JPWO2008102582A1 - Optical element manufacturing method and optical element - Google Patents

Abstract

In order to provide an optical element manufacturing method and an optical element capable of manufacturing an optical element having uniform performance in a large amount, the sealing member 30 is sandwiched between the upper mold 10 and the lower mold 20 so that the injected thermosetting is performed. Even if the viscosity of the functional resin is low, it does not leak out from the divided surfaces of the upper mold 10 and the lower mold 20. The injected thermosetting resin is cured by coming into contact with the heated upper cavity 11 and the lower cavity 21, thereby forming a circular member CY (FIG. 2) including the optical elements OE arranged in a matrix. it can.

Description

  The present invention relates to an optical element manufacturing technology, for example, an optical element manufacturing method and an optical element suitable for a small camera mounted on a mobile phone or the like.

  In recent years, mobile phones and handy personal computers (portable personal computers) incorporating small cameras have been developed. For example, a mobile phone equipped with a small camera can capture a caller's video with a built-in small camera, capture it as image data, and transmit the image data to the other party. Such a small camera is generally composed of an image sensor and a lens. That is, an optical image can be formed on the image sensor by the lens, and an electrical signal corresponding to the optical image can be generated by the image sensor.

By the way, cost reduction is being promoted for a small camera used in a mobile phone or a handy personal computer. Therefore, it is desired to reduce the cost of a lens mounted on the small camera by mass production. Here, in Patent Document 1, a lens array including a plurality of optical elements arranged in a matrix is formed, and after being stacked on a wafer on which image sensors are similarly formed in a matrix, cutting is performed by dicing. Discloses a technique for forming individual modules.
JP 2002-290842 A

  However, Patent Document 1 does not disclose how to form a lens array. For example, when trying to form a lens array using a thermoplastic resin generally known as a lens material, it is difficult to form a lens array that is thin with respect to its diameter because of its high viscosity and poor flowability. In particular, there is a risk that molding defects may occur in an optical element far from the gate.

  In addition, when the conventional thermoplastic resin is cut and separated by dicing or the like, the resin is easily melted by the generated processing heat, which adheres to the cutting edge and reduces the tool life. For this reason, it is necessary to change the tool frequently, and there is a risk of reducing the manufacturing efficiency of the optical element.

  The present invention has been made in view of the problems of the prior art, and an object thereof is to provide an optical element manufacturing method and an optical element capable of manufacturing a large number of optical elements having uniform performance.

The manufacturing method of the optical element according to claim 1 is:
Disposing a seal member between the first mold and the second mold;
A plurality of optical elements arranged in a matrix form by injecting and solidifying a liquid energy curable resin in a state where the sealing member is disposed between the first mold and the second mold; And a step of integrally forming the forming member.

  For example, a thermosetting resin is in a liquid state at room temperature, but is cured by heating to a certain temperature, and has a characteristic that after curing, it is difficult to melt and deform even if further heated. Since such a thermosetting resin has a low viscosity at room temperature, it easily enters between molds. Therefore, a molded member including a plurality of optical elements arranged in a matrix has a thickness with respect to the outer dimension. Even if it is thin, the resin flows to the cavity of each optical element, and a highly accurate optical element can be easily molded. That is, there is an advantage that a large amount of optical elements can be manufactured by one molding. However, since the thermosetting resin having a low viscosity is likely to enter the gap between the molds, the molding operation may be hindered if the resin that has entered the gap is cured there. On the other hand, by arranging a sealing member between a pair of first mold and second mold forming a cavity for molding a molding member, a plurality of optical elements arranged in a matrix form inside the sealing member. Since the molded member including the element is molded integrally, the leakage of thermosetting resin with low viscosity is suppressed, and clogging of the resin does not occur even if molding is repeated. Can be efficiently formed.

  The seal member may be insert molding incorporated as a separate member, but can also be formed between the first mold and the second mold using two-color molding. As the sealing member, any material may be used as long as it has characteristics such as withstanding the molding temperature of the optical element, having a certain degree of elasticity, and not being affected by the energy curable resin to be sealed. As a material for the seal member, silicone resin, fluororesin, polyimide, polyamideimide, 66 nylon, perfluoroelastomer, or the like is used.

