WO2015080575A1

WO2015080575A1 - A method for manufacturing an optical assembly

Info

Publication number: WO2015080575A1
Application number: PCT/NL2014/050803
Authority: WO
Inventors: Koen Gerard Demeyer; Edwin Maria Wolterink; Willem Matthijs BROUWER; Robertus Johannes Heeman
Original assignee: Anteryon Wafer Optics B.V.
Priority date: 2013-11-26
Filing date: 2014-11-26
Publication date: 2015-06-04
Also published as: NL2011843C2

Abstract

The present invention relates to a method for manufacturing an optical assembly, comprising the steps of: i) providing an intermediate substrate, wherein said intermediate substrate is not transparent to light, ii) providing a first optical element on one side of said intermediate substrate, iii) providing a second optical element on the other side of said intermediate substrate, iv) cutting the composite intermediate substrate obtained after step iii) along at least one cutting line, wherein the at least one cutting line passes through said first optical element, second optical element and said intermediate substrate for obtaining said optical assembly.

Description

Title: A method for manufacturing an optical assembly.

The present invention relates to a method for manufacturing an optical assembly, an optical assembly and to an optical separator, comprising such an optical assembly.

Optical units per se are known in the prior art.

International application WO 2009/158105 relates to an imaging module made up of a number of transparent substrates, which substrates are on either side provided with so-called aperture layers, a number of lens elements, wherein said lens is disposed on either side of the aforesaid substrate, such that said aperture layer is embedded between said lens and said substrate, and an image sensor of the pixel array type. European application No. 2 202 796 in the name of the present applicant relates to an optical unit, comprising, seen in a direction from the object side to the imaging surface, a first substrate, a first lens element, a flat, transparent intermediate layer, a second lens element and a second substrate, which intermediate layer has an optical correction function near the imaging surface. International application WO 2010/074743 relates to a method for forming an imaging module, wherein a lens stack wafer, a spacer wafer and an image sensor wafer are formed into a module. US 2010/01 18420 relates to an image capture lens comprising a first glass substrate, a first lens material on one side of said substrate and a second lens material on the other side of the substrate. From International application WO 2004/027880 in the name of the present applicant there is known a camera system comprising an image capturing element, a lens element for imaging an object at the image capturing element, a spacer for maintaining a predetermined distance between the lens element and the image capturing element, whilst furthermore a lens substrate is provided for carrying the lens.

US 7,289,693 relates to a method of fabricating a plurality of composite optical assemblies, wherein each optical assembly includes a first optical element and a second optical element. The method according to US 7,289,693 includes the steps of providing a first composite substrate divided into a plurality of first optical elements and forming on an exposed surface of the first composite substrate a second composite substrate divided into a plurality of second optical elements, the first and second composite substrates providing a composite structure. The optical circuit according to US 7,289,693 includes a plurality of discrete optical elements that are in optical contact with one another, wherein the optical circuit is formed by dividing a composite optical structure into a plurality of optical circuits.

DE 10 2007 031230 relates to a document acquisition system for verifying documents, for example for examining authenticity, and to a document acquisition method for optically acquiring a document, in particular a personal document, including at least one luminous device for illuminating the document, at least one optical sensor and an optical imaging unit for imaging the document onto the at least one optical sensor. In order to provide for the acquisition of the document, optical sensors such as CMOS sensors or CCD camera sensors are disposed on a printed circuit board in a matrix-type grid. In order to image the document onto the optical sensors an optical imaging unit 8 is provided which includes imaging microlens, wherein each of the imaging microlens arrays is associated with a respective one the optical sensors and the individual microlenses of the microlens are formed on a substrate which serves as a spacer element and is disposed between the microlenses of the microlens array and the corresponding optical sensors. The substrate is patterned such that for each microlens of a microlens array a dedicated channel is formed which is optically separated from neighboring channels by way of non-transparent wall layers in order to avoid optical cross-talk of the individual channels.

JP 20100 91718 relates to a method for manufacturing an microlens having a light shielding wall in a substrate, wherein a carbon nanotube is dielectrically migrated in an ultraviolet curing resin to form a light shielding wall 10 and a substrate is formed by curing the ultraviolet curing resin in a state that the light shielding wall is formed.

