CN116160134A - Multi-focus laser assembly, laser processing apparatus and method - Google Patents

Abstract

The embodiment of the invention provides a multi-focus laser component, a laser processing device and a laser processing method. The multi-focus laser assembly comprises a laser, a beam splitting element, a beam angle adjusting assembly, a first beam shaping assembly, a beam converging assembly and an objective lens which are sequentially arranged along the direction of a light path, wherein the laser is used for emitting laser beams; the beam splitting element is used for splitting the laser beam into a predetermined number of split beams; the beam angle adjusting assembly comprises a preset number of sub-adjusting units, wherein each sub-adjusting unit is used for adjusting the transmission angle of the corresponding split beam; the first beam shaping assembly comprises a predetermined number of sub-beam shaping elements, each sub-beam shaping element being for shaping the split beam adjusted by the corresponding sub-adjustment unit; the beam converging assembly is used for converging all the partial beams with preset optical parameters onto the objective lens, so that after the partial beams are focused by the objective lens, the partial beams form explosion points at a preset number of positions of the processed object respectively. The cutting efficiency of this solution is relatively high.

Description

Multi-focus laser assembly, laser processing apparatus and method

Technical Field

The present invention relates to the field of semiconductor processing technology, and more particularly, to a multi-focal laser assembly, a laser processing apparatus, and a laser processing method.

Background

In the field of object processing such as semiconductor devices (e.g., wafers), a dicing process of a semiconductor device is an important one, and there are two general dicing methods, one is a cutter wheel and the other is laser dicing. Specifically, laser cutting, which is also called invisible cutting in the industry, is called invisible cutting for short, mainly comprising the steps of focusing laser beams inside an object to be processed to form explosion points (namely, explosion points), forming microcracks inside the object by precisely controlling the distance between the explosion points, and separating grains adjacent to each other by a chopper or a vacuum splinter.

In a conventional laser processing apparatus, a laser is generally irradiated onto a single designated position of an object to be processed while the object to be processed is moved. In this way, a plurality of frying points can be formed at different positions of one cutting path of the processed object after a certain time. Because the laser is focused on a single position point, the traditional laser processing device can only cut all transverse cutting channels one by one and then cut the longitudinal cutting channels one by one. This cutting mode is relatively inefficient.

Disclosure of Invention

The present invention has been made in view of the above-described problems. The invention provides a multi-focus laser assembly, a laser processing device and a laser processing method.

According to an aspect of the present invention, there is provided a multi-focal laser assembly including a laser, a beam splitting element, a beam angle adjusting assembly, a first beam shaping assembly, a beam converging assembly and an objective lens, which are sequentially disposed along an optical path direction, wherein the laser is configured to emit a laser beam; the beam splitting element is used for splitting the laser beam into a predetermined number of split beams; the beam angle adjusting assembly comprises a preset number of sub-adjusting units, the preset number of sub-adjusting units are in one-to-one correspondence with the preset number of sub-beams, and each sub-adjusting unit is used for adjusting the transmission angle of the corresponding sub-beam; the first beam shaping component comprises a preset number of sub-beam shaping elements, the preset number of sub-beam shaping elements are in one-to-one correspondence with the preset number of sub-adjustment units, and each sub-beam shaping element is used for shaping the beam split adjusted by the corresponding sub-adjustment unit so that the beam split emitted from the corresponding sub-beam shaping element has preset optical parameters; the beam converging assembly is used for converging all the split beams with the preset optical parameters onto the objective lens, so that the split beams with the preset optical parameters form explosion points at the preset number of positions of the processed object after being focused by the objective lens, and the preset number of positions correspond to the preset number of split beams one by one.

The multi-focal laser assembly further comprises a second beam shaping assembly disposed between the laser and the beam splitting element for adjusting optical parameters of the laser beam emitted from the laser such that the adjusted optical parameters meet the incident requirements of the incident light of the beam splitting element.

The multi-focal laser assembly further comprises a control unit communicatively connected to the first beam shaping assembly, the control unit being configured to adjust an optical parameter of the sub-beam passing through each sub-beam shaping element to a preset optical parameter to adjust a depth of a blast point corresponding to each sub-beam within the object being processed, wherein the optical parameter comprises a diameter and/or a divergence angle of the beam.

Illustratively, the beam converging assembly is configured to adjust the angle of incidence of each of the sub-beams entering the objective lens such that the focused beams form a frying spot on different dicing lanes or at different locations of the same dicing lane, respectively.

