LED and laser diode combined lighting system
By combining LED and laser light sources, and utilizing a combination of waveguides and optical fibers, the limitations of existing light source types have been overcome, resulting in more efficient and uniform illumination and detection effects, and supporting inspection and imaging with greater flexibility and power density.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ORBOTECH LTD
- Filing Date
- 2024-10-25
- Publication Date
- 2026-04-17
AI Technical Summary
In existing inspection and imaging processes, the types of light sources are limited, making it difficult to achieve uniform illumination and efficient detection. This is especially true in electronic devices with small feature sizes, where the spot pattern of laser light sources and the divergence angle of LEDs and gas discharge lamps limit the illumination effect.
The system, which combines LED and laser light sources, achieves homogenized illumination of light and laser by combining first and second waveguides and optical fibers. The optical fiber isolates the laser light source from other components to avoid thermal effects, and the diffuser or curved surface increases the divergence angle to reduce space constraints.
It enables greater design flexibility, higher power density and uniform illumination, avoids space constraints near the optical column, and supports more efficient inspection and imaging processes.
Smart Images
Figure CN121889710A_ABST
Abstract
Description
[0001] Cross-reference of related applications
[0002] This application claims priority to provisional patent application No. 63 / 546,934, filed November 2, 2023, the disclosure of which is hereby incorporated by reference. Technical Field
[0003] This disclosure relates to a lighting system, and more specifically, to lighting for the inspection and imaging of electronic devices. Background Technology
[0004] The evolution of the electronics manufacturing industry places greater demands on yield management, and specifically on measurement and inspection systems. Critical dimensions continue to shrink, and the industry needs to reduce the time spent achieving high-yield, high-value production. Minimizing the total time from detecting a yield problem to fixing it maximizes the return on investment for electronics manufacturers.
[0005] Semiconductor devices, such as logic and memory devices, typically involve processing semiconductor wafers using numerous manufacturing processes to form the various features and multiple layers of the semiconductor device. For example, photolithography is a semiconductor manufacturing process involving transferring a pattern from a magnifying mask to a photoresist disposed on a semiconductor wafer. Additional examples of semiconductor manufacturing processes include, but are not limited to, chemical mechanical polishing (CMP), etching, deposition, and ion implantation. The arrangement of multiple semiconductor devices fabricated on a single semiconductor wafer can be divided into individual semiconductor devices.
[0006] Inspection processes are used at every stage of electronic device manufacturing to detect defects in wafers, electronic devices, or circuits, thereby promoting higher yields and, consequently, higher profits. Inspection has always been a crucial part of manufacturing electronic devices, such as integrated circuits (ICs) and printed circuit boards (PCBs), including assembled PCBs. However, as feature sizes shrink, inspection becomes even more critical for the successful manufacture of acceptable electronic devices, as even small defects can cause device and assembly failures. For example, as feature sizes decrease, the detection of smaller defects becomes necessary because even relatively small defects can introduce unwanted aberrations into the device.
[0007] During inspection or imaging processes, the workpiece may be illuminated by a light source such as a laser, LED, or gas discharge lamp. Some applications may rely on broad-spectrum sources, which limits the use of narrow-band lasers as a light source. Furthermore, lasers can produce speckled patterns that reduce illumination uniformity. While LEDs and gas discharge lamps emit broader spectra, compared to lasers, these sources have reduced illumination intensity and wide divergence angles, making them difficult to collect and focus. Additionally, gas discharge lamps may be less suitable for digital systems and cannot be operated in a pulsed manner. Space constraints within the inspection system further limit the types of light sources that can be used to illuminate the workpiece.
[0008] Therefore, an improved lighting system is needed for the inspection and imaging process. Summary of the Invention
[0009] Embodiments of this disclosure provide a system including a first waveguide and a second waveguide. The output of the first waveguide is coupled to the input of the second waveguide. The system may further include an LED light source configured to emit light from the input of the first waveguide and through the output of the second waveguide to illuminate a workpiece. The system may further include an optical fiber and a laser light source coupled to the input of the optical fiber. The output of the optical fiber is coupled to the input of the second waveguide. The laser light source is configured to emit laser light from the input of the optical fiber and through the output of the second waveguide to illuminate the workpiece.
[0010] In some embodiments, the first waveguide may have a cross-section smaller than that of the second waveguide, thereby forming a flange at the input end of the second waveguide, and the output end of the optical fiber is coupled to the input end of the second waveguide at the flange.
