JP2002100751A - Solid-state image pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small and thin solid-state image pickup device where an imaging characteristics and reliability are maintained. SOLUTION: The solid-state image pickup device is provided where a solid- state imaging element chip electrically connected to a flexible wiring board comprising an insulating film and a conductor wiring is bonded to a translucent optical glass cap provided on the image pickup element surface side of the solid-state image pickup element chip, with the solid-state image pickup chip and the outer perimeter of the optical glass cap sealed up with sealing resin. A preventing resin layer, comprising a resin whose linear expansion coefficient being equal to or above the optical glass cap, is provided to the rear surface side of the solid-state image pickup element chip.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid-state imaging device used as a small-sized imaging device for use in video cameras, digital still cameras, and the like.

[0002]

2. Description of the Related Art In recent years, solid-state imaging devices such as CCD or CMOS image sensors have been widely used in digital cameras and the like. As products become smaller and thinner, there is a strong demand for solid-state imaging devices to be smaller and thinner. In order to respond to this request, a TA as described in JP-A-7-99214 has been proposed.
There is a solid-state imaging device using a B (tape-automated bond) tape. This has a structure as shown in FIG.

That is, a TAB tape 2 is adhered to one surface of an optical glass cap 5 with a sealing material 7, and the TAB tape 2 is connected to an electrode of the solid-state imaging device chip 1 via a beam lead 3. It is connected to a bump 4 provided on the pad. In addition, TAB tape 2
It is also possible to connect directly to the bump 4 by ultrasonic bonding. Finally, the peripheral portions of the solid-state imaging device chip 1 and the optical glass cap 5 are sealed with a sealing resin 6.

A solid-state imaging device using such a TAB tape can be smaller and thinner than a ceramic package using wire bonding.

[0005]

In the conventional method, the solid-state image sensor chip and the optical glass cap have different coefficients of linear expansion. Therefore, the solid-state image sensor chip warps due to heating in a manufacturing process or a temperature change during use. Had occurred. One of the countermeasures is to use an optical glass cap whose linear expansion coefficient is relatively close to that of silicon, which is the main material of the solid-state imaging device chip. In many cases, an optical glass cap having a large difference in linear expansion coefficient must be used, and other solutions have been desired.

Further, when the optical glass cap and the solid-state image sensor chip are bonded together and sealed by heating, the air in the gap between the optical glass cap and the solid-state image sensor chip expands due to the heating and escapes from the inside of the seal. If the sealing is completed in this state, the air inside the sealing, which has returned to room temperature, contracts, causing a phenomenon that the solid-state imaging device chip is warped.

As a countermeasure, there is a method in which a portion without a sealing resin is provided in advance so that an air hole is formed after pressure bonding, and the portion is sealed later to complete the sealing. Increases extra and the cost increases. Further, the solid-state imaging device chip is warped due to the curing shrinkage of the sealing resin itself.

As described above, the warpage of the solid-state image sensor chip causes a problem that the focus position is different in each pixel of the solid-state image sensor and the image quality is deteriorated.

The present invention has been made in consideration of such problems of the prior art, and provides a solid-state imaging device capable of achieving miniaturization and thinning while maintaining imaging characteristics and reliability. The purpose is to:

[0010]

According to the present invention, there is provided a solid-state imaging device comprising: a solid-state imaging device chip to which a flexible wiring board made of an insulating film and conductive wiring is electrically connected; A solid-state imaging device in which a light-transmitting optical glass cap disposed on the solid-state imaging device chip is adhered and an outer peripheral portion of the optical glass cap is sealed with a sealing resin; On the side, a warp preventing resin layer made of a resin having a linear expansion coefficient equal to or higher than that of the optical glass cap is provided.

According to the present invention, the warpage preventing resin layer is formed for the warpage of the solid-state imaging device caused by the difference in linear expansion coefficient between the solid-state image sensor chip made of silicon and the optical glass cap made of glass. Accordingly, a force equivalent to a bending force on one side of the solid-state imaging device also acts in the opposite direction, so that a balance of forces is established, a warping phenomenon of the solid-state imaging device is prevented, and imaging characteristics and reliability are maintained. In addition, miniaturization and thinning can be achieved.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIG. 1 is a sectional view showing a first embodiment of the present invention. Here, reference numeral 1 denotes a solid-state imaging device chip on which a solid-state imaging device such as a CCD or a CMOS is formed on a semiconductor substrate such as a silicon wafer. Reference numeral 1a denotes a microlens for condensing light incident on the solid-state imaging device, and is provided on an imaging region of the solid-state imaging device chip 1.