Illustratively, the beam converging assembly includes a first mirror and at least one beam combining optic; the first reflector is arranged on an emergent light path of one sub-beam shaping element at the outermost side of the sub-beam shaping elements in the preset number and is used for reflecting the corresponding sub-beam; at least one beam combining lens is arranged on the emergent light path of the residual sub-beam shaping element in a one-to-one correspondence manner and is used for reflecting the split beams emitted from the corresponding sub-beam shaping element, wherein the first beam combining lens adjacent to the first reflecting mirror is also used for transmitting the beams reflected by the first reflecting mirror, each beam combining lens in the residual beam combining lens is also used for transmitting the beams emitted from the previous beam combining lens, and any beam combining lens is used for combining the transmitted light transmitted by the beam combining lens and the reflected light reflected by the beam combining lens onto the same light path.

Illustratively, at least one of the beam combining lenses has a different transmittance and reflectance ratio from each other.

The beam converging assembly further comprises a second mirror disposed between the last beam combining mirror and the objective lens for reflecting the light beam from the last beam combining mirror into the objective lens.

The position of the first mirror and the second mirror is fixed, and the multi-focal laser assembly further comprises a control unit for adjusting the position of the at least one beam combining mirror to change an angle between an optical axis of each of the at least one beam combining mirror and an optical axis of the second mirror such that incidence angles of the split beams reflected by the at least one beam combining mirror on the objective lens are different from each other.

Illustratively, a predetermined number of the partial beams exiting from the beam splitting element have different energy ratios from each other, the energy ratio being a ratio between the energy of the partial beam and the energy of the laser beam.

Illustratively, the spacing between any two adjacent frying points is equal to the grain spacing of the object being processed.

According to another aspect of the present invention, there is provided a laser processing apparatus including a stage for carrying an object to be processed and the above-described multi-focal laser assembly.

According to another aspect of the present invention, there is provided a laser processing method comprising: transmitting laser beams to the processed object by utilizing the multi-focus laser assembly so as to form a group of frying points at a preset number of positions of the processed object; the movement of the processed object is controlled to form multiple groups of frying points on different cutting paths or the same cutting path of the processed object.

Illustratively, the method further comprises: adjusting optical parameters of the sub-beam passing through each sub-beam shaping element in the first beam shaping assembly to adjust the depth of the explosion point corresponding to each sub-beam in the processed object, wherein the optical parameters comprise the diameter and/or divergence angle of the beam; and/or adjusting the incidence angle of each split beam entering the objective lens through the beam converging assembly, so that the focused beams respectively form frying points on different cutting tracks or at different positions of the same cutting track.

According to the multi-focus laser assembly, the laser processing device and the method, laser beams are split to form different split beams, and shaping and focusing are respectively carried out on each split beam, so that the split beams can form explosion points at a preset number of positions of an object to be processed after being focused by the objective lens. This arrangement allows for the simultaneous formation of modified spots at different locations within the object being processed, rather than being limited to a single spot at a single location. Therefore, the cutting efficiency of this solution is relatively high.

Drawings

The above and other objects, features and advantages of the present invention will become more apparent from the following more particular description of embodiments of the present invention, as illustrated in the accompanying drawings. The accompanying drawings are included to provide a further understanding of embodiments of the invention and are incorporated in and constitute a part of this specification, illustrate the invention and together with the embodiments of the invention, and not constitute a limitation to the invention. In the drawings, like reference numerals generally refer to like parts or steps.

FIG. 1 shows a schematic block diagram of a multi-focal laser assembly according to one embodiment of the invention;

FIG. 2 illustrates a schematic view of forming a blast point at different depths inside the same lane of an object being processed in accordance with one embodiment of the present invention;

FIG. 3 illustrates a schematic view of forming a plurality of burst points at different locations of a cutting lane parallel to the direction of material movement in accordance with one embodiment of the present invention;

FIG. 4 shows a schematic illustration of forming a plurality of burst points at corresponding locations on different cuts parallel to the direction of material movement in accordance with another embodiment of the present invention; and

fig. 5 shows a schematic flow chart of a laser processing method according to an embodiment of the invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. It should be apparent that the described embodiments are only some embodiments of the present invention and not all embodiments of the present invention, and it should be understood that the present invention is not limited by the example embodiments described herein. Based on the embodiments of the invention described in the present application, all other embodiments that a person skilled in the art would have without inventive effort shall fall within the scope of the invention.

In order to at least partially solve the above-described problems, according to an embodiment of the present invention, a multi-focal laser assembly is provided.

Fig. 1 shows a schematic block diagram of a multi-focal laser assembly 1000 according to one embodiment of the invention. As shown in fig. 1, the multi-focal laser assembly 1000 may include a laser 1100, a beam splitting element 1200, a beam angle adjusting assembly 1300, a first beam shaping assembly 1400, a beam condensing assembly 1500, and an objective lens 1600, which are sequentially disposed along an optical path direction. It should be noted that the configuration of the multi-focal laser assembly 1000 shown in fig. 1 and the arrangement of the elements therein are merely examples and are not limiting of the present invention, and the multi-focal laser assembly according to the embodiment of the present invention is not limited to the specific form shown in fig. 1. For example, fig. 1 shows a second beam shaping assembly 1700 that is optional, and that may be arranged and arranged in a manner that allows the laser beam emitted by laser 1100 to be directly incident on beam splitting element 1200, thus eliminating the need for second beam shaping assembly 1700. As another example, the beam condensing assembly 1500 shown in fig. 1 includes two mirrors and at least one beam combining lens, but the type and arrangement of the lenses included in the beam condensing assembly 1500 may vary.

