can adjust the position of the focus according to the working state of the solder ball separation mechanism.

[0009] Furthermore, the Z-axis sliding mechanism includes a Z-axis locking plate, a Z-axis motor is fixedly mounted on the Z-axis locking plate, a Z-axis guide rail is fixedly mounted on the Z-axis locking plate corresponding to the length direction of the Z-axis motor, a Z-axis screw rod is rotatably connected to the Z-axis guide rail, a Z-axis slider is slidably connected to the Z-axis guide rail, the Z-axis slider is threadedly connected to the Z-axis screw rod, the Z-axis screw rod is drivingly connected to the output shaft of the Z-axis motor, a Z-axis mounting plate is fixedly connected to the Z-axis slider, and the solder ball separation mechanism and the optical path system are mounted on the Z-axis mounting plate.

[0010] Furthermore, a manual slide fixing plate is fixedly installed on the Z-axis mounting plate, a Z-direction laser manual slide is fixedly installed on the manual slide fixing plate, a Y-direction laser manual slide is installed on the Z-direction laser manual slide, an X-direction laser manual slide is installed on the Y-direction laser manual slide, a collimating lens barrel clamping mechanism is installed on the X-direction laser manual slide, and the collimating lens barrel is installed on the collimating lens barrel clamping mechanism.

[0011] Furthermore, the solder ball separation mechanism includes a separation mechanism mounting plate fixedly mounted on the Z-axis mounting plate, the separation mechanism mounting plate being provided with an upper component laser through hole corresponding to the focusing mirror, a lower cover plate being fixedly and sealedly mounted on the bottom surface of the separation mechanism mounting plate, a lower component laser through hole being provided on the lower cover plate corresponding to the upper component laser through hole, a turntable being rotatably connected between the lower cover plate and the separation mechanism mounting plate, a solder ball conveying hole being provided on the turntable, a ball storage groove being provided on the separation mechanism mounting plate corresponding to the solder ball conveying hole, the inside of the ball storage groove being filled with solder balls, a solder ball dropping hole being provided on the lower cover plate corresponding to the solder ball conveying hole, and a nozzle assembly being fixedly connected on the lower cover plate corresponding to the solder ball dropping hole.

[0012] Furthermore, the nozzle assembly includes a nozzle base, which is fixedly connected to the bottom surface of the lower cover plate, and a nozzle is detachably connected to the nozzle base. A laser channel corresponding to the laser through hole of the lower assembly is opened on the nozzle base, and a tin ball sliding channel is opened on the nozzle base corresponding to the tin ball dropping hole. The tin ball sliding channel is connected to the laser channel, and the laser channel is coaxially connected to the nozzle.

[0013] Furthermore, a rotating shaft is connected to the separation mechanism mounting plate in a sealing rotation corresponding to the turntable, the rotating shaft is fixedly connected to the turntable, and one end of the rotating shaft away from the turntable is transmission-connected to a rotating motor, and the rotating motor is fixedly mounted on the Z-axis mounting plate.

[0014] Furthermore, a protective mirror frame is sealably installed on the separation mechanism mounting plate at a position corresponding to the laser through-hole of the upper component, a protective mirror is sealably installed inside the protective mirror frame, an air inlet hole is opened on the separation mechanism mounting plate, an air inlet channel is opened on the nozzle base corresponding to the air inlet hole, the air inlet channel is connected to the laser channel, a gas connector is fixedly and sealably installed on the separation mechanism mounting plate corresponding to the air inlet hole, and a pressure gauge, a proportional valve, a solenoid valve, an oil mist separator, and an air source are sequentially connected to the end of the gas connector away from the separation mechanism mounting plate.

[0015] Furthermore, the adjustment component includes a mounting sleeve, which is fixedly mounted inside the focusing lens frame, the lower end of the mounting sleeve is fixedly and sealedly connected with a first protective lens, the focusing lens is sealingly and slidably connected inside the mounting sleeve, a return spring is abutted and connected between the upper end of the mounting sleeve and the focusing lens, an intake pipe connected to the mounting sleeve is fixedly connected at a position between the first protective lens and the focusing lens on the focusing lens frame, an exhaust pipe connected to the laser through hole of the lower component is installed on the side of the lower cover plate, and the other end of the intake pipe is sealed and fixedly connected to the exhaust pipe; a pressure difference sensor is also connected to an end of the exhaust pipe away from the lower cover plate, the pressure difference sensor is connected to a control program, the control program is connected to the laser control, and the pressure difference sensor is connected to the control program, the control program is connected to the laser control.

[0016] Furthermore, the calibration system includes a calibration system mounting base plate, on which a laser energy meter bracket and a contact displacement sensor bracket are mounted, a laser energy meter is mounted on the laser energy meter bracket, a contact displacement sensor is mounted on the contact displacement sensor bracket, a laser displacement sensor bracket is fixedly mounted on the Z-axis mounting plate, and a laser displacement sensor is fixedly mounted on the laser displacement sensor bracket corresponding to the laser energy meter.

[0017] Furthermore, the solder ball is configured as a spherical solder, the diameter of the solder ball is between 50um and 2000um, and the diameter tolerance of the ball is controlled within ±1-3%.

[0018] Beneficial effects achieved:

[0019] 1. The laser heating soft soldering method adopted in this application not only does not need to contact the product and has no stress on the product during the welding process, but also can accurately control the heat delivered to the product to be welded. On the one hand, it has high energy utilization rate and is environmentally friendly and energy-saving; on the other hand, it avoids scalding and burns to the welded product caused by excessive heat, and adverse conditions such as lack of solder fluidity and insufficient solder pads due to insufficient heat.

