IL292234B2 - Three dimensional (3d) dielectric lattice - Google Patents

Description

292234/ TITLE THREE DIMENSIONAL (3D) DIELECTRIC LATTICE FIELD [0001] The present invention relates to 3D lattices having dielectric properties and to manufacture thereof. BACKGROUND [0002] Electrical insulators are used as structural components (e.g., supports and covers) which allow unrestricted Radio Frequency (RF) energy while physically protecting equipment such as antennas, e.g., radar and avionics equipment antennas. Typically, such structural components are desired to be low dielectric loss materials which prevents them from destructively affecting the RF signal and field. [0003] ROHACELLTM is a structural core material made of polymethacrylimide (PMI), that is electromagnetically transparent and is used as structural foam in RF and other antennae applications. Unfortunately, the ROHACELLTM foams are produced using complex processing methods including drilling, planing, milling, sawing, and sanding, resulting in a highly priced core material. SUMMARY [0004] Embodiments of the invention provide a simply manufactured low- cost 3D printed lattice that has an air-like dielectric constant (e.g., a dielectric constant of about 1, such as 1, 1.1, 1.2 1.3, 1.4, 1.5, 1.6, 1.7) and is thus electromagnetically transparent and can be advantageously used instead of known foams, as a structural component in RF and other fields, without affecting the RF signal. [0005] In addition, lattices according to embodiments of the invention provide strength and stress managing capabilities in three directions and can thus be used to replace currently used structures such as honeycomb structures (that provide strength and stress managing capabilities in one direction only). 292234/ id="p-6" id="p-6" id="p-6" id="p-6" id="p-6" id="p-6" id="p-6"

[0006] Additionally, a 3D printing model can be used to shape a structure having an internal lattice core, to be in any desired final external dimension and shape, for example, in a dimension and shape to accommodate an electronic device and/or an RF component within the device. Thus, embodiments of the invention help in preventing unnecessary machining or finishing operations. [0007] Some aspects of the invention provide a lattice having a dielectric constant of about 1.0 - 1.7. The 3D lattice may be an open-cell lattice configured to achieve a porosity of 70% or more. [0008] In one embodiment the lattice has a porosity of 70-95%. [0009] In another embodiment, the lattice has a porosity of 90% or more. [0010] The lattice may be built from a polymer, wherein the polymer has a dielectric constant lower than about 3.4. The polymer may include, for example, a photopolymer or a polyamide. [0011] In one embodiment, the lattice is built from a polyamide having a dielectric constant of about 2.7. [0012] In other embodiments, the lattice may be built from any other 3D printable material. [0013] The open-cell lattice may include, for example, a regular structure or a random structure. [0014] In one embodiment, the open-cell lattice includes one or a combination of unit cells, for example, one or a combination of body centered cubic (BCC) unit cell, body centered cubic with Z-truss (BCCZ) unit cell, face centered cubic (FCC) unit cell, PFCC unit cell, F2BCC unit cell, gyroid unit cell and rhombic unit cell. Other configurations enabled by 3D printing are also possible. [0015] In one embodiment, the open-cell lattice is built by a three-dimensional (3D) printer. [0016] Additional aspects of the invention provide a method for manufacturing a 3D dielectric lattice. In one embodiment, the method includes the step of providing to a 3D printer input material from which to build a lattice and providing to the 3D printer a digital model of the lattice, wherein the lattice is configured to achieve a porosity of 70% or more. [0017] The input material, which may include, for example, a polymer or any other 3D printable material, may have a dielectric constant of 3.4 or lower. 292234/ id="p-18" id="p-18" id="p-18" id="p-18" id="p-18" id="p-18" id="p-18"

