CN111992833B - A laser soldering method for pre-tinning - Google Patents

Abstract

The invention discloses a laser soldering method and a laser soldering device for presetting tin, wherein firstly, a tin ball is melted by laser to the surface of a base material to be soldered to form a tin cladding; the tin cladding is then melted using a laser and the wire to be soldered is embedded in the tin cladding. The method is simple and convenient to use, and utilizes the characteristics of stable average power, high heat energy conversion efficiency, uniform energy distribution and the like of a continuous laser, the soldering form of laser non-contact surface heat release and the concentrated and stable release of energy are fast, so that the working efficiency is better improved, meanwhile, the non-contact irradiation is carried out, the base material and the electronic component are undoubtedly not physically deformed, the quality of the component is greatly improved, and the damage and the deformation of the material are avoided.

Description

A kind of laser soldering method of pre-tinning

technical field

The invention relates to a laser soldering method and device, belonging to the technical field of 5G connector soldering, and specifically discloses a laser soldering method and device with pre-tinned tin.

Background technique

Laser as a heat source is widely used in modern soldering, laser soldering is suitable for soldering of network connectors, soldering of tiny connectors and thin wires, widely used in electronic and automotive industries, such as PCB boards and FPCB boards, connection terminals , sensor and other production work, laser soldering, as a combination of modern technology and traditional technology, has its unique characteristics compared with traditional electric iron, reflow soldering, and Haba soldering technology, and its own application field And the application level is very wide, which can greatly improve the efficiency and quality of soldering. Its non-contact surface exothermic soldering form, energy concentration and stable release fast, so as to better improve work efficiency, and its non-contact irradiation, no doubt that the substrate and electronic components have no physical deformation, and its devices The quality has been greatly improved, and it will not cause damage and deformation of the material. The emergence of laser soldering technology has realized the fields that traditional soldering technology cannot be applied, especially the soldering of network connectors on 5G communication. Its dense components and irregular shape layout solder joints, ultra-high transmission Efficiency requirements, all of which challenge traditional soldering methods and cannot meet such requirements. Laser soldering, because of the characteristics of laser as a heating source, enables it to achieve a 360-degree range according to the trajectory of the speed of light itself. Random changes in the interior, and this is undoubtedly an unimaginable advantage under the development of traditional soldering technology. In addition, because of laser soldering, it releases heat stably within a fixed time, and can be very stable soldering products with good consistency and high yield. It can release a lot of heat in a very short time, so it can quickly Soldering has lower environmental requirements and can be carried out at normal room temperature without special conditions. Laser soldering is one of the processing methods in the field of soldering today. With the comprehensive development of science and technology, laser soldering technology has been continuously consolidated and applied. , The new process drives the upgrade of products, and it is also the display and application of more technologies. After more than ten years of development of laser soldering, people have learned from the initial understanding of this technology to the current large-scale application. Wire, laser spray ball welding, laser solder paste welding and other laser soldering methods, however, in these existing soldering processes, the soldering between the connector of the network data line and the wire in the soldering field of the 5G connector is all There are certain problems. Since these soldering methods are used to fix the pads and wires with a carrier first, after adding soldering materials, laser irradiation is used to irradiate the pads, and the soldering methods are easy to cause the amount of tin. The package is uneven, and tiny holes appear in the tin, resulting in high impedance. For ordinary 4G network connectors, other internal connectors may be good products, but for the ultra-high efficiency of 5G connector network data lines, the transmission efficiency Products with relatively low transmission speed and relatively low transmission speed are classified as substandard products.

SUMMARY OF THE INVENTION

The present invention is to provide a laser soldering device and process method with pre-tinned tin to solve the situation of low transmission efficiency, low transmission speed, and substandard quality of the connection head of the 5G network data line in the above-mentioned background technology. The present invention uses a laser As the heat source, the laser irradiation soldering method is adopted in two steps, and the solder paste and solder balls of the solder material are placed on the surface of the pad substrate. , Melt the soldering material in three stages of melting and heat preservation, so that the melted tin material is melted on the surface of the pad to be processed, and the wire to be soldered is fixed to the surface of the pad by a fixture, and the energy and heat of the laser are used again to control the laser energy and time. , the movement trajectory, forming two stages of melting and heat preservation to melt the tin, so that the wire sinks under the action of the fixture, and the tin wraps the wire to complete the soldering.

