An antenna compensation test method for a millimeter wave radar PCB pad

Abstract

This invention provides an antenna compensation testing method for millimeter-wave radar PCB pads, relating to the field of printed circuit board (PCB) manufacturing technology. The method includes: Step 1, standardized test condition setting; unifying test substrate specifications and etching process parameters, solidifying all non-test variables, and constructing a repeatable control test environment; Step 2, multi-dimensional compensation scheme matrix design; designing CAM pre-compensation tools with various geometric shapes, setting multi-gradient compensation amounts, and cross-combining compensation tools and compensation amounts to form multiple sets of parallel test schemes. This invention, through standardized test environment construction, multi-dimensional compensation scheme design, integrated sample preparation, quantitative morphology detection, and a graded evaluation system, accurately selects the optimal combination of compensation tools and compensation amounts, achieving a near 90° right angle at the outer corner of the etched pad, thereby improving the soldering reliability and RF performance stability of millimeter-wave radar PCB pads.

Description

Technical Field

[0001] This invention relates to the field of printed circuit board (PCB) manufacturing technology, specifically to a method for testing antenna compensation of millimeter-wave radar PCB pads. Background Technology

[0002] In the manufacturing of millimeter-wave radar PCBs, the etching process is the core step that determines the quality of antenna pad forming. During the etching process, the metal outer corners of the PCB circuits (commonly known in the industry as ram's horns) are simultaneously eroded by the etching solution on three sides, resulting in more severe lateral etching loss than the circuit plane. This ultimately causes the outer corners of the pads to form a rounded outline, failing to achieve the 90° right angle shape required by the design. This defect will bring about a number of process and performance problems: the effective soldering area of ​​the pads is occupied by the rounded structure, the soldering contact surface is reduced, resulting in a decrease in the antenna soldering firmness. Long-term use is prone to cold solder joints and desoldering failures. In addition, the rounded corners will cause reflection and radiation loss of millimeter-wave high-frequency signals, causing radar signal fluctuations and ranging accuracy deviations, directly affecting the functional performance and yield of the finished product.

[0003] Existing technologies typically employ CAM pre-compensation to offset the effects of lateral etching, but lack standardized and systematic testing and verification methods. The selection of compensation tool type and compensation amount largely depends on experience, making it impossible to accurately match the lateral etching amount under specific copper thickness and specific etching processes. This results in unstable compensation effects and makes it difficult to meet the high precision requirements of millimeter-wave radar products.

[0004] Therefore, this invention proposes an antenna compensation test method for millimeter-wave radar PCB pads, thereby effectively solving the above-mentioned problems and difficulties. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies and provide an antenna compensation testing method for millimeter-wave radar PCB pads. By constructing a standardized testing environment, designing multi-dimensional compensation schemes, preparing integrated templates, and implementing a quantitative morphology detection and hierarchical evaluation system, the optimal compensation tools and compensation amount combinations are precisely selected to achieve the goal of the outer corner of the pad being close to a 90° right angle after etching, thereby improving the soldering reliability and RF performance stability of millimeter-wave radar PCB pads.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A method for testing antenna compensation on millimeter-wave radar PCB pads, the method specifically includes the following steps:

[0008] Step 1: Standardize test conditions; unify the test substrate specifications and etching process parameters, solidify all non-test variables, and build a repeatable control test environment;

[0009] Step 2: Multi-dimensional compensation scheme matrix design; design CAM pre-compensation tools with various geometric shapes, set multiple gradient compensation amounts, and cross-combine the compensation tools and compensation amounts to form multiple sets of parallel test schemes;

[0010] Step 3: Integrated fabrication of test samples; complete the pattern transfer and etching of all test schemes on the same test substrate to ensure that all groups are in a completely consistent process environment;

[0011] Step 4: Standardized inspection of pad morphology; Microscopic imaging and feature acquisition are performed on the outer corners of each group of pads using a linewidth measuring instrument, and the morphological parameters of the outer corners of the pads are quantitatively extracted;

[0012] Step 5: Evaluation of compensation effect and determination of optimal solution; Based on a unified standard of right angle restoration, the compensation effects of each group are compared horizontally and vertically to select the optimal combination of compensation tools and compensation amounts.

