JP4745016B2 - The camera module - Google Patents

Description

  The present invention relates to a camera module, and more particularly to a camera module including an image sensor such as a CCD or a CMOS and a signal processing element that processes an electric signal from the image sensor.

For in-vehicle cameras and mobile phone cameras, it is desired to reduce the size of the camera module. In addition, it is desirable that the distance between the image sensor and the signal processing element that processes a signal from the image sensor is short from the viewpoint of preventing noise from being mixed into the signal from the image sensor. In Patent Document 1, an image pickup device and a peripheral IC chip that processes a signal from the image pickup device are stacked, and the image pickup device and the peripheral IC chip are resin-sealed in a counterbore portion of a wiring board. A technique for reducing the size is disclosed.
JP 2002-231916 A

  However, as in Patent Document 1, when the signal processing element and the image sensor are arranged in contact with each other, heat generated by the signal processing element is transmitted to the image sensor, and is output from the image sensor due to the influence of the heat. There may be noise in the electrical signal.

  An object of the present invention is to provide a camera module that can be reduced in size while reducing the thermal influence of a signal processing element on an imaging element.

A camera module according to a first aspect of the present invention includes an imaging device that converts light incident on a light receiving surface into an electrical signal, and a back surface side of the light receiving surface of the imaging device that is spaced apart from the back surface. A signal processing element that processes an electrical signal converted by the element, a first holding unit that holds the imaging element, and a second holding unit that holds the signal processing element from the side opposite to the imaging element. The second holding portion and the first holding portion are sequentially interposed in the heat transfer path from the signal processing element to the imaging device, and the second holding portion is more heat transfer than the first holding portion. The rate is high and extends away from the first holding part.

  Preferably, the second holding unit surrounds the imaging element and the signal processing element, has conductivity, and is connected to the ground.

  Preferably, the first holding part is configured to include ceramics, and the second holding part is a metal mainly composed of at least one of Cu, Al, Cu—W alloy, and Fe—Ni—Co alloy. It is formed by.

Preferably, a circuit board including a conductive path connected to at least one of the imaging element and the signal processing element is provided, and the first holding unit includes at least a part of the circuit board.

Preferably, the circuit board is provided with a through hole, and the imaging element and the signal processing element are separated from each other in the through direction of the through hole and housed in the through hole, and the first holding unit is The circuit board; and a member that holds the image pickup device over the through hole on one main surface of the circuit board, and the second holding portion has the through hole on the other main surface of the circuit board. And a member for holding the signal processing element .

  Preferably, the circuit board is provided with an electronic circuit element that controls an operation of at least one of the imaging element and the signal processing element.

  Preferably, the circuit board is a ceramic multilayer board in which an arrangement direction of the imaging element and the signal processing element is a lamination direction.

  Preferably, the imaging element and the signal processing element are arranged in a space provided in the ceramic multilayer substrate, and the imaging element to the signal processing element among a plurality of substrates constituting the ceramic multilayer substrate. A second substrate located closer to the signal processing element than the predetermined first substrate in the direction of the first substrate protrudes toward the void side from the first substrate, and on the surface of the second substrate on the first substrate side, A bonding region to which a wire connecting the signal processing element and the ceramic multilayer substrate is fixed is formed.

Preferably, have a recess in which the imaging device and the signal processing device is housed, a multilayer substrate in which a plurality of substrates are formed by laminating an opening direction of the recess as a stacking direction, hermetically sealing the recess And a transparent member that transmits light to the imaging device, and the first holding unit includes a substrate of the multilayer substrate in which an opening that constitutes the recess is formed, and the transparent member, The second holding unit includes a substrate constituting the bottom of the recess of the multilayer substrate, and a heat radiating body that penetrates the bottom of the recess in the stacking direction of the multilayer substrate, and the second holding unit includes the heat dissipation The body has a higher heat transfer rate than the multilayer substrate, so that the heat transfer rate is higher than that of the first holding part, and the imaging element is fixed to the transparent member with the light receiving surface facing, It said signal processing device is supported on the bottom of the recess By being, said signal processing device is spaced apart from the rear surface of the imaging element.

