High-frequency components

Abstract

The present invention relates to a high-frequency component having at least one region suitable for and intended for conducting and / or radiating high-frequency signals, wherein the region comprises a body and a metal coating covering the body, the body having one or more walls forming a shape-imparting structure for the high-frequency component and having a wall thickness of 5 mm or less, and / or having a grid-like structure, and / or having a plurality of perforations, the ratio t / d where t is the thickness of the metal layer in the cross-section and d is the maximum cross-sectional area of ​​the body in the cross-section is 10 / 500 or more, and / or the ratio of the mass of the body to the mass of the metal coating is 1 or more, and / or the surface cross-sectional area ratio of the metal coating to the body is 0.025 or more.

Description

Technical Field

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[0001] The present invention relates to a high-frequency component suitable for conduction and / or radiation of a high-frequency signal and having at least one region for this purpose, and the above region includes a substrate and a metal coating covering the substrate.

Background Art

[0002] Such high-frequency (HF) components (hereinafter also referred to as "components") are known from the prior art. Known HF components are manufactured by 3D printing and metallization. In this case, the molding focuses only on achieving the desired HF characteristics and manufacturability of the components. When designing the structure of the substrate, for example, the perspective of resistance to common stress tests used later in the automotive field is not considered.

[0003] In known high-frequency components, the geometric design of regions that have little or no relevance to high-frequency transmission or radiation is likewise not considered with respect to optimization for stress tests. It is known that the coefficient of thermal expansion between 3D printed plastics and typical metals used for metallization is significantly different, i.e., several times different. Also, in the current technology, it is known that the heat deflection temperature and brittleness of materials (especially photopolymers) are in a trade-off relationship. That is, heat-resistant materials have a significantly low elongation at break coefficient. As a result, several drawbacks occur. For example, typical drop tests and vibration tests cannot pass even with metallization. Furthermore, since brittleness leads to a high failure rate, the labor and cost involved in post-treatment can be significant.

[0004] Separately from this, more fragile 3D printing materials result in poor printing results and are particularly subject to significant limitations in HF components used in frequency bands exceeding 50 GHz. Similar considerations also apply to the glass transition temperature and melting point. The limitations of known 3D printing materials from the prior art have an adverse impact on HF components as follows.

[0005] Metallization is performed at a specific temperature or expansion of the plastic material. Because the material expands differently at higher or lower temperatures, cracks and microcracks can occur. Visible cracks are a rejection criterion in visual inspection of parts. However, even more serious is the fact that cracks and almost invisible microcracks significantly degrade high-frequency characteristics, which also constitutes a rejection criterion.

[0006] Deformation during rapid temperature changes from high to low temperatures: When a part changes temperature from, for example, 125°C to -40°C in a typical transition time of 1 minute, the outer metallization and plastic core reach the new temperature at different rates. This means that the metallization cools rapidly due to its high thermal conductivity, thus taking on dimensional changes with temperature more quickly. In contrast, the underlying core, still flexible (low thermal deflection temperature) and at a high temperature, expands several times more than the metallization. This results in two failure patterns. First, cracks and microcracks develop. Visible cracks are a rejection criterion in visual inspection of the part. However, more serious are cracks and almost invisible microcracks, which significantly degrade the HF properties and are also a rejection criterion. Separately, the soft core is easily deformed by the stress arising from the deforming metallization. This also similarly leads to a significant change in HF properties. Experiments have shown that even if no defects are found in visual inspection, a single temperature cycle can lead to the complete unusability of an HF part.

[0007] Attempts to adapt plastics to have a lower coefficient of thermal expansion and / or a higher temperature of thermal distortion can lead to reduced print quality, increased brittleness, and higher costs, which is particularly problematic for mass production processes or volumes. [Overview of the project] [Problems that the invention aims to solve]

[0008] Therefore, the objective of the present invention is to provide HF components that are of high quality, can be manufactured cost-effectively, and exhibit excellent HF performance, thermal shock resistance, and resistance to mechanical stress such as vibration or drop tests. [Means for solving the problem]

[0009] This objective is achieved by a high-frequency component having the features of claim 1 (referred to as "HF component" within the scope of the present invention).