[0011] In some embodiments, the LED light source may include an LED array.
[0012] In some embodiments, the laser source may include multiple laser sources and the optical fiber may include multiple optical fibers. The multiple laser sources may be coupled to the multiple optical fibers, and the multiple optical fibers may be coupled to the input end of the second waveguide.
[0013] In some embodiments, the system may further include an optical diffuser disposed between the output end of the optical fiber and the input end of the second waveguide.
[0014] In some embodiments, the input end of the second waveguide may be included in a diffuse surface at the interface with the output end of the optical fiber.
[0015] In some embodiments, the output end of the optical fiber may have a curved surface.
[0016] In some embodiments, the system may further include a spherical lens disposed at the output end of the optical fiber.
[0017] In some embodiments, the LED light source may be configured to emit ultraviolet light, visible light, or near-infrared light, and the laser light source may be configured to emit ultraviolet laser, visible laser, or near-infrared laser.
[0018] In some embodiments, the LED light source and the laser light source may be configured to illuminate the workpiece simultaneously or in a modulated sequence.
[0019] In some embodiments, the output end of the second waveguide may have a cross-section larger than that of the input end of the second waveguide.
[0020] In some embodiments, the first waveguide and the second waveguide may be configured to homogenize the light from the input end of the first waveguide through the output end of the second waveguide.
[0021] Another embodiment of this disclosure provides a method. The method may include emitting light from an LED light source from an input end of a first waveguide through an output end of a second waveguide. The output end of the first waveguide may be coupled to the input end of the second waveguide. The method may further include emitting laser light from a laser light source from an input end of an optical fiber through the output end of the second waveguide. The output end of the optical fiber may be coupled to the input end of the second waveguide. The method may further include illuminating a workpiece using the light from the LED light source and the laser light from the laser light source.
[0022] In some embodiments, the LED light source may include an LED array, and emitting light from the LED light source from the input end of the first waveguide through the output end of the second waveguide may include emitting light from the LED array from the input end of the first waveguide through the output end of the second waveguide.
[0023] In some embodiments, the laser source may include multiple laser sources, and the optical fiber may include multiple optical fibers. The multiple laser sources may be coupled to the multiple optical fibers, and the multiple optical fibers may be coupled to the input end of the second waveguide. Emitting laser light from the laser sources from the input end of the optical fibers through the output end of the second waveguide may include emitting light from the multiple laser sources from the input end of the multiple optical fibers through the output end of the second waveguide.
[0024] In some embodiments, the method may further include diffusing the laser light from the output end of the optical fiber through the input end of the second waveguide.
[0025] In some embodiments, illuminating the workpiece using light from the LED light source and laser from the laser light source may include illuminating the workpiece simultaneously or in a modulated sequence using light from the LED light source and laser from the laser light source.
[0026] In some embodiments, the method may further include: homogenizing the light from the input end of the first waveguide through the output end of the second waveguide; and homogenizing the laser light from the input end of the second waveguide through the output end of the second waveguide. Attached Figure Description
[0027] For a more complete understanding of the nature and objectives of this disclosure, reference should be made to the following detailed description taken in conjunction with the accompanying drawings, wherein:
[0028] Figure 1 A diagram of a system according to an embodiment of the present disclosure;
[0029] Figure 2 This is a bottom view of a light source according to an embodiment of the present disclosure;
[0030] Figure 3 This is a top view of a second waveguide according to an embodiment of the present disclosure;
[0031] Figure 4 This is a top view of a laser light source according to an embodiment of the present disclosure;
[0032] Figure 5 This is a diagram of a system according to another embodiment of the present disclosure;
[0033] Figure 6 This is a diagram of a system according to another embodiment of the present disclosure;
[0034] Figure 7A This is a detailed view of the output end of an optical fiber according to an embodiment of the present disclosure, which has a spherical shape;
[0035] Figure 7B This is a detailed view of the output end of an optical fiber according to another embodiment of the present disclosure, which has a circular shape;
[0036] Figure 7C This is a detailed view of the output end of an optical fiber according to another embodiment of the present disclosure, which has a conical shape;
[0037] Figure 8 This is a detailed view of the output end of an optical fiber according to another embodiment of the present disclosure, which has a spherical lens;
[0038] Figure 9 A flowchart of a method according to an embodiment of this disclosure; and
[0039] Figure 10 This is a flowchart of a method according to another embodiment of the present disclosure. Detailed Implementation
[0040] Although the claimed object will be described with reference to specific embodiments, other embodiments (including those that do not provide all the benefits and features set forth herein) are also within the scope of this disclosure. Various structural, logical, procedural, and electronic changes may be made without departing from the scope of this disclosure. Therefore, the scope of this disclosure is defined only by reference to the appended claims.
