JP2013201568A - Imaging module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging module capable of obtaining an image of high image quality with less noise.SOLUTION: An imaging module comprises: an image chip that has a first portion including a photoelectric conversion unit having a plurality of pixels which are arranged in a two-dimensional matrix form and photoelectrically convert received light, and a second portion including a column scanning circuit which scans one direction of the photoelectric conversion unit; a first heat conductive member that conducts heat of the first portion; and a second heat conductive member that conducts heat of the second portion. A space is provided between the first heat conductive member and the second heat conductive member.

Description

  The present invention relates to an imaging module capable of outputting, for example, an electrical signal after photoelectric conversion from a plurality of pixels for imaging as image information.

  2. Description of the Related Art In recent years, high-definition and high frame rates have been advanced in moving image shooting in an imaging module such as a video camera. In addition, the image pickup device (image chip) in the image pickup module also includes a parallel A / D converter and a digital signal processing unit for reading out at higher speed, and the heat generation of the image pickup device due to the progress of higher integration. The amount is increasing. Since the noise increases due to the heat noise caused by the heat generation and the image quality of the acquired image decreases, higher heat dissipation performance is required from the viewpoint of suppressing the noise.

  FIG. 14 is a configuration diagram of a conventional basic CMOS image sensor shown as an example of an image sensor. In the CMOS image sensor, the light received in the previous stage is photoelectrically converted, and the processing unit of the photoelectrically converted signal is mounted on the same chip by the subsequent digital circuit. Actually, it has only been put into practical use in recent years due to problems such as digital noise and heat generation adversely affecting the photoelectric conversion unit and analog circuit during mixed mounting.

  The CMOS image sensor shown in FIG. 14 photoelectrically converts light from an optical system and outputs an electrical signal as image information, and stores a charge corresponding to the amount of light and a charge stored in the photodiode into a voltage. A plurality of pixels P100 each having a circuit for output in a two-dimensional matrix, and an electrical signal generated by a pixel arbitrarily set as a reading target among the plurality of pixels of the light receiving unit. As a readout section (vertical scanning circuit VC100 (row selection circuit) and horizontal scanning circuit HC100 (column selection circuit)). The vertical scanning circuit VC100 and the horizontal scanning circuit HC100 are connected to each pixel P100, and are circuits for controlling the pixel to be read.

  In the CMOS image sensor, by selecting a row (m) by a row selection pulse from the vertical scanning circuit VC100 (row selection circuit), a signal in which the charges of the pixels in the selected row are converted into a voltage is output. In response to a column selection pulse from the horizontal scanning circuit HC100 (column selection circuit), the readout gates of the columns selected in accordance with the column (n) number are opened to sequentially output pixel signals. For example, m = 1 is selected as the row, and the pixel signals are output to the pixels in each column in the order of the column (n). Thereafter, pixel signals are output from the pixels in each column for the selected row (m = 2,..., M).

  FIG. 15 is a diagram showing an example of a specific configuration of a conventional CMOS image sensor. A conventional CMOS image sensor includes a photoelectric conversion unit 110 having the above-described pixel P100 and a vertical scanning circuit VC100, and analog / digital conversion (A / D conversion) of a signal output from the photoelectric conversion unit 110. And a digital signal processing unit 111 for performing predetermined signal processing. In the pixel P100, for example, a photodiode PD that photoelectrically converts incident light into a signal charge amount corresponding to the amount of light, and a horizontal line that includes this unit pixel is selected as a line (row) to be read. And a selection transistor S-TR that is ON-controlled and outputs a change in voltage level due to the signal charge accumulated in the photodiode PD to a predetermined signal line.

  The column parallel A / D conversion circuit HC100a compares the signal level of each pixel (column) in the readout row with the voltage of the ramp pulse that is sequentially D / A converted in synchronization with the conversion clock, and the conversion clock until the signals match. The number is counted and converted as the gradation level of the digital image signal of the image signal. When the number of gradations required for the image signal level from black to white is larger than the number of horizontal pixels of the image sensor, the analog-to-digital conversion clock frequency is set to the clock of the readout unit by configuring in parallel. A solid-state imaging device capable of high-speed digital readout with one chip has been realized by increasing the speed at a driving frequency equal to or higher than the driving frequency. Further, the digital signal processing unit 111 is a signal that performs predetermined processing on the digital readout unit 111a including the horizontal scanning circuit HC100 and the column parallel A / D conversion circuit HC100a described above, and the signal output from the digital readout unit 111a. And a processing unit 111b. The signal processing unit 111b is provided around the effective pixel area, and is an image signal using, for example, a noise correction pixel and an OB value level of an optical black (OB) area that is a shaded pixel area. OB level correction unit (OBC101) for correcting the black level of the image, white balance correction unit (WB102) for correcting the white balance, pixel defect correction unit (DPC103) for correcting the pixel defect, and scaling unit (SCL104) for scaling the image ), A signal output unit (OIF 105) for outputting a signal to the outside, a timing control circuit C100 for controlling these operation timings, and the like.

  However, in a solid-state imaging device incorporating these digital signal processing functions (digital signal processing unit 111), the problem of heat generation has not been sufficiently solved in continuous image acquisition such as moving image acquisition. Here, regarding the distribution of power consumption in the image sensor, the photoelectric conversion unit 110 described above has low power consumption, and the digital signal processing unit 111 including the high-speed signal processing part has high power consumption. That is, the heat generation amount of the photoelectric conversion unit 110 is small, and the heat generation amount of the digital signal processing unit 111 including the high-speed signal processing part is large.

  Here, for high integration of the image sensor, a technique is disclosed in which a plurality of A / D conversion units for reading out digital signals at high speed are provided in parallel (see, for example, Patent Documents 1 and 2). Patent Documents 1 and 2 disclose that conversion is performed by an A / D converter capable of high-speed processing, and the converted digital signal is temporarily stored and read. Conventionally, for example, heat is transmitted to the outside of the apparatus by a member having a small thermal resistance, and heat is radiated by providing a radiation fin or the like in order to lower the thermal resistance of the spatial heat radiation.

  In the technology of transferring heat to the outside of the apparatus with a member having a small thermal resistance, for example, as one of the heat dissipation techniques for efficiently transferring the heat generated by the imaging device to the outside of the package, heat conduction is performed directly from the back surface of the semiconductor chip of the imaging device with a metal body A technique is disclosed (for example, see Patent Document 3). If the technology of Patent Document 3 is used, the heat generated by the image sensor can be transmitted to the outside of the package even in a configuration in which an A / D conversion circuit that performs parallel operation and a subsequent digital signal processing circuit are mounted on the same chip. Is easy to imagine.