A laser soldering method for pre-tinning of the present invention firstly uses laser to melt tin balls to the surface of the base material to be soldered to form a tin cladding layer; then use a laser to melt the tin cladding layer and embed the wire to be welded into the tin cladding layer.

In a preferred embodiment of the present invention, the surface of the substrate to be soldered is provided with flux paste.

In a preferred embodiment of the present invention, a glue dispenser is used to apply flux paste to the pad positions on the surface of the substrate to be soldered.

In a preferred embodiment of the present invention, the tin balls on the surface of the substrate to be welded are processed three times by using a continuous laser with a galvanometer and a field lens, so that they are melted on the surface of the substrate to be welded to form a tin cladding layer; The laser cooperates with the galvanometer and the field lens to process the tin cladding layer on the surface of the substrate to be welded twice, so that the wire material to be welded is embedded in the tin cladding layer.

In a preferred embodiment of the present invention, when processing the solder balls on the surface of the substrate to be soldered for the first time, the parameters of the continuous laser are set as: the laser power is 7-30W, the speed is 1500-3000 millimeters per second, and the number of times is 3-8 times. ; When processing the tin balls on the surface of the substrate to be welded for the second time, the parameters of the continuous laser are set to laser power of 20-50W, speed of 1000-2000 mm per second, and the number of times is 5-20; the third processing of the surface of the substrate to be welded When the solder ball is removed, the parameters of the continuous laser are set as, the laser power is 20-40W, the speed is 1500-2500 mm per second, and the number of times is 5-10 times.

In a preferred embodiment of the present invention, when processing the tin cladding layer on the surface of the substrate to be welded for the first time, the parameters of the continuous laser are set to the setting, the laser power is 30-50W, the speed is 1500-2500 millimeters per second, and the number of times is 5-20 times. ; When processing the tin cladding on the surface of the substrate to be welded for the second time, the parameters of the continuous laser are set, the laser power is 10-30W, the speed is 1000-3000 mm per second, and the number of times is 5-10 times.

In a preferred embodiment of the present invention, the wavelength of the continuous laser is 1060-1070 nanoseconds, the average power is 50-120 watts, the beam quality M2 factor is less than or equal to 1.2, the output spot size is 6-9 mm, and the output The spot beam ellipticity is greater than 90%, the beam divergence angle is less than 0.5 milliradian, the clear aperture of the galvanometer is 10 mm, the motion speed of the galvanometer is 0-7000 mm, and the focal length of the field mirror is 163-255 mm mm.

In a preferred embodiment of the present invention, it is used for soldering the terminal PCB board of the 5G network connection data line and the wire head of the data line.

The invention also discloses a laser soldering device with pre-tinned tin, which comprises a glue dispensing unit for adding flux paste to the surface of the substrate to be soldered, and a laser soldering machine for melting the tin material on the surface of the substrate to be soldered and a jig for positioning the substrate to be welded.

In a preferred embodiment of the present invention, the glue dispensing unit includes a three-axis moving platform and a syringe for dispensing paste disposed at the moving end of the three-axis moving platform; the laser soldering unit includes a continuous laser, a lift table and an XY axis working platform; the fixture includes a download plate, a middle positioning plate and an upper cover plate, the download plate is provided with a positioning taper pin, the middle positioning plate is provided with a positioning taper hole, and the upper cover plate is provided with a pressure line claw.

