JP5618736B2 - Mold and lens manufacturing method - Google Patents

Description

  The present invention relates to a lens mold and a lens manufacturing method.

  In general, an imaging unit used in a mobile phone or an optical head used in an optical disk recording / reproducing apparatus uses a lens made of a resin that is inexpensive and has excellent moldability (see, for example, Patent Documents 1 and 2). ).

  In general, the resin lens is manufactured using a molding die including an upper die and a lower die, and a barrel die surrounding the upper die and the lower die. Resin is deposited in the center of the molding surface of the lower mold, and is sandwiched between the molding surface of the upper mold and the molding surface of the lower mold in the barrel mold as the upper mold is lowered, and molded into a predetermined lens shape. Is done.

  In order to allow the upper and lower molds to be inserted into and removed from the trunk mold, between the inner circumferential surface of the trunk mold and the outer circumferential surface of the upper mold, and between the inner circumferential surface of the trunk mold and the outer circumferential surface of the lower mold A gap is provided. However, there are cases where the resin enters the gaps, and if the resin that has entered the gaps is cured and remains as burrs on the lens, the appearance of the lens is impaired and it takes time to remove it.

  In the lens manufacturing method described in Patent Document 2, an annular convex portion that comes into contact with the edge of at least one molding surface of the upper die and the lower die is provided on the inner peripheral surface of the barrel die. This convex portion closes the gaps formed between the inner peripheral surface of the barrel mold and the outer peripheral surface of the upper mold, or between the inner peripheral surface of the barrel mold and the outer peripheral surface of the lower mold, and the resin enters the gaps. To prevent it. However, an annular concave portion is formed on the edge of the molded lens by the convex portion provided on the inner peripheral surface of the body mold, and the effective diameter of the lens is narrowed.

JP 2009-98614 A JP 2001-205653 A

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to prevent the resin from entering the gaps in the mold and prevent the generation of burrs in the molded lens.

(1) An upper mold and a lower mold, and a body mold that surrounds the upper mold and the lower mold, and the resin is predetermined by sandwiching a resin between the upper mold and the lower mold in the body mold A molding die that is pressure- molded into a lens shape, between the inner peripheral surface of the barrel die and the outer peripheral surface of the upper die, and between the inner peripheral surface of the barrel die and the outer periphery of the lower die. A filler that fills the space between the surfaces, and the filler is formed on at least one of the inner peripheral surface of the barrel mold, the outer peripheral surface of the upper mold, and the outer peripheral surface of the lower mold A mold that is a coating and has liquid repellency with respect to the resin.
(2) Using a molding die including an upper die and a lower die, and a barrel die surrounding the upper die and the lower die, between the inner peripheral surface of the opposing barrel die and the outer peripheral surface of the upper die, And at least one of the inner peripheral surface of the barrel mold, the outer peripheral surface of the upper mold, and the outer peripheral surface of the lower mold between the inner peripheral surface of the barrel mold and the outer peripheral surface of the lower mold facing each other. A film formed on one side, which is filled with a film having liquid repellency with respect to the resin, and sandwiching the resin between the upper mold and the lower mold in the barrel mold, A method of manufacturing a lens that is pressure- molded into a lens shape.

  According to the present invention, it is possible to prevent the resin from entering the gap of the molding die and to prevent burrs from being generated in the molded lens.

The figure which shows an example of an imaging unit. The figure which shows an example of the shaping | molding die of a lens for describing embodiment of this invention. The figure which shows an example of the manufacturing method of the lens using the shaping | molding die of FIG. The figure which shows the modification of the shaping | molding die of FIG.

  FIG. 1 shows an example of an imaging unit.

  An imaging unit 1 shown in FIG. 1 includes a sensor unit 2 and a lens unit 3.

  The sensor unit 2 includes a substrate 10 made of a semiconductor such as silicon, and a solid-state image sensor 11 provided at a substantially central portion thereof. The solid-state imaging device 11 is a CCD image sensor or a CMOS image sensor, for example, and repeats a well-known film formation process, photolithography process, etching process, impurity addition process, and the like on the substrate 10 to receive a light receiving region on the substrate 10. , Electrodes, insulating films, wirings, and the like are formed.

