Laser preparation of vehicle antenna and preparation method

Abstract

The application discloses a kind of laser preparation vehicle antenna, is prepared by numerical control system control, applied to antenna technical field, including upper shell and bottom shell, the bottom shell is provided with screw below, the screw is connected to form a closed mounting space with the upper shell and the bottom shell, ceramic PCB is provided in the mounting space, ceramic body is installed above the ceramic PCB, a plurality of thimbles are installed in the side of the ceramic PCB, main antenna, diversity antenna, MOM4-antenna, WIFI-1 antenna, WIFI-2 antenna, GPS and BT antenna are sequentially connected with thimble on the ceramic PCB, the application has the characteristics that the drawing of multi-surface composite structure upper antenna circuit is realized.

Description

Technical Field

[0001] This invention relates to the field of antenna technology, specifically to a laser-based method for fabricating vehicle-mounted antennas. Background Technology

[0002] The vehicle antenna is the wireless interface of the automotive electronic system, responsible for receiving and transmitting various wireless signals to support core functions such as vehicle positioning, navigation, and safety communication.

[0003] With the development of modern technology, the industry has put forward more requirements for vehicle antennas. For example, with the development of automotive technology, vehicle antennas are required to gradually evolve from traditional single-function independent antennas to composite antennas. With the development of communication technology, vehicle antennas are required to stably receive and transmit higher frequency millimeter wave signals. The development of automotive technology and communication technology and other related technologies has continuously increased the precision requirements for the manufacturing process of vehicle antennas.

[0004] Currently, neither traditional etching processes, printed circuit processes, nor advanced LDS technology can achieve the fine patterns required for millimeter-wave antennas on composite multifaceted structures, and it is difficult to guarantee the processing accuracy of the circuit. How to achieve high-precision drawing on composite multifaceted structures has become an urgent problem to be solved by researchers in this field. Summary of the Invention

[0005] The purpose of this invention is to provide a laser-based fabrication method for vehicle-mounted antennas to solve the problems mentioned in the background section.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: The material is manufactured under the control of a CNC system, including an upper shell and a lower shell. A screw is located below the lower shell, connecting the upper shell and the lower shell to form a closed mounting space. A ceramic PCB is disposed within the mounting space, and a ceramic body is mounted on top of the ceramic PCB. Several pins are mounted on the sides of the ceramic PCB. A main antenna, a diversity antenna, a MOM-4 antenna, a WIFI-1 antenna, a WIFI-2 antenna, a GPS antenna, and a BT antenna are sequentially connected to the ceramic PCB via these pins.

[0007] A method for fabricating a vehicle-mounted antenna using laser technology includes the following steps:

[0008] S1: Select plastic or ceramic materials as raw materials for injection molding to obtain flexible dielectric substrate;

[0009] S2: Use ultrasonic waves to examine the surface and internal structure of the substrate, and clean the oil and impurities on the surface of the substrate. After confirming that the substrate structure is qualified, cover the substrate surface with a layer of resist coating.

[0010] S3: Laser engraving process. A CNC laser processing machine tool is used to draw a circuit on the surface of the substrate according to a preset circuit pattern. The laser engraved area is the required circuit path. The CNC program of the machine tool is continuously adjusted according to the processing result of the substrate to reduce production errors.

[0011] S4: Chemical plating process, depositing different metal coatings in the laser area;

[0012] S5: Remove the resist coating and test the circuit performance.

[0013] A method for fabricating a vehicle-mounted antenna using laser technology, wherein step S3 includes the following processes:

[0014] S3.1: Horizontal surface processing. The processing error is judged by the actual offset between the laser spot projection point and the baseline. The processing error is compensated by a combination of extending the processing time and reducing the laser power.

[0015] S3.2: Curved surface machining, using a CNC system to dynamically adjust the relative position and orientation of the laser head and the curved surface to adapt to curved surfaces with different curvatures;

[0016] Corner machining is performed by adjusting the laser's machining path and mode to machine corners of varying degrees.

[0017] Through-hole processing: By pre-setting the laser power and processing time, through-hole processing is completed precisely.

[0018] S3.3: Shape inspection. After the preset pattern is drawn on the substrate, the shape parameters of the drawn pattern are detected by the scanning unit. The shape parameters of the pattern include line width and aperture. The depth of the pattern is detected by the ultrasonic generator.

[0019] S3.4: Comparative inspection. After completing the external inspection, the circuit needs to be compared and inspected to eliminate errors caused by the accumulation of tolerances when a single qualified circuit is arranged in parallel.

[0020] A method for fabricating a vehicle-mounted antenna using laser technology, wherein step S3.1 includes the following steps:

[0021] The scanning unit detects the projection point of the light spot on the substrate surface, defines the path of the preset circuit on the substrate surface as the baseline, and records the actual offset between the projection point of the light spot and the baseline as X1. Ideally, X1=0, and the laser-engraved area coincides with the preset circuit pattern.

