Imaging apparatus and camera

Abstract

To provide an imaging apparatus capable of reducing a dark current which is generated by heat.SOLUTION: An imaging apparatus 100 comprises: an imaging section in which a first pixel outputting a first pixel signal generated by charge on which photoelectric conversion is performed and a second pixel outputting a second pixel signal generated by charge on which photoelectric conversion is performed are disposed; an imaging chip 101 including a first peripheral part formed outside of the imaging section and a second peripheral part formed outside of the imaging section; a first signal processing chip 121, which is a chip laminated on the imaging chip in the first peripheral part, including a first processing circuit for performing signal processing on the first pixel signal outputted from the first pixel; and a second signal processing chip 121, which is a chip laminated on the imaging chip in the second peripheral part, including a second processing circuit for performing signal processing on the second pixel signal outputted from the second pixel. The first signal processing chip and the second signal processing chip are disposed inside of the outer edge of the imaging chip while being separated from each other.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an imaging device and a camera.

Background Art

[0002] A semiconductor module in which a MOS image sensor chip and a signal processing chip are stacked is known. [Prior Art Document] [Patent Document] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-49361

Summary of the Invention

Problems to be Solved by the Invention

[0003] The signal processing chip has a processing circuit that processes the pixel signals output from the imaging chip. This processing circuit generates heat during operation. The heat generated in the processing circuit may concentrate on the imaging area of the imaging chip. Then, in the imaging area, the dark current increases due to the heat generated in the processing circuit. As a result, the image quality deteriorates.

Means for Solving the Problems

[0004] The imaging device according to the first aspect of the present invention includes an imaging unit in which a first pixel that outputs a first pixel signal generated by charges subjected to photoelectric conversion and a second pixel that outputs a second pixel signal generated by charges subjected to photoelectric conversion are arranged, a first peripheral portion formed outside the imaging unit, and a second peripheral portion formed outside the imaging unit, an imaging chip having the first peripheral portion and the second peripheral portion, a first signal processing chip that is a chip stacked on the imaging chip in the first peripheral portion and has a first processing circuit that performs signal processing on the first pixel signal output from the first pixel, and a second signal processing chip that is a chip stacked on the imaging chip in the second peripheral portion and has a second processing circuit that performs signal processing on the second pixel signal output from the second pixel, and the first signal processing chip and the second signal processing chip are arranged separately from each other inside the outer edge of the imaging chip.

[0005] The camera in the second aspect of the present invention includes the above imaging device.

[0006] Note that the above summary of the invention does not list all the necessary features of the present invention. Also, sub - combinations of these feature groups can also be inventions.

Brief Description of the Drawings

[0007]

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Embodiments for Carrying Out the Invention

[0008] Hereinafter, the present invention will be described through embodiments of the invention. However, the following embodiments do not limit the invention claimed in the claims. Also, not all combinations of features described in the embodiments are essential for the solution of the invention.

[0009] FIG. 1 is a schematic perspective view of the imaging device according to the present embodiment. The imaging device 100 includes an imaging chip 101, a cover glass 111 as an optical element, a signal processing chip 121, and a flexible substrate 141. In FIG. 1, for the purpose of simplifying the drawing, bumps between the imaging chip 101 and the signal processing chip 121, bumps between the signal processing chip 121 and the flexible substrate 141, etc. are omitted. Also, in order to make the adhesive layer 131 described later easier to see, the same hatching as in FIG. 2 is applied. In FIG. 1, the direction in which the subject light beam enters the imaging chip 101 is defined as the z-axis direction. The longitudinal direction of the imaging chip 101 is the x-axis direction, and the short-side direction is the y-axis direction. The positive x-axis direction is the right direction on the paper surface, and the negative x-axis direction is the left direction on the paper surface.

[0010] The imaging chip 101 has an imaging region on the first surface side, which is the surface on which the subject light beam enters. In this specification, the region facing the imaging region on the second surface, which is the surface opposite to the light-receiving surface of the imaging chip 101, is referred to as the facing region 110.

[0011] The signal processing chip 121 is laminated on the second surface side of the imaging chip 101. The signal processing chip 121 has a processing circuit that processes the pixel signals output from the imaging chip 101. The sizes of the imaging chip 101 and the signal processing chip 121 are different from each other. Here, the width of the signal processing chip 121 in the y-axis direction is substantially the same as the width of the imaging chip 101 in the y-axis direction. On the other hand, the width of the signal processing chip 121 in the x-axis direction is about 1 / 3 of the width of the imaging chip 101 in the x-axis direction.