  Furthermore, in the case of a thermosetting resin, once cured, it is difficult to melt even if heated, so when the matrix-shaped optical element in the molded member is cut, it melts and adheres to the blade. Is suppressed, and a large amount of optical elements can be manufactured efficiently. The “energy curable resin” refers to a resin that is cured by applying energy, and includes, for example, a thermosetting resin that is cured by applying heat, and a UV curable resin that is cured by applying ultraviolet light. In any case, immediately before curing, the liquid is low in viscosity and rich in fluidity.

  Here, “thermosetting resin” includes silicone resin, allyl ester, acrylic resin, epoxy resin, polyimide, urethane resin, and “UV curable resin” includes silicone resin, acrylic resin. , Epoxy resin, polyimide, urethane resin and the like.

  The method for manufacturing an optical element according to claim 2 is characterized in that, in the invention according to claim 1, the outer shape of the molded member is circular, but is polygonal. Also good. For example, when the outer peripheral shape of the molded member is a square with rounded corners, there is a merit that a positioning portion as described in claim 6 is unnecessary. However, in such a case, the molding shrinkage is not rotationally symmetric, and the shape after curing may be a pincushion shape or a barrel shape. As a result, the optical axis position of the optical element is shifted from place to place and is not evenly spaced, or the molding optical surface is deformed, so it is better that the outer peripheral shape of the molding member be as close to a rotationally symmetric shape as possible. If the corners are formed into a large arc shape, and preferably a perfect circle, since the rotationally symmetric shape, the curing shrinkage becomes rotationally symmetric and molding transferability is improved.

  The optical element manufacturing method according to claim 3 is the invention according to claim 1 or 2, wherein the seal member is formed so as to surround the molded member.

  The method for manufacturing an optical element according to claim 4 is the invention according to any one of claims 1 to 3, wherein the outer periphery of the molded member is thicker than the thickness of the optical element. The outer peripheral part is formed. Since the molded member including a large number of optical elements arranged in a matrix has a larger outer diameter with respect to the axial thickness of the optical element, the adhesion with the transfer surface of the mold is increased, and the molded member is molded. There is a risk of partial damage when releasing the mold. Therefore, in the present invention, by forming an outer peripheral portion thicker than the thickness of the optical element on the outer periphery of the molding member, the molding member is reinforced and separated from the mold integrally without being damaged during mold release. I can do it.

  The method for manufacturing an optical element according to claim 5 is the invention according to any one of claims 1 to 4, wherein a plurality of the molded members are molded, and a plurality of the molded members are formed. After the corresponding optical elements are superposed and bonded, the optical elements are separated as a unit. Thereby, the trouble of positioning and bonding individual optical elements can be saved, and a high-performance optical system in which a plurality of optical elements are stacked can be mass-produced.

  The method for manufacturing an optical element according to claim 6 is the invention according to claim 5, wherein at least one of the moldings is provided with a positioning portion for positioning when the plurality of molding members are overlapped. It is provided in the member.

  The method for manufacturing an optical element according to claim 7 is the invention according to any one of claims 1 to 6, wherein the molding member has a rib between the rows of the optical elements. Therefore, by reinforcing the molded member, the molded member can be separated from the mold integrally without being damaged at the time of mold release. In addition, you may use this rib as a positioning part which positions when it overlaps | superposes the said some shaping | molding member.

  The method for producing an optical element according to claim 8 is the invention according to any one of claims 1 to 7, wherein the liquid energy curable resin has a thickness of the molded member. When viewed in the direction, it is injected from the center of the cavity forming the molding member. As a result, the liquid energy curable resin injected between the first mold and the second mold spreads radially, so that a uniform optical element is formed regardless of the position of the matrix optical element. be able to.

  The method for manufacturing an optical element according to claim 9 is the invention according to any one of claims 1 to 7, wherein the liquid energy curable resin is injected from a plurality of locations. It is characterized by. This is because, depending on the dimensions of the molded member, injection from a plurality of locations may be more efficient.

