JP2008103957A - Imaging unit and image apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging unit or imaging apparatus preventing unneeded light from easily entering an imaging surface of the imaging element. <P>SOLUTION: The imaging unit 12 has: an imaging element 21 being a bare chip; a protective glass 24 being a transparent member facing an imaging light receiving surface 21a being an imaging surface of the imaging element 21; and an electric substrate having an opening 17a, wherein the imaging element 21 is mounted on one surface side so as to close the opening, and the protective glass 24 is mounted on the other surface side by an adhesive 25 having a light shielding effect and anti-reflection property to adhere the circumference of the opening 17a. In the imaging unit 12, since reflection of the unneeded light on an inner peripheral surface of an adhered part of the adhesive 25 around the opening 17a or the transmission of the adhesive 25 is suppressed, the unneeded light can be prevented from intruding onto the imaging light receiving surface 21a of the imaging element 21, and imaging data with little noise due to the imaging element 21 can be obtained. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an imaging unit formed by bonding and fixing an imaging element and a protective glass to an electric substrate.

  Conventionally, as an imaging unit incorporated in an imaging apparatus such as a digital camera, for example, there is an imaging element (bare chip) mounting structure disclosed in Patent Documents 1 and 2 and the like.

In the image sensor unit to which the conventional mounting structure is applied, a flexible printed circuit board (FPC) 117 having an opening 117a is bonded to a protective glass 124 as a light transmitting member by an adhesive 125 as in the image pickup unit 100 shown in FIG. Has been. The imaging element 121 made of a bare chip is electrically connected and bonded to the surface opposite to the bonding surface to which the protective glass 124 of the FPC 117 is bonded via the electrode pads and bumps 130. And the imaging surface (imaging light-receiving surface) 121a of the imaging device 121 is arrange | positioned so as to oppose the protective glass 124 through the opening part 117a. An adhesive 131 is applied to the electrode pads and bumps 130 so as to cover them. Thereby, the FPC 117 and the image sensor 121 are adhesively bonded, and a sealing structure for the image pickup surface 121a of the image sensor 121 is formed.
JP-A-11-164209 JP 2002-218293 A

  However, in the imaging unit 100 having the mounting structure shown in FIG. 10, the adhesive 125 for adhering the protective glass 124 is used without considering light transmittance and reflectance. The adhesive 125 has a certain thickness in the bonded state. Therefore, unnecessary light L 1 and L 2 in the peripheral part of the protective glass 124 is reflected by the opening-side inner peripheral surface of the adhesive 125 or transmitted through the adhesive 125 and reaches the imaging surface 121 a of the imaging device 121. For this reason, there is a possibility that a problem occurs that noise is added to the photographing data due to the unnecessary light.

  The present invention has been made in view of the above points, and in an imaging unit or an imaging apparatus having a mounting structure for mounting an imaging element and a light transmission member on an electric board, the imaging surface of the imaging element is provided. An object of the present invention is to provide an imaging unit or an imaging apparatus having a structure in which unnecessary light hardly enters.

  An imaging unit according to claim 1 of the present invention includes an electric board having an opening, an imaging element fixed to one surface of the electric board so as to cover the opening with an imaging surface, and the other of the electric board. And a light transmitting member that is fixed around the opening with a non-transparent adhesive so as to face the imaging surface.

  The imaging unit according to a second aspect of the present invention is the imaging unit according to the first aspect, wherein the adhesive is a black adhesive.

  According to a third aspect of the present invention, there is provided an image pickup unit having an image pickup device that is a bare chip, a transparent member that faces the image pickup surface of the image pickup device, an opening, the image pickup device being mounted on one surface, On the surface, the transparent member has an electric substrate mounted with a light-shielding adhesive disposed around the opening.

  According to a fourth aspect of the present invention, there is provided an image pickup unit having an image pickup device that is a bare chip, a transparent member that faces the image pickup surface of the image pickup device, an opening, the image pickup device being mounted on one surface, On the surface, the transparent member has an electric substrate mounted with an antireflection adhesive disposed around the opening.

  An image pickup apparatus according to claim 5 of the present invention has an image pickup device that is a bare chip, a transparent member that faces the image pickup surface of the image pickup device, an opening, and the image pickup device is mounted on one surface, On the surface, the transparent member has an electric substrate mounted with a light-shielding adhesive disposed around the opening.

