JP5595066B2 - Imaging device and imaging module - Google Patents

Description

  The present invention relates to an imaging apparatus using an imaging element such as a CCD (Charge Coupled Device) type or a CMOS (Complementary Metal Oxide Semiconductor) type and an imaging module using the imaging apparatus. Is.

  2. Description of the Related Art Conventionally, an imaging apparatus that is applied to a digital camera, an optical sensor, or the like, in which an imaging element such as a CCD type or a CMOS type is mounted on a wiring board is known. Such an image pickup device picks up light (image) input to the light receiving portion 13a of the image pickup device 13 mounted on the bottom surface of the recess 12 of the wiring board 11 as shown in the cross-sectional view of FIG. It is converted into an electric signal by the element 13 and output to an external circuit or the like in the digital camera via the connection member 15 such as a bonding wire and the wiring conductor 11c of the wiring board 11. The imaging device is configured such that the imaging element 13 is sealed by a transparent plate material 16 such as glass attached on the wiring board 11, and the lens 17 is disposed on the imaging element 13 by the lens fixing member 18, whereby the imaging module It becomes.

  In such an imaging apparatus and imaging module, there are cases where a plurality of electronic components such as an IC, a capacitor, a coil, and a resistor for processing an electrical signal from the imaging element are mounted in addition to the imaging element. As an imaging module on which electronic components are mounted, for example, an area in which the imaging element 13 is mounted in the recess 12 of the wiring board 11 as shown in the cross-sectional view of FIG. There are those in which the electronic component 14 is mounted on the surrounding bottom surface, and those in which a plurality of electronic components 14 are mounted on the upper surface around the recess 12 of the wiring board 11 as in the example shown in the sectional view in FIG. It is known (see, for example, Patent Document 1). Alternatively, as in the example shown in the sectional view of FIG. 6C, the imaging element 13 is mounted on the upper surface of the wiring board 11, and a plurality of electronic components 14 are mounted in the recesses provided on the lower surface of the wiring board 11. Is known (see, for example, Patent Document 2).

JP 11-103039 A JP-A-5-183135

  However, an imaging apparatus used in an electronic device such as a mobile phone or a digital camera where portability is important is required to be further reduced in size and thickness. On the other hand, the conventional imaging device in which electronic components are mounted around the area where the imaging device on the bottom surface of the recess is mounted or on the top surface around the recess of the wiring board, In order to provide a mounting area, the size of the wiring board in a top view is increased. In addition, an image pickup apparatus in which an electronic component is mounted in a concave portion provided on the lower surface of the wiring board has an amount of the image pickup apparatus corresponding to the thickness of the wiring board that is increased to form the thickness of the electronic component or the concave portion for storing the electronic component. The thickness would be increased. In addition, when electronic components are mounted below the image sensor, the wiring board below the image sensor becomes thicker and a space is formed between the circuit board and the external circuit board. Therefore, it is difficult to dissipate heat to the external circuit board, and the image quality of the image output due to thermal noise may be deteriorated. When the thickness of the wiring board between the imaging element and the electronic component becomes thin as the imaging device becomes thinner, there is a concern that the influence of thermal noise due to heat generated in the electronic component is more likely to occur. For this reason, it has been difficult for a conventional imaging device to be small and thin and to have high image quality.

  The present invention has been devised in view of the above-described problems of the prior art, and an object of the present invention is to achieve both miniaturization and thinning of the imaging device and to output a high-quality image signal. It is an object to provide an imaging device and an imaging module that can perform the above.

The imaging device of the present invention is an imaging device in which an imaging device is mounted on a bottom surface of a concave portion formed on an upper surface of a wiring board with a light receiving portion facing upward, and the concave portion is configured to receive the light reception of the imaging device in a top view. The wiring board has a lower opening than the bottom surface of the recess, and the lower surface of the upper wiring board having the opening and the upper surface of the lower wiring substrate having the bottom surface of the recess are bonded to the wiring board.
Is made by the provided electronic part is mounted to a periphery of the opening in the upper surface of the upper wiring board outside the region for mounting the lens fixing member, wherein the electronic component is in top perspective, and the upper wiring board It overlaps with a joining area | region with the said lower side wiring board, It is characterized by the above-mentioned.

  Moreover, the imaging device of the present invention is characterized in that, in the above configuration, a transparent plate material is attached so as to close the opening of the recess.

The imaging apparatus of the present invention having the above structure, the previous SL upper wiring board and annular step or annular uneven interdigitated so as to surround the opening at least one in a plan view of the joint surface of the lower wiring board It is characterized by being formed.