[0013] Furthermore, the standardization setting of test conditions in step 1 specifically includes:

[0014] Substrate parameter solidification: PCB substrate with a base copper thickness of 1oz was selected, and the substrate material and copper thickness tolerances were standardized.

[0015] Development process parameter control: Development temperature is controlled at 30±2℃, plate speed is 2000-3500mm / min, sodium carbonate solution concentration is 1.0±0.2%, development pressure is 1.0-2.0kg / cm², and development pressure is 1.0-1.5kg / cm².

[0016] Etching process parameter control: The etching temperature is controlled at 50±2℃, the concentration of hydrochloric acid in the etching solution is 2.0-4.0mol / L, the concentration of copper ions is 120-160g / L, the concentration of sodium chlorate is 450-560, the etching pressure is 1.5-3.0kg / cm², and the etching pressure is 1.5-2.5kg / cm².

[0017] Furthermore, in the process of designing the multi-dimensional compensation scheme matrix in step 2, four types of compensation tools are set up, namely square compensation tool, triangular compensation tool, spherical compensation tool, and strip-shaped compensation tool;

[0018] The square compensation tool has a regular square structure with uniform edge compensation, and is adapted to the basic compensation of the outer corner of a regular square pad.

[0019] The triangular compensation tool has an acute triangular structure, which forms a sharp corner transition after compensation, and is used to reduce stress concentration at the acute corner of the pad.

[0020] The spherical compensation tool has an arc surface structure, which forms a smooth transition after compensation, and is used to balance the current distribution at the outer corner and reduce the peak value of the electric field intensity.

[0021] The strip-shaped compensation tool has a slender structure, which is adapted to the outer corner compensation of narrow-pitch pads and is suitable for complex wiring scenarios.

[0022] Furthermore, in step 2, the compensation amount is set with four gradient values ​​of 15μm, 20μm, 25μm, and 30μm; the four types of compensation tools are combined with the four compensation amounts to form a total of 16 independent test schemes, and the graphics of all test schemes are arranged in different areas of the same test substrate.

[0023] Furthermore, step 3, the integrated preparation of the test sample, specifically includes the following process flow:

[0024] Step 301: Material preparation; Cut the substrate according to the set dimensions to obtain the test substrate;

[0025] Step 302: Pre-treatment of gold-coated substrates; cleaning and roughening the copper surface of the substrate to improve the adhesion of the dry film.

[0026] Step 303: Applying the film; evenly press the dry film onto the copper surface, controlling the film application temperature and pressure to remain consistent;

[0027] Step 304: LDI Exposure; Using laser direct imaging technology, the CAM compensation pattern containing all test schemes is transferred to the dry film layer, maintaining uniform exposure energy throughout the process.

[0028] Step 305: Development; Develop according to the set development parameters to remove the dry film in the unexposed areas and expose the copper surface to be etched;

[0029] Step 306: Etching; Etching is performed according to the set etching parameters, and the pads are formed through side etching.

[0030] Step 307: Demold; Remove residual dry film to obtain a test sample with multiple sets of compensation test pads.

[0031] Furthermore, step 4, the standardized inspection of pad morphology, specifically includes the following process flow:

[0032] Step 401: Multi-point sampling; For each test scheme, select at least 4 test points in different etching directions of the substrate to cover different areas of the board and offset the interference of uneven etching.

[0033] Step 402: Multi-light source microscopic imaging; Using a linewidth measuring instrument, each test point is imaged in a combined light source mode of coaxial light, upper light, and lower light. The imaging magnification is 104.6 times and the pixel accuracy is 0.0019mm / pixel.

[0034] Step 403: Morphological feature extraction; Extract the contour features of the outer corner of the pad from the microscopic image, and record the indicators including the outer corner radius, right angle sharpness, edge uniformity, and whether there are defects such as protrusions or over-etching.

[0035] Furthermore, the evaluation and judgment criteria for the graded evaluation of compensation effect and determination of the optimal solution in step 5 specifically include:

[0036] Gradient longitudinal comparison: For the same compensation tool, compare the changes in pad morphology under four compensation levels of 15μm, 20μm, 25μm and 30μm, and analyze the correlation between compensation level and side etching offset effect.

