Method for manufacturing OBD integrated multi-band antenna based on LDS process

Abstract

The invention relates to the technical field of antennas, in particular to an OBD (On-Board Diagnostic) integrated multi-band antenna manufacturing method based on an LDS (Laser Direct Structuring) process, which comprises the following steps of: carrying out injection molding on an OBD shell substrate by adopting a modified composite material containing a copper-nickel metal organic matter; cooperative processing is carried out through a 532nm and 1064nm dual-wavelength laser; treating in a chemical copper plating solution containing graphene quantum dots for 25-35 minutes; during treatment in a chemical nickel plating solution with the pH value of 8.5-9.5, pulse electroplating is synchronously carried out; local gold plating is assisted by femtosecond laser; processing an impedance gradient transition region in a nitrogen plasma environment; and S7, monitoring the components of the plating layer in real time through an online mass spectrometer, dynamically adjusting the parameters of the plating solution, and controlling the atomic ratio of Cu to Ni within the range of 3: 1 to 5: 1. Compared with the prior art, the method for manufacturing the OBD integrated multi-band antenna based on the LDS process can realize the structural integration of the antenna and the OBD shell, saves the internal space occupied by a traditional independent antenna, and facilitates the miniaturization of OBD equipment.

Description

[Technical Field] This invention relates to the field of antenna technology, and in particular to a method for manufacturing an OBD integrated multi-band antenna based on LDS technology. [Background Technology] With the increasing popularity of automobiles, especially the development of intelligent electric vehicles, vehicle intelligence has become a key performance indicator that major automakers and consumers are focusing on and pursuing. The increasing demands on communication quality and the integration of communication equipment in automobiles have led to a rapid increase in the adoption rate of various communication terminal devices. The most convenient and fastest method is wireless access, which requires an antenna.

[0001] On-Board Diagnostics (OBD), which can monitor engine operation, exhaust system status, and GPS positioning in real time, is increasingly favored by automakers and consumers. The integration of antennas into OBD products facilitates faster and more convenient information transmission, allowing consumers to monitor vehicle parameters at any time, which is of particular importance to the safety of drivers and passengers.

[0002] Because OBD products are small in size, the space available for antennas is very limited. Ordinary antennas cannot meet the requirements, so it is necessary to develop a high-performance small microstrip antenna to fill this gap. [Summary of the Invention] To overcome the above problems, this invention proposes a method for manufacturing an OBD integrated multi-band antenna based on LDS technology, which can effectively solve the above problems.

[0003] The present invention provides a technical solution to solve the above-mentioned technical problems: a method for manufacturing an OBD integrated multi-band antenna based on LDS technology, comprising the following steps: Step S1: The OBD shell substrate is injection molded using a modified composite material containing copper-nickel metal organic matter. During the injection molding process, an axial magnetic field of 0.5-1.2T is applied in the mold to make the plastic molecular chains arrange themselves in an orderly manner along the direction of the magnetic field. Step S2: Processing is performed using a dual-wavelength laser of 532nm and 1064nm. The 532nm laser performs the main path scanning, while the 1064nm laser performs a secondary trimming scan. The center-to-center distance between the two laser beams is controlled within 0.05-0.1mm. Step S3: Treat in a chemical copper plating solution containing graphene quantum dots for 25-35 minutes, during which ultrasonic vibration at 10-20 kHz is applied; Step S4: When treating in a chemical nickel plating solution with pH 8.5-9.5, pulse electroplating is performed simultaneously, with a pulse frequency of 100-200Hz and a duty cycle of 30-50%. Step S5: Use femtosecond laser-assisted local gold plating, with laser power of 5-8W, pulse width of 200-400fs, and gold layer thickness gradient controlled at 0.05-0.2μm; Step S6: Process the impedance gradient transition region in a nitrogen plasma environment with a plasma power of 300-500W and a processing time of 90-120 seconds. Step S7: Monitor the coating composition in real time using an online mass spectrometer, dynamically adjust the plating bath parameters, and control the Cu:Ni atomic ratio within the range of 3:1 to 5:1. Preferably, in step S1, a permanent magnet array is used to generate an axial magnetic field of 0.5-1.2T, the magnetic field gradient is controlled at 5-8T / m, the magnetic field is applied during the pressure holding stage after the melt filling is completed, and the magnetic field is applied for 3-5 seconds.

