A method for mounting a large-size CCD chip

Abstract

The present application relates to a kind of patching methods of large size CCD chip, comprising measuring the thickness of large size CCD chip and ceramic tube shell;With the thickness of large size CCD chip and ceramic tube shell to obtain target thickness by preset thickness reduction;High-precision wafer thinning processing is carried out to the silicon wafer, and multiple square silicon wafers are segmented;According to the serpentine, adhesive is coated on the connecting surface of ceramic tube shell, and the connecting surface of ceramic tube shell is divided into multiple rectangular mounting areas by adhesive;Multiple square silicon wafers are mounted in all rectangular mounting areas;Large size CCD chip is placed on the connecting surface of ceramic tube shell;Along the center of photosensitive surface of large size CCD chip, press large size CCD chip to the periphery, for the area and protruding area that exceed preset thickness, press again, so that the photosensitive surface of large size CCD chip is flat, the patching of large size CCD chip is completed, the patching flatness of large size CCD chip can be effectively guaranteed, and the yield of product is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of charge-coupled device packaging, and particularly relates to a patching method for large-size CCD chips. BACKGROUND

[0002] A CCD (charge-coupled device) is a kind of semiconductor device, and has many orderly arranged photodiodes, which can sense light and convert optical images into electrical signals. A CCD is implanted with tiny photosensitive substances, referred to as pixel units. The more pixel units a CCD chip contains, the higher resolution it provides. Under the current technical conditions, in order to improve the resolution of a CCD chip, the number of pixel units is usually increased. With the increase of the number of pixel units, the size of the CCD chip also increases. Currently, a CCD chip with a scale of hundreds of millions of pixels (such as 10240x10240) has a size of about 100x100mm. During the manufacturing process of a CCD chip, there is a large warping degree after high-temperature and thinning processes. The surface flatness of a large-size CCD chip is more serious than that of a small-size CCD chip. Therefore, the devices using large-size CCD chips have higher requirements for the flatness of the chip patching during assembly. However, the existing patching machines cannot meet the requirements. The main reasons for this situation are as follows. On the one hand, miniaturization is also an important development direction of electronic components and devices, opposite to the large size. The size of the chip that can be applied to the mainstream patching machine is usually small. For example, the maximum patching size of the patching machine produced by the BES I company in the United States is only 50x50mm. On the other hand, in order to meet the demand of miniaturization, the performance of the mainstream patching machine is mainly developed in the direction of improving the patching speed, and the flatness of the patching is not specially concerned. Therefore, it is difficult to find a device that can perform patching operation on a large-size CCD chip with a size of 100x100mm or above in the prior art.

[0003] At present, the patching operation of a traditional large-size CCD chip is usually completed manually. The thickness and flatness of a large-size charge-coupled device require high precision. It is difficult to ensure the flatness of the chip surface during the pressing process by manually patching the chip. The height of the installation position of the patching tube cannot be accurately controlled. The patching process cannot be adjusted according to the actual situation. After the device is packaged, the flatness of the large-size CCD chip packaged device does not meet the use requirements, which leads to a low product yield. SUMMARY

[0004] In view of the problems in the background art, the present application provides a method for mounting a large-size CCD chip; the end face of the large-size CCD chip is square, the side length of the square is greater than or equal to 100 mm, the front face of the large-size CCD chip is a photosensitive surface, and the back face of the large-size CCD chip is a connecting surface; the connecting surface of the large-size CCD chip is pasted to the connecting surface of a ceramic tube shell;

[0005] The specific steps for pasting the connecting surface of the large-size CCD chip to the connecting surface of the ceramic tube shell include:

[0006] S1: measuring the thicknesses of the large-size CCD chip and the ceramic tube shell by using a color laser coaxial displacement;

[0007] S2: obtaining a target thickness by subtracting the thicknesses of the large-size CCD chip and the ceramic tube shell from a preset thickness of a large-size image sensor;

[0008] S3: thinning the silicon wafer by using an ultrathin high-precision wafer thinning technology to obtain a silicon wafer with the target thickness, and segmenting the silicon wafer with the target thickness to obtain a plurality of square silicon wafers with a side length of D;

