TWI398670B - Method for making lens array - Google Patents

Description

Lens array manufacturing method

The invention relates to a lens, a lens array and a manufacturing method thereof, in particular to an embossed lens, a lens array and a manufacturing method thereof.

Currently, lenses are typically embossed on both sides of a light transmissive substrate to form an optical portion (see The Novel Fabrication Method and Optimum Tooling Design Used for Microlens Arrays, Proceedings of the 1st IEEE International Conference on Nano/Micro Engineered and Molecular Systems; January) Produced in the manner of 18-21, 2006, Zhuhai, China). Embossing refers to the application of a liquid or plastically deformed material to a substrate and then imprinting with an imprinting mold. Referring to FIG. 13, when both surfaces 806 and 808 of the lens are optical surfaces, they are generally stamped on both sides 802 and 804 of the substrate 80. At this time, the thickness of the substrate 80 determines the thickness of the lens.

However, under the trend of miniaturization of the size of the mobile phone lens, the lens needs to be thinner and thinner. At present, the thickness of the substrate can be reduced by the thinning technique of the transparent substrate, thereby reducing the thickness of the lens. However, the thinned substrate not only has low process yield, high price, but also has low mechanical strength characteristics such as being bendable and cracked, and cannot withstand the pressure in the imprint process.

In view of the above, it is necessary to provide a thin and light lens, an array of lenses, and a method of manufacturing the same.

A method for manufacturing a lens array, comprising the steps of: providing a transparent substrate having opposite first and second surfaces; etching the first surface of the transparent substrate to form a plurality of arrays a recess; forming a photoresist layer on the bottom surface of each of the recesses, removing the photoresist of the predetermined area by exposure and development, exposing the bottom surface to a portion of the surface, forming a non-optical region, forming a light-shielding film in the non-optical region; Residual photoresist in the groove forms an optical zone, a molding material is added to the optical zone, the first optical part is embossed, and the molding material of the first optical part is cured; on the first surface of the transparent substrate A scribe line is formed around each groove.

A lens comprising a transparent substrate having a first surface and a second surface opposite to each other, wherein the first surface of the transparent substrate is provided with a recess, and a bottom surface of the recess is provided with a first optical portion and A light shielding film is disposed around the periphery of the first optical portion.

An array of lenses includes a transparent substrate having a first surface and a second surface opposite to each other, and the first surface of the transparent substrate is provided with a plurality of rows of grooves, and the bottom surface of each groove is provided There is a first optical portion and a light shielding film, and the light shielding film is disposed around the periphery of the first optical portion.

Compared with the prior art, since the first optical portion of the lens array or the lens is formed on the bottom surface of the groove, the formed lens array or lens forms a first optical portion on the first surface of the transparent substrate. The lens is thinner, and since the transparent substrate is not thinned, the un-thinned area around the groove can simultaneously withstand the pressure during the imprinting process, thereby avoiding the bending and cracking of the transparent substrate in the lens manufacturing process.

806, 808‧‧‧ surface

80, 10‧‧‧ substrate

802, 804‧‧‧ both sides

11‧‧‧ Groove

13‧‧‧Photoresist layer

100‧‧‧ lens array

200‧‧‧ lenses

102‧‧‧ first surface

104‧‧‧ second surface

112‧‧‧ bottom

132‧‧‧negative photoresist

14‧‧‧Non-optical zone

12‧‧‧ cutting road

60‧‧‧Shade film

16‧‧‧ lens forming area

20‧‧‧Mold

202‧‧‧protrusion

2022‧‧‧ molding cavity

30‧‧‧First Optics

40‧‧‧Second Optics

17‧‧‧Adhesive layer

18‧‧‧ molding materials

1 is a flow chart of a method of manufacturing a lens according to an embodiment of the present invention.

2 to 12 are schematic views showing the process of the lens manufacturing method of the embodiment of the present invention.

Figure 13 is a schematic view showing the structure of a prior art lens.

The technical solution will be further described in detail below with reference to the accompanying drawings and embodiments.

Referring to FIG. 1 , FIG. 11 and FIG. 12 , the manufacturing method of the lens array 100 or the lens 200 of the present invention includes The following steps: providing a transparent substrate having opposite first and second surfaces; etching the first surface of the transparent substrate to form a plurality of rows of grooves; forming a photoresist layer in each of the grooves The bottom surface is removed by exposure and development, and the bottom surface is exposed to a portion of the surface to form a non-optical region, and a light-shielding film is formed in the non-optical region; the photoresist remaining in each of the grooves is removed to form an optical region. Adding a molding material to the optical zone, embossing the first optical portion, and curing the molding material of the first optical portion; and embossing the second optical portion on the second surface of the transparent substrate and the optical axis of the first optical portion a cutting path formed on each of the grooves on the first surface of the transparent substrate; forming an adhesive layer on the first surface of the transparent substrate; the area enclosed by each of the cutting streets; along the cutting path The light transmissive substrate is cut to form individual lenses.

The method of manufacturing the lens array 100 or the lens 200 will be described in detail below with reference to FIGS. 2 through 12.

As shown in FIG. 2, a transparent substrate 10 is first provided. The material of the transparent substrate 10 is a light transmissive material, such as glass. Preferably, it can be an optical glass having a transmittance of more than 95%. The light transmissive substrate 10 has two opposing surfaces, a first surface 102 and a second surface 104.

