JP2006278743A - Solid state imaging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solid state imaging device formed into a highly airtight package. <P>SOLUTION: The solid state imaging device comprises a flat plate-shaped substrate 2, a solid state imaging element 3 mounted on this substrate 2, a frame 4 built up at the predetermined height on the substrate 2 in a fashion to surround the solid state imaging element 3, and a lid 5 which is joined to the top edge of the frame 4 with a given space kept away from a mounting plane of the solid state imaging element 3 on the substrate 2 and used for the hermetic sealing of the solid state imaging element 3 on the substrate 2 in this given space. The outer edge of the frame 4 is in inclined form so that it may broaden toward the substrate 2 from the top edge. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a solid-state imaging device including a solid-state imaging device which is a light-receiving element such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor) sensor.

  2. Description of the Related Art A two-dimensional solid-state imaging device in which pixels including a photoelectric conversion element such as a photodiode and a means for taking out photoelectric charges generated by the photoelectric conversion element to an output signal line are arranged in a matrix (matrix) It is offered to.

  By the way, such a solid-state imaging device is roughly classified into a CCD type and a MOS type by means for reading (extracting) the photoelectric charge generated in the photoelectric conversion element. The CCD type is designed to transfer photocharges while accumulating them in a potential well, and has a drawback that the dynamic range is narrow. On the other hand, in the MOS type, the charge accumulated in the pn junction capacitance of the photodiode is directly read out through the MOS transistor.

  Such a solid-state imaging device is sealed by a package or the like in order to protect it from the outside air. A solid-state imaging device having a solid-state imaging device thus sealed in a package is shown in FIG. In the solid-state imaging device of FIG. 5, an optical semiconductor element (solid-state imaging element) 2 is placed on a substrate 1 made of ceramic, resin, or the like, and a frame 3 is erected on the substrate 1 so as to surround it. The frame 3 is covered with a translucent lid 4 to constitute a package in which the optical semiconductor element (solid-state imaging element) 2 is sealed.

  Thereby, the airtightness of the space in the package is maintained, and the optical semiconductor element (solid-state imaging element) 2 can be protected from the outside air. Further, a wire 8 connected to the pad 7 of the optical semiconductor element (solid-state imaging device) 2 for supplying electric power to the optical semiconductor element (solid-state imaging device) 2 or sending an output electric signal is provided inside the package. And connected to an electrode 6 provided around the optical semiconductor element (solid-state imaging element) 2 (for example, Patent Document 1).

JP 2004-95595 A

  However, in the technique described in Patent Document 1, since the frame is erected substantially vertically with respect to the substrate, when heat is applied in the process of manufacturing this package, a lid made of glass or the like and resin Since the coefficient of thermal expansion is different from that of the frame body, the connecting portion is easily peeled off.

  In order to prevent the lid and the frame from peeling off due to such a difference in thermal expansion coefficient, a structure in which a ring-shaped frame is provided at the connection portion is also conceivable. However, the frame is almost vertical to the substrate. Therefore, the ring-shaped frame is dropped on the substrate, and the labor for installing the ring-shaped frame at an appropriate position is great.

  The present invention has been made in view of the above problems, and the object thereof is to reduce the influence of peeling due to the difference in the thermal expansion coefficient between the lid and the frame, and to achieve an airtight package. The object is to provide a solid-state imaging device.

  In order to solve the above-mentioned problem, a solid-state imaging device according to claim 1 is a substrate having a flat plate shape, a solid-state imaging device mounted on the substrate, and a substrate surrounding the solid-state imaging device. Solid imaging on the substrate is bonded to the upper end of the frame with a predetermined space secured between the frame formed at a predetermined height on the solid imaging element mounting surface of the substrate. A solid-state imaging device having a lid portion formed by hermetically sealing an element in the predetermined space, wherein an outer edge shape of the frame body is inclined so as to spread from the upper end portion toward the substrate. It is characterized by that.

  In order to solve the above-mentioned problem, the solid-state imaging device according to claim 2 is characterized in that in the solid-state imaging device according to claim 1, the inner wall of the frame is substantially perpendicular to the substrate. To do.

  In order to solve the above-mentioned problem, the solid-state imaging device according to claim 3 is the solid-state imaging device according to claim 1, wherein the inner wall of the frame body is inclined along the outer edge shape. Features.

  In order to solve the above-mentioned problem, a solid-state imaging device according to a fourth aspect of the present invention is the solid-state imaging device according to any one of the first to third aspects, wherein the lid and the upper end of the frame body are covered. A ring-shaped frame for preventing peeling between the lid and the frame is installed, and the thermal expansion coefficient of the ring-shaped frame is smaller than the thermal expansion coefficient of the frame.

