Ultrafast laser integrated connection method and device for multiple layers of heterogeneous materials

Abstract

The invention provides a multilayer heterogeneous material ultrafast laser integrated connection method and device, and the method specifically comprises the steps: stacking and fixing a chip bonding pad, a spring pin and quartz glass on a three-dimensional motion platform, and adjusting the platform to enable a laser focal plane to be located at the center of the pin; aiming at the connection of a bonding pad and a pin, high-repetition-frequency ultrafast laser with a high Rayleigh length is obtained through spatial shaping, a two-dimensional galvanometer is used for carrying out spiral line or concentric circular ring scanning to act on the periphery of the pin, metal plasma is excited, molten metal is formed and deposited in a contact hole of the pin and the bonding pad, and the molten metal is continuously accumulated along with reverse heating, so that the metal is formed. Dissimilar metal welding is achieved; aiming at the connection of the pin and the glass, laser penetrates through the quartz glass, plasma is excited on a metal interface, molten metal with increased volume is formed, a material interface gap is filled, and welding from non-optical contact to optical contact is regulated and controlled; and two heterogeneous materials are successfully welded through single scanning until welding of the whole pin array is completed, and efficient integrated packaging is achieved.

Description

Technical Field

[0001] The patent of this invention relates to the field of ultrafast laser chip packaging, and specifically to a multi-layer heterogeneous material ultrafast laser integrated connection method and equipment. Background Art

[0002] System-in-Package (SIP) is an advanced chip packaging technology that integrates multiple integrated circuits and other electronic components in a single package to improve functional density and reduce manufacturing costs. Its structure usually contains multiple chips with different functions, passive components (such as resistors and capacitors), and various connection technologies (such as flip-chip and solder ball arrays) to ensure electrical connections between components. The main advantages of SIP packaging include high integration and miniaturization, which significantly reduces the overall size and improves electrical performance, thereby reducing signal delay. In addition, the design of SIP simplifies PCB layout and reduces the steps in the manufacturing process, thereby effectively reducing production costs and enhancing the reliability of components within the package. This technology is widely used in consumer electronics, IoT devices, wireless communications, and medical equipment, meeting the growing demand for high integration and high performance.

[0003] In order to further improve the integration of SIP packaging, three-dimensional packaging technology came into being. Three-dimensional packaging usually adopts a multi-layer stacking design to vertically stack chips with different functions (such as processors, memory and sensors). Through-silicon via technology TSV is used to create tiny vertical through holes on silicon wafers, allowing direct connection between different layers. TSV technology significantly shortens the signal transmission path and improves data transmission rate and overall performance. The entire packaging process of SIP packaging includes: wafer thinning-wafer dicing-substrate gluing-chip bonding-adhesive curing-wire bonding-plastic sealing-substrate ball planting-reflow-laser marking. In the SIP packaging process, according to the connection method between the chip and the substrate, it can be divided into wire bonding packaging and flip chip welding. Wire bonding packaging is a packaging form that connects the chip to the substrate through metal wires. Its characteristic is that the connection between the wires and the chip and the substrate is achieved by bonding, so it has high reliability. BGA packaging, or ball grid array (or solder ball array) packaging, is a large-scale integrated circuit chip packaging technology that uses solder balls or solder bumps as its external leads and is distributed in an array on the bottom plane of the package substrate. It is a type of surface mount packaging for chips. Its main advantages include high-density connections, which can accommodate more pins in a small area; excellent electrical performance, reducing signal delays; and good heat dissipation capabilities, which helps prevent overheating. In addition, BGA packaging simplifies the soldering process, improves soldering consistency, and enhances mechanical strength, which is suitable for the needs of modern electronic products.

[0004] For the assembly of high-frequency chip curved surfaces, the traditional spherical interconnect pins are on the same plane, which will cause the spherical pins at both ends to contact the curved surface while the local spherical pins in the middle are suspended, making it difficult to meet the high reliability assembly requirements. The use of spring-type pins provides a new idea by utilizing their compression deformation characteristics. In this regard, the authorized patent (CN108666275B) and the patent application (CN108666275A) encapsulate the chip in a two-dimensional mode in a package on the same package substrate; use columnar or micro-spring pins as the interconnection pins between the SIP device and the external curved surface PCB substrate, and make columnar or micro-spring pins that match the shape of the curved surface PCB substrate; then use the pin placement tool to place the columnar or micro-spring pins on the SIP device pad in an array form, fix them after welding and pass the coaxial test; then mount the SIP device implanted with columnar or micro-spring pins on the curved surface PCB substrate; finally, complete the conformal assembly of the curved surface PCB substrate and the SIP device through reflow soldering. This process can reduce the complexity of printed circuit boards, shorten the development cycle, and improve system integration. However, since the lower surface of the columnar or micro-spring pins is the bottom or side of the cylinder, it cannot completely fit the curved PCB substrate, so it will be limited in practical applications, resulting in reduced welding quality and reduced packaging reliability. In addition, the above patent uses reflow soldering when soldering curved materials, the solder flows, and the accuracy is reduced, so it is difficult to achieve effective welding with the existing reflow soldering method.

