JP5623184B2 - Wiring board and imaging device - Google Patents

Description

  The present invention relates to a wiring board for accommodating and mounting an electronic component such as a semiconductor element.

  Conventionally, a ceramic substrate is used as a wiring board on which electronic components are mounted and incorporated in an electronic device. Some electronic components mounted have physical properties such as electrical conductivity that change depending on temperature. For example, this characteristic is particularly remarkable in a semiconductor element. For example, in an imaging element such as a CMOS type or CCD type image sensor using a semiconductor, a change in element temperature affects light receiving sensitivity, and the temperature of the element. Sensitivity unevenness corresponding to the unevenness occurs, resulting in unevenness in the image. In addition, as an electronic component to be mounted, an infrared sensor element that measures the temperature of an object in a non-contact manner by heating the element with infrared rays using a property that physical properties change with temperature, or a night vision camera Infrared imaging devices used for the above are known. In a wiring board on which such an electronic component is mounted, a technique for releasing heat to the outside by attaching a heat sink to the wiring board is known in order to prevent the temperature of the electronic component from becoming non-uniform ( For example, see Patent Document 1.) In addition, the temperature of the element mounting surface is made uniform by technology that cools electronic components using cooling water and Peltier elements, and by heating the low-temperature part of the element using a heater. The technology to make is also known.

JP-A-2005-101484

  However, in recent years, it has become difficult to secure a portion where a heat sink, a flow path of cooling water, and a Peltier element are provided on the wiring board as the electronic device is reduced in size, thickness, and accuracy. In addition, when heating a low temperature part of an electronic component with a heater, the entire surface of the mounting part is heated with a heater in order to make the temperature of the mounting part of the electronic component uniform. It was.

  The present invention has been devised in view of the above problems of the prior art, and an object of the present invention is to provide an electronic component mounting board capable of uniformly setting the temperature of the mounted electronic component with low power consumption. is there.

The wiring board of the present invention includes an insulating substrate having a mounting region on the upper surface, a plurality of connection electrodes disposed on the upper surface of the insulating substrate, one end connected to the connection electrode and the other end on the outer surface of the insulating substrate. In a wiring board provided with a drawn wiring conductor, a plurality of low thermal conductivity parts having a lower thermal conductivity than the insulating substrate are formed around the mounting area so as to surround the mounting area. A low thermal conductive portion is further formed in the lower insulating substrate, and the low thermal conductive portion formed in the insulating substrate under the mounting region is opened only on the lower surface of the insulating substrate . It is characterized by.

  Moreover, the wiring board of the present invention is characterized in that, in the above configuration, a heater is disposed between the low thermal conductive portions of the insulating substrate.

  The wiring board according to the present invention is characterized in that, in the above configuration, the connection electrode is disposed outside the low heat conduction portion on the upper surface.

  The image pickup apparatus of the present invention is characterized in that an image pickup element is mounted in the mounting region of the wiring board of the present invention.

  According to the wiring board of the present invention, the insulating substrate having the mounting region on the upper surface, the plurality of connection electrodes arranged on the upper surface of the insulating substrate, one end connected to the connection electrode and the other end outside the insulating substrate. In a wiring board provided with wiring conductors drawn to the surface, a plurality of low thermal conductivity parts having a lower thermal conductivity than the insulating substrate are formed around the mounting area so as to surround the mounting area. Heat generated by the electronic component is not easily transmitted to the area around the mounting area. In addition, heat from the area around the mounting area and from the outside of the wiring board is less likely to be transmitted to the mounting area. Accordingly, the heat is diffused into the mounting region, and the wiring substrate has a uniform temperature in the mounting region.

  According to the wiring board of the present invention, when the low thermal conductive portion is formed in the insulating substrate below the mounting region, heat input / output from the lower surface of the mounting region is suppressed, and the temperature of the upper surface of the mounting region is reduced. Can be made more uniform.

  According to the wiring board of the present invention, when the heater is disposed between the low thermal conductive portions of the insulating substrate, the electronic component is mounted by heating the low thermal conductive portions of the insulating substrate with the heater. Or higher. Since the temperature of the electronic component is equal to or lower than the temperature of the heater, the heat of the electronic component is not transmitted to the outside through the space between the low thermal conductive portions of the insulating substrate. Therefore, the temperature of the mounting area can be made more uniform.

