A high-precision etching process for adjusting knob patterns

Abstract

This invention discloses a high-precision etching process for adjusting knob patterns, which relates to the field of high-precision etching technology. The etching process includes the following steps: (1) Substrate selection and precision leveling: Select stainless steel SUS304 / 316, brass, copper or aluminum alloy 5052 / 6061 cold-rolled fine-rolled material for leveling; (2) Multi-stage cleaning, degreasing and activation: Use alkaline degreasing agent for ultrasonic degreasing, activate with dilute acid, rinse with multi-stage pure water overflow, and dry with hot air; (3) Uniform photoresist coating: Use dry film photoresist for roller pressing and vacuum bonding, and form a uniform resist layer after pre-baking; By replacing the traditional film mask with LDI laser direct writing, there is no scaling deformation and high positioning accuracy. With closed-loop PID temperature control, online thickness measurement and real-time compensation and segmented fine etching, the line width accuracy can be stably achieved to ±0.01mm, the depth accuracy to ±0.005mm, and the pattern depth of the whole circle / Width difference ≤0.015mm, concentricity ≤0.02mm, significantly better than conventional etching processes, meeting the stringent requirements of high-end precision knobs.

Description

Technical Field

[0001] This invention relates to the field of high-precision etching technology, specifically a high-precision etching process for adjusting the pattern of a knob. Background Technology

[0002] Existing chemical etching methods mostly employ planar fixed spraying or immersion etching, which struggles to achieve uniform circumferential etching of rotationally symmetrical knob structures, generally resulting in severe lateral etching, large depth deviations, and low linewidth accuracy. Simultaneously, traditional photolithography relies on film substrates, which are prone to scaling distortion, poor positioning accuracy, and long changeover cycles, hindering flexible production of multiple varieties and small batches. Therefore, those skilled in the art have provided a high-precision etching process for adjusting knob patterns to address the problems mentioned in the background art. Summary of the Invention

[0003] The purpose of this invention is to provide a high-precision etching process for the pattern of adjustment knobs, so as to overcome the defects of existing machining, laser engraving and traditional chemical etching processes in the manufacturing of metal adjustment knob patterns, such as insufficient precision, poor uniformity, low side wall verticality, large side etching, easy generation of burrs and serrations, and weak batch stability.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] A high-precision etching process for adjusting knob patterns, the etching process comprising the following steps in sequence: (1) Selection and precision leveling of substrate: Select stainless steel SUS304 / 316, brass, copper or aluminum alloy 5052 / 6061 cold rolled precision material for leveling treatment; (2) Multi-stage cleaning, degreasing and activation: Alkaline degreasing agent is used for ultrasonic degreasing, followed by multi-stage pure water overflow rinsing and hot air drying after activation with dilute acid; (3) Uniform photoresist coating: Dry film photoresist is rolled and vacuum bonded, and a uniform resist layer is formed after pre-baking; (4) LDI laser direct writing exposure: pattern exposure is performed using a high-resolution LDI laser direct writing machine; (5) Development and retouching: Sodium carbonate solution is used for spray development, and the retouching is used to make the edges of the pattern straight and without residue; (6) Closed-loop control rotary spray etching: A rotary spray etching machine with rotation and revolution is used, combined with PID constant temperature and online thickness measurement and real-time compensation, to perform segmented etching and forming; (7) Degumming, neutralization and passivation: Use alkaline solution or special demolding agent for ultrasonic degumming, passivation of stainless steel and neutralization of aluminum parts to prevent discoloration; (8) Pure water rinsing and drying: Multi-stage pure water rinsing followed by dehydration and drying; (9) AOI full inspection: to conduct a full inspection of the product's dimensions and appearance; By combining LDI laser direct writing lithography with closed-loop rotary spray etching, we can achieve a pattern linewidth accuracy of ±0.01mm, a depth accuracy of ±0.005mm, a sidewall verticality of 85°-89°, a side etching ratio of ≤1:0.8, and a pattern depth / width difference of ≤0.015mm around the entire circumference.

