Laser dicing apparatus and method of dicing composite material

Abstract

The application provides a laser hidden cutting device and a cutting method of a composite material. The laser hidden cutting device comprises a beam expander, a second reflector and a laser focusing system. A first laser beam and a second laser beam are incident into the beam expander in time. After collimation and shaping by the beam expander, the first laser beam and the second laser beam change the exit direction by the second reflector and then enter the laser focusing system. The laser focusing system forms laser focusing spots on different layers of the composite material. The first laser beam has a first wavelength, and the second laser beam has a second wavelength. The laser focusing system comprises a conical mirror and an objective lens. The objective lens is embedded in the center hollow area of the conical mirror. The objective lens is used to focus the first laser beam on one layer of the composite material, and the conical mirror is used to focus the second laser beam on another layer of the composite material. The application can meet the cutting demand of multi-layer composite materials by a single device.

Description

Technical Field

[0001] This invention relates to the field of laser processing technology, and in particular to a laser hidden cutting device and a cutting method for composite materials. Background Technology

[0002] Laser lithography is an advanced material processing method in the semiconductor field. Its core principle is to use a specific wavelength of laser light to form a modified layer within the material, thereby achieving precise cutting. Specifically, when a high-energy-density laser beam is focused inside a transparent material (such as glass or silicon), a modified region is formed at the focal point due to the multiphoton absorption effect within the material. This modification does not immediately cause material separation, but it significantly reduces the mechanical strength of the region. By controlling the movement of the laser focus within the material, a predetermined cutting path can be formed, and finally, applying appropriate external force will cause the material to separate along the modified surface. This is a non-contact processing method, avoiding the wear problems of traditional tooling. The cut surface is smooth and flat with excellent edge quality, enabling precision machining of complex shapes. This method is characterized by no dust pollution, environmental friendliness, high processing speed, and high processing efficiency.

[0003] For multilayer composite materials, such as those consisting of silicon and glass layers, the laser wavelengths required for cutting the silicon and glass layers are different. However, existing laser lithography equipment can only emit lasers of a fixed wavelength. Therefore, to cut the two materials, two independent laser systems must be configured, which not only increases equipment costs but also makes the entire cutting process complex and inefficient. Summary of the Invention

[0004] In view of this, the present invention provides a laser concealed cutting device and a cutting method for composite materials, which can meet the cutting needs of multi-layer composite materials under a single device.

[0005] In a first aspect, the present invention provides a laser concealed cutting device suitable for cutting composite materials. The laser concealed cutting device includes: a beam expander, a second reflector, and a laser focusing system. A first laser beam and a second laser beam are incident on the beam expander in a time-division manner. After being shaped and collimated by the beam expander, the beam beam's exit direction is changed by the second reflector, and then the beam beam enters the laser focusing system. The laser focusing system forms laser focused spots on different layers of the composite material. The first laser beam has a first wavelength, and the second laser beam has a second wavelength.

[0006] The laser focusing system includes a conical lens and an objective lens that are fitted together. The conical lens has a central hollow area, and the objective lens is fitted into the central hollow area. The objective lens is used to focus the first laser beam onto one layer of the composite material to form a first laser focusing spot, and the conical lens is used to focus the second laser beam onto another layer of the composite material to form a second laser focusing spot.

[0007] Optionally, the objective lens consists of multiple lenses arranged vertically in parallel.

[0008] Optionally, the upper surface of the objective lens is coated with a first narrowband filter suitable for the first wavelength, which is used to control the focusing characteristics of the first laser beam having the first wavelength.

[0009] Optionally, the plane of the conical mirror is coated with a second narrowband filter suitable for the second wavelength, which is used to control the focusing characteristics of the second laser beam having the second wavelength.

[0010] Optionally, the first laser beam is a near-infrared laser beam with a wavelength of 1550nm, and the second laser beam is an ultraviolet laser beam with a wavelength of 355nm.

[0011] Optionally, the laser cloning device further includes:

[0012] A first laser is used to emit the first laser beam;

[0013] A second laser is used to emit the second laser beam, wherein the first laser beam and the second laser beam are emitted in a time-division manner;

[0014] First reflecting mirror;

[0015] And a beam splitter, wherein the first laser beam is reflected by the first reflector and then passes through the beam splitter, so that part of the first laser beam is incident on the beam expander, and the second laser beam is directly incident on the beam splitter, so that part of the second laser beam is incident on the beam expander.

[0016] Optionally, the first and second reflectors are 45° reflectors.

[0017] Optionally, the laser covert cutting device further includes: a mobile platform for carrying the composite material to be cut, which can achieve precise three-dimensional movement and control the first laser focusing spot or the second laser focusing spot to move in the composite material to be cut in order to achieve cutting along a set path.

