Multipole ion guide including FIN structure

Abstract

In some examples, a multipole ion guide may include a plurality of printed circuit boards (PCBs) that are circumferentially arranged about a central axis to form a conduit. The multipole ion guide may be formed based on utilization of plated edges of the PCBs.

Description

20240010-02 MULTIPOLE ION GUIDE INCLUDING FIN STRUCTURE CROSS-REFERENCE TO RELATED APPLICATION(S)

[0001] This application claims priority to U.S. Provisional Patent Application Serial Number 63 / 661,468, filed June 18, 2024, titled “MULTIPOLE ION GUIDE INCLUDING FIN STRUCTURE”, which is incorporated by reference in its entirety. BACKGROUND

[0002] A Quadrupole-Time-of-Flight (QTOF) mass spectrometer may generally include a quadrupole mass analyzer to select ions of desired mass-to-charge ratio and a collision cell to fragment the selected ions via collision-induced dissociation. The QTOF mass spectrometer may further include a series of ion lenses to transfer the ions downstream to a TOF mass analyzer that differentiates ions by the mass-to-charge ratio. An ion guide inside the collision cell may compress an ion beam to reduce beam diameter and kinetic energy via collisional cooling. This reduction in the beam diameter and kinetic energy may thus generate an ion beam that is well-conditioned at an exit as required by downstream optics for achieving desired resolution and sensitivity.20240010-02 BRIEF DESCRIPTION OF DRAWINGS

[0003] Features of the present disclosure are illustrated by way of example and not limited in the following figure(s), in which like numerals indicate like elements, in which:

[0004] Figure 1 illustrates side and cross-sectional views of a multipole ion guide including a fin structure (hereinafter “multipole ion guide”), where the fin structure includes printed circuit boards circumferentially arranged about an axis to form a conduit, in accordance with an example of the present disclosure;

[0005] Figure 2 illustrates side and cross-sectional views of the multipole ion guide of Figure 1, where each printed circuit board includes two shaped traces (e.g., conductive areas) isolated from each other, in accordance with an example of the present disclosure;

[0006] Figure 3 illustrates operation of the multipole ion guide of Figure 1, Illustrating one possible field distribution related to section B-B of Figure 2 where a fundamental multipole field is increasingly dominant towards an exit end, in accordance with an example of the present disclosure;

[0007] Figure 4 illustrates operation of the multipole ion guide of Figure 1, Illustrating one possible field distribution related to section A-A of Figure 2 where an auxiliary multipole field is gradually vanishing toward an exit end, in accordance with an example of the present disclosure;

[0008] Figure 5 illustrates operation of the multipole ion guide of Figure 1, where a direct current (DC) potential gradient is created along a central axis, in accordance with an example of the present disclosure;

[0009] Figure 6 illustrates a connection example of a two layer PCB with edge plating,20240010-02 in accordance with an example of the present disclosure;

[0010] Figure 7 illustrates a connection example of a three layer PCB with edge plating, in accordance with an example of the present disclosure;

[0011] Figure 8 illustrates examples of multi-field arrangements to optimize ion transport, in accordance with an example of the present disclosure;

[0012] Figure 9 illustrates a four layer PCB structure example, in accordance with an example of the present disclosure;

[0013] Figure 10 illustrates a six layer PCB structure example, in accordance with an example of the present disclosure; and

[0014] Figure 11 illustrates adding of thru cuts with an electrode, in accordance with an example of the present disclosure.20240010-02 DETAILED DESCRIPTION

[0015] For simplicity and illustrative purposes, the present disclosure is described by referring mainly to examples. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. It will be readily apparent however, that the present disclosure may be practiced without limitation to these specific details. In other instances, some methods and structures have not been described in detail so as not to unnecessarily obscure the present disclosure.

[0016] Throughout the present disclosure, the terms "a" and "an" are intended to denote at least one of a particular element. As used herein, the term "includes" means includes but not limited to, the term "including" means including but not limited to. The term "based on" means based at least in part on.

[0017] A multipole ion guide including a fin structure (hereinafter “multipole ion guide”) is disclosed herein. The multipole Ion guide may include printed circuit boards (PCBs) of two shaped traces to implement a fundamental electric multipole field superimposed by an auxiliary electric multipole field of a higher order, with the field gradually vanishing in the direction of ion propagation, and a direct current (DC) potential gradient along a central axis of the multipole Ion guide.

