NEXT LEVEL REQUIREMENTS FOR ULTRA FINE PITCH PRINTING
Authors: Richard Brooks, John Carr, and Marty Carr Company: Indium Corporation and Great Lakes Engineering Date Published: 2/12/2009
Pan Pacific Symposium
Abstract: New assembly technologies are being considered for production to reduce size and/or increase functionality. These new technologies include: 0201 & 01005 chip components and 0.4 mm & 0.3 mm pitch CSP devices. In order to implement these new technologies, some major changes in the manufacturing process may have to be addressed. First, the solder paste must provide the ability to print very small apertures, such as 0.008” (0.2mm) & below and with consistent paste release from the stencil. Therefore, one of the possible solutions may be to change the standard solder powder size, which is type 3 powder. Also, because we are printing very small aperture openings, we need to consider changes in the stencil technology. Some of those changes are the stencil type (laser versus electroformed) and the stencil thickness. Additionally, because we are attempting to print very small apertures, the printing process must be in control and characterized. This paper will review the new technology requirements and how they will affect the performance of the solder paste and stencil technology in the manufacturing process, as well as the printing process.
Key words: fine pitch printing, stencil technology, stencil design, pad design, solder powder, process characterization, solder paste