Apparatus and method for inspecting substantially transparent substrates

Abstract

The present invention relates to an apparatus and method for enabling the inspection of a substantially transparent substrate. The apparatus comprises a housing and a light source, and the method enables the effective analysis of a substantially transparent substrate placed within the housing.

Description

Technical Field

[0001] The present invention relates to an apparatus enabling inspection of a substantially transparent substrate. The present invention also relates to an assembly of such an apparatus and at least one imaging device, and to an imprint system comprising such an assembly. The present invention further relates to a method for inspecting a substantially transparent substrate.

Background Art

[0002] Determining defects in micro- and nanostructures is difficult, especially when determining defects over a large surface. In the technical field of imprinting, particularly nanoimprinting, it is essential that the products produced have a consistent quality meeting high quality standards. In order to maintain a certain quality, continuous quality control is required during or after each stage of the production process. An example of the overall imprint process is a sequence in which the texture of a master is transferred to a stamp, and the stamp, or an assembly of stamps formed by the master, then transfers the texture to a product. Thus, in each case, the texture is transferred from substrate to substrate. If there are defects on the surface of the master, these are also transferred to the stamp. The same applies to the transfer from the stamp to the product, and if the stamp contains an imperfection, i.e., a deficiency, a texture containing the defect is transferred. In order to check and manage the quality of the process, it is desirable to be able to determine and classify the defects of the stamp, the master, and / or the final product.

[0003] Therefore, an object of the present invention is to provide an apparatus and a method that enable relatively easy and effective quality control of a substrate, particularly a transparent substrate.

Summary of the Invention

[0004] The present invention is an apparatus configured to enable inspection of a substantially transparent substrate, At least one housing configured to accommodate at least one substantially transparent substrate, Optionally, at least one edge portion that surrounds and / or is configured to surround at least a portion of the substrate, At least one support surface configured to support at least a portion of the substrate, Optionally, at least one back cover configured to cover at least a portion of the circuit board and Including housing, A light source configured to illuminate at least a portion of the substrate and Equipped with, At least one light source is positioned at least partially within the housing such that at least one light source is directed towards at least one edge and / or side edge of the substrate housed within the housing, thereby, in particular, at least a portion of the light emitted by the at least one light source is incident on the substrate via at least one side edge so that the light can propagate through the substrate.

[0005] The apparatus according to the present invention enables inspection of substantially transparent substrates in an effective and controlled manner. The apparatus according to the present invention allows at least one substrate, preferably a substantially transparent substrate, to be placed on at least one support surface of a housing, while the substrate is at least partially surrounded by at least one edge of the housing and at least partially covered by at least one back cover. The apparatus is configured in particular to determine defects in at least one substrate before nanoimprinting and / or to determine defects in a nanoimprinted substrate. For this purpose, the housing substantially forms a frame in which the substrate is housed. As a result, the substrate is housed in a substantially non-destructive manner within the housing. The clever arrangement of at least one light source, such that at least one light source is at least partially positioned within the housing so as to be directed towards at least one edge and / or side edge of the substrate housed within the housing, makes it possible to illuminate the substrate from the side edge, i.e., from the lateral direction. The at least one light source is particularly positioned such that at least a portion of the light emitted by the at least one light source is incident on the substrate via at least one side edge so that the light propagates through the substrate. Therefore, light enters a substantially transparent substrate via at least one side edge and propagates through the substrate by total internal reflection. The image of the irradiated substrate is then captured by an imaging device such as a camera, allowing for analysis of the image for defects and / or irregularities. Irradiating at least one edge, particularly at least one side edge, of at least one substantially transparent substrate allows for the efficient and effective detection of any light scattering elements present within or on the substrate that distort total internal reflection. Irregularities or defects on the inside or surface of the substrate scatter at least some of the light emitted by the light source, producing detectable peaks in the image of the irradiated substrate. Experiments have shown that using a substrate irradiated from a side edge yields more reliable and detailed results than irradiating the surface being analyzed from an oblique angle, such as from the front or from below (e.g., using light shear).

[0006] At least one housing is configured, in particular, to accommodate at least one substrate. Thus, at least one substrate can be held by at least one housing. The housing thus provides a function of supporting and protecting the substrate. When we refer to housing, we may mean a frame. The housing may include, for example, at least one housing space for accommodating at least one substrate, preferably at least one substantially transparent substrate. The housing may also define at least one housing space. It is conceivable that at least one housing space is defined by at least one support surface and at least one edge of the housing. At least one light source may be housed within the housing space. The housing, i.e., frame, may be configured to at least partially surround the substrate. At least one support surface is preferably configured so that at least one substrate can be placed on at least a portion of the support surface. Thus, the support surface provides a function of supporting the substrate. It is conceivable that the support surface is configured to support at least one substrate through at least a portion of its periphery. In this way, the support surface does not adversely affect the illumination and / or image processing process. One conceivable example is that at least one support surface is configured to support a portion of the outer surface of the substrate. Preferably, at least one support surface is positioned such that the central region of the substrate is not supported.