[0018] The input material may include, for example, a polymer (e.g., a photopolymer or a polyamide), or additional suitable input materials. The input material may be provided to the 3D printer in solid form, powder, paste, resin, etc. [0019] The lattice built according to embodiments of the invention may be an open-cell structure which includes one or a combination of unit cells, e.g., as described above. The lattice may include a random structure. [0020] In other embodiments, the lattice includes a periodic, regular structure. [0021] Additional aspects of the invention provide an electronic device comprising an RF component and a lattice as described herein, the lattice to provide support and/or protection to the RF component. [0022] Another aspect of the invention provides a structural component for RF components, the structural component comprising a lattice as described herein. [0023] Yet another aspect of the invention provides a capacitor comprising at least two electrical conductors separated by a dielectric lattice as described herein. BRIEF DESCRIPTION OF THE FIGURES [0024] The invention will now be described in relation to certain examples and embodiments with reference to the following illustrative figures so that it may be more fully understood. In the drawings: [0025] Figs. 1A and 1B respectively show top side view and top view examples of lattice structures, according to embodiments of the invention; [0026] Figs. 1C-1G show 3D depictions of possible lattice structures, according to embodiments of the invention; [0027] Figs. 2A – 2G schematically illustrate possible geometries of unit cells that can be used to make a lattice, according to embodiments of the invention; [0028] Fig. 3A schematically illustrates a perspective view of an electronic device, according to embodiments of the invention; [0029] Fig. 3B schematically illustrates a slightly rotated perspective view of the electronic device of Fig. 3A, with the housing of the device not shown, according to embodiments of the invention; 292234/ id="p-30" id="p-30" id="p-30" id="p-30" id="p-30" id="p-30" id="p-30"

[0030] Fig. 3C schematically illustrates a bottom view of the electronic device of Fig. 3A, according to embodiments of the invention; [0031] Fig. 4 schematically illustrates a capacitor which includes a lattice, according to embodiments of the invention; and [0032] Figs. 5A and 5B schematically illustrate exemplary methods for manufacturing a lattice, according to embodiments of the invention. DETAILED DESCRIPTION [0033] In the following description, various aspects of the present invention will be described. For purposes of explanation, specific configurations and details are set forth in order to provide a thorough understanding of the present invention. However, it will also be apparent to one skilled in the art that the present invention may be practiced without the specific details presented herein. Furthermore, well known features may be omitted or simplified in order not to obscure the present invention. [0034] Embodiments of the invention provide a 3D printed dielectric lattice, namely, a lattice having an air-like dielectric constant (e.g., a dielectric constant of about 1, 1.1, 1.2, 1.3 ,1.4, 1.5, 1.6 or 1.7, where the dielectric constant is determined using, for example, the ASTM D150 standard). [0035] Embodiments of the invention use a combination of low dielectric material, such as a polymer or any other 3D printable material, and low volume fraction of the material, to provide the lattice. The low volume fraction of the material (e.g., porosity of 70% or more, for example a porosity of 70%-95%) enables to achieve, in the final lattice product, an even lower dielectric constant than that of the material used to build the lattice. [0036] The lattice, according to embodiments of the invention, has mechanical and/or dielectric properties that provide high compression and bending properties, wherein the lattice provides electromagnetic transparency and thus allows unrestricted RF energy while physically protecting, for example, RF components. Thus, the lattice can be advantageously used as structural core material for RF components (e.g., antennae, RF horns, wave guides, RADAR components, etc.) or in other applications where electromagnetic transparency is needed. 292234/ id="p-37" id="p-37" id="p-37" id="p-37" id="p-37" id="p-37" id="p-37"

[0037] Embodiments of the invention provide a low-density light-weight lattice, but with high compressive strength and bending properties. Lattices produced according to embodiments of the invention may have compressive strengths of over 30 MPa. For example, lattices according to embodiments of the invention may have compressive strength of 30-50 Mpa, thereby providing a useful and inexpensive scaffold for electronic and other devices, e.g., for use in aerospace and other weight-sensitive applications, such as in electronic vehicles, unmanned arial vehicles (UAV), drones, etc. [0038] According to some embodiments, the lattice may be manufactured by using a 3D printer, for example, in processes such as multi jet fusion (MJF), selective laser sintering (SLS), stereolithography (SLA) and digital light processing (DLP). [0039] Advantageously, the layer-by-layer approach for the fabrication of 3D objects, used by 3D printers, enables easy, efficient, and thus inexpensive manufacture of complex structures, such as the lattice described herein. [0040] In one embodiment, the lattice is a 3D open-cell lattice having a dielectric constant of about 1.0 - 1.7, the lattice configured to achieve a porosity of 70% or more. [0041] In one embodiment, the lattice is an open-cell lattice configured to achieve a porosity of 80% or more, e.g., a porosity of 80%-95%. [0042] In some embodiments, the lattice has a porosity of 90-95%. [0043] Porosity may be defined as the ratio of the volume of pores to the total volume of material (such as polymer) and is usually expressed as a percentage, for example according to the following Eq: Porosity = ( (Total Volume - Volume of the Solid ) / Total Volume ) x 100%. [0044] Thus, the volume of material comprises 30% or less, of the lattice volume (accordingly, a 30/70 or less material to air ratio, e.g., 10/90 or 5/95 or in the range between 30/70 and 5/95 material to air ratio). [0045] In some embodiments, the lattice may be a foam having a dielectric constant of about 1.0 - 1.7, the foam comprising an open-cell lattice configured to achieve a porosity of 70% or more. [0046] In some embodiments, the lattice is made of, for example, a polymer having a low dielectric constant, e.g., a dielectric constant lower than 3.4. In some embodiments, the polymer has a dielectric constant in the range of 2.7 – 3.4. 292234/ id="p-47" id="p-47" id="p-47" id="p-47" id="p-47" id="p-47" id="p-47"