[0037] Tool comparison: Under the same compensation level, compare the right angle restoration effect of the pad outer corner of the four types of compensation tools to select the best tool under a single compensation level;

[0038] Overall performance rating: The 16 solutions were rated based on the core criteria of the outer corner of the etched pad being closest to a 90° right angle, the edge contour being clear and uniform, and the absence of obvious protrusions and over-etching defects.

[0039] Optimal solution confirmation: Taking into account the accuracy of right-angle reproduction, edge uniformity, and batch adaptability, the final optimal compensation solution is determined.

[0040] Furthermore, in the process of confirming the optimal solution in step 5, for a millimeter-wave radar PCB with a bottom copper thickness of 1 oz, the optimal compensation solution is to use a square compensation tool with a compensation amount set to 30 μm.

[0041] This invention provides a method for testing antenna compensation on millimeter-wave radar PCB pads. It offers the following advantages:

[0042] 1. This invention provides a method for antenna compensation testing of millimeter-wave radar PCB pads. This method constructs a standardized testing system, which unifies substrate specifications, development and etching process parameters, and solidifies all non-test variables. The test results are repeatable and traceable, and can provide a general reference for setting compensation parameters for similar PCB products. Furthermore, it adopts a cross-test matrix of multiple types of compensation tools and multiple gradient compensation amounts, covering mainstream compensation forms and compensation ranges. This allows for comprehensive screening of the optimal solution under different scenarios, avoiding the blindness of experience-based selection.

[0043] 2. This invention provides an antenna compensation test method for millimeter-wave radar PCB pads. This method uses a quantitative detection method with multi-source microscopic imaging using a linewidth measuring instrument. It uses the sharpness of the pad's outer corner and the right angle deviation as objective judgment indicators to replace traditional subjective judgment. The evaluation standard is unified and quantifiable, ensuring the objectivity and accuracy of the results. Through integrated template preparation, all test groups are processed on the same substrate, completely eliminating the errors caused by batch process fluctuations, and the comparison results have high confidence. Attached Figure Description

[0044] Figure 1 This is a process step diagram of the antenna compensation test method for millimeter-wave radar PCB pads according to the present invention;

[0045] Figure 2 This is a schematic diagram of the structure of the four types of compensation tools of the present invention;

[0046] Figure 3 This is a comparison diagram of the pad etching effect of four types of tools under the 15μm compensation amount of the present invention;

[0047] Figure 4 This is a comparison diagram of the pad etching effect of four types of tools under the 20μm compensation amount of the present invention;

[0048] Figure 5 This is a comparison diagram of the pad etching effect of four types of tools under the 25μm compensation amount of the present invention;

[0049] Figure 6 This is a comparison chart of the pad etching effects of four types of tools under the 30μm compensation amount of the present invention. Detailed Implementation

[0050] 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.

[0051] Example 1:

[0052] like Figure 1-6 As shown, this embodiment uses the test method described in this invention to verify the compensation parameters and screen the optimal solution for the pads of a millimeter-wave radar PCB with a bottom copper thickness of 1 oz. The specific implementation steps are as follows:

[0053] Step 1: Standardize and set test conditions;

[0054] Substrate preparation: FR-4 substrate with a base copper thickness of 1oz (approximately 35μm) was selected and cut into test dimensions of 546mm×414mm to confirm uniform copper thickness and no oxidation scratches on the surface;

[0055] Curing of developing parameters: The developing line parameters were adjusted to a temperature of 30.3℃, a plate speed of 2400mm / min, a sodium carbonate solution concentration of 1%, an upper pressure of 1.5kg / cm², and a lower pressure of 1.3kg / cm². All parameters were within the process standard range.

[0056] Etching parameters were solidified: The etching line parameters were adjusted to a temperature of 49.9℃, a hydrochloric acid concentration of 3.14mol / L, a copper ion concentration of 144g / L, a sodium chlorate concentration of 530, an upper pressure of 2.1kg / cm², and a lower pressure of 1.8kg / cm². All parameters were within the process standard range.

[0057] All non-test variables are fixed to ensure that subsequent tests only have a single variable difference in compensation tool and compensation amount.

