KR20240121767A - Radio frequency and millimeter wave circuits and their manufacturing methods - Google Patents

Abstract

The present invention relates to methods for forming MmWave RF (MMW) circuits in multilayer additively manufactured electronic devices (AMEs). In particular, the present invention relates to methods for direct and/or indirect inkjet printing of reconfigurable and/or tunable RF and/or MMW AME circuit applications.

Description

RF and MMWAVE circuits and their manufacturing method

The present invention relates to methods for forming mmWave RF circuits in multilayer additively manufactured electronic devices (AMEs). In particular, the present invention relates to methods for direct and/or indirect inkjet printing of reconfigurable and/or tunable mmWave RF AME circuit applications.

Electronic devices with small form factors are increasingly in demand in all areas where weight, size, cost and footprint impose stringent design constraints. These include manufacturing, business, consumer goods, military, aerospace and the Internet of Things, to name a few. These smaller form factor products rely on tiny electronic circuits with closely spaced digital and analog circuits. In many of these applications, the ability of antennas to tune resonances, change polarization and modify radiation patterns is a fundamental requirement for antennas that are capable of performing relevant functions such as direction finding, beam steering, radar, control and command; as well as the scalability of wireless standards and the emerging fifth generation (5G) and millimeter wave technologies; multi-functional antennas that can remotely change their characteristics in a reversible manner, all within a very small package.

Additionally, the recent explosion of interest in the 5G spectrum is increasingly driving the need for more efficient manufacturing methods that can configure consumer electronics with high accuracy, low cost, and short production cycles.

Likewise, mmWave (MMW) communications technology offers a wide range of high-speed capabilities, especially with the advent of high-bandwidth data services such as (but not limited to) transmission or downloading of uncompressed high-definition (HD) TV data. The MMW band extends from about 28 to 300 GHz, enabling single- or multi-channel carrier signals capable of gigabit transmission rates.

The following disclosure addresses these needs.

In various exemplary implementations, methods for forming reconfigurable and/or tunable RF and/or MMW AME circuit applications in multilayer Additively Manufactured Electronics (AME) are disclosed. In other exemplary implementations, examples and applications of methods for direct and indirect inkjet printing of reconfigurable and/or tunable RF and/or MMW antennas in multilayer AME circuits are disclosed.

In an exemplary embodiment, a method of fabricating at least one of radio frequency (RF) and MMW circuits is provided herein, the method comprising the steps of providing an inkjet ink system, the inkjet ink system comprising a first print head sized and configured to eject a dielectric ink composition; a second print head sized and configured to eject a conductive ink composition; a conveyor operably coupled to the first and second print heads and configured to deliver a substrate to each of the first and second print heads; and a computer-aided manufacturing ("CAM") module including a central processing module (CPM), the CPM in communication with each of the first and second print heads, the CPM comprising instructions that, when executed by at least one processor, cause the CPM to: receive a three-dimensional (3D) visualization file representing a frequency pass filter (FPF); And at least one processor in communication with a non-transitory computer-readable storage medium device storing instructions that control the inkjet printing system by executing steps including: generating a library of files, each file having a plurality of files representing substantially 2D layers for printing at least one of the RF and MMW circuits, and a metafile representing at least a printing order; providing a dielectric ink composition and a conductive ink composition; using a CAM module, obtaining from the library a first file representing a first layer for printing at least one of the RF and MMW circuits, the first file comprising printing instructions for a pattern representing at least one of the dielectric ink and the conductive ink; using a first print head, forming a pattern corresponding to the dielectric ink; curing the pattern corresponding to the dielectric ink representation of a 2D layer of the multilayer PCB; using a second print head, forming a pattern corresponding to the conductive ink; sintering the pattern corresponding to the conductive ink; A method of fabricating a substrate, comprising: using a CAM module, obtaining a subsequent file representing a subsequent layer for printing at least one of the RF and MMW circuits, wherein the subsequent file comprises a printing command for a pattern representing at least one of the dielectric ink and the conductive ink; using a first print head, forming a pattern corresponding to the dielectric ink; repeating the steps of using the CAM module, obtaining a subsequent substantially 2D layer from a 2D file library; wherein when passing and/or sintering the final layer, at least one of the RF and MMW circuits comprises a first buried waveguide in communication with a power amplifier (PA); a buried selector in communication with the first buried waveguide; an antenna in communication with the selector; a second buried waveguide in communication with the selector; and a low noise amplifier (LNA) in communication with the second waveguide; and removing the substrate.

These and other features of the methods for direct and/or indirect inkjet printing of reconfigurable and/or tunable RF and/or MMW AME circuit applications will become apparent from the following detailed description when read in conjunction with the non-limiting illustrative drawings and examples.

For a better understanding of the methods for direct and/or indirect inkjet printing of reconfigurable and/or tunable RF and/or MMW AME circuit applications, reference is made to the accompanying examples and drawings, with respect to exemplary implementations, examples and applications thereof:
FIG. 1 illustrates an XZ cross-section of an exemplary implementation of a multilayer RF and/or MMW AME circuit fabricated using the disclosed methods;
FIG. 2 illustrates a plan view of the multilayer RF and/or MMW AME circuit illustrated in FIG. 1;
Figure 3 is an example of a post-wall waveguide;
Figure 4 is a schematic diagram of a slot-type (waveguide) antenna.

Exemplary embodiments of methods for direct and/or indirect inkjet printing of reconfigurable and/or tunable RF and/or MMW AME antennas in multilayer AME circuits are provided herein. As used herein, AME, in the context of the present invention, means low temperature co-fired ceramic (LTCC), high temperature co-fired ceramic (HTCC), and RF integrated passive devices (IPD), as well as high density interconnect (HDI) printed circuits. Those skilled in the art of electronic circuits will appreciate that the exemplary embodiments disclosed herein may be applicable to multilayer printed circuit boards (PCBs) and flexible printed circuits (FPCs). Other circuits used in various applications requiring multilayer RF and/or MMW AME circuits are likewise contemplated, such as flexible short-range communication devices, microstrip antennas, array antennas, etc.

Exemplary implementations and examples of stacked manufactured transmission lines (TLs) with tunable bandwidth and multilayer RF and/or MMW AME antennas are provided herein. The multilayer RF and/or MMW AME antenna (10) comprises, for example, a first buried waveguide (101) in communication with a power amplifier (PA) (102); a buried selector (103) in communication with the first buried waveguide (101); an antenna (104) in communication with the selector (103); a second buried waveguide (105) in communication with the selector (103); and a low noise amplifier (LNA) (106) in communication with the second buried waveguide (105) (e.g., see FIG. 1 ).

