Projection optical device and method for manufacturing optical structure

Abstract

Embodiments according to the present invention include a method for manufacturing an optical structure, where the method includes forming a first layer of the optical structure, where forming the first layer includes forming and curing a first curable material on a first molded structure to form the first layer such that a first optical lens surface is formed at a first side of the first layer, at the first side, the first layer is connected with the first molded structure. The method further includes providing a second layer of the optical structure at a second side of the first layer opposite the first side while the first layer is connected to the first molded structure at the first side of the first layer. Additional embodiments according to the invention include projection optics.

Description

Technical Field

[0001] Embodiments according to the invention relate to projection optics and methods for producing optical structures. Background Art

[0002] Modern camera systems are facing an increasing demand for miniaturization, higher performance and reduced costs. As an example, for medical applications, a camera system may have to meet strict restrictions in terms of its size in order to be suitable for the medical purpose of inserting the camera system into the human body in order to support surgery or decide on the next steps of the respective treatment. Despite these restrictions, it is important that a small camera system is able to provide high-quality images in order to provide the best possible support to the treating physician. At the same time, it is desirable to provide such systems with low-complexity manufacturing methods in order to keep costs low. Summary of the invention

[0003] It is therefore desirable to have a concept for an optical structure and its production as well as for projection optics which offers a better compromise between size, performance and complexity and therefore costs of the optical structure or projection optics and its respective production.

[0004] This is achieved by the subject-matter of the independent claims of the present application.

[0005] Further embodiments according to the invention are defined by the subject matter of the dependent claims of the present application.

[0006] An embodiment according to the present invention includes a method for manufacturing an optical structure, wherein the method includes: forming a first layer of the optical structure, wherein forming the first layer includes: forming and curing a first curable material on a first molded structure to form the first layer, so that a first optical lens surface is formed at a first side of the first layer, and at the first side, the first layer is adjacent to the first molded structure. The method also includes: arranging a second layer of the optical structure at a second side of the first layer opposite to the first side, and the first layer is adjacent to the first molded structure at the first side of the first layer.

[0007] Providing the second layer may be or may include, for example, forming the second layer based on a molding process. In other words, the second layer may thus be produced or established opposite to the first side of the first layer. In other words, the step of creating the second layer may include actively forming or actively creating (e.g. putting in position, e.g. arranging, e.g. placing, e.g. producing, e.g. constructing, e.g. shaping) the layer when the first layer abuts or more precisely still abuts the first molding structure at the first side of the first layer.

[0008] The inventors recognize that the stack of layers of the optical structure manufactured by the molding process can also be processed on the rear side opposite to the side subjected to the first molding step during manufacturing, that is, by using the molding structure for the first molding step when processing the rear side, so as to avoid any additional substrate at the rear side. That is, the molding structure may include an uneven (e.g., non-planar) surface for forming or replicating the first optical lens surface of the first layer of the optical structure at the first side of the first layer. At the second side opposite to the first layer, at least one processing step can be performed when the first molding structure has not been removed, thereby playing a role similar to a handle. For example, the processing may involve replicating another layer. For example, the second layer can be arranged at the second side without any substrate between the first layer and the second layer. Therefore, as an example, the second layer can be directly arranged on the first layer, or the two layers can be optionally separated only by one or more coatings. For this manufacturing step, the first layer is still adjacent to the first molding structure, and therefore, a stable basis can be provided for the precise application of the second layer and / or one or more coatings.

[0009] The inventors have realised that this can provide for low-complexity manufacturing of optical structures without the need for an intermediate substrate. For example, for mechanical reasons the thickness of the substrate used in conventional methods must be minimal, which is contrary to the desired miniaturization of the optical structure. In short, the inventors have realised that a moulded structure (which is anyway required to form the lens surface in conventional methods, for example) can be used not only for lens formation, but also as an alternative substrate. Thus, in addition, fewer components may be required for the manufacturing process, thereby reducing costs.

[0010] According to an embodiment of the present invention, setting the second layer includes: using a second molding structure to form and cure a second curable material at the second side of the first layer to form the second layer, so that a second optical lens surface is formed at the second side of the second layer, the second layer is adjacent to the second molding structure at the second side of the second layer and the second side is back to the second side of the first layer, and the second optical lens surface is aligned with the first optical lens surface and the optical axis of the optical structure.

[0011] In short, and by way of example, the inventors have recognized that the method for forming a first optical lens surface can be mirrored by "sandwiching" a layer stack including a first layer and a second layer between a first molding structure and a second molding structure to form a second optical lens surface. Thus, an optical lens surface can be formed on opposite surfaces of the layer stack (i.e., a first side of the first layer and a second side of the second layer) without introducing any intermediate substrate. Likewise, the first molding structure can provide stability to the cured first layer while forming and curing the second curable material.

[0012] As mentioned above, the first layer and the second layer may directly adjoin each other. However, it should be noted again that, for example, one or more coatings may be provided and optionally structured on the second surface of the first layer before the second layer is provided. Optionally, such coatings may form a filter or an aperture or a filter in combination with an aperture of the projection optical device or optical structure of the present invention.

[0013] Thus, embodiments include projection optics including a first layer of a first cured material, wherein the first layer includes a first optical lens surface at a first side of the first layer at an optical axis of the projection optics and includes a planar portion at a second side of the first layer opposite to the first side of the first layer at the optical axis. The projection optics also include a second layer of a second cured material, wherein the second layer includes a planar portion at a first side of the second layer at the optical axis and includes a second optical lens surface at a second side of the second layer opposite to the first side of the second layer at the optical axis.

[0014] Furthermore, the planar portion of the first layer adjoins the planar portion of the second layer at the optical axis, or the planar portion of the first layer is separated from the planar portion of the second layer at (or on) the optical axis only by one or more coatings.

[0015] Thus, the method of the present invention may comprise removing the first moulding structure and / or the second moulding structure after curing the first layer and the second layer in order to provide the projection optics explained before.

[0016] Furthermore, sandwiching or enclosing the first and second curable materials between first and second molding structures for manufacturing the first and second layers allows providing precise alignment of the first and second optical lens surfaces with the optical axis of the projection optics.

[0017] In addition, according to an embodiment, the projection optics may include a plurality of layer stacks. As explained previously, the layer stack may include a first and a second double-sided replicated layer having an optical lens surface on opposite sides. Therefore, the projection optics may include a first additional layer and a second additional layer that may be manufactured like the first layer and the second layer, wherein such an additional layer stack may be bonded to the second layer, for example, at the second side of the second layer, so that the first additional layer abuts the second layer. In this way, a projection optics having at least two double-sided replicated layer stacks may be provided, the projection optics including at least four optical elements in the form of optical lens surfaces. Therefore, the projection optics of the present invention may be formed by a plurality of modules including the first layer and the second layer, wherein the modules may be produced with a similar manufacturing process, which may reduce the cost and complexity of the corresponding manufacturing method.

[0018] It should be noted that between such further layers further coatings may also be provided.Regarding any coatings, the inventors realised that such coatings may provide apertures and / or filters in order to further increase the functional density of the projection optics or optical structure, respectively.

[0019] According to further embodiments, the projection optics may comprise a third layer of a third cured material, wherein the third layer adjoins the second layer at a second side of the second layer and a first side of the third layer, or wherein the third layer adjoins the second further layer at a second side of the second further layer and a first side of the third layer. Additionally, the third layer may comprise a third optical lens surface located at a second side of the third layer opposite to the first side at the optical axis of the projection optics.

[0020] Therefore, in order to set such a third layer, the method of the present invention may include: removing the second molding structure from the second layer, and forming and curing a third curable material at the second side of the second layer between the second layer and the third molding structure to form the third layer, so that at the first side of the third layer, the third layer is adjacent to the second layer, and at the second side of the third layer (the second side is away from the first side of the third layer, and at the second side the third layer is adjacent to the third molding structure), a third optical lens surface is formed, and the first optical lens surface is aligned with the third optical lens surface at the optical axis of the optical structure.

[0021] Thus, the third layer may be arranged on the second further layer of the projection optics or optical structure of the invention.

[0022] Thus, in the manufacturing process of the present invention, further layers may be stacked on the first and second layers. Thus, in short, one of the molding structures may be removed so that the next curable material may be applied to that layer and formed using the next molding structure. In short, to form the next layer, e.g. such a third layer, the layer stack may again be sandwiched between the first molding structure and the next (e.g. third) molding structure.

[0023] In general, embodiments according to the invention may allow the use of a precisely clamped or fixed first molded structure to align multiple or even all further layers replicated and / or joined to the first molded structure. This may simplify the manufacturing process and may allow high-precision alignment of the layers. Thus, in addition, the alignment structure may be arranged, for example, next to the optical axis of the projection optics or optical structure to further improve the alignment of the optical element (such as a lens surface). Alternatively, an optical alignment method may be used.

[0024] Furthermore, embodiments may include compensation structures configured to compensate for manufacturing tolerances and / or to set or provide a focus of the inventive structure or the inventive optical device. First, it should be noted that, in order to reduce costs, the manufacture of the inventive optical device or structure may be performed in parallel for a plurality of such devices, for example on a wafer level and / or arranged in an array.

[0025] The inventors recognize that, based on a series of data of the corresponding optical device or structure, a separate or universal compensation structure can be used for compensation. For example, through testing, a set of parameters characterizing the corresponding structure or optical device can be obtained, and if these parameters are similar for multiple optical devices or structures manufactured in parallel, a universal compensation structure for each of the structures or optical devices can be used. On the other hand, if this method produces too many defective products for each of the optical devices or structures, a separate compensation structure can be manufactured and bonded to the corresponding optical device or structure. Alternatively, the best matching compensation structure can be selected from a plurality of different compensation structures for the corresponding projection optical device or structure of the present invention.

[0026] Depending on the implementation, on a batch-by-batch basis, the corresponding approach may be selected, i.e. using a common compensation structure or individual compensation structures. This may allow a highly optimized manufacturing process to be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings are not necessarily drawn to scale, but emphasis is generally placed upon illustrating the principles of the invention. In the following description, various embodiments of the invention are described with reference to the following accompanying drawings, in which:

[0028] Figure 1a to Figure 1c shows a schematic diagram of a projection optics according to an embodiment of the present invention with additional optional features;

[0029] Figure 2a to Figure 2t A schematic side view of an optical structure and its components according to an embodiment of the present invention is shown, which illustrates a method for manufacturing the optical structure; and

[0030] Figure 3 A schematic diagram of another projection optical device according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0031] The same or equivalent elements or elements having the same or equivalent functions are denoted by the same or equivalent reference numerals in the following description even if they appear in different drawings.

