JPS6046593B2 - Solid-state imaging device and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a solid-state imaging device in which the periphery of a picture element portion and a predetermined portion such as a drive circuit are masked with a light-shielding film to prevent generation of unnecessary noise, and a method for manufacturing the same.

Solid-state image sensors are expected to become more popular in the future as elements used in small, lightweight video cameras.

FIG. 1 is a sectional view showing an example of a conventionally developed solid-state imaging device. The figure shows a structure in which a color filter is glued onto the image sensor, and if a mosaic color filter of Ξ colors (for example, red, green, cyan) is used, it can be used as a single-panel color camera device. . The image sensor 11 includes a picture element section 2 and a photoconductive film 3 formed on a silicon substrate 1.
, a transparent electrode 4, a drive unit 5, and a bonding pad 6, and a glass substrate 7 on which a light shielding film 8 made of a frame-shaped chrome film or the like, and a color filter 9 are formed.
are bonded together with an adhesive 10 that is substantially transparent in the visible light range.

As this adhesive 10, a photocurable resin is suitable;
It is possible to make the thickness of the adhesive 10 sufficiently thin, and when a Ξ/color color mosaic filter is used as the color filter 9, it is possible to align the patterns of the filter and the image sensor 11 with each other. It becomes easier. That is, the color filter 9 and the image sensor 11 may be aligned while being pressed together through the adhesive 10, and in this state, a curing light beam may be irradiated to bond them together. In this example, the reason why the light shielding film 8 is provided is that by limiting the inside surrounded by the frame-shaped light shielding film 8 as a section of the image sensor, unnecessary signal components ( In other words, this is to prevent the occurrence of noise. here,
The conventional configuration shown in FIG. 1 has the following problems.

In order to cure the photocurable resin, a curing light beam is irradiated from above the glass substrate 7, but the resin is not cured because the area below the light shielding film 8 is not exposed to light.

Therefore, in the past, the area under the light shielding film 8 was used uncured, or post-treatment was performed such as mixing a thermosetting initiator into the photocurable resin and curing the uncured area by heating. I was getting used to it. However, the color filter 9 and the photoconductive film 3 are sensitive to heat and pose a risk of deterioration, so thermal curing requires a long process at low temperatures. For this reason, the advantage of short curing time, which is a characteristic of photocurable resins, is lost, and reliability is likely to decrease. The present invention has been made in view of these problems.
The present invention will be explained below along with examples using the drawings.
FIG. 2 is a structural cross-sectional view showing one embodiment of the present invention, and FIGS. 3 a to 3 d are structural process cross-sectional views of the same embodiment.

To explain using both figures, first, the silicon substrate. A picture element section 2 and a drive section 5 are formed on the picture element section 1, a transparent electrode 4 is formed on the picture element section 2 via a photoconductive film 3, and a bonding pad 6 is formed on the drive section 5. Solid-state image sensor 1
5 is formed (Figure 3a).

Next, visible light is displayed on the solid-state image sensor 15! The area is coated with a substantially transparent resin film 13 (FIG. 3b). As the resin material, it is appropriate to use a photocurable resin, more specifically an ultraviolet curable resin, which is coated thinly by spin coating or the like and then cured. The parts of the bonding pad 6 and the like 4 may be exposed without being coated by masking them, irradiating them with a curing light beam, and cleaning the uncured parts. The appropriate thickness of the resin film 13 on the transparent electrode 4 is about 2 μm. The resin coating 13 protects the image sensor 15 physically and chemically. UV curable resins with heat resistance of about 250°C are easily available (for example, Norland NOA-61).
etc.), the heat resistance temperature of the photoconductive film 3, etc. is generally lower than that, so it is sufficient as a protective coating. Next, on this resin coating 13, a light shielding film 1 made of a material such as chromium is placed.
2 is formed in a frame shape around the picture element portion 2 by means such as photolithography or pattern vapor deposition to prevent the generation of unnecessary noise as described in the conventional example (FIG. 3c). Although it can be used as an imaging device in this state or in a state covered with a protective glass, in this embodiment, a glass plate 7 equipped with a color filter 9 is used as in FIG. 1. - In this case as well, it is appropriate to use a photocurable resin as the adhesive 14. That is, by adhering using a resin that has almost the same optical properties as the resin 13 used for coating when cured, reflection and refraction of light at the resin interface can be prevented (Fig. 3, d). In this way, the solid-state imaging device shown in FIG. 2 is completed. To describe the bonding method in detail, the image sensor 15 on which the light shielding film 12 is formed
An ultraviolet curable resin 14 is dropped approximately at the center of the substrate, and the glass substrate 7 having the color filter 9 is pressed onto the ultraviolet curable resin 14.

