A ppo-based composite antenna unit and a method for manufacturing the same

Abstract

This invention provides a PPO-based composite antenna element and its fabrication method, relating to the field of antenna technology. The antenna element comprises, from the outside to the inside, layers 1, 2, 3, 4, and 5, wherein layers 1 and 5 are PPO layers doped with glass fiber, layers 2 and 4 are PPO layers directly formed by laser, and layer 3 is an aluminum alloy layer. A single laser welding connection method is used to achieve laser welding of the outer periphery of layers 1 and 2, layer 2 penetrating through layers 3 and 4 and welding to layer 5, and welding the outer periphery of layers 4 and 5. The antenna element completely eliminates the adhesive bonding and insert injection molding processes of the prior art, solving the problems of high cost and complex process of the original adhesive bonding process, while avoiding the oxidation defects on the surface of the aluminum alloy layer caused by the later PVD of the metal insert.

Description

Technical Field

[0001] This invention relates to the field of antenna technology, specifically to PPO-based composite antenna elements and their fabrication methods. Background Technology

[0002] As communication technology advances towards multi-band and high-precision applications, the dielectric properties of antenna elements directly determine their adaptability and application range. Antenna elements with adjustable dielectric constants can flexibly adapt to different frequency band requirements, significantly improving versatility. Currently, most antenna dielectric materials have fixed dielectric constants, making it difficult to meet the needs of multiple scenarios. Furthermore, the fabrication process of multilayer PPO-based antennas has many defects, limiting their performance and large-scale production.

[0003] Polyphenylene oxide (PPO) is a preferred material for antenna substrates due to its low dielectric loss and good environmental stability. Adding glass fiber (GF) can enhance its mechanical properties, and laser-directly formed (LDS) PPO allows for precise fabrication of laser-engraved circuits. However, existing multilayer PPO-based antenna technologies suffer from the following key drawbacks: First, the dielectric constant is fixed, making it difficult to adjust flexibly for different application scenarios, resulting in poor versatility. Second, the interlayer connection methods are often unreasonable, relying heavily on adhesives, which not only increases material costs but also leads to complex processes, low production efficiency, and the adhesives may affect dielectric properties. Third, inaccurate dimensional positioning of multilayer boards can easily lead to interlayer misalignment, affecting structural integrity and subsequent welding accuracy. Fourth, the metallization process after insert injection molding is complex, requiring shielding and protection of exposed metal parts, which must be removed after metallization, making the process cumbersome.

[0004] Furthermore, existing multilayer antennas struggle to achieve dual-band antenna functionality through the structural and pattern design of metal components and LDS layers. The lack of precise positioning structures further exacerbates assembly misalignment issues. Therefore, developing a multilayer PPO-based antenna unit with adjustable dielectric constant, single laser welding connection, accurate positioning, and the ability to achieve dual-band antenna functionality through structural design has become a pressing technical challenge. Summary of the Invention

[0005] To address the shortcomings of existing technologies, a PPO-based composite antenna unit and its fabrication method are provided. The antenna unit comprises, from the outside to the inside, layers 1, 2, 3, 4, and 5. Layers 1 and 5 are PPO layers doped with glass fiber, layers 2 and 4 are PPO layers directly formed by laser, and layer 3 is an aluminum alloy layer. A single laser welding connection method is used to achieve laser welding of the outer periphery of layers 1 and 2, layer 2 penetrating through layers 3 and 4 and welding to layer 5, and welding the outer periphery of layers 4 and 5. The antenna unit completely eliminates the adhesive bonding and insert injection molding processes used in existing technologies, solving the problems of high cost and complex processes of the original adhesive bonding process, while avoiding the surface oxidation defects of the aluminum alloy layer caused by the later PVD of metal inserts.

[0006] The objective of this invention is achieved through the following technical solution: In a first aspect, the present invention provides a PPO-based composite antenna unit, wherein the antenna unit comprises, from the outside to the inside, layers 1, 2, 3, 4 and 5, wherein layers 1 and 5 are PPO layers doped with glass fiber, layers 2 and 4 are PPO layers doped with LDS additive, and layer 3 is an aluminum alloy layer. The dielectric constants of the 1st, 2nd, 4th and 5th layers are 2.8-3.6, and the dielectric loss tangent is <0.005; The connection between layers 1 and 2 is achieved by laser welding the welding groove and welding rib around the periphery of the layer plate; the connection between layers 4 and 5 is achieved by laser welding the welding groove and welding rib around the periphery of the layer plate. The connection between the 2nd and 5th layers is achieved by passing the welding rib through the joint and then laser welding it to the welding groove.

[0007] In some specific embodiments of the present invention, the dielectric constants of the 1st, 2nd, 4th and 5th layers are 2.8-3.6, and the dielectric loss tangent is <0.005; The laser transmittance of layers 1 and 5 is ≥60%; the laser absorption rate of layers 2 and 4 is ≥90%.

