JP2002135523A - Close contact sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a close contact sensor that can prevent characteristics of pixels from being prevented. SOLUTION: The close contact sensor comprises sensor chips 12 each provided with pixels that are laid out in a way that the pixel array of each sensor chip 12 forms a straight line. Each of the sensor chips 12 is provided with a metallic layer located between a chip end opposed to the adjacent sensor chips 12 and the pixel at the end of the pixel array. The metallic layer protects the pixels from being damaged due to a chipped or cracked chip.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a contact sensor used for an input section of a facsimile or a scanner.

[0002]

2. Description of the Related Art In recent years, with the speeding up of PCs, the performance of peripheral devices has been increasing. Above all, there is a need to improve the performance of image scanners, which are rapidly spreading due to price reductions. This is because the PC can process a large amount of image data and the like in a short time, and thus the PC can sufficiently cope with an increase in data due to an increase in resolution of the image scanner.

Image sensors used in the image input section of an image scanner include (1) a lens reduction type,
(2) It is roughly divided into a contact module type.
The close-contact type (2) does not require an optical system in the scanner body, is easy to manufacture, and uses a rod lens with a short focal length. It is widely used because it becomes smaller.

[0004]

In the close contact type image sensor, a plurality of chips are usually arranged in a straight line, and an original is read at the same magnification. In this contact sensor, the resolution of reading can be increased as the pixel pitch of each chip is shortened. Therefore, in order to obtain a high-resolution image, not only the pixel pitch in each chip but also the pixel pitch between adjacent chips must be reduced. For this reason, it is necessary to arrange the end pixel of each chip as close to the chip end as possible.

[0005] However, the chip end is a place where chips are likely to be chipped or cracked due to damage during dicing or assembling the wafer. The occurrence of chip chipping, cracks, and the like deteriorates various characteristics of end pixels arranged at the end of the chip, and becomes a factor of causing an abnormality in a read image.

An object of the present invention is to provide a contact sensor capable of solving the above-mentioned problems and reducing the damage to the edge pixels at the time of wafer dicing or module assembly, thereby preventing the characteristic deterioration of the edge pixels. With the goal.

[0007]

Means for Solving the Problems In order to solve the above-mentioned problems, a first feature of the present invention is that a plurality of semiconductor chips on which a plurality of pixels are arranged are arranged such that pixel rows of the semiconductor chips are aligned. A contact sensor comprising a metal layer disposed between an end of a chip facing an adjacent semiconductor chip and a pixel located at an end of the pixel column. It is a sensor.

According to a second feature of the present invention, in the contact sensor according to the first invention, the width of the metal layer is substantially equal to the width of the pixel column, or at least larger than the width of the pixel column. That is.

A third feature of the present invention is that, in the contact sensor according to the first invention, the metal layer is arranged along the outer periphery of the semiconductor chip so as to surround the pixel column.

According to a fourth feature of the present invention, in the contact sensor according to any one of the first to fourth aspects, the metal layer includes a metal wiring layer constituting a wiring in the semiconductor chip.

A fifth feature of the present invention is that in the contact sensor according to the fourth invention, the metal layer has a multilayer wiring structure.

In the first to fifth aspects of the present invention, the "contact sensor" refers to an image pickup device that brings a read original into close contact with the sensor and captures an optical image of the same magnification.

According to the first to fifth aspects, the presence of the metal layer disposed between the end pixel and the chip end reduces the damage to the end pixel at the time of wafer dicing or module assembly. In addition, it is possible to prevent the characteristic deterioration of the end pixel.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals.

FIG. 1 shows a schematic configuration of a general contact type image sensor in which a plurality of CCD image sensors and the like are arranged. In FIG. 1, this contact type image sensor 1
In the case of 0, for example, a plurality of sensor chips 12 composed of CCD image sensors are mounted with high accuracy so that the pixel array of the sensor chips 12 is aligned. In addition, sensitivity correction and pixel pitch adjustment are performed at the end of the chip in order to avoid non-uniformity of sensitivity at the joint of the sensor chip 12 and deviation of the pixel arrangement. The contact image sensor 10 includes eight sensor chips 12. The number of pixels of each sensor chip 12 is, for example, 1288. Of course, the present invention is not limited to the combination of these numbers, but can be variously changed depending on the document size and the like.

Hereinafter, the operation of the contact type image sensor 10 of FIG. 1 will be briefly described. First to eighth sensor chips 1
2 receives a clock pulse and outputs each output signal based on the clock pulse. For example, when a signal from the first sensor chip 12 is being output, the second and subsequent sensor chips 12 set their output terminals to a high impedance state. The first sensor chip 12 outputs a predetermined control pulse to the adjacent second sensor chip 12 20 bits before the output of 1288 bits. When the output of all bits is completed, the first sensor chip 12 switches its output terminal from the low impedance state to the high impedance state.

On the other hand, when the control pulse is input from the first sensor chip 12, the second sensor chip 12 starts the counting operation from the input time. Based on the counting operation, the output of all the bits of the first sensor chip 12 ends, and at the same time, the second chip sensor 12 switches its output terminal from the high impedance state to the low impedance state.

The same operation is performed sequentially after the third sensor chip 12. For this reason, the contact type image sensor 10
Are output serially from the first sensor chip 12 to the eighth sensor chip 12, respectively.

Next, the structure of the contact type image sensor according to the embodiment of the present invention will be described. FIG. 2 shows a structure of a main part of the contact image sensor according to the embodiment of the present invention. FIG. 2 shows two adjacent sensor chips 12.
The vicinity of the chip end of each of a and 12b is shown. As a comparative example, FIG. 3 shows a state near the chip ends of two adjacent sensor chips 12c and 12d of the contact type image sensor according to the related art.