The laser 1100 is used to emit a laser beam.

Alternatively, the wavelength band of the laser 1100 is selected to be transmissive into the material interior of the object being processed. For example, the laser 1100 may be a picosecond laser.

The beam splitting element 1200 is used to split the laser beam into a predetermined number of split beams.

In an embodiment, the predetermined number N is 1. Preferably, N is greater than or equal to 2. The laser beam emitted by the laser 1100 may be split into one or more split beams by the beam splitting element 1200. In the case where the sub-beams are multiple, the powers of any two sub-beams may be the same or different. The beam splitting element 1200 may be implemented using any existing or future-possible laser beam splitter.

The beam angle adjusting assembly 1300 may include a predetermined number of sub-adjusting units, each for adjusting a transmission angle of a corresponding sub-beam, in one-to-one correspondence with a predetermined number of sub-beams.

As shown in fig. 1, the beam angle adjustment assembly 1300 may include a predetermined number of sub-adjustment units 1301, 1302, 1303. The beam angle adjustment assembly 1300 may be used to adjust the angle of each of the sub-beams exiting the beam splitting element 1200 so that each sub-beam enters the first beam shaping assembly 1400 at a predetermined angle for adjustment of optical parameters of the beam, such as diameter and/or divergence angle. By way of example and not limitation, the individual beamlets after adjustment by beam angle adjustment assembly 1300 may be parallel to one another. Illustratively, each sub-adjustment unit in the beam angle adjustment assembly 1300 may be a mirror adapted for the target band to cooperate to adjust each sub-beam into a parallel beam. The target wave band refers to a laser beam wave band adopted by the system, for example, the laser beam wave band is infrared rays of 1000nm-1600nm, green light of 500nm-550nm, ultraviolet rays of 250nm-360nm and the like. Each sub-adjustment unit in the beam angle adjustment assembly 1300 may employ a coating layer suitable for the target band to facilitate reflection of the split beam.

The first beam shaping assembly 1400 may include a predetermined number of sub-beam shaping elements, which are in one-to-one correspondence with a predetermined number of sub-adjustment units, each of the sub-beam shaping elements being configured to shape the sub-beam adjusted by the corresponding sub-adjustment unit such that the sub-beam exiting from the corresponding sub-beam shaping element has a preset optical parameter.

The preset optical parameters may be set to any suitable parameters as needed, and the present invention is not limited thereto. The preset optical parameters corresponding to any two sub-beam shaping elements may be the same or different.

Illustratively, each sub-beam shaping element in the first beam shaping assembly 1400 may be a beam expander. Illustratively, each sub-beam shaping element in the first beam shaping assembly 1400 may be an electric beam expander, which facilitates automatic adjustment of the optical parameters corresponding to each sub-beam shaping element by the control unit. Of course, each sub-beam shaping element in the first beam shaping element 1400 may also be a manually controlled beam expander, and the user may manually adjust the optical parameters corresponding to each sub-beam shaping element. The first beam shaping assembly 1400 may comprise sub-beam shaping elements 1401, 1402, 1403, 140N, a predetermined number of sub-beam shaping elements being in one-to-one correspondence with the above-mentioned predetermined number of sub-adjustment units 1301, 1302, 1303, 130N. The depth of focus of each sub-beam can be adjusted by adjusting the optical parameters, e.g., the diameter and divergence angle, of the beam, corresponding to each sub-beam shaping element. Under the condition of the same optical parameters, the focusing depth of the light beams is also the same; on the contrary, when the optical parameters are different, the depth of focus of the light beam is also different.

The beam converging assembly 1500 is configured to converge all the sub-beams with the preset optical parameters onto the objective lens 1600, so that after the sub-beams with the preset optical parameters are focused by the objective lens 1600, the sub-beams form a frying point at a predetermined number of positions of the object to be processed, and the predetermined number of positions are in one-to-one correspondence with the predetermined number of sub-beams.

In one embodiment, the beam condensing assembly 1500 is disposed in sequence with the objective lens 1600. By way of example and not limitation, the beam converging assembly 1500 may include at least two mirrors, and at least one beam combining lens. Illustratively, the objective lens 1600 may be a compound lens group objective lens. Further, illustratively, the magnification of the objective 1600 is ≡10.

