JP2003188366A - Solid-state image pick-up device and solid-state image pick-up camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solid-state image pickup device easy to make itself thin as well as capable of compensating aberration due to curvature of an image plane in an imaging optical type. <P>SOLUTION: A spherical surface type of curvature plane 141 is formed in response to curvature of the image plane produced by the aberration of an image lens of the imaging optical type, to a back plane of a semiconductor bare chip 14 with a flip-chip mounted on a wiring board 12, and constructs a solid-state image device 302 by pasting the back plane of a solid-state image element 16, along the curved formation on a curvature plane 141 of this semiconductor bare chip 14. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid-state image pickup device including a solid-state image pickup device such as a CCD and a solid-state image pickup camera using the solid-state image pickup device, and more specifically to a solid-state image pickup device and a semiconductor bare chip for a signal processing IC thereof. The present invention relates to a solid-state imaging device that enables high-density mounting and thinning, and is less susceptible to the field curvature of a lens, and a solid-state imaging camera using the solid-state imaging device.

[0002]

2. Description of the Related Art A conventional solid-state image pickup device and a solid-state image pickup camera using this solid-state image pickup device will be described with reference to FIG. FIG. 5 is a sectional view showing a schematic configuration of a conventional solid-state imaging camera. In FIG. 5, the solid-state imaging camera includes a solid-state imaging device 500 and a lens assembly-6.
It is equipped with 00. The solid-state imaging device 500 has a ceramic package 501 whose upper surface is provided with an opening portion 501A for taking in light and whose lower surface is opened. The lower surface of the ceramic package 501 has its opening closed so as to close the wiring board 502. , And a semiconductor bare chip 503 forming a signal processing IC is mounted on the inner surface of the wiring substrate 502 on the package side. Further, a flat plate-shaped solid-state image pickup device 504 is flip-chip mounted at a position facing the opening 501A in the ceramic package 501, and further, on the upper surface of the ceramic package 501,
A seal glass 505 that seals the opening 501A is attached. The wiring board 502 and the ceramic package 501 are soldered. At this time, the solid-state imaging device 504 and the semiconductor bare chip 50 for the signal processing IC
Between 3 and 4, a spatial gap of about 0.2 mm was always generated due to the dimensional tolerance. In addition, the solid-state image sensor 5
The thickness of 04 is 0 to secure mechanical strength.
A thickness of about 3 mm is required.

The lens assembly 600 constitutes an image forming optical system for forming a photographic light image on the solid-state image pickup device 504 of the solid-state image pickup device 500, and is provided on the upper surface of the ceramic package 501 on the side of the opening 501A. A lens barrel 601 is provided, and an imaging lens 602 is mounted in the lens barrel 601 by a lens support member 603.
A diaphragm hole 604 is formed in the lens support member 603, and the image pickup lens 6 in the lens barrel 601 is further formed.
An infrared cut filter 605 is disposed on the light emission side of 02.

[0004]

However, in the lens used in the image forming optical system of such a solid-state image pickup camera, aberration called field curvature is generated. In this case, as shown in FIG. 6, even if the focus position of the imaging lens 602 is aligned with the central portion A of the light receiving surface of the solid-state image sensor 504, the peripheral portion of the solid-state image sensor 504 is imaged by the influence of the field curvature. The focal position of the lens 602 is point B, and defocus occurs. As a result, the image pickup characteristics are deteriorated such that the image quality becomes uneven in the central portion and the peripheral portion of the image.
In addition, in response to the demand for thinner overall solid-state imaging cameras such as ultra-small cameras built into mobile phones, the thinner the lens, the more difficult it becomes to design the lens of the solid-state imaging camera. It has been difficult to realize a thin solid-state imaging camera.

An object of the present invention is to provide a solid-state image pickup device which can correct aberration due to field curvature of an image forming optical system and can be easily thinned, and a thin solid-state image pickup camera using the same which is easily miniaturized. Especially.

[0006]

In order to achieve the above object, a solid-state image pickup device of the present invention is a semiconductor in which a curved surface corresponding to the field curvature caused by the aberration of the imaging optical system is formed on one surface. It is characterized by comprising a bare chip and a flexible solid-state imaging device attached to the curved surface of the semiconductor bare chip along the curved shape.