[0018] With respect to QTOF mass spectrometers generally, in some cases, a QTOF mass spectrometer may utilize a hexapole of tilted rods. In this regard, an inscribed diameter decreases, forming a converging conduit, along the direction of ions propagation. The rods may be coated with resistive layers to establish a DC potential gradient along the axis to advance ions. The hexapole of tilted rods may experience technical challenges in the form of a trade-off between the acceptance at the entrance20240010-02 and the focusing power at the exit due to the hexapole structure. Moreover, the resistive coating layer may limit the maximum RF voltages applied and thus the overall focusing power.

[0019] In another example, a QTOF mass spectrometer may utilize a first hexapole of converging and twisting structure which is surrounded by a second hexapole with rods staggered to the rods of the first hexapole. The rods may be coated with resistive layers to establish a DC potential gradient along the axis to advance ions. This setup may increase the acceptance at the entrance due to the combination of two sets of hexapoles operating at different frequencies, which however consequently increases the geometrical complexity and thus challenges in manufacturing and assembly. Moreover, the resistive coating layer may limit the maximum RF voltages applied and thus the overall focusing power.

[0020] Yet further, in another example, a QTOF mass spectrometer may utilize a quadrupole including a set of tapered PCBs that include a series of separate finger electrodes coupled and connected by a series of capacitors and resistors to receive radio frequency (RF) and DC voltages. This configuration may enable the application of high RF voltage to increase focusing power, but also increases the manufacturing complexity and proneness to contamination on dielectric surfaces exposed to the conduit through which ions travel.

[0021] According to an example disclosed herein, the multipole ion guide addresses at least the aforementioned technical challenges by implementing a DC potential gradient along a central axis without the need of resistive coating layers or combination of segmented passive electrical components (e.g., resistors), thus enabling the application20240010-02 of high RF voltages to increase focusing power.

[0022] According to another example, the multipole ion guide disclosed herein addresses at least the aforementioned technical challenges by implementing a DC potential gradient along a central axis without the need of resistor and capacitor chains, and the cutting at the edge of PCBs, which reduces the geometrical complexity and increases resistance to contamination.

[0023] According to another example, the multipole ion guide disclosed herein addresses at least the aforementioned technical challenges by superimposing an auxiliary multipole field of a higher order on the fundamental multipole field of a lower order for increasing acceptance at the entrance without the need of additional sets of electrodes, which reduces complexity in manufacturing and assembly.

[0024] According to a further example, the multipole ion guide disclosed herein addresses at least the aforementioned technical challenges by gradually vanishing the auxiliary multipole field of a higher order in the direction of ions propagation to increasingly promote dominance of the fundamental multipole field of a lower order for increasing the focusing power.

[0025] According to examples disclosed herein, a multipole ion guide may include a plurality of printed circuit boards (PCBs) that are circumferentially arranged about a central axis to form a conduit. The multipole ion guide may be formed based on utilization of plated edges of the PCBs. According to examples disclosed herein, each PCB of the plurality of PCBs may include a tapered portion that is tapered towards an exit end of the PCB, and the exit end may include a smaller exit opening diameter compared to an entrance opening diameter of an entrance end of the PCB. According to examples20240010-02 disclosed herein, each PCB of the plurality of PCBs may include at least two conductive areas that are isolated from each other. In this regard, each conductive area of the at least two conductive areas may include a conductive foil on a surface of the PCB. According to examples disclosed herein, the at least two conductive areas may be isolated by a nonlinear isolation band. According to examples disclosed herein, at least one PCB of the plurality of PCBs may include a first area that is configured to receive voltage through a connector attached adjacent to an edge of the first area, and a second area that is configured to receive voltage through another connector that is electrically connected to the second area by a narrow trace that extends towards the edge of the first area. According to examples disclosed herein, at least one PCB of the plurality of PCBs may include a first area that is configured to receive voltage through a connector attached adjacent to an edge of the first area, and a second area that is configured to receive voltage through another connector that is electrically connected to the second area by an interior layer of the PCB. According to examples disclosed herein, at least one PCB of the plurality of PCBs may include a first area that is configured to receive voltage through a connector attached adjacent to an edge of the first area, and a second area that is configured to receive voltage through another connector that is electrically connected to the second area by at least one internal via. According to examples disclosed herein, at least one PCB of the plurality of PCBs may include at least four conductive layers. According to examples disclosed herein, at least one PCB of the plurality of PCBs may include at least one thru cut.

