Ultrafast laser pulse welding system and method

Abstract

The invention relates to an ultrafast laser pulse welding system and method. The ultra-fast laser pulse welding system comprises a laser source, a first structure light field welding device and a second structure light field welding device, the space shaping module is configured to convert the first structured light field laser pulse into a second structured light field laser pulse; and the scanning galvanometer is configured to adjust the emitting direction of the second structured light field laser pulses so as to utilize the second structured light field laser pulses with the same parameters to conduct repeated scanning on the interface of the first material and the second material according to the planned welding track, enabling the first material and the second material to at least reach an optical contact condition through at least one scanning performed in advance; and the first material and the second material are fused through at least one scanning performed later so as to generate a welding point in a preset shape. The method is high in welding quality, can be applied to precise bonding of electronic components and the like, and is suitable for industrialization.

Description

Technical Field

[0001] The present application relates to the field of laser welding technology, and in particular to an ultrafast laser pulse welding system and method. Background Art

[0002] Laser welding is a technology that uses high-energy laser beams to connect materials. It is widely used in the automotive, aerospace, electronics and medical equipment industries. Compared with traditional welding methods, its main advantages include high precision, high speed and low heat-affected zone, which can achieve precision welding and connection of tiny parts.

[0003] Laser welding can be divided into traditional laser welding and ultrafast pulse laser welding. Among them, the light source of traditional laser welding is mainly continuous wave laser, nanosecond or picosecond laser. The principle is to use the principle of rapid laser heating to heat the welding surface so that it melts and connects together. It is usually welded on the edge. For example, its function is similar to traditional arc welding. Different from traditional laser welding, the principle of ultrafast pulse laser welding relies on the instantaneous energy deposition of ultrafast pulse laser to make the material at the interface undergo extremely fast nonlinear absorption, local melting and solidification, thereby achieving precise connection. It usually acts on the contact surface of the material, has strong bonding force and little destructive effect on the parts outside the welding area.

[0004] However, ultrafast pulse laser welding is more sensitive to material properties (such as reflectivity and absorptivity) and has higher requirements on material surface quality. It is easy for inconsistent sample conditions to cause different welding effects, affecting the welding quality, thus causing bottlenecks in mass production.

[0005] At present, in order to improve the welding quality, although there are some designs of ultrafast pulse laser welding methods, for example, when welding at the interface of glass and metal, a lower energy ultrafast pulse laser is first used for pre-scanning to only cause ablation and spattering of the lower metal, and it is necessary to avoid reaching the damage threshold of the glass so that the upper glass will not melt due to nonlinear effects, and then a higher energy ultrafast pulse laser is used to achieve welding. However, due to the step-by-step scanning of the pre-scan and the formal scan, the steps are cumbersome and it is easy to cause the high-temperature heating time of the lower metal to increase, which may affect the quality of the weld mark, for example, it may cause the weld mark to become wider, and therefore it cannot be applied to welding occasions that require high-precision and fine weld marks and cannot withstand long-term high-temperature heating, such as it is not suitable for use in the bonding of electronic components. Summary of the invention

[0006] In view of this, the embodiments of the present application provide an ultrafast laser pulse welding system and method to solve at least one problem existing in the background technology.

[0007] In a first aspect, an embodiment of the present application provides an ultrafast laser pulse welding system, the ultrafast laser pulse welding system comprising:

[0008] A laser source is configured to output a first structured light field laser pulse; the light intensity distribution rule of the first structured light field laser pulse is that the light intensity at the center of the light beam is the highest and decreases toward the edge of the light spot according to a first change trend;

[0009] A spatial shaping module is configured to transform the first structured light field laser pulse into a second structured light field laser pulse; the light intensity distribution law of the second structured light field laser pulse is that the light intensity remains constant in at least one set area within the beam cross section, and decreases toward the edge of the light spot according to a second change trend; the second change trend is steeper than the first change trend; and

[0010] The scanning galvanometer is configured to adjust the emission direction of the second structured light field laser pulse, so as to use the second structured light field laser pulse with the same parameters to perform multiple repeated scans at the interface of the first material and the second material according to the planned welding trajectory, so that at least one scan performed first can achieve at least optical contact between the first material and the second material; and at least one scan performed later can achieve the fusion of the first material and the second material to produce a welding point of a preset shape.