In certain exemplary implementations, the transmission lines (110, 112) (i.e., the lines transmitting electromagnetic (EM) signals point-to-point) may be coaxial (e.g., shielded microstrip) transmission lines that are integrated with the multilayer AME, forming a single-piece feeder structure that does not require external wiring or coupling to external components. Additionally, the coaxial transmission lines (110, 112) may, in certain instances, be substantially circular in cross-section. In the context of the present invention, the term "coaxial" means that the various layers/regions of the transmission lines (110, 112) have a common propagation axis. In other instances, the layers/regions of the transmission lines (110, 112) are manufactured such that the layers/regions have the same geometric center upon sintering and/or curing of the last printed layer file from the library. In certain instances, the transmission lines manufactured using the systems, methods, and programs disclosed herein are coaxial and concentric, while in other instances; The transmission lines are not concentric. Furthermore, due to the manufacturing method(s) disclosed herein, the transmission lines of the particular examples are not limited to those having circular cross sections, but rather, transmission lines having other cross sections, including but not limited to rectangular and oval cross sections, are contemplated. As used herein, the term "integrated" is defined as being molded, or otherwise formed, as a single integral part of the disclosed multilayer AME.

In certain exemplary implementations, the methods implementable in the systems described herein can be used to form multilayer AMEs having reconfigurable and/or tunable RF and/or MMW AME antenna arrays in a single pass using an inkjet printing device, or in a continuous or semi-continuous process using multiple passes. In a semi-continuous process of the methods described herein, a base layer of dielectric material used to form the multilayer AME can be manufactured separately and serve as a substrate for additional printing of conductive and dielectric layers forming the reconfigurable and/or tunable RF and/or MMW AME antennas thereon. Using the additive manufacturing printing methods described herein, it is possible to manufacture reconfigurable and/or tunable RF and/or MMW AME antennas semi-continuously or continuously.

In the context of the present invention, the terms "tunable", "tunable antenna", and/or derivatives thereof, refer to an antenna element or an array of elements coupled to at least one tunable component. The tunable component can be, for example, at least one of an RF switch, a voltage controlled tunable capacitor, a voltage controlled tunable phase shifter, a MEMS capacitor, a MEMS switch, a FET, a varactor diode, and a selector. Additionally or alternatively, the tunable component can include any component coupled to an antenna element and capable of adjusting its reactance.

In certain examples, the component that couples with the antenna element and can adjust its reactance may be a capacitor (109) that is integrated within the same multilayer AME and directly coupled without the need for external wiring. Thus, an RF and/or MMW AME antenna structure is provided herein that includes an antenna capacitor printed as part of the AME upon sintering and/or curing of the last printed layer file from the library. The switching structure may be accomplished by adding a biasing element, such as a selector (103), coupled to the radiating element(s) (104, 104') of the spaced antenna (e.g., a radiating patch array or a slot array) using a dielectric ink (100) with a predetermined thickness. Additionally, the integrally printed capacitors (109) and/or inductors (113-115) as well as the grounding pads (116, 116') and at least one of the inductors are configured to impart variable reactive loads to the radiating elements (104, 104'), thereby providing better tuning and/or reconfigurability. Accordingly, and in an exemplary embodiment, the RF and/or MMW AME circuit further comprises the integrally printed capacitor (109), the inductor(s) (113-115) sized and configured such that the RF and/or MMW AME antenna will not short circuit.

The systems, programs, methods and compositions described herein can be used to form/manufacture multilayer RF and/or MMW AMEs having reconfigurable and/or tunable antennas (antennas) using a combination of print heads having conductive and dielectric ink compositions in a continuous or semi-continuous additive manufacturing process using an inkjet printing device, or using multiple passes. Accordingly and in an exemplary embodiment, provided herein is a method of manufacturing at least one of a radio frequency (RF) and a MMW circuit, the method comprising the steps of providing an inkjet ink system, the inkjet printing system comprising: a first print head sized and configured to eject a dielectric ink composition; a second print head sized and configured to eject a conductive ink composition; a conveyor operably coupled to the first and second print heads and configured to deliver a substrate to each of the first and second print heads; And a computer-aided manufacturing ("CAM") module in communication with each of the first and second print heads, the CAM module further comprising a central processing module (CPM), the CPM further comprising at least one processor in communication with a non-transitory computer-readable storage medium device storing instructions that, when executed by the at least one processor, cause the inkjet printing system to control the inkjet printing system by executing the steps of: receiving a 3D visualization file representing a frequency pass filter (FPF); and generating a file library having a plurality of files, each file representing a substantially 2D layer for printing at least one of the RF and MMW circuits, and a metafile representing at least a printing order; providing a dielectric ink composition and a conductive ink composition; using the CAM module, obtaining from the library a first file representing a first layer for printing at least one of the RF and MMW circuits, the first file comprising a printing instruction for a pattern representing at least one of the dielectric ink and the conductive ink; using the first print head, forming a pattern corresponding to the dielectric ink; A method of forming a 2D layer of a multilayer PCB, the method comprising: curing a pattern corresponding to the dielectric ink representation; forming a pattern corresponding to the conductive ink using a second print head; sintering the pattern corresponding to the conductive ink; obtaining a subsequent file representing a subsequent layer for printing at least one of the RF and MMW circuits using a CAM module, the subsequent file including a printing command for a pattern representing at least one of the dielectric ink and the conductive ink; repeating the steps of forming a pattern corresponding to the dielectric ink using the first print head, and obtaining a subsequent substantially 2D layer from a 2D file library using the CAM module; wherein when passing through and/or sintering the final layer, at least one of the RF and MMW circuits comprises a first buried waveguide in communication with a power amplifier (PA); a buried selector in communication with the first buried waveguide; an antenna in communication with the selector; a second buried waveguide in communication with the selector; and a low noise amplifier (LNA) in communication with the second waveguide; and removing the substrate.

