JP2011183620A - Mold, molding method, wafer level lens array, wafer level lens array laminate, element array laminate, lens module, and imaging unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold and a molding method, which can suppress the positional dispersion of the lens part of a wafer level lens array to be produced. <P>SOLUTION: The mold for molding the wafer level lens array having a substrate part and a plurality of lens parts arranged in the substrate part has a mold surface including a lens transfer part in the shape of the inverted lens part and is made of a pair of mold members forming a cavity which is a space molding the wafer level lens array between mold surfaces. In at least one mold member of a pair of the mold members, a resin discharge hole which makes the inside and outside of the cavity communicate with each other and discharges part of a liquid resin which is the material of the wafer level lens array supplied in the cavity is formed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a mold, a molding method, a wafer level lens array, a wafer level lens array laminate, an element array laminate, a lens module, and an imaging unit.

  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, a lens for forming a subject image on the solid-state imaging device, It has.

  With the downsizing and thinning of portable terminals, there is a demand for downsizing and thinning of imaging units. Moreover, in order to reduce the cost of the portable terminal, it is desired to increase the efficiency of the manufacturing process. As a method of manufacturing a small number of lenses, a wafer level lens array having a configuration in which a plurality of lens portions are formed on a substrate portion is manufactured, and the plurality of lens portions are separated by cutting the substrate portion. A method of mass-producing lens modules is known.

  In addition, the substrate portion on which the plurality of lens portions are formed and the semiconductor wafer on which the plurality of solid-state image sensors are formed are combined together, and the semiconductor wafer is cut together with the substrate portion so as to include the lens portions and the solid-state image sensors as a set. Thus, a method of mass-producing imaging units is known.

Conventionally, it is known to manufacture a wafer level lens array by the following process.
(1) A resin is applied onto the master substrate, and a transfer body on which a transfer surface including a reverse shape of the shape of the lens unit is formed is pressed against the resin to transfer the shape of the lens unit.
(2) A master lens in which the shape of a large number of lenses (for example, 1500 to 2400) is transferred onto one wafer by repeating the process of transferring the shape of the lens to a resin on the master substrate by a transfer body. An array is formed.
(3) A stamper (Ni electroforming mold) is manufactured by depositing metal ions such as Ni by electroforming on the lens shape transfer surface onto which the shape of the lens portion of the master lens array is transferred.
(4) A stamper is used as a pair of mold members, and one of the pair of mold members is supplied with heat or energy ray curable resin such as a photocurable resin or a thermosetting resin.
(5) By pressing the supplied resin by sandwiching it between the pair of mold members, the resin is molded following the mold surfaces of the pair of mold members.
(6) Heat or energy rays are supplied to the resin, the resin is cured, and peeled from the pair of mold members to obtain a wafer level lens array.

  Patent Document 1 describes a method and apparatus for manufacturing a wafer level lens array in which a large number of lens portions are formed on one substrate by molding a resin with a mold.

  Patent Document 2 describes a method of preventing the resin injected between the upper and lower molds from leaking by sandwiching a sealing member between the upper mold and the lower mold for molding the optical element.

International Publication No. 08/153102 International Publication No. 08/102582

By the way, when the resin is sandwiched between the pair of mold members, a part of the resin sometimes protrudes from between the mold members.
FIG. 12 is a diagram schematically showing a state of the mold surface of the mold member in plan view. As shown in FIG. 12, the region R where the resin protrudes from the mold surface of the mold member M differs depending on the position on the outer periphery of the mold surface. In the mold member M having a regular circular mold surface in plan view as shown in FIG. 12, the amount of the resin protruding differs in the direction D1 and the direction D2 passing through the center. In the direction D1 of the mold surface, there is little protrusion of the resin, and in the direction D2, there is more protrusion of the resin. When the resin is cured in this state, a difference occurs in the shrinkage amount of the resin molded by the mold member M according to the difference in the amount of the resin protruding from the direction D2 and the direction D1, and the lens of the wafer level lens array to be molded The pitch of the part varies.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a molding die and a molding method capable of suppressing variations in the position of lens portions of a manufactured wafer level lens array.

A molding die for molding a wafer level lens array having a substrate portion and a plurality of lens portions arranged on the substrate portion,
The mold part includes a mold surface including a lens transfer part having a shape obtained by inverting the shape of the lens part, and a pair of mold members forming a cavity that is a space for molding the wafer level lens array between the mold surfaces. ,
In at least one mold member of the pair of mold members, a part of the liquid resin that is a material of the wafer level lens array supplied into the cavity and that communicates the inside and the outside of the cavity Mold that is provided with a resin discharge hole that discharges to the outside of the cavity.

A molding method for molding a wafer level lens array having a substrate portion and a plurality of lens portions arranged on the substrate portion,
Using a pair of mold members having a mold surface including a lens transfer part having a shape obtained by inverting the shape of the lens part,
A resin supplying step of supplying a liquid resin, which is a material of the wafer level lens array, in an amount larger than the volume of the wafer level lens array to the mold surface of one of the pair of mold members;
A setting step in which the mold surface of the other mold member faces the mold surface of the one mold member with the supplied resin sandwiched therebetween, and a cavity is formed between the mold surfaces;
Resin that connects a part of the resin to at least one of the pair of mold members and the outside of the mold member by pressing the resin by narrowing an interval between the mold surfaces A resin discharging step of discharging from the discharge hole to the outside of the cavity.