The beneficial effects of the present invention are as follows: the method of the present invention is simple and easy to use, and it utilizes the characteristics of continuous lasers with stable average power, high conversion heat energy efficiency, uniform energy distribution, etc. It can improve the working efficiency better. At the same time, the non-contact irradiation will undoubtedly make the substrate and electronic components not physically deformed, and the quality of the device will be greatly improved without causing material damage and deformation. The welding method of the two-time laser soldering adopts the two-step laser irradiation soldering method, which uses the placement of flux paste and soldering material solder balls on the surface of the pad substrate, and uses the energy and heat of the laser to control the laser energy and heat. Time, movement trajectory, forming three stages of preheating, melting and heat preservation to melt the solder material, so that the melted tin material is melted on the surface of the pad to be processed, and the wire to be soldered is fixed to the surface of the pad by a fixture, and the wire is to be soldered. It has been pre-tinned, and the energy and heat of the laser are again used to melt the tin in two stages of melting and heat preservation by controlling the laser energy and time, and the movement trajectory, so that the wire sinks under the action of the fixture, and the tin wraps the wire to complete the soldering. Compared with other laser soldering processes, its process in the soldering of the connector of the 5G network data line avoids the instability of the soldering wire in the laser wire-feeding soldering process, which is limited by the fixture and relies on the tin wire to conduct heat to the terminal. The board pads are easy to cause uneven heating and virtual soldering, which avoids the liquid solder ball connecting the wire and the pad in the laser spray ball welding. There is a gap between the wire and the pad, and voids are formed in the tin, which avoids the laser solder paste. In the process of flux volatilization in soldering, tin explosions and small voids are generated, and solder paste soldering does not have the problem of low efficiency when tin explosions occur. The laser soldering device and process method of pre-tinning can solve these problems very well. In the first laser soldering process of pre-tinning, the flux is added to the surface of the pad, and the amount of flux is accurately controlled, and the weight of the solder ball is controlled. Accurate control, coupled with the precise control of the laser irradiation method and the precise control of the laser heating energy, ensure that the tin is fully melted and the connection pads are firm. The second soldering uses pre-tinned wires and pads. The tin material on the tin material is welded, and the two irradiation methods are on the same material tin material, which avoids the difference in heat inconsistency caused by the material, resulting in gaps and voids, and greatly improves the contact area and wrapping area between the tin and the wire. And the heat is consistent, and its quality is also very consistent, which greatly reduces the impedance of the tin material at the tin welding connection, and improves its transmission efficiency and speed. , its yield is high, its process method is suitable for automatic soldering, and it can solve the soldering of ultra-high transmission efficiency connectors in extremely small devices.

Description of drawings

Figure 1 Schematic diagram of the exploded structure of the dispensing machine mechanism for spot flux paste;

Figure 2 is a schematic diagram of the exploded structure of the laser soldering machine;

Figure 3 is a schematic diagram of the simple optical path of the laser tin splicing machine;

Figure 4 is a schematic structural diagram of a fixture carrier;

Figure 5 is a schematic diagram of the mechanism for installing the terminal PCB board fixture;

6 is a schematic diagram of a simple structure of the cover plate 1;

Figure 7 is a schematic diagram of the simple structure of the solder terminal PCB board;

Fig. 8 is the welding layer trajectory diagram of the preset solder ball soldering, the shape and soldering sequence diagram of the superimposed laser spot focusing light spot;

9 is a schematic diagram of a simple structure of the cover plate 2;

Figure 10 is a schematic diagram of the wire to be soldered;

Figure 11 is a schematic diagram of a simple structure of the wire to be soldered;

Figure 12 Schematic diagram of the simple assembly of the solder terminal PCB board and the wire to be soldered;

Figure 13. The layer trajectory diagram of the solder terminal PCB board and the wire to be soldered, the shape of the superimposed laser spot focusing spot and the soldering sequence diagram;

In the figure: 1- the dispenser of the flux paste dispenser; 2- the parameter controller of the dispenser; 3- the Y-axis moving table; 4- the X-axis moving table; 5- the Z-axis moving table; Soldering machine; 7-CW fiber laser; 8-galvanometer lens; 9-lifting table; 10-field mirror; 11-soldering machine X.Y axis working platform; 12-focusing laser spot; 13-fixture carrier board; 14-Terminal PCB board fixture; 15-Solder ball cover plate 1; 16-Terminal board PCB board; 17-Solder ball soldering welding layer trace diagram; 18-Solder ball soldering laser spot focused spot superimposed Shape drawing; 19-welding wire cover plate; 20-crimping claw; 21-wire to be welded; 22-welding layer trajectory diagram of solder terminal PCB board and wire to be soldered; 23-laser spot of soldering wire A shape map of the superimposed spot of focus.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention.

A laser soldering method for pre-tinning shown in the accompanying drawings of the description is characterized in that: firstly, a tin cladding layer is formed by using a laser to melt the tin ball to the surface of the base material to be welded; The solder wire is embedded in the tin cladding.

Preferably, the surface of the substrate to be soldered is provided with flux paste.

Preferably, the soldering paste is applied to the pad positions on the surface of the substrate to be soldered by using a glue dispenser.

Preferably, firstly, the tin balls on the surface of the substrate to be welded are processed three times by using a continuous laser with a galvanometer and a field mirror, so that they are melted on the surface of the substrate to be welded to form a tin cladding layer; secondly, a continuous laser is used with the galvanometer and the field mirror to separate the tin balls. The tin cladding layer on the surface of the substrate to be welded is processed twice, so that the wire to be welded is embedded in the tin cladding layer.