[0008] In some specific embodiments of the present invention, the materials of the 1st and 5th layers are specifically composite materials comprising PPO resin, glass fiber and dielectric modifier; the dielectric modifier is silicon dioxide or boron nitride micro powder with a particle size of 1-5 μm; By weight, the PPO resin is 55-80 parts, the glass fiber is 15-40 parts, and the dielectric modifier is 2-8 parts.

[0009] In some specific embodiments of the present invention, the materials of the 2nd and 4th layers are specifically composite materials including PPO resin, LDS additive, glass fiber and dielectric modifier; By weight, the PPO resin is 50-75 parts, the LDS additive is 5-10 parts, the glass fiber is 10-35 parts, and the dielectric modifier is 2-8 parts.

[0010] In some specific embodiments of the present invention, the three-layer aluminum alloy layer is 6061 or 7075 aluminum alloy; the aluminum alloy layer can be etched or cut into structures of different shapes; The second layer has a metallized antenna pattern fabricated using LDS technology, and the fourth layer has a metallized antenna pattern fabricated using LDS technology. The diameter of the through joint is 0.02-0.05 mm larger than the cross-sectional size of the weld bead.

[0011] In some specific embodiments of the present invention, the first layer is provided with positioning posts, the fifth layer is provided with positioning posts, and the positioning posts are integrally injection molded with the first layer or the fifth layer; The positioning posts have a diameter of 1-2 mm, a height of 0.3-0.6 mm, a positioning accuracy of ≤ ±0.01 mm, and a quantity of 2-4, evenly distributed at the edge of the layer.

[0012] In some specific embodiments of the present invention, the welding power when laser welding the welding groove and welding rib around the periphery of the layer plate is 80-130W, the welding speed is 200-500mm / s, the welding width is 0.3-0.6mm, and the connection strength is ≥20N / cm. The welding power for laser welding the welding groove and welding rib around the outer edge of the layer plate is 80-130W, the welding speed is 200-500mm / s, and the welding width is 0.3-0.5mm. The welding power for laser welding of the weld bead through the joint and the joint to the weld groove is 80-130W, and the welding speed is 200-500mm / s.

[0013] In some specific embodiments of the present invention, the welding groove (11) and the welding rib (21) are connected by insertion, and the welding groove (51) and the welding rib (42) are connected by insertion.

[0014] In some specific embodiments of the present invention, the thickness of the first and fifth layers is 0.8-1.5 mm, and the thickness of the welding position is 0.5-1 mm; The thickness of the second and fourth layers is 0.5-1.5 mm; The thickness of the three layers is 0.5-2mm.

[0015] Secondly, the present invention provides a method for fabricating the PPO-based composite antenna element described in the first aspect, the method specifically comprising the following steps: S1. The PPO resin, the glass fiber and the dielectric modifier are mixed evenly according to the ratio, granulated by a twin-screw extruder, and then prepared by injection molding process to form an integral positioning column with a laser transmittance ≥60% and a dielectric constant of 2.8-3.6, thus obtaining the 1st layer and the 5th layer. S2. The PPO resin, LDS additive, low dielectric glass fiber and dielectric regulator are mixed evenly according to the ratio, mixed and granulated by a twin-screw extruder, and then prepared by injection molding. The substrate is activated by LDS laser and chemically plated with metal to form different metallization lines on the substrate surface. The laser absorption rate is ≥90% and the dielectric constant is 2.8-3.6, thus obtaining the 2nd layer and the 4th layer. S3. Using aluminum alloy sheet, the antenna structure and seam are prepared by etching or laser cutting process, and the surface is anodized to obtain the three layers; S4. Assemble the 1st, 2nd, 3rd, 4th, and 5th layers; S5. The assembled layer plate is then subjected to laser welding of layer 1 and layer 2, laser welding of layer 2 and layer 5, and laser welding of layer 4 and layer 5 in sequence to obtain the antenna unit.

[0016] The beneficial effects achieved by this invention are as follows: 1. The PPO-based composite antenna unit provided by the present invention adopts a single laser welding connection method to achieve laser welding of the outer periphery of the 1st and 2nd layers, the 2nd layer penetrating the 3rd and 4th layers and welding with the 5th layer, and the outer periphery welding of the 4th and 5th layers. This completely eliminates the adhesive bonding and insert injection molding process in the prior art, solves the problems of high cost and complex process of the original adhesive bonding process, and avoids the oxidation defects on the surface of the aluminum alloy layer caused by the later PVD of the metal insert. 2. The PPO-based composite antenna unit provided by this invention, by adding dielectric modifiers to layers 1 and 5 (PPO+GF layer) and layers 2 and 4 (LDSPPO layer), precisely adjusts the amount of glass fiber and dielectric modifier, so that the dielectric constant (DK) of each layer can be flexibly adjusted in the range of 2.8-3.6, and the dielectric loss tangent (DF) is <0.005. The dielectric parameters can be adjusted synchronously or independently according to different application scenarios, which greatly improves the versatility of the antenna, breaks through the limitation of fixed dielectric constant of existing multilayer PPO-based antennas, eliminates the need to redesign the antenna structure for different scenarios, and reduces R&D and production costs. 3. The PPO-based composite antenna unit provided by the present invention achieves multi-layer precise assembly by setting positioning posts in the 1st and 5th layers, thereby further improving positioning accuracy and structural integrity; 4. The PPO-based composite antenna unit provided by this invention achieves dual-band antenna function by using three layers (aluminum alloy layers) with different structural designs, combined with two and four layers (LDS PPO layers) containing metallized circuits formed by LDS process. This breaks through the limitation of the single function of existing multi-layer antennas, enabling the antenna to simultaneously realize the transmission of two independent signals, thus expanding the application scenarios. Attached Figure Description

