JPS63122167A - Manufacturing method of solid-state image sensor - Google Patents

Abstract

PURPOSE:To enhance the accuracy of bonding alignment and, at the same time, to make the distribution of a bonded layer uniform by a method wherein a protective film layer is formed on a transparent glass substrate where monochromatic filters or color-separating filters are formed at prescribed intervals and light-receiving parts at a wafer for a solid-state image pickup device are bonded and fixed through a bonded resin layer in such a way that the light-receiving parts are aligned with the respective monochromatic filters or the color- separating filters. CONSTITUTION:Chip-like color-separating filters 2 are formed on the surface of a transparent glass substrate 1 at prescribed intervals; in addition, a protective film layer 3 is formed on the transparent glass substrate 1 and the color-separating filters 2. Then, grooves 1 ' are made between the color-separating tilters 2 by making use of a dicing saw in such a way that the grooves do not touch bonding pad parts 8. Then, the respective light-receiving parts 6 at a water 5 for a solid-state imaging device are bonded and fixed to the transparent glass plate 1 and the protective film layer 3 by means of an aligner through a bonded resin material 4' which is transformed into a bonded resin layer 4 in such a way that the light- receiving parts 6 are aligned with the color-separating filters 2. Then, one face is polished by using cerium so as to obtain an optical mirror-plane. Then, the protective layer 3 and the bonded resin layer 4 are removed by using an O2 plasma solvent; after that, the assembly is cut by means of the dicing saw and is processed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing two-dimensional and one-dimensional solid-state image sensors for solid-state cameras and facsimiles.

[Conventional technology]

Currently, solid-state cameras are being rapidly developed to be smaller and have higher resolution, and the pixel sizes of both image sensors and color filters are becoming smaller. It is necessary to minimize the loss of face.

Therefore, the dimensions of the wiring section outside the light-receiving section become finer, and it becomes necessary to improve the total pitch and adhesion accuracy of each of the image sensor and the color filter.

Therefore, the total error of both is ±0.5 to ±11Lm.
The following levels are required.

[Problem that the invention seeks to solve]

By the way, in the conventional manufacturing method of solid-state image sensors, the adhesion accuracy is generally reduced because both the image sensor and the color filter are cut into chips and then glued. Due to the imaging characteristics due to internal variations, flickering and shading may occur.
In addition, defects occur due to the contamination of dust and foreign matter when handling chips in the chip state, and this type of bonding process has become an extremely serious problem in terms of workability9 yield and high resolution. there were.

On the other hand, current color filters have a thickness of about 0.5 mm to 1.5 mm.
Although it is formed on a 0 mm glass substrate, during imaging, the light reflected from the solid-state image sensor surface is reflected by the glass surface of the reflective surface of the color filter, which causes a flare phenomenon, which poses a problem in terms of high quality.

For this reason, on-chip technology that forms color filters directly on the image sensor is currently being considered, but in terms of yields for both the image sensor and the color filter, conventional color filters are difficult to form using chrome films, etc. There were various problems, such as consideration of dimensions for forming optical black with an optical density of 4.0 or higher, problems in managing color characteristics during dyeing, and damage to image pickup elements during color filter formation.

The present invention has been made to solve the above-mentioned problems, and aims to provide a method for manufacturing a solid-state image sensor that improves the accuracy of adhesive alignment and makes the adhesive layer distribution uniform.

[Means for solving problems]

The method for manufacturing a solid-state image sensor according to the present invention includes forming a protective film layer on a transparent glass substrate on which monochrome filters or color separation filters are formed at a predetermined pitch, and then attaching a solid-state image sensor wafer to the transparent glass substrate through an adhesive resin layer. Each light-receiving section is aligned with a monochrome filter or a color separation filter and fixed with adhesive, and then the transparent glass substrate is thinned and then cut to obtain a solid-state image sensor.

[Effect]

In this invention, after the monochrome filter or color separation filter is fixed in alignment with the solid-state image pickup device, it is possible to process the back side of the glass into a thin plate, which is almost the same level as on-chip state.

〔Example〕

FIGS. 1(a) to 1(e) are manufacturing process diagrams showing one embodiment of the present invention. In FIG. 1(a), 1 is a sheet-like transparent glass substrate with a diameter of 3 inches (75 mm) and a thickness of 0.5 mm, and a chip-shaped color separation filter 2 is predetermined on the surface of this transparent glass substrate. Further, a protective film layer 3 is formed on the transparent glass substrate 1 and the color separation filter 2.

Next, using a guising tool between each color separating filter 2, a depth O, 1 is created as shown by the two-dot chain line in FIG. 1(a).
The groove 1' is machined in such a way that the part where the bonding pad part 8 shown in FIG. 1(e) is formed does not overlap.

Next, as shown in FIG. 1(b), a solid-state image sensor with a diameter of 3 inches (75IIIm) is placed on the transparent glass substrate 1 and the protective film layer 3 via an adhesive resin material 4' which becomes an adhesive resin layer 4. Each light receiving section 6 of the wafer 5 is aligned with the color separation filter 2 and fixed by adhesive using an aligner, resulting in the state shown in FIG. 1(c). Next, as shown by the two-dot chain line in FIG. 1(C), the back surface of the transparent glass substrate 1 is ground on one side using a diamond grinding wheel with a surface grinder until it reaches at least the bottom of the groove 1'. The shape shown in Figure (d) is adopted, and the thickness of the transparent glass substrate 1 is 801 Lm. Further, in order to remove approximately 301 Lm of the grinding strain layer of the transparent glass substrate 1, one side is polished to an optical mirror surface using cerium oxide to a depth of 50 pm on each side. By this polishing, the transparent glass substrate 1 has a thickness of about 30 μLm.

