Evaluation of Nano-Coated Stencil for Ultra Fine Pitch Component Assembly
Authors: Rita Mohanty, Ph.D., Rajiv Iyer, Sharan Hoogar and Daryl Santos, Ph.D. Company: Speedline Technologies and Binghamton University Date Published: 10/24/2010
Abstract: The demand for product miniaturization, especially in the handheld device area, continues to challenge the board assembly industry. The desire to incorporate more functionality while making products smaller requires creative design and process development. It is not uncommon to find boards with castle like components right next to miniature components. This type of board has its own challenge, especially when it comes to printing. One way to address the printing challenge is to use creative stencil design to meet the solder paste requirements for both large and small components. Examples of creative stencil design includes step stencil, dual printing, over size aperture, etc.
Recent introduction of a new stencil technology, nano-coated stencil, has drawn the attention of many researchers. Nano-coated stencils are made by conventional methods such as laser cut or electroformed then, as the name implies, they are coated with nano particles to alter the surface characteristic of the stencil. This paper will compare and contrast the printing characteristics of a nano-coated stencil with a laser cut (uncoated) stencil on a specially designed test board. Special attention will be given to apertures with area ratio below 0.66.
Nano-coated stencil, Ultra fine pitch printing, statistical analysis