Laser scanner, pattern transfer system and method of scanning laser radiation from laser source onto target

Abstract

The invention relates to a laser scanner, a pattern transfer system and a method of scanning laser radiation from a laser source onto a target. A laser scanner is provided for scanning laser radiation from the laser source onto a target. The laser scanner includes a mirror having a reflection plane configured to reflect laser radiation from a laser source onto a target; a holder having an axis of rotation for mounting the mirror, the axis of rotation being located on a reflection plane of the mirror; and a motor configured to rotate the holder with the mirror about the rotation axis. The configuration of the rotating mirror allows for rapid and accurate scanning of narrow features, such as fine paste-filled trenches in a pattern transfer sheet for printing, by reflected laser radiation. Various mechanisms are provided to ensure the accuracy and stability of the laser scanner and incorporate the laser scanner into a pattern transfer system.

Description

Technical Field

[0001] The present invention relates to the field of laser scanning and pattern transfer, and more particularly to accurately scanning laser radiation onto a target using a rotating mirror assembly. Background Art

[0002] The Handbook of Optical and Laser Scanning, published by Marcel Dekker, Inc. Marshall in 2004, describes various types of scanners, for example, in Chapter 4, "Polygonal Scanners: Components, Performance, and Design," by Glenn E. Stutz. This and other chapters in the Handbook describe various types of beam scanning devices, such as polygonal mirrors, resonant mirrors, acousto-optic deflectors, galvanometer mirrors, MEMS (micro-electromechanical systems) mirrors, and rotating mirrors, each with its own advantages and disadvantages. U.S. Patents Nos. 4,870,274, 4,838,632, and 4,699,447, the entire contents of which are incorporated herein by reference, teach various types of beam scanners with rotating mirrors. Summary of the Invention

[0003] The following is a simplified summary of the invention to provide an initial understanding of the invention. The summary does not necessarily identify key elements or limit the scope of the invention, but merely serves as an introduction to the following description.

[0004] One aspect of the present invention provides a laser scanner, comprising: a laser source that transmits laser radiation; a mirror having a reflective surface configured to reflect the laser radiation from the laser source onto a target; a holder having a rotation axis, wherein the mirror is mounted on the holder so that the rotation axis lies on the reflective surface of the mirror; and a motor configured to rotate the holder with the mirror about the rotation axis. One aspect of the present invention provides a pattern transfer printing (PTP) system, comprising a laser scanner configured to scan a strip-shaped groove filled with a conductive adhesive.

[0005] One aspect of the present invention provides a method for scanning laser radiation from a laser source onto a target, the method comprising: mounting a mirror on a holder, wherein the mirror has a reflective plane and the holder has a rotation axis located at the reflective plane of the mirror; and rotating the holder with the mirror about the rotation axis to reflect the laser radiation from the laser source onto the target through the reflective plane.

[0006] These, additional and / or other aspects and / or advantages of the invention are set forth in the detailed description which follows, may be inferred from the detailed description, and / or may be learned by practice of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] For a better understanding of embodiments of the present invention and to show how they may be practiced, reference will now be made, by way of example only, to the accompanying drawings in which like reference numerals designate corresponding elements or sections throughout. In the drawings:

[0008] Figure 1A 、 Figure 1B and Figure 2 is a high-level schematic diagram of a laser scanner according to some embodiments of the present invention.

[0009] Figure 3A and Figure 3B is a high-level schematic diagram of a laser scanner with an alignment fixture according to some embodiments of the present invention.

[0010] Figure 4 is a high-level schematic diagram of a laser scanner including an enclosure according to some embodiments of the present invention.

[0011] Figure 5 is a high-level flow chart illustrating a method of scanning laser radiation according to some embodiments of the present invention.