[0006] Furthermore, the substrate thickness tolerance is ±0.01mm, and the surface roughness Ra≤0.2μm; the degreasing temperature is 50-60℃, the ultrasonic frequency is 40kHz, and the processing time is 5-8min; the drying temperature is 80℃, and the process is carried out in a dust-free environment.

[0007] Furthermore, the dry film photoresist thickness is 8-12 μm; the pre-baking temperature is 85±2℃, and the time is 5-8 min; the LDI laser direct writing resolution is ≥30k, the positioning accuracy is ±1μm, and the exposure energy is 350-450mJ / cm².

[0008] Furthermore, the developing solution is a 1.0%-1.2% Na2CO3 solution, with a temperature of 28-30℃, a spray pressure of 0.8-1.2 bar, and a developing time of 30-60 seconds.

[0009] Furthermore, the rotary spray etching machine has a rotation speed of 3-5 r / min, the etching temperature is controlled by PID with a fluctuation of ±0.3℃, the spray pressure is 1.5-2.5 bar, and the etching rate is 0.5-2 μm / min; the segmented etching process involves first coarse etching to 80% of the target depth, and then fine etching to the set depth, with real-time compensation using white light interferometry or eddy current thickness measurement.

[0010] Furthermore, the etching solution system is as follows: for stainless steel, FeCl3 40-44°Bé is used with hydrochloric acid and corrosion inhibitor; for copper, CuCl2 is used; and for aluminum, NaOH+H2O2 is used.

[0011] Furthermore, the adjustment knob has a circular pattern, radial pattern, scale, or micro-anti-slip texture, with a line width of 0.03-0.5mm, a depth of 0.05-0.3mm, and a product concentricity of ≤0.02mm.

[0012] Furthermore, the product is free of burrs, pinholes, serrations, and over-etching, making it suitable for high-end audio, instrumentation, automotive, or industrial control knobs.

[0013] By adopting the above technical solution Compared with the prior art, the beneficial effects of the present invention are: 1. By replacing traditional film masks with LDI laser direct writing, there is no scaling distortion and high positioning accuracy. Combined with closed-loop PID temperature control, online thickness measurement and real-time compensation, and segmented fine etching, it can stably achieve line width accuracy of ±0.01mm, depth accuracy of ±0.005mm, pattern depth / width difference of ≤0.015mm, and concentricity of ≤0.02mm, which is significantly better than conventional etching processes and meets the stringent requirements of high-end precision knobs. 2. The process employs a rotational spray etching method, combined with a special etching solution and corrosion inhibitor system, to achieve a sidewall verticality of 85°-89° and a side etching ratio of ≤1:0.8. The resulting pattern has straight, smooth edges without jagged edges, burrs, or over-etching, significantly improving the appearance, texture, and feel of the product. 3. The rotary spray method ensures a highly consistent etching environment around the knob. Combined with uniform liquid distribution and real-time monitoring and control, it completely solves the problems of local over-etching, under-etching, and poor concentricity that are prone to occur in traditional planar etching. The depth and width of the pattern are uniform throughout the entire circle, and the yield rate is greatly improved. 4. The process is compatible with a variety of commonly used knob materials such as stainless steel SUS304 / 316, brass, copper, and aluminum alloy 5052 / 6061. It matches a special etching system for different substrates, taking into account precision, efficiency and surface quality, and has a wide range of applications. Detailed Implementation