  The lens unit 3 includes an optical system 4 including one or more lenses and a lens barrel 5 that holds the optical system 4. In the illustrated example, the optical system 4 is disposed between the first lens 20 disposed on the incident side, the second lens 21 disposed on the exit side, and the first lens 20 and the second lens 21. It comprises a diaphragm 22. Both the first lens 20 and the second lens 21 are made of a translucent resin. The diaphragm 22 is made of a light-shielding material and is formed of a metal plate such as stainless steel. Note that the configuration of the optical system 4 is not limited to the illustrated example. For example, the number of lenses may be one or three or more, and the diaphragm 22 may be on the incident surface of the first lens 20. You may arrange | position in an appropriate location.

  The first lens 20 includes a lens part 30 having optical surfaces on the front and back sides, and an edge part 31 that spreads around the lens part 30 in a bowl shape. Similarly, the second lens 21 includes a lens part 32 having optical surfaces on the front and back sides and an edge part 33 that spreads around the lens part 32 in a bowl shape. The first lens 20 and the second lens 21 are overlapped with the optical axes of the lens portions 30 and 32 being matched.

  On the opposing surfaces of the edge portion 31 of the first lens 20 and the edge portion 33 of the second lens 21 that are opposed to each other, fitting portions that are fitted to each other are provided. The fitting part 34 provided in the edge part 31 of the first lens 20 is an annular convex part centering on the optical axis of the lens part 30. The fitting portion 35 provided on the edge portion 33 of the second lens 21 is an annular convex portion centered on the optical axis of the lens portion 32, and is fitted into the fitting portion 34 of the first lens 20. To do. The inner peripheral surface of the fitting portion 34 of the first lens 20 and the outer peripheral surface of the fitting portion 35 of the second lens 21 are tapered surfaces that are aligned with each other. The first lens 20 and the second lens 21 are positioned relative to each other so that the optical axes of the lens portions 30 and 32 coincide with each other by fitting the fitting portions 34 and 35.

  The lens barrel 5 includes a tube portion 40, a lid portion 41 provided at one end portion in the axial direction of the tube portion 40, a pedestal portion 42 provided at the other end portion in the axial direction of the tube portion 40, It is comprised by the pressing member 43 arrange | positioned facing the cover part 41 within the cylinder part 40. As shown in FIG. The lens barrel 5 is made of a light-shielding material, for example, a resin such as a black liquid crystal polymer.

  The optical system 4 is disposed in the cylindrical portion 40 with its optical axis aligned with the central axis of the cylindrical portion 40, sandwiched between the lid portion 41 and the pressing member 43, and held by the lens barrel 5. An opening 44 is provided at the center of the lid 41 through which the optical axis of the optical system 4 passes, and light enters the optical system 4 through the opening 44.

  On the opposing surfaces of the edge portion 31 and the lid portion 41 of the first lens 20 of the opposing optical system 4, fitting portions that are fitted to each other are provided. The fitting portion 36 provided in the edge portion 31 of the first lens 20 is an annular convex portion centered on the optical axis of the optical system 4 (the optical axis of the lens portion 30). Further, the fitting portion 45 provided in the lid portion 41 is an annular convex portion centering on the central axis of the cylindrical portion 40 and is fitted into the fitting portion 36 of the first lens 20. The inner peripheral surface of the fitting portion 36 of the first lens 32 and the outer peripheral surface of the fitting portion 45 of the lid portion 41 are tapered surfaces that are aligned with each other. The optical system 4 is positioned so that its optical axis coincides with the central axis of the cylindrical portion 40 by fitting the fitting portion 36 of the first lens 20 with the fitting portion 45 of the lid portion 41.

  The positioning of the optical system 4 with respect to the lens barrel 5 is performed by fitting the fitting portion 36 of the first lens 20 to the fitting portion 45 of the lid portion 41 as described above. A gap is provided between the outer peripheral surfaces of the first lens 20 and the second lens 21 and the inner peripheral surface of the cylindrical portion 40. This gap absorbs the difference in thermal expansion between the optical system 4 and the lens barrel 5 in a reflow process described later, and relaxes the stress acting on the optical system 4.

  The lens unit 3 is integrated with the sensor unit 2 by joining the pedestal 42 of the lens barrel 5 to the substrate 10 of the sensor unit 2. The light that has entered the optical system 4 through the opening 44 of the lens barrel 5 forms an image on the light receiving surface of the solid-state imaging device 11 of the sensor unit 2.