In an exemplary embodiment, the CPM is operable to generate a sub-library of conductive ink pattern files, each of which represents a substantially 2D layer of dielectric ink pattern, wherein each conductive ink pattern represents a substantially 2D layer for printing. Each of the sub-library of files can further include a metafile having at least one of a printing order, an identifier of a file of a substantially 2D layer of dielectric ink pattern associated therewith, and instructions for a printing speed. It is noted that the generated sub-library can include a plurality of files configured to have the same thickness (or height) as the corresponding cured dielectric ink layer once the final substantially 2D conductive ink pattern is sintered. For example, the sub-library can include about 10 to about 55 files, each of which represents a substantially 2D layer of conductive ink for printing. Additionally, the conductive ink pattern of each of the files can be identical, or at least one of the files can have a different pattern than the other files in the sub-library. Moreover, the thickness formed during the fabrication and sintering of the final substantially 2D conductive ink pattern may be higher or lower than the surface of the cured substantially 2D layer of the printed dielectric ink pattern. For example, when forming hollow vias, it may be desirable to raise the upper surface of the via above the thickness of the dielectric layer to ensure electrical contact between the layers. Similarly, when forming wells for integrated circuit legs (J-legs), it may be advantageous to lower the conductive ink pattern below the surface of the dielectric ink layer.

The predetermined number of blind vias, and/or buried vias used in the systems, methods and configurations for fabricating a reconfigurable and/or tunable AME-based antenna disclosed herein may be further sized and configured to optionally couple each of the radiating elements (104, 104') to the transmission lines (110, 112), and/or to the selector (103) (i.e., without affecting the structure, step or configuration of the operation and/or performance of unrelated components).

A more complete understanding of the components, methods, and devices disclosed herein can be obtained by reference to the accompanying drawings. The drawings (also referred to herein as “FIGS”) are merely schematic representations based on convenience and ease of use in demonstrating the present invention and are therefore not intended to depict the relative sizes and dimensions of the devices or their components, their relative size relationships, and/or to limit or restrict the scope of the exemplary implementations. Although specific terms are used in the following description for the sake of clarity, such terms are intended to refer to specific structures of the exemplary implementations selected for illustration in the drawings and are not intended to limit or restrict the scope of the present disclosure. It should be understood that in the drawings below and the following description, like numerical designations refer to components of similar functionality. Likewise, in a common rectangular coordinate system having XYZ axes, the Y axis represents front to back, the X axis represents left to right, and the Z axis represents up and down when referring to a cross-section.

As illustrated in FIG. 1, in the provided method, when using the disclosed system and curing and/or sintering the final layer, at least one of the first waveguide (101) and the second waveguide (105) can be a post-wall waveguide (see, e.g., FIG. 3 ). The post-wall waveguide can be comprised of a buried via forming the post-wall waveguide, whereby, referring now to FIG. 3, b refers to the thickness of the waveguide in the Z direction, the minimum Z direction can be about 36 μm, the distance p between the centers of the buried vias can be about 300 μm, and the via diameter d can be from about 100 μm to about 300 μm, while the width of the post-wall waveguide can be modified.

Additionally or alternatively, in the provided method, when using the disclosed system and curing and/or sintering the final layer, at least one of the first waveguide (101) and the second waveguide (105) can be fully coaxial. As indicated, in the context of the first and/or second buried waveguides, the term 'coaxial' means various layers/regions of at least one of the first waveguide (101) and the second waveguide (105) that are buried, and at least one of the first waveguide (101) and the second waveguide (105) each have a common propagation axis. In the context of the present invention, the term "buried" means that the entire structure is present in an intermediate layer, whereas the term "fully" means that the conductive sleeve forming part of the coaxial guide is continuous, as illustrated in FIG. 3 , rather than a post-wall.

Moreover, when curing and/or sintering the final layer in the disclosed method using the provided system and program, the array of antennas (104, 104') may be a slot array antenna (see, e.g., FIG. 4 ). The slits (401j) are configured to have a width less than 0.1 of a wavelength and a length of 0.5 wavelength (at the operating center frequency). Although FIG. 4 illustrates the slits (401j) being oriented along the X-axis, slits oriented along the Y-axis (402p) are also contemplated.

Additionally, when curing and/or sintering the final layer, the radiating antenna elements (104, 104') may be patch array antennas, where the patches may be on the same surface and/or may be stacked. In general, the impedance bandwidth of a particular patch antenna is typically proportional to the antenna volume, as measured in wavelength. However, by using a plurality of stacked patches (e.g., see 403, 404) having a dielectric material (100) having a predetermined thickness among the patches (with or without slots (401j, 402p)), an enhanced impedance bandwidth may be obtained. Thus, and in one embodiment, the methods, configurations and systems disclosed herein may be configured to produce multiple conductive layers in a single prototype while satisfying a patch thickness to dielectric ink-volume ratio that enables operation of the elements as antennas over a wide bandwidth.

As illustrated in FIG. 1, when curing and/or sintering the final layer, the first buried waveguide (101) is in communication with a buried power amplifier (PA) waveguide (107), whereby the buried PA waveguide (107) is coupled between the first buried waveguide (101) and the PA (102). In the context of the present invention, the term "power amplifier" means any device or chain of devices that amplifies signals prior to wireless transmission (i.e., at a transmitter) or after wireless signal reception (i.e., at a receiver). For a receiver, the power amplifier may include a low noise amplifier (LNA) (106), whereas for a transmitter, the power amplifier (PA) is an amplifying device used to amplify high S/N ratio signals prior to wireless transmission. The PA (power amplifier) may be a linear PA or a nonlinear PA. A "linear PA" generally refers to a PA that operates with a constant gain and must preserve amplitude information, whereas a "nonlinear PA" generally refers to a PA that is designed to operate with a constant PIN, whose output power can be varied by varying the gain.

In certain exemplary embodiments, a via hole that spans all layers of a multilayer AME, for example from the apex outer layer to the outer base layer (e.g., in the "Z-direction"), is referred to as a "through-hole via" which may be plated or filled (e.g., with a conductive metal such as silver, copper, gold, aluminum, nickel, etc.), whereas a via hole that starts in the apex outer layer or the base outer layer and ends in any intermediate layer is referred to as a "blind via"; and a via hole between any two intermediate layers (whether adjacent to each other) is referred to as a "buried via". Thus, and in an exemplary embodiment, when curing and/or sintering the final layer, the slots (301i) forming at least one of the first and/or second buried waveguides (101, 105) (respectively) and the buried PA waveguide (107), and the buried LNA waveguide (108) are filled with buried vias. Additionally or alternatively, in another exemplary embodiment and when curing and/or sintering the final layer, at least one of the first and/or second buried waveguides (101, 105) (respectively) and the buried PA waveguide (107), and the buried LNA waveguides (108) is fully coaxial. Thus and in another exemplary embodiment, when curing and/or sintering the final layer, the second waveguide is in communication with the buried LNA waveguide, and the buried LNA waveguide is coupled between the second waveguide and the LNA (referring to an amplifier whose input is or is intended to be directly or indirectly coupled to a receiving antenna, and having a noise level equal to or greater than a low cut filter).