[0014] Example 1 (Stainless Steel SUS304 Knob Pattern Etching) This invention provides an embodiment of a high-precision etching process for adjusting the pattern of a knob: 1. Selection of substrate materials and precision leveling SUS304 stainless steel cold-rolled precision material is selected, with thickness tolerance controlled within ±0.01mm and surface roughness Ra≤0.2μm. The substrate is precision leveled to ensure a flat surface without warping. 2. Multi-stage cleaning, degreasing, and activation Using an alkaline degreasing agent, the surface is degreased for 5-8 minutes at 50-60℃ with 40kHz ultrasonic waves; then it is activated by rinsing with dilute acid to remove the surface oxide layer, followed by multi-stage overflow rinsing with pure water; finally, it is dried in a dust-free environment with hot air at 80℃ to ensure that the surface is free of oil and watermarks. 3. Photoresist is evenly coated. A dry film photoresist with a thickness of 8-12μm is vacuum-bonded to the substrate surface by roll forming to ensure no bubbles or wrinkles; then it is pre-baked at 85±2℃ for 5-8 minutes to form a uniform and dense resist layer. 4. LDI Laser Direct Writing Exposure An LDI laser direct writing machine with a resolution of ≥30k was used to directly write the pattern on the knob surface with a positioning accuracy of ±1μm and an exposure energy of 350-450mJ / cm². 5. Development and retouching A Na2CO3 solution with a mass concentration of 1.0%-1.2% was used as the developing solution. The developing process was carried out at 28-30℃ and a spray pressure of 0.8-1.2 bar for 30-60 seconds. After development, the plate was retouched to ensure that the edges of the pattern were straight, without residual adhesive, and without jagged edges. 6. Closed-loop control of rotary spray etching A rotary spray etching machine with both self-rotation and revolution is used, with a rotation speed of 3-5 r / min; the etching solution is a 40-44°BéFeCl3 system, with added hydrochloric acid and corrosion inhibitor; the etching temperature is controlled at ±0.3℃, the spray pressure is 1.5-2.5 bar, and the etching rate is controlled at 0.5-2 μm / min through PID control. A segmented etching process is adopted: first, rough etching is performed to 80% of the target depth, and then fine etching is performed to the set depth; online thickness measurement and real-time compensation are carried out using white light interferometry or eddy current thickness gauge to ensure depth accuracy and uniformity.

[0015] Example 2 (Etching of brass knob pattern) This embodiment is basically the same as Embodiment 1, except that: The substrate is cold-rolled fine brass, and the etching solution is a CuCl2 system; the remaining processes, parameters, and control requirements are the same as in Example 1. The obtained brass adjustment knobs meet the design specifications in terms of pattern precision, appearance, and uniformity, and are suitable for automotive, industrial control, and other scenarios.

[0016] Example 3 (Etching of knob pattern on 6061 aluminum alloy) This embodiment is basically the same as Embodiment 1, except that: The substrate is 6061 cold-rolled precision aluminum alloy, and the etching solution is a NaOH+H2O2 system; after etching, neutralization treatment is performed to prevent surface discoloration; the remaining processes, parameters and control requirements are the same as in Example 1. The resulting aluminum adjustment knobs have high dimensional accuracy and uniform, defect-free appearance, meeting the requirements for lightweight, high-end knobs.

[0017] By replacing traditional film masks with LDI laser direct writing, there is no scaling distortion and high positioning accuracy. Combined with closed-loop PID temperature control, online thickness measurement and real-time compensation, and segmented fine etching, it can stably achieve line width accuracy of ±0.01mm, depth accuracy of ±0.005mm, pattern depth / width difference of ≤0.015mm, and concentricity of ≤0.02mm, which is significantly better than conventional etching processes and meets the stringent requirements of high-end precision knobs. Using a rotational spray etching process, combined with a special etching solution and corrosion inhibitor system, the sidewall verticality is 85°-89°, the side etching ratio is ≤1:0.8, the formed pattern edges are straight without jagged edges, burrs, or over-etching, and the appearance and feel are significantly improved. The rotary spray method ensures a highly consistent circumferential etching environment for the knob. Combined with uniform liquid distribution and real-time monitoring and control, it completely solves the problems of local over-etching, under-etching, and poor concentricity that are prone to occur in traditional planar etching. The depth and width of the pattern are uniform throughout the entire circle, and the yield rate is greatly improved. The process is compatible with a variety of commonly used knob materials, such as stainless steel SUS304 / 316, brass, copper, and aluminum alloy 5052 / 6061. It matches a special etching system for different substrates, taking into account precision, efficiency and surface quality, and has a wide range of applications.

