KR20100055023A - Method for fabricating lens using stemps - Google Patents

Abstract

PURPOSE: A method for manufacturing a lens using a stamp is provided to reduce manufacturing costs and manufacturing time by simultaneously molding a plurality of lens elements using a double-sided stamp for laminating the multiple lens elements having different refractive indexes. CONSTITUTION: A method for manufacturing a lens using a stamp comprises the following steps: preparing a plurality of stamps according to the number of laminated lens which is preset; preparing a plurality of lens substrates(210) according to the number of laminated lens; arranging the multiple stamps and the multiple lens substrates according to a lamination sequence; forming a plurality of lens elements by spreading a polymer for lens on the multiple lens substrate and hardening the polymer through UV irradiation; and eliminating the multiple stamps.

Description

Lens manufacturing method using stamp {METHOD FOR FABRICATING LENS USING STEMPS}

The present invention relates to a method for manufacturing a lens using a stamp, and more particularly, to manufacture a plurality of lens elements by using a plurality of stamps, in particular a double-sided stamp to stack two or more lens elements at the same time to reduce the manufacturing cost and production time It relates to a lens manufacturing method that can maximize the production efficiency.

As the pixel size of an image sensor used in recent years becomes smaller and smaller, an optical device mounted on an optical device using the image sensor is also miniaturized, and due to the miniaturization of the optical device, there is a great difficulty in assembling each optical device. In order to solve such a problem, an optical device is manufactured by a replication method such as hot embossing and UV embossing, which can be mass-produced and easy to manufacture on a wafer scale.

The replica method is a known technique for manufacturing a micro lens or an information storage device such as a CD or a DVD. A replica method is a method of manufacturing a lens on a wafer basis, and a polymer or the like is formed on a transparent lens substrate made of glass or the like. A method of manufacturing a replica lens by forming a thin replica layer using a transparent optical material.

When using a replica lens manufactured by such a replication method, it is possible to use a semiconductor process, so that the alignment and arrangement of the lens can be performed more easily than the conventional method, and the tolerance property can be improved. There is an advantage that can reduce the volume.

1 is an example of a lens configuration of a camera module having such a conventional replica lens.

As shown in FIG. 1, in the conventional camera module, three lens substrates S1, S2, and S3 are required to realize a resolution of 300,000 pixels, and the lens substrates S1, S2, and S3 are used. Single replica layers L1, L2, L3, L4, L5, and L6 are formed on both surfaces of each, and have a full length of 3.5 mm or more from the first replica layer L1 to the upper surface of the image sensor IS.

In the case of using a single replica layer as described above, a plurality of lens substrates S1, S2, and S3 are required to realize desired optical characteristics, and in order to maintain the distance between the lens substrates S1, S2, and S3. Many spacers (not shown) are required.

However, when the spacer is provided in this way, a separate material and a process for providing the spacer are required, which increases the manufacturing cost of the lens module, that is, the camera module, and increases the complexity of the work process.

On the other hand, in the conventional method of manufacturing a replica lens, a single replica layer is formed to form a lens element. Therefore, although the lens elements formed by using a replica method are formed on both surfaces of the lens substrates S1, S2, and S3, in this case, a replication process is performed when a replica layer is formed on one side and a replica layer is formed on the opposite side. As a result, there is a problem that the lens element is damaged.

In addition, when a single replica layer is formed on a plurality of lens substrates, the same work process for forming a replica layer must be repeated. Therefore, a method of forming one lens surface by one embossing process is limited in manufacturability. Has Moreover, the limit is prominent when a plurality of lens surfaces must be formed, such as a stacked lens module.

SUMMARY OF THE INVENTION The present invention has been proposed to solve the above problems, and an object thereof is to shorten manufacturing cost and manufacturing time by simultaneously molding a plurality of lens elements using a plurality of stamps, in particular a double-sided stamp, in order to stack two or more lens elements. To provide a lens manufacturing method that can maximize the production efficiency.