[0004] Preferably, in step S1, the polar molecules in the modified composite material are arranged in an orderly manner along the direction of the magnetic field lines under the action of the magnetic field to form an anisotropic dielectric structure.

[0005] Preferably, in step S1, the injection mold temperature is maintained at 85±2℃, the melt temperature is 235±5℃, and the cooling rate is reduced to 0.8℃ / s under the action of the magnetic field.

[0006] Preferably, in step S2, the 532nm laser beam quality M² < 1.2, the focal diameter is 20μm, the 532nm laser energy density is 12J / cm², the single pulse width is 50ns, and the repetition frequency is 80kHz; in step S2, the 1064nm laser adopts a flat-top beam distribution, a focal diameter of 50μm, a 1064nm laser energy density of 5J / cm², continuous wave mode, and the heat-affected zone depth is controlled at 3-5μm.

[0007] Preferably, in step S2, the morphology of the activated area is monitored in real time by an online CCD detection system, and the laser power fluctuation is adjusted to within ±2%.

[0008] Preferably, in step S3, the ultrasonic frequency is 18kHz, the power density is 0.5W / cm³, and the cavitation effect generates a microjets with a penetration depth of up to 50μm; in step S3, the temperature gradient in the ultrasonic action area is <0.3℃ / cm.

[0009] Preferably, in step S5, the femtosecond laser scanning employs a helical path filling with a step size of 0.8 μm and a power density of 1.5 × 10¹. 4 W / cm²; In step S5, the gold deposition rate in the laser-induced region reaches 0.3 μm / s, and the deposition rate in the non-irradiated region is <0.01 μm / s.

[0010] Preferably, in step S6, the radio frequency power supply frequency of the plasma system is 13.56MHz, the power density is 0.8W / cm², the nitrogen flow rate is 20sccm, the reaction chamber pressure is 30Pa, the electrode spacing is 50mm, and the substrate bias voltage is -100V.

[0011] Preferably, the antenna structure manufactured by the OBD integrated multi-band antenna manufacturing method based on LDS technology includes an OBD device housing body injection molded from LDS modified plastic, and the surface of the housing body is formed into a composite antenna radiation structure by laser activation. The composite antenna radiation structure includes a low-frequency radiator and a high-frequency radiator. The low-frequency radiator adopts a streamlined layout to cover the 617-894MHz frequency band, and the high-frequency radiator adopts a branched inverted F structure to cover the 1710-2690MHz frequency band. The surface of the composite antenna radiating structure is chemically plated to form a composite metallized structure consisting of a copper-based conductive layer and a nickel protective layer. The bottom of the housing body is provided with an impedance matching power supply point and at least two grounding points, which are connected to the OBD main control module through a flexible circuit board.

[0012] Compared with existing technologies, the OBD integrated multi-band antenna manufacturing method based on LDS technology of the present invention can realize the structural integration of the antenna and the OBD housing, saving the internal space occupied by traditional independent antennas and facilitating the miniaturization of OBD devices; the composite design of low-frequency and high-frequency bands solves the multi-band compatibility problem and supports the mainstream 4G frequency bands worldwide; the housing body serves as the antenna carrier, avoiding internal circuit interference, which is conducive to improving the signal-to-noise ratio and antenna performance, and can better meet the antenna usage requirements of OBD products. [Attached Image Description] Figure 1 This is a flowchart of the OBD integrated multi-band antenna manufacturing method based on LDS technology according to the present invention; Figure 2 This is a schematic diagram of the antenna structure manufactured using the OBD integrated multi-band antenna manufacturing method based on LDS technology of the present invention.