Optical units are known per se, they are used, inter alia, in camera systems, in relation to which systems an on-going effort exists to find smaller, lighter, thinner, better and cheaper camera systems. The camera modules used in mobile telephones require increasingly more resolution and optical functionalities within ever decreasing dimensions. One requirement of these optical units is that the phenomenon of cross talk should be minimized.

Many configurations with multiple parallel optical functions require a small footprint. This small footprint may lead to a risk for interference (cross talk) of optical functions. In addition, it is also requested that the thickness of intermediate (separating) elements being as thin as possible. ( <1 mm, preferably; < 0.3 mm). Because of additional Z-height limitations there is thus a need for using any surface for any optical/ electronic function.

Cross talk can be avoided in several ways. One option is to assemble intermediate spacers or spacer substrates upon/between optical wafers. The consequence is that only vertical surfaces are used as spacers. Existing wafer level optical assembles stack parallel substrates with spacers. I ntermediate elements are provided through spacers or spacer substrates, as disclosed in International application WO2004027880A2 and US application US201 10122308). A consequence is an additional layer, higher Z- heights and not effective for light blocking.

Another option is to provide apertures, diaphragms on the optical substrates aligned with the optical axis. In that situation its function is limited to light blocking only.

An option as well is filling the cavities between optical elements with light blocking materials, for example through filling a dicing lane with a moulding resin. A consequence of this option is limitation on optical designs, as disclosed in Japanese JP2005-072662. The activity of overmoulding requires additional process steps, which steps are carried out at high temperatures and mechanical impact. Filling aperture substrates with optical material is known from International application WO2013010285. A consequence is the limited possibilities in lens designs.

The object of the present invention is to provide a method for manufacturing an optical assembly having at least two distinct zones and a non allowed cross talk zone.

Another object of the present invention is to provide an optical assembly having optical and opto-electronical functions implemented on minimum surface.

Another object of the present invention is to provide a method for manufacturing an optical assembly in which an intermediate substrate is functionalized.

The present invention as mentioned above relates to a method for manufacturing an optical assembly, comprising the steps of:

i) providing an intermediate substrate, wherein said intermediate substrate is not transparent to light, ii) providing a first optical element on one side of said intermediate substrate,

iii) providing a second optical element on the other side of said intermediate substrate,

iv) cutting the composite intermediate substrate obtained after step iii) along at least one cutting line, wherein the at least one cutting line passes through said first optical element, second optical element and said intermediate substrate for obtaining said optical assembly.

The present inventors found that one or more of the above objects can be achieved by such a method. The present inventors found that the intermediate substrate for creating the first and second optical element can be also used as a functional intermediate element in the final product. By using the present method many functions can be integrated in the intermediate substrate. By using the present method no specific limitations on the design of first and second optical elements exist, except diceability for the subsequent singulation step. In addition optical elements according to any design can be applied through assembly, adhesion, replication, embossing or any combination thereof.

The term "not transparent to light" as used herein is always to be seen in relation to the spectral region where the optical function requires a barrier. Thus, for example silicon can be regarded as opaque in visual, i.e. the wavelength range of visible light, but transparent in the infrared wavelength range. An optical assembly according to the present invention with an intermediate substrate made of for example silicon separates the visible light, but allows optical communication in the far infrared. Analogous in an optical assembly according to the present invention the intermediate substrate can be made of for example glass and positioned on a quartz substrate resulting in a UV light blocking between the optical elements, whereas visible light passes through.

In a preferred embodiment the cutting area or cutting interface obtained after cutting the composite intermediate substrate undergoes an additional treatment for reducing its surface roughness. An example of such a treatment is polishing or etching. Another example is the application of a transparent lacquer on the cutting surface thereby creating an even surface.