[0012] It will be appreciated that, for simplicity and clarity of illustration, the elements shown in the drawings are not necessarily drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for the sake of clarity. Furthermore, where deemed appropriate, reference numerals may be repeated in the drawings to indicate corresponding or similar elements. DETAILED DESCRIPTION

[0013] In the following description, various aspects of the present invention will be described. For the purpose of explanation, specific configurations and details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention can be practiced without the specific details presented herein. In addition, in order not to obscure the present invention, well-known features may have been omitted or simplified. With specific reference to the accompanying drawings, it should be emphasized that the details shown are presented as examples and only for the purpose of illustrative discussion of the present invention, and in order to provide the most useful and easiest to understand description of the principles and concepts of the present invention. In this regard, no attempt is made to illustrate the structural details of the present invention in a more detailed manner than is necessary for a basic understanding of the present invention, and the description in conjunction with the accompanying drawings makes it apparent to those skilled in the art how several forms of the present invention can be implemented in practice.

[0014] Before explaining at least one embodiment of the present invention in detail, it should be understood that the invention is not limited in its application to the details of the construction and the arrangement of components set forth in the following description or illustrated in the accompanying drawings. The present invention is applicable to other embodiments and combinations of the disclosed embodiments that can be practiced or carried out in various ways. In addition, it should be understood that the phraseology and terminology used herein are for descriptive purposes only and should not be considered limiting.

[0015] Some embodiments of the present invention provide efficient and economical methods and mechanisms for accurately scanning laser radiation onto a target, and thereby provide improvements in the art of laser scanning and pattern transfer. A laser scanner is provided for scanning laser radiation from a laser source onto a target. The laser scanner includes: a mirror having a reflective plane configured to reflect laser radiation from the laser source onto the target; a holder having a rotational axis for mounting the mirror so that the rotational axis is on the reflective plane of the mirror; and a motor configured to rotate the holder with the mirror about the rotational axis. The configuration of the rotating mirror allows narrow features, such as fine paste-filled grooves in pattern transfer sheets for printing, to be quickly and accurately scanned by reflected laser radiation. Various mechanisms are provided to ensure the accuracy and stability of the laser scanners and to incorporate these laser scanners into pattern transfer systems.

[0016] The disclosed embodiments provide accurate weight balancing (alignment of the center of mass of the rotating assembly with the axis of rotation) by using the following mechanical design features: (i) compensating for the offset of the mirror's center of mass to one side of the axis of rotation by an equivalent offset of the mirror holder's center of mass to opposite sides of the axis of rotation on either side along the axis (imbalance compensation); and (ii) including specific areas (e.g., two dedicated recesses) that enable the addition or removal of small amounts of material to improve balancing accuracy. During production and testing, accurate balancing is achieved through the following balancing process that utilizes these design features: for example, measuring the degree of balance, calculating the amount of material to be added to achieve complete balance, adding that amount of material to a dedicated recess in the mirror holder, drying the mirror holder until the material solidifies and bonds to the holder material, and, if material removal is required, drilling through the dedicated recess to achieve accurate balancing.

[0017] Advantageously, the disclosed embodiments precisely position the axis of rotation on the mirror surface, thereby preventing drawbacks of prior art designs such as deviation of the mirror's center of mass from the axis of rotation, deformation of the mirror during high-speed rotation, uneven pressure on the motor shaft or bearings during rotation with associated vibrations, and increased mechanical wear. The disclosed embodiments also have a high moment of inertia, which reduces sensitivity to vibration and provides stability over a wide range of scanning frequencies, while not requiring complex motor control for stability as required by prior art designs. Furthermore, the disclosed embodiments control the timing of the laser source relative to the mirror's position, activating the laser only within a certain angular range of the rotating mirror, without requiring the complex timing control systems required in prior art designs. Finally, the disclosed embodiments enable alignment of the laser beam position relative to the scan area and protect the mirror surface from contamination, such as by dust particles, thereby reducing or eliminating laser beam scatter.

[0018] Figure 1A and Figure 1B is a high-level schematic diagram of a laser scanner 100 according to some embodiments of the present invention. Figure 1A is a front perspective view of the laser scanner 100, and Figure 1B is a rear view of the laser scanner 100 , as explained herein.

[0019] The laser scanner 100 includes: a laser source 90, which transmits laser radiation 95; a mirror 110, which has a reflection plane 112 configured to reflect the laser radiation 95 from the laser source 90 in the form of a light beam 85 onto a target 80; a holder 120, which has a rotation axis 105, wherein the mirror 110 is mounted on the holder 120 so that the rotation axis 105 is located on the reflection plane 112 of the mirror 110 (this situation is indicated by the reference numeral 106); and a motor 230, which is configured to rotate the holder 120 together with the mirror 120 around the rotation axis 105.