In one example, any two different sub-beams, after being focused by the objective 1600, may form a burst point at different depths of the object being processed, respectively. In another example, any two different sub-beams may form a frying spot on different cutting streets of the object being processed after being focused by the objective 1600. In yet another example, any two different sub-beams, after being focused by the objective 1600, may form a burst spot at a different location on the same scribe line of the object being processed, respectively. In the latter two examples, the frying points corresponding to any two different split beams can be at the same depth of the processed object or at different depths of the processed object. The manner in which the frying points in the above examples are formed will be described in the following embodiments.

The scheme is a laser non-contact processing scheme, so that the method has the advantages of no contact pollution and no mechanical deformation for the processed object. In addition, the modified region can be controlled within 10 mu m by adopting the laser focusing modification technology in the scheme, so that the loss of materials is almost small, for example, the size can be reduced as much as possible when the wafer chip is designed into the corridor, and the method has the advantage of saving the cost of materials.

According to the multi-focus laser assembly provided by the embodiment of the invention, laser beams are split to form different split beams, and shaping and focusing are respectively carried out on each split beam, so that the split beams can form explosion points at a preset number of positions of an object to be processed after being focused by the objective lens. This arrangement allows for the simultaneous formation of modified spots at different locations within the object being processed, rather than being limited to a single spot at a single location. Therefore, the cutting efficiency of this solution is relatively high.

Illustratively, the multi-focal laser assembly 1000 may further include a second beam shaping assembly 1700, the second beam shaping assembly 1700 being disposed between the laser 1100 and the beam splitting element 1200 for adjusting optical parameters of the laser beam emitted from the laser 1100 such that the adjusted optical parameters meet the incident requirements of the incident light of the beam splitting element 1200.

As shown in fig. 1, the multi-focal laser assembly 1000 may further include a second beam shaping assembly 1700. In one embodiment, second beam shaping component 1700 may be disposed between laser 1100 and beam splitting element 1200. By way of example and not limitation, second beam shaping assembly 1700 may include mirror 1710, beam expander 1720, mirror 1730, and focusing lens 1740. It is to be appreciated that mirror 1710 and/or mirror 1730 can be omitted. For example, the outgoing optical path of laser 1100 may coincide with the incoming optical path of beam expander 1720, at which time the laser beam emitted by laser 1100 may not need to be reflected using mirror 1710. The beam emitted by the laser 1100 is adjusted in diameter and divergence angle via the second beam shaping assembly 1700 to meet the incident requirements of the incident light of the beam splitting element 1200. For example, the above-mentioned incidence requirement may mean that the beam has a diameter of 6mm and an incidence angle is perpendicular to the center incidence of the beam splitter 1200. Alternatively, the diameter and the divergence angle of the laser beam may be automatically adjusted by the control unit, or may be manually adjusted according to the user's needs.

Through the second beam shaping component, the laser beam emitted by the laser can be adjusted into a beam which can meet the incidence requirement of the incident light of the beam splitting element, so that the laser beam shaping component is convenient to adapt to various different lasers and is beneficial to improving the application range of the multi-focus laser component.

Illustratively, the beam condensing assembly 1500 may include a first mirror and at least one beam combining optic; the first reflector is arranged on an emergent light path of one sub-beam shaping element at the outermost side of the sub-beam shaping elements in the preset number and is used for reflecting the corresponding sub-beam; at least one beam combining lens is arranged on the emergent light path of the residual sub-beam shaping element in a one-to-one correspondence manner and is used for reflecting the split beams emitted from the corresponding sub-beam shaping element, wherein the first beam combining lens adjacent to the first reflecting mirror is also used for transmitting the beams reflected by the first reflecting mirror, each beam combining lens in the residual beam combining lens is also used for transmitting the beams emitted from the previous beam combining lens, and any beam combining lens is used for combining the transmitted light transmitted by the beam combining lens and the reflected light reflected by the beam combining lens onto the same light path.

Referring again to fig. 1, the beam condensing assembly 1500 may include a first mirror 1510, beam combining lenses 1521, 1522, 1523, 152M, where m=n-1. The first reflecting mirror 1510 is provided on the outgoing light path of the sub-beam shaping element 1401. The first mirror 1510 may reflect the light rays exiting from the sub-beam shaping element 1401 onto the beam combining mirror 1521 adjacent to the first mirror 1510. The combiner lenses 1521, 1522, 1523, 152M may reflect light rays exiting the sub-beam shaping elements 1402, 1403, 1404, respectively. In addition, each beam combining lens can also transmit the light beam emitted from the previous lens. For example, the beam combining mirror 1521 may transmit the light beam reflected by the first reflecting mirror 1510, and the remaining beam combining mirrors 1522, 1523, 152M may transmit the light beam emitted from the previous beam combining mirror, respectively. Each beam combining lens can combine the corresponding transmitted light and reflected light to the same light path to be emitted.