[0026] According to examples disclosed herein, a multipole ion guide may include a plurality of tapered PCBs that are circumferentially arranged about a central axis to form20240010-02 a conduit. According to examples disclosed herein, each PCB of the plurality of tapered PCBs may include a tapered portion that is tapered towards an exit end of the PCB, and the exit end may include a smaller exit opening area compared to an entrance opening area of an entrance end of the PCB.

[0027] According to examples disclosed herein, a multipole ion guide may include a plurality of PCBs that are arranged about a central axis to form a conduit. According to examples disclosed herein, each PCB of the plurality of PCBs may include a tapered portion that is tapered towards an exit end of the PCB, and the exit end may include a smaller exit opening area compared to an entrance opening area of an entrance end of the PCB.

[0028] Figure 1 illustrates side and cross-sectional views of a multipole ion guide including a fin structure (hereinafter “multipole ion guide 100”), where the fin structure includes PCBs circumferentially arranged about a central axis to form a conduit, in accordance with an example of the present disclosure.

[0029] Referring to Figure 1, the multipole ion guide 100 may include four PCBs 102A- 102D circumferentially arranged about a central axis 104 to form a conduit. Each PCB may be tapered in the axial dimension, forming a larger inscribed diameter at an entrance end 106 and a smaller inscribed diameter at an exit end 108. In the example of Figure 1, taper angle 110 may be approximately 15°, and include, for example, a range of -45° to 45° relative to the central axis 104. The multipole ion guide 100 may be formed based on utilization of plated edges of the PCBs, examples of which are shown at 112. In this regard, the plating of the edges may refer to metallization of the edges of the PCBs. For example, the PCBs may include edge plating between top and bottom copper cladding20240010-02 along the peripheral edge or combination of connections to connect multiple copper cladded (e.g., foiled) edges on a PCB edge. The orthogonal, edge plated PCB in one example may include a linear, curved or shaped profile normally considered the PCB thickness between the copper cladded (foiled) edges.

[0030] Figure 2 illustrates side and cross-sectional views of the multipole ion guide of Figure 1, where each printed circuit board includes two shaped traces (e.g., conductive areas) isolated from each other, in accordance with an example of the present disclosure.

[0031] Referring to Figures 1 and 2, each PCB comprises two shaped traces (e.g., conductive areas) isolated from each other. In the example shown, eight traces are labeled as A1, A2, A3, A4, B1, B2, B3, and B4. The center of the PCBs 102A-102D may include dielectric material. Moreover, the areas 200 between the traces A1, A2, A3, A4, B1, B2, B3, and B4 may be formed of the dielectric material, or another type of material to isolate the traces from each other. Each shaped trace (e.g., conductive area) may include a conductive foil, examples of which are shown at 202, on a surface of the PCB. For example, the conductive foil may represent a conductive layer, formed, for example, of copper or other such materials, on the surface of PCB. In one example, the PCB may include four copper cladded, foiled areas, two on each side of the thickness of the PCB top and bottom layers connected by edge plating and / or connection via's thru the thickness of the PCB. In another example of the PCB, low dissipation PCB materials may be utilized to protect the structural performance from high field RF heating. In one specific example, Rogers 3000 and / or 4000, specifically 4003C, 4350B or 4850B, may be utilized as a base PCB material prior to trace etching and edge plating the thickness of the PCB for ion transportation guidance. Yet further, in one example, the PCB materials may20240010-02 include materials with a low to ultra low loss factor in a frequency range from 7 to 9 MHz. The low loss, ultra low loss, or dissipation factor ranges may be less than 0.004 to protect from RF heating of the PCB dielectric enveloped by a copper foil. Moreover, in another example, all PCBs may be disposed in a vacuum environment were minimal RF heating can be tolerated to maintain functionality of the multi field emanating PCB structure.

[0032] Figure 3 illustrates operation of the multipole ion guide of Figure 1, Illustrating one possible field distribution related to section B-B of Figure 2 where a fundamental multipole field is increasingly dominant towards an exit end, in accordance with an example of the present disclosure.

