TWI910643B - Method of forming adhesive thinning of miniature filter array - Google Patents

Abstract

A method of forming adhesive thinning of miniature filter array, which includes the following steps: making filter to form at least two different types of filters, cutting the filters to form different kinds of micro filters that include stacked substrates and coatings, bonding which arranges and bonds the micro filters, the substrate layers of the micro filters are located side by side to form the micro filter array, the micro filters are bonded by an impermeable adhesive, thinning which grinds the substrate layer of the micro filter to thin the micro filter array, transparent substrate attaching, the transparent substrate is attached to the thin micro filter array and is located in the substrate layer of the micro filter.

Description

Forming method for thinning and bonding micro-filter arrays

This invention relates to a micro-array of optical elements, and more particularly to a method for bonding and thinning a micro-filter array.

A micro-filter array is an array formed by uniformly distributing and arranging a plurality of tiny lenses. It is mainly used in optical microscopes, light field measurement cameras, 3D image displays, LiDAR systems, etc. The conventional method for fabricating micro-optical element arrays is to directly deposit multiple layers of transmission film on a substrate, and then control specific positions in the array by etching or acid washing to make the number and thickness of film layers at different positions different, so as to form a plurality of micro-lenses, each of which can transmit light beams of different wavelengths.

However, conventional methods for fabricating micro-optical element arrays involve complex etching or acid etching processes, which require extremely high positional accuracy. These processes are difficult to implement and affect product yield. Therefore, a method for fabricating micro-filter arrays with high positional accuracy and stability is needed.

This invention provides a method for bonding and thinning a micro-filter array, the main purpose of which is to make the position of each micro-lens in the micro-array precise.

Another objective of this invention is to provide a highly stable manufacturing method.

To achieve the aforementioned objective, the present invention provides a method for thinning and bonding a micro-filter array, comprising:

A filter manufacturing process involves manufacturing at least two different types of filters, each filter comprising a substrate layer and a coating layer stacked on top of each other;

A cutting step cuts the filters to form different types of micro filters, the micro filters comprising the substrate layer and the coating layer stacked on top of each other;

An adhesive assembly step involves arranging and bonding the microfilters, the substrate layers of the microfilters being arranged side by side to form a microfilter array, the microfilters being bonded together by an opaque adhesive;

A thinning step involves grinding the substrate layer of the microfilters to thin the microfilter array; and

A transparent substrate bonding step involves attaching a transparent substrate to the thinned micro-filter array, wherein the transparent substrate is located on the substrate layer of the micro-filters.

As can be seen from the foregoing, the present invention mainly obtains different types of micro-filters by cutting different types of filters, splicing and bonding these different types of micro-filters to form a micro-filter array, and attaching a transparent substrate to one side of the micro-filter array to achieve the purpose of making the position of each micro lens in the micro array accurate and the manufacturing stability high.

This invention provides a method for thinning and bonding a micro-filter array, as shown in Figures 1-9, including:

In filter fabrication step S1, please refer to Figure 5 to fabricate at least two different types of filters 10. These different types of filters 10 include, but are not limited to, bandpass filters (BPF), dual-bandpass filters (DBPF), and narrowband filters (NBPF). Each of these different types of filters 10 can pass through spectral bands covering invisible light, visible light, near-infrared light, and far-infrared light. The different types of filters 10 each include a substrate layer 11 and a coating layer 12 stacked on each other. The side length of the filters 10 is, for example, but not limited to, 10mm to 20mm. The side length can be the long side or the wide side. In this embodiment, there are three different types of filters 10, which are defined as a first filter 10A, a second filter 10B and a third filter 10C.

In step S2, referring to Figure 5, the different types of filters 10 are cut to form different types of micro filters 20. Each micro filter 20 includes a substrate layer 21 and a coating layer 22 stacked on top of each other. The size of the micro filters 20 is smaller than the size of the filters 10. The side length of the micro filters 20 is, for example, but not limited to, 500µm to 1mm. The side length can be the long side or the wide side. In this embodiment, the first filter 10A is cut to form a plurality of first micro filters 20A, the second filter 10B is cut to form a plurality of second micro filters 20B, and the third filter 10C is cut to form a plurality of third micro filters 20C.