The resin 14 is forced to the interface and spreads over the adhesive surface without creating bubbles. While pressing the glass substrate 7 to make the adhesive thickness as thin as possible, the patterns of the color filter 9 and the image sensor 15 are aligned while observing from above with a microscope, and when the alignment is completed, the microscope is removed. The adhesive 14 is cured by irradiating ultraviolet rays from above. In this case, it is necessary for the pressing means to be partially or entirely transparent to the wavelength used so that the pressing means does not interfere with pulsed ultraviolet exposure for microscopic observation.

Specifically, a transparent acrylic plate or the like may be used as the pressing means. Also, the driving force for alignment is acrylic and glass substrate 7.
can be transmitted by the frictional force of In the embodiments shown in FIGS. 2 and 3, no protective coating is provided on the surface of the color filter 9, but it can be easily handled if a protective coating is formed with a photocurable resin, similar to the image sensor. It is natural that this will be the case.

As described above, according to the present invention, when adhering color filters, it is possible to irradiate the curing light beam all over the adhesive, and complete adhesion can be completed at the same time as alignment. The process can be significantly simplified and shortened, and at the same time, the reliability of the device can be improved.

Further, since there is no need to form a light shielding film under and in contact with the color filter, the manufacturing yield and reliability of the filter are also improved. That is, since the light-shielding film is not in direct contact with either the image sensor or the color filter, there is increased latitude in designing and manufacturing the image sensor and the color filter, and overall reliability can be improved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the structure of a conventional solid-state imaging device, FIG. 2 is a sectional view of the structure of an embodiment of the present invention, and FIGS. 3a to 3d are sectional views of the manufacturing process of the same embodiment. DESCRIPTION OF SYMBOLS 1... Silicon substrate, 2... Picture element part, 3... Photoconductive film, 4... Transparent electrode, 5... Drive part, 6... Bonding pad, 7... Glass plate , 9... Color filter, 12... Light-shielding coating, 13, 14... Resin coating, 15... Solid-state image sensor.

Claims (1)

[Scope of Claims] 1. A solid-state image sensor having a light-receiving section on its surface, a first light-transmitting resin coating formed on the solid-state image sensor, and a first resin coating provided on the first resin coating. A light-shielding film that blocks light from a predetermined portion of the solid-state image sensor, and a light-transmitting plate formed on the first light-shielding film and on the light-shielding film with a light-transmitting second resin film interposed therebetween. Characteristic solid-state imaging device. 2. The solid-state imaging device according to claim 1, wherein the transparent plate has a color filter. 3. The solid-state imaging device according to claim 1, wherein the first and second resin coatings are made of a photocurable resin. 4. Forming a first light-transmitting resin coating on a solid-state image sensor having a light receiving portion on its surface, forming a resin coating on the solid-state image sensor that blocks light from a predetermined portion of the solid-state image sensor, A method for manufacturing a solid-state imaging device, characterized in that a light-transmitting plate is formed on the image sensor and on the light-shielding film with a light-transmitting second resin film interposed therebetween. 5. The method of manufacturing a solid-state imaging device according to claim 4, wherein the transparent plate has a color filter. 6. The method of manufacturing a solid-state imaging device according to claim 4, wherein the first and second resin coatings are made of a photocurable resin.