JPS6150102A - Production of color separating filter for solid state image pickup element - Google Patents

Abstract

PURPOSE:To prevent the generation of optical flares as a result of the incidence of unnecessary light from the side face part and the consequent generation of fogging, etc. by forming color separating filters into a desired pattern by the required number of colors on one side of a transparent glass substrate then forming a light shielding film by a spray painting method on the side face. CONSTITUTION:Many color separating filter layers 11 are formed on the large transparent glass substrate 10a and a protective film 13 is formed thereon by using a coating material (''Silitect II(R)'', the name of the product produced by Controline Inc., USA) which can form an easily strippable coated film. A stretchable PVC film 15 is then adhered to the bottom surface of the substrate 10. Cutting grooves 16 are scored to these films from the surface by a cutting machine using 600-mesh resin blades and thereafter the tape 15 is pulled in the direction shown by right and left arrows to form the grooves 16'. An acrylic paint contg. a black pigment is then spray-coated on the surface to form a black coated film 17 over the entire surface including the side faces in the respective projecting parts and thereafter the coated film is cured by heating. The tape 15 and the film 13 are stripped by which the individual color separating filter 18 is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention forms a coating film on the side surface using a spray coating method to block unnecessary light from the outside ffV, and prevents optical flare and fogging phenomena as a solid-state image sensor camera. This article relates to a method for producing color separation filters for solid-state imaging elements that can be prevented.

Solid-state imaging devices such as CCDs (charge-coupled devices) are used at the heart of television cameras.To colorize television cameras, one layer of color separation filters is directly applied to the light-receiving part of the solid-state imaging device (3). There are cases where it is installed in the soil, and cases where a separately manufactured color separation filter is attached to the solid-state image sensor. The latter bonding method is the mainstream for reasons such as low manufacturing yields for filters and elements in the "" shape.

In the bonding method, the color separation filter is formed on a glass transparent substrate with a certain thickness (for example, about 0.5 to 1.0#oI+), so unnecessary light enters from the side of the color separation filter. However, optical flare occurs, which tends to cause fogging on the camera.

FIG. 1 shows an explanatory diagram of a solid-state imaging device using a conventional color separation filter (no light shielding layer on the side surface).

According to this, the color separation filter (2) is attached to the adhesive layer (
3) Pasted together via 7. ). The solid-state imaging device 9J is configured to transmit electrical signals related to the image (C) from the CCI]j) to the outside of the solid-state imaging device package (6) via the conductive wire (4) and the lead frame (5). Light rays that have passed through the camera lens system (shown in the figure) are incident on the device.As shown in the figure, there is a flare prevention plate (8) on the bottom surface of the sealing glass plate (7).
) are provided around the periphery to block unnecessary light rays that enter obliquely from the outside. When light rays are incident from an angle, the light rays enter from the side of the transparent substrate (9) of the color separation filter (2), causing flare and fogging phenomena.To prevent this, a flare prevention plate (
8) was necessary. Such a flare prevention plate (8) needs to be aligned and bonded before attaching the sealing glass plate (7), which not only requires time and effort, but also As they become smaller, they are becoming extremely difficult to work with.

In view of the above-mentioned drawbacks of the prior art, the present invention proposes a color separation filter for solid-state imaging devices that eliminates the need for the above-mentioned flare prevention plate. Specifically, the color separation filter for a solid-state image sensor is obtained by spray painting on the side surface of a color separation filter for a solid-state image sensor, which is formed by forming a small number of color separation filter layers (with a desired number of colors and a desired number of colors) on one side of a transparent glass substrate. It is characterized by forming a coating film as a light-shielding layer.

As a means of forming a light-shielding layer on the side surface, dry plating methods such as vacuum steaming, sputtering, and ion blating, or electroless plating methods are considered. Increase the power by 10"-' to 1
It is necessary to create a high vacuum of about 0-5 torr, and there are problems in that the equipment for this is expensive and that it takes time to create a high vacuum. Furthermore, this case has the disadvantage that the materials that can be used to cover the side surfaces are limited. In other words, materials with corrosion resistance are desired, but these materials include metals such as nickel, chromium, and titanium, but they have relatively high melting points (and many oxides have even higher melting points, so they do not evaporate during deposition. Due to the radiant heat from the source, the color separation film maker that is the substrate is heated to about 200 degrees Celsius, causing the organic substances formed on the surface to deteriorate.Therefore, in the case of dry plating, it is important to choose a low melting point material. As a result, materials such as tin and aluminum are limited, and since these materials do not have corrosion resistance, they are often inconvenient when used for a long period of time.