Preferably, the first holding unit is a filter that blocks a part of incident light and transmits the incident light to the imaging element, and the filter is arranged at a position spaced from the signal processing element with the edge side supported. In addition, the signal processing element is disposed away from the back surface of the imaging element by fixing the imaging element with the light receiving surface facing the center side of the filter .

Preferably, the first holding portion includes a incident light transparent member is transparent member edge side for transmitting is arranged at a position spaced supported from said signal processing element to the imaging element, said transparent The image sensor is fixed to the center side of the member with the light receiving surface opposed to the signal processing element so that the signal processing element is spaced apart from the back surface of the image sensor and faces the image sensor of the transparent member. A conductor to be connected to the imaging element is disposed on the surface to be performed.

Preferably, a circuit board having a space in which the imaging element and the signal processing element are accommodated, and a transparent member fixed to the circuit board so as to cover the space, the first holding unit is The transparent member and at least a portion of the circuit board on the surface side where the transparent member is disposed , and the imaging element faces the light receiving surface on a surface of the transparent member facing the circuit substrate. A first conductor that is fixed and connected to the imaging element is provided, and a surface of the circuit board facing the transparent member is connected to the signal processing element and the first conductor. A second conductor is provided, and the transparent member and the circuit board are fixed and the first conductor and the second conductor are connected by solder.

Preferably, the first holding unit is a circuit board provided with a conductive path connected to at least one of the imaging element and the signal processing element, and the imaging element and the signal processing element pass through. A circuit board having through holes that are housed apart from each other in the direction, and a transparent member that seals one of the through holes and fixes the light receiving surface of the imaging element to the surface on the through hole side , The second holding unit includes a heat radiating body that seals the other of the through holes, the signal processing element is fixed to a surface on the through hole side, and has a higher heat transfer rate than the transparent member and the circuit board.

  ADVANTAGE OF THE INVENTION According to this invention, a camera module can be reduced in size, reducing the thermal influence which a signal processing element has on an image pick-up element.

  1 is a cross-sectional view of a camera module 1 according to an embodiment of the present invention, FIG. 2 is a rear view of the camera module 1 partially including a perspective view, and FIG. It is a disassembled perspective view shown.

  The camera module 1 is configured as, for example, an in-vehicle camera for imaging a white line on a road or a blind spot of a vehicle, and an ECU (electric control unit) (not shown) that controls the traveling of the automobile. ) Controls the operation. The electric signal output from the camera module 1 is processed by the ECU. For example, the ECU detects the position of a white line on the road based on the electrical signal from the camera module, assists the steering operation, and detects the position of surrounding vehicles and obstacles to control the vehicle. Then, an image is displayed on a display device (not shown).

  As illustrated in FIG. 1, the camera module 1 includes a lens group 2, an image sensor 3 on which light from the lens group 2 forms an image, a transparent base 4 that holds the image sensor 3, and signals from the image sensor 3. A signal processing element 5 to be processed, an electromagnetic shield heat dissipating body 6 on which the signal processing element 5 is mounted, an electronic circuit element 7 and a main substrate (laminate) 8 on which the electromagnetic shield heat dissipating body 6 is mounted; An external connector 9 that transmits and receives electrical signals to and from the outside is provided.

  The transparent substrate 4 or the transparent substrate 4 and the main substrate 8 are an example of a first holding unit, and the electromagnetic shield heat radiator 6 is an example of a second holding unit. The main base 8 is an example of a circuit board.

  In the lens group 2, for example, a first lens 11, a second lens 12, and a third lens 13 are aligned from the subject side, and each lens is made of glass or plastic. It should be noted that the number of lenses and the material of the lens group 2 may be optimized in accordance with the required angle of view and resolution characteristics.

  The lens group 2 is held and fixed by a substantially cylindrical lens barrel 14. The lens barrel 14 is made of, for example, a metal material such as aluminum or iron alloy or a resin material such as engineering plastic.

  The lens barrel 14 is accommodated in a substantially cylindrical lens holder 15. The lens holder 15 is formed of a metal material such as aluminum or iron alloy or a resin material such as engineering plastic.

