JP2003060187A - Cmos image sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive CMOS image sensor, which can be reduced in size and, in addition, with which an image pickup device can be obtained for a small-sized camera module whose optical support member can directly contact a region on a signal processing circuit section. SOLUTION: This CMOS image sensor 2 has a light receiving section 2a, in which color filters and microlens arrays are laminated on pixels and the signal processing circuit section 2c arranged around the section 2a. Since the color filters and microlens arrays are laminated upon another in at least a partial region B of the circuit section 2c and the optical support member presses the region B, the region B can resist the pressure applied from the pressing section of the support member. Consequently, the break or malfunction of this image sensor 3 can be suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CMOS image sensor, and more particularly to a CMOS image sensor suitable for use in an image pickup device that can be installed in a mobile phone, a personal computer or the like.

[0002]

2. Description of the Related Art In recent years, it has become possible to easily handle digital image data due to improvements in CPU performance and image processing technology. Especially mobile phones and P
In DA, a model equipped with a display capable of displaying an image is available on the market, and a dramatic improvement in wireless communication speed can be expected in the near future.
It is expected that image data will be frequently transferred between DAs.

By the way, at present, after converting a subject image into image data with a digital still camera or the like, such image data is transferred via the Internet via a personal computer or the like. However, in such a mode, in order to transfer image data, it is necessary to have both a digital still camera and a personal computer. On the other hand, in recent years, a small camera module in which an image pickup device and a photographing optical system are installed on the same circuit board has been proposed as an image input device of a portable information device. According to such a small camera module, it is not necessary to own a digital still camera or a personal computer, and it is possible to easily take an image with a mobile phone that can be easily carried and send it to the other party.

Further, as an image pickup device used in such a small-sized camera module, a CMOS type image sensor has attracted attention in place of the conventional CCD sensor for the following reason. CMOS of current semiconductor products such as photodiodes
The manufacturing process can be applied, and it can be manufactured at lower cost than the CCD sensor. It is possible to operate with a single power source, and it is possible to suppress power consumption lower than that of a CCD sensor. A signal processing circuit such as a CMOS logic circuit can be integrated in the sensor chip and can be made smaller than a CCD sensor.

[0005]

When considering the combination of the image pickup device mounted on the circuit board and the image pickup optical system, it is necessary to properly set the light receiving surface of the image pickup device at the focus position of the image pickup optical system. The problem is how to make such adjustments. For example, when the imaging device and the shooting optical system are installed on the same circuit board, the combination of the shooting optical system may be affected by factors such as variations in the thickness of the adhesive used to attach the circuit board and variations in the dimensions of the components. It can be said that it is difficult to assemble the light receiving surface of the image sensor at the focal position with high accuracy. Therefore, in order to improve the assembling accuracy of the focusing position of the photographing optical system and the light receiving surface of the image sensor, a highly accurate assembling technique is required, or a mechanism for separately adjusting the focusing position is required. . Then, there is a problem that the manufacturing cost increases.

The above-mentioned problems similarly occur even if a CMOS image sensor is adopted instead of the CCD sensor, and such a problem becomes a major obstacle in manufacturing a low-cost and compact small camera module. ing.

The present invention has been made in view of the above problems, and an object thereof is to provide a COMS type image sensor capable of obtaining an image pickup device which is a small camera module which is inexpensive and can be downsized. .

[0008]

A CMOS according to the first aspect of the present invention
The image sensor is a CMOS type image sensor including a light receiving portion and a signal processing circuit portion, and a color filter and a microlens array are stacked on the light receiving portion and at least one of the signal processing circuit portion is provided. A color filter is arranged in a partial area.

The CMOS image sensor of the second aspect of the present invention is a CMOS image sensor having a light receiving portion and a signal processing circuit portion, and a color filter and a microlens array are laminated on the light receiving portion. A microlens array is arranged in at least a part of the signal processing circuit section.

A CMOS image sensor according to a third aspect of the present invention is a CMOS image sensor having a light receiving portion and a signal processing circuit portion, and a color filter and a microlens array are laminated and arranged on the light receiving portion. A color filter and a microlens array are laminated and arranged in at least a partial area on the signal processing circuit unit.