[0012] The number of signal processing chips is appropriately determined according to the method of reading pixel signals. In this embodiment, two-channel reading is adopted as the method of reading pixel signals. Therefore, in this embodiment, the number of signal processing chips is two. One of the two signal processing chips 121 is arranged along the left end of the imaging chip 101, and the other is arranged along the right end of the imaging chip 101. The two signal processing chips 121 are arranged without protruding in the x-axis direction and the y-axis direction from the outer edge of the second surface of the imaging chip 101. Thereby, the imaging device 100 can be miniaturized in the x-axis direction and the y-axis direction.

[0013] The two signal processing chips 121 are arranged at intervals in the x-axis direction. Therefore, both of the two signal processing chips 121 only cover a part of the opposing region 110. In other words, the opposing region 110 has a portion that is not covered by the signal processing chip 121.

[0014] Here, if the entire opposing region 110 is covered by the signal processing chip 121, the heat generated in the processing circuit may concentrate in the imaging region. When heat concentrates in the imaging region, the dark current caused by the heat increases. As a result, the image quality deteriorates.

[0015] According to the imaging device 100 of this embodiment, the two signal processing chips 121 are arranged close to the left and right ends of the imaging chip 101 while avoiding the central portion of the opposing region 110. That is, a space is formed between the two signal processing chips 121. According to this configuration, part of the heat generated in the processing circuit of the signal processing chip 121 can be radiated to the space. Therefore, the retention of heat in the imaging region can be reduced. As a result, in the imaging region, the dark current generated due to heat can be reduced.

[0016] The signal processing chip 121 is connected to a flexible substrate 141 as a flexible substrate. The flexible substrate 141 is connected to an external circuit. The flexible substrate 141 is connected to the surface opposite to the third surface, which is the surface on the imaging chip 101 side, of the signal processing chip 121.

[0017] The adhesive layer 131 is formed at the outer edge of the surface of the imaging chip 101 where the subject light beam is incident. The adhesive layer 131 is formed so as to surround the imaging region. The adhesive layer 131 adheres the imaging chip 101 and the cover glass 111.

[0018] FIG. 2 is a schematic cross-sectional view of the imaging device. Specifically, it is a schematic cross-sectional view of the xz plane passing through the center of the imaging chip 101.

[0019] The imaging chip 101 is a surface-illuminated MOS image sensor. In addition to the imaging region 102 described above, the imaging chip 101 has a circuit pattern 103, a through electrode 104, and an electrode pad 105.

[0020] The imaging region 102 is formed in the central portion of the imaging chip 101. A plurality of pixels for photoelectrically converting the received subject image are arranged in the imaging region 102.

[0021] The circuit pattern 103, the through electrode 104, and the electrode pad 105 are formed in the peripheral region shifted to the right and the peripheral region shifted to the left from the outer edge of the imaging region 102, respectively. The electrode pad 105 is formed on the second surface of the imaging chip 101. The circuit pattern 103 and the electrode pad 105 are electrically connected via the through electrode 104. The circuit pattern 103 outputs the pixel signal read from the pixel to the through electrode 104. The through electrode 104 outputs the pixel signal output from the circuit pattern 103 to the electrode pad 105. The electrode pad 105 functions as an output unit that outputs the pixel signal to the electrode pad 125 described later.

[0022] In addition to the processing circuit described above, the signal processing chip 121 has a through electrode 124, an electrode pad 125, and an electrode pad 126. The electrode pad 125 is formed on the third surface of the signal processing chip 121. On the other hand, the electrode pad 126 is formed on the surface of the signal processing chip 121 on the flexible substrate 141 side. The electrode pad 125 and the electrode pad 126 are electrically connected via the through electrode 124. The through electrode 124 outputs the pixel signal processed by the processing circuit to the flexible substrate 141.

[0023] The electrode pad 125 of the signal processing chip 121 is electrically connected to the electrode pad 105 of the imaging chip 101 via the bump 132. The electrode pad 125 functions as an input unit that inputs the pixel signal output from the output unit. Note that the bump 132 intervening between the electrode pad 105 and the electrode pad 125 can also be regarded as an output unit or an input unit. The imaging chip 101 and the signal processing chip 121 are adhered by an adhesive 133.