Preferably, when processing the solder balls on the surface of the substrate to be soldered for the first time, the parameters of the continuous laser are set as: the laser power is 7-30W, the speed is 1500-3000 millimeters per second, and the number of times is 3-8; the second processing of the substrate to be soldered When the solder balls on the surface of the material are processed, the parameters of the CW laser are set as: the laser power is 20-50W, the speed is 1000-2000 mm per second, and the number of times is 5-20 times; when processing the solder balls on the surface of the substrate to be soldered for the third time, the parameters of the continuous laser The setting is, the laser power is 20-40W, the speed is 1500-2500 millimeters per second, and the number of times is 5-10 times. Preferably, when processing the tin cladding layer on the surface of the substrate to be welded for the first time, the parameters of the continuous laser are set, the laser power is 30-50W, the speed is 1500-2500 mm/s, and the number of times is 5-20; the second processing of the substrate to be welded is performed. When the surface of the material is tin clad, the parameters of the continuous laser are set, the laser power is 10-30W, the speed is 1000-3000 mm per second, and the number of times is 5-10 times.

Preferably, the wavelength of the continuous laser is 1060-1070 nanoseconds, the average power is 50-120 watts, the beam quality M2 factor is less than or equal to 1.2, the output spot size is 6-9 mm, and the output spot beam ellipticity is greater than 90%, The beam divergence angle is less than 0.5 milliradian, the clear aperture of the galvanometer is 10 mm, the movement speed of the galvanometer is 0-7000 mm, and the focal length of the field lens is 163-255 mm.

Preferably, it is used for soldering the terminal PCB board of the 5G network connection data line and the wire head of the data line.

The invention also discloses a laser soldering device with pre-tinned tin, comprising a glue dispensing unit for adding flux paste to the surface of the substrate to be soldered, a laser soldering unit for melting the tin material on the surface of the substrate to be soldered, and A jig for positioning the base material to be welded, wherein the glue dispensing unit can use a glue dispenser, and the laser soldering unit can use a laser solder machine. Syringe; the laser soldering unit includes a continuous laser, a lifting table and an XY axis working platform; the fixture unit includes a download plate, a middle positioning plate and an upper cover plate, the download plate is provided with a positioning taper pin, and the middle positioning plate is set There is a positioning taper hole, and the upper cover plate is provided with a thread pressing claw.

When the specific processing object of the present invention is the soldering of the terminal PCB board of the 5G network connection data line and the wire head of the data line, the specific operation steps are as follows:

First install and debug the dispensing equipment. The equipment mechanism is shown in Figure 1. The dispensing equipment controls the weight of the flux paste by adjusting the parameters to control the pressure and time of the air pressure. Adjust the motion trajectory to control the position of each pad on the terminal board. Click on the flux paste, install and debug the optical system of the soldering equipment, the equipment mechanism is shown in Figure 2, the light spot from the laser 1 passes through the galvanometer 2, and the galvanometer 2 controls the movement trajectory of the light spot, and is focused to 0.07 mm through the field lens 4 The circular light spot 7, the ellipticity of the light spot at the laser focus is greater than 95%, which is basically circular, and the following steps are performed:

The first step: place the terminal board to be soldered on the terminal board fixture, fix the terminal board through the cover plate on the fixture, and expose the substrate copper pads of the terminal board to be soldered.

Step 2: Place the fixture with the terminal board installed on the carrier board, install the carrier on the two-position platform, fix the carrier, and the two-dimensional platform drives the carrier to the position of the solder paste.

Step 3: Adjust the parameters of the dispenser, control the weight of the solder paste, and apply the solder paste to all the copper pads of the substrate to be soldered.

Step 4: Remove the terminal board-mounted jig that was filled with the solder paste.

Step 5: Manually place solder balls to ensure that each solder ball is placed on the surface of the substrate copper pads of the terminal board with the solder paste.

Step 6: Install the jig for placing the solder balls on the carrier board, place the carrier board on the second-position platform of the laser soldering machine, and move the second-position platform to the laser soldering position.

Step 7: Adjust the lift table to make the laser focus to a specific position, maintain sufficient power density, and promote the best and fastest tin melting effect.

Step 8: Edit the soldering pattern on the software, and the soldering pattern is edited according to the shape of the pad.

The ninth step: set the laser power, speed and times of laser emission. Edit graphics according to the shape of the pad, edit 3 identical graphics, set different layers for each graphics, and set different laser power, speed and times for different layers.

