JP2012185240A - Lens array, method of manufacturing lens array and method of manufacturing lens module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens array, a method of manufacturing the lens array and a method of manufacturing a lens module in which a light-shielding part can be formed with high accuracy.SOLUTION: The lens array 10 has a plurality of lens parts 6, and a substrate part 11 by which the plurality of the lens parts are integrally connected to each other. This lens array includes: a groove 8 formed in an area excluding a portion intersecting with an optical axis of the lens part; a light-shielding material 14 filled into the groove; and a stepped bank 8a formed in the boundary between the lens surface of the lens part and the groove.

Description

  The present invention relates to a lens array, a lens array manufacturing method, and a lens module.

  In recent years, portable terminals 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.

  In order to reduce the cost of the imaging unit, it is desired to improve the efficiency of the lens manufacturing method so that a large number of lenses mounted on the imaging unit can be manufactured at low cost. Such a lens is obtained by manufacturing a lens array having a configuration in which a plurality of lens portions are integrally formed on a substrate portion, and cutting the substrate portion to separate the plurality of lens portions, respectively. To be implemented.

  As a lens array in which a plurality of lens portions are formed on a substrate portion, there is one shown in Patent Document 1.

  In the lens array described in Patent Document 1, a concave groove is formed between adjacent lens portions. In the lens array, a light shielding portion is formed by coating a light shielding material on a region other than the light incident / exit surface by applying a paint. In Patent Document 1, an aperture is formed on the light incident / exit surface by the light shielding material.

JP 2000-316069 A

  In Patent Document 1, it is difficult to prevent the light-shielding material applied when the light-shielding part is formed by application from adhering to the lens surface, and the aperture cannot be formed with good accuracy. For this reason, the function in the imaging unit is reduced, such as a decrease in the amount of peripheral light for imaging and a ghost defect.

  The present invention provides a lens array, a lens array manufacturing method, and a lens module that can form a light-shielding portion with high accuracy.

(1) A lens array having a plurality of lens portions and a substrate portion integrally connecting the plurality of lens portions,
A groove formed in a region excluding a portion intersecting with the optical axis of the lens portion, a light shielding material filled in the groove, a stepped bank formed at a boundary between the lens surface of the lens portion and the groove; A lens array.
(2) A method of manufacturing a lens array having a plurality of lens portions and a substrate portion integrally connecting the plurality of lens portions,
Using the mold, the plurality of lens portions and the substrate portion are molded, and a groove is formed in a region excluding a portion intersecting the optical axis of the lens portion, and a lens surface of the lens portion and the boundary between the grooves are formed. Molded stepped dyke, then
Supplying a light shielding material to the groove;
A method of manufacturing a lens array, wherein a light shielding portion is formed by expanding the supplied light shielding material by its own weight and stopping the spreading of the light shielding material by the bank.
(3) A lens module formed by cutting the substrate portion of the lens array of (1) and dividing it into individual lens portions.

  ADVANTAGE OF THE INVENTION According to this invention, the lens array which can form a light-shielding part with high precision, the manufacturing method of a lens array, and the manufacturing method of a lens module can be provided.

It is sectional drawing which shows an example of the imaging unit for demonstrating embodiment of this invention. It is a figure which shows an example of the lens array for describing embodiment of this invention. FIG. 3 is a cross-sectional view of the lens array of FIG. 2 taken along the line III-III. It is a figure which shows the process of supplying a molding material to a shaping | molding die. It is a schematic diagram which shows the shaping | molding process using the shaping | molding die of FIG. It is sectional drawing which shows the lens molded object obtained by the shaping | molding process of FIG. It is sectional drawing which shows the process of apply | coating the light shielding material. It is sectional drawing which shows the structure of a lens array. It is sectional drawing which shows the modification of a structure of a lens array.

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

  The sensor module 2 includes a solid-state imaging device 4 and a sensor substrate unit 5. The sensor substrate unit 5 is formed of a semiconductor material such as silicon. The solid-state imaging device 4 is, for example, a CCD image sensor, a CMOS image sensor, or the like, and repeats a well-known film formation process, photolithography process, etching process, impurity addition process, and the like on the sensor substrate section 5 to thereby form the sensor substrate section 5. A light receiving region, an insulating film, an electrode, a wiring, and the like are formed thereon.

