JP2011065040A - Lens array laminated body and method for manufacturing the same, and imaging unit assembly and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens array laminated body which is formed by highly precisely positioning each lens of a lens array to the element of a base corresponding to it and then laminating and joining the lens array onto the base, and further to provide an imaging unit assembly. <P>SOLUTION: In a method for manufacturing the lens array laminated body by laminating two or more lens arrays and integrally joining them, the lens array has two or more lenses arranged in a predetermined row of one dimension or two dimensions and a substrate which is formed integrally with these lenses and mutually joining these lenses. The lens array is formed by using a pair of molds for molding a front surface and a rear surface respectively. One lens array or the laminated body obtained by laminating and joining two or more lens arrays is used as the base and one surface of the base is held by the mold for molding the surface and the surface of a side opposite to a joining surface with the base, of the lens array laminated on and joined to the base, is held by the mold for molding the surface, and the base and the lens array are laminated and joined in this state. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a lens array laminate and a manufacturing method thereof, and an imaging unit assembly and a manufacturing method thereof.

  In recent years, portable terminals of electronic devices such as mobile phones and PDAs (Personal Digital Assistants) are equipped with small and thin imaging units. Such an imaging unit generally includes a solid-state imaging device such as a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal-Oxide Semiconductor) image sensor, and a lens that forms an image in a light receiving region of the solid-state imaging device. ing.

  With the downsizing / thinning of portable terminals and the widespread use of portable terminals, further reduction in size / thinning is required for the imaging unit mounted on the portable terminal, and productivity is required. In response to such a requirement, one or a plurality of lens arrays in which a plurality of lens portions are similarly arranged are overlapped on a sensor array in which a plurality of solid-state imaging elements are arranged, and these are joined together, A method of mass-producing an imaging unit by dividing a sensor array and a lens array so as to include a corresponding one or a plurality of lens units is known (for example, see Patent Document 1).

  In the method disclosed in Patent Document 1, an upper mold having a transfer surface on which a plurality of lens molding surfaces are arranged, and a lower surface having a transfer surface on which lens molding surfaces that are paired with the lens molding surfaces of the upper mold are arranged. A lens array is formed using a mold. The lens array compresses a photocurable resin material or a thermosetting resin material between the upper mold transfer surface and the lower mold transfer surface to deform the resin material along both transfer surfaces, and in this state It is formed by irradiating light or applying heat to cure the resin material. A substrate in which a lens part is formed between a pair of lens molding surfaces of an upper mold and a lower mold, and the lens parts are connected to each other between transfer surfaces excluding the upper and lower mold molding surfaces. Part is formed. In the lens array used for the above-mentioned application, a wafer shape (disk shape) having a diameter of, for example, 6 inches, 8 inches, or 12 inches is formed as a whole, and, for example, thousands of lens portions are arranged therein. The Hereinafter, such a lens array is particularly referred to as a wafer level lens array. In the method disclosed in Patent Document 1, the formed wafer level lens array is released from the upper mold and the lower mold and laminated and bonded to a sensor array or another wafer level lens array.

International Publication No. 08/153102

  Generally, a resin material causes curing shrinkage. In a lens array formed of a resin material, curing shrinkage of the resin material is accumulated as residual stress while being restrained by the mold, and shrinkage occurs due to the accumulated residual stress after mold release. Along with the shrinkage, the lens array is warped, and an error occurs in the pitch of the lens portion. For example, in a 12-inch wafer level lens array as a whole, warpage of about 50 μm occurs due to shrinkage, and a pitch error of 20 to 30 μm occurs. When a lens array is laminated and bonded to a sensor array or another lens array or a laminate thereof (hereinafter collectively referred to as a base) due to pitch error or warpage of the lens portion, in some lens portions , Deviation or inclination of the optical axis occurs with respect to the corresponding base element (the solid-state image sensor of the sensor array or the lens portion of the lens array).

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to laminate each lens portion of the lens array and the corresponding element of the base with high precision and to laminate and bond the lens array to the base. The object is to provide a lens array stack and an imaging unit assembly.

(1) A method of manufacturing a lens array laminate formed by laminating a plurality of lens arrays and integrally joining the lens arrays, wherein the lens array includes a plurality of lens units arranged one-dimensionally or two-dimensionally. The lens array is formed by using a pair of molds that respectively mold the front and back surfaces of the lens array. The lens to be laminated and bonded to the base while holding one surface of the base with a mold in which the surface is molded, using one lens array or a laminated body in which a plurality of the lens arrays are laminated and bonded as a base. A method of manufacturing a lens array laminate, wherein a surface of the array opposite to a surface to be bonded to the base is held by a mold in which the surface is molded, and the base and the lens array are stacked and bonded in that state.
(2) A method of manufacturing an imaging unit assembly in which the lens array stack manufactured by the manufacturing method of (1) above is stacked on a sensor array and integrally joined thereto, wherein the sensor array is a semiconductor substrate In addition, a plurality of solid-state imaging devices are arranged in the same arrangement as the plurality of lens portions of the lens array, and the surface of the lens array laminate opposite to the bonding surface with the sensor array is formed as a surface thereof. A method of manufacturing an imaging unit assembly in which the lens array stack is stacked and joined to the sensor array while being held in a mold.
(3) A method for manufacturing an imaging unit assembly in which one or more lens arrays are sequentially stacked and integrally joined to a sensor array, wherein the lens array is a predetermined one-dimensional or two-dimensional array A plurality of lens portions formed on the substrate, and a substrate portion that is integrally formed with the lens portions and interconnects the lens portions. A plurality of solid-state imaging devices are arranged in the same arrangement as the lens unit, and the lens array is formed by using a pair of molds that respectively mold the front and back surfaces of the lens array, and is attached to the sensor array or the sensor array. A mold in which a surface of the lens array laminated and bonded to the base is formed on the surface opposite to the bonding surface with the base, using a laminated body in which two or more lens arrays are laminated and bonded. And the lens array is laminated and bonded to the base in this state.

