Bond Tip Design Mitigates Warpage and Solder Stretching
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Solution Overview
Problem
Existing semiconductor device assembly processes face challenges in forming adequate interconnects between stacked devices due to top die warpage and solder stretching during the reflow process, despite efforts to apply pressure and fluid flow through vacuum and purge ports.
Innovation Solution
A bond tip with a central vacuum port and peripheral purge ports, coupled with flow units that manage air withdrawal and fluid flow, is used to selectively attach and position the top semiconductor device, applying fluid pressure through the purge ports to prevent interconnect stretching by controlling the flow of air and fluid during the reflow process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If pressure is applied to the top surface of the bond tip to prevent interconnect stretching, then interconnect formation is improved, but the complexity of the bond tip structure increases
Solution Approach 1:
The bond tip is segmented into multiple functional zones with different port configurations. The peripheral purge ports are separated from the central vacuum port, allowing independent control of fluid flow in different regions. This segmentation enables targeted pressure application at the periphery without requiring complex overall structure
Solution Approach 2:
The bond tip structure serves multiple functions: the vacuum port provides both vacuum generation for device attachment and fluid delivery during reflow, while the purge ports provide pressure application and fluid purging. This multi-functionality reduces the need for additional separate components, thereby reducing overall structural complexity while maintaining manufacturing precision
2Manufacturing precision
If fluid flow is increased through the vacuum port to prevent interconnect stretching, then interconnect formation is improved, but the energy consumption increases
Solution Approach 1:
The fluid delivery system is segmented into multiple purge ports distributed around the periphery, allowing localized and targeted fluid flow application. This segmentation enables precise control of fluid flow rates, reducing overall energy consumption compared to high-volume flow through a single central port while still achieving the pressure needed to prevent interconnect stretching
Solution Approach 2:
The purge ports provide partial fluid flow action targeted specifically at the peripheral regions where interconnect stretching occurs. Rather than applying excessive fluid flow uniformly across the entire device surface, the system applies partial flow only where needed, reducing energy consumption while maintaining interconnect formation quality
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively prevents interconnect stretching at the edges of semiconductor devices, ensuring the formation of adequate interconnects between stacked devices by applying controlled fluid pressure and managing the vacuum and fluid flow to counteract warpage profiles.
Implementation Method 1
The withdrawal of air (not shown) through a vacuum port 263 via a flow unit 280 fluidly coupled to the vacuum port 263 via a conduit 285 creates a vacuum on the bottom surface 262
Implementation Method 2
fluid flowing through both the purge ports and the vacuum port may enable adequate interconnects to be formed
Data Source
AI summary
A semiconductor tool and methods of forming semiconductor device assemblies. The semiconductor tool is a bond tip having a vacuum port and a plurality of purge ports with channels coupling the vacuum port with the purge ports. Air may be withdrawn through the vacuum to create a vacuum on the bottom of the bond tip to selectively couple a semiconductor device with the bond tip. The bond tip positions the semiconductor device on top of a stack of semiconductor devices to form a semiconductor device assembly. The assembly may be heated to reflow interconnects between the semiconductor device and the top device of the stack of semiconductor devices. Fluid provided through the purge ports may help to counter warpage of the semiconductor device to help form adequate interconnects between the devices. Fluid may also be provided through the vacuum port to counter the warpage.