[0017] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a structural diagram of a PPO-based composite antenna unit. Figure 2 This is a diagram of a one-layer structure of a PPO-based composite antenna element, in which... Figure 2 In this context, 'a' represents the front side of the first-layer panel. Figure 1 In this context, 'b' represents the reverse side of the first-layer plate. Figure 3 This is a two-layer structure diagram of a PPO-based composite antenna element, in which... Figure 3 In this context, 'a' represents the front side of the two-layer board. Figure 3 In this context, 'b' represents the reverse side of the two-layer board. Figure 4 This is a three-layer structure diagram of a PPO-based composite antenna element, in which... Figure 4 In this context, 'a' represents the front side of the 3-layer board. Figure 4 In this context, 'b' represents the reverse side of the 3-layer board. Figure 5 This is a diagram of the four-layer structure of a PPO-based composite antenna element, where... Figure 5 In this context, 'a' represents the front side of the 4-layer board. Figure 5 In this context, 'b' represents the reverse side of the 4-layer board. Figure 6 This is a 5-layer structure diagram of a PPO-based composite antenna element, in which... Figure 6 In this context, 'a' represents the front side of the 5-layer board. Figure 6 In this context, 'b' represents the reverse side of the 5-layer board.

[0019] Reference numerals: 1-1 layer, 2-2 layer, 3-3 layer, 4-4 layer, 5-5 layer, 11-welding groove, 12-positioning post, 21-welding rib, 22-welding rib, 23-positioning hole, 24-metallized antenna pattern formed by LDS process, 31-through joint, 41-through joint, 42-welding rib, 43-positioning hole, 44-metallized antenna pattern formed by LDS process, 51-welding groove, 52-welding groove, 53-positioning post. Detailed Implementation

[0020] The present invention will be further described in detail below with reference to specific embodiments. The following embodiments are not intended to limit the present invention, but only to illustrate the present invention. Unless otherwise specified, the experimental methods used in the following embodiments are generally performed under conventional conditions. Unless otherwise specified, the materials and reagents used in the following embodiments are commercially available.

[0021] In the description of this invention, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. At the same time, the terms "first," "second," etc., are only used to distinguish the names of various components and do not have a primary or secondary relationship. Therefore, they should not be construed as limitations on this invention.

[0022] The term "positive" is used in various contexts, such as... Figure 1 As shown, the side of the first layer plate of the antenna element that is away from the second layer plate is the front side, and its direction is defined as "left". Similarly, the left side of the second layer plate of the antenna element is the front side, the left side of the third layer plate of the antenna element is the front side, the left side of the fourth layer plate of the antenna element is the front side, and the left side of the fifth layer plate of the antenna element is also the front side. The term "opposite", such as Figure 1 As shown, the side of the first layer plate of the antenna element closest to the second layer plate is the reverse side, and its direction is defined as "right". Similarly, the right side of the second layer plate of the antenna element is the reverse side, the right side of the third layer plate of the antenna element is the reverse side, the right side of the fourth layer plate of the antenna element is the reverse side, and the right side of the fifth layer plate of the antenna element is also the reverse side.

[0023] Example 1 A PPO-based composite antenna element with tunable dielectric constant is shown in the overall structure diagram below. Figure 1 As shown, from the outside in, the layers are: Layer 1 (PPO+GF layer), Layer 2 (LDS PPO layer), Layer 3 (aluminum alloy layer), Layer 4 (LDS PPO layer), and Layer 5 (PPO+GF layer). They are connected using a single laser welding process, eliminating adhesive bonding and insert injection molding. Layer 1 has positioning posts 12, and Layer 5 has positioning posts 53. The dual-band antenna function is achieved through a metal structure and a metallized circuit design formed by LDS technology. The structural diagram of Layer 1 is shown below. Figure 2 As shown, its front is Figure 2 The opposite of 'a' in the middle is as follows: Figure 2 The structure diagram of layer b;2 is as follows Figure 3 As shown, its front is Figure 3 The opposite of 'a' in the middle is as follows: Figure 3 The structure diagram of layer b; 3 is as follows Figure 4 As shown, its front is Figure 4 The opposite of 'a' in the middle is as follows: Figure 4 The structure diagram of layer b; 4 is as follows Figure 5 As shown, its front is Figure 5 The opposite of 'a' in the middle is as follows: Figure 5 The structural diagram of layer b;5 is as follows Figure 6 As shown, its front is Figure 6 The opposite of 'a' in the middle is as follows: Figure 6 b in the text.