Step 10: Adjust the position of the solder joints, keep the X and Y axes of the two-dimensional platform static, and the laser with a specific energy moves through the X and Y axes of the galvanometer to drive the laser movement, gather on the surface of the copper pad of the substrate, and set its Soldering sequence.

Step 11: Control the laser light to irradiate on the tin balls, so that the tin melts on the copper pads of the substrate.

Step 12: If the two sides of the terminal board need to be soldered, remove the terminal board, turn it over and place it, repeat the first step, the second step, the third step, the fourth step, the fifth step, the sixth step, the seventh step, Step 8, Step 9, Step 10, Step 11, make sure that both sides are pre-tinned.

The thirteenth step: Remove the terminal board carrier that has been pre-tinned on the two-position platform on the soldering machine, take off the cover, and install the data cable to be soldered on the cover with pressing claws. Install it on the terminal board On the carrier, each wire corresponds to the substrate copper pad.

Step 14: Install the carrier for installing the data cable and solder pad to be soldered on the two-position platform of the soldering machine, and move it to the laser soldering position.

Step 15: Adjust the lift table to make the laser focus to a specific position, maintain sufficient power density, and promote the best and fastest tin melting effect.

Step 16: Edit the soldering pattern on the software, and the soldering pattern is edited according to the shape of the pad.

Step 17: Set the laser power, speed and times of laser emission. Edit graphics according to the shape of the pad, set different layers, and set different laser power, speed and times for different layers.

Step 18: Adjust the position of the solder joints, keep the X and Y axes of the two-dimensional platform stationary, the laser with a specific energy moves through the X and Y axes of the galvanometer to drive the laser movement, and set the tin surface focused by the field lens to set its Soldering sequence.

Step 19: Control the laser light to irradiate the tin and the data wire to be soldered. After the tin is melted, the wire is pressed down under the action of the claw force. After the tin is cooled, the wire is wrapped to complete the tin soldering.

Step 20: If soldering is required on both sides, flip the terminal board and the data cable to be soldered, repeat steps 13, 14, 15, 16, 17, and 17 Eighteen steps, nineteenth step, complete the soldering.

In the present invention, a glue dispenser is used to dispense the soldering paste, and the weight of the soldering paste is controlled. The paste can melt into a liquid to cover all the pads, clean the copper oxide substrate pads, remove oxides, and fully promote the melting of the tin material to the surface of the pads to be processed. Place the solder balls manually. The size of the solder balls is determined according to the size of the substrate pads of the terminal board to be soldered to ensure that the amount of tin can be sufficient to cover the terminal board pads and wrap the wires. Using the light energy of the continuous laser, the laser parameters are the wavelength of 1060-1070 nanoseconds, the average power is between 50-120 watts, the beam quality M2 factor is less than or equal to 1.2, the laser is a continuous laser, and the frequency and pulse width cannot be set. The output spot size is 6-9 mm. The ellipticity of the output spot beam is greater than 90%, the beam divergence angle is less than 0.5 milliradian, the laser has no peak power, the average power is very stable, the conversion heat energy efficiency is high, and the energy distribution is uniform. The galvanometer 2 has a clear aperture of 10 mm and reflects laser with a wavelength of 1064 nanoseconds. The moving speed of the galvanometer is adjustable from 0 to 7000 mm per second. After focusing by the field mirror, the area to be soldered is brazed. The continuous laser is based on a specific layer. Setting parameters, the laser power set for the first layer is 7-30W, the speed is 1500-3000mm per second, the number of times is 3-8 times, the power set for the second layer is 20-50W, the speed is 1000-2000mm per second, the number of times is 5 -20 times, the power set by the third layer is 20-40W, the speed is 1500-2500 mm per second, and the number of times is 5-10 times. The function of the first layer parameter is to promote the melting of the flux paste, and the substrate covering the terminal board is soldered. On the disk, the temperature of the tin ball material increases, which increases the absorption rate of tin to the laser, and at the same time effectively reduces the reflection of the material to the laser, and promotes the heating of the material to more than 100 degrees. The function of the parameters set in the second layer is to promote the melting of the tin balls into liquid tin, and at the same time transmit energy to the metal pads through the liquid tin to promote the welding of the pads and the tin. The parameters set by the third layer are used for the heat preservation and cooling of tin. The energy and time are set to 40% of the parameters of the second layer to ensure that the tin is in a liquid state and promote the full melting of the internal tin and the internal gas. Fully volatilize to ensure that it forms solid tin without voids, melt the tin ball on the surface of the terminal pad, manually load the wire, and use a clamp to fix the claws, which can fix the wire in the center of the pad, and can ensure a certain downward pressure on the wire. Press the wire with a pressure of about 3N, and one end of the data line to be welded is a wire that has been pre-tinned. The length of the pre-tinned wire is the length that needs to be soldered. The galvanometer movement drives the laser soldering again, and the continuous laser is based on a specific layer. Setting parameters. The laser power of the first layer is 30-50W, the speed is 1500-2500mm per second, the number of times is 5-20 times, the power of the second layer is 10-30W, the speed is 1000-3000mm per second, the number of times is 5-10 times, the first layer The function of the parameter is to promote the heating of the wire and the melting of the tin into a liquid state, and the heating of the wire terminal and the tin at the same time, so that the heating between them can be uniform. The function of the parameters set in the second paragraph is to promote liquid tin, completely wet the wire, without gaps, and at the same time play a role of heat preservation.