  According to the present invention, the lens array is laminated and bonded to the base while one surface of the lens array is held by the mold, and the lens array is constrained by the mold and does not contract until the bonding with the base is completed. Therefore, it is possible to improve the alignment accuracy between each lens portion of the lens array and the corresponding base element.

It is a disassembled perspective view which shows an example of the lens array laminated body for describing embodiment of this invention. It is sectional drawing of the lens array laminated body of FIG. It is sectional drawing of the type | mold which forms the lens array contained in the lens array laminated body of FIG. 4A to 4C are schematic views showing an example of a method for manufacturing a lens array using the mold of FIG. 5A to 5C are schematic views showing an example of a method for manufacturing the lens array laminate of FIG. It is sectional drawing which shows the modification of the lens array laminated body of FIG. It is a schematic diagram explaining the modification of the manufacturing method of the lens array laminated body of FIG. It is a schematic diagram explaining the modification of the manufacturing method of the lens array laminated body of FIG. It is a schematic diagram explaining the modification of the manufacturing method of the lens array laminated body of FIG. It is sectional drawing which shows the other example of the lens array laminated body for describing embodiment of this invention. 11A to 11C are schematic views illustrating an example of a method for manufacturing the lens array laminate of FIG. It is a disassembled perspective view which shows an example of the imaging unit aggregate | assembly for demonstrating embodiment of this invention. It is sectional drawing of the imaging unit aggregate | assembly of FIG. 14A to 14C are schematic views illustrating an example of a method for manufacturing the imaging unit assembly of FIG. 15A to 15C are schematic views illustrating another example of the method for manufacturing the imaging unit assembly of FIG. 16A to 16C are schematic views showing a continuation of the manufacturing method of the imaging unit assembly of FIGS. 15A to 15C. 17A to 17C are schematic diagrams illustrating an example of a method for manufacturing the imaging unit. It is a schematic diagram which shows the other example of the manufacturing method of an imaging unit.

  1 and 2 show an example of the lens array laminate.

  The lens array laminate 1 shown in FIGS. 1 and 2 includes lens arrays 2 a and 2 b and a spacer 3.

  The lens array 2a has a plurality of lens portions 10 and a substrate portion 11 that connects these lens portions 10 to each other. The lens array 2a is a wafer level lens array in which a wafer having a predetermined size is formed as a whole, and a plurality of lens portions 10 are arranged there. The plurality of lens units 10 are arranged in a matrix in the illustrated example. Note that the arrangement of the lens units 10 is not limited to a matrix arrangement, and may be another two-dimensional arrangement or a one-dimensional arrangement. Each lens unit 10 has predetermined lens surfaces 12a and 12b on the front and back. In the illustrated example, the lens surfaces 12a and 12b are both convex spherical surfaces, but various combinations of convex spherical surfaces, concave spherical surfaces, aspherical surfaces, or flat surfaces are adopted depending on the application. obtain. The plurality of lens portions 10 and the substrate portion 11 are integrally formed of a translucent material.

  Similarly to the lens array 2a described above, the lens array 2b has a plurality of lens portions 10 and a substrate portion 11 that connects these lens portions 10 to each other. The lens array 2b is also a wafer level lens array in which a wafer having the same size as the lens array 2a is formed as a whole, and a plurality of lens portions 10 are arranged there. The plurality of lens units 10 are arranged in a matrix in the same arrangement as the plurality of lens units 10 of the lens array 2a. The plurality of lens portions 10 and the substrate portion 11 are integrally formed of a translucent material. Each lens unit 10 has predetermined lens surfaces 12a and 12b on the front and back. Hereinafter, for the sake of convenience, in the lens arrays 2a and 2b, a surface on which the plurality of lens surfaces 12a are arranged is referred to as a front surface, and a surface on which the plurality of lens surfaces 12b are arranged is referred to as a back surface.

  The spacer 3 is a wafer-like member having the same size as the lens array 2a, and is formed to have a thickness that is interposed between the lens array 2a and the lens array 2b so that a predetermined distance is provided between the lens arrays 2a and 2b. Has been. The spacer 3 is formed with a plurality of through holes 13 penetrating in the thickness direction. The through holes 13 are arranged in a matrix in the same arrangement as the plurality of lens portions 10 of the lens arrays 2a and 2b so as to be positioned between each lens portion 10 of the lens array 2a and the corresponding lens portion 10 of the lens array 2b. Is arranged.

  The lens array 2a is laminated and bonded to the lens array 2b with a spacer 3 interposed between the lens array 2b so that the optical axis of each lens unit 10 coincides with the optical axis of the lens unit 10 of the corresponding lens array 2b. Has been.

  FIG. 3 shows an example of a mold for forming the lens array 2a described above.