Since the vertical surface now becomes functional, the effect thereof is that the footprint and/or height can be significantly reduced. In addition, the present method enables manufacturing optical modules with optical axis non orthogonal to the module bottom. According to the present invention this is realised through providing an optical assembly comprising a first optical element on the top surface of an intermediate substrate and a second optical element at its bottom surface, singulating the optical axis into to two parts, each having a first optical element, a second optical element and an intermediate substrate, wherein the three parts share a coplanar surface created by the singulation process. The thus obtained optical module can be fixed on a mounting substrate, for example a glass wafer, a polymer foil, an adhesive layer etc. The surface on the intermediate element can be used for several functions other than light blocking, or those functions can be integrated in the intermediate element. Examples of these functions are: reflection (mirror), structured (diaphragm, apertures, spatial modulator), light absorption, polarization, birefringence, light guide, photoelectric, emitting, conductive, data processing.

In a preferred embodiment of the present method the optical assembly obtained after step iv) is mounted on a mounting substrate such that the cutting area created by the cutting line is positioned against the mounting substrate, wherein said mounting substrate is transparent to light.

In a special embodiment the cutting line is perpendicular to the intermediate substrate.

According to another embodiment the cutting line includes an angle with said intermediate substrate, said angle is in the range of 20 - 80 degr.

It is preferred to position the cutting line such that said first optical element is cut into two distinct parts, for example two somewhat equal halves, especially that the cutting line is positioned such that the second optical element is also cut into two distinct parts. The specific position of the first and second optical element on the intermediate substrate and the position of the cutting line determines the dimensions of the optical assembly obtained after carrying out the afore mentioned step iv).

In a preferred embodiment the first and second optical element are aligned on each side of said intermediate substrate.

As mentioned before, the present intermediate substrate is not transparent to light; especially the intermediate substrate is made from a material chosen from the group of synthetic materials, such as polymers, metals and silicon, or combinations thereof. Examples of these materials are thermoplastic materials, such as polycarbonates, PVC, thermosetting materials, UV curable materials, silicones, epoxy resins, acrylic resins, materials used for manufacturing printed circuit boards (PCB), such as FR4, polyimides.

A preferred method for manufacturing the first and second optical element is the replication process. A suitable replication process has been disclosed in US Pat. No. 6,773,638, EP1 572 430 and US Pat. No. 7, 169,828. According to another embodiment first and second optical elements are applied through a different process, such as assembly, adhesion, replication, embossing or any combination thereof. Especially when the shape of any one of the first and second optical elements is difficult to obtain through a replication process, for example a prism shape, one or more of the afore mentioned processes is used.

The present inventors also found that the present method for manufacturing an optical assembly can also be carried out by using wafer based assembly and singulation techniques, wherein steps ii) and iii) comprise the provision of an array of optical elements on the same intermediate substrate, such as a wafer, wherein the method further comprises a step of singulation of each adjacent optical assembly.

The functionality of the intermediate substrate can be increased when the intermediate substrate is provided with one or more optical devices, such as light sources, photo detectors and image detectors.

It is preferred that one or more light sources are positioned on the intermediate substrate such that the one or more light sources are embedded by any one of the first optical element and the second optical element.

According to a preferred embodiment of the present method for manufacturing an optical assembly the mounting substrate is provided with one ore more image detectors before mounting the optical assembly obtained after step iv) on said mounting substrate, especially wherein after mounting said optical assembly obtained after step iv) on said mounting substrate said one or more active optical elements, such as image detectors, are embedded by said optical assembly.

The present invention further relates to an optical assembly comprising a mounting substrate transparent for light and a light shielding wall, wherein said light shielding wall is positioned between a first optical element and a second optical element, said first optical element and said second optical element both abut said light shielding wall. This light shielding wall can be seen as the intermediate substrate as discussed above.

According to a preferred embodiment of the present optical assembly the light shielding wall is positioned perpendicular to said mounting substrate.

In another embodiment of the present optical assembly the light shielding wall includes an angle with said mounting substrate, said angle is in the range of 20 - 80 degr.

The present invention further relates to an optical separator, comprising an optical assembly as discussed before, wherein the optical assembly comprises one or more spacers for positioning said optical assembly on a support, wherein the area thus created between the support and the optical assembly is subdivided into two separate areas, wherein the first and second area thus created are separated by a baffle having a light shielding function, said baffle being positioned between said mounting substrate and said support.