[0032] In the following description, many details are set forth in order to provide a more thorough understanding of embodiments of the present invention. However, it will be apparent to those skilled in the art that embodiments of the present invention may be implemented without these specific details. In some instances, in order to avoid obscuring embodiments of the present invention, well-known structures and devices are shown in block diagram form rather than in detail. In addition, unless otherwise specifically stated, the features of the different embodiments described below may be combined with each other.

[0033] In addition, for the description of the embodiments, the first side of the element can be opposite to the second side of the element, and the sides of the consecutive elements can be oriented so that the first side of one element is adjacent to the second side of another element. Therefore, the first side of the element can be oriented in the same direction, and the second side of the element can be oriented in another same direction opposite to the direction of the first side. In short, the first side can be the top side of the element, and the second side can be the bottom side of the element.

[0034] First, it should be noted that embodiments according to the present invention include optical systems, for example in the form of projection optics and / or optical structures. Although some embodiments are discussed with respect to projection optics or manufacturing methods for optical structures, it should be noted that any features, details and functions of the corresponding projection optics and / or manufacturing methods thereof can be used in a similar or identical or equivalent manner for optical structures and / or manufacturing methods thereof, and vice versa. In addition, the arrangement of the first layer and the second layer of the present invention can be referred to as a layer stack or a double-sided replication layer.

[0035] Furthermore, it should be noted that, in general, as used herein, the arrangement of an element at or at the optical axis may be understood as an element arranged laterally at the optical axis, e.g. laterally in a plane relative to the corresponding layer, e.g. laterally near the optical axis, e.g. in a laterally adjacent volume perpendicular to the optical axis.

[0036] Figure 1a to Figure 1c Schematic diagrams of projection optical devices with additional optional features according to embodiments of the present invention are shown. Projection optical devices 100a to 100c each include a first layer 110 of a first cured material and a second layer 120 of a second cured material. The first layer 110 includes a first optical lens surface 112 at a first side of the first layer at an optical axis 130 of the projection optical device. In addition, the first layer 110 includes a planar portion 114 at a second side of the first layer opposite to the first side of the first layer at the optical axis 130. Vice versa, the second layer 120 includes a planar portion 122 at a first side of the second layer at the optical axis 130 and includes a second optical lens surface 124 at a second side of the second layer opposite to the first side of the second layer at the optical axis 130. As shown in 1a to 100c, Figure 1cAs shown, the planar portion 114 of the first layer optionally abuts the planar portion 122 of the second layer at the optical axis 130 .

[0037] However, as an optional feature, the projection optics 100a to 100c each include a coating 140. It should be noted that more than one layer 130 (or 140) may be arranged between the first layer 110 and the second layer 120. Figure 1a to Figure 1c As shown, the coating 140 may be a structured coating. In the embodiment shown, the respective coating 140 may form an aperture of the respective projection optics 100a to 100c.

[0038] As a further optional feature, the coating or one or more coatings may form a filter of the respective projection optics and / or an aperture and a filter of the respective projection optics. Thus, at the optical axis, one or more coatings (e.g. in the case of a filter) may be arranged between the first layer 110 and the second layer 120, such that the planar portion 114 of the first layer 110 is separated from the planar portion 122 of the second layer 120 at the optical axis 130 only by the one or more coatings (not shown). It is emphasized that in this case, the coating does not have to be a filter as mentioned before as an example, and the coating may be, for example, any thin layer suitable for providing any desired functionality for the projection optics.

[0039] As explained before, the layer stack including layers 110 and 120 can be produced in small sizes, because compared with conventional methods, no substrate is between the first layer and the second layer, so that the layer stack can be miniaturized. In addition to this, the inventors realized that even additional coatings can be arranged between the first layer and the second layer, so that, in short, not only the substrate that would enlarge the entire device is removed, but also another functional layer is additionally included, for example, providing the function of an aperture or a filter or even both, for example, with little impact on the size of the projection optics.

[0040] As an optional feature, the projection optics 100c comprises a second layer stack or in other words, a second double-sided replication layer. The projection optics 100c comprises a first further layer 110c of a first further cured material and a second further layer 120c of a second further cured material. The first further layer 110c comprises a first further optical lens surface 112c at a first side of the first further layer at the optical axis 130 of the projection optics and comprises a planar portion 114c at a second side of the first further layer opposite to the first side of the first further layer at the optical axis 130. The second further layer 120c comprises a planar portion 122c at a first side of the second further layer at the optical axis 130 and comprises a second further optical lens surface 124c at a second side of the second further layer opposite to the first side of the second further layer at the optical axis 130.

[0041] Furthermore, the planar portion 114c of the first further layer 110c adjoins the planar portion 122c of the second further layer 120c at the optical axis 130. Again, it should be noted that, as already explained in the context of the first and second layers, this direct adjoining is only optional. As a further optical feature, a further coating 140c arranged between the first further layer 110c and the second further layer 120c is shown. Again, this further coating 140c can for example be a structured layer, but can also optionally or alternatively form a filter.

[0042] In general, a coating according to an embodiment of the invention may be, for example, any thin layer comprising any suitable functionality. Thus, also as explained in the context of the first and second layers, the first further layer 100c may be, for example, separated from the second further layer 120c only by the coating 114c (or 140c) at the optical axis. Thus, instead of directly adjoining planar portions 114c and 122c at the optical axis 130, between these planar portions, the further coating 140c may be arranged at the optical axis 130.

[0043] Furthermore, as shown for the projection optics 100c , the first further layer 110c adjoins the second layer 120 at the second side of the second layer and at the first side of the first further layer.

[0044] It should be noted that the first layer and the second layer and the first further layer and the second further layer may, for example, be similar, identical or completely different layer stacks. It should also be noted that such a set-up allows providing multiple optical lens surfaces without having to include a conventional substrate. Thus, even complex optical projection paths through the projection optics 110c may be provided without having to significantly increase the size of the projection optics.

[0045] For the sake of completeness, it should be noted that more than one further coating 140c can be arranged between the first further layer and the second further layer. In addition, it should be noted that such a further layer stack can also be joined to any additional (eg third) layer, which can be arranged on the second layer 120.

[0046] As shown, as another optional feature, the projection optics 100c comprises a cavity 150c between the second optical lens surface 124 and the first further optical lens surface 112c at the optical axis 130 .

[0047] As another optional feature, the projection optics 100a to 100c each include an additional layer 160 of additional cured material, which adjoins the first layer 110 at a first side of the first layer and at a second side of the additional layer. Furthermore, the additional layer includes an additional optical lens surface 162 at the second side of the additional layer at the optical axis 130 of the projection optics. Optionally, as shown, the cavity 150 can exist between the first optical lens surface 112 and the additional optical lens surface 162 at the optical axis 130.

[0048] For example, in order to bond the additional layer 160 to the first layer 110, the projection optics of the present invention may optionally include an alignment structure. As an example, Figure 1c To further emphasize that this feature is only optional, the alignment structure 170 is only in Figure 1c , however, they may also be present in projection optics 100a and 100b. Figure 1c As shown, as an example, the alignment structure 170 may be arranged at a first side of the first layer 110 and at a second side of the additional layer 160. The alignment structure 170 is configured to align the first layer 110 and the additional layer 160 so that the first optical lens surface 112 is aligned with the additional optical lens surface 162 at the optical axis 130. As an example, the alignment structure 170 is shown as a small pyramid structure, however any form suitable for aligning two layers (or any other two layers to be joined together) may be used. As an example, one of the two layers (the first layer or the additional layer) may include the alignment structure 170, and the corresponding other layer may include a hole in the negative form or in short in the shape of the alignment structure, so that after joining the two layers, the optical lens surfaces are aligned.

[0049] It should be emphasized that the embodiments are not limited to such alignment structures. In the manufacturing method of the present invention, the layers can be aligned, for example, using an optical alignment method. In addition, alignment clips can also be arranged at the outer boundaries of the corresponding layer stacks to provide alignment. In addition, it should be noted that, for example, alignment can be performed at the wafer level or array level for the manufacture of projection optical devices, so that multiple devices of the present invention manufactured can be aligned simultaneously. Therefore, in summary, optical alignment using alignment structures and / or using mechanical (e.g., clamping) structures can be performed.

[0050] like Figure 1a and Figure 1cAs shown, the projection optical device can optionally include a support structure 180, which adjoins the additional layer 160 at a first side of the additional layer opposite to the second side. The support structure 180 can be, for example, a substrate or a molded structure and / or a molded structure with a planar topology. Therefore, the additional layer can be manufactured on a substrate (e.g., a glass substrate) for example in a conventional manufacturing process, and the entire structure including the additional layer 160 and the substrate can then be bonded to the first layer 110. However, instead of using a substrate, a molded structure can be used to manufacture the additional layer 160. Therefore, on the first side of the additional layer 160, optionally, another lens surface can be arranged, which is formed by a corresponding molded structure. As another optional feature, the support structure 180 can be a molded structure with a planar topology, in short, acting as a substrate.

[0051] As another optional feature, Figure 1b As shown, projection optical device 100b includes a third layer 190 of a third cured material. The third layer is adjacent to the second layer 120 at a first side of the third layer and at a second side of the second layer. In addition, the third layer 190 includes a third optical lens surface 192 at a second side of the third layer opposite to the first side at the optical axis 130 of the projection optical device. For example, in Figure 1c In the projection optics shown, the third layer may optionally adjoin the second further layer 120c (not shown) at the second side of the second further layer and at the first side of the third layer.

[0052] like Figure 1b The projection optics 100b shown may provide the functionality of an achromatic lens. Thus, optionally, two consecutive layers of the projection optics may include different optical properties, i.e. Figure 1b ), the second layer 120 and the third layer 190. Therefore, the optical lens surface of the first layer of the two consecutive layers may include a high refractive index and a low dispersion, and the optical lens surface of the second layer of the two consecutive layers facing the optical lens surface of the first layer of the two consecutive layers may include a low refractive index and a high dispersion to form an achromatic lens. Therefore, embodiments according to the present invention may allow the influence of chromatic aberration and spherical aberration to be limited. Therefore, adjacent lens surfaces may provide the functions of flint glass and crown glass.

[0053] As another optional feature, Figure 1a to Figure 1c As shown, the projection optical devices 100a to 100c may include a backside structure 200 and a cavity 210. Figure 1a As shown, the first surface of the backside structure 200 can be adjacent to the second layer 120 at the second side of the second layer, and the cavity 210 can be arranged between the backside structure 200 and the second optical lens surface 124 at the optical axis 130. Figure 1bAs shown, the first surface of the backside structure 200 can be adjacent to the third layer 190 at the second side of the third layer, and the cavity 210 can be arranged between the backside structure 200 and the third optical lens surface 192 at the optical axis 130. As another optional alternative, as Figure 1c As shown, the first surface of the backside structure 200 may adjoin the second further layer 120c at a second side of the second further layer, and the cavity 210 may be arranged between the backside structure 200 and the second further optical lens surface 124c at the optical axis 130 .

