JPH01202989A - Solid-state image pickup device - Google Patents

Abstract

PURPOSE:To make an image face and a pickup face coincident and to eliminate picture distortion or color mis-alignment by curving a holding face of a package adhering a solid-image pickup element chip the same shape as the curved image face, curving the solid-state image pickup element chip similarly and adhering it to the holding face. CONSTITUTION:A package 7 is made of a ceramic of aluminum oxide and the curved face is formed to the holding face 7a of the solid-state image pickup element chip in matching with the curved image face of an object 4 through a lens 3 of the optical system. Lots of photoelectric conversion sections are provided to the major face of the silicon substrate in the solid-state image pickup element chip 6. The thickness of the silicon wafer whose diameter is 100mm is nearly 0.5mm and the thickness of the solid-state image pickup element chip 6 is made thin as nearly 0.2mm by grinding in case of adhesion and the wafer is adhered along the curved shape of the holding face 7a of the package 7 by using silver paste being the mixture of silver powder to the epoxy adhesives. When the solid-state image pickup element chip 6 is deformed in tracing with the shape of the holding face 7a of the package 7, the shape of the image face and the shape of the pickup face are made coincident. Thus, the image face 5 without picture distortion, color mis-alignment or uneven focus is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a solid-state imaging device that corrects distortion in an optical system used in the solid-state imaging device.

[Conventional technology]

The development of solid-state imaging devices is extremely remarkable.6For example, -dimensional C
A CD image sensor with 7p pitch and 4096 pixels has been developed. In a two-dimensional CCD image sensor, the pixel size is 9.9 x 9.84, and the number of pixels is 1280.
An X970 version is being developed. The former one-dimensional C
The length of the imaging area of the CD image sensor is approximately 28 m. In the latter two-dimensional CCD image sensor, the size of the imaging area is approximately 12.7 x 9.5 m. What both solid-state imaging devices have in common is that the pixel pitch or pixel size is small and the imaging area is large.

In FIG. 6, which schematically shows the configuration of a conventional solid-state imaging device, a solid-state imaging device chip 1 in which a large number of photoelectric conversion units are arranged in a one-dimensional or two-dimensional arrangement on a semiconductor main surface is made of aluminum oxide ceramics. is adhered to the adhesive plane of the package 2. A lens 3 is placed in front of the solid-state image sensor chip 1. Although a normal lens is often a compound lens, a single lens is shown in this figure for the sake of simplicity. When capturing an image, there is an object 4 in front of the lens 3, and the image 5 is focused on the solid-state image sensor chip 1.
Adjust so that the image is focused on the photoelectric conversion section formed on the main surface of the.

[Problem to be solved by the invention]

By the way, actual lenses have various aberrations.

What we will discuss here is the curvature of the field. As shown in Figure 2, this is the image 5 of an object placed perpendicular to the optical axis.
is not formed in a plane perpendicular to the optical axis, but is curved as shown in the figure, and the image plane deviates from the plane perpendicular to the optical axis.

When the imaging area of a solid-state imaging device is large and the pixel size is small, the effect of a shift between the imaging plane on which the photoelectric conversion units are arranged and the image plane becomes large. As a result of the curvature of the image plane, the image is in focus near the center of the imaging plane, but the image is blurred at the periphery. Furthermore, image distortion occurs in the peripheral area, and color shift occurs in color imaging devices. In this way, the curvature of the image plane of the optical system significantly deteriorates the image quality.

An object of the present invention is to provide a solid-state imaging device that solves the above problems.

[Means to solve the problem]

In order to achieve the above object, a solid-state imaging device of the present invention includes a solid-state imaging device chip in which a large number of photoelectric conversion units are arranged on a semiconductor main surface, and a package for holding this solid-state imaging device chip. In the apparatus, the holding surface of the package that holds the solid-state image sensor chip is curved in accordance with the deviation of the image plane that occurs with respect to a plane perpendicular to the optical axis of the optical system, and the It is characterized by having a solid-state image sensor chip bonded to it.

[Effect]

The holding surface of the package to which the solid-state image sensor chip is bonded is curved in the same shape as the curvature of the image plane, and the solid-state image sensor chip is similarly curved and bonded to the holding surface. This situation is shown in FIG. As a result, the curvature of the image surface is corrected by the curvature of the imaging surface, resulting in a solid-state imaging device in which the image surface and the imaging surface match, there is no image distortion or color shift, and the entire imaging surface is in focus. It will be done.

〔Example〕

An embodiment of the invention will be described below with reference to FIG.

In FIG. 1, the same components as those in FIG. 2 are given the same numbers and their explanations will be omitted.

In the present invention, the package 7 is usually made of aluminum oxide ceramic, and the holding surface 7 of the solid-state image sensor chip 6 is
A curved surface is formed in accordance with the curved shape of the image plane of the object 4 that passes through the lens 3 of the optical system. The solid-state image sensor chip 6 has a large number of photoelectric conversion parts and C on the main surface of a silicon substrate.
A scanning circuit including a CD and an output section (both paths shown) are provided.

A silicon wafer with a diameter of 1001ff11 has a thickness of 0.5
It is about nm. During bonding, the thickness of the solid-state image sensor chip 6 is reduced to about 0.2 m by polishing. The solid-state image sensor chip 6 is adhered along the curved shape of the holding surface 7a of the package 7 using a silver paste made of an epoxy adhesive mixed with silver powder. Since silicon is much more elastic than aluminum oxide ceramics, when the solid-state image sensor chip 6 is pressed against the package 7 during adhesion, the solid-state image sensor chip 6 easily deforms to follow the shape of the curved surface of the package 7.

The reason why the solid-state image sensor chip 6 is polished to be thin is to allow the solid-state image sensor chip 6 to be easily elastically deformed. When the solid-state image sensor chip 6, that is, the imaging surface is deformed following the shape of the holding surface 7a of the package 7, the shape of the image surface and the shape of the imaging surface match. As a result, an image plane 5 without image distortion, color shift, or focal unevenness is obtained.

〔Effect of the invention〕

As described above, according to the present invention, the curvature of the image plane of the optical system is corrected, and a solid-state imaging device without image distortion, focal shift within the imaging plane, and color shift can be obtained. Also.

The present invention is effective not only for solid-state imaging devices for visible light, but also for solid-state imaging devices that detect light at other wavelengths such as infrared.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a solid-state imaging device according to an embodiment of the present invention, and FIG. 2 is a diagram showing a conventional solid-state imaging device.

Claims (1)

[Claims] 1. In a solid-state imaging device that has a solid-state imaging device chip in which a large number of photoelectric conversion units are arranged on a semiconductor main surface, and a package that holds the solid-state imaging device chip, holding the package that holds the solid-state imaging device chip. A solid-state imaging device characterized in that the surface is curved to match the deviation of the image plane that occurs with respect to a plane perpendicular to the optical axis of the optical system, and the solid-state imaging device chip is adhered along the curved shape of the holding surface. .