[0018] Secondly, the present invention provides a method for cutting composite materials, which is implemented using the laser concealed cutting device provided in the first aspect, the method comprising:

[0019] The composite material is placed on and fixed on a mobile platform. The composite material includes stacked silicon layers and glass layers, with the glass layers on the side closer to the laser incident and the silicon layers on the side farther away from the laser incident.

[0020] A first laser beam with a first wavelength is emitted. After being shaped and collimated by the beam expander, the first laser beam is then changed in direction by the second reflector and enters the laser focusing system. The objective lens in the laser focusing system focuses the first laser beam onto the silicon layer to form a first laser focused spot. The moving platform moves the composite material along a set path and uses the first laser focused spot to cut the silicon layer.

[0021] After confirming that the silicon layer has been completely cut through, only a second laser beam with a second wavelength is emitted. After the second laser beam is shaped and collimated by the beam expander, the emission direction is changed by the second reflector, and then it enters the laser focusing system. The conical mirror in the laser focusing system focuses the second laser beam onto the glass layer to form a second laser focused spot. The moving platform drives the composite material to move along the set path, and the glass layer is cut using the second laser focused spot.

[0022] Optionally, the set path is a zigzag path.

[0023] The laser hidden cutting device and composite material cutting method provided by this invention utilize a laser focusing system composed of a conical mirror and an objective lens. This system can focus laser spots on different layers of the composite material using a first and second laser beam of different wavelengths, achieving efficient utilization of multiple laser beams from a single device. This meets the cutting requirements of multi-layer composite materials using a single device. It simplifies the complexity of traditional dual-cutting equipment, reduces equipment costs and maintenance difficulty, and provides a continuous and efficient cutting process, significantly improving the processing efficiency of composite materials. Furthermore, the multiple laser beams share the same transmission optical path, ensuring cutting accuracy and avoiding positioning errors that may occur with traditional dual-cutting equipment. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of a laser stencil device in one embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of the structure of a laser focusing system in one embodiment of the present invention;

[0026] Figure 3 This is a schematic diagram of the laser focusing system for focusing two time-division incident laser beams in one embodiment of the present invention;

[0027] Figure 4 This is a schematic diagram of a method for cutting composite materials in one embodiment of the present invention. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and not intended to limit the scope of this disclosure. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. Furthermore, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessarily obscuring the concepts of this disclosure.

[0029] The accompanying drawings illustrate various structural schematics according to embodiments of the present disclosure. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0030] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0031] Figure 1 This is a schematic diagram of a laser lithography device. Figure 1 As shown, the laser concealed cutting device of this invention is suitable for cutting composite materials. The laser concealed cutting device includes: a beam expander 15, a second reflector 16, and a laser focusing system 17. A first laser beam and a second laser beam are incident on the beam expander 15 in a time-division manner. After being shaped and collimated by the beam expander 15, the beam beam exits through the second reflector 16 and then enters the laser focusing system 17. The laser focusing system 17 forms laser focused spots on different layers of the composite material. The first laser beam has a first wavelength, and the second laser beam has a second wavelength.

[0032] The laser focusing system 17 includes a conical lens and an objective lens, the conical lens having a central hollow area, the objective lens being fitted into the central hollow area, the objective lens being used to focus a first laser beam onto one layer of the composite material to form a first laser focused spot, and the conical lens being used to focus a second laser beam onto another layer of the composite material to form a second laser focused spot.

[0033] It should be noted that the first and second laser beams are time-division multiplexing, meaning that only one laser beam enters the beam expander at a time. The first and second laser beams are coaxially input, but for ease of display, they are shown as different lines and do not overlap (although their paths actually overlap). Both the first and second laser beams are high-energy, short-pulse laser beams.

[0034] Figure 2 This is a schematic diagram of a laser focusing system, in which... Figure 2 (a) is a cross-sectional view. Figure 2 (b) is a top view. For example... Figure 2 As shown, the laser focusing system 17 of this embodiment consists of two parts: a conical mirror 171 and an objective lens 172. The objective lens 172 is fitted into the central hollow area of ​​the conical mirror 171. From a top view, the laser focusing system includes two regions: the inner circular region is the high numerical aperture objective lens 172, which, according to an embodiment of the present invention, can be composed of multiple lenses arranged vertically in parallel; the outer annular region is the conical mirror 171. Different regions respectively control the laser beam of a specific wavelength to form a beam suitable for processing.

[0035] Furthermore, the upper surface of the objective lens 172 is coated with a first narrowband filter (not shown) suitable for the first wavelength, which is used to adjust the focusing characteristics of the first laser beam having the first wavelength;

[0036] The plane of the conical mirror 171 is coated with a second narrowband filter (not shown) suitable for the second wavelength, which is used to control the focusing characteristics of the second laser beam with the second wavelength.