In the solid-state image pickup device of the present invention, since the solid-state image pickup element is bonded to the curved surface of the semiconductor bare chip along the curved shape, the entire solid-state image pickup device including the semiconductor bare chip is thin. Further, since the light receiving surface of the solid-state image sensor is curved along the field curvature of the imaging optical system, it is possible to correct the aberration due to the field curvature of the imaging optical system, and It is possible to provide a solid-state imaging device in which the entire light-receiving surface of the solid-state imaging device is in focus, and a good image quality with less peripheral blur can be obtained.

The present invention also provides a solid-state image pickup camera having a solid-state image pickup device and an image-forming optical unit arranged on the light incident side of the solid-state image pickup device to form a photographic light image.
The solid-state imaging device includes a semiconductor bare chip and a solid-state imaging element, and the semiconductor bare chip has a curved surface corresponding to the field curvature caused by the aberration of the imaging optical system on one surface, and the solid-state imaging element is It has flexibility and is bonded to the curved surface of the semiconductor bare chip along the curved shape.

In the solid-state imaging camera of the present invention, a curved surface corresponding to the field curvature caused by the aberration of the imaging optical system is formed on one surface of the semiconductor bare chip, and the solid-state imaging element is bonded to this curved surface. Since the solid-state image pickup device is configured and the solid-state image pickup device is assembled to the imaging optical unit to form the solid-state image pickup camera, the solid-state image pickup device is made thinner and thinner. Can be converted.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1A and 1B are sectional views for explaining the manufacturing process of the solid-state imaging device according to the first embodiment of the present invention, and FIG. 2 is an image formed on the solid-state imaging device according to the first embodiment. It is an explanatory sectional view when a solid-state imaging camera is constituted by assembling an optical unit.

In FIG. 1, a solid-state image pickup device 10 includes a wiring board 12 for mounting, a semiconductor bare chip 14, a solid-state image pickup element 16 and the like. The semiconductor bare chip 14 is for configuring a signal processing IC (integrated circuit) of the solid-state image pickup device 10. For example, a function of outputting an analog signal from the solid-state image pickup device 16 in a YUV 8 bit format, and 12C bus communication from the outside. It has a function of receiving an input signal of a camera function and performing control, or a function of mounting a non-volatile memory and performing initial setting of user setting values of white balance, color reproduction setting values, defect correction parameters, and the like. Further, as shown in FIGS. 1A and 1B, on the back surface of the semiconductor bare chip 14, that is, the surface opposite to the surface on which the signal processing IC is formed, as shown in FIGS. Spherical curved surface 1 corresponding to surface curvature
41 are formed. In addition, such a semiconductor bare chip 14 is flip-chip mounted on the wiring substrate 12 with the signal processing IC formation surface side so that the curved surface 141 faces the upper surface. In addition, the semiconductor bare chip 14
On the curved surface 141 of the solid-state imaging device 16,
It is attached along the curved shape of.

Hereinafter, a method of manufacturing the solid-state image pickup device of the present invention will be described with reference to FIG. First, a curved surface 141 is formed by processing the back surface of the semiconductor bare chip 14 into a spherical shape by a mechanical cutting method or the like along the field curvature rate of the imaging lens of the imaging optical system. Alternatively, a receding resist may be used to provide a minute opening in the center of the semiconductor bare chip 14, and the spherical curved surface 141 may be processed by an isotropic dry etching technique. In this case, it is safe in terms of mechanical strength to set the thickness of the thinnest center part to about 200 μm, but it may be as thin as about 100 μm.

Next, after mounting the passive component 18 such as a capacitor on the wiring board 12, the semiconductor bare chip 14 is flip-chip mounted on the wiring board 12. At this time, the Au bumps 20 are formed on the Al electrodes of the semiconductor bare chip 14 and mounted on the electrodes of the wiring board 12 by ultrasonic bonding. Further, the semiconductor bare chip mounting method at this time may be a method such as bonding with Ag paste. Further, for semiconductor bare chip mounting, joining by ACF (anisotropic conductive film) is also possible. After the semiconductor bare chip 14 is mounted on the wiring board 12, resin underfill is performed to reinforce the mechanical coupling strength between the semiconductor bare chip 14 and the wiring board 12.