  In addition, a technique related to heat insulation with a drive system that drives an image sensor and a high heat generating portion of a signal processing system after reading is disclosed (for example, see Patent Document 4). In patent document 4, the dark current which generate | occur | produces in a photoelectric conversion part is reduced by vacating space or heat-insulating so that the heat which generate | occur | produced in the signal processing system may not be transmitted to the light-receiving part side. When the signal processing system and the image sensor are separated as in the technique shown in Patent Document 4, the image sensor is arranged by being separated from each other or by performing thermal insulation with a heat insulating member. Heat conduction was avoided.

Japanese Patent No. 4107269 Japanese Patent No. 4453761 Japanese Patent No. 4705125 Japanese Patent No. 474182

  By the way, with the recent high integration of the circuits built in the image sensor, the amount of heat generation increases especially in continuous frame reading for moving image applications, and the efficiency of cooling and heat dissipation is required.

  Here, in addition to the techniques disclosed in Patent Documents 1 and 2, in recent image sensors, in addition to A / D conversion, a driving circuit such as a timing generator, a white balance adjustment circuit, a pixel defect correction circuit, and a read pixel number conversion Some have a circuit or the like as a digital signal processing circuit, and a through current at the time of switching of an FET (field effect transistor) portion due to a data level change has become extremely large.

  In addition, for example, the digital signal processing unit 111 continuously processes multi-bit image data at a high pixel clock rate, so that the heat generation area increases and the heat generation amount per unit time becomes extremely large. In Patent Document 3, there is one heat dissipation path from the image sensor, and if the image sensor is a cooling target, the heat generated by the digital signal processing unit 111 is transferred to the pixels of the photoelectric conversion unit 110 in the same chip. It is transmitted in the immediate vicinity of the circuits such as the provided photodiodes and analog amplifiers, and has a detrimental effect of generating large thermal noise. The digital signal processing unit 111 performs count processing and arithmetic processing at a driving frequency as high as the pixel clock described above. For this reason, the digital signal processing unit 111 generates a large amount of heat, and when it is short-circuited thermally with a photodiode or an analog reference voltage generation part of the photoelectric conversion unit 110, a dark current increases and image quality deterioration due to noise occurs.

  In recent high integration, a driving circuit such as a timing generator and a parallel A / D converter disclosed in the technique of Patent Document 1 are arranged on the same chip. Unlike the disclosed technology, there is no possibility of increasing the distance or making a space. For this reason, in the technique disclosed in Patent Document 4, it may be difficult to perform thermal insulation.

  The present invention has been made in view of the above, and an object thereof is to provide an imaging module capable of obtaining a high-quality image with less noise.

  In order to solve the above-described problems and achieve the object, an imaging module according to the present invention includes a photoelectric conversion unit that is arranged in a two-dimensional matrix and includes a plurality of pixels that photoelectrically convert received light. And an image chip having a second part including a horizontal scanning circuit that scans in one direction of the photoelectric conversion unit, a first heat conducting member that conducts heat of the first part, and conducts heat of the second part And a second heat conducting member. A space is provided between the first heat conducting member and the second heat conducting member.

  The imaging module according to the present invention is the first thermal conductive bonding provided in the image chip region corresponding to the first part and bonding the image chip and the first thermal conductive member in the above invention. And a second thermally conductive adhesive provided in a region of the image chip corresponding to the second part and bonding the image chip and the second thermally conductive member, the first and The distance between the second heat conductive adhesives is wider than the distance between the first heat conductive member and the second heat conductive member.

  The imaging module according to the present invention is an area between the first heat conductive member and the second heat conductive member in the above invention, the first and second heat conductive members. The width of the heat insulation region having a high thermal resistance is wider than the distance between the first part and the second part, and the distance between the first and second heat conductive adhesives is the first part and the second part. It is characterized by being wider than the interval between the portions.

  Further, the imaging module according to the present invention, in the above invention, is insulated between the first and second thermally conductive adhesives in a region including a boundary between the first part and the second part. It is characterized by disposing an adhesive.

  The imaging module according to the present invention is characterized in that, in the above invention, a heat insulating member is provided in the space between the first heat conducting member and the second heat conducting member.

  In the imaging module according to the present invention as set forth in the invention described above, the second portion includes at least a high-speed driving circuit having a driving frequency equal to or higher than 1/8 of the driving frequency of the pixel readout clock.

  In the imaging module according to the present invention, in the above invention, the image chip is a portion where the first portion mainly performs analog processing, and the second portion is a portion which mainly performs digital processing. It is characterized by.

  The imaging module according to the present invention is characterized in that, in the above invention, the image chip is connected to at least one of the first and second heat conducting members by an anisotropic heat conducting member.

  The imaging module according to the present invention is characterized in that, in the above invention, the first portion and the second portion are stacked.

  The imaging module according to the present invention is characterized in that, in the above invention, the first portion and the first heat conducting member are connected by an elastic member.

  In the imaging module according to the present invention as set forth in the invention described above, the first heat conducting member is disposed between the first portion and the wiring board.

  According to the present invention, the temperature in the photoelectric conversion unit and the analog signal processing unit is reduced with respect to the image sensor which is highly integrated and has multiple functions and the amount of heat generation is increased, and the heat from the portion where the heat generation amount is larger is circulated. By reducing the dark current as a result, it is possible to obtain a high-quality image with less noise.

FIG. 1 is a schematic diagram illustrating a schematic configuration of the imaging module according to the first embodiment of the present invention. FIG. 2 is a schematic diagram illustrating a configuration of a main part of the imaging module according to the first embodiment of the present invention. FIG. 3 is an explanatory diagram showing a temperature distribution profile (a) and a dark current distribution (b) in the imaging module according to the first embodiment of the present invention. FIG. 4 is a schematic diagram illustrating a configuration of a main part of the imaging module according to the first embodiment of the present invention. FIG. 5 is a schematic diagram illustrating a configuration of a main part of the imaging module according to Modification 1-1 of Embodiment 1 of the present invention. FIG. 6 is a schematic diagram illustrating a configuration of a main part of the imaging module according to Modification 1-2 of Embodiment 1 of the present invention. FIG. 7 is a schematic diagram illustrating a configuration of a main part of an imaging module according to Modification 1-3 of Embodiment 1 of the present invention. FIG. 8 is a schematic diagram illustrating a configuration of a main part of an imaging module according to Modification 1-3 of Embodiment 1 of the present invention. FIG. 9 is a schematic diagram illustrating a configuration of a main part of an imaging module according to Modification 1-4 of Embodiment 1 of the present invention. FIG. 10 is a schematic diagram illustrating a configuration of a main part of an imaging module according to Modification 1-5 of Embodiment 1 of the present invention. FIG. 11 is a schematic diagram illustrating a schematic configuration of the imaging module according to the second embodiment of the present invention. FIG. 12 is a schematic diagram illustrating a schematic configuration of the imaging module according to the third embodiment of the present invention. FIG. 13 is a schematic diagram illustrating a configuration of an imaging module according to Modification 3-1 of Embodiment 3 of the present invention. FIG. 14 is a schematic diagram showing a configuration of a conventional basic CMOS image sensor. FIG. 15 is a diagram showing an example of a specific configuration of a conventional CMOS image sensor.