[0024] 1-layer and 5-layer (PPO+GF layer): PPO resin mass fraction is 77%, glass fiber mass fraction is 15%, dielectric modifier (silica micro powder, particle size 3μm) mass fraction is 8%, dielectric constant (DK) after modulation is 2.8, dielectric loss tangent (DF) is 0.002; thickness is 1.5mm, thickness at welding position is 1.3mm, laser transmittance at welding position is 60%; number of positioning posts is 3, evenly distributed at the edge of the layer, diameter is 1.5mm, height is 0.4mm, positioning accuracy is ±0.008mm, integral injection molding with the layer body, realizing precise assembly of 1-5 layers, replacing insert injection molding, and solving the problem of inaccurate positioning.

[0025] 2-layer and 4-layer (LDS PPO layer): PPO resin mass fraction is 71%, LDS additive mass fraction is 8%, glass fiber mass fraction is 13%, dielectric modifier (silica micro powder, particle size 3μm) mass fraction is 8%, dielectric constant (DK) after modulation is 2.8, dielectric loss tangent (DF) is 0.0030; thickness is 1mm, laser absorption rate is 92%; different metallization lines 24 and 44 are formed on the surface through LDS process, the 2nd layer penetrates the 3rd and 4th layers, the cross-sectional size of the penetration part is 0.8mm×0.8mm, replacing the insert injection molding process.

[0026] Layer 3 (aluminum alloy layer): Made of 6061 aluminum alloy, 1mm thick, with anodized surface to prevent oxidation; it features a through-joint 31 (0.83mm diameter); the through-joint 31 is compatible with the welding rib 22 at the through-joint of layer 2, ensuring that the welding rib 22 smoothly passes through through-joint 31 and through-joint 41 and contacts the welding groove 52 of layer 5, solving the problem of inaccurate positioning of the original insert during injection molding. Furthermore, layer 2 has positioning holes 23, and layer 4 has positioning holes 43.

[0027] The welding area of ​​the first layer is provided with a welding groove 11, and the welding area of ​​the fifth layer is provided with a welding groove 51, which are used to accommodate welding overflow and improve welding accuracy; the welding area of ​​the second layer is provided with a welding rib 21, and the welding area of ​​the fourth layer is provided with a welding rib 42, which are used to concentrate welding energy and improve welding strength. The size of the welding groove is adapted to the insertion requirements of the welding rib, so as to meet the assembly and welding operation space.

[0028] Laser welding: 1) Contact welding of the outer surfaces of layers 1 and 2: Laser welding of welding groove 11 and welding rib 21 on the outer surface of the layer plate, welding power 100W, welding speed 300mm / s, welding width 0.4mm, connection strength 22N / cm, replacing adhesive bonding and simplifying the process; 2) After layer 2 penetrates layers 3 and 4, its end is welded to layer 5: Welding rib 22 penetrates through joint 31 and joint 41 and is laser welded to welding groove 52, welding power 110W, welding speed 400mm / s; 3) Circular welding of the outer surfaces of layers 4 and 5: Laser welding of welding groove 51 and welding rib 42 on the outer surface of the layer plate, welding power 100W, welding speed 300mm / s, welding width 0.4mm, forming a closed welding ring; After welding, the overall structure is intact, the dielectric properties are stable, the aluminum alloy layer is free of oxidation, the positioning is accurate, and there is no dimensional misalignment.

[0029] The antenna element prepared in this embodiment has a stable dielectric constant of 2.8 and DF≤0.003, which fully meets the requirements of DK2.8-3.6 and DF<0.005. Precise assembly is achieved through positioning posts, eliminating dimensional misalignment issues. Single laser welding is used, eliminating adhesive bonding and insert injection molding, simplifying the process and reducing costs. The aluminum alloy layer is anodized, eliminating oxidation defects. The dual-band antenna function is achieved by designing different metal structures and metallized circuits formed by LDS process. The overall structure is stable and suitable for mass production.

[0030] Example 2 A PPO-based composite antenna unit with adjustable dielectric constant comprises, from the outside to the inside, a 1st layer (PPO+GF layer), a 2nd layer (LDS PPO layer), a 3rd layer (aluminum alloy layer), a 4th layer (LDS PPO layer), and a 5th layer (PPO+GF layer). It is connected by a single laser welding process, eliminating the need for adhesive bonding and insert injection molding. The 1st layer has a positioning post 12 and the 5th layer has a positioning post 53. The dual-band antenna function is achieved through the metal structure and the metallized circuit design formed by LDS process.