[0054] The backside structure can provide mechanical stability for the projection optics. Figure 1a to Figure 1c As shown, the backside structure may include a backside substrate 202, a filter 204, and a compensation structure 206. The compensation structure 202 (or 206) may be configured to compensate for manufacturing tolerances and set or improve the focus of the optical structure. As a result of manufacturing the layers of the projection optics, for example, their thickness may vary within a certain tolerance. However, this may deteriorate the desired beam path through the projection optics, and therefore may deteriorate the alignment of the desired light through the projection optics at a predetermined focus (e.g., at the location where the sensor is attached to the projection optics). In order to compensate for such tolerances, the compensation structure 202 (or 206) may be included in the projection optics.

[0055] As shown, the filter 204 optionally includes a first filter structure 2041 arranged on a first surface of the back substrate 202 and a second filter structure 2042 arranged on a second surface of the back substrate 202 opposite to the first surface. The double-sided application of the filter structure can allow compensation for warping effects during manufacturing, so that the back substrate 202 and the filter 204 can form a planar structure that can be precisely bonded to other layers and / or elements of the projection optical device.

[0056] For reference, the compensation structure 206 may include a first surface and a second surface, wherein the second surface is opposite to the first surface, and as shown in FIG. Figure 1a to Figure 1c As shown, the first surface of the compensation structure may adjoin the second filter structure 2042 , such that the first filter structure 2041 forms a first surface of the backside structure 200 .

[0057] However, it should be noted that, depending on the embodiment, the order of the compensation structure and the back substrate and the filter is interchangeable. Therefore, optionally (not shown), the first filter structure 2041 can be adjacent to the second surface of the compensation structure 202 (or 206), so that the first surface of the compensation structure forms the first surface of the back structure 200. In short, the back substrate and the filter including the filter structure can be, for example, arranged at the bottom of the back structure 200, while the compensation structure 202 (or 206) is arranged at the top of the back structure.

[0058] Additionally, it should be noted that, depending on the implementation, the backside structure 200 may alternatively include only the compensation structure 206 or only the backside substrate 202 and the filter 204 .

[0059] In addition, it should be noted that the filter may optionally include only the first filter structure and not the second filter structure. The first filter structure may be arranged on the first surface of the back substrate at least at the optical axis. Therefore, the first filter structure and the first surface of the back substrate may form the first surface of the back structure. In other words, the filter material may be arranged and structured on the back substrate only at the area surrounding (e.g., laterally surrounding) the optical axis. Therefore, the first filter structure may only partially form the first surface of the back structure.

[0060] Furthermore, in general, it should be noted that the cavity 210 may be formed at least in part by at least one of a recess in the second layer, a recess in the second additional layer, a recess in the third layer, a recess in the backside structure, a through hole in the backside structure, and / or a through hole in the compensation structure of the backside structure. The recess and / or through hole may be manufactured by at least one of etching, powder spraying, and / or laser induced deep etching LIDE. Thus, the cavity may be provided based on forming a spacer structure using a corresponding molding structure and / or based on a recess or through hole in the backside structure so as to provide a cavity for the corresponding lens structure. It should be noted that the cavity may be provided by one or both of the aforementioned techniques. Thus, the corresponding lens structure may be located in a recess or through hole in the backside structure, for example, in the case where the corresponding layer does not include a recess in which the lens structure is arranged.

[0061] Furthermore, it should be noted that the through hole in the backside structure may be a through hole that passes through a component of the backside structure, such as a compensation structure. Thus, for a subsequent filter, the through hole may be "closed" on one side, thereby forming a cavity or a portion of a cavity. In addition, a cavity may be understood as a "closed" cavity, wherein the internal volume of the cavity is completely sealed from the environment, but may also be understood as an "open" cavity, such as a natural cavity with an entrance, or in other words a cavity that is not completely closed from the environment.

[0062] Alternatively, the compensation structure 206 may be a universal compensation structure configured to compensate for manufacturing tolerances and / or to set or improve the focus of a plurality of projection optical devices on average. During batch manufacturing of a plurality of projection optical devices, measurements of the plurality of projection optical devices may be obtained in order to obtain appropriate dimensions for the compensation structure 206. For example, in the case where different projection optical devices are similar, for example with respect to their tolerances, a universal compensation structure may be formed and may be used equally for all projection optical devices. Thus, the compensation structure used may be configured to compensate (at least partially or substantially) for manufacturing tolerances and / or to set or improve the focus of a plurality of projection optical devices on average at least. In other words, the compensation structure may be formed as (in simple terms) a compromise to best improve a plurality of projection optical devices.

[0063] Thus, the compensation structure 206 may also be an individual compensation structure configured to compensate for manufacturing tolerances and / or to set or improve the focus of the projection optics. Thus, for each projection optics, an individual compensation structure may be formed, for example based on individual measurements of the respective projection optics, so as to best improve the properties of the respective optics.

[0064] Optionally, projection optics 100a, 100b, and 100c may include a lateral dimension of at least 100 μm, or at least 200 μm, or at least 300 μm, or at least 0.5 mm, and at most 2 mm, or at most 3 mm, or at most 5 mm in the plane of the first layer 110. Alternatively or in addition, the projection optics may include a height of at least 0.5 mm, or at least 1 mm, or at least 2 mm, and at most 2 mm, or at most 3 mm, or at most 5 mm, or orthogonal to the first and second layers. Thus, as previously described, projection optics having small dimensions may be provided. This may allow for use in challenging applications, such as providing visual support for surgery inside the human body.

[0065] As another optional feature, Figure 1a to Figure 1c The sensor structure 220 is shown bonded to the compensation structure 206. Thus, using the compensation structure 206, light traveling through the projection optics can be precisely focused onto the sensor chip of the sensor structure 220.

[0066] Reference below Figures 2a to 2t 2 shows a schematic side view of an optical structure and its components according to an embodiment of the present invention, and illustrates a method for manufacturing the optical structure. For example, the manufactured optical structure may be a projection optical device as shown in FIG. 1 .

[0067] Figure 2a to Figure 2d A first layer forming an optical structure and a second layer providing an optical structure are shown. Figure 1aAs shown, a first layer 310 can be formed, wherein forming the first layer includes: forming and curing a first curable material on a first molding structure 320 to form the first layer, so that a first optical lens surface 312 is formed at a first side of the first layer, and the first layer is adjacent to the first molding structure at the first side.

[0068] Alternatively, if Figure 2b As shown, the method according to the embodiment may include: providing one or more coatings between the first layer 310 and the second layer. Figure 2b As shown, the coating 330 can be disposed on the planar surface of the first layer 310 at the second side of the first layer 310. As another optional feature, one or more coatings 330 can be structured. As an example, Figure 2b As shown, one coating 330 forms an aperture. However, it should be noted that one or more coatings may alternatively form a filter in addition to an aperture and / or a filter and an aperture.

[0069] It should be noted that providing the coating is performed at a second side of the first layer 310 opposite to the first side, wherein the first layer 310 adjoins the first molding structure 320 at the first side of the first layer.

[0070] like Figure 2c As shown, the second layer of the optical structure can again be arranged at a second side of the first layer 310 opposite the first side, while the first layer 310 abuts the first molding structure 320 at the first side of the first layer. Figure 2c As shown, a second molding structure 350 may be used to form the second layer, however, it should be noted that this feature is merely optional.

[0071] Therefore, if Figure 2c As shown, providing the second layer 340 may include: using the second molding structure 350 to form and cure the second curable material at the second side of the first layer 310 to form the second layer, so that a second optical lens surface 344 is formed at the second side of the second layer 340, where the second layer is adjacent to the second molding structure 350, and the second side faces away from the second side of the first layer 310, and the second optical lens surface 344 is aligned with the first optical lens surface 312 at the optical axis 360 of the optical structure. Figure 2c As shown, the second optical lens surface 344 can be a convex lens, but alternatively, as Figure 2d As shown, a concave shape can also be provided. Figure 2d The illustrated molded structure 350 may include different forms.

[0072] As optionally shown, the corresponding molding structure can include a master support 322 and 354, respectively, and a master mold (PDMS) 324 and 352, respectively. For example, the master support can include or be made of glass, and the master mold can include polydimethylsiloxane. Figure 2a to Figure 2t In the illustrated embodiment, the first layer 310 may be a first replication layer, and the second layer 330 may be a second replication layer. Thus, the replication layer 2 and the replication layer 2a may be different examples of the second layer 330, and the shapes of the corresponding optical lens surfaces 344 of the different examples are different.

[0073] So, in other words, reference Figure 2a , according to an embodiment, a first process step may be to replicate a lens layer 1, e.g., a replicated layer 1, using a master mold 324 (e.g., a typical PDMS type material) including a master mold support 322 (e.g., a typical glass). The replicated layer may be applied by a stirring process and may then be UV cured. As an example, such a stirring process may include applying an epoxy material (e.g., replicated layer 1) on a substrate or wafer, or, according to a preferred embodiment, applying the epoxy material to the molded structure by a mechanical "paddle" to achieve the final thickness of the material. In addition, the stirring process may include removing excess material using a paddle.

[0074] As another example, spin coating may be performed for the above process steps.

[0075] refer to Figure 2b , as an example and in other words, in this process step, the replication layer can still remain in the master mold 324, and the coating 330 in the form of orifices can be applied by coating, for example, a thin layer of an opaque black material (which can be photolithographically structured, for example), for example by spin coating, which can be structured by a photolithographic process to produce the coating in the form of orifices. It should be noted that, in contrast to conventional methods in which the orifices are structured on a glass substrate with a typical black chrome, according to an embodiment, the orifices can be structured directly on the replication layer.

[0076] refer to Figure 2c , as an example and in other words, in this process step, the replication layer (including the structured openings) can still remain in the master mold and then replicate the replication layer 2 (lens 2, for example layer 340 including the second optical lens surface 344) by using a second master mold 352 (including the master mold support portion 354).

[0077] As shown in FIG. 2 , the method of the present invention according to an embodiment may be performed to provide a plurality of optical structures, for example, at a wafer level or arranged in an array. Thus, as shown, a plurality of optical lens surfaces 312 and 344 (see, for example, Figure 2q). Thus, later in the process the layers can be cut to provide a plurality of optical structures. In this regard, it is noted that, although wafer-level lenses can be produced, no glass substrate can be used between the replicated layers 1 and 2, and the replicated layer 2 can be replicated directly onto the aperture and replicated layer 1.