[0033] Referring to Figures 1 and 3, traces A1 and A3 are illustrated as receiving a first AC voltage labeled as rf1+, whereas traces A2 and A4 are illustrated as receiving the same AC voltage of the opposite phase labeled as rf1-. As a result, as shown at 300, a quadrupole field on the cross-sectional plane orthogonal to axis 104 is created as the fundamental multipole field inside the conduit. In this regard, due to the shapes of traces A1 – A4, the fundamental multipole field is increasingly dominant toward the exit end 108.

[0034] Figure 4 illustrates operation of the multipole ion guide of Figure 1, Illustrating one possible field distribution related to section A-A of Figure 2 where an auxiliary multipole field is gradually vanishing toward an exit end, in accordance with an example of the present disclosure.

[0035] Referring to Figures 1 and 4, traces B1, B2, B3 and B4 are illustrated as receiving a second AC voltage of the same phase, labeled as rf2. As a result, as shown at 400, an octopole field on the cross-sectional plane is created as the auxiliary multipole field superimposed on the fundamental multipole field. Due to the shapes of the traces,20240010-02 the auxiliary multipole field gradually vanishes towards the exit end 108.

[0036] Figure 5 illustrates operation of the multipole ion guide of Figure 1, where a direct current (DC) potential gradient is created along a central axis, in accordance with an example of the present disclosure.

[0037] Referring to Figures 1 and 5, traces A1, A2, A3, and A4 are illustrated as receiving a first DC voltage labeled as V1, whereas traces B1, B2, B3, and B4 are illustrated as receiving a second DC voltage labeled as V2. As a result, as shown at 500, a DC potential gradient is created along the central axis 104. For example, the potential at trace A3 at the entrance and at trace A3 at the exit is at V1. Whereas, the potential at trace B3 at the entrance and at trace B3 at the exit is at V2.

[0038] For the example of Figure 5, at least a portion of the dielectric material in the isolation region of each PCB may be removed to reduce heat dissipation.

[0039] For the examples of Figures 1-5, the number of PCBs may be greater than four to create multipole fields of higher orders than quadrupole as the fundamental multipole field, e.g., hexapole, octopole, etc. Correspondingly, in this case, the order of auxiliary multipole field would be twice that of the fundamental multipole field.

[0040] Figure 6 illustrates a connection example of a two layer PCB with edge plating, in accordance with an example of the present disclosure.

[0041] Referring to Figures 1 and 6, Figure 6 illustrates a connection example of a two layer PCB 600 with edge plating. In mid-range MHz application of connections, the secondary field has maximum field penetration by maximizing the surface area-B and minimizing the connection trace to edge plated area-A.20240010-02

[0042] In the example of Figure 6, voltage may be applied on the top of the PCB. The upper area (e.g., surface area-B) may receive voltages though a connector 602 that is attached to the PCB 600. The lower area (e.g., edge plated area-A) may receive voltages through a narrow trace 604 extended to the top of the PCB 600 with a connector 606 that is attached to the PCB 600. The implementation of the connectors 602 and 604 allows for different voltages to be applied to the respective traces (e.g., surface area-B versus edge plated area-A). Dielectric material may be utilized as shown at 608 and 610. In another implementation, low RF loss dielectric material may be utilized.

[0043] With continued reference to Figure 6, at the connector side edge, either edge plating or thru via plated holes may be utilized to connect both A and B sides to each other. For example, area-A opposite the connector 606 may be edge plated to connect each side and considered as the surface to transport ions.

[0044] Figure 7 illustrates a connection example of a three layer PCB with edge plating, in accordance with an example of the present disclosure.

[0045] Referring to Figures 1 and 7, Figure 7 illustrates a connection example of a three layer PCB 700 with edge plating. In mid-range MHz application of connections, the secondary field (e.g., surface area-B) has maximum field penetration by maximizing the surface area-B and minimizing the connection trace to edge plated area-A through internal connections (e.g., center layer of PCB). This results in maximum field penetration design opportunities.

[0046] In the example of Figure 7, voltage may be applied on the top of the PCB 700. The upper area (e.g., surface area-B) receives voltages though a connector 702 that is attached to the PCB 700. The lower area (e.g., edge plated area-A) may receive voltages20240010-02 by connecting to an interior layer 704 through buried vias 706 and 708, which extend to the top of the PCB 700 with a connector 710 that is attached to the PCB 700. Dielectric material may be utilized as shown at 712, 714, 716, and 718. The examples at 720, 722, and 724 show three variants of the cross-section A-A.