The first area may comprise a photo detector. The second area may comprise a mirror and/or a light source.

In the optical separator according to the present invention one or more elements chosen from the group of light sensors and data processing chips are positioned on the intermediate substrate, especially on one end of said intermediate substrate facing away from the support.

In a preferred embodiment of the optical separator the optical assembly is provided with one more elements chosen from the group of IR filters, colour filters, apertures and lenses. The present optical separator further comprises a construction wherein the baffle is positioned in alignment with said light shielding wall of said optical assembly. This embodiment is especially preferred when the light shielding wall is positioned perpendicular to the mounting substrate.

The present invention furthermore relates to an array of optical assemblies or optical separators to be used in, for example, shape or dimension recognition in a 3D line scanner, wherein each element scans from a different angle, or with another task. The electronics for controlling the functions between the various elements is preferably positioned on a support or mounting substrate.

It is however also possible to couple coherent light sources having certain phase differences. The light sources need to be positioned at a certain distance. The common feature of these embodiments is that the electronics present on the intermediate substrate, or light shielding wall, is shared by all elements. The electronics will have a controlling/regulating function between the elements positioned on the same plate.

The present invention will now be explained by way of examples which are used for illustrative purposes.

Fig. 1 shows a schematic view of an optical element according to the present invention.

Fig. 2 shows another embodiment of an optical element according to the present invention.

Fig. 3 shows an embodiment of an optical element according to the present invention.

Fig. 4 shows a top view of an optical element shown in Fig. 3.

Fig. 5 shows a side view of an optical element shown in Figs. 3-4.

Fig. 6 shows a wafer construction to be used in the present method for manufacturing an optical assembly.

Fig. 7 shows another embodiment of a frame construction to be used in the present method for manufacturing an optical assembly.

Fig. 8 shows different embodiments for the first and second optical element according to the present invention.

Fig. 9 shows an embodiment of an optical separator.

Fig. 10 shows another embodiment of an optical separator.

Fig. 1 1 shows another embodiment of an optical separator.

Fig. 12 shows another embodiment of an optical separator. Fig. 13 shows another embodiment of an optical separator.

Fig. 1 shows an optical element 10 according to the present invention. The present method for manufacturing an optical assembly starts with the provision of an intermediate substrate 3. Intermediate substrate 3 is made from a material chosen from the group of synthetic materials, metals and silicon, and combinations thereof. An example of synthetic materials is polymer, as mentioned before. The intermediate substrate 3 is provided with a first optical element 1 on one side of the intermediate substrate 3. Intermediate substrate 3 is also provided with a second optical element 2 on the other side of the intermediate substrate 3. Both optical elements 1 , 2 can be (a)spheric, (a)cylindric, prism, polygonal or any free form. Although intermediate substrate 3 is shown as a flat substrate, in specific embodiments the surface of intermediate substrate 3 can also be inclined or a wavy shape. First optical element 1 and second optical element 2 can be identical or different from each other. The application of the optical elements 1 , 2 on the intermediate substrate 3 takes place preferably through a replication process. In other embodiment optical elements 1 , 2 are applied through an adhesive, especially when the shape of optical elements 1 , 2 is difficult to obtain through a replication process, for example a prism shape. The intermediate substrate 3 can be provided with one or more functional layers, for example aspheric correction, diffractive, fresnel, coating and diaphragms. The application of the aforementioned deposited layers can be carried out by a replication process, but also through spin-coating, dip- coating, printing or vapor deposition.

Fig. 2 shows the step of singulation of at least adjacent optical units 10. Although Fig. 2 shows that individual optical elements are manufactured, it is also possible to manufacture dual optical components. As shown in Fig. 2, dicing line 6 creates a cutting line through the first optical element 1 , intermediate substrate 3 and second optical element 2. For the step of singulation individual optical units are created by cutting the intermediate substrate only through the intermediate substrate for obtaining the optical assembly. The optical assembly thus obtained comprises a first optical element 1 , intermediate substrate 3 and second optical element 2 and a cutting area 5, wherein said cutting area is the complete surface obtained after the cutting step. Fig. 2 shows that cutting line or dicing line 6 separates the optical assembly in two equal halves, but in a specific embodiment it is also possible to position the cutting line 6 such that at least two optical assemblies are obtained which are not identical in size.