[0009] S4: coating adhesive on the connecting surface of the ceramic tube shell in a snakelike manner, the adhesive dividing the connecting surface of the ceramic tube shell into a plurality of identical rectangular mounting areas, wherein the thickness of the adhesive is 2-3 times the target thickness, the width of the rectangular mounting area is 3D, and the width of the adhesive is 2D;

[0010] S5: arranging the plurality of square silicon wafers with the side length of D in all the rectangular mounting areas; wherein a small amount of adhesive is coated on two end faces of each square silicon wafer;

[0011] S6: placing the large-size CCD chip on the connecting surface of the ceramic tube shell, aligning the connecting surface of the ceramic tube shell with the connecting surface of the large-size CCD chip, pressing along the center of the photosensitive surface of the large-size CCD chip to make the large-size CCD chip tightly contact all the square silicon wafers, and obtaining a first large-size image sensor;

[0012] S7: measuring the thickness of the first large-size image sensor by using a color laser coaxial displacement measurement method, pressing again on the area exceeding the preset thickness to reduce the thickness to the preset thickness, and obtaining a second large-size image sensor;

[0013] S8: testing the flatness of the second large-size image sensor, pressing again on the protruding area to make the photosensitive surface of the second large-size image sensor flat, and completing the mounting of the large-size CCD chip.

[0014] The present application has at least the following beneficial effects

[0015] The present application does not need complex process equipment, and high-precision bonding glue thickness and flatness can be obtained, the method is easy to operate, can effectively ensure the flatness of the large-size CCD chip, improve the yield of products, has wide application range, the thickness of the bonding glue can be adjusted by setting square silicon wafers with different thicknesses, and the flatness of the large-size CCD chip is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 A flowchart of the method of the present application is shown in the figure.

[0017] Figure 2 A schematic diagram of the present application for coating bonding glue and mounting square silicon wafers is shown in the figure. DETAILED DESCRIPTION

[0018] The embodiments of the present application are described below through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the disclosure. The present application can also be implemented or applied through different specific embodiments, and various modifications or changes can be made to the details in the specification without departing from the spirit of the present application. It should be noted that the figures provided in the following examples only illustrate the basic concept of the present application in a schematic manner, and the following examples and features in the examples can be combined with each other without conflict.

[0019] Referring to FIG. 1, the present application provides a method for mounting a large-size CCD chip; the end face shape of the large-size CCD chip is square, the side length of the square is greater than or equal to 100 mm, the front face of the large-size CCD chip is a light-sensitive surface, and the back face of the large-size CCD chip is a connecting surface; the connecting surface of the large-size CCD chip is pasted to the connecting surface of a ceramic tube shell.

[0020] The specific steps for pasting the connecting surface of the large-size CCD chip to the connecting surface of the ceramic tube shell include:

[0021] S1: measuring the thicknesses of the large-size CCD chip and the ceramic tube shell by using a color laser coaxial displacement;

[0022] S2: obtaining a target thickness by subtracting the thicknesses of the large-size CCD chip and the ceramic tube shell from a predetermined thickness of the large-size image sensor;

[0023] S3: thinning the silicon wafer by using a super-thin high-precision wafer thinning technology to obtain a silicon wafer with the target thickness, and segmenting the silicon wafer with the target thickness to obtain a plurality of square silicon wafers with a side length D;

[0024] The side length D of the square silicon wafer is 1.5-3.5 mm.

[0025] The multiple square silicon chips with a side length of D are arranged in all the rectangular mounting areas, including: the multiple square silicon chips with a side length of D are uniformly arranged in multiple identical rectangular mounting areas, and the distance between the square silicon chips and the adhesive is greater than D.

[0026] S4: coating the adhesive on the connecting surface of the ceramic package in a serpentine shape, the adhesive divides the connecting surface of the ceramic package into multiple identical rectangular mounting areas, wherein the thickness of the adhesive is 2-3 times of the target thickness, the width of the rectangular mounting area is 3D, and the width of the adhesive is 2D; coating the adhesive on the connecting surface of the ceramic package in a serpentine shape can prevent the formation of a closed area and prevent the thermal expansion and contraction of the gas from affecting the bonding thickness.