[0024] The flexible substrate 141 has an electrode pad 144. The electrode pad 144 is electrically connected to the electrode pad 126 of the signal processing chip 121 via the bump 134. The connection portion between the electrode pad 144 and the electrode pad 126 is adhered by an adhesive 135. The flexible substrate 141 outputs the pixel signal received via the through electrode 124 of the signal processing chip 121 to an external circuit.

[0025] The cover glass 111 is formed of borosilicate glass, quartz glass, non-alkali glass, heat-resistant glass, etc. The cover glass 111 is disposed on the adhesive layer 131 facing the imaging region 102 and is adhered to the imaging chip 101 via the adhesive layer 131. The adhesive layer 131 is interposed between the imaging chip 101 and the cover glass 111 and is formed so as to surround the imaging region 102. As the material of the adhesive layer 131, a thermosetting adhesive or the like can be used. The cover glass 111 seals the imaging region 102 while being separated from the imaging chip 101 by the thickness of the adhesive layer 131.

[0026] FIG. 3 is a block diagram showing the configuration of the camera according to the present embodiment. The camera 150 includes a photographing lens 420 as a photographing optical system, and the photographing lens 420 guides a subject light beam incident along the optical axis OA to the imaging device 100. The photographing lens 420 may be an interchangeable lens that can be attached to and detached from the camera 150. The camera 150 mainly includes an imaging device 100, a system control unit 401, a work memory 404, a recording unit 405, and a display unit 406.

[0027] The photographing lens 420 is composed of a plurality of optical lens groups and forms an image of a subject light beam from a scene in the vicinity of its focal plane. Note that in FIG. 3, it is represented by a virtual single lens disposed near the pupil. The system control unit 401 executes charge accumulation control such as timing control and area control of the imaging device 100.

[0028] The imaging device 100 delivers a pixel signal to the image processing unit 411 of the system control unit 401. The image processing unit 411 performs various image processes using the work memory 404 as a work space to generate image data. For example, when generating image data in the JPEG file format, compression processing is executed after performing white balance processing, gamma processing, etc. The generated image data is recorded in the recording unit 405 and is also converted into a display signal and displayed on the display unit 406.

[0029] In the above description, the imaging device 100 is configured to include a flexible substrate 141 as a connection member to an external circuit, but it may be configured to include other connection members. FIG. 4 is a schematic cross-sectional view of the imaging device of Modification 1.

[0030] The imaging device 200 includes a wiring board 151 which is a rigid board instead of a flexible board. The imaging device 200 outputs pixel signals to an external circuit via the wiring board 151. As the wiring board 151, a ceramic board, a glass epoxy board, etc. can be used. In the imaging device 200, the through electrodes 124 of the signal processing chip 121 output pixel signals processed by the processing circuit to the wiring board 151. The wiring board 151 has electrode pads 152. The electrode pads 152 are electrically connected to the electrode pads 126 of the signal processing chip 121 via bumps 134. The wiring board 151 is fixed to the surface opposite to the third surface of the signal processing chip 121 via an adhesive 135. Thus, the wiring board 151 is arranged adjacent to the signal processing chip 121 and electrically connected thereto.

[0031] The configuration using the wiring board 151 as a connection member to an external circuit is not limited to the configuration shown in FIG. 4. FIG. 5 is a schematic cross-sectional view of the imaging device of Modification 2. The imaging device 300 includes an annular member 161 having a square annular shape. The annular member 161 is arranged on the wiring board 151 and surrounds the imaging chip 101. The annular member 161 is formed of a metal such as aluminum, brass, iron, nickel alloy, etc. A resin can also be used as the material of the annular member 161, or a material in which a metal and a resin are insert-molded can also be used. Although details will be described later, when emphasis is placed on enhancing the sealing performance of the imaging device 300, it is preferable to use a metal as the material of the annular member 161. The cover glass 111 is arranged on the annular member 161 and adhered by an adhesive layer 131.

