JP2008060121A - Solid-state imaging element sealing structure, and solid-state imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solid-state imaging element sealing structure excellent in optical characteristics and capable of obtaining an image of an excellent color tone over the entire surface, even if an imaging apparatus is reduced in thickness, and to provide the solid-state imaging apparatus employing the same. <P>SOLUTION: The solid-state imaging element sealing structure is provided with a solid-state imaging device 2 having a light receiver 1 formed on its main surface, a microlens 3 formed on the surface of the light receiver 1, and a light-transmitting substrate 4 bent so that its center can protrude and having an external portion attached on the main surface so that the inside of the bent portion can cover the microlens 3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  In recent years, there has been a rapid progress in reducing the size and price of cameras, including optical functional parts equipped with color solid-state image sensors such as CCDs and CMOSs, and along with this, optical functional parts such as camera modules are mounted. However, lighter, thinner and smaller parts are being reduced.

  Such an optical functional component generally corrects a reddish color tone and a lens made of a glass material or a plastic material for collecting incident light from outside and guiding it to a color solid-state imaging device in order to obtain an image. Using a cover glass made of a glass material after mounting a solid-state imaging device on an insulating substrate made of an electrically insulating material such as an aluminum oxide sintered body and an organic printed board It is comprised from the solid-state image sensor sealing structure which performed airtight sealing by doing, and the resin housing | casing which hold | maintains each of these components.

  However, in the configuration of such an optical functional component, there is a limit to reducing the thickness in order to obtain performance as a component, and as a result, it is difficult to reduce the thickness of a camera body using the component.

In addition, the optical characteristics depend on the thickness of the part, and it is difficult to reduce the thickness of the filter, but instead of the infrared cut filter glass, an optical element in which dielectric multilayer films are alternately laminated on borosilicate glass as a part that shields infrared rays. A filter member is used. This optical filter member is composed of a high refractive index dielectric layer made of a dielectric material having a refractive index of 1.7 or more, such as tantalum pentoxide, titanium oxide, niobium oxide, lanthanum fluoride, zirconium oxide, etc., and SiO ₂ , MgF ₂ , Na ₃ AlF. A dielectric multilayer film that shields infrared rays is formed by laminating several dozen layers of low refractive index dielectric layers having a refractive index of 1.6 or less such as ₆ on the entire surface of one side of the substrate or in an effective range for image recognition. Therefore, since the infrared shielding property does not depend on the thickness of the substrate, the camera can be thinned.

  In general, a dielectric multilayer film uses a light interference effect to change the optical film thickness that is an integral multiple of λ / 4 (λ is an arbitrary design wavelength) in each layer, thereby reflecting the reflection intensity at a specific wavelength. The function as an optical filter can be exhibited by controlling the local maximum and minimum. This is because each time the optical film thickness of the dielectric multilayer film becomes a quarter wavelength, the phase of light at that wavelength becomes the same or is reversed. In other words, by adjusting the optical film thickness of the dielectric multilayer film, the interface between the high refractive index dielectric layer and the low refractive index dielectric layer between the dielectric multilayer films and the interface between the dielectric multilayer film and the translucent substrate is used. By adjusting the phase of the light in the reflected light and interfering with the reflected light on the surface of the dielectric multilayer film, the reflection intensity can be increased or decreased. Therefore, by setting the optical film thickness to an even multiple of λ / 4 for light with a wavelength that you do not want to transmit the incident light, the transmitted light is reduced by increasing the reflection intensity for the incident light. It can have a light blocking effect on the band. Actually, an optical filter having good characteristics is obtained by adjusting the optical film thicknesses of the high refractive index dielectric layer and the low refractive index dielectric layer forming the dielectric multilayer film in more detail. The optical film thickness is represented by the product (n × d) of the refractive index n and the actual physical film thickness d.

  By joining the cover glass made of such an optical filter member to the insulating substrate, the infrared cut filter member can be omitted, and the optical functional component can be made thinner.