[0041] Embodiments of this disclosure provide a system 100, such as Figure 1 The system 100 may be part of an inspection system or imaging system configured to inspect or capture images of workpiece 101. Workpiece 101 may be a semiconductor wafer, substrate, IC, PCB, or display panel and is not limited herein. Workpiece 101 may be mounted on stage 105. Stage 105 may be movable (e.g., in the X, Y, and / or Z directions) to inspect or capture images of different portions of workpiece 101.
[0042] System 100 may further include an LED light source 110. The LED light source 110 may include a single LED or an array of LEDs 111 configured to emit light 112. For example, the LED light source 110 may include six LEDs 111 (e.g., ...). Figure 2 (as shown in the image), 8 LEDs, 10 LEDs, or any number of LEDs arranged in a rectangular array. In some embodiments, the light 112 emitted by the LED light source 110 may be ultraviolet, visible, or near-infrared light. For example, the light 112 emitted by the LED light source 110 may have a broadband wavelength of 300 to 2000 nm.
[0043] System 100 may further include a first waveguide 120. An LED light source 110 may be configured to emit light 112 through an input terminal 121 of the first waveguide 120. In one example, the LED light source 110 may be coupled to the input terminal 121 of the first waveguide 120. Alternatively, the LED light source 110 may be separated from the input terminal 121 of the first waveguide 120 by 1 mm or less. The first waveguide 120 may be a tube or solid structure made of glass or plastic having a substantially rectangular or cylindrical shape. The first waveguide 120 may be configured to homogenize the light 112 from the LED light source 110 passing from the input terminal 121 of the first waveguide 120 to the output terminal 122 of the first waveguide 120. For example, the diverging light 112 from the LED light source 110 may undergo one or more internal reflections within the first waveguide 120 to produce a uniform beam profile of light 112.
[0044] System 100 may further include a second waveguide 130. The output 122 of the first waveguide 120 may be coupled to the input 131 of the second waveguide. For example, the first waveguide 120 and the second waveguide 130 may be coupled together using an adhesive or other bonding method. The adhesive may be an optical-grade adhesive having a refractive index similar to that of the first waveguide 120 and the second waveguide 130. Alternatively, the first waveguide 120 and the second waveguide 130 may be integrally formed. The second waveguide 130 may be a tube or solid structure made of glass or plastic having a substantially rectangular or cylindrical shape. The second waveguide 130 may be configured to homogenize light 112 from the LED light source 110 passing from the input 131 of the second waveguide 130 to the output 132 of the second waveguide 130. For example, the light 112 may undergo one or more internal reflections in the second waveguide 130 to produce a uniform beam profile of the light 112. The second waveguide 130 may be longer than the first waveguide 120. The second waveguide 130 may be elongated relative to its cross-section to allow multiple internal reflections of the light 112 as it passes from the input 131 to the output 132. The second waveguide 130 may be divergent (to increase the area illuminated by the light 112) or convergent (to enhance the power density in a smaller area illuminated by the light 112). The second waveguide 130 may be configured to guide the light 112 from the LED light source 110 to illuminate the workpiece 101.
[0045] System 100 may further include a laser source 140. The laser source 140 may include a laser diode configured to emit a laser 142. In some embodiments, the laser 142 emitted by the laser source 140 may be an ultraviolet laser, a visible laser, or a near-infrared laser. For example, the laser 142 emitted by the laser source 140 may have a wavelength of 300 to 2000 nm. The laser source 140 may be configured to emit the laser 142 in continuous or pulsed mode. It should be understood that the laser source 140 may be more powerful than the LED source 110 and may generate heat. To regulate heat, the laser source 140 may be mounted on a cold plate 145 or other cooling system.