[0020] 2. This application uses spherical solder with a ball diameter of 50um-2000um, which has wide applicability and covers most practical needs. The diameter of the solder ball is as small as 50um, which can be used for miniaturized pads that are difficult to achieve with traditional methods. It has high compatibility with the miniaturization and complexity of the products to be welded, and can also accurately spray spherical solder for the three-dimensional structure of the products to be welded, thereby solving the welding problem of three-dimensional structure products.

[0021] 3. During the welding process, this application uses high-purity nitrogen or argon as an auxiliary inert gas to reduce oxidation during welding heating, solder melting, etc., thereby improving welding quality and reliability.

[0022] 4. In traditional welding methods, flux is required. When heated, flux easily forms gas. If the gas cannot completely escape from the solder, or partially remains in the solder, bubbles and voids will exist in the solder joint after cooling, causing defects. If the flux escapes quickly in the form of airflow, it is easy to cause splashing, and splashing to the surrounding pads can easily cause contamination or even short circuits. The present application uses a laser to directly heat the spherical solder. The spherical solder directly completes the heating-melting-resolidification process on the surface of the pad. There is no need to pre-place flux on the surface of the pad, which not only reduces the equipment and process of applying flux, but also ensures the welding quality and reduces the equipment and process of cleaning flux.

[0023] 5. This application uses laser direct heating, and the laser not only has a long life, stable performance, and low cost; and the method of using laser for heating only requires adjusting the output power and light output time to control the output heat, the method is simple and easy to adjust. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present application.

[0025] Figure 2It is a schematic diagram of the structural decomposition of the Z-axis sliding mechanism in one embodiment of the present application.

[0026] Figure 3 It is a schematic diagram of the structural decomposition of the optical path system in one embodiment of the present application.

[0027] Figure 4 It is a structural schematic diagram of a solder ball separation mechanism in an embodiment of the present application.

[0028] Figure 5 It is a schematic diagram of the structural decomposition of the upper component in one embodiment of the present application.

[0029] Figure 6 It is a schematic diagram of the structural decomposition of the lower components in one embodiment of the present application.

[0030] Figure 7 It is a schematic diagram of the structural decomposition of a rotating component in an embodiment of the present application.

[0031] Figure 8 It is a schematic diagram of the structural decomposition of the nozzle assembly in one embodiment of the present application.

[0032] Fig. 9 It is a schematic cross-sectional structural diagram of an adjustment component in one embodiment of the present application.

[0033] Fig.10 It is a schematic diagram of the structural decomposition of a calibration system in one embodiment of the present application.

[0034] Explanation of reference numerals: 100, solder ball separation mechanism; 110, upper component; 1101, bin cover; 1102, ball storage bin; 1103, ball storage tank; 1104, upper component laser through hole; 1106, air inlet hole; 1107, gas connector; 1108, first detection hole; 1109, shaft mounting hole; 1112, optical fiber sensor receiving end; 1113, separation mechanism locking hole; 1114, separation mechanism mounting plate; 120, lower component; 1201, annular pad; 1204, lower cover; 1205, solder ball drop hole; 1206, lower component laser through hole; 1207, second detection hole; 1210, solder ball runway; 1211, optical fiber sensor transmitting end; 1212, exhaust pipe; 130, rotating assembly; 1301, rotating motor; 1302, first coupling; 1303, rotating shaft; 1304, turntable; 1308, turntable detection hole; 1309, solder ball conveying hole; 140, nozzle assembly; 1401, nozzle base; 1403, nozzle nut; 1404, nozzle; 1405, laser channel; 1406, air inlet channel; 1407, solder ball sliding channel; 200, optical path system; 2 01, transmission optical fiber; 202, collimator; 203, collimator barrel; 204, collimator barrel clamping mechanism; 205, X-direction laser manual slide; 206, Y-direction laser manual slide; 207, Z-direction laser manual slide; 208, focusing mirror; 209, focusing mirror frame; 210, protective mirror; 211, protective mirror frame; 212, divergent beam; 213, parallel beam; 214, focusing beam; 215, focus; 216, manual slide fixing plate; 217, first protective mirror; 218, reset spring; 219, air inlet pipe; 220, installation sleeve ; 300, adjustment component; 400, Z-axis sliding mechanism; 401, Z-axis locking plate; 402, Z-axis motor; 403, Z-axis coupling; 404, Z-axis screw; 405, Z-axis slider; 406, Z-axis guide rail; 407, Z-axis mounting plate; 500, calibration system; 501, laser energy meter; 502, contact displacement sensor; 503, laser displacement sensor; 504, laser energy meter bracket; 505, contact displacement sensor bracket; 506, laser displacement sensor bracket; 507, calibration system mounting base; 600, mounting rack. DETAILED DESCRIPTION

[0035] The following is combined with Figure 1-10 This application is described in further detail.

[0036] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying 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 used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0037] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0038] The embodiment of the present application discloses a laser heating soft soldering device.

[0039] Please refer to Figure 1 In one embodiment of the present application, a laser heating soft soldering equipment includes a mounting frame 600, a Z-axis sliding mechanism 400 is mounted on the mounting frame 600, a solder ball separation mechanism 100 and an optical path system 200 are mounted on the Z-axis sliding mechanism 400, the solder ball separation mechanism 100 and the optical path system 200 are connected, and a calibration system 500 is mounted on the mounting frame 600 corresponding to the optical path system 200.

