JP2006332686A - Solid-state imaging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solid-state imaging device in which the influence on electric characteristic etc. due to distortion, is reduced by suppressing the generation of the distortion due to following of an imaging element to a substrate surface, even when the imaging element is joined to the substrate surface having insufficient flatness. <P>SOLUTION: The solid-state imaging device is provided with a casing 1 obtained by integrally forming a substrate section 2 and the rectangular frame-like rib 3 with a resin; a plurality of metallic lead pieces 9 buried in the casing and each having an inner terminal portion facing the internal space of the casing and an external terminal portion exposed to the outside of the casing; an imaging element 5 fixed on the substrate in the internal space of the casing; metallic fine wires 10 each connecting an electrode of the imaging element to the internal terminal portion of a metallic lead piece; and a translucent plate 7 joined to the upper end surface of the rib. Three or more projections 2a are provided on a region facing the imaging element in the substrate section, and the top height of projection support is higher than the surface of the metallic lead in a state where the imaging element is supported by the projections. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a solid-state imaging device having a configuration in which an imaging element such as a CCD is mounted in a casing.

  Solid-state imaging devices are widely used in video cameras, still cameras, and the like, and are provided in the form of a package in which an imaging element such as a CCD is mounted on a base made of an insulating material and a light receiving area is covered with a light-transmitting plate. In order to reduce the size of the apparatus, the image sensor is mounted on the base in a bare chip state. As a conventional example of such a solid-state imaging device, a solid-state imaging device described in Patent Document 1 is shown in FIG.

  In FIG. 9, reference numeral 41 denotes a housing, which includes a substrate portion 41a and a frame-like rib 41b integrally formed by a resin mold, and an internal space 42 is formed on the upper surface thereof. In the housing 41, a die pad 43 located at the center of the substrate portion 41a and a lead 44 located below the rib 41b are embedded. The image sensor chip 45 disposed in the central portion of the internal space 42 is fixed to the upper surface of the die pad 43. The lead 44 has an internal terminal portion 44a exposed to the internal space 42 on the upper surface of the substrate portion 41a inside the rib 41b, and an external terminal portion 44b exposed from the bottom surface of the substrate portion 41a below the rib 41b. The internal terminal portion 44a and the bonding pad of the image sensor chip 45 are connected by a bonding wire 46 made of a metal wire. In addition, a transparent sealing glass plate 47 is bonded to the upper end surface of the rib 41b to form a package for protecting the imaging element chip 45.

  This solid-state imaging device is mounted on a circuit board with the sealing glass plate 47 facing upward as shown in the figure, and the external terminal portion 44b is used for connecting to an electrode on the circuit board. Although not shown in the drawings, a lens barrel in which an imaging optical system is incorporated is mounted on the upper portion of the seal glass plate 47 with the mutual positional relationship with the light receiving area formed in the imaging element chip 45 adjusted to a predetermined accuracy. . During the imaging operation, the light from the imaging target is condensed and photoelectrically converted into the light receiving region through the imaging optical system incorporated in the lens barrel.

Since the solid-state imaging device having such a structure is connected to the electrode on the circuit board by the external terminal portion 44b exposed on the bottom surface of the housing, it has a structure using a connection by an outer lead bent downward from the side surface of the housing. Compared to this, the package has a smaller height and occupied area and is suitable for high-density mounting.
JP 2001-77277 A

  In the configuration of the above-described conventional solid-state imaging device, the substrate portion 41a of the housing 41 needs to have sufficient flatness. That is, the image pickup device chip 45 is usually bonded to the surface of the substrate portion 41a with an adhesive, and when the adhesive is solidified, a force is applied to bring the image pickup device chip 45 along the surface of the substrate portion 41a. Therefore, if the flatness of the substrate portion 41a is not good, the image sensor chip 45 is distorted and internal stress is generated, and the electrical characteristics and the like of the image sensor chip 45 are affected.

  However, when the substrate portion 41a is molded, it is difficult to avoid some degree of twisting or warping in the cross-sectional shape, and the flatness is not perfect.

  Therefore, according to the present invention, even when the imaging device is bonded to a substrate surface with insufficient flatness, the occurrence of distortion due to the imaging device being along the substrate surface is suppressed, and the influence of the distortion on the electrical characteristics and the like is reduced. An object of the present invention is to provide a solid-state imaging device.