Strip line junction circulators used in RF and/or MMW AMEs manufactured using the disclosed methods refer to circulators of three-port (based on cancellation of waves propagating through two different paths near the magnetized material) or four-port (based on Faraday rotation of waves propagating in the magnetized material, for example) devices formed of symmetrical Y-junction strip lines bonded to a magnetically biased ferrite material. The circulator may be a ferrite-containing circulator, or a non-ferrite circulator. The term "ferrite-containing circulator" is used herein to refer to a magnetic ferrite element, i.e., a diode, having at least three ports that allow radio frequency signals to propagate between adjacent ports in only one direction. In certain exemplary implementations, the multilayer RF and/or MMW AME may be printed in a semi-continuous manner, wherein initially a cavity is formed with appropriate contacts and a base matching plate (116'), while a circulator may be inserted and connected, followed by printing of the vertex matching plate (116) and the vertex radiating antenna elements (104).

While inkjet inks and their dispensing systems are mentioned, other additive manufacturing (AM) methods are also contemplated in embodiments of the disclosed methods. In an exemplary embodiment, the RF and/or MMW AMEs may likewise be manufactured by a selective laser sintering (SLS) process, although any other suitable AM process (also known as rapid prototyping, rapid manufacturing and 3D printing methods) may also be used, alone or in combination. For example, direct metal laser sintering (DMLS), electron beam melting (EBM), selective heat sintering (SHS) or stereolithography (SLA).

The RF and/or MMW AME antennas can be manufactured from any suitable additive manufacturing material, such as metal powder(s) (e.g., silver, gold, cobalt, chromium, steel, aluminum, titanium, and/or nickel alloys), gas atomized metal powder(s), thermoplastic powder(s) (e.g., polylactic acid (PLA), acrylonitrile butadiene styrene (ABS), and/or high-density polyethylene (HDPE)), photopolymer resin(s) (e.g., a UV curable photopolymer, e.g., PMMA), thermosetting resin(s), thermoplastic resin(s), or any other suitable material that enables functionality as described herein.

Depending on the type of metal particle (e.g., silver, copper, gold, aluminum, etc.) and aspect ratio (which refers to the ratio between the length of the metal particle and its respective thickness or diameter), the maximum theoretical conductivity that can be achieved in the conductive ink composition used in inkjet printing can be a fraction of the bulk conductivity of the same metal as compared to the pure bulk metal, for example, about 10% to about 90%, or about 20% to about 80%, or in further examples, about 30% to about 70%, or 50%.

For example, the conductive material used to form the radiating elements (104, 104') and/or the (micro)transmission lines (110, 112) is silver nanoparticles. In the context of the present invention, nanoparticles are defined as particles having a volume average particle size of less than 1 micrometer, for example less than about 0.5 micrometer, or less than about 0.2 micrometer (D _3.2 which can be central to obtain a suitable aspect ratio, i.e. R>>1, for example 3:1 to 10:1). Nanoparticles can be advantageous in inkjet printing applications, enabling low ink viscosities even with very high conductive material contents or loadings (thus ensuring that 2D and 3D site percolation thresholds are exceeded) as well as preventing clogging of nozzles on the inkjet print head ejector.

In exemplary embodiments, in the context of a print head used to fabricate RF and/or MMW AME antennas disclosed herein, the term "ejecting" may be used to designate the operation of a device, such as a print head that acts as an ejector, to eject ink drops. The ejector may be a device for ejecting small amounts of liquid, including, for example, micro-valves, piezoelectric ejectors, continuous jet print-heads, boiling (bubble jet) ejectors, and others that affect the temperature and properties of the fluid flowing through the ejector. In exemplary embodiments, the terms "print head" and "ejector" are interchangeable.

A method of forming RF and/or MMW AMEs using the computerized inkjet printing system disclosed herein may include providing a substrate (e.g., a strippable substrate such as a film). A print head (and derivatives thereof; which should be understood to refer to any device or technique for depositing, delivering, or generating material on a surface in a controlled manner) that deposits dielectric ink may be configured to provide ink droplet(s) on demand, that is, as a function of various process parameters, such as the conveyor speed, the desired AME sub-layer thickness, whether a via is filled or plated, or a combination thereof. It is noted that the radiating elements (104, 104') may not be arranged at the same thickness of the AME sub-layer as determined by the process-specific sub-layer thickness, but may be arranged at a thickness that is the same as or varies with the sub-layer thickness.

The substrate used in the computerized inkjet printing system disclosed herein may be, for example, a removable or peelable, and also a relatively rigid material, such as glass or crystal (e.g., sapphire). Alternatively, the substrate may be a flexible (e.g., rollable) substrate (or film) to allow easy peeling of the substrate from the AME, such as poly(ethylenenaphthalate) (PEN), polyimide (e.g., Kaptone ^® by DuPont), a silicone polymer, poly(ethyleneterephthalate) (PET), poly(tetrafluoroethylene) (PTFE) film, or the like.

Other functional steps (and thus means for influencing these steps) may be taken when using the computerized inkjet printing system disclosed herein prior to or after the first or second print heads (e.g., to sinter the conductive layer). These steps may include (but are not limited to) a heating step (affected by a heating element such as a chuck and/or hot air); photobleaching (e.g., using a UV light source and a photomask); drying (e.g., using a vacuum field or a heating element); (reactive) plasma deposition (e.g., using a pressurized plasma gun and plasma beam controller); crosslinking (e.g., optionally initiated by addition of a photoacid such as {4-[(2-hydroxytetradecyl)-oxyl]-phenyl}-phenyliodonium hexafluoro antimonate to the polymer solution prior to coating or using metal precursors or nanoparticles as dispersants); annealing or promoting a redox reaction.