[0007] When referring to a substantially transparent substrate, it can mean a master, stamp, and / or product, particularly an imprinted product. The substrate is specifically an imprint substrate or a substrate configured for imprinting. The substrate may be configured, for example, for use in a nanoimprint lithography transfer process. At least a portion of the substrate is preferably substantially transparent, or at least a portion of the substrate is substantially translucent. Alternatively, the substrate may be intrinsically transparent but may have an opaque reflective layer at the interface facing away from the imaging device. Such an opaque reflective layer may, for example, contain at least one metal, and such a layer may be a metal coating layer. It is conceivable that the substrate is transparent at least in the in-plane direction. At least one substrate may be at least partially made of, for example, glass, quartz and / or fused silica, polymers such as polycarbonate, PMMA, PET, and / or any combination of these materials. It is conceivable that the substrate is substantially flexible. However, it is also possible that at least a portion of the substrate is substantially rigid. It is also conceivable that the substrate has a mounting structure. However, the apparatus according to the present invention can also accommodate substrates without a mounting structure. Optionally, the substrate has a textured area. The textured area may have a texture with dimensions typically ranging from 500 micrometers to 25 nanometers. The apparatus according to the present invention is particularly suitable for use with relatively large substrates. The apparatus may have a substrate of, for example, at least 0.05 m 2 Preferably at least 0.2m 2 , more preferably at least 0.5m 2 It can be configured to accommodate a substrate having a surface area of ​​1 m². However, if the surface area of ​​the substrate is 1 m² 2It is conceivable that the thickness of at least one substrate is preferably at least 0.1 mm and / or up to 10 mm. It is also conceivable that the thickness of at least one substrate is in the range of 0.5 to 8 mm, 1 to 6 mm, or 2 to 4 mm. The substrate preferably includes a front surface, a back surface, and at least one side edge. If the substrate is substantially rectangular, it is conceivable that the substrate includes at least one pair of opposing side edges, particularly two pairs of opposing side edges. The side edges of the substrate are preferably substantially patternless and / or textureless. The apparatus according to the present invention may also be called an inspection apparatus.

[0008] In a preferred embodiment, at least a portion of at least one light source is located within the housing. The at least one light source is preferably arranged such that at least one light source is partially shielded by the housing. More specifically, at least a portion of one light source may be located within the housing, and at least one light source is arranged such that it is shielded by the housing as viewed from the point where the imaging device is positioned (visually) for substrate analysis. This embodiment ensures that the light emitted by the light source does not illuminate the imaging device directly and / or via reflections inside the housing and / or via reflections through the edges of the substrate, and therefore the imaging and / or analysis processes are not affected by the (primary) light source. In particular, since the edges of the substrate can still scatter and / or refract light from any light internally reflected by the substrate, it is preferable that (side) edges of the substrate that are not directly illuminated by the light source are also shielded by the housing. Therefore, the housing may be configured to shield at least a portion of at least one side edge of the substrate, in particular a portion of at least one side edge that is not (directly) illuminated by at least one light source. The housing may further provide protection for the light source. It is conceivable that at least a portion of at least one light source is attached to the housing, particularly to the edge of the housing. In this way, the position of the light source relative to the substrate housed in the housing can be further optimized. Optimizing the position of at least one light source has a positive impact on the accuracy of the subsequent imaging process and its analysis.

[0009] At least one light source is preferably an LED light source. Alternatively, at least one light source may include at least one light-emitting diode (LED) or a plurality of light-emitting diodes (LEDs). In yet another possible embodiment, at least one light source may include a plurality of optical elements, each optical element configured to emit light. At least one light source is preferably configured to emit light with wavelengths in the range of 275 to 950 nm. It is conceivable that at least one light source is configured to emit ultraviolet, (near) ultraviolet, (near) infrared, and / or a combination thereof. It is conceivable that at least one light source is configured to emit light with wavelengths in the range of 240 to 360 nm, 395 to 530 nm, 565 to 645 nm, or 660 to 900 nm. A more preferred range may be wavelengths in the range of 450 to 475 nm and / or 520 to 530 nm. At least one light source may emit, for example, white, green, yellow, blue, violet, red, blue, cyan and / or magenta, and / or combinations thereof. The output of at least one light source is preferably at least 10 lm / cm. At least one light source is preferably configured to emit non-collimated light. Thus, it is conceivable that at least one light source is configured to spread light in various directions, and / or that at least one light source does not have a defined directionality.

[0010] In a possible embodiment, at least one light source is configured to emit polarized light. In another possible embodiment, the intensity of at least one light source can be modulated. In yet another possible embodiment, the emission pattern of at least one light source can be optimized for efficient coupling of light to the substrate.