In the imaging module of the present invention, a lens is disposed above the opening of the wiring board of the imaging device of the present invention having the above-described configuration , and the lens fixing member that fixes the lens is an upper surface of the wiring board. It is mounted in a region between the opening and the electronic component .

  According to the imaging device of the present invention, the concave portion exposes the light receiving portion of the imaging element in a top view and has an opening smaller than the bottom surface of the concave portion, and the electronic component is mounted around the opening. Since electronic components are mounted in the mounting area provided on the upper surface without increasing the outer dimensions of the board, it is possible to dissipate heat from the image sensor from the lower surface of the wiring board as well as a small and thin imaging device. Therefore, the imaging apparatus can output a high-quality image signal.

  Further, according to the imaging apparatus of the present invention, in the above configuration, when a transparent plate is attached so as to close the opening of the recess, moisture or dust may enter the recess and adhere to the light receiving unit of the imaging element. Therefore, it is possible to protect the image sensor and to output a high-quality image signal without preventing light reception.

  According to the imaging device of the present invention, in the above configuration, the wiring board is formed by joining the lower surface of the upper wiring board having the opening and the upper surface of the lower wiring board having the bottom surface of the recess, When an annular step or an annular concavo-convex meshing with each other so as to surround the opening in a plan view is formed on at least one of the joint surfaces of the lower wiring substrate, Since light can be prevented from entering the recess from the joint where the lower wiring board is joined, unnecessary light can be prevented from reaching the light receiving part, and high-quality image signals can be output. Is possible.

  The imaging module of the present invention is an imaging module capable of outputting a small, thin and high-quality image signal because the lens is disposed above the opening of the wiring board of the imaging apparatus having the above configuration.

(A) is a top view which shows an example of embodiment of the imaging device of this invention, (b) is sectional drawing in the AA of (a). (A)-(c) is sectional drawing which shows an example of embodiment of the imaging module of this invention, respectively. (A)-(c) is sectional drawing which shows the other example of embodiment of the imaging device of this invention, respectively. (A) is a bottom view of the upper wiring board in FIG. 3 (c), and (b) is a top view of the lower wiring board in FIG. 3 (c). It is sectional drawing which shows an example of the conventional imaging module. (A)-(c) is sectional drawing which shows the other example of the conventional imaging module, respectively.

  The imaging apparatus of the present invention will be described with reference to the accompanying drawings. FIG. 1A is a plan view showing an example of an embodiment of an imaging apparatus of the present invention, and FIG. 1B is a cross-sectional view taken along the line AA in FIG. FIG. 2A to FIG. 2C are cross-sectional views showing examples of embodiments of the imaging module of the present invention. In these drawings, 1 is a wiring board, 1a is an upper wiring board, 1b is a lower wiring board, 1c is a wiring conductor, 1d is a convex part, 1e is a second concave part, 2 is a concave part, 2a is an opening, 3 is An imaging element, 3a is a light receiving portion, 4 is an electronic component, 5 is a connection member, 6 is a transparent plate, 7 is a lens, and 8 is a lens fixing member.

  The image pickup apparatus of the present invention is an image pickup apparatus in which the image pickup element 3 is mounted on the bottom surface of the recess 2 formed on the upper surface of the wiring board 1 with the light receiving portion 3a facing up, as in the example shown in FIG. The concave portion 2 has an opening 2a that is large enough to expose the light receiving portion 3a of the image pickup device 3 in a top view and smaller than the bottom surface of the concave portion 2, and the electronic component 4 is mounted around the opening 2a.

  In the example shown in FIG. 1, the image sensor 3 is mounted on the bottom surface of the recess 2 of the wiring substrate 1, and the wiring conductor 1 c on the bottom surface of the recess 2 and the image sensor 3 are electrically connected using a bonding wire as a connection member 5. Yes. Since the opening 2a of the concave portion 2 is smaller than the bottom surface of the concave portion 2 so as to expose the light receiving portion 3a of the image pickup device 3 when viewed from above, the upper surface of the wiring substrate 1 overlaps the bottom surface of the concave portion 2 when viewed from above. That is, the electronic component 4 can be mounted at a position overlapping the peripheral edge of the image sensor 3 or the connection region between the image sensor 3 and the wiring board 1 in a top view. Therefore, compared to the conventional case where the electronic component 4 is mounted outside the connection region in the recess 2 or outside the recess 2, the wiring board 1 may be enlarged by the mounting region of the electronic component 4. Therefore, it becomes a small imaging device. In the example shown in FIG. 1, the electronic component 4 is entirely mounted at a position overlapping the peripheral edge and the connection region of the image pickup device 3 in a top view, but a part of the electronic component 4 is in the concave portion 2 in a top view. If it is mounted so as to overlap with the bottom surface, the mounting area of the electronic component 4 provided outside the recess 2 can be reduced. In order to further reduce the size of the imaging device, the electronic component 4 may be mounted on the inner side.