  The imaging unit 1 configured as described above is mounted on a circuit board of an electronic device by reflow processing. That is, paste solder is printed in advance on the circuit board at a position where the imaging unit 1 is mounted, and the imaging unit 1 is placed there. The circuit board including the imaging unit 1 is subjected to a heat treatment such as infrared irradiation or hot air blowing, thereby melting the solder and mounting the imaging unit 1 on the circuit board.

  Since the entire imaging unit 1 is heated at the reflow temperature in the reflow process, the resin forming the first lens 20 and the second lens 21 has heat resistance enough to prevent thermal deformation even after the reflow process. As such a resin, an energy curable resin can be used. For example, a thermosetting resin that is cured by heat such as a silicone resin, an epoxy resin, or a phenol resin, or an ultraviolet ray such as an epoxy resin or an acrylic resin. It is possible to use a photo-curable resin that is cured by irradiation.

  Regarding the heat resistance of the resin forming the lenses 20 and 21, the glass transition temperature of the cured product is preferably 200 ° C or higher, more preferably 250 ° C or higher, and particularly preferably 300 ° C or higher. In order to impart such high heat resistance to the resin, it is necessary to constrain the mobility at the molecular level, and effective means include (1) means for increasing the crosslinking density per unit volume, (2 ) Means utilizing a resin having a rigid ring structure (for example, alicyclic structures such as cyclohexane, norbornane, tetracyclododecane, aromatic ring structures such as benzene and naphthalene, cardo structures such as 9,9′-biphenylfluorene, spirobiindane, etc. Resins having a spiro structure, specifically, for example, JP-A-9-137043, JP-A-10-67970, JP-A-2003-55316, JP-A-2007-334018, JP-A-2007-238883, etc. (3) means for uniformly dispersing a substance having a high Tg such as inorganic fine particles (for example, JP-A-5-20902) JP-described), and the like in the 10-298265 Patent Publication. A plurality of these means may be used in combination, and it is preferable to make adjustments within a range that does not impair other characteristics such as fluidity, shrinkage, and refractive index characteristics.

  Moreover, it is preferable that the resin forming the lenses 20 and 21 has an appropriate fluidity before curing from the viewpoint of moldability such as the shape transfer suitability of the mold. Specifically, it is liquid at room temperature and has a viscosity of about 1000 to 50000 mPa · s.

  The resin forming the lenses 20 and 21 is preferably a resin having a small volume shrinkage due to the curing reaction from the viewpoint of shape transfer accuracy. The curing shrinkage of the resin is preferably 10% or less, more preferably 5% or less, and particularly preferably 3% or less. Examples of the resin having a low cure shrinkage include (1) resins containing a high molecular weight curing agent (such as a prepolymer) (for example, JP-A Nos. 2001-19740, 2004-302293, and 2007-212147). The number average molecular weight of the high molecular weight curing agent is preferably in the range of 200 to 100,000, more preferably in the range of 500 to 50,000, and particularly preferably in the range of 1,000 to 20,000. The value calculated by the number average molecular weight of the curing agent / number of curing reactive groups is preferably in the range of 50 to 10,000, more preferably in the range of 100 to 5,000. Preferably, it is in the range of 200 to 3,000.), (2) Resins containing non-reactive substances (organic / inorganic fine particles, non-reactive resins, etc.) (Described in JP-A-6-298883, JP-A-2001-247793, JP-A-2006-225434, etc.), (3) Resins containing low-shrinkage crosslinking reactive groups (for example, ring-opening polymerizable groups (for example, epoxy groups ( For example, described in JP-A-2004-210932, etc.), oxetanyl group (for example, described in JP-A-8-134405), episulfide group (for example, described in JP-A-2002-105110), cyclic carbonate Groups (for example, described in JP-A-7-62065) and the like, ene / thiol curing groups (for example, described in JP-A 2003-20334, etc.), hydrosilylation curing groups (for example, JP-A-2005-15666). (4) Resin containing a rigid skeleton resin (fluorene, adamantane, isophorone, etc.) Described in JP-A-137043), and (5) a resin containing two types of monomers having different polymerizable groups to form an interpenetrating network structure (so-called IPN structure) (for example, JP-A-2006-131868) ), (6) Resins containing expansive substances (for example, described in JP-A-2004-2719, JP-A-2008-238417, etc.) and the like, and can be suitably used in the present invention. . In addition, it is preferable from the viewpoint of optimizing physical properties to use a plurality of curing shrinkage reducing means in combination (for example, a prepolymer containing a ring-opening polymerizable group and a resin containing fine particles).

