KR100847802B1 - Aspheric liquid lens and a method for producing the same - Google Patents

Abstract

The present invention relates to an aspherical liquid lens, and more particularly, to an aspherical liquid lens manufacturing method and method capable of forming a stable electrode, an insulating film and a uniform hydrophobic film, excellent sealing properties and easy to miniaturize the module. It relates to an aspherical liquid lens produced.

In the aspherical liquid lens module of the present invention, two transparent insulating substrates having an aspherical lens processing on one side and an electrode formed on the edge of the other side except for the central portion are arranged such that the electrodes face each other, and between the two insulating substrates. A conductive intermediate substrate having an opening formed in the center thereof is coupled thereto, and a hydrophobic insulating layer is formed on an inner side of the conductive intermediate substrate defining the opening, and a space between the two insulating substrates and the conductive intermediate substrate is formed. It is characterized by being filled with a non-conductive liquid.

Liquid lens, aspherical surface, insulating film, hydrophobic film

Description

Aspheric liquid lens and its manufacturing method {ASPHERIC LIQUID LENS AND A METHOD FOR PRODUCING THE SAME}

1 and 2 are explanatory diagrams of a liquid lens operating principle.

3 and 4 are structural diagrams of a conventional liquid lens.

5 is an explanatory diagram of optical characteristics of a spherical lens.

6 is an explanatory diagram of optical characteristics of an aspherical lens;

7 is a structural diagram of an aspherical liquid lens module according to a first embodiment of the present invention.

8 is an upper substrate manufacturing process diagram of the aspherical liquid lens module according to the first embodiment.

9 is an intermediate substrate manufacturing process diagram of the aspherical liquid lens module according to the first embodiment.

10 is a lower substrate manufacturing process diagram of the aspherical liquid lens module according to the first embodiment;

11 is a substrate bonding process diagram of the aspherical liquid lens module according to the first embodiment.

12 is a structural diagram of an aspherical liquid lens module according to a second embodiment of the present invention.

13 is an intermediate substrate manufacturing process diagram of the aspherical liquid lens module according to the second embodiment;

14 is a substrate bonding process diagram of the aspherical liquid lens module according to the second embodiment.

15 and 16 are exemplary plan views of the aspherical liquid lens module according to the first and second embodiments.

17 is a structural diagram of an aspherical liquid lens module according to a third embodiment of the present invention.

18 is a manufacturing process diagram of an aspherical liquid lens module according to the third embodiment.

19 is a structural diagram of an aspherical liquid lens module according to a fourth embodiment of the present invention.

20 is a manufacturing process diagram of an aspherical liquid lens module according to the fourth embodiment.

21-25 illustrate an exemplary O-ring arrangement of the aspherical liquid lens module according to the fourth embodiment.

26 and 27 are exemplary plan views of an aspherical liquid lens module according to the third and fourth embodiments.

The present invention relates to an aspherical liquid lens, and more particularly, to an aspherical liquid lens manufacturing method and method capable of forming a stable electrode, an insulating film and a uniform hydrophobic film, excellent sealing properties and easy to miniaturize the module. It relates to an aspherical liquid lens produced.

The liquid lens is an application of the human eye's lens to change the focus by changing its shape.The liquid lens has a simple structure and no mechanical driving part, so it is not only reliable, suitable for mass production, but also fast for reaction and very low power consumption. It can be downsized to several millimeters or less. Liquid lenses can be used in various ways such as digital cameras, camera phones, endoscopes, security systems, optical recording devices, and the like.

The principle of the liquid lens will be described with reference to FIGS. 1 and 2.

As shown in FIG. 1, when a drop of a conductive solution 1 such as water is placed on a substrate composed of an insulator 3 and a metal plate 4 and a voltage is applied between the metal plate 4 and the conductive solution 1, As the hydrophilicity of the insulator 3 increases, the shape of the droplets of the conductive solution 1 on the insulator 3 changes from the dotted line A to the solid line B. Such a phenomenon is called an electrowetting phenomenon.

On the other hand, instead of the water in the air as shown in Figure 1, as shown in Figure 2, even when using water (1) and oil (2) having the same density and different refractive index and not mixed with each other, the electrowetting phenomenon is found. can do. In the situation in which the droplet of oil (2), which is a non-conductive liquid, is immersed in the water (1), which is a conductive liquid, when the voltage is applied, the hydrophilicity of the insulator (3) increases according to the electrowetting phenomenon. The shape of 1) changes from the solid line A to the dotted line B.

In summary, the electrowetting phenomenon refers to the contact angle between the conductive liquid and the conductive liquid by controlling the surface tension of the conductive liquid by applying a voltage to the electrode and the conductive liquid from the outside when the conductive liquid and the non-conductive liquid contact each other on the electrode coated with the insulator. It means changing the shape of the interface of the liquid.

Philips presented a liquid lens as shown in FIGS. 3 and 4 at CeBIT in Hannover, Germany, in 2004.