In the above technical solution, the combination of the first reflecting mirror and the beam combining lens can collect the split beams from each sub-beam shaping element onto the same optical path, so as to facilitate further collection of the beams onto a subsequent objective lens.

Illustratively, the beam condensing assembly 1500 may further include a second mirror 1530 disposed between the last beam combining lens and the objective lens 1600 for reflecting the light beam from the last beam combining lens into the objective lens 1600.

As shown in fig. 1, a second mirror 1530 is disposed between the beam combining lens 152M and the objective lens 1600, and can reflect the light beam from the beam combining lens 152M into the objective lens 1600. By adjusting the angle of the second mirror 1530, the angle at which the beam is reflected into the objective lens 1600 can be adjusted. The second mirror 1530 is optional. For example, the objective lens 1600 may be directly disposed on the outgoing optical path of the beam combining lens 152M, and the second mirror 1530 may not be disposed.

In the above technical solution, according to the second reflecting mirror, the light beam from the last beam combining lens can be reflected into the objective lens, so that the angle of the light beam reflected into the objective lens can be flexibly adjusted to meet different cutting requirements for the processed object.

Illustratively, the multi-focal laser assembly 1000 may further comprise a control unit (not shown) communicatively coupled to the first beam shaping assembly 1400 for adjusting the optical parameters of the beamlets passing through each sub-beam shaping element to preset optical parameters to adjust the depth of the blast point within the object being processed corresponding to each beamlet, wherein the optical parameters include the diameter and/or divergence angle of the beam.

For example, the control unit may be implemented by using electronic components such as a comparator, a register, and a digital logic circuit, or using a processor chip such as a single chip microcomputer, a microprocessor, a Digital Signal Processor (DSP), a Field Programmable Gate Array (FPGA), a Programmable Logic Array (PLA), an Application Specific Integrated Circuit (ASIC), and peripheral circuits thereof. By way of example, the control unit may comprise one or a combination of several of a Central Processing Unit (CPU), an image processor (GPU), an Application Specific Integrated Circuit (ASIC), or other form of processing unit having data processing and/or instruction execution capabilities.

The control unit and the first beam shaping assembly 1400 may be connected and communicate by any existing or future possible wired or wireless connection. The sub-beam shaping elements 1401, 1402, 1403, 140N may be beam shaping elements driven by a motor, such as an electric beam expander. The motor in the sub-beam shaping element can drive the lens group in the sub-beam shaping element to change the multiplying power so as to adjust the optical parameters of each beam of the sub-beam shaping element, such as the diameter and the divergence angle of the beam, and further adjust the depth of the explosion point corresponding to each beam of the sub-beam in the processed object.

In a first embodiment, the object being processed is a silicon carbide wafer. Laser 1100 selects an infrared skin second laser. By the second beam shaping assembly 1700, the laser beam can be adjusted to a beam with a diameter of 6mm, vertically centered into the beam splitting element 1200, which is custom designed with five spots, split the laser beam into 5 beams (i.e., the split beams described herein), and the angles of the mirrors in the beam angle adjustment assembly 1300 are adjusted such that the 5 split beams are parallel and vertically centered into the 5 sub-beam shaping elements in the first beam shaping assembly 1400 in a one-to-one correspondence. In each of the sub-beam shaping elements 1401, 1402, 1403, 1404, 1405, the optical parameters of the 5 sub-beams are adjusted to different optical parameters. The 5 split beams are then brought together by a first mirror 1510 and 4 combiner mirrors 1521, 1522, 1523, 1524 in the beam converging assembly 1500, and focused into the interior of the material separately by passing the vertical center of the 5 split beams through the objective lens 1600 in cooperation with a second mirror 1530 in the beam converging assembly 1500. Fig. 2 shows a schematic view of forming a blast point at different depths inside the same scribe line of an object being processed according to one embodiment of the invention. As shown in fig. 2, the diameter and the divergence angle of each split beam emitted from the first beam shaping module 1400 can be adjusted to further adjust the depth of the laser focusing explosion point in the vertical section of the silicon carbide wafer, so as to form modified explosion points with different depths. In addition, the wafer is driven to move by a high-speed precise movement system, so that modified layers with different depths are formed in the material, and then the die cutting and separation are completed by matching with mechanical splinters and film expansion, so that the wafer cutting efficiency is improved.

The control unit adjusts the optical parameters of the sub-beams passing through each sub-beam shaping element, so that the depth of the explosion point corresponding to each sub-beam in the processed object can be adjusted, and the requirement on the cutting depth of the processed object can be met. The scheme of controlling the light path system by the control unit has the function of flexibly changing the space position of the cohesive point of the material, and can realize the cutting of the chips with different thickness materials and different sizes.

Illustratively, the beam converging assembly 1500 is configured to adjust the incidence angle of each of the sub-beams entering the objective lens 1600 such that the focused beams form a frying spot on different dicing lanes or at different positions of the same dicing lane, respectively.

