High quality laser welding manufacturing apparatus and method

Abstract

The application discloses a high-quality laser welding manufacturing device and method, and solves the problems of concentrated energy distribution, small inherent focal depth, insufficient deep-diameter ratio and welding thickness of existing ultrafast laser welding technology, and specifically comprises a laser source for emitting welding laser, a variable magnification collimation system, a cone mirror, an acousto-optic modulation unit and a long focal depth compression unit which are sequentially arranged on the light path of the welding laser in the direction of the welding laser emission; the variable magnification collimation system is used for changing the spot diameter of the welding laser and collimating the welding laser; the cone mirror is used for shaping the welding laser after the change of the diameter and collimation into long focal depth laser; the acousto-optic modulation unit divides the long focal depth laser into N sub-beams, and adjusts the spatial positions of the sub-beams, wherein N is greater than or equal to 1 and is a positive integer; and the long focal depth compression unit is used for adjusting the spot diameter and focal depth length of each sub-beam, so that the focal point position and energy of the sub-beam are suitable for laser welding.

Description

Technical Field

[0001] This invention relates to an apparatus and method for optical welding manufacturing, and more specifically to a high-quality laser welding manufacturing apparatus and method. Background Technology

[0002] In high-tech fields such as optoelectronics and aerospace, brittle materials (such as glass, silicon, and sapphire) are widely used due to their unique and excellent optical, electrical, acoustic, thermal, and chemical properties. They are often used as encapsulation materials to join materials of the same or different polarities, providing reliable sealing without affecting device functionality. Existing methods for joining brittle materials generally suffer from drawbacks such as poor stability, the need for additional materials, or stringent requirements on the surface quality of the materials being joined, and the requirement for their coefficients of thermal expansion to be close. Therefore, there is an urgent need for new, efficient, and precise joining and processing methods.

[0003] Material bonding / welding refers to the direct or indirect establishment of atomic and molecular bonds between two independent solid objects through appropriate physicochemical processes, thereby forming a bonded whole. With the continuous advancement of modern industrial production, material bonding technology has been widely applied in the manufacturing or assembly processes of aerospace, defense, precision optomechanics, biomedicine, and optoelectronic sensing, becoming an indispensable and crucial link. Due to the highly localized temperature field induced by lasers, ultrafast laser welding can be performed with the sample entirely at room temperature, making it particularly suitable for the packaging of thermistor-sensitive optoelectronic devices with low thermal damage thresholds. It is also applied in 3C precision welding, integrated circuit packaging bonding methods evolving from traditional wire bonding to ball bump welding, semiconductors, new electronics, and new energy applications, welding various materials such as ultrathin, ultrahard, brittle, and flexible materials, packaging microfluidic devices and sensors, and connecting window devices in consumer electronics and aerospace equipment. Furthermore, it is applied to the laser welding of metal bipolar plates in the hydrogen fuel cell industry, or bipolar plates for water electrolysis hydrogen production, suitable for lap welding and sealing welding of materials such as titanium alloys and 316L stainless steel.

[0004] Current welding technologies mainly include adhesive bonding, high-temperature sealing processes, solid-phase bonding, anodic bonding, electron beam welding, arc welding, fusion welding, and traditional laser welding.

[0005] 1. Adhesive bonding generally refers to the technique of achieving bonding between objects through the curing reaction process of organic or inorganic adhesives. Adhesive bonding is simple to operate and applicable to a wide range of materials, but it has disadvantages such as easy bleaching, easy aging, and release of harmful gases, making it difficult to use in aerospace, high-temperature, and high-load conditions. During service, this process often leads to gradual failure of the seal due to the gradual deterioration of the organic chemical adhesives.

[0006] 2. High-temperature sealing process involves sealing the glass and metal by maintaining them at high temperatures for an extended period. The problem with this process is that prolonged high-temperature insulation can damage the functional properties of the glass. Furthermore, if the metal is a material with poor oxidation resistance, such as aluminum alloy, stainless steel, or titanium alloy, its properties will also be adversely affected.

[0007] 3. Solid-state bonding refers to the overall connection of materials at their contact surfaces through plastic deformation or atomic diffusion without melting. It mainly includes methods such as friction welding, diffusion welding, ultrasonic welding, and explosive welding. Solid-state bonding can achieve large-area welding between objects, but it requires high-quality surface preparation of the objects to be welded and a long welding process. Furthermore, when welding dissimilar materials, a transition layer is often needed to alleviate problems such as mismatch of material physical properties and stress concentration.

[0008] 4. Anodic bonding is a bonding process that can rapidly achieve strong bonding at relatively low temperatures. Polished samples are stacked together, and under conditions of 300℃~500℃ and DC voltage 200V~2000V, ion migration forms a strong bonding layer at the interface. The welding method provided by this invention is widely used in microelectromechanical packaging due to its high stability. However, this technology requires a high degree of matching in the coefficients of thermal expansion of the two materials to be bonded; otherwise, it will greatly affect the fatigue resistance of the welded object.

[0009] 5. Electron beam welding is a fusion welding process in which a high-speed electron beam is applied to two materials to be joined. When the kinetic energy of the electrons is converted into heat upon impact, the workpieces melt and flow together. Electron beam welding is usually performed under vacuum conditions to prevent electron beam dissipation. This welding method has a relatively severe heat-affected zone, high residual stress, and the substrate is prone to deformation.

[0010] 6. Arc welding uses the metal to be welded as one electrode and the welding rod as the other. When the two electrodes are close together, an electric arc is generated, causing the material at the interface to melt and then solidify. This welding method has a relatively severe heat-affected zone, high residual stress, and the substrate is prone to deformation.

[0011] 7. Long-pulse / continuous laser thermofusion welding technology is a type of traditional fusion welding, utilizing a high-energy-density laser beam as a heat source for efficient and precise welding. This welding method has outstanding advantages such as high energy density, fast welding speed, low heat input, and minimal welding deformation. However, for achieving high-quality welding of transparent materials, traditional continuous lasers or long-pulse lasers are still not an ideal choice.

[0012] The traditional bonding / welding processes mentioned above have varying degrees of technical defects and limitations in processing precision, making it difficult to meet the demands of today's increasingly developed industrial production for high-efficiency, high-precision, and low-pollution processing.

