A wafer level packaging structure of a filter and a process thereof

Abstract

The invention discloses a wafer-level packaging structure of a filter and a process thereof, and the structure comprises a chip substrate, and the working surface of the chip substrate is provided with a bonding pad and an IDT. The structure further comprises a first film layer, a second film layer and a metal connecting piece. Wherein the first thin film layer is located on the working surface ofthe chip substrate and exposes a part of the bonding pad and the IDT; The second thin film layer is positioned on the surface of the first thin film layer and exposes part of the bonding pad; A protection cavity is formed among the second thin film layer, the first thin film layer and the working surface of the chip substrate, and the IDT is located in the protection cavity; And the metal connecting piece is electrically connected with the bonding pad and is provided with a welding part. The surface of the filter is covered with the two films, the cavity is formed, the packaging reliability can be improved, the technological process is greatly optimized, and the whole packaging cost is low. Due to the fact that the thin film is adopted to serve as the cavity cover plate, smaller warpage is achieved after wafer level packaging, and the process yield of products is improved.

Description

technical field [0001] The invention relates to the field of semiconductor packaging, in particular to a wafer-level packaging structure of a filter and a process thereof. Background technique [0002] The surface acoustic wave filter uses the excitation, propagation and reception of the surface acoustic wave on the piezoelectric material to complete its filtering characteristics. The surface acoustic wave wavelength is in the range of 100 μm to 2 μm, and it is a mechanical wave that is very sensitive to its propagation surface. In order for the surface acoustic waves in an acoustic wave component to propagate without disturbance, there is a cavity above the surface of the chip in the package. [0003] At present, the main packaging technology of filters is ceramic, metal, plastic packaging and flip-chip packaging with lead bonding, such as figure 1 A surface acoustic wave filter packaging structure, which includes a substrate (1), a groove (8) is provided on the back of t...

AI Technical Summary

Problems solved by technology

[0005] 1. The cost of the surface sealing cover is relatively high;

[0006] 2. The reliability of the product has strict requirements on the flatness of the substrate and the sealing cover, which is easy to cause failure

[0007] 3. A series of uncertainties such as the accuracy of device installation, the influence of signal guides, and the angle of welding will cause inconsistency in device performance and even damage the filter

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