Detailed Implementation Methods

[0013] It should be noted that in the embodiments of the present invention, all directional indications (such as up, down, left, right, front, back, etc.) are limited to relative positions on the specified view, rather than absolute positions.

[0014] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0015] Please see Figure 1 The present invention provides a method for manufacturing an OBD integrated multi-band antenna based on LDS technology, comprising the following steps: Step S1: The OBD shell substrate is injection molded using modified PC and ABS composite materials containing copper-nickel metal organics. During the injection molding process, an axial magnetic field of 0.5-1.2T is applied in the mold to make the plastic molecular chains arrange themselves in an orderly manner along the direction of the magnetic field.

[0016] In step S1, an axial magnetic field is introduced to regulate the orientation of plastic molecular chains. Compared with conventional injection molding, which relies solely on the mold structure to control orientation, this helps to reduce the anisotropy of dielectric constant and reduce dielectric loss in the high-frequency band.

[0017] Step S2: Processing is performed using a dual-wavelength laser of 532nm and 1064nm, wherein: The 532nm laser is used for main path scanning at a power of 60-80W and a speed of 500-800mm / s; A 1064nm laser is used for secondary trimming scanning at a power of 30-40W and a speed of 1200-1500mm / s, with the center-to-center distance between the two laser spots controlled at 0.05-0.1mm.

[0018] In step S2, a dual-mode processing mode of 532nm main activation + 1064nm post-processing is adopted. Compared with single-wavelength processing, this helps to reduce the roughness of the circuit edge and improve the conductivity uniformity of the activation area.

[0019] Step S3: Treat in a chemical copper plating solution containing graphene quantum dots (concentration 50-100ppm) for 25-35 minutes, during which ultrasonic vibration at 10-20kHz is applied.

[0020] In step S3, the chemical plating process is enhanced by nanomaterials, which solves the problem of dendrite formation in traditional plating solutions, improves the density of the plating layer, and increases the ductility of the copper layer.

[0021] Step S4: When treating in a chemical nickel plating solution with pH 8.5-9.5, pulse electroplating is performed simultaneously with a pulse frequency of 100-200Hz and a duty cycle of 30-50%.

[0022] In step S4, the timing of chemical plating and physical pulse electroplating is combined to reduce plating stress and increase the hardness of the nickel layer.

[0023] Step S5: Use femtosecond laser to assist in local gold plating, with a laser power of 5-8W, a pulse width of 200-400fs, and a gold layer thickness gradient controlled at 0.05-0.2μm.

[0024] In step S5, ultrafast laser-induced selective deposition is used, which helps to improve the adhesion of the gold layer and reduce the amount of gold consumed.

[0025] Step S6: Process the impedance gradient transition zone in a nitrogen plasma environment with a plasma power of 300-500W and a processing time of 90-120 seconds.

[0026] In step S6, nitrogen plasma interface modification helps to reduce contact resistance and improve resistance to damp heat.

[0027] Step S7: Monitor the coating composition in real time using an online mass spectrometer, dynamically adjust the plating bath parameters, and control the Cu:Ni atomic ratio within the range of 3:1 to 5:1.

[0028] In step S1, a permanent magnet array is used to generate an axial magnetic field of 0.5-1.2T, with the magnetic field gradient controlled at 5-8T / m. The magnetic field is applied during the pressure holding stage after the melt filling is completed, and the magnetic field is applied for 3-5 seconds.

[0029] In step S1, polar molecules in PC and ABS materials (such as cyano groups in ABS) are arranged in an orderly manner along the direction of magnetic field lines under the action of a magnetic field, forming an anisotropic dielectric structure.

