High-quality laser welding manufacturing device and method

Abstract

The invention discloses a high-quality laser welding manufacturing device and a high-quality laser welding manufacturing method, which solve the problems of concentrated energy distribution, small inherent focal depth, insufficient depth-diameter ratio of welding and insufficient welding thickness of the existing ultrafast laser welding technology. The zoom collimation system, the cone mirror, the acousto-optic modulation unit and the long focal depth compression unit are sequentially arranged on a light path where the welding laser is located in the emergent direction of the welding laser. The zoom collimation system is used for changing the spot diameter of the welding laser and collimating the spot diameter; the cone mirror is used for shaping the welding laser subjected to diameter-variable 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 position of each sub-beam, and N is a positive integer greater than or equal to 1; 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 position and energy of each sub-beam are suitable for laser welding.

Description

Technical Field

[0001] The invention relates to an optical welding manufacturing device and method, and in particular to a high-quality laser welding manufacturing device and method. Background Art

[0002] In the fields of optoelectronics, aerospace and other high-tech fields, brittle materials (such as glass, silicon, sapphire, etc.) are widely used due to their unique and excellent optical, electrical, acoustic, thermal and chemical properties. They are often used as packaging materials to connect with materials of the same or opposite sex, providing reliable sealing without affecting the function of the device. The existing methods of connecting brittle materials generally have shortcomings such as poor stability, the need to add additional materials or strict requirements on the surface quality of the welding materials, and the expansion coefficient must be close. Therefore, new efficient and precise connection processing methods are urgently needed.

[0003] Material bonding / welding refers to the direct or indirect establishment of atomic and molecular bonding between two independent solid objects through appropriate physical and chemical processes, thereby forming a bonded whole. With the continuous advancement of today's industrial production, material bonding technology has been widely used in the manufacturing or assembly process of aerospace, national defense, precision optics, biomedicine, optoelectronic sensing and other fields, and has become an indispensable and important link. Since the temperature field induced by the laser is highly localized in space, ultrafast laser welding can be carried out when the sample is at room temperature, which makes it particularly suitable for the packaging of heat-sensitive optoelectronic devices with low thermal damage threshold; it is applied to 3C fine welding, integrated circuit packaging bonding methods have evolved from traditional wire bonding to ball bump welding semiconductors, new electronics and new energy applications, and various materials such as ultra-thin, ultra-hard, brittle, and flexible are welded, microfluidic devices, sensor packaging, and consumer electronics, Aviation equipment window device connection; it is applied to the laser welding of metal bipolar plates in the hydrogen fuel cell industry, or bipolar plates for hydrogen production by electrolysis of water, and is suitable for lap welding and sealing welding of materials such as titanium alloys and 316L stainless steel.

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

[0005] 1. Gluing generally refers to the technology of using the curing reaction process of organic or inorganic adhesives to achieve the bonding effect between objects. The gluing operation process is simple 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 the aviation field, high temperature and high load conditions. When this process is in service, it often causes the organic chemical glue to gradually fail, thus gradually causing the seal to fail.

[0006] 2. High temperature sealing process is to keep glass and metal at high temperature for a long time to achieve sealing between the two. The problem with this process is that under the condition of high temperature and long time of heat preservation, the functional characteristics of the glass will be damaged, and when the metal is a material with poor oxidation resistance, such as aluminum alloy, stainless steel, and titanium alloy, the performance of the metal will also be adversely affected.

[0007] 3. Solid-phase bonding refers to the process of connecting the contact surfaces of objects through plastic deformation or atomic diffusion without melting. It mainly includes friction welding, diffusion welding, ultrasonic welding, explosion welding, etc. Solid-phase bonding can achieve large-area welding between objects, but it has high requirements for the surface preparation of the objects to be welded and the welding process takes a long time. In addition, when welding dissimilar materials, it is often necessary to embed a transition layer to alleviate problems such as mismatch of material physical property parameters and stress concentration.

[0008] 4. Anodic bonding is a bonding process that can quickly achieve strong bonding at a relatively low temperature, that is, the samples with polished surfaces are stacked together, and ions migrate to form a strong bonding layer between the interfaces under the conditions of a temperature of 300℃~500℃ and a DC voltage of 200V~2000V. The welding method provided by the present invention is widely used in micro-electromechanical packaging due to its high stability. However, this technology requires that the thermal expansion coefficients of the two materials to be bonded are highly matched, 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 the 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 the electron beam from escaping. This type of welding has a more severe thermal impact, higher residual stress, and the base material is easily deformed.

[0010] 6. Arc welding uses the metal to be welded as one pole and the electrode as the other pole. When the two poles are close to each other, an arc is generated, causing the material at the interface of the objects to melt and then solidify. This welding method has a more serious thermal impact, high residual stress, and the base material is easy to deform.

