SJ Semiconductor (SHA:688820) filed for an initial public offering of 255.5 million shares on the Star Market of the Shanghai Stock Exchange, according to a Tuesday filing with the bourse.

Proceeds will be used to fund the 3D multi-chip integrated packaging and ultra-high density interconnect 3D multi-chip integrated packaging projects to scale chiplet packaging platforms and expand bumping capacity.

The expected offering date is April 9.

China International Capital serves as lead underwriter. Citic Securities serves as joint lead underwriter.