[0005] The high-frequency chip curved integrated packaging technology includes heterogeneous metal welding between chip metal pads and metal spring pins, and transparent / metal heterogeneous material welding between metal spring pins and transparent quartz glass. Existing laser welding technology is difficult to achieve efficient integrated packaging of the above-mentioned multi-layer heterogeneous materials. In order to solve this technical problem, the present invention proposes a new ultra-high repetition rate ultrafast laser oscillation scanning integrated welding technology, including heterogeneous metal ultrafast laser "confined ablation-deposition-melting" connection technology, transparent / metal heterogeneous material ultrafast laser high-strength connection technology and multi-layer heterogeneous material ultrafast laser integrated connection technology. Summary of the invention

[0006] In response to the problems of low reliability of new pin packaging and complex welding process between metal spring pins and metal pads and quartz glass, the patent of this invention provides a multi-layer heterogeneous material ultrafast laser integrated connection method and equipment, including heterogeneous metal ultrafast laser "confined ablation-deposition-melting" connection technology, transparent / metal heterogeneous material ultrafast laser high-strength connection technology and multi-layer heterogeneous material ultrafast laser integrated connection technology.

[0007] To achieve the above-mentioned purpose, the present invention provides a multi-layer heterogeneous material ultrafast laser integrated connection method and equipment, comprising the following steps:

[0008] (1) The lower chip pad, the spring-type pin array and the upper quartz glass are stacked on a three-dimensional motion platform in sequence and fixed with a clamp. The three-dimensional motion platform is adjusted so that the focal plane of the laser is located at the central height of the spring-type pin array.

[0009] (2) Based on the spatiotemporal shaping of ultrafast laser, high repetition rate and high Rayleigh length ultrafast laser focusing is achieved, and a spiral or concentric ring oscillation scanning path is realized through a two-dimensional galvanometer. Under the oscillation scanning path, the ultrafast laser will act on the three-dimensional limited area around the spring pin (limited ablation);

[0010] (3) Ultrafast laser acts on the surface of the lower chip pad to excite metal plasma, and the heat accumulation formed by the ultra-high repetition rate will form molten metal material. The two will actively deposit a high-temperature plasma-molten metal mixture in the contact gap between the spring pin and the lower chip pad (confined deposition); under oscillation scanning, the above process is repeated, and the deposited high-temperature plasma-molten metal mixture is continuously heated and accumulated, and reversely heated to melt the spring pin (confined melting), thereby realizing heterogeneous metal welding between the chip metal pad and the metal spring pin.

[0011] (4) When the ultrafast laser oscillates and scans in a spiral or concentric ring, the ultrafast laser will synchronously act on the interface between the upper quartz glass and the spring pin. In this process, the ultrafast laser will directly transmit through the quartz glass, and due to the high linear absorption of the metal material to the ultrafast laser, the metal plasma will be excited at the interface. Under the effective heat accumulation of the ultrafast laser with ultrahigh repetition rate, a molten metal material with an increased volume can be formed to fill the interface gap between transparent / metal dissimilar materials and regulate non-optical contact welding to optical contact welding. Under ultrafast laser oscillation scanning, ultrafast laser high-strength welding of transparent / metal dissimilar materials can be achieved.

[0012] (5) After successfully connecting the upper quartz glass and the lower chip pad using the ultrafast laser on the spring pin, move to the next spring pin position to continue welding until the entire spring pin array is fully welded, thereby achieving efficient integrated packaging of the upper quartz glass, the spring pin array, and the lower chip pad.

[0013] Furthermore, the three-dimensional motion platform includes an electric Z-axis and a two-dimensional galvanometer, which can move or rotate independently or in conjunction on the X, Y, and Z axes, thereby achieving precise position and posture adjustment of the workpiece in three-dimensional space.