  The lens barrel 14 and the lens holder 15 are fixed to each other by an adhesive or solder. The lens holder 15 is supported on the first main surface 8 b on the subject side of the main base 8. The lens holder 15 and the main base 8 are fixed to each other by, for example, an adhesive or solder.

  The imaging element 3 is composed of an optical semiconductor element such as a CCD or a CMOS, for example, and converts the light incident on the light receiving surface 3a into an electrical signal and outputs it. The image sensor 3 is mounted with the light receiving surface 3a facing the transparent substrate 4.

  The transparent substrate 4 is formed of a light-transmitting material such as glass or sapphire. The transparent substrate 4 may be configured by a filter that blocks a part of incident light and transmits the light to the image sensor 3. The filter is, for example, an IR filter that blocks unnecessary infrared rays.

  As shown in FIGS. 1 and 3, a through-hole 8 a that can accommodate the imaging device 3 and the signal processing element 5 is formed in the center of the main base 8, and the transparent base 4 is the first of the main base 8. The main surface 8b spans the through hole 8a and closes the through hole 8a. In other words, the transparent substrate 4 is supported on the edge side by the first main surface 8 b of the main substrate 8. The image pickup device 3 is fixed with the light receiving surface 3a facing the center side of the surface of the transparent substrate 4 on the through hole 8a side.

  A signal processing element (DSP: digital signal processor) 5 is configured by an IC including, for example, a CPU, a RAM, a ROM, and the like, and processes an electrical signal output from the imaging element 3. For example, the signal processing element 5 converts an analog signal output from the imaging element 3 into a digital signal, and generates image data. The image data generated by the signal processing element 5 is output to the ECU.

  The electromagnetic shield heat dissipating body 6 is made of, for example, a metal material mainly composed of Cu—W alloy, Fe—Ni—Co alloy, Al, Cu or the like. The electromagnetic shield heat dissipator 6 supports the holding unit 16 that holds the signal processing element 5, the shield unit 17 that supports the holding unit 16, and accommodates the main base 8, and a lid that covers the back surface 17 a of the shield unit 17. 18.

  The holding portion 16 is formed so as to protrude from the back surface portion 17a of the shield portion 17 to the lens group 2 side. The holding portion 16 may be solid or hollow, and may be formed separately from the back surface portion 17a and fixed to each other, or may be formed integrally. The upper surface of the holding unit 16 has an area equal to or larger than that of the signal processing element 5, and the signal processing element 5 is supported with the back surface in contact with the upper surface of the holding unit 16. The signal processing element 5 and the holding unit 16 are fixed by, for example, an adhesive or solder.

  The holding part 16 is inserted into the through hole 8 a of the main base body 8. The back surface portion 17 a that supports the holding portion 16 is fixed in contact with the second main surface 8 c of the main base 8 on the side opposite to the lens group 2. The height of the holding unit 16 is set lower than the thickness of the main base 8, and the difference is larger than the thicknesses of the image sensor 3 and the signal processing element 5. Therefore, the signal processing element 5 is disposed at a position separated from the back surface 3 b of the light receiving surface 3 a of the image sensor 3. For example, even if the main substrate 8 is not thicker than the imaging element 3 and the signal processing element 5, if the holding position of the imaging element 3 is raised by another member, the imaging element 3 and the signal processing element 5 are connected. Can be separated.

  The force in the direction in which the image sensor 3 and the signal processing element 5 are brought close to each other works as a force for compressing the main substrate 8 via the transparent substrate 4 and the electromagnetic shield heat radiator 6 (the holding unit 16 and the back surface portion 17a). . That is, the main base 8 functions as a spacer that holds the image sensor 3 and the signal processing element 5 in a separated state.

  Further, since the back surface portion 17a can be regarded as the bottom of the hole provided in the main base 8, the signal processing element 5 is supported by the bottom of the hole of the main base 8 via the holding portion 16. Can be caught.

  The imaging element 3, the signal processing element 5, the through-hole 8a, and the holding unit 16 may have an appropriate shape in plan view (as viewed in the optical axis direction), but are formed in, for example, a rectangle. The holding portion 16 is set to a size that creates a gap with the wall portion of the through hole 8 a, and heat generated by the heat generated by the signal processing element 5 is not directly transmitted from the holding portion 16 to the main base 8. It is like that.