  Further, as in the example shown in FIG. 2B, when the lens 7 is arranged on the imaging device to form an imaging module, the lens fixing member 8 that fixes the lens 7 is provided on the upper surface of the upper surface of the wiring board 1. The electronic component 4 may be mounted on the outer edge portion of the upper surface of the wiring board 1 by being mounted at a position overlapping the bottom surface of the concave portion 2 as viewed. In this case, the example of the imaging module shown in FIG. 2A in which the lens fixing member 8 is mounted on the outer edge portion of the upper surface of the wiring board 1 of the imaging device shown in FIG. 1 is the position where the electronic component 4 is mounted. Only the position where the lens fixing member 8 is mounted is changed, and the imaging device and the imaging module are similarly small. That is, you may mount the electronic component 4 also in the position which does not overlap with the bottom face of the recessed part 2 in top view. The position that overlaps the bottom surface of the recess 2 in the top view around the opening 2a, that is, the portion protruding from the periphery above the recess 2 is thin and low in strength, as in the example shown in FIG. It is preferable to mount the lens fixing member 8 on the outer edge of the upper surface of the wiring board 1 because it is difficult for external force to be applied to this portion and the electronic component 4 can be protected by the lens fixing member 8.

  When the image pickup device 3 is flip-chip connected as in the example shown in FIG. 2C, it is not necessary to provide a connection region around the image pickup device 3, so that the size can be further reduced. The downsizing of the imaging device depending on the mounting position of the electronic component 4 as described above is more effective when the imaging device 3 and the wiring board 1 are connected by wire bonding. Even when the image pickup device 3 is flip-chip connected, if a light receiving unit 3a such as a DSP (Digital Signal Processor) is formed on the upper surface of the image pickup device 3, Since the area overlapping the image pickup element 3 in the top view around the opening 2a can be increased, the area in which the electronic component 4 can be mounted without increasing the outer dimension of the wiring board 1 is increased. It becomes easier to miniaturize. The length of the portion protruding from the periphery above the concave portion 2 is set according to the size of the concave portion 2, the image sensor 3 and the light receiving portion 3a. For example, if this length is about 1 to 2 mm, Many electronic components 4 having a size of about 0.6 mm × 0.3 mm can be mounted without changing the outer dimensions of the wiring board 1.

  Further, the thickness of the imaging device is increased by the thickness of the wiring board 1 which is increased to form the recess 2 for housing the electronic component 4 as compared with the case where the electronic component 4 is mounted on the lower surface of the conventional wiring board 1. Can be thinned. Although the thickness of the imaging device is thicker than that of mounting in the recess 2 by mounting the electronic component 4 on the upper surface of the wiring board 1, the lens of the digital camera in which the imaging device is incorporated or the example shown in FIG. A space having a height corresponding to the focal length of the normal lens exists between the lens 7 and the image sensor 3 of the imaging module, and the influence of the increase in thickness is eliminated by the electronic component 4 being accommodated in this space. The thickness of the imaging module is not increased. Further, it is not necessary to provide a space for mounting the electronic component 4 between the imaging device and the external circuit board, and the thickness of the wiring board 1 below the imaging element 3 can be reduced. It becomes an imaging device that can radiate the heat of the element 3 and can output a high-quality image signal that is less affected by thermal noise.

  The wiring substrate 1 has a wiring conductor 1c formed on the surface or inside of an insulating substrate made of an insulator such as ceramics or resin, and is used for mounting a through hole and an electronic component 4 serving as the opening 2a of the recess 2. The upper wiring board 1a having the wiring conductor 1c and the lower wiring board 1b having the wiring conductor 1c for electrically connecting to the electrode of the image sensor 3 are joined to each other. By mounting the imaging device 3 on the lower wiring substrate 1b and then bonding the upper wiring substrate 1a, the imaging device 3 larger than the opening 2a can be mounted on the bottom surface of the recess 2. In the example shown in FIG. 1 and FIG. 2 (a), the wiring board 1 includes a flat upper wiring board 1a having a through-hole serving as an opening 2a and a lower wiring board 1b having a concave part on the bottom side of the concave part 2. It is constituted by joining. In the example shown in FIG. 2B, the wiring board 1 includes a flat upper wiring board 1 a having a through-hole that is above the opening 2 a and the recess 2 and whose upper opening is smaller than the lower opening. The lower wiring board 1b having a concave portion that is the bottom surface side of the concave portion 2 is joined and configured. In the example shown in FIG. 2 (c), the wiring board 1 is a flat plate-like upper wiring board 1a having a through hole whose upper opening is smaller than the lower opening. The wiring board 1b is joined to the wiring board 1b.