Fig. 3 shows an embodiment in which the optical assembly, as shown in Fig. 2, is mounted on a mounting substrate 8 such that the cutting area 5 created by cutting line 6 is positioned against mounting substrate 8. Although not shown, the interface between the optical element 1 and the mounting substrate 8 can be provided with one or more layers embedded by the optical element 1 and the mounting substrate 8. From Fig. 3 it is clear that the intermediate substrate 3 is perpendicular to the mounting substrate 8. However, in specific embodiments it is also possible to apply a cutting line 6 such that the cutting line includes an angle with the intermediate substrate, wherein the angle is in the range of 20-80 degr. In such an embodiment the intermediate substrate 3 is not perpendicular to the mounting substrate 8 but shows an inclined construction. Although Fig. 3 shows that the contours of both the first and second optical element are in somewhat the same height as the intermediate substrate 3, it is also possible that the intermediate substrate 3 extends along the axis perpendicular to the mounting substrate 8. Such an extension of the intermediate substrate 3 can be used for the positioning of one or more elements chosen from the group of light sensors and data processing chips (not shown).

Fig. 4 shows a top view of the optical assembly according to Fig. 2. The optical assembly shown in Fig. 4 shows that the intermediate substrate 3 has a dimension which is longer than the contours of both the first optical element 1 and the second optical element 2. In addition, Fig. 4 shows that the optical shape of optical element 1 differs from the optical shape of optical element 2.

Fig. 5 shows a side view of the optical assembly according to Fig. 2, wherein the dimensions of intermediate substrate 3 are larger than the dimensions of the first optical element 1 .

Fig. 6 shows a step of the present method for manufacturing an optical assembly wherein wafer technology has been applied. Fig. 6 shows a top view of a wafer 20 on which on specific locations optical elements 21 are positioned, for example through a replication process. Dicing lines 23, 22 are examples of singulating single/pairs arrays.

Fig. 7 shows a structured substrate frame 30 to be used in a specific embodiment of the present method for manufacturing an optical assembly, wherein first optical elements 31 are positioned on intersections of frame 30. Dicing lines 32, 33, 34 show different embodiments for singulating single/pairs arrays.

Fig. 8 shows different shapes for first optical element 81 and second optical element 82.

Fig. 8A shows an embodiment in which the intermediate substrate 3 is provided with a convex shaped first optical element 81 , wherein the second optical element 82 has a triangular shape. Cutting line 83 provides an optical assembly in such a way that two identical halves are obtained. Fig. 8A' shows the situation before mounting on a mounting substrate (not shown). In the mounting step the intermediate substrate 3 will be placed on the mounting substrate (not shown) in a perpendicular way. Fig. 8B shows another embodiment of the optical assembly according to the present invention, wherein the first optical element 81 has a convex shape on the intermediate substrate 3, wherein the second optical element 82 has a triangular shape. The difference between Fig. 8A en 8B is that the second optical element 82 is somewhat shifted which means that the optical element 81 and the optical element 82 are not exactly aligned on each side of the intermediate substrate 3. The cutting line 85 creates a cutting area or cutting surface/interface as shown in Fig. 8B'. Dicing line 84 is used for singulation purposes. The element shown in Fig. 8B' can be placed on a mounting substrate (not shown), wherein the intermediate substrate 3 is positioned perpendicular to such a mounting substrate (not shown).

Fig. 8C shows an embodiment in which the second optical element 82 is divided in two parts. Cutting line 87 provides an optical assembly as shown in Fig. 8C\ wherein it is clear that the intermediate substrate 3 will not be positioned perpendicular to a mounting substrate (not shown). Dicing line 88 is used for singulation purposes. Such a Fig. 8C shows that the cutting line 87 includes an angle with the intermediate substrate 3 resulting in an inclined optical axis.