  The lens module 3 includes a lens unit 6 and a flange unit 7. The lens unit 6 has predetermined lens surfaces 6a and 6b on the front and back. Both lens surfaces 6a and 6b are convex spherical surfaces in the illustrated example, but various combinations of convex spherical surfaces, concave spherical surfaces, aspherical surfaces, or flat surfaces are adopted depending on the application. obtain. The flange portion 7 protrudes from the outer periphery of the lens portion 6 in a bowl shape and surrounds the outer periphery of the lens portion 6. The lens part 6 and the flange part 7 are integrally formed of a translucent material.

  The lens module 3 is laminated on the sensor module 2 via the spacer 9 between the flange portion 7 and the sensor substrate portion 5 and assembled to the sensor module 2. The spacer 9 is provided between the sensor substrate portion 5 of the sensor module 2 and the flange portion 7 of the lens module 3 so that the lens portion 6 of the lens module 3 forms an image on the light receiving surface of the solid-state imaging device 4 of the sensor module 2. The thickness is set at a predetermined distance. The spacer 9 and both the modules 2 and 3 are joined using, for example, an adhesive.

  The shape of the spacer 9 is not particularly limited as long as a predetermined distance can be placed between the sensor substrate portion 5 of the sensor module 2 and the flange portion 7 of the lens module 3, but surrounds the solid-state imaging device 4. Thus, it is preferable that the frame-shaped member is used to isolate the modules 2 and 3 from the outside. According to this, it is possible to prevent foreign matters such as dust from entering between the modules 2 and 3 and adhering to the light receiving surface of the solid-state imaging device 4. Furthermore, if the spacer 9 is formed of a light-shielding material, unnecessary light that enters the solid-state imaging device 4 from between the modules 2 and 3 can be blocked.

  In the illustrated example, one lens module 3 is assembled to the sensor module 2, but a plurality of lens modules 3 may be assembled. In this case, the plurality of lens modules 3 are sequentially stacked via a spacer equivalent to the spacer 9 and assembled to the sensor module 2. Further, the lens surfaces 6 a and 6 b of these lens portions 6 may be different for each lens module 3.

  The lens module 3 is provided with a light shielding portion 14. The light shielding portion 14 is formed in a region excluding a portion intersecting with the optical axis of the lens portion 6 (here, a portion partially overlapping the surface of the flange portion 7 and the lens surface 6a). The light shielding portion 14 is formed by filling the groove 8 formed on the surface of the lens module 3 with a light shielding material. The groove 8 is formed in an annular shape around the optical axis of the lens unit 6.

  A step-shaped bank 8 a is formed at the boundary between the lens surface 6 a and the groove 8. The bank 8a is located at the boundary between the light shielding portion 14 and the lens surface 6a. The procedure for forming the light shielding portion 14, the groove 8, and the bank 8a will be described later.

  The imaging unit 1 configured as described above is reflow-mounted on a circuit board such as a portable terminal. Paste solder is printed in advance on the circuit board at a position where the imaging unit 1 is mounted, and the imaging unit 1 is placed there. The circuit board including the imaging unit 1 is subjected to heat treatment such as infrared irradiation or hot air blowing. As a result, the solder is melted and the imaging unit 1 is mounted on the circuit board.

  The lens module 3 described above is obtained by dividing a lens array in which a plurality of lens units 6 are arranged one-dimensionally or two-dimensionally so as to include the lens units 6 individually. Similarly, the above-described sensor module 2 is obtained by dividing a sensor array in which a plurality of solid-state image sensors are arranged one-dimensionally or two-dimensionally so as to include individual solid-state image sensors. The lens array for obtaining the lens module 3 will be described below.

FIG. 2 is a plan view showing the lens array. FIG. 3 is a cross-sectional view of the lens array in FIG. 2 taken along the line III-III.
The lens array 10 shown in FIGS. 2 and 3 includes a plurality of lens portions 6 and a substrate portion 11 that integrally connects these lens portions 6. The lens array 10 has a wafer shape of a predetermined size as a whole, and is also referred to as a wafer level lens array in which a plurality of lens units 6 are arranged. In the illustrated example, the plurality of lens units 6 are two-dimensional. Is arranged. The lens unit 6 and the substrate unit 11 are integrally formed of a translucent material. In FIG. 2, the light shielding portion 14, the groove 8, and the bank 8 a are omitted from illustration.

  As shown in FIG. 3, in the lens array 10, a light shielding portion 14 is formed in a region excluding a portion that intersects the optical axis of the lens portion 6. In the lens array 10 shown in FIG. 3, there is a region where the light shielding portion 14 is not provided on the surface of the substrate portion 11 between the adjacent lens portions 6, but is provided on the entire surface of the substrate portion 11. Also good.