  According to the present invention, it is not necessary to supply an accurate amount of resin when supplying the resin, and it is possible to supply a larger amount of resin and hold the resin in the cavities between the matching mold members. At this time, if the distance between the pair of mold members is made closer according to the substrate part of the wafer level lens array to be manufactured, only excess resin is discharged from the mold surfaces of the pair of mold members through the resin discharge holes. The Therefore, by discharging excess resin more than the amount necessary to mold the wafer level lens array through the resin discharge hole, the resin leaks from between the pair of mold members at a place other than the resin discharge hole. Can be prevented. Therefore, it is possible to suppress variation in the pitch of the lens portions of the wafer level lens array to be molded.

Plan view of wafer level lens array AA line sectional view of the wafer level lens array shown in FIG. Cross section of lens module Cross section of the imaging unit Diagram showing schematic configuration of mold The figure which shows the shaping | molding process using the shaping | molding die of FIG. Diagram showing a modification of the mold The figure which shows the shaping | molding process using the shaping | molding die of FIG. Diagram showing a modification of the mold The figure which shows the shaping | molding process using the shaping | molding die of FIG. The figure which shows the modification of the resin discharge hole The figure which shows typically the state which planarly viewed the mold surface of the mold member

  First, the configuration of the wafer level lens array, the lens module, and the imaging unit will be described.

  FIG. 1 is a plan view of a wafer level lens array. The wafer level lens array includes a substrate unit 1 and a plurality of lens units 10 arranged on the substrate unit 1.

  The lens unit 10 is made of the same material as the substrate unit 1 and is integrally formed with the substrate unit 1.

  FIG. 2 is a cross-sectional view of the wafer level lens array shown in FIG. The lens portions 10 formed on both surfaces of the substrate portion 1 have a convex lens shape having a convex surface that protrudes from the planar portion of the substrate portion 1. The shape of the lens unit 10 is not particularly limited, and can be appropriately changed depending on the application.

  The wafer level lens array is obtained by molding a molding material using a mold and curing it.

FIG. 3 is a cross-sectional view of the lens module.
The lens module includes a substrate unit 1 and a lens unit 10 integrally formed with the substrate unit 1. In the lens module, a spacer 12 is provided on one surface of the substrate unit 1.

  The spacer 12 is a member that secures an interval when overlapping with other members.

  The lens module is obtained by dicing the substrate unit 1 of the wafer level lens array shown in FIG. 1 and FIG. The spacer 12 provided in the lens module is formed in advance in a region to be diced on the substrate unit 1, separated by dicing, and attached to the substrate unit 1 of each lens module.

FIG. 4 is a cross-sectional view of the imaging unit.
The imaging unit includes the lens module described above and a sensor module. The lens unit 10 of the lens module forms a subject image on the image sensor D provided on the sensor module side. The substrate part 1 of the lens module and the semiconductor substrate W of the sensor module have substantially the same rectangular shape in plan view.

  The sensor module includes a semiconductor substrate W and an image sensor D provided on the semiconductor substrate W. The semiconductor substrate W is formed by cutting a wafer formed of a semiconductor material such as silicon into a substantially rectangular shape in plan view. The image sensor D is provided at a substantially central portion of the semiconductor substrate W. The image sensor D is, for example, a CCD image sensor or a CMOS image sensor. The sensor module can have a configuration in which a chip-shaped image pickup device D is bonded to a semiconductor substrate on which wirings and the like are formed. Alternatively, the imaging element D is configured by repeating a well-known film formation process, photolithography process, etching process, impurity addition process, and the like on the semiconductor substrate W to form electrodes, insulating films, wirings, and the like on the semiconductor substrate. May be.

  In the lens module, the substrate portion 1 is superimposed on the semiconductor substrate W of the sensor module with the spacer 12 interposed therebetween. The spacer 12 of the lens module and the semiconductor substrate W of the sensor module are bonded using, for example, an adhesive. The spacer 12 is designed so that the lens unit 10 of the lens module forms a subject image on the image sensor D of the sensor module, and the lens unit 10 and the image sensor D are prevented from contacting the sensor module. And a thickness separating a predetermined distance from each other.

  The shape of the spacer 12 provided in the lens module and the imaging unit is particularly limited as long as the positional relationship between the lens module substrate 1 and the sensor module semiconductor substrate W can be maintained at a predetermined distance. It can be appropriately modified. For example, the spacer 12 may be a lattice-like member in a plan view of the substrate unit 1, or may be a columnar member provided around the lens unit 10. Further, the spacer 12 may be a frame-shaped member that surrounds the periphery of the image sensor D of the sensor module. If the image pickup device D is isolated from the outside by being surrounded by the frame-shaped spacer 12, the image pickup device D can be shielded from light other than the light passing through the lens. Moreover, it can prevent that dust adheres to the image pick-up element D by sealing the image pick-up element D from the outside.

  The lens module may include a plurality of substrate portions 1 on which the lens portions 10 are formed. At this time, the substrate portions 1 that are overlapped with each other are assembled together via the spacers 12. Alternatively, an imaging unit may be configured by joining a sensor module via a spacer 12 to the lowermost substrate portion 1 of the lens module including a plurality of substrate portions 1 on which the lens portions 10 are formed.