[0040] Please refer to Figure 1 and Figure 2 In one embodiment of the present application, the Z-axis sliding mechanism 400 includes a Z-axis locking plate 401, which is fixedly mounted on the mounting frame 600 by means of screw locking, a Z-axis motor 402 is fixedly mounted on the Z-axis locking plate 401, a Z-axis coupling 403 is transmission-connected to the output shaft of the Z-axis motor 402, a Z-axis guide rail 406 is fixedly mounted on the Z-axis locking plate 401 in a length direction corresponding to the Z-axis motor 402, a Z-axis screw rod 404 is rotationally connected to the Z-axis guide rail 406, a Z-axis slider 405 is slidingly connected to the Z-axis guide rail 406, the Z-axis slider 405 is threadedly connected to the Z-axis screw rod 404, the Z-axis screw rod 404 is transmission-connected to the Z-axis coupling 403, a Z-axis mounting plate 407 is fixedly connected to the Z-axis slider 405, and the solder ball separation mechanism 100 and the optical path system 200 are mounted on the Z-axis mounting plate 407.

[0041] Please refer to Figure 1 and Figure 3 In one embodiment of the present application, a manual slide fixing plate 216 is fixedly installed on the Z-axis mounting plate 407, and a Z-direction laser manual slide 207 is fixedly installed on the manual slide fixing plate 216. A Y-direction laser manual slide 206 is installed on the Z-direction laser manual slide 207, and an X-direction laser manual slide 205 is installed on the Y-direction laser manual slide 206. A collimating lens barrel clamping mechanism 204 is installed on the X-direction laser manual slide 205, and the optical path system 200 is installed on the collimating lens barrel clamping mechanism 204.

[0042] Please refer to Figure 1 and Figure 3 In one embodiment of the present application, the optical path system 200 includes a transmission optical fiber 201, the input end of the transmission optical fiber 201 is connected to a laser, the output end of the transmission optical fiber 201 is connected to a collimating lens barrel 203, a collimating lens 202 is installed inside the collimating lens barrel 203, the collimating lens barrel 203 is fixedly installed on a collimating lens barrel clamping mechanism 204, and a focusing lens frame 209 is mounted on one end of the collimating lens barrel 203 away from the transmission optical fiber 201, and a focusing lens 208 is installed inside the focusing lens frame 209.

[0043] In a specific embodiment of the present application, a laser refers to a device that generates a laser beam, and the laser includes a semiconductor laser and a fiber laser; the wavelength range of the laser is between 400nm-1100nm, and according to the wavelength, the lasers specifically include blue lasers, red lasers, and near-infrared lasers, and the specific wavelengths are 450nm, 808nm, 915nm, 975nm, 1060nm, 1070nm, and 1080nm; according to the operating mode of the laser, the laser includes lasers in continuous operating mode and pulsed operating mode.

[0044] In a specific embodiment of the present application, the transmission optical fiber 201 refers to an optical fiber. The laser beam generated by the laser is focused and coupled to the transmission optical fiber. The laser energy can be transmitted in the transmission optical fiber. Since the transmission optical fiber has a certain flexibility, it is convenient to transmit the laser energy to the position that needs to be processed during equipment integration.

[0045] In a specific embodiment of the present application, the collimator 202 is disposed at the end of the transmission optical fiber 201, and is capable of appropriately converging the divergent light beam emitted from the transmission optical fiber 201 to form a parallel light beam. The collimator 202 is a plano-convex lens, and its convex surface faces the incident direction of the light beam. It is understandable that in other embodiments of the present application, the collimator 202 may also be a double convex lens. The lens material of the collimator 202 is configured as quartz or glass, and the upper and lower surfaces of the lens are coated with an anti-reflection film for the wavelength of the laser used to increase the transmittance of the laser and reduce the laser loss.

[0046] In a specific embodiment of the present application, the focusing mirror 208 refers to focusing a parallel light beam to obtain a focused light beam. The focus of the focused light beam is the position with the highest laser energy density, and the vicinity of this position is generally used for laser processing. In the present invention, the tin ball (spherical solder) is also heated by a high-density laser near the focal position of the focused light beam. The focusing mirror 208 is configured as a plano-convex lens, with its plane facing the incident direction of the light beam. Of course, in other embodiments of the present application, the focusing mirror 208 can also be configured as a biconvex lens. The material of the focusing mirror 208 is generally quartz or glass, and the upper and lower surfaces of the focusing lens are coated with an anti-reflection film for the wavelength of the laser used to increase the transmittance of the laser and reduce the laser loss. The focal length of the focusing mirror is determined according to the diameter of the tin ball. After focusing, the beam size at the focal position is equivalent to the diameter of the tin ball used, so that the laser energy is irradiated to the surface of the tin ball as evenly as possible. The focal length range of the focusing mirror is between 30mm and 150mm.

[0047] In a specific implementation of the present application, the focusing mirror 208 is locked on the collimating lens barrel 203 via a focusing mirror frame 209 . When the focusing mirror 208 with a different focal length needs to be replaced, the focusing mirror 208 can be conveniently replaced by disassembling the focusing mirror frame 209 .

[0048] Please refer to Figure 3 In one embodiment of the present application, the divergent light beam 212 emitted by the transmission optical fiber 201 will become a parallel light beam 213 after passing through the collimating lens 202, and the parallel light beam 213 will become a focused light beam 214 after passing through the focusing lens 208, and the focused light beam 214 will converge into a focal point 215.

[0049] During the working process, the role of the X-direction laser manual adjustment slide 205 and the Y-direction laser manual adjustment slide 206 in the working process is to achieve fine-tuning of the horizontal position of the collimating lens barrel 203 through manual adjustment, thereby driving the focus 215 where the focusing light beam 214 converges to move on the XY horizontal plane, so that the focus 215 can accurately hit the solder ball that needs to be heated; the role of the Z-direction laser manual adjustment slide 207 is to achieve fine-tuning of the vertical position of the collimating lens barrel 203 through manual adjustment. Because the focusing mirror 208 is locked on the collimating lens barrel 203 through the focusing mirror frame 209, the focusing mirror 208 can be fine-tuned in the vertical direction, thereby adjusting the position of the focus 215 where the focusing light beam 214 converges in the vertical direction, and then ensuring that the focus 215 can be accurately focused on the solder ball, so as to improve the effect of heating the solder ball. Moreover, when the diameter of the solder ball is changed, the height of the focus 215 can be conveniently fine-tuned by manually adjusting the Z-direction laser manual adjustment slide 207 to ensure that the focus 215 can be accurately focused on the solder ball.