  In order to solve the above-mentioned problem, a solid-state imaging device according to claim 5 is the solid-state imaging device according to any one of claims 1 to 4, wherein the solid-state imaging device is used for chucking a part of the outer edge of the frame body. A recess is formed.

  According to the present invention, the shape of the outer edge portion of the frame body is an inclined shape that spreads with respect to the substrate, not the shape of the frame body standing substantially perpendicular to the substrate. It is possible to provide a solid-state imaging device capable of reducing or preventing the separation between the lid and the frame body due to the stress generated by the difference in thermal expansion coefficient between the lid and the frame.

  Hereinafter, an embodiment of a solid-state imaging device according to the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view showing a configuration in an embodiment of a solid-state imaging device according to the present invention. As shown in FIG. 1, the solid-state imaging device 1 of the present embodiment mainly includes a substrate 2, a solid-state imaging device 3, a frame body 4, and a lid portion 5 made of transparent glass.

  The substrate 2 has a flat plate structure and employs a glass epoxy substrate that generates less dust. An electrode 6 is patterned on the substrate 2. The electrode 6 is, for example, Au plated on a copper foil (copper electrode), and is disposed in the vicinity of the periphery of the solid-state imaging device 3. On the other hand, although not shown, this electrode 6 is extended by a VIA hole or the like provided between the element mounting surface of the substrate 2 and the opposite surface (lower surface in the figure), and the extended portion is connected to the back surface of the substrate. It is connected to the circuit installed in the.

  The solid-state imaging element 3 is composed of a CCD element or the like, and is mounted on the center of the upper surface of the substrate 2. A plurality of electrode portions (not shown) are formed on the peripheral edge of the upper surface of the solid-state imaging device 3, and a bonding wire 8 such as a gold wire drawn from these electrode portions is connected to one end portion 6 a of the electrode 6. ing.

  The frame 4 is formed so as to surround the solid-state imaging device 3 on the substrate 2. More specifically, the frame 4 is formed on the substrate 2 so as to cover a part of the electrode 6 outside the connecting portion between the one end 6 a of the electrode 6 and the bonding wire 8. Further, the outer edge shape of the frame body 4 is not substantially perpendicular to the substrate 2 as in the prior art, but is a tapered shape that is inclined so as to spread from the upper surface of the frame body 4 on which a lid portion described later is installed toward the substrate 2. I am doing. On the other hand, the inner wall of the frame 4 (the surface constituting the space in which the solid-state imaging device 3 is sealed together with the substrate 2 and the lid 5) is formed substantially perpendicular to the substrate 2.

  Examples of the material of the frame 4 include a resin having good adhesion to the substrate 2 and the lid 5 and thermosetting or ultraviolet curable, for example, a silicon resin such as silicon rubber, an epoxy resin, an acrylic resin, and the like. Can be adopted. Further, a silicon resin having moderate elasticity is preferable in terms of relaxation of thermal stress, and an epoxy resin, an acrylic resin, aluminum, (or alloy), polycarbonate, and the like are preferable in terms of moisture resistance.

  The lid 5 has a predetermined space between the element mounting surface of the substrate 2 and, in this case, a frame that secures a space that does not interfere with the bonding wires 8 drawn from the solid-state imaging device 3. 4 is joined to the upper end portion. Specifically, it is formed on the inner wall of the frame body 4 and joined in such a manner that it is placed on a girder protruding inward.

  The lid 5 is the same as the seal glass employed in the well-known hollow package structure, and the lid 5 closes the opening of the frame body 4 so that the solid-state imaging is performed in the predetermined space described above. The element 3 is hermetically sealed.

  Here, a procedure for manufacturing the solid-state imaging device 1 of the present embodiment will be briefly described. First, the substrate 2 formed by integrally forming the electrode 6 on the substrate is manufactured, and the solid-state imaging device 3 is bonded and fixed to the substrate 2 via a die bonding agent.

  Next, the electrode part 31 of the solid-state imaging device 3 and the one end part 6 a of the electrode 6 are connected by the bonding wire 8.

  Next, a high-viscosity resin is applied around the solid-state imaging device 3 on the substrate 2, thereby forming a frame 4 having a predetermined height on the substrate 2. At this time, the height of the frame body 4 is set slightly higher than the final specified height in order to secure a joint surface with the lid 5 described later.

  Subsequently, the lid 5 is joined to the upper end portion of the frame body 4 via an adhesive, and the height dimension of the frame body 4 is adjusted to the final specified height. Thereby, the solid-state imaging device 1 shown in FIG. 1 is obtained.

  In the present embodiment, a high-viscosity resin is applied onto the substrate 2 when forming the frame body 4, but in addition to this, for example, a semi-cured resin is previously formed into a frame shape. Alternatively, this may be sandwiched between the substrate 2 and the lid 5 and both may be thermocompression bonded simultaneously.