  The imaging unit is reflow mounted on a circuit board (not shown) built in a portable terminal or the like. The circuit board is preliminarily printed with paste-like solder at a position where the imaging unit is mounted, and the imaging unit is mounted on the circuit board. The circuit board including the imaging unit is irradiated with infrared rays or hot air is blown. Heat treatment is performed, and the imaging unit is welded to the circuit board.

  Next, a molding material used for molding the wafer level lens array will be described.

  As the molding material, a resin that has fluidity at the time of molding and is cured by heating or light irradiation after molding is used. Such a resin may be either a thermosetting resin or a resin that is cured by irradiation with an active energy ray (for example, an ultraviolet ray or an electron beam).

  The resin preferably has an appropriate fluidity before curing from the viewpoint of moldability, such as transferability of the mold shape at the time of molding. 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 that the resin has 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.

  The resin composition preferably has a small volumetric 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 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, 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 1,000. 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 is preferably 100 to 5,000. More preferably, it is in the range of 200 to 3,000, and (2) includes non-reactive substances (organic / inorganic fine particles, non-reactive resins, etc.). Resin compositions (for example, described in JP-A-6-298883, JP-A-2001-247793, JP-A-2006-225434, etc.), (3) Resin compositions containing low-shrinkage crosslinking reactive groups (for example, ring-opening) A polymerizable group (for example, an epoxy group (for example, described in JP-A No. 2004-210932), an oxetanyl group (for example, described in JP-A No. 8-134405), an episulfide group (for example, JP-A No. 2002-105110) ), Cyclic carbonate groups (for example, described in JP-A-7-62065), etc., ene / thiol curing groups (for example, described in JP-A 2003-20334), hydrosilylation curing groups (For example, described in JP-A-2005-15666) etc.), (4) Rigid skeleton resin (fluorene, adamantane, isophorone, etc.) (5) Resin composition containing two types of monomers having different polymerizable groups to form an interpenetrating network structure (so-called IPN structure) (E.g., described in JP-A-2006-131868), (6) resin compositions containing expandable substances (e.g., 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 resin composition containing a prepolymer containing a ring-opening polymerizable group and fine particles).

For the wafer level lens array, high-low two or more types of resins 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.
As such a resin, a resin having an aromatic structure is preferable. For example, a resin having a structure such as 9,9′-diarylfluorene, naphthalene, benzothiazole, benzotriazole and the like (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.

The resin is preferably a resin in which inorganic fine particles are dispersed in a matrix for the purpose of increasing the refractive index and adjusting 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. The fine particles are preferably dispersed. 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, additives such as known release agents such as silicon-based, fluorine-based, and long-chain alkyl group-containing compounds and antioxidants such as hindered phenols may be appropriately blended in the resin.

  A curing catalyst or an initiator can be blended with the resin 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]). 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.

  When other components can be dissolved in a liquid low molecular weight monomer (reactive diluent) or the like when the above components are appropriately blended with the resin, it is not necessary to add a separate solvent. However, in other cases, the resin is produced by dissolving each component by separately using a solvent. The solvent is not particularly limited and may be appropriately selected as long as the resin composition is uniformly dissolved or dispersed without precipitation. Specifically, for example, ketones (for example, 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), aromatic hydrocarbons (for example, toluene, xylene, etc.), water and the like. When the resin contains a solvent, it is preferable to perform an operation of transferring the mold shape after casting the resin on the substrate and / or the mold member and drying the solvent.

  Next, a mold used to mold the wafer level lens array will be described.

FIG. 5 is a diagram illustrating a schematic configuration of a mold.
The mold includes a pair of mold members 102 and 104. The pair of mold members 102 and 104 are arranged above and below in the vertical direction, the mold member 102 is a lower mold member, and the mold member 104 is an upper mold member. FIG. 5 shows a state in which the resin 10 </ b> R is supplied to the mold member 102.

  The pair of mold members 102 and 104 have mold surfaces including lens transfer portions 102a and 104a having a shape obtained by inverting the shape of the lens portion of the wafer level lens array to be manufactured. The resin 10R is molded by sandwiching the mold surfaces of the pair of mold members 102 and 104. For example, one mold member 102 has a mold surface including a lens transfer portion 102a having a shape obtained by reversing the shape of the entrance surface of the lens portion, and the other mold member 104 has the shape of the exit surface of the lens portion reversed. It has a mold surface including a lens transfer portion 10 having a shape. Each of the pair of mold members 102 and 104 has the same mold surface as the area of the wafer level lens array in the plan view of the substrate 1. In addition, the pair of mold members 102 and 104 have the same peripheral edge size, and the shape of the mold surface is a perfect circle.

  The mold member 102 has a side wall part 110 provided so as to surround the peripheral part of the mold surface on which the plurality of lens transfer parts 102a are formed. The side wall part 110 is formed in an annular shape in a plan view of the mold surface of the mold member 102. In addition, the inner side surface of the side wall portion 110 is perpendicular to the mold surface. The mold member 102 holds the supplied resin 10 </ b> R on the mold surface surrounded by the side wall part 110.

  The outer diameter of the mold member 104 is substantially equal to the diameter of the inner surface of the side wall 110 of the mold member 102. The pair of mold members 102 and 104 form a cavity for molding a wafer level lens array between both mold surfaces by fitting the mold member 104 inside the side wall portion 110 of the mold member 102.