In a second embodiment, the object to be processed is a micro LED (Mico LED) wafer. Laser 1100 may be an infrared skin second laser. The laser beam can be adjusted to a beam with a diameter of 6mm by the second beam shaping assembly 1700, and vertically centered into the beam splitting element 1200 designed with five spots customization, splitting the laser beam into 5 split beams, and vertically centered into 5 sub beam shaping elements in the first beam shaping assembly 1400 in a one-to-one correspondence by adjusting the angles of the mirrors in the beam angle adjusting assembly 1300 so that the 5 split beams are parallel. In each of the sub-beam shaping elements 1401, 1402, 1403, 1404, 1405, the optical parameters of the 5 sub-beams are adjusted to the same diameter and divergence angle. The 5 sub-beams are converged by the beam converging assembly 1500 to be substantially co-directional. Illustratively, the corresponding outgoing light paths of the 5 split beams in the beam converging assembly 1500 may form a slight angle with each other, and then cooperate with the second mirror 1530 to converge the 5 split beams onto different positions of the objective lens 1600. Through the objective 1600, each split beam is focused into the material, and the depth of the focused explosion point in the material is consistent, but the explosion points corresponding to different split beams are located on different dicing lanes or at different positions of the same dicing lane. For example, the angle between the first mirror 1510, at least one beam combining mirror 1521, 1522, 152M, and the second mirror 1530 may be fine-tuned such that the 5 sub-beams are perpendicular to the material cutting direction while cutting 5 cuts. The wafer is driven to move by a high-speed precise movement system, so that a modified layer with the same depth is formed in the material, and then the die cutting and separation are completed by matching with mechanical splinters and film expansion, thereby improving the wafer cutting efficiency.

Fig. 3 shows a schematic view of forming a plurality of frying points at different positions of a dicing lane parallel to a moving direction of a material according to an embodiment of the present invention, and fig. 4 shows a schematic view of forming a plurality of frying points at corresponding positions on a different dicing lane parallel to a moving direction of a material according to another embodiment of the present invention. As shown in fig. 3 and 4, after each of the split beams passes through the objective lens 1600, a burst point may be formed at the same depth on the same or different scribe lines of the object to be processed. Preferably, the frying point spacing may be equidistant.

According to the technical scheme, different cutting lines or different positions of the same cutting line of the processed object can be cut at the same time, so that the cutting efficiency of the processed object can be effectively improved.

Illustratively, at least one of the beam combining lenses has a different transmittance and reflectance ratio from each other.

Any two of the at least one beam combining lenses may have the same transmittance and reflectance ratio, or may have different transmittance and reflectance ratios, which may be set according to user needs. Illustratively, the ratio of transmittance to reflectance of any of the combined lenses may be 50:50.

At least one beam combining lens has different transmittance and reflectance ratio, so that the focusing energy of the beam splitting beams corresponding to the different beam combining lenses is different, and the beam combining lens can be suitable for various laser processing application scenes.

Illustratively, the positions of the first mirror 1510 and the second mirror 1530 are fixed, and the multi-focal laser assembly 1000 further includes a control unit for adjusting the position of at least one beam combining lens to change an angle between an optical axis of each of the at least one beam combining lens and an optical axis of the second mirror 1530 such that incidence angles of the split beams reflected by the at least one beam combining lens on the objective lens 1600 are different from each other.

Alternatively, the optical paths along the sub-beam shaping element 1401, the first mirror 1510, and the second mirror 1530 may be regarded as fixed optical paths, that is, the positions of the first mirror 1510 and the second mirror 1530 may be fixed. At this time, the angles between the optical axes of the beam combining lenses and the optical axis of the second reflecting mirror 1530 may be changed by adjusting the positions of the beam combining lenses 1521, 1522, 1523, and 152M, so that the incident angles of the split beams reflected by the beam combining lenses 1521, 1522, 1523, and 152M on the objective lens 1600 are different from each other.

Illustratively, any of the at least one combined lens may be a flat lens or a cube lens. In the case that the beam combining lens is a flat lens, the incident light and the emergent light of the flat lens have position deviations, that is, are not on the same straight line (the incident light and the emergent light of the cube lens are on the same straight line), so that the position of the beam combining lens in the first direction can be adjusted according to the actual situation, that is, the beam combining lens is controlled to translate in the first direction. The first direction refers to the direction of the outgoing light path of the sub-beam shaping element corresponding to the beam combining lens (i.e. the vertical direction shown in fig. 1). In the case where the beam combining lens is a flat lens, adjusting the position of the beam combining lens in the first direction may also change the incidence angle of the split beam reflected by the beam combining lens on the objective lens 1600.