  According to a sixth aspect of the present invention, there is provided an image pickup device having an image pickup element that is a bare chip, a transparent member that faces the image pickup surface of the image pickup element, an opening, the image pickup element being mounted on one surface, On the surface, the transparent member has an electric substrate mounted with an antireflection adhesive disposed around the opening.

  According to the present invention, an imaging unit having a mounting structure in which an imaging element and a light transmission member are mounted on an electric substrate, or an imaging unit having a structure in which unnecessary light is unlikely to enter the imaging surface of the imaging element in the imaging apparatus. Alternatively, an imaging device can be provided.

The present invention will be described below with reference to the illustrated embodiments.
1 and 2 are diagrams showing a mirror box portion of a digital single-lens reflex camera (hereinafter simply referred to as a digital camera) as an imaging apparatus to which an imaging unit according to an embodiment of the present invention is applied. Among these, FIG. 1 is a perspective view of the mirror box portion excluding the body mount and other unnecessary mechanism portions. 2 is a cross-sectional view taken along the line II-II in FIG.

  FIG. 3 is a front view showing the configuration of the imaging unit of the present embodiment. 4 and 6 are exploded perspective views showing the configuration of the imaging unit of the present embodiment. Among these, FIG. 4 is the figure seen from the front side. FIG. 6 is a view as seen from the back side. 5 and 7 are perspective views in a state where the imaging unit of the present embodiment is assembled. Among these, FIG. 5 is a view seen from the front side. FIG. 7 is a view from the back side. FIG. 8 is a cross-sectional view showing a state in which the imaging element and the protective glass are bonded and fixed to a flexible printed circuit board (hereinafter referred to as FPC) in the imaging unit of the present embodiment. FIG. 9 is an enlarged cross-sectional view of a main part in which a part of FIG. 8 is enlarged.

  As shown in FIG. 1, a mount placement surface 13 a on which a body mount 13 (not shown in FIG. 1, see FIG. 2) is placed is disposed on the front surface of the main body 11 of the mirror box 10. The body mount 13 is provided to make a photographic lens barrel (not shown) having a photographic optical system detachable from the main body 11. Therefore, when a lens barrel (not shown) is attached to the body mount 13, the optical axis O (see FIG. 2) of the imaging optical system of the lens barrel passes through a substantially central portion of the body mount 13. In addition, the mount surface of the body mount 13 is set to be a surface substantially orthogonal to the optical axis O of the photographing optical system.

  Behind the main body 11, an imaging unit 12 according to the present embodiment including an imaging element 21 and the like described later and including a fixing member 15, a protection member 16, an FPC 17, and the like is fixed to the main body 11. Yes.

  The imaging unit 12 of this embodiment is mainly composed of a fixing member 15, a protection member 16, an FPC 17 that is an electric substrate, a heat radiation member 20, an imaging element 21, and a light transmission member (transparent member) as shown in FIGS. 2 to 5. A protective glass 24 is used.

  The fixing member 15 is a member that serves as a reference for positioning the imaging unit 12 with respect to the mirror box 10. Note that the fixing member 15 is formed of a plate-like hard member, for example, a metal member such as an aluminum material, a stainless steel material, ceramic, a molded part, or the like.

  The protection member 16 is fixed to the FPC 17. The protection member 16 has a function of protecting the FPC 17 from bending caused by bending of the FPC 17 with respect to the bonded portion between the imaging element 21 or the protective glass 24 and the FPC 17, and the FPC 17 with respect to the fixing member 15 when the imaging unit is assembled. It is used for positioning.

  The imaging element 21 is a photoelectric conversion element that performs a photoelectric conversion process for generating an image signal corresponding to an optical subject image formed through a photographing optical system (not shown). The imaging element 21 is formed by a bare chip such as a charge coupled device (CCD), for example. An area of the imaging light receiving surface 21a (FIG. 8) corresponding to the imaging surface on one surface of the imaging element 21 forms an imaging pixel region. A plurality of electrodes 30 are provided on the same surface as the imaging light receiving surface 21 a and adjacent to the surface, that is, in the vicinity of the outer peripheral edge that is the periphery of the imaging element 21. The electrode 30 is connected to a connection pattern (not shown) of the FPC 17 by a bump, so that a signal is exchanged between the FPC 17 and the image sensor 21.

