This nonprovisional application claims priority under 35 U.S.C. §119(a) to Patent Applications No. 2008-246967 filed in Japan on Sep. 25, 2008, and No. 2009-199021 filed in Japan on Aug. 28, 2009, the entire contents of which are hereby incorporated by reference.
1. Field of the Invention
The present invention is related to an optical element provided with a lens and an optical function element. Further, the present invention is related to an optical element wafer provided with a plurality of optical elements, such as a plurality of lenses and a plurality of optical function elements, in a wafer state. Further, the present invention is related to an optical element wafer module in which the plurality of optical element wafers are laminated. Further, the present invention is related to an optical element module, which is made by cutting the optical element wafer or the optical element wafer module, and a method for manufacturing the optical element module. Further, the present invention is related to an electronic element wafer module in which the optical element wafer or optical element wafer module is modularized with an electronic element wafer. Further, the present invention is related to a method for manufacturing an electronic element module, in which the electronic element wafer module is cut simultaneously or the optical element or the optical element module is modularized with an electronic element. Further, the present invention is related to an electronic element module manufactured by the method for manufacturing the electronic element module. Further, the present invention is related to an electronic information device, such as a digital camera (e.g., a digital video camera or a digital still camera), an image input camera, a scanner, a facsimile machine, a camera-equipped cell phone device and a television telephone device, including the electronic element module used therein.
2. Description of the Related Art
Further downsizing and lowering the cost are requested for a camera-equipped cell phone device and a personal digital assistant (PDA) and so on as conventional optical devices that include an image capturing element and a light-focusing lens element thereabove.
In response to such a request, Reference 1 proposes a method for obtaining an image capturing element module, the method including the steps of: forming and connecting an image capturing element for performing a photoelectric conversion on and capturing an image of incident light and a lens element thereabove for focusing light at a wafer level; modularizing the image capturing element and the lens element as an image capturing element wafer module, which functions as an electronic element wafer module; and individualizing the modularized image capturing element wafer module by simultaneous cutting. According to the method, a transparent substrate is adhered above a semiconductor wafer having an image capturing element at the center portion, with a spacer interposed therebetween. A convex lens is formed as a light-focusing lens element on the transparent substrate in a closely-adhered manner. This image capturing element module will be described in detail with reference to
In
According to Reference 1, as illustrated in
Furthermore, Reference 2 discloses an example where a lens is formed in each of a plurality of through holes of a lens substrate. It is conceived that a plurality of such lens wafer modules are laminated on an image capturing element wafer to be modularized.
In
The image capturing element wafer module 250 is illustrated in
In References 3 and 4 as illustrated in
In addition, the cover substrate 304 is provided with a protection wall section 309 for the protection of the lens surface. The protection wall section 309 is provided on the opposite side from the base substrate 303 to surround each of the convex lens sections 306 and 308 and the protection wall section 309 protrudes more than the tip portion of each of the convex lens sections 306 and 308. The tip portion of each of the convex lens sections 306 and 308 are located closer to the side of the base substrate 303 than a flat surface including the upper tip surface of the protection wall section 309. As a result, each of the convex lens sections 306 and 308 is protected by the protection wall section 309 and therefore is less susceptible to scratches, thereby improving the yield rate of the manufacture and the reliability.
Reference 1: Japanese Laid-Open Publication No. 2004-63751
Reference 2: Japanese Laid-Open Publication No. 2005-539276
Reference 3: Japanese Laid-Open Publication No. 2007-225932
Reference 4: Japanese Laid-Open Publication No. 2007-227676
According to the conventional structure of References 1 and 2 described above, the surface of the convex lens is protruded to the uppermost surface of the back surface side during the cutting stage. There is a possibility that glue of the adhered cut-securing tape may adhere on the protruded surface of the convex lens. When a blade enters the material along the dicing line DL during the cutting stage, the blade finally reaches the cut-securing tape, and a force is applied to the cut-securing tape in the direction to peel off the adhered cut-securing tape from the protruded surface of the convex lens. As a result, the cut-securing tape is lifted and cutting water enters the space in between. Due to the cutting water and the glue of the cut-securing tape, the surface of the convex lens becomes dirty.
That is, in the conventional structure of Reference 1 described above, during the cutting state to perform the cutting in the step of simultaneous cutting along the dicing line DL as similar to the case of Reference 2, the cut-securing tape 106 is adhered on the convex lens surface protruded from the front surface for simultaneous cutting. In this case, the cutting direction and the peeling direction of the cut-securing tape 106 are the same. As a result, the adhesion of the cut-securing tape 106 to the convex lens surface becomes unstable, which makes the cut-securing tape 106 easy to be removed from the convex lens surface during the cutting and makes cutting water mixed with offcuts enter the space in between making the surface of the convex lens dirty. Further, there is a risk of making the convex lens surface dirty due to the transferring of the glue on the adhesion layer of the cut-securing tape 106 on the convex lens surface. Further, although this is not shown, the convex lens surface is protruded to the outside, and therefore, there is a risk of scratching the convex lens surface at the conveyance during the manufacturing steps if the cut-securing tape 106 or the cut-protection tape is not provided. When the convex lens surface is scratched, the scratch is also captured in an image, which leads to a poor image capturing.
In addition, in the conventional structure of References 3 and 4 described above, the upper tip surface of the protection wall section 309 on the outer circumference side of the convex lens sections 306 and 308 is further protruded than the top portions of the convex lens sections 306 and 308. However, it is not considered that, as a result of the use of the cut-securing tape, the glue of the cut-securing tape may adhere the top portions of the convex lens sections 306 and 308. Therefore, the protection wall section 309 is provided to largely surround the outer circumference of a plurality of elements, such as adjacent infrared ray emitting element 301 and infrared ray detecting element 302. Accordingly, even if the structure of Reference 3 or 4 is applied to the present invention, the distance between facing protection wall sections 309 is too wide (the opening is too large) and there is a possibility that the glue of the cut-securing tape may adhere to the top portion of the convex lenses 306 and 308 by the use of the cut-securing tape. Further, there is a possibility that the cut-securing tape may be removed easily and cutting water enters the side of the plurality of lens surfaces surrounded by the protection wall section 309 during the cutting stage.
