JP5570163B2 - Solid-state imaging device - Google Patents

Description

  The present invention relates to a solid-state imaging device using a solid-state imaging device such as a CCD or a CMOS.

  Solid-state imaging devices using sensors such as CCDs and CMOSs are mounted on products such as still cameras, video cameras, and surveillance cameras, and are used in various environments. Therefore, in order to realize high sensitivity and high resolution, solid-state imaging devices are required to have a magnetic noise countermeasure technique for reducing the influence of fluctuations in external electromagnetic waves and magnetic fields.

  Therefore, in a conventional solid-state image pickup device, one in which a loop of one or a plurality of turns made of a conductor surrounding a solid-state image pickup element is formed around a package housing the solid-state image pickup element or a lens mounting member surrounding the package. Yes (see Patent Document 1).

Japanese Patent Laid-Open No. 11-284163

  A solid-state imaging device such as Patent Document 1 is connected to a solid-state imaging device and an external circuit through a lead frame. For this lead frame, 42 alloy is generally used because of its good adhesion to the resin and its thermal expansion coefficient close to that of silicon. One of the features of 42 alloy is that it is a ferromagnetic material. Here, as shown in Patent Document 1, if a conductor is provided so as to surround the outer peripheral portion of the solid-state imaging device, the structure always includes the inner lead portion of the ferromagnetic material, and noise increases. It was causing the problem. This increase in noise occurs when a ferromagnetic material is arranged in a loop-shaped conductor. Conversely, in the vicinity of the position where the ferromagnetic material exists, the noise increases due to electromagnetic induction from the outside. It was the influence of the phenomenon. When this phenomenon occurs, in a photographed image (still image, moving image), strong spots or striped irregularities appear in a part of the image, and the image quality is deteriorated. Therefore, in the conventional solid-state imaging device, since the influence of the external magnetic field has not been sufficiently reduced, unevenness occurs in the image and it is difficult to obtain a high-quality image.

  The present invention is intended to solve the problems of such a conventional configuration, and to realize a solid-state imaging device capable of reducing image unevenness and obtaining a high-quality image. Objective.

In order to achieve the above object, a solid-state imaging device according to an aspect of the present invention includes a solid-state imaging device, a base body on which the solid-state imaging device is fixed, and ferromagnets disposed around the solid-state imaging device. a lead frame having, comprising a cover member for covering the solid-state imaging device, said fixed to said base away from said cover member between the base and the cover member, and a conductive member having an opening, said solid When viewed from the light incident side of the image sensor, the pixel unit and the signal readout unit of the solid-state image sensor are arranged inside the opening of the conductive member, and the lead frame is arranged outside the opening of the conductive member. It is set as the structure made.
In order to achieve the above object, a solid-state imaging device according to an aspect of the present invention includes a solid-state imaging device, a base body on which the solid-state imaging device is fixed, and ferromagnets disposed around the solid-state imaging device. A lead frame, a cover member that covers the solid-state imaging device, and a conductive member that has an opening disposed inside the base, and the conductive member of the conductive member as viewed from the light incident side of the solid-state imaging device. The pixel unit and the signal readout unit of the solid-state imaging device are arranged in a region inside the opening, and the lead frame is arranged in a region outside the opening of the conductive member.

  The solid-state imaging device of the present invention can reduce the influence of an external magnetic field, suppress image unevenness, and obtain a high-quality image.

It is a top view which shows one Example of the solid-state imaging device concerning this invention. It is a top view which shows one Example of the solid-state image sensor of the solid-state imaging device concerning this invention. It is a block diagram which shows the structural example of the solid-state image sensor of the solid-state imaging device concerning this invention. It is sectional drawing of the solid-state imaging device of FIG. It is the top view and sectional drawing which show one Example of the solid-state imaging device concerning this invention. It is the top view and sectional drawing which show one Example of the electrically-conductive member of the solid-state imaging device concerning this invention. It is sectional drawing which shows one Example of the solid-state imaging device concerning this invention. It is sectional drawing which shows one Example of the solid-state imaging device concerning this invention.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  1 is a plan view of a solid-state imaging device showing a first embodiment, FIG. 2 is a plan view showing in detail the solid-state imaging device of FIG. 1, and FIGS. 3 (a) and 3 (b) are FIG. FIG. 4 is a cross-sectional view taken along line XX ′ of FIG.

