Semiconductor Bump Allocation for RF Signal Shielding
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Solution Overview
Problem
High-frequency semiconductor wafer probing faces significant signal interference due to the close proximity of probe pins and conductors, which is not adequately addressed by existing shielding methods, particularly in RF environments.
Innovation Solution
A modified bump pattern is introduced where at least three ground bumps are arranged around signal bumps to provide a shielding effect similar to a coaxial transmission line, reducing interference by modifying the initial bump pattern and ensuring close proximity of ground bumps to signal bumps, thereby enhancing the shielding effect.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If probe pins and conductors are placed in close proximity for high-density probing, then probing density and productivity are improved, but signal interference and reliability deteriorate
Solution Approach 1:
Ground bumps are introduced as intermediary elements positioned between signal bumps to act as shields. These ground bumps serve as mediators that block electromagnetic interference between adjacent signal bumps, enabling high-density probing while maintaining signal integrity. The ground bumps are configured at specific positions relative to signal bumps to provide optimal shielding without increasing overall probe card complexity.
Solution Approach 2:
The bump pattern is designed with local variations in bump types and positions. Specifically, ground bumps are strategically placed in certain local regions between signal bumps to provide shielding where interference is most severe, while maintaining signal transmission in other areas. This localized approach to quality control allows selective shielding without compromising overall probing performance.
2Object-affected harmful factors
If ground bumps are added around signal bumps for shielding, then signal interference is reduced, but device complexity and manufacturing cost increase
Solution Approach 1:
Rather than implementing complete shielding around all signal bumps, the invention applies partial shielding only where most needed. Ground bumps are positioned selectively between adjacent signal bumps that are most susceptible to interference, providing sufficient shielding protection without the excessive complexity of complete surrounding shields. This partial action approach achieves adequate interference reduction with minimal added complexity.
3Ease of manufacture
If traditional bump patterns are used without modification, then manufacturing is simpler, but high-frequency probing reliability deteriorates due to interference
Solution Approach 1:
The ground bumps are pre-configured in the bump pattern design before the actual probing operation. By establishing the shielding structure in advance during wafer fabrication, the interference protection is built into the device architecture itself. This preliminary arrangement of ground bumps ensures that when high-frequency probing occurs, the shielding is already in place, maintaining reliability without complicating the manufacturing process.
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 configuration effectively shields signal bumps from interference, allowing for high-speed and high-frequency probing without the need for specialized probe pins or cards, while also achieving impedance control, thus enabling efficient and cost-effective semiconductor device testing.
Implementation Method 1
at least three ground bumps are arranged around signal bumps to provide a shielding effect similar to a coaxial transmission line
Data Source
AI summary
A semiconductor device includes a substrate and a bump pattern of a plurality of bumps on the substrate. The bump pattern includes a plurality of rows and a plurality of columns. Bumps of the plurality of bumps include one or more radio frequency (RF) signal bumps for transmission of RF signals during operation or probing of the semiconductor device. Each RF signal bump of the one or more RF signal bumps is surrounded by at least three neighboring bumps immediately adjacent the RF signal bump. Each neighboring bump is selected from the group consisting of (i) a ground bump configured to receive a ground voltage during the operation or probing of the semiconductor device, and (ii) another RF signal bump which defines, together with said RF signal bump, a pair of differential signal bumps for transmission of differential RF signals during the operation or probing of the semiconductor device.