  The lens array 2a is formed using the upper mold 20a and the lower mold 30a.

  The upper mold 20a has a transfer surface 21 on which a plurality of lens molding surfaces 22 are arranged. The plurality of lens molding surfaces 22 are arranged in a matrix corresponding to the arrangement of the plurality of lens portions 10 of the lens array 2a. Each lens molding surface 22 has a shape obtained by inverting the lens surface 12a of the lens unit 10, and in the example shown in the drawing, has a concave spherical surface obtained by inverting the lens surface 12a which is a convex spherical surface. That is, the upper mold 20a molds the front surface of the lens array 2a.

  The lower mold 30a has a transfer surface 31 on which a plurality of lens molding surfaces 32 are arranged. The plurality of lens molding surfaces 32 are arranged in a matrix corresponding to the arrangement of the plurality of lens portions 10 of the lens array 2a. Each lens molding surface 32 has a shape obtained by inverting the lens surface 12b of the lens unit 10, and in the example shown in the drawing, has a concave spherical surface obtained by inverting the lens surface 12b, which is a convex spherical surface. That is, the lower mold 30a molds the surface on the back side of the lens array 2a.

  On the outer periphery of the upper mold 20a, marks 23 as positioning means are provided at a plurality of locations. Similarly, marks 33 that are paired with the marks 23 of the upper mold 20a are provided at a plurality of locations on the outer periphery of the lower mold 30a. By aligning the marks 23 and 33, both molds 20a and 30a are positioned.

  With reference to FIGS. 4A to 4C, an example of a method for manufacturing the lens array 2a described above will be described.

  As shown in FIG. 4A, first, the molding material M is supplied onto the transfer surface 31 of the lower mold 30a, and the molding material M is spread over the transfer surface 31. When the fluidity of the molding material M is relatively low, for example, the molding material M is preheated and supplied onto the transfer surface 31 in a state where the fluidity is enhanced.

  As the molding material M, an energy curable resin composition can be used. The energy curable resin composition may be either a resin composition that is cured by heat or a resin composition that is cured by irradiation with active energy rays (for example, ultraviolet rays).

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

  On the other hand, it is preferable to have heat resistance that does not cause thermal deformation even after the reflow process after curing. From this viewpoint, 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 composition, it is necessary to constrain the mobility at the molecular level, and as effective means, (1) means for increasing the crosslinking density per unit volume, (2) Means utilizing a resin having a rigid ring structure (for example, an alicyclic structure such as cyclohexane, norbornane, tetracyclododecane, an aromatic ring structure such as benzene and naphthalene, a cardo structure such as 9,9′-biphenylfluorene, Resins having a spiro structure such as spirobiindane, specifically, for example, JP-A-9-137043, JP-A-10-67970, JP-A-2003-55316, JP-A-2007-334018, JP-A-2007-238883 (3) means for uniformly dispersing a high Tg substance such as inorganic fine particles (for example, JP-A-5-20 027, 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 rate, and refractive index characteristics.

  From the viewpoint of shape transfer accuracy, a resin composition having a small volume shrinkage due to the curing reaction is preferable. The curing shrinkage rate of the resin composition is preferably 10% or less, more preferably 5% or less, and particularly preferably 3% or less. Examples of the resin composition having a low curing shrinkage rate include (1) resin compositions containing a high molecular weight curing agent (such as a prepolymer) (for example, JP-A Nos. 2001-19740, 2004-302293, and 2007-). 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, as described in Japanese Patent No. 211247. The value calculated by the number average molecular weight of the curing agent / the number of curing reactive groups is preferably in the range of 50 to 10,000, and in the range of 100 to 5,000. More preferably, it is particularly preferably in the range of 200 to 3,000.), (2) Resins containing non-reactive substances (organic / inorganic fine particles, non-reactive resins, etc.) Composition (for example, described in JP-A-6-298883, JP-A-2001-247793, JP-A-2006-225434, etc.), (3) a resin composition containing a low shrinkage crosslinking reactive group (for example, ring-opening polymerization) Sex groups (for example, epoxy groups (for example, described in JP-A No. 2004-210932), oxetanyl groups (for example, described in JP-A No. 8-134405), episulfide groups (for example, JP-A No. 2002-105110) Etc.), cyclic carbonate groups (e.g. described in JP-A-7-62065 etc.), etc., ene / thiol curing groups (e.g. described in JP-A 2003-20334 etc.), hydrosilylation curing groups (e.g. (For example, described in JP-A-2005-15666), etc.), (4) rigid skeleton resins (fluorene, adamantane, isophorone, etc.) (5) Resin composition containing an interpenetrating network structure (so-called IPN structure) containing two types of monomers having different polymerizable groups (for example, described in JP-A-9-137043) For example, described in JP-A-2006-131868), (6) Resin composition containing an expansible substance (for example, described in JP-A-2004-2719, JP-A-2008-238417, etc.), etc. 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 resin composition containing a prepolymer containing a ring-opening polymerizable group and fine particles).

  Further, two or more types of resin compositions having different Abbe numbers are desired. 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. 2003-238842, No. 2004-83855, No. 2005-325331, No. 2007-238883, International Publication 2006. / 095610 publication, Japanese Patent No. 2537540 publication, etc.) are preferable.