[0058] Step 2: Design of a multi-dimensional compensation scheme matrix;

[0059] Compensation tool design: Design pre-compensation tools for four types of geometric shapes in CAM software;

[0060] Square compensation tool: A square structure with side length matching the compensation amount, after compensation the outer corner edges extend outwards evenly;

[0061] Triangular compensation tool: Right-angled triangle structure, with two right-angled sides respectively fitting the two sides of the outer corner of the pad, and the sharp corner extending outward;

[0062] Spherical compensation tool: a quarter-circle structure with straight edges fitting against the outer corners of the pads and the arc extending outwards;

[0063] Strip-shaped compensation tool: Two vertical, thin strip structures extend outwards along both sides of the pad and connect at the corner;

[0064] Compensation gradient settings: Set four compensation values ​​of 15μm, 20μm, 25μm, and 30μm, which correspond to the degree of side erosion offset from low to high, covering the side erosion range of conventional processes;

[0065] Test matrix construction: The four types of tools are combined with four compensation levels to form 16 test schemes, namely: 15μm square, 15μm triangle, 15μm sphere, 15μm strip, 20μm square, 20μm triangle, 20μm sphere, 20μm strip, 25μm square, 25μm triangle, 25μm sphere, 25μm strip, 30μm square, 30μm triangle, 30μm sphere, 30μm strip. The test pad patterns of the 16 schemes are evenly distributed in different areas of the same substrate to avoid process errors caused by positional differences.

[0066] Step 3: Integrated preparation of test samples;

[0067] Test samples were made in accordance with the standard PCB pre-processing and graphic transfer process, ensuring that all solutions were in the same process environment throughout the process.

[0068] Material cutting: Cut the large substrate into test boards of 546mm×414mm, with smooth and burr-free edges;

[0069] Pre-treatment of gold wire: The copper surface is cleaned and roughened through grinding and micro-etching processes to remove oxide layers and contaminants and ensure the adhesion of dry film;

[0070] Film application: Use an automatic film application machine to press dry film onto the copper surface, control the film application temperature and pressure to ensure that the dry film is free of bubbles and wrinkles;

[0071] LDI Exposure: Import the CAM patterns of 16 compensation schemes into the LDI equipment, set a uniform exposure energy, and complete the precise transfer of the pattern to the dry film layer;

[0072] Development: Pass the exposed plate into the development line, complete the development according to the preset parameters, wash and dry it with water, and check that the pattern is clear and complete, without incomplete development or over-development defects.

[0073] Etching: The developed board is passed through the etching line and the etching process is completed according to the preset parameters. The pads are finally formed by the lateral etching effect of the etching solution.

[0074] Film removal: Remove the remaining dry film on the pad surface using an alkaline film removal solution, and obtain a complete test sample after cleaning and drying;

[0075] Step 4: Standardized inspection of pad morphology;

[0076] Multi-point sampling: For each test scheme, four pads at different locations are selected as test points, corresponding to the upper left, upper right, lower left, and lower right areas of the board, respectively, covering different etching directions to offset the interference of uneven etching of the whole board.

[0077] Microscopic imaging: Using a linewidth measuring instrument, the magnification was set to 104.6 times, and the combination of upper light, lower light and coaxial light source was turned on to clearly image the outer corner of the pad of each test point. The imaging pixel accuracy was 0.0019mm / pixel.

[0078] Feature recording and preliminary judgment: Observe each imaging result and record the morphological characteristics of the outer corners of each group of pads according to the compensation gradient:

[0079] 15μm compensation group: Square tools have obvious rounded edges and right angles are not formed; Triangular tools have rounded corners at the apex, and the compensation effect is limited; Spherical tools have smooth outer corner contours and no sharp edges; Strip tools have uneven sides and the corners are still rounded; The overall compensation effect is not obvious and cannot meet the process requirements.

[0080] 20μm compensation group: The square tool angle has been improved to some extent, but there is still a significant difference from the standard right angle; the triangular tool edge still has a rounded feel and lacks sharpness; the spherical tool angle is smooth and clearly visible; the strip tool has limited improvement and uneven forming around the edges;

[0081] 25μm compensation amount group: The outer corner of the square tool pad is close to the ideal right angle shape; the shape of the triangular tool is significantly improved, and the effect is second best; the effect of the spherical tool is somewhat better, but the edge is still not sharp enough; the improvement of the strip tool is relatively limited.