[0046] System 100 may further include optical fiber 150. Laser source 140 may be coupled to an input end 151 of optical fiber 150. Output end 152 of optical fiber 150 may be coupled to an input end 131 of second waveguide 130. Optical fiber 150 may have a cladding diameter of 125 to 1100 μm. Optical fiber 150 may be configured to guide laser 142 from laser source 140 from input end 151 through second waveguide 130. Second waveguide 130 may be further configured to homogenize laser 142 from laser source 140 passing from input end 131 to output end 132 of second waveguide 130. For example, laser 142 may undergo one or more internal reflections in second waveguide 130 to produce a uniform beam profile of laser 142. Second waveguide 130 may be further configured to guide laser 142 from laser source 140 to illuminate workpiece 101. The fiber optic cable 150 allows the laser source 140 to maintain a distance from the second waveguide 130 and other components of the optical column. Therefore, any heat generated by the laser source 140 can have a minimal impact on the optics (which could reduce inspection and image quality). Furthermore, the laser source 140 can be positioned at a distance away from the spatial constraints of the optical column, which allows space for the cooling plate 145 or other cooling systems to control heat.
[0047] In some embodiments, the first waveguide 120 may have a smaller cross-section than the second waveguide 130. Therefore, the output terminal 122 of the first waveguide 120, coupled to the input terminal 131 of the second waveguide 130, may form a flange 135, such as... Figure 3 The shape of flange 135 can depend on the shape of the output terminal 122 of the first waveguide 120 and the shape of the input terminal 131 of the second waveguide 130. For example, flange 135 can have a rectangular shape (based on the first waveguide 120 and the second waveguide 130 having rectangular shapes), a crescent shape (based on the first waveguide 120 and the second waveguide 130 having circular shapes), or other shapes. In this example, flange 135 can have a width of 150 to 2000 μm. The output terminal 152 of optical fiber 150 can be coupled to the input terminal 131 of the second waveguide 130 at flange 135.
[0048] Optical fiber 150 may (e.g., at flange 135) be coupled to the input end 131 of second waveguide 130 at an angle α. In this example, angle α may be from 0 to 45°. The length of first waveguide 120 may be large enough to allow optical fiber 150 to bend away from the optical post at a height below LED light source 110 so as not to interfere with LED light source 110. The length of first waveguide 120 may depend on angle α and the bending radius of optical fiber 150 (e.g., a smaller angle α may require a longer length of first waveguide 120 to complete the bend compared to a larger angle α).
[0049] In some embodiments, the laser source 140 may include a plurality of laser sources 141, and the optical fiber 150 may include a plurality of optical fibers 153, such as... Figure 4 As shown in the diagram. For example, multiple laser sources 141 may include 20 or more laser sources 140 arranged linearly or stacked in a rectangular array. Multiple laser sources 141 may operate at the same wavelength or at different wavelengths. Different wavelengths improve the versatility of system 100 because it can be used for different processes involving different workpieces that respond to different wavelengths. Multiple laser sources 141 may be mounted on the same cold plate 145 or other cooling system. Multiple laser sources 141 may be coupled to the input ends 151 of multiple optical fibers 153. Multiple optical fibers 153 may be combined into an optical fiber bundle coupled to the input end 131 of a second waveguide 130. The optical fiber bundle may be arranged in a shape corresponding to the shape of the input end 131 of the second waveguide 130 that is not covered by the output end 122 of the first waveguide 120 (e.g., the shape of the flange 135).
[0050] System 100 may further include processor 160. Processor 160 may include a microprocessor, microcontroller, or other device.
[0051] Processor 160 may be coupled to components of system 100 in any suitable manner (e.g., via one or more transmission media, which may include wired and / or wireless transmission media) such that processor 160 can receive output. Processor 160 may be configured to perform several functions using the output. Inspection tools may receive instructions or other information from processor 160. Processor 160 may optionally communicate electronically with another inspection tool, metrology tool, repair tool, or re-inspection tool (not specified) to receive additional information or send instructions.
[0052] Processor 160 may be part of a variety of systems, including personal computer systems, graphics computers, mainframe computer systems, workstations, network devices, Internet devices, or other devices. The subsystem or system may also include any suitable processor known in the art (e.g., a parallel processor). Additionally, the subsystem or system may include a platform with high-speed processing and software (as a standalone or network-linked tool).
[0053] Processor 160 may be located in or otherwise become part of system 100 or another device. In examples, processor 160 may be part of a separate control unit or in a centralized quality control unit. Multiple processors 160 may be used to define multiple subsystems of system 100.
[0054] In practice, processor 160 can be implemented through any combination of hardware, software, and firmware. Furthermore, its functions as described herein can be performed by a single unit or divided among different components, each of which can in turn be implemented through any combination of hardware, software, and firmware. Program code or instructions for processor 160 to implement various methods and functions can be stored in a readable storage medium (e.g., memory).