  In addition, the resin forming the lenses 20 and 21 is desirably a mixture of two or more types of resins having different Abbe numbers. The resin on the high Abbe number side preferably has an Abbe number (νd) of 50 or more, more preferably 55 or more, and particularly preferably 60 or more. The refractive index (nd) is preferably 1.52 or more, more preferably 1.55 or more, and particularly preferably 1.57 or more. Such a resin is preferably an aliphatic resin, particularly a resin having an alicyclic structure (for example, a resin having a cyclic structure such as cyclohexane, norbornane, adamantane, tricyclodecane, tetracyclododecane, specifically, for example, JP-A-10-152551, JP-A-2002-212500, JP-A-2003-20334, JP-A-2004-210932, JP-2006-199790, JP-2007-2144, JP-2007-284650. And the resin described in JP-A-2008-105999. The resin on the low Abbe number side preferably has an Abbe number (νd) of 30 or less, more preferably 25 or less, and particularly preferably 20 or less. The refractive index (nd) is preferably 1.60 or more, more preferably 1.63 or more, and particularly preferably 1.65 or more. Such a resin is preferably a resin having an aromatic structure. For example, a resin having a structure such as 9,9′-diarylfluorene, naphthalene, benzothiazole, benzotriazole (specifically, for example, JP-A-60-38411). Publication No. 10-67977, No. 2002-47335, No. 2003-238848, No. 2004-83855, No. 2005-325331, No. 2007-238883, International Publication No. 2006/095610 pamphlet, Japanese Patent No. 2537540, and the like) are preferable.

  In addition, in the resin forming the lenses 20 and 21, it is preferable to disperse inorganic fine particles in the matrix in order to increase the refractive index or adjust the Abbe number. Examples of the inorganic fine particles include oxide fine particles, sulfide fine particles, selenide fine particles, and telluride fine particles. More specifically, for example, fine particles of zirconium oxide, titanium oxide, zinc oxide, tin oxide, niobium oxide, cerium oxide, aluminum oxide, lanthanum oxide, yttrium oxide, zinc sulfide, and the like can be given. In particular, it is preferable to disperse fine particles such as lanthanum oxide, aluminum oxide, and zirconium oxide for the high Abbe number resin, and titanium oxide, tin oxide, zirconium oxide, and the like for the low Abbe number resin. It is preferable to disperse the fine particles. The inorganic fine particles may be used alone or in combination of two or more. Moreover, the composite by several components may be sufficient. In addition, for various purposes such as reducing photocatalytic activity and water absorption, the inorganic fine particles are doped with different metals, the surface layer is coated with different metal oxides such as silica and alumina, silane coupling agents and titanate cups. The surface may be modified with a ring agent, an organic acid (carboxylic acid, sulfonic acid, phosphoric acid, phosphonic acid, etc.) or a dispersant having an organic acid group. The number average particle size of the inorganic fine particles is usually about 1 nm to 1000 nm, but if it is too small, the properties of the substance may change. If it is too large, the influence of Rayleigh scattering becomes remarkable, so 1 nm to 15 nm is preferable. 2 nm to 10 nm are more preferable, and 3 nm to 7 nm are particularly preferable. Further, it is desirable that the particle size distribution of the inorganic fine particles is narrow. There are various ways of defining such monodisperse particles. For example, a numerical value range as described in JP-A No. 2006-160992 applies to a preferable particle size distribution range. Here, the above-mentioned number average primary particle size can be measured by, for example, an X-ray diffraction (XRD) apparatus or a transmission electron microscope (TEM). The refractive index of the inorganic fine particles is preferably 1.90 to 3.00, more preferably 1.90 to 2.70, and more preferably 2.00 to 2.70 at 22 ° C. and a wavelength of 589 nm. It is particularly preferred that The content of the inorganic fine particles with respect to the resin is preferably 5% by mass or more, more preferably 10 to 70% by mass, and particularly preferably 30 to 60% by mass from the viewpoint of transparency and high refractive index.

  In order to uniformly disperse the fine particles in the resin, for example, a dispersant containing a functional group having reactivity with the resin monomer forming the matrix (for example, described in Examples of JP-A-2007-238884), hydrophobic segment And a block copolymer composed of a hydrophilic segment (for example, described in JP-A-2007-2111164), or a resin having a functional group capable of forming an arbitrary chemical bond with inorganic fine particles at the polymer terminal or side chain ( For example, it is desirable to disperse the fine particles by appropriately using JP-A-2007-238929, JP-A-2007-238930, and the like.