[0014] Furthermore, the ultrafast laser is a high repetition rate picosecond laser or femtosecond laser, with a wavelength of 532-1064nm, a repetition rate set to 200kHz-2MHz, and a power set to 10-100W.

[0015] Furthermore, the Rayleigh length is the distance at which the laser beam maintains its minimum cross-sectional dimension (i.e., beam waist) during propagation. A high Rayleigh length is achieved through spatial shaping, so that the laser beam maintains better focusing performance over a longer propagation distance, thereby improving the accuracy and efficiency of the integrated connection.

[0016] Furthermore, the oscillation scanning path is a spiral line or a concentric ring, and the size is between the inner circle diameter and the outer circle diameter of the spring.

[0017] Furthermore, the connection between the metal pad and the spring pin is based on a new connection method of ultrafast laser "confined ablation-deposition-melting", which realizes high-strength welding of heterogeneous metals between the chip metal pad and the metal spring pin.

[0018] Furthermore, the connection between the spring pin and the quartz glass is adjusted from non-optical contact to optical contact, and the laser energy is focused into a very small range by reducing the interface gap, thereby achieving high-precision, low-heat-affected ultrafast laser welding of transparent / metal heterogeneous materials.

[0019] Furthermore, the new ultra-high repetition rate ultrafast laser oscillation scanning integrated welding technology includes heterogeneous metal ultrafast laser "confined ablation-deposition-melting" connection technology, transparent / metal heterogeneous material ultrafast laser high-strength connection technology and multi-layer heterogeneous material ultrafast laser integrated connection technology.

[0020] Furthermore, the upper workpiece is a transparent material, the middle is a spring-type pin array, and the lower workpiece is a metal pad. The transparent material is quartz glass or sapphire, and the material can be a straight surface or an arc surface, and is polished on both sides. The metal pad is copper, aluminum alloy, or titanium alloy, and the material is a straight surface.

[0021] Furthermore, the spring pin array is formed by arranging spring pins, wherein the height of the spring pins is 1-2.5 mm, the diameter of the spring is 0.06-0.1 mm, the pitch of the spring is 0.025-0.15 mm, and the outer ring diameter of the spring is 0.4-0.6 mm.

[0022] In general, the above technical solution of the present invention has the following advantages compared with the prior art:

[0023] The use of spring pins expands the application scope of chip packaging. For high-frequency chip arc surface assembly, the traditional spherical interconnect pins are on the same plane, which will cause the spherical pins at both ends to contact the arc surface while the spherical pins in the middle are partially suspended, making it difficult to meet the high-reliability assembly requirements. The use of spring pins using their compression deformation characteristics provides a new idea for high-frequency chip arc surface assembly. At the same time, spring pins can also meet the heat dissipation requirements of high-power chips, which is conducive to further improving the reliability of chip packaging.

[0024] The use of laser welding enhances the reliability of chip packaging. Compared with traditional technologies such as reflow soldering, ultrafast laser can use the heat accumulation under high frequency to achieve heterogeneous material connection. It has the advantages of high precision, low thermal impact, and high connection strength. It is the only choice to enhance the reliability of chip packaging.

[0025] The use of integrated connection technology shortens the development cycle and reduces manufacturing costs. Through-glass via (TGV) is an effective supplement to through-silicon via (TSV) technology, and has significant advantages in high-frequency chips. It can be used as a packaging substrate for the conformal assembly of high-frequency chip arc surfaces. By selecting a suitable oscillation scanning path, the focused ultrafast laser with a high Rayleigh length can act on the contact gap between the spring-type pin and the lower chip pad to form an ultrafast laser "confined ablation-deposition-melting" connection of heterogeneous metals, and can also act simultaneously on the contact position between the upper quartz glass and the spring-type pin to weld transparent / metal heterogeneous materials, so as to achieve the purpose of efficient integrated welding of multi-layer heterogeneous materials, shortening the development cycle and reducing manufacturing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The ultra-high repetition rate ultrafast laser welding system for multi-layer heterogeneous materials of the present invention. In the figure: 1-ultrafast laser; 2-collimation optical path; 3-two-dimensional galvanometer; 4-field mirror; 5-upper layer quartz glass; 6-lower layer chip pad; 7-three-dimensional motion platform.