[0020] For example, motor 230 (see, for example, Figure 2 ) can be imparted with rotation via the motor shaft 130, which moves a support shaft 135 attached to or part of the holder 120. The holder 120 may also include a recess 125 (at Figure 1A Schematically illustrated in FIG).

[0021] Figure 1BAlso illustrated is a textured rear mirror surface 114 on the rear side 124 of the holder 120 (opposite the reflective plane 112 of the mirror 110), which is configured to scatter high-power laser radiation at rotational angles (rotational angles of the holder 120 about the axis 105) that are not usable for laser scanning - as a safety measure in the event that the laser is not turned off during rotation of the holder 120 through a position where the laser radiation 95 cannot be reflected by the reflective plane 112 of the mirror 110.

[0022] In various embodiments, the laser scanner 100 further includes specific areas on the side 124 of the holder 120 for adding or removing material to balance the holder 120 with the mirror 120 mounted thereon about the axis of rotation 105 (106) at the reflective plane 112 of the mirror 110. As examples of these specific areas, Figure 1B Also shown is a recess 140 on the rear side 124 of the holder 120, which is used to add and / or remove material to balance the holder 120 with the mirror 110 mounted thereon and position the center of mass of the holder 120 with the mirror 110 mounted thereon on the rotation axis 105 (or ensure that the center of mass is positioned on the rotation axis 105). Accurate weight balancing is required to align the center of mass of the rotating assembly (the holder 120 with the mirror 110 mounted thereon, as well as any other rotating elements disclosed herein) with the rotation axis 105 to prevent vibration and deflection and maintain the accuracy and reliability of the laser scanner 100. Accurate weight balancing can be achieved by any or a combination of the following configurations.

[0023] In some embodiments, the mechanical design and structure of the holder 120 and the mirror 110 can be adjusted to achieve accurate balance, for example by compensating for imbalance, such as by compensating for the offset of the center of mass of the mirror 110 to one side of the rotation axis 105 by an equivalent offset of the center of mass of the mirror holder 120 to the opposite side of the rotation axis 105 on both sides along the axis 105.

[0024] In some embodiments, the balance can be accurately adjusted by adding material to or removing material from the recesses 140, which are dedicated locations for accurately adjusting the balance. For example, a balancing compound can be added to one or more recesses 140 and / or material can be drilled out or otherwise removed from one or more recesses 140. Non-limiting examples of balancing compounds can include epoxy-based materials (such as BC-22 from Star Technology). The configuration of the recesses 140 can vary, for example, two recesses along parallel lines of the rotation axis 105 can be used, and / or additional or other locations of the recesses 140 can be selected to achieve accurate balance. For example, as part of testing the assembled laser scanner 100, the degree of balance can be measured and the amount of material to be added or removed for complete and accurate balance can be calculated. Thus, a calculated amount of material can be added to a dedicated recess 140 in the mirror holder 120 and dried until the material solidifies and bonds to the holder material (e.g. stainless steel AISI304) and / or a calculated amount of material can be removed from the recess 140, for example by drilling, wherein the shape of the recess 140 is configured to simplify centering of the drilling element.

[0025] Figure 2 is a high-level schematic diagram of a laser scanner 200 according to some embodiments of the present invention. Figure 2 is a perspective view of the laser scanner 200, except Figure 1A and Figure 1B In addition to the laser scanner 100 schematically illustrated in FIG1 with the holder 120 and the mirror 110, the laser scanner 200 also has a scanner body 210, a motor 230, and a seal 220. The configuration of the laser scanner 100 can be mounted to the configuration of the laser scanner 200 via the support 150 or directly on the motor shaft 130. The configuration of the laser scanner 100 can be connected to the motor 230 via the coupling 170, and the motor 230 can be a direct drive motor (for example, from the ECX SP22L series of Maxon International Ltd).