Specifically, when there are 18 pads to be soldered on one side of the terminal PCB as shown in Figure 7, the size of a single pad is 0.4 mm wide and 2 mm long, and the spacing between each pad is 0.5 mm. ) contains 6 groups of wires with aluminum foil, each group of aluminum foil wires contains 3 wire ends to be welded, the wire ends have been stripped, the diameter of the wire ends is 0.2 mm, the length of the pre-tinned wire ends is 1.5 mm, adjust the glue dispenser and solder welding After the optical path system of the machine is installed, perform the following steps:

Step 1: Place the terminal PCB board to be soldered as shown in Figure 7 on the terminal PCB board fixture as shown in Figure 5, and fix the terminal board through the cover plate with tin balls as shown in Figure 6 on the carrier, exposing the terminal board to be tinned Solder the substrate copper pads of the terminal board.

Step 2: As shown in Figure 4, the fixture carrier is installed on the Y-axis motion platform of the dispenser, and the carrier with the terminal board is placed on the fixture carrier as shown in Figure 4. Fix the carrier and the controller of the dispenser. Control the Y-axis platform to drive the carrier to the position of the solder paste.

The third step: adjust the parameters of the dispenser, control the weight of the spot flux paste, the weight of the spot flux paste is 0.3 mg, the dispenser controller controls the motion of the motion platform, and wait for all the substrate copper pads to be soldered in turn. Move to the point of solder paste, and apply solder paste in sequence.

Step 4: Remove the carrier with the terminal board installed with the solder paste applied.

Step 5: Manually place the solder balls to ensure that each solder ball is placed on the surface of the substrate copper pad of the solder paste on the terminal board, and then put 18 solder balls in sequence, and the diameter of each solder ball is 0.5 mm , the mass error of each solder ball is not more than 0.1 mg.

Step 6: Install the fixture carrier board as shown in Figure 4 on the power platform 11 of the soldering machine as shown in Figure 2, place the carrier terminal board with the solder balls placed on the fixture carrier board, and move the two-position platform to the laser tin Below the position of the galvanometer.

Step 7: Adjust the lift table to make the focus of the laser to a specific position. At 15 mm above the focus, keep enough power density to promote the best and fastest tin melting effect. , a rectangular light spot 18 is formed under the fast motion of the galvanometer, and the size of the light spot is 0.35 mm wide and 1.8 mm long.

Step 8: Edit the soldering pattern on the software. The soldering pattern is a rectangle according to the shape of the pad.

The ninth step: set the laser power, speed and times of laser emission. Edit 3 identical rectangles for a single pad, set different layers for each graphic, and set different laser power, speed, and times for different layers. The laser power set for the first layer is 28W, the speed is 2100 mm per second, and the number of times is 6 times. , the power of the second layer is set to 45W, the speed is 1600mm per second, the number of times is 14, the power of the third layer is set to 30W, the speed is 2000mm per second, the number of times is 8, there are 18 pads on the terminal PCB, and a single There are 18 copies of the soldering pattern of the pads.

Step 10: Adjust the position of the solder joints, adjust the position of 18 soldering patterns, ensure that the laser of each soldering pattern hits the pads, does not exceed the pads, keep the X and Y axes of the two-dimensional platform static, and the specific energy The laser moves through the X-axis and Y-axis of the galvanometer, driving the laser to move and gather on the surface of the copper pad of the substrate. The soldering sequence is as shown in Figure 8 below: a1; d1; g1; j1; m1; e1; h1; k1; n1; q1; c1; f1; i1; l1; o1; r1 are soldered in sequence.

