RDL Isolation Structure for High-Frequency Insertion Loss
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Solution Overview
Problem
The capacitive coupling between ground and high-frequency signal routing layers in semiconductor integrated circuits leads to significant insertion loss, complicating the manufacturing and performance of ICs.
Innovation Solution
Incorporating an isolation region between signal and ground redistribution layers, along with support structures in the isolation and signal regions, reduces capacitive coupling and process variation, thereby improving insertion loss at high frequencies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If ground and high-frequency signal routing layers are placed close together to increase functional density, then production efficiency and cost are improved, but capacitive coupling increases causing significant insertion loss
Solution Approach 1:
A polymer material layer is introduced as an intermediary substance between the ground routing layer and the high-frequency signal routing layer. This polymer layer acts as a dielectric barrier that reduces capacitive coupling while maintaining the close proximity of layers for high functional density. The polymer material specifically targets and mitigates the harmful capacitive effect without requiring increased spacing between layers.
2Productivity
If geometry size is decreased to increase functional density, then production efficiency is improved, but manufacturing complexity increases
Solution Approach 1:
The patent changes the material parameter of the layer between signal and ground routing from traditional materials to a specific polymer material. This parameter change reduces capacitive coupling inherently, allowing smaller geometry sizes to be implemented without proportionally increasing manufacturing complexity. The polymer material's properties enable effective capacitive coupling reduction even at reduced feature sizes.
3Loss of energy
If isolation region is added between signal and ground regions to reduce capacitive coupling, then insertion loss is reduced, but device complexity increases
Solution Approach 1:
The patent merges the isolation region function with the polymer material layer that already exists between signal and ground routing layers. Instead of adding a separate isolation structure, the polymer material is configured to serve both as the dielectric layer and as the isolation mechanism. This integration reduces structural complexity while achieving effective capacitive coupling reduction and insertion loss mitigation.
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 minimizes capacitive coupling and reduces insertion loss, enhancing the performance and manufacturing efficiency of semiconductor integrated circuits.
Implementation Method 1
The capacitive coupling between ground and high-frequency signal routing layers in semiconductor integrated circuits leads to significant insertion loss
Data Source
AI summary
A device includes a semiconductor chip and a redistribution layer (RDL) structure connected to the semiconductor chip. The redistribution layer structure comprises a first region including: a first bump connected to the semiconductor chip; a second bump; and a plurality of first redistribution layers connected between the first bump and the second bump. The RDL structure includes a second region laterally surrounding the first region, the second region including a plurality of second redistribution layers. The RDL structure includes an isolation region laterally separating the plurality of first redistribution layers from the plurality of second redistribution layer. The isolation region includes at least one region that is straight, continuous, extends from an upper surface of the redistribution layer structure to a lower surface of the first redistribution layer structure, and has at least a selected width.