The present invention comprises the steps of providing a plurality of stamps in accordance with a predetermined number of lens laminated to solve the above problems; Providing a plurality of lens substrates according to a preset number of lens stacks; Arranging the plurality of stamps and the plurality of lens substrates in a stacking order; Applying a polymer for a lens on the plurality of lens substrates, and curing by irradiating UV or applying heat to form a plurality of lens elements; And a step of removing the plurality of stamps.

In addition, the step of providing a plurality of stamps, the upper stamp; A plurality of inner double sided stamps; And a lower stamp.

The providing of the upper stamp or the lower stamp may include: forming a master by mounting a plurality of master molds including a lens element mold on one side of a base; Coating a polymer on one side of the base to cover the master mold; And forming a stamp having a plurality of stamp molds on the base substrate by compressing and separating the polymer from the upper side to the base substrate corresponding to the base.

In addition, the providing of the plurality of inner double sided stamps may include: forming a master by mounting a plurality of master molds including lens element molds on one side of the base; Applying a polymer on one side of the base to cover the master mold; And forming a double-sided stamp having a plurality of stamp molds on both sides of the base substrate by pressing and curing the polymer to one side where the stamp mold of the base substrate is not formed corresponding to the base. It is preferable to include.

In addition, the providing of the plurality of inner double sided stamps may include: forming a master by mounting a plurality of master molds including lens element molds on one side of each of the two bases; Respectively applying a polymer on one side of each of the two bases to cover the master mold; And aligning a base substrate between the two bases, pressing and curing the polymer from the upper side and the lower side of the base substrate to the base substrate, and forming a double-sided stamp having a plurality of stamp molds on both sides of the base substrate. It is preferable to further include;

Further, after the removing of the plurality of stamps, inserting and bonding spacers between the plurality of lens substrates on which the lens elements are formed; And a dicing step of cutting each of the plurality of lens elements integrally with each other.

The present invention is produced by reducing the production cost and production time by simultaneously molding a plurality of lens elements using a plurality of stamps, in particular a double-sided stamp in order to stack two or more lens elements having different refractive indices through the above problem solving means. It provides a lens manufacturing method that can maximize the efficiency.

According to a predetermined lens refractive index, the number of lens elements to be stacked and the curvature surface of the stamp can be set so that a plurality of lens elements can be integrally molded in a single process, thereby increasing design freedom and maximizing lens manufacturing efficiency.

Matters relating to the operational effects including the technical configuration for the above object of the lens manufacturing method using the stamp according to the present invention will be clearly understood by the detailed description with reference to the following drawings in which preferred embodiments of the present invention are shown.

2A to 2D are cross-sectional views illustrating a method of manufacturing a double-sided stamp according to an embodiment of the present invention, and FIGS. 3A to 3D are cross-sectional views illustrating a method of manufacturing a lens according to an embodiment of the present invention.

As shown in FIG. 2A, a method of manufacturing a lens according to an exemplary embodiment of the present invention includes a lens for replicating an imaging lens on one side of the base 200, for example, a lower side of the base 200. A master mold is formed by adhesively mounting a plurality of master molds including the lens element mold 201 having the same shape. The shape of the lens element mold 201 of the master mold may be in the form of a hemispherical convex lens, but is not limited thereto, and may be formed in the form of a concave lens, an aspherical surface having a positive or negative refractive power, or a diffractive surface. The refractive index of each lens element is designed in advance according to the design design of the final lens to form the lens element mold 401 corresponding thereto in advance.

In addition, the master mold may further include a partition mold (not shown) for separating the boundary of the lens element mold 201. The partition mold of the master mold may be formed to surround the lens mold 201 and protrude to a height higher than the height of the lens mold 202 and have a flat top surface.

Thereafter, as illustrated in FIG. 2B, the master having a plurality of master molds having the lens element mold 201 is inverted up and down, and the polymer 202 is applied to cover the master mold including the lens element mold 201. . The polymer 292 may be a UV curable polymer or a polymer such as a photopolymer epoxy, polycarbonate, polydimethylsiloane (PDMS), or polymethly methacrylate (PMMA) resin.