Furthermore, it has been proposed to make the size and thickness thinner by directly bonding a cover glass to a solid-state imaging device having a through electrode. (See Patent Document 1)
JP 2001-351997 A

  However, in the configuration as shown in Patent Document 1, when the adhesive is applied to the peripheral portion excluding the light receiving portion of the solid-state imaging device and the solid-state imaging device and the cover glass are joined, the surface of the light-receiving portion of the solid-state imaging device is It is necessary to keep the light receiving part and the cover glass at a predetermined distance so as not to come into contact with the microlens formed for each pixel. For this purpose, it is necessary to cure the adhesive with a certain thickness. There is. However, since the adhesive is a viscous liquid, there is a problem in that a certain thickness cannot be ensured uniformly. On the other hand, it has been proposed to prevent the cover glass from contacting the microlens by providing the cover glass with a recess corresponding to the light receiving portion. In this case, the surface of the recess facing the light receiving portion is flat. Since the processing for obtaining the degree is very difficult, there is a problem that causes high cost.

  In addition, as a result of thinning the cover glass by directly bonding it to the solid-state imaging device, the distance between the lens and the light receiving unit approaches, so the incident angle of incident light collected by the lens on the cover glass is As the distance from the center increases, the normal to the main surface of the cover glass increases. On the other hand, the dielectric multilayer film that shields infrared rays deposited on the surface of the cover glass changes in optical characteristics with the incident angle, so the difference in incident angle of incident light between the center and the periphery of the light receiving part is large. As a result, there is a problem that a good image cannot be obtained because the color tone tends to be reddish in the vicinity of the periphery as compared with the vicinity of the center.

  Accordingly, the present invention has been completed in view of the above problems, and its object is to encapsulate a solid-state image sensor excellent in optical characteristics that can obtain an image with good color tone on the entire surface even if the imaging apparatus is thinned. To provide a structure and a solid-state imaging device using the structure.

  The solid-state imaging device sealing structure of the present invention is curved so that a solid-state imaging device having a light receiving portion formed on the main surface, a microlens formed on the surface of the light receiving portion, and a central portion project. And a translucent substrate having an outer peripheral portion attached to the main surface so as to cover the microlens inside the curved portion.

  The solid-state imaging device sealing structure according to the present invention is characterized in that the translucent substrate has a constant thickness in the entire region.

  The solid-state imaging device sealing structure of the present invention is a dielectric formed by alternately laminating a plurality of high refractive index dielectric layers and low refractive index dielectric layers on the outside of the curved portion of the translucent substrate. It is characterized in that a multilayer film is deposited.

  The solid-state imaging device sealing structure according to the present invention includes a reflective layer formed by alternately laminating a plurality of high-refractive index dielectric layers and low-refractive index dielectric layers inside the curved portion of the translucent substrate. It is characterized in that a prevention film is deposited.

  In the solid-state imaging device sealing structure according to the present invention, the antireflection film is formed up to a junction between the translucent substrate and the solid-state imaging device, and the outermost layer on the solid-state imaging device side is made of silicon oxide. It is characterized by comprising.

  The solid-state device of the present invention includes a solid-state image sensor sealing structure according to the present invention, a base on which the solid-state image sensor sealing structure is mounted, and an optical lens for condensing light on the translucent substrate. It is characterized by comprising.

  In the solid-state device of the present invention, a through hole is formed in the base, and the solid-state imaging element sealing structure is formed in the base so that the translucent substrate faces the through hole and closes the through hole. It is mounted.

  The solid-state imaging device sealing structure of the present invention is curved so that a solid-state imaging device having a light receiving portion formed on the main surface, a microlens formed on the surface of the light receiving portion, and a central portion project. And a translucent substrate having an outer peripheral portion attached to the main surface so as to cover the microlens inside the curved portion, the surface of the light receiving unit of the solid-state imaging device is curved by the translucent substrate A sufficient distance can be ensured between the formed microlens and the translucent substrate, and the thickness of the adhesive is increased when the translucent substrate is joined to the peripheral portion of the solid-state imaging device except the light receiving portion. do not have to. Therefore, since the adhesive can be made very thin, thickness variations are less likely to occur.

  In addition, since the translucent substrate is a simple structure that is simply curved, the solid-state imaging device and the translucent substrate can be used without requiring processing that increases the cost as in the conventional configuration having a complicated shape such as a recess. Can be joined.

  The solid-state imaging device sealing structure according to the present invention includes a dielectric multilayer formed by alternately laminating a plurality of high-refractive index dielectric layers and low-refractive index dielectric layers outside a curved portion of a translucent substrate. Since the film is deposited, the angle of the incident light collected by the lens can be reduced with respect to the normal to the main surface of the translucent substrate, and the film is deposited on the translucent substrate surface. It is possible to effectively suppress the optical properties of the dielectric multilayer film that shields infrared rays from changing greatly with the incident angle.