[0026] Figure 2 Further illustrated is an optional stabilizing disk 160 and an internal through-beam sensor 250 with a laser control disk 270 as described herein. Figure 1A and Figure 1B Various embodiments of the laser scanner 100 schematically illustrated in FIG. 1 may be used as Figure 2 The core elements of the laser scanner 200 are schematically illustrated in FIG.

[0027] In various embodiments, the laser scanner 200 can further include a stabilizing disk 160 mounted on the axis of rotation 105 and having a moment of inertia greater than the moment of inertia of the holder 120 to which the mirror 110 is mounted. The stabilizing disk 160 can be configured to stabilize the final rotational velocity of the mirror 110 about the axis 105 because the increase in the total moment of inertia of the rotating assembly reduces sensitivity to all sources of vibration, both internal (e.g., within the support 135 or motor 230) and external (e.g., vibrations from other components of the laser scanner 200 and the surrounding area). The high moment of inertia of the stabilizing disk 160 can be achieved in various ways, such as by having a diameter (schematically indicated by D) and a weight (schematically indicated by W) of the stabilizing disk 160 that are greater than the diameter and weight (schematically indicated by d and w, respectively) of the holder 120 to which the mirror 110 is mounted. The moment of inertia of the stabilizing disk 160 can be achieved by making the stabilizing disk 160 larger and therefore heavier (e.g., larger diameter and weight compared to the holder 120 with the mirror 110) and / or manufacturing the stabilizing disk 160 from a heavy material (having a high specific gravity) including steel, lead, chromium, etc.

[0028] In various embodiments, the laser scanner 200 may further include a through-beam sensor 250 for controlling the operation of the laser source 90 and a control disk 270 mounted on the rotation axis 105 and having a peripheral edge 270A that does not interrupt the through-beam sensor 250 within a specific angular range 280 during rotation of the disk 270, thereby allowing the light beam to pass through the sensor 250 and enable activation of the laser source 90. Reference numeral 260 schematically indicates a light beam generated by the through-beam sensor 250 that is interrupted by the peripheral edge 270A of the disk 270 but not by its specific angular range 280.

[0029] In some embodiments, the control disc 270 can be configured to interrupt the through-beam sensor 250 at angles other than the specific angular range 280 at which the mirror 110 is required to reflect the laser radiation 95 for scanning, and the interrupted through-beam sensor 250 enables the laser source 90. In such embodiments, the laser source 90 can be turned on when the specific angular range 280 of the disc 270 is not in front of the through-beam sensor 250.

[0030] In various embodiments, the rotating mirror 110 can have an angular range within ±90° to reflect the laser beam 95 (forming the beam 85), wherein the corresponding angle of incidence of the beam relative to the normal of the reflecting plane 112 of the mirror 110 is within ±90°. In various embodiments, due to the focusing optics of the beam 85 delivered by the laser scanner 200, such as an F-Theta lens (see, for example, Figure 4The angular range of reflection can be much smaller (e.g. ±60°, ±45°, ±30° or intermediate values). Figure 2 As schematically illustrated in FIG, a through-beam sensor 250 and a control disk 270 can be used to stop the operation of the laser source 90 outside the angular range used to scan the target 80 with the laser beam 95. Specifically, the through-beam sensor 250 and the control disk 270 can be used to shut down the laser source 90 when the mirror 110 is rotated outside the effective reflection angle range. Shutting down the laser source 90 at unused angles can avoid undesirable dissipation of high-power laser radiation within the scanner and also conserve laser life. Advantageously, the disclosed through-beam sensor 250 and control disk 270 mechanism is more efficient and simpler than prior art devices for synchronizing laser timing with mirror angular position (e.g., precision motor encoders and associated electronics, which are costly and require calibration of encoder readings to the actual mirror position). A specific angular range 280 on the periphery 270A of the disk 270, mounted on the axis 105, is used to synchronize the mirror's angular position relative to the axis 105 with the activation of the laser source 90. The free angular range 280 allows the operating period of the laser source 90 to be defined relative to the position of the mirror 110 within or outside the effective reflection angle range. The specific angular range 280 can be configured to define an on-cycle or off-cycle of the laser source 90 depending on the configuration of the disk 270 and the through-beam sensor 250. For example, the laser source 90 can be turned off when the disk 270 crosses the beam of the through-beam sensor 250 outside of the angular range 280, and can be turned on (only within the effective reflection angle range of the mirror 110) when the angular range 280 allows the beam of the through-beam sensor 250 to pass uninterrupted. The angular range 280 of the disk 270 can be aligned relative to the angular position of the mirror 110 using, for example, a D-shaped mounting hole 275 on the disk 270 and a corresponding D-shaped rotating shaft segment that is part of the mirror holder 120 or the motor shaft 130.

