JPH065718B2 - Solid-state imaging device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid-state image pickup device, and more particularly to a structure of a glass face plate which constitutes a light receiving window of a sealing device which houses a semiconductor image pickup device chip.

[Conventional technology]

As a conventional solid-state imaging device, for example, JP-A-54-146
The one disclosed in Japanese Patent Publication No. 985 is known. This structure is
As shown in FIG. 1, a cap assembly 10 is combined with a base assembly 20 to form a hermetically sealed space therein, and a semiconductor image pickup device chip 30 housed in the hermetically sealed space of the encapsulator.

In the cap assembly 10, a ceramic frame 13 is fixed to a glass face plate 11 serving as a light receiving window via a fused glass layer 12, and a Kovar frame 15 is further provided via a silver brazing material layer 14.
Is fixed. In the base assembly 20, a Kovar 23 is fixed to a package 21 via a silver brazing material layer 22, a gold / tin brazing material layer 24 is further formed thereon, and external terminals 25 are provided on the side surfaces of the package 21. ing. Then, the gold / tin brazing material layer 2 of the base assembly 20
The Kovar 15 of the cap assembly 10 is fixed to 4 to form a sealing device. A semiconductor image pickup device chip 30 is fixed to the package 21, and wires 31 are bonded to each electrode on the chip 30 and a lead portion of the package 21.

[Problems to be Solved by the Invention]

Since such a solid-state image pickup device is set so as to form a two-dimensional image on the surface of the semiconductor image pickup element chip 30 through the camera lens and the glass face plate 11, a foreign substance or the like that blocks light is present on this optical path. It shouldn't be. When a foreign substance is present, it is shielded from light.
The image is projected onto the surface, photoelectrically converted, and a fixed shadow image appears in the captured image, which is recognized as a scratch. The scratches are distinct from the foreign matter near the surface of the semiconductor imaging device chip 30, that is, the foreign matter mixed in the sealing device. Further, foreign matter once mixed in the sealing device cannot be removed unless the sealing device is disassembled, which is a troublesome existence.

As described above, the solid-state imaging device needs to be handled differently from general semiconductor devices in that it handles light. Therefore, in the manufacturing process of the device, strict measures against foreign matter have been taken conventionally compared with the manufacturing of a general semiconductor device. That is, in the general semiconductor device, the sealing device was cleaned to the extent that mixing of water and gaseous impurities such as chlorine was avoided. However, in the solid-state imaging device, a foreign matter removing process and an inspection confirmation process are performed at various points in the process.

FIG. 2 shows a cleaning process of the cap assembly 10. After manufacturing the cap assembly 10, the cap assembly 1
0 cleaning is performed to perform inspection selection. Remove defects such as cracks, surface scratches or glass foam scratches,
If there is foreign matter, clean it again and inspect it again.

FIG. 3 shows the results of investigation of the cleaning effect of the cap assembly 10. The number of times the cleaning is repeated and the number of adhered foreign matters are compared. The number of adhered foreign matters decreases only when the number of times of cleaning is small, but gradually becomes constant. This tendency occurs when a dust source is present in the cleaning process. For example, when the cleaning liquid is contaminated, a certain proportion of foreign matter from the cleaning liquid adheres,
The cleaning effect is constant.

On the other hand, the cap assembly 10, the base assembly 20, and the semiconductor image sensor chip 30 that passed the foreign matter inspection were combined and sealed as shown in FIG. However, even in such a case, a considerable amount of foreign matter was mixed in the sealing device.

An object of the present invention is to provide a solid-state imaging device capable of preventing foreign matter from entering the encapsulator, improving yield, and reducing manufacturing cost.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the present invention is characterized in that both sides of a glass face plate serving as a light receiving window of a sealing device are taken.

[Action]

By taking both sides, chipping at the edge was reduced and contamination of foreign matter was extremely reduced. Further, by chamfering the adhesive surface side, problems such as distortion at the time of fusing can be reduced, the fusing strength can be increased, and abnormal protrusion of the fusing glass can be reduced.

Example of Invention

An embodiment of the present invention will be described below with reference to FIG. The same members as those in FIG. 1 are designated by the same reference numerals,
The description is omitted. Both sides of the glass face plate 11 are chamfered 1
1a and 11b. Thus, the double-sided chamfers 11a and 11b of the glass face plate 11 seem to be irrelevant to the inclusion of foreign matter in the sealing device, but it was confirmed that they are very effective means for the following reasons.

As described above, even though the cap assembly 10, the base assembly 20, and the semiconductor image pickup device chip 30 that passed the foreign matter inspection were combined and sealed, foreign matter was found mixed in the encapsulator. As a result of investigating the device, the following was found.

When the foreign matter mixed in the sealing device was analyzed, it was found that the foreign matter was a glass piece. No glass equipment was used in the washer and the sealing machine, and no glass fragments were found in the chemicals used. However, the fact that the glass pieces are attached to the cap assembly 10 that has passed the inspection means that
It seems that there is a dust source somewhere in the cleaning process. Therefore, it is assumed that the glass face plate 11 itself is a dust source, and as shown in FIG.
When the cap assembly 10 provided with a and 11b was prepared and combined with the base assembly 20 in which the chip 30 was housed, no foreign matter was found in the encapsulator, and very good results were obtained.