On the other hand, electroless plating uses nickel, a material with good corrosion resistance, but in addition to the complexity of the cleaning, degreasing, sensitization, activation, and plating processes, it also requires a color separation filter to be attached to the liquid. A stretchable film to temporarily hold this (190) has the disadvantage that liquid may seep into the space and precipitate on the back side of the color separation filter b'
-There was.

In order to improve the above-mentioned drawbacks, the present invention aims to form a light-shielding layer on the side of the paint film using a spray coating method. The present invention relates to a method of manufacturing a color separation filter for a solid-state image sensor.

Here, one embodiment of a color filter for color separation obtained by the manufacturing method of the present invention will be described in detail with reference to FIG.

First, the glass transparent substrate (lO) is 05~
1. The glass transparent substrate (10) has a thickness of about fl mm and is made of quartz glass, low expansion glass, or ordinary glass such as (111 silicate glass or soda lime glass). One side of the filter is provided with a filter layer for color separation.
As is known in Japanese Patent No. 17576, there is a single-layer filter made of an organic resin, which is made by dyeing a thin film of a photosensitive material of a water-soluble resin such as gelatin, gryu, or casein, dyed with a dye; A thin film with a high refractive index and a thin film with a low refractive index are alternately 1
Naturally, a single-layer inorganic interference filter formed by laminating 0 to 20 layers can also be used.

The thickness of the filter layer aυ is about 10 μm or less, and in FIG. 2, the thickness is greatly exaggerated compared to the transparent substrate 00). Moreover, although it is not clear from Fig. 2, the desired number of colors (1), for example, two colors (cyan and yellow) or three colors (red, green, blue, etc.), corresponds to the desired pattern, that is, the shape of the light-receiving part of the solid-state ji+f element. It is set up as follows. In many cases, one side of a transparent substrate (1φ) has not only a layer of filters for color separation (0υ), but also an overcoat layer to preserve the surface of the filter (Iυ), or a single layer of filters for each color. There is no speed-of-light light in the gap or surrounding area, te-・
There are few examples of color separation filters consisting only of a single filter layer (1υ) and a transparent substrate (lO).

However, such additional elements are conventionally known for older filters, and it goes without saying that the present invention applies to all of these conventionally known color separation filters.

A light shielding layer (121) is provided on the side surface of the color separation filter shown in FIG. It contains coloring pigments for acrylic purposes, such as /recon resin, polyester resin, but black is better in order to suppress the reflection of light from inside the color separation filter, so carbon black, acetylene Pigments such as black and graphite are used.

This light-shielding film (12) should have a high light-shielding performance with a concentration of 2.0 or more on the Macbeth densitometer, and in this sense,
It is desirable to use a black pigment that absorbs light.

The method for manufacturing a color separation filter for a solid-state image sensor according to the present invention will be described in detail below with reference to FIGS.

As shown in FIG. 3(a), the color separation filter for solid-state image sensors is called "multilayer", and in the filter manufacturing stage, a color separation filter is layered on the top surface of a single large transparent substrate (10a). There is a step of forming a large number of (10) and then cutting them one by one. Immediately before this cutting, the
), a single layer of color separation filters is fabricated by attaching multiple layers, the top surface is coated with a protective film (I3) to cover the filter layer αυ, and the bottom surface is coated with, for example, vinyl chloride resin having an adhesive layer (14). Stretchable film membranes such as films (151
Paste. Figure 5 (bl is a state in which cutting grooves (161) are formed between each color separation filter layer (1υ) using a dicing device, etc. As is already clear, the protective film αJ is This prevents the first layer of the filter from being contaminated by the generated glass debris.Next, as shown in Figure 3 [C], a stretchable film (15J) was coated as shown by the arrow in the figure. By applying force so as to spread it to both sides, the above-mentioned cutting groove (the width of 1610 is enlarged to form a groove L16)' is formed.

The color separation filter 08 cut into pieces in this state is as follows:
The distance between the sides increases, making it easier to clean these areas.

After thoroughly washing with water and drying, spray paint to form a coating on the sides.

Spray painting is a method of atomizing paint using a jet of compressed air sent from a compressor, and the air pressure during work is 1 to 5 kg/cn*. Place the color separation filter in the state shown in Figure 6(c) on a rotating table.

A spray gun is installed 10 to 100 square meters away from this at an angle of 20P-70° and sprays the paint.

