A millimeter wave radar PCB of an antenna region Hoz and a manufacturing method thereof

Abstract

This application discloses a millimeter-wave radar PCB with an antenna area Hoz and its fabrication method, belonging to the field of PCB fabrication technology. The method includes the following steps: material preparation, first pattern transfer, first etching to remove the protective film, first browning, lamination, drilling target holes, milling the frame, first browning removal, second browning, laser drilling, drilling, adhesive removal, first copper plating thickening, hole plugging, baking, polishing, second pattern transfer, first micro-etching to reduce copper, copper plating thickening, third pattern transfer, second micro-etching to reduce copper, fourth pattern transfer, second etching to remove the protective film, solder mask fabrication, surface treatment, silkscreen printing, shape processing, testing, and finished product inspection. The beneficial effect is that by using the method provided by this invention, the design and fabrication of a millimeter-wave radar PCB with an antenna area Hoz is realized, and the product performance and appearance fully meet the design requirements of this type of product.

Description

Technical Field

[0001] This application belongs to the field of PCB fabrication technology, specifically relating to a millimeter-wave radar PCB with an antenna region Hoz and its fabrication method. Background Technology

[0002] Millimeter-wave radar refers to radar operating in the millimeter-wave frequency band. It serves as a non-contact sensing technology, used to detect objects and provide information on their distance, speed, and angle. It is widely used in various fields for detection and sensing. Millimeter-wave products primarily utilize frequencies such as 24GHz, 60GHz, and 77-79GHz. The 24GHz band has a mature upstream and downstream industry chain and relatively low cost, mainly used in the consumer market and industrial sectors. The 60GHz band has a bandwidth of 4GHz, and chip manufacturers are currently mainly developing CMOS process millimeter-wave radar chips, widely used in industrial and IoT fields. In 2021, the Ministry of Industry and Information Technology (MIIT) issued the "Interim Provisions on Radio Management of Automotive Radar," designating the 76-79GHz frequency band for automotive radar and restricting the use of other ground-based radars in this band. Automotive-grade millimeter-wave radar products have become mainstream sensors in the automotive industry, and 60GHz millimeter-wave radar products will become the mainstream industrial-grade radar in the future. Millimeter-wave radar originated abroad in the 1940s and, after decades of development, entered China in 2013, subsequently entering a period of rapid development.

[0003] However, existing millimeter-wave PCBs with antenna area Hoz have the following technical problems during manufacturing: 1. It is impossible to achieve the design of local thin copper Hoz on the same plane; 2. The pattern docking accuracy of different copper thickness areas is insufficient; 3. The control of copper thickness uniformity and the compensation problem in the processing of patterns with different copper thicknesses on the same plane; 4. Pattern coating quality problems caused by the step difference of different copper thicknesses on the same plane. Summary of the Invention

[0004] The purpose of this application is to provide a millimeter-wave radar PCB with an antenna region Hoz, which achieves the design of a local Hoz on the same plane through local micro-etching. The uniformity of the micro-etched area is controlled by monitoring the copper thickness, thereby solving at least one of the technical problems involved in the background art.

[0005] To solve the above-mentioned technical problems, this application is implemented as follows:

[0006] This application provides a method for fabricating a millimeter-wave radar PCB with an antenna region Hoz, comprising the following steps:

[0007] Step S1: Cutting materials according to the design dimensions;

[0008] Step S2, first pattern transfer, coating the board with photosensitive material, exposing with film, and removing the required non-circuit photosensitive material with a weak alkaline chemical solution;

[0009] Step S3, first etching and film removal: use a strong oxidizing chemical to remove the exposed copper layer, and then use a strong alkaline chemical to remove all photosensitive materials.

[0010] Step S4, first browning, removes grease and dirt from the board surface, roughens the copper surface to increase the bonding area between the copper surface and the prepreg;

[0011] Step S5, lamination: using a traditional press with constant temperature and pressure, the core plates are bonded together with a prepreg, and release film is placed on the top and bottom of the plates;

[0012] Step S6, drill the target hole, and use an X-ray target drilling machine to drill the required positioning hole;

[0013] Step S7: Mill the edge. Use a CNC milling machine to remove excess copper foil and excess adhesive from the edge of the laminated board.