[0011] 7. Long pulse / continuous laser hot melt welding technology is a traditional melting welding method. It is an efficient and precise welding method that uses a high energy density laser beam as a heat source. This welding method has outstanding advantages such as high energy density, fast welding speed, small heat input and welding deformation. However, to achieve high-quality welding of transparent materials, traditional continuous laser or long pulse laser is still not an ideal choice.

[0012] The above-mentioned traditional bonding / welding processes have different degrees of technical defects and limitations on processing accuracy, and are unable to meet the processing requirements of today's growing industrial production for high efficiency, high precision and low pollution.

[0013] Therefore, ultrafast laser welding is widely used at present. Ultrafast laser welding is a precision welding technology based on the nonlinear absorption mechanism of ultrafast laser energy, which makes dissimilar materials plasmatized in a micro-scale range of the bonding interface and then reconstructed to achieve connection. It has the characteristics of high efficiency, high precision, high spatial selectivity, and high material applicability. When the ultrafast laser of micro-focus level is focused by a lens, the peak optical power density in the focal field area can reach 1013W / cm 2 Above. This is enough to induce nonlinear absorption of transparent materials, realize direct selective deposition of laser energy, and then form local high temperature at the laser focus inside the material. When the laser focus is located at the interface of the sample to be welded, the local high temperature induced by the laser energy deposition will cause the material near the interface to undergo phase change, ion migration, and even produce supercritical fluid. After the laser radiation ends, the material cools and solidifies to establish a strong connection by fusion or bonding. Due to the high peak power density and short action time of the focused ultrafast laser, only a small amount of laser energy is required to induce phase change in the local material. In addition, part of the energy deposited by the laser is consumed and converted at the picosecond to nanosecond level, which greatly reduces the laser-induced heat-affected zone, thereby reducing the stress of the welding interface, which is beneficial to improving the high and low temperature servo performance of the welding structure. Therefore, the precision selective welding technology based on ultrafast laser has many advantages over other welding processes. It has the advantages of low thermal impact, three-dimensional spatial selectivity, high welding strength and efficiency, and high operational controllability.

[0014] However, the current ultrafast laser welding technology uses Gaussian lasers, which have concentrated energy distribution and extremely high instantaneous energy density, exceeding 10 14 W / cm 2 , the temperature gradient between the irradiated area and the non-irradiated area is extremely large, and the molten pool fluid / gas cannot escape, resulting in high surface roughness and insufficient weld strength. In addition, the inherent focal depth of Gaussian laser is small due to the influence of the optical Rayleigh criterion, and the depth-to-diameter ratio and weld thickness of the weld are insufficient. Summary of the invention

[0015] In order to solve the technical problems of concentrated energy distribution, small inherent focal depth, insufficient depth-to-diameter ratio of welding and insufficient welding thickness in the existing ultrafast laser welding technology, the present invention provides a high-quality laser welding manufacturing device and method.

[0016] In order to achieve the above object, the present invention adopts the following technical solution:

[0017] A high-quality welding manufacturing device, which is special in that it includes a laser source for emitting welding laser, and a variable magnification collimation system, a cone mirror, an acousto-optic modulation unit and a telephoto depth compression unit which are sequentially arranged on the optical path of the welding laser along the emitting direction of the welding laser;

[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 reduction and collimation into a long-focus deep laser;

[0020] The acousto-optic modulation unit is used to divide the long-focus depth laser into N sub-beams through N sound waves of different and / or same frequencies, and 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 length of each sub-beam so that the focal position and energy thereof are suitable for laser welding.

[0022] Further, the acousto-optic modulation unit includes an X-direction acousto-optic modulator, a λ / 2 wave plate, a Y-direction acousto-optic modulator, and 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 respectively connected to the X-direction acousto-optic driver and the Y-direction acousto-optic driver; λ is the wavelength;

[0023] The controller is used to load different and / or same magnitude first electrical signal amplitude modulation to the X-direction acousto-optic modulator through the X-direction acousto-optic driver, so that the X-direction acousto-optic modulator obtains sound waves of different and / or same frequencies, thereby dividing the long focal depth laser into a plurality of first sub-beams with different and / or same energies and different and / or same spatial positions in the X-direction, and the number of the first sub-beams corresponds to the first electrical signal amplitude modulation; and load different and / or same magnitude second electrical signal amplitude modulation to the Y-direction acousto-optic modulator through the Y-direction acousto-optic driver, so that the Y-direction acousto-optic modulator obtains sound waves of different and / or same frequencies, thereby dividing the corresponding number of first sub-beams into a plurality of second sub-beams with different and / or same energies and different and / or same spatial positions in the Y-direction, and the number of the second sub-beams corresponds to the second electrical signal amplitude modulation; and obtain N sub-beams;

[0024] The λ / 2 wave plate is used to change the polarization state of the first sub-beam from linearly polarized light to circularly polarized light.