  The solid-state imaging device of the present invention includes a housing in which a substrate portion and a rectangular frame-shaped rib are integrally formed of a resin, an internal terminal portion that is embedded in the housing and faces an internal space of the housing, and the housing A plurality of metal lead pieces each having an external terminal portion exposed to the outside, an image pickup device fixed on the substrate portion in the internal space of the housing, an electrode of the image pickup device, and an inside of the metal lead piece In a solid-state imaging device including a thin metal wire connecting each of the terminal portions and a translucent plate bonded to the upper end surface of the rib, the region facing the imaging element in the substrate portion includes three or more A protrusion is provided, and the height of the top of the protrusion support is higher than the surface of the metal lead in a state where the imaging element is supported by the protrusion.

  The solid-state imaging device according to the present invention includes a housing in which a substrate portion and a rectangular frame-shaped rib are integrally formed of a resin, an internal terminal portion that is embedded in the housing and faces an internal space of the housing, and the A plurality of metal lead pieces each having an external terminal portion exposed to the outside of the housing; an imaging device fixed on the substrate portion in the internal space of the housing; an electrode of the imaging device; and the metal lead pieces In the solid-state imaging device provided with the thin metal wires connecting the internal terminal portions of each of the two and the translucent plate bonded to the upper end surface of the rib, three regions in the substrate portion facing the imaging element are provided. The protrusions described above are provided, and the portion where the protrusions support the image sensor is inside the connection region of the metal thin wire of the image sensor.

  According to the above configuration, since the image pickup device is joined in a state of being supported by the protrusions, the action of the image pickup device along the substrate surface is suppressed. Therefore, even if the imaging device is bonded to the substrate surface with poor flatness, the occurrence of distortion in the imaging device is suppressed, and the influence of the distortion on the electrical characteristics and the like is reduced.

  Hereinafter, a solid-state imaging device according to an embodiment of the present invention will be specifically described with reference to the drawings. 1 is a cross-sectional view of a solid-state imaging device, FIG. 2 is a bottom view, and FIG. 3 is a side view.

  Reference numeral 1 denotes a housing made of a plastic resin such as an epoxy resin, which is produced by integral molding of a structure in which a rectangular frame-shaped rib 3 is arranged on a flat substrate portion 2. An imaging element 5 is fixed by an adhesive 6 on the substrate portion 2 facing the internal space 4 of the housing 1. A translucent plate 7 made of glass, for example, is bonded to the upper end surface of the rib 3 by an adhesive 8, thereby sealing the internal space 4 of the housing 1 to form a package.

  A plurality of hemispherical protrusions 2 a are provided in the region of the upper surface of the substrate portion 2 facing the image sensor 5. Therefore, the imaging element 5 is joined to the substrate portion 2 by the adhesive 6 while being supported by the hemispherical protrusion 2a. For this reason, the image pickup device 5 does not follow the surface of the substrate portion 2, and the occurrence of distortion in the image pickup device 5 due to the substrate surface having poor flatness is reduced. In practice, the number of hemispherical protrusions 2a is desirably 3 or more and 5 or less. The shape of the protrusion is preferably substantially hemispherical, but may be other shapes.

  A plurality of metal lead pieces 9 are embedded in the housing 1 at the time of molding. The metal lead piece 9 is a member for electrically leading out from the internal space 4 of the housing 1 to the outside, and the internal terminal portion 9 a exposed on the surface on the internal space 4 side of the substrate portion 2 and the substrate portion 2. The external terminal portion 9b exposed at a position corresponding to the internal terminal portion 9a on the back surface of the housing 1 and the side electrode portion 9c exposed on the outer surface of the housing 1 are included. An electrode (not shown) of the image sensor 5 and the internal terminal portion 9a of each metal lead piece 9 are connected by a thin metal wire 10, respectively. The thickness of the entire package is set to 2.0 mm or less, for example. FIG. 4 shows a planar shape in a state in which the translucent plate 7 is removed from the solid-state imaging device of FIG.

  As shown in FIG. 1, in the metal lead piece 9, the back surface corresponding to the position of the internal terminal portion 9a becomes the external terminal portion 9b. In these portions, the metal lead piece 9 has substantially the same thickness as the substrate portion 2. The portion of the metal lead piece 9 located below the rib 3 is thinned by half etching, and the lower surface is covered with resin.

  As shown in FIGS. 1 and 3, each outer surface of the housing 1, that is, the outer peripheral surface of the rib 3 forms a plane that is substantially orthogonal to the surface of the substrate portion 2. Further, the end face of the translucent plate 7 and the surface of the side electrode part 9 c form substantially the same plane as the outer face of the housing 1. Such a coplanar shape can be formed with good flatness by, for example, cutting the rib 3 and the transparent plate 7 together in the manufacturing process.

