JPH0654802B2 - Solid-state imaging device - Google Patents

Description

The present invention relates to a mounting structure of a solid-state imaging device in which a plurality of chips are arranged.

[Outline of Invention]

According to the present invention, in a solid-state image pickup device in which a plurality of chips are arranged, when the connecting surface of the chips has an angle other than 90 ° with the element surface, an escape area for the adhesive is created and the effect of the adhesive on the element surface is eliminated. At the same time, the diffused reflection at the connection portion is reduced, and the arrangement accuracy is improved because it is close to the line connection.

[Conventional technology]

In this section, the size of element chips used in solid-state image pickup devices is increasing, but in the field of application such as facsimiles, it is useful to use image pickup devices of the same size and wide original size, which are excellent in downsizing of the entire device and economy. The sex is drawing attention. Further, by forming the driving portion of the light receiving element in the same chip, a solid-state image pickup device with a small number of wirings leading to the outside, high speed and high performance, and excellent economy can be obtained. However, it is extremely difficult to form an element chip having the size of the document width using the present apparatus for forming a high-performance semiconductor active element. Therefore, a multi-chip type solid-state imaging device in which a plurality of chips are arranged is conceivable, but there are many unsolved problems in the chip arrangement accuracy and the chip arrangement method.

Conventionally, as shown in FIG. 2, the connecting surface (23) is cut perpendicularly to the element surface (22) at the connecting portion, and the two connecting surfaces face each other in parallel with each other.

[Problems and Objectives to be Solved by the Invention]

However, in the prior art, when the chip is fixed to the substrate (21) with an adhesive, the adhesive propagates between the two connecting surfaces and wraps around to the element surface (22), and the light receiving element on the element surface is optically affected. Not only does it have an adverse effect, but it also affects the reliability, including active devices. This tendency becomes stronger as the element surfaces are brought closer to each other to improve the placement accuracy of the adjacent elements. In addition, it is extremely difficult to make the surface irregularities of the connection surface on the order of microns because of the connection between the surfaces, and the placement accuracy deteriorates, causing a large error in the distance between adjacent elements. This is also an error caused by the thickness of the adhesive that has entered between the connection surfaces. As described above, the conventional technique has an essential problem of the multi-chip solid-state imaging device in which the adjacent elements (bits) on the two chips to be connected cannot be brought close to each other or accurately arranged.

Therefore, the present invention solves such a problem, and an object of the present invention is to provide a structure capable of accurately arranging adjacent elements of two chips close to each other in a multi-chip solid-state imaging device.

[Means for solving problems]

The present invention is a solid-state imaging device in which element chips having a plurality of imaging elements arranged are planarly connected, and among the surfaces formed by the element chips, an element surface on which the imaging element is arranged, An angle formed by a surface adjacent to the element surface and a connection surface for connecting to another element chip is less than 90 °, and a space formed by the angle is applied with an adhesive for connecting the element chips. The application space prevents the adhesive from protruding to the element surface.

〔Example〕

FIG. 1 is a drawing of a connecting portion of two chips arranged according to the present invention. In this figure, pixel A (17) and pixel B (1
8) It is necessary to have the same spacing as the spacing between adjacent elements on the same chip (62.5 μm in a 16-dot / mm device). That is,
If the element width is 50 μm, the edge is 12.5 μm.
Must connect in width. In the present invention, the element surface (1
When the angle (15) formed by 2) and the connecting surface (14) is an acute angle of less than 90 °, they are connected with an inverted wedge-shaped space when viewed from the side surface of the chip. The magnitude of this angle will be described later, but by making such a shape, the contact portions of the two chips become 13 connection lines and are in line contact. As a result, the connection interval is close to zero without being affected by the unevenness of the connection surface. When a quartz plate having a thickness of about 1 mm is used as a chip material, it is difficult to reduce the unevenness to 10 μm or less only by cutting. Sufficient alignment accuracy can be obtained by simply aligning two chips.

With the above structure, the chip is fixed to the substrate (11). However, if an adhesive is used for fixing, in the conventional example, the adhesive 25 in FIG. 2 travels along the connection surface and reaches the element surface 22. This will affect the pixels by acting as a lens.
In the present invention, not only the connection becomes a line contact, but also the wraparound of the adhesive is alleviated by the inverted wedge-shaped gap between the connecting surfaces (14), so that the adhesive does not wrap around to the element surface (12). In other words, the influence on elements such as pixels is eliminated.

Here, when considering a solid-state imaging device of a type in which light is incident from the substrate side of 11 using transparent materials for the substrate (11) and the chip, pixels should be arranged close to the connection surface (first Diffuse reflection of light occurs at the connection surface of the pixels A and B in the figure). Therefore, for example, a method of filling an adhesive between the connection surfaces with an adhesive having a refractive index close to that of the substrate material can be considered, but it has been an important problem in mounting because it wraps around the element surface for the above reason. By using the structure of the present invention, this problem is inevitably solved and the adhesive can be filled between the chips (between the connecting surfaces) without difficulty.

In FIG. 1, there are 15 corners, but they vary depending on the material of the chip, the type of adhesive, and the shape of the chip. As an example, the results of arranging using a chip material having a quartz thickness of 0.2 mm to 3.0 mm and using an UV curing type with an adhesive having a viscosity of 10 poise are shown. The angle of 15 in Fig. 1 is 89.5
When the contact line (13) is completely contacted under the above conditions, the gap at the bottom of the chip is about 20 μm), the wraparound of the adhesive to the element surface is about to occur and the connection surface ( 14) Unevenness of (cut surface) (10μ
(about m) affects the array accuracy. Also,
When the angle exceeds 84.5 degrees (the angle at which the gap at the bottom of the chip is about 200 μm) or more, the strength of the connecting line (B), which is the connecting part between chips, begins to become insufficient, and quartz, which is the chip material, is lacking, and it becomes an element such as a pixel. Begin to influence. Therefore, the angle between the element surface and the connection surface is optimally 84.5 to 89.5 degrees for the above materials and shapes. However, the suitable angle varies greatly depending on the material, shape, type of adhesive, and the like.

〔The invention's effect〕

As described above, according to the present invention, the angle formed between the element surface and the connection surface is less than 90 ° to form an inverted wedge-shaped gap between the connection surfaces, and the unevenness of the connection surface affects the connection accuracy. To prevent the adhesive from wrapping around the element surface and to substantially prevent clogging of the adhesive between the chips (substantially preventing the adhesive from acting as a spacer). Further, in the solid-state imaging device of the type that allows light to enter from the substrate side, the gap can be reliably filled with the adhesive, so that deterioration of optical characteristics can be prevented.

As described above, the chip arrangement accuracy in the multi-chip type solid-state imaging device is significantly improved, and the problem of the adhesive wrapping around the element surface is solved, which is an excellent effect.

[Brief description of drawings]

FIG. 1 is an enlarged view of a connecting portion in the structure according to the present invention,
FIG. 2 is an enlarged view of a conventional connecting portion.

Claims (2)

[Claims] 1. A solid-state image pickup device comprising a plurality of image pickup devices arranged in a plane, wherein the device chips are connected to each other. An angle between the surface adjacent to the element surface and a connection surface for connecting to another element chip is less than 90 °, and an adhesive agent for connecting the element chip to the space formed by the angle is applied. A solid-state imaging device, characterized in that a space is provided, and the application space prevents the adhesive from protruding to the element surface. 2. The element chip has a thickness of 0.2 mm to 0.3 m.
The solid-state image pickup device according to claim 1, wherein the solid-state image pickup device is a quartz plate of m, and the angle is 84.5 ° or more and 89.5 ° or less.