[0055] If system 100 comprises more than one subsystem, then different processors 160 can be coupled to each other, enabling the transmission of images, data, information, instructions, etc., between the subsystems. For example, a subsystem can be coupled to an additional subsystem via any suitable transmission medium that can contain any suitable wired and / or wireless transmission medium known in this art. Two or more such subsystems can also be effectively coupled by sharing a computer-readable storage medium (not shown).
[0056] Processor 160 may be configured to perform several functions using the outputs of system 100 or other outputs. For example, processor 160 may be configured to send outputs to an electronic data storage unit or another storage medium. Processor 160 may be further configured as described herein.
[0057] Processor 160 may be configured according to any of the embodiments described herein. Processor 160 may also be configured to perform other functions or additional steps using the output of system 100 or using images or data from other sources.
[0058] Processor 160 can be communicatively coupled to any of the various components or subsystems of system 100 in any manner known in the art. Furthermore, processor 160 can be configured to receive and / or acquire data or information (e.g., inspection results from an inspection system (e.g., a re-inspection tool), a remote database containing design data, and the like) from other systems via a transmission medium that may include wired and / or wireless portions. In this manner, the transmission medium can serve as a data link between processor 160 and other subsystems of system 100 or systems external to system 100. Various steps, functions, and / or operations of system 100 and the methods disclosed herein are implemented by one or more of the following: electronic circuits, logic gates, multiplexers, programmable logic devices, ASICs, analog or digital controllers / switches, microcontrollers, or computing systems. Program instructions for implementing methods such as those described herein can be transmitted via or stored on a carrier medium. The carrier medium may include storage media such as read-only memory, random access memory, magnetic disks or optical disks, non-volatile memory, solid-state memory, magnetic tape, and the like. The carrier medium may include transmission media, such as wires, cables, or wireless transmission links. For example, the various steps described throughout this disclosure may be implemented by a single processor 160 (or computer subsystem) or, alternatively, by multiple processors 160 (or multiple computer subsystems). Furthermore, different subsystems of system 100 may comprise one or more computing or logic systems. Therefore, the foregoing description should not be construed as a limitation of this disclosure but is merely illustrative.
[0059] Processor 160 can electronically communicate with LED light source 110 and laser light source 140. Processor 160 can be configured to send instructions to LED light source 110 to emit light 112. Therefore, processor 160 can be configured to control LED light source 110 and use light 112 to illuminate workpiece 101. Processor 160 can be further configured to send instructions to laser light source 140 to emit laser 142. Therefore, processor 160 can be configured to control laser light source 140 and use laser 142 to illuminate workpiece 101. In addition, processor 160 can be configured to control LED light source 110 and laser light source 140 to simultaneously illuminate workpiece 101 using both light 112 and laser 142. Therefore, compared to pure LED illumination, the illumination power can be significantly increased while maintaining a wide spectrum. In this example, workpiece 101 can be first illuminated by either light 112 or laser 142, and then illuminated by the other of light 112 or laser 142. Therefore, the modulated illumination of light 112 and laser 142 can highlight different features in subsequent imaging frames.
[0060] In some embodiments, the output end 132 of the second waveguide 130 may have a cross-section larger than that of the input end 131 of the second waveguide 130. In other words, the second waveguide 130 may have a tapered profile from the input end 131 to the output end 132. The tapered profile of the second waveguide 130 may increase the illumination area on the workpiece 101 while reducing the divergence angle of the light 112 and the laser 142.
[0061] In some embodiments, system 100 may further include an optical diffuser 170, such as Figure 5 The optical diffuser 170 may be made of an optically transparent material, wherein one or more of its surfaces are treated to increase divergence and scatter the laser 142. The surface may be randomly refractive by roughening it (e.g., by grinding or sandblasting the optical surface). Alternatively, scattering may be caused by an ordered refractive surface (e.g., a single lens or microlens array). The optical diffuser 170 may be diffractically scattering, having ordered features designed to produce a desired diffraction pattern in the incoming laser 142. The optical diffuser 170 may also be volumetrically scattering, wherein the bulk of the optical material itself is used to refract or diffract the light. The optical diffuser 170 may be positioned between the output end 152 of the optical fiber 150 and the input end 131 of the second waveguide 130. In some embodiments, a single optical diffuser 170 may receive laser 142 from multiple optical fibers 153. The optical diffuser 170 can be configured to increase the divergence angle of the laser 142 passing from the output end 152 of the optical fiber 150 to the input end 131 of the second waveguide 130. Therefore, the optical diffuser 170 can allow a larger angle α, which can reduce the space required to bend the optical fiber 150, thereby reducing the length of the first waveguide 120.