Next, the protective film layer 3 and the adhesive resin layer 4 are removed using 02 plasma solvent to obtain the shape shown in FIG. 1(e).

Thereafter, the diagonally shaded portion between the two-dot chain lines shown in FIG. 1(e) is cut using a cutting tool to obtain individual solid-state image sensors 7.

Figure 2 is an explanatory diagram showing the grooved part in Figure 1(&) and the cutting part in Figure 1(e) in plan view.
) The same symbols indicate the same parts, and the shaded parts are the parts to be cut. The color separation filter 2 is surrounded by a light-shielding region 2' made of a chromium-deposited film called optical black. In this embodiment, only the grooves 1' are formed in the transparent glass substrate 1, and the rest can be manufactured by grinding, cutting, etc.

FIGS. 3(a) to 3(g) are manufacturing process diagrams showing other embodiments of the present invention. In FIG. 3(a), 1 is a transparent glass substrate having a diameter of 4 inches (100!1111) and a thickness of 1 mm, for example. Chip-shaped color separation filters 2 are formed on the surface of this transparent glass substrate 1 at a predetermined pitch, and then, as shown in FIG. 3(b), a protective film layer 3 is formed, and an adhesive resin layer 4 is further formed. The light receiving portions 6 of the solid-state image sensing device wafer 5 are aligned with the color separation filters 2 on the adhesive resin layer 4, and are bonded and fixed using an aligner.

Next, as shown in FIG. 3(C), the back surface of the transparent glass substrate 1 was ground to make the thickness of the transparent glass substrate 1 70 μm, and then one side was further polished to an optical mirror surface with a thickness of 20 μm. Finish.

Next, after coating a photosensitive resin on the transparent glass substrate 1,
Pattern exposure and development are performed to form a protective film 9 having a width such that a portion of the light receiving portion 6 where a bonding butt portion 8 will be formed can be opened as shown in FIG. 3(d).

Next, the portion of the transparent glass substrate 1 not covered with the protective film 9 is etched using hydrofluoric acid or the like as shown in FIG. 3(e).

Next, as shown in FIG. 3(f), a protective film 3. The adhesive resin layer 4 is removed with 02 plasma to expose the bonding butt part 8 of the light receiving part 6, and the protective film 9 on the transparent glass substrate 1 is removed.
is removed by cleaning with a solvent such as trichlene.

Next, as shown in FIG. 3(g), the solid-state imaging device 7 is obtained by cutting the diagonally shaded portion between the two-dot chain lines into a chip shape.

FIG. 4 is an explanatory plan view showing the cutting portion of FIG. 3(g), where the same reference numerals as in FIGS. 2 and 3 indicate the same portions, and the diagonally shaded portions are the portions to be cut.

As described above, in the present invention, after bonding the transparent glass substrate 1 on which a large number of color separation filters are formed and the solid-state image sensor wafer 5 on which a large number of solid-state image sensors are formed, the transparent glass substrate is polished. It is possible to make the plate thinner to 1101L or less, with a flatness of 1 μm or less, which is almost the same level as the on-chip state.

In each of the above embodiments, the color separation filter 2 is used as the filter, but the present invention can also be applied to a monochrome filter. Further, the numerical values in each of the above embodiments are merely examples, and it goes without saying that other numerical values may be used.

〔Effect of the invention〕

As explained above, in the present invention, a protective film layer is formed on a transparent glass substrate on which monochrome filters or color separation filters are formed at a predetermined pitch, and then each light receiving portion of a solid-state image sensor wafer is are bonded and fixed in alignment with the monochrome filter or color separation filter, and then the transparent glass substrate is thinned and then cut to obtain a solid-state image sensor, improving the accuracy of bonding alignment. Adhesion distribution becomes uniform. In addition, since processing and cutting are performed after bonding in a flat state, unlike the conventional handling of individual chips,
Processing and cleaning are extremely easy, and there is no possibility of contamination or adhesion of dust or foreign matter, and no damage to the photodiode or color filter layer. Furthermore, since the process is carried out in a flat state, it has the advantage that the efficiency of the bonding process can be improved.

[Brief explanation of the drawing]

Fig. 1 is a manufacturing process diagram showing one embodiment of the present invention, Fig. 2 is a manufacturing process diagram showing the groove processing portion and cutting processing portion of Fig. 1 in plan view, and Fig. 3 is another embodiment of the invention. FIG. 4 is an explanatory plan view showing the cutting portion of FIG. 3. In the figure, 1 is a transparent glass substrate, 1' is a groove, 2 is a color separation filter, 3 is a protective film layer, 4 is an adhesive resin layer, 5 is a solid-state image sensor unit, 6 is a light receiving part, 7 is a solid-state image sensor, 8 is a pounding butt part. Fig. 1 4s layer #rIII 1 layer Fig. 2 Fig. 4

Claims (1)

[Claims] A protective film layer is formed on a transparent glass substrate on which monochrome filters or color separation filters are formed at a predetermined pitch, and then each of the light-receiving parts of the solid-state image sensor wafer is attached to the solid-state image sensor wafer via an adhesive resin layer. 1. A method for manufacturing a solid-state image sensor, which comprises bonding and fixing the transparent glass substrate in alignment with a filter, and then cutting the transparent glass substrate into a thin plate to obtain a solid-state image sensor.