[0022] when If the projection point does not fall on the baseline, the laser-engraved area will be offset from the preset circuit pattern, resulting in an error between the actual circuit and the preset pattern. The size of X1 will be detected by the scanning unit.

[0023] Among them when When the offset is within the allowable tolerance, laser engraving can continue.

[0024] Among them when When the offset is close to the critical value of 10μm, the CNC system controls the laser head to run at a low speed and observes the offset trend. If the offset continues to increase to 10μm, the machine should be stopped to investigate the cause of the offset. When reducing the speed, the laser power should be reduced simultaneously. The processing error is compensated by combining the increase in processing time with the decrease in laser power. The increase in time is proportional to the decrease in power.

[0025] A method for fabricating a vehicle-mounted antenna using laser technology, wherein step S3.2 includes the following steps:

[0026] To achieve precise processing of composite multifaceted structures on substrates, appropriate processing methods are required for curved surfaces, corners, and vias. In the processing of curved surfaces, convex surfaces tend to cause the laser focus to fall inside the substrate, while concave surfaces tend to cause the focus to be located above the processing surface. The height information of the curved surface is obtained by scanning unit, and the relative position and attitude of the laser head are dynamically adjusted by CNC system to ensure that the laser is perpendicular to the tangent of the processing point and the focus falls on the curved surface.

[0027] During corner processing, the type of corner is determined by the scanning unit. If there is a dead zone that the laser cannot reach in an acute corner, the formation of acute corners is reduced by optimizing the injection molding process or adjusting the preset circuit pattern to avoid the dead zone. Processable acute corners are processed by pulse mode. Right-angle corners are processed on both the horizontal and vertical surfaces and a small residual area is reserved. The residue is cleared by pulse mode to connect the two areas. Obtuse corners are processed by CNC system to adjust the height and tilt of the laser head to ensure that the light is perpendicular to the tilted surface and the spot falls on the processing surface. At the same time, the laser head moving speed is reduced to reduce trajectory deviation and the laser power is reduced to avoid overburning of the material. The processing error is compensated by the combination of extending the processing time and reducing the power.

[0028] When machining vias, blind holes require precise control of the machining depth to avoid penetrating the bottom layer. Buried holes require pre-machining of the intermediate layer before laminating multiple substrates. Through holes can be drilled out in one go after lamination or opened and aligned at corresponding positions in each single layer before lamination to form a passage.

[0029] A method for fabricating a vehicle-mounted antenna using laser technology, wherein step S3.3 includes the following steps:

[0030] After the preset pattern is drawn on the substrate, the shape parameters of the drawn pattern are detected by the scanning unit. The shape parameters of the pattern include line width and aperture. The depth of the pattern is detected by the ultrasonic generator. The actual line width, aperture and depth are compared with the preset values ​​to ensure that the actual parameters are within the allowable tolerance range.

[0031] S3.4 includes the following methods:

[0032] The spacing between parallel circuits is detected using a scanning unit, and the detection results are compared and analyzed with the detection results of S3.4 to eliminate spacing errors caused by tolerance accumulation.

[0033] The scanning unit records data on various errors on the substrate and transmits the error data to the CNC system. The CNC system adjusts the CNC program and changes the machining path to reduce errors.

[0034] Unresolved error data is transmitted to the CNC system as a known system deviation. With the known deviation added, the CNC program is readjusted and the preset circuit pattern is optimized.

[0035] If the process parameters are not properly controlled in S3, the laser engraving may cause unexpected damage to the substrate. The substrate after laser engraving is cleaned and inspected by ultrasound in S2 to ensure that there is no additional damage to the substrate before proceeding to the next step.

[0036] A method for fabricating a vehicle-mounted antenna using laser technology, wherein step S4 includes the following processes:

[0037] S4.1: Surface treatment, which involves using chemical reagents and catalysts to treat the surface of the processed substrate in preparation for subsequent coating processes;

[0038] S4.2: Coating treatment, which involves sequentially depositing different metal layers on the processing area of ​​the substrate through methods such as chemical plating and electroplating. The multi-layer metal plating improves the electrical properties of the substrate.

[0039] A method for fabricating a vehicle-mounted antenna using laser fabrication, wherein step S4.1 specifically comprises:

[0040] The substrate is immersed in a chemical reagent for roughening treatment, which improves the roughness of the laser-engraved area, enhances the adsorption force, and facilitates the adhesion of the coating.

[0041] The substrate surface is sensitized and a catalyst is added so that the laser area adsorbs the catalyst.

[0042] The catalyst attached to the substrate surface prepares for nickel undercoating. The catalyst in non-laser-engraved areas is removed by alkaline washing to prevent metallization in non-target areas.

