JPH03280574A - Solid-state image sensing device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an improvement of a solid-state imaging device comprising a solid-state imaging device having a microlens array formed on a light-receiving surface.

<Prior Art> Conventionally, there is a solid-state imaging device as shown in FIG. This solid-state imaging device has a microlens array made up of a plurality of microlenses (convex lenses) formed on the light-receiving surface of a solid-state imaging device such as a charge-coupled device (COD). In the above-mentioned solid-state imaging device, light 4 incident toward the position of the Ti cargo transport section 3 consisting of the transfer electrode 2 and the like is refracted by the microlens 1 and transmitted to the photodiode 5.
The light is focused toward the light receiving section 6, which is made up of a photoelectric conversion element such as. Therefore, the amount of light incident on the light receiving section 6 increases compared to the case where the microlens l is not formed, and the sensitivity improves accordingly. Here, 7 is a protective layer and 8 is a color filter.

Recently, with the spread of COD-based VTR cameras, facsimile machines, copying machines, etc. in homes, the miniaturization of these devices has been promoted, and as a result CODs have become smaller and the light-receiving area of the photodiode has become smaller. It's coming. In this case, the amount of light incident on the photodiode decreases and the sensitivity decreases, so focusing the light using the microlens l as described above is extremely effective.

By the way, the above-mentioned COD is usually housed in a ceramic package 13 as shown in FIG. 2 in order to protect the microlens monitor and the like.

However, recently, in order to reduce costs, a molded material made of transparent resin such as epoxy resin, as shown in FIG. 3, has been proposed.

<Problems to be Solved by the Invention> As shown in FIG. 2, when the CCD 12 is housed in the ceramic package 13, the gap between the upper side of the microlens 11 attached to the light-receiving surface of the CCD 12 and the glass plate 10 is In space, N! Since the inert gas or air is sealed, the light condensing effect by the microlens 11 can be sufficiently obtained. Here, 14 is a lead pin.

However, as shown in FIG. 3, when the COD 16 is molded with a transparent resin mold body 17, the C
Microlens 15 attached to the light receiving surface of 0D16
The upper side is covered with a molded body 17 made of epoxy resin or the like. Here, as mentioned above, since the transparent resin mold body I7 is made of a polymer resin such as epoxy, its refractive index is 1.5 to 1.6. On the other hand, microlens 15
The material is a polymer resin based on polystyrene, acrylic resin, novolac resin, polyethylene, methyl methacrylate, etc., and its refractive index is also high! .

5 to 1.6. In other words, the surface of the microlens 15 is covered with a substance having the same refractive index.

Therefore, if the microlens 15 is simply molded with the polymer resin mold body 17, there is a problem in that the light focusing effect of the microlens 15 disappears.

SUMMARY OF THE INVENTION An object of the present invention is to provide a solid-state imaging device in which the light focusing effect of the microlens does not disappear even when molded with transparent resin by increasing the refractive index of the microlens.

Means for Solving the Problems In order to achieve the above object, the present invention provides a method in which a microlens array consisting of a plurality of microlenses is formed on a light receiving surface so that incident light is converged on a photoelectric conversion section. This is a solid-state imaging device in which a solid-state imaging device is molded with a transparent resin, and the microlens is optically formed by adding a metal oxide, introducing an aromatic ring, or introducing a halogenated alkyl group. It is characterized in that it is formed to have a refractive index higher than that of the transparent resin by increasing the density.

Effect〉 When light is incident on the transparent resin molding the solid-state image sensor in which a microlens array consisting of a plurality of microlenses is formed on the light-receiving surface, this incident light passes through the transparent resin and is further exposed to the microlens array described above. incident on the lens.

Here, the microlens has a refractive index higher than that of the transparent resin by adding a metal oxide, introducing an aromatic ring, or introducing a halogenated alkyl group to increase the optical density. It is formed to have a refractive index. Therefore, the light incident on the microlens is refracted by the microlens and converged on the photoelectric conversion section of the solid-state image sensor, thereby increasing the sensitivity of the solid-state image sensor.

<Example> Hereinafter, this invention will be explained in detail with reference to Examples.

This invention increases the optical density of microlenses formed on the light-receiving surface of a CCD to increase the refractive index of the microlenses.
Even if D is molded with a transparent resin mold body such as epoxy, the light focusing effect of the microlens does not disappear.

In this example, when forming microlenses from polymer resins such as polystyrene, acrylic resin, novolac resin, polyethylene, and methyl methacrylate, the optical density of the microlens is increased by forming it using the following method. It raises it.

■ Add metal oxide.

For example, titanium oxide, indium oxide, tin oxide.

Adding metal oxides such as aluminum oxide add

■ Introducing aromatic rings such as benzene rings and naphthalene rings.

For example, polydiphenylmethyl methacrylate.

Polymer resins such as polyvinylnaphthalene get.

■Introducing halogenated alkyl groups at a high rate.

For example, a polymer resin such as polyP-chloromethylstyrene is obtained.

When microlenses made of polymer resin are formed by the methods (1), (2), and (2) above, the optical density of the microlenses increases. As a result, the refractive index is 1.5-1.
It increases from 6 to 1.7 to 1.8 or more.

In this way, as the refractive index of the microlens increases, a difference occurs between the refractive index of the microlens and the refractive index of the transparent resin mold body in which the microlens is molded. Even if the COD formed on the light-receiving surface is molded with a transparent polymer resin, the light-gathering effect of the microlens will not disappear.

Therefore, according to this embodiment, it is possible to obtain a small-sized COD that is advantageous in terms of cost and has good sensitivity.

<Effects of the Invention> As is clear from the above, the solid-state imaging device of the present invention has the following effects:
By adding metal oxides or introducing aromatic rings,
Alternatively, by introducing a halogenated alkyl group to increase the optical density, the refractive index of the microlens is made higher than the refractive index of the transparent resin in which the microlens is molded. Light incident on the microlens is refracted by the microlens and focused on the photoelectric conversion section of the solid-state image sensor.

That is, in the solid-state imaging device of the present invention, even if the microlens is molded with transparent resin, the light-condensing effect of the microlens does not disappear.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of a COD with a microlens formed therein, Figure 2 is an explanatory diagram of the COD in Figure 1 housed in a ceramic package, and Figure 3 is an explanatory diagram of the COD in Figure 1.
It is an explanatory view when molded with transparent resin. 1.11.15... Microlens, 3... Charge transfer unit, 5... Photodiode, 6... Light receiving unit, + 2.16... CCD. ■3...Ceramic package, 14.18...Lead pin, 17...Mold body.

Claims (1)

[Claims] (1) A solid-state imaging device in which a solid-state imaging device in which a microlens array consisting of a plurality of microlenses is formed on a light-receiving surface so that incident light is converged on a photoelectric conversion part is molded with transparent resin, comprising: The microlens has a refractive index higher than the refractive index of the above-mentioned transparent resin by adding a metal oxide, introducing an aromatic ring, or introducing a halogenated alkyl group to increase the optical density. A solid-state imaging device characterized in that it is formed as follows.