[0078] refer to Figure 2d , in other words and as an example, Figure 2d Alternative methods can be shown, e.g. Figure 2c An alternative to the method shown in , in which the replica layer 2 is no longer a convex lens, but includes a concave shape (replica layer 2a) so as to be able to build an achromatic lens. For example, the lens layer 2a (e.g., the second layer 340) can include a relatively low Abbe number (e.g., the V number or the inverse dispersion coefficient of a transparent material) and can represent a flint-type material.

[0079] refer to Figure 2e and Figure 2f As another optional feature, a third layer 370 of optical structure may be provided. Figure 2e As shown, providing the third layer 370 may include: removing the second molding structure 350 from the second layer 340, and forming and curing a third curable material (also optionally including a master mold 352a and a master mold support portion 354a) at a second side of the second layer 340 between the second layer and the third molding structure 350a, as shown in FIG. Figure 2f As shown, the third layer is formed so that at a first side of the third layer 370, the third layer is adjacent to the second layer 340, and at a second side of the third layer, the second side is opposite to the first side of the third layer, and the third layer is adjacent to the third molded structure 350a at the second side, as shown. Figure 2f As shown, a third optical lens surface 372 is formed, and the first optical lens surface 312 is aligned with the third optical lens surface 372 at the optical axis 360 of the optical structure.

[0080] As shown, optionally, a third layer 370 may be provided while the first layer 310 abuts the first molding structure 320 at a first side of the first layer.

[0081] In other words, reference Figure 2e In this step, the concave lens (e.g. Figure 2d The master mold 352 of the lens surface 344 shown is removed, but the entire wafer still remains in the master mold 324 of lens 1.

[0082] It should be noted that Figure 2e and Figure 2f The manufacturing steps are based on Figure 2d However, providing a third layer can also be directed to Figure 2cThe optical structure shown or any other alternative layer stack according to embodiments of the present invention may be implemented.

[0083] Likewise, in other words and by way of example, reference Figure 2f , in order to complete the alternative method, e.g. Figure 2d As shown, and in order to construct an achromatic lens, another layer (replica layer 2b, for example, including a biconvex shape) can be coated on the replica layer 2a to enable the construction of an achromatic lens. For example, the lens layer 2b (e.g., the third layer 370) can include a relatively high Abbe number and can represent a crown material that may be needed to construct an achromatic lens and improve chromatic aberration. Therefore, in summary, embodiments include constructing an achromatic lens on a wafer-level optical device, for example, especially compared to conventional methods.

[0084] As another optional feature, you can use Figure 2a to Figure 2d The steps shown in , so as to provide and form a first additional layer and a second additional layer. Therefore, in a similar or identical manner, a stack of additional layers may be provided, wherein the first additional layer forming the optical structure comprises: forming and curing a first additional curable material on a first additional molded structure, so as to form the first additional layer, so that a first additional optical lens surface is formed at a first side of the first additional layer, at which the first additional layer is adjacent to the first additional molded structure. In addition, providing a second additional layer of the optical structure at a second side of the first additional layer opposite to the first side, while the first additional layer is adjacent to the first additional molded structure at the first side of the first additional layer, may include: forming and curing a second additional curable material at a second side of the first additional layer using a second additional molded structure, so as to form a second additional layer, so that a second additional optical lens surface is formed at a second side of the second additional layer, at which the second additional layer is adjacent to the second additional molded structure, and the second side is opposite to the second side of the first additional layer, and so that the second additional optical lens surface is aligned with the first additional optical lens surface at the optical axis of the optical structure.

[0085] So, in short, Figure 2a to Figure 2d In the steps shown, layer 310 may represent a first further layer, layer 340 may represent a second further layer, first molded structure 320 may represent a first further molded structure, and molded structure 350 may represent a second further molded structure.

[0086] It should be noted that, therefore, one or more further coatings may be provided between the first further layer and the second further layer, and at least one of the one or more further coatings may be structured. In addition, as explained in the context of one or more coatings, one or more further coatings may thus form an aperture and / or a filter, or both.

[0087] In this regard, it should be noted that the thickness of the coating of one or more coatings between the first and second layer, and / or the thickness of the coating of one or more further coatings between the first further layer and the second further layer may comprise at most 10% or at most 5% or at most 2% or at most 1% of the thickness of the first layer or the thickness of the second layer, respectively, and / or at most 10% or at most 5% or at most 2% or at most 1% of the thickness of the first further layer and / or the thickness of the second further layer.

[0088] The second layer stack comprising the first further layer and the second further layer can thus be joined to the first layer stack comprising the first layer and the second layer. Figure 2e As shown, the second molded structure 350 can be removed. In addition, (not shown) for bonding, the first additional molded structure can be removed. Then, (not shown) the first additional layer can be bonded to the second layer 340 so that the first additional layer abuts the second layer at the second side of the second layer and the first side of the first additional layer, and so that the first additional optical lens surface is aligned with the second optical lens surface 344 at the optical axis 360 of the optical structure. Thus, as shown in FIG. Figure 1c As explained in the context of , the first further optical lens surface and the second optical lens surface can be formed so that the optical structure comprises a cavity between the first further optical lens surface and the second optical lens surface at the optical axis of the optical structure. Likewise, it should be noted that the further layer stack can also be bonded to the third layer of the optical structure.

[0089] Figure 2g Another optical process step according to an embodiment is shown, wherein, for example, as Figure 2c The next step of the structure shown may be to remove the first molding structure 320 and the second molding structure 350. In other words, the next process (eg, in the case where the optical structure is not an achromatic lens) may be to remove the main wafer on both sides.

[0090] Figure 2h Examples of further optical method steps are shown, for example for Figure 2f The structure shown includes removing the first molding structure 320 and the third molding structure 350a. In other words, the next process step in the alternative method (achromatic lens) may be to remove the main wafer on both sides.

[0091] However, it should be noted that removing the respective molded structures may be performed sequentially. Figure 2i and Figure 2jAdditional optional method steps of arranging an optical substructure are shown. The optical substructure 380 includes a support structure 382 and an additional layer 384. Arranging the optical substructure may include forming and curing an additional curable material between an additional molding structure 390 and the support structure 382 to form the additional layer 384, such that an additional optical lens surface 386 is formed at a second side of the additional layer 384, at which the additional layer abuts the additional molding structure 390, and such that the additional layer abuts the support structure 382 at a first side of the additional layer, the first side of the additional layer being opposite to the second side of the additional layer.

[0092] Likewise, the additional molding structure 390 may optionally include a master mold 392 and a master mold support 394. Furthermore, as shown, the additional layer may be a replication layer, namely replication layer 3, and in the same manner, the support structure may be a replication base layer.

[0093] like Figure 2i As shown in the example of , the support structure can be a substrate. Alternatively, as Figure 2j As shown, the support structure 382 can be a molded structure, and / or for example Figure 2j As specifically shown in FIG. , it can be a molded structure with a planar topology. As another optional feature, in Figure 2j In the figure, the planar molding structure also includes a mother mold support portion 3801 and a mother mold 3822.

[0094] refer to Figure 2i As an example and in other words, in this process step, the lens replication layer 3 can be made by replication directly on the glass substrate, for example in the form of a replication base layer and using a master mold 392 (PDMS) and a master mold support 394.

[0095] Therefore, in other words and with reference to Figure 2j , Figure 2j An alternative method can be shown in which a substrate (front glass) is not used to replicate lens layer 3, such as replicating layer 3, but only a master mold support 3821 including a flat PDMS layer 3822 is used. As an example, a lens layer (e.g., 384) can be replicated by using a master mold (e.g., 392) having a layer 3 structure and a master mold support (e.g., 394).

[0096] Thereafter, as an optional feature, the master molds 382 and 390 may be removed, for example as shown in FIG. g) and FIG. h) (e.g. Figure 2g )and Figure 2h Thus, embodiments may include optical structures without a cover glass in the final product but with a substrate-less design.

[0097] like Figure 2k and Figure 2lAs shown in FIG. 1 as an optical and / or optional feature, at least after removing the first molded structure 320 from the first layer 310, for example Figure 2g and Figure 2h As shown, and after removing the additional molding structure 390, the additional layer 384 can be bonded to the first layer 310 so that the additional layer 384 abuts the first layer 310 at a first side of the first layer and a second side of the additional layer, and so that the additional optical lens surface 386 is aligned with the first optical lens surface 312 at the optical axis of the optical structure. Figure 2l As optionally shown in , the method of the present invention may further include: removing the support structure 382 from the additional layer 384. It should be noted that the removal of the support structure is independent of the form of the structure, so the support structure can be removed in the form of a glass substrate or substrate, or in the form of a molded structure, or even in the form of a planar molded structure, for example, Figure 2j shown.

[0098] As Figure 2k Another optional feature shown, according to an embodiment, the method may include: bonding the first surface of the backside structure 410 to the second layer 340 at the second side of the second layer, so that the second optical lens surface 344 and the first surface of the backside structure form a cavity 450 (such as Figure 2m As shown in Figure 2g As shown, for the bonding of the backside structure 410 , the method may include, for example, removing the second molding structure 350 from the second layer 340 in advance.

[0099] Therefore, if Figure 2l As shown, in the case where the optical structure includes a third layer 370, for example Figure 2h As shown, the third molded structure 380 can be removed and the first surface of the backside structure 410 can be bonded to the third layer 370 at the second side of the third layer so that the third optical lens surface 372 and the first surface of the backside structure form a cavity 450 (as shown in FIG. Figure 2n shown).

[0100] like Figure 2k and Figure 2l Optionally, the backside structure 410 may include a substrate 412 and a filter 414. The filter may include a first filter structure 4141 disposed on a first surface of the backside substrate and a second filter structure 4142 disposed on a second surface of the backside substrate opposite to the first surface. Thus, the first filter structure 414 may form a first surface of the backside structure 410.

[0101] refer to Figure 2k, in other words, the backside substrate 412 may be or may act as a filter carrier, and layer 4141 may be a filter compensation or filter compensation layer, and layer 4142 may be a filter layer. As explained before, the double-sided application of the filter layer may mitigate the warping effect and may allow providing a flat backside structure 410 that may be precisely bonded to the corresponding layer 340 or 370. Furthermore, as an example and in other words, when the lens layers 1, 2 and 3 are completed, they may be stacked and bonded together, and then the backside glass (e.g. 410) may be bonded, which may be, for example, just glass, wherein the thickness may be well defined, for example with low TTV (low total thickness variation).