When using the computerized inkjet printing system disclosed herein, formulating the conductive and/or dielectric ink composition(s) may take into account the requirements imposed by the deposition tool, if any, and the surface properties of the (optionally removable) substrate (e.g., at least one of hydrophilicity or hydrophobicity, and surface energy). For example, when using inkjet printing with a piezo head, the viscosity (measured at 20° C.) of the conductive ink and/or dielectric ink can be, for example, greater than or equal to about 5 cP, such as greater than or equal to about 8 cP, or greater than or equal to about 10 cP, and less than or equal to about 30 cP, such as less than or equal to about 20 cP, or less than or equal to about 15 cP. The conductive ink and/or dielectric ink can be configured (e.g., formulated) to have a dynamic surface tension (referring to the surface tension when an inkjet ink droplet is formed at a print head aperture) of from about 25 mN/m to about 35 mN/m, for example from about 29 mN/m to about 31 mN/m, as measured by maximum bubble pressure tensimetry at 25° C., and a surface age of 50 ms, respectively. The dynamic surface tension can be formulated to provide a contact angle with the strippable substrate or dielectric layer(s) of from about 100° to about 165°.

In exemplary embodiments, the inkjet ink system compositions and methods for forming RF and/or MMW AMEs can be patterned by ejecting droplets of the liquid inkjet ink provided herein one at a time from an orifice while the print head (or substrate/chuck) is manipulated in, for example, two dimensions (X-Y) (it should be understood that the print head can also move in the Z-axis) at a predetermined distance over the substrate or any subsequent layer. The inkjet print heads provided for use in the methods described herein can provide a minimum layer film thickness of from about 3 μm to less than or equal to 10,000 μm.

In exemplary embodiments, the volume of each droplet of conductive ink, and/or dielectric ink can range from 0.5 to 300 picoLiter (pL), for example from 1 to 4 pL, depending on the strength of the drive pulse and the properties of the ink. The waveform for ejecting a single droplet can be a 10 V to about 70 V pulse, or from about 16 V to about 20 V, and can be ejected at a frequency of from about 5 kHz to about 500 kHz.

Additionally, the dielectric ink compositions described herein can have a continuous phase comprising a crosslinking agent, a co-monomer, a co-oligomer, a co-polymer or a composition comprising one or more of the foregoing. Likewise, the oligomer and/or polymer backbone can be induced to form crosslinks by contacting the polymer with an agent that forms free radicals on the backbone, thereby allowing crosslinking sites. In exemplary embodiments, the composition comprising a crosslinking agent, a co-monomer, a co-oligomer, a co-polymer or one or more of the foregoing can be configured to form a solution, emulsion, gel or suspension within the continuous phase or can be part of it.

In an exemplary embodiment, the continuous phase used in the AME (FPC and HDI circuits) manufactured using the disclosed method to form a multilayer AME having reconfigurable and/or tunable antenna arrays may include a multifunctional acrylate monomer, oligomer, polymer or combinations thereof; a crosslinker; and a radical photoinitiator, which may be partially or fully dissolved in the continuous phase.

Initiating the polymerization of the genetic resin backbone can be accomplished using an initiator, such as benzoyl peroxide (BP) and other peroxide-containing compounds. The term "initiator" as used herein generally refers to a substance that initiates a chemical reaction, specifically any compound that initiates a polymerization or generates a reactive species that initiates a polymerization, including, without limitation, co-initiators and/or photoinitiator(s).

In another exemplary embodiment, the dielectric resin used in the described ink composition comprises an active and/or live component of a polymer capable of undergoing photoinitiation using a photoinitiator. These live monomers, live oligomers, live polymers or combinations thereof capable of undergoing photoinitiation can be, for example, a polyfunctional acrylate, for example, a polyfunctional acrylate, which can be a polyfunctional acrylate, is selected from the group consisting of 1,2-ethanediol diacrylate, 1,3-propanediol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, dipropylene glycol diacrylate, neopentyl glycol diacrylate, ethoxylated neopentyl glycol diacrylate, propoxylated neopentyl glycol diacrylate, tripropylene glycol diacrylate, bisphenol-A-diglycidyl ether diacrylate, hydroxypivalic acid neopentanediol diacrylate, ethoxylated bisphenol-A-diglycidyl ether diacrylate, polyethylene glycol. A polymer selected from the group consisting of diacrylate, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, propoxylated glycerol triacrylate, tris(2-acryloyloxyethyl)isocyanurate, pentaerythritol triacrylate, ethoxylated pentaerythritol triacrylate, pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate.

Photoinitiators that can be used with the multifunctional acrylates described herein can be, for example, radical photoinitiators. These radical photoinitiators can be, for example, Irgacure® 500, Irgacure® 819, Irgacure® 184, TPO-L (ethyl (2,4,6, trimethyl benzoyl) phenyl phosphinate) benzophenone and acetophenone compounds from CIBA SPECIALTY CHEMICAL and Darocur®. For example, the radical photoinitiator can be a cationic photoinitiator, such as a mixed triarylsulfonium hexafluoroantimonate salt. Another example of a radical photoinitiator used in the active continuous phase described herein can be 2-isopropylthioxanthone.

The terms "live monomer", "live oligomer", "polymer" or their equivalents (e.g., co-monomers) combinations refer in exemplary embodiments to a polymer having at least one functional group capable of forming a monomer, a short group of monomers or a radical reaction (i.e., the reaction can continue and is not otherwise terminated by an end group).

Crosslinkers used in the compositions, systems and methods described herein to form RF and/or MMW AMEs can be, for example, primary or secondary polyamines and adducts thereof, or in other examples, anhydrides, polyamides, C ₄ -C ₃₀ polyoxyalkylenes wherein the alkylene groups independently contain 2 to 6 carbon atoms, or compositions comprising one or more of the foregoing.

The conductive and/or dielectric ink compositions may each require the presence of a surfactant and optionally a co-surfactant. The surfactant and/or co-surfactant may be a cationic surfactant, anionic surfactant, nonionic surfactant and amphiphilic copolymer, such as a block copolymer.

Moreover, the dielectric (insulating) layer portion can have a substantially uniform thickness throughout, thereby creating a substantially flat (e.g., planar) surface for receiving additional conductive circuit patterns. The dielectric layer can be a UV-curable adhesive or other polymeric material. For example, the dielectric ink comprises a UV-curable polymer. Other dielectric polymers include, for example, polyester (PES), polyethylene (PE), polyvinyl alcohol (PVOH), and poly-methyl methacrylate (PMMA), poly(vinylpyrrolidone) (PVP, water-soluble, and which may be advantageous in not clogging print head orifices). Other dielectric materials can be photoresist polymers, for example, SU-8 based polymers, polymer-derived ceramics, or combinations thereof; copolymers may also be used.