[0011] In combination with the first aspect, in an optional implementation, the laser source includes at least one of the following: a femtosecond laser source; a picosecond laser source; a nanosecond laser source.

[0012] In combination with the first aspect, in an optional implementation, the second structured light field laser pulse includes at least one of the following: a Besso beam; a flat-top beam.

[0013] In combination with the first aspect, in an optional implementation, the parameters of the second structured light field laser pulse include at least one of the following: average power; peak power; pulse energy; pulse repetition rate; pulse width; and pulse train mode.

[0014] In combination with the first aspect, in an optional implementation, the spatial shaping module includes at least one of the following: a diffractive optical component; a spatial phase modulator.

[0015] In combination with the first aspect, in an optional implementation manner, the ultrafast laser pulse welding system further includes:

[0016] The external regulator is configured to compress the first structured light field laser pulse to obtain an extremely short pulse.

[0017] In combination with the first aspect, in an optional implementation, the external regulator includes at least one of the following: a frequency multiplier; an optical parametric amplifier; a multi-crystal solid-state spread spectrum module; a multi-pass cavity spread spectrum compression module; or a hollow fiber spread spectrum module.

[0018] In combination with the first aspect, in an optional implementation manner, the ultrafast laser pulse welding system further includes:

[0019] The electrically controlled translation stage is configured to control the movement of the first material and the second material to achieve the multiple repeated scans.

[0020] In a second aspect, an embodiment of the present application provides an ultrafast laser pulse welding method, the ultrafast laser pulse welding method comprising:

[0021] Based on the second structured light field laser pulse with the same parameters, multiple repeated scans are performed at the interface of the first material and the second material according to the planned welding trajectory, so that at least one of the first scans can achieve at least an optical contact condition between the first material and the second material; and at least one of the subsequent scans can achieve the fusion of the first material and the second material to produce a preset shape welding point;

[0022] Among them, the light intensity distribution law of the second structured light field laser pulse is that the light intensity remains constant in at least one set area within the cross-section of the light beam, and decreases toward the edge of the light spot according to the second change trend; the second structured light field laser pulse is determined according to the first structured light field laser pulse; the light intensity distribution law of the first structured light field laser pulse is that the light intensity at the center point of the light beam is the highest, and decreases toward the edge of the light spot according to the first change trend; the second change trend is steeper than the first change trend.

[0023] The beneficial effects of the technical solution provided by the embodiment of the present application include: by using the second structured light field laser pulse with the same parameters in multiple scans, the welding steps are simplified, and by performing multiple welding scans on the same path, the bonding strength, reliability and stability of ultrafast laser welding can be greatly improved. Unlike single-scan welding, multiple scanning welding divides the entire welding process into two parts. First, the material is melted to ensure that the gap between the two pieces of material is filled and the optical contact condition is achieved, so that the weld mark can be controlled within the preset high-precision range, thereby improving the quality of the weld mark; then welding is performed to overcome the defects of microcracks and pores that are easily generated during welding, and the welding time is shortened. It can be applied to precision bonding of electronic components, etc., solves the problem of poor welding effect caused by uneven material surface, reduces the requirements of ultrafast laser welding on sample quality, and ensures that different samples can have consistent welding effects, which can greatly improve the laser welding effect and further improve the possibility of industrialization.