[0062] In some embodiments, the input end 131 of the second waveguide 130 may be included in a diffuse surface 136 at the interface with the output end 152 of the optical fiber 150, such as... Figure 6 As shown in the diagram. By roughening the surface (e.g., by grinding or sandblasting the optical surface), the diffuse surface 136 can be randomly refractive. Alternatively, the diffuse surface 136 can be diffractically scattering, having ordered features designed to produce the desired diffraction pattern in the incoming laser 142. For example, the diffuse surface 136 can cover the entire input end 131 of the second waveguide 130. Alternatively, the diffuse surface 136 can cover the flange 135 of the second waveguide 130. The diffuse surface 136 can be configured to increase the divergence angle of the laser 142 passing from the output end 152 of the fiber 150 to the input end 131 of the second waveguide 130. Therefore, the diffuse surface 136 can allow a larger angle α, which can reduce the space required to bend the fiber 150, thereby reducing the length of the first waveguide 120 without requiring space for the optical diffuser 170.
[0063] In some embodiments, the output end 152 of the optical fiber 150 may have a curved surface 155, such as Figures 7A to 7C As shown in the image. For example, the curved surface 155 can be spherical (e.g., Figure 7A (as shown in the middle), circular (e.g.) Figure 7B (as shown in the middle), conical (such as) Figure 7C (as shown in the image) or other shapes. The curved surface 155 can increase the divergence angle of the laser 142 from the laser source 140 as it leaves the optical fiber. The curved surface 155 of the optical fiber 150 can be achieved by thermal means (e.g., by heating the output end 152 of the optical fiber 150 to a moldable state, deforming it into a curved shape and then cooling it), chemical treatment (e.g., by etching it into a curved shape), or mechanical treatment (e.g., cutting it into a curved shape). In some embodiments, each of the plurality of optical fibers 153 may have a curved surface 155 at its output end 152. The curved surface 155 can be configured to increase the divergence angle of the laser 142 passing from the output end 152 of the optical fiber 150 to the input end 131 of the second waveguide 130. Therefore, the curved surface 155 can allow for a larger angle α, which can reduce the space required to bend the optical fiber 150, thereby reducing the length of the first waveguide 120 without requiring space for the optical diffuser 170.
[0064] In some embodiments, the system 100 may further include a spherical lens 175 disposed at the output end 152 of the optical fiber 150, such as Figure 8 As shown in the diagram. A spherical lens 175 can be used to increase the divergence angle of the laser 142 from the laser source 150 before it enters the input end 131 of the second waveguide 130. In some embodiments, each of the plurality of optical fibers 150 may have a spherical lens 175 disposed at its output end 152. The spherical lens 175 can be configured to increase the divergence angle of the laser 142 passing from the output end 152 of the optical fiber 150 to the input end 131 of the second waveguide 130. Therefore, the spherical lens 175 allows for a larger angle α, which reduces the space required to bend the optical fiber 150, thereby reducing the length of the first waveguide 120 in a space smaller than that of the optical diffuser 170.
[0065] Using system 100, LED light source 110 and laser light source 140 are combined to illuminate workpiece 101 using both light 112 and laser 142, which allows for greater design flexibility, power density, and illumination uniformity. Because laser light source 140 is coupled to optical fiber 150, it can be positioned remotely from other components of system 100, avoiding space constraints near optical columns and allowing more space for the cooling system of laser light source 140, thereby enabling higher power illumination.
[0066] Another embodiment of this disclosure provides a method 200. Method 200 may include, for example: Figure 9The following steps are shown in the image.
[0067] In step 210, light from the LED light source is emitted from the input end of the first waveguide through the output end of the second waveguide. In some embodiments, the light emitted by the LED light source may be ultraviolet, visible, or near-infrared light. For example, the light emitted by the LED light source may have a broadband wavelength of 300 to 2000 nm. The output end of the first waveguide may be coupled to the input end of the second waveguide. The first and second waveguides may be tubes or solid structures made of glass or plastic with a substantially rectangular or cylindrical shape.
[0068] In some embodiments, the LED light source may include an LED array. For example, the LED light source may include 6 LEDs, 8 LEDs, 10 LEDs, or any number of LEDs arranged in a rectangular array. Step 210 may include emitting light from the LED array from the input end of the first waveguide through the output end of the second waveguide.