[0011] It is conceivable that the device may have multiple light sources. For example, the device may have at least two light sources. However, it is also possible that the device may have at least three or at least four light sources. At least one light source may optionally include multiple optical elements, such as multiple LEDs. At least one light source may be, for example, an elongated light source. At least one light source may include, for example, strip lights and / or string lights, such as LED strips and / or LED strings or LED arrays. It is also possible that the device may have at least two light sources, and at least two light sources may be facing each other. In a preferred embodiment, the device may have at least two light sources arranged in a facing configuration, with each light source directed to at least one edge, particularly a side edge, of a substrate housed in a housing. It is conceivable that the device may have at least four light sources, or at least one light source having at least four sections, with each light source or section directed to at least one side edge of a substrate. Preferably, at least one light source, or more light sources, are arranged such that the light source or more light sources substantially surround at least one substrate housed in a housing. Such embodiments can ensure constant and uniform illumination of the substrate. It is conceivable that the apparatus, in particular at least one light source, has at least one edge light, the edge light is along the inner surface of the edge of the housing.

[0012] At least one light source is optionally positioned at a distance from at least one support surface. However, it is also conceivable that at least one light source is positioned on at least one support surface. The preferred configuration may depend on the type and dimensions of the substrate and the type of light source applied. It is conceivable that the light source is in contact with the substrate. However, it is also possible that the light source is positioned at a distance from the substrate during use, for example, at a distance in the range of 0.02-2 cm, 0.05-1 cm, 0.1-0.5 cm or a combination thereof. It is preferable that at least one light source is positioned inside at least one edge of the housing. In this way, the edge of the housing can provide a function of supporting and / or protecting the light source. At least one light source may optionally form part of the housing.

[0013] In a preferred embodiment, the apparatus, in particular the housing, comprises at least one shielding element, in particular at least one displaceable shielding element, configured to shield at least a portion of a substrate and / or at least a portion of at least one light source. The at least one shielding element may be configured, for example, to prevent undesirable light emission away from the substrate. The at least one shielding element is preferably displaceably mounted to the housing such that the shielding element is displaceable between an open configuration and a closed configuration. The open configuration is preferably configured to allow the substrate to be placed in the apparatus without deforming the substrate. The closed configuration is preferably configured so that the substrate is surrounded and / or embedded by the housing and / or at least one shielding element. It is beneficial that the at least one shielding element is pivotably mounted to at least a portion of the housing, in particular at least a portion of at least one edge of the housing. The pivoting of the shielding element can provide controlled displacement of the shielding element, in particular displacement between the open configuration and the closed configuration. If the apparatus comprises multiple shielding elements, it is desirable that at least two, preferably multiple, shielding elements are pivotable. In a preferred embodiment, all shielding elements are pivotable. It is conceivable that at least one shielding element is attached to the housing, particularly via at least one hinge, to at least one edge of the housing. The shielding elements are preferably configured to be positioned at a distance from the housing space of the housing in which the substrate is housed, particularly in at least the closed configuration, and more specifically in the open and closed configurations. It is desirable that the shielding elements do not come into direct contact with the substrate, as this could adversely affect the analysis process or damage the substrate. The apparatus may include at least one limiter to restrict the displacement of at least one shielding element. It is preferable that at least one shielding element is positioned at a distance from at least one support surface, thereby reducing the risk of the shielding element coming into contact with the substrate located on the support surface. In a beneficial embodiment, at least a portion of the shielding element absorbs light. It is conceivable that the inside of at least one shielding element has a light-absorbing material and / or light-absorbing color.One conceivable example is that the inside of at least one shielding element is dark in color, preferably black or a derivative of black.

[0014] In a beneficial embodiment, at least a portion of at least one support surface absorbs light. A conceivable example is that the support surface has a light-absorbing material and / or a light-absorbing color. A conceivable example is that the support surface has a dark color, preferably black or a derivative of black. In a preferred embodiment, at least one support surface is positioned at a distance from at least one back cover. This embodiment can prevent the back cover from directly contacting the substrate placed on the support surface. This is beneficial in preventing the back cover from affecting the analysis process. A conceivable example is that at least a portion of at least one support surface is positioned substantially parallel to at least a portion of at least one back cover. In particular, the inner surface of at least one back cover may be positioned substantially parallel to at least a portion of at least one support surface. For example, at least one back cover may be attached to at least one edge of the housing. In this way, the combination of at least one back cover and at least one edge can form a protective casing for at least one substrate.

[0015] The back cover can provide protection in a constructive way, and the same applies to the irradiation mode. It is beneficial if at least one of the back covers, the surface facing the back of the substrate, has at least one light-absorbing color and / or at least one light-absorbing material. It is beneficial if at least a portion of the back cover absorbs light, which is beneficial for the accuracy of substrate analysis. Reflection or transmission from the background behind the substrate can affect the image of the substrate and, further, its analysis. It is beneficial if the back cover, or at least the portion of the back cover that overlaps with the substrate, has a single color. It is preferable that at least the portion of the back cover that faces the substrate has uniform properties. At least a portion of the back cover that overlaps with the substrate, and if present, the active region of the substrate, preferably has uniform properties, and preferably the active region is a region of the substrate that has been textured or patterned by an imprint process. It is possible for at least a portion of the back cover, for example, the surface of the back cover that faces the substrate, and in particular the back of the substrate, to have a dark color, preferably black, gray, or a derivative thereof. Dark colors can be classified as colors with low lightness and / or relatively low brightness. A desirable property of dark colors is that they absorb light. Most preferably, at least a portion of the back cover facing the substrate is black.