[0082] 30μm compensation amount group: The outer corners of the square tool pads are sharp 90° right angles with clear edge contours. Only a few places have slight bulges due to uneven etching. The four corners of the triangular tool are unevenly sharp, and some places still have slight rounding. The spherical tool has sharp corners in some places, but most places have bulges or rounding. The strip tool has bulges in some places and still has rounding in some places. The overall effect is average.

[0083] Step 5: Evaluation of compensation effectiveness and determination of the optimal solution;

[0084] Vertical gradient analysis: All four types of tools show a positive correlation between the larger the compensation amount and the better the right-angle restoration effect. The 15μm compensation amount cannot completely offset the side erosion; the compensation effect begins to appear at 20μm; the effect is significantly improved at 25μm; and the best right-angle restoration effect is achieved at 30μm.

[0085] Horizontal tool comparison: At all compensation levels, the square compensation tool has better right-angle reproduction accuracy than the other three types of tools, and has the best edge uniformity and the strongest ability to withstand uneven etching; the triangular tool performs second; the spherical and strip tools have relatively weak versatility and are only suitable for specific narrow pitch or special wiring scenarios.

[0086] Overall performance rating: The core evaluation criteria are that the outer corner of the pad is closest to a 90° right angle, the edge contour is clear and uniform, and there are no obvious protrusions or over-etching defects. The 16 groups of solutions are rated as follows: the 30μm square solution is the best level, the 25μm square and 30μm triangle solutions are good level, and the remaining groups are in the level of needing optimization.

[0087] Optimal solution confirmed: Considering the accuracy of right angle reproduction, edge uniformity, and adaptability to mass production, the optimal compensation solution for millimeter-wave radar PCB pads with a copper thickness of 1oz was finally determined to be: using a square compensation tool with a compensation amount set to 30μm. After etching, this solution results in sharp outer corners and clear outlines of the pads, which can offset the three-way lateral etching loss to the greatest extent, restore the right angle shape of the design, and show good consistency across the entire board, making it suitable for mass production requirements.

[0088] The following points should be noted in this article:

[0089] 1. The accompanying drawings of the embodiments disclosed herein only relate to the structures involved in the embodiments disclosed herein; other structures can be referred to in general design.

[0090] 2. Where there is no conflict, the embodiments of this disclosure and the features in the embodiments can be combined with each other to obtain new embodiments.

[0091] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A method for testing antenna compensation on millimeter-wave radar PCB pads, characterized in that: The method specifically includes the following steps: Step 1: Standardize test conditions; unify the test substrate specifications and etching process parameters, solidify all non-test variables, and build a repeatable control test environment; Step 2: Multi-dimensional compensation scheme matrix design; design CAM pre-compensation tools with various geometric shapes, set multiple gradient compensation amounts, and cross-combine the compensation tools and compensation amounts to form multiple sets of parallel test schemes; Step 3: Integrated fabrication of test samples; complete the pattern transfer and etching of all test schemes on the same test substrate to ensure that all groups are in a completely consistent process environment; Step 4: Standardized inspection of pad morphology; Microscopic imaging and feature acquisition are performed on the outer corners of each group of pads using a linewidth measuring instrument, and the morphological parameters of the outer corners of the pads are quantitatively extracted; Step 5: Evaluation of compensation effect and determination of optimal solution; Based on a unified standard of right angle restoration, the compensation effects of each group are compared horizontally and vertically to select the optimal combination of compensation tools and compensation amounts.

2. The antenna compensation test method for millimeter-wave radar PCB pads according to claim 1, characterized in that: The standardized setting of test conditions in step 1 specifically includes: Substrate parameter solidification: PCB substrate with a base copper thickness of 1oz was selected, and the substrate material and copper thickness tolerances were standardized. Development process parameter control: Development temperature is controlled at 30±2℃, plate speed is 2000-3500mm / min, sodium carbonate solution concentration is 1.0±0.2%, development pressure is 1.0-2.0kg / cm², and development pressure is 1.0-1.5kg / cm². Etching process parameter control: The etching temperature is controlled at 50±2℃, the concentration of hydrochloric acid in the etching solution is 2.0-4.0mol / L, the concentration of copper ions is 120-160g / L, the concentration of sodium chlorate is 450-560, the etching pressure is 1.5-3.0kg / cm², and the etching pressure is 1.5-2.5kg / cm².