[0010] Therefore, the substrate has a grid-like structure that forms a shape-imparting structure for high-frequency components and has multiple openings. When the layer thickness in the cross-section of the metal coating is t and the maximum cross-sectional area in the cross-section of the substrate is d, the ratio t / d is 10 / 500 or more, and / or • The ratio of the mass of the metal coating to the mass of the substrate is 1 or greater, and / or • The ratio of the cross-sectional area between the metal coating and the substrate is 0.025 or greater. It is said that...

[0011] The cross-section passing through the coated lattice strut has a structure in which a metal surface of layer thickness "t" surrounds at least one shaping structure of diameter "d" (d in the case of a rectangular substrate). As a result, when the metal layers are counted on both sides (outside and inside), the resulting wall thickness w = d + 2 * t. The cross-section is preferably a cross-section perpendicular to the extension of the lattice strut.

[0012] Alternatively or additionally, the mass ratio of metal to skeletal material is greater than 1:1. In other words, in the region where the HF component is considered, there is more (i.e., a greater mass) of metal in the form of a metal coating than the mass of the substrate, which is preferably made of or contains plastic.

[0013] Alternatively or additionally, the area ratio of the cross-sections in the minimum spatial range between the metal and the plastic is considered to be greater than 0.025. Therefore, when considering a cross-section perpendicular to the extension of the lattice strut, there are two area portions: one is the area of ​​the metal coating and the other is the area of ​​the substrate. According to this feature, this area ratio is greater than 0.025.

[0014] The design of HF components according to the present invention combines all relevant aspects (especially for 3D printed and coated plastic bodies): namely, high-quality and cost-effective manufacturing, outstanding high-frequency performance, resistance to thermal shock (e.g., 125°C to -40°C, transition time 1 minute), and resistance to mechanical stress such as vibration testing (e.g., 20g or equivalent in the range of 10Hz to 2kHz according to MIL-STD-202G testing) or drop testing.

[0015] Conventional technology, at best, can satisfy one selected characteristic separately. For example, using high-temperature resistant plastics might achieve resistance to slow temperature cycling, but in that case, mechanical durability and thermal shock resistance are inferior, and the manufacturing is unreliable.

[0016] The present invention provides a high-frequency component in which the characteristics of the component are determined by the properties of the metal. The substrate only needs to have shape-imparting properties. The substrate is provided only in the parts necessary for high-frequency characteristics or mechanical characteristics. As a result, cost reduction is possible in two respects. That is, cheaper plastics or materials can be used, and less plastic or material is needed for the substrate than known from the prior art.

[0017] For example, a base formed as a plastic lattice simply functions as a framework that gives shape. Therefore, the basic framework only needs to withstand the manufacturing process and thereafter plays no technical role, or only a subordinate role, so the lattice struts are made as thin as technically possible / possible.

[0018] The HF components according to the present invention are robust additive manufacturing products. "Robust" means technical ease of use and, in particular, resistance to various environmental influences such as thermal shock, sustained temperature loads, vibration, impact, and other mechanical stresses.

[0019] Preferably, the metal coating completely covers the substrate in that area, that is, the substrate is completely, or entirely, covered by the metal coating in that area.

[0020] In the region, the ratio t / d is 10 / 500 or more, preferably 20 / 500 or more, and particularly 30 / 500 or more, and / or the ratio of the mass of the metal coating to the mass of the substrate is 1 or more, preferably 2 or more, and particularly 3 or more, and / or the area ratio in the cross-section is 2.5% or more, preferably 10% or more.

[0021] In a further embodiment of the present invention, in that region, at least 20%, preferably at least 40%, and particularly at least 70% of the cross-sectional dimensions of the substrate in the minimum spatial extent are 5 mm or less, preferably 2 mm or less, and particularly 1 mm or less.

[0022] The substrate may further be made to have openings with a volume proportion of at least 10%, preferably at least 15%, and particularly at least 25%, with each having a tolerance of ±2.5%.

[0023] The substrate preferably has a monolithic structure and / or is manufactured by an additive manufacturing process, particularly 3D printing. In this case, the openings and lattice structure already form part of the additive manufacturing model and do not need to be introduced later. However, according to the present invention, it is also possible to introduce or add them later.