[0016] The apparatus according to the present invention may optionally include at least one control unit. The at least one control unit may be configured, for example, to control at least one parameter of a light source. The control unit may be configured, for example, to control at least the intensity and / or wavelength of at least one light source. It is also conceivable that the apparatus includes at least one display. The display may be coupled with at least one control unit, if applicable.

[0017] The apparatus may further comprise at least one support structure. The support structure may be configured, for example, to position the housing, and therefore the substrate housed therein, in a predetermined location. The support structure may be configured, for example, to align the housing, and therefore the support, with respect to the imaging device. In yet another embodiment, the apparatus may comprise at least one housing. It is conceivable that the apparatus comprises a housing and a housing in which at least one imaging device can be optionally housed. It is particularly beneficial if at least one housing is configured to provide a substantially dark environment. If the influence of the environment can be minimized, the inspection of the substrate can be further improved.

[0018] The present invention also relates to an assembly of at least one apparatus according to the present invention and at least one imaging device. The imaging device is, for example, a camera. It is also possible that the at least one imaging device includes at least one camera. In a preferred embodiment, the at least one imaging device is positioned at a predetermined distance from the apparatus. For example, the assembly may include at least one distance element configured to align the at least one imaging device with the apparatus according to the present invention. It is conceivable that such a distance element is configured to keep the at least one imaging device at a preferred position and distance with respect to the apparatus according to the present invention.

[0019] The present invention further relates to an imprint system comprising at least one device or assembly according to the present invention. Such an imprint system is preferably configured to transfer at least one pattern and / or at least one structure to at least one substrate, in particular at least one substantially transparent substrate. It is also conceivable that the system is configured to transfer at least one pattern and / or at least one structure to at least one substrate, in particular at least one substantially transparent substrate. Devices and / or assemblies according to the present invention may, for example, form an (integral) part of the imprint system. For example, it is conceivable that at least one device and / or assembly forms part of at least one input section and / or at least one output section of the imprint system.

[0020] The present invention further relates to a method for inspecting a substantially transparent substrate, the method being: The apparatus according to the present invention includes at least one substrate, in particular at least one substantially transparent substrate. Illuminating at least a portion of at least one side edge of at least one substrate with at least one light source, To capture at least one image of the substrate (to be inspected), particularly at least a portion of the irradiated substrate, By detecting light scattering elements, at least one image can be analyzed for defects. This includes the following steps.

[0021] This method can also be called a method for detecting light scattering elements in a substantially transparent substrate. In practice, the present invention relates to a method for detecting and labeling light scattering elements in a transparent substrate using a vision setup and / or software analysis. Any of the described embodiments of the apparatus according to the present invention also apply to the method according to the present invention.

[0022] It is conceivable that at least one substrate is freely arranged in the housing of the device. Preferably, at least one substrate is (freely) arranged on at least one support surface. Preferably, clamping attachment is not applied because it may have an adverse effect on the analysis accuracy of the substrate. After arranging the substrate, it is conceivable to close the housing. Irradiation of at least a part of at least one side edge of at least one substrate is performed by at least one light source. All of the described light sources and their configurations are applicable. For example, it is preferable that light irradiates the substrate through at least two side edges. In particular, it is also possible that light is emitted substantially over the entire length of each side edge of the substrate so that a uniform light pattern is formed within the substrate. It is conceivable that at least a part of the light source is in direct contact with the side edge of the substrate. However, it is also possible to provide a gap smaller than preferably 2 mm between the light source and the substrate. At least one image of the (irradiated) substrate can be captured by at least one imaging device, for example a camera. In order to determine defects and / or irregularities, analysis of at least one image, preferably a series of images, can be performed. These defects and / or irregularities can be determined particularly by detection of light scattering elements. The light scattering elements can be classified according to their relevance when analyzing the quality of the substrate during inspection. Thus, the method according to the invention provides detection and labeling of light scattering elements such as defects on a transparent substrate, contaminations and other patterns in a reproducible and reliable manner.