  Further, since the inner wall of the frame body 4 is formed so as to be substantially perpendicular to the substrate, the bonding area between the frame body 4 and the substrate 2 becomes larger than before, and the outer end portion of the frame body 4 (frame Since the distance from the outer edge of the body 4 to the inner edge of the frame 4 (the portion where the inner wall of the frame 4 and the substrate 2 are installed) is increased, moisture (in the space where the solid-state imaging device 3 is sealed) Moisture) is less likely to infiltrate, and the hermeticity and waterproofness of the solid-state imaging device 3 are improved.

  On the other hand, in this embodiment, as shown in FIG. 2, in order to reduce the stress caused by the difference in thermal expansion coefficient between the lid 5 and the frame body 4, and to ensure hermeticity in the outer periphery of the lid 5. Therefore, a ring-shaped frame body 7 having an L-shaped cross section may be installed so as to cover the lid section 5 and the frame body 4 over the upper end portions of the lid section 5 and the frame body 4. The thermal expansion coefficient of the ring-shaped frame 7 is preferably smaller than the thermal expansion coefficient of the frame 4.

  In this way, by providing the ring-shaped frame 7 that exhibits a thermal expansion coefficient smaller than the thermal expansion coefficient of the frame 4, the outer periphery of the lid 5 and the upper end of the frame 4 are tightened, and the lid 5 And the frame 4 can be prevented from peeling off.

  Furthermore, as another embodiment of the solid-state imaging device according to the present invention, as shown in FIG. 3, the inner wall of the frame body 4 may be inclined along the outer edge shape of the frame body 4. In other words, this is an aspect in which the frame 4 standing vertically with respect to the substrate 2 in the configuration of the conventional solid-state imaging device is inclined inward, and the difference from the above-described embodiment is that the inner wall is the substrate 2. The inner wall is inclined at substantially the same angle as the angle formed between the outer edge and the substrate 2.

  As described above, since the inner wall of the frame body 4 is inclined along the outer edge shape of the frame body 4, the space in which the solid-state imaging device 3 is sealed can be widened. In particular, a wide wire bonding area can be taken.

  In addition, as another embodiment of the solid-state imaging device according to the present invention, as shown in FIG. 4, a chucking jig holds a recess 9 for holding the solid-state imaging device in the manufacturing process of the solid-state imaging device. You may form in the outer edge part of the body 4. FIG. By forming such a recess 9 in the frame 4, when the chucking jig holds the solid-state image pickup device, the solid-state image pickup device is damaged due to an unspecified place to hold. Not only can it be avoided, but the solid-state imaging device can be held smoothly, so that the yield can be improved.

  In the above embodiment, a glass epoxy substrate is used as the substrate 2, but a ceramic substrate or the like can also be used in addition to this.

  In addition, various modifications can be made according to the design or the like as long as they do not depart from the technical idea of the present invention.

1 is a cross-sectional view illustrating a configuration in an embodiment of a solid-state imaging device according to the present invention. Sectional drawing which shows the structure which installed the ring-shaped frame in one Embodiment of the solid-state imaging device which concerns on this invention. Sectional drawing which shows the structure in other embodiment of the solid-state imaging device concerning this invention. Sectional drawing which shows the structure in other embodiment of the solid-state imaging device concerning this invention. Sectional drawing which shows the structure of the conventional solid-state imaging device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Solid-state imaging device 2 Board | substrate 3 Solid-state image sensor 4 Frame body 5 Cover part 6 Electrode 7 Ring-shaped frame body 8 Bonding wire 9 Recessed part

Claims (5)

A flat substrate,
A solid-state image sensor mounted on the substrate;
A frame formed at a predetermined height on the substrate in a manner surrounding the solid-state imaging device;
Joined to the upper end of the frame in a state where a predetermined space is secured between the solid-state image sensor mounting surface of the substrate, and the solid-state image sensor on the substrate is hermetically sealed in the predetermined space. A solid-state imaging device having a lid,
An outer edge shape of the frame body is inclined so as to spread from the upper end portion toward the substrate.   The solid-state imaging device according to claim 1, wherein an inner wall of the frame is substantially perpendicular to the substrate.   The solid-state imaging device according to claim 1, wherein the frame has a uniform thickness.   A ring-shaped frame for preventing peeling of the lid and the frame is installed over the lid and the upper end of the frame, and the coefficient of thermal expansion of the ring-shaped frame is the heat of the frame. The solid-state imaging device according to claim 1, wherein the solid-state imaging device is smaller than an expansion coefficient. The solid-state imaging device according to claim 1, wherein a recess for chucking is formed on an outer edge of the frame body.

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