  According to the wiring board of the present invention, when the connection electrode is disposed outside the low heat conduction portion on the upper surface, the wiring conductor extends across the mounting region and the region outside the low heat conduction portion in the insulating substrate. Since it is not disposed, heat is not transmitted between the mounting region and the low thermal conduction portion via the wiring conductor. Therefore, the temperature of the mounting area can be made more uniform.

  In addition, since the imaging device of the present invention is mounted in the mounting area of the wiring board having the above-described configuration, the imaging device is small and can output a uniform image signal.

(A) is a top view which shows an example of embodiment of the wiring board of this invention, (b) is sectional drawing in the AA of (a). It is a top view which shows the other example of embodiment of the wiring board of this invention. (A) is a top view which shows the other example of embodiment of the wiring board of this invention, (b) is sectional drawing in the AA of (a). (A) is a top view which shows the other example of embodiment of the wiring board of this invention, (b) is sectional drawing in the AA of (a). (A) is a top view which shows the other example of embodiment of the wiring board of this invention, (b) is sectional drawing in the AA of (a), (c) is (a). It is sectional drawing in the BB line. (A) is a top view which shows the other example of embodiment of the wiring board of this invention, (b) is sectional drawing in the AA of (a). (A) is a top view which shows the other example of embodiment of the wiring board of this invention, (b) is sectional drawing in the AA of (a). (A) is sectional drawing which shows an example of embodiment of the imaging device of this invention, (b) is sectional drawing which shows the other example of embodiment of imaging device of this invention.

  The imaging device and imaging device module of the present invention will be described with reference to the accompanying drawings. 1 to 8, 1 is an insulating substrate, 2 is a mounting region, 3 is a connection electrode, 4 is a wiring conductor, 5 is a low heat conduction part, 5a is a through hole, 6 is a heater, 7 is an image sensor, and 7a is a light receiving device. , 8 is a connection member, 9 is a lid, 10 is a translucent member, 11 is a bonding material, and X is a bridge. In addition, although Fig.1 (a) and FIG. 2 are top views, the bridge part X is provided with hatching so that it may be recognized easily.

  1 to 8, the wiring board of the present invention includes an insulating substrate 1 having a mounting region 2 on the upper surface, a plurality of connection electrodes 3 disposed on the upper surface of the insulating substrate 1, and one end thereof. In a wiring board provided with a wiring conductor 4 connected to the connection electrode 3 and having the other end drawn to the outer surface of the insulating substrate 1 around the mounting area 2, the mounting area 2 is provided around the mounting area 2. Since a plurality of low thermal conductive parts 5 having a lower thermal conductivity than the insulating substrate 1 are formed so as to surround the mounting substrate 2, the mounting region 2 and the region around the mounting region 2 are between the low thermal conductive units 5. They are connected in a region X having a small width. Therefore, even if a part of the mounted electronic component generates heat, the heat is not easily transmitted to the area around the mounting area 2 through the small area X, and is easily diffused to the mounting area 2. Further, the heat transmitted from the outside of the wiring board to the mounting area 2 is generated by the electronic components mounted around the electronic device when the electronic device having the electronic components mounted on the wiring board is mounted on the external circuit board. It is. Since such heat is transmitted to the wiring board via the external circuit board, the wiring conductor 4 of the external circuit board, or the gas around the wiring board, the amount of heat transferred from the outer peripheral side of the wiring board to the mounting region 2 in a plan view. Many. Therefore, with the above configuration, heat from the area around the mounting area 2 and the outside of the wiring board is less likely to be transmitted from the periphery of the mounting area 2 to the mounting area 2 through the area X having a small width. The wiring board can be made uniform in temperature.

  Further, in each of the examples shown in FIGS. 1 and 2, the mounting region 2 is disposed in the center of the insulating substrate 1, and the wiring conductor 4 and the connection electrode 3 serving as external terminals are disposed outside the low heat conducting portion 5 on the upper surface. Has been. In such a case, the wiring conductor 4 is not disposed in the insulating substrate 1 across the mounting region 2 and the region outside the low heat conducting portion 5. Therefore, heat is not transmitted between the mounting region 2 and the region outside the low thermal conductive portion 5 via the wiring conductor 4, and the region X (hereinafter “bridge”) between the low thermal conductive portions 5 of the insulating substrate 1. Heat is transferred only through part X). Therefore, it is effective for making the temperature of the mounting region 2 more uniform.