[0011]

Now, the operation and effect of the optical support member brought into contact with the CMOS image sensor will be described.
An optical support member (including a lens frame) that supports a lens as a photographic optical system is brought into contact with a circuit board to position the CMO without positioning.
If the S-type image sensor is mounted in contact with the S-type image sensor, variations in the thickness of the adhesive between the circuit board and the CMOS-type image sensor, variations in the height from the circuit board to the light-receiving surface of the CMOS-type image sensor, etc. There is no need to consider it, positioning in the optical axis direction can be performed accurately,
In addition, the assembly work is reduced. Particularly, in the one-chip CMOS image sensor in which not only the light receiving portion but also the signal processing circuit portion and the like are integrated in the same semiconductor chip, a signal of an area sufficient to bring the optical support member into contact with the outside of the light receiving portion Since it has the processing circuit section, it has a configuration in which the optical support member is more easily brought into contact with the CCD sensor as compared with the CCD sensor. However, if the optical support member is indiscriminately brought into contact with the CMOS image sensor, it may be damaged.

On the other hand, the CM according to the first aspect of the present invention
According to the OS type image sensor, the image sensor is a CMOS type image sensor including a light receiving portion and a signal processing circuit portion, and a color filter and a microlens array are stacked and arranged on the light receiving portion, Since the color filter is arranged in at least a part of the area, the optical support member can be brought into contact with the area, and as a result,
In addition to eliminating the need to consider the adverse effects of variations in the thickness of the adhesive between the circuit board and the CMOS image sensor, it is possible to prevent damage and malfunction of the CMOS image sensor due to this The device can be downsized.

Further, it is preferable that the signal processing circuit section includes a digital circuit section, and the at least a part of the area is an area on the digital circuit section.

Further, it is preferable that the color filter arranged in the at least a part of the region is any one of blue, red and green color filters.

Further, it is preferable that an optical supporting member is placed on the color filter on the signal processing circuit section.

The CMOS image sensor of the second aspect of the present invention is a CMOS image sensor having a light receiving portion and a signal processing circuit portion, wherein a color filter and a microlens array are laminated on the light receiving portion. Since the microlens array is arranged in at least a part of the area on the signal processing circuit section, the optical supporting member can be brought into contact with the area, and as a result, the circuit board and the CMOS image sensor are connected. Not only it is not necessary to consider the adverse effect due to the variation in the thickness of the adhesive, but it is possible to suppress the damage and malfunction of the CMOS image sensor due to it, and it is also possible to downsize the imaging device.

Further, it is preferable that the signal processing circuit section includes a digital circuit section, and the at least a part of the area is an area on the digital circuit section.

It is preferable that an optical support member is placed on the microlens array on the signal processing circuit section.

The CMOS image sensor of the third aspect of the present invention is a CMOS image sensor having a light receiving portion and a signal processing circuit portion, and a color filter and a microlens array are laminated on the light receiving portion. Since the color filter and the microlens array are laminated and arranged in at least a part of the area of the signal processing circuit portion, the optical supporting member can be brought into contact with the area, and as a result, the circuit board and the CMOS image sensor. Not only it is not necessary to consider the adverse effects due to the variation in the thickness of the adhesive between the image sensor and the like, but it is possible to suppress damage and malfunction of the CMOS image sensor due to it, and it is also possible to downsize the imaging device. Become.

Further, it is preferable that the signal processing circuit section includes a digital circuit section, and the at least a part of the area is an area on the digital circuit section.

Further, it is preferable that the color filter arranged in the at least a part of the area is any one of a blue color filter, a red color filter and a green color filter.

Further, it is preferable that an optical support member is placed on the microlens array on the signal processing circuit section.

The light receiving section in this specification means a plurality of pixels (each having a photoelectric conversion element) as a photoelectric conversion section.
Means a portion where is arranged two-dimensionally. Each pixel generates a signal charge according to the amount of received light. For example, a pixel of a general CMOS image sensor includes a photodiode that performs photoelectric conversion and an MO that functions as a charge amplifier or a switch.
It is composed of an S transistor.

Further, the signal processing circuit section in this specification is
It is composed of a drive circuit section for sequentially driving pixels to obtain signal charges, an A / D conversion section for converting the signal charges into a digital signal, a signal processing section for forming an image signal output using the digital signals, and the like. is there.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a top view of a CMOS image sensor according to this embodiment. Figure 2
FIG. 2 is a view of the CMOS image sensor of FIG. 1 attached to a circuit board, taken along line II-II and viewed in the direction of the arrow.