Next, the back surface of the solid-state image sensor 16, that is, the surface opposite to the light-receiving surface is ground to process the solid-state image sensor 16 to a thickness of 50 μm or less. Preferably 2
Process to a thickness of about 0 μm. As a result, the solid-state image sensor 16 has flexibility. Next, the semiconductor bare chip 1
4 curved surface 141 or the back surface of the solid-state imaging device 16,
Alternatively, an adhesive is applied to both of them, and the back surfaces of the semiconductor bare chip 14 and the solid-state image sensor 16 are bonded to each other by compressed air. By doing so, the light-receiving surface of the solid-state imaging device 16 is mounted in a state of being curved along the curved surface 141 of the semiconductor bare chip 14, that is, in a state of being curved to the field curvature of the imaging lens of the imaging optical system. You can Next, the Al electrode of the solid-state imaging device 16 and the electrode of the wiring board 12 are electrically connected by the bonding wire 22.

According to the solid-state image pickup device 10 according to the first embodiment, the back surface of the semiconductor bare chip 14 flip-chip mounted on the wiring board 12 corresponds to the field curvature of the image pickup lens of the image forming optical system. The solid-state imaging device 10 including the semiconductor bare chip 14 has a structure in which the spherical curved surface 141 is formed and the solid-state imaging element 16 is bonded to the curved surface 141 of the semiconductor bare chip 14 along the curved shape. It is possible to reduce the overall thickness, and since the light receiving surface of the solid-state imaging device 16 is curved along the field curvature of the imaging optical system, it is possible to correct the aberration due to the field curvature of the imaging optical system. It is possible to provide the solid-state imaging device 10 in which the entire light-receiving surface of the solid-state imaging device 16 is in focus, and good image quality with less peripheral blurring can be obtained. Further, according to this embodiment, the semiconductor bare chip 14 and the wiring substrate 12 of the solid-state imaging device 16 can be shared,
The solid-state imaging device 10 can be further reduced in thickness and size.

Incidentally, the total thickness including the semiconductor bare chip and the solid-state image pickup device in the conventional solid-state image pickup device shown in FIG. 5 is 0.3 mm of the semiconductor bare chip + the spatial gap between the semiconductor bare chip and the solid-state image pickup device chip. 0.2
mm + thickness of solid-state image sensor chip is 0.3 mm = 0.8 mm. On the other hand, in the solid-state imaging device 10 according to the embodiment of the present invention, the solid-state imaging device 16 has the semiconductor bare chip 1
Since the structure is accommodated in the spherical curved surface 141 of No. 4, the semiconductor bare chip 14 and the solid-state imaging device 16
The total thickness including is substantially 0.3 mm only for the bare semiconductor chip 14. Therefore, the thickness of the solid-state imaging device 10 including the semiconductor bare chip and the solid-state imaging device shown in this embodiment is about 1 / thick of that of the conventional solid-state imaging device.
It can be about 3.

In the above embodiment, the semiconductor bare chip 1 is used.
Although the case where the back surface of 4 is processed into a spherical shape has been described,
According to the present invention, even if it is processed into a cylindrical surface, there is an effect that peripheral blurring due to lens aberration can be improved. However, in the case of processing into a spherical shape, defocusing around the screen due to lens aberration is improved over the entire screen. Further, as the solid-state image pickup device 16, even if it is a CCD image sensor or a CMOS image sensor, the same effect can be obtained.

Next, the structure of a solid-state image pickup camera in which an image forming optical unit is assembled to the solid-state image pickup device shown in the first embodiment will be described with reference to FIG. In FIG. 2, the solid-state imaging camera 30 is assembled with the solid-state imaging device 10 on the light incident side of the solid-state imaging device 10.
An image forming optical unit 32 for forming a photographing light image on the solid-state image sensor 16 of 0.