[0043] A method for fabricating a vehicle-mounted antenna using laser technology, wherein step S4.2 specifically comprises:

[0044] The substrate is immersed in a plating solution containing nickel ions, palladium ions and a reducing agent. Under the action of the resist layer, nickel ions and palladium ions are reduced and deposited in the laser-etched area to form a palladium-nickel alloy layer. The substrate is then immersed in a copper plating solution, and copper ions are deposited in the laser area to form a thin, continuous copper layer of 0.5-1 micrometers.

[0045] A substrate with a thin copper layer is placed in a copper plating bath. The substrate is used as the cathode and a copper rod is used as the anode. Direct current is applied to the cathode and anode, and copper ions from the anode are continuously migrated to the surface of the copper layer on the cathode and deposited, increasing the thickness of the copper layer.

[0046] After completing the thick copper process, the pure metallic copper on the surface of the copper layer is not active enough. The substrate is immersed in an activation solution, and palladium ions in the activation solution are adsorbed on the copper surface to form an extremely thin and highly active palladium atom layer.

[0047] The substrate is immersed in a chemical nickel plating solution. Under the catalysis of palladium, nickel ions in the solution are deposited in the laser area to form a nickel layer. By electroplating or chemical plating, a dense gold layer, usually 0.05-0.2 micrometers in size, is formed on the surface of the nickel layer.

[0048] A method for fabricating a vehicle-mounted antenna using laser technology, wherein step S5 includes the following steps:

[0049] The metal plating layer is used to influence the slight organic solvent or corrosion inhibitor to dissolve the resist coating on the substrate surface. Optical and electrical tests are then used to check whether the performance of the final circuit is up to standard. Unqualified products are recycled and scrapped, while qualified products enter the subsequent production process.

[0050] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: The present invention uses a scanning unit to transmit the substrate shape data and processing error data to the CNC system. The system adjusts the CNC program accordingly to change the laser engraving processing path, thereby enabling the drawing of antenna circuits on composite structures such as curved surfaces, corners and through holes of the substrate. Attached Figure Description

[0051] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0052] Figure 1 This is a schematic diagram of the overall antenna structure of the present invention;

[0053] Figure 2 This is an exploded view of the antenna structure of the present invention;

[0054] In the diagram: 1. Top shell; 2. Bottom shell; 3. Ceramic PCB; 4. Ceramic body; 5. Main antenna; 6. Diversity antenna; 7. MOM-4 antenna; 8. WIFI-1 antenna; 9. WIFI-2 antenna; 10. GPS; 11. BT antenna; 12. Pin; 13. Screw. Detailed Implementation

[0055] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0056] Example 1, please refer to Figures 1-2 To conform to the present invention, a laser-fabricated vehicle antenna is provided, comprising an upper shell 1, a bottom shell 2, and a CNC system. The CNC system is used for circuit drawing. The upper shell 1 and the bottom shell 2 are connected to form a closed installation space. A ceramic PCB 3, i.e., a printed circuit board, is provided in the installation space for connecting various electronic components to realize circuit conduction and transmission. A ceramic body 4 is installed on top of the ceramic PCB 3. Several pins 12 are installed on top of the ceramic PCB 3. A main antenna 5, a diversity antenna 6, a MOM-4 antenna 7, a WIFI-1 antenna 8, a WIFI-2 antenna 9, a GPS 10, and a BT antenna 11 are provided on top of the ceramic PCB 3. The pins 12 are used to support the above-mentioned antennas. A screw 13 is provided on the bottom shell 2 for connecting the upper shell 1 and the bottom shell 2.

[0057] Example 2: The present invention provides a technical solution: a method for fabricating vehicle antennas using laser technology. The mechanism of this method is to roughen the surface of a common substrate with laser, so that the substrate surface has a strong adsorption force to adsorb the activating material. After the activation process, the activating material serves as the activation center for metal plating, thereby achieving high-precision metallization of the structural surface. This method can achieve the performance indicators of LDS process without modifying materials, and is basically applicable to all common plastics and ceramics. It can achieve high-precision patterning on any visible surface.

[0058] It should be noted that the technical solution provided by this invention is used for the circuit design of the main antenna 5, diversity antenna 6, MOM-4 antenna 7, WIFI-1 antenna 8, and WIFI-2 antenna 9.

[0059] Specifically, a method for fabricating a vehicle-mounted antenna using laser technology includes the following steps:

[0060] S1: Injection molding of the substrate

[0061] Plastic or ceramic materials are selected as raw materials for injection molding to obtain the required three-dimensional substrate. Preferably, the substrate material in S1 can be polyimide or ceramic composite material to make a flexible dielectric substrate with good electrical properties and spatial adaptability.

[0062] S2: Substrate pretreatment

[0063] First, the surface and internal structure of the substrate are explored using an ultrasonic generator. After the exploration, the oil and impurities on the surface of the substrate are cleaned using an ultrasonic generator to avoid affecting the subsequent laser processing of the substrate surface. After the cleaning of the substrate surface is completed, the surface and internal structure of the substrate are explored again using an ultrasonic generator.