[0032] If dust, foreign matter, etc. adhere to the cover glass 111 or the cover glass 111 is scratched, there is a risk that they will be reflected in the captured image. By interposing the surrounding member 161 between the wiring board 151 and the cover glass 111 and increasing the distance between the imaging chip 101 and the cover glass 111, the influence of reflection can be reduced. In addition, it becomes difficult for stray light due to reflection from the end face of the cover glass 111 to reach the imaging region 102. By using the surrounding member 161, the distance between the imaging chip 101 and the cover glass 111 can be increased, while the thickness of the imaging device 300 in the z-axis direction becomes larger than when the surrounding member 161 is not used. The thickness of the surrounding member 161 is appropriately adjusted from the viewpoints of reducing reflection and miniaturizing the imaging device 100.

[0033] A sealed space is formed by the cover glass 111, the wiring board 151, and the surrounding member 161. The imaging chip 101 is disposed in the sealed space. Here, if moisture and gas in the external environment enter the inside of the imaging device 300, the imaging performance of the imaging chip 101 deteriorates. Specifically, when moisture in the external environment enters the sealed space, dew condensation occurs on the imaging chip 101 and the cover glass 111 due to the temperature difference between the inside and outside of the sealed space. If mold grows due to dew condensation and condensation, the optical image to be imaged is distorted, so the noise increases. On the other hand, when gas in the external environment enters the sealed space, oxidation and corrosion of the circuit inside the imaging chip 101 are promoted, leading to the destruction of the imaging chip 101. By disposing the imaging chip 101 in the sealed space, the imaging chip 101 is less likely to be affected by moisture and gas in the external environment, so an increase in noise can be suppressed and destruction of the imaging chip 101 can be avoided.

[0034] Another configuration using the wiring board 151 as a connection member to an external circuit will be described. FIG. 6 is a schematic cross-sectional view of the imaging device according to Modification 3.

[0035] The imaging device 400 includes electrode pads 106 on the surface of the imaging chip 101. The electrode pads 106 are electrically connected to the electrode pads 105 via the through electrodes 104. The wiring board 151 includes electrode pads 152. The electrode pads 152 are electrically connected to the electrode pads 106 via wire bonding 171.

[0036] According to the configuration of the imaging device 400, the pixel signal read from the pixel is once output to the signal processing chip 121 via the through electrode 104. After the pixel signal is processed by the processing circuit of the signal processing chip 121, it is output to the imaging chip 101 again. Then, it is output to the wiring board 151 via the wire bonding 171.

[0037] In the imaging device 200 shown in FIG. 4 and the imaging device 300 shown in FIG. 5, the signal processing chip 121 was configured to be electrically connected to the wiring board 151. For this reason, the signal processing chip 121 included the through electrode 124 for outputting the pixel signal to the wiring board 151. On the other hand, according to the configuration of the imaging device 400, since the signal processing chip 121 does not include the through electrode 124, it is advantageous from the viewpoints of the manufacturing process and the manufacturing cost.

[0038] The configuration in which the through electrode is not formed on the signal processing chip 121 is not limited to the configuration shown in FIG. 6. FIG. 7 is a schematic cross-sectional view of the imaging device of Modification 4.

[0039] The wiring board 151 of the imaging device 500 has convex land portions 153 protruding toward the region (i.e., the opposing region) opposing the imaging region 102 on the second surface. The land portions 153 are formed in the central portion of the wiring board 151 avoiding the region where the signal processing chip 121 is disposed. The land portions 153 function as heat dissipation members for releasing the heat generated in the imaging chip 101. That is, it can be said that the land portions 153 are heat dissipation members that contact the opposing region. Thus, in the imaging device 500, the heat dissipation member is disposed in the space between the two signal processing chips 121. When emphasizing the heat dissipation characteristics, the larger the adhesion surface between the land portion 153 and the imaging chip 101, the better.

[0040] On the one hand, the linear expansion coefficient of the imaging chip 101 and that of the wiring board 151 are different from each other. Therefore, when the imaging chip 101 and the wiring board 151 are joined and then heated or cooled, warping occurs in them. This is due to the fact that the amount of expansion or contraction due to heating or cooling is different between the imaging chip 101 and the wiring board 151. When emphasizing prevention of warping, the smaller the adhesion surface between the land portion 153 and the imaging chip 101, the better.