  In addition, the resins forming the lenses 20 and 21 are appropriately blended with known release agents such as silicone-based, fluorine-based, and long-chain alkyl group-containing compounds and additives such as antioxidants such as hindered phenols. May be.

  Moreover, a curing catalyst or an initiator can be blended in the resin forming the lenses 20 and 21 as necessary. Specifically, for example, a compound that accelerates a curing reaction (radical polymerization or ionic polymerization) by the action of heat or active energy rays described in JP-A-2005-92099 (paragraph numbers [0063] to [0070]) and the like. Can be mentioned. The amount of addition of these curing reaction accelerators varies depending on the type of catalyst and initiator, or the difference in the curing reactive site, and cannot be specified in general. On the other hand, about 0.1-15 mass% is preferable, and about 0.5-5 mass% is more preferable.

  The resin forming the lenses 20 and 21 can be manufactured by appropriately blending the above components. At this time, if other components can be dissolved in the liquid low molecular weight monomer (reactive diluent), etc., it is not necessary to add a separate solvent, but if this is not the case, use a solvent. A curable resin can be produced by dissolving each component. The solvent that can be used for the curable resin is not particularly limited and may be appropriately selected as long as the composition can be uniformly dissolved or dispersed without precipitation. Specifically, for example, ketones (Eg, acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.), esters (eg, ethyl acetate, butyl acetate, etc.), ethers (eg, tetrahydrofuran, 1,4-dioxane, etc.) alcohols (eg, methanol, ethanol, isopropyl, etc.) Alcohol, butanol, ethylene glycol, etc.), aromatic hydrocarbons (eg, toluene, xylene, etc.), water and the like. When the curable resin contains a solvent, it is preferable to perform molding after drying the solvent.

  Hereinafter, the manufacturing of the lens will be described using the first lens 20 as an example.

  FIG. 2 shows an example of a lens mold.

  The molding die 50 includes an upper die 51, a lower die 52, and a body die 53. The trunk mold 53 is formed in a cylindrical shape. The upper mold 51 has a columnar shape and is inserted into the trunk mold 53 from the upper opening of the trunk mold 53. The lower mold 52 also has a column shape, and is inserted into the trunk mold 53 from the lower opening of the trunk mold 53.

  The front end surface of the upper mold 51 is a molding surface 60 and has a shape obtained by inverting one of the front and back surfaces of the lens 20. An optical surface molding unit 61 having a shape obtained by inverting one optical surface of the lens unit 30 is provided. The front end surface of the lower mold 52 is also a molding surface 62 and has a shape obtained by reversing the other surface shape of the front and back surfaces of the lens 20. An optical surface molding part 63 having a shape obtained by inverting the other optical surface is provided. The lens portion 30 of the lens 20 shown in FIG. 1 has an incident-side optical surface that is a convex spherical surface and an output-side optical surface that is a concave spherical surface. The portion 61 is shaped into a convex spherical shape that is an inverted optical surface on the exit side, and the optical surface shaping portion 63 of the lower mold 52 is shaped into a concave spherical shape that is an inverted optical surface on the incident side.

  The upper mold 51 and the lower mold 52 are inserted into the body mold 53 and surrounded by the molding surface 60 of the upper mold 51, the molding surface 62 of the lower mold 52, and the inner peripheral surface of the body mold 53. Is formed, and the molding die 50 is molded by accommodating the resin in the cavity.

  A slight gap is set between the outer peripheral surface of the upper die 51 and the outer peripheral surface of the lower die 52 and the inner peripheral surface of the body die 53 in order to allow the upper die 51 and the lower die 52 to be inserted and removed. . These gaps are filled with a filler 65, respectively. The filling body 65 is a coating formed on the inner peripheral surface of the trunk mold 53 and covers the entire inner peripheral surface of the trunk mold 53. The filling body 65 may be provided so as to cover only the region facing the outer peripheral surface of the upper mold 51 and the outer peripheral surface of the lower mold 52 on the inner peripheral surface of the body mold 53. The filler 65 may be provided on the outer peripheral surface of the upper mold 51 and the outer peripheral surface of the lower mold 52, or the outer peripheral surface of the upper mold 51, the outer peripheral surface of the lower mold 52, and the inner peripheral surface of the trunk mold 53. It may be provided above.

