Three-dimensional integrated structure, preparation method and assembly method

Abstract

The invention provides a three-dimensional integrated structure and a preparation and assembly method. The purposes of microminiaturization, improvement of the integration level, good mechanical stability, wide application range, high efficiency and low cost can be achieved. The structure comprises two sub-silicon substrates, and one end of each sub-silicon substrate is provided with an interdigital structure; the interdigital structure comprises a plurality of interdigitals, each interdigital comprises an interdigital head and an interdigital neck, one end of the interdigital neck is fixedly connected with one end of the interdigital head, the width of the interdigital head is greater than that of the interdigital neck, and the interdigital neck on one sub-silicon substrate and the interdigital head on the other sub-silicon substrate are staggered and occluded to form an interdigital hinge structure; the structure further comprises a supporting and positioning structure, the supporting and positioning structure comprises a plurality of supporting and positioning columns, the ends, provided with the interdigital structures, of the sub-silicon substrates are arranged in a one-to-one correspondence mode to form two rows of supporting and positioning columns, welding caps are arranged at the top ends of the supporting and positioning columns, and in the folded state, the welding caps at the top ends of the corresponding supporting and positioning columns are welded together to form welding spots.

Description

technical field [0001] The invention belongs to the technical field of integrated circuit design and manufacture and advanced packaging technology, and specifically relates to a three-dimensional integrated structure, preparation and assembly method. Background technique [0002] At present, in two-dimensional multi-chip packages, and three-dimensional multi-chip packages of multi-chip stacking and package substrate stacking (PoP), the normal directions of the surfaces of multiple chips are the same or opposite, that is, the surfaces of each chip are generally parallel to each other. Furthermore, the surfaces of the packaging substrates carrying these chips are also generally parallel to each other. However, for some sensing systems, in order to perform three-dimensional measurement, a three-axis sensor needs to be composed of three mutually orthogonal sensitive axes, such as a nine-axis inertial measurement sensor for motion guidance, navigation and control, which needs to ...

AI Technical Summary

Problems solved by technology

However, this method based on the installation of rigid circuit boards on the third-party orthogonal surface to realize the mutual orthogonality of surface-mounted sensors on them has the disadvantages of low integration and large volume, which cannot meet the needs of miniaturized applications.

US patents "THREE DIMENSIONAL FOLDED MEMS TECHNOLOGY FORMULTI-AXIS SENSOR SYSTEMS" (Patent No. US8368145 B2) and "THROUGH-WAFER INTERCONNECTSFOR MEMS DOUBLE-SIDED FABRICATION PROCESS (TWIDS)" (Patent Publication No. US2016 / 0167958A1) Three-dimensional foldable MEMS technology for multi-axis sensor systems. In this patent, different sensor monolithic and foldable structures, that is, flexible and easy-bending hinges made of insulating materials, are integrated on the device layer (top silicon layer) of the same substrate. , but this technology requires the same or compatible manufacturing process of the integrated sensors, which leads to severe limitations on the types and structures of sensors that can be integrated, and from the perspective of implementation, this technology is difficult to realize, and different sensor processes need to be compatible, which is unavoidable A process solution compromise is required, and the optimal process cannot be achieved for each sensor, resulting in a loss of performance of a single sensor; in addition, the applicability of the vertical conductive interconnection hole structure described in this patent is very limited, for Devices with electrodes prepared on the substrate on the front (upper surface) of the substrate cannot realize the function of vertical conductive interconnection; moreover, the flexible and easy-bending hinges used in this patent are still flexible after the adjacent chips are bent and formed, lacking Rigid hard connection cannot limit the lateral relative movement of adjacent chips, and the relative position of adjacent chips will move or vibrate with external force, which will have a great impact on the measurement accuracy of the sensor

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