[0027] S5: arranging multiple square silicon chips with a side length of D in all the rectangular mounting areas; wherein both end surfaces of each square silicon chip are coated with a small amount of adhesive;

[0028] S6: placing a large-size CCD chip on the connecting surface of the ceramic package, and aligning the connecting surface of the ceramic package with the connecting surface of the large-size CCD chip; pressing the large-size CCD chip along the center of the photosensitive surface of the large-size CCD chip to make the large-size CCD chip tightly contact with all the square silicon chips, to obtain a first large-size image sensor.

[0029] S7: measuring the thickness of the first large-size image sensor by a color laser coaxial displacement measurement method, and pressing again to reduce the thickness to a preset thickness for the area exceeding the preset thickness, to obtain a second large-size image sensor;

[0030] S8: testing the flatness of the second large-size image sensor, and pressing again to make the photosensitive surface of the second large-size image sensor flat, to complete the patching of the large-size CCD chip.

[0031] The multiple square silicon chips with a side length of D are arranged in all the rectangular mounting areas, including: the multiple square silicon chips with a side length of D are uniformly arranged in multiple identical rectangular mounting areas, and the distance between the square silicon chips and the adhesive is greater than D; and the adhesive overflowed to the area near the small chip after the large-size CCD chip is pressed will not reach the upper and lower areas of the small chip.

[0032] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present application.

Claims

1. A method for taping a large size CCD chip, comprising the steps of: The end face shape of the large-size CCD chip is square, the side length of the square is greater than or equal to 100 mm, the front face of the large-size CCD chip is a photosensitive surface, and the back face of the large-size CCD chip is a connecting surface; and the connecting surface of the large-size CCD chip is pasted with the connecting surface of the ceramic tube shell. ​ The specific steps of pasting the connecting surface of the large-size CCD chip with the connecting surface of the ceramic tube shell include: S1: measuring the thicknesses of the large-size CCD chip and the ceramic tube shell by using a color laser coaxial displacement; S2: obtaining a target thickness by subtracting the thicknesses of the large-size CCD chip and the ceramic tube shell from a preset thickness of the large-size image sensor; S3: thinning the silicon wafer by using an ultrathin high-precision wafer thinning technology to obtain a silicon wafer with the target thickness, and segmenting the silicon wafer with the target thickness to obtain a plurality of square silicon wafers with a side length D; S4: coating adhesive on the connecting surface of the ceramic tube shell in a snakelike manner, the adhesive dividing the connecting surface of the ceramic tube shell into a plurality of identical rectangular mounting areas, wherein the thickness of the adhesive is 2-3 times the target thickness, the width of the rectangular mounting area is 3D, and the width of the adhesive is 2D; S5: arranging the plurality of square silicon wafers with the side length D in all the rectangular mounting areas; wherein a small amount of adhesive is coated on two end faces of each square silicon wafer; S6: placing the large-size CCD chip on the connecting surface of the ceramic tube shell, aligning the connecting surface of the ceramic tube shell with the connecting surface of the large-size CCD chip, and pressing along the center of the photosensitive surface of the large-size CCD chip to make the large-size CCD chip tightly contact all the square silicon wafers, to obtain a first large-size image sensor; S7: measuring the thickness of the first large-size image sensor by using the color laser coaxial displacement measurement, and pressing again on the area exceeding the preset thickness to reduce the thickness to the preset thickness, to obtain a second large-size image sensor; S8: testing the flatness of the second large-size image sensor, and pressing again on the protruding area to make the photosensitive surface of the second large-size image sensor flat, to complete the pasting of the large-size CCD chip.

2. The method of claim 1, wherein The side length D of the square silicon wafer is 1.5-3.5 mm.

3. The method of claim 1, wherein the method further comprises: The arranging of the plurality of square silicon wafers with the side length D in all the rectangular mounting areas includes: uniformly arranging the plurality of square silicon wafers with the side length D in the plurality of identical rectangular mounting areas, and the distance between the square silicon wafer and the adhesive is greater than D.

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