JPS63275133A - Image sensor - Google Patents

Abstract

PURPOSE:To enable the precise cutting operation, by providing an Si wafer with scribing lines for positioning of chip-cutting. CONSTITUTION:On a scribing line 2 for positioning of chip-cutting which is formed simultaneously with an image sensor element on an Si wafer, the distance from an end-portion 1 of the image sensor chip is shown with an accuracy of 0.5mum. A scribing line 3 is formed on the Si wafer in the same manner as the scribing line 2. An trial cutting operation is made between both scribing lines, and the blade width can be measured with an accuracy of 0.5mum. Thereby, a pitch of cutting operation for the image sensor can be obtained by the displacement from the position of trial cutting operation to a suitable cutting position and the accurate blade width, so that the precise cutting operation for the image sensor is enabled.

Description

[Detailed Description of the Invention] The present invention is applicable to high-speed facsimile, intelligent PPC,
The present invention relates to an image sensor for inputting images of OA equipment.

Conventional technology In recent years, high-speed facsimiles, intelligent PPCs, and image input terminals for computers have been
The need for high-resolution image sensors is increasing. There are two methods for reading the original: a reduction method in which a reduced image is formed and read, and a close contact method in which a same-size image is formed and read. In the case of a St multi-chip contact type image sensor using bipolar IC technology, for example, in order to read an A4 size document; effective sensor length 224■ as a line type image sensor, the sensing elements must be arranged to the edge of the chip. It is necessary to arrange a plurality of image sensor chips in a straight line with high precision. In order to improve the resolution, image sensors of 16 dots/mm to 32 dots/1 m have been developed in recent years, but a technique for cutting the image sensor chip with high precision is required.

FIG. 4 shows an example in which a plurality of image sensor chips are arranged in a straight line. A plurality of sensor chips are arranged and fixed in close contact one after another with the left end chip as a reference, but in reality, the spacing between the light receiving windows of each sensor chip connection section varies depending on the cutting precision of the sensor chips. For example, in the case of an image sensor with a resolution of 16 dots/1 m, the light-receiving windows are arranged with a pinch of 62.5 μm, but the tolerance of the light-receiving window spacing that occurs at the sensor chip connection is smaller than the ideal value of 62.5 μm. 15 μm or less is required.

Further, in the case of an image sensor with a resolution of 32 dots/trundle, the permissible error is 7.5 μm or less.

Generally, image sensor chips are formed on $i wafers several hundred μm thick, which are cut into individual image sensor chips using a precision cutting tool, and then cut onto an alumina substrate printed with adhesive. multiple image sensor chips are arranged and fixed in a straight line.

Figure 5 shows the connection part of the image sensor chip, but if the cutting position of the image sensor chip is not appropriate, the light receiving element of the image sensor chip may be damaged as shown in Figure 6, or the image sensor chip may be damaged as shown in Figure 7. The tolerance for the distance between the light receiving windows may be exceeded.

Conventionally, when cutting with precision dicing, etc., processing positioning was done with the naked eye using a microscope.
Dosoto/■Peng's 15 μm or less and 32 dots/ml's 7
, 5 μm or less, it is difficult to process at an appropriate position.

Problems to be Solved by the Invention As mentioned above, a high resolution image sensor;
It is difficult to cut a Si wafer of 1 m, 32 dots/11, etc. at an appropriate position, and there is a problem in that the yield rate of non-defective products decreases.

The present invention overcomes the above-mentioned problems and provides a high-quality image sensor using a Si wafer that allows cutting of image sensor chips with high precision.

Means for Solving the Problems In order to solve the above problems, the Si wafer of the image sensor of the present invention is one in which an image sensor element is formed on the Si wafer and dimension lines for cutting positioning are formed at the same time. .

Function: By using the Si wafer for the image sensor as described above, the present invention can cut the image sensor chip with high precision.

Embodiment Hereinafter, an image sensor according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a plan view of the Si wafer of the image sensor of the present invention. In FIG. 1, the A-A' cutting line requires high precision, and the B-B' cutting line requires high precision. Not done.

FIG. 2 is an enlarged view of the end portion of the image sensor chip in FIG. 1. FIG. In FIG. 2, reference numeral 1 indicates the end of the image sensor chip, and if cutting is performed at this position, no cutting position error will occur. 2 is a cutting positioning dimension line formed at the same time as the image sensor element on the Si wafer, and the distance from 1 is shown with an accuracy of 0.5 μm.

Similar to 2, 3 is formed on a Si wafer, and
Trial cutting of the wafer is performed between 2 and 3, and the blade width can be measured with an accuracy of 0.5 μm. FIG. 3 is a diagram in which trial cutting was performed near the end of the image sensor shown in FIG. 2. 1.2.3 are the same as in FIG. 2, and 4 and 5 indicate the positions of the cut surfaces obtained by trial cutting.

In Fig. 3, the dimension between the trial cutting position and the ideal cutting position of the image sensor chip is 2 to 4, which is 1.0.
It can be read as 05511, and the blade width is (3 to 5) - (2
~4) -1,2055-1,0055=0.20
Accordingly, the amount of movement to the appropriate cutting position i is 1.055 m1 and the accurate blade width is 0.20.
Using C1n, the image sensor cutting process is determined, and the image sensor can be cut with high precision.

Effects of the Invention As described above, the image sensor of the present invention can be cut with high precision, making it possible to increase the production rate of non-defective products.

[Brief explanation of the drawing]

FIG. 1 is a plan view of the 81 wafer of the image sensor of the present invention, FIG. 2 is an enlarged view of the edge of the image sensor chip in FIG. 1, and FIG. It is an explanatory view showing the connection part of the disensor chip - explanation of notch processing. 1... End of image sensor chip, 2...
... Cutting positioning dimension line, 3... Cutting positioning dimension line; Blade width measurement, 4, 5... Cutting surface position by trial cutting concave machining.

Claims (1)

[Claims] An image sensor characterized in that a Si multi-chip image sensor is provided with dimension lines for chip cutting positioning on a Si wafer.