[0031] Layer 1 and Layer 5 (PPO+GF layer): PPO resin mass fraction is 73%, glass fiber mass fraction is 25%, dielectric modifier (boron nitride micro powder, particle size 1μm) mass fraction is 2%, after modulation dielectric constant (DK) = 3.1, dielectric loss tangent (DF) = 0.0028; thickness is 1mm, thickness at welding position is 0.75mm, laser transmittance is 66%; there are 2 positioning posts, symmetrically distributed at the edge of the layer, diameter 1.2mm, height 0.5mm, positioning accuracy ±0.01mm, integrally injection molded with the layer body to achieve precise assembly and solve the problem of inaccurate positioning of the original insert injection molding. In addition, layer 2 has positioning hole 23 and layer 4 has positioning hole 43.

[0032] 2-layer and 4-layer (LDS PPO layer): PPO resin mass fraction is 68%, LDS additive mass fraction is 7%, low dielectric glass fiber mass fraction is 24%, dielectric modifier (boron nitride micro powder, particle size 1μm) mass fraction is 3%, after modulation dielectric constant (DK) = 3.1, dielectric loss tangent (DF) = 0.0032; thickness is 1.2mm, laser absorption rate is 90%; different metallization lines 24 and 44 are formed on the surface through LDS process, the 2nd layer penetrates the 3rd and 4th layers, the cross-sectional size of the penetration part is 1.0mm×1.0mm, replacing the insert injection molding process.

[0033] The third layer (aluminum alloy layer) is made of 7075 aluminum alloy, 1.5mm thick, and anodized to prevent surface oxidation. It features a through-joint 31 (1.05mm diameter) that matches the welding rib 22 at the through-joint of the second layer, ensuring the rib 22 smoothly passes through through-joints 31 and 41 and contacts the welding groove 52 of the fifth layer, thus resolving the inaccurate positioning issue of the original insert during injection molding. The welding area of ​​the first layer has a welding groove 11, and the welding area of ​​the fifth layer has a welding groove 51, used to accommodate welding overflow and improve welding accuracy. The corresponding welding areas of the second layer and the fourth layer have welding ribs 42, used to concentrate welding energy and increase welding strength. The dimensions of the welding grooves are adapted to the insertion requirements of the welding ribs, satisfying the assembly and welding operation space requirements.

[0034] Laser welding: 1) Contact welding of the outer surfaces of layers 1 and 2: Laser welding of welding groove 11 and welding rib 21 on the outer surface of the layer plate, welding power 80W, welding speed 200mm / s, welding width 0.3mm, connection strength 20N / cm, replacing adhesive bonding and simplifying the process; 2) After layer 2 penetrates layers 3 and 4, its end is welded to layer 5: Welding rib 22 penetrates through joint 31 and joint 41 and is laser welded to welding groove 52, welding power 90W, welding speed 250mm / s; 3) Circular welding of the outer surfaces of layers 4 and 5: Laser welding of welding groove 51 and welding rib 42 on the outer surface of the layer plate, welding power 80W, welding speed 200mm / s, welding width 0.3mm, forming a closed welding ring; After welding, the overall structure is intact, the dielectric properties are stable, the aluminum alloy layer is free of oxidation, the positioning is accurate, and there is no dimensional misalignment.

[0035] The antenna element prepared in this embodiment has a stable dielectric constant of 3.2 and DF≤0.0032, meeting the core requirements of DK2.8-3.6 and DF<0.005. It abandons the adhesive bonding and insert injection molding process and adopts a single laser welding process, which is simple and reduces costs. The positioning post ensures assembly accuracy and eliminates misalignment problems. The aluminum alloy layer is free of oxidation defects. The dual antenna function is realized by designing different metal structures and metallized circuits formed by LDS process. The overall performance is stable and it is suitable for a variety of application scenarios.

[0036] Example 3 A PPO-based composite antenna unit with adjustable dielectric constant consists of five layers from the outside to the inside: a 1-layer (PPO+GF layer), a 2-layer (LDS PPO layer), a 3-layer (aluminum alloy layer), a 4-layer (LDS PPO layer), and a 5-layer (PPO+GF layer). The layers are connected by a single laser welding process, eliminating the need for adhesive bonding and insert injection molding. The 1-layer has a positioning post 12, and the 5-layer has a positioning post 53. The dual-band antenna function is achieved through the metal structure and the metallized circuit design formed by LDS process.

[0037] Layer 1 and Layer 5 (PPO+GF layer): PPO resin mass fraction is 60%, glass fiber mass fraction is 30%, dielectric modifier (silica micro powder, particle size 5μm) mass fraction is 10%, after modulation dielectric constant (DK) = 3.5, dielectric loss tangent (DF) = 0.003; thickness is 0.8mm, thickness at welding position is 0.65mm, laser transmittance at welding position is 87%; there are 4 positioning posts, evenly distributed at the edge of the layer, diameter 1.8mm, height 0.3mm, positioning accuracy ±0.009mm, integrally injection molded with the layer body to achieve precise assembly and solve the problem of inaccurate positioning of inserts during injection molding. Furthermore, layer 2 has positioning holes 23, and layer 4 has positioning holes 43.