The image forming optical unit 32 includes an image pickup lens 321 and a lens barrel 322. The lens barrel 322 has a length necessary for mounting the image pickup lens 321 and packaging the semiconductor bare chip 14 mounted on the wiring board 12.
The rear end of 22 is coupled to the wiring board 12 so that the semiconductor bare chip 14 is housed inside the lens barrel 322. An image pickup lens 321 is mounted by a lens support member 323 at a position near the front end in the lens barrel 322. The lens supporting member 323 has a structure in which a male screw 323A formed on the outer peripheral surface of the lens supporting member 323 is screwed into a female screw 322A formed on the inner peripheral surface of the lens barrel 322.
By moving the lens barrel 322 in the axial direction of the lens barrel 322, the focus position of the imaging lens 321 with respect to the light receiving surface of the solid-state imaging device 16 of the solid-state imaging device 10 can be adjusted.

A field stop member 324 for limiting the field of view is provided at the front end of the lens barrel 322. Also,
An infrared cut filter 325 is arranged at the light emission side of the imaging lens 321 facing the solid-state imaging device 16 of the solid-state imaging device 10. In order to prevent dust from entering the solid-state imaging device 10, the gap between the rear end of the lens barrel 322 and the wiring board 12 is sealed with a resin material.

According to the solid-state image pickup camera 30 in this embodiment, the curved surface 141 corresponding to the field curvature of the image pickup lens 321 is formed on the back surface of the semiconductor bare chip 14 mounted on the wiring board 12. Since the solid-state image pickup device 30 in which the solid-state image pickup device 16 is attached to the curved surface 141 is assembled to the image forming optical unit 32 to configure the solid-state image pickup camera 30, the solid-state image pickup device 10 itself can be made thin, and thus the solid-state image pickup camera can be thinned. The 30 can be made smaller and thinner. Further, according to this embodiment, since the light-receiving surface of the solid-state imaging device 16 is curved along the field curvature of the imaging optical system, various curvatures of the semiconductor bare chip 14 can be changed. Is available.

Next, a second embodiment of the solid-state image pickup device and the solid-state image pickup camera of the present invention will be described with reference to FIGS. FIG. 3 is a sectional view for explaining the solid-state imaging device according to the second embodiment, and FIG. 4 shows a case where the solid-state imaging device shown in the second embodiment is assembled with an imaging optical unit to form a solid-state imaging camera. It is an explanatory sectional view.

In FIG. 3, a solid-state image pickup device 40 includes a semiconductor bare chip 14 and a solid-state image pickup device 16 which are constructed in the same manner as in the case of the first embodiment, and a package 42 for hermetically containing them. I have it. The package 42 is formed of plastic, ceramic, or the like, and the bottom of the package 42 is hermetically covered by the wiring board 43 on which the semiconductor bare chip 14 is mounted. In addition, the top plate 42 of the package 42
An opening 42B is formed in A.

The semiconductor bare chip 14 constitutes a signal processing IC of the solid-state image pickup device 16, and the back surface thereof is generated by the aberration of the image forming optical system as in the case of the first embodiment. A curved surface 141 having a spherical shape corresponding to the curvature of field is formed. The semiconductor bare chip 14 thus processed is flip-chip mounted on the wiring board 43 in the package 42 with the curved surface 141 thereof facing upward. At the time of this mounting, the wiring board 43
A lead-out electrode pad for joining to the semiconductor bare chip 14 is provided on the above, and the lead-out electrode pad and the Al electrode of the semiconductor bare chip 14 are joined by Au bumps 44.
Further, this joining method includes an ultrasonic joining method or a joining method using Ag paste, and another method may be used.

After the semiconductor bare chip 14 is mounted on the substrate 42A, an underfill material is filled between the semiconductor bare chip 14 and the wiring board 43 to form the semiconductor bare chip 1
4 and the mechanical strength of the package 42 are strengthened. Next, the back surface of the solid-state imaging device 16 is polished in the same manner as in the case of the first embodiment, and is polished to 50 μm or less, preferably 2 μm.
The solid-state imaging device 16 is made flexible by processing it to a thickness of about 0 μm.