  In the solid-state imaging device sealing structure of the present invention, since the translucent substrate has a constant thickness in the entire region, the path length when the light collected by the lens passes through the translucent substrate is translucent. The curved portion of the conductive substrate can be made almost uniform. As a result, it is possible to effectively suppress the light absorption rate when passing through the translucent substrate from being greatly different between the central portion and the outer peripheral portion, and the optical characteristics become better.

  The solid-state imaging device sealing structure of the present invention includes an antireflection film in which a plurality of high-refractive index dielectric layers and low-refractive index dielectric layers are alternately stacked inside a curved portion of a translucent substrate. Therefore, by adjusting the formation conditions of the antireflection film, the shrinkage rate difference between the antireflection film and the translucent substrate can be appropriately adjusted. Can be easily bent. By changing the curvature, the angle of incident light collected by the lens can be made smaller than the normal to the main surface of the translucent substrate. The dielectric multilayer film that shields infrared rays can be more effectively suppressed from changing optical characteristics with the incident angle.

  In the solid-state imaging device sealing structure of the present invention, the antireflection film is formed up to the junction between the translucent substrate and the solid-state imaging device, and the outermost layer on the solid-state imaging device side is made of silicon oxide. Applying an adhesive to the peripheral part of the image sensor excluding the light receiving part and contacting the microlens formed on the surface of the light receiving part of the solid state image sensor, without requiring processing that increases costs When bonding the translucent substrate, a stronger bonding strength can be obtained by performing hydrogen bonding via a hydroxyl group in bonding the adhesive and the antireflection film surface.

  The solid-state device of the present invention includes a solid-state imaging element sealing structure of the present invention, a base on which the solid-state imaging element sealing structure is mounted, an optical lens for condensing light on a translucent substrate, Therefore, it is possible to reduce the thickness of the solid-state imaging device and to provide a solid-state imaging device with excellent optical characteristics that can obtain an image with a good color tone.

  In the solid-state device of the present invention, a through-hole is formed in the base, and the solid-state image sensor sealing structure is mounted on the base so that the translucent substrate faces the through-hole and closes the through-hole. Therefore, it is possible to effectively prevent light that becomes noise other than the light collected from the lens through the through hole from being incident on the solid-state imaging device, and to obtain an image with a better color tone. It becomes.

  The solid-state image sensor sealing structure of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a cross-sectional view showing an example of an embodiment of a solid-state imaging device sealing structure of the present invention. 1 is a light receiving unit, 2 is a solid-state imaging device, 3 is a microlens formed on the surface of the light receiving unit 1, 4 is curved so that the center part protrudes, and the microlens 3 is placed inside the curved part. A translucent substrate having an outer peripheral portion attached to the main surface so as to cover, 5 is a wiring layer for taking out a signal from the light receiving unit to the outside, and 6 is an adhesive for fixing the translucent substrate 4 to the solid-state imaging device 2. , 7 is a connection wiring for connecting a signal from the solid-state imaging device 2 to the external wiring substrate, 8 is a base, and 9 is a connection material for electrically connecting the wiring layer 5 of the solid-state imaging device 2 to the connection wiring 7. Reference numeral 10 denotes an optical lens for guiding light to the light receiving unit 1, and arrows schematically describe the optical path.

  The translucent substrate 4 is made of a glass material such as borosilicate glass, a birefringent material such as lithium niobate, crystal, or sapphire, or a polymer material such as acrylic resin.

  The translucent substrate 4 is made of, for example, platinum (Pt), which can effectively prevent the melting of impurities, in a container made of a metal having a melting point higher than the melting temperature of the glass, preferably a molten high-purity glass raw material. After pouring into the container, it is gradually cooled over several days to form a block. Thereafter, it is cut into a predetermined plate thickness and outer dimensions, and is curved so that the central portion protrudes by mechanical cutting, and then lapping is performed using an abrasive made of alumina or the like, and further, alumina, The light-transmitting substrate 4 can be obtained by optical polishing using an abrasive made of cerium oxide or the like. By creating in this way, it is possible to prevent the impurities that generate α-rays that adversely affect the solid-state imaging device 2 from being dissolved in the high-purity glass raw material.