[0023] The substrate is preferably placed in front of a light-absorbing background, such as a light-absorbing back cover according to the present invention. More preferably, imaging is performed in a substantially dark environment, which can optionally be generated by using a housing according to the present invention. The substrate is illuminated on at least one side edge by at least one light source, for example, at least one LED array. Because the light source illuminates at least one side edge of the substrate, internal reflection traps most of the light inside the substrate, and the light leaks out only at the edges of the substrate and / or at locations on the surface that contain light-scattering elements such as defects, contamination, or other patterns. By using a light-absorbing background and / or a substantially dark environment, the light-scattering elements can have high contrast with the background. The contrast can be further enhanced, for example, by placing an opaque black frame, for example in the form of a shielding element, beyond the edge of the substrate. If shielding elements are applied, they are preferably folded into an open configuration before inserting the substrate into the housing. A focused image of the substantially transparent substrate is created using an (visual) imaging device such as a camera or optical sensor. Those skilled in the art recognize the optimal settings, such as focus, aperture, sensitivity, and shutter speed, that yield good contrast of light-scattering elements within the substrate against the background. The method may include a step of comparing correlated images obtained on the same substrate before and after one or more handling steps and / or imprint steps and / or processing steps.

[0024] This embodiment enables tracking the progression of defects, contamination, and / or other patterns within a particular substrate. The method may also include a step of comparing correlated images obtained from different substrates that have undergone the same processing steps, such as a pattern replication process. For example, different substrates that have undergone a pattern replication process performed on the same stamp, the same submaster, or the same master can be examined. This embodiment enables monitoring the progression of defects during processing steps, such as a replication process, and identifying at what stage of the (replication) process a particular defect was introduced or removed. It is conceivable that at least one image processing algorithm is used to analyze the presence and / or absence of light scattering elements in at least one image, for example, one image. The image processing algorithm may be configured, for example, to count the number of light scattering elements and / or to provide the coordinates of the (identified) light scattering elements. The image processing algorithm may also be configured to classify the detected light scattering elements. Preferably, one or more additional images are taken from either the same substrate after undergoing the process under investigation, or another substrate that has undergone a pattern replication process similar to that of the first substrate. For the embodiments described above, it is conceivable that a series of images are generated and analyzed. The images are preferably analyzed for the presence and / or absence of light scattering elements. Detected light scattering elements can then be classified. It is conceivable that at least one image processing algorithm is used to analyze the presence and / or absence of light scattering elements, e.g., light scattering images. Preferably, at least one image processing algorithm includes image operations to detect similarities and differences between at least two correlated images. The method may further include the step of providing a comparison image in which the differences between at least two images are depicted. Such a comparison image can be used to count, label, and / or provide coordinates of detected light scattering elements. The method according to the present invention can be applied during any interval of the overall imprint process. Typically, a transparent substrate undergoes a (sub)process to be investigated. Examples of an (sub)process to be investigated include a handling process, a cleaning process, a coating process, or an imprint process.Optionally, a wiping or cleaning process may be performed on the back side of the substantially transparent substrate to remove or replace backside contamination prior to analysis.

[0025] At least one additional image of the substrate may be taken and used, for example, to distinguish light scattering elements on the back of the substrate from elements on the front. When using an image processing algorithm, converting the color image to grayscale to improve processing speed and accuracy, increasing the contrast of the image, and / or aligning at least two images to each other to correct small translational, rotational, and / or perspective deviations may be performed as later optional operations in various orders. To facilitate the alignment process, two or more markers may be used on a transparent substrate and / or on a work stamp or submaster used to create the duplicate substrate. Further optional operations such as cropping the image to select a region of interest, expanding the pixels of the image to increase the surface area of ​​scattering elements in the image, and comparing at least two images to each other using image operations may be performed using an image processing algorithm. To detect similarities between images, a new image may be constructed, which is the (normalized) product of two or more images. The resulting image will contain only the elements present in all the multiplied images. To detect differences between a pair of images, a new image may be constructed by subtracting one image from the other. Optionally, a scalar can be added to all pixel values ​​to enable the display of otherwise negative pixel values. Another method for detecting differences between two or more images is to split the images into parts. The sequence of arithmetic operations described above may be used depending on the specific use case. The resulting comparison images may be used to label light scattering elements in the images. For this purpose, further image processing steps may be performed, such as increasing the contrast of the resulting images, binarizing the resulting images using a specific threshold, counting the number of individual detected elements or groups of elements that are close to each other, listing the coordinates of the detected elements or groups of elements, and / or labeling the detected elements using (colored) visual aids in text or images. Any of the steps described above may be included in the method according to the present invention.

[0026] The present invention is further described by the following non-limiting clauses.

[0027] Section 1. A device that enables inspection of a substantially transparent substrate, At least one housing configured to accommodate at least one substantially transparent substrate, At least one edge for surrounding at least a portion of the substrate, At least one support surface for supporting at least a portion of the substrate, At least one back cover to cover at least a portion of the circuit board and Including housing, A light source configured to illuminate at least a portion of the substrate and Equipped with, An apparatus wherein at least one light source is at least partially positioned within a housing such that the at least one light source is directed toward at least one side edge of a substrate housed within the housing, thereby, in particular, at least a portion of the light emitted by the at least one light source is incident on the substrate via the at least one side edge so that the light can propagate through the substrate.