[0037] In one embodiment, the composite material to be cut may include a stacked silicon layer and a glass layer, with the glass layer on the side closer to the laser incident and the silicon layer on the side farther away from the laser incident, but the structure of the composite material is not limited to this.

[0038] To cut the aforementioned composite material, the first laser beam can be a near-infrared laser beam with a wavelength of 1550 nm, and the second laser beam can be an ultraviolet laser beam with a wavelength of 355 nm. However, the selection of the wavelengths of the first and second laser beams is not limited to the above wavelengths; other wavelengths can be selected as needed. This embodiment is designed for two different lasers, but the method involved is not limited to two different lasers; more lasers can be selected as needed.

[0039] Figure 3 A schematic diagram showing the focusing of near-infrared and ultraviolet laser beams through a laser focusing system is shown. Figure 3As shown, a near-infrared laser beam with a wavelength of 1550nm passes through the objective lens area to form a short-focus beam for cutting silicon layers; a ultraviolet laser beam with a wavelength of 355nm passes through the conical mirror area to form a long-focus deep Bezier beam for cutting glass layers.

[0040] Further reference Figure 1 The laser stencil device of this embodiment also includes:

[0041] A first laser 11 is used to emit a first laser beam;

[0042] The second laser 13 is used to emit a second laser beam, and the first and second laser beams are emitted in a time-division manner;

[0043] First reflecting mirror 12;

[0044] And the beam splitter 14, after the first laser beam is reflected by the first reflector 12, it passes through the beam splitter 14, so that part of the first laser beam is incident on the beam expander 15, and the second laser beam is directly incident on the beam splitter 14, so that part of the second laser beam is incident on the beam expander 15.

[0045] To ensure that the first and second laser beams are coaxially input into the beam expander 15, this embodiment uses a beam splitter 14. When the incident laser passes through the beam splitter, part of the laser beam is reflected, while the other part passes through the beam splitter.

[0046] In one implementation, the beam splitter 14 can be a semi-transparent mirror, where 100% of the light source passes through the mirror, resulting in 50% reflected light and 50% transmitted light. Considering the energy loss of the beam splitter, the emission power of the laser can be appropriately increased if necessary.

[0047] In one embodiment, the first reflector 12 and the second reflector 16 are 45° reflectors.

[0048] Further reference Figure 1 The laser hidden cutting device of this embodiment also includes: a mobile platform 18, which is used to carry the composite material to be cut, and can realize precise three-dimensional movement to control the first laser focusing spot or the second laser focusing spot to move in the composite material to be cut so as to realize the cutting of the set path.

[0049] The laser hidden cutting device provided in this invention utilizes a laser focusing system composed of a conical mirror and an objective lens. This system can focus laser spots on different layers of the composite material using a first and second laser beam of different wavelengths, achieving efficient utilization of multiple laser beams from a single device. This meets the cutting requirements of multi-layer composite materials under a single device. It simplifies the complexity of traditional dual-cutting equipment, reduces equipment costs and maintenance difficulty, and provides a continuous and efficient cutting process, significantly improving the processing efficiency of composite materials. Furthermore, the multiple laser beams share the same transmission optical path, ensuring cutting accuracy and avoiding positioning errors that may occur with traditional dual-cutting equipment.

[0050] On the other hand, another embodiment of the present invention provides a method for cutting composite materials, which is implemented using the laser concealed cutting device described in the above embodiment, such as... Figure 4 The method includes the following steps:

[0051] S401, The composite material is placed on the moving platform and fixed. The composite material includes a stacked silicon layer and a glass layer, with the glass layer on the side closer to the laser incident and the silicon layer on the side away from the laser incident.

[0052] S402 emits only a first laser beam with a first wavelength. After being shaped and collimated by a beam expander, the first laser beam is then changed in direction by a second reflector and enters a laser focusing system. The objective lens in the laser focusing system focuses the first laser beam onto the silicon layer to form a first laser focused spot. The moving platform drives the composite material to move along a set path and uses the first laser focused spot to complete the cutting of the silicon layer.

[0053] S403, after confirming that the silicon layer has been completely cut through, only a second laser beam with a second wavelength is emitted. After the second laser beam is shaped and collimated by a beam expander, its emission direction is changed by a second reflector, and then it enters the laser focusing system. The conical mirror in the laser focusing system focuses the second laser beam onto the glass layer, forming a second laser focused spot. The moving platform drives the composite material to move along the set path, and the glass layer is cut using the second laser focused spot.

[0054] Throughout the cutting process, the moving platform can precisely adjust its position according to a preset program, driving the composite material to move along a set path to ensure cutting accuracy. For example, in one embodiment, the moving platform drives the composite material to move along a zigzag path to achieve the cutting of the silicon layer and the glass layer.