[0102] Thus, generally speaking, embodiments according to the invention may include a backside structure that also only includes a backside substrate. The backside glass (e.g. 410) may have integrated filters (e.g. 414), such as NIR cut-off filters, notch filters, bandpass filters, etc. As explained before, in order to not produce any or only limited or little warping on the filter substrate, the filters may be applied on both sides so that there is compensation and the substrate remains flat. Reference Figure 2l , it can be shown that Figure 2k The same or similar process as shown in , but now utilizing an alternative approach for lenses 1, 2a / 2b and lens 3 (the achromatic lens).

[0103] Figure 2k and Figure 2l The result of the stacking step is shown in Figure 2m and Figure 2n As shown, optionally, the first optical lens surface 312 and the additional optical lens surface 386 may be formed such that the optical structure includes a cavity 420 between the first optical lens surface and the additional optical lens surface at the optical axis 360 of the optical structure.

[0104] As an example and in other words, Figure 2m The final bonded stack can be shown still in wafer format, while Figure 2n The final bonded stack can be shown still in wafer format (alternative achromat approach).

[0105] Figure 2o and Figure 2p A further optional feature of the method according to an embodiment is shown, wherein the optical structure is provided with compensation structures 430, respectively 4301, 4302 and 4303. The compensation structures may be configured to compensate for manufacturing tolerances and / or to set or improve the focus of the optical structure. In addition, the backside structure 410 may include a compensation structure.

[0106] Thus, the corresponding compensation structure can be bonded to the first filter structure and / or the second filter structure. As explained before, in short, the order of the compensation structures and the substrate 412 and the filter 414 can be changed. Therefore, as an alternative, the method of the present invention may optionally include: bonding the first filter structure to the second surface of the compensation structure, so that the first surface of the compensation structure forms the first surface of the back structure 410, so that the compensation structure is bonded to the second layer or respectively the third layer, or for example a second further layer. Alternatively, the method of the present invention may optionally include: bonding the first surface of the compensation structure to the second filter structure 4142, so that the first filter structure 4141 forms the first surface of the back structure 410, for example, as Figure 2o and Figure 2p shown.

[0107] However, it should be noted that the backside structure 410 may, for example, only include the compensation structure 430 or respectively 4301 , or only include the elements 412 and 414 .

[0108] like Figure 2o As shown, the compensation structure can be a universal compensation structure, which is used for each optical structure in the optical structure group. Figure 2o As shown, for example, the compensation structure 430 can thus be a globally matched back glass. Optionally, the method can also include: determining multiple sets of parameters, each set of parameters characterizing an optical structure in the multiple optical structures, and providing the compensation structure as a universal compensation structure. Providing the compensation structure can also include: adjusting the compensation structure based on the determined multiple sets of parameters to compensate for manufacturing tolerances and averagely set or improve the focus of the optical structure.

[0109] like Figure 2o As shown and as previously described, the separation into a plurality of optical structures may be performed, here for simplicity as an example into three different optical structures I, II and III. It should be noted that, in general, a large number of structures, e.g., hundreds or thousands or tens of thousands of optical structures or projection optical devices or lens stacks may be arranged in a row, e.g., on a wafer or array arrangement, depending on the implementation. In other words, in practice, the accompanying drawings may only show cross-sections of three structures in a row of typical more structures (there may easily be 10,000 or possibly 100 structures on an 8" wafer).

[0110] Thus, for each of these stacks, measurements can be performed and, as an example, in the case where the corresponding characteristics of the stacks that can be cut into different optical structures may be sufficiently similar (e.g. in terms of yield or performance) so that a common structure is used so that manufacturing tolerances are compensated on average (e.g. to allow “trade-off compensation” for the three optical structures I, II, III).

[0111] So, for example, Figure 2p As shown, in cases where the layer stacks that can be cut into the individual optical structures I, II, III are not similar enough or where, for example, a globally matched back glass approach might produce too many defective devices, individual compensation structures 4301, 4302, and 4303 can be provided based on corresponding measurements and / or parameter groups that characterize the corresponding optical structures, wherein the respective compensation structures are adjusted based on the respective parameter groups in order to compensate for manufacturing tolerances and / or set or improve the focus of the respective optical structures.

[0112] In other words, as an example, refer to Figure 2o In order to compensate for tolerances and build a camera with a well-defined optimal focus position, it may be necessary to add additional glass spacer wafers (e.g., compensation structure 430). For example, the MTF (modulation transfer function), BFL (back focal length), EFL (effective focal length), etc. of all lenses on a stacked wafer or array arrangement can be measured, for example, using an automatic test system, and a wafer map or array map of multiple optical structures can be generated. In the case where the tolerance of the parameter group (e.g., BFL) within the wafer or array is not too large, a globally matched back glass method can be used, which means, for example, that the average value of the BFL of all lenses or layer stacks on the wafer or in the optical structure array can be calculated, and the compensation structure (e.g., back glass wafer) can be ground to this thickness. Lenses with poor MTF (e.g., layer stacks I, II, and / or III) or in which the BFL is too short or even too short or too long or even too long may not or will not be used, and the yield may or will decrease.

[0113] Therefore, reference Figure 2p , if the tolerance is too high and the yield is unacceptable when using a globally matched back glass, then alternatively, a separate spacer match can be used. Similarly, characterization parameters of all lenses on a stacked wafer, such as MTF, BFL, EFL, etc., can be measured, for example, using an automatic test system, and a wafer or array diagram can be generated. A set of cut compensation structures with predefined sizes, such as glass substrates, such as 4301, 4302, 4303, can or will be prepared, the set of compensation structures having different (well-defined) thicknesses (e.g., multiple (e.g., 5) different thicknesses with specific differences), and then these small glass substrates can be joined to separate lens stacks in a single piece. As an example, a shorter BFL may require a thinner back glass, etc. For example, typically, in the end, only lenses with poor MTF need to be skipped.

[0114] However, it should be noted that embodiments are not limited to compensation structures in the form of glass spacers. The compensation structure according to embodiments may also be another replication layer, for example a layer comprising an epoxy material which may be subsequently applied and UV-cured. In particular, such a compensation layer may thus be applied on wafer level before cutting into individual projection optics. As discussed previously, the testing of the projection optics (e.g., with respect to the entire aperture of the respective optic) may be performed on wafer level, for example individually for each projection optic, or to obtain a single result for the projection optics of the entire wafer.

[0115] Optionally, according to an embodiment of the invention, the compensation structure can be adjusted according to such a test, for example on wafer level, in order to set or improve the back focal length of the projection optics of the wafer. This can correspond to a global setting of one or more focal lengths of the projection optics of the wafer. Thus, the thickness of the compensation structure can be adjusted, for example over the entire wafer, for example, so that the compensation structure comprises the same thickness over the entire wafer. Alternatively, individual adjustments can also be performed.

[0116] Using the manufacturing method of the invention, the focal length of the projection optics of a wafer can be set with good accuracy, for example, with low individual tolerances from one projection optic to another of the wafer. This can allow a global adjustment of the compensation structure to be performed, for example instead of adjusting the spacers individually, in order to fine-tune the focal length within a set tolerance.

[0117] Thus, in general, depending on the embodiment, the compensation layer can be a solidified material (e.g., a first, second, additional and / or another solidified material) and can be configured to compensate for manufacturing tolerances and / or set or improve the focus of a projection optical device and / or set or improve the focus of multiple projection optical devices at wafer level.

[0118] Therefore, optionally, the back side structure 410 may include a back side substrate 412, a filter 414 and a compensation structure, wherein the compensation structure is configured to compensate for manufacturing tolerances and / or set and / or improve the focus of the optical structure, wherein the filter includes a first filter structure 4141 arranged on a first first surface of the back side substrate, wherein the filter includes a second filter structure 4142 arranged on a second surface of the back side substrate opposite to the first surface, or wherein the filter includes a first filter structure arranged on the first surface of the back side substrate at least at the optical axis, and wherein the first filter structure and the first surface of the back side substrate form the first surface of the back side structure.

[0119] In addition, the method optionally includes: joining the first filter structure 4141 to the second layer at the second side of the second layer so that the second optical lens surface forms a cavity with the first filter structure 4141 at the optical axis; or joining the first filter structure 4141 to the second additional layer at the second side of the second additional layer so that the second additional optical lens surface forms a cavity with the first filter structure 4141 at the optical axis, or joining the first filter structure 4141 to the third layer at the second side of the third layer so that the third optical lens surface forms a cavity with the first filter structure 4141.

[0120] In addition, the method may optionally include: forming and curing a curable material on the second filter structure 4142 or on the back substrate to form a compensation structure, for example as explained previously, having a predefined thickness to compensate for manufacturing tolerances and / or set the focal length of the corresponding optical device.

[0121] As another optional feature, the method according to an embodiment may include: forming and curing a curable material on a substrate and / or a molded structure to form a compensation structure, removing the compensation structure from the substrate and / or the molded structure, and joining the compensation structure to the second layer at a second side of the second layer so that the second optical lens surface and the compensation structure form a cavity at the optical axis; or joining the compensation structure to a second additional layer at a second side of the second additional layer so that the second additional optical lens surface and the compensation structure form a cavity at the optical axis, or joining the compensation structure to a third layer at a second side of the third layer so that the third optical lens surface and the compensation structure form a cavity.

[0122] Optionally, the method may include forming and curing a curable material on a substrate and / or a molded structure to form a compensation structure, removing the compensation structure from the substrate and / or the molded structure, and bonding the compensation structure to a second filter structure or to a backside substrate.

[0123] As an example, in short, a globally matched rear glass can thus be replaced by a globally matched cured material.

[0124] refer to Figure 2q and Figure 2r , the method according to an embodiment may optionally include: performing cutting to separate the optical structures I, II and III in the plurality of optical structures. In other words and as an example, after everything is done, the entire wafer or array may be cut, for example, using a wafer saw using blue tape or UV release tape. Figure 2q An example of a back glass 430 using global matching is shown, Figure 2r Shown as an example in FIG. 1 is a separately matched rear glass for an alternative approach (achromatic lens).

[0125] like Figure 2s and Figure 2t As shown, the method of the present invention may optionally include: bonding the sensor structure 440 to the optical structure. As shown, the sensor may include a cover glass. In other words and as an example, once the optical stack is completed, the CMOS image sensor can be bonded to the lens. Figure 2t An alternative approach using an achromatic lens can be shown.

[0126] Figure 1a )and Figure 1b ) can be shown respectively according to Figure 2a )to Figure 2s )and Figure 2t ) is the final result of the manufacturing method. Therefore, according to the embodiment explained in the context of FIG. Figure 1a )and Figure 1b ), layer 110 may be replicated layer 1, and layer 120 may be replicated layer 2 (in Figure 1a ) and accordingly, the replica layer 2a (in Figure 1b ), layer 180 may be a replication base layer, layer 160 may be a replication layer 3, and coating 140 may be an orifice, Figure 1b ) in which layer 190 may be a replica layer 2b, element 202 may be a filter carrier, wherein element 2041 is a filter compensation and element 2042 is a filter layer, wherein element 206 is a matching spacer and wherein element 220 is a sensor with cover glass.