  Hereinafter, as an embodiment for implementing the present invention (hereinafter referred to as “embodiment”), an imaging module capable of outputting an electrical signal after photoelectric conversion from a plurality of imaging pixels as image information will be described. Moreover, this invention is not limited by this embodiment. Furthermore, the same code | symbol is attached | subjected to the same part in description of drawing. Furthermore, the drawings are schematic, and it should be noted that the relationship between the thickness and width of each member, the ratio of each member, and the like are different from the actual ones. Moreover, the part from which a mutual dimension and ratio differ also in between drawings.

(Embodiment 1)
FIG. 1 is a schematic diagram illustrating a schematic configuration of the imaging module 1 according to the first embodiment. FIG. 1A illustrates a partial cross-sectional view of a side surface, and FIG. The typical perspective view of the imaging module 1 (wiring board 30) is shown. FIG. 2 is a schematic diagram illustrating a configuration of a main part of the imaging module 1 according to the first embodiment.

  As shown in FIG. 1, the imaging module 1 includes a lens frame 10 holding a lens 10a, a first portion Rh1 including the photoelectric conversion unit 110 described above, and a second portion Rh2 including the digital signal processing unit 111 described above. Image chip 20, first heat conducting member 21a (first heat conducting member) that conducts heat of the first part Rh1, and second heat conducting member 21b (second heat conducting the heat of the second part Rh2). A conductive member) and a wiring board 30 to which a processing signal processed by the digital signal processing unit 111 is output. Note that the digital signal processing unit 111 includes a high-speed driving circuit that can perform processing at a high speed at a driving frequency that is 1/8 or more of the driving frequency of the read clock of the photoelectric conversion unit 110.

  Here, the imaging module 1 has a structure in which the image chip 20 is inserted and joined into an internal space formed by the lens frame 10 and the wiring substrate 30. The image chip 20 is provided so that the main surface is substantially perpendicular to the central axis of the lens 10a.

  The image chip 20 has a substantially plate shape, and includes the photoelectric conversion unit 110 and the digital signal processing unit 111 as illustrated in FIGS. Further, the first portion Rh1 and the second portion Rh2 are regions divided so as to include the photoelectric conversion unit 110 and the digital signal processing unit 111 with respect to the plate surface. An input / output pad IP for inputting and outputting signals is provided on the surface (light receiving surface) side of the image chip 20.

  The wiring board 30 has a substantially plate shape, and a foot pattern FP for inputting / outputting signals to / from the image chip 20 is provided on the surface. In addition, the wiring board 30 includes a wiring pattern part 31 that forms a wiring pattern that connects each part of the wiring board 30 and an I / F connector part 32 that is an interface that communicates with the outside of the imaging module 1. The wiring pattern portion 31 is provided on the front surface of the image chip 20, while the I / F connector portion 32 is provided on the back surface. The wiring pattern portion 31 and the I / F connector portion 32 are electrically connected through a through hole TH1 penetrating in the thickness direction of the wiring substrate 30.

  The wiring board 30 is formed with a plurality of through holes TH2 to TH4 penetrating in the thickness direction of the wiring board 30 and having a metal film disposed on the inner wall surface. The through hole TH <b> 2 is formed so as to be positioned outside the lens frame 10 when the lens frame 10 is attached to the wiring board 30. The through hole TH3 is located on the inner side of the lens frame 10 when the lens frame 10 is attached to the wiring board 30 and is located on the first portion Rh1 side when the image chip 20 is stacked on the wiring board 30. Is formed. The through-hole TH4 is located on the inner side of the lens frame 10 when the lens frame 10 is attached to the wiring board 30, and is located on the second portion Rh2 side when the image chip 20 is stacked on the wiring board 30. Is formed.

  The first heat conducting member 21a and the second heat conducting member 21b are provided on a surface (back surface) on a different side from the lens 10a (light receiving surface) of the image chip 20 (see FIG. 2), and extend toward different heat radiation destinations. ing. The first heat conducting member 21 a and the second heat conducting member 21 b can transfer heat from the back surface of the image chip 20 to the outside of the lens frame 10. Here, as shown in FIG. 1B, a region where the first heat conducting member 21a transmits heat and dissipates heat is a heat dissipating region Rr1, and a region where the second heat conducting member 21b transmits heat and dissipates heat. Is defined as a heat radiation target region Rr2. In the first embodiment, a heat insulating region Ri1 including an air layer is provided between the heat radiation target region Rr1 and the heat radiation target region Rr2 formed by the first heat conduction member 21a and the second heat conduction member 21b. In addition, this heat insulation area | region Ri1 is larger than area | region Rg1 (space | interval) between 1st part Rh1 and 2nd part Rh2.

  Specifically, the first heat conducting member 21 a and the second heat conducting member 21 b are provided between the image chip 20 and the wiring board 30. In addition, the third heat conductive member 22a and the fourth heat conductive member 22b are provided on the surface (back surface) opposite to the surface on which the first heat conductive member 21a and the second heat conductive member 21b are provided. . The first heat conducting member 21a, the second heat conducting member 21b, the third heat conducting member 22a, and the fourth heat conducting member 22b are plate members made of a material such as metal or carbon graphite (graphite). Note that those materials can be used as long as they have a higher thermal conductivity than the material constituting the image chip 20.

  Further, the image chip 20 and the first heat conductive member 21a are fixed by a heat conductive paste 23a (first heat conductive adhesive). Similarly, the image chip 20 and the second heat conductive member 21b are fixed by a heat conductive paste 23b (second heat conductive adhesive). Thereby, even if it is a case where the unevenness | corrugation of the micron level of each surface of the contact side of the image chip 20 and the 1st heat conductive member 21a exists and is rough, the mutual adhesiveness of a surface can be raised. The heat conductive pastes 23a and 23b can be applied to any metal or resin having a higher thermal conductivity than the material constituting the image chip 20, or a metal powder having a higher thermal conductivity, or a resin containing graphite powder. It is.