The liquid lens shown in FIG. 3 processes the substrate 10, the side walls 20, and the upper plate 30 using transparent glass as a base material, and follows the outer circumference of the substrate 10 and the side walls 20. FIG. The lower electrode 40 and the intermediate electrode 50 are formed, respectively. Inside the side wall 20, an insulator 60 is coated to generate an electrowetting phenomenon, and a hydrophobic film 70 is coated on the insulator 60. The contact between the two liquids 80 and 90 and the intermediate electrode 50 is interrupted by the insulator 60 and the hydrophobic film 70, and only the conductive liquid 80 is in contact with the end of the lower electrode 40.

When a voltage is applied as shown in FIG. 4, charges accumulate on the intermediate electrode 50 and opposite charges collect near the interface between the conductive liquid 80 and the hydrophobic film 70. The resulting electrostatic force lowers the surface tension between the conductive liquid 80 and the hydrophobic film 70, thereby reducing the contact angle θ and the focal length of the lens.

One of the important issues in the manufacture of such a liquid lens is the electrode and the insulating film. In order to operate a stable liquid lens, it is necessary to continuously apply a uniform voltage. Therefore, the material and shape of the electrode for this purpose must be considered, and the material and shape of the insulator capable of stably insulating the working liquid from the metal electrode. It should also be considered important.

In the case of the conventional liquid lens shown in FIGS. 3 and 4, the electrode must be formed of ITO (Indium Tin Oxide), which is a transparent electrode material, using glass as a base material, and then coated with an insulating film and then a hydrophobic film. . However, it is not easy to form the ITO electrode, the insulating film, and the hydrophobic film on the vertically formed glass surface, and the insulating film formed by the coating becomes difficult to exhibit good characteristics.

On the other hand, it is indispensable to prevent the outflow of the conductive liquid and non-conductive liquid and to prevent the inflow of bubbles from the outside to the liquid when manufacturing the liquid lens.

In the liquid lens as shown in FIGS. 3 and 4, sealing of the lens structure containing the liquid using an adhesive material in the form of a liquid epoxy generally causes the epoxy to harden due to outgasing from the epoxy. Bubbles are formed in the liquid, and the properties of the epoxy are changed in the contact state of the liquid and the epoxy, thereby making it difficult to obtain reliable adhesion.

In addition, the volume change of the liquid with temperature makes the sealing of the liquid more difficult. For example, when the volume of liquid expands or contracts due to temperature increase or decrease, pressure may be generated inside the liquid lens that stores the liquid, causing cracks in the epoxy or even destroying the liquid lens structure.

Lastly, optical functions such as spherical aberration problem and focusing function of the liquid lens have an important influence on the operating performance. In the case of the liquid lens as shown in FIGS. Thus, the upper and lower substrates do not affect the optical properties at all.

Therefore, in order to manufacture a reliable liquid lens and cost-effective production, it is possible to form electrodes and insulating films stably and reliably, to prevent bubble formation, to effectively seal the liquid, and to improve optical characteristics of upper and lower substrates. There is a need for providing a new liquid lens manufacturing method.

In order to solve the problems of the conventional liquid lens as described above, an object of the present invention is to provide a reliable liquid lens module and a method of manufacturing the same by forming an electrode and an insulating film stably using a conductive material of silicon as a substrate material. It is done.

In addition, the present invention is to seal the liquid using the O-ring in the solid state to suppress the generation of bubbles due to gas leakage, and by using a separate packaging module to fix the liquid lens structure using a liquid lens module greatly improved the robustness and reliability and It aims at providing the manufacturing method.

In addition, an object of the present invention is to provide a liquid lens module and a method of manufacturing the same, in which a process can be simplified and a film can be formed uniformly by simultaneously producing an insulating film and a hydrophobic film by using a hydrophobic insulating film.

In addition, the present invention prevents the formation of bubbles during the manufacturing of the liquid lens module, and by forming a seal using the same material between the substrates, a liquid lens that realizes a hermetic sealing, that is, a hermetic sealing without a separate fixing mechanism It is an object to provide a module and a method of manufacturing the same.

In addition, an object of the present invention is to provide an aspherical liquid lens module and a method of manufacturing the same having improved optical characteristics of the lens by using an aspherical lens-type upper and lower substrate.

Furthermore, an object of the present invention is to provide a method for mass production of an aspherical liquid lens module having the above characteristics.

Aspheric liquid lens module manufacturing method of the present invention for achieving the above object comprises the steps of providing a silicon substrate with a hole formed in the center; Forming an insulating film on the silicon substrate and coating a hydrophobic film; Providing a transparent lower substrate on which an electrode is formed; Bonding the silicon substrate to maintain a seal on the lower substrate; Filling a liquid reservoir enclosed by the hole and the lower substrate with a conductive liquid and a non-conductive liquid; Bonding a transparent upper substrate to maintain a seal on the silicon substrate, wherein the upper substrate and the lower substrate are aspherically lens-processed at a central portion thereof.

