Photodefinable Collars for 3D Structure Adhesion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor device fabrication methods face challenges in achieving adequate adhesion and shear strength of 3D structures to substrates, particularly in configurations where metallurgical bonds are not formed between the 3D structures and underlying passivation materials, leading to compromised reliability during handling and assembly.
Innovation Solution
The implementation of photodefinable materials, such as polyimides, which are applied over 3D structures and exposed to controlled doses of radiant energy to create collars that enhance adhesion without altering the electrical characteristics or package design, acting as shear stress buffers and support elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If 3D structures are formed without metallurgical bonding to underlying passivation materials, then manufacturing complexity is reduced and electrical characteristics are maintained, but adhesion strength and reliability are compromised
Solution Approach 1:
A collar structure is introduced as an intermediary element between the 3D structure and the substrate. This collar acts as a mediator that provides mechanical support and adhesion enhancement without requiring metallurgical bonding between the 3D structure and passivation materials, thus maintaining electrical characteristics while improving reliability
Solution Approach 2:
The support function is segmented from the 3D structure itself and transferred to a separate collar element. This segmentation allows the 3D structure to maintain its electrical function while the collar provides mechanical support and adhesion, resolving the conflict between manufacturing simplicity and reliability
2Strength
If 3D structures are metallurgically bonded to underlying metal structures, then adhesion strength is improved, but manufacturing complexity and process difficulty increase
Solution Approach 1:
The collar serves as an intermediary that provides adhesion strength without requiring complex metallurgical bonding processes. It simplifies the manufacturing by replacing difficult metallurgical bonds with a more straightforward collar formation and attachment process
3Productivity
If pillar diameter is reduced to increase circuit density, then productivity and circuit density are improved, but adhesion strength and structural stability deteriorate
Solution Approach 1:
The support function is moved from the vertical dimension (pillar diameter) to the lateral dimension (collar structure). This allows the pillar diameter to be reduced for higher circuit density while the collar provides the necessary adhesion strength in a different spatial dimension
Solution Approach 2:
The adhesion function is segmented from the pillar and assigned to a separate collar structure. This enables the pillar to be made smaller for higher density while the collar compensates for the reduced adhesion area through its larger lateral footprint
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 significantly increases the shear strength of 3D structures, enhancing the robustness of semiconductor device assemblies and improving reliability during packaging processes, with yields of functional die stacks increasing up to five times that of unsupported structures, while maintaining package dimensions and electrical integrity.
Implementation Method 1
The implementation of photodefinable materials, such as polyimides, which are applied over 3D structures and exposed to controlled doses of radiant energy to create collars that enhance adhesion
Data Source
AI summary
Methods of forming supports for 3D structures on semiconductor structures comprise forming the supports from photodefinable materials by deposition, selective exposure and curing. Semiconductor dice including 3D structures having associated supports, and semiconductor devices are also disclosed.