  In FIG. 3, an example of the manufacturing method of the lens 20 using the shaping | molding die 50 is shown.

(Supply process)
First, the lower mold 52 is inserted into the trunk mold 53. Then, the above-mentioned energy curable resin M is quantitatively supplied to the central portion on the molding surface 62 of the lower mold 52. The supply of the resin M can be performed using, for example, a dispenser. Note that the lower mold 52 may be inserted into the trunk mold 53 after the resin is supplied onto the molding surface 62 (FIG. 3A).

(Molding process)
Next, the upper mold 51 is inserted into the trunk mold 53. The upper mold 51 can be moved using a driving means such as a press. As the upper mold 51 is inserted, the distance between the molding surface 60 of the upper mold 51 and the molding surface 62 of the lower mold 52 is narrowed, and the resin M is sandwiched between the molding surfaces 60 and 62. Accordingly, the resin M is deformed along the molding surfaces 60 and 62 while being spread between the molding surfaces 60 and 62. The lens surface 30 of the lens 20 is molded by the optical surface molding portions 61 and 63 provided on the molding surfaces 60 and 62, respectively, and the portions of the molding surfaces 60 and 62 other than the optical surface molding portions 61 and 63 are formed. And the edge part 31 of the lens 20 is shape | molded by the internal peripheral surface of the trunk | drum 53 (FIG.3B).

(Curing process)
Next, the curing energy E is supplied to the resin M molded in the molding process, and the resin M is cured. When the resin M is a thermosetting resin, the mold 50 is heated and heat is supplied to the resin M through the mold 50. Further, when the resin M is a photo-curable resin, at least one of the upper mold 51, the lower mold 52, and the body mold 53 is formed of a translucent material such as glass, and the resin is transmitted through the resin. Light is supplied to M (FIG. 3C).

(Release process)
Next, the upper mold 51 is removed from the body mold 53, and the lens 20 made of the cured resin M is taken out from the mold 50. The lens 20 can be taken out automatically using, for example, a robot arm (FIG. 3D).

  In the molding process and the curing process described above, the resin M is sandwiched and pressed between the molding surface 60 of the upper mold 51 and the molding surface 62 of the lower mold 52. Further, the viscosity of the energy curable resin generally decreases once during the curing process. Although the resin M that has been pressurized and has a reduced viscosity can enter even a slight gap, the gap between the outer peripheral surface of the upper mold 51 and the inner peripheral surface of the trunk mold 53, and the outer peripheral surface of the lower mold 52 and the trunk mold. The gaps with the inner peripheral surface of 53 are filled with the fillers 65, respectively, and the resin M is prevented from entering the gaps. This prevents burrs from occurring in the lens 20 formed by curing the molded resin M.

  The filler 65 preferably has liquid repellency with respect to the resin M. Specifically, the contact angle with the resin M is preferably 90 ° or more, and more preferably 110 ° or more. More preferred. According to this, it is possible to prevent the lens 20 from adhering to the filler 65 and to smoothly release the lens 20. Furthermore, from the viewpoint of filling the gap, the filler 65 preferably has elasticity. And when the upper mold | type 51 and the lower mold | type 52 are inserted in the trunk | drum 53, the upper mold | type 51 and the lower mold | type 52 are the filling bodies 65 with which the clearance gap between those outer peripheral surfaces and the inner peripheral surface of the trunk | drum 53 is filled. Slid in contact. Therefore, it is preferable that the filler 65 has low friction so as not to hinder the insertion of the upper mold 51 and the lower mold 52. As such a filler 65, a fluorine-type film can be illustrated. Further, as the filler 65, fluid such as grease such as fluorine grease or silicone grease, machine oil, etc. can be used. In this case, the upper mold 51 and the lower mold 52 are placed in the body mold 53. Prior to insertion, the above-described grease, machine oil, or the like is applied to the outer peripheral surface of the upper mold 51, the outer peripheral surface of the lower mold 52, or the inner peripheral surface of the trunk mold 53 to form the filler 65.

  In the above description, the lens 20 constitutes the imaging unit 1 to be reflowed and is formed of a heat-resistant energy curable resin. However, heat resistance is particularly required. If not, the lens 20 may be formed of a thermoplastic resin.

