Pi Power Filtering Structure for IC Package Noise Isolation
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Solution Overview
Problem
Conventional power distribution networks in integrated circuits face challenges in efficiently isolating self-induced noise between adjacent circuit blocks, leading to complex designs and increased costs due to the need for multiple power distribution networks.
Innovation Solution
A power filter circuit, or π power filtering structure, is introduced, which includes a first power isolation circuit with one inductance for the die connector and a second power isolation circuit with another inductance for the PCB connector, connected by a power plane, along with a de-coupling capacitor, to form a cost-effective noise isolation and filtering solution without requiring material changes or etching of power and ground planes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If multiple power distribution networks are used to isolate self-induced noise between adjacent circuit blocks, then noise isolation is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
A ground isolation circuit is introduced as an intermediary element between adjacent power distribution networks. This ground isolation circuit includes a via structure that connects ground regions, effectively isolating the power distributions between circuit blocks without requiring multiple separate PDNs. The via structure acts as a mediator that provides ground reference while preventing noise coupling.
Solution Approach 2:
The ground isolation circuit serves multiple functions simultaneously: it provides ground reference for adjacent circuit blocks, isolates noise between power distribution networks, and maintains electrical continuity where needed. This multi-functional approach eliminates the need for separate isolation structures and reduces overall system complexity.
2Object-affected harmful factors
If multiple power distribution networks are used for each circuit block, then noise isolation is improved, but manufacturing cost increases
Solution Approach 1:
Multiple ground regions that were previously separated are merged through the ground isolation circuit's via structure. This merging approach allows a single unified ground system to serve multiple circuit blocks while maintaining noise isolation, thereby reducing the total component count and manufacturing cost compared to implementing separate PDNs for each block.
3Ease of manufacture
If conventional PDN design is used without additional filtering structures, then manufacturing simplicity is maintained, but noise filtering capability is insufficient
Solution Approach 1:
The existing ground via structures in the PDN are made to serve dual purposes: their original function of providing ground reference and an additional function of noise filtering through the ground isolation circuit. By optimizing the impedance characteristics of these existing vias, the system achieves noise filtering without adding separate filtering components, maintaining manufacturing simplicity.
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 π power filtering structure effectively reduces power supply noise cross-coupling, simplifies PCB PDN design, and decreases the bill of materials cost by merging power domains and reducing the number of independent supply rails, while maintaining signal integrity.
Implementation Method 1
A first power isolation circuit, having a first inductance, is configured to isolate power provided to a die connector for provision to an integrated circuit die. A second power isolation circuit, having a second inductance, is configured to isolate power provided to a printed circuit board (PCB) connector for provision to a PCB.
Implementation Method 2
A de-coupling capacitor can be provided as a surface-mount capacitor, or as an embedded capacitor in a core layer of an integrated circuit package.
Data Source
AI summary
A power filter circuit is provided for use in a package substrate for integrated circuits. A first power isolation circuit, having a first inductance, is configured to isolate power provided to one or more die connectors for provision to an integrated circuit die. A second power isolation circuit, having a second inductance, is configured to isolate power provided to one or more printed circuit board (PCB) connectors for provision to a PCB. A power plane electrically connects a first end of the first power isolation circuit to a first end of the second power isolation circuit, forming a “π” power filtering structure in some embodiments. A de-coupling capacitor can be provided as a surface-mount capacitor, or as an embedded capacitor in a core layer of an integrated circuit package.