Segmented Conductive Layer Vents for Interconnect Void Reduction
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Solution Overview
Problem
Interconnect voids between semiconductor die bumps and interconnect sites on substrates reduce reliability and cause manufacturing defects, necessitating a solution to enhance interconnect reliability.
Innovation Solution
A method involving the formation of a conductive layer with segmented structures and vents over a substrate to channel bump material, reducing voids and increasing contact area between bumps and interconnect sites.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a continuous conductive layer is used to connect bumps to interconnect sites, then electrical connectivity is achieved, but interconnect voids form reducing reliability
Solution Approach 1:
The conductive layer is divided into multiple discrete segments rather than forming a continuous structure. These segmented conductive regions are positioned to make contact with the bump, and the segmentation allows bump material to flow into the spaces between segments during reflow, eliminating voids while maintaining electrical connectivity.
Solution Approach 2:
The segmented conductive layer structure creates a porous-like configuration with gaps between conductive segments. This allows the bump material to penetrate and fill the interconnect region during reflow, ensuring complete wetting and eliminating voids that would otherwise form in a continuous conductive layer.
2Reliability
If the conductive layer contact area is increased to improve electrical connection, then connectivity improves, but bump material distribution becomes uneven causing voids
Solution Approach 1:
The conductive layer is segmented into multiple discrete regions distributed across the bump contact area. This segmentation allows bump material to flow uniformly into the spaces between segments during reflow, achieving even material distribution while maintaining adequate total contact area for electrical connectivity.
Solution Approach 2:
The conductive layer segments are arranged in a distributed pattern across the contact area, utilizing spatial distribution in multiple dimensions. This dimensional arrangement ensures uniform bump material flow and distribution while maintaining sufficient total conductive contact area for reliable electrical connection.
3Reliability
If vents are added to channel bump material to reduce voids, then void formation decreases, but device structure becomes more complex
Solution Approach 1:
The conductive layer is segmented into multiple discrete regions, and these segments themselves serve as the venting structure. The gaps between segments function as channels for bump material flow, eliminating the need for separate vent features and reducing overall structural complexity while effectively reducing void formation.
Solution Approach 2:
The segmented conductive layer structure serves multiple functions simultaneously: it provides electrical connectivity through the conductive segments, creates venting channels through the gaps between segments, and enables uniform bump material distribution. This multi-functionality reduces the need for additional separate structures, thereby reducing device complexity.
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 effectively reduces interconnect voids, enhances joint reliability, and improves the manufacturing process by ensuring better electrical connections between semiconductor die and substrates.
Implementation Method 1
forming a conductive layer including a first segment and second segment separated by a vent over the substrate... channel bump material
Data Source
AI summary
A semiconductor device has a semiconductor die with a plurality of bumps formed over a surface of the semiconductor die. A first conductive layer having first and second segments is formed over a surface of the substrate with a first vent separating an end of the first segment and the second segment and a second vent separating an end of the second segment and the first segment. A second conductive layer is formed over the surface of the substrate to electrically connect the first segment and second segment. The thickness of the second conductive layer can be less than a thickness of the first conductive layer to form the first vent and second vent. The semiconductor die is mounted to the substrate with the bumps aligned to the first segment and second segment. Bump material from reflow of the bumps is channeled into the first vent and second vent.