  A taper 112 is formed inside the end of the side wall 110. When the mold member 104 is fitted into the mold member 102, the periphery of the mold member 104 is guided to the inside of the side wall part 110 by the taper 112, so that the mold member 104 can be fitted smoothly.

  The mold member 102 is provided with a plurality of resin discharge holes 114 communicating from the mold surface of the mold member 102 to the opposite surface. The resin discharge hole 114 has one opening provided on the mold surface of the mold member 102 and the other opening provided on the surface opposite to the mold surface. Therefore, the resin discharge hole 114 communicates the inside and the outside of the cavity formed between the pair of mold members by fitting them together. The resin discharge hole 114 is a hole having a substantially circular cross section perpendicular to the vertical direction.

  The resin discharge hole 114 has a narrow portion 114a having an opening area smaller than other portions of the resin discharge hole 114 in the vicinity of the opening in the mold surface. Specifically, the resin discharge hole 114 is formed such that the opening in the mold surface is smaller than the diameter of the other part of the resin discharge hole 114.

  Here, the opening area of the narrow portion 114a is such that the resin 10R is only subjected to its own weight, the resin 10R cannot pass through under no pressure from the outside, and the resin 10R is under pressure. The size is such that the resin 10R can pass therethrough.

  Further, the resin discharge hole 114 is provided so as to open at a portion other than the lens transfer portion 102a on the mold surface.

  The resin discharge hole 114 has a discharge pipe 116 connected to the other opening side. The discharge pipe 116 has a flow path formed so as to reach from the end connected to the resin discharge hole 114 to the end that discharges the resin 10 </ b> R to the container 120.

  The container 120 collects and stores the resin 10 </ b> R that has flowed from the resin discharge hole 114 through the discharge pipe 116.

  Next, a procedure for manufacturing a wafer level lens array using a mold will be described.

  When molding the wafer level lens array, first, the resin 10R is supplied onto the mold surface surrounded by the side wall 110 of the mold member 102. At this time, the resin 10R is held on the mold surface without flowing into the resin discharge hole 114 by designing the opening of the resin discharge hole 114 in the mold surface to be sufficiently small.

  FIG. 6 is a diagram showing a molding process using the mold of FIG. The resin 10R is sandwiched between the pair of mold members 102 and 104 by fitting the outer peripheral surface of the mold member 104 to the inner surface of the side wall portion 110 of the mold member 102 and reducing the distance between the mold surfaces. At this time, a cavity for molding the wafer level lens array is formed between the pair of mold members 102 and 104. Specifically, the mold surface of the mold member 102 transfers the lens shape of one surface of the wafer level lens array to the resin 10R, and the mold surface of the mold member 104 transfers the other surface of the wafer level lens array to the resin 10R. Transfer the lens shape.

  When the pair of mold members 102 and 104 are fitted together, the air sandwiched together with the resin 10 </ b> R passes through the gap between the inner surface of the side wall portion of the mold member 102 and the outer peripheral surface of the mold member 104. It is discharged outside.

  When the resin 10R is sandwiched between the mold surfaces of the pair of mold members 102 and 104, pressure is applied to the resin 10R. Then, a part of the resin 10R flows into the resin discharge hole 114 from the opening of the resin discharge hole 114, and is collected in the container 120 through the flow path. Thus, excess resin 10R is discharged.

  At this time, the amount of the resin 10R to be discharged is determined according to the distance between the mold surfaces of the pair of mold members 102 and 104. Here, the distance between the mold surfaces of the pair of mold members 102 and 104 is substantially equal to the thickness of the substrate portion of the wafer level lens array to be manufactured, and the resin 10R corresponding to the amount exceeding the volume of the wafer level lens array is discharged. To do.

After part of the resin 10R is discharged, a step of curing the resin 10R held between the pair of mold members 102 and 104 is performed.
When the resin 10R is an energy ray curable resin such as a thermosetting resin or an ultraviolet curable resin, the resin between the pair of mold members 102 and 104 is heated while the positions of the pair of mold members 102 and 104 are maintained. Or, it is cured by irradiating with ultraviolet rays.

  In the curing step, heat or energy rays are supplied from the mold member 104 side where the resin discharge holes 114 are not provided.

  At the time of curing, the resin between the pair of mold members 102 and 104 contracts due to the curing. In this procedure, before curing, excess resin 10R corresponding to an amount exceeding the amount necessary to mold the manufactured wafer level lens array is discharged through the resin discharge hole 114. At this time, the resin 10R does not spill out around the mold members 102 and 104 from between the mold surfaces and expand into an indefinite shape while being connected to the resin between the mold surfaces. Therefore, the shrinkage of the resin accompanying the curing becomes substantially uniform in the circumferential direction with respect to the center of the mold surface, and it is possible to suppress the occurrence of variations in the pitch of the lens portions of the wafer level lens array obtained by molding.

  After the resin 10R is cured, the mold member 104 is removed from the mold member 102, and the wafer level lens array is released.

Providing the narrow portion 114a has the following effects.
When the resin is supplied, the resin 10R can be prevented from flowing into the resin discharge hole 114.
At the time of curing, the supply of heat or energy rays is partially blocked by the narrow portion 114a, thereby preventing the resin 10R in the resin discharge hole 114 from being cured.
At the time of mold release, the wafer level lens array can be easily separated at a portion corresponding to the narrow portion 114a, and the mold release can be performed smoothly.