First, in the case of the contact type image sensor according to the prior art shown in FIG. 3, the disturbance of the pixel interval period due to the absence of the pixel at the joint between the sensor chips 12c and 12d is directed inward from each chip end. Thus, the third pixels (No. 1, No. 2, No. 3) 14c and 14d are absorbed by deviating from the normal pixel positions. The fourth and subsequent pixels 14c and 14d are arranged at regular positions. For this reason, when the resolution is further improved and the pixel pitch is shortened, it is necessary to bring the end pixels closer to the chip end. However, the dicing lines 16c and 16d
If the distance between the pixel 14c and the pixel 14c becomes too short, for example, cracks or chipping may occur in the edge pixels 14c and 14d close to the chip edge due to damage during dicing, and as a result, the edge pixel 14c , 14d may deteriorate. The same may occur due to damage during assembly.

Therefore, in the contact type image sensor according to the embodiment of the present invention shown in FIG. 2, the first pixel 1 closest to the chip end of the adjacent sensor chips 12a and 12b is provided.
4a, 14b and a metal layer 18 between each chip end.
a, 18b are arranged. That is,
In the embodiment of the present invention, the first pixels 14a, 14a
b, the presence of the metal layers 18a and 18b disposed on the dicing lines 16a and 16b side prevents cracks and chipping caused by an impact applied at the time of dicing or assembly from reaching the pixels 14a and 14b. It is possible to prevent the characteristics of the pixels 14a and 14b from deteriorating.

The metal layer 16a according to the embodiment of the present invention,
16b may use, for example, the in-chip wiring of each of the sensor chips 12a and 12b as they are. The metal layers 16a, 16b can be formed without adding an extra manufacturing process.
Is formed. When the sensor chips 12a and 12b have a multilayer wiring structure, the metal layers 16a and 16ba may be formed of at least one wiring layer. Of course, all wiring layers may be used. As a material of the metal layers 16a and 16b and the metal wiring layer, aluminum (Al) is generally used. Of course, the invention is not limited to this, for example,
Of course, copper (Cu), tungsten (W) or the like may be used.

As described above, the metal layers 16a, 1
Since 6b is formed at the same time as the wiring inside the chip arranged in the sensor chips 12a and 12b, it does not normally remain on the dicing lines 16a and 16b. Therefore, abrasion of the diamond cutter and diamond blade during wafer dicing is suppressed, and the service life of the diamond cutter and diamond blade is not shortened.

Further, metals such as aluminum constituting the metal layers 16a and 16b have extremely high processing accuracy. Therefore, even when the distance between the end pixels 14a and 14b and the chip end is small and high processing accuracy is required for the metal layers 16a and 16b, it is possible to cope with the case.

The metal layers 16a and 16b are connected to a reference potential, typically a ground potential, so as not to be in a floating state.

As described above, the invention made by the present inventor has been described by the above embodiments. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples, and operation techniques will be apparent to those skilled in the art.

In the above embodiment, the metal layers 18a, 18a, 1
The width (height) of 8b is made larger than the pixels 14a and 14b. However, for example, as in the case of the metal layers 18e and 18f in FIG. 4, the width (height) may be the same as that of the pixels 14e and 14f.
Basically, it is sufficient that the width (height) of the metal layer is not smaller than that of the pixel.

Further, like the metal layers 18g and 18h shown in FIG. 5, the sensor chips 12g and 12h may be arranged so as to go around once.

As described above, it should be understood that the present invention includes various embodiments and the like not described herein. Accordingly, the present invention is limited only by the matters specifying the invention according to the claims that are reasonable from this disclosure.

[0030]

According to the present invention, it is possible to realize a contact sensor that prevents deterioration of characteristics of end pixels by reducing damage to end pixels during wafer dicing or module assembly.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a general contact image sensor.

FIG. 2 is a diagram illustrating a structure of a main part of the contact image sensor according to the embodiment of the present invention;

FIG. 3 is a view showing a structure of a main part of a contact type image sensor according to the related art.

FIG. 4 is a diagram showing a structure of a main part of a contact image sensor according to another embodiment of the present invention.

FIG. 5 is a diagram showing a structure of a main part of a contact image sensor according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Contact sensor (contact image sensor) 12 Sensor chip 14 Pixel 16 Dicing line 18 Metal layer

 ──────────────────────────────────────────────────続 き Continued on front page F term (reference) 4M118 AA08 AB01 BA03 HA40 5C024 AX01 BX00 CY47 EX01 EX21 GY01 5C051 AA01 BA04 DA03 DB01 DB04 DB05 DB06 DC02 DC07

Claims (5)

[Claims] 1. A contact sensor in which a plurality of semiconductor chips on which a plurality of pixels are arranged are arranged so that pixel rows of the semiconductor chips are aligned, wherein each of the semiconductor chips is an adjacent semiconductor chip. A contact layer comprising a metal layer disposed between an end of the chip facing the pixel and a pixel located at an end of the pixel column. 2. The contact sensor according to claim 1, wherein the width of the metal layer is substantially equal to the width of the pixel column, or at least larger than the width of the pixel column. 3. The contact sensor according to claim 1, wherein the metal layer is disposed along an outer periphery of the semiconductor chip so as to surround the pixel column. 4. The contact sensor according to claim 1, wherein the metal layer is formed of a metal wiring layer forming a wiring in the semiconductor chip. 5. The contact sensor according to claim 4, wherein the metal layer has a multilayer wiring structure.