In metal etching, in addition to etching stainless steel, molybdenum, and titanium, one of the special ones is copper etching. Compared with aluminum etching, copper etching is easier than aluminum processing, because the activity of aluminum is in contact with When using chemical agents, it is easy to produce strong chemical reactions such as high temperature, which leads to an increase in the complexity of the process. For copper etching, there are three types of copper alloys: brass, bronze, and white copper.
Among them, the contact etching has three types: For copper, oxygen-free copper, pure copper, etc., the copper etching solution is different from the stainless steel etching solution, and the waste solution can be reused. However, due to the characteristics of copper, the copper etching solution has a fast reaction speed and a low use temperature during the etching process. , post-processing is relatively easy, less environmental pollution. Copper etching has a wide range of applications, including copper eyeglass frames, copper gaskets, copper handicrafts, etc., and the etching process of copper can meet the thickness between 0.01MM-2MM. Since copper has certain oxidative properties, it is necessary to pay attention to the surface treatment and the protection of copper in a specific environment.
Etching Process Application of Printed Copper
Serial number: Q/YS.115 (Yishun brand)
Scope of application:
It is suitable for the etching of printed copper, and the etching speed is fast. Etching speed up to 4~5um/min. Waste liquid recovery is simple, widely used in printed boards, circuit boards. This agent can also be used for etching copper handicrafts, etc. The etched surface is smooth and bright.
- 1 Blue transparent liquid with odor.
- Specific gravity: 1.10~1.13.
- PH value: >7.0.
- How to use:
- Just use the soaking method. During the soaking process, the etching solution should be stirred or the workpiece should be moved. The etching temperature is normal temperature, and it is operated in a ventilated and exhausted place, and the cover should be closed during operation.
- Processing time: depends on the thickness (etching time can be determined according to the depth of etching).
Matters needing attention:
- ① Corrosive, do not contact with skin.
- ② Do not expose to the sun, but put it in a cool and ventilated place.
Copper etching processing scheme
Process flow of metal etching
Different types of metals have different etching processes, but the general process is as follows: metal etching plate → degreasing → water washing → etching → water washing → drying → screen printing → drying → water immersion for 2~3 minutes → etching pattern Text → washing → ink removal → washing → pickling → washing → electrolytic polishing → washing → dyeing or electroplating →
Water washing→hot water washing→drying→soft cloth polishing (polishing)→spraying transparent varnish→drying→inspection→finished product packaging.
The process before metal etching is pretreatment, which is the key process to ensure good adhesion between screen printing ink and metal surface, so it is necessary to completely remove oil and oxide film on the metal etching surface. Degreasing should be determined according to the oil pollution of the workpiece. It is best to perform electrolytic degreasing before silk screen printing to ensure the effect of degreasing. In addition to the oxide film, the best etching solution should be selected according to the type of metal and the thickness of the film to ensure that the surface is cleaned. It should be dried before screen printing. If there is moisture, it will also affect the adhesion of the ink, and affect the effect of subsequent pattern etching or even aliasing, affecting the decorative effect.
Screen printing needs to make a standard pattern screen printing screen according to the needs of printing. In the pattern decoration process, silk screen printing mainly plays a protective role, and the number of times when applying photosensitive glue is more, so as to make a thicker screen template, so that the covering performance is good, and the etched pattern is high-definition. Under the action of light, the adhesive film of the screen plate produces a photochemical reaction, so that the illuminated part is cross-linked into a water-insoluble adhesive film, and the unirradiated part is dissolved by water to expose the screen space, so that the film-coated silk The screen pattern is photo-engraved to match the pattern of the black and white Zhengyang film.
Fix the screen printing screen with pattern on the screen printing machine, use alkali-soluble acid-resistant ink to print the required pattern on the metal plate, and then etch it after drying.
The screen printing ink must be removed after etching. General acid-resistant inks are easily soluble in alkali. Immerse the etched board in 40-60g/L sodium hydride solution at a temperature of 50 to 80°C, and the ink can be removed after a few minutes without staining. After removal, if high brightness is required, it can be polished, and then dyed. In order to prevent discoloration and increase wear resistance and corrosion resistance, transparent varnish can be sprayed. For some metals that have good corrosion resistance and no staining, transparent varnish may not be applied, depending on actual needs.
Chemical etching solution formula and process conditions
Etching different metals requires different solution formulations and process conditions. For the etching solution formulations and process conditions of commonly used metal materials, see Table 6-4 and Table 6-6. Table 6-4 Formula and process conditions of metal chemical etching solution Table 6-5 Formula and process conditions of metal copper chemical etching solution Table 6-6 Formula and process conditions of zinc casting chemical etching solution
Influence of process operating conditions
Etching is the key in the pattern decoration process of metal plate molds. In order to obtain patterned products with clear stripes and strong decoration, attention must be paid to controlling the conditions of the etching process. Mainly the temperature of the etching solution and the etching time. The temperature of the solution is slightly higher, which can increase the speed of metal dissolution, that is, the speed of metal etching, and shorten the time required for etching and engraving. However, the etching solution is generally a strong acid solution. The protective coating or corrosion-resistant ink softens or even dissolves, which reduces the adhesion of the corrosion-resistant layer on the non-etched part of the metal, causing the corrosion-resistant coating at the junction of etching and non-etching to fall off or melt, making the etching pattern blurred and out of shape, affecting The pattern is beautiful, realistic and decorative, so the temperature should not exceed 45°C.