The present invention is intended to solve the conventional problems described above. The objective of the present invention is to provide an optical element wafer capable of maintaining a surface of an optical element, such as a convex lens surface that functions optically, clean in a more definite manner in a manufacturing process thereof; an optical element individualized from the optical element wafer; an optical element wafer module in which the plurality of optical element wafers are laminated; an optical element module individualized from the optical element wafer module; a method for manufacturing the optical element module in which the optical element module is manufactured by cutting the optical element wafer or optical element wafer module; an electronic element wafer module in which the optical element wafer or optical element wafer module is modularized with an electronic element wafer; a method for manufacturing an electronic element module in which the electronic element wafer module is simultaneously cut into pieces or the optical element or the optical element module is modularized with the electronic element, to manufacture the electronic element module; an electronic element module manufactured by the method for manufacturing the electronic element module; and an electronic information device, such as a camera-equipped cell phone device, including the electronic element module used as an image input device in an image capturing section thereof.
An optical element according to the present invention includes: an optical surface at a center portion thereof; and a spacer section having a predetermined thickness on an outer circumference side of the optical surface, wherein a surface height of the spacer section is configured to be higher than a surface height of the optical surface, thereby achieving the objective described above.
Preferably, in an optical element according to the present invention, the spacer section is provided for each optical surface.
Still preferably in an optical element according to the present invention, the spacer section is a protruded portion or a planarized portion, which is further protruded than a convex shape of the optical surface, surrounding the optical surface area from an outer circumference end portion of the optical surface.
Still preferably in an optical element according to the present invention, the protruded portion is annularly protruded, or is protruded as part of the annular shape, more than the convex shape of the optical surface, from the outer circumference end portion of the optical surface.
Still preferably in an optical element according to the present invention, when a securing tape is adhered on the spacer section to cover an upper part thereof during individual cutting, the surface height of the spacer section is configured to be higher than the surface height of the optical surface so that the securing tape does not adhere on the optical surface.
Still preferably in an optical element according to the present invention, the optical surface and a protruded portion or planarized portion, which is more protruded than the optical surface, are provided on either a front surface or a back surface of the optical element.
Still preferably in an optical element according to the present invention, a part or all of a top surface of the annular protruded portion includes a planarized surface.
Still preferably in an optical element according to the present invention, a difference between the surface height of the spacer section and the surface height of the optical surface is within 20 μm to 100 μm.
Still preferably in an optical element according to the present invention, a difference between the surface height of the spacer section and the surface height of the optical surface is 50 μm plus or minus 10 μm.
Still preferably in an optical element according to the present invention, the optical surface and the spacer section are simultaneously formed with a transparent resin material.
Still preferably in an optical element according to the present invention, the optical surface is a lens surface.
Still preferably in an optical element according to the present invention, the optical surface is an optical function element surface for directing output light straight to be output and refracting and guiding incident light in a predetermined direction.
Still preferably in an optical element according to the present invention, the optical surface is a circle with a diameter of 1 mm plus or minus 0.5 mm.
Still preferably in an optical element according to the present invention, a bottom portion for positioning an adhesive material is provided on a further outer circumference side of the spacer section with a step portion interposed therebetween.
Still preferably in an optical element according to the present invention, a support plate including a through hole penetrating only a portion corresponding to the optical surface is provided inside the transparent resin material.
Still preferably in an optical element according to the present invention, the support plate has light shielding characteristics, an outer circumference portion side of the through hole corresponds to the spacer section, and the outer circumference portion side of the through hole is thicker than a further outer circumference portion side thereof.
Still preferably in an optical element according to the present invention, a penetration portion and/or a concave portion is provided for releasing the resin material when forming resin in a further outer peripheral portion of the support plate.
An optical element module according to the present invention is provided, in which a plurality of the optical elements according to the present invention are laminated, wherein of an upper most side and an lower most side, a height of a surface of a spacer section of at least either optical element is higher than a height of a surface of an optical surface of the optical element.
Preferably, in an optical element module according to the present invention, among the plurality of the optical elements, a lens space between the upper optical element and the lower optical element is controlled by a planarized surface of the spacer section of the upper optical element and a planarized surface of the spacer section of the lower optical element in direct contact with each other.
Still preferably, in an optical element module according to the present invention, an adhesive is positioned in a space portion surrounded by a bottom portion on a further outer circumference side of each of the planarized surfaces of the spacer section of the upper optical element and the spacer section of the lower optical element, so that the upper optical element and the lower optical element are adhered to each other.
Still preferably, in an optical element module according to the present invention, the space portion of the bottom portion is a sufficient space for the adhesive to be put between and be spread by bottom portions of the upper and lower optical elements when adhering.
Still preferably, in an optical element module according to the present invention, the adhesive is provided on an outside of the optical surface and an inside of a quadrilateral along dicing lines at a predetermined width, and a vent is provided at a corner portion and/or a side portion of the quadrilateral adhesive.
Still preferably, in an optical element module according to the present invention, an adhesive for capturing dust is further provided on an outside of the optical surface and an inside of a quadrilateral along dicing lines at a predetermined width, the adhesive being cohesive even after a curing of the resin.
Still preferably, in an optical element module according to the present invention, part or all of the adhesive for capturing dust is provided facing the vent inside the quadrilateral adhesive.
Still preferably, in an optical element module according to the present invention, the adhesive has light shielding characteristics.
Still preferably, in an optical element module according to the present invention, of an upper surface, except for the optical surface, and a side surface of the plurality of optical elements, the optical element module further includes, a light shielding holder for shielding at least the upper surface.
Still preferably, in an optical element module according to the present invention, of an upper surface, except for the optical surface, and a side surface of the optical element according to the present invention, the optical element module further includes a light shielding holder for shielding at least the upper surface.