On basis of the above-discussed embodiment it is clear that the present method for manufacturing an optical assembly enables the integration of many optical functions in the intermediate substrate. As a result of the present method the vertical surface, i.e. the intermediate substrate, becomes now functional. The benefit of the "turn over" of the intermediate substrate is that the final height of the optical assembly can be significantly reduced. In addition, the present method for manufacturing optical assemblies enables positioning optical modules with an optical axis not-orthogonal to the mounting substrate. Furthermore, the present method for manufacturing an optical assembly can be carried out by wafer based assembly and singulation techniques.

Fig. 9 shows an optical separator 1 10 wherein an optical assembly comprising a first optical element 1 12, intermediate substrate 1 1 1 and second optical element 1 13 are positioned on a mounting substrate 1 14. Mounting substrate 1 14 is positioned on a support 121 , for example a semiconductor, printed circuit board substrate, through a spacer 1 16. The area thus created between the support 121 and the optical assembly is subdivided in two separate areas, wherein the first and second area thus created are separated by a baffle 100 having a light shielding function, said baffle being positioned between the mounting substrate 1 14 and the support 121 . I n the first area (left side) a photodetector 1 17 is positioned on support 121 . In the second area (right side) a mirror 1 19 is positioned and the incoming light from the second optical element 1 13 reflected by mirror 1 19. The curvature of first optical element 1 12 and the curvature of second optical element 1 13 are such that the intermediate substrate 1 1 1 extends somewhat from the mounting substrate 1 14 to an area which is "free" of both optical elements 1 12, 1 13. This "free" end of intermediate substrate 1 1 1 can be used for positioning one or more elements chosen from the group of light sensors and data processing chips (not shown).

Fig. 10 shows an optical separator 210 comprising a support 221 , for example a semiconductor or printed circuit board substrate, spacer 216, mounting substrate 214, first optical element 212, intermediate substrate 21 1 and second optical element 213. The area between the support 221 and the mounting substrate 214 is divided in two separate areas, wherein the first (left side) is provided with a photodetector 217. The second area (right side) is provided with a light source. Between the first and second area thus created a baffle 200 having a light shielding function is present.

Fig. 1 1 shows an optical separator 310, comprising a support 321 , for example a semiconductor substrate or a printed circuit board substrate, spacer 316, mounting substrate 314 provided with a first optical 312, intermediate substrate 31 1 and second optical element 313. Spacer 316 creates a certain distance between the support 321 and the mounting substrate 314 resulting in an area between the mounting substrate 314 and the support 321 . The area thus created is subdivided in two separate areas, wherein the first area (left side) contains a light source 318, whereas the second area (right side) contains a light/image detector 317. The first and second areas are separated by a baffle 300 having a light shielding function.

Fig. 12 shows an optical assembly 410, comprising a mounting substrate 414, for example a semiconductor substrate or a printed circuit board, provided with a light/image detector positioned between the first optical element 412 and the mounting substrate 414. The light/image detector is positioned such that the detector 418 is completely surrounded by the first optical element 412 and the mounting substrate 414. The light source 417 is present on the intermediate substrate 41 1 and embedded by the second optical element 413. On the interface between the second optical element 413 and the mounting substrate 414 a mirror 419 is present. Fig. 13 shows another embodiment of an optical assembly 510 for proximity sensing. The optical assembly 510 is somewhat similar to the optical assembly 31 1 shown in Fig. 1 1 , but the intermediate substrate 51 1 has been provided with several functions, i.e. a ambient light sensor 522, a reference sensor 524 for light source and a data processing chip 523. The optical assembly 510 further comprises a support 521 , for example a semiconductor or a printed circuit board substrate, a I R photodetector 517, a light source 518, spacer 516 and a baffle 500 having a light shooting function positioned between the mounting substrate 514 and the support 521 such that a first area (left side) and a second area (right side) are created.

Claims

1 . A method for manufacturing an optical assembly, comprising the steps of:

i) providing an intermediate substrate, wherein said intermediate substrate is not transparent to light,

ii) providing a first optical element on one side of said intermediate substrate,

2. A method for manufacturing an optical assembly according to claim 1 , wherein said cutting area, obtained after step iv), undergoes an additional treatment for reducing its surface roughness, especially, a step of polishing, etching or the application of a transparent lacquer on the cutting surface, or a combination thereof.