[0050] Please refer to Figure 1 and Figure 4 In one embodiment of the present application, the solder ball separation mechanism 100 includes an upper component 110 and a lower component 120. The upper component 110 includes a separation mechanism mounting plate 1114. The separation mechanism mounting plate 1114 is provided with a separation mechanism locking hole 1113. The separation mechanism mounting plate 1114 is fixedly mounted on the Z-axis mounting plate 407 by screw locking through the separation mechanism locking hole 1113.

[0051] Please refer to Figure 4 and Figure 5 In one embodiment of the present application, an upper component laser through hole 1104 is opened on the separation mechanism mounting plate 1114 corresponding to the focusing mirror 208, and a protective mirror frame 211 is sealed and installed at a position corresponding to the upper component laser through hole 1104 on the separation mechanism mounting plate 1114, and a protective mirror 210 is sealed and installed inside the protective mirror frame 211.

[0052] In a specific embodiment of the present application, the protective mirror 210 is configured as a flat lens, and the upper and lower surfaces thereof are coated with an anti-reflection film for the wavelength of the laser used to increase the transmittance of the laser and reduce the laser loss. During operation, the protective mirror 210 can allow the laser beam to pass through the protective lens with low loss into the interior of the solder ball separation mechanism 100, while preventing dust from entering the interior of the solder ball separation mechanism 100. The protective mirror 210 can be easily disassembled and replaced if it is contaminated.

[0053] Please refer to Figure 5 In a specific embodiment of the present application, the protective lens frame 211 is configured in a cylindrical shape, which can reduce dust from falling onto the lens surface of the protective lens 210 .

[0054] Please refer to Figure 4 and Figure 5 In one embodiment of the present application, a ball storage tank 1103 is provided on the separation mechanism mounting plate 1114, and a ball storage bin 1102 is fixedly installed on the separation mechanism mounting plate 1114 corresponding to the ball storage tank 1103. Solder balls are filled inside the ball storage bin 1102, and the ball storage bin 1102 is sealed and connected to the ball storage tank 1103. One end of the ball storage bin 1102 away from the separation mechanism mounting plate 1114 is sealed and connected to a bin cover 1101. An air inlet hole 1106 is provided on the separation mechanism mounting plate 1114, and a gas connector 1107 is fixedly and sealedly installed on the separation mechanism mounting plate 1114 corresponding to the air inlet hole 1106. A first detection hole 1108 is provided on the separation mechanism mounting plate 1114, and a fiber optic sensor receiving end 1112 is fixedly and sealedly installed on the separation mechanism mounting plate 1114 corresponding to the first detection hole 1108.

[0055] In a specific embodiment of the present application, the end of the gas connector 1107 away from the separation mechanism mounting plate 1114 is connected in sequence with a pressure gauge, a proportional valve, a solenoid valve, an oil mist separator, and a gas source. The gas source uses high-purity inert gas, and the types of inert gas can be argon, nitrogen, carbon dioxide gas, etc., and the purity of the gas is more than 99%. The oil mist separator can remove impurities such as oil, water, and foreign matter in the gas. The solenoid valve controls the opening and closing of the valve according to the electrical signal, thereby realizing the on and off of the gas. The electrical proportional valve is a device that adjusts the gas pressure according to the size of the control signal; the electrical proportional valve can control the gas pressure through the electrical signal, can realize continuous and stepless regulation of the gas pressure, can realize remote control and program control, and its characteristics are that the output changes with the input (current value or voltage value), and there is a certain proportional relationship between the output and the input. The function of the pressure gauge is to display the input gas pressure in digital form to facilitate the value of the gas pressure. The differential pressure sensor can detect the input gas pressure in real time and compare it with the atmospheric pressure. The difference is output in the form of current and voltage, thereby realizing real-time detection of the difference between the input gas pressure and the atmospheric pressure.

[0056] In a specific embodiment of the present application, the tin ball refers to a spherical solder, and its composition can be various, including lead-containing tin balls, lead-free tin balls, etc. Common solder compositions include: Au80Sn20, Sn3Ag, Sn3Ag0.5Cu, Sn9Zn, Sn63Pb37, etc. The diameter of the tin ball is between 50um-2000um, and the diameter tolerance of the ball is controlled within ±1~3% (depending on the different tolerances of balls with different diameters), so that the volume tolerance of the ball is controlled within ±3~9%. The tin ball does not contain flux (brazing flux) components, so the method of the present invention does not have the pollution caused by the splashing of flux during the heating process, and there is no need to clean the flux process and equipment after welding. Tin balls are common materials in the semiconductor packaging and electronic assembly industries and can be easily obtained.

[0057] Please refer to Figure 4 and Figure 6 In one embodiment of the present application, the lower component 120 includes a lower cover plate 1204, the top surface of the lower cover plate 1204 is fixedly connected to the bottom surface of the separation mechanism mounting plate 1114, and an annular pad 1201 is sealed between the lower cover plate 1204 and the separation mechanism mounting plate 1114. A lower component laser through hole 1206 is provided on the lower cover plate 1204 corresponding to the upper component laser through hole 1104. A second detection hole 1207 is provided on the lower cover plate 1204 corresponding to the first detection hole 1108, and an optical fiber sensor transmitting end 1211 is fixedly and sealedly installed inside the second detection hole 1207. A solder ball runway 1210 is provided on the lower cover plate 1204 corresponding to the ball storage bin 1102, and a solder ball drop hole 1205 is provided on the solder ball runway 1210. An exhaust pipe 1212 connected to the lower component laser through hole 1206 is installed on the side of the lower cover plate 1204. The end of the exhaust pipe 1212 away from the lower cover plate 1204 is connected to a pressure difference sensor. The pressure difference sensor is connected to a control program, and the control program is connected to the laser control.