An optical element module according to the present invention includes a plurality of the optical elements according to the present invention simultaneously formed and arranged in two dimensions, thereby achieving the objective described above.
An optical element wafer module according to the present invention includes the plurality of optical element wafers according to the present invention laminated by aligning the optical surfaces thereof, thereby achieving the objective described above.
An optical element wafer module according to the present invention includes the plurality of optical element modules according to the present invention arranged in two dimensions.
A method for manufacturing an optical element module according to the present invention includes: a step of adhering a securing tape to at least either of a front surface side or a back surface side of the optical element wafer according to the present invention, an optical element wafer module in which a plurality of the optical element wafers are laminated, or the optical element wafer module according to the present invention; and a cutting step of simultaneously cutting the optical element wafer or the optical element wafer module along dicing lines to be individualized, thereby achieving the objective described above.
An electronic element wafer module according to the present invention includes: an electronic element wafer in which a plurality of electronic elements are arranged; a resin adhesion layer formed in a predetermined area on the electronic element wafer; a transparent support substrate covering the electronic element wafer and fixed on the resin adhesion layer; and the optical element wafer according to the present invention of claim 28, an optical element wafer module in which a plurality of the optical element wafers are laminated, or the optical element wafer module according to the present invention of claim 30, any of which is adhered on the transparent support substrate so that each optical element corresponds to each of the plurality of electronic elements, thereby achieving the objective described above.
Preferably, in an electronic element wafer module according to the present invention, a space between the lowermost optical element wafer and the electronic element is controlled by a planarized surface of a spacer section of the lowermost optical element wafer and a planarized surface of the transparent support substrate in direct contact with each other.
Still preferably, in an electronic element wafer module according to the present invention, an adhesive is positioned in a space portion surrounded by a bottom portion on a further outer circumference side of a planarized surface of the spacer section of the lower most optical element wafer and the transparent support substrate, so that the lower most optical element wafer and the transparent support substrate are adhered to each other.
Still preferably, in an electronic element wafer module according to the present invention, the space portion by the bottom portion is a sufficient space for the adhesive to be put between and be spread by a top and bottom when adhering.
Still preferably, in an electronic element wafer module according to the present invention, the electronic element is an image capturing element including a plurality of light receiving sections for performing an electronic conversion on and capturing an image of image light from a subject.
Still preferably, in an electronic element wafer module according to the present invention, the electronic element is a light emitting element for outputting output light and a light receiving element for receiving incident light.
A method for manufacturing an electronic element module according to the present invention includes: a step of adhering a securing tape to a front surface side of the optical element wafer or the optical element wafer module of the electronic element wafer module according to the present invention; and a cutting step of simultaneously cutting the electronic element wafer module from the electronic element wafer side along dicing lines to be individualized.
A method for manufacturing an electronic element module according to the present invention includes: an image capturing element wafer unit forming step of adhering and fixing a transparent support substrate by a resin adhesion layer in such a manner to cover an electronic element wafer, in which a plurality of electronic elements are arranged, to form an image capturing element wafer unit; a cutting step of simultaneously cutting the image capturing element wafer unit from the electronic element wafer side along dicing lines to be individualized into image capturing element units; and a step of adhering the optical element module manufactured by the method for manufacturing the optical element module according to the present invention to the image capturing element unit in such a manner that the image capturing element corresponds to the optical element, thereby achieving the objective described above.
An electronic element module according to the present invention is cut from the electronic element wafer module according to the present invention for each or a plurality of the electronic element modules, thereby achieving the objective described above.
An electronic information device according to the present invention includes an electronic element module individualized by cutting the electronic element wafer module according to the present invention, as a sensor module used in an image capturing section, thereby achieving the objective described above.
An electronic information device according to the present invention includes an electronic element module individualized by cutting the electronic element wafer module according to the present invention, used in an information recording and reproducing section, thereby achieving the objective described above.
An electronic information device according to the present invention includes an electronic element module manufactured by the method for manufacturing the electronic element module according to the present invention.
The functions of the present invention having the structures described above will be described hereinafter.
According to the present invention, the height of a spacer section, which is provided on an outer circumference side of one optical element area, is configured to be higher than the surface height of an optical element area (optical surface) at the center portion. As a result, in the manufacturing process, a securing tape does not adhere to the surface of the optical element area during the cutting stage, and the securing tape is prevented from being removed so that an optical surface of a lens can be prevented from becoming dirty from cutting water and a reduction of the optical characteristics can be prevented. Furthermore, the surface of the optical element (optical surface), such as a convex lens surface that functions optically, can be maintained clean.
According to the present invention with the structure described above, the surface height of the spacer section provided on the outer circumference side of the optical element area is configured to be higher than the surface height of the optical element area at the center portion. As a result, in the manufacturing process, a securing tape does not adhere to the surface of the optical element area during the cutting stage, and the securing tape is prevented from being removed. Thus, an optical surface of a lens can be prevented from becoming dirty from cutting water, the lowering of the optical characteristics can be prevented, and the surface of the optical element, such as a convex lens surface that functions optically, can be maintained clean. Further, the cost can be maintained at a low level because there is no change from the conventional cutting process.