  The shield part 17 is formed in a substantially rectangular parallelepiped shape as a whole, a back surface part 17 a fixed to the second main surface 8 c of the main base body 8, a side face part 17 b surrounding the side of the main base body 8, and the main base body 8. And a front surface portion 17c having an opening from which the lens holder 15 protrudes. 1 and 3 illustrate the case where the back surface portion 17a, the side surface portion 17b, and the front surface portion 17c are separately formed and joined to each other, but the back surface portion 17a and the side surface portion 17b are bent. For example, appropriate members may be integrally formed.

  The shield part 17 has a shielding function by being connected to the ground of the main base 8. The shield part 17 is connected to the ground of the main base 8 by, for example, contacting the back part 17 a with a ground electrode (not shown) provided on the second main surface 8 c of the main base 8. The shield unit 17 also serves as a housing that houses the imaging device 3, the transparent substrate 4, the signal processing device 5, the main substrate 8, and the like.

  A through hole 17d is provided in the back surface portion 17a, and the second main surface 8c of the main base 8 is exposed. The electronic circuit element 7 disposed on the second main surface 8c of the main base 8 is accommodated in the through hole 17d. The through hole 17 d is closed by the lid portion 18. The lid portion 18 is connected to the ground of the main base 8 through the back surface portion 17 a and shields the electronic circuit element 7. 1 to 3 exemplify a case where four through holes 17d are provided, and the four through holes 17d are closed by a single lid portion 18 having the same area as the back surface portion 17a. In addition, if the back surface part 17a and the cover part 18 are regarded as one member, it can also be regarded that the concave portion for accommodating the electronic circuit element 7 is provided in the member that contacts the second main surface 8c of the main base body 8.

  The electronic circuit element 7 is electrically connected to the image pickup element 3 and the signal processing element 5 through the in-base wiring of the main base body 8. The electronic circuit element 7 is, for example, an oscillation element such as a crystal for generating signal synchronization of the imaging element 3 and the signal processing element 5, a thermistor for monitoring the temperature of the camera module 1, a ceramic multilayer capacitor, a resistor, and a coil. FIG. 2 illustrates a case where a plurality of electronic circuit elements 7 are arranged in each of the plurality of through holes 17d.

  The main base 8 is made of, for example, a ceramic multilayer substrate. FIG. 3 illustrates a case where the main substrate 8 is configured by laminating seven substrates 19A to 19G (hereinafter referred to as “substrate 19”, each substrate may not be distinguished) 8d. . In the first main surface 8b, the second main surface 8c of the main base 8, the surface of each substrate 19, and the through holes (via holes) provided in each substrate 19, the image pickup element 3, the signal processing element 5, and the electronic circuit element Conductive paths connected to 7 etc. are provided. The main base 8 has the optical axis direction of the lens group 2 as the stacking direction, and the imaging element 3 and the signal processing element 5 are arranged in the stacking direction of the main base 8.

  For example, the connector 9 is disposed on the first main surface 8 b of the main base 8 and is electrically connected to the main base 8. For example, the connector 9 protrudes from an opening provided in the side surface portion 17b. A signal line (not shown) extends from the connector 9 and is connected to the ECU. The signal line is, for example, an electromagnetic shield signal line whose periphery is electromagnetically shielded. When the ECU is installed close to the camera module 1, a flat cable may be used as the signal line. In this case, the flat cable may be connected to the connector 9, or the flat cable may be directly connected to the main base body 8. It may be connected with solder or the like.

  FIG. 4 is an enlarged cross-sectional view showing the periphery of the image sensor 3 and the signal processing element 5.

  The transparent substrate 4 is fixed to the first main surface 8b of the main substrate 8 by, for example, solder 31. As shown by the hatching region R1 in FIG. 3, the solder 31 is disposed around the through hole 8a, and the first main surface 8b side of the through hole 8a is sealed by the transparent substrate 4. The back surface portion 17a of the shield portion 17 and the main base 8 are fixed by, for example, soldering or brazing. The fixing is performed at least around the through hole 8a, and the second main surface 8c side of the through hole 8a is sealed by the back surface portion 17a. Therefore, the through hole 8 a is hermetically sealed by the transparent substrate 4 and the shield part 17. In addition, it is preferable that a metallized layer is formed by a metal film such as Au or Al in the areas to be soldered of the transparent substrate 4 and the main substrate 8.