[0041] The wiring board 151 is fixed to the imaging chip 101 by an adhesive 136 via the land portion 153. It is preferable to use an elastic adhesive as the adhesive 136. As the elastic adhesive, an acrylic resin, a silicone resin, an epoxy resin, etc. can be used. By using an elastic adhesive as the adhesive 136, when the imaging chip 101 and the wiring board 151 are joined and then heated or cooled, the stress caused by the difference in the linear expansion coefficients of the imaging chip 101 and the wiring board 151 can be absorbed.

[0042] The wiring board 151 and the signal processing chip 121 are in contact via a heat dissipation medium 137. The heat dissipation medium 137 is, for example, silicone grease. The wiring board 151 and the signal processing chip 121 are thermally connected by the heat dissipation medium 137. Thereby, the heat generated in the processing circuit of the signal processing chip 121 can be dissipated to the wiring board 151. Therefore, the heat dissipated from the processing circuit to the imaging chip 101 side can be reduced.

[0043] FIG. 8 is a schematic cross-sectional view of the imaging device of Modification 5. The wiring board 151 of the imaging device 600 has an opening 155 corresponding to the imaging region 102 and is fixed to the light receiving surface side of the imaging chip 101. The cover glass 111 covers the opening 155 and is adhered to the wiring board 151 by an adhesive layer 131.

[0044] The wiring board 151 has electrode pads 154. The electrode pads 154 are electrically connected to the electrode pads 106 of the imaging chip 101 via bumps 138. The connection portion between the electrode pads 154 and the electrode pads 106 is adhered by an adhesive 139. The adhesive 139 is formed so as to surround the imaging region 102.

[0045] In the configuration of the imaging device shown in FIGS. 4 to 7, the wiring board 151 is disposed on the surface opposite to the third surface of the signal processing chip 121. On the contrary, according to the configuration of the imaging device 600, the wiring board 151 is disposed on the light receiving surface side of the imaging chip 101. Therefore, the distance between the imaging chip 101 and the cover glass 111 can be increased as compared with the case where the cover glass 111 is disposed on the imaging chip 101 without using the above-described surrounding member.

[0046] In the above description, the two signal processing chips 121 are disposed without protruding in the x-axis direction and the y-axis direction from the outer edge of the imaging chip 101, but may be disposed so as to protrude from the outer edge of the imaging chip 101. FIG. 9 is a schematic cross-sectional view of the imaging device according to Modification 6.

[0047] The signal processing chip 121 of the imaging device 700 is provided with electrode pads 127 on the third surface. The electrode pads 127 are formed in a portion of the signal processing chip 121 that protrudes in the x-axis direction from the outer edge of the imaging chip 101. According to this configuration, the electrode pads 127 can be formed on the third surface. Therefore, it is not necessary to form electrode pads on the surface opposite to the third surface and to form through electrodes for electrically connecting the electrode pads. The electrode pads 127 are electrically connected to the electrode pads 145 of the flexible substrate 141 via bumps 140. The connection portion between the electrode pads 127 and the electrode pads 145 is adhered by an adhesive 135.

[0048] By disposing the signal processing chip 121 so as to protrude in the x-axis direction from the outer edge of the imaging chip 101, it can be stacked on the imaging chip 101 while completely avoiding the facing region. As a result, the heat generated in the processing circuit is more difficult to radiate to the imaging region 102.

[0049] Even when two signal processing chips 121 are arranged so as to protrude in the x-axis direction from the outer edge of the imaging chip 101, the various configurations described above can be adopted. FIG. 10 is a schematic cross-sectional view of the imaging device of Modification 7. The imaging device 800 includes a wiring board 151 as a connection member and an ambient member 161 in addition to the imaging chip 101, the signal processing chip 121, and the cover glass 111. The electrode pads 127 of the signal processing chip 121 are electrically connected to the electrode pads 152 of the wiring board 151 via wire bonding 171. Therefore, according to this configuration, the pixel signal output to the signal processing chip 121 can be output to the wiring board 151 without being output to the imaging chip 101 again. Further, as described above, since the imaging chip 101 is less likely to be affected by moisture and gas in the external environment due to the ambient member 161, an increase in noise can be suppressed and destruction of the imaging chip 101 can be avoided.