  Further, as in the example illustrated in FIGS. 4 to 6, the low thermal conductive portion 5 may be formed inside the insulating substrate 1 below the mounting region 2. In such a case, since the bridge portion X can be made smaller, it is difficult for heat to be transmitted to the outside from the lower portion of the mounting region 2. Therefore, even if a part of the mounted electronic component generates heat, the heat is hardly transmitted to the outside, and the temperature of the mounting region 2 can be made more uniform. Further, when the thickness of the insulating substrate 1 is reduced, the heat conducted in the thickness direction of the insulating substrate 1 is larger than the heat conducted in the planar direction of the insulating substrate 1. It is more effective to provide the low thermal conduction portion 5 on the insulating substrate 1.

  Further, as in the example shown in FIG. 4, when the low thermal conductivity portion 5 is formed to be smaller than the mounting region 2 in a plan view, the thickness of the insulating substrate 1 below the mounting region 2 can be reduced. This is effective for making the temperature of the substrate 1 uniform. Moreover, compared with the case where the low heat conduction part 5 is not provided in the insulated substrate 1 under the mounting area | region 2, the part which connects the mounting area 2 and the outer side of the low heat conduction part 5 in the lower surface side of the low heat conduction part 5 is. Since it becomes long, it becomes difficult to transmit heat from the lower surface side of the insulating substrate 1.

Further, as shown in the example of FIG. 5, when the low thermal conductivity portion 5 below the mounting region 2 and the low thermal conductivity portion 5 around the mounting region 2 are connected in plan view, Since heat is unlikely to accumulate in the low heat conducting portion 5, it is effective for making the mounting region 2 uniform while lowering the temperature.

  Further, as in the example shown in FIG. 6, the low thermal conductive portion 5 may be opened on the lower surface of the wiring board. In such a case, processing is easier than in the examples shown in FIGS.

  Moreover, when the heater 6 is arrange | positioned between the low heat conductive parts 5 of the insulated substrate 1 like the example shown in FIG. 7, the bridge part X is heated with the heater 6, and the temperature of the bridge part X is shown. The temperature can be higher than the temperature of the electronic component to be mounted. Since the temperature of the electronic component is equal to or lower than the temperature of the heater 6, the heat of the electronic component is not transmitted to the outside through the bridge portion X. Therefore, a wiring board capable of making the temperature of the mounting region 2 more uniform is obtained.

  The insulating substrate 1 is made of an insulator such as ceramics or resin. When made of ceramics, for example, aluminum oxide sintered bodies (alumina ceramics), aluminum nitride sintered bodies, mullite sintered bodies, glass ceramic sintered bodies, and the like can be mentioned. , Fluororesins such as epoxy resin, polyimide resin, acrylic resin, phenol resin, polyester resin, and tetrafluoroethylene resin. Moreover, what impregnated resin to the base material which consists of glass fibers like glass epoxy resin is mentioned.

When the insulating substrate 1 is made of, for example, an aluminum oxide sintered body, organic materials suitable for raw material powders such as alumina (Al ₂ O ₃ ), silica (SiO ₂ ), calcia (CaO), and magnesia (MgO) are used. A ceramic green sheet is obtained by adding a solvent and a solvent to form a slurry, and forming this into a sheet using a conventionally known doctor blade method, calendar roll method, etc. The sheet is manufactured by performing an appropriate punching process, stacking a plurality of sheets as necessary, and firing at a high temperature (about 1500 to 1800 ° C.). When a recess is provided in the wiring board as in the example shown in FIG. 8B, a through hole for the recess is punched out by a mold or punching or laser in some of the ceramic green sheets for the insulating substrate 1. It can be formed by forming by a processing method or the like. Further, in FIG. 8B, a plurality of recesses are provided, which are formed by forming through holes for recesses having different sizes in a ceramic green sheet and laminating these ceramic green sheets. A plurality of recesses can be formed.