  The lens module 3 (see FIG. 1) described above is obtained by cutting the substrate portion 11 between adjacent lens portions 6 in the lens array 10. The substrate part 11 cut and attached to each lens part 6 becomes the flange part 7 of the lens module 3. It is possible to obtain a lens array laminate in which a plurality of lens arrays in FIG. 3 are stacked and the overlapping lens arrays are bonded together. At this time, the lens portions of the lens array are aligned and overlapped so that the optical axes coincide with the lens portions of the overlapped lens arrays. Then, the lens array laminate obtained in this manner is cut at the substrate portion, and a lens module in which a plurality of lens portions are stacked so that their optical axes coincide can be obtained.

  Next, an example of a method for manufacturing the lens array 10 will be described.

  First, based on FIG. 4, the structure of the shaping | molding die used for a shaping | molding process is demonstrated. The mold includes a pair of upper and lower molds 20 and 30. In the mold 20, the transfer surface 21 shapes the shape of one surface of the lens array 10, and the mold 30 shapes the shape of the other surface of the lens array 10. In the following example, the mold 20 is used to mold the surface of the lens array 10 shown in FIG.

  The mold 20 includes a transfer surface 21. The transfer surface 21 of the mold 20 has a shape obtained by inverting the surface shape of the lens array 10 on the side where the grooves 8 are formed. A lens molding surface 22 is two-dimensionally arranged on the transfer surface 21 corresponding to the arrangement of the lens portions 6 of the lens array 10. The lens molding surface 22 is molded into a concave spherical surface corresponding to the lens surface 6a which is a convex spherical surface. Further, on the transfer surface 21, groove forming portions 23 that protrude from the transfer surface 21 are arranged corresponding to the arrangement of the grooves 8. The groove forming portion 23 has a shape obtained by inverting the shape of the groove 8 of the lens array 10 in FIG. 3 and is formed in an annular shape when the transfer surface 21 is viewed in plan view.

  The mold 30 includes a transfer surface 31. The transfer surface 31 of the mold 30 has a shape obtained by inverting the surface shape of the lens array 10 on the side where the groove 8 is not formed. A lens molding surface 32 is two-dimensionally arranged on the transfer surface 31 corresponding to the arrangement of the lens portions 6 of the lens array 10. The lens molding surface 32 is molded into a concave spherical surface corresponding to the lens surface 6a which is a convex spherical surface.

Next, the procedure of the manufacturing method will be described.
As shown in FIG. 4, it is a figure which shows the process of supplying a molding material.
A molding material M is supplied onto the transfer surface 31 of the mold 30. Then, by closing the molding die, the molding material M is sandwiched between the transfer surface 21 of the die 20 and the transfer surface 31 of the die 30, and the shapes of the transfer surface 21 and the transfer surface 31 are transferred to the molding material M. Then, the molding material M is cured.

  As the molding material M, an energy curable resin composition is 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 or electron beam irradiation).

  As shown in FIG. 5, a lens molded body is obtained by curing the molding material M. Here, the lens molded body refers to the one in which the plurality of lens parts 6, the substrate part 11, the groove 8, and the bank 8a are molded and before the light shielding part 14 is formed. In this example, a dike 8a located at the boundary between the lens surface 6a of the lens portion 6 and the groove 8 and a dike 8b located at the boundary between the surface of the substrate portion 11 and the groove 8 are formed in the lens molded body. ing.

  And as shown in FIG. 6, it has a some lens part 6 and the board | substrate part 11 which connects several lens parts 6 integrally by releasing a lens molded object from the type | molds 20 and 30, and it is a groove | channel. 8 and a lens molded body in which the bank 8a is formed.

  Next, a process of applying a light shielding material to the lens molded body is performed.

FIG. 7 is a cross-sectional view showing a process of applying a light shielding material.
As shown in FIG. 7, the liquid light shielding material 14a is supplied to the groove | channel 8 of a lens molded object from supply parts 40, such as a dispenser.