  Further, by supplying heat or energy rays from the mold member 104 side where the resin discharge hole 114 is not provided, curing of the resin 10R inside the resin discharge hole 114 is prevented, and the resin 10R constituting the wafer level lens array It becomes easy to separate, and mold release can be performed easily.

  A wafer level lens array can be obtained by the above procedure. The wafer level lens array has a trace at a position corresponding to the resin discharge hole 114 in a region other than the lens portion. This mark is generated when the resin 10R constituting the wafer level lens array is separated from the resin 10R inside the resin discharge hole 114 at the time of mold release. You may perform the process of removing a trace after mold release.

  FIG. 7 is a view showing a modification of the mold. The mold of this example includes a pair of mold members 202 and 204. The pair of mold members 202 and 204 are arranged above and below in the vertical direction, the mold member 202 is a lower mold member, and the mold member 204 is an upper mold member.

  The pair of mold members 202 and 204 has basically the same configuration as the mold members 102 and 104 shown in FIG. 5. In this example, a plurality of resin discharge holes 214 are provided in the upper mold member 204. Is different.

  The mold member 204 has a recess 206 formed on the surface opposite to the mold surface (upper surface in FIG. 7). The depression 206 has a depth in the vertical direction.

  The resin discharge hole 214 communicates the mold member 204 from the mold surface to the opposite side thereof, and the vertical cross section in the vertical direction is substantially circular. The resin discharge hole 214 connects the inside and outside of the cavity formed between the pair of mold members 202 and 204 by fitting them together. Here, one opening is provided in a part other than the lens transfer part 204 a on the mold surface of the mold member 204, and the other opening is provided in the bottom part of the recess 206.

  An opening in the mold surface of the mold member 204 of the resin discharge hole 214 is provided with a narrow portion 214a having a smaller opening area than other portions of the resin discharge hole 214.

  When molding a wafer level lens array using the molding die of this example, first, resin is supplied to the mold surface surrounded by the side wall portion 210 of the mold member 202 or on the mold surface.

  FIG. 8 is a diagram showing a molding process using the mold of FIG. After supplying the resin 10R to the mold surface of the mold member 202, the outer peripheral surface of the mold member 204 is fitted to the inner surface of the side wall portion 210 of the mold member 202, and the distance between the mold surfaces of the pair of mold members 202 and 204 is set to the wafer. The resin 10R is sandwiched by approaching the distance corresponding to the thickness of the substrate portion of the level lens array.

  Due to the pressure sandwiched between the pair of mold members 202, 204, a part of the resin 10 R flows into the recess 206 of the mold member 204 through the resin discharge hole 214 and is stored in the recess 206.

  Further, when the mold surface of the lower mold member 202 is fitted to the inner surface of the side wall portion 210 with the mold surface of the upper mold member 202 facing the mold surface of the lower mold member 202 in a state where the resin 10R is supplied to the mold surface of the lower mold member 202, At the same time, air is caught. The sandwiched air is discharged from the gap between the inner surface of the side wall portion of the mold member and the outer peripheral surface of the mold member 204 and is also discharged from the resin discharge hole 214. When the air is discharged and the mold surface of the upper mold member 204 comes into contact with the liquid surface of the resin 10R, the resin is pressed against the mold surface, and a part of the resin 10R is discharged from the resin discharge hole 214.

  In the curing step, heat or energy rays are supplied from the mold member 202 side where the resin discharge holes 214 are not provided.

  During curing, the resin between the pair of mold members 202 and 204 contracts due to curing. In this procedure, before curing, excess resin 10R corresponding to an amount exceeding the amount necessary to mold the wafer level lens array to be manufactured is discharged to the depression 206 of the mold member 204 through the resin discharge hole 214. ing. For this reason, the resin 10R does not overflow into the periphery of the mold members 202 and 204 from the mold surface and expand into an indefinite shape while being connected to the resin between the mold surfaces. Therefore, the shrinkage of the resin accompanying the curing becomes substantially uniform in the circumferential direction with respect to the center of the mold surface, and it is possible to suppress the occurrence of variations in the pitch of the lens portions of the wafer level lens array obtained by molding.

  After the resin 10R is cured, the mold member 204 is removed from the mold member 202, and the wafer level lens array is released.

  Since the narrow portion 214a is provided in the opening in the mold surface of the resin discharge hole 214, the wafer level lens array is easily separated at the portion corresponding to the narrow portion 214a at the time of mold release, and the mold release is smooth. Can be done.

  Further, by supplying heat or energy rays from the mold member 202 side where the resin discharge hole 214 is not provided, curing of the resin 10R inside the resin discharge hole 214 is prevented, and the resin 10R constituting the wafer level lens array It becomes easy to separate, and mold release can be performed easily.

  FIG. 9 is a diagram showing a modification of the mold. The mold of this example includes a pair of mold members 302 and 304. The pair of mold members 302 and 304 are disposed vertically above and below, the mold member 302 is a lower mold member, and the mold member 304 is an upper mold member.

  The pair of mold members 302 and 304 basically have the same configuration as the mold members 102 and 104 shown in FIG. 5. In this example, a plurality of resin discharge holes 314 are provided in the side wall portion 310 of the lower mold member 302. Is different.

  The resin discharge hole 314 communicates from the inner surface to the outer surface of the side wall portion 310, and is a hole having a substantially circular cross section perpendicular to the mold surface. The resin discharge hole 314 communicates the inside and the outside of the cavity formed between the pair of mold members 302 and 304 by fitting them together.