[0028] Section 2. At least a portion of at least one light source is arranged within the housing such that at least one light source is partially shielded by the housing. The apparatus described in item 1.

[0029] Section 3. At least one light source, at least a portion of it, is mounted on the housing. The apparatus described in item 1 or 2.

[0030] Section 4. At least one of the light sources is an LED light source. The apparatus described in any one of items 1 to 3.

[0031] Section 5. At least two light sources are arranged in a configuration facing each other, with each light source directed towards at least one side edge of a substrate housed within the housing. The apparatus described in any one of items 1 to 4.

[0032] Section 6. At least one light source, or more light sources, are arranged to surround at least one substrate in which the light source or more light sources are housed in a housing. The apparatus described in any one of items 1 to 5.

[0033] Section 7. At least one light source is positioned at a distance from at least one support surface. The apparatus described in any one of items 1 to 6.

[0034] Section 8. At least one light source is located on at least one support surface. The apparatus described in any one of items 1 to 7.

[0035] Section 9. At least one light source is located inside at least one edge of the housing. The apparatus described in any one of items 1 to 8.

[0036] Section 10. A shielding element comprising at least one displaceable shielding element, configured to shield at least a portion of the substrate and / or at least a portion of at least one light source, The apparatus described in any one of items 1 to 9.

[0037] Section 11. At least one shielding element is pivotably attached to at least a portion of the housing, particularly at least a portion of at least one edge of the housing. The apparatus described in item 10.

[0038] Section 12. At least one shielding element is positioned at a distance from at least one support surface. The apparatus described in item 10 or 11.

[0039] Section 13. At least one support surface is positioned at a distance from at least one rear cover. The apparatus described in any one of items 1 to 12.

[0040] Section 14. At least one support surface is positioned substantially parallel to at least a portion of at least one rear cover, The apparatus described in any one of items 1 to 13.

[0041] Section 15. At least a portion of at least one back cover facing the substrate has at least one light-absorbing color and / or at least one light-absorbing material. The apparatus described in any one of items 1 to 14.

[0042] Section 16. At least a portion of one of the back covers facing the substrate is dark in color, preferably black or a derivative of black. The apparatus described in any one of items 1 to 15.

[0043] Section 17. It comprises at least one control unit for controlling at least one parameter of at least one light source, The apparatus described in any one of items 1 to 16.

[0044] Section 18. It has at least one enclosure, The apparatus described in any one of items 1 to 17.

[0045] Section 19. An assembly comprising at least one apparatus described in any one of items 1 to 18 and at least one imaging device.

[0046] Section 20. An imprint system comprising at least one apparatus as described in any one of items 1 to 18, or at least one assembly as described in item 19, preferably an imprint system configured to transfer at least one pattern and / or at least one structure onto at least one substrate, in particular at least one substantially transparent substrate.

[0047] Section 21. A method for inspecting a substantially transparent substrate. The apparatus described in any one of items 1 to 18 includes at least one substrate, in particular at least one substantially transparent substrate. Illuminating at least a portion of at least one side edge of the substrate with at least one light source, Capture at least one image of at least a portion of the circuit board being inspected. By detecting light scattering elements, at least one image can be analyzed for defects. A method that includes the following steps.

[0048] Section 22. At least one substrate is placed on at least one support surface. The method described in item 21.

[0049] Section 23. At least one image processing algorithm is used to analyze the presence and / or absence of light scattering elements in at least one image. The method described in item 21 or 22.

[0050] Section 24. One or more handling steps and / or processing steps and / or imprint steps, including a step of comparing correlated images obtained on the same substrate before and after each handling step and / or processing step and / or imprint step, The method described in any one of items 21 to 23.

[0051] Section 25. The process includes comparing correlated images obtained from different substrates that have undergone the same processing steps. The method described in any one of items 21-24.

[0052] Section 26. The image is analyzed for the presence and / or absence of light scattering elements. The method described in paragraphs 24 and / or 25.

[0053] Section 27. At least one image processing algorithm is used to analyze the light scattering elements, and at least one image processing algorithm includes an image operation to detect similarities and differences between at least two correlated images. The method described in any one of items 24-26.

[0054] Section 28. The process includes a step of providing comparison images, in which the difference between at least two images is depicted. The method described in any one of items 21 to 27.