  In addition, borosilicate glass becomes a material with excellent heat resistance and chemical resistance by adding boric acid to the glass raw material, and it is also suitable as a material with few optical defects because it has a transparent, flat and nonporous surface. Used for. Such a borosilicate glass can be made into a light-transmitting flat substrate with little variation in plate thickness without polishing by using a melted high-purity glass raw material by a downdraw method. As will be described later, by adjusting the conditions when the dielectric multilayer film 11a is formed on the surface from which the central portion of the translucent flat substrate protrudes, or the antireflection film 11b is formed at the center of the translucent flat substrate. By adjusting the conditions when forming on the opposite side of the surface from which the part protrudes, it is possible to give a difference in the shrinkage rate between the dielectric multilayer film and the translucent substrate, and using this shrinkage rate difference As shown in FIG. 2, the translucent substrate 4 is curved so that the central portion protrudes. Thereby, a translucent board | substrate can be curved easily, without requiring the process which raises cost.

  In addition, lithium niobate, quartz, and sapphire are obtained by artificially growing a seed crystal in a growth furnace at high pressure and high temperature to obtain a block made of a single crystal, and then the cut surface has a predetermined angle with respect to the crystal axis. Then, the wafer is cut out using a wire saw or a band saw. The wafer is cut into a predetermined plate thickness and outer dimensions, and after c-plane processing is performed by mechanically cutting each ridge line portion, lapping is performed using an abrasive made of alumina or the like. A light-transmitting flat substrate can be obtained by optical polishing using an abrasive made of alumina, cerium oxide or the like. As will be described later, by adjusting the conditions when the dielectric multilayer film 11a and the antireflection film 11b are formed on the upper surface, the lower surface, or the upper and lower surfaces of the light transmissive flat substrate, the dielectric multilayer film and the light transmissive substrate are adjusted. 2 can be made to have a difference in shrinkage rate, and by using this difference in shrinkage rate, the light-transmitting substrate 4 that is curved so that the central portion protrudes as shown in FIG. 2 can be obtained. Thereby, a translucent board | substrate can be curved easily, without requiring the process which raises cost.

  The translucent substrate 4 preferably has a thickness of 0.03 mm to 0.35 mm. If the thickness of the translucent substrate 4 is smaller than 0.03 mm, the translucent substrate 4 is greatly deformed by the stress at the time of forming the dielectric multilayer film 11a or the antireflection film 11b, and the central portion protrudes. It is difficult to bend, and it tends to be difficult to form a uniform dielectric layer thickness by deformation, and the strength tends to be insufficient. If the thickness of the translucent substrate 4 is greater than 0.35 mm, the bending strength of the translucent substrate 4 increases, and therefore the dielectric multilayer film 11a and the antireflection film 11b are formed to form the translucent substrate 4. If it is attempted to bend so that the central portion protrudes, on the contrary, the stress applied to the dielectric layer becomes too large, and cracks are likely to occur in the dielectric layer.

  Further, immediately before the dielectric multilayer film 11a and the antireflection film 11b are deposited, the surface of the translucent substrate 4 is chemically polished by cleaning with a 10% to 30% sodium hydroxide aqueous solution. At the same time, it is desirable to activate the surface of the translucent substrate 4 by plasma cleaning in which the surface of the translucent substrate 4 is irradiated with plasma. By performing these cleaning operations, it is possible to improve the adhesion between the surface of the translucent substrate 4 and the dielectric layer, the optical transparency, and the reflectivity.

  The shape of the translucent substrate 4 in plan view may be a square shape such as a square or a rectangle, but an octagonal shape with four corners chamfered, a shape with a rounded corner, a substantially circular shape such as a circle or an ellipse. However, since the thickness of the adhesive 6 can be thinly joined, moisture resistance is easily improved, which is preferable.

  FIG. 3 shows an enlarged cross-sectional view of a main part of the translucent substrate 4 on which the dielectric multilayer film 11a and the antireflection film 11b are applied.

  The dielectric multilayer film 11a includes a high refractive index dielectric layer 12 usually made of a dielectric material having a refractive index of 1.7 or more, and a low refractive index dielectric usually made of a dielectric material having a refractive index of 1.6 or less. The body layer 13 is formed by laminating a plurality of layers alternately over several tens of layers using vapor deposition or sputtering.

  The dielectric multilayer film 11a produced in this way generally has a maximum reflectance in a wavelength range of 400 nm to 600 nm, which is a function necessary as an optical filter that blocks incident waves having a wavelength in the near infrared range. It has a function of 20% or less and a minimum reflectance of 90% or more in a wavelength range of 700 nm to 1000 nm.