[0038] 2-layer and 4-layer (LDS PPO layer): PPO resin mass fraction is 53%, LDS additive mass fraction is 10%, low dielectric glass fiber mass fraction is 27%, dielectric modifier (silica micro powder, particle size 5μm) mass fraction is 10%, after modulation dielectric constant (DK) = 3.5, dielectric loss tangent (DF) = 0.0041; thickness is 0.8mm, laser absorption rate is 91%; different metallization lines 24 and 44 are formed on the surface through LDS process, the 2nd layer penetrates the 3rd and 4th layers, the cross-sectional size of the penetration part is 0.9mm×0.9mm, replacing the insert injection molding process.

[0039] The welding area of ​​the first layer is provided with a welding groove 11, and the welding area of ​​the fifth layer is provided with a welding groove 51, which are used to accommodate welding overflow and improve welding accuracy; the welding area of ​​the second layer is provided with a welding rib 21, and the welding area of ​​the fourth layer is provided with a welding rib 42, which are used to concentrate welding energy and improve welding strength. The size of the welding groove is adapted to the insertion requirements of the welding rib, so as to meet the assembly and welding operation space.

[0040] 3rd layer (aluminum alloy layer): Made of 6061 aluminum alloy, 2mm thick, with anodized surface to prevent oxidation; different structures and through-joints (0.94mm diameter) are provided. The through-joint 31 is adapted to the welding rib 22 of the through part of the 2nd layer, ensuring that the welding rib 22 can smoothly pass through the through-joint 31 and through-joint 41 and contact the welding groove 52 of the 5th layer, with accurate positioning.

[0041] Laser welding: 1) Contact welding of the outer surfaces of layers 1 and 2: Laser welding of welding groove 11 and welding rib 21 on the outer surface of the layer plate, welding power 120W, welding speed 450mm / s, welding width 0.6mm, connection strength 23N / cm, replacing adhesive bonding and simplifying the process; 2) After layer 2 penetrates layers 3 and 4, its end is welded to layer 5: Welding rib 22 penetrates through joint 31 and joint 41 and is laser welded to welding groove 52, welding power 130W, welding speed 500mm / s; 3) Circular welding of the outer surfaces of layers 4 and 5: Laser welding of welding groove 51 and welding rib 42 on the outer surface of the layer plate, welding speed 450mm / s, welding width 0.5mm, forming a closed welding ring; reliable welding quality, tight interlayer connection, no oxidation of aluminum alloy layer, accurate positioning, and no dimensional misalignment.

[0042] The antenna element prepared in this embodiment has a stable dielectric constant of 3.5 and DF≤0.0041, meeting the core requirements of DK2.8-3.6 and DF<0.005; the process is simplified, eliminating adhesive bonding and insert injection molding, thus reducing costs; the positioning is accurate and the structure is stable; the aluminum alloy layer is free of oxidation defects; the dual antenna functions are stable, making it suitable for mass production and widespread application.

[0043] Example 4 A PPO-based composite antenna unit with adjustable dielectric constant consists of five layers from the outside to the inside: a 1-layer (PPO+GF layer), a 2-layer (LDS PPO layer), a 3-layer (aluminum alloy layer), a 4-layer (LDS PPO layer), and a 5-layer (PPO+GF layer). The layers are connected by a single laser welding process, eliminating the need for adhesive bonding and insert injection molding. The 1-layer has a positioning post 12, and the 5-layer has a positioning post 53. The dual-band antenna function is achieved through the metal structure and the metallized circuit design formed by LDS process.

[0044] 1-layer and 5-layer (PPO+GF layer): PPO resin mass fraction is 55%, low dielectric glass fiber mass fraction is 40%, dielectric modifier (silica micro powder, particle size 3μm) mass fraction is 5%, dielectric constant (DK) after modulation is 3.6, dielectric loss tangent (DF) is 0.0034; thickness is 0.8mm, thickness at welding position is 0.6mm, laser transmittance at welding position is 74%; number of positioning posts is 3, evenly distributed at the edge of the layer, diameter is 1.5mm, height is 0.4mm, positioning accuracy is ±0.008mm, integral injection molding with the layer body, realizing precise assembly of 1-5 layers, replacing insert injection molding, and solving the problem of inaccurate positioning.

[0045] 2-layer and 4-layer (LDS PPO layer): PPO resin mass fraction is 54%, LDS additive mass fraction is 5%, low dielectric glass fiber mass fraction is 33%, dielectric modifier (silica micro powder, particle size 3μm) mass fraction is 8%, after modulation dielectric constant (DK) = 3.6, dielectric loss tangent (DF) = 0.0048; thickness is 0.5mm, laser absorption rate is 92%; different metallization lines 24 and 44 are formed on the surface through LDS process. The 2nd layer penetrates the 3rd and 4th layers, and the cross-sectional size of the penetration part is 0.8mm × 0.8mm, which replaces the insert injection molding process and avoids subsequent PVD treatment.