After the polymer 202 is applied to cover the master mold composed of the lens element mold 201, the polymer 202 is pressed and cured from the upper side to the first substrate 210 in correspondence with the base 200, and then the polymer ( 202 to adhere to the bottom surface of the first substrate 210.

In this case, a UV embossing treatment for curing the polymer 202 by applying UV radiation or a hot embossing treatment for curing the polymer 202 by applying heat may be performed.

In particular, when the first substrate 410 illustrated in FIG. 2B is a transparent substrate, glass, silica (fused silica), quartz, polydimethylsiloane (PDMS), polymethly methacrylate (PMMA), or polyethylene terephthalate (PET) may be used. ) And a UV embossing process to cure the polymer 202.

After the polymer 202 has been cured, the master with the lens element mold 201 is detached. Then, as shown in FIG. 2C, the stamp mold 202-formed with the polymer 202 on the lower side of the first substrate 210 is shown. 1) is formed, which can be used as an upper stamp or a lower stamp in the lens manufacturing method according to an embodiment of the present invention.

The first substrate using the master mold including the lens element mold 201 in the order shown in FIGS. 2A to 2C on the upper side of the first substrate 210 having the stamp mold 202-1 formed thereon. An inner double-sided stamp may be prepared in which the polymer 202 is formed 202-2 on the upper side of 210.

In addition, according to another embodiment, when manufacturing the inner double-sided stamp, it is provided with two bases 200 formed with the lens element mold 201 as shown in Figure 2a, on each base 200 The polymer 202 is applied to cover the lens element mold 201. Thus, the two bases 200 coated with the polymer are pressed and cured to the upper side and the lower side of the first substrate 210, respectively, so that the polymer 202 adheres to the upper and lower surfaces of the first substrate 210, respectively. The inner double sided stamp can also be manufactured.

That is, the plurality of stamps for the lens manufacturing method according to an embodiment of the present invention, the upper stamp and the lower stamp, the stamp mold 202-1 is formed on one side of the first substrate 210 as shown in Figure 2c It includes, and as shown in Figure 2d includes a double-sided stamp formed on both sides of the first substrate 210, the stamp mold (202-1, 202-2) is formed.

The existing process for manufacturing a substrate-type lens is to form the lens surface on the glass substrate as shown in the figure using a stamp of the cross section. The photocurable resin was dropped onto the substrate, pressurized using a preformed stamp, and then cured, and thus, in order to mold the plurality of lens surfaces, there was a process inconvenience in that the above process was repeated with a plurality of stamps. Since the stacked lens module is composed of at least four or more lens surfaces, the limit is more pronounced when it is to be composed of many lens surfaces such as the stacked lens module.

However, in the present invention, when the plurality of lens surfaces are formed by using the double-sided stamp, as shown in FIG. 2D, the double-sided stamp may be used to simultaneously mold the plurality of lens surfaces.

A process of manufacturing a lens using a plurality of stamps as shown in FIGS. 2C and 2D is illustrated in FIGS. 3A-3D.

First, a plurality of stamps and a plurality of lens substrates 310 and 320 are provided according to a preset number of lens stacks. In order to manufacture a stacked lens, the number of required lenses is determined according to the design, and accordingly, a lens substrate is provided, and according to the refractive index of each lens element, the positive or negative refractive power, aspherical shape, or diffractive surface of the lens element is determined. Determine the form, etc. In addition, a plurality of stamps corresponding thereto are provided.

Here, according to the prior art, although only the number of gaps of the lenses to be laminated stamp is required, the present invention includes an upper stamp and a lower stamp, and an internal double-sided stamp is provided between each lens substrate. For example, when four lenses are stacked, three stamps may be provided as an upper stamp, an inner double-sided stamp, and a lower stamp. When laminating six lenses, an upper stamp, two inner double-sided stamps, and a lower stamp may be used. Four stamps may be provided.

The plurality of stamps and the plurality of lens substrates thus provided are aligned in the stacking order as shown in FIG. 3A. 3A to 3D illustrate stacking four lens elements according to one embodiment. Therefore, an internal double-sided stamp is inserted between the first lens substrate 310 and the second lens substrate 320, the upper stamp is aligned above the first lens substrate 310, and the second lens substrate 320 is disposed. Align the lower stamp on the lower side.

