Method for filling micropores by utilizing tin whisker growth

Abstract

The invention provides a method for filling micropores by utilizing tin whisker growth. The method comprises the following steps: an adhesive layer and a metal layer are deposited on the surface of a substrate with blind holes or through holes, metal is deposited in the blind holes in an electroplating manner to the openings of the blind holes, and a cavity is naturally formed in the deposited metal; photoresist is coated on the surfaces of the blind holes or the through holes and between the adjacent blind holes or through holes in a spinning manner; the metal layer and the adhesive layer beyond the spinning coated photoresist are corroded to form a metal interconnection line communicating the blind holes or the through holes; and two ends of the metal interconnection line are connected with electrodes and electrified to make metal whiskers in the blind holes grow quickly till the whiskers fill the cavity or the metal layer whiskers grow quickly to fill the through holes. By adopting the method, the cavity reserved during electroplating of micro blind holes can be effectively filled, and the defect that electroplating solution with surface tension can not enter the micro blind holes to electroplate is avoided, so that through holes with smaller diameters can be filled.

Description

technical field [0001] The invention relates to the field of microelectronics manufacturing and packaging, in particular to a method for filling micropores by using tin whisker growth. Background technique [0002] As the overall thickness of the packaging structure remains constant or even decreases, the thickness of each layer of chips used in the chip stack inevitably needs to be reduced. Through-silicon via metal interconnection technology (TSV) is a vertical interconnection technology in a chip, and its electrical signal passes through the through hole of the silicon chip. Compared with the traditional planar metal interconnection line, TSV can significantly increase the packaging density. It has the advantages of saving space, reducing signal delay and improving chip performance. When the thickness of the silicon wafer is reduced, the silicon wafer is not easy to clamp, and must be attached to the glass substrate or blind holes must be drilled first and then thinned. ...

AI Technical Summary

Problems solved by technology

For metal filling blind holes, defects such as voids often appear when filling holes due to the effect of gas in the holes and the surface tension of the metal with ordinary methods, so it is urgent to find a way to reduce or even eliminate these defects.

Images