  A method of manufacturing the solid-state imaging device having the above configuration will be described with reference to FIGS.

  First, as shown in FIG. 5A, a lead frame 21 is prepared. The lead frame 21 is formed by connecting a plurality of lead portions 22 for forming the metal lead piece 9 shown in FIG. The thickness of each lead portion 22 at a position corresponding to the internal terminal portion 9 a is set to be substantially the same as the thickness of the substrate portion 2. The lead portion 22 has a concave portion 23 formed by half-etching on the lower surface thereof, and is cut at this portion in a later process, so that the shape of the metal lead piece 9 shown in FIG. 1 is obtained.

  Next, as shown in FIG. 5B, the lead frame 21 is embedded, and a plurality of housings 26 each including the substrate portion 24 and the rib forming member 25 are collectively manufactured by integral molding of resin. A plurality of (four in each case in the figure) hemispherical protrusions 24 a are formed on the upper surface of the substrate portion 24. The planar shape after molding is shown in FIG. The upper and lower surfaces of the lead portion 22 are embedded so as to be exposed from the upper and lower surfaces of the substrate portion 24 to form the internal terminal portion 9a and the external terminal portion 9b, respectively. The rib forming member 25 is formed by combining the ribs of adjacent casings 26 into one.

  Next, as illustrated in FIG. 5C, the adhesive 6 is applied to the region where the imaging element 5 in which the hemispherical protrusions 24 a of each housing 26 are formed is to be fixed. Then, the imaging element 5 is placed so as to be supported on the hemispherical protrusion 24 a and bonded by the adhesive 6. Further, a pad electrode (not shown) of the image sensor 5 and each internal terminal portion 9 a are connected by a thin metal wire 10.

  Next, as shown in FIG. 5D, an adhesive 28 is applied to the upper end surface of the rib forming member 25, and the transparent plate 27 is placed and bonded.

  Next, as shown in FIG. 5 (e), the transparent plate 27, the rib forming member 25, the lead portion 22 and the substrate portion 24 are cut by a dicing blade 29, and each solid as shown in FIG. 5 (f). Separated into pieces that form the imaging device. As shown in FIG. 5E, the cutting is performed in a direction orthogonal to the substrate portion 24 and in a direction that bisects the width of each rib forming member 25 in the planar shape. As a result, the transparent plate 27, the rib forming member 25, the lead portion 22, and the substrate portion 24, which are divided, form the transparent plate 7 constituting one solid-state imaging device, and the housing 1 including the substrate portion 2 and the rib 3. A metal lead piece 9 is formed. Further, the side electrode portion 9c of the metal lead piece 9 is exposed.

  According to this manufacturing method, the single rib forming member 25 in which the two ribs of the adjacent casings 26 are united integrally has a width smaller than twice the width when the single rib is individually molded. Can be set. Therefore, if this is cut in half as shown in FIG. 5 (e), the width of the rib 3 in each solid-state imaging device shown in FIG. 5 (f) is the same as when one rib is molded individually. Compared to this, the area becomes smaller and the area of the solid-state imaging device is reduced accordingly.

  Further, by cutting the rib forming member 25 in half in the width direction, the cut surface becomes perpendicular to the substrate portion 24, and the transparent plate 27, the rib forming member 25 and the lead portion 22 are batched by the same dicing blade 29. Thus, the end surface of the transparent plate 27, the side surface of the housing 1, and the side surface of the package formed by the end surface of the metal lead piece 9 are substantially the same plane, and good flatness can be obtained. Therefore, when the lens barrel containing the optical system is mounted, the optical system can be positioned with high accuracy with respect to the light receiving portion of the image sensor 5 by using the side surface of the package.

  Next, the molding process of the casing made of resin shown in FIG. 5B of the manufacturing process described above will be specifically described with reference to FIG.

  First, as shown in FIG. 8A, a lead frame is disposed between the upper mold 30 and the lower mold 31, and the upper and lower surfaces of the lead portion 22 are clamped by the upper mold 30 and the lower mold 31. . Although the upper surface of the lower mold 31 is a flat surface, a recess 32 is provided on the lower surface of the upper mold 30. The space 33 formed between the upper mold 30 and the lower mold 31 through the lead 22, the space of the recess 32 of the upper mold 30, and the space of the recess 23 of the lead 22 are made of resin. A molding cavity is formed. On the surface of the upper mold 30 corresponding to the space portion 33 for forming the substrate portion 24, a hemispherical depression 30a is provided at a position corresponding to the hemispherical protrusion 24a of the substrate portion 24 (see FIG. 5B). Is formed.