[0055] Section 29. The steps include counting the number of light scattering elements, providing the coordinates of the light scattering elements, and / or classifying the light scattering elements. The method described in any one of items 21 to 28. [Brief explanation of the drawing]

[0056] The present invention is further illustrated by non-limiting exemplary embodiments shown in the following figures. [Figure 1] A first possible embodiment of the apparatus according to the present invention is shown. [Figure 2] A schematic cross-sectional view of another possible embodiment of the apparatus according to the present invention is shown. [Figure 3A] This is a detailed view of a part of Figure 2, showing the effect of defects on the substrate. [Figure 3B] This is a detailed view of a part of Figure 2, showing the effect of defects on the substrate. [Figure 4]Further possible examples of the apparatus according to the present invention are shown. In these figures, similar reference numerals correspond to similar or equivalent elements or features. [Modes for carrying out the invention]

[0057] Figure 1 is a schematic perspective view of a first possible embodiment of the apparatus 101 according to the present invention. In particular, the figure shows an assembly according to the present invention comprising the apparatus 101 and an imaging device 10. The apparatus 101 is a tool configured to enable effective inspection of a substrate (S). The apparatus 101 comprises a housing 102 including at least one edge 103 for surrounding at least a portion of the substrate S, at least one support surface 104 for supporting at least a portion of the substrate S, and a rear cover 105 for covering at least a portion of the substrate S. In the shown perspective view, the rear cover 105 is located behind the substrate S. Preferred positions of the substrate S within the housing 101 are shown in detail in Figures 2, 3A, and 3B. The apparatus 101 further comprises at least one light source 106. In the shown embodiment, the light source 106 substantially surrounds the substrate S. The light source 106 is configured to irradiate the substrate S and is at least partially located within the housing 101 such that the light source 106 is directed toward at least one edge of the substrate S housed within the housing 101. The light source 106 is positioned such that its optical elements face each other on both sides of the substrate S. The apparatus 101 further comprises a display 110. The figure shows that the imaging device 10, specifically the camera 10, is positioned at a distance from the apparatus 101 and therefore from the substrate S received therein.

[0058] Figure 2 is a schematic cross-sectional view of another possible embodiment of the apparatus 201 according to the present invention. The apparatus 201 comprises a housing 202 configured to house a substrate S. The housing 202 includes an edge 203, a support surface 204, and a rear cover 205. The edge 203 of the housing 202 is configured to surround at least a portion of the substrate S. The support surface 204 is configured to support at least a portion of the substrate S, specifically its peripheral edge. The cross-sectional view further shows the rear cover 205 covering at least a portion of the substrate S. The apparatus 201 further comprises a light source 206 configured to illuminate at least a portion of the substrate S. The light source 206 is at least partially positioned within the housing 202 such that the light emitted by the light source 206 is directed towards the edge of the substrate S housed within the housing 202, particularly the side edge. It can be seen that the light source 206 is shielded by the housing 202. Furthermore, the light source 206 is shielded by a shielding element 207. The shielding element 207 is displaceable relative to the edge 203 of the housing 202. The figure shows that the shielding element 207 is pivotably mounted to the edge 203 of the housing 202, particularly the housing 203. The shielding element 207 covers or shields the light source 206 from the imaging device 20. The pivotability of the shielding element 207 is beneficial for the ease of the device 201, as the shielding element 207 can pivot away from the support surface 204 so that the substrate S can be easily placed on the surface 204 without being affected by the shielding element 207. The shielding element 207 is positioned at a distance from the support surface 204. In the shown embodiment, the light source 206 is positioned adjacent to the support surface 204. In this way, the transfer of light from the light source 206 to the substrate S is perfectly optimized. The imaging device 20 is, for example, a camera 20. The imaging device 20 is positioned at a predetermined distance from the substrate S. In the shown embodiment, the light source 206 is shielded by the housing 202, particularly by the shielding element 207, so that the imaging device 20 is not affected by the light emitted from the light source 206. The substrate S is positioned substantially parallel to the rear cover 205. The rear cover 205 in the shown embodiment has a dark, uniform color and completely covers the back of the substrate S.The light source 206 is positioned so that the light is directed towards the side edge of the substrate S. For this reason, the light source 206 is positioned particularly inside the edge 203 of the frame 202.

[0059] Figures 3A and 3B are detailed views of parts of Figure 2, illustrating the effects of defects on the substrate S. Defect D acts as a light scattering element. Figure 3A shows the effect of light scattering due to defect D on the upper surface of the substrate S, and Figure 3B shows the same effect of defect D on the lower surface of the substrate S. The substrate S is housed in the housing 202 and is positioned on the support surface 204.

[0060] Figure 4 shows a further possible example of the apparatus 301 according to the present invention. The figure shows a perspective view of the apparatus 301 comprising a housing 302 configured to house a substrate S. The housing 302 includes an edge 303, a support surface (not shown), and a rear cover positioned behind the substrate. The edge 303 of the housing 302 surrounds the substrate S. The substrate S is further shielded by a hinged shielding element 307. The shielding element 307 is connected to the housing 302 via a hinge 308. The apparatus 301 further comprises a support structure 309 in which the housing 302 is positioned.

[0061] The present invention is not limited to the exemplary embodiments illustrated and described herein, and countless modifications are possible within the scope of the appended claims, which will be obvious to those skilled in the art. In this case, it is conceivable to combine, in whole or in part, the different inventive ideas and / or technical means of the various embodiments described above without departing from the inventive idea set forth in the appended claims.

[0062] The verb "comprise" and its conjugations used in this patent document are understood to include not only "comprise" but also "contain," "substantially contain," "formed by," and their conjugations.