Step 11: Control the laser light to irradiate on the tin balls, so that the tin melts on the copper pads of the substrate.

Step 12: This product is single-sided soldering. If soldering is required on both sides of the terminal board, you need to remove the terminal board, turn it over, and repeat the first, second, third, and fourth steps. Step 5, Step 6, Step 7, Step 8, Step 9, Step 10, Step 11, make sure that both sides are pre-tinned.

The thirteenth step: remove the pre-tinned terminal board carrier on the carrier board of the soldering machine as shown in Figure 5, take off the solder ball cover 1 as shown in Figure 6, and connect the data line to be soldered as shown in Figure 10. Install it on the terminal board carrier, and install the cover plate 2 with the pressing claws on the terminal board carrier as shown in Figure 9. Each wire and the substrate copper pad correspond to the fixing claws, which can fix the wire in the center of the pad, There is a pressure of about 4N to press the wire, and one end of the wire to be soldered on the data line adopts the wire that has been pre-tinned. The length of the pre-tin is 1.5 mm, and one wire is arranged on each pad.

Step 14: Install the carrier for installing the data lines and solder pads to be soldered on the fixture carrier board as shown in Figure 4, and move the two-position platform below the position of the laser soldering galvanometer.

Step 15: Adjust the lift table to make the focus of the laser to a specific position. At 5 mm above the focus, keep enough power density to promote the best and fastest tin melting effect. The light spot follows a rectangular trajectory as shown in Figure 13. At 22 o'clock, a rectangular light spot 23 is formed under the fast motion of the galvanometer, and the size of the light spot is 0.3 mm wide and 1.6 mm long.

Step 16: Edit the soldering pattern on the software, and the soldering pattern is a rectangle according to the shape of the pad.

Step 17: Set the laser power, speed and times of laser emission. Edit graphics according to the shape of the pad, set different layers, set different laser power, speed and times for different layers, edit 2 same graphics, set different layers for each graphics, set different laser power and speed for different layers , times, the laser power of the first layer is 48W, the speed is 1600 mm/s, the times are 16 times, the power of the second layer is 28W, the speed is 2000 mm/s, the times are 8 times, there are 18 pads on the terminal PCB, and a single solder 18 copies of the welding pattern of the disk are displayed.

Step 18: Adjust the position of the solder joints, adjust the position of 18 soldering patterns, ensure that the laser of each soldering pattern hits the pads and does not exceed the pads, keep the X and Y axes of the two-dimensional platform static, and the specific The energy laser moves through the X-axis and Y-axis of the galvanometer, driving the laser to move and gather on the surface of the copper pad of the substrate. The soldering sequence is as shown in Figure 8, as shown in the following a2; d2; b2; e2; h2; k2; n2; q2; c2; f2; i2; l2;

Step 19: Control the laser light to irradiate the tin and the data wire to be soldered. After the tin is melted, the wire is pressed down under the action of the claw force. After the tin is cooled, the wire is wrapped to complete the tin soldering.

Step 20: This product is single-sided soldering. If soldering is required on both sides, flip the terminal board and the data cable to be soldered. Repeat steps 13, 14, and 15. Step 16, Step 17, Step 18, Step 19, complete the soldering.

It should be understood that the above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily imagine changes or Substitutions should be covered within the protection scope of the present invention.

Claims (2)

1. A laser soldering method of preset tin is characterized in that: the device is used for soldering a terminal PCB (printed Circuit Board) of a 5G network connection data line and a data line end, and adopts a laser soldering device with preset tin, and the device comprises a dispensing unit for adding soldering flux to the surface of a base material to be soldered, a laser soldering unit for melting tin on the surface of the base material to be soldered and a clamp unit for positioning the base material to be soldered; the specific operation steps are as follows:

the first step is as follows: placing the terminal board to be soldered on a terminal board clamp, fixing the terminal board through a cover plate on the clamp, and exposing a substrate copper sheet pad of the terminal board to be soldered;

the second step is that: placing the clamp provided with the terminal board on a carrier board, mounting the carrier on a two-dimensional platform, fixing the carrier, and driving the carrier to a position for dispensing the soldering paste by the two-dimensional platform;

the third step: adjusting the parameters of the dispensing machine, controlling the weight of the point soldering paste, and dispensing the soldering paste at all positions of the copper sheet bonding pads of the substrate to be soldered;