These and other advantages of the present invention will become apparent to those skilled in the art upon reading and understanding the following detailed description with reference to the accompanying figures.
a) to 3(c) are each an essential part longitudinal cross sectional view illustrating each step for manufacturing an image capturing element module by modularizing a first lens wafer, a second lens wafer and an image capturing element wafer and subsequently individualizing them.
a) is an essential part longitudinal cross sectional view illustrating a cutting step of a lens wafer module of
a) to 5(c) are each an essential part cross sectional view illustrating each manufacturing step for forming a first lens and a second lens, which are formed by cutting and individualizing a first lens wafer and second lens wafer of
a) to 7(c) are each an essential part longitudinal cross sectional view illustrating each manufacturing step of a method for manufacturing a first lens wafer of a lens wafer module of
a) to 9(c) are each a plan view schematically illustrating each example of an adhesive positioning structure when a vent is provided at a part of an adhesive in
a) to 10(c) are each a plan view schematically illustrating other examples of an adhesive positioning structure when a vent is provided at a part of an adhesive in
a) to 11(c) are each an essential part longitudinal cross sectional view for describing one example of a method for forming a first lens wafer of
a) to 12(c) are each an essential part longitudinal cross sectional view for describing another example of a method for forming a first lens wafer of
a) and 13(b) are each an essential part longitudinal cross sectional view for describing still another example of a method for forming a first lens wafer of
a) is a longitudinal cross sectional view illustrating an exemplary variation of each lens of
a) is a longitudinal cross sectional view illustrating an exemplary variation of each lens of
Hereinafter, as Embodiments 1 and 2 of an optical element wafer, an optical element wafer module, a method for manufacturing an optical element module, an electronic element wafer module, an electronic element module, and a method for manufacturing the electronic element module according to the present invention, the case where the present invention is applied to a lens wafer, a lens wafer module, a method for manufacturing a lens module, an image capturing element wafer module, an image capturing element (sensor module) and a method for manufacturing the image capturing element module, will be described in detail with reference to the attached figures. Further, as Embodiment 3 of an optical element individualized from the optical element wafer, and an optical element module individualized from the optical element wafer module, a lens and a lens module will be described in detail with reference to the attached figures. Further, as Embodiment 4, an electronic information device, such as a camera-equipped cell phone device and a television telephone device, will be described in detail with reference to the attached figures, and the electronic information device includes the image capturing element module with the lens or lens module of Embodiment 3 used therein, or the image capturing element module of Embodiment 1 or 2, as a sensor module in an image capturing section, which functions as an image input section, of the electronic information device.
In
The image capturing element wafer 3 includes a large number of the image capturing elements 2 in a matrix on the front surface side (a plurality of light receiving sections, which constitute a plurality of pixels, are provided for each image capturing element 2), and a plurality of through holes penetrating a wafer back surface to below a pad (electrode pad) of a front surface for each image capturing element 2. A side wall and back surface of each of the through holes are covered with an insulation film, and a wiring layer contacting the pad is formed to the back surface through the through hole. An insulation film 32 is formed on an external connection terminal 31, which is connected to the wiring layer, and on the back surface. The insulation film 32 has an opening at a portion where a solder ball (not shown) is formed above the external connection terminal 31 of the wiring layer, so that the solder ball (not shown) is formed exposed to the outside. Herein, a case has been described where the image capturing element wafer 3 includes a penetrating electrode for each image capturing element 2; however there is also a case where such penetrating electrode is not included.
The resin adhesion layer 4 is formed in the periphery part of the image capturing element 2 on the wafer surface to adhere the image capturing element wafer 3 and the transparent support substrate 5. When the upper part of the semiconductor surface is covered by the transparent support substrate 5, the resin adhesion layer 4 encloses an internal space above a sensor area where the image capturing element 2, as an electronic element above the image capturing element wafer 3, is provided. The resin adhesion layer 4 is formed at a predetermined location on the image capturing element wafer 3 using an ordinary photolithography technique. The transparent support substrate 5 is adhered on the resin adhesion layer 4. The resin adhesion layer 4 can also be formed using a screen printing method or a dispense method, other than the photolithography technique.
The lens wafer module 6 includes a first lens wafer 65 and a second lens wafer 66 laminated on the transparent support substrate 5 in such a manner to correspond to the image capturing element 2. The first lens wafer 65 functions as an optical element wafer in which a plurality of first lenses 61 are arranged in two dimensions. The second wafer 66 functions as an optical element wafer in which a plurality of second lenses 62 are arranged in two dimensions. An optical surface A of the first lens 61 is in a shape of a convex lens and is externally protruded. The outer circumference portion of the optical surface A is annularly protruded more than the most-protruded top portion at the center portion of the optical surface A. In
In the first lens wafer 65: the plurality of first lenses 61 are provided in two dimensions as optical elements; the optical surface A of the lens area is provided at the center portion of each of the plurality of first lenses 61; the protruded sections 61a and 61b having a predetermined thickness are provided on the outer circumference side of the optical surface A as a spacer section; and the surface height of the protruded sections 61a and 61b as a spacer section is higher than the surface height of the lens area (optical surface A) and a difference S exists, which is a difference between the surface height of the protruded sections 61a and 61b and the surface height of the lens area (optical surface A). Prior to the cutting stage, a cut-securing tape 9 to be described later is adhered to each planarized surface of the protruded sections 61a and 61b to cover the upper part of the optical surface A of the lens area. In this case, as the difference S, the surface height of each planarized surface of the protruded sections 61a and 61b is configured to be higher than the surface height of the top portion of the lens area (optical surface A) so that an adhesive surface of the cut-securing tape 9 to be described later does not adhere to the lens area (optical surface A).
As described above, in the protruded sections 61a and 61b as a spacer section, the top surface of the protruded sections 61a and 61b are annularly protruded from the outer circumference end portion of the lens area (optical surface A) as an optical element area and are higher than the top portion of the convex surface of the optical surface A, and the top surface is a planarized surface. When the optical surface A is a round shape with a diameter of 1 mm plus or minus 0.5 mm, the difference S between the surface height of the spacer section (protruded section 61a) and the surface height of the lens area (optical surface A) is 20 μm to 100 μm. Further, preferably, in this case, the difference S between the surface height of the spacer section (protruded section 61a) and the surface height of the lens area (optical surface A) is about 50 μm (50 μm plus or minus 10 μm).
