Phased Array RF Module Bump Layout for Signal Leakage Isolation
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Solution Overview
Problem
High-frequency modules face challenges in maintaining isolation between solder bumps and inner metal patterns due to potential signal leakage, particularly in smaller form factors handling high-frequency signals.
Innovation Solution
The implementation of GND bumps on the shortest line segment connecting RF bumps and inner metal patterns in a plan view, along with strategic placement of GND bumps between adjacent RF bumps, forms a barrier to suppress signal leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the module size is reduced by using the substrate portion overlapping with the IC package to form inner metal patterns, then the compactness of the high-frequency module is improved, but the isolation between solder bumps and inner metal patterns deteriorates due to potential signal leakage
Solution Approach 1:
A GND bump is introduced as an intermediary element between the RF bump and the inner metal pattern. This GND bump acts as a mediator that blocks the leakage path of high-frequency signals from the RF bump to the inner metal pattern, thereby maintaining isolation while enabling the compact layout where inner metal patterns overlap with the IC package in plan view.
Solution Approach 2:
The harmful effect of signal leakage is extracted and blocked by introducing a dedicated GND bump structure. The GND bump is specifically positioned on the shortest line segment connecting the RF bump and the inner metal pattern to extract and eliminate the leakage path, allowing the inner metal pattern to be placed in the overlapping region without compromising isolation.
2Reliability
If GND bumps are added to improve isolation between RF bumps and inner metal patterns, then the isolation performance is improved, but the device complexity increases due to additional bump arrangements
Solution Approach 1:
Instead of uniformly increasing isolation measures across the entire module, the GND bumps are strategically placed only at critical locations - specifically on the shortest line segments connecting RF bumps to inner metal patterns. This localized approach provides necessary isolation performance while minimizing the increase in device complexity.
Solution Approach 2:
The patent applies partial action by placing GND bumps only where absolutely necessary - on the shortest line segments between RF bumps and inner metal patterns - rather than adding GND bumps everywhere. This selective placement achieves the required isolation performance with minimal additional complexity.
Data Source
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AI summary
The present invention relates to a high-frequency module including an IC package in which a plurality of solder bumps are arranged on a plane and a substrate which has a mounting surface for mounting the IC package, wherein an inner metal pattern which is not electrically grounded is formed on the mounting surface at a portion overlapping with the IC package in a plan view, wherein the plurality of solder bumps include an RF bump through which a high-frequency signal passes and a GND bump which is electrically grounded, and wherein the GND bump is disposed on a shortest line segment connecting the RF bump and the inner metal pattern in a plan view.