Nistec Develops Advanced Step Stencil Technology for High-Density AI PCBs

Nistec has developed a new technological solution that addresses one of the most challenging aspects of advanced SMT assembly: accurately controlling solder paste volume for each individual component across a circuit board, even in highly complex designs integrating dense AI technologies.

To develop this solution, Nistec collaborated with a leading international stencil manufacturer to create an advanced Step Stencil incorporating dedicated inserts—specialized metal structures that locally increase stencil thickness in specific areas of the board. As a result, the stencil no longer maintains a uniform thickness but instead features variable thicknesses optimized for the different components mounted on the PCB.

The technology enables the creation of multiple thickness zones within a single stencil. For example:

• Fine-pitch areas for Micro BGA and Micro QFN components with a pitch of only 0.35 mm, utilizing an ultra-thin stencil thickness of approximately 3 mils.
• Connector areas, such as Samtec connectors with a 1.25 mm pitch, utilizing a thicker stencil of 5–6 mils to ensure sufficient solder paste deposition.

According to Michael Schneider, Process Technology Manager at Nistec’s Petach Tikva facility:

“The combination of different stencil thicknesses enables significantly more accurate solder paste printing, improves manufacturing yield, and reduces the risk of shorts and insufficient solder deposition—critical challenges in complex AI, data processing, and high-speed electronic systems.”

In addition, the stencils are treated with a unique Nano Coating that enhances aperture wall smoothness and improves solder paste release performance, even in extremely small openings. The result is greater process stability and the ability to support next-generation electronic assemblies with exceptionally high component density.

This innovative technology strengthens Nistec’s capability to manufacture advanced AI, data processing, communications, defense, medical, and high-performance computing products while maintaining the highest standards of quality and reliability.