In an exemplary embodiment, the curing step is separate and distinct from the sintering step. Thus, curing is effected by exposing the printed dielectric pattern to electromagnetic radiation of a predetermined wavelength of from about 196 nm to about 400 nm, for example from about 300 nm to about 400 nm, or from about 350 nm to about 380 nm. Conversely, sintering is effected by exposing the printed conductive pattern to a focused heat source, such as, for example, an IR focused lamp or a laser beam operable to follow the conductive pattern.

The inkjet systems used to implement the methods provided herein may further include a computer-aided manufacturing ("CAM") module, the module including a data processor, a non-volatile memory, and a set of executable instructions stored on the non-volatile memory, the set of instructions configured to, when executed, cause at least one processor to: receive a 3D visualization file representing a printed circuit board including infrastructure elements; generate a library of files, each file representing at least one substantially 2D layer for printing RF and/or MMW AME to generate a substantially 2D representation image; and receive a selection of parameters related to the RF and/or MMW AME; wherein the CAM module is configured to control each of the first and second print heads. Accordingly, the set of executable instructions is further configured to, when executed, cause the processor to generate a library of files of a plurality of subsequent layers from the 3D visualization file. Each subsequent file represents a substantially two-dimensional (2D) subsequent layer for printing a subsequent portion of the RF and/or MMW AME, and each subsequent layer file is indexed by a print order. Furthermore, the set of executable instructions can be configured to analyze conductive and dielectric portions of each 2D layer and to generate a unique pattern for each layer from the first and second layers, which will instruct an appropriate print head to print that portion of the 2D layer.

Accordingly, the CAM module may include a 2D file library storing files converted from 3D visualization files of the reconfigurable and/or tunable antenna. The term "library," as used herein, refers to a collection of 2D layer files containing information necessary to print each conductive and dielectric pattern derived from the 3D visualization file, which are accessible and usable by the data acquisition application and executable by a computer-readable medium. The CAM further includes a processor in communication with the library; a non-transitory storage device storing a set of operational instructions for execution by the processor; a micromechanical inkjet print head or heads in communication with the processor and the library; and a print head (or heads) interface circuit in communication with the 2D file library, the non-transitory storage device and the micromechanical inkjet print head or heads, wherein the 2D file library is configured to provide operational parameters specific to the functional (printed) layer to the printer.

In certain exemplary implementations, the library includes files representing only dielectric patterns, files representing only conductive patterns (e.g., for forming a ground intermediate layer, e.g., 302, 303 of FIG. 3), or layer files including both dielectric and conductive patterns. In layers including both dielectric and conductive patterns, a metafile generated by a program included in the system, stored on the memory storage device, will further specify priorities for which pattern is to be printed first and the curing or sintering order.

The 3D visualization file representing the multilayer PCB having reconfigurable and/or tunable antenna arrays can be a file comprising ODB, ODB++, asm, STL, IGES, STEP, Catia, SolidWorks, Autocad, Creo, 3D Studio, Gerber, Rhino, Altium, Orcad or one or more of the foregoing; and the file representing at least one substantially 2D layer (and uploaded to the library) can be, for example, a JPEG, GIF, TIFF, BMP, PDF file or a combination comprising one or more of the foregoing files.

In addition, the computer program may include a computer program product comprising program code means for performing the steps of the methods described herein, as well as program code means stored on a computer-readable medium. The non-transitory storage device(s) used in the methods described herein may be any of various types of non-volatile memory devices or storage devices (i.e., memory devices that do not lose their information in the absence of power). The term "memory device" is intended to include an installation medium, such as a CD-ROM, a floppy disk, or a tape device, or a magnetic medium, such as a hard drive, an optical storage device, or a non-volatile memory, such as a ROM, EPROM, FLASH, etc. The memory device may also include other types of memory or combinations thereof. In addition, the memory medium may be located on the first computer (e.g., the provided 3D inkjet printer) on which the programs are executed, and/or may be located on a different second computer that is connected to the first computer via a network, such as the Internet. In the latter example, the second computer may additionally provide program instructions to the first computer for execution. The term "memory device" may also include two or more memory devices that may reside at different locations, e.g., on different computers that are connected via a network. Thus, for example, a bitmap library may reside on a memory device that is remote from a CAM module coupled to a provided 3D inkjet printer, and may be accessible by the provided 3D inkjet printer (e.g., via a wide area network).

The use of the term "module" does not imply that all of the components or functionality described or claimed as part of the module are organized into a (single) common package. In fact, any or all of the various components of the module, whether control logic or other components, may be combined into a single package or maintained separately and further distributed into multiple groups or packages or across multiple (remote) locations and devices. Moreover, in certain exemplary implementations, the term "module" refers to a monolithic or distributed hardware unit.

The term "comprising" and variations thereof, as used herein, are intended to be open-ended terms which specify the presence of stated features, elements, components, groups, integers, and/or steps, but do not exclude the presence of other unrecited features, elements, components, groups, integers, and/or steps. The foregoing also applies to words having similar meanings, such as the terms "including," "having," and variations thereof.

Unless otherwise specifically stated, as is evident from the following discussions, discussions throughout the specification utilizing terms such as "processing," "loading," "communicating," "detecting," "calculating," "determining," "analyzing," and the like, are to be understood to refer to operations and/or processes of a computer or computing system, or similar electronic computing device, that manipulate and/or transform data represented physically, such as a transistor architecture, into other data similarly represented as physical structural (i.e., resin or metal/metal) layers.

In the context of the present invention, the term "operable" means a system and/or device and/or program or includes elements for performing the stated function when certain elements or steps are fully functional and sized, adjusted, calibrated, activated, coupled, implemented, operated, affected, realized or when the executable program is executed by at least one processor associated with the system and/or device and meets the corresponding operability requirements. With respect to systems and circuits, the term "operable" means that the system and/or circuit is fully functional and calibrated and includes circuitry as well as logic having the necessary hardware and firmware to perform the stated function when executed by at least one processor and meets the corresponding operability requirements.

