Masters Abstracts (1997)

PRASAD, SWAMINATH
(October 1997), Senior Engineer, ChipPac Incorporated, Santa Clara, CA

Email: prasad.swaminath@chippac.com

Adhesive Deposition Through Stencil Printing for Surface Mount Assembly

This research focused on 'optimizing' the adhesive deposition process through stencil printing. Through extensive systematic experimentation the process of stencil printing adhesives was 'optimized' and the print quality obtained was correlated to the rheological data obtained through experimentation. Two different stencil materials, the traditional steel stencil and the new plastic stencil, were evaluated. The 'optimization' experiments were validated by placing components and measuring the spread of the adhesive between the pads. A better understanding of the process was also obtained by evaluating three adhesives with different viscosities. The highlight of this effort was to prove that the stencil printing process is a viable method of depositing adhesives. This research provides a process engineer with aperture dimensions (aspect ratios) for a wide range of passive surface mount components (1210s to 0402s), a choice of a type of stencil (plastic or steel), appropriate adhesive knowledge, and the 'optimum' levels of the stencil printing parameters.