3. A method for manufacturing an optical assembly according to claim 1 , wherein said optical assembly obtained after step iv) is mounted on a mounting substrate such that the cutting area created by the cutting line is positioned against the mounting substrate, wherein said mounting substrate is transparent to light.

4. A method for manufacturing an optical assembly according to any one or more of the preceding claims, wherein said cutting line is perpendicular to said intermediate substrate.

5. A method for manufacturing an optical assembly according to claims 1 -3, wherein said cutting line includes an angle with said intermediate substrate, said angle is in the range of 20 - 80 degr.

6. A method for manufacturing an optical assembly according to any one or more of the preceding claims, wherein said cutting line is positioned such that said first optical element is cut into two distinct parts, for example two equal halves.

7. A method for manufacturing an optical assembly according to any one or more of the preceding claims, wherein said cutting line is positioned such that said second optical element is cut into two distinct parts, for example two equal halves.

8. A method for manufacturing an optical assembly according to any one or more of the preceding claims, wherein said first and second optical element are aligned on each side of said intermediate substrate.

9. A method for manufacturing an optical assembly according to any one or more of the preceding claims, wherein said intermediate substrate is made from a material chosen from the group of synthetic materials, metals and silicon, or combinations thereof.

10. A method for manufacturing an optical assembly according to any one or more of the preceding claims, wherein at least one of said first and second optical element is obtained via a replication process.

1 1 . A method for manufacturing an optical assembly according to any one or more of the preceding claims, wherein steps ii) and iii) comprise the provision of an array of optical elements on the same intermediate substrate.

12. A method according to claim 1 1 , wherein said method further comprises a step of singulation of each adjacent optical assembly.

13. A method for manufacturing an optical assembly according to any one or more of the preceding claims, wherein in step i) said intermediate substrate is provided with one or more optical devices, such as light sources, photo detectors and image detectors.

14. A method according to claim 13, wherein said one or more light sources are positioned on said intermediate substrate such that said one or more light sources are embedded by any one of the first optical element and the second optical element.

15. A method for manufacturing an optical assembly according to any one or more of the preceding claims, wherein said mounting substrate is provided with one ore more image detectors before mounting said optical assembly obtained after step iv) on said mounting substrate.

16. A method according to claim 15, wherein after mounting said optical assembly obtained after step iv) on said mounting substrate said one or more active optical elements, such as image detectors, are embedded by said optical assembly.

17. Optical assembly comprising a mounting substrate transparent for light and a light shielding wall, wherein said light shielding wall is positioned between a first optical element and a second optical element, said first optical element and said second optical element both abut said light shielding wall.

18. Optical assembly according to claim 17, wherein said light shielding wall is positioned perpendicular to said mounting substrate.

19. Optical assembly according to claim 17, wherein said light shielding wall includes an angle with said mounting substrate, said angle is in the range of 20 - 80 degr.

20. Optical separator, comprising an optical assembly according to any or more of the claims 17-19, wherein said optical assembly comprises one or more spacers for positioning said optical assembly on a support, wherein the area thus created between the support and the optical assembly is subdivided into two separate areas, wherein the first and second area thus created are separated by a baffle having a light shielding function, said baffle being positioned between said mounting substrate and said support.

21 . Optical separator according to claim 20, wherein said first area comprises a photo detector.

22. Optical separator according to claims 20-21 , wherein said second area comprises a mirror.

23. Optical separator according to claims 20-22, wherein said second area comprises a light source.

24. Optical separator according to claims 20-23, wherein one or more elements chosen from the group of light sensors and data processing chips are positioned on said light shielding wall, especially on one end of light shielding wall facing away from said support.

25. Optical separator according to any one or more of the claims 20-24, wherein the optical assembly is provided with one more elements chosen from the group of I R filters, colour filters, apertures and lenses.

26. Optical separator according to any one or more of the claims 20-25, wherein said baffle is positioned in alignment with said light shielding wall of said optical assembly.