[0013] Therefore, ultrafast laser welding is currently widely used. Ultrafast laser welding is a precision welding technology based on the nonlinear absorption mechanism of ultrafast laser energy, which enables the plasma atomization and reconstruction of dissimilar materials within a microscale range at the interface to achieve connection. It features high efficiency, high precision, high spatial selectivity, and high material applicability; when a micro-focal-level ultrafast laser is focused by a lens, the peak optical power density in the focal field region can reach 10¹³ W / cm². 2 The above is sufficient to induce nonlinear absorption in transparent materials, enabling direct selective deposition of laser energy and creating localized high temperatures at the laser focal point within the material. When the laser focal point is located at the interface of the sample to be welded, the localized high temperatures induced by laser energy deposition will cause phase transitions, ion migrations, and even the generation of supercritical fluids in the material near the interface. After the laser radiation ends, the material cools and solidifies, establishing a strong connection through fusion or bonding. Due to the high peak power density and short duration of the focused ultrafast laser, only a small amount of laser energy is needed to induce phase transitions in the localized material. In addition, some of the energy deposited by the laser is consumed and converted in the picosecond to nanosecond range, greatly reducing the laser-induced heat-affected zone, thereby reducing the stress at the weld interface and improving the high and low temperature servo performance of the welded structure. Therefore, ultrafast laser-based precision selective welding technology has many advantages over other welding processes, including low heat-affected zone, three-dimensional spatial selectivity, high welding strength and efficiency, and high operational controllability.

[0014] However, current ultrafast laser welding technologies all use Gaussian lasers. Gaussian lasers have a concentrated energy distribution and extremely high instantaneous energy density, exceeding 10. 14 W / ㎝ 2 The temperature gradient between the irradiated and non-irradiated areas is extremely large, and the molten pool fluid / gas cannot escape, resulting in high surface roughness and insufficient weld strength. In addition, Gaussian lasers are inherently shallow due to the influence of the optical Rayleigh criterion, leading to insufficient weld depth-to-diameter ratio and weld thickness. Summary of the Invention

[0015] To address the technical problems of concentrated energy distribution, small inherent depth of focus, insufficient depth-to-diameter ratio, and insufficient weld thickness in existing ultrafast laser welding technology, this invention provides a high-quality laser welding manufacturing apparatus and method.

[0016] To achieve the above objectives, the present invention adopts the following technical solution:

[0017] A high-quality welding manufacturing apparatus is characterized by comprising a laser source for emitting welding laser, and a variable magnification collimation system, a conical lens, an acousto-optic modulation unit, and a long focal depth compression unit arranged sequentially along the direction of the welding laser emission in its optical path.

[0018] The variable magnification collimation system is used to change the spot diameter of the welding laser and collimate it;

[0019] The conical mirror is used to shape the welding laser after diameter adjustment and collimation into a long focal depth laser.

[0020] The acousto-optic modulation unit is used to divide the long focal depth laser into N sub-beams using N different and / or identical frequency sound waves, and to adjust the spatial position of each sub-beam, where N ≥ 1 and is a positive integer.

[0021] The long focal depth compression unit is used to adjust the spot diameter and focal depth of each sub-beam so that its focal position and energy are suitable for laser welding.

[0022] Furthermore, the acousto-optic modulation unit includes an X-direction acousto-optic modulator, a λ / 4 waveplate, and a Y-direction acousto-optic modulator sequentially arranged in the optical path of the long focal depth laser, as well as an X-direction acousto-optic driver connected to the X-direction acousto-optic modulator, a Y-direction acousto-optic driver connected to the Y-direction acousto-optic modulator, and a controller connected to the X-direction acousto-optic driver and the Y-direction acousto-optic driver respectively; λ is the wavelength.

[0023] The controller is used to apply different and / or the same magnitude of first electrical signal amplitude modulation to the X-direction acousto-optic modulator via an X-direction acousto-optic driver, so that the X-direction acousto-optic modulator obtains sound waves of different and / or the same frequency, thereby dividing the long focal depth laser into multiple first sub-beams with different and / or the same energy and different and / or the same spatial position in the X direction. The number of the first sub-beams corresponds to the amplitude modulation of the first electrical signal. The controller is also used to apply different and / or the same magnitude of second electrical signal amplitude modulation to the Y-direction acousto-optic modulator via a Y-direction acousto-optic driver, so that the Y-direction acousto-optic modulator obtains sound waves of different and / or the same frequency, thereby dividing a corresponding number of first sub-beams into multiple second sub-beams with different and / or the same energy and different and / or the same spatial position in the Y direction. The number of the second sub-beams corresponds to the amplitude modulation of the second electrical signal. This results in N sub-beams.

[0024] The λ / 4 waveplate is used to change the polarization state of the first sub-beam from linearly polarized light to circularly polarized light.

[0025] Furthermore, the X-direction acousto-optic modulator includes an X-direction acousto-optic crystal and an X-direction pressure transducer;

[0026] The X-direction acousto-optic crystal is positioned in the optical path of the long focal depth laser.

[0027] The input end of the X-direction pressure transducer is connected to the output end of the X-direction acousto-optic driver. The X-direction pressure transducer is bonded to the X-direction acousto-optic crystal and is used to receive first electrical signals of different and / or the same magnitude for amplitude modulation and convert them into a first mechanical wave field. This causes the X-direction acousto-optic crystal to vibrate with the first mechanical wave field. The refractive index of the X-direction acousto-optic crystal changes according to the amplitude modulation law of the first electrical signal to form a first ultrasonic grating. The first ultrasonic grating modulates the long focal depth laser, causing the long focal depth laser to be deflected at different angles, thereby splitting it into multiple first sub-beams with different and / or the same energy and different and / or the same spatial position in the X direction.

[0028] Furthermore, the Y-direction acousto-optic modulator includes a Y-direction acousto-optic crystal and a Y-direction pressure transducer;

[0029] The Y-direction acousto-optic crystal is positioned on the optical path of the first sub-beam.