[0050] FIG. 11 is a schematic cross-sectional view of the imaging device of Modification 8. The wiring board 151 of the imaging device 900 includes convex land portions 153 that protrude toward the opposing region. The wiring board 151 is fixed to the imaging chip 101 by an adhesive 136 via the land portions 153. Thereby, the heat generated in the imaging chip 101 can be dissipated. Thus, in the imaging device 900, a heat dissipation member is arranged in the space between the two signal processing chips 121. Further, by using an elastic adhesive as the adhesive 136, the stress caused by the difference in the linear expansion coefficients of the imaging chip 101 and the wiring board 151 can be absorbed. The wiring board 151 and the signal processing chip 121 are in contact with each other via a heat dissipation medium 137. Thereby, the heat generated in the processing circuit of the signal processing chip 121 can be dissipated to the wiring board 151.

[0051] FIG. 12 is a schematic cross-sectional view of the imaging device. The wiring board 151 of the imaging device 1000 has an opening 155 corresponding to the imaging chip 101. The imaging chip 101 is housed in the opening 155 of the wiring board 151. The wiring board 151 is fixed to the third surface of the signal processing chip 121. The electrode pads 127 of the signal processing chip 121 are electrically connected to the electrode pads 156 of the wiring board 151 via the bumps 140. The connection portion between the electrode pad 127 and the electrode pad 156 is adhered by the adhesive 135.

[0052] FIG. 13 is a schematic cross-sectional view of the imaging device. The signal processing chip 121 on the left side of the imaging device 1100 is arranged to enter from the left end of the imaging chip 101 in the +x-axis direction. On the other hand, the signal processing chip 121 on the right side is arranged to enter from the right end of the imaging chip 101 in the -x-axis direction. The flexible board 141 is arranged in the space generated by the displacement of the signal processing chip 121 from the end of the imaging chip 101. Thus, the flexible board 141 may be electrically connected to the imaging chip 101 instead of the signal processing chip 121. According to the configuration of the imaging device 1100, it can be miniaturized in the x-axis direction compared to the imaging device 700 shown in FIG. 9.

[0053] FIG. 14 is a schematic cross-sectional view of the imaging device. The land portion 153 of the wiring board 151 of the imaging device 1200 is formed at the outer edge portion of the wiring board 151. The wiring board 151 has electrode pads 157 on the land portion 153. The electrode pads 157 are electrically connected to the electrode pads 107 of the imaging chip 101 via the bumps 140. Thus, the land portion 153 of the wiring board 151 may be formed outside the central portion of the wiring board 151.

[0054] FIG. 15 is a schematic cross-sectional view of the imaging device. The wiring board 151 of the imaging device 1300 has an opening 155 corresponding to the signal processing chip 121. The signal processing chip 121 is housed in the opening 155 of the wiring board 151. The electrode pads 157 of the wiring board 151 are electrically connected to the electrode pads 107 of the imaging chip 101 via the bumps 140. In this way, when the wiring board 151 and the imaging chip 101 are electrically connected by bump bonding, the wiring board 151 can also be arranged on the surface opposite to the light receiving surface of the imaging chip 101.

[0055] In the above description, the land portion 153 of the wiring board 151 that functions as a heat dissipation member was adhered to the imaging chip 101. The heat dissipation member may be adhered to the signal processing chip 121. FIG. 16 is a schematic cross-sectional view of the imaging device. The imaging device 1400 has a heat dissipation member 181. The heat dissipation member 181 is in contact with the signal processing chip 121 via the heat dissipation medium 137. Thereby, the heat generated in the signal processing chip 121 is dissipated through the heat dissipation member 181. Therefore, the heat dissipated to the imaging chip 101 side can be reduced. As a result, the dark current generated by the heat generated in the signal processing chip 121 can be reduced. The heat dissipation member 181 is preferably fin-shaped. Thereby, since the heat dissipation area of the heat dissipation member 181 becomes large, the heat dissipation characteristics can be further enhanced.

[0056] FIG. 17 is a schematic cross-sectional view of the imaging device. The flexible board 141 of the imaging device 1500 has a structure sandwiched between the imaging chip 101 and the signal processing chip 121. The thicknesses of the bumps 134 and 132 are different from each other. Specifically, the thickness of the bump 132 is thicker than the thickness of the bump 134 by the thickness of the flexible board 141. By devising the thickness of the bump in this way, a structure in which the flexible board 141 is sandwiched between the imaging chip 101 and the signal processing chip 121 can be realized.