[0047] The polymer may comprise 5- 30% of the lattice volume. In additional embodiments, the polymer comprises 10% or less, of the lattice volume. [0048] In some embodiments, the polymer may be, for example, a photopolymer or a polyamide. [0049] Examples of lattices having an air-like dielectric constant, according to embodiments of the invention, are illustrated in Figs. 1A and 1B. [0050] The lattices 100 and 102 (in Fig. 1A and 1B, correspondingly) are examples of lattices that may be used, e.g., as structural components (possibly similar to foams), each including a lattice structure 103 and 113 (correspondingly) made of a material having a typically low dielectric constant. In one embodiment, lattice structures 103 and 113 are open-cell structures built of, for example, a polymer. [0051] In other embodiments, the lattice is not necessarily an open-cell structure and other materials may be used to build the lattice. [0052] In one embodiment, the lattice structures 103 and 113 are made mostly of unit cells 105 that aren’t completely encapsulated, rather, the cells are open and filled with air. The lattice structures 103 and 113 are configured to achieve a pre-determined percent of material (e.g., polymer) from lattice volume and to achieve a porosity of 70% or more so as to provide a lattice having an air-like dielectric constant (e.g., a dielectric constant of about 1.0, 1.2, 1.3, 1.4, 1.5, 1.6 or 1.7). [0053] In one example, the lattice is made of a polymer, e.g., a polyamide having a dielectric constant lower than 3.4, e.g., having a dielectric constant of 2.7. In some embodiments the polyamide may include, e.g., nylon 12, which has a dielectric constant of 3.4 or lower. In some embodiments the polyamide may include, e.g., DuraFormTM PA which has a dielectric constant of 2.73. In additional embodiments the polymer is a photopolymer. [0054] Figs. 1C and 1D show additional views of the lattice structures 103 and 113, in accordance with embodiments of the invention. Lattice structures 103 and 113 are typically periodic open cell smooth structures made up of open unit cells 105. The lattice structures 103 and 113 are 3D structures designed to achieve a pre-determined ratio of material to air (e.g., porosity of 70% or more), in the final product, lattice 100 or lattice 102. In one embodiment, the lattice structures 103 and 113 are shaped to achieve a predetermined 292234/ volume fraction, e.g., a volume fraction of 30% or less, or in another embodiment, a volume fraction of 10% or less, or in another embodiment a volume fraction of between 5% to 30% (e.g., porosity of 70% or more). In the examples illustrated in Figs. 1 C and 1D, lattice 1is denser (including more unit cells per given area) than lattice 102. [0055] Lattice structures 103 and 113 may be made of one or a combination of unit cells. The lattice structures may include regular, periodic structures or random structures. Figs. 1E-G show some examples of lattice structures that may be used according to embodiments of the invention. [0056] Fig. 1E shows a lattice structure 123 made of unit cells 115 arranged in a random structure, which may include several different unit cell types or the same unit cell arranged with no particular order. [0057] Fig. 1F shows a lattice structure 133 made of rhombic unit cells 115’ (exemplified below in Fig. 2G) arranged in a periodic, regular (non-random) structure, in accordance with embodiments of the invention. [0058] Fig. 1G shows a lattice structure 143 made of gyroid unit cells 115’’ (exemplified below in Fig. 2F) arranged in a periodic, regular (non-random) structure, in accordance with embodiments of the invention. [0059] In addition to their dielectric properties, the lattices described above can also be designed, e.g., by using specific unit cell structures, to provide specific strengths in three dimensions and may thus be advantageously used, e.g., as structural components in devices, such as electronic /RF devices, replacement for honeycomb structures, etc. [0060] Lattices 100 and 102 may be made into a final shape desired to cover or support an RF or other component. For example, lattice 100 in Fig. 1A includes a slot 107 to accommodate an electronic component (not shown), such as an electronic card or antenna, such that lattice 100 may support and/or protect the electronic component. In Fig. 1B lattice 102 includes niches 101 to accommodate to the shape of components in a device, where lattice 102 may be used to support and/or protect the electronic components. [0061] Figs. 2A-2G schematically illustrate possible geometries of cell unit such as open-cell unit cell structures that can make up a low-density lattice core having high energy absorption capabilities, such as lattices 100 and 102. The unit cells shown in Figs. 2A-2G 292234/ are 3D cells, more clearly envisioned by the 3D Cartesian coordinate system shown with the figures. [0062] Fig. 2A schematically illustrates a body centered cubic (BCC) unit cell, which has one lattice point in the center of the unit cell in addition to eight corner points. [0063] Fig. 2B schematically illustrates a body centered cubic with Z-truss (BCCZ) unit cell, which is similar to the BCC unit cell geometry, but with four additional vertical struts along the four vertical edges of the cell. [0064] Fig. 2C schematically illustrates a face centered cubic (FCC) unit cell, which has two crossed struts on each of the vertical faces of the cell. [0065] Fig. 2D schematically illustrates an F2BCC unit cell, which combines the struts in the FCC and BCC geometries into a single cell. The F2BCC unit cell is composed of twelve struts, four of which