[0064] During the initial inspection, a baseline test is conducted using ultrasound. If structural defects are found within the substrate itself, the substrate is deemed defective and scrapped. The initial inspection allows for quick screening and removal of defective products. During the second inspection after cleaning, if the defects found in the initial inspection disappear, it indicates that the defects were contaminants attached to the surface, and the cleaning is deemed satisfactory. If some defects still exist after cleaning, they are inherent structural defects within or on the surface of the object. Once the existence of structural defects is confirmed, the substrate should be scrapped and re-prepared using S1.

[0065] Furthermore, a layer of resist coating is applied to the surface of the substrate by spraying or printing. The resist coating will not be dissolved or penetrated by the plating solution during the chemical plating process, and is used to protect non-activated areas from metallization.

[0066] S3: Laser engraving

[0067] After preprocessing, the substrate is moved to a CNC laser processing machine tool, where it is fixed in place by the machine tool's fixtures. The relevant circuit data is pre-set in the CNC system for processing, including the overall circuit pattern, the circuit line width and spacing determined by production requirements, and the via diameter. For example, if the substrate is ceramic, the minimum line width is 0.15mm, the minimum line spacing is 0.05mm, and the minimum via diameter is 0.1mm. During processing, the CNC program of the machine tool is adjusted based on the processing results of the substrate, thereby reducing production errors.

[0068] The machine tool has multiple built-in laser heads, each with an integrated scanning unit for scanning the shape of the substrate and transmitting the scanned data to the CNC system. The system then adjusts the CNC program accordingly to change the laser engraving path, enabling the drawing of antenna circuits on complex structures such as curved surfaces, corners, and through holes on the substrate. The multiple laser heads allow for integrated processing of the substrate. After the circuit is drawn, the surface is activated using chemical agents.

[0069] S3.1: Horizontal surface processing. Specifically, laser engraving is a process that uses a laser beam to etch or cut the surface of a material, leaving a permanent mark by causing the material to evaporate. In this method, the laser engraving area is the required circuit path. When processing on a horizontal surface, the laser head directly draws the circuit pattern on the surface of the substrate. The position of the laser focus relative to the processing surface directly affects the processing accuracy. When the focus is located on the surface of the substrate, the spot size is the smallest, the energy density is the highest, and the processing accuracy is also the highest.

[0070] The initial position of the laser focus is determined by the structure of the laser head itself and can be dynamically adjusted during processing using the machine tool's focusing mechanism. If the focus is above the processing surface, it will result in insufficient processing depth, rough edges, and affect accuracy. If the focus is below the processing surface (inside the substrate), it will cause overcutting and damage to the substrate. Therefore, the laser head and substrate must be aligned and calibrated before processing to ensure that the focus falls precisely on the processing surface.

[0071] Furthermore, the scanning unit detects the projection point of the light spot on the substrate surface, defines the path of the preset circuit on the substrate surface as the baseline, and records the actual offset between the projection point of the light spot and the baseline as X1. Ideally, This indicates that the light spot falls on the baseline and the laser-engraved area coincides with the preset circuit pattern.

[0072] when If the projection point does not fall on the baseline, the laser-engraved area is offset from the preset circuit pattern, resulting in an error between the actual circuit and the preset pattern. By detecting the size of X1 using the scanning unit, the following measures can be taken:

[0073] when If the offset is within the allowable tolerance, laser engraving can continue.

[0074] when When the offset is close to the critical value, the CNC system controls the laser head to run at a low speed to observe the offset trend. If the offset continues to increase, the machine should be stopped to investigate the cause of the offset.

[0075] It should be noted that reducing the speed will increase the time the laser stays at the same position. If the laser power remains unchanged, the energy received by the substrate per unit area will increase sharply, and the substrate will form an obvious ablation zone. Therefore, the laser power needs to be reduced simultaneously during processing. The processing error is compensated by combining the increase in processing time with the reduction in laser power. The increase in time is proportional to the decrease in power.

[0076] During operation, machine tool vibration or loosening of the substrate fixing device may cause the substrate to move, thereby causing the spot offset to expand instantaneously. If this occurs, the machine tool should be stopped immediately, the base material replaced, and the machine recalibrated.

[0077] S3.2: Curved surface processing. Specifically, when performing laser engraving on curved surfaces, convex surfaces cause the laser focus to be located inside the substrate, while concave surfaces cause the laser focus to be located above the processing surface, neither of which can achieve the desired processing results. Therefore, when processing curved surfaces, the height information of the curved surface is obtained through the scanning unit, and the relative position and attitude of the laser head and the curved surface are dynamically adjusted through the CNC system to ensure that the laser is perpendicular to the tangent of the processing point and that the focus falls on the curved surface.