[0046] The welding area of ​​the first layer is provided with a welding groove 11, and the welding area of ​​the fifth layer is provided with a welding groove 51, which are used to accommodate welding overflow and improve welding accuracy; the welding area of ​​the second layer is provided with a welding rib 21, and the welding area of ​​the fourth layer is provided with a welding rib 42, which are used to concentrate welding energy and improve welding strength. The size of the welding groove is adapted to the insertion requirements of the welding rib, so as to meet the assembly and welding operation space.

[0047] 3rd layer (aluminum alloy layer): Made of 6061 aluminum alloy, 1mm thick, with anodized surface to prevent oxidation; different structures and through-holes (0.83mm diameter) are provided. The through-hole 31 is adapted to the welding rib 22 of the through part of the 2nd layer, ensuring that the welding rib 22 can smoothly pass through the through-hole 31 and through-hole 41 and contact the welding groove 52 of the 5th layer, solving the problem of inaccurate positioning of the original insert during injection molding.

[0048] Laser welding: 1) Contact welding of the outer surfaces of layers 1 and 2: Laser welding of welding groove 11 and welding rib 21 on the outer surface of the layer plate, welding power 100W, welding speed 350mm / s, welding width 0.4mm, connection strength 22N / cm, replacing adhesive bonding and simplifying the process; 2) After layer 2 penetrates layers 3 and 4, its end is welded to layer 5: Welding rib 22 penetrates through joint 31 and joint 41 and is laser welded to welding groove 52, welding power 110W, welding speed 400mm / s; 3) Circular welding of the outer surfaces of layers 4 and 5: Laser welding of welding groove 51 and welding rib 42 on the outer surface of the layer plate, welding power 100W, welding speed 350mm / s, welding width 0.4mm, forming a closed welding ring; All welding parts are free from incomplete welding and detachment, the overall structure is free from deformation, and the aluminum alloy layer is free from oxidation.

[0049] The antenna element prepared in this embodiment has a stable dielectric constant of 3.6 and DF≤0.0048, which fully meets the requirements of DK2.8-3.6 and DF<0.005. Precise assembly is achieved through positioning posts, eliminating dimensional misalignment issues. Single laser welding is used, eliminating adhesive bonding and insert injection molding, simplifying the process and reducing costs. The aluminum alloy layer is anodized, eliminating oxidation defects. Dual-band antenna functionality is achieved through different structural and graphic designs, with a stable overall structure suitable for mass production.

[0050] Example 5 A method for fabricating a PPO-based composite antenna element specifically includes the following steps: S1 Preparation of 1-layer and 5-layer (PPO+GF layer): PPO resin, glass fiber and dielectric modifier are mixed evenly according to the ratio and granulated by twin-screw extruder, and then prepared by injection molding process to form a positioning column in one piece, ensuring that the laser transmittance is ≥60% and the dielectric constant is 2.8-3.6, thus obtaining the 1-layer and the 5-layer. S2 Preparation of 2-layer and 4-layer (LDS PPO layer): PPO resin, LDS additive, low dielectric glass fiber and dielectric regulator are mixed and granulated by twin-screw extruder, and then prepared by injection molding process. By LDS laser activation and chemical metallization, different metallization lines 24 and 44 are formed on the surface of the substrate, ensuring that the laser absorption rate is ≥90% and the dielectric constant is 2.8-3.6, to obtain the 2-layer and the 4-layer. S3 Preparation of 3 Layers (Aluminum Alloy Layer): Using aluminum alloy sheet, the antenna structure and through-seams are prepared by etching or laser cutting process, and the surface is anodized to avoid surface oxidation, thus obtaining the 3 layers; S4 Precision Assembly: Using the positioning posts of layers 1 and 5, layers 1, 2, 3, 4, and 5 are aligned sequentially to ensure that layer 2 passes through the seam of layer 3 and contacts layer 5 for assembly. S5 laser welding: Using a single laser welding process, the assembled layers are sequentially laser welded between layers 1 and 2, between layers 2 and 5, and between layers 4 and 5. Welding parameters are controlled to ensure welding quality and obtain the antenna unit. The antenna unit is manufactured without any adhesives or inserts, simplifying the process and reducing costs.

[0051] The above specific embodiments further illustrate the purpose, technical solution and beneficial effects of this application. It should be understood that the above are only specific embodiments of this application and are not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made on the basis of the technical solution of this application should be included within the scope of protection of this application.

Claims

1. A PPO-based composite antenna element, characterized in that, The antenna unit is a composite structure consisting of 1 layer (1), 2 layers (2), 3 layers (3), 4 layers (4) and 5 layers (5) from the outside to the inside. The 1st layer (1) and the 5th layer (5) are PPO layers doped with glass fiber, the 2nd layer (2) and the 4th layer (4) are PPO layers doped with LDS additive, and the 3rd layer (3) is an aluminum alloy layer. The dielectric constants of the 1st layer (1), 2nd layer (2), 4th layer (4) and 5th layer (5) are 2.8-3.6, and the dielectric loss tangent is <0.005; The connection between layer 1 (1) and layer 2 (2) is to laser weld the welding groove (11) and welding rib (21) on the periphery of the layer plate; the connection between layer 4 (4) and layer 5 (5) is to laser weld the welding groove (51) and welding rib (42) on the periphery of the layer plate. The connection between the 2nd layer (2) and the 5th layer (5) is to pass the welding rib (22) through the through joint (31) and the through joint (41) and laser weld it to the welding groove (52).