[0014] Step S8, first de-browning, using a mechanical brush to remove the browning film and resin dots from the outer core board;

[0015] Step S9, second browning, removes grease and dirt from the board surface, applies a browning film to the surface copper, and reduces copper to meet the requirements of laser drilling;

[0016] Step S10, laser drilling, drilling the required blind hole using a laser method;

[0017] Step S11, Drilling: Drill the required through hole using mechanical drilling.

[0018] Step S12, Degumming: Use strong oxidizing chemicals to remove residual resin and drill sludge from the borehole;

[0019] Step S13, the first copper plating thickens the resin and glass fiber of the non-conductive part of the hole wall;

[0020] Step S14, plugging holes: use resin to plug the blind holes and the holes in the disc.

[0021] Step S15, baking, drying and curing the semi-cured resin;

[0022] Step S16: Grind and clean the resin from the orifice.

[0023] Step S17, second pattern transfer, coating the board with photosensitive material, selectively exposing with film, removing the required non-circuit photosensitive material with a weak alkaline chemical solution, and dry film masking the vias and device holes.

[0024] Step S18, First micro-etching copper reduction, using strong oxidizing chemical solution to reduce copper on the entire outer layer of the board;

[0025] Step S19: Thicken the copper plating and cap the blind vias and in-disk vias with POFV.

[0026] Step S20, third pattern transfer, coating the board with photosensitive material, selectively exposing with film, removing the required non-circuit photosensitive material with a weak alkaline chemical solution, exposing the required Hoz area of ​​the antenna.

[0027] Step S21, Second micro-etching copper reduction: Use a strong oxidizing chemical solution to reduce copper in the required Hoz area of ​​the exposed antenna.

[0028] Step S22, fourth pattern transfer: Coat the board with photosensitive material, use outer layer circuit data and expose it, and remove the required non-circuit photosensitive material with a weak alkaline chemical solution.

[0029] Step S23, second etching and film removal: use a strong oxidizing chemical to remove the exposed copper layer, and then use a strong alkaline chemical to remove all photosensitive materials.

[0030] Step S24, solder resist fabrication: Photosensitive solder resist material is screen-printed onto the board using a screen printing method. Selective exposure is performed using film, and the photosensitive material on the required solder pads is removed using a weak alkaline chemical solution, and the green oil is cured.

[0031] Step S25, surface treatment: perform surface treatment on the welding area;

[0032] Step S26, screen printing characters: use a screen to screen print a layer of thermosetting ink on the product surface;

[0033] Step S27, outer shaping, cutting out the required shape;

[0034] Step S28, Testing: Use a testing machine to test the electrical performance between each network;

[0035] Step S29: Finished product inspection. Visually inspect the appearance of the panels. If there are no defects, they are put into storage.

[0036] Optionally, in step S16, a ceramic brush and a non-woven fabric brush are used to grind the resin at the orifice clean.

[0037] Optionally, in step S26, the surface treatment includes immersion silver, immersion gold, and OSP.

[0038] Optionally, in step S27, the required shape is cut out using a CNC milling machine.

[0039] Optionally, in step S28, the electrical performance includes open / short circuit, resistance, and inductance.

[0040] The present invention also provides a millimeter-wave radar PCB with an antenna region Hoz, which is fabricated using the aforementioned method.

[0041] This application has the following advantages over the prior art:

[0042] 1. The design of local Hoz on the same plane was achieved by local micro-etching. The uniformity of the micro-etched area was controlled by copper thickness monitoring, which ensured the uniformity of copper thickness and solved the problem of compensation in the processing of patterns with different copper thicknesses on the same plane.

[0043] 2. Simultaneous pattern transfer between the thin copper Hoz and 1OZ areas ensures the pattern alignment accuracy of areas with different copper thicknesses;

[0044] 3. The coating is made using a wet film + dry film method. The wet film filling ensures the flatness of the board surface and prevents the etching solution in the subsequent process from attacking the different copper thickness steps.

[0045] 4. By using the method provided by the invention for production, the design and fabrication of millimeter-wave radar PCBs with antenna area Hoz has been realized, and the product performance and appearance can fully meet the design requirements of this type of product. Attached Figure Description

[0046] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein:

[0047] Figure 1 A flowchart illustrating the fabrication method of a millimeter-wave radar PCB with an antenna region Hoz provided by this invention. Detailed Implementation

[0048] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0049] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0050] Please see Figure 1 As shown in the figure, this application provides a method for fabricating a millimeter-wave radar PCB with an antenna region Hoz, including the following steps:

[0051] Step S1: Cutting materials according to the design dimensions;

[0052] Step S2, first pattern transfer, coating the board with photosensitive material, exposing with film, and removing the required non-circuit photosensitive material with a weak alkaline chemical solution;

[0053] Step S3, first etching and film removal: use a strong oxidizing chemical to remove the exposed copper layer, and then use a strong alkaline chemical to remove all photosensitive materials.