[0024] In this region, the substrate has a lattice-like structure in at least some areas.

[0025] The region can form the whole component or a part thereof. Therefore, the present invention also includes HF components having one or more regions without the characteristics of the present invention.

[0026] The HF component can be, for example, a waveguide, a coupler, a reflector, an antenna and / or an antenna array, or a combination of two or more of the aforementioned components, or a part of one of the aforementioned components.

[0027] The material of the substrate in the region is preferably plastic, and particularly a material containing one or more plastics from the following group: polyamide, urethane, or acrylate.

[0028] The metal coating in the region is by the following techniques: I. Electroplating process, particularly nickel electroplating or copper electroplating II. Electroless chemical coating process III. Immersion process, particularly immersion in a dispersion containing microparticles or nanoparticles IV. CVD or PVD It can be applied by one or more of the above.

[0029] Combinations of the aforementioned techniques are also conceivable and are included in the present invention.

[0030] Preferably, this component is suitable for operation in a frequency range exceeding 50 GHz and is intended for use in such a range.

[0031] The metal coating can be implemented as a single layer or multiple layers in the region. Particularly, when using a layer system, the deposited metal surface can also be resistant to oxidation, moisture, etc., and can further be suitable for use in a corrosive environment. Particularly, this can be achieved by electrolessly or particularly galvanically (i.e., by current-driven wet chemical deposition) depositing nickel as the final surface.

[0032] Therefore, it is conceivable that the metal coating in that region is oxidation-resistant and / or moisture-resistant and / or corrosion-resistant.

[0033] According to the present invention, the metal coating is made of a particularly ductile material such as copper, and is expected to follow the deformation (expansion / contraction / softening) of the plastic to some extent without immediately forming cracks.

[0034] However, according to the present invention, it is equally conceivable that the metal layer be made of a less ductile material (e.g., nickel) so that the metal layer prevents deformation of the plastic. In particular, the thickness of the metal is made constant with respect to the thickness of the plastic in order to generate the force necessary to effectively counteract the deformation force of the plastic.

[0035] In a further embodiment of the present invention, the component in that region is heat resistant in a temperature range of -40°C to +125°C without the formation of cracks or microcracks.

[0036] The present invention further relates to a method of using an HF component as described in any one of claims 1 to 15, wherein the product is used for HF applications.

[0037] The method of use may include arranging the HF components as waveguides, couplers, reflectors, antennas, and / or antenna arrays.

[0038] Here, it should be noted that the terms "a" and "an" (in one possible embodiment) do not necessarily refer precisely to one element, but can also refer to multiple elements. Similarly, the use of the plural form includes the existence of each element in the singular form, and conversely, the singular form also includes the plural of that element.

[0039] Furthermore, all features of the present invention described herein can be combined with each other in any given manner, or claimed separately. [Modes for carrying out the invention]

[0040] Further details and advantages of the present invention will be described in more detail by the exemplary embodiments described below.

[0041] Exemplary embodiments relate to HF components used for conducting and / or radiating HF waves in a frequency range above 50 GHz.

[0042] The HF component has, for example, a grid-like substrate. The substrate is made of plastic and is 3D printed. The substrate is monolithic. As a result, the grid forms a shape-imparting wall structure for the HF component, which can include, for example, waveguide channels and waveguide slot antennas. Therefore, the grid-like shape-imparting monolithic wall structure also has radiating slots for the waveguide slot antenna.

[0043] After the substrate is manufactured, the substrate is coated with a metal coating, preferably so that the metal coating completely covers the substrate, that is, the substrate is coated with a metal coating so that it does not have any surfaces that come into contact with the ambient atmosphere, at least in functionally relevant areas, preferably as a whole.

[0044] The metal coating is applied by a multi-stage immersion process, which may include, for example, electroplating deposition. In this exemplary embodiment, the metal coating is applied to a thickness such that the t / d ratio is 40 / 500 or greater. Considering the cross-section passing through the grid strut, the thickness t of the metal coating and the thickness d of the plastic are obtained from that cross-section. The ratio of the two values ​​t and d is 0.08 or greater, meaning that a large amount of metal is applied relative to the substrate. As a result, the area ratio of the metal area to the plastic area in the cross-section of the grid strut is 0.3 or greater.