Claims

1. A device that enables inspection of a substantially transparent substrate, At least one housing configured to accommodate at least one substantially transparent substrate, At least one edge portion to surround at least a part of the substrate, At least one support surface for supporting at least a portion of the substrate, At least one back cover for covering at least a portion of the substrate and Including housing, At least one light source configured to irradiate at least a portion of the substrate, Equipped with, An apparatus in which at least a portion of the at least one light source is disposed within the housing, the at least one light source is partially shielded by the housing, and the at least one light source is directed toward at least one side edge of the substrate housed within the housing, so that at least a portion of the light emitted by the at least one light source is incident upon the substrate via the at least one side edge so that the light propagates through the substrate.

2. The housing includes at least one housing space defined by at least a portion of at least one support surface and at least one edge of the housing, and at least one light source is housed within the housing space. The apparatus according to claim 1.

3. At least a portion of at least one light source is attached to the housing. The apparatus according to claim 1 or 2.

4. At least one of the light sources is an LED light source. The apparatus according to any one of claims 1 to 3.

5. At least two light sources are arranged in a configuration facing each other, and each light source is directed toward at least one side edge of the substrate housed within the housing. The apparatus according to any one of claims 1 to 4.

6. At least one light source, or a plurality of light sources, are arranged to surround at least one substrate in which the light source or the plurality of light sources are housed in the housing. The apparatus according to any one of claims 1 to 5.

7. At least one light source is configured to emit non-collimated light. The apparatus according to any one of claims 1 to 6.

8. At least one light source is positioned at a distance from at least one support surface. The apparatus according to any one of claims 1 to 7.

9. At least one light source is positioned on at least one support surface, and / or at least one light source is positioned inside at least one edge of the housing, The apparatus according to any one of claims 1 to 8.

10. A shielding element comprising at least one displaceable shielding element, configured to shield at least a portion of the substrate and / or at least a portion of at least one light source, The apparatus according to any one of claims 1 to 9.

11. At least one shielding element is pivotably attached to at least a portion of the housing, particularly at least a portion of at least one edge of the housing. The apparatus according to claim 10.

12. At least one shielding element is positioned at a distance from at least one support surface. The apparatus according to claim 10 or 11.

13. At least one support surface is positioned at a distance from at least one rear cover. The apparatus according to any one of claims 1 to 12.

14. At least one support surface is positioned substantially parallel to at least a portion of at least one rear cover, The apparatus according to any one of claims 1 to 13.

15. At least a portion of at least one back cover facing the substrate has at least one light-absorbing color and / or at least one light-absorbing material. The apparatus according to any one of claims 1 to 14.

16. At least a portion of one of the back covers facing the substrate has a dark color, preferably black or a derivative of black. The apparatus according to any one of claims 1 to 15.

17. It comprises at least one control unit for controlling at least one parameter of at least one light source, The apparatus according to any one of claims 1 to 16.

18. It has at least one enclosure, The apparatus according to any one of claims 1 to 17.

19. An assembly comprising at least one apparatus according to any one of claims 1 to 18 and at least one imaging apparatus.

20. An imprint system comprising at least one apparatus according to any one of claims 1 to 18, or at least one assembly according to claim 19, wherein the imprint system is configured to transfer at least one pattern and / or at least one structure onto at least one substrate, in particular at least one substantially transparent substrate.

21. A method for inspecting a substantially transparent substrate. The apparatus according to any one of claims 1 to 18 includes at least one substrate, in particular at least one substantially transparent substrate. Irradiating at least a portion of at least one side edge of the substrate with at least one light source, To capture at least one image of at least a portion of the substrate being inspected, By detecting light scattering elements, at least one image can be analyzed for defects. This includes the following steps: A method in which at least one image processing algorithm is used to analyze the presence and / or absence of light scattering elements in at least one image.

22. At least one substrate is placed on at least one support surface. The method according to claim 21.

23. At least one image processing algorithm is configured to count the number of light scattering elements and / or provide the coordinates of the identified light scattering elements. The method according to claim 21 or 22.

24. The process includes a step of comparing correlated images obtained on the same substrate before and after one or more handling steps and / or processing steps and / or imprint steps, The method according to any one of claims 21 to 23.

25. The process includes comparing correlated images obtained from different substrates that have undergone the same processing steps. The method according to any one of claims 21 to 24.

26. The aforementioned image is analyzed for the presence and / or absence of light scattering elements. The method according to claim 24 and / or 25.

27. To analyze the light scattering elements, at least one image processing algorithm is used, and the at least one image processing algorithm includes an image operation to detect similarities and differences between at least two correlated images. The method according to any one of claims 24 to 26.

28. The process includes a step of providing comparison images, in which the difference between at least two images is depicted. The method according to any one of claims 21 to 27.

29. The steps include counting the number of light scattering elements, providing the coordinates of the light scattering elements, and / or classifying the light scattering elements. A method according to any one of claims 21 to 28.

Images