Stacked Metal Semiconductor Packaging for Electromigration Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The increasing size and cost reduction of semiconductor devices lead to high temperatures and premature packaging failures due to increased power and current density, causing issues like electromigration and packaging failures as die shrinkage occurs.
Innovation Solution
A semiconductor packaging structure that eliminates solder, uses multiple metal layers for wide area coupling, surrounds copper with barrier metals to prevent migration, and lacks wire bonds and additional encapsulation, allowing for high-temperature operation and efficient power transfer without a lead frame or mold compound.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If die size is reduced to lower cost and increase functionality, then device integration and functionality improve, but power density and current density increase leading to electromigration and packaging failures
Solution Approach 1:
The patent transitions from two-dimensional planar interconnects to three-dimensional vertically-stacked metal layers. Multiple metal layers are stacked above the die, with each layer providing additional current carrying capacity and electrical connection paths, thereby increasing power handling capability without increasing the die area.
Solution Approach 2:
The patent implements nested metal layers where subsequent metal layers are positioned over and around previous layers, creating a nested structure. Each metal layer is surrounded by insulating material and barrier metals, forming concentric nested configurations that maximize space utilization and current distribution.
2Adaptability or versatility
If die size is reduced, then cost and integration improve, but temperature increases causing premature packaging failures
Solution Approach 1:
The patent uses vertically-stacked metal layers to distribute heat generation across multiple vertical levels rather than concentrating it in a single planar layer. This three-dimensional heat distribution reduces localized temperature hotspots on the die surface.
Solution Approach 2:
The patent segments the current path and heat generation across multiple separate metal layers, each surrounded by insulating material. This segmentation distributes the thermal load across multiple layers and interfaces, improving heat dissipation and reducing peak temperatures.
3Power
If multiple metal layers are added to increase current carrying capacity, then power density handling improves, but device complexity increases
Solution Approach 1:
The insulating material serves multiple functions simultaneously: it electrically isolates adjacent metal layers, provides mechanical support and spacing, and acts as a structural matrix for the stacked configuration. The barrier metals similarly provide both electrical isolation and structural definition for each metal layer.
Solution Approach 2:
The patent combines multiple functions into integrated structures: the insulating material both isolates and supports the metal layers, while barrier metals simultaneously prevent electromigration and define layer boundaries. This merging reduces the need for separate components and simplifies the overall fabrication process.
Data Source
AI summary
A semiconductor packaging structure includes a die including a bond pad and a first metal layer structure disposed on the die, the first metal layer structure having a first width, the first metal layer structure including a first metal layer, the first metal layer electrically coupled to the bond pad. The semiconductor packaging structure also includes a first photosensitive material around sides of the first metal layer structure and a second metal layer structure disposed over the first metal layer structure and over a portion of the first photosensitive material, the second metal layer structure electrically coupled to the first metal layer structure, the second metal layer structure having a second width, where the second width is greater than the first width. Additionally, the semiconductor packaging structure includes a second photosensitive material around sides of the second metal layer structure.