Filter chip and processing method thereof

Abstract

The invention provides a filter chip and a processing method thereof, and relates to the technical field of filters. The filter chip comprises a wafer, and a chip effective area is arranged on the wafer. Scribing channels are arranged outside the chip effective area; a resonator and a bonding pad are arranged in the effective area of the chip; the bonding pad is connected with the resonator through a metal line; solder balls are planted in the ball planting area of the bonding pad; and a silicon dioxide protection layer covers the surface of the effective area of the chip except the solder balls and the resonators. The resonator area of the filter chip is not covered with a silicon dioxide protection layer, so that the flexible input and output and high-frequency conversion functions of the resonator are kept; the influence of the silicon dioxide protection layer on the performance of the filter chip is reduced, the resonance energy efficiency of the filter is improved, and particularly, the anti-interference effect of the high-frequency filter is stronger. The semi-etched cavity corresponding to the resonator on the wafer is arranged on the scaling powder brush coating and ball mounting steel mesh, so that the resonator is prevented from being damaged in the machining process.

Description

technical field [0001] The invention relates to the technical field of filters, in particular to a filter chip and a processing method thereof. Background technique [0002] The resonance area of ​​the low, medium and high frequency filter is covered with a silicon dioxide protective layer. The advantage is that it helps to protect the resonator from external force damage and environmental pollution; the disadvantage is that it has a certain impact on the performance of the filter. Compared with the medium and low frequency filter , the protective layer covered by the high-frequency filter has a greater impact on performance. [0003] In the traditional bumping process, the flux brushing and ball planting stencil will be attached to the surface of the filter wafer. When there are foreign objects or scratches on the two stencils during the process of brushing and ball planting, it is easy to cause internal resonance in the chip. device damaged. When there is no protective l...

AI Technical Summary

Problems solved by technology

[0002] The resonance area of ​​the low, medium and high frequency filter is covered with a silicon dioxide protective layer. The advantage is that it helps to protect the resonator from external force damage and environmental pollution; the disadvantage is that it has a certain impact on the performance of the filter. Compared with the medium and low frequency filter , the high-frequency filter covering the protective layer has a great influence on the performance

[0003] In the traditional bumping process, the flux brushing and ball planting stencil will be attached to the surface of the filter wafer. When there are foreign objects or scratches on the two stencils during the process of brushing and ball planting, it is easy to cause internal resonance in the chip. organ damage

Resonators are highly susceptible to damage when there is no protective silica layer in the resonator area

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