First, the outline of the solid-state imaging device of the present embodiment will be described with reference to FIG.
As shown in FIG. 1, the solid-state imaging device includes a solid-state imaging device 1, a base 2 having an opening, to which the solid-state imaging device 1 is fixed, and a cover member 4 fixed on a frame portion 21 of the base 2. And a conductive member 5. The solid-state imaging device 1 is electrically connected to the inner lead 22 a of the lead frame of the base 2 via the bonding wire 3. The outer lead 22b is electrically connected to a circuit board (not shown).

Next, a solid-state image sensor will be described with reference to FIG.
As shown in FIG. 2, the solid-state imaging device 1 includes a signal processing region A and a peripheral circuit region B disposed around the signal processing region A. The signal processing area A includes a pixel area 11 in which photodiodes for converting light into an electrical signal are arranged in a matrix, and a signal readout unit 12 having an amplifier circuit, a memory, and the like arranged around the pixel area 11. Including. The peripheral circuit region B is the same as the peripheral circuit unit 13 including a scanning circuit, a timing generator, a register, an electrode pad, and the like. The bonding wire 3 is connected to the electrode pad 14 of the solid-state imaging device 1.

Next, the solid-state imaging device will be described in more detail with reference to FIG.
FIG. 3A is a block diagram illustrating a configuration example of the solid-state imaging device 1. The solid-state imaging device 1 has a signal processing area A and a peripheral circuit area B arranged around the signal processing area A. And it has the pixel part 11 in which the pixel containing a photoelectric conversion element was arranged in two dimensions, and has the read-out circuit parts 102a and 102b for reading the signal from the pixel part 11 arrange | positioned next to the pixel part 11. . A signal from the pixel unit 11 has a configuration in which the signal is distributed and output to 102a and 102b, and 102a and 102b have the same configuration. 102a and 102b have a column amplifier circuit that amplifies a signal from the pixel portion, a memory that holds a signal amplified by the column amplifier circuit, and the like, as will be described later. Then, common signal wiring portions 103a and 103b for transferring signals from the read circuit portions 102a and 102b are provided. Read amplifiers 104a and 104b for removing noise and amplifying signals by signals transferred from the common signal wiring units 103a and 103b are provided. And the signal which passed through the read amplification part is output from output terminal part 105a and 105b, respectively. The configuration after the common signal wiring is a configuration in which two systems of outputs are performed. The signal readout unit 12 includes 102 to 104. Reference numerals 106a and 106b denote horizontal scanning circuit portions, and 107 denotes a vertical scanning circuit portion. These are portions that output signals for driving the pixel portion and reading signals from the reading circuit portion, and are part of the peripheral circuit portion. .

  FIG. 3B is a diagram corresponding to the pixel unit 11 to the readout amplification unit 104 in FIG. 3A. For simplicity, only the path through which signals for one column are output to the output terminal unit 105a is shown. It is shown.

  Each pixel 111 arranged two-dimensionally includes a photodiode (hereinafter referred to as PD) PD that is a photoelectric conversion element, and a transfer MOS transistor Tx that transfers charges from the PD. Further, a floating diffusion region (hereinafter referred to as FD) FD, to which charges from PD are transferred, FD, and a reset MOS transistor RES for resetting PD and PD are included. An amplification MOS transistor SF for outputting a signal based on the charge transferred to the FD is included. A signal from the pixel 111 having such a configuration is output to the vertical output line 112.

  The signal of the vertical output line 112 is output to the reading circuit unit 102a. The read circuit unit 102 a includes a column amplifier circuit 121, a switch 122, a memory 123, and a switch 124. The column amplifier circuit 121 amplifies the signal from the vertical output line 112. The column amplifier circuit 121 may include a clamp circuit. The memory 123 holds the signal amplified by the column amplifier circuit 121. For example, two memories S and N are arranged for each vertical output line 112. The switch 122 is a switch group for inputting and holding a signal to the memory 123, and the switch 124 is a switch group for outputting a signal from the memory 123. The signal from the memory 123 is output to the common signal line 103a through the switches of the switch group 124.

  The signals from the common signal wirings 103a and 103a are differentially output by the read amplifier circuit 141. Each wiring is appropriately set to a predetermined potential by reset means (not shown).