For example, an organic light shielding liquid (monomer or solvent system) is used as the light shielding material 14a. The light shielding material 14a is preferably highly fluid so that it can be easily filled when supplied to the groove 8. That is, as the light shielding material, a material having a low viscosity and a low surface tension is desirable in order to facilitate wetting and spreading when supplied to the groove.
Further, as the light shielding material, a material having a low glossiness in a cured state is desirable in order to prevent performance degradation such as ghost as an imaging unit due to reflection on the film surface after the light shielding film is formed. Specifically, the 60 degree gloss (JIS K-7105) is preferably 10% or less, more preferably 5% or less, and most preferably 3% or less.
Further, as the light shielding material, a material having a high content of a light shielding pigment or dye is desirable so that a sufficient optical density can be obtained with a thin film as much as possible.

  The light shielding material 14a is applied to the groove 8 with rough accuracy, and then flows and expands into the groove 8 due to its own weight. The light shielding material 14a is filled only in the portion where the flow is blocked by the bank 8a and bank 8b and the groove 8 of the lens molded body is formed. Thus, as shown in FIG. 8, the light shielding portion 14 is formed in the groove 8.

  As shown in FIG. 8, the supplied light shielding material 14a is filled only in the groove 8 by the banks 8a and 8b, and is prevented from protruding to the surface side of the lens surface 6a. Therefore, the light shielding part 14 of the lens array 10 obtained can be formed with high accuracy. According to the lens array 10 and the manufacturing method thereof, the aperture can be formed with high accuracy.

  When the light shielding material is supplied to the groove 8 that does not have the bank 8 a to form the light shielding portion, the fluidized light shielding material may adhere to other portions than the groove 8. According to the lens array 10 of the present invention, the spread due to the flow of the light shielding material 14 a can be suppressed by the bank 8 a of the groove 8.

  In addition, when a light shielding material is applied to the lens surface as in the prior art, and then the light shielding material only for the lens portion is removed by a photolithography process or a rubber ablation, an increase in manufacturing cost due to the addition of the process or reaction There is a concern that the lens surface is contaminated due to the high-quality liquid adhering to the lens surface. However, if the bank 8a is provided in the groove 8 as in the present invention, it is not necessary to perform a manufacturing process such as a photolithography process, so that an increase in manufacturing cost and contamination of the lens surface can be prevented.

  Next, a modified example of the above-described embodiment will be described.

FIG. 9 is a cross-sectional view showing a modification of the configuration of the lens array.
As shown in FIG. 9, in the lens array 10, an undercoat portion 16 is formed on the surface of the groove 8 to adjust the paintability of the light shielding material 14 a of the light shielding portion 14. The undercoat portion 16 is formed before supplying the light shielding material 14 a to the groove 8.
In this way, the light shielding part 14 can be formed with higher accuracy. The material of the undercoat portion is, for example, a melanin resin, urea resin, or epoxy resin having a high surface energy. In addition, as a method for forming the undercoat portion, there is a method of selectively forming an undercoat layer by following unevenness, such as ink jet printing, jet dispenser, pad printing, and screen printing. Depending on the selection of the undercoat material, other properties such as adhesion of the light-shielding film to the base material and film uniformity can be improved.

  Moreover, it is not limited to an undercoat part, You may perform the surface treatment for adjusting the wettability with a light shielding material to the bottom face of a groove | channel. This surface treatment is performed before supplying the light shielding material.

  The lens array preferably has fine irregularities formed on the surface of the groove. By so doing, light is scattered by the fine irregularities, so that flare and ghost due to light reflection on the inner surface of the lens can be reduced. As a procedure for manufacturing such a lens array, fine irregularities are formed on the surface of the groove before the step of molding the lens module or supplying the light shielding material. In addition, it is desirable that this undercoating treatment or surface irregularity forming treatment is selectively performed on the surface of the groove. However, as long as it does not affect the optical characteristics of the lens surface, the entire surface is integrated regardless of the lens surface and the groove. You may process by.

  The groove bank only needs to be formed at the boundary between the lens surface and the groove, and the bank at the boundary between the groove and the substrate portion may not be provided.

  The groove can adopt a shape that can be easily filled with the supplied light shielding material, and may be, for example, a comb shape.