  The FPC 17 is an electric board provided to supply an image signal generated by performing a photoelectric conversion process by the image sensor 21 to an electric circuit (not shown) such as an image processing circuit. A substantially rectangular opening 17a (see FIG. 4) is formed in a substantially central portion of the FPC 17. The opening 17a is provided to allow a light beam to be imaged to pass therethrough. Accordingly, the opening 17a is set to be larger than the imaging light receiving surface 21a of the imaging element 21, smaller than the outer shape of the imaging element 21, and inside the position where the electrode 30 is located. A connection pattern (not shown) connected to the electrode 30 of the image sensor 21 is formed in the vicinity of the edge of the opening 17a.

  The heat radiating member 20 is provided to release the heat accumulated in the image sensor 21. The heat radiating member 20 is formed of a plate-like member such as ceramic.

  The protective glass 24 is a protective cover provided to protect the imaging light-receiving surface 21 a of the imaging element 21 by being provided at a portion that is larger in outer shape than the imaging element 21 and is opposed to the imaging light-receiving surface 21 a of the imaging element 21. . The protective glass 24 is formed of a transparent member such as flat glass.

  The protective glass 24 covers the opening 17a on the surface opposite to the surface to which the image pickup device 21 of the FPC 17 is fixed, in other words, the second adhesive is formed around the opening so as to close the opening 17a. It is adhered and fixed by 25. Details of the adhesive 25 will be described later.

  As shown in FIG. 2, a high frequency component is generated on the front side of the protective glass 24 from a light beam (hereinafter referred to as an auxiliary vehicle light beam) from a subject that is transmitted through a photographing optical system (not shown). An optical low-pass filter (hereinafter referred to as an optical LPF) 26 to be removed and a shutter 27 for controlling the irradiation time of the subject light beam incident on the imaging light receiving surface 21a of the imaging device 21 are sequentially arranged.

  The member arrangement of each constituent member in the imaging unit of the present embodiment is as follows.

  On one surface of the FPC 17, that is, the back surface side, the image sensor 21 is disposed so as to cover the opening 17a, in other words, close the opening 17a. The FPC 17 and the image sensor 21 are at least mechanically fixed by the first adhesive 31.

  That is, the periphery of the opening 17a on the back surface side of the FPC 17 and one surface of the image sensor 21, that is, the outer periphery on the same surface side as the imaging light receiving surface 21a are bumps of the electrode 30 (see FIG. 8). It adheres with the 1st adhesive agent 31 except a part.

  More specifically, the first adhesive 31 is between the image sensor 21 and the FPC 17 from the outer edge of the image sensor 21 to at least an electrical connection portion between the connection pattern of the FPC 17 and the electrode 30 of the image sensor 21, and the image sensor. It is applied annularly with a first band width along the periphery of 21. That is, the first adhesive 31 is applied around the opening 17 a of the FPC 17.

The first adhesive 31 is applied so as to cover the periphery of the electrode 30. This
The image pickup device 21 is arranged so that the image pickup light receiving surface 21a of the image pickup device 21 is exposed from the opening 17a in a state of being fixed to a predetermined part on the back side of the FPC 17.

  The other surface of the FPC 17, that is, the front surface side and the peripheral edge portion of the opening 17 a is bonded to the outer peripheral edge portion of the protective glass 24 on the back surface side by a second adhesive 25.

  More specifically, the second adhesive 25 is applied annularly around the opening 17a of the FPC 17 with a second band width. As the second adhesive 25, a non-transparent adhesive having light shielding properties and / or antireflection properties or one of them is applied. Moreover, the adhesive agent which exhibits light-shielding property and antireflective property in the state after hardening may be sufficient. The second adhesive 25 is of an ultraviolet curable type or a heat curable type. For example, when an ultraviolet curable adhesive is used, a dye for preventing the ultraviolet rays from being used is used. When a thermosetting adhesive is used, a black adhesive mixed with carbon powder can be applied. The degree of the light shielding property or antireflection property of the adhesive is not limited to high light shielding property or extremely low reflectance property, but has higher light shielding property or antireflection property. If it exists, the effect mentioned later can be expected.

  By adhering this protective glass 24 and the FPC 17, a space in the vicinity of the imaging light receiving surface 21a of the image sensor 21 is sealed to the outside, and a sealing structure for protecting the imaging light receiving surface 21a from the outside is formed. Is done.

