Abstract: Methods and semiconductor devices are provided. A method includes determining a location of a polyimide opening (PIO) corresponding to an under-bump metallization (UBM) feature in a die. The die includes a substrate and an interconnect structure over the substrate. The method also includes determining a location of a stacked via structure in the interconnect structure based on the location of the PIO. The method further includes forming, in the interconnect structure, the stacked via structure comprising at most three stacked contact vias at the location of the PIO.

Abstract: The present disclosure provides a linear polypropylene foam with, for example, low density and/or high expansion ratio, said linear polypropylene foam comprising at least one polypropylene, at least one alpha nucleating agent, and at least one beta nucleating agent. The present disclosure also provides compositions and processes for making said linear polypropylene foam.

Abstract: The present disclosure provides improved polypropylene-based compositions (formulations). The present disclosure further provides improved micro-pellets (non-foamed), which comprise the improved polypropylene-based composition. The improved polypropylene-based compositions have a reduced melting point (Tm) for the polypropylene resin while maintaining the stiffness of the micro-pellets for use in foaming procedures. Also, the disclosure further provides a new, dry method of preparing expanded polypropylene beads from micro-pellets without a liquid medium or steam, which thereby simplifies the production process and saves both energy and production costs.

Abstract: Polymer foam and a method for preparing the same are disclosed. In the present disclosure, the method sequentially comprises the following steps: providing a polymer body; performing a pressure-induced flow (PIF) process on the polymer body at a first predetermined temperature and a first predetermined pressure for a pressure holding time, to obtain a polymer sheet; and performing a foaming process on the polymer sheet by using a foaming agent at a second predetermined temperature and a second predetermined pressure for a saturation time, to obtain polymer foam.

Abstract: The present disclosure provides a process of preparing linear polypropylene foam, comprising the following steps: (a) preparing a specimen comprising at least one linear polypropylene; and at least one nucleating agent selected from the group consisting of alpha nucleating agents and beta nucleating agents; (b) deforming the specimen under a deforming pressure and at a deforming temperature for a period of time; and (c) subjecting the deformed specimen obtained in the step (b) to a foaming process to obtain the linear polypropylene foam. The present disclosure further provides a specimen after PIF treatment and a linear polypropylene foam prepared by the above process.

Abstract: The present disclosure provides a linear polypropylene foam with, for example, low density and/or high expansion ratio, said linear polypropylene foam comprising at least one polypropylene, at least one alpha nucleating agent, and at least one beta nucleating agent. The present disclosure also provides compositions and processes for making said linear polypropylene foam.

Abstract: Polymer foam and a method for preparing the same are disclosed. In the present disclosure, the method sequentially comprises the following steps: providing a polymer body; performing a pressure-induced flow (PIF) process on the polymer body at a first predetermined temperature and a first predetermined pressure for a pressure holding time, to obtain a polymer sheet; and performing a foaming process on the polymer sheet by using a foaming agent at a second predetermined temperature and a second predetermined pressure for a saturation time, to obtain polymer foam.