  FIG. 4 shows a modification of the mold 50.

  4 includes a plurality of sets of an upper mold 51 and a lower mold 52, and the body mold 53 is provided with a plurality of receiving holes 54 into which the upper mold 51 and the lower mold 52 of each set are respectively inserted. It has been. The inner peripheral surface of each accommodation hole 54 is provided with a filler 65 that fills a gap between the outer peripheral surface of the upper mold 51 and the outer peripheral surface of the lower mold 52 inserted therein. The plurality of upper dies 51 are connected by the connecting member 55 and moved together, and the plurality of lower dies 52 are similarly connected by the connecting member 56 and moved together. According to the mold 50a having the above configuration, a plurality of lenses can be molded simultaneously.

  As described above, the present specification includes an upper mold and a lower mold, and a trunk mold that surrounds the upper mold and the lower mold. Between the upper mold and the lower mold in the trunk mold, A mold for molding the resin into a predetermined lens shape with a resin sandwiched between the inner peripheral surface of the barrel mold and the outer peripheral surface of the upper mold facing each other, and the inner circumference of the barrel mold facing each other There is disclosed a mold including a filler that fills a space between the surface and the outer peripheral surface of the lower mold.

  In addition, the molding die disclosed in the present specification has a smaller affinity for the filler with the resin than for the upper die, the lower die, and the barrel die.

  Further, in the mold disclosed in this specification, the contact angle of the filler with the resin is 90 ° or more.

  In the mold disclosed in the present specification, the filler is formed on at least one of the inner peripheral surface of the barrel mold, the outer peripheral surface of the upper mold, and the outer peripheral surface of the lower mold. Coating.

  Further, in the present specification, a molding die including an upper die and a lower die and a barrel die surrounding the upper die and the lower die is used, and an inner peripheral surface of the barrel die and an outer periphery of the upper die are opposed to each other. And between the inner peripheral surface of the barrel mold and the outer peripheral surface of the lower mold, which are opposed to each other, are filled with a filler, and a resin is placed between the upper mold and the lower mold in the barrel mold. A method for manufacturing a lens is disclosed in which the resin is molded into a predetermined lens shape by sandwiching the resin.

  Further, in the lens manufacturing method disclosed in this specification, the affinity of the filling body with the resin is smaller than the affinity with the upper mold, the lower mold, and the trunk mold.

  In the method for manufacturing a lens disclosed in this specification, the contact angle of the filler with the resin is 90 ° or more.

DESCRIPTION OF SYMBOLS 1 Imaging unit 2 Sensor unit 3 Lens unit 4 Optical system 5 Lens tube 10 Substrate 11 Solid-state image sensor 20 Lens 21 Lens 50 Mold 51 Upper mold 52 Lower mold 53 Mold 60 Molding surface 62 Molding surface 65 Filler

Claims (4)

An upper mold and a lower mold, and a barrel mold surrounding the upper mold and the lower mold, and a resin is sandwiched between the upper mold and the lower mold in the barrel mold so that the resin has a predetermined lens shape. A mold for pressure molding to
A filling body for filling the space between the inner peripheral surface of the body mold facing the outer peripheral surface of the upper mold and the space between the inner peripheral surface of the body mold facing the outer peripheral surface of the lower mold;
The filling body is a coating formed on at least one of the inner peripheral surface of the barrel mold, the outer peripheral surface of the upper mold, and the outer peripheral surface of the lower mold, and is liquid repellent with respect to the resin A mold having properties. The mold according to claim 1, wherein
The filling body is a mold having a contact angle with the resin of 90 ° or more. Using a mold including an upper mold and a lower mold, and a body mold surrounding the upper mold and the lower mold,
Between the inner peripheral surface of the barrel mold and the outer peripheral surface of the upper mold facing each other, and between the inner peripheral surface of the barrel mold and the outer peripheral surface of the lower mold facing each other, A film formed on at least one of the outer peripheral surface of the upper mold and the outer peripheral surface of the lower mold, and filled with a film having liquid repellency with respect to the resin,
A method of manufacturing a lens, wherein a resin is sandwiched between the upper mold and the lower mold in the body mold and the resin is pressure- molded into a predetermined lens shape. A method of manufacturing a lens according to claim 3,
The said coating film is a manufacturing method of the lens whose contact angle with the said resin is 90 degrees or more.

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