In the bonding assembly step S3, referring to Figure 6, the micro-filters 20 are arranged and bonded according to actual needs. The substrate layers 21 of the micro-filters 20 are arranged side by side, and the coating layers 22 of the micro-filters 20 are arranged side by side, thereby forming a micro-filter array 30. The micro-filter array 30 can be rectangular, triangular, hexagonal, or octagonal. Shaped like a circle, etc., when the microfilter array 30 is rectangular, the microfilter array 30 is, for example, but not limited to, an array with both length and width of 0.55mm. These microfilters 20 are bonded together by an opaque adhesive 40 to prevent light from interfering with each other when passing through them. For example, the opaque adhesive 40 can be 3M™... Scotchcal™ Opaque Adhesive Film 50 Series products, but not limited thereto, in this embodiment, the first microfilters 20A, the second microfilters 20B, and the third microfilters 20C can be arranged at intervals according to actual needs, and the first microfilters 20A, the second microfilters 20B, and the third microfilters 20C are coated with the opaque adhesive 40.

In a thinning step S4, referring to Figure 8, the substrate layer 21 of the micro-filters 20 is polished to thin the micro-filter array 30. Specifically, the substrate layer 21 has a top side 211 and a bottom side 212 that are opposite to each other. The top side 211 is the side of the substrate layer 21 that is in contact with the coating layer 22. In this step, the bottom side 212 of the substrate layer 21 is polished by a polishing machine M.

In step S5, referring to Figure 9, a transparent substrate 50 is attached to the thinned micro-filter array 30. The transparent substrate 50 is located on the bottom side 212 of the substrate layer 21 of the micro-filters 20. The transparent substrate 50 can be a quartz transparent substrate to increase the overall structural strength. In other embodiments, an AR anti-reflective film can also be used to replace the transparent substrate 50.

In a preferred embodiment, referring to Figure 3, a flipping step S6 is provided between the bonding assembly step S3 and the thinning step S4, in which the micro-filter array 30 is flipped up and down so that the coating layer 22 of the micro-filters 20 abuts against a platform, and the bottom side 212 of the substrate layer 21 of the micro-filters 20 faces upward, so that the polishing machine M can polish the substrate layer 21 from top to bottom during the thinning step S4;

In a preferred embodiment, referring to Figure 4, a transmission film application step S7 is provided between the bonding assembly step S3 and the flipping step S6. Referring to Figure 7, a transmission film 60 is attached to the micro-filter array 30. The transmission film 60 is located on the coating layer 22. Before the transparent substrate application step S5, the user removes the transmission film 60. Thus, when performing the flipping step S6, the transmission film 60 will rest against the plane, thereby preventing the coating layer 22 of the micro-filters 20 from directly resting against the plane, thus achieving the effect of protecting the coating layer 22.

In a preferred embodiment, referring to FIG9, in the transparent substrate bonding step S5, another transparent substrate 50 is attached to the coating layer 22 of the thinned micro filter array 30, so that both opposite sides of the thinned micro filter array 30 have transparent substrates 50 to protect the micro filter array 30.

As can be seen from the foregoing, the present invention mainly obtains different types of micro-filters 20 by cutting different types of filters 10, splicing and bonding these different types of micro-filters 20 to form the micro-filter array 30, and attaching a transparent substrate 50 to one side of the micro-filter array 30, so as to achieve the purpose of making the position of each micro lens in the micro array accurate and the manufacturing stability high.

Step S1: Filter Fabrication Step S2: Cutting Step S3: Bonding and Assembly Step S4: Thinning Step S5: Transparent Substrate Lamination Step S6: Flipping Step S7: Transport Membrane Lamination 10: Filter 10A: First Filter 10B: Second Filter 10C: Third Filter 11, 21: Substrate Layer 12, 22: Coating Layer 20: Microfilter 20A: First Microfilter 20B: Second Microfilter 20C: Third Microfilter 211: Top Side 212: Bottom Side 30: Miniature filter array 40: Opaque adhesive 50: Transparent substrate 60: Transport membrane M: Polishing machine