Forming a plurality of arrays of grooves 11 on the first surface 102 by etching, the etching method may be physical etching, such as sputter etching, ion beam etching (Ion Beam Etching), chemical etching, Such as plasma chemical etching (Plasma Chemical Etching); or physical, chemical compound etching, such as reactive ion etching (Reactive Ion Etching) .

The photoresist layer 13 is formed on the bottom surface 112 of each of the grooves 11 by a slit coating or a spin coating method or other coating method. The photoresist layer 13 may be a negative photoresist or a positive photoresist.

The photoresist layer 13 is exposed to ultraviolet light by a photomask (not shown) having a predetermined pattern. If a negative photoresist, such as polyisoprene, is used, the exposed portion will be insoluble in the developer due to the negative photoresist being sensitive to ultraviolet light.

Referring to Figure 3, after the developer is used, the unexposed negative photoresist is dissolved leaving the exposed negative photoresist 132. The bottom surface 112 of the recess 11 exposes a portion of the surface to form a non-optical zone 14.

Referring to FIG. 4, a light shielding material 60 is formed on the non-optical region 14 by using a conventional coating technique, such as sputtering, to form a light shielding film 60 for reducing stray light. The light shielding film 60 covers at least the non-optical zone 14 as shown in FIG. The thickness of the light shielding film 60 is smaller than the thickness of the negative photoresist 132.

Referring to FIG. 5, the negative photoresist 124 as shown in FIG. 4 is dissolved by a solvent which dissolves the negative photoresist but does not react with the light-shielding material chromium, such as an acetone solution, to expose the lens forming region 16.

The first optical portion is then stamped into the lens forming zone 16 using an imprinting mold.

See Figure 6 through Figure 12 for the molding process. Referring to FIG. 6, the imprinting mold 20 is made of a material that transmits ultraviolet light, and has a plurality of protrusions 202 corresponding to the grooves 11, each of the protrusions 202 having a molding cavity 2022 for The shape of the optical portion of the molded lens. In this embodiment, the shape of the molding cavity 2022 is a concave spherical surface.

First, a molding material 18 is added to the lens forming region 16, which is a thermoplastic material or a thermosetting material, and is in a liquid or molten state at this time, and the optical molding material 18 is cured by being heated or irradiated with ultraviolet light.

Referring to Figure 7, the imprinting mold 20 is aligned with the molding material 18 for imprinting. Then, ultraviolet light from the mold 20 is irradiated to the molding material 18 to cure the molding material 18.

Referring to FIG. 8, after the curing is completed, the imprinting mold 20 is removed, and the first optical portion 30 is formed on the bottom surface 112 of each of the grooves 11.

Referring to FIG. 9 , the second optical portion 40 is imprinted on the second surface 104 of the transparent substrate 10 and the first optical portion 30 at the same optical axis.

Referring to FIG. 10, a scribe line 12 is formed on the first surface 102 around each of the grooves 11, which can be formed by laser cutting or cutting.

Referring to FIG. 11, an area of each of the dicing streets 12 on the first surface 102 of the transparent substrate 10 is formed into an adhesive layer 17 by a coating method, that is, the lens array 100 is formed. The adhesive layer 17 functions to allow the light-transmitting substrate 10 to bond a plurality of substrates having optical elements, and to form a multilayer optical element structure, and then cut the whole. The optical element can be a complex photoreceptor (CMOS or CCD) or a complex lens.

Referring to FIG. 12, the transparent substrate 10 is cut along the scribe line 12 to form a single lens 200.

Compared with the prior art, since the first optical portion 30 of the lens array 100 or the lens 200 is formed on the bottom surface 112 of the groove 11, the lens array 100 or the lens 200 formed is the first one compared to the transparent substrate 10. The lens forming the first optical portion on the surface 102 is thinner, and since the transparent substrate 10 is not thinned, the un-thinned region around the recess 11 can simultaneously withstand the pressure during the imprinting process, avoiding the lens array. The bending and cracking of the transparent substrate 10 in the process of 100 or the lens 200.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by persons skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims.

Claims (6)

A method for manufacturing a lens array, comprising the steps of: providing a transparent substrate having opposite first and second surfaces; etching a first surface of the transparent substrate to form a plurality of rows of grooves; forming a The photoresist layer is formed on the bottom surface of each of the grooves by exposure and development to remove the photoresist in the predetermined area, so that the bottom surface is exposed to a part of the surface to form a non-optical area, and a light shielding film is formed in the non-optical area; a photoresist, forming an optical zone, adding a molding material to the optical zone, embossing the first optical portion, and curing the molding material of the first optical portion; forming a periphery of each groove on the first surface of the transparent substrate cutting line. The method for manufacturing a lens array according to claim 1, further comprising: after curing the molding material of the first optical portion, imprinting the second optical portion on the second surface of the transparent substrate and the first The step of the position of an optical portion with the optical axis. The method for manufacturing a lens array according to claim 2, further comprising: after forming the second optical portion, forming an adhesion on a region surrounded by each of the dicing streets on the first surface of the transparent substrate; The steps of the layer. The method for manufacturing a lens array according to claim 3, further comprising the step of cutting the transparent substrate along the scribe line to form each lens after forming the adhesive layer. The method for manufacturing a lens array according to claim 1, wherein in the step of embossing the first optical portion, an imprinting mold is used for imprinting, the imprinting mold having a plurality of corresponding to the groove The protrusions each have a molding cavity for shaping the shape of the optic portion of the lens. The method for manufacturing a lens array according to claim 1, wherein the photoresist layer is advantageous It is formed by a crack coating or a spin coating method which is formed by laser cutting device or cutter cutting, which is ultraviolet curing.