[0058] Please refer to Figure 5 and Figure 6 In one embodiment of the present application, the first detection hole 1108 is coaxially arranged with the second detection hole 1207 so that the optical fiber sensor receiving end 1112 can receive the light beam energy of the optical fiber sensor transmitting end 1211. Therefore, in other embodiments of the present application, the optical fiber sensor receiving end 1112 can also be installed in the second detection hole 1207, and the optical fiber sensor transmitting end 1211 can be correspondingly installed inside the first detection hole 1108.

[0059] Please refer to Figure 1 , Figure 4 and Figure 7In one embodiment of the present application, the solder ball separation mechanism 100 includes a rotating assembly 130, and the rotating assembly 130 includes a rotating motor 1301, which is fixedly mounted on the Z-axis mounting plate 407. A first coupling 1302 is fixedly mounted on the output shaft of the rotating motor 1301, and a rotating shaft 1303 is fixedly mounted on the end of the first coupling 1302 away from the rotating motor 1301. A rotating shaft mounting hole 1109 is opened on the separation mechanism mounting plate 1114 corresponding to the rotating shaft 1303, and the separation mechanism mounting plate 1114 is sealed and rotatably connected with the rotating shaft 1303 through the rotating shaft mounting hole 1109. A turntable 1304 is fixedly connected to one end of the rotating shaft 1303 away from the first coupling 1302. The turntable 1304 is rotatably installed between the lower cover plate 1204 and the separation mechanism mounting plate 1114 and located inside the annular pad 1201. A tin ball conveying hole 1309 is opened on the turntable 1304 corresponding to the tin ball runway 1210, and a turntable detection hole 1308 is opened on the turntable 1304 corresponding to the tin ball conveying hole 1309. The turntable detection hole 1308 and the tin ball conveying hole 1309 are both evenly distributed in a ring shape, and the turntable detection hole 1308 is correspondingly located between the first detection hole 1108 and the second detection hole 1207.

[0060] In one embodiment of the present application, the rotating motor 1301 is connected to a rotating control program, and the rotating control program is connected to the optical fiber sensor transmitting end 1211 and the optical fiber sensor receiving end 1112 .

[0061] Please refer to Figure 4 and Figure 8 In one embodiment of the present application, the solder ball separation mechanism 100 includes a nozzle assembly 140, and the nozzle assembly 140 includes a nozzle base 1401. The nozzle base 1401 is fixedly mounted on the bottom surface of the lower cover plate 1204, and the nozzle 1404 is detachably connected to the nozzle base 1401. The nozzle 1404 is detachably mounted on the nozzle base 1401 through a nozzle nut 1403. A laser channel 1405 sealed and connected to the laser through hole 1206 of the lower assembly is opened on the nozzle base 1401, and the laser channel 1405 is coaxially connected to the nozzle 1404. A solder ball sliding channel 1407 is opened on the nozzle base 1401 corresponding to the solder ball falling hole 1205, and the solder ball sliding channel 1407 is connected to the laser channel 1405. An air inlet channel 1406 is opened on the nozzle base 1401 corresponding to the air inlet hole 1106, and the air inlet channel 1406 is connected to the laser channel 1405.

[0062] Please refer to Figure 1 and Fig. 9In one embodiment of the present application, the adjustment component 300 includes a mounting sleeve 220, which is fixedly mounted inside the focusing lens frame 209, the lower end of the mounting sleeve 220 is fixedly and sealedly connected to the first protective lens 217, the focusing lens 208 is sealingly and slidably connected to the inside of the mounting sleeve 220, a return spring 218 is abutted and connected between the upper end of the mounting sleeve 220 and the focusing lens 208, and an intake pipe 219 connected to the mounting sleeve 220 is fixedly connected at a position between the first protective lens 217 and the focusing lens 208 on the focusing lens frame 209, and the other end of the intake pipe 219 is sealed and fixedly connected to the exhaust pipe 1212.

[0063] Please refer to Figure 1 and Fig.10 In one embodiment of the present application, the calibration system 500 includes a calibration system mounting base plate 507, which is fixedly mounted on the mounting frame 600. The calibration system mounting base plate 507 is mounted with a laser energy meter bracket 504 and a contact displacement sensor bracket 505. The laser energy meter bracket 504 is mounted with a laser energy meter 501, the contact displacement sensor bracket 505 is mounted with a contact displacement sensor 502, the Z-axis mounting plate 407 is fixedly mounted with a laser displacement sensor bracket 506, and the laser displacement sensor bracket 506 is fixedly mounted with a laser displacement sensor 503 corresponding to the laser energy meter 501.

[0064] In a specific embodiment of the present application, the laser energy meter 501 includes a probe that converts photon energy into a current signal. The current signal in the probe is digitally processed and processed by a control card, and finally the measured value is displayed on the display screen of the meter head or the software interface of the computer. The laser energy meter 501 can detect the energy of the laser beam emitted by the software-controlled laser, so the laser energy parameters can be digitized. In addition, because the laser will produce energy attenuation after long-term use, the laser energy meter can be used to detect and feedback the attenuation of the laser and make corresponding compensation.

