Novel packaging method of MEMS (Micro-electromechanical Systems) structure and processing circuit integrated system

Abstract

The invention relates to a novel packaging method of an MEMS (Micro-electromechanical Systems) structure and a processing circuit integrated system. The method comprises the following steps: (1) preserving a plurality of circuit chip holding areas on each substrate unit of an MEMS wafer, and putting circuit chips on the MEMS wafer to form integration of the MEMS structure with a processing circuit; (2) utilizing a vertical intercoupling technique, using silicon as a cover plate in which a vertical through hole is formed, filling a conductive material into the through hole to form an input port and an output port of the structure; (3) forming a plurality of grooves in the binding surface of the cover plate for providing a vacuum airtight environment necessary for working of an MEMS device and a space required by the circuit, wherein an air sucking agent film inside the cover plate groove is used for maintaining the vacuum degree; (4) performing wafer binding on the cover plate and the MEMS wafer so as to achieve the wafer grade vacuum integrated packaging. The method is not only simple in process, wide in application range and remarkable in effect, but also can avoid thermal stress caused by the coefficient of thermal expansion, and can remarkably improve the temperature coefficient of a device.

Description

technical field [0001] The invention relates to a system-integrated wafer-level vacuum packaging method, in particular to a novel packaging method for an MEMS structure and processing circuit integrated system. Background technique [0002] MEMS is the abbreviation of micro-mechanical electronic system, and the system integration of MEMS structure and processing circuit is the development goal of MEMS field. At present, there are MEMS devices that integrate MEMS structures and COMS circuits into one chip abroad, but this process is very complicated and is limited to some specific sensitive structures and circuits, such as silicon micro-microphones and other MEMS systems that use surface silicon technology. Not of general application. In addition, the integration of MEMS structures and processing circuits can also be achieved through device-level integrated packaging, that is, MEMS chips and processing circuits are packaged together in a package. This method has low integrat...

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Problems solved by technology

In addition, according to the concept of wafer-level packaging, only wafer-level bonding technology has been realized in China at this stage, which cannot be equivalent to wafer-level packaging, because the symbol of wafer-level packaging is that once the chip is cut, it can be used normally without additional bonding wire

In China, there is a method of making holes on silicon and filling bumps to achieve wafer-level hermetic packaging. However, this method first thins the silicon cover to 120μm-160μm, and then opens the holes. The process is complicated and the yield is low.

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