  As shown in FIG. 4, the imaging device 3 is fixed to the surface of the transparent substrate 4 on the main substrate 8 side by, for example, solder (solder balls) 33. The position of the solder 33 may be set as appropriate. For example, the solder 33 is disposed along the outer periphery of the image sensor 3.

  A conductive path 34 (first conductor) connected to the image sensor 3 is provided on the surface of the transparent substrate 4 on the main substrate 8 side. The conductive path 34 is configured by forming a conductive film made of a metal such as Au or Al on the surface of the transparent substrate 4 in a predetermined pattern. The conductive path 34 is connected to a terminal (not shown) provided on the light receiving surface 3 a side of the image sensor 3 by, for example, solder 33. In this case, at least a part of the solder 33 is used both for fixing the imaging device 3 to the transparent base 4 and for connecting the imaging device 3 and the conductive path 34.

  The conductive path 34 is electrically connected to a conductive path 35 provided on the main base 8. The conductive path 35 is exposed on the first main surface 8 b of the main base 8, and the conductive path 34 and the conductive path 35 are connected to each other by solder 36. The solder 36 is made of the same material as that of the solder 31, for example.

  A step is formed in the through hole 8a by reducing the diameter of the second main surface 8c from the vicinity of the signal processing element 5. The step is provided by forming the through holes of the substrates 19C to 19G smaller than the through holes of the substrates 19A and 19B on the first main surface 8b side.

  The conductive path 35 penetrates the substrates 19A and 19B from the first main surface 8b, and then extends into the through hole 8a along the surface of the substrate 8C to the bonding region BR formed on the surface of the substrate 19C on the substrate 19B side. Extend. The conductive path 35 in the bonding region BR and a terminal (not shown) provided on the surface of the signal processing element 5 facing the image sensor 3 are connected by wire bonding. In FIG. 4, all the substrates after the substrate 19C protrude into the through hole 8a. However, the bonding region BR is formed in the through hole 8a by protruding only the substrate 19C or an appropriate number. Is also possible.

  The outline of the assembly process of the camera module 1 having the above configuration is as follows.

  First, the main base 8 on which the electronic circuit element 7 is mounted and the back surface portion 17a on which the signal processing element 5 is mounted are fixed to each other. However, the electronic circuit element 7 and the signal processing element 5 may be mounted after the main base body 8 and the back surface portion 17a are fixed. Then, the signal processing element 5 and the conductive path 35 are connected by wire bonding.

  Next, the transparent substrate 4 on which the image sensor 3 is mounted is fixed to the main substrate 8. Specifically, the solder 31 and the solder 36 are disposed between the transparent base 4 and the main base 8 and heated to melt the solder 31 and the solder 36, and then the heating is finished to remove the solder 31 and the solder 36. Fix by solidifying. At this time, it is preferable that the solder 33 is made of a material having a higher melting point than the solder 31 and the solder 36 and is heated at a temperature lower than the melting point so that the image pickup device 3 does not fall from the transparent substrate 4.

  Then, the lens holder 15 is fixed to the main base 8, and the lens barrel 14 holding the lens group 2 is fixed to the lens holder 15. When the lens barrel 14 and the lens holder 15 are fixed, for example, a photographing chart is arranged at an optimum position on the front surface of the lens as a subject, and a photographing chart image passing through the lens group is photographed by the imaging device 3 as a subject. By fixing the lens group at the optimal position in the optical axis direction while viewing the image, it is possible to adjust the imaging characteristics so that the camera module 1 is focused at an appropriate position in light of the purpose of use.