[0018] This specification describes embodiments, but not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A high-precision etching process for adjusting knob patterns, characterized in that, The etching process includes the following steps in sequence: (1) Selection and precision leveling of substrate: Select stainless steel SUS304 / 316, brass, copper or aluminum alloy 5052 / 6061 cold rolled precision material for leveling treatment; (2) Multi-stage cleaning, degreasing and activation: Alkaline degreasing agent is used for ultrasonic degreasing, followed by multi-stage pure water overflow rinsing and hot air drying after activation with dilute acid; (3) Uniform photoresist coating: Dry film photoresist is rolled and vacuum bonded, and a uniform resist layer is formed after pre-baking; (4) LDI laser direct writing exposure: pattern exposure is performed using a high-resolution LDI laser direct writing machine; (5) Development and retouching: Sodium carbonate solution is used for spray development, and the retouching is used to make the edges of the pattern straight and without residue; (6) Closed-loop control rotary spray etching: A rotary spray etching machine with rotation and revolution is used, combined with PID constant temperature and online thickness measurement and real-time compensation, to perform segmented etching and forming; (7) Degumming, neutralization and passivation: Use alkaline solution or special demolding agent for ultrasonic degumming, passivation of stainless steel and neutralization of aluminum parts to prevent discoloration; (8) Pure water rinsing and drying: Multi-stage pure water rinsing followed by dehydration and drying; (9) AOI full inspection: to conduct a full inspection of the product's dimensions and appearance; By combining LDI laser direct writing lithography with closed-loop rotary spray etching, we can achieve a pattern linewidth accuracy of ±0.01mm, a depth accuracy of ±0.005mm, a sidewall verticality of 85°-89°, a side etching ratio of ≤1:0.8, and a pattern depth / width difference of ≤0.015mm around the entire circumference.

2. The high-precision etching process for adjusting knob patterns according to claim 1, characterized in that, The substrate thickness tolerance is ±0.01mm, and the surface roughness Ra≤0.2μm; the degreasing temperature is 50-60℃, the ultrasonic frequency is 40kHz, and the processing time is 5-8min; the drying temperature is 80℃, and the process is carried out in a dust-free environment.

3. The high-precision etching process for adjusting knob patterns according to claim 1, characterized in that, The dry film photoresist thickness is 8-12μm; the pre-baking temperature is 85±2℃, and the time is 5-8min; the LDI laser direct writing resolution is ≥30k, the positioning accuracy is ±1μm, and the exposure energy is 350-450mJ / cm².

4. The high-precision etching process for adjusting knob patterns according to claim 1, characterized in that, The developing solution is a 1.0%-1.2% Na2CO3 solution, with a temperature of 28-30℃, a spray pressure of 0.8-1.2 bar, and a developing time of 30-60 seconds.

5. The high-precision etching process for adjusting knob patterns according to claim 1, characterized in that, The rotary spray etching machine operates at a speed of 3-5 r / min, with the etching temperature controlled by PID and fluctuating within ±0.3℃. The spray pressure is 1.5-2.5 bar, and the etching rate is 0.5-2 μm / min. The segmented etching process involves first coarse etching to 80% of the target depth, and then fine etching to the set depth. Real-time compensation is achieved using white light interferometry or eddy current thickness measurement.

6. The high-precision etching process for adjusting knob patterns according to claim 1, characterized in that, The etching solution system is as follows: for stainless steel, FeCl3 40-44°Bé is used with hydrochloric acid and corrosion inhibitor; for copper, CuCl2 is used; and for aluminum, NaOH + H2O2 is used.

7. The high-precision etching process for adjusting knob patterns according to claim 1, characterized in that, The adjustment knob has a circular pattern, radial pattern, scale, or micro-anti-slip texture, with a line width of 0.03-0.5mm, a depth of 0.05-0.3mm, and a product concentricity of ≤0.02mm.

8. The high-precision etching process for adjusting knob patterns according to claim 1, characterized in that, The product is free of burrs, pinholes, serrations, and over-etching, and is suitable for high-end audio, instrumentation, automotive, or industrial control knobs.