In the second lens 62, both the front surface and the back surface are a convex shaped optical surface A, and protruded sections 62a and 62b are annularly protruded from an outer circumference end portion B, which is the outer circumference of the optical surface A, and are higher than the convex shape of the optical surface A, and the top surface is a planarized surface. The annular protruded section 61b, which is on the outer circumference side of the optical surface A on the back surface of the first lens 61, and the annular protruded section 62a, which is on the outer circumference side of the optical surface A on the front surface of the second lens 62, contact with each other on the respective planarized surfaces. An adhesive 7 is provided in a space made by lower portions or bottom portions (step portions) further outside of the annular protruded sections 61b and 62a. The first lens 61 and the second lens 62 are vertically adhered and fixed to each other at the space in between them by the adhesive 7. Similar to this, the transparent support substrate 5 and the annular protruded section 62b at the outer circumference end portion B of the optical surface A on the back surface contact each other at the respective planarized surfaces. The adhesive 7 is provided in the space made by the lower portion or bottom portions (step portion) on the further outside of the annular protruded section 62b. The transparent support substrate 5 and the second lens 62 are vertically adhered and fixed to each other at the space in between them by the adhesive 7.
Because of the structure described above, the space between the first lens 61 and the second lens 62 as well as the space between the second lens 62 and the transparent support substrate 5 touch each other and are regulated by the respective planarized surfaces of the annular protruded sections 61b and 62a and the annular protruded section 62b. As a result, the variation of the thickness or amount of the adhesive 7 will not negatively influence the lens module, and the overall thickness of the lens module 6 becomes stable. That is, the spaces between the lenses are determined by the contacting surfaces (protruded sections 61b, 62a and 62b) of the first lens 61 and the second lens 62, and the adhesion is made in the space portion (gap portion) made by the bottom portion further outside the contacting surfaces. Therefore, even if the amount of the adhesive 7 is too much, the adhesive 7 only spreads within the gap portion, and the variation of the thickness or amount of the adhesive 7 does not cause a problem. As a result, the thickness of the overall lens module 6 becomes stable, and further, the optical characteristics of the lens module 6 become stable.
Provided at a position higher than the high position (top portion) in the center portion of the convex lens surface of the first lens 61 on the opposite side from the image capturing element 2 is the annular top planarized surfaces (planarized surface of the annular protruded section 61a) of a peripheral flange (spacer section; protruded sections 61a and 61b) with a predetermined thickness on the outer circumference side of the convex lens surface.
Hereinafter, a method for manufacturing the image capturing element wafer module 1 with the structure described above will be described.
First, a method for forming the first lens 61 of
In
The upper metal mold 63 and the lower metal mold 64 constitute a metal form that arranges the shape of the plurality of first lenses 61 in a two dimensional matrix at a wafer scale. As the method for forming the metal molds, a front surface lens shape is formed with the upper metal mold 63 and a back surface lens shape is formed with the lower metal mold 64 by cutting process or Ni (nickel) electroplating.
Herein, the method for manufacturing the first lens wafer 65, which is constituted of the plurality of first lenses 61 of
Next, a method for manufacturing an image capturing element module (sensor module 10) by modularizing the first lens wafer 65 and the second lens wafer 66 with the image capturing element wafer 3 and then individualizing it into the image capturing element module as an electronic element module.
a) to 3(c) are each an essential part longitudinal cross sectional view illustrating each manufacturing step for manufacturing an image capturing element module by modulating the first lens wafer and the second lens wafer with the image capturing element wafer to be individualized.
First, as illustrated in a lens adhering step of
Next, an optical axis C of the first lens 61 and an optical axis C of the second lens 62 are aligned so that they coincide to each other. The first lens wafer 65 of the upper first lens 61 and the second lens wafer 66 of the lower second lens 62 formed at the wafer scale are adhered and laminated by the adhesive 7 in such a manner to be stacked vertically as illustrated in
Further, as illustrated in a modularizing step of
On the transparent support substrate 5 of the image capturing element wafer unit 8, the lens wafer module 6, which is constituted of two lens wafers 65 and 66, is adhered with the image capturing element wafer unit 8 in such a manner that each of the optical axes C of the first lens 61 and the second lens 62 is aligned with the center of each image capturing element 2 of the image capturing element wafer 3, to manufacture the image capturing element wafer module 1 illustrated in
Next, as illustrated in a cutting step of
When cutting the image capturing element wafer module 1, the optical surface of the front surface of the first lens 61 is protected by the cut-securing tape 9 adhered on the planarized surface of the annular protruded section on the outer circumference side of the optical surface, and therefore, cutting water does not enter inside the optical surface. In addition, the cut-securing tape 9 does not contact the optical surface of the front surface of the first lens 61, and therefore, the adhesive of the cut-securing tape 9 does not adhere to the optical surface of the first lens 61. In addition, in the cutting with a dicer or a wire along the dicing line DL, the conventional cut-securing tape 9 is used, so that there is no change in the conventional process with regard to the cutting step.
Next, as described with reference to
a) is an essential longitudinal cross sectional view illustrating a cutting step of the lens wafer module of
As illustrated in a cutting step of the lens wafer module of
As illustrated in a combining step of the image capturing element module of
Next, as described with reference to
As illustrated in a cutting step of the first lens wafer 65 of
Similarly, as illustrated in a cutting step of the second lens wafer 66 of
As illustrated in a combining step of the image capturing element module of
The lens module 60 and the image capturing element unit 80 of good quality are adhered to each other, so that there will be little influence on the cost, since the products of good quality are combined even if the overall quality rate is low in either of the products.
According to Embodiment 1 with the structure described above, the annular top planarized surface (planarized surface of the annular protruded section 61) of the peripheral flange on the outer circumference side of the convex lens surface is provided at a position higher than the highest position at the center portion of the convex lens surface of the first lens 61 on the opposite side of the image capturing element 2 side. Conventionally, stress is applied in the direction of peeling off the cut-securing tape 9 between the convex lens surfaces. According to the present specification, on the other hand, the cut-securing tape 9 is adhered on the top planarized surface (planarized surface of the annular protruded section 61a) of the peripheral flange, no stress is applied to the cut-securing tape 9, so that the cut-securing tape 9 becomes difficult to be peeled off, no glue of the cut-securing tape 9 is adhered to the convex lens surface, and the cutting water does not penetrate the cut-securing tape 9 and make the convex lens surface dirty. Thus, it is suitable for the top planarized surface (planarized surface of the annular protruded section 61a) of the peripheral flange (spacer section) on the outer circumference side to be higher than at least the convex lens surface of the upper most first lens 61. That is, it is suitable for the top planarized surface (planarized surface of the annular protruded section) of the peripheral flange (spacer section) on the outer circumference side to be higher than the lens surface (optical surface A) on at least either the front surface or back surface of the lens.