  As shown in FIGS. 3A to 3C, the joint between the upper wiring board 1a and the lower wiring board 1b is connected to at least one of the upper wiring board 1a and the lower wiring board 1b. A ring-shaped step or ring-shaped unevenness surrounding the opening 2a may be provided. According to this, the bonding strength is increased by increasing the bonding area, and if the unevenness to be fitted to each other is provided, the alignment between the upper wiring board 1a and the lower wiring board 1b is facilitated. Further, when the wiring conductor 1c of the upper wiring board 1a and the wiring conductor 1c of the lower wiring board 1b are joined by solder at the joint, the flux and solder particles contained in the cream solder are scattered and the imaging element 3 It is possible to prevent the light from adhering to the light receiving portion 3a and the like. Also in the case of joining with a conductive resin, it is possible to prevent the conductive resin from flowing into the recess 2 and short-circuiting the wiring conductors 1c in the recess 2.

  Further, the wiring substrate 1 is formed by bonding the lower surface of the upper wiring substrate 1a having the opening 2a and the upper surface of the lower wiring substrate 1b having the bottom surface of the recess 2 to join the upper wiring substrate 1a and the lower wiring substrate 1b. It is preferable that at least one of the surfaces is formed with an annular step or an annular concavo-convex meshing with each other so as to surround the opening 2a in plan view. By adopting such a configuration, there is an annular step or an annular concavo-convex meshing with each other on the joint surface, so that light enters the recess 2 from the joint where the upper wiring board 1a and the lower wiring board 1b are joined. Can be prevented.

An imaging device having such a structure is particularly useful when using an imaging device that captures light in a wavelength region wider than visible light, including light in the infrared region and ultraviolet region, and is capable of detecting a small amount of light. This is more effective when a sensitive image sensor is used. Further, for example, an anisotropic conductive film (ACF) or an anisotropic conductive paste (Anisotropic conductive paste) is used as a bonding material.
As in the case of Conductive Paste (ACP), there is a limit to the binder that can be used, and it is more effective when it is used when sufficient light shielding cannot be achieved with only the bonding material.

  In the example shown in FIG. 3 (a), the wiring board 1 has a through hole serving as an opening 2a and a flat plate shape having an annular step on the lower surface so as to reduce the outer peripheral thickness so as to surround the through hole. The upper wiring board 1a and the lower wiring board 1b having a concave portion to be the concave portion 2 on the upper surface are arranged such that the lower surface on the outer peripheral side with respect to the step of the upper wiring substrate 1a and the upper surface of the side wall portion of the lower wiring substrate 1b It is configured to be joined so as to be engaged. In the example shown in FIG. 3B, the wiring board 1 has a through-hole that becomes the opening 2a, and has an upper wiring board 1a that has a concave portion that is an upper side of the concave portion 2 on the lower surface, and a bottom surface side of the concave portion 2. And the lower wiring board 1b having an annular step which lowers the outer peripheral side of the upper surface of the side wall portion of the concave portion, and the lower surface of the side wall portion of the upper wiring board 1a and the lower wiring board 1b. The outer peripheral side of the upper surface of the side wall portion is joined to be engaged with each other. In the example shown in FIG. 3C, the wiring board 1 includes a flat upper wiring board 1a having a through hole serving as an opening 2a and an annular protrusion 1d on the lower surface so as to surround the through hole. The lower wiring substrate 1b having the concave portion to be the concave portion 2 on the upper surface and the annular second concave portion 1e so as to surround the concave portion on the upper surface of the side wall portion of the concave portion is the lower surface of the side wall portion of the upper wiring substrate 1a. And the upper surface of the side wall portion of the lower wiring substrate 1b are joined so that the convex portion 1d and the second concave portion 1e are engaged with each other.

  Further, for example, when forming an annular unevenness on the joint surface, an opening 2a is formed on the lower surface of the upper wiring substrate 1a as shown in FIGS. 3C, 4A, and 4B. An annular convex portion 1d that is larger than the opening of the concave portion of the lower wiring substrate 1b is formed so as to surround it, and an annular shape that surrounds the opening of the concave portion of the lower wiring substrate 1b on the upper surface of the side wall portion of the lower wiring substrate 1b. The second recess 1e may be formed. 4A is a bottom view of the upper wiring board 1a, and FIG. 4B is a top view of the lower wiring board 1b. In addition, what is necessary is just to form similarly to the case of the cyclic | annular unevenness | corrugation mentioned above also when forming a cyclic | annular level | step difference in a joint surface.