  The first heat conducting member 21a and the second heat conducting member 21b described above are fixed to the image chip 20 to release the heat generated in the image chip 20 to the outside. At this time, the first heat conductive member 21a and the heat conductive paste 23a are disposed on the first portion Rh1 side so that the end portions thereof are aligned with one end portion of the heat insulating region Ri1, and the second heat conductive member 21b and the heat conductive paste 23b are The second portion Rh2 is arranged so that the end portion is aligned with the other end portion of the heat insulating region Ri1. Thereby, heat insulation area | region Ri1 is maintained also between the 1st heat conductive member 21a and the heat conductive paste 23a, and the 2nd heat conductive member 21b and the heat conductive paste 23b.

  The third heat conducting member 22a is disposed on the first portion Rh1 side, and the fourth heat conducting member 22b is disposed on the second portion Rh2 side. At this time, the first heat conducting member 21a and the third heat conducting member 22a are connected by the through hole TH3 so as to be capable of conducting heat. Further, the second heat conducting member 21b and the fourth heat conducting member 22b are connected to each other through the through holes TH2 and TH4 so as to be able to conduct heat.

  The heat transfer structure from the image chip 20 includes not only the first heat conductive member 21a and the second heat conductive member 21b provided on the surface of the wiring substrate 30 on the image chip 20 side, but also the back surface of the wiring substrate 30 ( It is possible to dissipate heat using the third heat conduction member 22a and the fourth heat conduction member 22b provided on the side opposite to the image chip 20). At this time, the metal film of the through holes TH3 and TH4 is used for heat conduction to the back surface of the wiring board 30. Since the heat generation amount of the heat radiation target region Rr2 is larger than that of the heat radiation target region Rr1, the total heat radiation amount (thermal conductivity) of the second heat conduction member 21b, the through hole TH4, and the fourth heat conduction member 22b is sufficient. Larger is desirable. In the imaging module 1 according to the first embodiment, a large heat dissipation amount is secured by further providing a heat sink 40 at the end of the second heat conducting member 21b on the side different from the image chip 20 side. When the image chip 20 is continuously driven to increase the amount of heat generated, such as when shooting a movie, the first heat conducting member 21a and the second heat conducting member 21b are extended so as to be applied to the housing of another device. It is preferable to secure a larger heat dissipation capacity by performing a process such as contact.

  Here, in the imaging module 1, the input / output pad IP of the image chip 20 and the foot pattern FP of the wiring substrate 30 are electrically bonded by wire bonding using wires W 1 and W 2, respectively.

  Subsequently, a basic separation mode of the heat radiation path will be described. In the following description, two heat dissipation paths will be described, but there may be three or more systems. As shown in FIG. 15, in the solid-state imaging device, the photoelectric conversion unit 110 and the vertical scanning circuit VC100 having a low driving frequency are set as the same heat dissipation system, and the other functional units (digital signal processing unit 111) are set as another heat dissipation system. To do. The boundary between these two heat dissipation systems (in the first embodiment, the first part Rh1 and the second part Rh2) is defined as an image sensor function change position, and a heat insulating region Ri1 is provided therebetween (see FIG. 1). In the first embodiment, a region including the photoelectric conversion unit 110 having a small heat generation amount is described as a heat dissipation target region Rr1, and a region including the digital signal processing unit 111 having a large heat generation amount is described as a heat dissipation target region Rr2. In the photoelectric conversion unit 110, only the electric current for converting the charge accumulated in each pixel into charge-voltage is generated in the order of reading, the power consumption is low, and the photoelectric conversion unit 110 is dispersed in the photoelectric conversion region. Local heat generation is extremely small. Similarly, since the vertical scanning circuit VC100 has a low driving frequency, the power consumption is low and the heat generation amount is small. Even if these two circuit blocks are used as the same heat dissipation system (heat dissipation target region Rr1), the amount of adverse influence on the dark current that causes image noise of the photoelectric conversion unit 110 is extremely small. On the other hand, the digital signal processing unit 111 including a high-speed signal processing unit has high power consumption and a large amount of heat generation.

  In the first embodiment, as shown in FIG. 2, the heat insulation region Ri1 provided between the heat radiation target region Rr1 and the heat radiation target region Rr2 is an air layer. At this time, the heat generated in the heat dissipation target region Rr1 and the heat generated in the heat dissipation target region Rr2 are not thermally short-circuited and are independent from each other. The temperature of Rr1 does not increase.

  FIG. 3 is an explanatory diagram showing a temperature distribution profile (a) and a dark current distribution (b) in the imaging module according to the first embodiment and the conventional imaging module. The conventional imaging module has a single heat conducting member in which heat transfer is not divided by the heat radiation target area. In FIG. 3A, a curved line L1 indicated by a solid line indicates a temperature distribution profile of the image chip 20 in the imaging module 1 according to the first embodiment. A curved line L10 indicated by a broken line indicates the temperature distribution profile of the image chip in the conventional imaging module. The temperature profile shown in FIG. 3A shows the temperature distribution when the thermal equilibrium state is maintained in the image chip 20.

In FIG. 3, the left side in the drawing is a heat radiation target region Rr <b> 1 with a small amount of heat generated mainly from the photoelectric conversion unit 110, and the right side is a heat radiation target region Rr <b> 2 with a large heat generation amount mainly composed of the digital processing unit 111. Here, in the conventional imaging module, since the heat dissipation path from the image chip is not separated into the heat dissipation target region Rr1 and the heat dissipation target region Rr2, the heat dissipation target region Rr2 side having a large heat generation amount is changed to the heat radiation target region Rr1 side having a small heat generation amount. Since heat transfer is large, the gradient of the temperature distribution is small near the boundary between the heat radiation target region Rr1 and the heat radiation target region Rh2, and the temperature distribution is indicated by the curve L10. Here, in FIG. 3A, the temperature Tr1 is a detection upper limit level temperature at which the thermal noise generated by the dark current can be confirmed as an image. In the conventional temperature profile (curve L10), the temperature Tr1 below position is the _{P 1,} a small image area of the dark current in FIG. 3 (b), the left region _{R P1} of the radiating target area Rr1. That is, in the conventional image chip, the range that can be used as a high-quality image is smaller than the heat radiation target region Rr1. Incidentally, in the heat radiation region of interest Rr1, in the region R _PO above the temperature Tr1, dark current is large, an image corresponding to the image signal output from the pixels of this region R _PO is a noise larger the.