As illustrated in
A method for manufacturing the first lens wafer 65A and the second lens wafer 66A of the lens wafer module 6A will be described with reference to
As illustrated in
Next, as illustrated in
Although not shown, it is also possible to prepare a plural number of metal molds and press the plurality number of metal molds simultaneously on the lens-forming transparent resin 13 to simultaneously form the plurality of first lens front surface shapes.
As a result, the front surface shape of the first lens is formed on the front surface of the transparent support plate 11 and the back surface shape of the first lens is formed on the back surface of the transparent support plate 11.
As another example of the transparent support plate 11, the case where a lens wafer is manufactured with a lens support plate having a through hole penetrating only a lens shape area, will be described in detail in Embodiment 2.
In
The image capturing element wafer 3 includes a large number of the image capturing elements 2 in a matrix on the front surface side (a plurality of light receiving sections, which constitute a plurality of pixels, are provided for each image capturing element 2), and a plurality of through holes penetrating a wafer back surface to below a pad (electrode pad) of a front surface for each image capturing element 2. A side wall and back surface of each of the through holes are covered with an insulation film, and a wiring layer contacting the pad is formed to the back surface through the through hole. An insulation film 32 is formed on an external connection terminal 31, which is connected to the wiring layer, and on the back surface. The insulation film 32 has an opening at a portion where a solder ball (not shown) is formed above the external connection terminal 31 of the wiring layer, so that the solder ball (not shown) is formed exposed to the outside. Herein, a case has been described where the image capturing element wafer 3 includes a penetrating electrode for each image capturing element 2; however there is also a case where such penetrating electrode is not included.
The resin adhesion layer 4 is formed in the periphery part of the image capturing element 2 on the wafer surface to adhere the image capturing element wafer 3 and the transparent support substrate 5. When the upper part of the semiconductor surface is covered by the transparent support substrate 5, the resin adhesion layer 4 encloses an internal space above a sensor area where the image capturing element 2, as an electronic element, above the image capturing element wafer 3 is provided. The resin adhesion layer 4 is formed at a predetermined location on the image capturing element wafer 3 using an ordinary photolithography technique. The transparent support substrate 5 is adhered on the resin adhesion layer 4. In this case, the resin adhesion layer 4 can also be formed using a screen printing method or a dispense method, other than the photolithography technique.
The lens wafer module 6B includes a first lens wafer 65B and a second lens wafer 66B laminated on the transparent support substrate 5 in such a manner to correspond to the image capturing element 2. The first lens wafer 65 is constituted of a plurality of first lenses 61B. The second wafer 66 is constituted of a plurality of second lenses 62B. An optical surface A of the first lens 61B is in a shape of a convex lens and is externally protruded. The outer circumference portion of the optical surface A is annularly protruded more than the most-protruded top portion at the center portion of the optical surface A. In
In the second lens 62B, both the front surface and the back surface are a convex shaped optical surface A, and protruded sections 62Ba and 62Bb are annularly protruded from an outer circumference end portion B, which is the outer circumference of the optical surface A, and are higher than the convex shape of the optical surface A, and the top surface is a planarized surface. The annular protruded section 61Bb, which is on the outer circumference side of the optical surface A on the back surface of the first lens 61B, and the annular protruded section 62Ba, which is on the outer circumference side of the optical surface A on the front surface of the second lens 62B, contact with each other at the respective planarized surfaces. An adhesive 7 is provided in a space made by lower portions or bottom portions (step portions) further outside of the annular protruded sections 61Bb and 62Ba. The first lens 61B and the second lens 62B are vertically adhered and fixed to each other at the space in between them by the adhesive 7. Similar to this, the transparent support substrate 5 and the annular protruded section 62Bb at the outer circumference end portion B of the optical surface A on the back surface contact each other at the respective planarized surfaces. The adhesive 7 is provided in the space made by the lower portion or bottom portion (step portion) on the further outside of the annular protruded section 62Bb. The transparent support substrate 5 and the second lens 62B are vertically adhered and fixed to each other at the space in between them by the adhesive 7.
Because of the structure described above, the space between the first lens 61B and the second lens 62B as well as the space between the second lens 62B and the transparent support substrate 5 touch each other and are regulated by the respective planarized surfaces of the annular protruded sections 61Bb and 62Ba and the annular protruded section 62Bb. As a result, the variation of the thickness or amount of the adhesive 7 will not negatively influence the lens module 6B, and the overall thickness of the lens module 6B becomes stable. That is, the space between the lenses are determined by the contacting surfaces (protruded sections 61Bb, 62Ba and 62Bb) of the first lens 61 and the second lens 62, and the adhesion is made by the adhesive 7 in the space portion made by the bottom portion further outside the contacting surfaces. Therefore, even if the amount of the adhesive 7 is too much, the adhesive 7 only spreads within the gap portion, and the variation of the thickness or amount of the adhesive 7 does not cause a problem. As a result, the thickness of the overall lens module 6B becomes stable, and further, the optical characteristics of the lens module 6B become stable.