connect the corners of different faces of the cell while another eight connect the corners sharing a face. [0066] Fig. 2E schematically illustrates a PFCC unit cell, which is similar to the FCC unit cell geometry but with struts added along the Z axis. [0067] Fig. 2F schematically illustrates a gyroid type unit cell, which can be formally described as a triply periodic minimal surface, with zero mean curvature. [0068] Fig. 2G schematically illustrates a rhombic unit cell, which is a three-dimensional figure with six faces which are rhombi. [0069] Other unit cell configurations may be used instead of or in addition to the configurations exemplified herein. [0070] Using one or a combination of unit cell types (such as the unit cell types described above) to manufacture a lattice, can achieve a material volume fraction of 30% or lower, namely, a porosity of 70% or more (e.g., a porosity of 70% - 95%, 80%-95% or 90%-95%). The dielectric constant of the lattice decreases with the decrease in material volume fraction. Thus, the high porosity/low volume fraction combined with the use of a low dielectric material enables the manufacture of a lattice having an air-like dielectric constant. [0071] Additionally, the use of unit cells to manufacture lattice structure such as the lattice structures described herein, may provide a low-density core material, from which light-weight, but stiff and strong structures can be manufactured. In one embodiment, lattices 292234/ 100 and/or 102 have compressive strengths of over 30 MPa. The lattices may have compressive strength of 30-50 MPa. Additionally, lattices made up of 3D unit cells (e.g., as described above) enable stress management and strength in three directions, providing a much-improved structural component. [0072] In some embodiments, lattices 100 and 102 may be made of one or more of the unit cell types described above. The choice of type of unit cells that make up the lattice, their number, the cell size, its degree of orientation, strut length and strut diameter may all influence the mechanical performance of the final lattice structure. [0073] Parameters of the unit cells making up the lattice structure (such as cell size, strut length and strut diameter) can be changed to achieve different levels of functionalities and to optimize strength-to-weight ratio characteristics of the lattice. Combining more than one type of unit cells with different topologies may result in different performances in mechanical behavior of the lattice. [0074] Lattices according to embodiments of the invention (lattices 100 and 102, for example), may be manufactured by using a 3D printer, e.g., in an additive manufacture process, or other 3D printing processes. [0075] The lattices 100 and 102 may be advantageously used as structural components for RF and other electronic elements. For example, lattices 100 and/or 102 may be used to create structural components such as substrates, spacers, covers, supports, etc., for electronic or RF components such as antennae, RF horns, wave guides, RADAR components, RADAR components, etc. Additionally, due to the mechanical properties of the lattices 100 and 102, they can be used as a scaffold (e.g., instead of currently used honeycomb structures) for composite components, such as wing frames, doors, blades, struts, radomes, etc. [0076] Figs. 3A, 3B and 3C schematically illustrate perspective views (Figs. 3A and 3B) and a bottom view (Fig. 3C) of an electronic device 300. [0077] The electronic device 300 schematically illustrated in Fig. 3A, includes a housing 308 attached to a base 304. Within the housing 308 device 300 includes RF components 301 and 307 (e.g., electronic cards and/or antennae) and lattices 100 and 102 that provide support and/or protection to the RF components 301 and 307. In Fig. 3B, device 300 is 292234/ slightly rotated and the housing is not shown so as to better visualize the other features of the drawing. [0078] In accordance with some embodiments, lattices 100 and 102 have an air-like dielectric constant and include a lattice structure (not shown) as described above, which is configured to achieve a pre-determined volume fraction of material (e.g., polyamide, photopolymer, or any other 3D printable material.), such as, a volume fraction of 30% or lower (e.g., porosity of 70% or more). [0079] The lattices 100 and 102 may be shaped to fit and accommodate the RF components 301 and 307 which they are meant to cover and/or support. In one example, the dimensions of lattice 100 are 78x79x59mm and the dimensions of lattice 102 are198x198x65mm. [0080] The lattices 100 and 102 include a lattice structure (not shown) which is a low-density cellular core structure that may be based upon, e.g., unit cell lattices as described above. Lattices 100 and 102 have low through-thickness thermal conductivity and high compressive strength and flexural stiffness so that they can provide good vibration damping, support and protection to RF components 301 and 307. [0081] Fig. 4 schematically illustrates an example of another possible use of a lattice according to embodiments of the invention. Fig. 4 shows a capacitor 40 which uses a lattice built according to embodiments of the invention, as a dielectric material to separate at least two electric conductors, such as conductive plates 42 and 42’ of capacitor 40. The use of lattices having a low dielectric constant, such as lattice 41, can determine the amount of energy that capacitor 40 can store when voltage 43 is applied. Thus, lattice 41 may be used as a structural component for an element such as a capacitor and may also favorably affect the properties of the capacitor. [0082] In