  When the insulating substrate 1 is made of, for example, a resin, it can be molded by a transfer molding method, an injection molding method, or the like using a mold that can be molded into a predetermined wiring board shape. Further, for example, a glass fiber base material impregnated with a resin, such as glass epoxy resin, in this case, a glass fiber base material is impregnated with an epoxy resin precursor, The epoxy resin precursor can be formed by thermosetting at a predetermined temperature. In the case where the low thermal conductive portion 5 is formed inside the wiring board, the low heat conduction part 5 may be shaped into a predetermined shape using a plurality of molds, and then bonded together using an adhesive or the like to form a wiring board. When the heater 6 is provided on the wiring board using the insulating substrate 1 made of resin, the resin preferably has heat resistance.

  The low thermal conductive portion 5 can be formed by forming a hole for the low thermal conductive portion 5 in the insulating substrate 1 and filling the hole with a member having a lower thermal conductivity than the insulating substrate 1. As the member having a low thermal conductivity, a resin having a thermal conductivity lower than that of the insulating substrate 1 or an atmosphere (for example, air) in a use environment can be used. As the resin having a low thermal conductivity, for example, if the insulating substrate 1 is made of ceramics, a resin material such as an epoxy resin, a polyimide resin, and an acrylic resin can be used. In addition, it is more effective when the low heat conductive part 5 or the insulating substrate 1 is sealed with a metal, glass, or the like to place the low heat conductive part 5 in a vacuum state.

  Moreover, the low heat conductive part 5 may have the through-hole 5a which penetrated a part of the insulated substrate 1 like the example shown in FIG. 3, and the low heat conductive part 5 like the example shown in FIG. All may penetrate through the insulating substrate 1. If sealing is necessary at this time, a sealing material (glass, resin, etc.) having a lower thermal conductivity than that of the insulating substrate 1 may be put in the through hole 5a, and sealing is performed partially in the depth direction. You may put a sealing material as much as possible. As the sealing material, for example, a member having a low thermal conductivity used for the low thermal conductivity portion 5 can be used. In such a case, compared with the case where the through hole 5a is not formed, the cross-sectional area of the portion connecting the mounting region 2 and the outside of the low heat conductive portion 5 on the lower surface side of the low heat conductive portion 5 is reduced. Therefore, the heat is more difficult to be transmitted to the outside, and the heat of the high temperature part of the electronic component is not easily transmitted to the low temperature part of the electronic component. Therefore, a wiring board capable of making the temperature of the mounting region 2 more uniform is obtained. Moreover, when the sealing material is put in a part of the through hole 5a in the depth direction, the atmosphere of the operating environment enters the part where the sealing material is not put, so the sealing material is put in the whole depth direction. Compared to the case, the thermal conductivity of the low thermal conduction part 5 can be lowered.

  Moreover, if the insulating substrate 1 is made of ceramics, the low thermal conductive portion 5 is prepared by preparing a plurality of ceramic green sheets having through holes to be the low thermal conductive portions 5, and arranging these ceramic green sheets in an appropriate order. A hole to be the low heat conduction portion 5 can be formed by stacking and firing. In addition, the size of the low heat conduction part 5 is about 0.1 mm to 0.5 mm in width when the low heat conduction part 5 is grooved to prevent the opening of the low heat conduction part 5 from being closed during firing. In this case, the thickness is preferably about 0.1 mm to 0.5 mm. Further, when the insulating substrate 1 is made of resin, it can be formed by a transfer mold method, an injection mold method, or the like using a mold capable of forming a hole for the low heat conduction portion 5.

  Further, when the insulating substrate 1 is made of ceramics, when the laminated body that becomes the wiring substrate is fired in a state where the low thermal conductive portion 5 in the insulating substrate 1 under the mounting region 2 is sealed, the low thermal conductive portion 5 Since the internal substance may expand and deform or damage the insulating substrate 1, it is preferable to open the low heat conducting portion 5. The opening of the low thermal conductive portion 5 in the insulating substrate 1 below the mounting region 2 is located on the inner surface of the hole for the low thermal conductive portion 5 formed so as to surround the mounting region 2 around the mounting region 2 in plan view. Just do it. Further, after providing a plurality of ceramic green sheets by providing openings in the low thermal conductive portion 5 to obtain a plurality of wiring boards, the plurality of wiring boards are made of a conductive resin (anisotropic conductive resin or the like) or the like. You may obtain the wiring board by which the low heat conductive part 5 was sealed by joining.

