Recessed Through Silicon Via Pads for High Density IC Packaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current technologies face challenges in manufacturing high-speed computer devices exceeding one TeraHertz, with limitations in assembly, cooling, reliability, and cost-effectiveness, particularly in achieving smaller package footprints and robust computer chips for next-generation portable electronics.
Innovation Solution
The method involves creating an integrated circuit system with a substrate having a via and a trench, filled with a conductive pillar, a recessed contact pad partially filled with solder, and an under-bump metal extending beyond the substrate's face surface, enhancing electrical connections and assembly precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If conventional through-silicon via structures are used, then manufacturing is simpler, but package footprint is larger and I/O density is lower
Solution Approach 1:
The patent transitions from conventional planar contact pads to three-dimensional recessed contact pads formed within trenches etched into the substrate back surface. This vertical dimensionality change allows contact pads to be embedded within the substrate volume rather than occupying only the surface area, thereby reducing package footprint while maintaining electrical connection functionality
Solution Approach 2:
The contact pads are nested within trenches etched into the substrate, creating a hierarchical structure where the conductive material is contained within the substrate volume. This nesting approach allows multiple I/O connections to be packed more densely within the same package footprint area
2Productivity
If recessed contact pads in trenches are implemented, then I/O density increases and package footprint decreases, but manufacturing complexity and production cost increase
Solution Approach 1:
The manufacturing process is segmented into distinct sequential steps: trench etching, conductive material deposition, and solder bump formation. This segmentation allows each complex step to be optimized independently and enables the use of standard semiconductor manufacturing equipment and processes for each individual step
Solution Approach 2:
The trenches are etched and conductive materials are deposited into the trenches before the final solder bump formation step. This preliminary preparation of the recessed contact pad structures enables subsequent automated soldering processes to proceed efficiently with standard equipment, reducing overall manufacturing complexity
3Reliability
If larger contact pads are used, then assembly is more robust, but package footprint increases
Solution Approach 1:
The contact pads are extended into the vertical dimension by forming them within trenches that penetrate into the substrate back surface. This allows the contact pad area to be increased for better mechanical robustness and solder joint strength without proportionally increasing the horizontal package footprint, as the additional contact pad area is achieved through vertical embedding rather than lateral expansion
Data Source
AI summary
A method of manufacture of an integrated circuit system includes: providing a substrate with a face surface having a via therein and a back surface having a trench therein; filling the via with a conductive pillar; forming a recessed contact pad in the trench; filling the recessed contact pad partially with solder; and forming an under-bump metal having a base surface in electrical contact with the conductive pillar, and having sides that extend away from the face surface of the substrate and further extend beyond the base surface.