3 and FIG. 4, for example, when the insulating substrate of the wiring board 1 is made of ceramics, the annular step or the annular unevenness that meshes with each other is a ceramic green sheet for the insulating substrate. Can be formed by laminating them with a die or punching method by punching or laser processing method. When it is difficult to hold the ceramic green sheet alone after punching the annular convex portion as in the example shown in FIG. 4, the ceramic green sheet is held with a sheet made of organic matter or the like that scatters after firing. And may be laminated at the same time as the punching process. Alternatively, an annular step or an annular unevenness may be formed by applying a ceramic paste made of substantially the same material as that of the insulating substrate 1. In such a case, the ceramic paste may be applied a plurality of times in order to increase the height of the annular step or the annular unevenness. Further, an annular step or an annular unevenness may be formed by applying a ceramic paste so that the cross section thereof is stepped. In such a case, it is possible to reduce the deformation of the stepped or uneven sidewall due to its own weight when the ceramic paste is stacked. Moreover, you may form the cyclic | annular level | step difference or cyclic | annular unevenness | corrugation which mutually meshes by cutting after baking. In the case where the insulating substrate is made of a resin, an annular step or an annular concavo-convex meshing with each other using an appropriate mold may be formed or formed by cutting.

  The wiring conductor 1c is formed on the upper surface of the upper wiring substrate 1a and serves as a mounting electrode for mounting the electronic component 4, and is formed on the bottom surface of the concave portion 2 of the lower wiring substrate 1b. What is to be a connection electrode connected to the electrode of the image pickup device 3, what is formed on the outer surface of the lower wiring board 1b and becomes an external terminal electrode for connecting to the wiring conductor of the external circuit board, the upper wiring board 1a and the lower wiring board 1a Some (not shown) are formed inside the side wiring board 1b and serve as internal wiring conductors that connect the mounting electrode, the connection electrode, and the external electrode to each other.

  As in the example shown in FIG. 2B, a stepped portion that is one step higher may be provided outside the bottom surface of the recess 2, and the connection electrode may be disposed thereon. Since the internal wiring conductor is electrically connected when the upper wiring board 1a and the lower wiring board 1b are bonded together, a part of the internal wiring conductor is exposed at each bonding surface. The portion exposed to the joint surface of the internal wiring conductor is a portion where the penetrating conductor penetrating each of the insulating substrates of the upper wiring substrate 1a and the lower wiring substrate 1b is exposed. If wide connection pads are formed on the joint surfaces of the wiring board 1a and the lower wiring board 1b, the wiring conductor 1c of the upper wiring board 1a and the wiring conductor 1c of the lower wiring board 1b can be easily joined well. This is preferable.

  Further, in the example shown in FIG. 2A, the wiring conductor 1c serving as the external terminal electrode is disposed on the lower surface of the wiring board 1, but on the side surface of the wiring board 1 as in the example shown in FIG. It may be arranged, and may be formed as a so-called castellation conductor formed on the inner surface of a recess (notch) formed on the side surface or filled with a conductor in the recess (notch).

  The imaging device is manufactured as follows. First, the upper wiring board 1a and the lower wiring board 1b as described above are prepared.

  The insulating substrate of the wiring board 1 (upper wiring board 1a, lower wiring board 1b) is made of an insulator such as ceramics or resin. When made of ceramics, for example, aluminum oxide sintered bodies (alumina ceramics), aluminum nitride sintered bodies, mullite sintered bodies, glass ceramic sintered bodies, etc. can be mentioned. And fluorine resins such as epoxy resin, polyimide resin, acrylic resin, phenol resin, polyester resin or ethylene tetrafluoride resin. Moreover, what impregnated resin to the base material which consists of glass fibers like glass epoxy resin is also mentioned.

When the insulating substrate is made of, for example, an aluminum oxide sintered body, an organic solvent suitable for raw material powders such as alumina (Al ₂ O ₃ ), silica (SiO ₂ ), calcia (CaO), and magnesia (MgO), A ceramic green sheet is obtained by forming a sheet by adding a solvent and mixing it into a slurry, and forming this into a sheet using a conventionally known doctor blade method, calendar roll method, etc. It is manufactured by performing appropriate stamping and laminating a plurality of sheets as necessary and firing at a high temperature (about 1500 to 1800 ° C.). The recesses 2 of the wiring board 1 are formed by forming through holes for the recesses 2 in some ceramic green sheets for the insulating substrate by a punching method using a die or punching, a laser processing method, or the like. be able to. At this time, the through hole to be the opening 2a may be made smaller than the other through holes. When the step portion is provided in the recess 2 as in the example shown in FIG. 2B, it can be formed by forming and stacking through holes having different sizes in the ceramic green sheet.