[0055] Furthermore, according to one embodiment of the present invention, the first laser beam is a near-infrared laser beam with a wavelength of 1550 nm, which can penetrate the glass layer to form a focused spot on the silicon layer. The second laser beam is an ultraviolet laser beam with a wavelength of 355 nm.

[0056] The composite material cutting method provided in this invention achieves precise processing of composite materials through step-by-step cutting. First, a selected near-infrared laser is used to cut the silicon layer, and then the process switches to a selected ultraviolet laser to cut the glass layer. The entire cutting process is continuous and efficient, significantly improving the processing efficiency of composite materials. Furthermore, the multiple laser beams share the same transmission optical path, ensuring cutting accuracy and avoiding positioning errors that may occur with traditional dual-cutting equipment.

[0057] The above description does not provide detailed explanations of the technical aspects of each layer's patterning, etching, etc. However, those skilled in the art should understand that various technical means can be used to form layers and regions of the desired shape. Furthermore, to form the same structure, those skilled in the art can also design methods that are not entirely identical to those described above. Additionally, although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination.

[0058] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A laser concealed cutting device, suitable for cutting composite materials, characterized in that, The laser concealment device includes: a beam expander, a second reflector, and a laser focusing system. A first laser beam and a second laser beam are incident on the beam expander in a time-division manner. After being shaped and collimated by the beam expander, the beam beam's exit direction is changed by the second reflector, and then the beam beam enters the laser focusing system. The laser focusing system forms laser focused spots on different layers of the composite material. The first laser beam has a first wavelength, and the second laser beam has a second wavelength. The laser focusing system includes a conical lens and an objective lens that are fitted together. The conical lens has a central hollow area, and the objective lens is fitted into the central hollow area. The objective lens is used to focus the first laser beam onto one layer of the composite material to form a first laser focusing spot, and the conical lens is used to focus the second laser beam onto another layer of the composite material to form a second laser focusing spot.

2. The laser stencil cutting device according to claim 1, characterized in that, The objective lens consists of multiple lenses arranged vertically in parallel.

3. The laser stencil cutting device according to claim 1, characterized in that, The upper surface of the objective lens is coated with a first narrowband filter suitable for the first wavelength, which is used to control the focusing characteristics of the first laser beam having the first wavelength.

4. The laser stencil cutting device according to claim 1, characterized in that, The conical mirror has a second narrowband filter suitable for the second wavelength coated on its flat surface, which is used to control the focusing characteristics of the second laser beam with the second wavelength.

5. The laser stencil cutting device according to claim 1, characterized in that, The first laser beam is a near-infrared laser beam with a wavelength of 1550nm, and the second laser beam is an ultraviolet laser beam with a wavelength of 355nm.

6. The laser stencil cutting device according to claim 1, characterized in that, The laser concealed cutting device also includes: A first laser is used to emit the first laser beam; A second laser is used to emit the second laser beam, wherein the first laser beam and the second laser beam are emitted in a time-division manner; First reflecting mirror; And a beam splitter, wherein the first laser beam is reflected by the first reflector and then passes through the beam splitter, so that part of the first laser beam is incident on the beam expander, and the second laser beam is directly incident on the beam splitter, so that part of the second laser beam is incident on the beam expander.

7. The laser stencil cutting device according to claim 6, characterized in that, The first and second reflectors are 45° reflectors.

8. The laser stencil cutting device according to claim 1, characterized in that, The laser concealed cutting device also includes: a mobile platform for carrying the composite material to be cut, which can achieve precise three-dimensional movement and control the first laser focusing spot or the second laser focusing spot to move in the composite material to be cut in order to achieve cutting along a set path.

9. A method for cutting composite materials, characterized in that, The method comprises using the laser stencil device as described in any one of claims 1 to 8, wherein the method includes: The composite material is placed on and fixed on a mobile platform. The composite material includes stacked silicon layers and glass layers, with the glass layers on the side closer to the laser incident and the silicon layers on the side farther away from the laser incident. A first laser beam with a first wavelength is emitted. After being shaped and collimated by the beam expander, the first laser beam is then changed in direction by the second reflector and enters the laser focusing system. The objective lens in the laser focusing system focuses the first laser beam onto the silicon layer to form a first laser focused spot. The moving platform moves the composite material along a set path and uses the first laser focused spot to cut the silicon layer. After confirming that the silicon layer has been completely cut through, only a second laser beam with a second wavelength is emitted. After the second laser beam is shaped and collimated by the beam expander, the emission direction is changed by the second reflector, and then it enters the laser focusing system. The conical mirror in the laser focusing system focuses the second laser beam onto the glass layer to form a second laser focused spot. The moving platform drives the composite material to move along the set path, and the glass layer is cut using the second laser focused spot.

10. The method according to claim 9, characterized in that, The set path is a zigzag path.

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