[0127] therefore, Figure 1a ) can show the final product with 3 aspheric surfaces and an aperture, and no substrate between layers 1 and 2, and with a substrate on replicated layer 3 (which can also act as a cover glass). Figure 1b ) can be shown as a final product with 4 aspheric surfaces ( 2a and 2b , for example, acting as achromatic lenses) and an aperture, with no substrate between layer 1 and layers 2a / b and no substrate on the replicated layer 3.

[0128] In general, it should be noted that embodiments according to the present invention may include aspherical and / or spherical optical lens surfaces. In other words and by way of example, all lens surfaces (e.g. as shown in the figures) may generally have an aspherical shape, but may also be spherical, depending on the specific design. In addition, as previously explained, the process according to the embodiments may be a wafer format, such as a 6", 8" or 12" circular substrate, but may also be a square or rectangular substrate. As an example, typical dimensions of the final product may be approximately 1 mm×1 mm and 2 mm height, with a spacing of, for example, 1.4 mm between lenses.

[0129] Figure 3A schematic diagram of another projection optical device according to an embodiment of the present invention is shown. Figure 3 A schematic top view 510 of a plurality of projection optics I, II and III arranged at wafer level or array level is shown. As an example, the respective projection optics may be cut along dashed lines 512, 514.

[0130] also, Figure 3 A schematic side view 520 is shown along the section AA as shown in the schematic top view 510. As explained before, the projection optics 500(III) comprises a first layer 522 of a first cured material, which is in the form of a replication layer (Replication Layer 2) by way of example, comprising a first optical lens surface 524 at a first side of the first layer at an optical axis 526 of the projection optics and comprising a planar portion 528 at a second side of the first layer opposite to the first side of the first layer at the optical axis. The projection optics 500(III) further comprises a second layer 530 of a second cured material in the form of another replication layer (Replication Layer 3) comprising a planar portion 532 at a first side of the second layer at the optical axis 526 and comprising a second optical lens surface 534 at a second side of the second layer opposite to the first side of the second layer at the optical axis 526.

[0131] As an optional feature, the projection optics 500 includes an additional layer 536 of additional cured material adjacent to the first layer 522 at a first side of the first layer and a second side of the additional layer. Furthermore, the additional layer includes an additional optical lens surface 538 at the second side of the additional layer at the optical axis 526 of the projection optics and includes a cavity 540 between the first optical lens surface 524 and the additional optical lens 538 at the optical axis.

[0132] Furthermore, as a further optional feature, the projection optics comprises a support structure 542 adjoining the additional layer at a first side of the additional layer opposite to the second side, wherein the support structure is a substrate in the form of a front glass.

[0133] Furthermore, the projection optics 500 comprises a photolithographically structured coating 544 (eg made of a polymer material) in the form of apertures.

[0134] As another optional feature, the projection optical device 500 includes a backside structure 546 and a cavity 548, wherein a first surface of the backside structure is adjacent to the second layer 530 at a second side of the second layer, and the cavity 548 is arranged between the backside structure 546 and the second optical lens surface 534 at the optical axis 526.

[0135] As an example, the backside structure 546 includes a backside substrate with a filter 550 in the form of a back glass with a filter and a compensation structure 552 for spacer matching in the form of a spacer glass. As explained before, the compensation structure is configured to compensate for manufacturing tolerances and / or set or improve the focus of the optical structure.

[0136] The filter comprises a first filter structure arranged on a first surface of the back substrate and a second filter structure arranged on a second surface of the back substrate opposite to the first surface. The compensation structure comprises a first surface and a second surface, wherein the second surface is opposite to the first surface.

[0137] exist Figure 3 In the example shown, the first filter structure adjoins the second surface of the compensation structure such that the first surface of the compensation structure forms the first surface of the backside structure.

[0138] Figure 3 Also shown is an enlarged schematic side view 560 of section B shown in view 520, highlighting the layer setup. Figure 3 An enlarged schematic side view 570 of section C shown in view 560 is shown, further highlighting the thin structured coating 544 between the first and second layers.

[0139] Additionally, embodiments consistent with the present invention include miniaturized wafer-level cameras.

[0140] Embodiments according to the present invention include a miniaturized wafer-level camera with a wide field of view, the miniaturized wafer-level camera comprising or, for example, consisting of: a first glass substrate (e.g., 180 ( FIG. 1 ) in the object direction; e.g., 540 ( Figure 3 )), followed by a first lens (e.g., 162 (FIG. 1); e.g., 386 (FIG. 2); e.g., 538 ( Figure 3 )) of the replicated epoxy layer (e.g., layer 160 (FIG. 1); e.g., layer 382 (FIG. 2); e.g., layer 536 ( Figure 3 )), the first lens has a concave aspheric surface in the direction of the sensor side. For example, the epoxy resin layer can also have an integrated column / spacer around the lens so that the next layer can be stacked on top. As an example of a corresponding molding structure, for example, an additional molding structure can include a column spacer (e.g., a column / spacer) to form a cavity between the lens surfaces (e.g., 150 (Figure 1), for example, 420 (Figure 2), for example, 540 ( Figure 3 )). The first lens is followed by a replicated second lens (e.g., layer 110 (FIG. 1); e.g., layer 310 (FIG. 2); e.g., layer 522 ( Figure 3)), the second lens has a convex aspheric surface (e.g. 112 (FIG. 1); e.g. 312 (FIG. 2); e.g. 524 ( Figure 3 )) and only comprises epoxy resin or, for example, only consists of epoxy resin. Optionally, once the second lens wafer (for example, layer 110 (FIG. 1); for example, layer 310 (FIG. 2); for example, layer 522 ( Figure 3 )), the black material can or will be structured on a flat surface, generally as a coating (e.g. 140 (FIG. 1); e.g. 330 (FIG. 2); e.g. 544 ( Figure 3 )), which can optionally be structured by a photolithography process and thus can form an aperture. As a next step on top of the aperture, another convex aspheric lens structure (e.g. 124 (FIG. 1); e.g. 344 (FIG. 2); e.g. 534 ( Figure 3 )) of the third lens (e.g., layer 120 (FIG. 1); e.g., layer 340 (FIG. 2); e.g., layer 530 ( Figure 3 )). For example, the two replicated convex surface layers may also have integrated pillars so that the wafers can be bonded together (e.g., so that corresponding cavities are formed (150 and 210 (FIG. 1); 420 and 450 (FIG. 2); 540 and 450 ( Figure 3 )).

[0141] This may also be one of the fundamental differences from conventional methods, such as shown in US2017031089A, where they always use a glass substrate to replicate lens 2 and lens 3 (e.g. Figure 3 ), or in most of the claims also two glass substrates are used, wherein the opening is structured in the middle of the two glass substrates.

[0142] Another way to optimize the performance of a lens design (and / or to provide an alternative lens design) may be to split the lens 3 into two parts, which means creating an achromatic lens by first replicating a lens 3a having a concave surface (e.g., as shown in replica layer 2a in FIG. 2 ), and the lens material has a refractive index of, for example, at least 1.5 and at most 2.0 (e.g., 1.6) and a low Abbe number, for example, less than 50 (e.g., 28 (flint)), and then overmolding a convex layer of lens 3b (e.g., as shown in replica layer 2b in FIG. 2 ), which is a lens material having a refractive index of, for example, 1.52 or less and an Abbe number, for example, greater than 50 (e.g., 52 (crown)).

[0143] The third lens will have already integrated posts / spacers (e.g. to provide a cavity, e.g. Figure 1cIn the case of 210 in FIG. 1 ), there may be another substrate (e.g., 202 in FIG. 1 , e.g., 412 in FIG. 2 ) bonded thereto, for example, a glass substrate (e.g., a second glass substrate). The second glass substrate may also include or contain a wavelength filter (e.g., 204 in FIG. 1 , e.g., 414 in FIG. 2 ), such as a NIR cutoff filter. One option is to place the filter layers on both sides of the second glass substrate, for example, to compensate for stress and / or thermal mismatch and minimize wafer warpage. Another option is to apply the filter to the second glass wafer only on one side of the object, but, for example, not over the entire wafer area, but only structured and applied at areas where optical requirements are required.

[0144] Another option is that the glass substrate 2 consists of or includes an etched cavity in the third lens direction. In this case, the replicated third lens layer does not need or may not need to have integrated posts / spacers, for example, because the lenses find space in the cavities in the glass. Moreover, both sides (third lens layer and etched cavity in glass) can optionally be integrated and act as spacers.

[0145] Another way to create a spacer is to use a glass spacer with integrated through holes, which can be produced, for example, by etching, powder spraying and / or by LIDE (Laser Induced Deep Etching).

[0146] The spacers can also be manufactured by replicating the spacer structure on top of a glass substrate.

[0147] Once the entire optical stack is bonded together, the image sensor can be attached. The image sensor can have or include a cover glass that can be bonded directly to the surface of the image sensor. Since the image sensor may require per-pixel microlenses to enhance the fill factor and minimize crosstalk before the cover glass is applied to the sensor at the wafer level, a transparent material with a low refractive index (low-n material) can or will be coated so that even if these microlenses are completely covered by the material, they are still optically functional. A glass cover can be glued on top of the low-n material, which can then be glued to the optical stack.

[0148] Furthermore, according to embodiments, as an optional feature, the curable material may be, for example, any material suitable for forming a layer (e.g., a replication layer). As an example, the material may be curable by UV light (or generally by radiation) and / or, for example, by heat, for example, via a process with a defined temperature profile.

[0149] Although some aspects have been described in the context of an apparatus, it is apparent that these aspects also represent a description of a corresponding method, wherein a block or device corresponds to a method step or a feature of a method step. Similarly, aspects described in the context of a method step also represent a description of an item or feature of a corresponding block or corresponding apparatus.

[0150] The above embodiments are intended only to illustrate the principles of the present invention. It should be understood that modifications and variations of the arrangements and details described herein will be apparent to other persons skilled in the art. Therefore, it is intended that the scope of the present invention be limited only by the scope of the appended patent claims, and not by the specific details presented in the description and explanation of the embodiments herein.