Another aspherical liquid lens module manufacturing method of the present invention for achieving the above object comprises the steps of providing a conductive intermediate substrate having an opening formed in the center; Forming an intermediate electrode on an upper surface of the conductive intermediate substrate; Forming a hydrophobic insulating film on an inner surface and a lower surface of the intermediate substrate; Providing a transparent lower substrate having an upper electrode formed at an edge of an upper surface thereof; Coating a second hydrophobic insulating film on at least a portion of an upper surface of the upper electrode formed on the lower substrate; Bonding the intermediate substrate and the lower substrate through a sealing coupling between the hydrophobic insulating film and the second hydrophobic insulating film; Filling a conductive liquid and a non-conductive liquid in a space surrounded by the opening and the lower substrate; Providing a transparent upper substrate having an upper electrode formed at an edge of an upper surface thereof; Forming a metal bump on at least a portion of an upper surface of the upper electrode; And bonding the upper substrate and the intermediate substrate through a sealing coupling of the metal bump and the intermediate electrode, wherein the upper substrate and the lower substrate are aspherically lens-processed at a central portion thereof.

On the other hand, in the aspherical liquid lens module of the present invention for achieving the above object, two transparent substrates formed with an aspherical lens processing on one side and an electrode formed on the other side of the edge except for the center portion are disposed such that the electrodes face each other. A conductive intermediate substrate having an opening formed in a center thereof is coupled between the two insulating substrates, and a hydrophobic insulating layer is formed on an inner surface of the conductive intermediate substrate to define the opening; The space between the substrates is characterized in that the conductive liquid and the non-conductive liquid is filled.

Hereinafter, the present invention will be described in detail with reference to exemplary embodiments shown in the accompanying drawings.

FIG. 5 shows the optical properties of the spherical lens, and FIG. 6 shows the optical properties of the aspheric lens.

Since the optical properties of the conventional liquid lens are determined only by the curvature of the interface between the liquids, in order to compensate for the difficulty in adjusting the optical properties, the present invention uses an upper and lower substrate in the form of an aspheric lens instead of the upper and lower planar substrates of the liquid lens. do.

In the case of the spherical lens 110 illustrated in FIG. 5, when light passes through the lens, light passing through the periphery of the lens forms a focus at a shorter distance than light passing through the center of the lens. It is called spherical aberration. If spherical aberration causes light to scatter around the point instead of as a point, the image becomes less clear. In case of using a top and bottom substrate in the form of a spherical lens 110 instead of a top and bottom substrate in a conventional liquid lens, such a spherical aberration problem occurs. When using another spherical lens to correct this, it is difficult to make a compact liquid lens module. It becomes difficult.

Meanwhile, when the aspherical lens 120 as illustrated in FIG. 6 is used, spherical aberration can be eliminated to form an accurate focus and make the liquid lens module more compact.

Meanwhile, the aspherical lens 120 may be manufactured by a known injection molding method using a mold having a shape suitable for each material or a lens molding method using a known high temperature molding machine in the case of a small glass substrate or a synthetic resin substrate. It can also be machined using a computer controlled aspheric grinding machine. Aspheric lenses and methods for processing aspherical lenses of a different type from those shown in FIG. 6 are well known, and thus description thereof is omitted herein. The method will be described in detail.

7 is a schematic diagram of a structure of an aspherical liquid lens module according to a first embodiment of the present invention. 7 illustrates a cross-sectional view of the three-dimensional aspherical liquid lens module cut in the longitudinal direction.

The aspheric liquid lens module of FIG. 7 is composed of a combination of an upper substrate structure 200, an intermediate substrate structure 300, and a lower substrate structure 400.

The upper substrate structure 200 is formed of an insulating material such as glass, and an upper substrate 210 having a central portion processed in the form of an aspherical lens, and a bonding layer 220 formed by depositing a material such as Cr or Ti on the upper substrate 210. ), The upper electrode layer 230 formed by depositing Au, Sn or the like on the bonding layer 220, and the metal such as Au or Sn on the upper electrode layer 230 for conductive connection with the intermediate substrate 310. It is configured to include a metal bump 240 formed of a material, and is coupled to the intermediate substrate structure 300 in the state in which the upper substrate structure 200 is inverted in FIG.

In the intermediate substrate structure 300, a bonding layer 320 and an intermediate electrode layer 330 for connecting to the metal bump 240 are sequentially formed on the conductive intermediate substrate 310, which is easy to deposit an insulating layer, such as silicon. Side and bottom surfaces of the substrate 310 are configured to be coated with a hydrophobic insulating film 340 such as parylene.

In addition, the lower substrate structure 400 may be formed of an insulating material such as glass, and a bonding layer formed by depositing a material such as Cr or Ti on the lower substrate 410 having a central portion processed into an aspheric lens shape. 420, a lower electrode layer 430 formed by depositing a material such as Au and Sn on the bonding layer 420, and a hydrophobic insulating layer 440 such as parylene formed on the lower electrode layer 430.

In the configuration of FIG. 7, the metal bumps 240 provide upper and lower spaces to secure sufficient capacity of the aqueous solution required for smooth operation, such as adjusting the focal length of the liquid lens module, and at the same time, the upper electrode layer 230 of the upper substrate structure 200. And the intermediate electrode layer 330 of the intermediate substrate structure 300 and the intermediate substrate 310 main body. In addition, since the lower surface of the upper electrode layer 230 of the upper substrate structure 200 is spaced apart from the upper surface of the middle electrode layer 330 of the intermediate substrate structure 300 by the metal bumps 240, the lower surface of the upper electrode layer 230 is disposed on the lower surface of the upper electrode layer 230. It becomes easy to install a wire (not shown) for power supply.