[0024] Additional aspects and advantages of the embodiments of the present application will be given in part in the description below and in part will become apparent from the description below or will be learned through the practice of the embodiments of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings herein are incorporated into the specification and constitute a part of the specification, showing embodiments consistent with the present application, and together with the specification, are used to explain the principles of the present application. In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can also be obtained based on these drawings without creative work. These drawings and textual descriptions are not intended to limit the scope of the concept of the present application in any way, but to illustrate the concept of the present application for those skilled in the art by referring to specific embodiments. In the drawings:

[0026] Figure 1 A schematic diagram of a principle block diagram of a specific example of an ultrafast laser pulse welding system in an embodiment of the present application;

[0027] Figure 2 A reaction change diagram of a specific example of single laser welding scanning using a first structured light field laser pulse in the related art;

[0028] Figure 3 A reaction change diagram of a specific example of performing two laser welding scans using a second structured light field laser pulse in an embodiment of the present application;

[0029] Figure 4 A schematic diagram of a principle block diagram of another specific example of an ultrafast laser pulse welding system in an embodiment of the present application;

[0030] Figure 5 A schematic diagram of a principle block diagram of another specific example of an ultrafast laser pulse welding system in an embodiment of the present application;

[0031] Figure 6 This is a flow chart of a specific example of the ultrafast laser pulse welding method in the embodiment of the present application. DETAILED DESCRIPTION

[0032] In order to make the technical solutions and beneficial effects of the present application more obvious and easy to understand, the following is a detailed description by listing specific embodiments. The drawings are not necessarily drawn to scale, and local features may be enlarged or reduced to more clearly show the details of the local features; unless otherwise defined, the technical and scientific terms used herein have the same meanings as those in the technical field to which the present application belongs.

[0033] The embodiments of the present application are not exhaustive, but are only illustrative of some embodiments, and are not intended to be a specific limitation on the scope of protection of the present application. In the absence of contradiction, each step in a certain embodiment can be implemented as an independent embodiment, and the steps can be arbitrarily combined. For example, in a certain embodiment, the solution after removing some steps can also be implemented as an independent embodiment, and the order of the steps in a certain embodiment can be arbitrarily exchanged. In addition, the optional implementations in a certain embodiment can be arbitrarily combined; in addition, the embodiments can be arbitrarily combined, for example, some or all of the steps of different embodiments can be arbitrarily combined, and a certain embodiment can be arbitrarily combined with the optional implementations of other embodiments.

[0034] In each embodiment of the present application, unless otherwise specified or there is a logical conflict, the terms and / or descriptions between the embodiments are consistent and can be referenced to each other. The technical features in different embodiments can be combined to form a new embodiment based on their internal logical relationships.

[0035] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application.

[0036] In the embodiments of the present application, unless otherwise specified, elements expressed in the singular form, such as "a", "an", "the", "above", "said", "aforementioned", "this", etc., may mean "one and only one", or "one or more", "at least one", etc. For example, when using articles such as "a", "an", "the" in English in translation, the noun after the article may be understood as a singular expression or a plural expression.

[0037] In the embodiments of the present application, "plurality" refers to two or more.

[0038] In some embodiments, the terms "at least one", "one or more", "a plurality of", "multiple", etc. can be used interchangeably.

[0039] The prefixes such as "first" and "second" in the embodiments of the present application are only used to distinguish different description objects, and do not constitute restrictions on the position, order, priority, value or content of the description objects. The statement of the description object refers to the description in the context of the claims or embodiments, and should not constitute unnecessary restrictions due to the use of prefixes. For example, the numerical value of the description object is not limited by the ordinal number, and can be one or more. Take "first device" as an example, where the numerical value of "device" can be one or more. In addition, the objects modified by different prefixes can be the same or different. For example, if the description object is "device", the "first device" and the "second device" can be the same device or different devices, and their types can be the same or different.

[0040] In some embodiments, the term "connection" may indicate that an electrical signal or data is transmitted between a connected end and a connected end, and may be understood as "electrical connection", "communication connection", etc. "Connection" may be a direct connection between two components, an indirect connection established through other components, internal communication between two components, or any other possible connection form.