  According to the above embodiment, since the signal processing element 5 is arranged on the back surface 3b side of the image pickup device 3 so as to be separated from the back surface 3b, the heat generated by the signal processing element 5 is directly applied to the image pickup device 3. In addition, since at least part of the dead space on the back side of the image sensor 3 is used as at least part of the arrangement space of the signal processing element 5, the signal processing element 5 exerts on the image sensor 3. The camera module 1 can be reduced in size while reducing the thermal effect. Since the signal processing element 5 is disposed on the back surface of the imaging element 3 and the distance between the imaging element 3 and the signal processing element 5 is short, it is possible to prevent noise from being mixed with the signal from the imaging element 3.

  Since the signal processing element 5 is held by the holding portion 16 of the electromagnetic shield heat dissipating body 6 having a higher heat transfer rate than the transparent base 4 and the main base 8, the heat generated by the signal processing element 5 passes through the electromagnetic shield heat dissipating body 6. Therefore, the influence of the signal processing element 5 on the image pickup element 3 is further reduced.

  Since the electromagnetic shield heat dissipating body 6 is also used as a heat dissipating member in contact with the signal processing element 5 and a shield body such as the image pickup element 3 and the signal processing element 5, it is possible to reduce the size while improving heat dissipation. Can do.

  The electromagnetic shield heat dissipating body 6, more specifically, the holding portion 16, is formed of a metal containing at least one of Cu, Al, Cu—W alloy, and Fe—Ni—Co alloy as a main component. In addition to good heat dissipation, these metals have a relatively close expansion coefficient to ceramics. Therefore, heat can be efficiently radiated from the electromagnetic shield heat radiating body 6 and positional deviation between the electromagnetic shield heat radiating body 6 and the main base body 8 due to thermal expansion is suppressed.

  Since the spacer that separates the image pickup element 3 and the signal processing element 5 includes the main substrate 8 as a circuit board, there is no need to newly arrange a member as the spacer, and the camera module can be downsized. It is done. Since the main substrate 8 is composed of a ceramic multilayer substrate, the thickness of the main substrate 8 can be easily set. As a result, the image sensor 3 and the signal processing elements 5 arranged in the stacking direction of the substrate are arranged. Position setting is easy.

  Furthermore, the connection between the image pickup element 3 and the signal processing element 5 and the conductive path of the main base 8 can be easily made three-dimensionally. For example, by bonding the substrate 19C to the through-hole 8a side from the substrates 19A and 19B closer to the imaging element 3 than the substrate 19C, a bonding region that connects the signal processing element 5 and the conductive path 35 of the ceramic multilayer substrate. BR can be easily formed.

  The image processing element 5 and the signal processing element 5 are fixed to the transparent base 4 and the electromagnetic shield heat dissipating body 6 that hermetically seal the through hole 8a, thereby separating the signal processing element 5 from the back surface 3b of the image capturing element 3. Further, it is not necessary to provide a new member for separating the image pickup device 3 and the signal processing device 5, and the camera module can be reduced in size.

  By fixing the image sensor 3 to the filter of the image sensor 3, the signal processing element 5 is separated from the back surface 3 b of the image sensor 3, and thus a new member for separating the image sensor 3 and the signal processing element 5. Therefore, the camera module can be reduced in size.

  Since the conductive path 34 is disposed in the transparent substrate 4 that holds the image pickup device 3 away from the signal processing device 5, the size can be reduced, and when the image pickup device 3 is fixed to the transparent substrate 4, The imaging element 3 can be connected to the conductive path 34, and the assembly is facilitated.

  Since the transparent base 4 and the main base 8 are fixed to each other and the conductive path 34 and the conductive path 35 are connected by solder (31, 36), the transparent base 4 is fixed to the main base 8 and conductive. The connection between the path 34 and the conductive path 35 can be performed simultaneously by the heating process, and the assembly process is shortened.

  Further, by combining the above features, it is possible to reduce the size while reducing the thermal influence on the image pickup device 3 more effectively.

  The present invention is not limited to the above embodiment, and may be implemented in various aspects.

  The image pickup element and the signal processing element may be held by the transparent substrate, the circuit board (main substrate), and the electromagnetic shield heat radiator as long as the signal processing element is separated from the back side of the image pickup element. It is not limited to things.