Reference numeral 2 denotes a TAB tape, which surrounds the solid-state imaging device chip 1, and has a beam lead 3 on a side opposed to the solid-state imaging device chip. Reference numeral 4 denotes a bump provided on a terminal in the periphery of the imaging area of the solid-state imaging device chip 1, and connects the solid-state imaging device chip 1 and the TAB tape 2 via the beam lead 3.

Reference numeral 5 denotes an optical glass cap made of glass (for example, CG-1: Kyocera Corporation). The TAB tape 2 to which the solid-state image pickup device chip 1 is connected is covered with a sealing resin 6 by an outer peripheral portion. It is fixed with adhesive. As the sealing resin 6, a thermosetting adhesive such as CV5333A (Matsushita Electric Works, Ltd.) is used.

Reference numeral 7 denotes a sealing material provided on the optical glass cap 5 so as to cover the outer periphery of the imaging region so that the sealing resin 6 does not cover the imaging region of the solid-state imaging device chip 1. Is provided. Numeral 8 denotes a light-shielding film made of black resin, which is also provided on the optical glass cap 5, and is provided so as to cover the outer periphery of the imaging area. In the light-shielding film 8, a part of the light that has passed through the optical glass cap 5 is irregularly reflected by the beam leads 3 and the bumps 4 and enters the imaging region on the solid-state imaging device chip 1, causing a problem such as a ghost in an image. Is preventing that.

Reference numeral 9 denotes a film-like warpage preventing resin, which is adhered and fixed to the back surface of the image sensor of the solid-state image sensor chip 1. At this time, the solid-state imaging device chip 1 is made of a silicon wafer, its linear expansion coefficient α1 is 2.6E ⁻⁶ / ° C., and the optical glass cap 5 is made of glass (CG-1, Kyocera Corporation). Expansion coefficient α2 is 6.7E ^-6
/ ° C, and a resin whose warp preventing resin 9 has a coefficient of linear expansion α3 ≧ α2> α1 is selected. The amount of the anti-warp resin 9 is determined by the optical glass cap 5.
The difference between α3 and α2 is determined in consideration of the balance between thermal expansion and contraction.

By forming the warp preventing resin 9 in this manner, a force equivalent to the force of the solid-state imaging device trying to bend in one direction acts in the opposite direction, so that the force balance is established. However, the warpage of the solid-state imaging device is prevented.

(Second Embodiment) FIG. 2 is a sectional view showing a second embodiment of the present invention. Here, reference numeral 10 denotes a paste-like anti-warpage resin, which also has a function of a sealing resin that adhesively seals the optical glass cap 5 and the solid-state imaging device chip 1 at the outer periphery thereof. The other configuration is the same as that of the first embodiment, and the description is omitted.

As described above, by using the same material for the warp preventing resin and the sealing resin, the adhesive sealing between the optical glass cap 5 and the solid-state imaging device chip 1 and the addition of the warp preventing function can be performed in the same manner. In the process, the solid-state imaging device can be prevented from warping without increasing the cost.

[0020]

According to the present invention, it is possible to reduce the warpage of the solid-state imaging device caused by the difference in linear expansion coefficient between the solid-state imaging device chip made of silicon and the optical glass cap made of glass, and the imaging characteristics and A solid-state imaging device capable of achieving miniaturization and thinning while maintaining reliability can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention.

FIG. 2 is a sectional view showing a second embodiment of the present invention.

FIG. 3 is a cross-sectional view of a conventional solid-state imaging device using a TAB tape.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Solid-state image sensor chip 1a Micro lens 2 TAB tape 3 Beam lead 4 Bump 5 Optical glass cap 6 Sealing resin 7 Sealing material 8 Light shielding film 9 Warp prevention resin (film form) 10 Warp prevention resin (paste form)

Claims (4)

[Claims] 1. A solid-state image sensor chip electrically connected to a flexible wiring board composed of an insulating film and a conductor wiring, and a light-transmitting optical glass cap disposed on the image sensor surface side of the solid-state image sensor chip. In the solid-state imaging device in which the outer peripheral portions of the solid-state imaging device chip and the optical glass cap are sealed with a sealing resin, a linear expansion coefficient of the optical glass cap is set on the back surface side of the solid-state imaging device chip. A solid-state imaging device comprising a warp prevention resin layer made of a resin of equal or greater than equivalent. 2. The solid-state imaging device according to claim 1, wherein the warp prevention resin layer is a film-shaped resin, and is adhered and fixed to a back surface side of the imaging device of the solid-state imaging device chip. 3. The solid-state imaging device according to claim 1, wherein the warp prevention resin layer is made of the same material as the sealing resin. 4. The solid-state imaging device according to claim 1, wherein the warpage prevention resin layer is formed simultaneously with sealing the outer peripheral portions of the solid-state imaging device chip and the optical glass cap. apparatus.