In addition, in the configuration of FIG. 7, a space defined by an upper portion of the upper substrate 210, that is, an edge portion 230, and a lower electrode layer 430 formed at an edge portion of the lower substrate 410 may be provided. The confined space forms an optical path of the same size. In this specification, the cross-sectional diameter of the optical path through which light passes through the liquid lens is called a lens effective diameter.

In addition, as shown in FIG. 7, the hydrophobic insulating layer 340, which is stably coupled to the intermediate substrate 310 and the lower electrode 440, such as parylene, is made of a material having both insulation and hydrophobicity. Since the intermediate substrate structure 300 and the lower substrate structure 400 are sealed to each other by using 440, the insulating film and the hydrophobic film need not be formed separately, thereby simplifying the process and forming a uniform film on the inner wall of the liquid lens structure in one step. In this case, since the solid and easy coupling between the hydrophobic insulating layers 340 and 440 is possible, the hermetic sealed small aspherical liquid lens module can be configured.

In the first embodiment of the present invention, parylene, a polycrystalline amorphous linear polymer having excellent deposition property, insulation property, hydrophobicity, and film uniformity, was used as the material of the hydrophobic insulating films 340 and 440. And other known materials with uniformity of film are not excluded.

Nevertheless, parylene proved to be the most suitable material because of the following properties of parylene

Parylene is a coating agent suitable for the coating of thin films and thin layers having excellent dielectric properties, gas barrier properties and mechanical properties. Excellent insulation, hydrophobicity and surface protection, no pinhole formation, uniform coating over the entire coating surface, inert material harmless to human body, electrical insulation, moisture protection, chemical isolation, mechanical protection, It has functions such as increased lubricity and surface protection.

Parylene coatings are also possible at room temperature, minimizing the thermal stress on the structure during coating and the low degree of cure to minimize mechanical stress on the structure. Parylene is also a transparent material with no light absorption, making it suitable for optical applications.

8 is a process diagram of manufacturing a top substrate of an aspherical liquid lens module according to a first embodiment of the present invention.

First, the upper portion 210 is prepared by processing a central portion of an insulating material made of a transparent material such as glass in the form of an aspheric lens, and then depositing the upper electrode layer 230 through deposition of a metal material such as Au on the upper substrate 210. It forms (S110). When the adhesion between the electrode material and the upper substrate is low, a metal having excellent adhesion to glass, such as Cr and Ti, is first deposited to form the bonding layer 220, and the metal for the electrode is again formed on the bonding layer 220. The upper electrode layer 230 is formed by depositing Au.

Subsequently, in order to conductively seal the intermediate substrate and the upper substrate 210, the metal bumps (Au), tin (Sn), etc., preferably made of the same material as the upper electrode layer 230 may be formed on the upper electrode layer 230. bumps 240 are formed. In order to form the metal bumps 240, the bump material is plated using the patterned photoresist 235 (S120), and then the photoresist 235 is removed (S140), or a patterned screen (not shown) is formed. A known method such as a screen printing method using the above method can be used.

The shape of the metal bumps 240 is not limited, but the structure of the metal bumps 240 may be a structurally simple shape such as a rectangular or circular band having a radius between the edge of the upper substrate 210 and the lens effective diameter 215 at the center of the upper substrate 210. It is preferable in the process. In FIG. 8, the metal bumps 240 are exemplarily illustrated as having a rectangular structure.

Next, after the photoresist 245 having a pattern corresponding to the lens effective diameter 215 is formed on the upper electrode layer 230 as an anti-etching film (S150), the bonding layer 220 and the upper electrode layer formed of an opaque material are formed. The central portion of the 230 is removed to the size of the lens effective diameter 215 to complete the upper substrate structure 200 in which the bonding layer 220 and the upper electrode layer 230 are formed only at the edge portion (S160).

9 is an intermediate substrate manufacturing process diagram of an aspherical liquid lens module according to a first embodiment of the present invention.

First, a suitable material is prepared as the intermediate substrate 310. As the material of the intermediate substrate 310, an insulating film and a hydrophobic film can be stably formed on the surface, such as silicon (Si), and even if a continuous operating voltage is applied to the lens structure, a change in the properties of the lens structure is prevented, resulting in reliable operation. It is possible to use a conductive material, and because of its excellent workability, a material suitable for mass production should be used.

Subsequently, an opening is formed in the center of the intermediate substrate 310 by etching, inductively coupled plasma (ICP), drilling, sandblasting, or the like to provide an optical path and store liquid for the lens (S210). In this case, in order to secure a sufficient capacity of the lens liquid, the opening of the intermediate substrate 310 may be formed larger than the lens effective diameter 215.

Meanwhile, when an opening is formed in the intermediate substrate 310, a native oxide may be formed on the surface of the intermediate substrate 310 to prevent bonding with the metal layer. Thus, hydrogen fluoride (HF) or buffered oxide etchant The naturally occurring oxide film should be removed by a wet etching method using a).