[0030] The input end of the Y-direction pressure transducer is connected to the output end of the Y-direction acousto-optic driver. The Y-direction pressure transducer is bonded to the Y-direction acousto-optic crystal and is used to receive second electrical signals of different and / or the same magnitude for amplitude modulation, and convert them into a second mechanical wave field. This causes the Y-direction acousto-optic crystal to vibrate with the second mechanical wave field. The refractive index of the Y-direction acousto-optic crystal changes according to the amplitude modulation law of the first electrical signal, forming a second ultrasonic grating. The second ultrasonic grating modulates a corresponding number of first sub-beams, causing the corresponding number of first sub-beams to deflect at different angles, thereby dividing them into multiple second sub-beams with different and / or the same energy and different and / or the same spatial position in the Y direction. The sum of the number of undivided first sub-beams and the number of divided second sub-beams is N.

[0031] Furthermore, the long focal depth compression unit includes a plano-convex mirror, a filter, and a focusing objective lens arranged sequentially along the optical path of the N sub-beams;

[0032] The plano-convex mirror is used to proportionally converge the spatial positions of the N sub-beams.

[0033] The filter is used to adjust the energy of the N-beam beam online by using different transmittances;

[0034] The focusing objective is used to focus each sub-beam separately.

[0035] Furthermore, the zoom collimation system is a zoom lens set in the optical path of the welding laser.

[0036] Furthermore, the long focal depth compression unit also includes a reflector disposed between the acousto-optic modulation unit and the plano mirror;

[0037] The reflector is used to reflect the N-beam sub-beams to the plano-convex mirror.

[0038] Furthermore, the laser source is a Gaussian laser source;

[0039] The filter is a liquid crystal filter.

[0040] A high-quality welding manufacturing method, employing the aforementioned high-quality welding manufacturing apparatus, is characterized by comprising the following steps:

[0041] Step 1: Analyze the welding requirements and determine the number N of sub-beams used for welding and the spot shape of each sub-beam based on the welding requirements; the spot shape includes the spot diameter, focal depth, energy and spatial distribution position of each sub-beam.

[0042] Step 2: Set the welding parameters for the variable magnification collimation system, conical lens, acousto-optic modulation unit, and long focal depth compression unit according to the determined number of sub-beams N and the spot shape of each sub-beam.

[0043] Step 3: Start the laser source; the laser source emits a welding laser.

[0044] Step 4: The variable magnification collimation system receives the welding laser, changes the spot diameter of the welding laser, and collimates it;

[0045] Step 5: The conical mirror receives the welding laser after it has been collimated by the diameter change and shapes it into a long focal depth laser.

[0046] Step 6: The acousto-optic modulation unit receives the long focal depth laser, divides the long focal depth laser into N sub-beams through N different and / or the same frequency sound waves, and adjusts the spatial position of each sub-beam.

[0047] Step 7: The long focal depth compression unit receives N sub-beams and adjusts the spot diameter and focal depth of each sub-beam so that its focal position and energy are suitable for laser welding.

[0048] Step 8: Perform welding using the adjusted N-beam sub-beam.

[0049] Furthermore, step 2 specifically involves:

[0050] The magnification of the variable magnification collimation system is adjusted according to the spot diameter of each sub-beam; the angle of the conical mirror and the focal length of the plano-convex mirror and focusing objective in the long focal depth compression unit are adjusted according to the focal depth length of each sub-beam; and the controller is adjusted to output first electrical signals of different and / or the same magnitude and frequency to the X-direction acousto-optic modulator through the X-direction acousto-optic driver and to output second electrical signals of different and / or the same magnitude and frequency to the Y-direction acousto-optic modulator through the Y-direction acousto-optic driver for amplitude modulation, according to the number N, energy, and spatial distribution of the sub-beams.

[0051] Step 6 specifically involves:

[0052] The X-direction pressure transducer receives multiple first electrical signals of different and / or the same magnitude and frequency, modulates them, and converts them into a first mechanical wave field. The X-direction acousto-optic crystal vibrates with the first mechanical wave field, causing the refractive index of the X-direction acousto-optic crystal to change according to the variation law of the first electrical signal amplitude modulation, forming a first ultrasonic grating. The first ultrasonic grating modulates the long focal depth laser, causing the long focal depth laser to be deflected at different angles, thereby dividing it into multiple first sub-beams with different and / or the same energy and different and / or the same spatial position in the X direction. The first sub-beams correspond to the first electrical signal amplitude modulation.

[0053] The first sub-beam, after passing through a λ / 4 waveplate, has its polarization state changed from linearly polarized to circularly polarized.

[0054] The Y-direction pressure transducer receives multiple second electrical signals of different and / or the same magnitude and frequency, modulates them, and converts them into a second mechanical wave field. The Y-direction acousto-optic crystal vibrates with the second mechanical wave field, causing the refractive index of the Y-direction acousto-optic crystal to change according to the amplitude modulation law of the second electrical signal, forming a second ultrasonic grating. The second ultrasonic grating modulates a corresponding number of first sub-beams, causing the corresponding number of first sub-beams to be divided into multiple second sub-beams with different and / or the same energy and different and / or the same spatial position in the Y direction. The number of second sub-beams corresponds to the amplitude modulation of the second electrical signal; the sum of the number of undivided first sub-beams and the number of divided second sub-beams is N.

[0055] The beneficial effects of this invention are:

[0056] 1. The high-quality welding manufacturing apparatus and method provided by this invention, due to the setting of a conical mirror and a long focal depth compression unit, can adjust the welding laser to a long focal depth laser; at the same time, it also sets an acousto-optic modulator, which can perform three-dimensional adjustment of the welding laser emitted by the laser source, that is, it can divide the long focal depth laser into N sub-beams through N different and / or the same frequency sound waves, and adjust the spatial position of each sub-beam; this not only improves the thickness of ultrafast laser welding, but also allows welding of components within the curvature range to be completed by laser direct writing without relying on a motion platform.

[0057] 2. The high-quality welding manufacturing apparatus and method provided by the present invention can control the X-direction acousto-optic driver and the Y-direction acousto-optic driver in the optical modulation unit to send electrical signals of different magnitudes and frequencies to the X-direction acousto-optic modulator and the Y-direction acousto-optic modulator respectively for amplitude modulation, so as to achieve homogenization / long focal depth three-dimensional shaping of arbitrary light spot shape, such as realizing two-dimensional homogenization of various shapes such as C-shape, ring, T-shape, and three-point shape. In addition, the homogenized light spot also takes into account the long focal depth shaping capability, realizing three-dimensional shaping.