[0078] The tangent of a large curvature arc surface changes rapidly. By controlling the laser head to swing synchronously with the tangent through the CNC system, it is ensured that the laser is always perpendicular to the tangent at the processing point. The tangent of a small curvature arc surface is difficult to observe. By switching the laser head to pulse mode and performing multiple fixed-point processing, the circuit pattern can be drawn.

[0079] Furthermore, corner processing: Specifically, when performing laser engraving at corner positions, different corner angles cause the processed surface to tilt. By using a scanning unit to determine the corner type, the following measures can be taken:

[0080] When acute corners exist, they can easily create dead zones in the substrate that the laser cannot irradiate. If the preset circuit pattern passes through the dead zone, it indicates that the injection-molded substrate does not meet the processing requirements. In this case, the injection molding process should be optimized to reduce the formation of acute corners on the substrate, or the preset circuit pattern should be optimized to prevent the pattern from passing through the acute corner area. In laser-processable acute corner structures, in order to allow the laser to transition from one processing surface to another through the acute corner, the incident angle of the light is tilted. At this time, the light spot becomes an ellipse, causing the processing linewidth to change and affecting the accuracy. In this case, the laser is set to pulse mode, and the corner area is processed by multiple fixed-point processing.

[0081] When there is a right angle, first process the horizontal and vertical surfaces separately, and extend the processing path to both sides of the corner edge, leaving a small residual area. Set the laser to pulse mode to clear the residual area, so that the processing areas of the horizontal and vertical surfaces are connected.

[0082] When there is an obtuse angle, the obtuse angle structure will cause the processing surface of the substrate to tilt, causing the focal point to deviate from the processing surface. Therefore, the height and tilt of the laser head are adjusted using a CNC system to ensure that the light is perpendicular to the tilted surface and the spot falls on the processing surface. At the obtuse angle, in order to ensure the accuracy of the processing trajectory, the moving speed of the laser head needs to be reduced. Otherwise, the laser head will cause the processing trajectory to deviate due to inertia, turning the obtuse angle into a rounded corner, which will affect the accuracy. However, reducing the speed will increase the dwell time of the laser at the same position. If the laser power remains unchanged, the energy received by the substrate per unit area will increase sharply, causing the material in the corner area to be overburned and the amount of material removed to be excessive, thus forming an obvious ablation zone. Therefore, in the obtuse angle area, the laser power needs to be reduced simultaneously. The processing error is compensated by a combination of extending the processing time and reducing the laser power.

[0083] Furthermore, via fabrication: Specifically, in antenna design, in order to achieve electrical connections in multi-layer structures, vias need to be made in multi-layer substrate structures. The inner walls of the vias are made conductive through chemical plating. Therefore, lasers are used to directly create vias in the substrate.

[0084] Specifically, the types of vias include blind vias that only penetrate the surface and intermediate layers, buried vias hidden in the inner layers, and through-holes that penetrate the entire layer;

[0085] When machining blind holes in multilayer substrates, it is necessary to precisely control the machining depth to avoid penetrating the underlying layer;

[0086] For buried vias, holes need to be pre-processed in the intermediate substrate before laminating multiple substrates. The through holes after lamination can be laser-drilled in one go after lamination, or holes can be pre-drilled in the corresponding positions of each single substrate before lamination. After lamination and alignment, these holes together form a through passage.

[0087] When performing through-hole machining, the laser power and machining time are preset in the CNC system according to the machining requirements, so that the laser can accurately complete the through-hole machining.

[0088] It should be noted that lamination should be a subsequent process in this method. In this method, the processing of vias is performed on a single substrate.

[0089] S3.3: Shape inspection. After the preset pattern is drawn on the substrate, the shape parameters of the drawn pattern are inspected by the scanning unit. The shape parameters of the pattern include line width and aperture. The depth of the pattern is detected by the ultrasonic generator.

[0090] Specifically, the actual line width after processing is defined as X2, the actual aperture as X4, and the actual depth as X5.

[0091] Define the line width tolerance as Aperture tolerance is defined as Depth tolerance is defined as .

[0092] Define the preset line width as D2, the preset aperture as D4, and the preset depth as D5.

[0093] when At that time, X2 met the tolerance requirements, and the machined line width was qualified;

[0094] when or When X2 exceeds the tolerance range, the processed line width is unqualified.

[0095] The detection principles for aperture and depth are the same as those described above, and will not be elaborated further here.

[0096] S3.4: Comparative Inspection. Since the circuit is drawn on the surface of the substrate, the circuits should be drawn side by side to avoid short circuits caused by circuit crossing. Based on S3.3, the relevant shape of the circuit conforms to the standard. When any two circuits are drawn side by side, there may be an accumulation of the shape tolerances of the two circuits, which may cause errors in the spacing between the circuits. Therefore, it is necessary to inspect the line spacing of the parallel circuits and compare it with the inspection results of S3.3 to further improve the processing accuracy.

[0097] Specifically, the actual line spacing is defined as X3, and the line spacing tolerance is defined as... Define the preset line spacing as D3.