[0030] In step S1, the injection mold temperature is maintained at 85±2℃, the melt temperature is 235±5℃, and the cooling rate is reduced to 0.8℃ / s under the action of the magnetic field.

[0031] In step S2, the 532nm laser beam quality M² < 1.2, the focal diameter is 20μm, and a galvanometer scanning system is used, achieving an accuracy of ±1μm. The 532nm laser energy density is 12J / cm², the single pulse width is 50ns, and the repetition frequency is 80kHz.

[0032] In step S2, the 1064nm laser uses a flat-top beam distribution with a focal diameter of 50μm. The compensation amount is calculated to be between 0.05-0.1mm using a scanning path offset compensation algorithm. The 1064nm laser has an energy density of 5J / cm², operates in continuous wave mode, and the heat-affected zone depth is controlled between 3-5μm.

[0033] In step S2, the morphology of the activated region is monitored in real time using an online CCD detection system, and the laser power fluctuation is adjusted to within ±2%. The resolution of the online CCD detection system is 0.5 μm.

[0034] In step S3, the chemical copper plating solution containing graphene quantum dots includes basic components and additives. The basic components include 20 g / L copper sulfate, 40 g / L disodium ethylenediaminetetraacetate, and 10 ml / L formaldehyde. The additives include 80 ppm carboxylated graphene quantum dots (particle size 3-5 nm) and 0.5 g / L sodium dodecyl sulfonate.

[0035] In step S3, the ultrasonic frequency is 18kHz, the power density is 0.5W / cm³, and the cavitation effect generates a microjets with a penetration depth of up to 50μm.

[0036] In step S3, the temperature gradient in the ultrasonic treatment area is <0.3℃ / cm to avoid local overheating of the plating solution.

[0037] In step S3, the formed coating has the following characteristics: scanning electron microscopy (SEM) shows a grain size of 30-50 nm; the sheet resistance measured by the four-point probe method is 0.015 Ω / □.

[0038] In step S4, the pulse waveform has a forward current density of 3A / dm² (pulse width of 2ms) and a reverse current density of -1A / dm² (pulse width of 0.5ms).

[0039] In step S4, the pulse cycle frequency is 150Hz, the duty cycle is 40%, and the total processing time is 10 minutes.

[0040] In step S4, the nanoindentation test of the obtained coating showed a hardness of HV320.

[0041] In step S5, the femtosecond laser scanning employs a helical path filling with a step size of 0.8 μm and a power density of 1.5 × 10¹. 4 W / cm².

[0042] In step S5, the gold deposition rate in the laser-induced region reaches 0.3 μm / s, and the deposition rate in the non-irradiated region is <0.01 μm / s.

[0043] In step S5, the focused ion beam (FIB) shows that the thickness of the gold-nickel interface diffusion layer is 50 nm.

[0044] In step S6, the radio frequency power supply frequency of the plasma system is 13.56MHz, the power density is 0.8W / cm², the nitrogen flow rate is 20sccm, the reaction chamber pressure is 30Pa, the electrode spacing is 50mm, and the substrate bias voltage is -100V.

[0045] Please see Figure 2 The antenna structure manufactured by the OBD integrated multi-band antenna manufacturing method based on LDS process of the present invention includes an OBD device housing body 1 made of LDS modified plastic injection molding, and a composite antenna radiation structure 2 is formed on the surface of the housing body 1 by laser activation.

[0046] The composite antenna radiating structure 2 includes a low-frequency radiator and a high-frequency radiator. The low-frequency radiator adopts a streamlined layout to cover the 617-894MHz frequency band, and the high-frequency radiator adopts a branched inverted F structure to cover the 1710-2690MHz frequency band.

[0047] The surface of the composite antenna radiating structure 2 is chemically plated to form a composite metallized structure consisting of a copper-based conductive layer and a nickel protective layer.

[0048] The bottom of the outer casing 1 is provided with an impedance matching power supply point and at least two grounding points, which are connected to the OBD main control module through a flexible circuit board.