[0058] 3. The high-quality welding manufacturing apparatus and method provided by the present invention, by employing a conical lens and a long focal depth compression unit, enables the minimum feature size of the focused spot of each sub-beam to reach the micrometer level, thereby achieving welding precision at the micrometer level and greatly reducing the thermal damage to the product caused by the welding process.

[0059] 4. The high-quality welding manufacturing apparatus and method provided by this invention can achieve welding of heterogeneous materials without the need for an embedded layer. Due to the unique effect of the induced nonlinear absorption of ultrafast lasers, high-precision welding of different materials can be achieved, such as glass-metal, glass-semiconductor materials, glass-glass, etc. Moreover, the welding process has extremely high spatial selectivity. Transparent materials such as quartz glass, sapphire wafers, and polymers are often sensitive to stress. When subjected to continuous laser action, the induced thermal effect can easily cause severe distortion and fragmentation of the material. This invention can solve the problem of direct selective deposition of laser energy on transparent materials by adjusting the spatial position of the sub-beam. Ultrafast laser welding is applicable to a wide range of materials.

[0060] 5. By adjusting the spatial position of the sub-beam, this invention allows nitrogen bubbles to escape from the welding area, thereby improving the width-to-depth ratio of the weld, reducing oxidation and eliminating hot cracks. For example, the T-shaped welding shape can be scanned along the weld, thereby improving the post-weld annealing, reducing the weld angle, and increasing the weld strength. Attached Figure Description

[0061] Figure 1 This is a schematic diagram of an embodiment of a high-quality laser welding manufacturing device according to the present invention;

[0062] Figure 2 This is a schematic diagram of the acousto-optic modulation unit in an embodiment of the present invention;

[0063] Figure 3 This is a schematic diagram of six sub-beams forming a C-shaped light spot in an embodiment of the present invention;

[0064] Figure 4 This is a schematic diagram of the scanning welding path in an embodiment of the present invention;

[0065] Figure 5 This is a schematic diagram of five sub-beams forming a T-shaped light spot in an embodiment of the present invention.

[0066] Icon labels:

[0067] 1-Laser source, 2-Variable magnification collimation system, 3-Conical lens, 4-Acousto-optic modulation unit, 41-X-direction acousto-optic modulator, 411-X-direction acousto-optic crystal, 412-X-direction pressure transducer, 42-λ / 4 waveplate, 43-Y-direction acousto-optic modulator, 431-Y-direction acousto-optic crystal, 432-Y-direction pressure transducer, 44-X-direction acousto-optic driver, 45-Y-direction acousto-optic driver, 46-Controller, 5-Long focal depth compression unit, 51-Plan-convex lens, 52-Filter, 53-Focusing objective lens, 54-Reflecting mirror. Detailed Implementation

[0068] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0069] This invention provides a high-quality welding manufacturing apparatus, such as... Figure 1 As shown, it includes a laser source 1 for emitting welding laser, and a variable magnification collimation system 2, a conical mirror 3, an acousto-optic modulation unit 4 and a long focal depth compression unit 5 arranged sequentially along the direction of the welding laser emission in its optical path; the laser source 1 is a Gaussian laser source.

[0070] The variable magnification collimation system 2 is used to change the spot diameter of the welding laser and collimate it; the variable magnification collimation system 2 is a zoom lens set in the optical path of the welding laser, and in this embodiment, a 2x zoom lens is preferred.

[0071] Conical mirror 3 is used to shape the welding laser after diameter adjustment and collimation into a long focal depth laser;

[0072] like Figure 2As shown, the acousto-optic modulation unit 4 is used to divide a long-depth-of-focus laser into N sub-beams using N different and / or identical acoustic waves, and to adjust the spatial position of each sub-beam, where N ≥ 1 and is a positive integer. The acousto-optic modulation unit 4 includes an X-direction acousto-optic modulator 41, a λ / 4 waveplate 42, and a Y-direction acousto-optic modulator 43, which are sequentially arranged on the optical path of the long-depth-of-focus laser. It also includes an X-direction acousto-optic driver 44 connected to the X-direction acousto-optic modulator 41, a Y-direction acousto-optic driver 45 connected to the Y-direction acousto-optic modulator 43, and a controller 46 connected to both the X-direction and Y-direction acousto-optic drivers 44 and 45, respectively. λ is the wavelength. The controller 46 is used to apply different and / or identical first electrical signals to the X-direction acousto-optic modulator 41 via the X-direction acousto-optic driver 44 for amplitude modulation, so that the X-direction acousto-optic modulator 41... The optical modulator 41 obtains acoustic waves of different and / or the same frequency, thereby dividing the long focal depth laser into multiple first sub-beams with different and / or the same energy and different and / or the same spatial positions in the X direction. The number of first sub-beams corresponds to the amplitude modulation of the first electrical signal. The Y-direction acousto-optic driver 45 loads a second electrical signal amplitude modulation of different and / or the same magnitude onto the Y-direction acousto-optic modulator 43, so that the Y-direction acousto-optic modulator 43 obtains acoustic waves of different and / or the same frequency, thereby dividing the corresponding number of first sub-beams into multiple second sub-beams with different and / or the same energy and different and / or the same spatial positions in the Y direction. The number of second sub-beams corresponds to the amplitude modulation of the second electrical signal. N sub-beams are obtained. A λ / 4 waveplate is used to change the polarization state of the first sub-beams from linearly polarized light to circularly polarized light. The X-direction acousto-optic modulator 41 includes an X-direction acousto-optic crystal 411 and an X-direction pressure transducer 412. The X-direction acousto-optic crystal 411 is disposed in the optical path of the long-depth-of-focus laser. The input end of the X-direction pressure transducer 412 is connected to the output end of the X-direction acousto-optic driver. The X-direction pressure transducer 412 is bonded to the X-direction acousto-optic crystal 411 and is used to receive first electrical signals of different and / or the same magnitude for amplitude modulation and convert them into a first mechanical wave field. This causes the X-direction acousto-optic crystal 411 to vibrate with the first mechanical wave field. The refractive index of the X-direction acousto-optic crystal 411 changes according to the amplitude modulation law of the first electrical signal to form a first ultrasonic grating. The first ultrasonic grating modulates the long-depth-of-focus laser, causing the long-depth-of-focus laser to deflect at different angles, thereby splitting it into multiple first sub-beams with different and / or the same energy and different and / or the same spatial position in the X direction.The Y-direction acousto-optic modulator 43 includes a Y-direction acousto-optic crystal 431 and a Y-direction pressure transducer 432. The Y-direction acousto-optic crystal 431 is disposed in the optical path of the first sub-beam. The input end of the Y-direction pressure transducer 432 is connected to the output end of the Y-direction acousto-optic driver 45. The Y-direction pressure transducer 432 is bonded to the Y-direction acousto-optic crystal 431 and is used to receive second electrical signals of different and / or the same magnitude for amplitude modulation, and convert them into a second mechanical wave field, so that the Y-direction acousto-optic crystal 431 vibrates with the second mechanical wave field. The refractive index of the Y-direction acousto-optic crystal 431 changes according to the amplitude modulation law of the first electrical signal, forming a second ultrasonic grating. The second ultrasonic grating modulates a corresponding number of first sub-beams, so that the corresponding number of first sub-beams are deflected at different angles, thereby dividing them into multiple second sub-beams with different and / or the same energy and different and / or the same spatial position in the Y direction. The sum of the number of undivided first sub-beams and the number of divided second sub-beams is N.