Subsequently, as soon as the naturally occurring oxide film is removed, an electrode metal such as Au is deposited on the intermediate substrate 310 to form the intermediate electrode layer 330 (S220). In this case, in order to stably bond the intermediate substrate 310 and the intermediate electrode layer 330, a metal having excellent adhesion such as Cr and Ti may be deposited first to form the bonding layer 320.

Next, a hydrophobic insulating film 340 is formed by coating a material that is stably bonded to the intermediate substrate 310 such as parylene and has insulation and hydrophobicity at the same time by deposition or the like (S230), and the intermediate layer is a conductive layer. The intermediate substrate structure 300 is completed by removing the hydrophobic insulating layer 340 on the intermediate electrode layer 330 to expose the electrode layer 330 (S240 and S250).

FIG. 10 is a process diagram of manufacturing a lower substrate of an aspherical liquid lens module according to a first exemplary embodiment of the present invention.

In order to form the lower substrate structure 400, first, the bonding layer 420 and the lower electrode layer 430 are formed on the lower substrate 410 formed of an insulating material and processed at the center thereof in the form of an aspheric lens. The substrate 210 may be formed by an etching method using a photoresist process, or may be performed by a lift-off method as described below.

First, a lower substrate 410 of an insulator made of a transparent material such as glass is prepared, and a photoresist 415 having a lens effective diameter 215 pattern is coated on the upper substrate 410 (S310). The bonding layer 420 is formed by first depositing a metal layer having excellent adhesion to the lower substrate 410 such as Ti, and the upper electrode layer 330 is formed by depositing an electrode metal such as Au on the bonding layer 420. After (S320), the photoresist 415 is removed (Lift-off) (S330).

Subsequently, a hydrophobic insulating film 440 is coated with a material such as parylene, which is stably bonded to the lower substrate 410, the bonding layer 420, and the lower electrode layer 433, and has an insulating property and a hydrophobic property by a deposition method. ) And the hydrophobic insulating film 440 inside the lens effective mirror 215 using the photoresist 445 (S350) to complete the lower substrate structure 400 (S360 and S370). In this case, the hydrophobic insulating layer 440 should be patterned to properly expose the upper surface of the lower electrode layer 430 in consideration of a wire connection for applying power to the lower electrode layer 430.

11 is a substrate bonding process diagram of the aspherical liquid lens module according to the first embodiment of the present invention.

In FIG. 11, the aspherical liquid lens module is completed by combining the upper substrate structure 200, the intermediate substrate structure 300, and the lower substrate structure 400 prepared through the processes of FIGS. 8 to 10.

First, heat and pressure are applied to the hydrophobic insulating layer 440 of the lower substrate structure 400 and the hydrophobic insulating layer 340 of the intermediate substrate structure 300 to bond them by a thermocompression bonding method (S410). In this case, the positions of the hydrophobic insulating layers 340 and 440 are preferably spaced inward from the edge of the lower electrode layer 430 so as to expose a part of the lower electrode layer 430 to facilitate wire connection.

In order to prevent bubbles from being trapped in the lower substrate 410, the bonding layer 420, the lower electrode layer 430, and the hydrophobic insulating layers 340 and 440 during the subsequent injection of the aqueous electrolyte solution 500, oxygen (O ₂ ) and The same hydrophilic gas plasma is used to modify the interior of the structure to be hydrophilic.

Subsequently, the electrolyte solution 500 such as water and the non-electrolyte solution 600 such as oil are sequentially injected into the hydrophilic modified structure (S420). The injection amount of the electrolyte aqueous solution 500 and the non-electrolyte aqueous solution 600 should be adjusted so that the focus change function of the liquid lens can be smoothly performed. In particular, the non-electrolyte aqueous solution 600 considers a natural leak when the upper substrate structure 200 is combined. Should be sufficiently injected.

Next, the metal bumps 240 of the upper substrate structure 200 and the intermediate electrode layer 330 of the intermediate substrate structure 300 are bonded by, for example, bonding using a homogeneous metal diffusion phenomenon using heat. Complete the liquid lens module (S430).

12 is a schematic diagram of a structure of an aspherical liquid lens module according to a second embodiment of the present invention.

Comparing the aspheric liquid lens module of FIG. 12 with the aspheric liquid lens module of FIG. 7, the intermediate substrate 310 and the upper electrode layer 230 are directly coupled through the metal bumps 340, thereby simplifying the manufacturing process. There is an advantage.

FIG. 13 is a process chart of manufacturing an intermediate substrate structure of an aspherical liquid lens module according to a second exemplary embodiment of the present invention.

In the case of the aspherical liquid lens module of the second embodiment, since the structure and manufacturing method of the upper substrate structure 200 and the lower substrate structure 400 are not different from those of the first embodiment, only the manufacturing method of the intermediate substrate structure 300 is used here. Let's explain.

First, an opening is formed in the center of the intermediate substrate 310 (S510).