[0098] when At that time, X3 met the tolerance requirements, and the line spacing of the machining was qualified;

[0099] when or At that time, X3 exceeded the tolerance range, and the line spacing of the machined line was not up to standard;

[0100] When the actual offset X1 and actual line width X2 of any two parallel circuits are both qualified, it may cause the actual line spacing X3 of the two circuits to be unqualified. For example, in two parallel circuits, X1 and X2 of each circuit are qualified, but the circuit on the left is offset to the right and the circuit on the right is offset to the left, which forces the X3 of the two circuits to shrink. Conversely, it forces the X3 of the two circuits to expand. In multiple sets of parallel circuits, the unqualified X3 of any two circuits will lead to a chain reaction and reduce the accuracy of the circuit.

[0101] Furthermore, when the actual line spacing X3 of any two parallel circuits is qualified, there may be two circuits whose actual offset X1 or actual line width X2 is unqualified. For example, if the X3 of two parallel circuits is qualified, the X1 and X2 of the left circuit are both qualified, the X1 of the right circuit is qualified, and the X2 is slightly smaller than the minimum tolerance, but the right circuit is offset to the left, making the X3 of both circuits qualified. This will trigger a chain reaction in multiple sets of parallel circuits and reduce the circuit accuracy.

[0102] Furthermore, in multilayer substrate structures, in order to achieve electrical connection, the circuit is connected to the via. The size of the via and the orientation of the via directly affect the current carrying capacity of the via. In the preset pattern of the circuit, the via is usually opened at the end of the target circuit. In the actual circuit drawing, due to the offset of the circuit, there is a deviation in the positional relationship between the real circuit and the real via, which reduces the circuit accuracy.

[0103] Furthermore, the scanning unit records data on various errors on the substrate and transmits the error data to the CNC system. The CNC system then adjusts the CNC program and changes the machining path to reduce errors.

[0104] Furthermore, after adjusting the CNC program, a new substrate with good pretreatment is selected for processing. Ideally, the processing error of the first set of substrates should be completely resolved. However, in actual processing, some errors still cannot be resolved. The unresolved error data is sent to the CNC system as a known system deviation. With the known deviation added, the CNC program is readjusted, and even the preset circuit pattern is optimized to reduce errors and improve accuracy as much as possible.

[0105] If the process parameters are not properly controlled in S3, the laser engraving may cause unexpected damage to the substrate. The substrate after laser engraving is cleaned and inspected by the ultrasonic generator in S2 to ensure that there is no additional damage to the substrate before proceeding to S4. If there is additional damage to the substrate, the process parameters in S3 need to be adjusted and the substrate needs to be laser engraved again.

[0106] S4: Chemical plating treatment, including the following steps:

[0107] S4.1: Surface treatment, the substrate is immersed in a chemical reagent for roughening treatment, which improves the roughness of the laser-engraved area, enhances the adsorption force, and facilitates the adhesion of the coating.

[0108] The substrate surface is sensitized and a catalyst is added so that the laser area adsorbs the catalyst.

[0109] The catalyst attached to the substrate surface prepares for nickel underlayment. The catalyst in non-laser-engraved areas is removed by alkaline washing to prevent metallization in non-target areas.

[0110] S4.2: Plating treatment, the substrate is immersed in a plating solution containing nickel ions, palladium ions and a reducing agent. Under the action of the resist layer, nickel ions and palladium ions are reduced and deposited in the laser-etched area to form a palladium-nickel alloy layer. The substrate is then immersed in a copper plating solution, and copper ions are deposited in the laser area to form a thin, continuous copper layer of 0.5-1 micrometers. It should be noted that chemical plating is a self-catalytic redox reaction and does not require additional current.

[0111] To meet the current carrying capacity, the copper layer needs to be thickened to several micrometers to tens of micrometers to reduce resistance. Specifically, a substrate with a thin copper layer is placed in a copper electroplating bath, with the substrate as the cathode and a copper rod as the anode. Direct current is applied to the cathode and anode, and copper ions from the anode are continuously migrated to the surface of the copper layer at the cathode to deposit, increasing the thickness of the copper layer. After the thick copper process is completed, the pure metallic copper on the surface of the copper layer is not active enough, so the substrate is immersed in an activation solution. Preferably, colloidal palladium can be used as the activation solution. Palladium is a highly efficient catalyst for electroless nickel plating. Palladium ions in the activation solution are adsorbed on the copper surface to form an extremely thin and highly active layer of palladium atoms.

[0112] The substrate is immersed in a chemical nickel plating solution. Under the catalysis of palladium, nickel ions in the solution are deposited into a nickel layer in the laser area. Further, a dense gold layer, typically 0.05-0.2 micrometers in size, is formed on the surface of the nickel layer by electroplating or chemical plating. Gold has good conductivity and corrosion and oxidation resistance, providing excellent surface properties for the circuit surface.