  A narrow portion 314 a having a smaller opening area than other portions of the resin discharge hole 314 is provided in the opening on the inner side surface of the side wall portion 310 of the resin discharge hole 314.

  When molding the wafer level lens array using the molding die of this example, first, resin is supplied onto the mold surface surrounded by the side wall portion 310 of the mold member 302.

  FIG. 10 is a diagram showing a molding process using the mold of FIG. After the resin 10R is supplied to the mold surface of the mold member 302, the outer peripheral surface of the mold member 304 is fitted to the inner surface of the side wall portion 310 of the mold member 302, and the distance between the mold surfaces of the pair of mold members 302 and 304 is set to the wafer. The resin 10R is sandwiched by approaching the distance corresponding to the thickness of the substrate portion of the level lens array.

  Due to the pressure sandwiched between the pair of mold members 302 and 304, a part of the resin 10R flows out of the mold member 302 through the resin discharge hole 314 and is sent to the discharge pipe 316 connected to the resin discharge hole 314. It is.

  In addition, when the pair of mold members 302 and 304 is sandwiched, the air sandwiched with the resin 10 </ b> R is discharged from the gap between the inner side surface of the side wall portion of the mold member 302 and the outer peripheral surface of the mold member 304.

  In the curing process, heat or energy rays are supplied from the mold member 304 side where the resin discharge holes 314 are not provided, and are not supplied to the side wall portion 310 side of the mold member 302.

  Prior to curing, excess resin 10R corresponding to an amount exceeding that required to mold the manufactured wafer level lens array is discharged to the outside of the mold member 302 through the resin discharge hole 314. For this reason, the resin 10R does not overflow into the periphery of the mold members 302 and 304 from the mold surface and expand into an indefinite shape while being connected to the resin between the mold surfaces. Therefore, the shrinkage of the resin 10R due to the curing becomes substantially uniform in the circumferential direction with respect to the center of the mold surface, and it is possible to suppress variation in the pitch of the lens portions of the wafer level lens array obtained by molding.

  After the resin 10R is cured, the mold member 304 is removed from the mold member 302, and the wafer level lens array is released.

  Since the narrow portion 314a is provided in the opening on the inner side surface of the side wall portion 310 of the resin discharge hole 314, the wafer level lens array is easily separated at the portion corresponding to the narrow portion 314a at the time of mold release. Mold release can be performed smoothly.

  Further, by supplying heat or energy rays from the mold member 304 side where the resin discharge hole 314 is not provided, avoiding the side wall part 310 of the mold member 302, the resin 10R inside the resin discharge hole 314 of the side wall part 310 is supplied. Is prevented from being hardened, it becomes easy to separate from the resin 10R constituting the wafer level lens array, and the mold can be easily released.

  As described above, the resin discharge hole is configured such that the narrow portion and the other part of the resin discharge hole are connected via a step, but the present invention is not limited to this.

FIG. 11 is a view showing a modified example of the resin discharge hole. In FIG. 11, the upper opening is the mold surface side of the mold member.
The resin discharge hole 414 may be provided with a narrow portion 414a formed by sharpening the opening edge of the resin discharge hole 414 with a taper 414b. This makes it easier to separate the resin constituting the wafer level lens array and the resin in the resin discharge hole 414 by the sharpened portion of the narrowed portion 414a at the time of mold release.

  A plurality of resin discharge holes may be provided in the mold member as in the above example, or only one resin discharge hole may be provided.

  A wafer level lens array laminate can be obtained by laminating a plurality of wafer level lens arrays including at least one wafer level lens array obtained by the above molding procedure. Moreover, a lens module can be obtained by separating from the wafer level lens array laminate including the lens portions arranged in the lamination method.

  At least one wafer level lens array obtained by the above molding procedure, and a sensor array in which a plurality of solid-state image sensors are arranged on the wafer in the same arrangement as a plurality of lens portions in the wafer level lens array, By laminating the lens array on the sensor array, an element array laminate can be obtained. In addition, an imaging unit can be obtained by separating from the element array stack including the solid-state imaging elements and the lens portions arranged in the stacking direction.