[0049] The low-frequency radiator comprises three asymmetric ring units, which are connected in series by microstrip lines with a width of 0.8-1.2 mm. The spacing between adjacent ring units is λ / 8 (λ is the wavelength of 617 MHz). The inner diameter of the ring unit is 3-5 mm and the outer diameter is 8-10 mm. The ring units are arranged in a three-dimensional space through an arc transition with a curvature radius of R2-R5.

[0050] The high-frequency radiator includes a main radiating arm and two parasitic branches. The length of the main radiating arm corresponds to 1 / 4 wavelength of 2690MHz. The parasitic branches are loaded at 30% and 70% positions of the main radiating arm, respectively. The length difference of the branches is designed to be λ / 16 (λ is the wavelength of 1710MHz). The ends of the branches are provided with a width gradient structure, and the gradient rate is controlled at 0.15-0.25mm / mm.

[0051] In the composite metallized structure, the copper-based conductive layer has a thickness of 8-12 μm, the nickel protective layer has a thickness of 2-4 μm, and a selective gold plating area is provided on the surface of the nickel protective layer. The gold plating layer has a thickness of 0.05-0.1 μm and covers an area of ​​15-20% of the total area of ​​the radiator. It is mainly distributed around the feed point and in the current density concentration area of ​​the high-frequency radiator.

[0052] The dielectric constant of the outer shell body 1 is controlled within the range of 3.2-3.8, the loss tangent is less than 0.02, the surface roughness Ra value is controlled within the range of 0.8-1.6μm, and an overflow prevention groove with a depth of 0.2-0.5mm is set in the non-radiation area, and the groove is filled with a silicon-based composite material with a dielectric constant ≤2.6.

[0053] Compared with existing technologies, the OBD integrated multi-band antenna manufacturing method based on LDS technology of this invention realizes the structural integration of the antenna and the OBD housing, saving the internal space occupied by traditional independent antennas and facilitating the miniaturization of OBD devices; the composite design of low-frequency band (617-894MHz) and high-frequency band (1710-2690MHz) solves the multi-band compatibility problem and supports the mainstream 4G frequency bands worldwide; the housing body serves as the antenna carrier, avoiding internal circuit interference, which is conducive to improving the signal-to-noise ratio and enhancing antenna performance, thus better meeting the antenna usage requirements of OBD products.

[0054] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any modifications, equivalent substitutions and improvements made within the concept of the present invention should be included within the patent protection scope of the present invention.

Claims

1. A method for manufacturing an OBD integrated multi-band antenna based on LDS technology, characterized in that, Includes the following steps: Step S1: The OBD shell substrate is injection molded using a modified composite material containing copper-nickel metal organic matter. During the injection molding process, an axial magnetic field of 0.5-1.2T is applied in the mold to make the plastic molecular chains arrange themselves in an orderly manner along the direction of the magnetic field. Step S2: Processing is performed using a dual-wavelength laser of 532nm and 1064nm. The 532nm laser performs the main path scanning, while the 1064nm laser performs a secondary trimming scan. The center-to-center distance between the two laser beams is controlled within 0.05-0.1mm. Step S3: Treat in a chemical copper plating solution containing graphene quantum dots for 25-35 minutes, during which ultrasonic vibration at 10-20 kHz is applied; Step S4: When treating in a chemical nickel plating solution with pH 8.5-9.5, pulse electroplating is performed simultaneously, with a pulse frequency of 100-200Hz and a duty cycle of 30-50%. Step S5: Use femtosecond laser-assisted local gold plating, with laser power of 5-8W, pulse width of 200-400fs, and gold layer thickness gradient controlled at 0.05-0.2μm; Step S6: Process the impedance gradient transition region in a nitrogen plasma environment with a plasma power of 300-500W and a processing time of 90-120 seconds. Step S7: Monitor the coating composition in real time using an online mass spectrometer, dynamically adjust the plating bath parameters, and control the Cu:Ni atomic ratio within the range of 3:1 to 5:

1.