Claims

1. A projection optical device (100a-c, 500), comprising: a first layer (110, 310, 522) of a first solidified material, wherein the first layer comprises a first optical lens surface (112, 312, 524) at a first side of the first layer at an optical axis (130, 360, 526) of the projection optical device, and wherein the first layer includes a planar portion (114, 528) at a second side of the first layer opposite the first side of the first layer at the optical axis; and a second layer (120, 340, 530) of a second solidified material, wherein the second layer comprises a planar portion (122, 532) at a first side of the second layer at the optical axis (130, 360, 526), ​​and wherein the second layer comprises, at the optical axis, a second optical lens surface (124, 344, 534) at a second side of the second layer opposite to the first side of the second layer; wherein the planar portion (114, 528) of the first layer abuts the planar portion (122, 532) of the second layer at the optical axis, or wherein the planar portion (114, 528) of the first layer is separated from the planar portion (122, 532) of the second layer at the optical axis only by one or more coatings (140, 330, 544).

2. The projection optical device (100a-c, 500) according to claim 1, further comprising: A first additional layer (110c) of a first additional cured material wherein the first further layer comprises a first further optical lens surface (112c) at a first side of the first further layer at an optical axis (130, 360, 526) of the projection optics, and wherein the first further layer comprises, at the optical axis, a planar portion (114c) at a second side of the first further layer opposite to the first side of the first further layer; and A second additional layer (120c) of a second additional cured material wherein the second further layer comprises a planar portion (122c) at a first side of the second further layer at the optical axis, and wherein the second further layer comprises, at the optical axis (130, 360, 526), ​​a second further optical lens surface (124c) at a second side of the second further layer opposite to the first side of the second further layer; wherein the planar portion (114c) of the first further layer abuts the planar portion (122c) of the second further layer at the optical axis; or wherein the planar portion of the first further layer is separated from the planar portion of the second further layer at the optical axis only by one or more further coatings (140c); and wherein the first further layer adjoins the second layer (120, 340, 530) at a second side of the second layer and at a first side of the first further layer.

3. The projection optical device (100a-c, 500) according to claim 1 or 2, in, The one or more coatings (140, 330, 544) include a structured coating; and / or Wherein the one or more additional coatings (140c) include a structured coating.

4. The projection optical device (100a-c, 500) according to any one of the preceding claims, in, At least one of the one or more coatings (140, 330, 544) and / or at least one of the one or more further coatings (140c) forms an aperture of the projection optics; and / or wherein at least one of the one or more coatings and / or at least one of the one or more further coatings forms a filter of the projection optics; and / or Therein, at least one of the one or more coatings and / or at least one of the one or more further coatings forms an aperture and a filter of the projection optics.

5. The projection optical device according to any one of claims 2 to 4, further comprising: A cavity (150c) is located between the second optical lens surface (124, 344, 534) and the first additional optical lens surface at the optical axis (130, 360, 526).

6. The projection optical device (100a-c, 500) according to any one of the preceding claims, further comprising: an additional layer (160, 384, 536) of additional cured material adjoining the first layer (110, 310, 522) at a first side of the first layer and at a second side of the additional layer; Wherein the additional layer comprises an additional optical lens surface (162, 386, 538) at a second side of the additional layer at the optical axis (130, 360, 526) of the projection optics.

7. The projection optical device (100a-c, 500) according to claim 6, further comprising: A cavity (150, 420, 540) is located between the first optical lens surface (112, 312, 524) and the additional optical lens surface (162, 386, 538) at the optical axis (130, 360, 526).

8. The projection optical device (100a-c, 500) according to claim 6 or 7, further comprising: An alignment structure (170) is arranged at a first side of the first layer (110, 310, 522) and at a second side of the additional layer (160, 384, 536), wherein the alignment structure is configured to align the first layer with the additional layer so that the first optical lens surface (112, 312, 524) is aligned with the additional optical lens surface (162, 386, 538) at the optical axis (130, 360, 526).

9. The projection optical device (100a-c, 500) according to any one of claims 6 to 8, in, The projection optics comprises a support structure (180, 382, ​​3821, 3822) adjoining the additional layer (160, 384, 536) at a first side of the additional layer opposite to the second side.

10. The projection optical device (100a-c, 500) according to claim 9, in, The support structure (180, 382) is a substrate; or wherein the support structure (180, 382) is a molded structure; and / or Wherein, the support structure (180, 382) is a molded structure (3821, 3822) having a planar topology.

11. The projection optical device (100a-c, 500) according to any one of the preceding claims, further comprising: a third layer (190, 370) of a third solidified material, wherein the third layer adjoins the second layer (120, 340, 530) at a second side of the second layer and at a first side of the third layer, or wherein the third layer (190, 370) adjoins the second further layer at a second side of the second further layer and at a first side of the third layer; and Wherein, the third layer comprises a third optical lens surface (192, 372) at a second side of the third layer opposite to the first side at the optical axis (130, 360, 526) of the projection optical device.

12. The projection optical device (100a-c, 500) according to any one of the preceding claims, further comprising: a dorsal structure (200, 410, 546) and a cavity (210, 540, 548); wherein the first surface of the backside structure abuts the second layer (120, 340, 530) at a second side of the second layer, and wherein the cavity (210, 540, 548) is arranged between the backside structure and the second optical lens surface (124, 344, 534) at the optical axis (130, 360, 526), ​​or wherein the first surface of the backside structure adjoins the second further layer (120c) at a second side of the second further layer, and wherein the cavity (210, 540, 548) is arranged between the backside structure and the second further optical lens surface (124c) at the optical axis, or wherein the first surface of the backside structure is adjacent to the third layer (190, 370) at the second side of the third layer, and wherein the cavity (210, 540, 548) is arranged between the backside structure and the third optical lens surface (192, 372) at the optical axis.

13. The projection optical device (100a-c, 500) according to claim 12, in, The backside structure (200, 410, 546) includes a backside substrate (202, 412) and a filter (204, 414); wherein the filter comprises a first filter structure (2041, 4141) arranged on a first surface of the back substrate, wherein the first filter structure forms a first surface of the back structure; and wherein the filter comprises a second filter structure (2042, 4142) arranged on a second surface of the back substrate opposite to the first surface, or The filter comprises a first filter structure (2041, 4141) arranged on the first surface of the back substrate at least at the optical axis, and the first filter structure and the first surface of the back substrate form the first surface of the back structure.

14. The projection optical device (100a-c, 500) according to claim 12, in, The backside structure (200, 410, 546) is a compensation structure (206, 430, 4301, 4302, 4303) configured to compensate for manufacturing tolerances and / or to set or improve the focus of the projection optics.

15. The projection optical device (100a-c, 500) according to claim 12, in, The backside structure (200, 410, 546) comprises a backside substrate (202, 412), a filter (204, 414) and a compensation structure (206, 430, 4301, 4302, 4303), wherein the compensation structure is configured to compensate for manufacturing tolerances and / or to set or improve the focus of the projection optical device, wherein the filter comprises a first filter structure (2041, 4141) arranged on a first surface of the back substrate; wherein the filter comprises a second filter structure (2042, 4142) arranged on a second surface of the back substrate opposite to the first surface, or wherein the filter comprises, at least at the optical axis, a first filter structure arranged on a first surface of the back substrate, and wherein the first filter structure and the first surface of the back substrate form a first surface of the back structure; wherein the compensation structure comprises a first surface and a second surface, wherein the second surface is opposite to the first surface; and wherein the first surface of the first filter structure and / or the backside structure is adjacent to the second surface of the compensation structure, so that the first surface of the compensation structure forms the first surface of the backside structure, or The first surface of the compensation structure is adjacent to the second filter structure or the second side of the back substrate, so that the first surface of the first filter structure and / or the back substrate forms the first surface of the back structure.

16. The projection optical device (100a-c, 500) according to any one of claims 14 to 15, in, The compensation structure is a universal compensation structure (206, 430) configured to compensate for manufacturing tolerances and / or to set or improve the focus of a plurality of projection optics on average.

17. The projection optical device (100a-c, 500) according to any one of claims 14 to 15, in, The compensation structure is a separate compensation structure (4301, 4302, 4303) configured to compensate for manufacturing tolerances and / or to set or improve the focus of the projection optics.

18. The projection optical device (100a-c, 500) according to any one of the preceding claims, in, The projection optics comprise, in the plane of the first layer (110, 310, 522), lateral dimensions of at least 100 μm or at least 200 μm or at least 300 μm or at least 0.5 mm and / or comprise lateral dimensions of at most 2 mm or at most 3 mm or at most 5 mm; and / or Therein, the projection optical device comprises a height of at least 0.5 mm or at least 1 mm or at least 2 mm and at most 2 mm or at most 3 mm or at most 5 mm orthogonal to the first layer and the second layer (120, 340, 530).

19. The projection optical device (100a-c, 500) according to any one of the preceding claims, in, At least two consecutive layers of the projection optics comprise different optical properties, and wherein the optical lens surface of the first of the two consecutive layers comprises a high refractive index and a low dispersion, and wherein the optical lens surface of the second of the two consecutive layers facing the optical lens surface of the first of the two consecutive layers comprises a low refractive index and a low dispersion so as to form an achromatic lens.

20. A method for manufacturing an optical structure (100a-c, 500), the method comprising: forming a first layer (110, 310, 522) of the optical structure, wherein forming the first layer comprises: forming and curing a first curable material on a first molding structure (320) to form the first layer so that a first optical lens surface (112, 312, 524) is formed at a first side of the first layer where the first layer abuts the first molding structure; and a second layer (120, 340, 530) of the optical structure is arranged at a second side of the first layer opposite to the first side, At the same time the first layer abuts the first molded structure at a first side of the first layer.

21. The method according to claim 20, wherein: Setting the second layer (120, 340, 530) includes: forming and curing a second curable material at a second side of the first layer (110, 310, 522) using a second molding structure (350) to form the second layer, so that a second optical lens surface (124, 344, 534) is formed at a second side of the second layer, where the second layer is adjacent to the second molding structure and the second side of the second layer faces away from the second side of the first layer; and The second optical lens surface is aligned with the first optical lens surface (112, 312, 524) at the optical axis (130, 360, 526) of the optical structure (100a-c, 500).

22. The method according to claim 21, further comprising: forming a first further layer of the optical structure (100a-c, 500), wherein forming the first further layer comprises: forming and curing a first further curable material on the first further moulding structure so as to form the first further layer such that at a first side of the first further layer a first further optical lens surface is formed, at the first side of the first further layer the first further layer adjoins the first further moulding structure; and a second further layer of the optical structure (100a-c, 500) is arranged at a second side of the first further layer opposite to the first side, at the same time the first further layer adjoins the first further moulding structure at a first side of the first further layer; Wherein, setting the second additional layer comprises: forming and curing a second further curable material at a second side of the first further layer using a second further moulding structure to form the second further layer, such that a second further optical lens surface is formed at a second side of the second further layer, where the second further layer adjoins the second further moulding structure and the second side of the second further layer faces away from the second side of the first further layer; and aligning the second further optical lens surface with the first further optical lens surface at the optical axis (130, 360, 526) of the optical structure; and removing the first further moulding structure; and removing the second molded structure (350); and joining the first further layer to the second layer (120, 340, 530), such that the first further layer adjoins the second layer at the second side of the second layer and at the first side of the first further layer, and The first further optical lens surface is aligned with the second optical lens surface (124, 344, 534) at the optical axis of the optical structure (100a-c, 500).

