TSV Chip Stack Metal Structure for Bonding Warpage Control
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Solution Overview
Problem
The challenge in the semiconductor industry is the warpage of semiconductor chips during bonding processes, particularly when using Through Silicon Via (TSV) technology, due to concentrated forces and temperature increases, which can lead to mechanical stress and potential electrical disconnections or damage.
Innovation Solution
A semiconductor device design that incorporates a warpage prevention metal structure on the surface of the semiconductor chips, electrically insulated from the semiconductor devices, to mitigate thermal expansion and reduce warpage by strategically positioning metal structures with higher thermal expansion coefficients to counteract stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple semiconductor chips are bonded together using TSV technology, then high bandwidth and high capacity are achieved, but warpage occurs due to concentrated forces and temperature increase
Solution Approach 1:
The patent introduces a warpage prevention metal structure with specific physical parameters (material composition, thickness, area) designed to counteract thermal expansion effects. By carefully selecting the metal structure's parameters to differ from the semiconductor chip parameters, the system compensates for warpage caused by temperature changes during bonding operations.
Solution Approach 2:
The patent combines the semiconductor chip with a warpage prevention metal structure to form a composite structure. This composite design leverages the different thermal expansion properties of metal and semiconductor materials to neutralize warpage effects while maintaining the high bandwidth and capacity benefits of TSV technology.
2Strength
If bonding process temperature is increased, then bonding strength is improved, but warpage occurs due to thermal expansion
Solution Approach 1:
The patent explicitly utilizes thermal expansion principles by incorporating a warpage prevention metal structure that expands or contracts in response to temperature changes. This metal structure is designed to counterbalance the thermal expansion of the semiconductor chip, allowing high-temperature bonding processes to proceed while preventing warpage.
Solution Approach 2:
The warpage prevention metal structure acts as a counterweight to the thermal expansion forces acting on the semiconductor chip. By positioning and dimensioning the metal structure appropriately, it provides an opposing force that balances the warpage-inducing thermal expansion, enabling strong bonding without deformation.
3Reliability
If forces are concentrated on TSV, conductive pads, and micro bumps during bonding, then electrical connection is achieved, but the chip bends under concentrated stress
Solution Approach 1:
The patent introduces a separate warpage prevention metal structure that is distinct from the TSV, conductive pads, and micro bumps. This segmentation allows the bonding forces to remain concentrated on the electrical connection elements while the metal structure independently handles the mechanical stress, preventing chip bending.
Solution Approach 2:
The warpage prevention metal structure serves as an intermediary element that mediates between the bonding forces and the semiconductor chip. It absorbs and distributes the concentrated stresses during bonding, protecting the chip from bending while allowing the TSV and conductive pads to maintain their electrical connection 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
The solution effectively reduces the occurrence of warpage, enhancing the reliability and stability of semiconductor devices by managing thermal stress and maintaining electrical connections, thus improving the overall performance and longevity of the semiconductor package.
Implementation Method 1
mitigate thermal expansion and reduce warpage by strategically positioning metal structures with higher thermal expansion coefficients to counteract stress
Data Source
AI summary
A semiconductor device includes a first semiconductor chip having a first through silicon via (TSV). A second semiconductor chip is arranged on the first semiconductor chip and includes a second TSV positioned on a same vertical line as the first TSV. A conductive pad is disposed on each of the first TSV and the second TSV. The conductive pad electrically connects the first semiconductor chip and the second semiconductor chip to each other. A warpage prevention metal structure is disposed on an upper surface of the first semiconductor chip or an upper surface of the second semiconductor chip.