Subsequently, a hydrophobic insulating film 340 is formed on the surface of the intermediate substrate 310 by using a material easily deposited on the material of the intermediate substrate 310 (S520). In the case of using the silicon intermediate substrate 310, parylene, which is well deposited on silicon, is suitable as the hydrophobic insulating layer 340. In particular, in the case of parylene, there is an advantage in that a uniform hydrophobic film may be formed on the sidewall of the silicon intermediate substrate 310 because of excellent step coverage.

Next, in order to form a fine passage for the metal bump 240 of the upper substrate structure 200, after applying a dry film photoresist (DFR) 345 having a fine passage pattern with an etching prevention film (S530), The parylene hydrophobic insulating layer 340 corresponding to the passage is removed (S540) to complete the intermediate substrate structure 300 having the metal bump passage formed therein.

14 is a substrate bonding process diagram of an aspherical liquid lens module according to a second embodiment of the present invention.

First, the hydrophobic insulating film 440 of the lower substrate structure 400 and the hydrophobic insulating film 340 of the intermediate substrate structure 300 are bonded (S610).

In order to prevent bubbles from being trapped in the lower substrate 410, the bonding layer 420, the lower electrode layer 430, and the hydrophobic insulating layers 340 and 440 during the subsequent injection of the electrolyte aqueous solution 500, such as oxygen (O ₂ ). The interior of the structure is hydrophilically modified using a hydrophilic gas plasma.

Subsequently, the electrolyte solution 500 such as water and the non-electrolyte solution 600 such as oil are sequentially injected into the hydrophilic modified structure (S620). The injection amount of the electrolyte aqueous solution 500 and the non-electrolyte aqueous solution 600 should be controlled to smoothly perform the focus change function of the liquid lens, and the non-electrolyte aqueous solution 600 is sufficient considering the leakage when the upper substrate structure 200 is coupled. Should be injected.

Next, the metal bump 240 of the upper substrate structure 200 is inserted into the micropath of the hydrophobic insulating layer 340 deposited on the intermediate substrate 310 of the intermediate substrate structure 300, and then, for example, by using a thermal diffusion process or the like. The bump 240, the intermediate substrate 310, and the hydrophobic insulating film 340 are bonded to each other to complete the liquid lens module (S630).

On the other hand, there is no limitation on the planar shape of the aspherical liquid lens module of the present invention, it can be appropriately processed in the field and applications to which the liquid lens is applied. 15 and 16 show exemplary top views of such aspherical liquid lens modules. As shown in FIGS. 15 and 16, the upper substrate 210 of the aspherical liquid lens module may be manufactured in various forms, for example, a rectangle and a circle. However, the lens effective diameter 215 is formed in a circle due to the characteristics of the lens.

17 is a schematic diagram of the structure of an aspherical liquid lens module according to a third embodiment of the present invention.

The aspherical liquid lens of FIG. 17 includes an insulating film (silicon oxide film) 1130 and a hydrophobic film (teflon film) on a silicon substrate 1100 in which a hole for receiving a conductive liquid (water) and a non-conductive liquid (oil) is formed in the center. 1140 is formed to form an intermediate substrate, the lower electrode 1160 is formed on the lower substrate 1150 made of glass, and then the lower glass substrate 1150 is bonded to the silicon substrate 1100 which is an intermediate substrate, The liquid 1000 and the non-conductive liquid 1050 are sequentially injected, and the upper glass substrate 1170 is bonded to the upper portion of the silicon substrate 1100 to complete an aspherical liquid lens module, wherein curing such as thermosetting epoxy or UV epoxy is performed. Sealing the glass substrates 1150 and 1170 and the silicon substrate 1100 using an epoxy o-ring (not shown), and the glass substrates 1150 and 1170 and the silicon substrate using the first and second packaging modules (not shown). It is completed by fixing the 1100 firmly.

18 is a diagram illustrating a manufacturing process of an aspherical liquid lens manufacturing module according to a third embodiment of the present invention.

First, a hole 1120 is formed on the silicon substrate 1100, and an insulating film 1130 is formed on the silicon substrate 1100 on which the hole 1120 is formed. The insulating film 1130 is preferably a silicon oxide film (SiO ₂ ) formed through a thermal oxidation process of the silicon substrate 1100. Subsequently, a hydrophobic film 1140 such as a Teflon film or a parylene film is coated on the insulating film 1130 (S1110). When the hydrophobic film 1140 is coated, the conductive liquid water contacts only the hydrophilic lower glass substrate 1150 and the hydrophobic film 1140 is coated so that the hydrophobic film 1140 is not in contact with the sidewall of the hydrophobic hole 1120. You can maintain a constant shape. On the contrary, when the silicon sidewall is hydrophilic, the boundary line between the water, which is a conductive liquid, and the sidewall, is not in a constant position, and thus the interfacial curvature of the conductive liquid and the nonconductive liquid used as the lens becomes inconsistent, thereby reducing the reliability of the lens. The hydrophobic membrane 1140 may be obtained by dipping or spraying the coating using a Teflon coating solution produced by Dupont or 3M as a material of the hydrophobic membrane 1140.