  The method for producing an optical element according to claim 10 is the invention according to any one of claims 1 to 9, wherein the liquid energy curable resin is cured under a pressure of 20 MPa or more. Because it is characterized by processing, it suppresses gas that is likely to be generated during curing, eliminates bubbles remaining inside the optical element as much as possible, and further suppresses the occurrence of sink marks during shrinkage, resulting in high-quality and high-precision optics. The element can be molded. In addition, when an energy curable resin is injected under pressure, sealing with a seal member is particularly effective.

  The method of manufacturing an optical element according to claim 11 is the invention according to any one of claims 1 to 10, wherein the seal member has a recess, and a side of the recess. One outer surface of the liquid crystal is opposed to the first mold, the other outer surface is opposed to the second mold, and the liquid energy curable resin is injected into the recess. . As a result, even when the liquid energy curable resin is injected under high pressure, the sealing effect is enhanced according to the pressure, so that resin leakage can be suppressed as much as possible.

  The method for manufacturing an optical element according to claim 12 is the invention according to any one of claims 1 to 10, wherein the seal member is an O-ring. Therefore, the sealing effect can be realized with a simple configuration.

  The method for producing an optical element according to claim 13 is the invention according to any one of claims 1 to 12, wherein the energy curable resin is optically transparent. Therefore, a desired optical function can be exhibited when the molded product is used as an optical element.

  The optical element according to claim 14 is manufactured by the method for manufacturing an optical element according to any one of claims 1 to 13.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method and optical element of an optical element which can manufacture the optical element which has uniform performance in large quantities can be provided.

It is a figure which shows the manufacturing process of the optical element concerning 1st Embodiment, (d) has expanded the IC part shown by the arrow of (b). It is a figure which shows the circular member containing the optical element manufactured by the manufacturing method of this Embodiment. It is a perspective view which shows the manufacturing process of a camera module. It is a figure which shows the metal mold | die used at the manufacturing process of the optical element concerning 2nd Embodiment. It is a figure which shows the circular member formed with the metal mold | die shown in FIG. 4, (c) has expanded the VC part shown by the arrow of (b). It is a figure which shows the metal mold | die used at the manufacturing process of the optical element concerning 3rd Embodiment. It is a figure which shows the circular member formed with the metal mold | die shown in FIG. It is a figure which shows the other example of the injection | pouring position of a thermosetting resin.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Upper mold | type 10A 1st upper mold | type 10B 2nd upper mold | type 11 Upper cavity 12 Upper cylindrical recessed part 13 Upper annular recessed part 14 Upper linear recessed part 15 Runner 16 Cavity 16a Circular pipe part 16b Inner peripheral surface 17 Runner 17 Upper annular recessed part 17a Peripheral surface 20 Lower mold 21 Lower cavity 22 Lower cylindrical recess 23 Lower annular recess 24 Lower linear recess 25 Circumferential groove 30 Seal member 30 'O-ring 31 Peripheral groove 32 Side surface 40 Heater ASY assembly CY Circular member CY1 to CY3 Circular member CY1a Outer part CY2a Outer part CY3a Outer part CYb Rib DB Dicing blade IS Image sensor OE Optical element OE1 to OE3 Optical element W Semiconductor wafer

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a manufacturing process of the optical element according to the first embodiment, and shows a cross section of a mold. FIG. 2 is a diagram showing a circular member that is a molded member including an optical element manufactured by the manufacturing method of the present embodiment.

  In FIG. 1, a circular convex upper cavity 11 is arranged in a matrix on the lower surface of the upper mold 10, and an upper cylindrical concave portion 12 is formed at the center thereof. An upper annular recess 13 is formed so as to surround. Further, the upper straight concave portion 14 extends from the upper cylindrical concave portion 12 to the upper annular concave portion 13 between the upper cavities 11 in a cross radial manner. In addition, the upper linear recessed part 14 is connected to the nozzle (not shown) which discharges thermosetting resin through the runner 15 which is a penetration path.