[0113] It should be noted that the area of ​​the substrate plating layer is the required circuit. When the above chemical plating steps are connected, the substrate should be cleaned to remove impurities such as residual chemical solutions and metal powders from the previous step to avoid cross-contamination. The cleaning methods after each step are existing technologies and will not be elaborated on here.

[0114] S5: Removal of resist layer and performance testing

[0115] Organic solvents or corrosion inhibitors are used to dissolve the resist coating on the substrate surface. These solvents or inhibitors can effectively dissolve the resist coating and have little effect on the metal coating. Optical and electrical tests are used to check whether the performance of the final circuit is up to standard. Unqualified products are recycled and scrapped, while qualified products enter the subsequent production process.

[0116] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0117] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for fabricating a vehicle-mounted antenna using laser technology, characterized in that: Includes the following steps: S1: Select plastic or ceramic materials as raw materials for injection molding to obtain flexible dielectric substrate; S2: Use ultrasonic waves to examine the surface and internal structure of the substrate, and clean the oil and impurities on the surface of the substrate. After confirming that the substrate structure is qualified, cover the substrate surface with a layer of resist coating. S3: Laser engraving process. A CNC laser processing machine tool is used to draw a circuit on the surface of the substrate according to a preset circuit pattern. The laser engraved area is the required circuit path. The CNC program of the machine tool is continuously adjusted according to the processing result of the substrate to reduce production errors. S4: Chemical plating process, depositing different metal coatings in the laser area; S5: Remove the resist layer and test the circuit performance; S3 includes the following processes: S3.1: Horizontal surface processing. The processing error is judged by the actual offset between the laser spot projection point and the baseline. The processing error is compensated by a combination of extending the processing time and reducing the laser power. S3.2: Curved surface machining, using a CNC system to dynamically adjust the relative position and orientation of the laser head and the curved surface to adapt to curved surfaces with different curvatures; Corner machining is performed by adjusting the laser's machining path and mode to machine corners of varying degrees. Through-hole processing: By pre-setting the laser power and processing time, through-hole processing is completed precisely. S3.3: Shape inspection. After the preset pattern is drawn on the substrate, the shape parameters of the drawn pattern are detected by the scanning unit. The shape parameters of the pattern include line width and aperture. The depth of the pattern is detected by the ultrasonic generator. S3.4: Comparative inspection. After completing the external inspection, the circuit needs to be compared and inspected to eliminate errors caused by the accumulation of tolerances when a single qualified circuit is arranged in parallel. S3.2 includes the following methods: To achieve precise processing of composite multifaceted structures on substrates, appropriate processing methods are required for curved surfaces, corners, and vias. In the processing of curved surfaces, convex surfaces tend to cause the laser focus to fall inside the substrate, while concave surfaces tend to cause the focus to be located above the processing surface. The height information of the curved surface is obtained by scanning unit, and the relative position and attitude of the laser head are dynamically adjusted by CNC system to ensure that the laser is perpendicular to the tangent of the processing point and the focus falls on the curved surface. During corner processing, the type of corner is determined by the scanning unit. If there is a dead zone that the laser cannot reach in an acute corner, the formation of acute corners is reduced by optimizing the injection molding process or adjusting the preset circuit pattern to avoid the dead zone. Processable acute corners are processed by pulse mode. Right-angle corners are processed on both the horizontal and vertical surfaces and a small residual area is reserved. The residue is cleared by pulse mode to connect the two areas. Obtuse corners are processed by CNC system to adjust the height and tilt of the laser head to ensure that the light is perpendicular to the tilted surface and the spot falls on the processing surface. At the same time, the laser head moving speed is reduced to reduce trajectory deviation and the laser power is reduced to avoid overburning of the material. The processing error is compensated by the combination of extending the processing time and reducing the power. When machining vias, blind holes require precise control of the machining depth to avoid penetrating the bottom layer. Buried holes require pre-machining of the intermediate layer before laminating multiple substrates. Through holes can be drilled out in one go after lamination or opened and aligned at corresponding positions in each single layer before lamination to form a passage.

2. The method for fabricating a vehicle-mounted antenna using laser technology according to claim 1, characterized in that: S3.1 includes the following methods: The scanning unit detects the projection point of the light spot on the surface of the substrate, defines the path of the preset circuit on the substrate surface as the reference line, and records the actual offset between the light spot projection point and the reference line as X1. In an ideal state, X1 = 0, and the laser engraving area coincides with the preset circuit pattern; When X1>0, it means that the projection point does not fall on the reference line. At this time, the laser engraving area is offset from the preset circuit pattern, resulting in an error between the actual circuit and the preset pattern. The size of X1 is detected by the scanning unit; When 0<X1<10μm, it indicates that the offset is within the allowable tolerance, and laser engraving continues; When 5μm≤X1≤10μm, the offset is close to the critical value of 10μm. The numerical control system controls the laser head to run at a low speed, observes the offset trend. If the offset continues to increase towards 10μm, the machine should be stopped to check the cause of the offset. When reducing the speed, the laser power should be reduced synchronously. By combining the extension of the processing time and the reduction of the laser power, the processing error is compensated, and the increase ratio of time is the same as the decrease ratio of power.