  Further, a reflection having a maximum reflectance of 2% or less on a principal surface opposite to the principal surface on which the dielectric multilayer film 11a having a function of an optical filter is deposited is at least in a wavelength region of 450 nm to 600 nm. It is preferable to form the prevention film 11b. As a result, the loss of desired incident light can be reduced, and a better image signal can be obtained.

  The antireflective film 11b includes a high refractive index dielectric layer 12 'made of a dielectric material usually having a refractive index of 1.7 or more, and a low refractive index dielectric made of a dielectric material usually having a refractive index of 1.6 or less. The body layer 13 ′ is formed by laminating a plurality of layers alternately by several layers using vapor deposition or sputtering.

  As an insulating material having a refractive index of 1.7 or more suitable for the dielectric multilayer film 11a and the antireflection film 11b, for example, tantalum pentoxide, titanium oxide, niobium pentoxide, lanthanum oxide, zirconium oxide or the like is used. Examples of the insulating material having a refractive index of 1.6 or less include silicon oxide, aluminum oxide, lanthanum fluoride, and magnesium fluoride. From the mechanical characteristics such as hardness and stability, and the optical characteristics such as refractive index necessary for imparting a function as a desired optical filter, titanium oxide is used as the high refractive index dielectric layers 12 and 12 ′. The low refractive index dielectric layers 13 and 13 ′ are preferably silicon oxide.

  As a method of depositing and forming the dielectric multilayer film 11a on the translucent substrate 4, it is preferable to use an ion beam assist method. The ion beam assist method is a vacuum deposition method in which cation irradiation is used in combination with a vacuum deposition method which is a film forming process. As the cation used in the ion beam assist method, for example, a cation generated from plasma obtained by introducing both an inert gas composed of argon and an active gas composed of oxygen gas into an ion source of the apparatus is used.

In the ion beam assist method, for example, a translucent flat substrate is placed in a crucible installed in a vacuum deposition apparatus, and oxygen is sufficiently added so as not to cause oxygen deficiency in order to obtain an optically good dielectric multilayer film 11a. Then, vacuum deposition is performed while using cation irradiation in a state where the degree of vacuum is set to about 1 × 10 ⁻³ Pa in the vacuum deposition apparatus. The surface temperature of the translucent substrate 4 when the dielectric multilayer film 11a is deposited in the vacuum deposition apparatus is managed by measuring the temperature in the vicinity of the translucent substrate 4 with a thermocouple. The temperature is maintained at about 30 to 350 ° C. using a heater or the like. Thereafter, the high refractive index dielectric layer 12 and the low refractive index dielectric layer 13 are placed on the entire main surface of the translucent substrate 4 or in a desired region facing the solid-state imaging device 2 by masking. The light-transmitting substrate 4 on which the dielectric multilayer film 11a is deposited is formed by depositing a total of about 10 to 100 dielectric layers alternately while using the irradiation.

When the cations collide with the gas molecules of the vapor deposition material flying in the vacuum, the gas molecules of the vapor deposition material are excited to obtain a large kinetic energy. And when the gas molecule of the vapor deposition material which has obtained this large kinetic energy reaches the surface of the transparent substrate 4 which is the adherend, it moves on a wide area of the surface of the adherend and with the movement of the wide area. This greatly increases the probability of finding a lower energy state on the surface of the adherend, so that the deposition material molecules are uniformly deposited on the surface of the adherend without agglomerating with each other, and vapor deposition exists in the vicinity. Since the dielectric multilayer film 11a can be formed densely without agglomerating atoms to form nuclei, the dielectric multilayer film 11a in which compressive stress remains can be obtained. The center part of the translucent board | substrate 4 can be made to protrude.

  In addition, in the present invention, it is preferable to irradiate the surface with only cations for a predetermined time after depositing and forming one layer of the high refractive index dielectric layer 12 or the low refractive index dielectric layer 13. As a result, when a cation collides with a molecule of the vapor deposition material that has lost energy on the surface of the adherend, the molecule of the vapor deposition material is pushed into the thin film, and a denser amorphous thin film can be obtained. The cations are struck against the surface of each deposited layer, so that a more densely filled dielectric multilayer film 11a can be formed. Therefore, the dielectric multilayer film 11a in which compressive stress remains can be obtained. By this compressive stress, the central part of the translucent substrate 4 can be protruded more.