[0073] The modulation signal of the welding laser used in the acousto-optic modulation unit 4 is applied to the pressure energy transducer in the form of an amplitude-modulated electrical signal, and then converted into a mechanical wave field that changes in the form of an electrical signal. The relationship between the applied electrical signal modulation power and the strain tensor S of the medium (X-direction acousto-optic crystal, Y-direction acousto-optic crystal) is as follows:

[0074] P = 1 / 2ρV 3 S 2 LH

[0075] Where P is the power of the amplitude modulation of the electrical signal, L and H are the length and width of the pressure transducer, V is the velocity of the sound wave in a specific transmission direction in the acousto-optic crystal, and ρ is the density of the acousto-optic crystal.

[0076] The change in acoustic refractive index ne is:

[0077] ne = 1 / 2n i Θ eff S

[0078] Where ni is the refractive index of the acousto-optic crystal, Θ eff The effective acoustic-optic coefficient.

[0079] When the two frequencies are f1 and f i (corresponding wavelengths are λ1 and λ) i An ultrasonic wave with a wave speed of V s propagates simultaneously along the x-direction in an acousto-optic crystal with a refractive index of n. e The thickness of the ultrasonic grating (along the z-axis) is L. A collimated spatial beam is incident on the acousto-optic crystal at an angle θ with the z-axis. After the two ultrasonic waves interact with the light, the diffracted principal diffracted mode beam forms a 2θ angle with the incident beam. i The angle, where the incident long focal depth laser wavelength is λ, is the sub-beam deflection angle θ. iThe relationship is as follows:

[0080] 2θ i =2sin -1 (λf i / 2n e V s ).

[0081] The long focal depth compression unit 5 is used to adjust the spot diameter and focal depth of each sub-beam so that its focal position and energy are suitable for laser welding. The long focal depth compression unit 5 includes a reflecting mirror 54, a plano-convex mirror 51, a filter 52 (liquid crystal filter), and a focusing objective lens 53 arranged sequentially along the optical path of the N sub-beams. The reflecting mirror 54 reflects the N sub-beams to the plano-convex mirror 51. The plano-convex mirror 51 is used to proportionally converge the spatial positions of the N sub-beams; the filter 52 is used to adjust the energy of the N sub-beams online by using different transmittances; and the focusing objective lens 53 is used to focus each sub-beam separately.

[0082] The aforementioned welding equipment was used for welding dissimilar materials (stainless steel and glass, component thickness 500 μm, weld line width 5 μm, damage thresholds of 0.05 J / cm for stainless steel and glass, respectively). 2 0.75J / cm 2 The welding process includes the following steps:

[0083] Step 1: Analyze the welding requirements. Based on these requirements, determine the number of sub-beams used for welding, N=6, and the spot shape of each sub-beam. This spot shape includes: spot diameter < 5 μm, focal depth ≥ 500 μm, energy > 30 μJ, and spatial distribution (diffraction angle) of each sub-beam as follows: Figure 3 The C-shape shown;

[0084] Step 2: Based on the determined number of sub-beams N=6 and the spot shape of each sub-beam, set the welding parameters of the zoom collimation system 2, the conical mirror 3, the acousto-optic modulation unit 4, and the long focal depth compression unit 5; specifically, adjust the zoom magnification of the zoom collimation system 2 by 2 times based on the spot diameter of each sub-beam (1.3μm); adjust the angle of the conical mirror 3 to 5° and the focal length of the plano-convex mirror 51 in the long focal depth compression unit 5 to 54mm and the focal length of the focusing objective lens 53 to 3.6mm based on the focal depth of each sub-beam; based on the number of sub-beams (6), diffraction angle (0.1rad), energy (30µjoules), and spatial distribution position (C-shaped), make the controller 46 output two identical beams of the same size and frequency to the X-direction acousto-optic modulator 41 through the X-direction acousto-optic driver 44. The first electrical signal is amplitude modulated at 150W, and the controller 46 outputs two second electrical signals of the same magnitude and frequency, each also amplitude modulated at 150W, to the Y-direction acousto-optic modulator 43 via the Y-direction acousto-optic driver 45. In other embodiments, the first electrical signal amplitude modulated and the second electrical signal amplitude modulated at different magnitudes and frequencies can also be output. Given that the maximum refresh frequency of the acousto-optic modulator is 150kHz, the applied acousto-optic frequency is refreshed every 6.6s, thereby enabling the opening of the C-shaped light spot to rotate toward the center point during the welding process, specifically as follows: Figure 4 As shown.

[0085] Step 3: Start laser source 1. Laser source 1 emits a welding laser with a spot diameter of 5.4 mm.

[0086] Step 4: The 2x collimation system 2 receives the welding laser, changes the laser spot diameter to 10.8mm, and collimates it.

[0087] Step 5: Conical lens 3 receives the welding laser after diameter adjustment and collimation, and shapes it into a long focal depth laser with a focal length of 135mm.