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

[0026] The X-direction acousto-optic crystal is arranged on the optical path where the long focal depth laser is located;

[0027] The input end of the X-direction pressure energy transducer is connected to the output end of the X-direction acousto-optic driver. The X-direction pressure energy transducer is bonded to the X-direction acousto-optic crystal and is used to receive the first electrical signal amplitude modulation of different and / or the same size and convert it into a first mechanical wave field, so that the X-direction acousto-optic crystal vibrates with the first mechanical wave field, and the refractive index of the X-direction acousto-optic crystal changes according to the change law of the first electrical signal amplitude modulation to form a first ultrasonic grating. The first ultrasonic grating modulates the long-focus depth laser so that the long-focus depth laser is deflected at different angles, thereby dividing it into a plurality of first sub-beams with different and / or the same energy and different and / or the same spatial positions in the X direction.

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

[0029] The Y-direction acousto-optic crystal is arranged on the optical path where the first sub-beam is located;

[0030] The input end of the Y-direction pressure energy transducer is connected to the output end of the Y-direction acousto-optic driver, and the Y-direction pressure energy transducer is bonded to the Y-direction acousto-optic crystal, and is used to receive the second electrical signal amplitude modulation of different and / or the same size, and convert it into a second mechanical wave field, so that the Y-direction acousto-optic crystal vibrates with the second mechanical wave field, and the refractive index of the Y-direction acousto-optic crystal changes according to the change law of the first electrical signal amplitude modulation, forming a second ultrasonic grating, and the second ultrasonic grating modulates a corresponding number of first sub-beams, so that a 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 positions 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.

[0031] Furthermore, the telephoto depth compression unit comprises a plano-convex mirror, a filter, and a focusing objective lens which are sequentially arranged along the optical path where the N sub-beams are located;

[0032] The plano-convex mirror is used to converge the spatial positions of the N sub-beams in proportion;

[0033] The filter is used to adjust the energy of N sub-beams online through different transmittances;

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

[0035] Furthermore, the variable magnification collimation system is a variable magnification mirror arranged on the optical path of the welding laser.

[0036] Furthermore, the telephoto depth compression unit further comprises a reflecting mirror disposed between the acousto-optic modulation unit and the plano-convex mirror;

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

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

[0039] The filter is a liquid crystal filter.

[0040] A high-quality welding manufacturing method, using the above-mentioned high-quality welding manufacturing device, is characterized in that it includes the following steps:

[0041] Step 1, analyzing welding requirements, and determining the number N of sub-beams used for welding and the spot shape of each sub-beam according to the welding requirements; the spot shape includes the spot diameter, focal depth, energy and spatial distribution position of each sub-beam;

[0042] Step 2: setting welding parameters of the zoom collimation system, the axicon, the acousto-optic modulation unit and the telephoto 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, and the laser source emits 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 diameter reduction and collimation, and shapes it into a long-focus deep laser;

[0046] Step 6: The acousto-optic modulation unit receives the long-focus depth laser, divides the long-focus depth laser into N sub-beams through N acoustic waves of different and / or same frequencies, 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 length of each sub-beam so that the focal position and energy are suitable for laser welding;

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

[0049] Furthermore, step 2 is specifically as follows:

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

[0051] Step 6 is as follows:

[0052] The X-direction pressure energy transducer receives a plurality of first electrical signal amplitude modulations of different and / or same magnitudes and frequencies, and converts them into a first mechanical wave field, then the X-direction acousto-optic crystal vibrates along with the first mechanical wave field, so that the refractive index of the X-direction acousto-optic crystal changes according to the variation law of the first electrical signal amplitude modulation, and forms a first ultrasonic grating, and 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 a plurality of first sub-beams with different and / or same energies and different and / or same spatial positions in the X direction, and the first sub-beams correspond to the first electrical signal amplitude modulation;

[0053] The first sub-beam passes through a λ / 2 wave plate, and its polarization state is changed from linearly polarized light to circularly polarized light;

[0054] The Y-direction pressure energy transducer receives a plurality of second electrical signal amplitude modulations of different and / or same magnitudes and frequencies, and converts them into a second mechanical wave field, and the Y-direction acousto-optic crystal vibrates along with the second mechanical wave field, so that the refractive index of the Y-direction acousto-optic crystal changes according to the variation law of the second electrical signal amplitude modulation, thereby forming a second ultrasonic grating, and the second ultrasonic grating modulates a corresponding number of first sub-beams, so that a corresponding number of first sub-beams are divided into a plurality of second sub-beams with different and / or same energies and different and / or same spatial positions in the Y direction, and the number of second sub-beams corresponds to the second electrical signal amplitude modulation; the sum of the number of undivided first sub-beams and the number of divided second sub-beams is N.

[0055] Beneficial effects of the present invention:

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

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

[0058] 3. The high-quality welding manufacturing device and method provided by the present invention adopts a conical mirror and a long focal depth compression unit, so that the minimum characteristic size of the focused spot of each sub-beam can reach the micron level, which can achieve micron-level welding accuracy and greatly reduce the thermal damage to the product caused by the welding process.