On the other hand, in the image chip 20 according to the first embodiment, since the first heat conductive member 21a and the second heat conductive member 21b are provided according to the heat dissipation target region Rr1 and the heat dissipation target region Rr2, the heat conductivity is increased. Since there is no heat transfer between the members and each radiates heat independently, the amount of heat transferred from the heat radiation target region Rr2 having a large heat generation amount to the heat radiation target region Rr1 side is drastically reduced. Actually, when the image chip 20 is formed of a silicon semiconductor, heat leaks through the silicon substrate that serves as a base of the heat insulating region Ri1, but compared with a metal heat conducting member. Since the heat transfer coefficient is as low as 10 2, the influence is small. For this reason, at the boundary between the heat radiation target region Rr1 and the heat radiation target region Rr2, the temperature distribution has a large gradient and the temperature changes abruptly. Further, since the heat transfer is small from the heat radiation target region Rr2 side with a large heat generation amount to the heat radiation target region Rr1 side with a small heat generation amount, the temperature rise in the heat radiation target region Rr1 is suppressed, and the position below the temperature Tr1 is P _2. next, a small image area of the dark current in FIG. 3 (b), a region _{R P2.} That is, the image region with a small dark current becomes the region _RP2 , and the range that can be used as a high-quality image is relatively larger (for example, the region R1) than the conventional one.

  FIG. 4 is a schematic diagram illustrating a configuration of a main part of the imaging module 1 according to the first embodiment. In the imaging module 1 according to the first embodiment, the region Rs1 (gap) between the heat conductive pastes 23a and 23b provided on the first heat conductive member 21a and the second heat conductive member 21b is a heat dissipation target region Rr1. And it is preferable that it is larger than the area | region (heat insulation area | region Ri1) corresponding between heat dissipation object area | region Rr2.

  In recent years, due to the market demand for the downsizing of the imaging module and the advancement of semiconductor miniaturization, the circuit interval on the image chip 20 has been narrowed, and the distance between the boundary region between the photoelectric conversion unit 110 and the digital signal processing unit 111 has become very small. ing. For this reason, it becomes more difficult to increase the accuracy of the assembling processing of the imaging module in accordance with this, while the heat radiation path is reliably separated by the first heat conducting member 21a and the second heat conducting member 21b. It is also necessary to avoid typical shorts.

  For example, even if the heat conductive pastes 23a and 23b are separately coated on the image chip 20 while maintaining the distance between the first heat conductive member 21a and the second heat conductive member 21b, the heat insulating resin having low heat conductivity. Before or during the injection, there is a possibility that the thermal conductive pastes 23a and 23b come into contact with each other due to dripping due to the viscosity of the paste agent, resulting in a thermal short circuit. Due to this short circuit, heat is transferred from the heat dissipation target region Rr2 to the heat dissipation target region Rr1, so that the temperature of the photoelectric conversion unit 110 disposed on the side of the heat dissipation target region Rr1 of the image chip 20 rises, and as described above, the heat noise increases The screen area that can be used for image quality is reduced.

  Here, as also shown in FIG. 4, the region Rs1 (gap) between the heat conductive pastes 23a and 23b is more than the region (heat insulating region Ri1) corresponding to the region between the heat radiation target region Rr1 and the heat radiation target region Rr2. By increasing the size, it is possible to reliably prevent contact between the heat conductive pastes 23a and 23b, to separate the heat radiation path, and to avoid a thermal short circuit.

  According to the first embodiment described above, the temperature in the photoelectric conversion unit and the analog signal processing unit is set to be larger than that of the image chip 20 that is highly integrated and multi-functional and has an increased heat generation amount. A high-quality image with less noise can be obtained by reducing the dark current by separating the heat from the portion and reducing the heat flow.

  Further, according to the first embodiment, the heat generated in the photoelectric conversion unit 110 can be radiated by the first heat conducting member 21a, so that a high-quality image with small noise can be obtained reliably. Therefore, it is possible to enlarge the pixel region where the high-quality image can be obtained as compared with the conventional case.

  FIG. 5 is a schematic diagram illustrating a configuration of the heat conducting member 24 of the imaging module according to Modification 1-1 of the first embodiment. In the first embodiment described above, it has been described that a plurality of heat conducting members are used as the first and second heat conducting members. However, the heat conducting members do not have to have a plurality of completely separated structures. The image chip 20 may be thermally coupled at a position away from the position where the functional blocks are arranged. The heat conducting member 24 shown in FIG. 5 is provided with a notch 24a that cuts and separates the main surface of the heat conducting member 24 in accordance with the heat radiation target region Rr1 and the heat radiation target region Rr2. At this time, the length of the notch 24a in the longitudinal direction extends with a length larger than the length in the boundary line direction (the width of the image chip 20) of the first portion Rh1 and the second portion Rh2 in the image chip 20.

  Also by the heat conducting member 24 according to the modified example 1-1 described above, the temperature in the photoelectric conversion unit and the analog signal processing unit is generated by heat with respect to the image chip 20 that is highly integrated and has multiple functions and generates a large amount of heat. A high-quality image with less noise can be obtained by separating from a larger amount portion and suppressing the wraparound of heat to reduce dark current. Note that the opening width D1 of the notch 24a is preferably equal to or greater than the width of the heat insulating region Ri1 described above.

  FIG. 6 is a schematic diagram illustrating a configuration of a main part of an imaging module according to Modification 1-2 of the first embodiment. The single heat conducting member may be the anisotropic heat conducting member 24b in addition to the heat conducting member 24 described above. The anisotropic heat conductive member 24b has a substantially sheet shape, and fixes the image chip 20, the first heat conductive member 21a, and the second heat conductive member 21b. Here, the anisotropic heat conductive member 24b has a heat transfer coefficient in the sheet-like thickness direction (direction perpendicular to the sheet surface: arrow Ya) compared to the heat transfer coefficient in the direction parallel to the sheet surface. It is extremely high and heat insulation in a direction parallel to the surface of the sheet can be secured.

  The anisotropic heat conductive member 24b includes a function of improving thermal bondability between the image chip 20, the first heat conductive member 21a, and the second heat conductive member 21b by continuously disposing the heat including the heat insulating region. In addition, both the function having the heat insulating property and the function having both heat insulation properties are achieved in the direction perpendicular to the joining direction. The anisotropic heat conductive member 24b includes a structure using carbon nanotubes, a film in which carbon graphite is laminated, or a resin mixed with metal particles called ACF, sandwiched between the films and crushed in the thickness direction so that anisotropy is obtained. The ones that are given are known.

  Also with the anisotropic heat conductive member 24b according to the modified example 1-2 described above, the temperature in the photoelectric conversion unit and the analog signal processing unit is set for the image chip that is highly integrated and has multiple functions and generates a large amount of heat. Further, by separating from a portion where the heat generation amount is larger and suppressing the wraparound of heat to reduce dark current, a high-quality image with less noise can be obtained.