In the third embodiment, since silicon, which is a conductive material, is used as the substrate material, it is possible to overcome the difficulty in forming the electrode, and also, as one of the semiconductor processes, a more stable insulating film is used by using a thermal oxidation process that has proven stability. Since it can be formed, a uniform voltage can be continuously applied, so that driving of the manufactured liquid lens can be performed stably. In addition, since the silicon substrate 1100, which is an intermediate substrate, functions as an electrode itself, there is no need to install a separate electrode.

Next, the lower electrode 1160 is formed on the lower substrate 1150 made of glass (S1120).

Subsequently, the lower glass substrate 1150 on which the lower electrode 1160 is formed is bonded to the silicon substrate 1100 (S1130).

Next, the conductive liquid 1000 and the non-conductive liquid 1050 are sequentially injected (S1140), and the upper glass substrate 1170 is bonded to the upper portion of the silicon substrate 1100 to complete an aspherical liquid lens module (S1150).

Meanwhile, when the aspheric glass substrates 1150 and 1170 and the silicon substrate 1100 are bonded to each other using liquid epoxy, bubbles may be generated due to outgasing while the epoxy is cured. In the aspherical liquid lens module according to the fourth embodiment of the present invention, the glass substrates 1250 and 1290 and the silicon substrate 1200 are sealed by using a cured epoxy o-ring 1270 and 1280 such as thermosetting epoxy or UV epoxy. Bubble generation can be prevented, in which case hardened solid epoxy O-rings 1270 and 1280 are formed at the junction between the two substrates.

20 is a diagram illustrating a manufacturing process of an aspherical liquid lens module according to a fourth exemplary embodiment of the present invention.

First, a hole 1220 is formed on the silicon substrate 1200, an insulating film 1230 is formed of a silicon oxide film through a thermal oxidation process on the silicon substrate 1200 on which the hole 1220 is formed, and the hole 1220 is formed. The hydrophobic film 1240 is coated on the formed insulating film 1230 on the inner surface (S1210).

Next, the lower electrode 1260 is formed on the lower substrate 1250 made of glass (S1220).

Next, an O-ring 1270 for sealing the liquid is formed on the lower electrode 1260 (S1230). The O-ring may use a general rubber O-ring, a urethane O-ring or an epoxy O-ring which is cured by dispensing or screen printing.

Subsequently, the lower glass substrate 1250 and the silicon substrate 1200 on which the O-rings 1270 are formed are bonded to each other by using the first packaging module 1300 (S1240). Since the silicon substrate 1200 itself functions as an electrode, there is no need to install a separate electrode.

Next, the conductive liquid 1000 and the non-conductive liquid 1050 are sequentially filled in the liquid storage part, that is, the hole 1220 (S1250). In this case, the non-conductive liquid 1050 is filled with the surface tension of the liquid so that the surface of the non-conductive liquid 1050 is convex higher than the surface of the silicon substrate 1200.

Next, the non-conductive liquid is pushed out onto the upper glass 1290 formed with the O-ring 1280 to cover the silicon substrate 1200 so that no bubbles are generated, and the solution inside the liquid lens flows using the second packaging module 1310. The upper glass 1290 and the silicon substrate 1200 are secondly firmly fixed so as not to come out.

Meanwhile, in FIG. 20, the O-rings 1280 are formed on both the upper and lower surfaces of the upper glass 1290, and the O-rings 1270 are formed on the upper surface of the lower glass substrate 1250. , 22, 23, and 24 may be modified, and the inner surface structure of the silicon substrate 1200 may also be formed as shown in FIG. 25.

Meanwhile, the cross section of the upper glass 1290 and the lower glass 1270 may be rectangular as shown in FIG. 26 or may be circular as shown in FIG. 27. In FIGS. 26 and 27, the inner surface of the silicon substrate 1200 on which the insulating film 1230 and the hydrophobic film 1240 are formed is shown through the lens of the center portion, but the size of the hole 1220 of the silicon substrate 1200 is shown. It may vary depending on, it does not limit the scope of the invention.

Although the present invention has been described above using a preferred embodiment of the present invention, the principles of the present invention are not limited by the scope described in the above embodiments, and those skilled in the art can make various modifications within the technical scope defined by the claims. And modifications, and such modified modifications should also be interpreted as falling within the scope of the present invention.

Meanwhile, in the drawings of the present specification and the detailed description of the present invention, for convenience of description, the terms, such as an upper substrate and a lower substrate, are used to distinguish the upper and lower sides based on the vertical state of the liquid lens module, but the manufacture of the liquid lens module is performed. If the arrangement direction is changed at the time of use or use, the division of the upper and lower sides is no longer valid, so the appended claims should also be interpreted in consideration of this.

According to the present invention, a stable aspherical liquid lens module and a manufacturing method thereof are provided by stably forming an electrode and an insulating film using silicon as a substrate material as a substrate material.

In addition, according to the present invention, by sealing the liquid by using the O-ring in the solid state to suppress the generation of bubbles due to gas leakage, and by using a separate packaging module to fix the liquid lens structure by using a separate packaging module significantly improved the robustness and reliability A lens module and a method of manufacturing the same are provided.

In addition, according to the present invention, an aspherical liquid lens module and a method of manufacturing the same are provided in which a process can be simplified and a film can be formed uniformly by simultaneously generating an insulating film and a hydrophobic film by using a hydrophobic insulating film.