[0031] Figure 3A and Figure 3B is a high-level schematic diagram of a laser scanner 200 with an alignment fixture 300 according to some embodiments of the present invention. Figure 3A A front view of the laser scanner 200 is provided, and Figure 3B A rear view is provided of the laser scanner 200. The laser scanner 200 may also include an alignment fixture 300 for temporarily fixing the mirror 110 in a zero angle position during the scanner alignment phase, in which laser beam position calibration is performed relative to the scan line.

[0032] The alignment fixture 300 may include a tenon 310 configured to contact the rear panel 124 of the lens holder (see Figure 1B) to the front mirror plane 112 (see Figure 1A ) is positioned at a nominal angular position (zero mirror position) relative to the laser beam, thereby aligning the scanner with the mirror 110 at a predetermined setting. Advantageously, the fixture 300 is capable of aligning the zero position of the mirror 110 to allow the laser beam of the scanner to be directed at a nominal angle (typically 45°, but different angles are possible) relative to the mirror front plane 112 and toward the center of the scan line (in the example of the target 80). The alignment fixture 300 can also be configured to remove the tenon 310 from contacting the rear side 124 of the holder 120 after alignment and during operation to allow the holder 120 with the mirror 110 mounted thereon to rotate freely. Advantageously, the disclosed embodiments are capable of using a mechanical design to achieve alignment of the mirror 110 with the target object 80 while keeping the mirror 110 operable to rotate freely and without resorting to implementing more complex and expensive angular motion control. An alignment fixture 300 having a tenon 310 (e.g., connected to the fixture 300 by a tenon holder) contacts the mirror holder rear surface 124, for example, on both sides of the textured rear surface, and is temporarily mounted to the scanner body 210 during the system alignment phase and holds the mirror 110 in a static zero position. Once the laser beam alignment is complete, the tenon 310 can be removed and stored on the scanner body 210 for future use. The laser radiation 95 can enter the laser scanner 200 from the rear (at Figure 3B ), and the beam can be directed onto the mirror 110 within the laser scanner 200 (at Figure 3A Schematically illustrated in FIG).

[0033] Figure 4 is a high-level schematic diagram of a laser scanner 400 including an enclosure 405 according to some embodiments of the present invention. It should be noted that the laser scanner 400 (including embodiments of a full laser scanner based on a rotating mirror, which also includes a laser and laser beam focusing optics) may include Figure 1A and Figure 1B Various embodiments of the laser scanner 100 (including the rotating mirror assembly) schematically illustrated in FIG. Figure 2 and various embodiments of a laser scanner 200 (including a rotating mirror assembly with a body and a sensor) schematically illustrated in Figure 3. It should be noted that the laser scanner configurations 100 and / or 200 can be implemented in different designs of a full laser scanner 400 using the disclosed principles.

[0034] Either laser scanner 100, 200 may be disposed within an enclosure 405 (e.g., to form laser scanner 400), which may have an inlet 415 for purging the interior volume of the laser scanner 400 with clean air or gas (e.g., clean compressed air—CPA or a clean gas such as nitrogen) to avoid contamination of the mirror 110. In addition to a CPA purge inlet 414 and an outlet 415 (e.g., the outlet 415 may include a one-way valve with a specific break point), the enclosure 405 may fully or partially seal the rotating mirror 110 and the holder 120 (see seal 220).

[0035] Figure 4 The beam transmission unit 430 is further illustrated and includes two mirrors and other optional optical components (internal, not shown) for accurate alignment of the beam, as well as a laser beam collimator 420 and an optical fiber of the fiber laser 410 (e.g., from or as a laser source 90, e.g., via Figure 3A and Figure 3B The aperture 320 shown in FIG. 1 transmits the laser beam 95 ).

