Chemical etching, also known as metal etching, is a process of dissolving metals or glasses in acids to make them into a particular shape. There are two main types of chemical etching: the process as it was first developed, and a more modern method known as photochemical machining. The etching process is preferred for fine metalwork and metal panels, especially those that need specific designs like panels used in making computer parts. Originally, such pieces needed to be made by hand or with expensive machines that took time to calibrate and maintain, but chemical etching vastly reduced the time and expense it took to create fine metal work.
In chemical etching, the starting piece of metal is covered with certain coatings, known as a mask, which resists the corrosive acid. The metal is then placed in an acid solution to eat away at the uncovered parts, usually ferric chloride or cupric chloride, acids that have a particularly strong effect on the metal. After a certain amount of time, the metal will be dissolved except where the mask has been applied, in which case the mask itself takes most of the corrosive effects of the acid. The result is a metal piece in the precise shape desired, with the correct contours on the surface. This is generally a one-step process: with an accurately applied mask, the metal can be dissolved once, washed carefully off, and then be package for use. According to Mech-Tronics and similar precision fabrication companies, this saves a large amount of time and cost.
According to Industrial Quick Search overview, photochemical etching takes the process one step further and uses light-reactive chemicals to form the mask. The pattern is applied on top this mask, then exposed to UV light, which causes the open spaces to form protective coatings. This means that multiple metal panels can be very quickly prepared for the chemical solution without manufacturing a mask covering for each item.
While chemical etching is a very efficient process, it does have problems, especially in its environmental impact. While chemical etching is necessary to create many of our electronic devices, it also produces a large amount of waste materials, including hazardous waste that must be disposed of very carefully. Scientists are currently working on a number of nanotechnology applications designed to make a safe chemical etching process.
What Is Etching?
Etching has been around for nearly 500 years. It is a type of engraving, where ink is forced through tiny lines and...
How to Do Concrete Etching
Forget those boring gray slabs. Concrete etching offers revolutionary color and design options for new and existing concrete areas. Depending on the...
How to Etch Metal
This is about etching metal plates with nitric acid
How to do Metal Acid Etching
Etching metal with acid produces interesting artistic effects, with the finished piece displaying a varied and complicated topography, thanks to the acid's...
What Is Self-Etching Primer?
Anyone who has had to paint metal knows that the first step is to strip off the old paint, or at least...
Techniques for Etching Stainless Steel
Etching stainless steel is done for a variety of reasons including the creation of prints, decorations and personalization. The etching process is...
Alternatives to Ferric Chloride Acid for Etching Metal
Metal etching is a time-honored method of engraving metal. A mask is placed over the metal, with areas cut out. Acid is...
Copper Etching Process
Chemicals eat away at copper in the rapid etching process. Learn about the copper etching process in this free electronics video.