Underfill Flow Uniformity via Substrate Openings
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Solution Overview
Problem
The existing methods for depositing underfill material between a semiconductor die and substrate result in non-uniform flow rates, leading to uneven material distribution, bleed-out, and void formation, which compromises the reliability of the semiconductor device.
Innovation Solution
Creating openings in the substrate or insulating layer to alter and maintain a uniform flow rate of the underfill material, ensuring consistent deposition across the surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If underfill material is deposited between semiconductor die and substrate using conventional methods, then the material fills the gap between die and substrate, but the flow rate is non-uniform causing uneven material distribution, bleed-out, and void formation
Solution Approach 1:
The patent introduces openings at specific locations (perimeter regions) where bumps are present to create local variations in flow resistance. This local modification of the substrate structure allows the underfill material to flow more uniformly across different regions, compensating for the presence of bumps that cause non-uniform flow without requiring global changes to the entire deposition process.
2Manufacturing precision
If openings are created in the substrate or insulating layer, then the flow rate of underfill material is uniform, but the substrate structure becomes more complex
Solution Approach 1:
The substrate is segmented by creating discrete openings at specific locations rather than modifying the entire substrate uniformly. These openings are strategically placed in perimeter regions where bumps are located, dividing the flow path into controlled segments that regulate material flow. This segmented approach achieves uniform flow with minimal structural modification.
Solution Approach 2:
The openings act as intermediary structures that mediate between the underfill material and the bumps. By providing controlled flow paths through the openings, the patent intermediates the interaction between the deposited material and the obstacle (bumps), allowing uniform flow without direct confrontation between the material and the complex bump structure.
Data Source
AI summary
A semiconductor device has a substrate and insulating layer formed over a surface of the substrate. A first conductive layer is formed over the surface of the substrate. A second conductive layer is formed over an opposing surface of the substrate. A conductive via is formed through the substrate. An opening is formed in the insulating layer while leaving the first conductive layer intact. The opening narrows with a non-linear side or linear side. The opening can have a rectangular shape. A semiconductor die is mounted over the surface of the substrate. An underfill material is deposited between the semiconductor die and substrate. The opening in the insulating layer reduces a flow rate of the underfill material proximate to the opening. The flow rate of the underfill material proximate to the opening is substantially equal to a flow rate of the underfill material away from the opening.