Side-Connected Die Interconnects Using Volumetric Thermal Expansion
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Solution Overview
Problem
Conventional semiconductor device assembly techniques face challenges in creating reliable, well-connected interconnects between stacked semiconductor dies due to alignment and expansion constraints of conductive materials, which can lead to voids or structural failures.
Innovation Solution
The use of reservoirs of conductive material adjacent to openings in dielectric layers, which expand thermally to form interconnects at non-horizontal surfaces, allowing for robust and flexible electrical coupling between semiconductor dies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conductive material is used to form interconnects between stacked semiconductor dies, then electrical coupling is achieved, but alignment and expansion constraints lead to voids or structural failures
Solution Approach 1:
The patent changes the physical state of conductive material from solid to liquid by heating it above its melting point, allowing it to flow and expand freely into the opening without alignment constraints. This parameter change (solid→liquid) resolves the contradiction by eliminating the need for precise alignment during the interconnect formation process while maintaining reliable electrical coupling.
Solution Approach 2:
The patent utilizes the phase transition of conductive material from solid to liquid state through heating. The conductive material is heated to melt and flow into the opening between dies, then cooled to solidify, forming a robust interconnect. This phase transition enables the material to adapt to dimensional variations and alignment tolerances, resolving the contradiction between reliability and manufacturing precision.
2Reliability
If conventional horizontal interconnects are used, then electrical coupling is achieved, but contact surface area is limited and structural integrity is compromised
Solution Approach 1:
The patent transitions from conventional horizontal interconnects to vertical/diagonal interconnects that extend through the opening between stacked dies. This dimensional change allows the interconnect to achieve contact at non-horizontal surfaces, increasing the contact surface area and improving structural integrity by distributing mechanical loads across multiple surfaces rather than a single horizontal interface.
Solution Approach 2:
The conductive material is contained within an opening formed in the dielectric layer, creating a nested structure where the interconnect is embedded within the dielectric matrix. This nesting provides mechanical support and increases the effective contact surface area between the interconnect and the surrounding dielectric structure, enhancing overall structural integrity.
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 enables reliable and robust interconnects that are less constrained by expansion variations, providing a larger contact surface and structural integrity, thus enhancing the reliability and design flexibility of semiconductor device assemblies.
Implementation Method 1
The reservoir of conductive material is heated to cause it to expand
Data Source
AI summary
A semiconductor device assembly is described that includes two semiconductor dies. The semiconductor dies each include a layer of dielectric material and a reservoir of conductive material located adjacent to openings in the layer of dielectric material. The opening at the layer of dielectric material of the first semiconductor die and the opening at the layer of dielectric material of the second semiconductor die are aligned to create an interconnect opening. The reservoirs of conductive material are heated to volumetrically expand the reservoirs of conductive material past one another such that they contact at respective non-horizontal surfaces to form an interconnect electrically coupling the semiconductor dies. In this way, a connected semiconductor device may be assembled.