[0047] For the example of Figure 7, all parts shown may be used in a quadrupole (e.g., 4), hexapole (e.g., 6) or multi-pole arrangement.

[0048] Figure 8 illustrates examples of multi-field arrangements to optimize ion transport, in accordance with an example of the present disclosure.

[0049] Referring to Figure 8, possible multi-field arrangements to optimize ion transport are illustrated, where Aiis edge plated and used for ion transport, whereas areas Biand Cimay be used to manipulate ion motion. In the example of Figure 8, the surface areas may be symmetric in 2-layer, 3-layer and / or multilayer PCB arrangements. In the example of Figure 8, the number of electrically isolated areas may be greater than two. Moreover, the isolation band(s) that separate different areas may be of any shape.

[0050] In Figure 8, the setup at 800 shows a scheme in which area-B is closer to the bottom edge at the side of the entrance at 808. The setup at 802 shows a scheme in which area-B is closer to the bottom edge at the side of the exit at 810. The setup at 804 shows a scheme in which the shape of isolation band 812 is nonlinear. The setup at 806 shows a scheme in which there are three electrically isolated areas. For each of the isolated areas, different types of signals may be applied to the isolated areas.

[0051] Figure 9 illustrates a four layer PCB structure example, in accordance with an example of the present disclosure.20240010-02

[0052] Referring to Figure 9, a four layer PCB structure example is shown at 900, and includes a shaping field that includes various directions, including a longitudinal direction. The PCB layers are shown at 902, 904, 906, and 908. The four layer PCB and electrode field arrangement allows for optimum shaping of an orthogonal field. Further, the four layer PCB with a shaped cross-section provides for optimization of the electric field. The curved shape at 910 marks an envelop of the PCB corners at the bottom in the orientation of Figure 9. The cross sections illustrate the three-dimensional field implementation using a four-layer printed circuit board topology. Further, the illustrations show an internal or bridged trace connection to Airegions. For the four layer PCB structure shown in Figure 9, the ion guiding edge plated edge may be connected through a copper clad trace internal to the four layer PCB structure with variations to bridge the connection trace with dielectric or use a gap between the copper clad planes. For example, Variation 1 of section C-C includes vias at 912 and dielectric material at 914, whereas Variation 2 does not include any vias or dielectric material in the corresponding regions. Alternatively, the Bi bridge may be made with an additional copper piece (not shown).

[0053] Figure 10 illustrates a six layer PCB structure example, in accordance with an example of the present disclosure.

[0054] Referring to Figure 10, a six layer PCB structure example is shown at 1000, and includes a shaping field that includes various directions, including a longitudinal direction. The PCB layers are shown at 1002, 1004, 1006, 1008, 1010, and 1012. The six layer PCB and electrode field arrangement allows for optimum shaping of an orthogonal field. Further, the six layer PCB with a shaped cross-section provides for optimization of the electric field. The six layer symmetric arrangement may operate with20240010-02 matched pair electrode shapes. For example, the six layer PCB may create three shaped electrode pairs where at least one pair is edge plated along the thickness, periphery of the PCB. In Figure 10, the plated edge may be across the central electrode pair. The six layer PCB stepped edges may be shaped symmetrical to create an emanating complex field in a one body structure.

[0055] Figure 11 illustrates adding of thru cuts with an electrode, in accordance with an example of the present disclosure.

[0056] Referring to Figure 11, thru cuts may be added with an electrode (e.g., copper clad of a PCB) and a dielectric PCB structure as shown at 1100. The thru cuts provide for connection of differential RF and DC fields in mid MHz RF. In one example, the RF range is from 7 MHz to 9 MHz. For the example shown, center dielectric connection “C” at 1102 may be omitted or function as a stabilizer in relatively long length ion guides. The thru cuts may further minimize dielectric heating of PCBs.

[0057] What has been described and illustrated herein is an example along with some of its variations. The terms, descriptions and figures used herein are set forth by way of illustration only and are not meant as limitations. Many variations are possible within the spirit and scope of the subject matter, which is intended to be defined by the following claims -- and their equivalents -- in which all terms are meant in their broadest reasonable sense unless otherwise indicated.