[0041] This specification provides method operation steps such as embodiments or flow charts, but may include more or fewer operation steps based on conventional or non-creative labor. The order of steps listed in the embodiments is only one way of executing the order of many steps and does not represent the only execution order. When the actual device, system or server product is executed, it can be executed in the order of the method shown in the embodiments or the drawings or in parallel (for example, in a parallel processor or multi-threaded processing environment).

[0042] Pulse width: refers to the duration of a pulse in time, usually measured in seconds, at the width of the pulse energy intensity of 50%.

[0043] Pulse repetition rate: refers to the number of pulses output per second, measured in Hertz.

[0044] Pulse Energy: The energy of each pulse, measured in joules.

[0045] Average power: Pulse energy multiplied by the pulse repetition rate, which is the output energy of the pulse per second, measured in watts (W).

[0046] Peak power: Pulse energy divided by pulse width, the instantaneous output energy of the pulse, measured in watts (W).

[0047] Bandwidth: The width of the spectrum contained in a pulse of laser light, measured in nanometers.

[0048] Spread spectrum: The bandwidth of the pulse is increased through optical nonlinear effects.

[0049] Burst mode: Burst mode in a laser is a mode of operation in which the laser emits light pulses in rapid succession of groups or bursts of pulses rather than as single continuous pulses.

[0050] The present application embodiment provides an ultrafast laser pulse welding system, Figure 1 A schematic diagram of a principle block diagram of a specific example of an ultrafast laser pulse welding system in an embodiment of the present application is shown. As shown in the figure, the ultrafast laser pulse welding system includes:

[0051] The laser source 10 is configured to output a first structured light field laser pulse L1; the light intensity distribution rule of the first structured light field laser pulse L1 is that the light intensity at the center of the light beam is the highest and decreases toward the edge of the light spot according to a first change trend;

[0052] The spatial shaping module 20 is configured to transform the first structured light field laser pulse L1 into a second structured light field laser pulse L2; the light intensity distribution law of the second structured light field laser pulse L2 is that the light intensity remains constant in at least one set area within the beam cross section, and decreases toward the edge of the light spot according to a second change trend; the second change trend is steeper than the first change trend; and

[0053] The scanning galvanometer 30 is configured to adjust the emission direction of the second structured light field laser pulse L2, so as to use the second structured light field laser pulse L2 with the same parameters to perform multiple repeated scans (N≥2, N is the number of scans) at the interface IF between the first material A1 and the second material A2 according to the planned welding trajectory, so that at least one scan performed first can achieve at least optical contact conditions between the first material A1 and the second material A2; and at least one scan performed later can achieve the fusion of the first material A1 and the second material A2 to produce a preset shape welding point.

[0054] In the embodiment of the present application, the structured light field of laser pulses may refer to a type of spatial light beam with set amplitude, phase, polarization state distribution, coherence or orbital angular momentum. The first structured light field laser pulse L1 and the second structured light field laser pulse L2 may be light pulses emitted in a burst mode, or may be other forms of light pulses.

[0055] In an exemplary embodiment, reference Figure 1The first structured light field laser pulse L1 is usually a Gaussian beam. However, if a Gaussian beam is used directly for welding, due to the light intensity distribution law of the Gaussian beam, the beam energy is highly concentrated at the focus, which can easily cause a self-focusing effect, and it is very easy to produce microcracks and pores during the welding process. It is also difficult to overcome this problem by controlling the process parameters, resulting in poor welding quality.

[0056] The second structured light field laser pulse L2 may include at least one of the following: Bessel Beam; Top-Hat Beam; and so on. The second structured light field laser pulse L2 may have a light spot with uniform light intensity distribution on the focal plane (i.e., the interface IF between the first material A1 and the second material A2), or may have two, three, four, or other multiple light spots with consistent and uniform light intensity, so that the light intensity remains constant in one or more set areas. And because the second structured light field laser pulse L2 has a steep light intensity change trend, such as the spatial distribution before and after the focal plane is dispersed, it is not easy to cause a self-focusing effect, so that stable and sufficient material melting can be generated during the first scan to achieve optical contact conditions, so that the defects of microcracks and pores that are easily generated when welding with the first structured light field laser pulse L1 can be overcome, and the gap between the first material A1 and the second material A2 can be fully filled to improve the welding quality, which is particularly suitable for easily damaged materials.