That is, the contacting surface of the first lens wafer 65B and the contacting surface of the second lens wafer 66B directly contact each other, and the contacting surface of the second lens wafer 66B and the transparent support substrate 5 directly contact each other, so as to adhere them at the gap portions of the outer circumference portions. As a result, the first lens wafer 65B and the second lens wafer 66B can be manufactured with high precision, so that a lens space b and a space d between the lens and the image capturing element 2 do not vary. In this case, the adhesive 7 is provided in a space portion (gap portion) made by the bottom portion (step portion) on the further outer circumference side of the lens contact surface. The adhesive 7 does not fill the space portion (gap portion) made by the bottom portion (step portion), but the adhesive 7 is provided in the space portion (gap portion) in such a manner to leave a partial space therein, so that the adhesive 7 only spreads within the space even if the amount of the adhesive 7 is too much, and the variation of the thickness or amount of the adhesive 7 does not cause a problem. As a result, the thickness of the overall lens module 6B becomes stable, and the optical characteristics of the lens module 6 become stable.
The lens space b and the space d between the lens and the image capturing element 2 in this case vary largely due to the thickness of the adhesive 7 because the adhesive 7 is put between the first lens wafer 65B and the second lens wafer 66B, and the adhesive 7 is put between the second lens wafer 66B and the upper surface of the transparent support substrate 5, as conventionally performed. For example, when an adhesive sheet with the adhesive 7 of the thickness of 50 μm is used, the variation will be plus or minus 10 μm. When the adhesive 7 is in a liquid form, the variation will be greater at the application of the adhesive 7.
Further, at the time of the conventional reflow soldering (soldering process at 250 degrees Celsius), when the internal enclosed space between the lenses expands, there is no escape route for inside air. Because of this, the first lens wafer 65B and the second lens wafer 66B with the adhesive 7 interposed therebetween, and the second lens wafer 66B and the transparent support substrate 5 are peeled off, in addition to the image capturing element wafer 3 and the transparent support substrate 5 with the resin adhesion layer 4 interposed therebetween. In order to solve this problem, the resin adhesion layer 4 and the adhesive 7 are formed in such a manner not to surround the circumference completely but to provide an air hole (vent).
a) to 9(c) and
In
In
In
In
Subsequently, In
Further, in
That is, in a plan view, the adhesive 7 is provided at a predetermined width outside the lens area (lens optical surface A) and inside the quadrilateral along the dicing line. The vent 71 and/or 72 are provided at least at one corner portion and/or one side portion of the four corner portions and four side portions of the quadrilateral adhesive 7. Furthermore, in a plan view, the adhesive 7a for capturing dust, which is cohesive even after the curing of the resin, is provided outside the lens area and inside the quadrilateral along the dicing line. Part or all of the adhesive 7a for capturing dust is provided in such a manner to face the vent 71 and/or 72 in the space portion 7b inside the outer vent in a plan view.
Alternatively, a lens support plate 61C is provided inside the transparent lens material of each first lens 61B of the first lens wafer 65B. The lens support plate 61C includes a through hole penetrating only a lens shape area, which is the lens optical surface A of a convex shape. Further, a lens support plate 62C is provided inside the transparent lens material of each second lens 62B of the second lens wafer 66B. The lens support plate 62C includes a through hole penetrating only a lens shape area, which is the lens optical surface A of a convex shape.
In this case, for the shielding of light for the image capturing element 2 from above, a light shielding plate 69 having an opening (window) above the lens optical surface A is provided by being adhered by the adhesive 7 on the front surface side of each first lens 61B of the first lens wafer 65B. Further, the shielding of light for the image capturing element 2 from the side is performed by the lens support plates 61C and 62C. The lens support plates 61C and 62C include through holes penetrating only a lens shape area (area corresponding to the lens optical surface A). A taper is provided for the through hole. The outer circumference side of the through hole is configured to be thicker than the further outer circumference side. The circumference portion of the through hole is expanded so that it becomes difficult for the light from the side to pass it through, and a tapered section 69b is provided on the further outer circumference side. A light shielding material 69a is positioned on the side wall of the transparent support substrate 5. Carbon is mixed, to provide a light shielding function, in the adhesive 7 between the light shielding plate 69 and the first lens wafer 65, the adhesive 7 between the first lens wafer 65B and the second lens wafer 66B, and the adhesive 7 between the second lens wafer 66B and the transparent support substrate 5. These adhesives enable shielding of light from the image capturing element 2 in a more definite manner.
Next, the lens thicknesses a and c of the first lens wafer 65B and the second lens wafer 66B vary. This is because the transparent lens resin does not have a place to escape from the pressure of the metal mold. Therefore, when the amount of the transparent lens resin is high, the contact pressure becomes high and the lens thicknesses a and c also become thick. The peripheral portion of each through hole of the lens support plates 61C and 62C expands, and a through hole 68 is provided on the further outer circumference side. Because of the through hole 68, when the transparent lens resin material is put between the metal molds, the resin material will have a space to escape through the through hole 68 due to the pressure of the metal molds, and the contact pressure on the resin material will not become high during the forming of the resin. Because of this, it becomes possible to avoid the variation of the lens thicknesses a and c of the first lens wafer 65B and the second lens wafer 66B. Further, instead of or together with the through hole 68, a front portion of the trough hole 68 can be widened or recessed so that it also becomes possible to control the contact pressure to the resin material at the forming stage.
First, a method for forming the first lens wafer 65B in
As illustrated in
Next, as illustrated in
Further, as illustrated in
Next, another method for forming the first lens wafer 65B of
As illustrated in
Next, as illustrated in
Further, as illustrated in
Next, another method for forming the first lens wafer 65B will be described in detail with reference to
As illustrated in
Next, as illustrated in
As described above, and also in Embodiment 2, the surface height of the spacer section provided on the outer circumference side of the lens optical surface A, functioning as an optical element area, is configured to be higher than the surface height of the lens optical surface A, functioning as an optical element area, at the center portion. As a result, in the manufacturing process, the lens optical surface A can be prevented from becoming dirty from cutting water and the lowering of the optical characteristics can be prevented. Furthermore, the surface of the optical element, such as a convex lens surface that functions optically, can be maintained clean.