  On the other hand, on the upper surface of the lower mold 20, circular lower concave cavities 21 are formed side by side in a matrix corresponding to the upper cavities 11, and a lower cylindrical concave 22 is formed at the center thereof, and a ring-like shape is formed around this A lower annular recess 23 is formed so as to surround the outside of the lower cavity 21. Further, a lower straight concave portion 24 extends from the lower cylindrical concave portion 22 between the lower cavities 21 in a cross-shaped manner toward the lower annular concave portion 23.

  The seal member 30 is made of silicone resin or fluorine resin, and has an annular shape. A circumferential groove 34 is formed on the inner periphery of the seal member 30.

  Next, a method for manufacturing an optical element will be described. First, before clamping, the seal member 30 is attached so as to fit into the lower annular recess 23 of the lower mold 20 from the state where the upper mold 10 and the lower mold 20 are separated as shown in FIG. Further, the upper die 10 is brought closer to the lower die 20 so that the axis of the upper cavity 11 coincides with the axis of the lower cavity 21 (see FIG. 1D which is an enlarged view). Thereby, the seal member 30 is pressed between the upper annular recess 13 and the lower annular recess 23 to be elastically deformed, and comes into close contact with both (see FIG. 1B). Although not shown, the positioning of the upper mold 10 and the lower mold 20 can be performed by, for example, engaging a pin formed on one side with a hole formed on the other side, but is not limited thereto.

  Next, as shown in FIG. 1B, the periphery of the cavity portion of the upper mold 10 and the lower mold 20 is heated by the heater 40 to the curing temperature of the thermosetting resin. In this state, a liquid thermosetting resin is injected between the upper mold 10 and the lower mold 20 through the runner 15 while being pressurized at 20 MPa or more. Since the runner 15 is disposed at the center of a circular cavity formed between the upper mold 10 and the lower mold 20, the resin flows uniformly from the center toward the peripheral sealing member 30, and the thermosetting resin Since the flowability due to the low viscosity is good, an optical element can be formed without causing molding defects.

Furthermore, since the seal member 30 seals between the upper annular recess 13 and the lower annular recess 23, the divided surfaces of the upper mold 10 and the lower mold 20 can be obtained even when the viscosity of the injected thermosetting resin is low. Leakage from the outside is suppressed. The injected thermosetting resin is cured by being in contact with the heated upper cavity 11 and lower cavity 21, whereby the outer peripheral shape including the optical elements OE arranged in a matrix is formed into a molded member CY having a circular shape. FIG. 2) can be formed. Hereinafter, the circular molded member is also referred to as a circular member. After that, when the upper mold 10 is separated from the lower mold 20 and the mold is opened, the seal member 30 becomes the inner peripheral surface and the outer periphery of the lower annular recess 23 of the lower mold 20. Since the surface is constrained by the surface, the circular member CY whose outer peripheral edge is solidified in the circumferential groove 34 remains attached to the lower mold 20 side together with the seal member 30. Therefore, the circular member CY is peeled off from the lower mold 20 together with the seal member 30, and the seal member 30 is further cut to take out the circular member CY including the optical elements OE arranged in a matrix (see FIG. 2). . At this time, even if the optical element OE is thin relative to the diameter of the circular member CY, the annular outer peripheral portion CYa formed by the upper annular recess 13 and the lower annular recess 23 is formed thicker than the thickness of the optical element. Since the rib CYb formed by the upper linear recess 14 and the lower linear recess 24 ensures the rigidity of the circular member CY, it is possible to suppress the circular member CY from being damaged by the force at the time of mold release.

  FIG. 3 is a diagram showing a process of joining the circular member CY formed in this way to the image sensor. As shown in FIG. 3A, the optical element OE of the circular member CY has a matrix shape corresponding to the image sensor IS formed on the semiconductor wafer W. Therefore, when the circular member CY is bonded to the semiconductor wafer W while being positioned, the optical axes of the optical elements OE coincide with the center of the corresponding image sensor IS.

  Thereafter, the assembly ASY formed by bonding the circular member CY and the semiconductor wafer W is linearly cut using the dicing blade DB. Thereby, a camera module in which the optical element OE and the image sensor IS are combined can be obtained.