In summary, the control unit may be configured to adjust the position of at least one beam combining lens to change an included angle between an optical axis of one or more of the at least one beam combining lenses and an optical axis of the second mirror 1530 and/or change a position of one or more of the at least one beam combining lenses in the first direction, so that incidence angles of the split beams reflected by the at least one beam combining lenses on the objective lens 1600 are different from each other.

Illustratively, a predetermined number of the partial beams exiting from the beam splitting element 1200 have different energy ratios from each other, the energy ratio being a ratio between the energy of the partial beam and the energy of the laser beam.

Having different energy ratios of the split beams relative to each other may facilitate application of the multi-focal laser assembly to certain specific laser processing scenarios, such as different material properties at different depths, and different focusing energies required. Alternatively, any two split beams may have the same energy ratio, or may have different energy ratios, which may be set as desired. In one example, the energy of a predetermined number of sub-beams may be set on average. For example, assuming a total of five split beams, the energy of each split beam may each be one fifth of the energy of the laser beam.

Illustratively, the spacing between any two adjacent frying points is equal to the grain spacing of the object being processed.

Illustratively, the spacing between any two adjacent frying points is equal to the grain spacing of the object being processed and < 50 μm. Therefore, the middle areas of different passages can be cut, and further, grains are prevented from being cut, and the processed object is protected.

According to another aspect of the present invention, there is also provided a laser processing apparatus. The laser machining apparatus may comprise a stage for carrying an object to be machined and a multi-focal laser assembly as described above.

Illustratively, the object to be processed may be a wafer. The wafer is placed on the carrier, and when the carrier moves, the wafer can be driven to move, so that a modified layer is conveniently formed in the material.

According to yet another aspect of the present invention, a laser processing method is also provided. Fig. 5 shows a schematic flow chart of a laser processing method 500 according to an embodiment of the invention, as shown in fig. 5, the laser processing method 500 may comprise the following steps.

Step S510 of emitting laser beams to the object to be processed using the multi-focal laser assembly as described above to form a set of frying points at a predetermined number of positions of the object to be processed.

The above embodiments for emitting laser beams to a processed object by using a multi-focal laser assembly to form a set of frying points at a predetermined number of positions of the processed object have been described in detail, and are not repeated here for brevity.

In step S520, the object to be processed is controlled to move so as to form multiple groups of frying points on different cutting lanes or the same cutting lane of the object to be processed.

For example, the moving carrier can drive the processed object to move, so that multiple groups of frying points are formed on different cutting tracks or the same cutting track of the processed object.

In the technical scheme, a group of frying points can be formed at the same time by utilizing the multi-focus laser assembly, and then a plurality of groups of frying points can be formed in the processed object rapidly by matching with the movement of the processed object, so that the cutting efficiency can be greatly improved.

Illustratively, the laser machining method 500 may further include: adjusting optical parameters of the sub-beam passing through each sub-beam shaping element in the first beam shaping assembly to adjust the depth of the explosion point corresponding to each sub-beam in the processed object, wherein the optical parameters comprise the diameter and/or divergence angle of the beam; and/or adjusting the incidence angle of each split beam entering the objective lens through the beam converging assembly, so that the focused beams respectively form frying points on different cutting tracks or at different positions of the same cutting track.

One of ordinary skill in the art can understand the embodiments of the two methods by reading the above description about adjusting the optical parameters of the sub-beam passing through each sub-beam shaping element in the first beam shaping assembly to adjust the depth of the frying point corresponding to each sub-beam inside the object to be processed, and adjusting the incidence angle of each sub-beam passing through the beam converging assembly and entering the objective lens, so that the focused beams form the relevant description of the frying point on different cutting tracks or at different positions of the same cutting track, which is not repeated herein for brevity.

Although the illustrative embodiments have been described herein with reference to the accompanying drawings, it is to be understood that the above illustrative embodiments are merely illustrative and are not intended to limit the scope of the present invention thereto. Various changes and modifications may be made therein by one of ordinary skill in the art without departing from the scope and spirit of the invention. All such changes and modifications are intended to be included within the scope of the present invention as set forth in the appended claims.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means may be embodied by one and the same item of hardware. The use of the words first, second, third, etc. do not denote any order. These words may be interpreted as names.

The foregoing description is merely illustrative of specific embodiments of the present invention and the scope of the present invention is not limited thereto, and any person skilled in the art can easily think about variations or substitutions within the scope of the present invention. The protection scope of the invention is subject to the protection scope of the claims.