This specification discloses the following contents.
(1) A lens array having a plurality of lens portions and a substrate portion integrally connecting the plurality of lens portions,
A groove formed in a region excluding a portion intersecting with the optical axis of the lens portion, a light shielding material filled in the groove, a stepped bank formed at a boundary between the lens surface of the lens portion and the groove; A lens array.
(2) The lens array according to (1),
A lens array in which a bottom surface of the groove is subjected to a surface treatment for adjusting wettability with the light shielding material.
(3) The lens array according to (1) or (2),
A lens array in which a surface of the groove is coated with an undercoat portion for adjusting the paintability of the light shielding material.
(4) The lens array according to any one of (1) to (3),
A lens array in which fine irregularities are formed on the surface of the groove.
(5) A method of manufacturing a lens array having a plurality of lens portions and a substrate portion integrally connecting the plurality of lens portions,
Using the mold, the plurality of lens portions and the substrate portion are molded, and a groove is formed in a region excluding a portion intersecting the optical axis of the lens portion, and a lens surface of the lens portion and the boundary between the grooves are formed. Molded stepped dyke, then
Supplying a light shielding material to the groove;
A method of manufacturing a lens array, wherein a light shielding portion is formed by expanding the supplied light shielding material by its own weight and stopping the spreading of the light shielding material by the bank.
(6) A method of manufacturing a lens array according to (5),
A method of manufacturing a lens array, wherein surface treatment for adjusting wettability with the light shielding material is performed on the bottom surface of the groove before supplying the light shielding material.
(7) A method of manufacturing a lens array according to (5) or (6),
Before supplying the light shielding material, a method of manufacturing a lens array in which a surface of the groove is coated with an undercoat portion for adjusting the wettability with the light shielding material.
(8) The method for manufacturing a lens array according to any one of (5) to (7),
A method of manufacturing a lens array in which fine irregularities are formed on the surface of the groove before molding the lens module or supplying the light shielding material.
(9) A lens module obtained by cutting the substrate portion of the lens array according to any one of (1) to (4) and dividing the substrate portion into lens portions.
(10) A lens array laminate obtained by stacking a plurality of the lens arrays according to any one of (1) to (4) and adhering the overlapping lens arrays.
(11) A lens module obtained by cutting the lens array laminate according to (10) at the substrate portion and stacking the plurality of lens portions so that their optical axes coincide.

DESCRIPTION OF SYMBOLS 1 Imaging unit 2 Sensor module 3 Lens module 6 Lens part 8 Groove 8a Bank 10 Lens array 11 Substrate part 14 Light-shielding part 16 Undercoat parts 20 and 30 Mold

Claims (11)

A lens array having a plurality of lens portions and a substrate portion integrally connecting the plurality of lens portions;
A groove formed in a region excluding a portion intersecting with the optical axis of the lens portion, a light shielding material filled in the groove, a stepped bank formed at a boundary between the lens surface of the lens portion and the groove, A lens array. The lens array according to claim 1,
A lens array in which a bottom surface of the groove is subjected to a surface treatment for adjusting wettability with the light shielding material. The lens array according to claim 1 or 2,
A lens array in which a surface of the groove is coated with an undercoat portion for adjusting the paintability of the light shielding material. The lens array according to any one of claims 1 to 3,
A lens array in which fine irregularities are formed on the surface of the groove. A method of manufacturing a lens array having a plurality of lens portions and a substrate portion integrally connecting the plurality of lens portions,
Using the mold, the plurality of lens portions and the substrate portion are molded, and a groove is formed in a region excluding a portion intersecting the optical axis of the lens portion, and a lens surface of the lens portion and the boundary between the grooves are formed. Molded stepped dyke, then
Supplying a light shielding material to the groove;
A method of manufacturing a lens array, wherein a light shielding portion is formed by expanding the supplied light shielding material by its own weight and stopping the spreading of the light shielding material by the bank. It is a manufacturing method of the lens array according to claim 5,
A method of manufacturing a lens array, wherein surface treatment for adjusting wettability with the light shielding material is performed on the bottom surface of the groove before supplying the light shielding material. A method of manufacturing a lens array according to claim 5 or 6,
Before supplying the light shielding material, a method of manufacturing a lens array in which a surface of the groove is coated with an undercoat portion for adjusting the wettability with the light shielding material. A method for manufacturing a lens array according to any one of claims 5 to 7,
A method of manufacturing a lens array in which fine irregularities are formed on the surface of the groove before molding the lens module or supplying the light shielding material.   The lens module formed by cut | disconnecting the said board | substrate part of the lens array of any one of Claim 1 to 4, and dividing | segmenting into a lens part individually.   A lens array laminate comprising a plurality of the lens arrays according to any one of claims 1 to 4 stacked and bonded together.   11. A lens module obtained by cutting the lens array laminate according to claim 10 at the substrate portion and stacking the plurality of lens portions so that the optical axes thereof coincide with each other.

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