[0054] Step S4, first browning, removes grease and dirt from the board surface, roughens the copper surface to increase the bonding area between the copper surface and the prepreg;

[0055] Step S5, lamination: using a traditional press with constant temperature and pressure, the core boards are bonded together with a prepreg, and release film is placed on the top and bottom of the board to ensure the board surface is flat;

[0056] Step S6, drill the target hole, and use an X-ray target drilling machine to drill the required positioning hole;

[0057] Step S7: Mill the edge. Use a CNC milling machine to remove excess copper foil and excess adhesive from the edge of the laminated board to ensure that the edge of the board is neat.

[0058] Step S8, first de-browning, using a mechanical brush to remove the browning film and resin dots from the outer core board;

[0059] Step S9, second browning, removes grease and dirt from the board surface, applies a browning film to the surface copper, and reduces copper to meet the requirements of laser drilling;

[0060] Step S10, laser drilling, drilling the required blind hole using a laser method;

[0061] Step S11, Drilling: Drill the required through hole using mechanical drilling.

[0062] Step S12, Degumming: Use strong oxidizing chemicals to remove residual resin and drill sludge from the borehole;

[0063] Step S13, the first copper plating thickens the resin and glass fiber of the non-conductive part of the hole wall;

[0064] Step S14, plugging holes: use resin to plug the blind holes and the holes in the disc.

[0065] Step S15, baking, drying and curing the semi-cured resin;

[0066] Step S16: Grind the resin at the orifice to ensure that the resin is flat with the orifice.

[0067] Step S17, second pattern transfer, coating the board with photosensitive material, selectively exposing with film, removing the required non-circuit photosensitive material with a weak alkaline chemical solution, and dry film masking the vias and device holes.

[0068] Step S18, First micro-etching copper reduction, using strong oxidizing chemical solution to reduce copper on the entire outer layer of the board;

[0069] Step S19: Thicken the copper plating and cap the blind vias and in-disk vias with POFV.

[0070] Step S20, third pattern transfer, coating the board with photosensitive material, selectively exposing with film, removing the required non-circuit photosensitive material with a weak alkaline chemical solution, exposing the required Hoz area of ​​the antenna.

[0071] Step S21, Second micro-etching copper reduction: Use a strong oxidizing chemical solution to reduce copper in the required Hoz area of ​​the exposed antenna.

[0072] Step S22, fourth pattern transfer: Coat the board with photosensitive material, use outer layer circuit data and expose it, and remove the required non-circuit photosensitive material with a weak alkaline chemical solution.

[0073] Step S23, second etching and film removal: use a strong oxidizing chemical to remove the exposed copper layer, and then use a strong alkaline chemical to remove all photosensitive materials.

[0074] Step S24, solder resist fabrication: Photosensitive solder resist material is screen-printed onto the board using a screen printing method. Selective exposure is performed using film, and the photosensitive material on the required solder pads is removed using a weak alkaline chemical solution, and the green oil is cured.

[0075] Step S25, surface treatment: perform surface treatment on the welding area;

[0076] Step S26, screen printing characters: use a screen to screen print a layer of thermosetting ink on the product surface;

[0077] Step S27, outer shaping, cutting out the required shape;

[0078] Step S28, Testing: Use a testing machine to test the electrical performance between each network;

[0079] Step S29: Finished product inspection. Visually inspect the appearance of the panels. If there are no defects, they are put into storage.

[0080] Optionally, in step S16, a ceramic brush and a non-woven fabric brush are used to grind the resin at the orifice clean.

[0081] Optionally, in step S26, the surface treatment includes immersion silver, immersion gold, and OSP.

[0082] Optionally, in step S27, the required shape is cut out using a CNC milling machine.

[0083] Optionally, in step S28, the electrical performance includes open / short circuit, resistance, and inductance.

[0084] It should be further explained that the coating is made using a wet film + dry film method. The wet film filling ensures the flatness of the board surface and prevents the etching solution in the subsequent process from attacking the different copper thickness steps.

[0085] The present invention also provides a millimeter-wave radar PCB with an antenna region Hoz, which is fabricated using the aforementioned method.