  Further, when the insulating substrate is made of, for example, a resin, it can be formed by molding by a transfer molding method, an injection molding method, or the like using a mold that can be molded into a predetermined shape of the insulating substrate. The insulating substrate may be a substrate made of glass fiber impregnated with resin, such as glass epoxy resin. In this case, it can be formed by impregnating a substrate made of glass fiber with an epoxy resin precursor and thermally curing the epoxy resin precursor at a predetermined temperature.

Further, the upper wiring substrate 1a and the lower wiring substrate 1b constituting the insulating substrate may be made of different materials. When the upper wiring board 1a has a thermal expansion coefficient between the thermal expansion coefficient of the transparent plate member 6 or the lens fixing member 8 bonded thereon and the thermal expansion coefficient of the lower wiring board 1b, the wiring board 1 and This is preferable because distortion of the imaging device due to a difference in thermal expansion from the transparent plate 6 or the lens fixing member 8 can be suppressed. For example, the lower wiring substrate 1b is made of alumina ceramics (thermal expansion coefficient: about 7 × 10 ⁻⁶ / ° C.), and the transparent plate 6 made of quartz (thermal expansion coefficient: about 11 × 10 ⁻⁶ / ° C.) is the upper wiring. If the bonding is performed so as to close the opening 2a of the substrate 1a, the upper wiring substrate 1a may be made of steatite ceramics (thermal expansion coefficient: about 9 × 10 ⁻⁶ / ° C.).

  When the insulating substrate is made of ceramic, the wiring conductor 1c is made of metal powder metallization such as tungsten (W), molybdenum (Mo), manganese (Mn), silver (Ag), or copper (Cu), and is used for the insulating substrate. A conductive paste for the wiring conductor 1c is printed in a predetermined shape on the ceramic green sheet by a screen printing method or the like, and is fired simultaneously with the ceramic green sheet for the insulating substrate, thereby being formed at a predetermined position on the insulating substrate. Among the internal conductors, a through conductor that penetrates the ceramic green sheet in the thickness direction can be formed by filling a through hole formed in the ceramic green sheet by printing a conductor paste. Such a conductive paste is prepared by adding an appropriate solvent and a binder to the metal powder and kneading to adjust to an appropriate viscosity. The conductor paste may contain glass or ceramics in order to increase the bonding strength with the insulating substrate.

  When the insulating substrate is made of resin, the wiring conductor 1c is made of a metal material such as copper, gold, aluminum, nickel, chromium, molybdenum, titanium, or an alloy thereof. For example, the copper foil processed into the shape of the wiring conductor 1c is transferred onto a resin sheet made of glass epoxy resin, and the resin sheet to which the copper foil is transferred is laminated and bonded with an adhesive. Of the internal conductors, the through conductors that penetrate the resin sheet in the thickness direction can be deposited on the inner surface of the through holes formed in the resin sheet by conductor paste printing or plating, or by filling the through holes. Good. Further, it is formed by integrating a metal foil or a metal column by resin molding, or by depositing it on an insulating substrate using a sputtering method, a vapor deposition method or a plating method.

A plating layer is deposited on the exposed surface of the wiring conductor 1c by a plating method such as an electrolytic plating method or an electroless plating method. The plating layer is made of a metal having excellent corrosion resistance such as nickel or gold and the connectivity of the connecting member 5. For example, a nickel plating layer having a thickness of about 1 to 10 μm and a gold plating layer having a thickness of about 0.1 to 3 μm. Are sequentially deposited. Thus, corrosion of the wiring conductor 1c can be effectively suppressed, the imaging element 3 and the wiring conductor 1c are fixed, the wiring conductor 1c is bonded to the connection member 5 such as a bonding wire, and the wiring conductor 1c. And the connection between the wiring component 1c and the wiring conductor of the external electric circuit board can be strengthened.