  The solid-state imaging device 2 and the translucent substrate 4 are generally joined via an adhesive 6 made of an ultraviolet curable epoxy resin or a thermosetting epoxy resin. For example, when a thermosetting epoxy resin is used as the adhesive 6, the adhesive 6 is applied to the translucent substrate 4 by a conventionally known screen printing method or the like, and is superposed on the substrate 8, and then at a temperature of 90 to 250 ° C. It becomes a solid-state image sensor sealing structure by heating under pressure for 60 to 90 minutes. When the antireflection film 11b is formed on the translucent substrate 4, the outermost layer of the antireflection film 11b is formed of silicon oxide, and is formed up to the junction with the solid-state imaging device 2 to be joined. Since the joining strength at the time of joining the board | substrate 4 and the solid-state image sensor 2 with the adhesive agent 6 becomes strong, it is preferable.

  In addition, from a viewpoint of reducing the stress between the members at the time of joining the solid-state imaging device 2 and the translucent substrate 4, heating at a low temperature of about 90 to 110 ° C. is preferable. The adhesive 6 is used not only for bonding the solid-state imaging device 2 and the translucent substrate 4 but also for heat generated by reflow or the like when mounting the subsequent individual imaging device on an external wiring board (not shown). Furthermore, a material that relieves stress between members caused by heat generated when the solid-state imaging device 2 operates and effectively prevents the translucent substrate 4 from being destroyed is selected. Examples of the adhesive 6 include bisphenol A type epoxy resin, bisphenol A modified epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, special novolac type epoxy resin, and phenol derivative epoxy. It is made of epoxy resin such as resin, biphenol skeleton type epoxy resin, etc. with addition of curing agent such as imidazole, amine, phosphorus, hydrazine, imidazole adduct, amine adduct, cationic polymerization, dicyandiamide. Yes. Two or more types of epoxy resins may be mixed and used. The organic material powder contained in the adhesive 6 includes silicon rubber, silicon resin, LDPE, HDPE, PMMA, crosslinked PMMA, polystyrene, crosslinked, which has a lower elastic modulus than a thermosetting resin mainly composed of an epoxy resin. It is preferable to use a soft resin such as polystyrene, ethylene-acrylic copolymer, polyethyl methacrylate, butyl acrylate, or urethane.

  The substrate 8 is made of an inorganic insulating material such as an aluminum oxide sintered body, a mullite sintered body, an aluminum nitride sintered body, a silicon nitride sintered body, a silicon carbide sintered body, an epoxy resin, a phenol resin, It is composed of organic insulating materials such as liquid crystal polymer, polyphenylene sulfide, and polyimide resin. For example, when it is composed of an aluminum oxide sintered body, it is suitable for raw material powders such as aluminum oxide, silicon oxide, magnesium oxide, and calcium oxide. An organic binder, a solvent, a plasticizer, and a dispersant are added and mixed to make a slurry, and this slurry is formed into a sheet by a sheet forming method such as a doctor blade method or a calender roll method, which is conventionally known. Sheet), and then appropriate punching is performed on the ceramic green sheets. Both laminating a plurality, it is manufactured by firing at a high temperature of about 1600 ° C.. Alternatively, in the case of an epoxy resin, it is generally formed by molding and curing a resin compound filled with silica powder into a mold shape heated to about 180 ° C. by an injection molding machine.

In addition, a through hole is formed in the base 8, and a connection wiring 7 that is joined to the wiring layer 5 of the solid-state imaging device 2 is formed in the periphery of the lower surface of the through hole. The connection wiring 7 of the base 8 is formed with a plurality of conductors for leading an electric signal from the solid-state imaging device 2 from the peripheral portion of the through hole to an external electric circuit (not shown). By electrically connecting the wiring layer 5 and the connection wiring 7 with the connection material 9, a solid-state imaging device is obtained. When a brazing material is used as the connecting material 9, the bonding strength may be strengthened by using an insulating resin together for bonding the base body 8 and the solid-state imaging device 2. In addition, the wiring layer 5 of the solid-state image pickup device 2 and the connection wiring 7 of the base 8 are electrically joined using an adhesive having anisotropic conductivity in which conductive particles are dispersed in an epoxy resin, and mechanically. You may join.