It is considered that dust is generated due to chipping at the edge of the glass face plate 11 when the cap assembly 10 is handled. That is, in the cleaning process, the glass face plate 11 and the device are touched by a mechanism such as transportation, and the edge of the glass face plate 11 is chipped, and the entire device is contaminated by glass fragments. It is imagined that reattachment of foreign matter will occur. It is supposed that the adhesion of the glass piece to the non-defective cap assembly 10 at the time of sealing is a similar phenomenon.

As described above, the glass chip in the outer peripheral portion of the glass face plate 11 which seems to be irrelevant at first glance is sealed in the encapsulator to cause a foreign matter defect.
1a is extremely effective.

Further, when the solid-state imaging device is fixed to the lens system, in many cases, the periphery is surrounded by a light shielding rubber.
Such rubber is scraped by the edge of the glass face plate 11 of the solid-state image pickup device at the time of mounting, and foreign matter remains in the optical system. Therefore, if the outer peripheral chamfering of the glass face plate 11 is performed as in the present invention, the generation of foreign matter in such a case is also prevented.
It can be reduced as much as possible.

The chamfered portion 11b on the inner surface of the glass face plate 11 seems to be useless at first glance, but is more effective than the following. When there is no chamfer 11b, strong distortion occurs in the edge portion in the fusion process of the fused glass layer 12, the ceramic plate 13, the silver brazing material layer 14 and the Kovar 15, and the mechanical strength is weakened, Microscopically, the exposed edge part remains, so when a force is applied, dust is generated due to vibration and the like. That is, by chamfering 11b, a mechanically weak acute angle can be removed, and dust can be prevented in the manufacturing process of the cap assembly 10.
The adhesion of foreign matter before cleaning is small, and the frequency of adhesion of foreign matter after cleaning can be reduced overall.

Further, there is also an effect that the adhesive strength is increased by the fused glass entering the chamfered portion 11b. Further, if the fusion-bonding glass overflows to the foreign matter, it becomes defective, but the presence of the chamfer 11b prevents the fusion-bonding glass from protruding extremely due to some fluctuation.

In addition, the cap assembly 1 is provided by applying the inner chamfer 11b.
0 can be easily produced. That is, double sided 11a, 1
By performing 1b, the front and back directions of the glass face plate 11 are unnecessary in the fusing step of the fusing glass layer 12, facilitating mechanization or automation of fusing, and the manufacturing cost of the cap assembly 10 can be significantly reduced as compared with single chamfering. .

The chamfering angles of the chamfers 11a and 11b are preferably about 45 °, but are not limited to this angle.

〔The invention's effect〕

As is clear from the above description, according to the present invention, the glass face plate is double-sided, and therefore the following effects can be obtained. Dust in the cleaning process and reattachment of glass fragments can be prevented, and dust in the sealing process and mixing into the sealing device can be avoided. The re-inspection, re-inspection, or re-cleaning that was targeted can be omitted. That is, the steps such as inspection and cleaning can be significantly shortened and reduced, and the cost can be reduced. Further, since the dust generation of the glass piece is suppressed in the manufacturing process, it is possible to reduce the defective adhesion of the glass piece to the effective window surface of the glass face plate and the abrasion failure caused by the glass piece. Further, by chamfering, it is possible to remove the microcrack portion at the time of cutting the glass face plate, and it is also possible to avoid the concentration of strain in the fused portion.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a conventional solid-state imaging device, FIG. 2 is a cleaning process diagram of a cap assembly, FIG. 3 is a diagram showing cleaning effects, and FIG. 4 is an embodiment of the solid-state imaging device according to the present invention. It is a schematic sectional drawing which shows. 10 ... Cap assembly, 11 ... Glass face plate, 1
1a, 11b ... Chamfer, 20 ... Base assembly,
30 ... Semiconductor image sensor chip.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shoya Izumi 3300 Hayano, Mobara-shi, Chiba Hitachi Mobara Plant, Ltd. (72) Inventor Yoshio Iwata 3300 Hayano, Mobara-shi, Chiba Hitachi Ltd. Mobara Plant, Ltd. (72) Inventor Makoto Auchi 1479, Kamimizuhonmachi, Kodaira-shi, Tokyo In-house, Hitachi Micro Computer Engineering Co., Ltd. (56) Reference JP-A-54-98178 (JP, A)

Claims (1)

[Claims] 1. A solid-state imaging device comprising a glass face plate serving as a light receiving window and having a hermetically sealed space formed therein, and a semiconductor image sensor chip housed in the hermetically sealed space of the hermetically sealed device. The glass face plate is double-sided, and,
The solid-state imaging device, wherein the glass face plate is fixed by a fused glass, and the fused glass exists up to the chamfered portion.