  FIG. 4 is a diagram illustrating a mold used in the manufacturing process of the optical element according to the second embodiment. FIG. 5 is a view showing a circular member formed by the mold shown in FIG. In the present embodiment, three circular members are formed using three sets of molds, these are combined and bonded together, and cut with a dicing blade or the like to form an optical system including three optical elements. . More specifically, the circular member CY1 is formed using the mold shown in FIG. 4A, the circular member CY2 is formed using the mold shown in FIG. 4B, and the mold shown in FIG. Is used to shape the circular member CY3 (see FIG. 5A). Details of the molding are the same as those in the above-described embodiment, and thus description thereof is omitted.

  The mold used in the present embodiment has basically the same configuration as the upper mold 10 and the lower mold 20 in the above-described embodiment, but uses an O-ring 30 'as a seal member. More specifically, a circumferential groove 25 is formed in the vicinity of the outer periphery of the lower mold 20, an O-ring 30 ′ is disposed therein, and is brought into contact with the lower surface of the upper mold 10 at the time of clamping, so that the liquid heat The leakage of the curable resin is suppressed.

  Furthermore, in the present embodiment, as shown in FIG. 5A, the inner diameter φ2 of the outer peripheral portion CY2a of the circular member CY2 and the outer diameter φ1 of the outer peripheral portion CY1a of the circular member CY1 are made to coincide with each other. The inner diameter φ2 of the outer peripheral portion CY2a of the member CY2 is matched with the outer diameter φ3 of the outer peripheral portion CY3a of the circular member CY3, and when the circular members CY1 to CY3 are combined as shown in FIG. It is used as a positioning reference for alignment (that is, a positioning portion). Further, as shown in FIG. 5A, the grooves CY1c and CY3c in which the upper and lower ribs CY2b of the circular member CY2 are accurately fitted are formed on the lower surface of the rib CY1b of the circular member CY1 and the rib CY3b of the circular member CY3. As shown in FIG. 5B, the circular members CY1 to CY3 are fitted to each other and used as a positioning reference for positioning (ie, a positioning portion). Thus, by using the outer peripheral portion and the rib as the positioning reference, the optical axes of all the optical elements OE1 to OE3 can be made to coincide with each other only by positioning the circular members as shown in FIG. it can.

  FIG. 6 is a diagram illustrating a mold used in the manufacturing process of the optical element according to the third embodiment. FIG. 7 is a view showing a circular member formed by the mold shown in FIG. In this embodiment, two types of upper molds and one type of lower mold are used to form the seal member and the circular member.

  More specifically, as shown in FIG. 6A, the first upper mold 10 </ b> A is clamped with respect to the lower mold 20. The first upper mold 10 </ b> A is opposed to the lower annular recess 23 of the lower mold 20, and forms an annular cavity 16 corresponding to the upper surface of the seal member 30. Furthermore, a circular pipe portion 16a having a tapered cross section that is thinner toward the tip is formed at the bottom (upper surface in FIG. 6) of the concave annular cavity 16. A predetermined draft angle is provided on the inner peripheral surface 16b of the cavity 16, and a runner 17 extending from the side surface so as to communicate with the cavity 16 is formed on the lower surface of the first upper mold 10A. .

  In a state where the first upper mold 10A and the lower mold 20 are combined, a molten thermoplastic resin is injected through the runner 17. Since the thermoplastic resin has a relatively high viscosity, there is almost no risk of leakage from the gap between the first upper mold 10A and the lower mold 20. After the first upper mold 10A and the lower mold 20 are cooled to solidify the thermoplastic resin, the first upper mold 10A is separated from the lower mold 20 to perform mold opening. At this time, since a predetermined draft is provided on the inner peripheral surface 16b of the annular cavity 16, the thermoplastic resin is easily separated and remains attached to the lower annular recess 23 of the lower mold 20 with the seal member 30. Become. In this state, a circumferential groove 31 that becomes narrower toward the back is formed on the upper surface of the seal member 30 corresponding to the circular pipe portion 16a, and its side surface 32 is tapered corresponding to the inner circumferential surface 16b. It becomes a shape.