Computer-aided design/computer-aided manufacturing (CAD/CAM) generated information relating to an AME comprising embedded passive and embedded active components described herein to be manufactured, which is used in the method, program and library, may be based on a converted CAD/CAM data package, which may be, for example, an IGES, DXF, DWG, DMIS, an NC file, a GERBER® file, an EXCELLON®, STL, an EPRT file, an ODB, ODB++, asm, STL, IGES, STEP, Catia, SolidWorks, Autocad, ProE, 3D Studio, Gerber, Rhino, Altium, Orcad, Eagle file or a package including one or more of the foregoing. Additionally, properties attached to the graphical objects may convey meta information necessary for fabrication and accurately define the PCB. Therefore and in an exemplary implementation, using the preprocessing algorithm, GERBER®, EXCELLON®, DWG, DXF, STL, EPRT ASM, etc. are converted into 2D files as described herein.

All ranges disclosed herein are inclusive of the endpoints and the endpoints are independently combinable with one another. "Combination" includes blends, mixtures, alloys, reaction products, etc. The terms "a," "an," and "the" as used herein do not denote a limitation of quantity, and are to be construed to include both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The suffix "(s)", as used herein, is intended to include both the singular and the plural of the term it modifies, and thereby includes one or more of those terms (e.g., element(s) includes one or more elements).

Throughout this specification, references to “one exemplary embodiment,” “another exemplary embodiment,” “an exemplary embodiment,” etc., where present, mean that particular elements (e.g., features, structures, and/or characteristics) described in connection with the exemplary embodiments are included in at least one exemplary embodiment described herein, and may or may not be present in other exemplary embodiments. Furthermore, it should be understood that the described elements may be combined in any suitable manner among the various exemplary embodiments.

All ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with one another. Also, the terms "first," "second," etc. are used herein not to denote any order, quantity, or importance, but rather to denote one element from another.

Likewise, the term "about" will be understood to mean that the amounts, sizes, formulations, parameters and other quantities and characteristics are not and need not be exact, but may be approximate and/or larger or smaller than desired, and may reflect tolerances, conversion factors, rounding, measurement errors, and the like, and other factors known to those of skill in the art. In general, the amount, size, formulation, parameter or other quantity or characteristic is "about" or "approximately" whether explicitly stated to be such.

Accordingly and in an exemplary embodiment, provided herein is a method of fabricating at least one of a radio frequency (RF) and mmWave circuit, the method comprising the steps of providing an inkjet ink system, the inkjet ink system comprising a first print head sized and configured to eject a dielectric ink composition; a second print head sized and configured to eject a conductive ink composition; a conveyor operably coupled to the first and second print heads and configured to deliver a substrate to each of the first and second print heads; and a computer-aided manufacturing ("CAM") module in communication with each of the first and second print heads, the CAM module comprising a central processing module (CPM), the CPM having instructions that, when executed by at least one processor, cause the CPM to: receive a 3D visualization file representing a frequency pass filter (FPF); And at least one processor in communication with a non-transitory computer-readable storage device configured to store instructions that control the inkjet printing system by executing steps including: generating a library of files, each file having a plurality of files representing substantially 2D layers for printing at least one of the RF and mmWave circuits, and a metafile representing at least a printing order; providing a dielectric ink composition and a conductive ink composition; using a CAM module, obtaining from the library a first file representing a first layer for printing at least one of the RF and mmWave circuits, the first file comprising printing instructions for a pattern representing at least one of the dielectric ink and the conductive ink; using a first print head, forming a pattern corresponding to the dielectric ink; curing the pattern corresponding to the dielectric ink representation of a 2D layer of the multilayer PCB; using a second print head, forming a pattern corresponding to the conductive ink; sintering the pattern corresponding to the conductive ink; A method of forming a substrate for printing at least one of the RF and mmWave circuits, the method comprising: obtaining a subsequent file using a CAM module, the subsequent file comprising a printing command for a pattern representing at least one of a dielectric ink and a conductive ink; forming a pattern corresponding to the dielectric ink using a first print head; and repeating the steps of obtaining a subsequent substantially 2D layer from a 2D file library using the CAM module, wherein when passing and/or sintering the final layer, at least one of the RF and mmWave circuits comprises a first buried waveguide in communication with a power amplifier (PA); a buried selector in communication with the first buried waveguide; an antenna in communication with the selector; a second buried waveguide in communication with the selector; and a low-noise amplifier (LNA) in communication with the second waveguide; and removing the substrate, wherein (i) in the step of generating a file library having a plurality of files, the set of executable instructions, when executed, generate, for each substantially 2D layer, a file comprising a dielectric ink pattern for printing; For each of the generated dielectric ink patterns, a step of generating a sub-library of a plurality of files including the conductive ink pattern; For each file including the conductive ink pattern, a step of generating a metafile including at least a printing order; and further comprising a step of generating, for each file including the dielectric ink pattern, a metafile including at least a printing order; (ii) the number of files in the sub-library comprising a plurality of substantially 2D layer files of the conductive ink pattern for printing each substantially 2D layer file of the dielectric ink pattern is configured to have the same thickness as the cured printed dielectric ink pattern when sintering the last substantially 2D layer of the printed conductive ink pattern, or (iii) or the number of files in the sub-library comprising a plurality of substantially 2D layer files of the conductive ink pattern for printing each substantially 2D layer file of the dielectric ink pattern is configured to have a different thickness or height than the thickness or height of the cured printed dielectric ink pattern when sintering the last substantially 2D layer of the printed conductive ink pattern, or (iv) the patterns in each file in the sub-library of the substantially 2D layer files for printing the conductive ink pattern are the same, or (v) at least one file in the sub-library of the substantially 2D layer files for printing the conductive ink pattern has a different conductive ink pattern than the conductive ink pattern in at least another file in the sub-library, (vi) the circuit is an RF circuit, and (vii) when curing and/or sintering the last layer, the antenna in the RF circuit is an antenna. (viii) when curing and/or sintering the final layer, at least one of the first and second buried waveguides is a post-wall waveguide and/or a fully coaxial waveguide, (ix) the antenna array is at least one of a slot array antenna and a patch array antenna, (x) when curing and/or sintering the final layer, the first waveguide is in communication with a buried power amplifier (PA) waveguide, and the buried PA waveguide is coupled between the first waveguide and the PA, (xi) when curing and/or sintering the final layer, the slots forming at least one of the first buried waveguide and the buried PA waveguide are filled with buried vias, (xii) when curing and/or sintering the final layer, the buried PA waveguide is a fully coaxial waveguide and/or a twisted waveguide, and (xiii) when curing and/or sintering the final layer, the second buried waveguide is in communication with a buried low noise amplifier (LNA) waveguide. and (xiv) when the final layer is cured and/or sintered, the slots forming at least one of the second buried waveguide and the LNA waveguide are filled with buried vias, (xv) at least one of the second buried waveguide and the LNA waveguide is a fully coaxial waveguide, (xvi) when the final layer is cured and/or sintered, the buried PA waveguide is further coupled to a capacitor in communication with a strip line connected to the PA, (xvii) the strip line is a microstrip line coupled to the capacitor by a blind via operable to provide a mode change, and (xviii) when the final layer is cured and/or sintered, the buried LNA waveguide is in communication with the strip line connected to the LNA by the via operable to provide a mode change.