[0057] The imaging chip 101 may be a back-illuminated MOS image sensor. In this case, in the imaging chip 101, a plurality of pixels are arranged on the incident side of the subject image with respect to a wiring layer including wiring for outputting pixel signals to through electrodes. In the case of the back-illuminated imaging chip 101, since the imaging chip is polished, its thickness becomes thinner than that of a front-illuminated imaging chip. Therefore, a support substrate may be bonded to the surface of the imaging chip opposite to the light receiving surface, and a signal processing chip may be arranged on the support substrate. In this case, it is preferable to form through electrodes on the support substrate. Thereby, the imaging chip and the signal processing chip can be electrically connected via the through electrodes of the support substrate.

[0058] The pixel signals of the imaging chip 101 may be transmitted to the signal processing chip 121 by wireless communication using electromagnetic coupling. In this case, each of the imaging chip 101 and the signal processing chip 121 has a coil formed to face each other.

[0059] In the above description, the land portion 153 of the wiring board 151 functions as a heat dissipation member that releases the heat generated in the imaging chip 101, but the wiring board 151 and the heat dissipation member do not have to be integrally formed. Also, heat dissipation members may be individually arranged for each of the imaging chip 101 and the signal processing chip 121.

[0060] In the above description, the number of signal processing chips 121 is two, but it may be one. Also, the number of signal processing chips 121 may be three or more. In the above description, the cover glass 111 is used as the optical element, but a low-pass filter, an IR cut filter, etc. may be used instead of the cover glass 111.

[0061] As described above, the present invention has been described using embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments. It is obvious to those skilled in the art that various changes or improvements can be made to the above embodiments. It is clear from the description of the claims that forms with such changes or improvements can also be included in the technical scope of the present invention.

Description of Symbols

[0062] 100 Imaging device, 200 Imaging device, 300 Imaging device, 400 Imaging device, 500 Imaging device, 600 Imaging device, 700 Imaging device, 800 Imaging device, 900 Imaging device, 1000 Imaging device, 1100 Imaging device, 1200 Imaging device, 1300 Imaging device, 1400 Imaging device, 1500 Imaging device, 101 Imaging chip, 102 Imaging area, 103 Circuit pattern, 104 Through electrode, 105 Electrode pad, 106 Electrode pad, 107 Electrode pad, 110 Opposing area, 111 Cover glass, 121 Signal processing chip, 124 Through electrode, 125 Electrode pad, 126 Electrode pad, 127 Electrode pad, 131 Adhesive layer, 132 Bump, 133 Adhesive, 134 Bump, 135 Adhesive, 136 Adhesive, 137 Heat dissipation medium, 138 Bump, 139 Adhesive, 140 Bump, 141 Flexible substrate, 144 Electrode pad, 145 Electrode pad, 150 Camera, 151 Wiring substrate, 152 Electrode pad, 153 Land portion, 154 Electrode pad, 155 Opening, 156 Electrode pad, 157 Electrode pad, 161 Surrounding member, 171 Wire bonding, 181 Heat dissipation member, 401 System control unit, 404 Work memory, 405 Recording unit, 406 Display unit, 411 Image processing unit, 420 Photographing lens

Claims

【Claim 1】 An imaging unit including a rectangular imaging region in which a first pixel that outputs a first pixel signal generated by charges photoelectrically converted and a second pixel that outputs a second pixel signal generated by charges photoelectrically converted are arranged; a first peripheral portion formed outside the imaging unit; a second peripheral portion formed outside the imaging unit; and a wiring layer including a wiring through which the first pixel signal is output and a wiring through which the second pixel signal is output, an imaging chip having: a first signal processing chip, which is a rectangular chip laminated on the imaging chip in the first peripheral portion and has a first processing circuit that performs signal processing on the first pixel signal output from the first pixel; a second signal processing chip, which is a rectangular chip laminated on the imaging chip in the second peripheral portion and has a second processing circuit that performs signal processing on the second pixel signal output from the second pixel; comprising: the imaging chip has a first surface on which light is incident and a second surface opposite to the first surface; the first pixel and the second pixel are arranged on the first surface side with respect to the wiring layer; the long side of the first signal processing chip is longer than the short side of the imaging region; the long side of the second signal processing chip is longer than the short side of the imaging region; the first signal processing chip and the second signal processing chip are arranged separately from each other inside the outer edge of the imaging chip; an imaging device.

Images