In addition, according to the present invention, the formation of bubbles during the manufacturing of the liquid lens module is prevented, and by forming a seal using the same material between the substrates, a completely hermetic sealing, that is, a hermetic sealing is realized without a separate fixing mechanism. An aspherical liquid lens module and a method of manufacturing the same are provided.

In addition, according to the present invention, an aspherical liquid lens module having improved optical properties of a lens by using an aspherical lens-type upper and lower substrate and a method of manufacturing the same are provided.

Furthermore, according to the present invention, an aspherical liquid lens module suitable for mass production is provided by easily forming an insulating film and a hydrophobic film by using a silicon wafer as a substrate material, and a manufacturing method thereof.

Claims (12)

Providing a silicon substrate having a hole formed in the center thereof; Forming an insulating film on the silicon substrate and coating a hydrophobic film; Providing a transparent lower substrate on which an electrode is formed; Bonding the silicon substrate to maintain a seal on the lower substrate; Filling a liquid reservoir enclosed by the hole and the lower substrate with a conductive liquid and a non-conductive liquid; Bonding a transparent upper substrate to maintain a seal on the silicon substrate, The aspherical liquid lens module manufacturing method of the upper substrate and the lower substrate is characterized in that the center portion is aspheric lens processing. The method of claim 1, The insulating film is a silicon oxide film formed using a thermal oxidation process. The method of claim 1, In the bonding step of the lower substrate and the silicon substrate, an o-ring is formed on at least one surface of an upper surface or a lower surface of the lower substrate, and sealing is performed by fixing the lower substrate and the silicon substrate using a first packaging module. Assembling the lower substrate and the silicon substrate to maintain the aspheric liquid lens module. The method of claim 1, The bonding of the upper substrate and the silicon substrate may include sealing by forming an O-ring on at least one surface of an upper surface or a lower surface of the upper substrate, and fixing the upper substrate and the silicon substrate using a second packaging module. Assembling the upper substrate and the silicon substrate to maintain the aspheric liquid lens module. delete Providing a conductive intermediate substrate having an opening formed in the center thereof; Forming an intermediate electrode on an upper surface of the conductive intermediate substrate; Forming a hydrophobic insulating film on an inner surface and a lower surface of the intermediate substrate; Providing a transparent lower substrate having an upper electrode formed at an edge of an upper surface thereof; Coating a second hydrophobic insulating film on at least a portion of an upper surface of the upper electrode formed on the lower substrate; Bonding the intermediate substrate and the lower substrate through a sealing coupling between the hydrophobic insulating film and the second hydrophobic insulating film; Filling a conductive liquid and a non-conductive liquid in a space surrounded by the opening and the lower substrate; Providing a transparent upper substrate having an upper electrode formed at an edge of an upper surface thereof; Forming a metal bump on at least a portion of an upper surface of the upper electrode; And Bonding the upper substrate and the intermediate substrate through a sealing coupling of the metal bump and the intermediate electrode, The aspherical liquid lens module manufacturing method of the upper substrate and the lower substrate is characterized in that the center portion is aspheric lens processing. The method of claim 6, The hydrophobic insulating film is a parylene film, characterized in that the aspherical liquid lens module manufacturing method. A conductive intermediate substrate having an aspherical lens processing on one surface and two transparent insulating substrates having electrodes formed on the edge of the other surface except the central portion so that the electrodes face each other, and an opening formed in the center between the two insulating substrates. And a hydrophobic insulating film is formed on an inner surface defining the opening of the conductive intermediate substrate, and a space between the two insulating substrates and the conductive intermediate substrate is filled with a conductive liquid and a non-conductive liquid. Aspheric liquid lens module. The method of claim 8, The hydrophobic insulating film is formed on an open surface of an electrode of at least one of the two insulating substrates, and the hydrophobic insulating film is formed on one surface of the conductive intermediate substrate facing the open surface of the electrode on which the hydrophobic insulating film is formed. Aspheric liquid lens module, characterized in that. The method of claim 9, The hydrophobic insulating film is formed on an open surface of an electrode of one of the two insulating substrates, and the hydrophobic insulating film is formed on one surface of the conductive intermediate substrate facing the open surface of the electrode on which the hydrophobic insulating film is formed. A conductive bump is formed on an open surface of the electrode of the other substrate, and an electrode for electrical coupling with the conductive bump is formed on the other surface of the conductive intermediate substrate facing the open surface of the electrode on which the conductive bump is formed. An aspherical liquid lens module, characterized in that. The method of claim 8, The hydrophobic insulating layer is formed on an open surface of an electrode of one of the two insulating substrates, and a conductive bump is formed on an open surface of the electrode of the other one of the substrates, and the conductive intermediate substrate facing the two insulating substrates is formed. The hydrophobic insulating film is formed on both sides of the aspheric liquid lens module, characterized in that the conductive bump is electrically connected to the conductive intermediate substrate through the hydrophobic insulating film formed on one surface of the conductive intermediate substrate. The method according to any one of claims 8 to 11, The hydrophobic insulating film is an aspheric liquid lens module, characterized in that the parylene film.

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