In FIG. 1, the CMOS type image sensor 2 has a light receiving section 2a in which a plurality of pixels (not shown) are two-dimensionally arranged as a photoelectric conversion section in the center of the upper surface thereof.
And a signal processing circuit section 2c around it, which are formed in the same semiconductor chip such as a single crystal silicon substrate. Each pixel has a photodiode functioning as a photoelectric conversion element and an MO functioning as a charge amplification and switch.
It is composed of an S-transistor and generates signal charges according to the amount of received light. The signal processing circuit 2c drives a pixel (photoelectric conversion element) sequentially to obtain a signal charge, an A / D converter that converts the signal charge into a digital signal, and forms an image signal output using the digital signal. It has a signal processing unit and so on. As shown in FIG. 1, a large number of pads 2d are arranged near the outer edge of the signal processing circuit unit 2c.

As shown in FIG. 2, the CMOS image sensor 2 is adhered and fixed at a predetermined position on the circuit board PC, and the pad 2d and the wire W which are terminals for connection thereof.
Is electrically connected to a predetermined circuit on the circuit board PC via.

Further, as shown in FIG. 2, a color filter 2f for forming a color digital image is arranged on the light receiving portion 2a, and a microlens array 2g is further laminated thereon. The color filter 2f is
It is arranged and formed so as to correspond to each pixel of the light receiving portion 2a by a photolithography technique or the like.
It is composed of three types of primary color filters of R (red), G (green), and B (blue), and a color image can be obtained by synthesizing output signals from each pixel.

The microlens array 2g uses a two-dimensional array of hemispherical microlenses on each pixel in order to increase the amount of light incident on a photodiode serving as a photoelectric conversion element of each pixel. Has been.
This can be formed, for example, by using a transparent synthetic resin as a material and using a photolithography technique and a technique utilizing the heat fluidity of the resin in combination.

Here, the color filter 2f and the microlens array 2g are formed in the same process on the signal processing circuit portion 2c when they are formed on the light receiving portion 2a in manufacturing, but in the conventional case, However, only the portion formed on the light receiving portion 2a is left and the other portions are removed. On the other hand, in the present embodiment, as will be described later, the color filter 2f and the microlens array 2g are left in at least the necessary area (B).

The contact portion 1b of the optical support member 1 is a CMOS
It is in contact with the upper surface of the mold image sensor. In addition, 3 is a lens part. Here, the contact position of the contact portion 1b of the optical support member 1 will be considered. Abutting portion 1b of the optical support member 1
In order to reduce the surface pressure between the CMOS image sensor 2 and the CMOS type image sensor 2, the contact portion 1b needs a certain contact area. Here, in FIG. 1, the light receiving portion 2a of the CMOS image sensor 2 is a place where pixels for photoelectrically converting an optical image are arranged, and therefore, it is inappropriate for bringing the optical support member 1 into contact. On the other hand, in the signal processing circuit section 2c around the light receiving section 2a, the pad 2d is connected by the wire W as shown in FIG. Appropriate.

On the other hand, in the signal processing circuit portion 2c, there is a region having a large area between the pad 2d and the light receiving portion 2a so that the contact portion 1b can be brought into contact therewith. Further, in the signal processing circuit section 2c, especially the digital circuit section 2e which is a digital signal processing circuit section, has a contact force (pressing force).
It has a relatively strong property. Therefore, in the CMOS image sensor 2 according to the present embodiment, the contact portion 1b of the optical support member 1 is particularly provided on the upper surface of the digital circuit portion 2e.
Are made to abut.

More specifically, in the CMOS type image sensor 2 of this embodiment, the digital circuit portion 2e is arranged in a rectangular C shape when viewed from the upper surface (a region shown by a chain line in FIG. 1). A). Therefore, within the area A, the contact portion 1b of the optical support member 1 can be brought into contact. However, in consideration of the balance when the optical support member 1 is placed, it is preferable that the contact portions 1b are provided at three or four or more places. In the present embodiment, the contact portions 1b at four locations are brought into contact with each other.

Furthermore, by providing the above-mentioned color filter 2f and microlens array 2g on the contact surface, a stress relaxation function at the time of contact can be expected. Therefore, in the CMOS image sensor 2 of the present embodiment, the contact portion 1
Areas B (shown by a chain double-dashed line in FIG. 1) in which the color filter 2f and the microlens array 2g are left in a rectangular shape are formed around the position where b (the contact surface shape is shown by a dotted line in FIG. 1) abuts, respectively. Is forming. Further, the color filter 2f and the microlens array 2g may be left so as to cover almost the entire surface of the digital circuit section 2e.