[0057] In the embodiment of the present application, the number of repeated scans can be set according to the actual requirements of the characteristics of the welding material. The materials of the first material A1 and the second material A2 are not limited to the same material. The wavelength of the laser source used can penetrate the first material A1 to the interface. The welding material can include at least one of the following: insulator (such as glass), semiconductor (such as silicon wafer), conductor (such as metal), etc. The scanning speed and the number of repetitions can be adjusted by the scanning galvanometer 30 to meet the actual needs.

[0058] In an exemplary embodiment, a second structured light field laser pulse L2 with the same parameter conditions may be used to perform repeated scanning welding on the same track twice. Figure 2 A reaction change diagram of a specific example of single laser welding scan using a first structured light field laser pulse in the related art is shown. Figure 3 The reaction change diagram of a specific example of using the second structured light field laser pulse to perform two laser welding scans in the embodiment of the present application is shown. Figure 2 and Figure 3, during a single laser welding scan, one scan can cause reaction changes from X1 to X3 at the interface. X1: directly produces nonlinear effects, generates plasma, and produces self-focusing effects; X2: as heating continues, an avalanche effect occurs; X3: after cooling, a droplet-shaped welding point is formed. Although a single beam scan can complete welding, the floating range of the finished product bonding force is extremely large, and it cannot guarantee the success of each bonding. Because Figure 2 In a single scan, firstly, the nonlinear effect is directly generated at the interface of the material by virtue of the characteristics of the ultrafast pulse, and then the same point is continuously heated by subsequent pulses to produce an avalanche effect, so that the upper and lower layers of the originally independent interfaces are blended together, and after cooling, a raindrop-shaped welding structure is formed, and the upper and lower samples are fixed. The premise for the smooth completion of this process is that when the avalanche effect occurs, the upper and lower layers of the originally independent materials can contact each other and blend, otherwise they will still be two independent structures after subsequent cooling, not only will the welding not be completed, but the surface flatness will even be destroyed. Then, only a single scan is likely to cause the following problems: 1. Poor stability: Due to the inconsistency between the flatness of the bonding material and the stability of the light source, the result of only a single scan welding may cause a great difference in the welding results within the track, and only a small part of the area may be welded, resulting in poor welding effect. 2. Poor reliability: If only a single welding scan is performed, the consistency of the bonding material is required, otherwise the welding effect of different pieces of material cannot be ensured to be consistent, which is not suitable for application in the production of industrial products. 3. High requirements for material quality: If the flatness of the material itself is too poor, or the gap between the samples is too large, even if the plasma is successfully generated by the laser, the two pieces of material may not be able to blend with each other because the distance between them is too far, and ultimately the welding cannot be completed, but the surface of the material will be damaged.

[0059] Compared to a single laser welding scan, in the two laser welding scans of the embodiment of the present application, in the first laser welding scan, reaction changes from Y1 to Y3 may occur at the interface. Y1: Melting of at least one of the first material A1 and the second material A2; Y2: As heating continues, the melted material deforms and fills the gaps and voids at the junction; Y3: Optical contact conditions are achieved after cooling. In the second laser welding scan, reaction changes from Z1 to Z3 may occur at the interface. Z1: Produces a nonlinear effect, generates plasma, and produces a self-focusing effect; Z2: As heating continues, an avalanche effect occurs; X3: A droplet-shaped welding point is formed after cooling.