Claims (13)

1. A multi-focus laser component is characterized by comprising a laser, a beam splitting element, a beam angle adjusting component, a first beam shaping component, a beam converging component and an objective lens which are sequentially arranged along the direction of a light path,

the laser is used for emitting laser beams;

the beam splitting element is used for splitting the laser beam into a predetermined number of split beams;

the beam angle adjusting assembly comprises a preset number of sub-adjusting units, the preset number of sub-adjusting units are in one-to-one correspondence with the preset number of split beams, and each sub-adjusting unit is used for adjusting the transmission angle of the corresponding split beam;

the first beam shaping component comprises a preset number of sub-beam shaping elements, the preset number of sub-beam shaping elements are in one-to-one correspondence with the preset number of sub-adjustment units, and each sub-beam shaping element is used for shaping the beam split adjusted by the corresponding sub-adjustment unit so that the beam split emitted from the corresponding sub-beam shaping element has preset optical parameters;

the beam converging assembly is used for converging all the split beams with the preset optical parameters onto the objective lens, so that the split beams with the preset optical parameters are focused by the objective lens and then form explosion points at a preset number of positions of an object to be processed, and the preset number of positions are in one-to-one correspondence with the preset number of split beams.

2. The multi-focal laser assembly of claim 1 further comprising a second beam shaping assembly,

the second beam shaping component is arranged between the laser and the beam splitting element and is used for adjusting optical parameters of the laser beam emitted from the laser so that the adjusted optical parameters meet the incidence requirements of the incident light of the beam splitting element.

3. The multi-focal laser assembly of claim 1 or 2, further comprising a control unit,

the control unit is in communication connection with the first beam shaping assembly and is used for adjusting the optical parameters of the sub-beams passing through each sub-beam shaping element to the preset optical parameters so as to adjust the depth of the explosion point corresponding to each sub-beam in the processed object, wherein the optical parameters comprise the diameter and/or the divergence angle of the beam.

4. The multi-focal laser assembly of claim 1 or 2, wherein the beam converging assembly is configured to adjust the incidence angle of each of the sub-beams entering the objective lens such that the focused beams form a frying spot on different dicing streets or at different positions of the same dicing streets, respectively.

5. The multi-focal laser assembly of claim 4 wherein the beam converging assembly includes a first mirror and at least one beam combining optic;

the first reflector is arranged on an emergent light path of one sub-beam shaping element at the outermost side of the sub-beam shaping elements in the preset number and is used for reflecting the corresponding sub-beam;

the at least one beam combining lens is arranged on the emergent light path of the residual sub-beam shaping element in a one-to-one correspondence manner and is used for reflecting the split beams emitted from the corresponding sub-beam shaping element, wherein the first beam combining lens adjacent to the first reflecting mirror is also used for transmitting the beams reflected by the first reflecting mirror, each beam combining lens in the residual beam combining lens is also used for transmitting the beams emitted from the previous beam combining lens, and any beam combining lens is used for combining the transmitted light transmitted by the beam combining lens and the reflected light reflected by the beam combining lens onto the same light path.

6. The multi-focal laser assembly of claim 5 wherein the at least one combined beam lens has a different transmittance and reflectance ratio from each other.

7. The multi-focal laser assembly of claim 5 wherein the beam focusing assembly further comprises a second mirror,

the second reflector is arranged between the last beam combining lens and the objective lens and is used for reflecting the light beam from the last beam combining lens into the objective lens.

8. The multi-focal laser assembly of claim 7 wherein the positions of the first mirror and the second mirror are fixed,

the multi-focus laser assembly further comprises a control unit for adjusting the position of the at least one beam combining lens to change an included angle between an optical axis of each beam combining lens in the at least one beam combining lens and an optical axis of the second reflecting mirror, so that incidence angles of the split beams reflected by the at least one beam combining lens on the objective lens are different from each other.

9. The multi-focal laser assembly of claim 1 or 2 wherein the predetermined number of partial beams exiting the beam splitting element have different energy ratios from each other, the energy ratio being the ratio between the energy of the partial beam and the energy of the laser beam.

10. A multi-focal laser assembly as claimed in claim 1 or claim 2 wherein the spacing between any two adjacent frying points is equal to the grain spacing of the object being processed.

11. A laser machining apparatus comprising a stage for carrying the object to be machined and a multi-focal laser assembly as claimed in any one of claims 1 to 10.

12. A laser processing method, comprising:

transmitting a laser beam to the object to be processed using the multi-focal laser assembly of any one of claims 1 to 10 to form a set of frying points at a predetermined number of positions of the object to be processed;

and controlling the movement of the processed object to form multiple groups of frying points on different cutting paths or the same cutting path of the processed object.

13. The laser processing method of claim 12, wherein the method further comprises:

adjusting optical parameters of the sub-beam passing through each sub-beam shaping element in the first beam shaping assembly to adjust the depth of the explosion point corresponding to each sub-beam in the processed object, wherein the optical parameters comprise the diameter and/or divergence angle of the beam; and/or

And adjusting the incidence angle of each split beam entering the objective lens through the beam converging assembly, so that the focused beams form explosion points on different cutting channels or at different positions of the same cutting channel respectively.

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