  For example, the image pickup device 3 may be directly supported by the first main surface 8b of the main substrate 8 without providing the transparent substrate 4, or instead of the transparent substrate 4, the image pickup device is formed by a frame spanning the through hole 8a. 3 may be supported. Instead of supporting the transparent substrate 4 by the main substrate 8, a boss protruding from the back surface portion 17a of the electromagnetic shield heat dissipating body 6 toward the lens group 2 may be provided, and the transparent substrate 4 may be supported by the boss. Instead of holding the signal processing element 5 by the electromagnetic shield radiator 6, the signal processing element 5 may be supported by the main substrate 8.

  FIG. 5 is an enlarged cross-sectional view around the imaging device 3 and the signal processing device 5 showing a modification of the embodiment of the present invention. In FIG. 5, a recess 108 a is formed in the main base 108 instead of the through hole 8 a of the embodiment. And the signal processing element 5 is being fixed to the bottom part of the recessed part 108a. A plurality of thermal via holes 141 filled with a metal 142 are formed from the bottom of the recess 108 a to the second main surface 108 c of the main base 108. That is, a heat radiator having higher heat conductivity than the transparent substrate 4 and the main substrate 8 is disposed so as to penetrate the substrate, and is in contact with the signal processing element 5. The heat generated by the signal processing element 5 is efficiently released to the second main surface 108 c side through the metal 142 of the thermal via hole 141.

  In the modification of FIG. 5 as well, the force for bringing the image sensor 3 and the signal processing element 5 close to each other is the direction in which the portion Sp on the image sensor 3 side from the mounting surface of the signal processing element 5 in the main base 108 is compressed. Therefore, it can be said that the spacer that separates the imaging device 3 and the signal processing device 5 includes a part (Sp) of the circuit board.

  When the spacer that separates the imaging element and the signal processing element includes a part of the circuit board, the space where the imaging element and the signal processing element are arranged is not limited to the through hole. For example, a recess as shown in FIG. 5 may be used. Further, as shown in FIG. 6A, when viewed in the optical axis direction, a space is provided in the main base body 208 by the cutout portion 208a, and the transparent substrate 4 may be stretched over the cutout portion 208. However, as shown in FIG. 6B, a void may be formed by the gap 308a between the main base bodies 308, and the transparent base 4 may be spanned across the gap 308a. However, if the void is a hole that is closed when viewed in the optical axis direction as in the through hole of the embodiment, it is easy to seal the imaging element or the like with the transparent substrate 4.

  In the present application, the term “vacant space” includes a hole that is closed when viewed in the optical axis direction as in the embodiment, and the optical axis direction as shown in FIGS. 6 (a) and 6 (b). The term “hole” includes a through hole as in the embodiment and a concave portion as shown in FIG. 5.

Sectional drawing of the camera module of embodiment of this invention. FIG. 2 is a rear view including a perspective view of a part of the camera module of FIG. 1. FIG. 2 is an exploded perspective view of a part of the camera module of FIG. 1. Sectional drawing which expands and shows the image pick-up element periphery of FIG. The partially expanded sectional view which shows the modification of embodiment of this invention. The top view which shows the modification of embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Camera module, 3 ... Image pick-up element, 3a ... Light-receiving surface, 3b ... Back surface, 5 ... Signal processing element.

Claims (13)