some embodiments, since lattice 41 is typically a three dimensional structure, a 3D capacitor may be manufactured using lattice 41. [0083] In some embodiments, lattice 41 may include any of the lattice structures illustrated in Figs 1C, 1D, 1E, 1F or 1G. [0084] Figs. 5A and 5B schematically illustrate methods for manufacturing a 3D lattice having an air-like dielectric constant, according to embodiments of the invention. [0085] In one embodiment, which is schematically illustrated in Fig. 5A, the method includes using a 3D printer, for example, in an additive manufacture process, to 292234/ manufacture the 3D lattice from a low dielectric material, such as a polymer such as nylon 12, DuraFormTM PA or acrylic or epoxy resins. The method includes 3D printing a lattice from the low dielectric material to achieve the air-like dielectric constant of the final product. The lattice may be an open-cell structure. [0086] In one embodiment, the method includes providing a digital model of a lattice (502) to a 3D printer (506) and providing to the 3D printer printable material (504), such as the materials described herein. The lattice is typically configured to achieve a material to air ratio of 30/ 70 or less, e.g., as described above. [0087] Based on instructions in the 3D printer software (e.g., using applicable slicing software), a lattice is built from the printable material to provide a final product, such as a structural component (508). [0088] The digital model of the lattice (502) may include, for example, a meshed 3D computer model that can be created by acquired image data or structures built in computer-aided design (CAD) software, as typically used in additive manufacture processes. The model of the lattice may include a lattice of unit cells, e.g., as described above. The model of the lattice is designed to build a lattice having a predetermined volume fraction, e.g., a volume fraction of 30% or less, or in another embodiment, a volume fraction of 10% or less, or in another embodiment a volume fraction of between 5% to 20%. [0089] In one embodiment, which is schematically illustrated in Fig. 5B, a structural component having a lattice core as described herein, may be printed in a desired final external dimension and shape, e.g., in the dimension and shape of a capacitor or an RF component which the structural component is mean to cover and/or support. [0090] In this example, the method includes providing a digital model of the shape and dimensions of an RF or other component (511) and a digital model of a lattice (512) to a 3D printer (516). The method further includes providing to the 3D printer printable material (514), typically, having a dielectric constant lower than 3.4, e.g., as exemplified herein. Based on instructions in the 3D printer software (e.g., using applicable slicing software), a lattice core is built from the printable material in a desired shape and dimensions (e.g., to accommodate an RF or other component), to provide a structural component (518). [0091] 3D printing of a lattice into a final desired shape to cover or support an RF or other component, or for use in other elements, according to embodiments of the invention, 292234/ provides an efficient method for producing structural components for RF and other applications and helps in preventing unnecessary machining or finishing operations. [0092] Known additive manufacture processes may be used in the method described above. These processes may include, for example, printing methods based on fusing powder (such as polyamide (e.g., nylon 12 or DuraFormTM PA) powder or filaments), such as multi jet fusion (MJF) or selective laser sintering (SLS). Alternatively or in addition, the processes may include, for example, printing methods based on curing of resin (e.g., photopolymer resin, such as acrylic or epoxy resins), such as stereolithography (SLA) and digital light processing (DLP). [0093] Polymers or other suitable printable materials having a low dielectric constant (e.g., lower than 3.4) are typically used. [0094] Additive manufacturing offers advantages, such as, reduced lead times, on-demand manufacturing, increased supply chain proficiency, shorter times to market and reduced waste. As such, additively manufacturing a lattice, according to embodiments of the invention, provides an easily obtained and inexpensive structural component having an air-like dielectric constant, that can be advantageously used in RF and other applications, as described herein. [0095] By 3D printing of a low dielectric material and using specific lattice geometries, a lattice having an air-like dielectric constant can be built using, for example, a polymer with no additional additives required, using a simple production method and at a very low cost. [0096] In the above description, an embodiment is an example or implementation of the inventions. The various appearances of "one embodiment," "an embodiment" or "some embodiments" do not necessarily all refer to the same embodiments. Furthermore, it is to be understood that the invention can be carried out or practiced in various ways and that the invention can be implemented in embodiments other than the ones outlined in the description above. [0097] Although various features of the invention may be described in the context of a single embodiment, the features may also be provided separately or in any suitable combination. For example, where flow charts are exemplified, flow need not move through each illustrated box or state, or in exactly the same order as illustrated and described. 292234/ id="p-98" id="p-98" id="p-98" id="p-98" id="p-98" id="p-98" id="p-98"

