Wafer Bumping for Wafer-Level CSPs and Flip Chips using Stencil Printing Technology

In this paper the experimental work of stencil printing for creating solder bumps on wafer-level CSP (CSP-WL) is described in detail. In the first part the basic process steps for wafer-level CSP's as well as for stencil printing are described. The second part shows the experimental work how maximum solder bump height can be achieved using stencil printing for a specific wafer-level CSP. Based on the experimental work the achieved bump height using conventional bumping methods and stencil printing are discussed.