[0088] Step 6: The acousto-optic modulation unit 4 receives the long-depth-of-focus laser and splits it into six sub-beams using six acoustic waves of the same frequency to form a C-shape; specifically:

[0089] The X-direction pressure transducer 412 receives three first electrical signals of the same magnitude and frequency, modulates them, and converts them into a first mechanical wave field. The X-direction acousto-optic crystal 411 vibrates with the first mechanical wave field, causing the refractive index of the X-direction acousto-optic crystal 411 to change according to the variation law of the first electrical signal amplitude modulation, forming a first ultrasonic grating. The first ultrasonic grating modulates the long focal depth laser, causing the long focal depth laser to be deflected at different angles, thereby splitting it into three first sub-beams with the same energy and different spatial positions in the X direction.

[0090] The three first sub-beams pass through a λ / 4 waveplate, and their polarization state changes from linearly polarized light to circularly polarized light.

[0091] The Y-direction pressure transducer 432 receives two second electrical signals of the same magnitude and frequency, modulates them, and converts them into a second mechanical wave field. The Y-direction acousto-optic crystal 431 vibrates with the second mechanical wave field, causing the refractive index of the Y-direction acousto-optic crystal 431 to change according to the amplitude modulation law of the second electrical signal, forming a second ultrasonic grating. The second ultrasonic grating modulates the three first sub-beams, causing the three first sub-beams to be divided into six second sub-beams with the same energy but different spatial positions in the Y direction. The six sub-beams then form a C-shape.

[0092] Step 7: The long focal depth compression unit 5 receives 6 sub-beams and adjusts the spot diameter of each sub-beam to 1.3μm and the focal depth of each sub-beam to 600μm so that its energy is suitable for laser welding; a distance sensor is used to measure the distance between the laser focus and the processing point, and the laser focus is placed at the center of the thickness of the welded component.

[0093] Step 8: Following the adjusted 6 sub-beams... Figure 4 Welding is performed by scanning the welding path shown. Since the focal depth can completely cover the welding thickness of the entire component, welding can be performed directly by scanning. After initial positioning, there is no need to adjust the working distance between the spot and the component through the motion platform.

[0094] Machine vision is used to continuously capture multiple welding images of the target being welded, allowing for real-time monitoring of weld seam changes. Since the weld linewidth remains fixed at 5μm, there's no need to change the focusing spot of the six sub-beams; only the opening of the C-shaped spot needs adjustment. The C-shaped spot primarily facilitates the escape of plasma, molten material, and vaporized substances from the welding area, suppressing the thermal impact of the laser focal region, improving the aspect ratio, reducing oxidation, and minimizing noticeable cracks and defects. A temperature sensor is used to obtain the sensing temperature of the target being welded. When the measured welding temperature is 10% lower or higher than the preset welding temperature, the welding state is considered abnormal. The energy density of the laser spot is increased or decreased by adjusting the transmittance of the liquid crystal filter.

[0095] The aforementioned welding equipment was used for welding dissimilar materials (stainless steel and glass, component thickness 500μm-1000μm, weld line width 8μm, damage thresholds of 0.05J / cm for stainless steel and glass, respectively). 2 0.75J / cm 2 The welding process includes the following steps:

[0096] Step 1: Analyze the welding requirements and determine the number of sub-beams used for welding and distributed in a T-shape as N=5, as well as the spot shape of each sub-beam: the spot diameter of each sub-beam < 5μm, the focal depth of each sub-beam ≥ 800μm, the energy of each sub-beam > 30uJ, and the spatial distribution of each sub-beam is T-shaped.

[0097] Step 2: Based on the determined number of sub-beams 5 and the spot shape of each sub-beam, set the welding parameters for the variable magnification collimation system 2, the conical lens 3, the acousto-optic modulation unit 4, and the long focal depth compression unit 5; specifically including:

[0098] The magnification of the magnification collimation system 2 is adjusted to 2 based on the spot diameter of each sub-beam (3μm); the angle of the conical mirror 3 is adjusted to 2° based on the focal depth of each sub-beam; the focal length of the plano-convex mirror 51 in the long focal depth compression unit 5 is adjusted to 150mm and the focal length of the focusing objective (53) is adjusted to 10mm; based on the number of sub-beams 5, diffraction angles (0.06, 0.08rad, 0.1rad), energy of 30 microjoules, and T-shaped spatial distribution, the controller 46 outputs three first electrical signals of different magnitudes and frequencies (60W, 80W, 100W) to the X-direction acousto-optic modulator 41 via the X-direction acousto-optic driver 44, and the controller 46 outputs three second electrical signals of different magnitudes and frequencies (60W, 80W, 100W) to the Y-direction acousto-optic modulator 43 via the Y-direction acousto-optic driver 45.

[0099] Step 3: Start laser source 1. Laser source 1 emits welding laser, and the laser spot diameter is 5.4mm.

[0100] Step 4: The 2x variable diameter collimation system 2 receives the welding laser, changes the spot diameter of the welding laser to 10.8mm, and collimates it.

[0101] Step 5: Conical lens 3 receives the welding laser after magnification and collimation, and shapes it into a long focal depth laser of 216mm;

[0102] Step 6: The acousto-optic modulation unit 4 receives the long focal depth laser and divides it into 5 sub-beams using 5 sound waves of the same frequency to form a T-shaped distribution.

[0103] The X-direction pressure transducer 412 receives three or more first electrical signals of different magnitudes and frequencies, modulates them, and converts them into a first mechanical wave field. The X-direction acousto-optic crystal 411 vibrates with the first mechanical wave field, causing the refractive index of the X-direction acousto-optic crystal 411 to change according to the variation law of the first electrical signal amplitude modulation, forming a first ultrasonic grating. The first ultrasonic grating modulates the long focal depth laser received by the X-direction acousto-optic crystal 411, causing the long focal depth laser to deflect at different angles, thereby splitting the long focal depth laser into three first sub-beams along the X-direction.

[0104] The polarization state of the first sub-beam changes from linearly polarized light to circularly polarized light after passing through the λ / 4 waveplate.