[0098] Although the invention may be described herein in the context of separate embodiments for clarity, the invention may also be implemented in a single embodiment. While the invention has been described with respect to a limited number of embodiments, these should not be construed as limitations on the scope of the invention, but rather as exemplifications of some of the preferred embodiments. Other possible variations, modifications, and applications are also within the scope of the invention.

Claims (16)

1./ CLAIMS 1. A three dimensional (3D) open-cell lattice having a dielectric constant of about 1.0 - 1.7, wherein the lattice comprising a polymer said polymer comprises a polyamide and has a dielectric constant lower than about 3.4, and wherein the lattice configured to achieve a porosity of 70% or more.

2. The lattice of claim 1, having a porosity of 70-95%.

3. The lattice of claim 1, having a porosity of 90% or more.

4. The lattice of claim 1, wherein the polymer comprises a photopolymer.

5. The lattice of claim 1, wherein the polyamide has a dielectric constant of about 2.7.

6. The lattice of claim 1, comprising one or a combination of unit cells selected from: body centered cubic (BCC) unit cell, body centered cubic with Z-truss (BCCZ) unit cell, face centered cubic (FCC) unit cell, PFCC unit cell, F2BCC unit cell, gyroid unit cell and rhombic unit cell.

7. The lattice of claim 1, comprising a random structure.

8. The lattice of claim 1, which is built by a three-dimensional (3D) printer.

9. An electronic device comprising a Radio Frequency (RF) component and a 3D open-cell lattice as in claims 1-8, the lattice to provide support or protection to the RF component.

10. A structural component for electronic devices, the structural component comprising a 3D open-cell lattice as in claims 1-8.

11. A capacitor comprising at least two electrical conductors separated by a 3D open-cell lattice as in claims 1-8.

12. A method for manufacturing a 3D dielectric lattice, the method comprising: providing to a 3D printer input material from which to build the lattice; providing to the 3D printer a digital model of the lattice, wherein the lattice is configured to achieve a porosity of 70% or more, and wherein the input material comprises a polymer, said polymer has a dielectric constant lower than 3.4, and wherein said polymer is a photopolymer or polyamide.

13. The method of claim 12, comprising providing the polyamide in solid form. 292234/

14. The method of claim 12, wherein the lattice is an open-cell structure.

15. The method of claim 12, wherein the lattice comprises a random structure.

16. The method of claim 12, wherein the lattice comprises one or a combination of unit cells selected from: BCC, BCCZ, FCC, PFCC, F2BCC, gyroid and rhombic. For the Applicant, By: