Magnetic Build-Up Layers for Semiconductor Package Impedance Matching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The impedance discontinuity between semiconductor package substrates and external devices limits signaling bandwidth and computing performance due to the high capacitance and low inductance of conductive pads, restricting the communication speed between CPUs and external devices.
Innovation Solution
Incorporating magnetic build-up layers with high permeability in semiconductor package substrates to improve impedance matching by positioning them proximate conductive pads and vias, which helps to match the impedance of the semiconductor package to external wiring and devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If relatively large conductive pads are used to couple the substrate to external devices, then the coupling strength and connectivity are improved, but the impedance discontinuity increases due to high capacitance and low inductance
Solution Approach 1:
A magnetic build-up layer is introduced as an intermediary element between the conductive pad and the external device. This magnetic layer serves as a mediator that transforms the electrical characteristics of the interface, specifically increasing inductance to compensate for the capacitive nature of the large conductive pad, thereby achieving impedance matching without reducing coupling strength
Solution Approach 2:
The patent changes the electrical parameters of the interface by introducing a magnetic material with high permeability. This changes the inductance parameter of the pad structure, transforming the impedance characteristics from capacitive-dominated to inductance-balanced, enabling high-speed signaling while maintaining the large pad geometry for strong coupling
2Reliability
If the inductance of conductive pads is increased to improve impedance matching, then the signaling bandwidth is improved, but the physical size and complexity of the pad structure increases
Solution Approach 1:
The patent uses composite material structures where a magnetic material layer is combined with the conductive pad structure. This composite approach achieves the desired inductance increase through material properties rather than geometric complexity, maintaining a relatively simple pad structure while improving impedance matching
Solution Approach 2:
The magnetic build-up layer is applied locally at the pad interface where impedance matching is most critical, rather than throughout the entire substrate. This localized application achieves the necessary inductance enhancement only where needed, minimizing overall structural complexity and material usage
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 use of magnetic build-up layers enhances impedance matching, leading to improved signaling bandwidth and computing performance by reducing impedance discontinuity and increasing inductance, thereby supporting higher communication speeds between CPUs and external devices.
Implementation Method 1
Incorporating magnetic build-up layers with high permeability in semiconductor package substrates to improve impedance matching by positioning them proximate conductive pads and vias
Data Source
AI summary
The present disclosure is directed to systems and methods for improving the impedance matching of semiconductor package substrates by incorporating one or more magnetic build-up layers proximate relatively large diameter, relatively high capacitance, conductive pads formed on the lower surface of the semiconductor package substrate. The one or more magnetic layers may be formed using a magnetic build-up material deposited on the lower surface of the semiconductor package substrate. Vias conductively coupling the conductive pads to bump pads on the upper surface of the semiconductor package substrate pass through and are at least partially surrounded by the magnetic build-up material.