  The anisotropic heat conductive member 24b only needs to be connected to at least one of the first heat conductive member 21a and the second heat conductive member 21b, and the other heat conductive member is connected to the above-described heat conductive paste. It may be a thing.

  FIG. 7 is a schematic diagram illustrating a configuration of a main part of an imaging module according to Modification 1-3 of Embodiment 1. FIG. 8 is a schematic diagram illustrating a configuration of a main part of an imaging module according to Modification 1-3 of Embodiment 1. As illustrated in FIG. FIG. 9 is a schematic diagram illustrating a configuration of a main part of an imaging module according to Modification 1-4 of Embodiment 1. As illustrated in FIG. Although Embodiment 1 mentioned above demonstrated as what is between the heat conductive pastes 23a and 23b (heat insulation area | region Ri1) of the 1st heat conductive member 21a and the 2nd heat conductive member 21b, it is a heat insulating member in the meantime. 25 may be arranged.

  As shown in FIGS. 7-9, the heat insulation member 25 is provided between the heat conductive pastes 23a and 23b. The heat insulating member 25 is made of, for example, a heat insulating resin having a high thermal resistance. Thereby, the heat insulation between the heat conductive paste 23a and the heat conductive paste 23b can be made more reliable.

  Moreover, the arrangement | positioning order with the heat conductive paste 23a, 23b and the heat insulation member 25 in the case of providing the heat insulation member 25 like the modification 1-2 mentioned above is demonstrated. First, in fixing the image chip 20 to the first heat conductive member 21a and the second heat conductive member 21b, the heat conductive pastes 23a and 23b and the heat insulating member 25 are provided on the image chip 20 side, and then the first heat conductive. When the member 21a and the second heat conductive member 21b are fixed, after the heat insulating member 25 is disposed on the image chip 20, the heat conductive pastes 23a and 23b are respectively applied to the first heat conductive member 21a and the second heat conductive member 21b. The heat conducting member 21b is fixed. It should be noted that when applying the heat conductive pastes 23a and 23b and the heat insulating member 25, it is preferable to separate the heat conductive pastes 23a and 23b from the non-application portion using a metal mask or the like.

  Further, in fixing the image chip 20 to the first heat conductive member 21a and the second heat conductive member 21b, the heat conductive pastes 23a and 23b and the heat insulating member 25 are used as the first heat conductive member 21a and the second heat conductive member 21b. When the image chip 20 is fixed after being provided on the side (see FIG. 8), after the heat insulating member 25 is disposed on the first heat conducting member 21a and the second heat conducting member 21b arranged in a predetermined positional relationship. Then, the thermal conductive pastes 23a and 23b are respectively applied to fix the image chip 20. As described above, the heat insulating member 25 is disposed between the first heat conductive member 21a and the second heat conductive member 21b before the heat conductive pastes 23a and 23b, so that the heat radiation target regions Rr1 and Rr2 are interposed. Insulation can be made more reliable.

  By disposing the heat conductive pastes 23a and 23b and the heat insulating member 25 in the order described above, it is possible to achieve reliable heat insulation between the heat conductive pastes 23a and 23b. Further, after the heat insulating member 25 is disposed between the first portion Rh1 and the second portion Rh2 (region Rg1) on the image chip 20, the heat conductive pastes 23a and 23b are disposed, and the first heat conductive member 21a and The second heat conducting member 21b may be fixed (see FIG. 9). Note that the arrangement of the heat conductive pastes 23a and 23b and the heat insulating member 25 is not limited to this as long as the heat conductive pastes 23a and 23b and the heat insulating member 25 are disposed. For example, one heat conductive paste is disposed after the heat insulating member 25 is disposed. Then, after fixing one heat conductive member and arrange | positioning the other heat conductive paste after that, the other heat conductive member may be fixed. Further, the heat insulating member 25 can be applied as long as it is a material having a heat insulating property in addition to a liquid adhesive.

  FIG. 10 is a schematic diagram illustrating a configuration of a main part of an imaging module according to Modification 1-5 of the first embodiment. As in Modification 1-5, in addition to the above-described heat insulating member 25, for example, the second heat conductive member 21b in the heat dissipation target region Rr2 having a large calorific value covers the outer periphery of the first heat conductive member 21a side. The member 26 may be provided. Thereby, the heat transfer between the 1st heat conductive member 21a and the 2nd heat conductive member 21b can be prevented, and a more reliable heat insulation structure can be comprised. In addition, in order to prevent contact between multiple thermal conductive members due to inadequate positioning accuracy, deformation or movement in the adhesive effect process, at least one of the adjacent thermal conductive members may be coated with a heat insulating adhesive or the like. Further, it is possible to ensure the thermal insulation more reliably by filling the heat insulating region Ri1 between the heat conductive members with the heat insulating member.

(Embodiment 2)
FIG. 11 is a schematic diagram illustrating a schematic configuration of the imaging module 2 according to the second embodiment. FIG. 11A is a partial cross-sectional view of a side surface, and FIG. 11B is a top view. A schematic perspective view of the imaging module 2 (wiring board 30a) is shown. In addition, the same code | symbol is attached | subjected to the component same as the structure demonstrated in FIG. In the imaging module 2 shown in FIG. 11, description will be made on the assumption that an opening 301 corresponding to incident light from the lens 10a is formed in the wiring board 30a. At this time, the wiring pattern portion 31a is provided on the surface of the wiring board 30a on the side different from the lens 10a. The image chip 20 and the wiring board 30a are electrically connected by the wiring pattern portion 31a and the solder bump B1. The signal is transmitted from the wiring pattern portion 31a to the wiring pattern portion 31b through the through hole TH5, and is transmitted to the outside from the I / F connector portion 32a.

  At this time, the imaging module 2 is provided with a heat conductive mold 27 that connects the side surface of the image chip 20 and the back surface of the wiring board 30a (surface on the wiring pattern portion 31a side). The thermally conductive mold 27 is made of resin, metal, or the like having the same thermal characteristics as the above-described thermally conductive paste, and is wound around the side surface of the image chip 20 and connected to the wiring board 30a. Thereby, the heat generated in the image chip 20 is dissipated by the first heat conductive member 21a and the second heat conductive member 21b described above, and the wiring board 30a and the wiring pattern portion 31a, via the heat conductive mold 27, It is also transmitted to 31b and radiated.

  Further, as shown in FIG. 11A, the imaging module 2 is different from the first embodiment described above in that the back surface of the image chip 20 is not covered with the wiring board 30a, so that a heat radiation path is directly provided on the back surface. Can be provided.