[0036] Optionally, the laser scanner 400 may further include a laser distance sensor 460, which is configured to accurately measure the distance between the scanner 400 and a receiving substrate of the target 80, and maintain or adjust the distance within predetermined specifications, for example, within a range of 50 μm to 500 μm, to achieve specified printing quality and resolution requirements.

[0037] The laser scanner 400 may also include a motor drive 440 which may include a motor controller such as, for example, an EPOS4 Compact50 / 5CAN controller and driver from Maxon International Ltd.

[0038] In some embodiments, the rotation of the mirror 110 about the rotation axis 105 can be used for fast scanning, and the laser scanner 400 can further include a mechanical motion system (not shown) for moving the scanner 400 along an orthogonal slow-scan axis to scan, thereby forming a two-dimensional scan. Thus, the disclosed accurate and fast 1D rotating mirror scanner configurations 100, 200, 400 can be used to implement a 2D scanner by adding a slow-motion axis, for example, (i) using a linear motor axis configured to move the 1D scanner in an orthogonal direction, or (ii) using a second scanning mirror, such as a galvanometer (galvanometer) scanner, to implement the slow axis in the orthogonal direction.

[0039] The laser scanner 400 may also include an F-Theta lens 470 and / or other optical devices to focus the laser beam 85 exiting the laser scanner 400 (after the laser beam 95 is reflected by the mirror 110 ).

[0040] Any of the laser scanner configurations 100, 200, and 400 can be used in a pattern transfer printing (PTP) system configured to apply a pattern of conductive material to a wafer by non-contact printing. For example, grooves in a pattern transfer sheet (e.g., on a continuous pattern transfer tape) can be filled with a conductive adhesive, which is released from the grooves onto an adjacent wafer when the grooves are scanned by the laser scanner 400, as described, for example, in U.S. Patent No. 11,910,537, the entire contents of which are incorporated herein by reference.

[0041] Advantageously, the high scanning speeds and precise positioning of the focused beam provided by the rotating mirror scanner configurations 100, 200, 400 are important features for various industrial laser-based processing systems where high spatial resolution is required, and are particularly valuable for high-resolution laser printing systems. For example, the rotating mirror scanner 400 can be very effective for PTP systems, where they enable a small, high-power laser beam to scan very narrow grooves in a tape carrier or sheet filled with conductive adhesive.

[0042] Figure 5 is a high-level flow chart illustrating method 200 according to some embodiments of the present invention. The method stages may be performed for the laser scanners 100, 200, 400 described above, which may optionally be configured to implement method 200. Method 500 may be implemented at least in part by at least one computer processor, such as at least one computer processor in a controller of the laser scanners 100, 200, 400. Certain embodiments include a computer program product comprising a computer-readable storage medium having a computer-readable program embodied therein, the computer-readable program being configured to perform the relevant stages of method 500. Method 500 may include the following stages, regardless of their order.

[0043] Method 500 of scanning laser radiation from a laser source onto a target (stage 505) may include: mounting a mirror on a holder, wherein the mirror has a reflective plane and the holder has a rotation axis located at the reflective plane of the mirror (stage 510); and rotating the holder with the mirror about the rotation axis to reflect the laser radiation from the laser source onto the target through the reflective plane (stage 520).

[0044] The method 500 may further include positioning the center of mass of the holder with the mounted mirror on the axis of rotation (stage 512). In some embodiments, the method 500 may further include stabilizing the axis of rotation with a stabilizing disk mounted on the axis of rotation and having a greater moment of inertia, e.g., being larger and heavier than the holder and the mounted mirror (stage 514).

[0045] In some embodiments, method 500 may further include controlling operation of the laser source via the through-beam sensor (stage 530), for example, by mounting a control disk on the rotational axis to interrupt the through-beam sensor within a specific angular range during rotation of the disk (stage 535). For example, method 500 may include configuring the interruption angular range to correspond to angles at which the mirror-reflected laser radiation is not required for scanning—and disabling the laser source via the through-beam sensor during the interruption.