[0059] 4. The high-quality welding manufacturing device and method provided by the present invention can realize the welding of heterogeneous materials without the need for an embedding layer; due to the unique action process of induced nonlinear absorption of ultrafast laser, high-precision welding of different materials can be achieved, such as glass-metal, glass-semiconductor material, glass-glass, etc., and the welding process has extremely high spatial selectivity. Transparent materials such as quartz glass, sapphire wafers, high molecular polymers, etc. are often sensitive to stress. When continuous laser is applied, the induced thermal effect can easily cause serious distortion and fragmentation of the material. The present 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. The present invention can allow nitrogen bubbles to escape from the welding area by adjusting the spatial position of the sub-beam, thereby improving the width-to-depth ratio of the welding, reducing oxidation and eliminating thermal cracks. For example, the T-shaped welding shape can be scanned along the weld, thereby improving the post-weld annealing condition, reducing the weld angle and improving the weld strength. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0063] Figure 3 is a schematic diagram of 6 sub-beams forming a C-shaped light spot in an embodiment of the present invention;

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

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

[0066] Figure Number:

[0067] 1-laser source, 2-variable magnification collimation system, 3-conical mirror, 4-acousto-optic modulation unit, 41-X-direction acousto-optic modulator, 411-X-direction acousto-optic crystal, 412-X-direction pressure energy transducer, 42-λ / 2 wave plate, 43-Y-direction acousto-optic modulator, 431-Y-direction acousto-optic crystal, 432-Y-direction pressure energy transducer, 44-X-direction acousto-optic driver, 45-Y-direction acousto-optic driver, 46-controller, 5-telephoto depth compression unit, 51-plano-convex mirror, 52-filter, 53-focusing objective lens, 54-reflector. DETAILED DESCRIPTION

[0068] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0069] An embodiment of the present invention provides a high-quality welding manufacturing device, such as Figure 1 As shown, it includes a laser source 1 for emitting welding laser, and a variable magnification collimation system 2, a cone mirror 3, an acousto-optic modulation unit 4 and a telephoto depth compression unit 5 which are sequentially arranged on the optical path along the emitting direction of the welding laser; 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 variable magnification mirror arranged on the optical path of the welding laser, and a 2x variable magnification mirror is preferably used in this embodiment.

[0071] The cone mirror 3 is used to shape the welding laser after diameter reduction and collimation into a long-focus deep laser;

[0072] like Figure 2As shown, the acousto-optic modulation unit 4 is used to divide the long-focus depth laser into N sub-beams through N acoustic waves of different and / or the same frequency, and adjust the spatial position of each sub-beam, N ≥ 1 and is a positive integer; the acousto-optic modulation unit 4 includes an X-direction acousto-optic modulator 41, a λ / 2 wave plate 42, a Y-direction acousto-optic modulator 43, which are sequentially arranged on the optical path where the long-focus depth laser is located, and 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 the first electrical signal amplitude modulation of different and / or the same size to the X-direction acousto-optic modulator 41 through the X-direction acousto-optic driver 44, so that the X-direction acousto-optic modulator The optical modulator 41 obtains sound waves of different and / or the same frequency, thereby dividing the long focal depth laser into a plurality of first sub-beams with different and / or the same energy and different and / or the same spatial positions in the X direction, and the number of the first sub-beams corresponds to the amplitude modulation of the first electrical signal; and the Y-direction acousto-optic driver 45 loads the Y-direction acousto-optic modulator 43 with a second electrical signal amplitude modulation of different and / or the same size, 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 a plurality of second sub-beams with different and / or the same energy and different and / or the same spatial positions in the Y direction, and the number of the second sub-beams corresponds to the amplitude modulation of the second electrical signal; N sub-beams are obtained; and the λ / 2 wave plate is used to change the polarization state of the first sub-beam from linearly polarized light to circularly polarized light. The X-direction acousto-optic modulator 41 comprises an X-direction acousto-optic crystal 411 and an X-direction pressure energy transducer 412; the X-direction acousto-optic crystal 411 is arranged on the optical path of the long focal depth laser; the input end of the X-direction pressure energy transducer 412 is connected to the output end of the X-direction acousto-optic driver, and the X-direction pressure energy transducer 412 is bonded to the X-direction acousto-optic crystal 411, and is used to receive the first electrical signal amplitude modulation of different and / or the same size, and convert it 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 change law of the first electrical signal amplitude modulation, forming a first ultrasonic grating, and the first ultrasonic grating modulates the long focal depth laser, so that the long focal depth laser is deflected at different angles, thereby dividing it into a plurality of first sub-beams with different and / or the same energy and different and / or the same spatial positions in the X direction.The Y-direction acousto-optic modulator 43 includes a Y-direction acousto-optic crystal 431 and a Y-direction pressure energy transducer 432; the Y-direction acousto-optic crystal 431 is arranged on the optical path where the first sub-beam is located; the input end of the Y-direction pressure energy transducer 432 is connected to the output end of the Y-direction acousto-optic driver 45, and the Y-direction pressure energy transducer 432 is bonded to the Y-direction acousto-optic crystal 431, and is used to receive the second electrical signal amplitude modulation of different and / or the same size, and convert it into a second mechanical wave field, so that the Y-direction acousto-optic crystal 431 vibrates with the second mechanical wave field, and the refractive index of the Y-direction acousto-optic crystal 431 changes according to the change law of the first electrical signal amplitude modulation, forming a second ultrasonic grating, and the second ultrasonic grating modulates the 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 positions 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.