Next, the CCD type or CMOS type imaging device 3 is mounted on the lower wiring substrate 1b with the light receiving portion 3a facing the upper surface side. In the example shown in FIGS. 1, 2 (a) and 2 (b), the image pickup device 3 is mounted on the bottom surface of the recess 2 by bonding with a conductive adhesive made of, for example, epoxy resin containing silver powder or solder. It is fixed by a material, and the electrode of the image pickup device 3 and the wiring conductor 1c are electrically connected as a connecting member 5 with a bonding wire made of gold or the like. In this case, when the lower wiring board 1b is a flat plate having no recess, the bonding tool does not hit the inner wall of the recess 2 when the bonding tool moves, and the bonding tool is placed outside the wiring conductor 1c on the bottom surface of the recess 2. Since it is not necessary to provide a space for preventing the image from being hit, the image pickup apparatus can be made smaller. Further, compared to the case where the concave portion is formed in the lower wiring substrate 1b, the warp generated in the lower wiring substrate 1b is small in the manufacturing process, and the mounting portion of the imaging element 3 is easily formed flat. Since the imaging element 3 can be mounted on a flat surface, an imaging apparatus capable of outputting a higher quality image signal can be obtained. Further, as in the example shown in FIG. 2C, the wiring conductor 1c disposed on the bottom surface of the recess 2 is flipped by bonding with solder, ultrasonic bonding of Au bumps, or adhesion with anisotropic conductive resin. It may be mounted by chip bonding. When performing flip chip bonding using solder or Au bumps, an underfill material (not shown) is filled in the space below the image sensor 3.

  Next, the upper wiring board 1a and the lower wiring board 1b are bonded together while electrically connecting the wiring conductors 1c exposed on the respective bonding surfaces. For example, by electrically connecting the upper and lower wiring conductors 1c with a conductive bonding material such as solder and applying a bonding material such as epoxy resin around the upper and lower wiring conductors 1c and 1b, And the space between the upper wiring board 1a and the lower wiring board 1b is sealed. Alternatively, the bonding of the upper wiring board 1a and the lower wiring board 1b and the electrical connection of the upper and lower wiring conductors 1c may be performed simultaneously using ACF or ACP.

  The electronic component 4 is an IC, a capacitor, a coil, a resistor, or the like that processes an electrical signal, and is mounted by being connected to the wiring conductor 1c by a conductive bonding material such as solder. The electronic component 4 may be mounted on the wiring board 1 after the upper wiring board 1a and the lower wiring board 1b are joined to form the wiring board 1, or on the upper wiring board 1a before joining them. May be. However, when the electronic component 4 is mounted after the upper wiring substrate 1a and the lower wiring substrate 1b are joined, the insulating substrate around the opening 2a is thin, and the space below the recess 2 is provided below the insulating substrate. Therefore, a crack may occur around the opening 2a of the wiring board 1 due to an impact when the electronic component 4 is mounted. Therefore, the electronic component 4 is mounted on the upper wiring board 1a and the imaging element is mounted on the lower wiring board 1b. After mounting 3, it is preferable to join the upper wiring board 1a and the lower wiring board 1b. Even when the electronic component 4 is mounted on the upper wiring board 1a, the same applies when the electronic component 4 is mounted on the upper wiring board 1a as in the examples shown in FIGS. 2 (b) and 2 (c). In order to suppress the occurrence of damage or the like, it is preferable that the upper wiring substrate 1a is placed on a support plate having a convex portion corresponding to the shape of the through hole of the upper wiring substrate 1a.

  Further, in the imaging apparatus as described above, as shown in FIGS. 2A, 2B, and 3A to 3C, the recess 2 is formed on the upper surface of the wiring board 1. It is preferable that the transparent plate 6 is attached so as to close the opening 2a. With such a configuration, moisture or dust does not enter the concave portion 2 and adhere to the light receiving portion 3a of the image pickup device 3, so that the image pickup device 3 can be protected and light reception is not hindered. It is possible to output an image signal with high image quality. For example, it is possible to prevent dust generated when the fixing member 8 to which the lens 7 is fixed is bonded to the upper surface of the wiring board 1 from entering the recess 2 from the opening 2a. In addition, when the electronic component 4 is mounted with solder after the upper wiring substrate 1a and the lower wiring substrate 1b are joined, if the electronic component 4 is mounted after the transparent plate 6 is mounted, the flux contained in the cream solder It is possible to prevent the solder particles from scattering and entering the concave portion 2 from the opening 2a and adhering to the light receiving portion 3a and the like of the image sensor 3.

  The transparent plate 6 is made of a resin such as crystal, glass or epoxy resin, and is bonded to the wiring substrate 1 with an adhesive such as a thermosetting type or ultraviolet curing type epoxy resin or glass. For example, an ultraviolet curable epoxy resin is applied to the periphery of the opening 2a on the upper surface of the wiring substrate 1 or the outer edge of the transparent plate 6 by a dispensing method, and the transparent plate 6 is placed on the wiring substrate 1 and irradiated with ultraviolet rays. By doing so, an adhesive agent hardens | cures, the transparent board | plate material 6 is attached, and the recessed part 2 is sealed.