[0105] The Y-direction pressure transducer 432 receives two second electrical signals of different magnitudes and frequencies, modulates them, and converts them into a second mechanical wave field. The Y-direction acousto-optic crystal 431 vibrates with the second mechanical wave field, causing its refractive index to change according to the amplitude modulation pattern of the second electrical signals, forming a second ultrasonic grating. The second ultrasonic grating modulates the first sub-beam received by the Y-direction acousto-optic crystal 431, causing the middle first sub-beam to split into three second sub-beams at different spatial positions in the Y direction. The sum of the number of undivided first sub-beams and the number of divided second sub-beams is 5, forming a pattern as shown in the image. Figure 5 The T-shaped pattern shown, along with the partial superposition of the three second sub-beams distributed along the Y-axis, increases the energy density at the superposition point, resulting in a wider processing width and greater processing depth.

[0106] Step 7: The long focal depth compression unit 5 receives 5 sub-beams and adjusts the spot diameter of each sub-beam to 3.0 μm and the focal depth length to 960 μm so that its energy is suitable for laser welding; a distance sensor is used to measure the distance between the laser focus and the processing point, and the laser focus is placed at the center of the thickness of the welded component;

[0107] Step 8: Welding is performed using the adjusted 5 sub-beams. Since the focal depth can fully cover the welding thickness of the entire component, direct scanning and processing are sufficient. After initial positioning, there is no need to adjust the working distance between the spot and the component via a motion platform. When the welding thickness measured by the laser rangefinder changes from 1000μm to 500μm, the magnification collimation system changes from 2x to 1x.

[0108] Machine vision is used to continuously capture multiple welding images of the target being welded, allowing for real-time monitoring of weld seam changes. Since the weld linewidth is fixed at 5μm, there is no need to change the focusing spot of the five sub-beams. The T-shaped welding shape can be scanned along the weld seam, and because its hot spot is in the center, it improves post-weld annealing, reduces the weld angle, and increases weld strength. Three-point homogenization generates two small spots and a central spot; when scanning during brazing, this central point melts the metal line between the two plates. It is worth noting that the "I" and "1" sections of the T-shaped spot can be arbitrarily adjusted in the X and Y directions, for example... Figure 4 As shown, increasing the overlap rate of the three light spots in the "1" section can increase the energy density of the unit area without adjusting the single pulse energy, thereby increasing the welding line width and weld width. Similarly, the positions of the two light spots in the "I" shaped section can also be flexibly adjusted according to the welding line width. After the extreme movement of the above device, a three-point light spot distribution is formed, that is, two small light spots and one central light spot are generated. When scanning is performed during the brazing process, the central point will melt the metal line between the two plates, heating and cleaning both sides of the weld at the same time.

[0109] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present invention should be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A high-quality welding manufacturing method, employing a high-quality welding manufacturing apparatus, characterized in that: The high-quality welding manufacturing apparatus includes a laser source (1) for emitting welding laser, and a variable magnification collimation system (2), a conical mirror (3), an acousto-optic modulation unit (4), and a long focal depth compression unit (5) arranged sequentially along the optical path of the welding laser. The variable magnification collimation system (2) is used to change the spot diameter of the welding laser and collimate it. The conical mirror (3) is used to shape the weld laser after diameter change collimation into a long focal depth laser. The acousto-optic modulation unit (4) is used to divide the long focal depth laser into N sub-beams through N different and / or the same frequency sound waves, and adjust the spatial position of each sub-beam, where N ≥ 1 and is a positive integer. The long focal depth compression unit (5) is used to adjust the spot diameter and focal depth of each sub-beam so that its focal position and energy are suitable for laser welding. The acousto-optic modulation unit (4) includes components arranged sequentially along the optical path of the long focal depth laser. The system includes an X-direction acousto-optic modulator (41), a λ / 4 waveplate (42), a Y-direction acousto-optic modulator (43), an X-direction acousto-optic driver (44) connected to the X-direction acousto-optic modulator (41), a Y-direction acousto-optic driver (45) connected to the Y-direction acousto-optic modulator (43), and a controller (46) connected to the X-direction acousto-optic driver (44) and the Y-direction acousto-optic driver (45), respectively; λ is the wavelength; the controller (46) is used to load a first electrical signal amplitude modulation of different and / or the same size onto the X-direction acousto-optic modulator (41) through the X-direction acousto-optic driver (44), so that the X-direction acousto-optic modulator (41) obtains sound waves of different and / or the same frequency, thereby dividing the long focal depth laser into multiple first sub-beams with different and / or the same energy and different and / or the same spatial position in the X direction, the number of the first sub-beams corresponding to the amplitude modulation of the first electrical signal; The Y-direction acousto-optic driver (45) loads a second electrical signal amplitude modulation of different and / or the same magnitude onto the Y-direction acousto-optic modulator (43), so that the Y-direction acousto-optic modulator (43) obtains sound waves of different and / or the same frequency, thereby dividing the corresponding number of first sub-beams into multiple second sub-beams with different and / or the same energy and different and / or the same spatial position in the Y direction, resulting in N sub-beams; the number of the second sub-beams corresponds to the amplitude modulation of the second electrical signal; the λ / 4 waveplate is used to change the polarization state of the first sub-beam from linear polarization to circular polarization; The high-quality welding manufacturing method includes the following steps: Step 1: Analyze the welding requirements and determine the number N of sub-beams used for welding and the spot shape of each sub-beam based on the welding requirements; the spot shape includes the spot diameter, focal depth, energy and spatial distribution position of each sub-beam; the spatial distribution position of each sub-beam is C-shaped. Step 2: Set the welding parameters of the variable magnification collimation system (2), cone lens (3), acousto-optic modulation unit (4) and long focal depth compression unit (5) according to the determined number of sub-beams N and the spot shape of each sub-beam; refresh the loaded acousto-optic frequency to realize that the opening of the C-shaped spot rotates toward the center point during the welding process; Step 3: Start the laser source (1), and the laser source (1) emits a welding laser; Step 4: The variable magnification collimation system (2) receives the welding laser, changes the spot diameter of the welding laser, and collimates it; Step 5: The conical lens (3) receives the welding laser after the diameter is adjusted and collimated, and shapes it into a long focal depth laser. Step 6: The acousto-optic modulation unit (4) receives the long focal depth laser, divides the long focal depth laser into N sub-beams through N different and / or the same frequency sound waves, and adjusts the spatial position of each sub-beam. Step 7: The long focal depth compression unit (5) receives N sub-beams and adjusts the spot diameter and focal depth of each sub-beam so that its focal position and energy are suitable for laser welding. Step 8: Perform welding using the adjusted N-beam sub-beam.