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

[0074] P=1 / 2ρV 3 S 2 LH

[0075] Where P is the power of the electrical signal amplitude modulation, L and H are the length and width of the pressure energy transducer, V is the speed 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] Then the acoustic refractive index change ne is:

[0077] ne=1 / 2n i Θ eff S

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

[0079] When the two frequencies are f 1 and f i (The corresponding wavelengths are λ 1 and λ i ), the ultrasonic wave with a wave velocity of V s propagates in the acousto-optic crystal along the x direction at the same time, and its refractive index is 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 of θ to the z-axis. After the two ultrasonic waves interact with the light, the main diffraction mode beam diffracted is 2θ from the incident beam. iAngle, the incident long focal depth laser wavelength is λ, that is, the sub-beam deflection angle θ i , the 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 length 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 reflector 54, a plano-convex mirror 51, a filter 52 (liquid crystal filter), and a focusing lens 53 arranged in sequence along the optical path where the N sub-beams are located; the reflector 54 is used to reflect the N sub-beams to the plano-convex mirror 51. The plano-convex mirror 51 is used to make the spatial positions of the N sub-beams converge proportionally; the filter 52 is used to adjust the energy of the N sub-beams online through different transmittances; and the focusing lens 53 is used to focus each sub-beam separately.

[0082] The above welding manufacturing device is used to weld heterogeneous materials (stainless steel and glass heterogeneous welding, component thickness 500μm, welding line width 5μm, stainless steel and glass damage thresholds are 0.05J / cm 2 , 0.75J / cm 2 )Welding includes the following steps:

[0083] Step 1, analyze the welding requirements, and determine the number of sub-beams N=6 and the spot shape of each sub-beam for welding according to the welding requirements. The spot shape includes that the spot diameter of each sub-beam is less than 5μm, the focal depth of each sub-beam is greater than or equal to 500μm, the energy of each sub-beam is greater than 30uJ, and the spatial distribution position (diffraction angle) of each sub-beam is as follows: Figure 3 The C-shape shown;

[0084] Step 2, according to 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 aconic mirror 3, the acousto-optic modulation unit 4 and the long focal depth compression unit 5; specifically. According to the spot diameter of each sub-beam 1.3μm, adjust the zoom ratio of the zoom collimation system 2 by 2 times; according to the focal depth length of each sub-beam, adjust the angle of the aconic mirror 3 to 5°, 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 lens 53 to 3.6mm; according to the number of sub-beams 6, the diffraction angle 0.1rad, the energy 30 microjoules, and the spatial distribution position (C-shaped), the controller 46 outputs two identical sizes and frequencies to the X-direction acousto-optic modulator 41 through the X-direction acousto-optic driver 44. The first electrical signal is modulated with an amplitude of 150W, and the controller 46 outputs two second electrical signals with the same amplitude and frequency of 150W to the Y-direction acousto-optic modulator 43 through the Y-direction acousto-optic driver 45; in other embodiments, the first electrical signal with different amplitudes and frequencies and the second electrical signal with different amplitudes and frequencies can also be output; in view of the maximum refresh frequency of the acousto-optic modulator of 150kHz, the loaded acousto-optic frequency is refreshed every 6.6s, so that the opening of the C-shaped light spot starts to rotate toward the center point during the welding process, as shown in the following figure. Figure 4 shown.

[0085] Step 3, start the laser source 1, the laser source 1 emits a welding laser, and the spot diameter of the welding laser is 5.4 mm;

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

[0087] Step 5, the conical mirror 3 receives the welding laser after diameter reduction and collimation, and reshapes it into a long focal depth laser with a focal length of 135 mm;

[0088] Step 6, the acousto-optic modulation unit 4 receives the long focal depth laser, and divides the long focal depth laser into 6 sub-beams through 6 sound waves of the same frequency to form a C shape; specifically:

[0089] The X-direction pressure energy transducer 412 receives three first electrical signal amplitude modulations of the same magnitude and frequency and converts them into a first mechanical wave field, and the X-direction acousto-optic crystal 411 vibrates along with the first mechanical wave field, so that the refractive index of the X-direction acousto-optic crystal 411 changes according to the change rule of the first electrical signal amplitude modulation, forming a first ultrasonic grating, and the first ultrasonic grating modulates the long-focus depth laser, so that the long-focus depth laser is deflected at different angles, thereby dividing 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 the λ / 2 wave plate, and their polarization states are changed from linearly polarized light to circularly polarized light;