[0046] In certain embodiments, the method 500 may further include balancing the holder with the mounted mirror about the axis of rotation at the reflective plane of the mirror by adding or removing material at specific areas on the back side of the holder (stage 516). In various embodiments, finely balancing the holder with the mounted mirror about the axis of rotation at the reflective plane of the mirror 516 may further include, for example, performing a wobble measurement, calculating the required mass addition / removal, adding / removing the required mass in a dedicated recess, and verifying the achieved balance by repeating the wobble measurement.

[0047] In certain embodiments, method 500 may further include temporarily fixing the mirror in the zero angle position during a scanner alignment phase in which the laser beam position is calibrated relative to the scan line (phase 518).

[0048] In certain embodiments, method 500 may further include positioning at least the mirror, holder, and at least a portion of the rotation axis within an enclosure having an inlet (stage 540 ), and purging the interior volume of the enclosure with clean air or gas via the inlet (stage 545 ).

[0049] In some embodiments, method 500 may further include scanning in two directions (stage 550), by rotating the mirror about a rotation axis for fast scanning (stage 552), and moving at least the mirror, holder, and at least a portion of the rotation axis for scanning along an orthogonal slow scan axis (stage 554).

[0050] In some embodiments, method 500 may further include implementing scanning of laser radiation from a laser source onto a target as part of a pattern transfer printing (PTP) system (stage 560), for example, where the target includes stripe-shaped grooves filled with a paste.

[0051] From Figures 1A to 5 The elements may be combined in any operable combination, and the depiction of certain elements in some figures and not in other figures is for illustrative purposes only and is not limiting.

[0052] Advantageously, the disclosed scanner is simpler in structure (providing inherent advantages over polygonal mirrors and acousto-optic deflectors (AODs)) and has fewer performance limitations than other designs—for example, it is more accurate than polygonal mirrors, has a more uniform scanning speed than resonant mirrors and a wider spectral range than AODs, has a wider frequency range than galvanometer mirrors, and has a wider angular range (and a larger mirror) than MEMS mirrors. While rotating mirrors are known to provide high accuracy of laser beam position across a scan area, prior art designs have drawbacks in several design aspects, including accurate mirror positioning and balancing, stability of mirror motion and prevention of mirror vibration, coordination between the laser source and mirror rotation, and maintaining mirror cleanliness. Advantageously, the disclosed scanner addresses these technical issues, thereby providing an accurate and reliable rotating mirror laser scanner for a variety of applications.

[0053] In the above description, an embodiment is an example or implementation of the present invention. The various appearances of "one embodiment," "an embodiment," "certain embodiments," or "some embodiments" do not necessarily all refer to the same embodiment. Although various features of the present invention may be described in the context of a single embodiment, these features may also be provided individually or in any suitable combination. Conversely, although the present invention may be described herein in the context of separate embodiments for the sake of clarity, the present invention may also be implemented in a single embodiment. Certain embodiments of the present invention may include features from different embodiments disclosed above, and certain embodiments may combine elements from other embodiments disclosed above. The elements of the present invention disclosed in the context of a particular embodiment should not be construed as limiting the use of the elements only in that particular embodiment. Furthermore, it should be understood that the present invention may be carried out or practiced in various ways, and that the present invention may be implemented in certain embodiments other than the embodiments outlined in the above description.

[0054] The present invention is not limited to those diagrams or corresponding descriptions. For example, the process does not need to move through each illustrated box or state, or move in exactly the same order as illustrated and described. Unless otherwise defined, the meaning of the technical terms and scientific terms used herein should be generally understood by those of ordinary skill in the art to which the present invention belongs. Although the present invention has been described with respect to a limited number of embodiments, these embodiments should not be interpreted as limiting the scope of the invention, but as examples of some preferred embodiments. Other possible variations, modifications and applications are also within the scope of the present invention. Therefore, the scope of the present invention should not be limited by what has been described so far, but should be limited by the appended claims and their legal equivalents.

Claims

1. A laser scanner for receiving laser radiation from a laser source, the laser scanner comprising: a mirror having a reflective surface configured to reflect laser radiation from the laser source onto a target, a holder having an axis of rotation, wherein the mirror is mounted on the holder such that the axis of rotation is located at the reflection plane of the mirror, and a motor configured to rotate the holder with the mirror about the rotation axis, The center of mass of the holder on which the mirror is mounted is located on the rotation axis.