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

  Moreover, additives, such as well-known mold release agents, such as a silicone type, a fluorine type, and a long-chain alkyl group containing compound, and antioxidants, such as a hindered phenol, may be mix | blended with the resin composition suitably.

  Moreover, a curing catalyst or an initiator can be mix | blended with a resin composition as needed. 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 these curing reaction accelerators to be added varies depending on the type of catalyst and initiator, or the difference in the curing reactive site, and cannot be specified unconditionally, but in general, the total solid content of the curing reactive resin composition About 0.1-15 mass% is preferable with respect to a minute, and about 0.5-5 mass% is more preferable.

  The resin composition can be produced 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 composition can be produced by dissolving each component. The solvent that can be used in the curable resin composition is not particularly limited as long as the composition is uniformly dissolved or dispersed without precipitation, and 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 alcohol, butanol, ethylene glycol, etc.), aromatic hydrocarbons (eg, toluene, xylene, etc.), water and the like. When the curable composition contains a solvent, it is preferable to perform a mold shape transfer operation after casting the composition on a substrate and / or a mold and drying the solvent.

  Next, as shown in FIG. 4B, the mark 23 of the upper mold 20a and the mark 33 of the lower mold 30a are put together to position both molds 20a and 30a, and the upper mold 20a is lowered. The molding material M is sandwiched between the transfer surface 21 of the upper mold 20a and the transfer surface 31 of the lower mold 30a and compressed to deform the molding material M following both the transfer surfaces 21 and 31.

  Next, as shown in FIG. 4C, after the upper mold 20a has been lowered, curing energy is applied to the molding material M by heating or irradiation with an active energy ray, and the molding material M is cured to obtain the lens array 2a. The lens portion 10 is formed between each lens molding surface 22 of the upper mold 20a and the lens molding surface 32 of the lower mold 30a that is paired therewith. Further, the substrate portion 11 is molded between the transfer surface 21 of the upper mold 20a excluding the lens molding surfaces 22 and 32 and the transfer surface 31 of the lower mold 30a.

  Similarly, for the lens array 2b, using the upper mold that molds the front side surface and the lower mold that molds the back side surface, the molding material M is deformed following the transfer surfaces of both molds, and thereafter Is formed by applying curing energy to the molding material M and curing it.

  Next, an example of a method for manufacturing the lens array laminate 1 described above will be described with reference to FIGS. 5A to 5C. In the following description, it is assumed that the lens array 2b is laminated on the lens array 2a, the lens array 2b is bonded to the back surface, and the lens array 2a is bonded to the front surface.

  As shown in FIG. 5A, in the lens array 2a, the surface on the front side joined to the lens array 2b is exposed, and the back surface on the opposite side is held by a lower mold 30a formed by molding the surface. Further, the lens array 2b exposes the back side surface to be joined to the lens array 2a, and the surface on the opposite side is held by an upper mold 20b formed by molding the surface. In addition, an adhesive is applied to each of the front and back surfaces of the spacer 3.

  The lens arrays 2a and 2b are arranged so that the exposed front surface of the lens array 2a and the rear surface of the lens array 2b are opposed to each other, and the spacer 3 is arranged therebetween. Then, the marks 33 of the lower mold 30a holding the lens array 2a and the marks 23 of the upper mold 20b holding the lens array 2b are aligned to position both molds 20b and 30a.

  Next, as shown in FIG. 5B, the lens array 2b is stacked on the lens array 2a via the spacer 3, and the lens arrays 2a, 2b and the spacer 3 are joined together to obtain the lens array stacked body 1. One surface of the lens array 2b is held by the upper mold 20b, and the other surface of the lens array 2a is held by the lower mold 30a, and each lens array 2a is restrained, and contraction is restricted. Therefore, by positioning the both molds 20b and 30a, the optical axis of each lens unit 10 of the lens array 2b and the optical axis of the lens unit 10 of the corresponding lens array 2a coincide, and in this state, the lens arrays 2a and 2b Be joined.

  Next, as shown in FIG. 5C, the upper mold 20b and the lower mold 30a are removed. By removing the upper mold 20b and the lower mold 30a, the constraint can be released and the lens arrays 2a and 2b can contract. However, since the lens arrays 2a and 2b are joined and integrated, The optical axis does not shift. In addition, the lens arrays 2a and 2b are joined and integrated so that the lens arrays 2a and 2b are constrained to each other, and contraction is suppressed as compared to when the lens arrays are separated.

  FIG. 6 shows a modification of the lens array laminate 1 described above.

  The lens array laminate 1 shown in FIG. 6 is provided with a plurality of ribs 14 on the joint surfaces of the lens arrays 2a and 2b instead of the spacer 3 described above, and the lens arrays 2a and 2b are brought into contact with each other. A predetermined distance is placed between the two.

  Each rib 14 extends along a row or a column between adjacent rows or adjacent columns of the lens units 10 arranged in a matrix and intersects in a lattice shape. Each lens unit 10 is surrounded by a plurality of ribs 14.

  When the lens arrays 2a and 2b are laminated and bonded, the lens array 2a exposes the front surface, which is a bonding surface with the lens array 2b, and the back surface is held by the lower mold 30a. Further, the lens array 2b exposes the back side surface, which is a joint surface with the lens array 2a, and the front side surface is held by the upper mold 20b. Then, an adhesive is applied to the front surface of the lens array 2a and the end surfaces of the plurality of ribs 14 provided on the rear surface of the lens array 2b. In this state, the lens arrays 2a and 2b are laminated by bringing the ribs 14 into contact with each other, and the ribs 14 are bonded to each other so as to be integrally joined.

