Wafer-level packaging method of image sensor chips

Abstract

A wafer-level packaging method of image sensor chips comprises the steps of providing wafers, mixed substrates and carrier plates. The wafers comprise a plurality of image sensor chips, and the mixed substrates comprise a supporting frame and a plurality of transparent substrate units. The supporting frame comprises a plurality of windows, the transparent substrate units cover the windows correspondingly, and the wafers, the mixed substrates and the carrier plates are fixed together in sequence in an overlapped mode. The back faces of the wafers are subjected to a line redistribution process and a welding flux protrusion manufacturing process, and the wafers and the mixed substrates are cut along cutting channels, so that the image sensor chips are separated to a plurality of image sensor chip modules which comprise separated mixed substrate units and image sensor chip units bonded with the mixed substrate units. By means of the method, the image sensor chips are maintained to be clean in the whole packaging process without being damaged, and the packaged image sensor chip modules have high reliability.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a wafer-level packaging method for an image sensor chip. Background technique [0002] An image sensor is a device that converts one-dimensional or two-dimensional optical information (optical information) into electrical signals. Image sensors can be further divided into two different types: Complementary Metal Oxide Semiconductor (CMOS) image sensors and Charge Coupled Device (CCD) image sensors. Image sensor chips must be packaged to protect against corrosion, mechanical damage, dust particles, etc. The traditional image sensor chip packaging method is usually packaged by wire bonding (Wire Bonding), but with the rapid development of integrated circuits, longer leads make the product size unable to meet the ideal requirements. [0003] Wafer Level Package (WLP) is a packaging method in which after the front-end process of the wafer is completed, the back-end process i...

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Problems solved by technology

[0005] The wafer-level packaging method of the existing image sensor chip above has three disadvantages: 1. The above-mentioned packaging technology uses a whole piece of optical glass 105, and only the optical glass 105 provides strength, but because the overall brittleness of the glass is relatively large, the package The mechanical strength of the structure is low, it is easy to break, and the large piece of optical glass 105 is expensive, so the packaging cost is increased; 2. Since the cavity wall 103 is obtained by exposing and developing photosensitive materials, its raw material cost and process cost are relatively high, and the cavity wall 103 will be incompletely exposed during the manufacturing process, resulting in dust (particle) pollution, which will lead to the scrapping of the entire large piece of optical glass 105, further increasing the packaging cost; 3. Due to There is a certain degree of vacuum in the cavity 104, so when it is not heated, the optical glass 105 will be subject to a relatively high atmospheric pressure, making the optical glass 105 more likely to break during packaging, cutting or use.

[0009] For this reason, a new wafer-level packaging method for image sensor chips is needed to solve the problem that the existing wafer-level packaging methods for image sensor chips have complex processes, low process efficiency, and the surface of the image sensor chip is easily contaminated or damaged. question

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