Abstract: In an embodiment, a device includes: an interposer including: a back-side redistribution structure; an interconnection die over the back-side redistribution structure, the interconnection die including a substrate, a through-substrate via protruding from the substrate, and an isolation layer around the through-substrate via; a first encapsulant around the interconnection die, a surface of the first encapsulant being substantially coplanar with a surface of the isolation layer and a surface of the through-substrate via; and a front-side redistribution structure over the first encapsulant, the front-side redistribution structure including a first conductive via that physically contacts the through-substrate via, the isolation layer separating the first conductive via from the substrate.

Abstract: A first polymer layer is formed across a package region and a test region. A first metal pattern is formed in the package region and a first test pattern is simultaneously formed in the test region. The first metal pattern has an upper portion located on the first polymer layer and a lower portion penetrating through the first polymer layer, and the first test pattern is located on the first polymer layer and has a first opening exposing the first polymer layer. A second polymer layer is formed on the first metal pattern in the package region and a second test pattern is simultaneously formed on the first test pattern in the test region. The second polymer layer has a second opening exposing the upper portion of the first metal pattern, and the second test pattern has a third opening greater than the first opening of the first test pattern.