[0060] In this way, the embodiment of the present application simplifies the welding steps by using the second structured light field laser pulse with the same parameters in multiple scans, and by performing multiple welding scans on the same path, the bonding strength, reliability and stability of ultrafast laser welding can be greatly improved. Unlike single-scan welding, multiple-scan welding divides the entire welding process into two parts. First, the material is melted to ensure that the gap between the two pieces of material is filled and the optical contact condition is achieved, so that the weld mark can be controlled within the preset high-precision range, improving the quality of the weld mark; then welding is performed, which can overcome the defects of microcracks and pores that are very easy to produce in welding, and shorten the welding time. It can be applied to precision bonding of electronic components, etc., solves the problem of poor welding effect caused by uneven material surface, reduces the requirements of ultrafast laser welding on sample quality, and ensures that different samples can have consistent welding effects, which can greatly improve the laser welding effect and further improve the possibility of industrialization.

[0061] In the embodiment of the present application, the beam after shaping and parameter adjustment can be controlled by the scanning galvanometer 30 to control the speed and trajectory of the beam hitting the sample (interface IF of the first material A1 and the second material A2), but it is not limited to this. The beam direction can also be adjusted spatially by using a prism, a wedge lens, etc. The planned welding trajectory (trajectory graph) can be adjusted according to the actual needs of the sample size and shape. The preset shape of the welding point can be a water drop shape, but it is not limited to this, and it can also be a sphere, etc.

[0062] In an optional implementation, the laser source 10 includes at least one of the following: a femtosecond laser source; a picosecond laser source; or a nanosecond laser source.

[0063] As a preferred embodiment, a femtosecond laser source may be used to obtain a better welding effect. For example, a femtosecond laser source with a wavelength of 1030 nm may be used, and the wavelength may be converted according to material requirements to penetrate the first material A1 and reach the interface IF.

[0064] In an optional embodiment, the parameters of the second structured light field laser pulse L2 include at least one of the following: average power; peak power; pulse energy; pulse repetition rate; pulse width; and pulse train mode.

[0065] In this way, the parameters of the laser pulse can be adjusted according to the needs of the material, so as to complete and meet the requirements of laser welding that does not damage the material and has good bonding strength. The average power, peak power and pulse energy can be matched with different condition parameters according to different materials. The increase in pulse repetition rate can increase the welding speed, because the number of pulses per unit length can be adjusted by the welding speed, and the increase in repetition rate helps to increase the moving speed. The narrower the pulse width, the lower the diffusion of thermal effects, which can avoid deformation or damage to materials other than welding due to heat. The adjustment of the pulse train mode (pulse train sequence) can change the heat accumulation on the welding track. Some materials with high melting points can achieve the feasibility of welding by changing the pulse train sequence.

[0066] In an optional embodiment, the spatial shaping module 20 includes at least one of the following: a diffractive optical element (DOE); a spatial phase modulator.

[0067] In the embodiment of the present application, the spatial shaping module 20 can realize the shaping of the light beam to obtain the required second structured light field laser pulse L2. The light beam can be shaped by various types of optical devices, which can be set according to actual needs. Different spot shapes can also control the feasibility of welding on different materials. For example, Gaussian beam is a commonly used beam, but it is not suitable for welding fragile materials. The spot characteristics of the flat-top light are not easy to cause self-focusing effect and the spatial distribution before and after the focus is dispersed, so it is suitable for use on fragile materials.

[0068] Figure 4 A schematic diagram of a principle block diagram of another specific example of an ultrafast laser pulse welding system in an embodiment of the present application is shown. As shown in the figure, in an optional embodiment, the ultrafast laser pulse welding system further includes:

[0069] The external regulator 40 is configured to compress the first structured light field laser pulse L1 to obtain an extremely short pulse.

[0070] In an optional embodiment, the external regulator 40 includes at least one of the following: a frequency multiplier; an optical parametric amplifier; a multi-crystal solid-state spread spectrum module; a multi-pass cavity spread spectrum compression module; or a hollow fiber spread spectrum module.