  According to the second embodiment described above, the temperature in the photoelectric conversion unit and the analog signal processing unit is set to be larger than that of the image chip 20 that is highly integrated and multi-functional and has an increased heat generation amount. A high-quality image with less noise can be obtained by reducing the dark current by separating the heat from the portion and reducing the heat flow.

  In addition, according to the second embodiment, the first heat conducting member 21a and the second heat conducting member 21b are not in contact with the image chip 20 through other members such as the wiring board 30a. It becomes possible to increase the heat radiation efficiency as compared with the first mode.

(Embodiment 3)
FIG. 12 is a schematic diagram illustrating a schematic configuration of the imaging module 3 according to the third embodiment. In addition, the same code | symbol is attached | subjected to the component same as the structure demonstrated in FIG. In the first embodiment described above, the photoelectric conversion unit 110 and the digital signal processing unit 111 are described as being provided on the same image chip. However, the photoelectric conversion unit 110 and the digital signal processing unit 111 are separated from each other. It is assumed that the image chip is in the form of a unit called a chip-on-chip that is separated and stacked and mounted.

  The imaging module 3 shown in FIG. 12 has a structure in which the image chip 20a is inserted and joined into an internal space formed by the lens frame 10 and the wiring board 30b. The image chip 20a has a substantially plate shape, and includes an upper chip 20b including the photoelectric conversion unit 110 as illustrated in FIGS. 15 and 16 and a lower chip 20c including the digital signal processing unit 111 as described above. The upper chip 20b and the lower chip 20c are fixed in positional relationship by, for example, a heat insulating member 28 made of a heat insulating resin and electrically connected by solder bumps B2. The space between the upper chip 20b and the lower chip 20c is not limited to the heat insulating member 28 and may be an air layer. Here, in the third embodiment, the upper chip 20b is described as corresponding to the heat dissipation target region Rr1 (first portion Rh1), and the lower chip 20c is described as corresponding to the heat dissipation target region Rr2 (second portion Rh2). . The image chip 20a is divided to include the photoelectric conversion unit 110 and the digital signal processing unit 111 in different chips. An input / output pad (not shown) for inputting / outputting signals is provided on the surface of the lower chip 20c (upper chip 20b side).

  The wiring board 30b has a substantially plate shape. The wiring board 30b includes a wiring pattern part 31 that forms a wiring pattern that electrically connects each part of the wiring board 30b, and an I / F connector part 32 that is an interface that communicates with the outside of the imaging module 3. Have. The wiring pattern portion 31 is provided on the surface of the wiring substrate 30b on the image chip 20a side, while the I / F connector portion 32 is provided on the back surface. The wiring pattern portion 31 and the I / F connector portion 32 are electrically connected through a through hole TH1 penetrating in the thickness direction of the wiring substrate 30b. Here, in the wiring board 30b, the input / output pads of the lower chip 20c and a foot pattern (not shown) are wire-bonded by wires W1 and W2, respectively, and are electrically connected.

  The wiring board 30b is formed with a plurality of through holes TH2, TH3a, TH4 and a through hole TH4a that penetrate the wiring board 30b in the thickness direction and have a metal film disposed on the inner wall surface. The through holes TH2 and TH4 are formed so as to be disposed at positions corresponding to the wiring board 30 described above. The through hole TH4a is formed at a position corresponding to the position where the second heat conducting member 21d of the wiring board 30b is disposed. The through hole TH3a is located on the inner side of the lens frame 10 when the lens frame 10 is attached to the wiring board 30b, and is different from the arrangement area of the lower chip 20c when the image chip 20a is stacked on the wiring board 30b. It is formed so as to be disposed in the region.

  The first heat conducting member 21c and the second heat conducting member 21d are provided on the surface (surface) of the wiring board 30b on the image chip 20a side, and extend toward different heat radiation destinations. The first heat conducting member 21c and the second heat conducting member 21d can transmit heat generated by the image chip 20a to the outside of the lens frame 10. Moreover, in this Embodiment 3, it demonstrates as what is the heat insulation area | region which consists of an air layer between the 1st heat conductive member 21c and the 2nd heat conductive member 21d.

  Specifically, the first heat conducting member 21c and the second heat conducting member 21d are provided between the image chip 20a and the wiring board 30b. Further, the third heat conductive member 22c and the fourth heat conductive member 22d are provided on the surface (back surface) opposite to the surface on which the first heat conductive member 21c and the second heat conductive member 21d are provided of the wiring board 30b. . The first heat conducting member 21c, the second heat conducting member 21d, the third heat conducting member 22c, and the fourth heat conducting member 22d are plate-like members each made of a metal material. The metal material can be applied as long as it has a higher thermal conductivity than the material constituting the image chip 20a.

  The upper chip 20b and the first heat conducting member 21c are connected by a metal spring 50 (elastic member). One end of the metal spring 50 is in contact with the upper chip 20b, and the other end is exposed to the outside by being soldered to the third heat conducting member 22c through the through hole TH3a. Has been communicated. Further, the lower chip 20c and the second heat conductive member 21d are fixed by the heat conductive paste 23c. Thereby, the heat generated in the upper chip 20 b is transmitted to the first heat conducting member 21 c via the metal spring 50. Further, even when the surface on the contact side of the lower chip 20c and the second heat conducting member 21d has irregularities on the micron level and is rough, the adhesion between the surfaces can be improved. The heat conductive paste 23c can be applied as long as it is a metal or resin having a higher thermal conductivity than the material constituting the lower chip 20c, or a metal powder having a high thermal conductivity, or a resin containing graphite powder. .

  The first heat conducting member 21c and the second heat conducting member 21d described above are fixed to the wiring board 30b, respectively, and are generated in the image chip 20a via the first heat conducting member 21c and the second heat conducting member 21d. Release heat to the outside. At this time, the first heat conductive member 21c dissipates the heat of the upper chip 20b transmitted through the metal spring 50, and the second heat conductive member 21d transmits the upper chip 20b transmitted through the heat conductive paste 23c. Dissipate the heat. The space between the first heat conducting member 21c and the second heat conducting member 21d is a space layer, and the heat insulating region is maintained between the first heat conducting member 21c and the second heat conducting member 21d. Moreover, in this space layer, the wire W1 is extended and the lower chip | tip 20c and the wiring board 30b are connected.