An image sensor that converts light incident on the light receiving surface into an electrical signal;
A signal processing element that is disposed on the back side of the light receiving surface of the image sensor and is separated from the back surface, and that processes an electrical signal converted by the image sensor;
A first holding unit for holding the image sensor;
A second holding unit that holds the signal processing element from the side opposite to the imaging element;
With
In the heat transfer path from the signal processing element to the imaging element, the second holding unit and the first holding unit are sequentially interposed,
The second holding unit has a higher heat transfer rate than the first holding unit, and extends away from the first holding unit . The camera module according to claim 1 , wherein the second holding unit surrounds the imaging element and the signal processing element, has conductivity, and is connected to a ground. The first holding part is configured to include ceramics,
Said second holding unit, a camera module according Cu, Al, a Cu-W alloy, Fe-Ni-Co claim 1 or 2 is formed by metal mainly composed of at least one of the alloy. A circuit board including a conductive path connected to at least one of the imaging element and the signal processing element;
The camera module according to claim 1, wherein the first holding unit includes at least a part of the circuit board. The circuit board is provided with a through hole,
The image sensor and the signal processing element are housed in the through hole apart from each other in the through direction of the through hole,
The first holding unit includes the circuit board and a member that is stretched over the through-hole in one main surface of the circuit board and holds the imaging element .
The camera module according to claim 4 , wherein the second holding unit includes a member that is spanned by the through hole on the other main surface of the circuit board and holds the signal processing element . The camera module according to claim 4 , wherein the circuit board is provided with an electronic circuit element that controls an operation of at least one of the imaging element and the signal processing element. The camera module according to any one of claims 4 to 6 , wherein the circuit board is a ceramic multilayer board in which an arrangement direction of the imaging element and the signal processing element is a lamination direction. The image sensor and the signal processing element are disposed in a space provided in the ceramic multilayer substrate,
Of the plurality of substrates constituting the ceramic multilayer substrate, a second substrate positioned closer to the signal processing element than the predetermined first substrate in the direction from the imaging element to the signal processing element is from the first substrate. projecting also to the cavity side, the the surface of the first substrate side of the second substrate, wherein the signal processing element and the ceramic multilayer substrate and connected to claim bonding region is formed where the wire is secured 7 The camera module as described in. Have a recess in which the imaging device and the signal processing device is housed, a multilayer substrate in which a plurality of substrates are formed by laminating an opening direction of the recess as a stacking direction,
A transparent member that hermetically seals the recess and transmits light to the imaging element;
With
The first holding unit includes a substrate in which an opening constituting the concave portion of the multilayer substrate is formed, and the transparent member.
The second holding unit includes a substrate constituting the bottom of the concave portion of the multilayer substrate, and a radiator that penetrates the bottom of the concave portion in the stacking direction of the multilayer substrate,
The second holding part is formed to have a higher heat transfer rate than the first holding part because the heat radiator has a higher heat transfer rate than the multilayer substrate.
The image pickup device is fixed to the transparent member with the light receiving surface facing each other, and the signal processing device is supported on the bottom of the recess , so that the signal processing device is arranged away from the back surface of the image pickup device. The camera module according to claim 1. The first holding unit includes a filter that blocks a part of incident light and transmits the incident light to the imaging element, and is arranged at a position spaced from the signal processing element with the edge side supported .
2. The camera according to claim 1, wherein the signal processing element is spaced apart from the back surface of the imaging element by fixing the imaging element with the light receiving surface facing the center side of the filter. module. The first holding unit includes a transparent member that transmits incident light to the imaging element and is disposed at a position spaced from the signal processing element by supporting an edge side .
The image sensor is fixed to the center side of the transparent member with the light receiving surface opposed to the signal processing element so that the signal processing element is spaced apart from the back surface of the image sensor, and the image sensor of the transparent member The camera module of Claim 1. The conductor connected with the said image pick-up element is arrange | positioned at the surface which opposes. A circuit board having a space in which the imaging element and the signal processing element are stored;
A transparent member fixed to the circuit board so as to cover the void;
With
The first holding part includes the transparent member and a portion of the circuit board on the surface side where at least the transparent member is disposed,
A surface of the transparent member that faces the circuit board is provided with a first conductor that is fixed with the imaging element facing the light receiving surface and connected to the imaging element,
The surface of the circuit board facing the transparent member is provided with the second conductor connected to the signal processing element and the first conductor,
The camera module according to claim 1, wherein the transparent member and the circuit board are fixed and the first conductor and the second conductor are connected by solder. The first holding part is
A circuit board provided with a conductive path connected to at least one of the image sensor and the signal processing element, wherein the image sensor and the signal processing element are housed separately from each other in a penetration direction A circuit board having
A transparent member that seals one of the through-holes and fixes the light-receiving surface of the imaging element to the surface on the through-hole side ;
The second holding portion includes a heat radiating body that seals the other of the through holes, the signal processing element is fixed to a surface on the through hole side, and has a higher heat transfer rate than the transparent member and the circuit board.
The camera module according to claim 1 .

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