[0069] In step 220, laser light from a laser source is emitted from the input end of the optical fiber through the output end of the second waveguide. The laser source may include a laser diode configured to emit laser light. In some embodiments, the laser light emitted by the laser source may be ultraviolet, visible, or near-infrared laser light. For example, the laser light emitted by the laser source may have a wavelength of 300 to 2000 nm. The laser source may be configured to emit laser light in continuous or pulsed mode. The output end of the optical fiber may be coupled to the input end of the second waveguide. The optical fiber may have a cladding diameter of 125 to 1100 μm. The optical fiber may be configured to guide the laser light from the laser source from the input end of the optical fiber through the second waveguide. The optical fiber may allow the laser source to maintain a distance from the second waveguide and other components of the optical pillar.
[0070] In some embodiments, the laser source may include multiple laser sources, and the optical fiber may include multiple optical fibers. The multiple laser sources may be coupled to the multiple optical fibers. Step 220 may include emitting light from the multiple laser sources from the input ends of the multiple optical fibers through the output ends of a second waveguide. The multiple laser sources may operate at the same wavelength or different wavelengths. Different wavelengths improve the versatility of method 200 because it can be used for different processes involving different workpieces that respond to different wavelengths.
[0071] In step 230, the workpiece is illuminated from the output of the second waveguide using light from an LED light source and laser light from a laser light source. The workpiece may be a semiconductor wafer, substrate, IC, PCB, or display panel and is not limited herein. It should be understood that steps 210 and 220 may be performed in the order shown in FIG. 7 or in reverse order. Alternatively, steps 210 and 220 may be performed simultaneously.
[0072] In some embodiments, step 230 may include illuminating the workpiece simultaneously or sequentially using light from an LED light source and laser light from a laser light source. Therefore, the illumination power can be significantly increased compared to pure LED illumination, while maintaining a broad spectrum. Alternatively, the workpiece may be illuminated first by one of the light or laser, and then by the other. Thus, the modulated illumination by light and laser can highlight different features in subsequent imaging frames.
[0073] In some embodiments, method 200 may further include Figure 10 The following steps are shown in the image.
[0074] In step 215, the light from the input end of the first waveguide through the output end of the second waveguide is homogenized. The first waveguide may be configured to homogenize the light from the LED light source passing from the input end of the first waveguide to the output end of the first waveguide. For example, the diverging light from the LED light source may undergo multiple internal reflections in the first waveguide 120 to produce a uniform beam profile. The lengths of the first and second waveguides may allow for multiple internal reflections to homogenize the light.
[0075] In step 225, the laser light from the input end of the second waveguide through the output end of the second waveguide is homogenized. The second waveguide can be configured to homogenize the light from the LED light source from the input end of the second waveguide through to the output end of the second waveguide 130. For example, the laser light can undergo multiple internal reflections in the second waveguide to produce a uniform beam profile. The length of the second waveguide allows for multiple internal reflections to homogenize the laser light. It should be understood that in steps 220 and 225 (as... Figure 8 Steps 210 and 215 are executed before or after steps 220 and 225 (as shown in the image). If steps 210 and 220 are executed simultaneously, then steps 215 and 225 can also be executed simultaneously.
[0076] In some embodiments, method 200 may further include step 221. In step 221, laser light from the output end of the optical fiber through the input end of the second waveguide is diffused. In one example, an optical diffuser may be positioned between the output end of the optical fiber and the input end of the second waveguide. In another example, the input end of the second waveguide may include a diffuser surface at the interface with the output end of the optical fiber. In another example, the output end of the optical fiber may be bent to diffuse the laser light. In yet another example, a spherical lens may be positioned at the output end of the optical fiber to diffuse the laser light. Diffusing the light increases the divergence angle of the laser light from the output end of the optical fiber through to the input end of the second waveguide. Therefore, the angle α will be larger, which reduces the space required to bend the optical fiber 150, thereby reducing the length of the first waveguide 120.
[0077] In method 200, the LED light source and the laser light source are combined to illuminate the workpiece, which allows for greater design flexibility, power density, and illumination uniformity. Because the laser light source is coupled to an optical fiber, it can be positioned remotely from other components of the system. This avoids the space constraints near the optical column and allows for more space for the laser light source's cooling system, thereby enabling higher power illumination.