  With reference to FIGS. 7-9, the modification of the manufacturing method of the above-mentioned lens array laminated body 1 is demonstrated.

  In the manufacturing method shown in FIG. 7, a plurality of insertion holes 34 are provided in the lower mold 30a that holds the back surface of the lens array 2a, and the upper mold 20b that holds the front surface of the lens array 2b is provided on the lower mold 30a. A plurality of insertion holes 24 to be paired with the respective layer through holes 34 are provided, and the pins 20 are inserted through the both insertion holes 24 and 34 to position the both molds 20b and 30a.

  In the manufacturing method shown in FIG. 8, a tapered surface 35 is provided on the outer peripheral portion of the lower mold 30a that holds the surface on the back side of the lens array 2a, and on the outer peripheral portion of the upper mold 20b that holds the surface on the front side of the lens array 2b. A tapered surface 25 that matches the tapered surface 35 of the lower mold 30a is provided, and the both molds 20b and 30a are positioned by aligning both the tapered surfaces 25 and 35.

  In the manufacturing method shown in FIG. 9, a convex step 36 is provided on the outer periphery of the lower mold 30a that holds the back surface of the lens array 2a, and the upper mold 20b that holds the front surface of the lens array 2b is provided. A concave step portion 26 that fits with the step portion 36 of the lower mold 30a is provided on the outer peripheral portion, and the both molds 20b and 30a are positioned by fitting the both step portions 26 and 36 together.

  FIG. 10 shows another example of the lens array laminate.

  A lens array laminate 101 shown in FIG. 10 is obtained by further laminating and bonding a lens array 2 c to the above-described lens array laminate 1 via a spacer 3.

  Similarly to the lens arrays 2a and 2b described above, the lens array 2c includes a plurality of lens units 10 and a substrate unit 11 that connects these lens units 10 to each other. The lens array 2c is also a wafer level lens array having a wafer shape of the same size as the lens arrays 2a and 2b as a whole, and a plurality of lens portions 10 arranged thereon. The plurality of lens units 10 are arranged in a matrix in the same arrangement as the plurality of lens units 10 of the lens arrays 2a and 2b. Each lens unit 10 has predetermined lens surfaces 12a and 12b on the front and back. The plurality of lens portions 10 and the substrate portion 11 are integrally formed of a translucent material. Hereinafter, for the sake of convenience, in the lens array 2c, the surface on which the plurality of lens surfaces 12a are arranged is referred to as a front surface, and the surface on which the plurality of lens surfaces 12b are arranged is referred to as a back surface.

  With reference to FIGS. 11A to 11C, an example of a method for manufacturing the above-described lens array laminate 101 will be described. A lens array 2c is laminated on the lens array laminate 1 with the lens array laminate 1 as a base, the lens array 2c is on the back side thereof, and the lens array laminate 1 is a lens array laminate. 1 will be described as being bonded to each other on the front surface of the lens array 2b constituting the lens 1. In the method for manufacturing the lens array laminate 1 described above, after the lens arrays 2a and 2b and the spacer 3 are joined, the upper mold 20b that holds the lens array 2b and the lower mold 30a that holds the lens array 2a are provided. However, in the following description, it is assumed that only the upper die 20b is removed and the lower die 30a is left in a state where the lens array 2a is held as it is.

  As shown in FIG. 11A, the lens array 2c exposes the back surface to be joined to the lens array laminate 1, and the opposite front surface is held by the upper mold 20c formed by molding the surface. Further, the lens array laminate 1 exposes the front side surface to be joined to the lens array 2c, that is, the front side surface of the lens array 2b, and the opposite back side surface, that is, the back side surface of the lens array 2a. The surface is held by the lower mold 30a. In addition, an adhesive is applied to each of the front and back surfaces of the spacer 3.

  The lens array 2c and the lens array laminate 1 are disposed so that the exposed back surface of the lens array 2c and the front surface of the lens array 2b of the lens array laminate 1 are opposed to each other, and the spacer 3 is disposed therebetween. To do. Then, by aligning the mark 23 of the upper mold 20c holding the lens array 2c and the mark 33 of the lower mold 30a holding the lens array 2a of the lens array laminate 1, both molds 20c and 30a are positioned. To do.

  Next, as shown in FIG. 11B, the lens array 2c is laminated on the lens array laminated body 1 via the spacer 3, and the lens array 2c, the lens array laminated body 1 and the spacer 3 are joined together to form a lens array. A laminate 101 is obtained. One surface of the lens array 2c is held by the upper mold 20c, and one surface of the lens array laminate 1 is held by the lower mold 30a. The lens array 2c is restrained and restricted from contracting. Therefore, by positioning the both molds 20c and 30a, the optical axis of each lens unit 10 of the lens array 2c and the optical axis of the lens unit 10 of the lens array 2a and 2b of the corresponding lens array laminate 1 are matched. In this state, the lens array 2c and the lens array stacked body 1 are bonded.