[0065] During operation of the laser energy meter 501, when the laser beam irradiates the probe of the laser energy meter, the probe absorbs the laser energy. The absorbed laser energy is converted into an electrical signal. This process can be achieved by a photosensitive element (such as a silicon photodiode) or a thermistor. The converted signal is amplified and measured. This process includes an amplifier circuit and a sampling circuit for converting the converted signal into a measurable and recordable form. The measured signal is converted into the actual energy value of the laser beam through a calibration coefficient and a calculation formula. The calibration coefficient takes into account the characteristics of the detector and the characteristics of the instrument itself.

[0066] The working principle of the laser displacement sensor 503 is based on the principle of light interference and triangulation. The laser displacement sensor 503 emits a beam of laser light, which is reflected by the surface of the object and received by the receiver. By measuring the time difference or phase difference of the laser beam going back and forth, the displacement of the target object can be calculated. During the measurement, the laser beam is irradiated on a certain point on the object to be measured. The point on the surface of the object to be measured serves as the reflection surface of the light, and the reflected light will interfere with the emitted light. The optical path difference generated by the interference is proportional to the distance between the object and the sensor. By measuring the change in this optical path difference, the change in the distance between the object and the sensor, that is, the displacement, can be obtained. Therefore, the laser displacement sensor 503 can be used to accurately measure the height of each pad of the processed product. Therefore, after the laser displacement sensor 503 can be controlled by software to measure the height of each pad of the processed product, the Z-axis height is adjusted according to the height information of the pad, and a different Z-axis height is set at each pad position, so that the distance from the nozzle outlet to the pad is always kept consistent, thereby ensuring the consistency of the processing effect.

[0067] The function of the contact displacement sensor 502 is that when the nozzle is just above the contact displacement sensor 502, the Z axis drives the nozzle 1404 to descend, and the nozzle 1404 will contact and squeeze the upper part of the contact displacement sensor 502. At this time, the contact displacement sensor 502 will generate an electrical signal to the software, and the position of the Z axis will be recorded, which means that the lower surface of the nozzle 1404 is just flush with the upper surface of the contact displacement sensor 502. Therefore, if the thickness of the processed product is known later, it is only necessary to input the thickness of the processed product into the software, and the software can automatically calculate the height of the upper surface position of the product.

[0068] The implementation principle of a laser heating soft soldering device in the embodiment of the present application is:

[0069] During operation, the solder balls are first poured into the ball storage bin 1102, and then enter the ball storage tank 1103 of the upper assembly 110 and accumulate in the ball storage tank 1103. Before the solder balls enter the ball storage tank 1103, the solder ball delivery holes 1309 below the ball storage tank 1103 are all empty. When the solder balls enter the ball storage tank 1103 and accumulate in the ball storage tank 1103, the solder balls just fall into the several solder ball delivery holes 1309 below the ball storage tank 1103. The rotating motor 1301 can be controlled by the program to slowly drive the turntable 1304 to rotate. When the detection hole 1308 of the detection turntable on the turntable 1304 is aligned with the first detection hole 1108 and the second detection hole 1207, the optical fiber sensor receiving end 1112 is aligned with the receiving optical fiber sensor transmitting end 1211. At this time, the light beam energy received by the optical fiber sensor receiving end 1112 is the largest, which means that the solder ball delivery hole 1309 is aligned with the solder ball drop hole 1205 of the lower component. At this time, the solder ball falls from the solder ball delivery hole 1309 into the solder ball drop hole 1205 of the lower component, and the solder ball delivery hole 1309 becomes empty. Continue to control the rotating motor 1301 to rotate at a fixed angle a through the program. At this time, the next solder ball delivery hole 1309 is aligned with the solder ball drop hole 1205 of the lower component, and the second solder ball falls.

[0070] As the turntable 1304 rotates, empty solder ball delivery holes 1309 continuously enter the area below the ball storage tank 1103, so the solder balls accumulated in the ball storage tank 1103 fall into the solder ball delivery holes 1309 one by one, and follow the solder ball delivery holes 1309 to rotate in the solder ball runway area of ​​the lower cover plate. When the solder ball delivery hole 1309 coincides with the solder ball drop hole 1205 of the lower component, the solder ball falls into the solder ball drop hole 1205 of the lower component, and then falls into the solder ball sliding channel 1407 on the nozzle component 140, slides downward along the solder ball sliding channel 1407, and then falls into the nozzle 1404, and just stops at the lower end outlet of the nozzle 1404.

[0071] When the solder ball stops at the lower exit of the nozzle 1404, the divergent light beam 212 emitted by the laser through the transmission optical fiber 201 will become a parallel light beam 213 after passing through the collimator 202. The parallel light beam 213 will become a focused light beam 214 after passing through the focusing lens 208. The focused light beam 214 passes through the upper component laser through hole 1104, the protective lens 210, the lower component laser through hole 1206, and the laser channel 1405 on the nozzle component 140 and enters the nozzle 1404. The focus 215 formed by the focused light beam 214 is aligned with the laser beam 214. The centers of the solder balls staying at the outlet at the lower end of the nozzle 1404 overlap, so the high energy density laser at the focus 215 heats the solder balls, and the solder balls melt due to the heat. After melting, the liquid solder balls change their shape and can be ejected from the outlet at the lower end of the nozzle 1404. At this time, the laser heating is stopped, and the outlet below the nozzle 1404 is facing the solder pad of the processed product, so the liquid solder balls fall onto the solder pad of the processed product and immediately begin to cool and re-solidify, forming a re-solidified spherical solder joint on the solder pad of the processed product, thereby completing the welding process.