2. The high-quality welding manufacturing method according to claim 1, characterized in that: Step 2 is as follows: The magnification of the variable magnification collimation system (2) is adjusted according to the spot diameter of each sub-beam; the angle of the conical mirror (3) and the focal length of the plano-convex mirror (51) and the focusing objective (53) in the long focal depth compression unit (5) are adjusted according to the focal depth length of each sub-beam; the controller (46) outputs a first electrical signal amplitude modulation of different and / or the same magnitude and frequency to the X-direction acousto-optic modulator (41) through the X-direction acousto-optic driver (44) according to the number N, energy and spatial distribution of the sub-beams; and the controller (46) outputs a second electrical signal amplitude modulation of different and / or the same magnitude and frequency to the Y-direction acousto-optic modulator (43) through the Y-direction acousto-optic driver (45). Step 6 specifically involves: The X-direction pressure transducer (412) receives multiple first electrical signals of different and / or the same magnitude and frequency, modulates them, and converts them into a first mechanical wave field. The X-direction acousto-optic crystal (411) vibrates with the first mechanical wave field, causing the refractive index of the X-direction acousto-optic crystal (411) to change according to the variation law of the first electrical signal amplitude modulation, forming a first ultrasonic grating. The first ultrasonic grating modulates the long focal depth laser, causing the long focal depth laser to deflect at different angles, thereby dividing it into multiple first sub-beams with different and / or the same energy and different and / or the same spatial position in the X direction. The first sub-beams correspond to the first electrical signal amplitude modulation. The first sub-beam, after passing through a λ / 4 waveplate, changes its polarization state from linear polarization to circular polarization. The Y-direction pressure transducer (432) receives multiple second electrical signals of different and / or the same magnitude and frequency, modulates them, and converts them into a second mechanical wave field. The Y-direction acousto-optic crystal (431) vibrates with the second mechanical wave field, causing the refractive index of the Y-direction acousto-optic crystal (431) to change according to the variation law of the second electrical signal amplitude modulation, forming a second ultrasonic grating. The second ultrasonic grating modulates a corresponding number of first sub-beams, causing the corresponding number of first sub-beams to be divided into multiple second sub-beams with different and / or the same energy and different and / or the same spatial position in the Y direction. The number of second sub-beams corresponds to the amplitude modulation of the second electrical signal. The sum of the number of undivided first sub-beams and the number of divided second sub-beams is N.

3. The high-quality welding manufacturing method according to claim 2, characterized in that: In the high-quality welding manufacturing apparatus, the X-direction acousto-optic modulator (41) includes an X-direction acousto-optic crystal (411) and an X-direction pressure transducer (412); the X-direction acousto-optic crystal (411) is disposed on the optical path of the long focal depth laser; the input end of the X-direction pressure transducer (412) is connected to the output end of the X-direction acousto-optic driver, the X-direction pressure transducer (412) is bonded to the X-direction acousto-optic crystal (411), and is used to receive first electrical signals of different and / or the same magnitude for amplitude modulation, and convert them into a first mechanical wave field, so that the X-direction acousto-optic crystal (411) vibrates with the first mechanical wave field, and the refractive index of the X-direction acousto-optic crystal (411) changes according to the variation law of the amplitude modulation of the first electrical signal, forming a first ultrasonic grating, the first ultrasonic grating modulates the long focal depth laser, so that the long focal depth laser deflects at different angles, thereby dividing it into multiple first sub-beams with different and / or the same energy and different and / or the same spatial position in the X direction.

4. The high-quality welding manufacturing method according to claim 3, characterized in that: In the high-quality welding manufacturing apparatus, the Y-direction acousto-optic modulator (43) includes a Y-direction acousto-optic crystal (431) and a Y-direction pressure transducer (432); the Y-direction acousto-optic crystal (431) is disposed on the optical path of the first sub-beam; the input end of the Y-direction pressure transducer (432) is connected to the output end of the Y-direction acousto-optic driver (45), and the Y-direction pressure transducer (432) is bonded to the Y-direction acousto-optic crystal (431) for receiving second electrical signals of different and / or the same magnitude, and converting them into the first... The second mechanical wave field causes the Y-direction acousto-optic crystal (431) to vibrate with the second mechanical wave field. The refractive index of the Y-direction acousto-optic crystal (431) changes according to the amplitude modulation law of the first electrical signal, forming a second ultrasonic grating. The second ultrasonic grating modulates a corresponding number of first sub-beams, causing the corresponding number of first sub-beams to deflect at different angles, thereby dividing them into multiple second sub-beams with different and / or the same energy and different and / or the same spatial position in the Y direction; then the sum of the number of undivided first sub-beams and the number of divided second sub-beams is N.

5. The high-quality welding manufacturing method according to claim 4, characterized in that: In the high-quality welding manufacturing apparatus, the long focal depth compression unit (5) includes a plano-convex mirror (51), a filter (52), and a focusing objective (53) arranged sequentially along the optical path of the N sub-beams; the plano-convex mirror (51) is used to converge the spatial positions of the N sub-beams proportionally; the filter (52) is used to adjust the energy of the N sub-beams online by different transmittances; and the focusing objective (53) is used to focus each sub-beam separately.

6. The high-quality welding manufacturing method according to claim 5, characterized in that: In the high-quality welding manufacturing device, the zoom collimation system (2) is a zoom lens set in the optical path of the welding laser.

7. The high-quality welding manufacturing method according to claim 6, characterized in that: In the high-quality welding manufacturing apparatus, the long focal depth compression unit (5) further includes a reflector (54) disposed between the acousto-optic modulation unit (4) and the plano-convex mirror (51); the reflector (54) is used to reflect the N-beam sub-beams to the plano-convex mirror (51).

8. The high-quality welding manufacturing method according to claim 7, characterized in that: In the high-quality welding manufacturing apparatus, the laser source (1) is a Gaussian laser source; the filter (52) is a liquid crystal filter.

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