Further, it is not always necessary to stack both the color filter 2f and the microlens array 2g on the signal processing circuit section, and only one of them may be arranged. Further, when a color filter is arranged on the signal processing circuit unit, the color filter may be composed of at least one of blue, red and green color filters.

The color filter and the microlens array referred to in the present invention need to have an optical function at least on the light receiving portion, and have an optical function on the signal processing circuit portion. You don't have to.

In the present embodiment, the optical support member 1
Is not mounted on the circuit board PC but is mounted so as to abut on the signal processing circuit section 2c of the CMOS image sensor 2, so that the optical support member 1 and the light receiving section 2a are mounted.
It is possible to accurately position and in the optical axis direction.

Although the present invention has been described above with reference to the embodiments, the present invention should not be construed as being limited to the above embodiments, and it goes without saying that appropriate modifications and improvements are possible. is there. For example, in this embodiment, the CMOS
Although the connection between the image sensor 2 and the substrate PC is performed by the wire W, there is also a configuration in which wiring is provided inside the CMOS image sensor 2 to take out a signal from the back surface or the side surface of the CMOS image sensor 2. Conceivable. With such a configuration, the signal processing circuit unit 2c of the CMOS image sensor 2 can be widely secured, and the wiring can be easily performed. The image pickup device of the present invention includes a digital camera, a mobile phone, a personal computer, a PDA, an AV device, a television,
It is considered possible to incorporate it into various things such as home appliances.

[0039]

According to the present invention, it is possible to obtain an image pickup apparatus which is a small camera module which is inexpensive and can be miniaturized, and which is capable of directly contacting the optical support member with the area on the signal processing circuit section. An image sensor can be provided.

[Brief description of drawings]

FIG. 1 is a top view of a CMOS image sensor according to the present embodiment.

2 is a view taken along line II-II of the CMOS image sensor of FIG. 1 attached to a substrate and viewed in the direction of the arrow.

[Explanation of symbols]

1 Optical support member 1b Abutment part 2 CMOS image sensor 2a Light receiving part 2c Signal processing circuit section 2d pad 2e Digital circuit section 2f color filter 2g micro lens array 3 lens part

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) (72) Inventor Kazuo Niu 2970 Ishikawa-cho, Hachioji, Tokyo Konica Co., Ltd. (72) Inventor Yasushi Hoshino Hachioji, Tokyo 2970 Ishikawa-cho, Konica stock company (72) Inventor Masafumi Mizukami 2970 Ishikawa-cho, Hachioji-shi, Tokyo (72) Konica stock company (72) Inventor Sato 444-1 Hyundai Apartment 109-805

Claims (11)

[Claims] 1. A CM including a light receiving portion and a signal processing circuit portion.
An OS type image sensor, wherein a color filter and a microlens array are stacked and arranged on the light receiving portion, and a color filter is arranged in at least a partial region on the signal processing circuit portion. Image sensor. 2. The C according to claim 1, wherein the signal processing circuit section includes a digital circuit section, and the at least a part of the area is an area on the digital circuit section.
MOS type image sensor. 3. The color filter arranged in the at least a part of the area is any one of a blue color filter, a red color filter, and a green color filter.
CMOS type image sensor described in 1. 4. The CMOS type image sensor according to claim 1, wherein an optical support member is placed on the color filter on the signal processing circuit unit. 5. A CM provided with a light receiving section and a signal processing circuit section.
An OS type image sensor, characterized in that a color filter and a microlens array are stacked and arranged on the light receiving part, and a microlens array is arranged in at least a partial region on the signal processing circuit part.
OS type image sensor. 6. The C according to claim 5, wherein the signal processing circuit unit includes a digital circuit unit, and the at least a part of the region is a region on the digital circuit unit.
MOS type image sensor. 7. The CMOS image sensor according to claim 5, wherein an optical support member is placed on the microlens array on the signal processing circuit unit. 8. A CM including a light receiving section and a signal processing circuit section
In the OS type image sensor, a color filter and a microlens array are stacked and arranged on the light receiving unit, and a color filter and a microlens array are stacked and arranged on at least a part of the signal processing circuit unit. Characteristic CMOS image sensor. 9. The C according to claim 8, wherein the signal processing circuit unit includes a digital circuit unit, and the at least a part of the region is a region on the digital circuit unit.
MOS type image sensor. 10. The CMOS type image sensor according to claim 8, wherein the color filter arranged in the at least a part of the area is any one of a blue color filter, a red color filter, and a green color filter. 11. The CMOS image sensor according to claim 8, wherein an optical support member is placed on the microlens array on the signal processing circuit unit.