2. The antenna element according to claim 1, characterized in that, The laser transmittance of the 1st layer (1) and the 5th layer (5) is ≥60%; the laser absorption rate of the 2nd layer (2) and the 4th layer (4) is ≥90%.

3. The antenna element according to claim 1 or 2, characterized in that, The materials of the 1st layer (1) and the 5th layer (5) are specifically composite materials containing PPO resin, glass fiber and dielectric modifier; the dielectric modifier is silicon dioxide or boron nitride micro powder with a particle size of 1-5 μm; By weight, the PPO resin is 55-80 parts, the glass fiber is 15-40 parts, and the dielectric modifier is 2-8 parts.

4. The antenna element according to claim 1 or 2, characterized in that, The materials of the two layers (2) and the four layers (4) are specifically composite materials including PPO resin, LDS additive, glass fiber and dielectric modifier; By weight, the PPO resin is 50-75 parts, the LDS additive is 5-10 parts, the glass fiber is 10-35 parts, and the dielectric modifier is 2-8 parts.

5. The antenna element according to claim 1, characterized in that, The aluminum alloy layer of the three layers (3) is 6061 or 7075 aluminum alloy, etc.; the aluminum alloy layer can be etched or cut into different shapes. The second layer (2) has a metallized antenna pattern (24) prepared by LDS process on its layer plate, and the fourth layer (4) has a metallized antenna pattern (44) prepared by LDS process on its layer plate. The diameter of the through joint (31) and the through joint (41) is 0.02-0.05 mm larger than the cross-sectional size of the welded bar (22).

6. The antenna element according to claim 1 or 5, characterized in that, The first layer (1) is provided with a positioning post (12), and the fifth layer (5) is provided with a positioning post (53). The positioning post is integrally injection molded with the first layer (1) or the fifth layer (5). The positioning posts have a diameter of 1-2 mm, a height of 0.3-0.6 mm, a positioning accuracy of ≤ ±0.01 mm, and a quantity of 2-4, evenly distributed at the edge of the layer.

7. The antenna element according to claim 1, characterized in that, The welding power of the welding groove (11) and the welding rib (21) when laser welding is performed on the outer periphery of the layer plate is 80-130W, the welding speed is 200-500mm / s, the welding width is 0.3-0.6mm, and the connection strength is ≥20N / cm. The welding power for laser welding the welding groove (51) and welding rib (42) on the periphery of the layer plate is 80-130W, the welding speed is 200-500mm / s, and the welding width is 0.3-0.5mm. The welding power for laser welding of the weld bar (22) through the joint (31) and the joint (41) to the weld groove (52) is 80-130W, and the welding speed is 200-500mm / s.

8. The antenna element according to claim 1, characterized in that, The welding groove (11) and the welding rib (21) are connected by insertion, and the welding groove (51) and the welding rib (42) are connected by insertion.

9. The antenna element according to claim 8, characterized in that, The thickness of the 1st layer (1) and the 5th layer (5) is 0.8-1.5 mm, and the thickness of the welding position is 0.5-1 mm; The thickness of the two layers (2) and the four layers (4) is 0.5-1.5 mm; The thickness of the three layers (3) is 0.5-2 mm.

10. A method for fabricating a PPO-based composite antenna element according to any one of claims 1 to 9, characterized in that, The preparation method specifically includes the following steps: S1. The PPO resin, the glass fiber and the dielectric regulator are mixed evenly according to the ratio, granulated by a twin-screw extruder, and then prepared by injection molding process to form an integral positioning column with a laser transmittance ≥60% and a dielectric constant of 2.8-3.6, thus obtaining the 1st layer (1) and the 5th layer (5). S2. The PPO resin, LDS additive, glass fiber and dielectric regulator are mixed evenly according to the ratio, mixed and granulated by a twin-screw extruder, and then prepared by injection molding process. The metallized circuit is formed on the surface of the substrate by LDS laser activation and chemical metallization. The laser absorption rate is ≥90% and the dielectric constant is 2.8-3.6, thus obtaining the 2nd layer (2) and the 4th layer (4). S3. Using aluminum alloy sheet, the antenna structure and the through-seam are prepared by etching or laser cutting process, and the surface is anodized to obtain the three layers (3). S4. Assemble the 1st layer (1), 2nd layer (2), 3rd layer (3), 4th layer (4), and 5th layer (5); S5. The assembled layer plate is laser welded sequentially to the 1st layer (1) and the 2nd layer (2), the 2nd layer (2) and the 5th layer (5), and the 4th layer (4) and the 5th layer (5) to obtain the antenna unit.

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