  The third heat conducting member 22c is provided in the region where the through hole TH3a is provided. The region where the third heat conducting member 22c is disposed does not include the through holes TH2, TH4 and TH4a. The fourth heat conducting member 22d is provided in a region including the through holes TH2, TH4, and TH4a, and is connected so as to be able to conduct heat of the second heat transfer member 21d. The through hole only needs to be arranged at a position where heat can be transmitted from the first and second heat conducting members to the third and fourth heat conducting members, respectively, and is limited to the arrangement position in the present embodiment. is not.

  As a heat transfer structure from the image chip 20a, not only the first heat conductive member 21c and the second heat conductive member 21d provided on the surface of the wiring substrate 30b on the image chip 20a side, but also the back surface of the wiring substrate 30b ( It is possible to dissipate heat using the third heat conduction member 22c and the fourth heat conduction member 22d provided on the side opposite to the image chip 20a. In addition, since the emitted-heat amount of heat dissipation object area | region Rr2 is large compared with heat dissipation object area | region Rr1, it is desirable for the heat dissipation amount (thermal conductivity) of the 2nd heat conductive member 21d to be large enough. Also in the imaging module 3 according to the third embodiment, the heat sink 40 is further provided at the end of the second heat conducting member 21d on the side different from the image chip 20a side to ensure a large heat dissipation amount. When the heat generation amount is increased by continuously driving the image chip 20a, such as when shooting a movie, the first heat conducting member 21c and the second heat conducting member 21d are extended to be brought into contact with the housing of the apparatus. It is preferable to secure a larger heat dissipation capacity by performing such a process.

  According to the third embodiment described above, the temperature in the photoelectric conversion unit and the analog signal processing unit is set to a portion where the heat generation amount is larger with respect to the image chip which is highly integrated and has multiple functions and the heat generation amount is increased. Therefore, it is possible to obtain a high-quality image with less noise by reducing the dark current by suppressing the heat wraparound.

  FIG. 13 is a schematic diagram illustrating a configuration of an imaging module 3a according to the modification 3-1 of the third embodiment. FIG. 13A illustrates a partial cross-sectional view of the side surface, and FIG. These show the typical perspective views of imaging module 3a (wiring board 30a) seen from the upper surface. 13A is a partial cross-sectional view corresponding to the cross section of the α line (dashed line) in FIG. 13B on the left side of the drawing, and β in FIG. 13B is on the right side of the drawing. It is a partial cross-sectional view corresponding to a line (dashed line) cross section. In the second embodiment described above, even when the image chip 20a is used, the heat conduction path can be separated. In this case, the upper chip 20b has the side surface of the upper chip 20b fixed to the wiring board 30a with the resin adhesive 27a. A first heat conductive member 21e is disposed between the upper chip 20b and the wiring board 30a via a heat conductive paste 23d. Here, the heat conductive paste 23d may connect the upper chip 20b and the first heat conductive member 21e via the fifth heat conductive member 21f. The lower chip 20c is provided with a second heat conductive member 21g on the bottom surface of the lower chip 20c (the surface opposite to the upper chip 20b) via the heat conductive paste 23e. The image chip 20a and the wiring board 30a (wiring pattern 31a) are electrically connected by solder bumps B3.

  In the modified example 3-1, the heat generated in the upper chip 20b is radiated from the first heat conductive member 21e via the heat conductive paste 23a, and the heat generated in the lower chip 20c is transferred to the second heat conductive member 21g. By dissipating heat to the outside, it is possible to obtain a high-quality image with little noise by separating from a portion where the amount of heat generation is larger to suppress heat wraparound and reducing dark current.

  The resin adhesive 27a may be made of a resin having thermal conductivity. Further, in the above-described modification 3-1, the thermal conductive paste is interposed between the lower chip 20c of the image chip 20a and the second thermal conductive member 21g so that the thermal conductivity is not hindered by the surface roughness. Although described as what applies 23e, even if it is the structure which does not use a heat conductive paste, it is applicable.

1, 2, 3, 3a Imaging module 10 Mirror frame 10a Lens 20, 20a Image chip 20b Upper chip 20c Lower chip 21a, 21c, 21e First heat conducting member 21b, 21d, 21g Second heat conducting member 21f Fifth heat conducting Member 22a, 22c 3rd heat conductive member 22b, 22d 4th heat conductive member 23a, 23b, 23c, 23d, 23e Thermal conductive paste 24 Thermal conductive member 24a Notch 24b Anisotropic thermal conductive member 25, 26, 28 Thermal insulation member 27 Thermal conductive mold 27a Resin adhesive 30, 30a, 30b, 30c Wiring board 31, 31a, 31b Wiring pattern 32, 32a I / F connector portion 40 Heat sink 50 Metal spring

Claims (11)

A first part including a photoelectric conversion unit having a plurality of pixels that are arranged in a two-dimensional matrix and photoelectrically converts received light, and a second part including a column scanning circuit that scans the photoelectric conversion unit in one direction. Image chip,
A first heat conducting member that conducts heat of the first part;
A second heat conducting member for conducting heat of the second part;
With
An imaging module, wherein a space is provided between the first heat conducting member and the second heat conducting member. A first thermally conductive adhesive that is provided in a region of the image chip corresponding to the first part and bonds the image chip and the first heat conductive member;
A second thermally conductive adhesive provided in an area of the image chip corresponding to the second part, and for bonding the image chip and the second thermal conductive member;
Further comprising
The imaging module according to claim 1, wherein a distance between the first and second heat conductive adhesives is wider than a distance between the first heat conductive member and the second heat conductive member. The width of the heat insulation region between the first heat conducting member and the second heat conducting member, which is higher in thermal resistance than the first and second heat conducting members, Wider than the distance between the second part,
The imaging module according to claim 2, wherein an interval between the first and second thermally conductive adhesives is wider than an interval between the first portion and the second portion.   The heat insulating adhesive is disposed in a region between the first and second heat conductive adhesives and including a boundary between the first part and the second part. The imaging module described.   The imaging module according to claim 1, wherein a heat insulating member is provided in the space between the first heat conducting member and the second heat conducting member.   2. The imaging module according to claim 1, wherein the second portion includes a high-speed driving circuit having a driving frequency of at least 1/8 of a driving frequency of a pixel readout clock.   2. The imaging module according to claim 1, wherein in the image chip, the first portion is a portion that mainly performs analog processing, and the second portion is a portion that mainly performs digital processing.   The imaging module according to claim 1, wherein the image chip is connected to at least one of the first and second heat conducting members by an anisotropic heat conducting member.   The imaging module according to claim 1, wherein the first part and the second part are stacked.   The imaging module according to claim 9, wherein the first portion and the first heat conducting member are connected by an elastic member.   The imaging module according to claim 9, wherein the first heat conducting member is disposed between the first portion and the wiring board.

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