3B, a metal film or a photosensitive polymer film, such as aluminum (Al) or chromium (Cr), is used on the upper and lower surfaces of the first lens substrate 310 and the second lens substrate 320. To form a stop 330.

Specifically, when the stop 330 is formed of a metal film such as aluminum (Al) or chromium (Cr), due to the high hydrophobicity of the metal film, the lens polymers 340, 350, and 360 are subsequently applied on the stop 330. , 370 is inferior in adhesion force, so that it is necessary to form a separate adhesive layer on the metal film.

On the other hand, when the stop 330 is formed of the photosensitive polymer, since the adhesiveness with the polymers 340, 350, 360, and 370 is excellent due to the high hydrophilicity of the photosensitive polymer, it is necessary to further form an adhesive layer on the photosensitive resin layer. Disappear. In addition, when the stop 330 is formed of a metal film, a sequential process of exposure, deposition of a metal film, and removal of the metal film is required. However, when the stop 330 is formed of a photosensitive polymer, only an exposure process may be performed due to the characteristics of the photosensitive polymer. The stop 330 can be formed, thereby reducing manufacturing cost and time.

On the other hand, metal films such as aluminum (Al) or chromium (Cr) have high reflectance, so that light passing through the stop 330 is reflected back to the lens substrates 310 and 320 or other lens elements, resulting in image degradation. On the other hand, when using the photosensitive resin layer having a high light absorption in the visible light region, it is possible to solve the problem of image degradation due to the total internal reflection as described above. Here, the photosensitive polymer constituting the stop 330 preferably has a light absorption of 90% or more in the visible light region.

As described above, the stop 330 is formed on the upper and lower surfaces of the lens substrates 310 and 320, and the transparent polymer for the lens is disposed on the lens substrates 310 and 320 including the stop 330 as shown in FIG. 3B. (340, 350, 360, 370) is applied. Here, the lens polymers 340, 350, 360, and 370 may use a UV curable polymer or a polymer such as a photopolymer epoxy, polycarbonate, polydimethylsiloane (PDMS), or polymethlymethacrylate (PMMA) resin.

After applying the transparent polymer 340, 350, 360, 370 for the lens on the lens substrate (310, 320), using the upper stamp, the inner double-sided stamp, and the lower stamp for the lens on the lens substrate (310, 320) The transparent polymers 340, 350, 360, and 370 are compressed and cured. Here, in the case of compressing the lens transparent polymers 340, 350, 360, and 370 on the lens substrates 310 and 320 using the upper stamp, the inner double-sided stamp, and the lower stamp, the stamp mold and the transparent polymer for the lens are mutually compressed. By selectively applying a release agent to the inner surface of the stamp molds 202-1 and 202-2 so as not to contact, the stamp molds 202-1 and 202-2 can be easily separated from the transparent polymer for the lens. have.

Accordingly, when the plurality of stamps are separated by pressing and curing the transparent polymer for a lens, as shown in FIG. 3C, the first lens substrate and the second lens are intact as the inner shapes of the stamp molds 202-1 and 202-2. Lens members including respective lens elements 341, 351, 361, 371 may be replicated on the substrates 310, 320.

Then, as shown in FIG. 3D, a spacer 400 is inserted between the first lens substrate 310 on which the lens elements 341 and 351 are formed and the second lens substrate 320 on the lens elements 361 and 371. To bond. Simultaneously molding all the surfaces required for the lens module and then removing the stamp while maintaining the lens substrate in the equipment and bonding the spacer between the lens substrate can improve the manufacturability of the laminated lens module.

Thereafter, a dicing process is performed along the cut surface (dotted line) shown in FIG. 3D. According to one embodiment, such a dicing process may proceed by adhering the dicing tape to a partition (not shown) of either the top lens element 341 or the bottom lens element 371. As mentioned above, according to one embodiment, the partition wall, which may be formed by the partition wall mold, is higher than the height of the lens element and has a flat top surface, so that it is easy to adhere the dicing tape for performing the dicing process. something to do.

