Etching processing is a method that uses chemical solutions to selectively corrode metal materials in order to obtain the desired patterns, dimensions, holes, and contours. Unlike traditional mechanical processing, etching does not require tools to directly cut the metal, making it more suitable for processing thin sheets, micro-holes, complex contours, and precision patterns.
So, what are the steps in the etching process? Generally speaking, from the entry of raw materials into production to the shipment of the final product, multiple stages are involved, including drawing confirmation, material preparation, pre-treatment, film application, exposure, development, etching, film removal, cleaning, and inspection.
1. Drawing Confirmation and Process Evaluation
The first step in etching processing is usually to confirm the product drawings provided by the customer.
It is important to verify the product’s overall dimensions, hole diameters, hole spacing, line width, spacing, material type, material thickness, and accuracy requirements. If the product has microholes, narrow gaps, or complex irregular structures, process evaluation is also needed based on the material characteristics and product dimensions.
The etching properties of different metal materials vary, and when the same drawing is produced with different materials, the actual process parameters may also need adjustment. Therefore, early drawing and process confirmation is an important foundation for subsequent production.
2. Metal Substrate Preparation
After determining the processing plan, it is necessary to prepare metal substrates that meet the requirements.
Common etching materials include stainless steel, copper, titanium, molybdenum, and some alloy materials. The thickness, surface condition, flatness, and material stability of the substrate all affect the final processing results.
For precision-etching products, the quality of the substrate itself is particularly important. If the material surface has noticeable scratches, oxidation, oil, or thickness deviations, it may lead to pattern defects, dimensional changes, and other issues during subsequent processing.
3. Material Pre-treatment
Before metal materials enter etching production, surface pre-treatment is generally required.
Pre-treatment mainly includes cleaning, degreasing, oxide layer removal, and improving the surface condition of the material to make the metal surface suitable for subsequent film application.
This step may seem simple, but it directly affects the adhesion between the photoresist film and the metal surface. If the material surface has oil or other impurities, it may cause poor film adhesion, resulting in film peeling, corrosion, and other problems during subsequent development or etching.
4. Applying the Photoresist Film
After the pretreatment is completed, a photosensitive material needs to be applied to the surface of the metal
The photoresist film is mainly used to protect areas that do not need to be etched. Subsequently, through exposure and development, the patterns in the product design are transferred onto the surface of the metal.
The thickness, uniformity, and adhesion of the photoresist film to the substrate all affect the etching results. Therefore, during the film application process, it is necessary to avoid issues such as bubbles, wrinkles, and impurities as much as possible.
5. Exposure
Exposure is a crucial step in transferring the designed product patterns onto the photoresist film.
In production, corresponding films or other pattern transfer methods are usually used. Through illumination, the photoresist film undergoes the necessary changes. After exposure, the product’s pattern outline is formed on the material surface according to design requirements.
For precision etching products, the accuracy of the exposure directly affects the final pattern dimensions, so it is necessary to control exposure time, light source conditions, and alignment accuracy according to product requirements.
6. Development
After exposure, the material enters the development stage.
The purpose of development is to remove the parts of the photoresist film that need to be eliminated, creating the areas on the metal surface that need to be etched while retaining the areas that need protection.
After development, the patterns can be preliminarily inspected. If problems such as missing patterns, incomplete lines, or irregular hole positions appear, adjustments need to be made promptly to prevent defective products from entering the subsequent etching stage.
7. Etching
After development, the material enters the actual etching process.
During etching, the exposed areas of the metal react with the etching solution, while the areas protected by the photoresist film remain as intact as possible. As the process continues, the required holes, slots, contours, and patterns of the product are finally formed.
Key factors in the etching process include the state of the etching solution, temperature, spray pressure, etching time, material thickness, and product structure.
If process parameters are not properly controlled, issues such as over-etching, under-etching, side etching, and dimensional deviations may occur. Therefore, etching parameters need to be adjusted according to different materials and product structures.
8. Resist Stripping
After etching is completed, a protective film may still remain on the surface of the product, which needs to be removed through the resist stripping process.
Once the resist is stripped, both the originally protected areas and the etched areas of the product will be exposed, allowing for a more intuitive observation of the overall pattern of the product.
9. Cleaning and Post-Treatment
Products after resist stripping usually need to be cleaned to remove residual chemicals, film layers, and other impurities.
Depending on the specific use of the product, some etched parts may also require subsequent surface treatments such as passivation, plating, coating, PVD, or anodizing.
Whether surface treatment is required depends on the product material, usage environment, and customer requirements; not all etched products need this step.
10. Dimension and Appearance Inspection
After the product has completed processing, quality inspection is required.
Common inspection items include external dimensions, hole diameter, hole spacing, line width, spacing, thickness, and surface condition. For precision products, equipment such as microscopes, optical measuring instruments, and projectors may also be used for inspection.
In terms of appearance, the main checks are for burrs, residual film, stains, deformation, notches, uneven etching, and other issues.
Only products that pass the corresponding inspections and meet the drawing requirements can proceed to subsequent packaging and shipment stages.
The etching process is not fixed
It should be noted that the etching process for different products is not exactly the same.
For example, ordinary metal gaskets, precision microhole parts, metal mesh, code discs, and new energy components vary in materials, thickness, pattern structures, and precision requirements, and the corresponding process parameters will also differ.
Therefore, in actual production, it is usually necessary to make targeted adjustments to pretreatment, film application, exposure, development, and etching parameters based on the product drawings and material characteristics.
Overall, the etching process can be summarized as:
Drawing confirmation → Material preparation → Pretreatment → Film application → Exposure → Development → Etching → Film removal → Cleaning and post-treatment → Finished product inspection.
Each step will affect the final product. For precision metal parts, conducting proper preliminary process evaluation and controlling key parameters during production is the important basis for ensuring product dimensions, patterns, and surface quality.
Post time: Oct-16-2026