  On the other hand, the heat radiating member 20 is bonded to the back surface side of the image sensor 21, that is, the surface opposite to the imaging light receiving surface 21a of the image sensor 21 with an adhesive (see FIG. 2).

  Further, the fixing member 15 is bonded and fixed to the rear surface side of the heat radiating member 20 with an adhesive 32 through a hole 15 a formed in the fixing member 15. The holes 15 b are used when the heat radiating member 20 is bonded to the fixing member 15. The details of the means for adhering the heat radiating member 20 to the fixing member 15 are not related to the present invention, and the description thereof will be omitted.

  The fixing member 15 is fixed to a predetermined part of the main body 11 by means such as screwing. Accordingly, the image pickup device 21 is thereby fixed to a predetermined part of the main body 11 of the mirror box 10.

  Next, the adhesion part of FPC17, the protective glass 24, and the image pick-up element 21 is explained in full detail below.

  As described above, the outer peripheral edge of the image sensor 21 on the imaging light receiving surface 21 a side and the rear surface of the FPC 17 and the peripheral edge of the opening 17 a are bonded by the first adhesive 31 that surrounds the periphery of the electrode 30. Fixed. In particular, the first adhesive 31 is an insulating one. In addition, the first adhesive 31 is distributed so as to cover the periphery of the electrode 30, thereby ensuring insulation in the vicinity of the electrode 30.

  Here, out of the adhesion range (application range) of the image sensor 21 and the FPC 17 by the first adhesive 31, the outermost of the adhesive 31 attached to the outside of the outer periphery of the image sensor 21 from the center position of the electrode 30. The range of the part indicated by the symbol A in FIGS. 8 and 9 up to the edge is represented by the symbol B. The range indicated by the symbol B is the first band width.

  On the other hand, the peripheral edge part of the opening 17 a on the front surface side of the FPC 17 and the outer peripheral edge part on the back surface side of the protective glass 24 are bonded by the second adhesive 25.

  Here, the adhesion range of the FPC 17 and the protective glass 24 by the second adhesive 25 (application range of the second adhesive 25), that is, from the outermost edge of the adhesive 31 to the center of the electrode 30. Further, the range up to the opening 17a side is represented by reference numeral C as shown in FIG. The range indicated by the symbol C is the second band width.

  In this way, when the imaging device 21 and the protective glass 24 are bonded and fixed to the FPC 17 by the first adhesive 31 and the second adhesive 25, respectively, the arrow F1 in FIG. Assuming that an external force in the direction is applied, the stress that will be generated will be a stress that causes the FPC 17 to peel off at the adhesion site indicated by symbol A in FIG.

  Further, in this state, if, for example, a pressing force on the back surface of the image sensor 21, that is, an external force in the direction of the arrow F2 in FIG. 9 is applied, the stress generated from this will be a stress that presses the image sensor 21 from the back surface. Thus, the stress is caused to peel off the FPC 17 at the adhesion site indicated by the symbol A in FIG.

  Therefore, in the imaging unit of the present embodiment, as shown in FIG. 9, the adhesion range C by the second adhesive 25 is a predetermined application range of the adhesion range by the first adhesive 31, that is, the electrode 30. A range B from the center position to the part indicated by the symbol A in FIGS. 8 and 9 is included.

  That is, when viewed from the direction orthogonal to the plane of the opening 17 a of the FPC 17 (see FIGS. 8 and 9), the first band width B by the first adhesive 31 is the second width by the second adhesive 25. The second adhesive 25 is applied so as to overlap the band width C.

  In the imaging unit of the present embodiment, as shown in FIGS. 8 and 9, the front side of the opening 17 a of the FPC 17 is covered with the protective glass 24, and the periphery of the opening 17 a is sealed with the second adhesive 25. Further, as described above, the second adhesive 25 having light shielding properties and antireflection properties is applied. Therefore, the reflection of the invading unnecessary light L1 that has passed through the protective glass 24 on the adhesive inner peripheral surface 25a of the second adhesive 25 is suppressed. Further, the unnecessary light L2 and L3 transmitted through the protective glass 24 around the protective glass 24 is prevented from passing through the second adhesive 25, and unnecessary light is prevented from reaching the imaging light receiving surface 21a.