Claims

20240010-02 What is claimed is:

1. A multipole ion guide comprising: a plurality of printed circuit boards (PCBs) that are circumferentially arranged about a central axis to form a conduit, wherein the multipole ion guide is formed based on utilization of plated edges of the PCBs.

2. The multipole ion guide according to claim 1, wherein each PCB of the plurality of PCBs includes a tapered portion that is tapered towards an exit end of the PCB, and wherein the exit end includes a smaller exit opening diameter compared to an entrance opening diameter of an entrance end of the PCB.

3. The multipole ion guide according to claim 1, wherein each PCB of the plurality of PCBs includes at least two conductive areas that are isolated from each other, and wherein each conductive area of the at least two conductive areas includes a conductive foil on a surface of the PCB.

4. The multipole ion guide according to claim 3, wherein the at least two conductive areas are isolated by a nonlinear isolation band.20240010-02 5. The multipole ion guide according to claim 1, wherein at least one PCB of the plurality of PCBs includes a first area that is configured to receive voltage through a connector attached adjacent to an edge of the first area, and a second area that is configured to receive voltage through another connector that is electrically connected to the second area by a narrow trace that extends towards the edge of the first area.

6. The multipole ion guide according to claim 1, wherein at least one PCB of the plurality of PCBs includes a first area that is configured to receive voltage through a connector attached adjacent to an edge of the first area, and a second area that is configured to receive voltage through another connector that is electrically connected to the second area by an interior layer of the PCB.

7. The multipole ion guide according to claim 1, wherein at least one PCB of the plurality of PCBs includes a first area that is configured to receive voltage through a connector attached adjacent to an edge of the first area, and a second area that is configured to receive voltage through another connector that is electrically connected to the second area by at least one internal via.

8. The multipole ion guide according to claim 1, wherein at least one PCB of the plurality of PCBs includes at least four conductive layers.

9. The multipole ion guide according to claim 1, wherein at least one PCB of the20240010-02 plurality of PCBs includes at least one thru cut.

10. A multipole ion guide comprising: a plurality of tapered printed circuit boards (PCBs) that are circumferentially arranged about a central axis to form a conduit, wherein the multipole ion guide is formed based on utilization of plated edges of the PCBs.

11. The multipole ion guide according to claim 10, wherein each PCB of the plurality of tapered PCBs includes a tapered portion that is tapered towards an exit end of the PCB, and wherein the exit end includes a smaller exit opening area compared to an entrance opening area of an entrance end of the PCB.

12. A multipole ion guide comprising: a plurality of printed circuit boards (PCBs) that are arranged about a central axis to form a conduit.

13. The multipole ion guide according to claim 12, wherein each PCB of the plurality of PCBs includes a tapered portion that is tapered towards an exit end of the PCB, and wherein the exit end includes a smaller exit opening area compared to an entrance opening area of an entrance end of the PCB.20240010-02 14. The multipole ion guide according to claim 12, wherein each PCB of the plurality of PCBs includes at least two conductive areas that are isolated from each other, and wherein each conductive area of the at least two conductive areas includes a conductive foil on a surface of the PCB.

15. The multipole ion guide according to claim 14, wherein the at least two conductive areas are isolated by a nonlinear isolation band.

16. The multipole ion guide according to claim 12, wherein at least one PCB of the plurality of PCBs includes a first area that is configured to receive voltage through a connector attached adjacent to an edge of the first area, and a second area that is configured to receive voltage through another connector that is electrically connected to the second area by a narrow trace that extends towards the edge of the first area.

17. The multipole ion guide according to claim 12, wherein at least one PCB of the plurality of PCBs includes a first area that is configured to receive voltage through a connector attached adjacent to an edge of the first area, and a second area that is configured to receive voltage through another connector that is electrically connected to the second area by an interior layer of the PCB.

18. The multipole ion guide according to claim 12, wherein at least one PCB of the20240010-02 plurality of PCBs includes a first area that is configured to receive voltage through a connector attached adjacent to an edge of the first area, and a second area that is configured to receive voltage through another connector that is electrically connected to the second area by at least one internal via.

19. The multipole ion guide according to claim 12, wherein at least one PCB of the plurality of PCBs includes at least four conductive layers.

20. The multipole ion guide according to claim 12, wherein at least one PCB of the plurality of PCBs includes at least one thru cut.

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