Gradually turn the rotary table and paint the sides of the color separation letters to a coating thickness of 5 to 100 μm.

Thereafter, drying or curing is performed at a temperature of room temperature to 150° C. for about 5 to 60 minutes. Spray painting like this 5
In 'Ji, a coating film 07 as shown in FIG. 6 (dl) is formed on the entire protective surface and side surfaces of the color separation filter α.

After this, the extensible "FJ Rem III" with an adhesive layer (
Remove the individual color separation filters (181 from +51,
After that, if you peel it off from the protective film α3 coated with adhesive tape such as cellophane tape, you will see that it is a separate and independent color separation filter decoy as shown in Figure 6 (el), and its side surface is spray painted A coated light-shielding layer (12) is obtained.

The above-mentioned paint does not easily adhere to the glass surface due to its smoothness, but as in this method, the cut surface has irregularities ranging from fine irregularities of 1 μm or less to coarse irregularities of several tens of μm, so it is difficult to adhere to the surface of glass due to its smoothness. Adhesion strength (-'Nilotape peeling λ: L property) is sufficiently obtained. In order to achieve even stronger adhesion, a silane coupling agent may be applied as a primer.

Examples of the present invention will be described below.

〔Example〕

Thickness 1. 'OM, on a transparent substrate made of Pyrex glass (manufactured by Corning, USA) with a diameter of 10 crn...
A single layer of rectangular filters with sides of approximately iQIIIm are applied on multiple sides using a known method, and a coating material that forms an easily removable coating film on the surface filter side [Silitect ■: trade name J manufactured by Controlline, Inc. in the United States] is applied. It was applied and dried to form a protective film. Next, the stretchable tape S l'\7-224 (Nitto Denko (printed product name), which has an adhesive layer on one side of a stretchable polyvinyl chloride film, and the lower surface of the transparent substrate were pasted together as shown in Figure 5 of the drawing). As a foreshadowing of a).

Subsequently, cutting grooves were cut from the surface using a 600 mm resin blade, and the ends of the stretchable tape were pulled to form the state shown in Fig. 3 (cl).

Next, a coating film was formed on the side surface of the filter to a thickness of 20±5 μm by spray coating using a black paint product name Lyopol Black (acrylic urethane resin paint) manufactured by Toyo Ink Manufacturing (■). The curing conditions were 80°C for 20 minutes.

After that, by peeling off the stretchable tape attached to the back side of the color separation filter and the protective film on the front side, a color separation filter for solid-state imaging single-image elements with a coating layer applied only to the sides was obtained. . This nickel toco is 5 on the Macbeth concentration meter.
The adhesive strength was also satisfactory, with a value of ±0.5.

As explained above, the color separation...':t filter of the present invention is multi-layered on one transparent glass substrate. By setting up the coating process using the spray method, it is possible to apply the coating film light-shielding layer only to the desired area, ie, the side surface of the filter, and the simplicity of the manufacturing method is of great use in industry.

Furthermore, the paint film light-shielding layer obtained by the present invention is simpler and less expensive than metal light-shielding layers obtained by electroless plating or dry plating, and is corrosion-resistant due to the use of organic materials. It is cheap and has a high value because it is not a problem car.

FIG. 4 shows a state in which the color one-separation filter for a solid-state imaging device according to the present invention is incorporated into a CCD type solid-state imaging device. As is clear from the figure, the coating film light-shielding layer (121
Since this is applied, there is no need to provide the solid-state imaging device with a flare prevention plate, and the solid-state imaging device can be manufactured extremely easily.

As described above, the method for manufacturing a color separation filter of the present invention includes:
The combination of ease of manufacture and convenience when incorporated into a solid-state imaging device makes it extremely excellent in practice.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an example of a conventional solid-state imaging device, and FIG. 2 is a schematic cross-sectional view showing an embodiment of a color-separated IW filter for a solid-state imaging device according to the present invention. 1) to (cl) are cross-sectional views showing an example of the method for manufacturing a color separation filter according to the present invention in the order of steps;
The figure is an explanatory diagram showing how the color separation filter according to the present invention is incorporated into a solid-state imaging device. (10)...Transparent substrate Qll...Filter layer +121...Light shielding layer

Claims (1)

[Claims] A solid material characterized by forming at least a color separation filter layer in a desired pattern with a predetermined number of colors on one side of a transparent glass substrate, and then forming a coating film obtained by spray painting on the side surface as a light-shielding layer. A method for manufacturing a color separation filter for an image sensor.