  Next, as shown in FIG. 11C, the upper mold 20c and the lower mold 30a are removed. By removing the upper mold 20c and the lower mold 30a, the constraint is released, and the lens array 2c and the lens arrays 2a and 2b of the lens array stacked body 1 may contract, but the lens array 2c and the lens array stacked pair 1 Since the lens arrays 2a and 2b are joined and integrated, the optical axis of the corresponding lens unit 10 does not shift. In addition, the lens arrays 2a, 2b, and 2c are joined and integrated so that the lens arrays 2a, 2b, and 2c are constrained to each other, and contraction is suppressed as compared to when the lens arrays are separated.

  A lens array can be further laminated and bonded to the lens array laminate 101.

  12 and 13 show an example of the imaging unit assembly.

  An imaging unit assembly 201 shown in FIGS. 12 and 13 includes the lens array stack 1 described above, a sensor array 202, and a spacer 203.

  The sensor array 202 has a semiconductor wafer 211 on which a plurality of solid-state imaging elements 210 are formed. The semiconductor wafer 211 is formed in the same size as the lens arrays 2 a and 2 b of the lens array stacked body 1. The plurality of solid-state imaging elements 210 are arranged in a matrix in the same arrangement as the plurality of lens units 10 of the lens arrays 2a and 2b. The solid-state imaging device 210 is, for example, a CCD image sensor or a CMOS image sensor, and repeats a well-known film formation process, photolithography process, etching process, impurity addition process, and the like on the semiconductor wafer 211 to be formed on the semiconductor wafer 211. A light receiving region, an insulating film, an electrode, wiring, and the like are formed.

  The spacer 203 is a wafer-like member having the same size as that of the sensor array 202, and is interposed between the sensor array 202 and the lens array stack 1 so as to have a predetermined distance between the sensor array 202 and the lens array stack 1. It is formed in the thickness which puts. The predetermined distance here refers to the solid-state imaging device 210 of the sensor array 202 in which the optical system 15 configured by the lens portions 10 of the lens arrays arranged in the lens array stack 1 in the stacking direction of the lens arrays 2a and 2b. The distance for forming an image in the light receiving area. The spacer 203 is formed with a plurality of through holes 212 penetrating in the thickness direction. The through holes 212 are arranged in a matrix in the same arrangement as the plurality of solid-state imaging devices 210 of the sensor array 202.

  The lens array laminate 1 has a spacer 203 interposed between the lens array 2a and the optical array 15 so that the optical axis of each optical system 15 coincides with the center of the light receiving area of the solid-state image sensor 210 of the sensor array 202 corresponding thereto. The sensor array 202 is laminated and joined.

  With reference to FIGS. 14A to 14C, an example of a method for manufacturing the above-described imaging unit assembly 201 will be described. In the method of manufacturing the lens array laminate 1 described above, after the lens arrays 2a and 2b and the spacer 3 are joined, the upper mold 20b that holds the lens array 2b and the lower mold 30a that holds the lens array 2a are provided. However, in the following description, it is assumed that only the lower mold 30a is removed and the upper mold 20b is left as it is while holding the lens array 2b.

  As shown in FIG. 14A, the lens array laminate 1 exposes the surface on the back side of the lens array 2a joined to the sensor array 202, and the surface on the opposite side, that is, the surface on the front side of the lens array 2b is the surface. Is held by an upper mold 20b. In addition, an adhesive is applied to each of the front and back surfaces of the spacer 203.

  The lens array laminate 1 and the sensor array 202 are arranged so that the exposed back surface of the lens array 2a of the lens array laminate 1 and the front surface of the sensor array 202 (the surface on which the solid-state imaging device 210 is formed) face each other. And a spacer 203 is disposed between them.

  Next, as shown in FIG. 14B, the lens array stack 1 is stacked on the sensor array 202 via the spacer 203, and the lens array stack 1, the sensor array 202, and the spacer 203 are joined together to form an imaging unit. An aggregate 201 is obtained. The lens array laminate 1 is restrained by holding the entire surface of the lens array laminate 1 by the upper mold 20b, and the contraction is restricted. Therefore, the optical axis of each optical system 15 of the lens array stack 1 and the center of the light receiving area of the solid-state image sensor 210 of the corresponding sensor array 202 coincide with each other, and in this state, the lens array stack 1 and the sensor array 202 Are joined.

  Next, as shown in FIG. 14C, the upper mold 20b is removed. Since the lens array stack 1 and the sensor array 202 are joined and integrated, the optical axis of each optical system 15 does not deviate from the center of the light receiving region of the corresponding solid-state imaging device 210.

  With reference to FIG. 15A-FIG. 15C and FIG. 16A-FIG. 16C, the other example of the manufacturing method of the above-mentioned imaging unit assembly 201 is demonstrated. In the manufacturing method of the imaging unit assembly 201 described below, the lens arrays 2a and 2b are sequentially laminated and joined to the sensor array 202 described above.

  First, as shown in FIG. 15A, in the lens array 2a, the back side surface joined to the sensor array 202 is exposed, and the front side surface on the opposite side is held by the upper mold 20a formed by molding the surface. Yes. In addition, an adhesive is applied to each of the front and back surfaces of the spacer 203.

  The lens array 2a and the sensor array 202 are disposed so that the exposed back surface of the lens array 2a and the front surface of the sensor array 202 face each other, and the spacer 203 is disposed therebetween.