[0045] This has the advantage that the properties of HF components are largely determined by the metal coating rather than the plastic substrate. The substrate functions solely as a shaping element to which the coating is applied. HF components are robust, meaning they are resistant to thermal shock, sustained temperature loads, and vibration, impact, and other mechanical stresses.

Claims

1. A high-frequency component having at least one region suitable for and intended for conducting and / or radiating high-frequency signals, wherein the region includes a substrate and a metal coating covering the substrate, The substrate has one or more walls that form the shape-imparting structure of the high-frequency component and have a wall thickness of 5 mm or less, and / or has a lattice structure, and / or has a plurality of openings. - When the layer thickness of the metal coating in the cross-section is t and the maximum cross-sectional area of ​​the substrate in the cross-section is d, the ratio t / d is 10 / 500 or more, and / or - The ratio of the mass of the metal coating to the mass of the substrate is 1 or more, and / or - The ratio of the cross-sectional area of ​​the metal coating to the substrate is 0.025 or more. A high-frequency component characterized by the following features.

2. The component according to claim 1, characterized in that the metal coating in the region completely covers the substrate, and / or the lattice struts of the lattice structure in the region are completely encased by the metal coating.

3. The part according to claim 1 or 2, characterized in that in the region, the ratio t / d is 30 / 500 or more, preferably 40 / 500 or more, and / or the ratio of the mass of the metal coating to the mass of the substrate is 2 or more, and / or the area ratio in the cross-section is 2.5% or more, preferably 10% or more.

4. The component according to any one of claims 1 to 3, characterized in that, in the region, at least 20%, preferably at least 40%, and particularly at least 70% of the cross-sectional dimensions of the base in the smallest spatial range are 5 mm or less, preferably 2 mm or less, and particularly 1 mm or less.

5. The component according to any one of the claims, wherein the substrate in the region has openings with a volume fraction of at least 10%, preferably at least 15%, and particularly at least 25% ± 2.5%.

6. The component according to any one of claims 1 to 5, characterized in that the substrate in the region has a monolithic structure and / or is manufactured by an additive manufacturing process, particularly 3D printing.

7. The component according to any one of claims 1 to 6, characterized in that the wall thickness of the base body wall is 2 mm or less, and more particularly 1 mm or less.

8. The component according to any one of claims 1 to 7, wherein in the region, the base has a grid-like structure having longitudinal struts and transverse struts connecting them in at least some regions.

9. The component according to any one of claims 1 to 8, characterized in that the region includes the entire component or a part thereof.

10. The component according to any one of claims 1 to 9, characterized in that the component is a waveguide, a coupler, a reflector, an antenna and / or an antenna array, or a combination of two or more of the components, or a part of the components.

11. The component according to any one of claims 1 to 10, characterized in that the material of the substrate in the region is a plastic, particularly a material comprising one or more plastics from the group consisting of polyamide, urethane, or acrylate.

12. The metal coating in the aforementioned region is based on the following technology: I. Electroplating processes, particularly nickel electroplating or copper electroplating II. Electroless Chemical Coating Process III. Immersion process, particularly immersion in dispersions containing microparticles or nanoparticles IV. CVD or PVD A component according to any one of claims 1 to 11, characterized in that it is constructed by one or more of the methods described above.

13. The component according to any one of claims 1 to 12, characterized in that the component in the region is suitable for and intended to operate in a frequency range exceeding 50 GHz.

14. The component according to any one of claims 1 to 13, characterized in that the metal coating in the region is a single layer or a multilayer.

15. The component according to any one of claims 1 to 14, characterized in that the metal coating in the region is oxidation-resistant and / or moisture-resistant and / or corrosion-resistant.

16. The component according to any one of claims 1 to 15, characterized in that the component in the region is heat resistant in a temperature range between -40°C and +125°C without the formation of cracks or microcracks.

17. A method for using an HF component according to any one of claims 1 to 16, characterized in that the component is used for HF applications.

18. The method of use according to claim 17, characterized in that the component is used as a waveguide, coupler, reflector, antenna, and / or antenna array.

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