A filter may be formed on the transparent plate 6. It is preferable to form the filter directly on the transparent plate 6 because the thickness of the imaging device can be reduced as compared with the case where a separately prepared filter is arranged on the transparent plate 6. As this filter, there is a low-pass filter that overlaps two or three quartz plates having different crystal orientation angles and prevents the moire phenomenon that occurs in the image captured by the imaging device 3 by utilizing the birefringence characteristics of the quartz plate. . When a crystal plate is used as the transparent plate material 6, the transparent plate material 6 can be used as one crystal plate of the low-pass filter. Also, in order to match the image pickup device 3 whose sensitivity in the red to infrared region is generally higher than that of human vision with the hue sensitivity of the human eye, light having a wavelength in the red to infrared region is used. There is also an IR (InfraRed) cut filter for cutting. The IR cut filter can be manufactured by alternately forming several tens of dielectric multilayer films on the surface of the transparent plate 6. The dielectric multilayer film is generally formed by a high refractive index dielectric layer made of a dielectric material having a refractive index of 1.7 or more and a low refractive index dielectric layer made of a dielectric material having a refractive index of 1.6 or less by an evaporation method or the like. It is formed by alternately laminating several tens of layers using a sputtering method or the like. As the dielectric material having a refractive index of 1.7 or more, for example, tantalum pentoxide, titanium oxide, niobium pentoxide, lanthanum oxide, zirconium oxide or the like is used, and as the dielectric material having a refractive index of 1.6 or less, for example, silicon oxide,
Aluminum oxide, lanthanum fluoride, magnesium fluoride or the like is used.

  In addition, the imaging module of the present invention has a lens above the opening of the wiring board 1 of the imaging device of the present invention having the above-described configuration, as shown in the cross-sectional views of FIGS. 2 (a) to 2 (c). 7 is arranged. With such a configuration, an imaging module capable of outputting a small, thin and high-quality image signal is obtained. The lens 7 is made of glass, resin such as epoxy resin, acrylic resin, or the like, and is attached to the lens fixing member 8 so that light transmitted through the lens 7 through the opening of the lens fixing member 8 is efficiently transmitted to the light receiving unit 3a. Can be incident. The lens fixing member 8 is made of resin, metal, or the like, and is fixed to the upper surface of the wiring board 1 with an adhesive such as epoxy resin or solder, as in the example shown in FIGS. 2 (a) to 2 (c). Alternatively, the lens fixing member 8 is fixed to the wiring board 1 by a flange provided in advance.

  Note that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention. For example, as in the example shown in the cross-sectional view of FIG. 3C, the opening 2a may have an inclined side surface so that the upper side becomes smaller. With such an opening 2a, it becomes easy to allow external light to enter the light receiving portion 3a of the image sensor 3 satisfactorily. A plurality of (double or triple) annular steps or annular irregularities that mesh with each other may surround the opening 2a in plan view. In this case, intrusion of light from the joint can be prevented more reliably.

DESCRIPTION OF SYMBOLS 1 ... Wiring board 1a ... Upper wiring board 1b ... Lower wiring board 1c ... Wiring conductor 1d ... Convex part 1e ... Second recessed part 2 ... Concave part 2a ... Opening 3 ... Image sensor 3a ... Light receiving part 4 ... Electronic component 5 ... Connection member 6 ... Transparent plate 7 ... Lens 8 ... Lens fixing member

Claims (4)

An imaging device in which an imaging element is mounted with a light receiving portion facing up on a bottom surface of a recess formed on an upper surface of a wiring board,
The concave portion has an opening smaller than the bottom surface of the concave portion in a size that exposes the light receiving portion of the imaging element in a top view.
The wiring substrate is formed by bonding the lower surface of the upper wiring substrate having the opening and the upper surface of the lower wiring substrate having the bottom surface of the recess,
Electronic components are mounted on the outer surface of the upper surface of the upper wiring board and outside the area around which the lens fixing member is mounted ,
The imaging apparatus according to claim 1, wherein the electronic component overlaps a bonding region between the upper wiring board and the lower wiring board in a top perspective view .   The imaging apparatus according to claim 1, wherein a transparent plate is attached so as to close the opening of the recess. Claim 1 or, characterized in that the previous SL upper wiring board and annular step or annular uneven interdigitated so as to surround the opening in plan view in at least one of the bonding surfaces of the lower wiring board is formed The imaging device according to claim 2.   4. The imaging device according to claim 1, wherein a lens is disposed above the opening of the wiring board, and the lens fixing member that fixes the lens is an upper surface of the wiring board. The imaging module is mounted in a region between the opening and the electronic component.

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