  Next, as shown in FIG. 15B, the lens array 2a is stacked on the sensor array 202 via the spacer 203, and the lens array 2a, the sensor array 202, and the spacer 203 are joined together to obtain a stacked body 201 ′. . One surface of the lens array 2a is held and restrained by the upper mold 20a, and contraction is restricted. Therefore, the optical axis of each lens unit 10 of the lens array 2a coincides with the center of the light receiving area of the solid-state imaging device 210 of the corresponding sensor array 202, and the lens array 2a and the sensor array 202 are joined in this state.

  Next, as shown in FIG. 15C, the upper mold 20a is removed. By removing the upper mold 20a, the lens array 2a is released from the restraint by the upper mold 20a, but is joined to the sensor array 202 and restrained by the sensor array 202, so that the contraction is still restricted.

  Using the laminated body 201 ′ obtained as described above as a base, a lens array 2b is further laminated and bonded thereto with a spacer 3 interposed therebetween.

  As shown in FIG. 16A, in the lens array 2b, the back side surface joined to the laminate 201 ′ is exposed, and the opposite front side surface is held by an upper mold 20b formed by molding the surface. . In addition, an adhesive is applied to each of the front and back surfaces of the spacer 3.

  The lens array 2b and the laminated body 201 ′ are arranged so that the exposed back surface of the lens array 2b and the front side surface of the laminated body 201 ′, that is, the front side surface of the lens array 2a are opposed to each other, and a spacer is provided therebetween. 3 is arranged.

  Next, as shown in FIG. 16B, the lens array 2b is stacked on the stacked body 201 ′ via the spacer 3, and the lens array 2b, the stacked body 201 ′, and the spacer 3 are joined together to form an imaging unit assembly. 201 is obtained. The lens array 2a of the laminated body 201 ′ is bonded and restrained to the sensor array 202, and contraction is restricted. Further, the lens array 2b is restrained by being held by the upper mold 20b on one side, and the contraction is restricted. Therefore, the optical axis of each lens unit 10 of the lens array 2b coincides with the optical axis of the lens unit 10 of the lens array 2a of the corresponding stacked body 201 ′. As a result, the solid-state image sensor 210 of the corresponding sensor array 202 It coincides with the center of the light receiving region, and in this state, the lens array 2b and the laminated body 201 ′ are joined.

  Next, as shown in FIG. 16C, the upper mold 20b is removed. Since the lens array 2b, the lens array 2a, and the sensor array 202 are joined and integrated, the optical axis of each lens unit 10 of the lens array 2b, the optical axis of the lens unit 10 of the corresponding lens array 2a, and the sensor array. The center of the light receiving region of the solid-state image sensor 210 of 202 is not shifted.

  Next, a method for manufacturing an imaging unit using the lens array stack 1 or the imaging unit assembly 201 described above will be described.

  17A to 17C show an example of a method for manufacturing an imaging unit using the lens array stack 1.

  As shown in FIG. 17A, the above-described lens array laminate 1 is separated into a plurality of lens modules 302 each including the lens portions 10 of the lens array 2a and the lens portions 10 of the corresponding lens array 2b. Separately from this, as shown in FIG. 17B, the above-described sensor array 202 is separated into a plurality of sensor modules 303 each including a solid-state imaging device 210. Then, as shown in FIG. 17C, the lens module 302 is assembled to the sensor module 303 to obtain the imaging unit 301. According to the method for manufacturing the imaging unit 301, the optical axes of the plurality of lens units 10 included in the lens module 302 are the same. Therefore, it is possible to avoid a decrease in the imaging performance of the optical system 15 due to the deviation of the optical axis of these lens portions 10.

  FIG. 18 shows an example of a method for manufacturing an imaging unit using the imaging unit assembly 201 described above.

  As shown in FIG. 18, the above-described imaging unit assembly 201 is cut into a lattice so as to individually include each solid-state imaging device 210 of the sensor array 202 and the lens portions 10 of the corresponding lens arrays 2a and 2b. Thus, the imaging unit 301 is obtained. According to this method for manufacturing the image pickup unit 301, it is possible to significantly reduce the labor required to manufacture a large number of image pickup units 301 compared to the case where the lens modules 302 are individually assembled to the sensor module 303.

  As described above, the method for manufacturing a lens array laminate disclosed in the present specification is a method for manufacturing a lens array laminate in which a plurality of lens arrays are laminated and integrally joined. Includes a plurality of one-dimensional or two-dimensional array of predetermined lens units, and a substrate unit formed integrally with these lens units and interconnecting these lens units, A lens array is formed using a pair of molds that respectively mold the front and back surfaces thereof, and one surface of the base is formed by using one lens array or a laminate in which a plurality of the lens arrays are laminated and bonded. The surface of the lens array that is laminated and bonded to the base is held by a molded mold, and the surface opposite to the bonding surface with the base is held by a mold that molds the surface. The Laminated joining the Zuarei.

  Further, the manufacturing method of the imaging unit assembly disclosed in the present specification is an imaging in which the lens array stacked body manufactured by the above-described manufacturing method of the lens array stacked body is stacked on a sensor array and integrally joined. In the method of manufacturing a unit assembly, the sensor array includes a semiconductor substrate, in which a plurality of solid-state imaging elements are arranged in the same arrangement as the plurality of lens portions of the lens array, and the lens array stacked body includes the sensor array. The lens array laminate is laminated and bonded to the sensor array in a state where the surface opposite to the bonding surface with the sensor array is held by a mold in which the surface is molded.