Figure 1 is a schematic diagram of a micro-filter array. Figure 2 is a flowchart illustrating the molding method for bonding and thinning the micro-filter array of the present invention. Figure 3 is a flowchart illustrating a preferred embodiment of the molding method for bonding and thinning the micro-filter array of the present invention. Figure 4 is a flowchart illustrating a preferred embodiment of the molding method for bonding and thinning the micro-filter array of the present invention. Figure 5 is a schematic diagram illustrating the fabrication process of the molding method for bonding and thinning the micro-filter array of the present invention. Figure 6 is a schematic diagram illustrating the fabrication process of the molding method for bonding and thinning the micro-filter array of the present invention. Figure 7 is a schematic diagram illustrating the fabrication process of the molding method for bonding and thinning the micro-filter array of the present invention. Figure 8 is a schematic diagram illustrating the fabrication process of the micro-filter array bonding and thinning method of the present invention. Figure 9 is a schematic diagram illustrating the fabrication process of the micro-filter array bonding and thinning method of the present invention.

S1: Filter Making Steps

S2: Cutting Steps

S3: Adhesive assembly steps

S4: Thinning step

S5: Transparent substrate lamination step

Claims (10)

A method for thinning and bonding a micro-filter array includes: a filter fabrication step, fabricating at least two different types of filters, each filter comprising a substrate layer and a coating layer stacked on top of each other; a cutting step, cutting the filters to form different types of micro-filters, each micro-filter comprising the substrate layer and the coating layer stacked on top of each other; and a bonding assembly step, arranging and bonding the filters... The microfilters are arranged side-by-side on a substrate layer to form a microfilter array, and the microfilters are bonded together by an opaque adhesive; a thinning step, which involves grinding the substrate layer of the microfilters to thin the microfilter array; and a transparent substrate bonding step, which involves attaching a transparent substrate to the thinned microfilter array, the transparent substrate being located on the substrate layer of the microfilters. As described in claim 1, in the method for bonding and thinning a micro-filter array, in the transparent substrate bonding step, another transparent substrate is attached to the coating layer of the thinned micro-filter array, so that both opposite sides of the micro-filter array have transparent substrates. The method for forming a micro-filter array by bonding and thinning as described in claim 1, wherein the side length of the micro-filters is between 500µm and 1mm. The method for forming a thinned micro-filter array as described in claim 1, wherein the micro-filter array is rectangular and has a length and width of 0.55 mm. The method for thinning and bonding a micro-filter array as described in claim 1, wherein the substrate layer has a top side and a bottom side opposite to each other, the top side being the side in contact with the coating layer, and the bottom side of the substrate layer is ground by a grinding machine in the thinning step, and the transparent substrate is located on the bottom side of the substrate layer of the micro-filters. The method for forming a thinned micro-filter array as described in claim 1, wherein the transparent substrate is a quartz transparent substrate. The method for bonding and thinning a micro-filter array as described in claim 5 includes a flipping step between the bonding assembly step and the thinning step, in which the micro-filter array is flipped up and down so that the bottom side of the substrate layer of the micro-filters faces upward. The method for forming a micro-filter array by bonding and thinning as described in claim 7 includes a transfer film bonding step between the bonding assembly step and the flipping step, wherein a transfer film is attached to the micro-filter array after bonding is completed, the transfer film is located on the coating layer, and the transfer film is removed before performing the transparent substrate bonding step. The method for forming a micro-filter array by bonding and thinning as described in claim 1, wherein the micro-filter array is any shape, such as rectangular, triangular, hexagonal, octagonal or circular. A method for thinning and bonding a micro-filter array includes: a filter fabrication step, fabricating at least two different types of filters, each filter comprising a substrate layer and a coating layer stacked on top of each other; a cutting step, cutting the filters to form different types of micro-filters, the micro-filters comprising the substrate layer and the coating layer stacked on top of each other; and a bonding assembly step, arranging and bonding the micro-filters. The microfilters are arranged side-by-side on substrate layers to form a microfilter array, the microfilters being bonded together with an opaque adhesive; a thinning step, grinding the substrate layers of the microfilters to thin the microfilter array; and a transparent substrate lamination step, attaching an AR anti-reflective film to the thinned microfilter array, the AR anti-reflective film being located on the bottom side of the substrate layers of the microfilters.