Next, the curved surface 14 of the semiconductor bare chip 14
1, an adhesive is applied to the back surface of the solid-state image sensor 16, or both, and the semiconductor bare chip 14 and the back surfaces of the solid-state image sensor 16 are bonded to each other by compressed air. By doing so, the light-receiving surface of the solid-state image sensor 16 is curved along the curved surface 141 of the semiconductor bare chip 14, that is, a curved surface that corrects the field curvature due to the aberration of the imaging lens of the imaging optical system. Can be implemented in a state.
Next, the Al electrode of the solid-state imaging device 16 and the electrode of the wiring board 43 are electrically connected by the bonding wire 45. Next, the upper surface opening 42B of the package 42
Is hermetically sealed by a transparent seal glass 46. An infrared cut filter film 47 is formed on the outer surface of the seal glass 44 by vapor deposition or the like. As described above, the solid-state image sensor 16 is curved and bonded to the curved surface 141 of the semiconductor bare chip 14, and the package 42
The solid-state imaging device 40 packaged by

Next, the structure of the solid-state image pickup camera in which the image-forming optical unit is assembled to the solid-state image pickup device shown in the second embodiment will be described with reference to FIG. In FIG. 4, a solid-state imaging camera 50 is assembled with the packaged solid-state imaging device 40 and the light incident side of the solid-state imaging device 40, and forms a photographing light image on the solid-state imaging device 16 of the solid-state imaging device 40. The imaging optical unit 52.

The image forming optical unit 52 includes an image pickup lens 521 and a lens barrel 522. The lens barrel 522 has a length required to mount the imaging lens 521, and the imaging lens 521 is mounted by a lens support member 523 at a position near the front end in the lens barrel 522. The lens supporting member 523 has a structure in which a male screw 523A formed on the outer peripheral surface thereof is screwed into a female screw 522A formed on the inner peripheral surface of the lens barrel 522. The lens supporting member 523 is attached to the lens barrel 522. By moving the lens barrel 522 in the axial direction of the lens barrel 522, the focus position of the imaging lens 521 with respect to the light receiving surface of the solid-state imaging device 16 of the solid-state imaging device 40 can be adjusted. A field stop member 524 that limits the field of view is provided at the front end of the lens barrel 522. Such an imaging optical unit 52 is mounted on the solid-state imaging device 40 by connecting the rear end of the lens barrel 322 to the upper end surface of the package 42.

According to the solid-state image pickup device 40 in the second embodiment, the field curvature of the image pickup lens of the image forming optical system is formed on the back surface of the semiconductor bare chip 14 as in the case of the first embodiment. Since the solid-state imaging device 16 is bonded to the curved surface 141 of the semiconductor bare chip 14 along the curved shape, the solid-state image pickup device 16 including the semiconductor bare chip 14 is formed. The entire imaging device 40 can be made thin, and the light receiving surface of the solid-state imaging device 16 is curved along the field curvature of the imaging optical system. It is possible to provide the solid-state imaging device 10 that can be corrected and is in focus over the entire light-receiving surface of the solid-state imaging device 16, and a good image quality with less peripheral blurring can be obtained. Further, according to this embodiment, the semiconductor bare chip 14 and the wiring board 43 of the solid-state imaging device 16 can be shared, and the package 42 can also be shared.
Accordingly, it is possible to further reduce the thickness and size of the solid-state imaging device 40. In addition, by packaging the solid-state image sensor 16 including the semiconductor bare chip 14 in the package 42, it is possible to completely prevent dust from entering the surface of the solid-state image sensor and improve the manufacturing yield.

Further, since the solid-state image pickup device 50 according to the second embodiment is assembled to the image forming optical unit 52 to form the solid-state image pickup camera 50, as the solid-state image pickup device 40 itself becomes thinner, The solid-state imaging camera 50 can be made smaller and thinner.

[0031]

As described above, according to the solid-state image pickup device of the present invention, a thin solid-state image pickup device is obtained by bonding a semiconductor bare chip having a function such as a signal processing system and a drive system and a solid-state image pickup device. Can be realized. Also, the back surface of the semiconductor bare chip is processed into a spherical shape or a cylindrical shape,
By adhering a thinly processed solid-state image sensor along the curved shape, the element surface of the solid-state image sensor can be curved so as to absorb the aberration of the lens, and it is thin and covers the entire area of the screen. It is possible to obtain a solid-state imaging device that is in focus.