  The connection wiring 7 functions as a conductive path that electrically connects each wiring layer 5 of the solid-state imaging device 2 to an external electric circuit. For example, when the base 8 is made of an inorganic insulating material, a high melting point such as tungsten, molybdenum, manganese, or the like. A metal paste obtained by adding and mixing an appropriate organic solvent, a solvent, a plasticizer, and the like to the metal powder is preliminarily printed and applied to a ceramic green sheet serving as the substrate 8 by a thick film technique such as screen printing. A predetermined pattern is formed by firing at the same time as the sheet.

  The connection wiring 7 has a thickness of 0.1 to 20 [mu] m formed by electrolytic plating or electroless plating on a surface of a metal having excellent conductivity and corrosion resistance such as nickel and gold and good wettability with the connection material 9. It is good to attach to. Thereby, the oxidative corrosion of the connection wiring 7 can be effectively prevented, and the connection between the connection wiring 7 and the wiring layer 5 and the connection between the connection wiring 7 and the wiring conductor of the external electric circuit board can be strengthened. it can. The substrate 8 can be manufactured as described above.

  Then, the wiring layer 5 and the connection wiring 7 are electrically connected by bonding the solid-state imaging device 2 to the connection wiring 7 formed around the through hole of the base body 8 with a connection material 9 or the like which is mainly composed of conventionally known tin or gold. Connect.

  FIG. 4 is a cross-sectional view showing another example of the embodiment of the solid-state image sensor sealing structure of the present invention. At the stage of forming the solid-state imaging device 2, a through via is formed by a method such as etching, the wiring layer 5 is conducted to the opposite surface of the light receiving unit 1 by via conduction or the like, and the microlens 3 is formed on the surface of the light receiving unit 1. The translucent substrate 4 is produced in the same manner as in the example of FIG. 1 and bonded to the solid-state image sensor 2 with the adhesive 6, whereby a solid-state image sensor sealing structure can be obtained. Thus, by using a solid-state imaging device sealing structure without using a base, the imaging device can be significantly reduced in size.

  In addition, this invention is not limited to the said embodiment and Example, A various change may be performed in the range which does not deviate from the summary of this invention.

It is sectional drawing which shows an example of embodiment of the solid-state image sensor sealing structure of this invention. It is sectional drawing of the translucent board | substrate in the solid-state image sensor sealing structure of FIG. It is a principal part expanded sectional view of the translucent board | substrate in the solid-state image sensor sealing structure of FIG. It is sectional drawing which shows the other example of embodiment of the solid-state image sensor sealing structure of this invention.

Explanation of symbols

1: Light-receiving unit 2: Solid-state imaging device 3: Micro lens 4: Translucent substrate 5: Wiring layer 6: Adhesive 7: Connection wiring 8: Substrate 9: Connection material 10: Optical lens 11a: Dielectric multilayer film 11b: Antireflective films 12, 12 ': High refractive index dielectric layers 13, 13': Low refractive index dielectric layers

Claims (7)

A solid-state imaging device having a light receiving portion formed on the main surface, a microlens formed on the surface of the light receiving portion, a curved portion protruding from the center, and the microlens inside the curved portion And a translucent substrate having an outer peripheral portion attached to the main surface so as to cover the solid-state imaging element sealing structure. 2. The solid-state image sensor sealing structure according to claim 1, wherein the translucent substrate has a constant thickness in the entire region. A dielectric multilayer film formed by alternately laminating a plurality of high-refractive index dielectric layers and low-refractive index dielectric layers is formed on the outer side of the curved portion of the light-transmitting substrate. The solid-state imaging device sealing structure according to claim 1 or 2. An antireflection film comprising a plurality of alternately laminated high refractive index dielectric layers and low refractive index dielectric layers is formed on the inner side of the curved portion of the translucent substrate. The solid-state image sensor sealing structure according to any one of claims 1 to 3. 5. The solid according to claim 4, wherein the antireflection film is formed up to a junction between the translucent substrate and the solid-state imaging device, and an outermost layer on the solid-state imaging device side is made of silicon oxide. Imaging element sealing structure. A solid-state imaging device sealing structure according to any one of claims 1 to 5, a base body on which the solid-state imaging device sealing structure is mounted, and light for condensing light on the translucent substrate A solid-state imaging device comprising an optical lens. A through hole is formed in the base, and the solid-state imaging device sealing structure is mounted on the base so that the translucent substrate faces the through hole and closes the through hole. The solid-state imaging device according to claim 6.

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