Interdigitated Capacitor Varying Digit Widths

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional interdigitated capacitors face challenges in maximizing capacitance density due to current loss issues, which are mitigated by shortening digit lengths, resulting in inefficient use of capacitor area and the need for additional electrodes outside the interdigitated structure.

Innovation Solution

The design incorporates conductive digits of varying widths, with wider digits closer to the ends and narrower ones closer to the center, allowing for increased capacitance density while minimizing current loss and electrode space consumption, and the widths can be determined based on magnetic H field distribution or current carried.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the length of the digits is increased to maximize capacitance density, then the capacitance density is improved, but the current loss increases

Engineering Contradiction:
Improvecapacitance densityVSAvoidcurrent loss
Core Design Contradiction:
Quantity of substanceVSLoss of energy

Solution Approach 1:

The patent applies local quality by varying the width of digits along their length. Digits are wider at regions where they carry more current (near the bars) and narrower where they carry less current (at the ends). This non-uniform width distribution optimizes the balance between capacitance density and current loss by concentrating conductive material where it is most needed for current carrying while maintaining long digit lengths for high capacitance density.

Inventive Principle:
Principle #3Local quality

2Loss of energy

If the length of the digits is shortened to minimize current loss, then the current loss is reduced, but the capacitance density is lowered

Engineering Contradiction:
Improvecurrent lossVSAvoidcapacitance density
Core Design Contradiction:
Loss of energyVSQuantity of substance

Solution Approach 1:

The patent changes the geometric parameters of the digits by implementing non-uniform width variation along the digit length. This parameter change allows the digits to be made longer than conventional designs while compensating for current loss through strategic width distribution, thereby achieving high capacitance density without excessive current loss.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If uniform width digits are used, then the manufacturing is simplified, but the capacitance density and current loss optimization is limited

Engineering Contradiction:
Improvedigit fabrication simplicityVSAvoidcapacitance density
Core Design Contradiction:
Ease of manufactureVSQuantity of substance

Solution Approach 1:

The patent implements local quality through non-uniform digit widths that are optimized for electrical performance. The varying width profile is designed to match the current distribution, with wider sections at high-current regions and narrower sections at low-current regions, achieving superior capacitance density and current loss characteristics compared to uniform width designs.

Inventive Principle:
Principle #3Local quality

4Device complexity

If digits of equal width are used, then the structure is symmetric and simple, but the capacitor area is not utilized efficiently

Engineering Contradiction:
Improvedigit structure simplicityVSAvoidcapacitor area utilization
Core Design Contradiction:
Device complexityVSArea of stationary object

Solution Approach 1:

The patent applies asymmetry by using digits with non-uniform widths that vary along their length. This asymmetric geometry allows more efficient packing and utilization of the capacitor area, with wider digits at the ends and narrower digits toward the center, maximizing the use of available space while maintaining the interdigitated structure.

Inventive Principle:
Principle #4Asymmetry

Data Source

PatentEP2754189B1Interdigitated capacitor having digits of varying width
Publication Date: 2020.12.16 XILINX INC
  • EP2754189B1 patent drawingFigure 1
  • EP2754189B1 patent drawingFigure 2
  • EP2754189B1 patent drawingFigure 3

AI summary

An interdigitated capacitor having digits of varying width is disclosed. One embodiment of a capacitor (100) includes a first plurality of conductive digits (110) and a second plurality of conductive digits (110) positioned in an interlocking manner with the first plurality of conductive digits (110), such that an interdigitated structure is formed. The first plurality of conductive digits (110) and the second plurality of conductive digits (110) collectively form a set of digits, where the width of a first digit in the set of digits (110) is non-uniform with respect to a second digit in the set of digits.