[0078] Although this disclosure has been described with respect to one or more specific embodiments, it should be understood that other embodiments of this disclosure may be made without departing from the scope of this disclosure. Therefore, this disclosure is to be regarded as limited only by the appended claims and their reasonable interpretation.
Claims
1. A system comprising: First waveguide; The second waveguide, wherein the output end of the first waveguide is coupled to the input end of the second waveguide; An LED light source is configured to emit light from the input end of the first waveguide and through the output end of the second waveguide to illuminate a workpiece; An optical fiber, wherein the output end of the optical fiber is coupled to the input end of the second waveguide; and A laser source coupled to the input end of the optical fiber, wherein the laser source is configured to emit a laser from the input end of the optical fiber through the output end of the second waveguide to illuminate the workpiece.
2. The system of claim 1, wherein the first waveguide has a cross-section smaller than that of the second waveguide, thereby forming a flange at the input end of the second waveguide, and the output end of the optical fiber is coupled to the input end of the second waveguide at the flange.
3. The system according to claim 1, wherein the LED light source comprises an LED array.
4. The system according to claim 1, wherein the laser source comprises a plurality of laser sources, the optical fiber comprises a plurality of optical fibers, the plurality of laser sources are coupled to the plurality of optical fibers, and the plurality of optical fibers are coupled to the input end of the second waveguide.
5. The system according to claim 1, further comprising: An optical diffuser is disposed between the output end of the optical fiber and the input end of the second waveguide.
6. The system of claim 1, wherein the input end of the second waveguide is contained in a diffuse surface at the interface with the output end of the optical fiber.
7. The system of claim 1, wherein the output end of the optical fiber has a curved surface.
8. The system according to claim 1, further comprising: A spherical lens is positioned at the output end of the optical fiber.
9. The system of claim 1, wherein the LED light source is configured to emit ultraviolet light, visible light or near-infrared light, and the laser light source is configured to emit ultraviolet laser, visible laser or near-infrared laser.
10. The system of claim 1, wherein the LED light source and the laser light source are configured to illuminate the workpiece simultaneously or in a modulated sequence.
11. The system of claim 1, wherein the output end of the second waveguide has a cross-section larger than that of the input end of the second waveguide.
12. The system of claim 1, wherein the first waveguide and the second waveguide are configured to homogenize the light from the input end of the first waveguide through the output end of the second waveguide.
13. A method comprising: Light from an LED light source is emitted from the input end of a first waveguide through the output end of a second waveguide, wherein the output end of the first waveguide is coupled to the input end of the second waveguide; Laser light from a laser source is emitted from the input end of an optical fiber through the output end of the second waveguide, wherein the output end of the optical fiber is coupled to the input end of the second waveguide; and The workpiece is illuminated using light from the LED light source and laser light from the laser light source.
14. The method of claim 13, wherein the first waveguide has a cross-section smaller than that of the second waveguide, thereby forming a flange at the input end of the second waveguide, and the output end of the optical fiber is coupled to the input end of the second waveguide at the flange.
15. The method of claim 13, wherein the LED light source comprises an LED array, and emitting light from the LED light source from the input end of the first waveguide through the output end of the second waveguide comprises: Light from the LED array is emitted from the input end of the first waveguide through the output end of the second waveguide.
16. The method of claim 13, wherein the laser source comprises a plurality of laser sources, the optical fiber comprises a plurality of optical fibers, the plurality of laser sources are coupled to the plurality of optical fibers, the plurality of optical fibers are coupled to the input end of the second waveguide, and emitting laser light from the laser sources from the input end of the optical fibers through the output end of the second waveguide comprises: Light from the plurality of laser sources is emitted from the input ends of the plurality of optical fibers through the output ends of the second waveguide.
17. The method of claim 13, further comprising: The laser light is diffused from the output end of the optical fiber through the input end of the second waveguide.
18. The method of claim 13, wherein the light emitted by the LED light source is ultraviolet light, visible light, or near-infrared light, and the laser emitted by the laser light source is ultraviolet laser, visible laser, or near-infrared laser.
19. The method of claim 13, wherein illuminating the workpiece using the light from the LED light source and the laser from the laser light source comprises: The workpiece is illuminated simultaneously or in a modulated sequence using light from the LED light source and laser light from the laser light source.
20. The method of claim 13, further comprising: The light passing from the input end of the first waveguide to the output end of the second waveguide is homogenized. and The laser light passing from the input end of the second waveguide through the output end of the second waveguide is homogenized.