[0027] Figure 2 It is a heterogeneous metal ultrafast laser "confined ablation-deposition-melting" technology. In the figure: 1-oscillation scanning path (concentric ring type); 2-focused ultrafast laser; 3-spring-type pin array; 4-confined ablation deposition particles; 5-lower chip pad.

[0028] Figure 3 It is a heterogeneous metal ultrafast laser "confined ablation-deposition-melting" technology. In the figure: 1-oscillation scanning path (spiral); 2-focused ultrafast laser; 3-spring-type pin array; 4-confined ablation deposition particles; 5-lower chip pad.

[0029] Figure 4 It is a high-strength ultrafast laser connection technology for transparent / metallic heterogeneous materials. In the figure: 1-focused ultrafast laser; 2-upper layer of quartz glass; 3-spring-type pin array; 4-lower layer chip pad.

[0030] Figure 5 It is a multi-layer heterogeneous material ultrafast laser integrated connection technology. In the figure: 1-focused ultrafast laser; 2-upper layer of quartz glass; 3-spring-type pin array; 4-lower layer chip pad. DETAILED DESCRIPTION

[0031] In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, the following will be described in detail with reference to the accompanying drawings and specific embodiments. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0032] The high-frequency chip curved integrated packaging technology includes heterogeneous metal welding between the chip metal pad and the metal spring pin, and transparent / metal heterogeneous material welding between the metal spring pin and the transparent quartz glass. The existing laser welding technology is difficult to achieve efficient integrated packaging of the above-mentioned multi-layer heterogeneous materials. In order to solve this technical problem, the project proposes a new ultra-high repetition rate ultrafast laser oscillation scanning integrated welding technology, including heterogeneous metal ultrafast laser "confined ablation-deposition-melting" connection technology, transparent / metal heterogeneous material ultrafast laser high-strength connection technology and multi-layer heterogeneous material ultrafast laser integrated connection technology. They are introduced as follows:

[0033] (1) Heterogeneous metal ultrafast laser "confined ablation-deposition-melting" connection technology: Based on the time shaping of ultrafast laser, ultrafast laser output with ultrahigh repetition rate is realized, and a spiral or concentric ring oscillation scanning path is realized through a two-dimensional galvanometer; based on the spatial shaping of ultrafast laser, a focused ultrafast laser with high Rayleigh length is realized, and the ultrafast laser will act on the three-dimensional confined area around the spring pin under the oscillation scanning path (confined ablation); ultrafast laser with ultrahigh repetition rate acts on the surface of the lower chip pad to excite metal plasma, and the heat accumulation formed by the ultrahigh repetition rate will form molten metal material, and the two will actively deposit a high-temperature plasma-molten metal mixture in the contact pore between the spring-type lead and the lower chip pad (confined deposition); under oscillation scanning, the above process is repeated, and the deposited high-temperature plasma-molten metal mixture is continuously heated and accumulated, and reversely heated to melt the spring pin (confined melting), thereby realizing heterogeneous metal welding between the chip metal pad and the metal spring pin.

[0034] (2) Ultrafast laser high-strength connection technology for transparent / metal heterogeneous materials: When the ultrafast laser oscillates and scans in a spiral or concentric ring, it will simultaneously act on the interface between the upper quartz glass and the spring pin. In this process, the ultrafast laser will directly transmit through the quartz glass. Due to the high linear absorption of the ultrafast laser by the metal material, the metal plasma will be excited at the interface. Under the effective heat accumulation of the ultrahigh repetition rate ultrafast laser, a molten metal material with an increased volume can be formed to fill the interface gap between the transparent / metal heterogeneous materials and adjust the non-optical contact welding to optical contact welding. Under ultrafast laser oscillation scanning, ultrafast laser high-strength connection of transparent / metal heterogeneous materials can be achieved.

[0035] (3) Ultrafast laser integrated connection technology for multi-layer heterogeneous materials: By selecting an appropriate oscillation scanning path, the focused ultrafast laser with a high Rayleigh length can act on the contact gap between the spring-type pin and the lower chip pad to form an ultrafast laser "confined ablation-deposition-melting" connection of heterogeneous metals, and can also act on the contact position between the upper quartz glass and the spring-type pin. Therefore, the transparent / metal heterogeneous material welding between the spring-type pin and the transparent quartz glass and the heterogeneous metal welding between the chip metal pad and the metal spring-type pin can occur simultaneously, achieving the purpose of efficient integrated welding of multi-layer heterogeneous materials.