3. The method for fabricating a vehicle-mounted antenna using laser technology according to claim 1, characterized in that: The S3.3 includes the following methods: After the preset pattern is drawn on the substrate, the scanning unit is used to detect the shape parameters of the drawn pattern. The pattern shape parameters include line width and aperture. The ultrasonic generator is used to detect the depth of the pattern. The detected actual line width, aperture and depth are compared with the preset values to ensure that the actual parameters are within the allowable tolerance; The S3.4 includes the following methods: The scanning unit is used to detect the spacing between parallel circuits, and the detection results are compared and analyzed with the detection results of S3.4 to eliminate the spacing error caused by tolerance accumulation; The scanning unit records the data of various errors on the substrate, and transmits the error data to the numerical control system. The numerical control system adjusts the numerical control program and changes the processing path to reduce the error; The error data that cannot be solved is sent to the numerical control system as a known system deviation. With the known deviation added, the numerical control program is readjusted to optimize the preset circuit pattern; If the process parameters are not properly controlled in S3, it may cause unexpected damage to the substrate during laser engraving. After cleaning and detecting the laser-engraved substrate with the ultrasonic wave in S2 to ensure that the substrate has no additional damage, it enters the subsequent process.

4. The method for fabricating a vehicle-mounted antenna using laser technology according to claim 1, characterized in that: The S4 includes the following processes: S4.1: Surface treatment. The processed substrate is surface-treated with chemical reagents and catalysts to prepare for subsequent plating; S4.2: Plating treatment. By chemical plating and electroplating methods, different metal layers are sequentially plated on the processed area of the substrate, and the multi-layer metal plating improves the electrical properties of the substrate.

5. The method for fabricating a vehicle-mounted antenna using laser technology according to claim 4, characterized in that: The S4.1 is specifically: The substrate is immersed in chemical reagents for roughening treatment to increase the roughness of the laser engraving area, improve the adsorption force, and facilitate the adhesion of the plating; The substrate surface is sensitized by adding a catalyst to make the laser area adsorb the catalyst; The catalyst attached to the substrate surface prepares for nickel underlay. The catalyst in the non-laser engraving area is removed by alkali washing to avoid metallization in the non-target area.

6. The method for fabricating a vehicle-mounted antenna using laser technology according to claim 4, characterized in that: The S4.2 is specifically: The substrate is immersed in a plating solution containing nickel ions, palladium ions and a reducing agent. Under the action of the resist layer, nickel ions and palladium ions are reduced and deposited in the laser-etched area to form a palladium-nickel alloy layer. The substrate is then immersed in a copper plating solution, and copper ions are deposited in the laser area to form a thin, continuous copper layer of 0.5-1 micrometers. A substrate with a thin copper layer is placed in a copper plating bath. The substrate is used as the cathode and a copper rod is used as the anode. Direct current is applied to the cathode and anode, and copper ions from the anode are continuously migrated to the surface of the copper layer on the cathode and deposited, increasing the thickness of the copper layer. After completing the thick copper process, the pure metallic copper on the surface of the copper layer is not active enough. The substrate is immersed in an activation solution, and palladium ions in the activation solution are adsorbed on the copper surface to form an extremely thin and highly active palladium atom layer. The substrate is immersed in a chemical nickel plating solution. Under the catalysis of palladium, nickel ions in the solution are deposited in the laser area to form a nickel layer. By electroplating or chemical plating, a dense gold layer, usually 0.05-0.2 micrometers in size, is formed on the surface of the nickel layer.

7. The method for fabricating a vehicle-mounted antenna using laser technology according to claim 1, characterized in that: S5 includes the following methods: The metal plating layer is used to influence the slight organic solvent or corrosion inhibitor to dissolve the resist coating on the substrate surface. Optical and electrical tests are then used to check whether the performance of the final circuit is up to standard. Unqualified products are recycled and scrapped, while qualified products enter the subsequent production process.

8. A laser-based method for fabricating vehicle-mounted antennas, comprising the laser-based method for fabricating vehicle-mounted antennas as described in claim 7, characterized in that: The device includes an upper shell (1) and a bottom shell (2). A screw (13) is provided on the bottom shell (2). The screw (13) connects the upper shell (1) and the bottom shell (2) to form a closed installation space. A ceramic PCB (3) is provided in the installation space. A ceramic body (4) is installed on the top of the ceramic PCB (3). Several pins (12) are installed on the side of the ceramic PCB (3). The main antenna (5), diversity antenna (6), WIFI-1 antenna (8), WIFI-2 antenna (9), GPS (10) and BT antenna (11) are sequentially connected to the ceramic PCB (3) through the pins (12).

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