UBM Breach Structure for Bump Shear Resistance
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Solution Overview
Problem
Conventional electronic elements with smaller bump sizes suffer from reduced shear-force resistance, leading to easy detachment under external forces, which increases repair costs and affects the reliability of electronic apparatuses.
Innovation Solution
A manufacturing method that involves forming a breach structure on the under bump metal (UBM) layer between the bump and the substrate, enhancing the shear-force resistance by adjusting the cross-sectional areas and using etching operations to create a stable attachment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the bump size is reduced to achieve smaller electronic element layout, then the contact area and attaching capability between the bump and driving chip are reduced, but the shear-force resistance deteriorates causing easy detachment under external force
Solution Approach 1:
The patent introduces a breach structure that extends vertically through the UBM layer, transforming a two-dimensional attachment problem into a three-dimensional solution. The breach creates a recessed region that allows the bump to penetrate deeper into the UBM layer, increasing the effective bonding interface area in the vertical dimension while maintaining a small top-view footprint. This dimensional transition enables small bump size to coexist with high shear-force resistance.
Solution Approach 2:
The breach structure creates a porous or hollow region within the UBM layer that the bump penetrates. This porous structure increases the surface area of contact between the bump and UBM layer without increasing the overall bump volume. The hollow space within the breach allows the bump material to wrap around and bond to the UBM layer walls, significantly enhancing attaching capability while maintaining compact dimensions.
2Volume of moving object
If the bump size is reduced to achieve smaller electronic element layout, then the electronic element size is reduced, but the reliability deteriorates due to increased detachment risk
Solution Approach 1:
By creating a vertical breach structure through the UBM layer, the patent enables the bump to establish a deeper penetration path into the substrate. This vertical dimension enhancement provides mechanical interlocking that significantly improves attachment reliability. The breach allows the bump to anchor into the UBM layer, creating a more secure connection that resists detachment forces while keeping the overall element footprint small.
Solution Approach 2:
The patent employs a composite structure consisting of the bump material, UBM layer, and the breach configuration. The combination of these materials and the geometric breach structure creates a multi-phase attachment system where each component contributes to overall reliability. The breach region may be filled with different materials or remain hollow, creating a composite attachment mechanism that enhances bonding strength and reliability beyond what a simple solid bump could achieve.
3Strength
If a breach structure is formed in the UBM layer to improve shear-force resistance, then the attachment strength is improved, but the manufacturing complexity increases due to additional etching operations
Solution Approach 1:
The breach structure is formed in the UBM layer before the bump is deposited. This preliminary action allows the bump material to be deposited directly into the pre-formed breach region, ensuring proper filling and bonding. By preparing the breach structure in advance, subsequent bump deposition and bonding processes are simplified, and the overall manufacturing complexity is managed more effectively than if the breach were created after bump formation.
Solution Approach 2:
The patent replaces complex mechanical bonding processes with a chemical etching process to create the breach structure. Instead of using mechanical means to create the recessed region, a chemical etchant selectively removes material from the UBM layer to form the breach. This substitution simplifies the manufacturing process by using well-established semiconductor etching techniques rather than complex mechanical machining or bonding operations.
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
The breach structure significantly improves the shear-force resistance of electronic elements, preventing bump detachment and reducing repair costs, while allowing for more flexible and compact electronic device designs.
Implementation Method 1
processing an etching operation at the UBM layer to form a breach structure
Data Source
AI summary
The present invention provides a manufacturing method for an electronic element of an electronic apparatus. The electronic element includes a substrate, a bump and at least one under bump metal (UBM) layer. The manufacturing method includes sequentially disposing the UBM layer and the bump onto the substrate; and processing an etching operation at the UBM layer to form a breach structure.