[0091] The Y-direction pressure energy transducer 432 receives two second electrical signal amplitude modulations of the same size and frequency and converts them into a second mechanical wave field. Then, the Y-direction acousto-optic crystal 431 vibrates along with the second mechanical wave field, so that the refractive index of the Y-direction acousto-optic crystal 431 changes according to the changing law of the second electrical signal amplitude modulation, forming a second ultrasonic grating. The second ultrasonic grating modulates the three first sub-beams, so that the three first sub-beams are divided into six second sub-beams with the same energy and different spatial positions in the Y direction. Then, the six sub-beams 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 1.3 μm and the focal depth length of each sub-beam to 600 μm, so that its energy is suitable for laser welding; a distance measuring sensor is used to measure the distance between the laser focus and the processed point, and the laser focus is placed at the thickness center of the welding component;

[0093] Step 8: Use the adjusted 6 sub-beams according to Figure 4 The scanning welding path shown is used to perform welding. Since the focal depth can completely cover the welding thickness of the entire component, direct scanning welding is sufficient. After the initial positioning, there is no need to adjust the post-working distance between the spot and the component through the motion platform.

[0094] Machine vision is used to continuously shoot the welded target and obtain multiple continuous welding images, and the changes in the welding weld are monitored in real time. Since the welding line width is fixed at 5μm, there is no need to change the focusing spot of the 6 sub-beams, and only the opening of the C-shaped spot needs to be adjusted. The C-shaped spot is mainly conducive to the escape of plasma, melt, vapor and other substances from the welding area, suppressing the thermal influence of the laser focus area, improving the aspect ratio, reducing oxidation and reducing obvious cracks and defects. A temperature sensor is used to obtain the sensing temperature of the welding target. When the measured welding temperature is lower or higher than the preset welding temperature by 10%, the welding state is judged to be abnormal. By adjusting the transmittance of the liquid crystal filter, the energy density of the spot is increased or decreased.

[0095] The above welding manufacturing device is used to weld heterogeneous materials (stainless steel and glass, component thickness 500μm-1000μm, welding line width 8μm, stainless steel and glass damage thresholds are 0.05J / cm 2 , 0.75J / cm 2 )Welding includes the following steps:

[0096] Step 1, analyzing welding requirements, and determining the number of sub-beams used for welding and distributed in a T-shape as N=5 and the spot shape of each sub-beam according to the welding requirements: the spot diameter of each sub-beam is less than 5 μm, the focal depth of each sub-beam is ≥800 μm, the energy of each sub-beam is greater than 30 uJ, and the spatial distribution position of each sub-beam is T-shaped;

[0097] Step 2, setting welding parameters of the variable magnification collimation system 2, the axicon 3, the acousto-optic modulation unit 4 and the telephoto depth compression unit 5 according to the determined number of sub-beams 5 and the spot shape of each sub-beam; specifically including:

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

[0099] Step 3, start the laser source 1, the laser source 1 emits welding laser, and the laser source spot diameter is 5.4 mm;

[0100] Step 4, the 2-fold variable diameter collimation system 2 receives the welding laser, receives the welding laser, changes the spot diameter of the welding laser to 10.8 mm, and collimates it;

[0101] Step 5, the conical mirror 3 receives the welding laser after variable magnification collimation and shapes it into a long-focus depth laser of 216 mm;

[0102] Step 6, the acousto-optic modulation unit 4 receives the long focal depth laser, and divides the long focal depth laser into five sub-beams through five acoustic waves of the same frequency to form a T-shaped distribution;

[0103] The X-direction pressure energy transducer 412 receives three or more first electrical signal amplitude modulations of different sizes and frequencies, and converts them into a first mechanical wave field, and the X-direction acousto-optic crystal 411 vibrates with the first mechanical wave field, so that the refractive index of the X-direction acousto-optic crystal 411 changes according to the change law of the first electrical signal amplitude modulation, forming a first ultrasonic grating, and the first ultrasonic grating modulates the long-focus depth laser received by the X-direction acousto-optic crystal 411, so that the long-focus depth laser is deflected at different angles, thereby dividing the long-focus depth laser into three first sub-beams along the X direction;

[0104] The first sub-beam passes through the λ / 2 wave plate, and its polarization state changes from linear polarized light to circular polarized light;

[0105] The Y-direction pressure energy transducer 432 receives two second electrical signal amplitude modulations of different sizes and frequencies and converts them into a second mechanical wave field. Then, the Y-direction acousto-optic crystal 431 vibrates along with the second mechanical wave field, so that the refractive index of the Y-direction acousto-optic crystal 431 changes according to the variation law of the second electrical signal amplitude modulation, forming a second ultrasonic grating. The second ultrasonic grating modulates the first sub-beam received by the Y-direction acousto-optic crystal 431, so that the first sub-beam in the middle is divided into three second sub-beams with different spatial positions in the Y direction. Then, the sum of the number of the undivided first sub-beams and the number of the divided second sub-beams is 5, and the following is formed. Figure 5 As shown in the T-shape, the three second sub-beam light spots distributed along the Y-axis are partially overlapped, which can increase the energy density at the overlapping point and make the processing width and processing depth larger.