This specification discloses the following matters.
(1) A mold for molding a wafer level lens array having a substrate portion and a plurality of lens portions arranged on the substrate portion,
The mold part includes a mold surface including a lens transfer part having a shape obtained by inverting the shape of the lens part, and a pair of mold members forming a cavity that is a space for molding the wafer level lens array between the mold surfaces. ,
In at least one mold member of the pair of mold members, a part of the liquid resin that is a material of the wafer level lens array supplied into the cavity and that communicates the inside and the outside of the cavity Mold that is provided with a resin discharge hole that discharges to the outside of the cavity.
(2) The mold according to (1),
The pair of mold members is composed of a lower mold member in which a side wall portion is formed on the periphery of the mold surface, and an upper mold member in which an outer peripheral surface is fitted to an inner side surface of the side wall portion,
A molding die in which the lower mold member is provided with the resin discharge hole communicating from the mold surface to the outside of the lower mold member.
(3) The mold according to (2),
The resin discharge hole is a molding die provided so as to communicate with a surface opposite to the mold surface from a portion other than the lens transfer portion of the mold surface of the lower mold member.
(4) The mold according to (1),
The pair of mold members is composed of a lower mold member in which a side wall portion is formed on the periphery of the mold surface, and an upper mold member in which an outer peripheral surface is fitted to an inner side surface of the side wall portion,
The said resin discharge hole is a shaping | molding die provided in communication from the inner surface of the said side wall part of the said lower mold member to the outer surface of the said side wall part.
(5) The mold according to (1),
The pair of mold members is composed of a lower mold member in which a side wall portion is formed on the periphery of the mold surface, and an upper mold member in which an outer peripheral surface is fitted to an inner side surface of the side wall portion,
The resin discharge hole is a molding die provided so as to communicate with a surface opposite to the mold surface from a portion other than the lens transfer portion of the mold surface of the upper mold member.
(6) The mold according to (5),
A molding die in which a recess communicating with the resin discharge hole is provided on a surface of the upper mold member opposite to the mold surface.
(7) The mold according to any one of (1) to (6),
The said resin discharge hole is a shaping | molding die which has a narrow part whose opening area of the opening part in the said cavity is smaller than the cross-sectional area in the other site | part of this resin discharge hole.
(8) A molding method for molding a wafer level lens array having a substrate portion and a plurality of lens portions arranged on the substrate portion,
Using a pair of mold members having a mold surface including a lens transfer part having a shape obtained by inverting the shape of the lens part,
A resin supplying step of supplying a liquid resin, which is a material of the wafer level lens array, in an amount larger than the volume of the wafer level lens array to the mold surface of one of the pair of mold members;
A setting step in which the mold surface of the other mold member faces the mold surface of the one mold member with the supplied resin sandwiched therebetween, and a cavity is formed between the mold surfaces;
Resin that connects a part of the resin to at least one of the pair of mold members and the outside of the mold member by pressing the resin by narrowing an interval between the mold surfaces A resin discharging step of discharging from the discharge hole to the outside of the cavity.
(9) The molding method according to (8),
The pair of mold members is composed of a lower mold member in which a side wall portion is formed on the periphery of the mold surface, and an upper mold member in which an outer peripheral surface is fitted to an inner side surface of the side wall portion,
The resin discharge hole is provided in the lower mold member in communication with the mold surface forming the cavity and the outside of the lower mold member;
A molding method for discharging a part of the resin from the resin discharge hole to the outside of the cavity by pressing the resin supplied to the mold surface of the lower mold member with the mold surface of the upper mold member.
(10) The molding method according to (8),
The pair of mold members is composed of a lower mold member in which a side wall portion is formed on the periphery of the mold surface, and an upper mold member in which an outer peripheral surface is fitted to an inner side surface of the side wall portion,
The resin discharge hole is provided in the lower mold member so as to communicate the inner side surface of the side wall part forming the cavity and the outer side surface of the side wall part,
A molding method for discharging a part of the resin from the resin discharge hole to the outside of the cavity by pressing the resin supplied to the mold surface of the lower mold member with the mold surface of the upper mold member.
(11) The molding method according to (8),
The pair of mold members is composed of a lower mold member in which a side wall portion is formed on the periphery of the mold surface, and an upper mold member in which an outer peripheral surface is fitted to an inner side surface of the side wall portion,
The resin discharge hole is provided in the upper mold member in communication with the mold surface forming the cavity and the outside of the upper mold member;
A molding method for discharging a part of the resin from the resin discharge hole to the outside of the cavity by pressing the resin supplied to the mold surface of the lower mold member with the mold surface of the upper mold member.
(12) The molding method according to (11),
A molding method in which a recess communicating with the resin discharge hole is provided on a surface opposite to the mold surface of the upper mold member, and a part of the resin discharged from the resin discharge hole flows into the recess.
(13) The molding method according to any one of (8) to (12),
The resin is a heat or energy ray curable resin,
The resin deformed into the shape of the mold surface of the pair of mold members by supplying heat or energy rays from the other mold member side where the resin discharge hole is not provided in the pair of mold members. A molding method having a curing step of curing.
(14) A wafer level lens array obtained by the molding method according to any one of (8) to (13).
(15) A wafer level lens array laminate in which a plurality of wafer level lens arrays including at least one wafer level lens array according to (14) are laminated.
(16) comprising at least one wafer level lens array according to (14), and a sensor array in which a plurality of solid-state imaging devices are arranged on the wafer in the same arrangement as the plurality of lens portions in the wafer level lens array, An element array laminate in which the wafer level lens array is laminated on the sensor array.
(17) A lens module separated from the wafer level lens array according to (14), including one lens unit.
(18) A lens module separated from the wafer level lens array laminate according to (15) including a lens portion arranged in a lamination method.
(19) An imaging unit separated from the element array stack according to (16), including a solid-state imaging device and a lens unit arranged in the stacking direction.

