Protective Sacrifice Layer for High-Topography Cu Pads
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In semiconductor manufacturing, high-topography electroplated copper pads are prone to passivation material cracking during solder bumping, and existing protective measures are costly and increase manufacturing complexity and time.
Innovation Solution
A semiconductor device manufacturing method involving a substrate with a protective sacrifice layer formed over the passivation layer to shield it from damage during solder bumping, which can be removed after the process to expose the passivation material, thereby protecting the polyimide/copper interface from fluxing chemicals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple protective metal layers and UBM structures are used to protect passivation material during solder bumping, then passivation material integrity is improved, but manufacturing cost and complexity increase
Solution Approach 1:
The patent applies preliminary action by forming the protective牺牲 layer over the passivation layer before the solder bumping process. This pre-formed protective structure prevents passivation material cracking during subsequent high-temperature reflow soldering, eliminating the need for complex multi-layer protective metal structures and UBM layers that would otherwise be required.
Solution Approach 2:
The patent employs a sacrificial protective layer made of spin-on-glass or similar material that serves its protective function temporarily during solder bumping, then can be removed or remains as a non-critical layer. This disposable protective approach replaces expensive and complex multi-layer metal protective structures, significantly reducing manufacturing cost and process complexity.
2Reliability
If multiple protective metal layers and UBM structures are used to protect passivation material during solder bumping, then passivation material integrity is improved, but manufacturing time increases
Solution Approach 1:
The protective牺牲 layer is formed in advance using a simple spin-coating process followed by patterning, completing the protection structure before solder bumping begins. This preliminary formation eliminates the need for time-consuming multi-layer metal deposition and UBM structure fabrication that would extend manufacturing cycles.
Solution Approach 2:
The patent changes the material parameter from traditional multi-layer metal protective structures to a spin-on-glass or similar polymer-based sacrificial layer. This material substitution enables formation via low-cost, rapid spin-coating processes rather than multiple sputtering or evaporation steps, dramatically reducing manufacturing time while maintaining protective functionality.
3Reliability
If conventional protective measures are used during solder bumping, then passivation material is protected, but manufacturing cost increases
Solution Approach 1:
The patent uses an inexpensive spin-on-glass or polymer-based sacrificial layer that can be applied via low-cost spin-coating equipment already present in semiconductor fabs. This cheap protective layer replaces expensive multi-layer metal protective structures and complex UBM formulations, significantly reducing material and processing costs while providing adequate protection during solder bumping.
Solution Approach 2:
The patent substitutes mechanical/physical vapor deposition processes (sputtering, evaporation) used for forming protective metal layers with a chemical solution-based spin-coating process. This replacement eliminates expensive vacuum equipment requirements and reduces processing steps, making the protective structure formation much more cost-effective while achieving the same protective function.
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 method reduces manufacturing costs and complexity by eliminating the need for multiple protective metal layers and UBM structures, ensuring passivation material integrity and improving solder bumping process efficiency while protecting the polyimide/copper interface.
Implementation Method 1
high-topography electroplated copper pads
Implementation Method 2
solder bumping process
Data Source
AI summary
A semiconductor device has a first conductive layer formed over a substrate. A first insulating layer is formed over the substrate and first conductive layer. A second conductive layer is formed over the first conductive layer and first insulating layer. A second insulating layer is formed over the first insulating layer and second conductive layer. The second insulating layer has a sidewall between a surface of the second insulating material and surface of the second conductive layer. A protective layer is formed over the second insulating layer and surface of the second conductive layer. The protective layer follows a contour of the surface and sidewall of the second insulating layer and second conductive layer. A bump is formed over the surface of the second conductive layer and a portion of the protective layer adjacent to the second insulating layer. The protective layer protects the second insulating layer.