2. The method for manufacturing an OBD integrated multi-band antenna based on LDS technology as described in claim 1, characterized in that, In step S1, a permanent magnet array is used to generate an axial magnetic field of 0.5-1.2T, with the magnetic field gradient controlled at 5-8T / m. The magnetic field is applied during the pressure holding stage after the melt filling is completed, and the magnetic field is applied for 3-5 seconds.

3. The method for manufacturing an OBD integrated multi-band antenna based on LDS technology as described in claim 1, characterized in that, In step S1, the polar molecules in the modified composite material are arranged in an orderly manner along the direction of the magnetic field lines under the action of the magnetic field, forming an anisotropic dielectric structure.

4. The method for manufacturing an OBD integrated multi-band antenna based on LDS technology as described in claim 1, characterized in that, In step S1, the injection mold temperature is maintained at 85±2℃, the melt temperature is 235±5℃, and the cooling rate is reduced to 0.8℃ / s under the action of the magnetic field.

5. The method for manufacturing an OBD integrated multi-band antenna based on LDS technology as described in claim 1, characterized in that, In step S2, the 532nm laser beam quality M² < 1.2, the focal diameter is 20μm, the 532nm laser energy density is 12J / cm², the single pulse width is 50ns, and the repetition frequency is 80kHz. In step S2, the 1064nm laser adopts a flat-top beam distribution, a focal diameter of 50μm, an energy density of 5J / cm², a continuous wave mode, and the heat-affected zone depth is controlled at 3-5μm.

6. The method for manufacturing an OBD integrated multi-band antenna based on LDS technology as described in claim 1, characterized in that, In step S2, the morphology of the activated area is monitored in real time by an online CCD detection system, and the laser power fluctuation is adjusted to within ±2%.

7. The method for manufacturing an OBD integrated multi-band antenna based on LDS technology as described in claim 1, characterized in that, In step S3, the ultrasonic frequency is 18kHz, the power density is 0.5W / cm³, and the cavitation effect generates a microjets with a penetration depth of up to 50μm; in step S3, the temperature gradient in the ultrasonic action area is <0.3℃ / cm.

8. The method for manufacturing an OBD integrated multi-band antenna based on LDS technology as described in claim 1, characterized in that, In step S5, the femtosecond laser scanning employs a helical path filling with a step size of 0.8 μm and a power density of 1.5 × 10¹. 4 W / cm²; In step S5, the gold deposition rate in the laser-induced region reaches 0.3 μm / s, and the deposition rate in the non-irradiated region is <0.01 μm / s.

9. The method for manufacturing an OBD integrated multi-band antenna based on LDS technology as described in claim 1, characterized in that, In step S6, the radio frequency power supply frequency of the plasma system is 13.56MHz, the power density is 0.8W / cm², the nitrogen flow rate is 20sccm, the reaction chamber pressure is 30Pa, the electrode spacing is 50mm, and the substrate bias voltage is -100V.

10. The antenna structure manufactured by the OBD integrated multi-band antenna manufacturing method based on LDS technology as described in any one of claims 1-9, characterized in that, The device includes an OBD device housing body injection molded from LDS modified plastic, wherein a composite antenna radiation structure is formed on the surface of the housing body by laser activation; The composite antenna radiation structure includes a low-frequency radiator and a high-frequency radiator. The low-frequency radiator adopts a streamlined layout to cover the 617-894MHz frequency band, and the high-frequency radiator adopts a branched inverted F structure to cover the 1710-2690MHz frequency band. The surface of the composite antenna radiating structure is chemically plated to form a composite metallized structure consisting of a copper-based conductive layer and a nickel protective layer. The bottom of the housing body is provided with an impedance matching power supply point and at least two grounding points, which are connected to the OBD main control module through a flexible circuit board.

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