23. The method according to claim 21, in, A first further optical lens surface and the second optical lens surface (124, 344, 534) are formed such that the optical structure (100a-c, 500) comprises a cavity (150c) between the first further optical lens surface and the second optical lens surface at the optical axis (130, 360, 526) of the optical structure.

24. The method according to any one of claims 20 to 23, further comprising: one or more coatings (140, 330, 544) are disposed between the first layer and the second layer (120, 340, 530); and / or One or more further coating layers (140c) are arranged between the first further layer and the second further layer.

25. The method according to claim 24, further comprising: At least one of the one or more coatings (140, 330, 544) and / or at least one of the one or more further coatings (140c) is structured.

26. The method according to any one of claims 24 and 25, in, The thickness of the one or more coatings (140, 330, 544) between the first layer and the second layer, and / or the thickness of the one or more additional coatings (140c) between the first additional layer and the second additional layer, is at most 10% or at most 5% or at most 2% or at most 1% of the thickness of the first layer (110, 310, 522) or the thickness of the second layer (120, 340, 530), and / or at most 10% or at most 5% or at most 2% or at most 1% of the thickness of the first additional layer or the thickness of the second additional layer, respectively.

27. The method according to any one of claims 24 to 26, in, At least one of the one or more coatings (140, 330, 544) and / or at least one of the one or more further coatings (140c) forms an aperture of the projection optics; and / or wherein at least one of the one or more coatings and / or at least one of the one or more further coatings forms a filter of the projection optics; and / or Therein, at least one of the one or more coatings and / or at least one of the one or more further coatings forms an aperture and a filter of the projection optics.

28. The method according to any one of claims 20 to 27, further comprising: removing the first molded structure (320) from the first layer (110, 310, 522); as well as providing an optical substructure (380), wherein the optical substructure comprises a support structure (180, 382, ​​3821, 3822) and an additional layer (160, 384, 536) of the optical structure (100a-c, 500); and Wherein, setting the optical substructure comprises: forming and curing additional curable material between an additional molding structure (390) and the support structure (180, 382, ​​3821, 3822) to form the additional layer of the optical substructure, such that an additional optical lens surface (162, 386, 538) is formed at a second side of the additional layer where the additional layer abuts the additional molded structure, and causing the additional layer to abut the support structure at a first side of the additional layer opposite to a second side of the additional layer; removing the additional molded structure; and bonding the additional layer (160, 384, 536) to the first layer (110, 310, 522), such that the additional layer abuts the first layer at a first side of the first layer and at a second side of the additional layer, and The additional optical lens surface (162, 386, 538) is aligned with the first optical lens surface (112, 312, 524) at the optical axis (130, 360, 526) of the optical structure (100a-c, 500).

29. The method according to claim 28, in, The method also includes removing the support structure (180, 382, ​​3821, 3822) from the additional layer (160, 384, 536).

30. The method according to any one of claims 28 and 29, in, The support structure (180, 382) is a substrate; or wherein the support structure (180, 382) is a molded structure; and / or Wherein, the support structure (180, 382) is a molded structure (3821, 3822) having a planar topology.

31. The method according to any one of claims 28 to 30, in, The first optical lens surface (112, 312, 524) and the additional optical lens surface (162, 386, 538) are formed such that the optical structure (100a-c, 500) includes a cavity (150, 420, 540) between the first optical lens surface and the additional optical lens surface at the optical axis (130, 360, 526) of the optical structure.

32. The method according to any one of claims 20 to 31, further comprising: removing the second molding structure (350) from the second layer (120, 340, 530) and bonding the first surface of a backside structure (200, 410, 546) to the second layer at a second side of the second layer such that the second optical lens surface (124, 344, 534) forms a cavity (210, 540, 548) with the first surface of the backside structure at the optical axis; or The second further molded structure is removed from the second further layer and the first surface of the backside structure (200, 410, 546) is joined to the second further layer at a second side of the second further layer so that the second further optical lens surface (124, 344, 534) forms a cavity (210, 540, 548) with the first surface of the backside structure at the optical axis.

33. The method according to any one of claims 20 to 32, further comprising: A third layer (190, 370) of the optical structure (100a-c, 500) is disposed at a second side of the second layer (120, 340, 530), wherein the third layer is disposed comprises: removing the second molded structure from the second layer (350), and forming and curing a third curable material at a second side of the second layer between the second layer and a third molding structure (350a) to form the third layer, The third layer is disposed adjacent to the second layer at a first side of the third layer and forms a third optical lens surface (192, 372) at a second side of the third layer, the second side of the third layer faces away from the first side of the third layer, and at the second side of the third layer, the third layer is adjacent to the third molding structure, and Such that the first optical lens surface (112, 312, 524) is aligned with the third optical lens surface at the optical axis (130, 360, 526) of the optical structure; or providing a third layer (190, 370) of the optical structure (100a-c, 500) at a second side of the second further layer, wherein providing the third layer comprises: removing a second further molded structure from the second layer; and forming and curing a third curable material at a second side of the second further layer between the second further layer and a third moulding structure (350a) to form the third layer such that the third layer abuts the second further layer at a first side of the third layer and a third optical lens surface (192, 372) is formed at a second side of the third layer, the second side of the third layer faces away from the first side of the third layer and the third layer abuts the third moulding structure at the second side of the third layer, and The first optical lens surface (112, 312, 524) is aligned with the third optical lens surface at the optical axis (130, 360, 526) of the optical structure.

34. The method according to claim 33, in, The third layer (190, 370) is set, and the first layer (110, 310, 522) abuts the first molding structure (320) at a first side of the first layer.

35. The method according to claim 33 or 34, further comprising: removing the third molded structure (350a) from the third layer (190, 370); as well as A first surface of a backside structure (200, 410, 546) is bonded to the third layer at a second side of the third layer such that the third optical lens surface (192, 372) forms a cavity (210, 540, 548) with the first surface of the backside structure.

36. The method according to claim 32 or 35: in, The cavity is formed at least in part by at least one of: the recess in the second layer, the recess in the second further layer, The concave part in the third layer, The recess in the back structure, The through hole in the backside structure, and / or A through hole in the compensation structure of the backside structure.

37. The method according to claim 36, in, The recesses and / or through holes are produced by at least one of: etching, powder spraying and / or laser induced deep etching LIDE.

38. A method according to any one of claims 32 or 35 to 37, in, The backside structure (200, 410, 546) includes a backside substrate (202, 412) and a filter (204, 414), wherein the filter comprises a first filter structure (2041, 4141) arranged on a first surface of the back substrate, wherein the first filter structure forms a first surface of the back structure; and wherein the filter comprises a second filter structure (2042, 4142) arranged on a second surface of the back substrate opposite to the first surface, or The filter comprises a first filter structure (2041, 4141) arranged on the first surface of the back substrate at least at the optical axis, and the first filter structure and the first surface of the back substrate form the first surface of the back structure.

39. The method according to any one of claims 32 or 35 to 37, in, The backside structure (200, 410, 546) is a compensation structure (206, 430, 4301, 4302, 4303) configured to compensate for manufacturing tolerances and / or set or improve the focus of the optical structure (100a-c, 500).

40. The method according to any one of claims 32 or 35 to 37, in, The backside structure (200, 410, 546) comprises a backside substrate (202, 412), a filter (204, 414) and a compensation structure (206, 430, 4301, 4302, 4303), wherein the compensation structure is configured to compensate for manufacturing tolerances and / or set or improve the focus of the optical structure (100a-c, 500), wherein the filter comprises a first filter structure (2041, 4141) arranged on a first surface of the back substrate, wherein the filter comprises a second filter structure (2042, 4142) arranged on a second surface of the back substrate opposite to the first surface, or wherein the filter comprises, at least at the optical axis, a first filter structure arranged on a first surface of the back substrate, and wherein the first filter structure and the first surface of the back substrate form a first surface of the back structure; wherein the compensation structure comprises a first surface and a second surface, wherein the second surface is opposite to the first surface; and Wherein, the method further comprises: bonding the first filter structure and / or the first surface of the backside substrate to the second surface of the compensation structure so that the first surface of the compensation structure forms the first surface of the backside structure, or The first surface of the compensation structure is bonded to the second filter structure or the second side of the backside substrate such that the first surface of the first filter structure and / or the backside substrate forms the first surface of the backside structure.

41. The method according to any one of claims 20 to 40, in, The method is performed at wafer level to provide a plurality of optical structures (100a-c, 500), and / or The method is performed to obtain a plurality of optical structures (100a-c, 500) arranged in an array.

42. The method according to any one of claims 29 and 40, in, The method is performed at wafer level to provide a plurality of optical structures (100a-c, 500), and / or wherein the method is performed to obtain a plurality of optical structures (100a-c, 500) arranged in an array, and Wherein, the method further comprises: determining a plurality of sets of parameters, each set of parameters characterizing an optical structure of the plurality of optical structures; and providing a compensation structure as a universal compensation structure (206, 430), the universal compensation structure being used for each optical structure in the set of optical structures; Wherein, setting the compensation structure comprises: adjusting the compensation structure based on the determined multiple groups of parameters so as to compensate for manufacturing tolerances and / or to set or improve the focus of the optical structure group on average.

43. The method according to any one of claims 39 and 40, in, The method is performed at wafer level to provide a plurality of optical structures (100a-c, 500), and / or wherein the method is performed to obtain a plurality of optical structures (100a-c, 500) arranged in an array, and Wherein, the method further comprises: determining a plurality of sets of parameters, each set of parameters characterizing an optical structure among the plurality of optical structures; Providing a separate compensation structure (4301, 4302, 4303) for each optical structure in the optical structure group; and The respective individual compensating structures are adjusted based on the respective set of parameters in order to compensate for manufacturing tolerances and / or to set or improve the focus of the respective optical structure.

44. The method according to any one of claims 20 to 43, in, The method is performed at wafer level to provide a plurality of optical structures (100a-c, 500), and / or wherein the method is performed to obtain a plurality of optical structures (100a-c, 500) arranged in an array, and Wherein, the method further comprises: Cutting is performed to separate optical structures among the plurality of optical structures.

45. The method according to any one of claims 20 to 44, wherein: The method further comprises: A sensor structure (220, 440) is bonded to the optical structure (100a-c, 500).

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