  Next, as shown in FIG. 8B, the substrate portion 24 and the rib forming member 25 are molded by filling the cavity with resin. A hemispherical protrusion 24 a is formed on the upper surface of the substrate portion 24. Thereafter, as shown in FIG. 8 (c), the mold is opened, and the molded body connected to the casing as shown in FIG. 5 (b) is taken out.

  According to this molding process, the hemispherical protrusion 24a can be easily formed by adding a slight change to the upper mold 30 and without adding other processes.

  In this molding process, the upper and lower surfaces of the lead portion 22 are clamped by the upper die 30 and the lower die 31 to stably obtain a state where the die surface and the upper and lower surfaces of the lead portion 22 are in close contact with each other. be able to. Further, the boundary portion of the concave portion 32 of the upper mold 30 is disposed on the upper surface of the lead portion 22. As a result, the occurrence of resin flash due to molding is effectively suppressed.

  Further, when the resin molding of the housing is performed, if a resin sheet for suppressing the generation of resin flash burrs is interposed between the mold and the lead frame 21, the generation of flash can be more effectively suppressed.

  The solid-state imaging device of the present invention suppresses the occurrence of distortion due to the imaging element being along the substrate surface even when the imaging element is bonded to the substrate surface with insufficient flatness, and the electrical characteristics due to the distortion are reduced. The influence is reduced, and it can be effectively applied to a video camera, a still camera, and the like.

Sectional drawing which shows the structure of the solid-state imaging device in one embodiment of this invention 1 is a bottom view of the solid-state imaging device of FIG. Side view of the solid-state imaging device of FIG. The top view which removed and showed the transparent plate of the solid-state imaging device of FIG. Sectional drawing which shows the manufacturing method of the solid-state imaging device of FIG. Plan view showing a lead frame in the manufacturing method Plan view showing a resin molded body formed by embedding a lead frame in the manufacturing method Sectional drawing which shows specifically the process of resin molding in the manufacturing method Sectional view of a conventional solid-state imaging device

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Case 2 Substrate part 2a Hemispherical protrusion 3 Rib 4 Internal space 5 Image pick-up element 6 Adhesive material 7 Translucent plate 8 Adhesive material 9 Metal lead piece 9a Internal terminal part 9b External terminal part 9c Side electrode part 10 Metal thin wire 21 Lead frame 22 Lead portion 23 Recess portion 24 Substrate portion 24a Hemispherical protrusion 25 Rib 26 Housing 27 Transparent plate 28 Adhesive material 29 Dicing blade 30 Upper die 30a Hemispherical recess 31 Lower die 32 Recess 33 Space portion 34 Transparent plates 35, 36 Fillet

Claims (2)

A housing in which a substrate portion and a rectangular frame-shaped rib are integrally formed of resin, an internal terminal portion that is embedded in the housing and faces an internal space of the housing, and an external terminal portion that is exposed to the outside of the housing A plurality of metal lead pieces each having a plurality of metal lead pieces; an image pickup device fixed on the substrate portion in the internal space of the housing; and a metal connecting the electrodes of the image pickup device and the internal terminal portions of the metal lead pieces. In a solid-state imaging device comprising a thin wire and a light transmitting plate bonded to the upper end surface of the rib,
In the substrate portion, the region facing the imaging device is provided with three or more projections, and the imaging device is supported by the projections, and the height of the top of the projection support is the surface of the metal lead. A solid-state imaging device characterized by being higher. A housing in which a substrate portion and a rectangular frame-shaped rib are integrally formed of resin, an internal terminal portion that is embedded in the housing and faces an internal space of the housing, and an external terminal portion that is exposed to the outside of the housing A plurality of metal lead pieces each having a plurality of metal lead pieces; an image pickup device fixed on the substrate portion in the internal space of the housing; and a metal connecting the electrodes of the image pickup device and the internal terminal portions of the metal lead pieces. In a solid-state imaging device comprising a thin wire and a light transmitting plate bonded to the upper end surface of the rib,
In the region facing the image sensor in the substrate portion, three or more projections are provided, and the portion where the projection supports the image sensor is inside the connection region of the metal thin wire of the image sensor. There is a solid-state imaging device.

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