In Embodiment 3, the lens as an optical element and the lens module as an optical element module will be described in detail.
a) is a longitudinal cross sectional view illustrating an exemplary variation of each lens of
Similar to the case with the
Further, a lens module 86 illustrated in
The difference between the lens module 86 illustrated in
In this case, the annular planarized surface of the spacer section of the upper first lens 84A directly contacts with the annular planarized surface of the spacer section of the lower second lens 85A, and the adhesive 7 is provided in the space portion surrounded by the bottom portion on the further outer circumference side of each planarized surface, so that the first lens 84A is adhered to the second lens 85A.
Further, the first lens 84A, which is illustrated by a dash line in
In summary, it is proper as long as the optical surface A and the more protruded, protruded section F2 or planarized section F1 are provided at least on either of the front surface or the back surface.
Further, as illustrated in
Instead of the lens and the lens module of
a) is a longitudinal cross sectional view illustrating an exemplary variation of each lens of
It is possible to obtain a large number of first lenses 184 as well as second lenses 185 as illustrated in
Further, a lens module 186 illustrated in
The difference between the lens module 186 illustrated in
In this case, the annular planarized surface of the spacer section of the upper first lens 184A directly contacts with the annular planarized surface of the spacer section of the lower second lens 185A, and the adhesive 7 is provided in the space portion surrounded by the bottom portion on the further outer circumference side of each planarized surface, so that the first lens 184A is adhered to the second lens 185A.
Further, the first lens 184A in
In summary, it is proper as long as the optical surface A and the more protruded, protruded section F2 or planarized section F1 are provided at least on either of the front surface or the back surface.
Further, as illustrated in
The lens modules 188 and 189 can also be manufactured using another manufacturing method. As illustrated in
Next, as illustrated in
In Embodiment 3, for example, a combination of two lenses (lens module 186) of the first lens 184 and the second lens 185, or for example, a single lens of the first lens 184 or second lens 185 have been described; however, without the limitation to these, it is also possible to combine three or more lenses as an optical element to configure a lens module as an optical element module. Other optical elements may be used instead of the lens, the other optical elements including a prism and an optical function element (hologram optical element, for example). The prism and optical function element (hologram optical element, for example) can be formed in the optical surface A of the lens.
In
As the electronic information device 90, an electronic information device that includes an image input device is conceivable, such as a digital camera (e.g., digital video camera or digital still camera), an image input camera (e.g., a monitoring camera, a door phone camera, a camera equipped in a vehicle, or a television camera), a scanner, a facsimile machine, a camera-equipped cell phone device, or a personal digital assistance (PDA).
Therefore, according to Embodiment 4 of the present invention, the color image signal from the solid-state image capturing apparatus 91 can be: displayed on a display screen properly by the display section 93, printed out on a sheet of paper using an image output section 95, communicated properly as communication data via a wire or a radio by the communication section 94, stored properly at the memory section 92 by performing predetermined data compression processing; and various data processes can be properly performed.
Without the limitation to the electronic information device 90 according to Embodiment 4 described above, an electronic information device, such as a pick up apparatus including the electronic element module according to the present invention used in an information recording and reproducing section thereof, is also conceived. An optical element of the pick up apparatus in this case is an optical function element (hologram optical element, for example) that directs output light straight to be output and refracting and guiding incident light in a predetermined direction. In addition, as the electronic element of the pick up apparatus, a light emitting element (semiconductor laser element or laser chip, for example) for emitting output light and a light receiving element (photo IC, for example) for receiving incident light are included.
Although not specifically described in detail in Embodiment 1 to 4, the surface height of the spacer section is configured to be higher than the surface height of the lens area as an optical element area, thereby achieving the objective of the present invention to maintain the surface of the optical element, such as a convex lens surface that functions optically, clean in a more definite manner.
As described above, the present invention is exemplified by the use of its preferred Embodiments 1 to 4. However, the present invention should not be interpreted solely based on Embodiments 1 to 4 described above. It is understood that the scope of the present invention should be interpreted solely based on the claims. It is also understood that those skilled in the art can implement equivalent scope of technology, based on the description of the present invention and common knowledge from the description of the detailed preferred Embodiments 1 to 4 of the present invention. Furthermore, it is understood that any patent, any patent application and any references cited in the present specification should be incorporated by reference in the present specification in the same manner as the contents are specifically described therein.
The present invention can be applied in the field of an optical element provided with a lens and an optical function element; an optical element module, such as a plurality of lenses and a plurality of optical function elements; an optical element wafer provided with a plurality of optical elements, such as a plurality of lenses and a plurality of optical function elements, in a wafer state; an optical element wafer module in which the plurality of optical element wafers are laminated; a method for manufacturing the optical element module by cutting the optical element wafer or the optical element wafer module; an electronic element wafer module in which the optical element wafer or optical element wafer module is modularized with an electronic element wafer; a method for manufacturing an electronic element module, in which the electronic element wafer module is cut simultaneously into electronic element modules; an electronic element module manufactured by the method for manufacturing the electronic element module; an electronic information device, such as a digital camera (e.g., a digital video camera or a digital still camera), an image input camera, a scanner, a facsimile machine, a camera-equipped cell phone device or a television telephone device, including the electronic element module used therein. According to the present invention, the height of a spacer section, which is provided on an outer circumference side of one optical element area, is configured to be higher than the surface height of an optical element area at the center portion. As a result, in the manufacturing process, a securing tape does not adhere to the surface of the optical element area during the cutting stage, and the securing tape is prevented from being removed so that an optical surface of a lens can be prevented from becoming dirty from cutting water and the lowering of the optical characteristics can be prevented. Furthermore, the surface of the optical element, such as a convex lens surface that functions optically, can be maintained clean.
Various other modifications will be apparent to and can be readily made by those skilled in the art without departing from the scope and spirit of this invention. Accordingly, it is not intended that the scope of the claims appended hereto be limited to the description as set forth herein, but rather that the claims be broadly construed.
Number | Date | Country | Kind |
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2008-246967 | Sep 2008 | JP | national |
2009-199021 | Aug 2009 | JP | national |