JPH0732441B2 - Image sensor chip cutting method - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image sensor, and more particularly to an elongated image sensor capable of reading document information at high speed and high resolution.

Configuration of Conventional Example and Its Problems In recent years, with the development of office automation equipment, various image sensors (optical reading devices) for facsimiles, office equipment and input terminals of computers have been developed. The reading device is roughly divided into a reduction type and a contact type. In the reduction type optical reader, the document information is passed through the reduction lens system.
The image is read on the image on a 20 mm to 40 mm long image sensor (CCD image sensor, MOS image sensor, etc.) to optically read the document information. In this case, since a reduction lens system is used, a long optical path length (about 50 cm for A4 size) is required. Therefore, there are problems in that the device is downsized, the resolution is increased, and the adjustment is easy.

A contact image sensor is being developed as a solution to this problem. The contact-type image sensor forms the document information on the image sensor at a ratio of 1: 1, so the optical path length is 10 to 50.
It has a feature that only mm is required and high resolution can be obtained over the entire range. However, an image sensor of the same size as the original length (216 mm for A4, 296 mm for A3) is required to form a 1: 1 image.

At present, when a silicon crystal is used, the sensor length is determined by the size of the silicon wafer, and it is difficult to increase the length. There is also an approach aiming at lengthening by arranging multiple chips in a zigzag manner, but a chip mounting method and line processing of output from each chip and a memory for line processing are required.

In contrast to the method using these crystals, there are CdS-based and a-Si-based image sensors as a thin film type that can be easily elongated. The CdS system has a slow reading speed, and the a-Si system has a high reading speed, but there is a problem in that the total cost becomes high because it is a hybrid type with a scanning LSI in terms of mounting.

An object of the present invention is to provide a method of cutting an image sensor chip, which enables a plurality of crystal type image sensors to be arranged linearly with high accuracy and lengthened to read original information at high speed and high resolution. With the goal.

Configuration of the Invention An image sensor cutting method of the present invention connects by performing a high-precision cutting method of an image sensor chip that enables a linear arrangement of a plurality of image sensor chips in order to elongate the image sensor chip. The section also allows the sensor pitch to be within a certain error range. This makes it possible to read the document information at high speed and with high resolution over the entire area of the document.

Description of Embodiments An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a diagram of an image sensor chip obtained by precisely cutting a wafer on which an image sensor is formed with a dicing saw. In FIG. 1, 1 is a cut portion, 2 is an optical sensor array, and 3 is a scanning circuit unit. In order to enable a linear array, the optical sensor is arranged up to the vicinity of the cutting point. At the time of cutting, it is necessary to cut on both sides of the chip, that is, the optical sensor or the element near the cutting point 1 without being damaged by chipping or cracks.

Next, cutting with few chippings and cracks will be described.

Further, FIG. 2 is a view in which a guide of a cutting blade is provided with a material having high strength such as a silicon oxide film or a silicon nitride film. Reference numeral 7 is a guide of a cutting blade made of silicon oxide or the like. FIG. 3 is a view after cutting. By using this guide, the swing of the cutting blade is reduced, chipping and cracks are less likely to occur, and high-precision cutting can be performed without damaging the optical sensor or elements near the cutting surface.

A method of arranging a plurality of image sensor chips, which are cut with high precision by the above method, in a straight line will be described. FIG. 4 is a view of the connection portion of the image sensor chip cut with high accuracy by the above method. B indicates the image sensor chip on the left side of the connecting portion, and B indicates the image sensor chip on the right side of the connecting portion. a, a'is the distance from the center of the optical sensor at the end to the chip end, b, b'is the distance between the optical sensors, and c, c'is the center of the optical sensor and the bottom edge X _I ,
The distance to X _I ′, d, d ′ is from the center of the optical sensor to the upper end X _II , X
It is the distance to _II '. When cutting from a wafer, a = a ', c = c', d because it is cut with high precision by the above method.
= D ', b, b' is b = b 'depending on the mask pattern. When the resolution is 16 dots / mm, b = b '= 62.5 μm When disconnecting so as to be 31.25 μm, when a and b are connected, the distance between the photosensors at the connecting portion becomes a + a ′ = b, which is the same as the other photosensor intervals, and there is no resolution error. That is, the horizontal error shown in the figure disappears. This connection is shown in FIG. Chips lower in the figure, X _I is i, it is sufficient to match the X _I 'in Russia. That is, if X _I and X _I ′ match the reference in the sub-scanning direction, c
= C ', the error in the arrangement in the sub-scanning direction is eliminated.
D = d 'even when the chip tops X _II and X _II ′ are used
The same can be done from the relationship of.

In the actual mounting, n image sensor chips 9 are arranged on a reference 8 in the sub-scanning direction shown in FIG. This completes the arrangement in the sub-scanning direction. Next, if a moderate force is applied to the chips on both ends (chip1 and chip n in the figure) in the direction of the arrow, the gap between the connection parts is eliminated and chip1
The intervals of the photosensors from to chip n are all the same (62.5 μm in the case of 16 dots / mm). This completes the array in the main scanning direction.

EFFECTS OF THE INVENTION As is clear from the above description, according to the present invention, by providing a guide with a material having high strength along the cut portion of the sensor chip and cutting along the groove between the guides, it is possible to reduce chipping and cracks. Precise cutting is possible. In addition, since multiple image sensor chips are arranged in a straight line in order to make the image sensor chip that has been subjected to high-precision cutting long, the optical sensor group is arranged in a straight line and the same line Can be read, and the line processing of the output signal and the memory therefor are unnecessary. In addition, since the optical sensor group is arranged in a straight line, it is possible to use the center of the imaging lens system (rod lens array), and it is possible to read at high speed and high resolution without line processing. Is obtained.

Also, since each image sensor chip is cut with high precision, it is possible to achieve a highly accurate arrangement by arranging them at a reference location during mounting and applying an appropriate force from both sides. To be

INDUSTRIAL APPLICABILITY The present invention enables a high-speed, high-resolution contact image sensor using a silicon single crystal, which has the most proven performance, and has a great industrial effect.

[Brief description of drawings]

FIG. 1 is a diagram showing an image sensor chip subjected to high precision cutting, FIG. 2 is a diagram in which a guide for a cutting blade is provided with a material having high strength such as a silicon oxide film or a silicon nitride film, and FIG. FIG. 2 is a diagram showing a state after cutting, FIG. 4 is a diagram showing a connecting portion of an image sensor chip which is highly accurately cut, FIG. 5 is a diagram showing a connecting portion in FIG. 4, and FIG. 6 is a diagram showing the image sensor chip. It is a figure which shows a mounted state. 1 ... High-precision cutting point, 2 ... Optical sensor array, 3 ...
Scanning circuit, 7 ... Guide material, 8 ... Arrangement reference, 9
...... Image sensor chip, 5 ...... Crystal substrate, 6 ...... Cutting point.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasunaga Yamamoto 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP-A-49-98512 (JP, A) JP-A-54- 77087 (JP, A) JP 58-166741 (JP, A) JP 58-137228 (JP, A)

Claims (1)

[Claims] 1. A material having a high strength such as a silicon oxide film or a silicon nitride film along a cut portion when cutting each sensor chip of an image sensor elongated by arranging a plurality of image sensor chips in a straight line. A method of cutting an image sensor chip, in which a guide made of is provided and cutting is performed along the groove between the guides.