  In addition, the manufacturing method of the imaging unit assembly disclosed in the present specification is a manufacturing method of an imaging unit assembly in which one or more lens arrays are sequentially stacked and integrally joined to the sensor array, The lens array includes a plurality of predetermined one-dimensional or two-dimensional lens units, and a substrate unit formed integrally with these lens units and interconnecting these lens units, In the sensor array, a plurality of solid-state imaging devices are arranged in the same arrangement as the plurality of lens portions of the lens array on a semiconductor substrate, and a pair of molds that respectively mold the front and back surfaces of the lens array are formed. And using the sensor array or a laminated body in which one or more lens arrays are laminated and bonded to the sensor array as a base. The bonding surface of the base to hold the surface on the opposite side in the mold formed by molding its surface is laminated bonding the lens array to the base in that state.

  The lens array laminate disclosed in this specification is manufactured by the above-described method for manufacturing a lens array laminate.

  Further, the lens module disclosed in the present specification is a lens module separated from the lens array stacked body, and is arranged in a stacking direction of the plurality of lens arrays constituting the lens array stacked body. An optical system configured by the lens portions of each of the lens arrays is included.

  Further, an imaging unit disclosed in the present specification includes the lens module described above and a sensor module including a solid-state imaging element, and the lens so that the optical system forms an image on a light receiving region of the solid-state imaging element. A module is assembled to the sensor module.

  Moreover, the imaging unit assembly disclosed in this specification is manufactured by the above-described manufacturing method of the imaging unit assembly.

  An imaging unit disclosed in the present specification is an imaging unit separated from the imaging unit assembly, and is a stack of the sensor array and the one or more lens arrays constituting the imaging unit assembly. A solid-state image sensor of the sensor array and the lens portions of the lens array are arranged in the direction.

DESCRIPTION OF SYMBOLS 1 Lens array laminated body 2a, 2b, 2c Lens array 3 Spacer 10 Lens part 11 Board | substrate part 12a, 12b Lens surface 13 Through-hole 14 Rib 15 Optical system 20a, 20b Upper mold | type 21 Transfer surface 22 Lens molding surface 23 Mark 24 Insertion hole 25 Tapered surface 26 Stepped portion 30a Lower mold 31 Transfer surface 32 Lens molding surface 33 Mark 34 Insertion hole 35 Tapered surface 36 Stepped portion 40 Pin 101 Lens array stacked body 201 Imaging unit assembly 202 Sensor array 203 Spacer 210 Solid-state imaging device 211 Semiconductor Wafer 212 Through-hole 301 Imaging unit 302 Lens module 303 Sensor module M Molding material

Claims (8)

A method for manufacturing a lens array laminate, in which a plurality of lens arrays are laminated and joined together,
The lens array includes a plurality of one-dimensional or two-dimensional predetermined and arranged lens portions, and a substrate portion formed integrally with these lens portions and interconnecting these lens portions. And
The lens array is formed using a pair of molds that respectively mold the front and back surfaces thereof,
One lens array or a laminate in which a plurality of lens arrays are laminated and bonded, and one surface of the base is held by a mold in which the surface is molded, and the lens array is laminated and bonded to the base. A method of manufacturing a lens array laminate, wherein a surface opposite to a surface to be bonded to the base is held by a mold in which the surface is molded, and the base and the lens array are stacked and bonded in that state. A lens array laminate manufactured by the manufacturing method according to claim 1, wherein the lens array laminate is laminated on a sensor array and integrally joined.
In the sensor array, a plurality of solid-state imaging devices are arranged in the same arrangement as the plurality of lens portions of the lens array on a semiconductor substrate,
An imaging unit assembly for laminating and joining the lens array laminate to the sensor array in a state where the surface opposite to the joint surface of the lens array laminate to the sensor array is held by a mold that molds the surface. Production method. A method of manufacturing an imaging unit assembly in which one or more lens arrays are sequentially stacked and integrally joined to a sensor array,
The lens array includes a plurality of predetermined one-dimensional or two-dimensional lens units, and a substrate unit formed integrally with these lens units and interconnecting these lens units,
In the sensor array, a plurality of solid-state imaging devices are arranged in the same arrangement as the plurality of lens portions of the lens array on a semiconductor substrate,
The lens array is formed using a pair of molds that respectively mold the front and back surfaces thereof,
A surface of the sensor array, or a surface of the lens array that is laminated and bonded to the base, on the opposite side of the surface of the lens array that is bonded to the base. The image pickup unit assembly manufacturing method in which the lens array is held on the base and the lens array is laminated and bonded to the base in this state.   The lens array laminated body manufactured by the manufacturing method of Claim 1. A lens module separated from the lens array laminate according to claim 4,
A lens module including an optical system configured by the lens portions of each of the plurality of lens arrays arranged in a stacking direction of the plurality of lens arrays constituting the lens array stack. A lens module according to claim 5, and a sensor module including a solid-state imaging device,
An imaging unit in which the lens module is assembled to the sensor module so that the optical system forms an image on a light receiving region of the solid-state imaging device.   An imaging unit assembly manufactured by the manufacturing method according to claim 2. An imaging unit separated from the imaging unit assembly according to claim 7,
An imaging unit including a solid-state imaging device of the sensor array and the lens portions of the lens array, which are arranged in a stacking direction of the sensor array and the one or more lens arrays constituting the imaging unit assembly.

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