According to the solid-state image pickup camera of the present invention,
A curved surface corresponding to the field curvature caused by the aberration of the imaging optical system is formed on one surface of the semiconductor bare chip, and a solid-state imaging device is bonded to this curved surface to form a solid-state imaging device. Since the solid-state image pickup camera is configured by assembling the solid-state image pickup optical unit, the solid-state image pickup camera can be made smaller and thinner as the solid-state image pickup device itself is made thinner.

[Brief description of drawings]

1A and 1B are cross-sectional views for explaining a manufacturing process of a solid-state imaging device according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view for explaining a case where a solid-state imaging camera is configured by assembling an imaging optical unit with the solid-state imaging device according to the first embodiment of the present invention.

FIG. 3 is a sectional view for explaining a solid-state imaging device according to a second embodiment of the present invention.

FIG. 4 is an explanatory cross-sectional view of a case where a solid-state image pickup camera according to a second embodiment of the present invention is assembled with an imaging optical unit to form a solid-state image pickup camera.

FIG. 5 is a sectional view showing a schematic configuration of a conventional solid-state imaging camera.

FIG. 6 is an explanatory diagram of field curvature caused by aberration of the imaging lens.

[Explanation of symbols]

10 ... Solid-state imaging device, 12 ... Wiring board, 14 ... Semiconductor bare chip, 16 ... Solid-state imaging device, 141 ... Curved surface, 30 ... Solid-state imaging camera, 32 ... Imaging optical unit 32, 40 ... ... Solid-state imaging device, 42 ... Package, 43 ... Wiring board, 46 ... Seal glass, 50 ...
... Solid-state image pickup camera, 52 ... Imaging optical unit.

Claims (11)

[Claims] 1. A semiconductor bare chip having a curved surface corresponding to a field curvature caused by aberration of an imaging optical system on one surface, and a semiconductor bare chip bonded to the curved surface of the semiconductor bare chip along the curved shape. A solid-state imaging device comprising: a flexible solid-state imaging device; 2. The solid-state imaging device according to claim 1, wherein a signal processing integrated circuit is formed on the other surface of the semiconductor bare chip, and the other surface is flip-chip mounted on a substrate or a package. 3. The solid-state imaging device according to claim 1, wherein the curved surface of the semiconductor bare chip is cylindrical or spherical. 4. The solid-state imaging device has a light-receiving surface and a back surface which is a surface opposite to the light-receiving surface, and the surface of the solid-state imaging device bonded along the curved surface of the semiconductor bare chip is the 2. The solid according to claim 1, which is a back surface, and the flexibility of the solid-state imaging device is provided by grinding the back surface until the solid-state imaging device has a predetermined thickness. Imaging device. 5. The solid-state imaging device according to claim 2, wherein the other surface of the semiconductor bare chip is underfilled with resin on the substrate or the package. 6. A solid-state image pickup camera comprising: a solid-state image pickup device; and an imaging optical unit arranged on a light incident side of the solid-state image pickup device to form a photographic light image, wherein the solid-state image pickup device is a semiconductor bare chip. A solid-state image sensor, the semiconductor bare chip has a curved surface corresponding to the field curvature caused by the aberration of the imaging optical system on one surface, the solid-state image sensor has flexibility, the semiconductor A solid-state imaging camera, which is attached to a curved surface of a bare chip along the curved shape. 7. The solid-state imaging camera according to claim 6, wherein an integrated circuit for signal processing is formed on the other surface of the semiconductor bare chip, and the other surface is flip-chip mounted on a substrate or a package. 8. The solid-state imaging camera according to claim 6, wherein the curved surface of the semiconductor bare chip is cylindrical or spherical. 9. The solid-state imaging device has a light-receiving surface and a back surface which is a surface opposite to the light-receiving surface, and the surface of the solid-state imaging device bonded along the curved surface of the semiconductor bare chip is the 7. The solid according to claim 6, which is a back surface, and the flexibility of the solid-state imaging device is provided by grinding the back surface until the solid-state imaging device has a predetermined thickness. Imaging camera. 10. The solid-state image pickup camera according to claim 7, wherein the other surface of the semiconductor bare chip is underfilled with resin on the substrate or the package. 11. The solid-state imaging camera according to claim 6, further comprising an infrared cut filter provided on a light incident side of the solid-state imaging device.