  It is preferable to reduce the number of bridge portions X while reducing the cross-sectional area. However, when the low thermal conductivity portion 5 is vacuum or gas, reducing the cross-sectional area of the bridge portion X and reducing the number of the bridge portions X increases the possibility that the bridge portion X will be damaged by impact or the like. In addition, the bridge portion X is preferably in the shape of a prism having a size of about 1 mm × 1 mm in plan view and about 2 to 4 places. In addition, it is preferable that the prismatic bridge portion be chamfered because the corner portion X can be prevented from being broken by an impact or the like. Moreover, when the low heat conductive part 5 is filled with resin, for example, and sufficient strength can be secured, the bridge part X having the above dimensions may be provided at one place.

  The connection electrode 3 is preferably disposed outside the low thermal conductive portion 5 of the insulating substrate 1. By arranging the connection electrode 3 in this way, heat does not enter from the outside through the wiring conductor 4 which is an external terminal, and is not transmitted to the mounting region 2 through the wiring conductor 4 which is a metal and has high thermal conductivity. Moreover, since the wiring conductor 4 does not pass through the bridge portion X, the arrangement of the wiring conductor 4 is easy.

The wiring conductor 4 serving as an external terminal is preferably arranged outside the low heat conducting portion 5 of the insulating substrate 1. Since the external terminal into which heat enters is located outside the mounting region 2, it is more effective to suppress the heat from being transferred to the mounting region 2 by the low heat conduction portion 5 around the mounting region 2. When the low thermal conductive portion 5 is present in the insulating substrate 1 below the mounting region 2, external terminals are arranged so that the low thermal conductive portion 5 is located between the mounting region 2 and the wiring conductor 4 serving as an external terminal. Just place it.

  When the insulating substrate 1 is made of ceramic, the connection electrode 3 and the wiring conductor 4 are made of metal powder metallization such as tungsten (W), molybdenum (Mo), manganese (Mn), silver (Ag), and copper (Cu). The conductor paste for the wiring conductor 4 is printed in a predetermined shape on the ceramic green sheet for the insulating substrate 1 by a screen printing method or the like, and is fired simultaneously with the ceramic green sheet for the insulating substrate 1, whereby a predetermined position on the wiring substrate is obtained. Formed. Of the internal conductors, the through conductor that penetrates the ceramic green sheet in the thickness direction may be filled with a through hole formed in the ceramic green sheet by printing a conductor paste. Such a conductive paste is prepared by adding an appropriate solvent and a binder to the metal powder and kneading them to adjust to an appropriate viscosity. In order to increase the bonding strength with the wiring board, glass or ceramics may be included.

  Further, when the insulating substrate 1 is made of resin, the connection electrode 3 and the wiring conductor 4 are made of a metal material such as copper, gold, aluminum, nickel, chromium, molybdenum, titanium, and alloys thereof. For example, the copper foil processed into the shape of the connection electrode 3 and the wiring conductor 4 is transferred onto a resin sheet made of glass epoxy resin, and the resin sheet to which the copper foil is transferred is laminated and bonded with an adhesive. . Of the internal conductors, the through conductors that penetrate the resin sheet in the thickness direction can be deposited on the inner surface of the through holes formed in the resin sheet by conductor paste printing or plating, or by filling the through holes. Good. Further, it is formed by integrating a metal foil or a metal column by resin molding, or by depositing the insulating substrate 1 using a sputtering method, a vapor deposition method, a plating method or the like.