  As described above, according to the above-described embodiment, the adhesion range C (second band width) by the second adhesive 25 is the predetermined application range B (of the adhesion range by the first adhesive 31). For example, the FPC 17 is peeled off at the adhesion portion indicated by the pressing force (external stress in the direction of arrow F2 in FIG. 9) against the back surface of the image sensor 21 or the symbol A in FIG. The structure having sufficient strength against the stress to be generated can be obtained.

  Further, according to the one embodiment, as described above, unnecessary light that has passed through or reflected through the second adhesive 25 for bonding the protective glass 24 reaches the imaging light receiving surface 21a of the imaging element 21. Is prevented. Therefore, the trouble that the noise due to the unnecessary light is added to the image data captured by the image sensor 21 can be prevented, and accurate image data can be obtained.

  In the above-described embodiment, as an application example of the protective glass 24, a transparent member such as a plate-shaped glass is used. However, the present invention is not limited to this. As an example of the protective glass 24, a low-pass filter, for example, or an infrared cut filter can be similarly applied.

  In the above-described embodiment, the FPC 17 is used as an example of the electric board, but the present invention is not limited to this. As an application example of the electric substrate, for example, the same applies even when a hard thin substrate or the like is applied.

  Furthermore, in the above-described embodiment, the imaging element 21 and the FPC 17 that is the electric substrate are bonded to each other using the adhesive 31 having insulating properties, but the present invention is not limited to this. For example, the image sensor 21 and the FPC 17 may of course use an adhesive containing conductive particles having conductivity by pressing.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention at the stage of implementation. Further, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements.

  An image pickup unit or an image pickup apparatus according to the present invention includes an image pickup unit or an image pickup apparatus having a mounting structure in which an image pickup element and a light transmission member are mounted on an electric board, and unnecessary light enters an image pickup surface of the image pickup element. It can be used as an imaging unit or an imaging device having a difficult structure.

It is a perspective view which takes out and shows the mirror box part of the digital single-lens reflex camera which is an imaging device with which the imaging unit of one embodiment of the present invention is applied. It is II-II sectional drawing of FIG. It is a front view which shows the structure of the imaging unit applied to the camera of FIG. It is a disassembled perspective view which shows the structure of the imaging unit of FIG. 3 from the front side. It is the perspective view which looked at the state which assembled the imaging unit of FIG. 3 from the front side. It is a disassembled perspective view which shows the structure of the imaging unit of FIG. 3 from the back side. It is a perspective view which shows the state which assembled the imaging unit of FIG. 3 from the back side. 4 is a cross-sectional view illustrating a state in which an imaging element and a protective glass are bonded and fixed to an FPC in the imaging unit of FIG. 3. It is a principal part expanded sectional view which expands and shows a part of FIG. It is sectional drawing of the conventional imaging unit.

Explanation of symbols

12 ... Imaging unit 17 ... FPC (electrical board)
17a ... opening (opening of electric board)
21: Imaging element 21a: Imaging light receiving surface (imaging surface)
24 ... Protective glass (transparent member, light transmitting member)
25 ... Second adhesive (non-transparent adhesive, light-shielding adhesive)

Claims (6)

An electrical substrate having an opening;
An image pickup device fixed to one surface of the electric substrate so as to cover the opening with an image pickup surface;
A light transmissive member fixed to the other surface of the electric substrate by a non-transparent adhesive around the opening so as to face the imaging surface;
An imaging unit comprising: The imaging unit according to claim 1, wherein the adhesive is a black adhesive. An image sensor that is a bare chip;
A transparent member facing the imaging surface of the imaging element;
An electric board having an opening, the imaging element is mounted on one surface, and the transparent member is mounted on the other surface by a light-shielding adhesive disposed around the opening;
An image pickup unit comprising: An image sensor that is a bare chip;
A transparent member facing the imaging surface of the imaging element;
An electric board having an opening, the imaging element is mounted on one surface, and the transparent member is mounted on the other surface with an anti-reflection adhesive disposed around the opening;
An image pickup unit comprising: An image sensor that is a bare chip;
A transparent member facing the imaging surface of the imaging element;
An electric board having an opening, mounting the imaging element on one surface, and mounting the transparent member on the other surface with a light-shielding adhesive disposed around the opening;
An imaging device comprising: In the imaging device,
An image sensor that is a bare chip;
A transparent member facing the imaging surface of the imaging element;
An electric board having an opening, the imaging element is mounted on one surface, and the transparent member is mounted on the other surface with an anti-reflection adhesive disposed around the opening;
An imaging device comprising:

Images