Next, the conductive member will be described with reference to FIG.
As shown in FIG. 4, the solid-state imaging device of the present embodiment surrounds a signal processing region A including a signal readout unit having a pixel unit 11 and a column amplifier circuit 121 that are particularly susceptible to magnetic noise when viewed from the light incident side. Thus, the conductive member 5 is arranged. Since the pixel unit and the column amplifier circuit are particularly susceptible to external magnetism due to the high gain of the amplifier circuit, the configuration in which the column amplifier circuit as the pixel unit and the signal readout unit is arranged inside the opening is a noise. It is effective in reducing. Further, in the closed loop around the opening of the conductive member 5, an electromotive force is generated by an external magnetic field and an eddy current is generated. A magnetic field in the opposite direction to the external magnetic field generated by the eddy current is The closer to the closed loop, the stronger. Therefore, when the signal processing region A is a pixel portion and a column amplifier circuit, the fact that the column amplifier circuit is close to a closed loop, that is, close to the opening end of the conductive member 5, is effective in reducing noise. The outside of the signal processing area A of the solid-state imaging device 1 is a peripheral circuit area B. The conductive member 5 has an opening, which is indicated by an opening region C. The opening region C is wider than the signal processing region A so as to include the pixel portion and the signal readout portion of the solid-state imaging device inside the opening, and the conductive member 5 surrounds the periphery of the signal processing region A. Since the conductive member 5 forms a closed loop so that magnetic noise can be further reduced, the shape of the closed loop may be any shape as long as it surrounds a predetermined position, and a circular shape, a rectangular shape, or the like is appropriately selected. It is possible. Further, there is no particular limitation on the width and thickness of the conductive member. With such a configuration, the influence of noise due to magnetism from the outside can be reduced in the signal processing region including the pixel portion and the column amplifier circuit.

  Therefore, by arranging the lead frame outside the opening, that is, by arranging the opening of the conductive member inside the lead frame arrangement region D, the ferromagnetic material is not arranged inside the conductive member 5, Noise can be reduced.

The conductive member 5 may be made of a material such as a metal plate material such as aluminum, SUS, or a copper alloy, or a metal oxide having conductivity such as ITO or SnO _2. It may be a forged plate or a film formed by vapor deposition, plating, or the like. Moreover, there is no problem even if it is a metal paste or a metal oxide paste.

  Among the above materials, it is preferable to use a non-magnetic material for the conductive member because noise due to magnetism is not increased in the vicinity of the conductive member 5, and aluminum, copper, SUS304, and the like are preferable.

  As a constituent material of the substrate, a known material such as ceramic or resin can be used.

  As described above, the solid-state imaging device according to the present embodiment can reduce the influence of external magnetism on signals. Further, since the opening of the conductive member is arranged inside the lead frame arrangement region D made of a ferromagnetic material, it is possible to reduce the influence of the ferromagnetic lead frame on the signal due to magnetism from the outside.

  FIG. 5 shows a second embodiment of the present invention, FIG. 5 (a) is a plan view of the solid-state imaging device, and FIG. 5 (b) is taken along line YY 'in FIG. 5 (a). It is sectional drawing. FIG. 5C is a cross-sectional view showing another configuration of the solid-state imaging device of the present embodiment. 6A and 6B show the conductive member used in the present embodiment. FIG. 6A is a plan view of the conductive member, and FIG. 6B is a ZZ ′ line in FIG. FIG.

  This embodiment is different from the solid-state imaging device according to the first embodiment in that a metal plate having a closed loop structure is inserted into the substrate as a conductive member. Description of the same parts as those of the first embodiment will be omitted.

  As shown in FIG. 5A, the conductive member 5 has a portion extending from a part of the outer periphery of the base 2. The opening 51 of the conductive member 5 is disposed so as to surround the solid-state imaging device 1 as in the first embodiment. In addition, the conductive member 5 has a through hole 52, and the through hole 52 facilitates attachment of the solid-state imaging device to a camera or the like.

  As shown in FIGS. 5B and 5C, the conductive member 5 is inserted into the base 2. In the case of the solid-state imaging device of FIG. 5C, since the solid-state imaging device 1 and the conductive member 5 are arranged so as to surround the signal processing region A, the solid-state imaging device viewed from the light incident side. The area can be reduced and downsizing can be realized.

  The conductive member 5 is a metal plate made of a nonmagnetic material such as aluminum, SUS, or copper alloy. As shown in FIGS. 6A and 6B, a metal plate having an opening 51 at the approximate center and a through hole 52 for mounting around is prepared, and is integrally molded with the lead frame 22. Is done. The substrate formed by such a method can be manufactured at low cost because the manufacturing process is simplified.

  As described above, since the conductive member is integrally formed with the base body in the present embodiment, the influence of noise due to magnetism from the outside caused by the conductive member can be reduced, and the ease of attachment and the frame portion 21 can be reduced. The improvement of moisture resistance in the case of resin can be realized.