The above examples and descriptions are, of course, provided for illustrative purposes only and are not intended to limit the disclosed technology in any way. As will be appreciated by those skilled in the art, the disclosed technology can be carried out in a wide variety of ways using one or more of the techniques described above, all without exceeding the scope of the present invention.

Claims (19)

A method of manufacturing at least one of radio frequency (RF) and mmWave circuits, comprising:
a. A step of providing an inkjet printing system, wherein the inkjet printing system:
i. a first print head sized and configured to dispense a genetic ink composition;
ii. a second print head sized and configured to dispense a conductive ink composition;
iii. a conveyor operably coupled to said first and second print heads and configured to deliver a substrate to each of said first and second print heads; and
iv. further comprising at least one processor in communication with a non-transitory computer-readable storage device storing instructions that control the inkjet printing system by executing the steps of: receiving a 3D visualization file representing a frequency pass filter (FPF); and generating a file library having a plurality of files, each file representing a substantially 2D layer for printing at least one of the RF and the mmWave circuits, and at least a metafile representing a printing order;
b. A step of providing the dielectric ink composition and the conductive ink composition;
c. using the CAM module, obtaining from the library a first file representing a first layer for printing at least one of the RF and mmWave circuits, wherein the first file includes a printing command for a pattern representing at least one of the dielectric ink and the conductive ink;
d. A step of forming the pattern corresponding to the dielectric ink using the first print head;
e. a step of curing the pattern corresponding to the dielectric ink expression of the 2D layer of the multilayer PCB;
f. A step of forming the pattern corresponding to the conductive ink using the second print head;
g. a step of sintering the pattern corresponding to the conductive ink;
h. using the CAM module, obtaining a subsequent file representing a subsequent layer for printing at least one of the RF and mmWave circuits, the subsequent file including a printing command for a pattern representing at least one of the dielectric ink and the conductive ink;
i. a step of forming the pattern corresponding to the dielectric ink using the first print head, and a step of repeating the step of obtaining the subsequent substantially 2D layer from the 2D file library using the CAM module - when curing and/or sintering the final layer, at least one of the RF and the mmWave circuits
i. A first buried waveguide communicating with a power amplifier (PA);
ii. A buried selector communicating with the first buried waveguide;
iii. Antenna communicating with said selector;
iv. a second buried waveguide communicating with the above selector; and
v. comprising a low noise amplifier (LNA) communicating with the second buried waveguide; and
j. A method comprising the step of removing the substrate.
In the first aspect, in the step of generating a file library having the plurality of files, the set of executable instructions, when executed, further comprises:
a. For each substantially 2D layer, generating a file containing a dielectric ink pattern for printing;
b. For each of the generated genetic ink patterns, a step of generating a sub-library of a plurality of files including the conductive ink pattern;
c. for each file including the conductive ink pattern, generating a metafile including at least a printing order; and
d. For each file containing the above genetic ink pattern, a step of generating a metafile containing at least the printing order.
A method in claim 2, wherein the circuit is an RF circuit.
A method in accordance with claim 3, wherein when curing and/or sintering the final layer, the antennas within the RF circuits are antenna arrays.
A method in accordance with claim 2, wherein when curing and/or sintering the final layer, at least one of the first and second embedded waveguides is at least one of a post-wall waveguide and a fully coaxial waveguide.
A method in accordance with claim 5, wherein when curing and/or sintering the final layer, the antenna array is at least one of a slot array antenna and a patch array antenna.
A method in accordance with claim 6, wherein when curing and/or sintering the final layer, the first waveguide communicates with a buried power amplifier (PA) waveguide, and the buried PA waveguide is coupled between the first waveguide and the PA.
A method in accordance with claim 7, wherein when curing and/or sintering the final layer, slots forming at least one of the first buried waveguide and the buried PA waveguide are filled with buried vias.
A method in accordance with claim 7, wherein when curing and/or sintering the final layer, the embedded PA waveguide is a fully coaxial waveguide.
A method in accordance with claim 6, wherein when curing and/or sintering the final layer, the second buried waveguide communicates with a buried low-noise amplifier (LNA) waveguide, and the buried LNA waveguide is coupled between the second buried waveguide and the LNA.
A method in accordance with claim 10, wherein when curing and/or sintering the final layer, the slots forming at least one of the second buried waveguide and the LNA waveguide are filled with buried vias.
A method in claim 10, wherein when curing and/or sintering the final layer, at least one of the second buried waveguide and the LNA waveguide is a fully coaxial waveguide.
A method in accordance with claim 7, wherein when curing and/or sintering the final layer, the embedded PA waveguide is additionally coupled to a capacitor communicating with a strip line connected to the PA.
A method in accordance with claim 13, wherein when curing and/or sintering the final layer, the strip line is a microstrip line coupled to the capacitor by a blind via operable to provide a mode change.
A method in accordance with claim 7, wherein when curing and/or sintering the final layer, the embedded LNA waveguide communicates with a strip line connected to the LNA by a via operable to provide mode switching.
In the second aspect, a method wherein the number of files in the sub-library including a plurality of substantially 2D layer files of the conductive ink pattern for printing each substantially 2D layer file of the dielectric ink pattern is configured such that when the last substantially 2D layer of the printed conductive ink pattern is sintered, it has the same thickness as the cured printed dielectric ink pattern.
In the second aspect, a method wherein the number of files in the sub-library including a plurality of substantially 2D layer files of the conductive ink pattern for printing each substantially 2D layer file of the dielectric ink pattern is configured to have a different thickness from the cured printed dielectric ink pattern when sintering the last substantially 2D layer of the printed conductive ink pattern.
In the second paragraph, a method wherein the patterns in each file within the sub-library of the substantially 2D layer files for printing the conductive ink pattern are identical.
A method in the second aspect, wherein at least one file in the sub-library of the substantially 2D layer files for printing the conductive ink pattern has a conductive ink pattern different from the conductive ink patterns in at least another file in the sub-library.

Images