[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 processed point, and the laser focus is placed at the thickness center of the welding component;

[0107] Step 8. Perform welding with the adjusted 5 sub-beams. Since the focal depth can completely cover the welding thickness of the entire component, direct scanning processing is sufficient. After the initial positioning, there is no need to adjust the back working distance between the light spot and the component through the motion platform. When the laser ranging sensor measures that the welding thickness changes from 1000μm to 500μm, the zoom collimation system changes from 2x to 1x.

[0108] The machine vision is adopted to continuously shoot the welding target and obtain a series of consecutive welding images, and the change of the welding seam is monitored in real time. Since the welding line width is fixed at 5 μm, there is no need to change the focused spots of the five sub-beams. The T-shaped welding shape can be scanned along the welding seam. Because its hot spot is in the middle, the post-weld annealing situation can be improved, the welding seam angle can be reduced, and the welding seam strength can be increased. The three-point homogenization generates two small spots and a central spot. When scanning during the brazing process, the central point will melt the metal wire between the two plates. It should be noted that the spots in the "one" and "1" parts of the T-shaped spot can be adjusted arbitrarily in the X and Y directions. For example Figure 4 as shown, by increasing the overlap rate of the three spots in the "1" part, the energy density of the unit area can be increased without adjusting the single-pulse energy, thereby increasing the welding line width and the welding seam width. Similarly, the positions of the two spots in the "one" part can also be flexibly adjusted according to the welding line width. After the extreme movement of the above device, a three-point spot distribution is formed, that is, two small spots and a central spot are generated. When scanning during the brazing process, the central point will melt the metal wire between the two plates and clean both sides of the welding seam while heating.

[0109] As mentioned above, the above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any change or replacement within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A high-quality welding manufacturing device, characterized in that: It comprises a laser source (1) for emitting welding laser, and a variable magnification collimation system (2), a cone mirror (3), an acousto-optic modulation unit (4) and a long-focus depth compression unit (5) which are sequentially arranged on the optical path of the welding laser along the emitting direction of the welding laser. The variable magnification collimation system (2) is used to change the spot diameter of the welding laser and to collimate it; The conical mirror (3) is used to shape the welding laser after diameter reduction and collimation into a long-focus depth laser; The acousto-optic modulation unit (4) is used to divide the long-focus depth laser into N sub-beams through N sound waves of different and / or same frequencies, and adjust the spatial position of each sub-beam, where N is ≥ 1 and is a positive integer; The long focal depth compression unit (5) is used to adjust the spot diameter and focal depth length of each sub-beam so that the focal position and energy thereof are suitable for laser welding.

2. The high quality welding manufacturing device according to claim 1, characterized in that: The acousto-optic modulation unit (4) comprises an X-direction acousto-optic modulator (41), a λ / 2 wave plate (42), a Y-direction acousto-optic modulator (43) which are sequentially arranged on the optical path where the long focal depth laser is located, 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) respectively connected to the X-direction acousto-optic driver (44) and the Y-direction acousto-optic driver (45); λ is a wavelength; The controller (46) is used to load different and / or same magnitude first electrical signal amplitude modulation to 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 same frequency, thereby dividing the long focal depth laser into a plurality of first sub-beams with different and / or same energy and different and / or same spatial positions in the X-direction, wherein the number of the first sub-beams corresponds to the first electrical signal amplitude modulation; A second electrical signal amplitude modulation of different and / or the same magnitude is loaded to the Y-direction acousto-optic modulator (43) through a Y-direction acousto-optic driver (45), so that the Y-direction acousto-optic modulator (43) obtains sound waves of different and / or the same frequency, thereby dividing a corresponding number of first sub-beams into a plurality of second sub-beams with different and / or the same energy and different and / or the same spatial positions in the Y direction, thereby obtaining N sub-beams; the number of the second sub-beams corresponds to the second electrical signal amplitude modulation; The λ / 2 wave plate is used to change the polarization state of the first sub-beam from linear polarization to circular polarization.

3. The high quality welding manufacturing device according to claim 2, characterized in that: The X-direction acousto-optic modulator (41) comprises an X-direction acousto-optic crystal (411) and an X-direction pressure energy transducer (412); The X-direction acousto-optic crystal (411) is arranged on the optical path of the long focal depth laser; The input end of the X-direction pressure energy transducer (412) is connected to the output end of the X-direction acousto-optic driver. The X-direction pressure energy transducer (412) is bonded to the X-direction acousto-optic crystal (411) and is used to receive first electrical signal amplitude modulations of different and / or the same magnitude 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 first electrical signal amplitude modulation, forming a first ultrasonic grating. The first ultrasonic grating modulates the long-focus depth laser so that the long-focus depth laser is deflected at different angles, thereby dividing it into a plurality of first sub-beams with different and / or the same energy and different and / or the same spatial positions in the X direction.