  As the heater 6, a resistance heating element such as a nickel-chromium alloy (nichrome wire), a chromium-aluminum-iron alloy (kanthal wire), molybdenum (Mo), tantalum (Ta), or tungsten (W) can be used. . When such a heater 6 is formed of the same material as that of the wiring conductor 4, that is, the insulating substrate 1 is made of ceramics, it is preferable to simultaneously form the heater 6 using, for example, molybdenum, tungsten or the like because productivity can be improved. In such a case, the heater 6 can be easily formed by forming the wiring conductor 4 in a vortex shape or a meandering shape at the bridge portion X so that the amount of heat generated is larger than that of the other wiring conductors 4. Moreover, the through-hole 5a may be arrange | positioned as the low heat conductive part 5 between the heater 6 and the mounting area | region 2 like the example shown in FIG. In such a case, since the through-hole 5a is provided between the heater 6 and the mounting region 2, it is possible to reliably prevent the mounting region 2 from being excessively heated by the heater 6. At the same time, it is preferable because heat can be prevented from being transmitted from the bridge portion X to the outside. Further, if the heater 6 is provided inside the insulating substrate 1 of the bridge portion X, the entire insulating substrate 1 of the bridge portion X can be heated, so that the surroundings of the mounting region 2 and the mounting region 2 are interposed via the insulating substrate 1. It is effective to suppress the transmission of heat between the two. In the case where the insulating substrate 1 is made by stacking a plurality of ceramic green sheets, a conductor paste to be the heater 6 is formed on the ceramic green sheets by, for example, screen printing, and then the ceramic green sheets are further laminated to form a heater. 6 can be easily formed inside the insulating substrate 1.

A plating layer is deposited on the exposed surfaces of the connection electrode 3 and the wiring conductor 4 by a plating method such as an electrolytic plating method or an electroless plating method. The plating layer is made of a metal having excellent corrosion resistance, such as nickel and gold, and connectivity with the connection member 8, for example, a nickel plating layer having a thickness of about 1 to 10 μm and a gold plating having a thickness of about 0.1 to 3 μm. The layers are deposited sequentially. Accordingly, corrosion of the connection electrode 3 and the wiring conductor 4 can be effectively suppressed, the connection electrode 3 and the connection member 8 are joined, the wiring conductor 4 exposed to the outside, and the wiring conductor of the external circuit board. Can be strengthened.

Further, the image pickup apparatus of the present invention is characterized in that an image pickup element 7 is mounted in the mounting region 2 of the wiring board having the above-described configurations as in the example shown in FIGS. Is. With such a configuration, the imaging device can output a small and uniform image signal.

  In the imaging apparatus of the example shown in FIG. 8, the imaging element 7 is disposed in the mounting area 2 of the wiring board having the above-described configuration, and the imaging element 7 and the connection electrode 3 are electrically connected using the connection member 8. ing. When the imaging device 7 is mounted on the wiring board by wire bonding as in the example shown in FIG. 8, since the bonding wire is used as the connection member 8, the connection member 8 is thin, and heat is transmitted through the connection member 8. This is preferable because it can be prevented from being transmitted to the outside.

  For example, when the electronic component is a flip-chip type image pickup device 7, it is connected to the electrode of the image pickup device 7 through a connection member 8 such as a solder bump, a gold bump, or a conductive resin (anisotropic conductive resin or the like). This is performed by electrically and mechanically connecting the electrode 3. In this case, an underfill may be injected between the image sensor 7 and the mounting region 2 after connecting via the bumps that are the connecting members 8. Alternatively, as in the example shown in FIG. 8, for example, when the image sensor 7 is electrically connected to the wiring board by wire bonding, the image sensor 7 is mounted by a bonding material such as glass, resin, or brazing material. After fixing to 2, the electrode of the image sensor 7 and the connection electrode 3 are electrically connected via a bonding wire which is the connection member 8. In either case, a small electronic component such as a resistor element or a capacitor element may be mounted on the wiring board as necessary.

  8A, when the imaging device includes the lid 9, the lid 9 includes a translucent member 10 and is made of resin, ceramics, glass, or the like, and is translucent. It is formed in a box shape provided with an opening in which the member 10 is disposed. The lid 9 preferably has a thermal expansion coefficient close to the thermal expansion coefficient of the insulating substrate 1, has heat resistance, and is easily processed. For example, the insulating substrate 1 is made of an aluminum oxide sintered body, If the body 9 is made of a resin, a resin made of phenol resin, melamine resin, polypropylene, polystyrene, ABS resin or the like may be used. If an infrared imaging device is mounted as the imaging device 7, the translucent member 10 or the lid 9 is made of germanium (Ge), silicon (Si), zinc sulfide (ZnS), or an alloy containing these. A metal material may be used.

