PCB Ion Guide Electrode Layout for Polarity-Independent Containment

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Solution Overview

Problem

Conventional PCB ion guides trap ions of only a single polarity, requiring additional RF electrodes and complex electronics, complicating design and manufacture.

Innovation Solution

An ion guide configuration with opposing electrodes on two surfaces, where first and third electrodes receive the same phase RF voltages, and second and fourth electrodes receive phase-shifted RF voltages, generating polarity-independent containment electric fields along multiple axes using the same electrodes and electronic drive circuitry.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If additional RF electrodes are added to achieve polarity-independent trapping, then ion containment capability is improved, but device complexity increases

Engineering Contradiction:
Improvepolarity-independent trappingVSAvoiddevice complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies universality by enabling the same RF electrodes to perform multiple functions: they provide both vertical confinement (through capacitive coupling between opposing PCBs) and horizontal confinement (through edge portions extending beyond the ion path). This multi-functionality eliminates the need for separate electrode types for different polarity handling, achieving polarity-independent trapping without increasing device complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the functions of vertical and horizontal confinement into a single electrode structure. The edge portions of the electrodes extend beyond the ion path to provide horizontal confinement, while the same electrodes provide vertical confinement through capacitive coupling. This merging eliminates the need for additional dedicated electrodes, resolving the contradiction between versatility and complexity

Inventive Principle:
Principle #5Merging (Combining)

2Adaptability or versatility

If additional driving electronics are added to control multiple RF electrodes, then ion containment capability is improved, but device complexity increases

Engineering Contradiction:
Improvepolarity-independent trappingVSAvoidelectronic complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies universality by using a single RF voltage source to drive all electrodes, with the same voltage applied to both vertical and horizontal confinement electrodes. This universal driving approach eliminates the need for multiple independent RF sources and complex phase control electronics, achieving polarity-independent trapping while minimizing electronic complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the electrical driving requirements into a single unified system. All electrodes are driven by the same RF voltage source, combining what would traditionally require separate electronic control systems into one simple electronic architecture, thus resolving the contradiction between versatility and electronic complexity

Inventive Principle:
Principle #5Merging (Combining)

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

Simplifies construction and operation by using the same RF voltages for both horizontal and vertical ion containment, allowing for polarity-independent trapping and reducing complexity.

Implementation Method 1

Ion guides are devices that guide ions along an ion path by application of electrostatic and electrodynamic fields

Methodology Applied
Scientific EffectElectric Field: Electric Field

Implementation Method 2

to maintain ions within the ion path, some PCB ion guides apply a radio frequency (RF) voltage to inner RF electrodes to provide a trapping potential in a Y (vertical) direction

Methodology Applied
Scientific EffectRadio frequency trapping:

Data Source

PatentEP4312247B1Ion guide electrode configurations for polarity-independent ion containment
Publication Date: 2025.10.15 THERMO FINNIGAN LLC
  • EP4312247B1 patent drawingFigure 1
  • EP4312247B1 patent drawingFigure 2
  • EP4312247B1 patent drawingFigure 3A~3B

AI summary

An ion guide includes a first arrangement of electrodes on a first surface, a second arrangement of electrodes on a second surface, and an ion containment space in a gap therebetween. The first arrangement includes first electrodes and second electrodes. Each first electrode includes a first main portion and a first edge portion. The first edge portion is wider than the first main portion. The second arrangement includes third electrodes and fourth electrodes. Each fourth electrode includes a fourth main portion and a fourth edge portion. The fourth edge portion is wider than the fourth main portion. The first edge portions are positioned opposite the fourth edge portions. The first electrodes and the third electrodes are configured to receive first RF voltages and the second electrodes and the fourth electrodes are configured to receive second RF voltages that are phase-shifted with respect to the first RF voltages.