[0072] After the solder ball melts, it is ejected from the outlet at the lower end of the nozzle 1404 with the power of the inert gas. The inert gas continuously enters the upper component 110 from the air inlet 1106 on the upper component 110 and reaches the top of the turntable 1304. When there is a solder ball in the solder ball delivery hole 1309, the inert gas can exert a downward force on the solder ball, making it easier for the solder ball to fall into the solder ball drop hole 1205 of the lower component and continue to fall downward. When the turntable 1304 rotates and there is no solder ball delivery hole 1309 facing the solder ball drop hole 1205 of the lower component, the inert gas fills the entire space inside the solder ball separation mechanism along the gap between the turntable 1304 and the upper component, and between the turntable 1304 and the lower component. Because the upper component 110 is sealed with a protective mirror 210 and a compartment cover 1101, the inert gas will not escape from the upper component 110. When the solder ball slides into the nozzle 1404 on the nozzle assembly 140, the solder ball stops just when it slides down because the diameter of the lower outlet of the nozzle 1404 is equal to or slightly smaller than the diameter of the solder ball. At this time, a closed cavity is formed inside the entire solder ball separation mechanism 100. Since the inert gas continuously flows into the solder ball separation mechanism 100, the air pressure inside the solder ball separation mechanism 100 rises. The rising air pressure inside the solder ball separation mechanism 100 will transmit the air pressure to the pressure difference sensor through the exhaust pipe 1212 on the outside of the lower assembly 120. The pressure difference sensor senses that its internal pressure is greater than the external atmospheric pressure and sends a signal to the control program. The control program immediately controls the laser to emit a laser beam to heat the solder ball. The solder ball is liquefied and deformed after being heated. The process of the solder ball being heated and liquefied is protected by the inert gas to prevent the solder ball from reacting with oxygen in the air and oxidizing during laser heating. After the solder ball is liquefied and deformed by heat, it falls from the lower end outlet of the nozzle 1404, and the inert gas inside the solder ball separation mechanism 100 escapes from the nozzle 1404. Because the distance from the nozzle 1404 to the solder pad of the processed product is very small, generally less than 1 mm, the inert gas escaping from the nozzle will be sprayed onto the solder pad of the processed product. When the liquid solder ball is cooled at the solder pad position of the processed product, it is still protected by the inert gas to prevent it from reacting with oxygen in the air and being oxidized.

[0073] When the air pressure inside the solder ball separation mechanism 100 rises, the rising air pressure inside the solder ball separation mechanism 100 will also transmit the air pressure to the inside of the mounting sleeve 220 through the exhaust pipe 1212 and the air inlet pipe 219 on the outside of the lower component 120. After the air pressure inside the mounting sleeve 220 increases, it will push the focusing mirror 208 to overcome the return spring 218 and slide upward, so that the focus 215 formed by the focusing light beam 214 coincides with the center of the solder ball staying at the lower end outlet of the nozzle 1404. When the solder ball is heated, liquefied, and deformed, that is, ejected from the lower end outlet of the nozzle 1404, the air pressure inside the mounting sleeve 220 will return to atmospheric pressure, and the return spring 218 will push the focusing mirror 208 downward in the opposite direction, so that the focus 215 formed by the focusing light beam 214 moves downward. In this way, the solder ball is continuously heated for a short time after it is heated and liquefied, which can avoid the solder ball being ejected before it is completely liquefied, resulting in poor welding, thereby ensuring the welding quality.

[0074] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A laser heating soldering equipment, characterized in that: The invention comprises a mounting frame (600), wherein a Z-axis sliding mechanism (400) is mounted on the mounting frame (600), wherein a solder ball separation mechanism (100) and an optical path system (200) are mounted on the Z-axis sliding mechanism (400), wherein the solder ball separation mechanism (100) and the optical path system (200) are connected, and wherein a calibration system (500) is mounted on the mounting frame (600) corresponding to the optical path system (200); wherein the optical path system (200) comprises a transmission optical fiber (201), wherein an input end of the transmission optical fiber (201) is connected to a laser, and an output end of the transmission optical fiber (201) is connected to a collimating lens barrel (203), wherein a collimating lens (202) is mounted inside the collimating lens barrel (203), and wherein the collimating lens (202) is mounted inside the collimating lens barrel (203). A focusing lens frame (209) is mounted on one end of the straight lens barrel (203) away from the transmission optical fiber (201); a first protective lens (217) is fixedly and sealedly connected to the upper end of the focusing lens frame (209); a focusing lens (208) is sealed and slidably connected to the interior of the focusing lens frame (209); the solder ball separation mechanism (100) is capable of separating a plurality of solder balls one by one to a focus (215) under the focusing lens (208) in the optical path system (200); an adjustment component (300) is connected to the focusing lens frame (209) and the solder ball separation mechanism (100); and the adjustment component (300) is capable of adjusting the position of the focus (215) according to the working state of the solder ball separation mechanism (100); The Z-axis sliding mechanism (400) comprises a Z-axis locking plate (401), a Z-axis motor (402) is fixedly mounted on the Z-axis locking plate (401), a Z-axis guide rail (406) is fixedly mounted on the Z-axis locking plate (401) in a length direction corresponding to the Z-axis motor (402), a Z-axis screw rod (404) is rotatably connected to the Z-axis guide rail (406), a Z-axis slider (405) is slidably connected to the Z-axis guide rail (406), the Z-axis slider (405) is threadedly connected to the Z-axis screw rod (404), the Z-axis screw rod (404) is drivingly connected to the output shaft of the Z-axis motor (402), a Z-axis mounting plate (407) is fixedly connected to the Z-axis slider (405), and the solder ball separation mechanism (100) and the optical path system (200) are mounted on the Z-axis mounting plate (407); A hand-adjustable slide fixing plate (216) is fixedly mounted on the Z-axis mounting plate (407); a Z-direction laser hand-adjustable slide (207) is fixedly mounted on the hand-adjustable slide fixing plate (216); a Y-direction laser hand-adjustable slide (206) is cooperatively mounted on the Z-direction laser hand-adjustable slide (207); an X-direction laser hand-adjustable slide (205) is cooperatively mounted on the Y-direction laser hand-adjustable slide (206); a collimating lens barrel clamping mechanism (204) is cooperatively mounted on the X-direction laser hand-adjustable slide (205); and the collimating lens barrel (203) is cooperatively mounted on the collimating lens barrel clamping mechanism (204).