[0036] Specific examples:

[0037] The structure of an example provided by the present invention is as follows Figure 1 As shown, a multi-layer heterogeneous material ultrafast laser integrated connection method and equipment is provided. The equipment is composed of an ultrafast laser 1, a collimated optical path 2, a two-dimensional galvanometer 3, a field lens 4, an upper quartz glass 5, a lower chip pad 6 and a three-dimensional motion platform 7.

[0038] In this example, the ultrafast laser 1, the collimated optical path 2, the two-dimensional galvanometer 3 and the field lens 4 are located on the same optical path. The ultrafast laser 1 is collimated by the collimated optical path 2, moved by the two-dimensional galvanometer 3, focused by the field lens 4, and finally acts on the upper quartz glass 5, the lower chip pad 6 and the spring-type pin array between them (not shown in the figure). The two-dimensional galvanometer 3 controls the horizontal movement of the ultrafast laser, and the three-dimensional motion platform 7 controls the vertical movement of the multi-layer heterogeneous material.

[0039] The multilayer heterogeneous materials in this example are transparent quartz glass, spring pins, and metal chip pads. The transparent quartz glass has a size of 20 mm × 10 mm × 2 mm and is polished on both sides. The spring pins are phosphor bronze compression springs with a size of 0.2 mm × 1 mm × 5 mm × 13 turns. The metal chip pads have a size of 20 mm × 10 mm × 2 mm and are polished on both sides.

[0040] In the ultrafast laser integrated connection experiment, a femtosecond pulse laser was used with a wavelength of 1035nm, a repetition rate of 1MHz, a power of 30W, a scanning galvanometer scanning speed of 20mm / s, a field lens focal length of 80mm, and a laser defocus value that can be set between plus or minus 100um. A lower clamping force can be applied between the workpieces or they can be naturally stacked, and the number of welding times is 1.

[0041] First, the lower chip pad, spring-type pin array and upper quartz glass are stacked and fixed on a three-dimensional motion platform, and the laser focal plane is located in the center of the pin by adjusting the platform.

[0042] like Figure 2 , Figure 3As shown, a high-repetition-rate ultrafast laser 1 is used to perform a spiral or concentric ring oscillation scanning path 2 through a two-dimensional galvanometer to scan the peripheral area of ​​the interface between the spring pin 3 and the chip pad 4, thereby exciting metal plasma, and heat accumulation forms molten metal particles 5, which are deposited in the contact gap between the pin and the pad. With reverse heating, the plasma-molten metal mixture continues to accumulate, thereby achieving heterogeneous metal welding.

[0043] like Figure 4 As shown, at the same time, the ultrafast laser 1 passes through the quartz glass 2, excites plasma at the metal interface of the spring pin 3, and the heat accumulates to form a molten metal with an increased volume, which fills the interface gap between the transparent material and the metal material, and regulates the non-optical contact to optical contact welding.

[0044] like Figure 5 As shown, after the ultrafast laser 1 completes the welding of the quartz glass 2 and the spring pin 3, and the spring pin 3 and the chip pad 4, the laser moves to the next pin position until the welding of the entire pin array is completed, thereby realizing the efficient integrated packaging of the quartz glass 2, the spring pin array 3 and the chip pad 4.

Claims

1. A multi-layer heterogeneous material ultrafast laser integrated connection method and equipment, used for high-frequency chip curved surface ultrafast laser packaging, characterized in that: The following steps are involved: Step 1: stack the lower chip pad, the spring pin array and the upper quartz glass in sequence on a three-dimensional motion platform and fix them with a clamp, and adjust the three-dimensional motion platform so that the focal plane of the laser is located at the central height of the spring pin array; Step 2: Based on the spatiotemporal shaping of ultrafast laser, high repetition rate and high Rayleigh length ultrafast laser focusing is realized, and a spiral or concentric ring oscillation scanning path is realized through a two-dimensional galvanometer. Under the oscillation scanning path, the ultrafast laser will act on the three-dimensional limited area around the spring pin (limited ablation); Step 3: Ultrafast laser acts on the surface of the lower chip pad to excite metal plasma, and the heat accumulation formed by the ultra-high repetition frequency will form molten metal material, and the two will actively deposit a high-temperature plasma-molten metal mixture in the contact pore between the spring pin and the lower chip pad (confined deposition); under oscillation scanning, the above process is repeated, and the deposited high-temperature plasma-molten metal mixture is continuously heated and accumulated, and reversely heated to melt the spring pin (confined melting), thereby realizing heterogeneous metal welding between the chip metal pad and the metal spring pin; Step 4. When the ultrafast laser oscillates and scans in a spiral or concentric ring, the ultrafast laser will synchronously act on the interface between the upper quartz glass and the spring pin. In this process, the ultrafast laser will directly transmit through the quartz glass, and due to the high linear absorption of the ultrafast laser by the metal material, the metal plasma will be excited at the interface. Under the effective heat accumulation of the ultrahigh repetition rate ultrafast laser, a molten metal material with an increased volume can be formed to fill the interface gap between transparent / metal dissimilar materials and regulate non-optical contact welding to optical contact welding. Under ultrafast laser oscillation scanning, ultrafast laser high-strength welding of transparent / metal dissimilar materials can be achieved; Step 5. After successfully connecting the upper quartz glass and the lower chip pad using the ultrafast laser on the spring pin, move to the next spring pin position to continue welding until the entire spring pin array is fully welded, thereby achieving efficient integrated packaging of the upper quartz glass, spring pin array and lower chip pad.