4. The high quality welding manufacturing device according to claim 3, characterized in that: The Y-direction acousto-optic modulator (43) comprises a Y-direction acousto-optic crystal (431) and a Y-direction pressure energy transducer (432); The Y-direction acousto-optic crystal (431) is arranged on the optical path where the first sub-beam is located; The input end of the Y-direction pressure energy transducer (432) is connected to the output end of the Y-direction acousto-optic driver (45). The Y-direction pressure energy transducer (432) is bonded to the Y-direction acousto-optic crystal (431) and is used to receive the second electrical signal amplitude modulation of different and / or the same size and convert it into a second mechanical wave field, so that the Y-direction acousto-optic crystal (431) vibrates with the second mechanical wave field, and the refractive index of the Y-direction acousto-optic crystal (431) changes according to the change law of the first electrical signal amplitude modulation to form 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 positions in the Y direction; 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 device according to any one of claims 1 to 4, characterized in that: The long focal depth compression unit (5) comprises a plano-convex mirror (51), a filter (52), and a focusing objective lens (53) which are sequentially arranged along the optical path where the N sub-beams are located; The plano-convex mirror (51) is used to converge the spatial positions of the N sub-beams in proportion; The filter (52) is used to adjust the energy of the N beams of sub-beams online through different transmittances; The focusing objective lens (53) is used to focus each sub-beam separately.

6. The high quality welding manufacturing device according to claim 5, characterized in that: The variable magnification collimation system (2) is a variable magnification mirror arranged on the optical path of the welding laser.

7. The high quality welding manufacturing device according to claim 6, characterized in that: The long focal depth compression unit (5) further comprises a reflecting mirror (54) arranged between the acousto-optic modulation unit (4) and the plano-convex mirror (51); The reflecting mirror (54) is used to reflect the N sub-light beams to the plano-convex mirror (51).

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

9. A high-quality welding manufacturing method, using the high-quality welding manufacturing device according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step 1, analyzing welding requirements, and determining the number N of sub-beams used for welding and the spot shape of each sub-beam according to the welding requirements; the spot shape includes the spot diameter, focal depth, energy and spatial distribution position of each sub-beam; Step 2, setting welding parameters of the variable magnification collimation system (2), the aconic mirror (3), the acousto-optic modulation unit (4) and the telephoto depth compression unit (5) according to the determined number of sub-beams N and the spot shape of each sub-beam; Step 3, starting the laser source (1), the laser source (1) emits 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 mirror (3) receives the welding laser after diameter reduction and collimation, and shapes it into a long-focus depth laser; Step 6, the acousto-optic modulation unit (4) receives the long-focus depth laser, divides the long-focus depth laser into N sub-beams through N sound waves of different and / or same frequencies, and adjusts the spatial position of each sub-beam; Step 7, the long focal depth compression unit (5) receives the N sub-beams, and adjusts the spot diameter and focal depth length of each sub-beam so that the focal position and energy are suitable for laser welding; Step 8: Perform welding using the adjusted N sub-beams.

10. The high quality welding manufacturing method according to claim 9, characterized in that: Step 2 is as follows: The zoom ratio of the zoom 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 lens (53) in the long focal depth compression unit (5) are adjusted according to the focal depth length of each sub-beam; according to the number N, energy, and spatial distribution position of the sub-beams, the controller (46) is adjusted to output 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), and the controller (46) is adjusted to output 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 is as follows: The X-direction pressure energy transducer (412) receives a plurality of first electrical signal amplitude modulations of different and / or same magnitudes and frequencies, and converts the first electrical signal amplitude modulations into a first mechanical wave field, and the X-direction acousto-optic crystal (411) vibrates along with the first mechanical wave field, so that the refractive index of the X-direction acousto-optic crystal (411) changes according to the change rule of the first electrical signal amplitude modulation, thereby forming a first ultrasonic grating, and the first ultrasonic grating modulates the long-focus depth laser so that the long-focus depth laser deflects at different angles, thereby dividing the laser into a plurality of first sub-beams with different and / or same energies and different and / or same spatial positions in the X direction, and the first sub-beams correspond to the first electrical signal amplitude modulation; The polarization state of the first sub-beam is changed from linear polarization to circular polarization after passing through a λ / 2 wave plate; The Y-direction pressure energy transducer (432) receives a plurality of second electrical signal amplitude modulations of different and / or same magnitudes and frequencies, and converts them into a second mechanical wave field, and the Y-direction acousto-optic crystal (431) vibrates along with the second mechanical wave field, so that the refractive index of the Y-direction acousto-optic crystal (431) changes according to the variation law of the second electrical signal amplitude modulation, thereby forming a second ultrasonic grating, and the second ultrasonic grating modulates a corresponding number of first sub-beams, so that a corresponding number of first sub-beams are divided into a plurality of second sub-beams with different and / or same energies and different and / or same spatial positions in the Y direction, and the number of second sub-beams corresponds to the second electrical signal amplitude modulation; the sum of the number of undivided first sub-beams and the number of divided second sub-beams is N.

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