the fourth step: taking down the fixture which is provided with the terminal board and provided with the solder paste;

the fifth step: manually placing the solder balls to ensure that each solder ball is placed on the surface of the copper sheet pad of the substrate with the soldering paste;

and a sixth step: mounting the fixture with the solder balls on a carrier plate, placing the carrier plate on a two-dimensional platform of a laser soldering machine, and moving the two-dimensional platform to a laser soldering position;

the seventh step: the lifting platform is adjusted to enable the focus of the laser to reach a specific position, and sufficient power density is kept, so that the position with the best tin melting effect and the fastest efficiency can be promoted;

eighth step: editing a soldering graph on software, and editing the graph according to the shape of the pad by using the soldering graph;

the ninth step: setting the laser power, speed and times of laser emission of a laser; editing graphs according to the shape of the bonding pad, editing 3 same graphs, setting different layers for each graph, and setting different laser powers, speeds and times for the different layers; wherein, the laser power of the first layer is 7-30W, the speed is 1500-, the energy and time of the tin heat preservation and cooling device are set to be forty percent of the parameters of the second layer, so that the tin is ensured to be in a liquid state, the full melting of the internal tin is promoted, the internal gas is fully volatilized, and the formation of solid tin without gaps is ensured;

the tenth step: adjusting the position of a soldering point, keeping the X axis and the Y axis of the two-dimensional platform static, driving laser with specific energy to move through the X axis and the Y axis of a galvanometer, gathering the laser on the surface of a copper sheet bonding pad of the substrate, and setting the soldering sequence;

the eleventh step: controlling laser light to irradiate on the tin ball, so that the tin is melted on the copper sheet bonding pad of the substrate;

the twelfth step: if the two sides of the terminal board need to be soldered, taking down the terminal board, turning over and placing, repeating the first step, the second step, the third step, the fourth step, the fifth step, the sixth step, the seventh step, the eighth step, the ninth step, the tenth step and the tenth step, and ensuring that the two sides are all soldered;

the thirteenth step: taking down a terminal board carrier pre-loaded with tin on a two-dimensional platform on a soldering machine, taking down a cover plate, installing data lines to be soldered on the terminal board carrier, installing the cover plate with a pressing claw on the terminal board carrier, and fixing a wire rod in the center of a bonding pad by each line corresponding to a copper sheet bonding pad of a substrate;

the fourteenth step is that: mounting a carrier for mounting a data line to be soldered and a soldering pad on a two-dimensional platform of a soldering machine, and moving the carrier to a laser soldering position;

the fifteenth step: the lifting platform is adjusted to enable the focus of the laser to reach a specific position, and sufficient power density is kept, so that the position with the best tin melting effect and the fastest efficiency can be promoted;

sixteenth, step: editing a soldering graph on software, wherein the soldering graph is an edited graph according to the shape of the bonding pad;

seventeenth step: setting the laser power, speed and times of laser emission of a laser; editing 2 same graphs according to the shape of the bonding pad, wherein each graph is provided with a different layer, and the different layers are provided with different laser powers, speeds and times; wherein, the first layer laser power is 30-50W, the speed is 1500-;

and eighteenth step: adjusting the position of a welding spot, keeping an X axis and a Y axis of the two-dimensional platform static, driving laser with specific energy to move through the X axis and the Y axis of a galvanometer, focusing the laser on the surface of tin through a field lens, and setting the soldering sequence of the tin;

the nineteenth step: controlling laser light to irradiate on the tin and a data wire to be soldered, after the tin is melted, pressing the wire under the action of claw force, cooling the tin and then wrapping the wire rod to finish tin soldering;

the twentieth step: and if the two sides of the terminal board are required to be soldered, turning over the terminal board and the data wire to be soldered, and repeating the thirteenth step, the fourteenth step, the fifteenth step, the sixteenth step, the seventeenth step, the eighteenth step and the nineteenth step to finish soldering.

2. The laser soldering method of preplaced tin according to claim 1, characterized in that: the dispensing unit comprises a three-axis moving platform and a paste outlet needle cylinder arranged at the moving end of the three-axis moving platform; the laser soldering unit comprises a continuous laser, a lifting platform and an XY-axis working platform; the clamp unit comprises a lower support plate, a middle positioning plate and an upper cover plate, wherein the lower support plate is provided with a positioning taper pin, the middle positioning plate is provided with a positioning taper hole, and the upper cover plate is provided with a line pressing claw.

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