2. The method and equipment for ultrafast laser integrated connection of multi-layer heterogeneous materials according to claim 1, characterized in that: The three-dimensional motion platform includes an electric Z-axis and a two-dimensional galvanometer, which can move or rotate independently or in conjunction on the X, Y, and Z axes, thereby achieving precise position and posture adjustment of the workpiece in three-dimensional space.

3. The method and equipment for ultrafast laser integrated connection of multi-layer heterogeneous materials according to claim 1, characterized in that: The ultrafast laser is a high repetition rate picosecond laser or femtosecond laser, with a wavelength of 532-1064nm, a repetition rate set at 200kHz-2MHz, and a power set at 10-100W.

4. The method and equipment for ultrafast laser integrated connection of multi-layer heterogeneous materials according to claim 1, characterized in that: The Rayleigh length is the distance at which the laser beam maintains its minimum cross-sectional dimension (i.e., beam waist) during propagation. A high Rayleigh length is achieved through spatial shaping, so that the laser beam maintains better focusing performance over a longer propagation distance, improving the accuracy and efficiency of the integrated connection.

5. The method and equipment for ultrafast laser integrated connection of multi-layer heterogeneous materials according to claim 1, characterized in that: The oscillation scanning path is a spiral line or a concentric ring, and the size is between the inner circle diameter and the outer circle diameter of the spring.

6. The method and equipment for ultrafast laser integrated connection of multi-layer heterogeneous materials according to claim 1, characterized in that: The connection between the metal pad and the spring pin is based on a new connection method of ultrafast laser "confined ablation-deposition-melting", which realizes high-strength welding of heterogeneous metals between the chip metal pad and the metal spring pin.

7. The method and equipment for ultrafast laser integrated connection of multi-layer heterogeneous materials according to claim 1, characterized in that: The connection between the spring pin and the quartz glass is adjusted from non-optical contact to optical contact, and the laser energy is focused into a very small range by reducing the interface gap, thereby realizing high-precision, low-heat-affected ultrafast laser welding of transparent / metal heterogeneous materials.

8. The method and equipment for ultrafast laser integrated connection of multi-layer heterogeneous materials according to claim 1, characterized in that: The new ultra-high repetition rate ultrafast laser oscillation scanning integrated welding technology includes heterogeneous metal ultrafast laser "confined ablation-deposition-melting" connection technology, transparent / metal heterogeneous material ultrafast laser high-strength connection technology and multi-layer heterogeneous material ultrafast laser integrated connection technology.

9. The method and equipment for ultrafast laser integrated connection of multi-layer heterogeneous materials according to claim 1, characterized in that: The upper workpiece is a transparent material, the middle is a spring-type pin array, and the lower workpiece is a metal pad. The transparent material is quartz glass or sapphire, and the material can be a straight surface or an arc surface, and is polished on both sides. The metal pad is copper, aluminum alloy, or titanium alloy, and the material is a straight surface.

10. The method and equipment for ultrafast laser integrated connection of multi-layer heterogeneous materials according to claim 1, characterized in that: The spring pin array is formed by arranging spring pins, wherein the height of the spring pins is 1-2.5 mm, the diameter of the spring is 0.06-0.1 mm, the pitch of the spring is 0.025-0.15 mm, and the outer diameter of the spring is 0.4-0.6 mm.

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