[0086] It should be noted that, in this document, 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 a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0087] Furthermore, it should be noted that the scope of the methods and systems in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions in a substantially simultaneous manner or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. In addition, features described with reference to certain examples may be combined in other examples.

[0088] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A method for fabricating a millimeter-wave radar PCB with an antenna region Hoz, characterized in that, Includes the following steps: Step S1: Cutting materials according to the design dimensions; Step S2, first pattern transfer, coating the board with photosensitive material, exposing with film, and removing the required non-circuit photosensitive material with a weak alkaline chemical solution; Step S3, first etching and film removal: use a strong oxidizing chemical to remove the exposed copper layer, and then use a strong alkaline chemical to remove all photosensitive materials. Step S4, first browning, removes grease and dirt from the board surface, roughens the copper surface to increase the bonding area between the copper surface and the prepreg; Step S5, lamination: using a traditional press with constant temperature and pressure, the core plates are bonded together with a prepreg, and release film is placed on the top and bottom of the plates; Step S6, drill the target hole, and use an X-ray target drilling machine to drill the required positioning hole; Step S7: Mill the edge. Use a CNC milling machine to remove excess copper foil and excess adhesive from the edge of the laminated board. Step S8, first de-browning, using a mechanical brush to remove the browning film and resin dots from the outer core board; Step S9, second browning, removes grease and dirt from the board surface, applies a browning film to the surface copper, and reduces copper to meet the requirements of laser drilling; Step S10, laser drilling, drilling the required blind hole using a laser method; Step S11, Drilling: Drill the required through hole using mechanical drilling. Step S12, Degumming: Use strong oxidizing chemicals to remove residual resin and drill sludge from the borehole; Step S13, the first copper plating thickens the resin and glass fiber of the non-conductive part of the hole wall; Step S14, plugging holes: use resin to plug the blind holes and the holes in the disc. Step S15, baking, drying and curing the semi-cured resin; Step S16: Grind and clean the resin from the orifice. Step S17, second pattern transfer, coating the board with photosensitive material, selectively exposing with film, removing the required non-circuit photosensitive material with a weak alkaline chemical solution, and dry film masking the vias and device holes. Step S18, First micro-etching copper reduction, using strong oxidizing chemical solution to reduce copper on the entire outer layer of the board; Step S19: Thicken the copper plating and cap the blind vias and in-disk vias with POFV. Step S20, third pattern transfer, coating the board with photosensitive material, selectively exposing with film, removing the required non-circuit photosensitive material with a weak alkaline chemical solution, exposing the required Hoz area of ​​the antenna. Step S21, Second micro-etching copper reduction: Use a strong oxidizing chemical solution to reduce copper in the required Hoz area of ​​the exposed antenna. Step S22, fourth pattern transfer: Coat the board with photosensitive material, use outer layer circuit data and expose it, and remove the required non-circuit photosensitive material with a weak alkaline chemical solution. Step S23, second etching and film removal: use a strong oxidizing chemical to remove the exposed copper layer, and then use a strong alkaline chemical to remove all photosensitive materials. Step S24, solder resist fabrication: Photosensitive solder resist material is screen-printed onto the board using a screen printing method. Selective exposure is performed using film, and the photosensitive material on the required solder pads is removed using a weak alkaline chemical solution, and the green oil is cured. Step S25, surface treatment: perform surface treatment on the welding area; Step S26, screen printing characters: use a screen to screen print a layer of thermosetting ink on the product surface; Step S27, outer shaping, cutting out the required shape; Step S28, Testing: Use a testing machine to test the electrical performance between each network; Step S29: Finished product inspection. Visually inspect the appearance of the panels. If there are no defects, they are put into storage.

2. The preparation method according to claim 1, characterized in that, In step S16, a ceramic brush and a non-woven fabric brush are used to grind the resin at the orifice clean.

3. The preparation method according to claim 1, characterized in that, In step S26, the surface treatment includes immersion silver, immersion gold, and OSP.

4. The preparation method according to claim 1, characterized in that, In step S27, the required shape is cut out using a CNC milling machine.

5. The preparation method according to claim 1 or 4, characterized in that, In step S28, electrical performance includes open / short circuit, resistance, and inductance.

6. A millimeter-wave radar PCB with an antenna region of Hoz, characterized in that, It is prepared by the preparation method described in any one of claims 1-5.

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