2. The laser scanner according to claim 1, further comprising a specific area located on the rear side of the holder, the specific area being used to add or remove material to balance the holder on which the mirror is mounted about the rotation axis at the reflection plane of the mirror. 3 . The laser scanner according to claim 1 , further comprising a stabilizing disk mounted on the rotation axis and having a moment of inertia greater than a moment of inertia of the holder on which the mirror is mounted.

4. The laser scanner according to any one of claims 1 to 4, further comprising: a through-beam sensor for controlling the operation of the laser source, and a control disc mounted on the rotation axis and having a peripheral edge that interrupts the through-beam sensor within a specific angular range during rotation of the disc, The control disk is configured to interrupt the through-beam sensor at angles other than the specific angle range where the mirror is not required to reflect the laser radiation for scanning, and the interrupted through-beam sensor disables the laser source.

5. The laser scanner according to any one of claims 1 to 4, further comprising: a through-beam sensor for controlling the operation of the laser source, and a control disc mounted on the rotation axis and having a peripheral edge that interrupts the through-beam sensor within a specific angular range during rotation of the disc, The control disk is configured to interrupt the through-beam sensor at an angle where the mirror is required to reflect the laser radiation for scanning, except for a specific angle range, and the interrupted through-beam sensor enables the laser source.

6. The laser scanner according to any one of claims 1 to 6, further comprising a temporarily used alignment fixture for temporarily fixing the mirror in a zero angle position during a scanner alignment phase in which the laser beam position is calibrated relative to the scan line.

7. A laser scanner according to any one of claims 1 to 7, provided within an enclosure having an inlet for purging the interior volume of the laser scanner with clean air or gas.

8. The laser scanner according to any one of claims 1 to 8, wherein: The mirror is rotated about the rotation axis for fast scanning, and the laser scanner further comprises a mechanical motion system for moving the scanner to scan along an orthogonal slow scan axis to form a two-dimensional scan.

9. A pattern transfer printing (PTP) system comprising the laser scanner according to any one of claims 1 to 9, wherein the PTP system is configured to scan a strip-shaped groove filled with a paste.

10. A method of scanning laser radiation from a laser source onto a target, the method comprising: mounting a mirror on a holder, wherein the mirror has a reflecting plane and the holder has a rotation axis located at the reflecting plane of the mirror, rotating the holder with the mirror about the rotation axis to reflect laser radiation from the laser source onto the target via the reflection plane, and The center of mass of the holder with the mirror mounted thereon is positioned on the axis of rotation.

11. The method of claim 10, further comprising balancing the holder with the mirror mounted thereon about the axis of rotation at the reflective plane of the mirror by adding or removing material at specific areas on a back side of the holder.

12. The method of claim 10 or 11, further comprising stabilizing the axis of rotation by a stabilizing disk mounted on the axis of rotation and having a greater moment of inertia than the holder and the mounted mirror.

13. The method according to any one of claims 10 to 12, further comprising: controlling the operation of the laser source via a through-beam sensor, and a control disc mounted on the axis of rotation to interrupt the through-beam sensor within a specific angular range during rotation of the disc, in which the mirror is not required to reflect the laser radiation for scanning, wherein interruption of the through-beam sensor disables the laser source.

14. The method of any one of claims 10 to 13, further comprising temporarily fixing the mirror in a zero angle position during a scanner alignment phase in which laser beam position calibration is performed relative to a scan line.

15. The method according to any one of claims 10 to 14, further comprising: disposing at least the mirror, the holder, and at least a portion of the rotational axis within an enclosure having an access opening, and The interior volume of the enclosure is purged with clean air or gas via the inlet.

16. The method according to any one of claims 10 to 15, further comprising scanning in two directions by: rotating the mirror about the rotation axis for rapid scanning, and At least the mirror, the holder, and at least a portion of the rotation axis are moved for scanning along an orthogonal slow-scan axis.

17. The method of any one of claims 10 to 16, further comprising implementing scanning of laser radiation from the laser source onto the target as part of a pattern transfer printing (PTP) system, wherein The target comprises strip-shaped grooves filled with a paste.

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