[0071] In this way, before entering the processing scanning galvanometer, various nonlinear methods (such as double frequency, triple frequency, optical parameter amplifier, etc.) can be used to convert the wavelength and characteristics of the light source. For example, the output wavelength range can be 300 nanometers to 3000 nanometers, and the output pulse width can be 10 femtoseconds to 2 picoseconds. It is also possible to use a multi-crystal solid-state spread spectrum module, a multi-pass cavity spread spectrum compression module or a hollow fiber spread spectrum module to compress the laser pulse to an extremely short pulse (such as less than 100 femtoseconds). For example, optical crystals can be used to produce nonlinear effects and thus increase the laser bandwidth; multiple thin sheets with a thickness of less than 2mm can be used as spread spectrum media, and the spot size and shape can be controlled by spatial shaping to achieve a nonlinear effect that can produce self-phase modulation and self-focusing effects. Then, a series of multiple groups of solid-state media with specific arrangement spacing are used to form a continuous spread spectrum to make up for the defects of damage caused by laser intensity due to the medium being too thick or insufficient nonlinear spread spectrum coefficients due to the medium being too thin. By using multiple thin sheets with a thickness of less than 2 mm as the spectrum spreading medium, compared with using gas as the spectrum spreading medium, the solid medium can provide more nonlinear effects and achieve better spectrum spreading effects. Compared with the traditional use of a thicker single block of about 1 cm, the use of multiple thin sheets can increase the pulse energy that the system can withstand and can better generate laser pulses that meet the needs of today's industry.

[0072] The embodiment of the present application uses an external regulator to perform pulse compression, which can reduce the thermal effect again to achieve more precise control, achieve high-precision welding, and improve the quality of weld marks. By transferring high energy in a very short time, local plasma is formed to achieve micron-level welding. Its cold processing characteristics have almost no thermal impact, and it is suitable for fields such as microelectronics and medical equipment, and can achieve high-precision, low-thermal-impact microscale welding. Therefore, the thermal effect can be more effectively and accurately controlled, and the bonding strength of the welding can be improved.

[0073] Figure 5 FIG. 1 is a schematic diagram of a principle block diagram of another specific example of an ultrafast laser pulse welding system in an embodiment of the present application. Figure 5 As shown, the ultrafast laser pulse welding system also includes:

[0074] The electrically controlled translation stage 50 is configured to control the movement of the first material A1 and the second material A2 to achieve the multiple repeated scans.

[0075] In the embodiment of the present application, the electrically controlled translation stage 50 can move the sample, and the scanning galvanometer 30 can move the laser pulse irradiated on the sample to realize welding scanning of the planned welding trajectory on the sample. That is, multiple repeated optical scans can be performed by using the scanning galvanometer to move the light beam, and the same process can also be completed by controlling the motion platform carrying the sample. Compared with the optical scanning galvanometer, the motion platform is inferior in speed and accuracy, but it can perform large-area mobile scanning welding. The electrically controlled translation stage 50 can expand the scanning area and realize a large-scale welding scan. The movement mode of the sample is not limited to three-axis linear movement, but can also be various spatial displacement modes such as rotation and angular displacement.

[0076] The present application also provides an ultrafast laser pulse welding method. Figure 6 A flowchart of a specific example of an ultrafast laser pulse welding method in an embodiment of the present application is shown. As shown in the figure, the ultrafast laser pulse welding method includes:

[0077] S1: Based on the second structured light field laser pulse with the same parameters, multiple repeated scans are performed at the interface of the first material and the second material according to the planned welding trajectory, so that at least one of the first scans can achieve at least an optical contact condition between the first material and the second material; and at least one of the subsequent scans can achieve the fusion of the first material and the second material to produce a welding point of a preset shape;

[0078] Among them, the light intensity distribution law of the second structured light field laser pulse is that the light intensity remains constant in at least one set area within the cross-section of the light beam, and decreases toward the edge of the light spot according to the second change trend; the second structured light field laser pulse is determined according to the first structured light field laser pulse; the light intensity distribution law of the first structured light field laser pulse is that the light intensity at the center point of the light beam is the highest, and decreases toward the edge of the light spot according to the first change trend; the second change trend is steeper than the first change trend.

