INTERPOSER SUBSTRATE AND METHOD OF FABRICATING THE SAME

摘要

An interposer substrate includes a first insulating layer having opposite first and second surfaces; a first wiring layer formed in the first insulating layer, with a surface of the first wiring layer exposed from the first surface; first conductive pillars formed in the first insulating layer; a second wiring layer formed on the second surface; second conductive pillars formed on the second wiring layer; a second insulating layer formed on the second surface and covering the second conductive pillars and the second wiring layer, with end surfaces of the second conductive pillars exposed from the second insulating layer; and immersion tin layers formed on the first wiring layer and the end surfaces of second conductive pillars. The immersion tin layers are used as surface processing layers to be applied to products having ball pads that need to be exposed extensively. A method for fabricating the interposer substrate is also provided.

主权项

1. An interposer substrate, comprising:
a first insulating layer having a first surface and an opposing second surface; a first wiring layer formed in the first insulating layer and having a surface exposed from the first surface of the first insulating layer; a plurality of first conductive pillars formed in the first insulating layer and on the first wiring layer, each of the first conductive pillars having an end surface exposed from the second surface of the first insulating layer; a second wiring layer formed on the second surface of the first insulating layer and the first conductive pillars and electrically connected with the first conductive pillars via the exposed end surfaces thereof; a plurality of second conductive pillars formed on the second wiring layer and electrically connected with the second wiring layer; a second insulating layer formed on the second surface of the first insulating layer and covering the second conductive pillars and the second wiring layer, with end surfaces of the second conductive pillars exposed from the second insulating layer; and a plurality of immersion tin layer formed on the exposed surface of the first wiring layer and the end surfaces of the second conductive pillars.