Glass Frit Jetting for Advanced Wafer-Level Hermetic Packaging

Wafer-level sealing is a critical step in fabricating micro-electromechanical systems. Traditional methods rely on screen printing for glass frit application, which is effective but limited in precision. Prior research has shown that screen printing is suitable for less sensitive wafers due to its mechanical contact. However, this gap motivated the exploration of alternative non-contact methods. No prior work had resolved the feasibility of jet dispensing for glass frit on device wafers. This uncertainty drove the investigation into jetting as a potential solution. The need for contactless patterning arose from applications involving complex topographies and optics. The study aimed to address these limitations while maintaining hermeticity and cost-effectiveness.

This study aimed to evaluate jet dispensing as an alternative to screen printing for glass frit application on silicon wafers. The specific problem was the need for a non-contact method to preserve delicate device structures. The motivation stemmed from limitations in screen printing for high-precision or complex geometries. The researchers proposed to assess jetting parameters such as distance, power, and temperature. They also sought to determine the impact of jetted pitch size on bond-line thickness. The goal was to establish a single-step, additive approach for hermetic sealing. The study focused on optimizing jet printing for glass frit materials. The outcome would inform the feasibility of this method for advanced packaging applications.

The researchers applied jet dispensing to deposit glass frit paste on silicon wafers. They varied jetting distance, power, and temperature to find optimal conditions. The jetting process was evaluated for its ability to create precise patterns. Wafers were bonded under low vacuum to assess sealing performance. The bond-line thickness was measured based on the jetted pitch size. Characterization included visual inspection and mechanical testing of the sealed wafers. The study compared jet printing to traditional screen printing in terms of precision and cost. The approach was designed as a non-contact, additive method for wafer-level packaging.

Jet printing of glass frit paste was successfully performed on silicon wafers. The optimal jetting distance, power, and temperature were determined through experimentation. The bond-line thickness was found to correlate with the jetted pitch size. Wafers with jetted glass frit were conclusively bonded under low vacuum. The jetting process demonstrated precision suitable for complex topographies. The method proved to be a single-step, additive approach for sealing. The bond strength met the requirements for hermetic packaging applications. The results suggest jet printing is a viable alternative to screen printing for device wafers.

The study demonstrated that jet dispensing can be used for glass frit application on silicon wafers. The optimized parameters enabled precise and non-contact patterning. The bond-line thickness was effectively controlled by adjusting the jetted pitch size. The method was shown to be suitable for sealing wafers with complex geometries. The researchers propose that jet printing is a cost-effective and flexible approach. The findings suggest that this method can be applied to device wafers requiring contactless patterning. The study supports the use of jet printing for advanced hermetic packaging. The authors suggest that this approach may offer advantages over traditional screen printing in specific applications.