[0079] It should be understood that the above embodiments are exemplary and are not intended to include all possible implementations included in the claims. Various modifications and changes may be made on the basis of the above embodiments without departing from the scope of the present disclosure. Similarly, the various technical features of the above embodiments may be arbitrarily combined to form other embodiments of the present application that may not be explicitly described. Therefore, the above embodiments only express several implementations of the present application and do not limit the scope of protection of the patent of this application.

Claims

1. An ultrafast laser pulse welding system, characterized in that: The ultrafast laser pulse welding system comprises: A laser source is configured to output a first structured light field laser pulse; the light intensity distribution rule of the first structured light field laser pulse is that the light intensity at the center of the light beam is the highest and decreases toward the edge of the light spot according to a first change trend; A spatial shaping module is configured to transform the first structured light field laser pulse into a second structured light field laser pulse; the light intensity distribution law of the second structured light field laser pulse is that the light intensity remains constant in at least one set area within the beam cross section, and decreases toward the edge of the light spot according to a second change trend; the second change trend is steeper than the first change trend; and The scanning galvanometer is configured to adjust the emission direction of the second structured light field laser pulse, so as to use the second structured light field laser pulse with the same parameters to perform multiple repeated scans at the interface of the first material and the second material according to the planned welding trajectory, so that at least one scan performed first can achieve at least optical contact between the first material and the second material; and at least one scan performed later can achieve the fusion of the first material and the second material to produce a welding point of a preset shape.

2. The ultrafast laser pulse welding system according to claim 1, characterized in that: The laser source includes at least one of the following: a femtosecond laser source; a picosecond laser source; a nanosecond laser source.

3. The ultrafast laser pulse welding system according to claim 1, characterized in that: The second structured light field laser pulse includes at least one of the following: a Besso beam; a flat-top beam.

4. The ultrafast laser pulse welding system according to claim 1, characterized in that: The parameters of the second structured light field laser pulse include at least one of the following: average power; peak power; pulse energy; pulse repetition rate; pulse width; and pulse train mode.

5. The ultrafast laser pulse welding system according to claim 1, characterized in that: The spatial shaping module includes at least one of the following: a diffractive optical component; a spatial phase modulator.

6. The ultrafast laser pulse welding system according to claim 1, characterized in that: The ultrafast laser pulse welding system also includes: The external regulator is configured to compress the first structured light field laser pulse to obtain an extremely short pulse.

7. The ultrafast laser pulse welding system according to claim 6, characterized in that: The external regulator includes at least one of the following: a frequency multiplier; an optical parametric amplifier; a multi-crystal solid-state spread spectrum module; a multi-pass cavity spread spectrum compression module; and a hollow optical fiber spread spectrum module.

8. The ultrafast laser pulse welding system according to any one of claims 1 to 7, characterized in that: The ultrafast laser pulse welding system also includes: The electrically controlled translation stage is configured to control the movement of the first material and the second material to achieve the multiple repeated scans.

9. An ultrafast laser pulse welding method, characterized in that: The ultrafast laser pulse welding method comprises: Based on the second structured light field laser pulse with the same parameters, multiple repeated scans are performed at the interface of the first material and the second material according to the planned welding trajectory, so that at least one of the first scans can achieve at least an optical contact condition between the first material and the second material; and at least one of the subsequent scans can achieve the fusion of the first material and the second material to produce a preset shape welding point; Among them, the light intensity distribution law of the second structured light field laser pulse is that the light intensity remains constant in at least one set area within the cross-section of the light beam, and decreases toward the edge of the light spot according to the second change trend; the second structured light field laser pulse is determined according to the first structured light field laser pulse; the light intensity distribution law of the first structured light field laser pulse is that the light intensity at the center point of the light beam is the highest, and decreases toward the edge of the light spot according to the first change trend; the second change trend is steeper than the first change trend.

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