  Subsequently, the second upper mold 10B and the lower mold 20 are combined and clamped. At this time, as shown in FIG. 6C, the sealing member 30 has an inner peripheral surface of the upper annular recess 18 of the second upper mold 10B provided with a draft on the lower end side corresponding to the sealing member 30. The second upper die 10B and the lower die 20 are brought into close contact with each other by being pushed in the radial direction by 18a. Further, when a liquid thermosetting resin is injected through the runner 15, the pressurized thermosetting resin enters into the circumferential groove 31 of the seal member 30 and acts to push it open. The member 30 comes to further adhere to the second upper mold 10B and the lower mold 20. Thereby, the leakage of the thermosetting resin having a low viscosity can be suppressed.

  Similarly, circular members CY1 to CY3 (see FIG. 7 (a)) are respectively formed, and are overlapped and bonded in a state where the optical axes of the optical elements are aligned as shown in FIG. 7 (b). By cutting into two, an optical system composed of three optical elements is formed.

The present invention has been described above with reference to the embodiments. However, the present invention should not be construed as being limited to the above-described embodiments, and can be modified or improved as appropriate. For example, the injection position of the thermosetting resin is not limited to a single one, and may be injected from a plurality of runners that are equidistant from the position corresponding to the center of the circular member and equally spaced in the circumferential direction, for example. good.
FIG. 8 is a diagram illustrating another example of the injection position of the thermosetting resin. FIG. 8 is a view of the mold 10B as seen from the outer upper surface side.
FIG. 8A shows an injection position T provided at two locations equidistant from the center C of the circular member indicated by a broken line and at intervals of 180 ° in the circumferential direction. FIG. 8B shows the injection positions T provided at three locations equidistant from the center C of the circular member indicated by a broken line and at 120 ° intervals in the circumferential direction. FIG. 8C shows an injection position T provided at four locations at equal intervals from the center C of the circular member indicated by a broken line and at intervals of 90 ° in the circumferential direction.

Claims (14)

Disposing a seal member between the first mold and the second mold;
A plurality of optical elements arranged in a matrix form by injecting and solidifying a liquid energy curable resin in a state where the sealing member is disposed between the first mold and the second mold; And a step of integrally molding the molding member.   2. The method of manufacturing an optical element according to claim 1, wherein the outer peripheral shape of the molded member is a circle.   3. The method of manufacturing an optical element according to claim 1, wherein the seal member is formed so as to surround the molded member.   The optical element manufacturing method according to any one of claims 1 to 3, wherein an outer peripheral portion thicker than a thickness of the optical element is formed on an outer periphery of the molded member.   A plurality of the molding members are molded, and the corresponding optical elements are overlapped and bonded to each other among the plurality of molding members, and then the optical elements are integrally separated. 5. A method for producing an optical element according to any one of items 4 to 4.   6. The method of manufacturing an optical element according to claim 5, wherein a positioning portion for positioning when the plurality of molding members are overlapped is provided in at least one of the molding members.   The method for manufacturing an optical element according to any one of claims 1 to 6, wherein the molding member has a rib between the rows of the optical elements.   The liquid energy curable resin is injected from the center of a cavity forming the molding member when the molding member is viewed in its thickness direction. The manufacturing method of the optical element in any one of.   The method for manufacturing an optical element according to any one of claims 1 to 7, wherein the liquid energy curable resin is injected from a plurality of locations.   The method of manufacturing an optical element according to any one of claims 1 to 9, wherein the liquid energy curable resin is cured under a pressure of 20 MPa or more.   The seal member has a recess, one outer surface on the side of the recess faces the first mold, the other outer surface faces the second mold, and the liquid energy curing in the recess. The method of manufacturing an optical element according to any one of claims 1 to 10, wherein the resin is arranged so as to be injected.   The method for manufacturing an optical element according to any one of claims 1 to 10, wherein the seal member is an O-ring.   The method of manufacturing an optical element according to any one of claims 1 to 12, wherein the energy curable resin is optically transparent.   An optical element manufactured by the method for manufacturing an optical element according to any one of claims 1 to 13.