When the dicing process is performed along the cutting line, as illustrated in FIG. 4, the first lens element 341, the first lens substrate 310, the second lens element 351, the spacer 400, and the third lens are illustrated. A stacked lens is sequentially fabricated with elements 361, a second lens substrate 320, and a fourth lens element 371.

As described above, when the laminated lens using the double-sided stamp is manufactured according to the manufacturing method of the lens according to the embodiment of the present invention, the manufacturing efficiency is increased by simultaneously molding a plurality of lens elements. The embossing process of a conventional substrate-type lens is a cross-sectional process using one stamp, and one lens surface is formed in one process, resulting in low manufacturing efficiency. However, in the present invention, a plurality of wafer lenses may be formed using double-sided stamps, and then bonded to spacers may be used to shorten a manufacturing process and time required for the multilayer lens module.

Preferred embodiments of the present invention described above are disclosed for the purpose of illustration, and various substitutions, modifications and changes within the scope of the technical spirit of the present invention for those skilled in the art to which the present invention pertains. Changes may be made, but such substitutions, changes and the like should be regarded as belonging to the following claims.

1 is a cross-sectional view showing a camera module having a conventional replica lens.

2A to 2D are cross-sectional views illustrating a method of manufacturing a double-sided stamp according to an embodiment of the present invention.

3A to 3D are cross-sectional views illustrating a method of manufacturing a lens according to an exemplary embodiment of the present invention.

4 is a cross-sectional view of a lens manufactured by the lens manufacturing method according to the embodiment of the present invention.

<< Explanation of symbols for main part of drawing >>

310. First lens substrate 320. Second lens substrate

341. First Lens Element 351. Second Lens Element

361. Third Lens Element 371. Fourth Lens Element

400. Spacers

Claims (6)

Providing a plurality of stamps according to a preset number of lens stacks; Providing a plurality of lens substrates according to a preset number of lens stacks; Arranging the plurality of stamps and the plurality of lens substrates in a stacking order; Applying a polymer for a lens on the plurality of lens substrates, and curing by irradiating UV or applying heat to form a plurality of lens elements; And Removing the plurality of stamps; Lens manufacturing method using a stamp comprising a. The method of claim 1, wherein the providing of the plurality of stamps comprises: Upper stamp; A plurality of inner double sided stamps; And Lens manufacturing method using a stamp comprising a lower stamp. The method of claim 2, wherein the providing of the upper stamp or the lower stamp comprises: Mounting a plurality of master molds including lens element molds on one side of the base to form a master; Applying a polymer on one side of the base to cover the master mold; And Pressing-curing and separating the polymer from the upper side to the base substrate corresponding to the base to form a stamp having a plurality of stamp molds on the base substrate; Lens manufacturing method using a stamp, characterized in that it further comprises. The method of claim 3, wherein the providing of the plurality of inner double sided stamps comprises: Mounting a plurality of master molds including lens element molds on one side of the base to form a master; Applying a polymer on one side of the base to cover the master mold; And Forming a double-sided stamp having a plurality of stamp molds on both sides of the base substrate by pressing and curing the polymer to one side where the stamp mold of the base substrate is not formed corresponding to the base; Lens manufacturing method using a stamp, characterized in that it further comprises. The method of claim 3, wherein the providing of the plurality of inner double sided stamps comprises: Mounting a plurality of master molds including lens element molds on one side of each of the two bases to form a master; Respectively applying a polymer on one side of each of the two bases to cover the master mold; And Aligning a base substrate between the two bases, and by pressing and curing the polymer from the upper and lower sides of the base substrate to the base substrate to form a double-sided stamp having a plurality of stamp molds on both sides of the base substrate step; Lens manufacturing method using a stamp, characterized in that it further comprises. The method of claim 4 or 5, wherein after removing the plurality of stamps, Inserting and bonding a spacer between a plurality of lens substrates on which the lens element is formed; And Dicing to cut each of the plurality of lens elements integrally; Lens manufacturing method using a stamp, characterized in that it further comprises.

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