2. The laser heating soldering equipment according to claim 1, characterized in that: The solder ball separation mechanism (100) comprises a separation mechanism mounting plate (1114) fixedly mounted on the Z-axis mounting plate (407); the separation mechanism mounting plate (1114) is provided with an upper component laser through hole (1104) corresponding to the focusing mirror (208); a lower cover plate (1204) is fixedly and sealedly mounted on the bottom surface of the separation mechanism mounting plate (1114); a lower component laser through hole (1206) is provided on the lower cover plate (1204) corresponding to the upper component laser through hole (1104); the lower cover plate (1204) and the separation mechanism mounting plate are connected to each other. A turntable (1304) is rotatably connected between (1114), and a solder ball delivery hole (1309) is provided on the turntable (1304). A ball storage tank (1103) is provided on the separation mechanism mounting plate (1114) corresponding to the solder ball delivery hole (1309), and solder balls are filled in the ball storage tank (1103). A solder ball drop hole (1205) is provided on the lower cover plate (1204) corresponding to the solder ball delivery hole (1309), and a nozzle assembly (140) is fixedly connected to the lower cover plate (1204) corresponding to the solder ball drop hole (1205).

3. The laser heating soldering equipment according to claim 2, characterized in that: The nozzle assembly (140) comprises a nozzle base (1401), wherein the nozzle base (1401) is fixedly connected to the bottom surface of the lower cover plate (1204), the nozzle base (1401) is detachably connected to the nozzle (1404), the nozzle base (1401) is provided with a laser channel (1405) corresponding to the laser through hole (1206) of the lower assembly, the nozzle base (1401) is provided with a solder ball sliding channel (1407) corresponding to the solder ball dropping hole (1205), the solder ball sliding channel (1407) is connected to the laser channel (1405), and the laser channel (1405) is coaxially connected to the nozzle (1404).

4. The laser heating soldering equipment according to claim 2, characterized in that: A rotating shaft (1303) is connected to the separation mechanism mounting plate (1114) in a sealed and rotatable manner corresponding to the rotating disk (1304); the rotating shaft (1303) is fixedly connected to the rotating disk (1304); one end of the rotating shaft (1303) away from the rotating disk (1304) is transmission-connected to a rotating motor (1301); and the rotating motor (1301) is fixedly mounted on the Z-axis mounting plate (407).

5. The laser heating soldering equipment according to claim 3, characterized in that: A protective mirror frame (211) is sealed and installed on the separation mechanism mounting plate (1114) at a position corresponding to the laser through hole (1104) of the upper component, and a protective mirror (210) is sealed and installed inside the protective mirror frame (211). An air inlet hole (1106) is opened on the separation mechanism mounting plate (1114), and an air inlet channel (1406) is opened on the nozzle base (1401) corresponding to the air inlet hole (1106). The air inlet channel (1406) is connected to the laser channel (1405). A gas connector (1107) is fixedly and sealed and installed on the separation mechanism mounting plate (1114) corresponding to the air inlet hole (1106), and the end of the gas connector (1107) away from the separation mechanism mounting plate (1114) is connected in sequence to a pressure gauge, a proportional valve, a solenoid valve, an oil mist separator, and an air source.

6. The laser heating soldering equipment according to claim 5, characterized in that: The adjustment component (300) comprises a mounting sleeve (220), the mounting sleeve (220) being fixedly mounted inside the focusing lens frame (209), the lower end of the mounting sleeve (220) being fixedly and sealedly connected to a first protective lens (217), the focusing lens (208) being sealingly and slidably connected inside the mounting sleeve (220), a return spring (218) being abutted and connected between the upper end of the mounting sleeve (220) and the focusing lens (208), and a communicating mounting spring (218) being fixedly connected at a position between the first protective lens (217) and the focusing lens (208) on the focusing lens frame (209). The lower cover plate (1204) is provided with an air inlet pipe (219) connected to the laser through hole (1206) of the lower component, and an exhaust pipe (1212) connected to the laser through hole (1206) of the lower component is installed on the side of the lower cover plate (1204); the other end of the air inlet pipe (219) is sealed and fixedly connected to the exhaust pipe (1212); the end of the exhaust pipe (1212) away from the lower cover plate (1204) is also connected to a pressure difference sensor, the pressure difference sensor is connected to a control program, the control program is connected to the laser control, and the pressure difference sensor is connected to the control program, the control program is connected to the laser control.

7. The laser heating soldering equipment according to claim 1, characterized in that: The calibration system (500) comprises a calibration system mounting base plate (507), the calibration system mounting base plate (507) being mounted with a laser energy meter bracket (504) and a contact displacement sensor bracket (505), the laser energy meter bracket (504) being mounted with a laser energy meter (501), the contact displacement sensor bracket (505) being mounted with a contact displacement sensor (502), the Z-axis mounting plate (407) being fixedly mounted with a laser displacement sensor bracket (506), and the laser displacement sensor bracket (506) being fixedly mounted with a laser displacement sensor (503) corresponding to the laser energy meter (501).

8. A laser heating soldering equipment according to any one of claims 1 to 7, characterized in that: The solder ball is configured as a spherical solder, the diameter of the solder ball is between 50um-2000um, and the diameter tolerance of the ball is controlled within ±1-3%.

Images