DESCRIPTION OF SYMBOLS 1 Substrate part 10 Lens part 102,202,302 Mold member 104,204,304 Mold member 110,210,310 Side wall part 114,214,314,414 Resin discharge hole 114a, 214a, 314a, 414a Narrow part

Claims (19)

A molding die for molding a wafer level lens array having a substrate portion and a plurality of lens portions arranged on the substrate portion,
The mold part includes a mold surface including a lens transfer part having a shape obtained by inverting the shape of the lens part, and a pair of mold members forming a cavity that is a space for molding the wafer level lens array between the mold surfaces. ,
In at least one mold member of the pair of mold members, a part of the liquid resin that is a material of the wafer level lens array supplied into the cavity and that communicates the inside and the outside of the cavity Mold that is provided with a resin discharge hole that discharges to the outside of the cavity. The mold according to claim 1, wherein
The pair of mold members is composed of a lower mold member in which a side wall portion is formed on the periphery of the mold surface, and an upper mold member in which an outer peripheral surface is fitted to an inner side surface of the side wall portion,
A molding die in which the lower mold member is provided with the resin discharge hole communicating from the mold surface to the outside of the lower mold member. The mold according to claim 2, wherein
The resin discharge hole is a molding die provided so as to communicate with a surface opposite to the mold surface from a portion other than the lens transfer portion of the mold surface of the lower mold member. The mold according to claim 1, wherein
The pair of mold members is composed of a lower mold member in which a side wall portion is formed on the periphery of the mold surface, and an upper mold member in which an outer peripheral surface is fitted to an inner side surface of the side wall portion,
The said resin discharge hole is a shaping | molding die provided in communication from the inner surface of the said side wall part of the said lower mold member to the outer surface of the said side wall part. The mold according to claim 1, wherein
The pair of mold members includes a lower mold member having a side wall portion formed on the periphery of the mold surface, and an upper mold member having an outer peripheral surface fitted on the inner side surface of the side wall portion,
The resin discharge hole is a molding die provided so as to communicate with a surface opposite to the mold surface from a portion other than the lens transfer portion of the mold surface of the upper mold member. The mold according to claim 5, wherein
A molding die in which a recess communicating with the resin discharge hole is provided on a surface of the upper mold member opposite to the mold surface. The mold according to any one of claims 1 to 6,
The said resin discharge hole is a shaping | molding die which has a narrow part whose opening area of the opening part in the said cavity is smaller than the cross-sectional area in the other site | part of this resin discharge hole. A molding method for molding a wafer level lens array having a substrate portion and a plurality of lens portions arranged on the substrate portion,
Using a pair of mold members having a mold surface including a lens transfer part having a shape obtained by inverting the shape of the lens part,
A resin supplying step of supplying a liquid resin, which is a material of the wafer level lens array, in an amount larger than the volume of the wafer level lens array to the mold surface of one of the pair of mold members;
A setting step in which the mold surface of the other mold member faces the mold surface of the one mold member with the supplied resin sandwiched therebetween, and a cavity is formed between the mold surfaces;
Resin that connects a part of the resin to at least one of the pair of mold members and the outside of the mold member by pressing the resin by narrowing an interval between the mold surfaces A resin discharging step of discharging from the discharge hole to the outside of the cavity. The molding method according to claim 8,
The pair of mold members is composed of a lower mold member in which a side wall portion is formed on the periphery of the mold surface, and an upper mold member in which an outer peripheral surface is fitted to an inner side surface of the side wall portion,
The resin discharge hole is provided in the lower mold member in communication with the mold surface forming the cavity and the outside of the lower mold member;
A molding method for discharging a part of the resin from the resin discharge hole to the outside of the cavity by pressing the resin supplied to the mold surface of the lower mold member with the mold surface of the upper mold member. The molding method according to claim 8,
The pair of mold members is composed of a lower mold member in which a side wall portion is formed on the periphery of the mold surface, and an upper mold member in which an outer peripheral surface is fitted to an inner side surface of the side wall portion,
The resin discharge hole is provided in the lower mold member so as to communicate the inner side surface of the side wall part forming the cavity and the outer side surface of the side wall part,
A molding method for discharging a part of the resin from the resin discharge hole to the outside of the cavity by pressing the resin supplied to the mold surface of the lower mold member with the mold surface of the upper mold member. The molding method according to claim 8,
The pair of mold members is composed of a lower mold member in which a side wall portion is formed on the periphery of the mold surface, and an upper mold member in which an outer peripheral surface is fitted to an inner side surface of the side wall portion,
The resin discharge hole is provided in the upper mold member in communication with the mold surface forming the cavity and the outside of the upper mold member;
A molding method for discharging a part of the resin from the resin discharge hole to the outside of the cavity by pressing the resin supplied to the mold surface of the lower mold member with the mold surface of the upper mold member. The molding method according to claim 11,
A molding method in which a recess communicating with the resin discharge hole is provided on a surface opposite to the mold surface of the upper mold member, and a part of the resin discharged from the resin discharge hole flows into the recess. A molding method according to any one of claims 8 to 12,
The resin is a heat or energy ray curable resin,
The resin deformed into the shape of the mold surface of the pair of mold members by supplying heat or energy rays from the other mold member side where the resin discharge hole is not provided in the pair of mold members. A molding method having a curing step of curing.   A wafer level lens array obtained by the molding method according to any one of claims 8 to 13.   A wafer level lens array laminate in which a plurality of wafer level lens arrays including at least one wafer level lens array according to claim 14 are laminated.   15. A wafer level lens array according to claim 14, and a sensor array in which a plurality of solid-state imaging devices are arranged on a wafer in the same arrangement as a plurality of lens portions in the wafer level lens array, and the wafer level An element array laminate in which a lens array is laminated on the sensor array.   The lens module separated from the wafer level lens array of Claim 14 including the one said lens part.   The lens module separated from the wafer level lens array laminated body of Claim 15 including the lens part arranged in a lamination | stacking method.   An imaging unit separated from the element array stack according to claim 16 including a solid-state imaging device and a lens unit arranged in the stacking direction.

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