3. The antenna compensation test method for millimeter-wave radar PCB pads according to claim 1, characterized in that: In the process of designing the multi-dimensional compensation scheme matrix in step 2, four types of compensation tools are set up, namely square compensation tool, triangle compensation tool, spherical compensation tool, and strip compensation tool; The square compensation tool has a regular square structure with uniform edge compensation, and is adapted to the basic compensation of the outer corner of a regular square pad. The triangular compensation tool has an acute triangular structure, which forms a sharp corner transition after compensation, and is used to reduce stress concentration at the acute corner of the pad. The spherical compensation tool has an arc surface structure, which forms a smooth transition after compensation, and is used to balance the current distribution at the outer corner and reduce the peak value of the electric field intensity. The strip-shaped compensation tool has a slender structure, which is adapted to the outer corner compensation of narrow-pitch pads and is suitable for complex wiring scenarios.

4. The antenna compensation test method for millimeter-wave radar PCB pads according to claim 3, characterized in that: In step 2, the compensation amount is set with four gradient values ​​of 15μm, 20μm, 25μm, and 30μm. The four types of compensation tools are combined with the four compensation amounts to form a total of 16 independent test schemes. The graphics of all test schemes are arranged in different areas of the same test substrate.

5. The antenna compensation test method for millimeter-wave radar PCB pads according to claim 1, characterized in that: Step 3, the integrated preparation of the test sample, specifically includes the following process flow: Step 301: Material preparation; Cut the substrate according to the set dimensions to obtain the test substrate; Step 302: Pre-treatment of gold-coated substrates; cleaning and roughening the copper surface of the substrate to improve the adhesion of the dry film. Step 303: Applying the film; evenly press the dry film onto the copper surface, controlling the film application temperature and pressure to remain consistent; Step 304: LDI Exposure; Using laser direct imaging technology, the CAM compensation pattern containing all test schemes is transferred to the dry film layer, maintaining uniform exposure energy throughout the process. Step 305: Development; Develop according to the set development parameters to remove the dry film in the unexposed areas and expose the copper surface to be etched; Step 306: Etching; Etching is performed according to the set etching parameters, and the pads are formed through side etching. Step 307: Demold; Remove residual dry film to obtain a test sample with multiple sets of compensation test pads.

6. The antenna compensation test method for millimeter-wave radar PCB pads according to claim 1, characterized in that: Step 4, the standardized inspection of pad morphology, specifically includes the following process flow: Step 401: Multi-point sampling; For each test scheme, select at least 4 test points in different etching directions of the substrate to cover different areas of the board and offset the interference of uneven etching. Step 402: Multi-light source microscopic imaging; Using a linewidth measuring instrument, each test point is imaged in a combined light source mode of coaxial light, upper light, and lower light. The imaging magnification is 104.6 times and the pixel accuracy is 0.0019mm / pixel. Step 403: Morphological feature extraction; The contour features of the outer corners of the pads are extracted from the microscopic images, and the recorded indicators include the radius of the outer corners, the sharpness of the right angles, the uniformity of the edges, and whether there are defects such as protrusions or over-etching.

7. The antenna compensation test method for millimeter-wave radar PCB pads according to claim 1, characterized in that: The evaluation and judgment criteria for step 5, which involves the graded evaluation of compensation effects and the determination of the optimal solution, specifically include: Gradient longitudinal comparison: For the same compensation tool, compare the changes in pad morphology under four compensation levels of 15μm, 20μm, 25μm and 30μm, and analyze the correlation between compensation level and side etching offset effect. Tool comparison: Under the same compensation level, compare the right angle restoration effect of the pad outer corner of the four types of compensation tools to select the best tool under a single compensation level; Overall performance rating: The 16 solutions were rated based on the core criteria of the outer corner of the etched pad being closest to a 90° right angle, the edge contour being clear and uniform, and the absence of obvious protrusions and over-etching defects. Optimal solution confirmation: Taking into account the accuracy of right-angle reproduction, edge uniformity, and batch adaptability, the final optimal compensation solution is determined.

8. The antenna compensation test method for millimeter-wave radar PCB pads according to claim 7, characterized in that: In the process of confirming the optimal solution in step 5, for a millimeter-wave radar PCB with a bottom copper thickness of 1 oz, the optimal compensation solution is to use a square compensation tool with a compensation amount set to 30 μm.

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