  FIG. 7 shows a third embodiment of the present invention, and shows a cross-sectional view of a solid-state imaging device.

  The difference between the present embodiment and the solid-state imaging device of the above-described embodiment is that the conductive member is disposed on the cover member.

  As shown in FIG. 7, the conductive member 5 can be provided on the surface (light incident side) of the cover member 4. The inside or back surface (light emission side) of the cover member 4 may be used. That is, the fact that the signal region A including the pixel portion 11 and the signal output portion 12 having the column amplifying portion is disposed inside the opening region C with respect to the conductive member 5 having the opening portion causes noise caused by magnetism from the outside. This is an important configuration for reducing the influence.

  The cover member 4 is preferably made of glass or quartz. Glass is preferably used to insert the conductive member into the cover member.

  In addition, since the conductive member is disposed on the front surface or the back surface of the 5 cover member 4, it is necessary to consider that stray light to the photoelectric conversion element due to reflection or scattering of incident light affects the image. It is necessary to arrange. As a countermeasure against such stray light, the light reflection of the conductive member 5 can be reduced by having a light absorbing portion on the surface of the conductive member 5. The light absorbing portion can be formed by applying a paint mixed with iron black, carbon black, titanium black or the like and a binder resin to the surface of the conductive member. In order to prevent the influence on the image quality, it is also suitable for improving the image quality to arrange the light shielding means so that the light does not enter the conductive member 5.

  FIG. 8 is a cross-sectional view of a solid-state imaging device showing a fourth embodiment of the present invention, which is a solid-state imaging device having a configuration combining the first embodiment and the third embodiment.

  Each of the two conductive members 5 surrounds the outside of the signal processing area A, and the end of the opening is arranged inside the lead frame arrangement area D.

  As described above, by providing a plurality of closed loop structures made of conductive members, noise due to the influence of magnetism from the outside can be further reduced, and a good image can be obtained.

  In the present embodiment, the conductive members 5 are arranged at two locations on the surface of the cover member 4 and the concave portion of the base body 2, but three or more conductive members may be arranged. By arranging a plurality of conductive members, the effect of noise reduction can be further increased. Further, the position of the conductive member can be appropriately selected from the front and back sides and the inside of the cover member, the concave portion of the base, the inside and the back side, and a double closed loop may be formed at the same location.

DESCRIPTION OF SYMBOLS 1 Solid-state image sensor 2 Base | substrate 3 Bonding wire 4 Cover member 5 Conductive member 11 Pixel part 12 Signal readout part 13 Peripheral circuit part 14 Electrode pad 21 Frame part 22 Lead frame

Claims (7)

And the solid-state image sensor, wherein a solid substrate on which the imaging element is fixed, the lead frame having a ferromagnetic arranged around the solid-state imaging device, the solid and a cover member for covering the imaging element, Ru includes a solid-state imaging A device,
The fixed to the base body and the base away from the cover member between said cover member comprises a conductive member having an opening,
When viewed from the light incident side of the solid-pixel portion and a signal reading section of the solid-state imaging device inside the area of the opening of the conductive member is disposed outside the region of the opening of the conductive member A solid-state image pickup device, wherein the lead frame is disposed on the solid-state imaging device. A solid-state image pickup device comprising: a solid-state image pickup device; a base body on which the solid-state image pickup device is fixed; a ferromagnetic lead frame disposed around the solid-state image pickup device; and a cover member that covers the solid-state image pickup device. There,
A conductive member having an opening disposed inside the substrate;
When viewed from the light incident side of the solid-state imaging device, the pixel portion and the signal readout unit of the solid-state imaging device are arranged in a region inside the opening of the conductive member, and a region outside the opening of the conductive member A solid-state image pickup device, wherein the lead frame is disposed on the solid-state imaging device. The solid-state imaging device according to claim 2, wherein the base and the conductive member are integrally molded. The solid-state imaging device according to claim 3, wherein the conductive member has a portion extending from a part of the outer periphery of the base, and the extended portion has a through hole. The bonding wire for connecting the solid-state imaging device and the lead frame is further provided, and the bonding wire is located between the conductive member and the cover member. The solid-state imaging device according to item 1. 2. The base member and the lead frame are integrally molded, and the conductive member is located in a region that does not overlap the lead frame when viewed from the light incident side of the solid-state imaging device. 6. The solid-state imaging device according to any one of items 1 to 5. The conductive member is a solid-state imaging device according to any one of claims 1 to 6, characterized in that a non-magnetic material.

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