  When such a lid 9 is made of resin, it is formed by a transfer mold method, an injection mold method, or the like using a mold that can be molded into the shape of the predetermined lid 9, and then the translucent member 10. Are prepared at predetermined positions. Further, the lid body 9 may be divided into a plurality of members according to a desired shape and then assembled. In such a case, it is possible to combine a plurality of resins according to the required properties, and the arrangement of the translucent member 10 is facilitated.

  As the bonding material 11, a resin material such as an acrylic resin, an epoxy resin, a phenol resin, a cresol resin, a silicone resin, or a polyether amide resin, such as thermosetting or photocurable, can be used. The bonding material 11 may be mixed with dark pigments or dyes such as black, brown, dark brown, dark green, or dark blue as necessary. It is possible to block unwanted visible light from entering the imaging apparatus through the bonding material 11.

  The insulating substrate 1 and the lid body 9 are joined, for example, as follows. First, the uncured bonding material 11 made of an insulating resin is applied to the outer peripheral portion of the insulating substrate 1 using a dispenser or the like. Thereafter, the lid body 9 is disposed on the bonding material 11 before curing, and the wiring substrate and the lid body 9 are bonded via the bonding material 11 by curing the bonding material 11 before curing by heating or ultraviolet irradiation. To do.

When the lid 9 is a metal material, the lid 9 is joined to the insulating substrate 1 via a brazing material or solder as the joining material 11. As the bonding material 11, gold (Au), silver (Ag), zinc (Zn), tin (Sn), copper (Cu), and a metal mainly composed of these alloys can be used.

  Note that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

  For example, the corner portion of the low heat conducting portion 5 may have a curved surface with an R. In such a case, it is possible to suppress the occurrence of cracks in the wiring board starting from the corners of the low heat conducting portion 5 and the destruction of the narrowed wiring board such as the bridge portion X. .

  Further, for example, a metal film that reflects infrared rays may be formed on the inner peripheral surface of the hole that becomes the low thermal conductivity portion 5. In such a case, it is possible to prevent the insulating substrate 1 from being heated by irradiating the low thermal conductive portion 5 with infrared rays. Such a metal coating may be formed simultaneously with the wiring conductor using the same material as the wiring conductor 4, or may be formed by vapor deposition, for example. In order to prevent heat from being transmitted through the metal film, the metal film is preferably formed discontinuously.

  Also, as in the example shown in FIG. 8B, a plurality of recesses may be provided on the wiring board to form a so-called cavity structure. In such a case, it is preferable because sealing for protecting the light receiving portion 7a of the image sensor 7 from dust and moisture can be easily performed using a flat light-transmitting member.

DESCRIPTION OF SYMBOLS 1 ... Wiring board 2 ... Mounting area 3 ... Connection electrode 4 ... Wiring conductor 5 ... Low heat conduction part 5a ... Through hole 6 ... Heater 7 ... ... Image sensor 7a ... Light receiving part 8 ... Connection member X ... Bridge part

Claims (4)

An insulating substrate having a mounting area on the upper surface, a plurality of connection electrodes disposed on the upper surface of the insulating substrate, one end connected to the connection electrode and the other end drawn to the outer surface of the insulating substrate In a wiring board provided with a wiring conductor
Around the mounting region, a plurality of low thermal conductive parts having a lower thermal conductivity than the insulating substrate are formed so as to surround the mounting region ,
A low thermal conduction part is further formed in the insulating substrate under the mounting region,
The wiring board according to claim 1, wherein the low thermal conductive portion formed in the insulating substrate under the mounting region is opened only on a lower surface of the insulating substrate. The wiring board according to claim 1, wherein a heater is disposed between the low thermal conductive portions of the insulating substrate. The connection electrode, the wiring board according to claim 1 or claim 2, characterized in that it is disposed outside of the low thermal conductive portion of the top surface. Imaging apparatus characterized by imaging element is mounted on the mounting region of the wiring board according to any one of claims 1 to 3.

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