Chemical grinding in the industry is also known as engraving. Here, bases, acids or other chemicals are used to dissolve unwanted materials, such as semiconductor materials, glass or metal.
This process is used in a variety of metals and eliminates depths of up to 0.5 inches or 12 mm. It has applications in semiconductor manufacturing and in the circuit board industry, and is also used in the aerospace industry to remove thin layers of metal / material from large aircraft components, such as extruded parts and rocket cladding panels.
There are several types of chemical grinding. One is wet etching and another is photochemical etching. Different materials require different types of engravers, for example, sodium hydroxide is used for aluminum and ferric chloride, or ammonia or ammonium persulfate for copper. It is often used for the manufacture of integrated circuits, and the semiconductor industry uses plasma etching.
Another type is photochemical grinding. This is a process in which 2D shapes and parts are created by creating a chemical resistance mask on the surface of the sheet and then chemically dissolving the material from the maskless areas.
The photochemical grinding processes are as follows:
o A light-resistant layer that makes the metal photosensitive
o A photomask is placed on the sensitized sheet.
o The sheet is exposed to ultraviolet light.
o The photoresist develops in a mask pattern.
o The sheet is engraved to remove exposed metal areas leaving the last part
o Then the piece is cleaned
This type can provide high precision and detailed shapes in thin sheets, and the method is particularly competitive for complex shapes and parts.
It can produce almost any 2D shape in thin sheet. Applications may include:
or electric shields
or optical switches
or eraser molds
or stamps
or washers
Electrochemical milling is a process to remove metal by electrochemical processes and is commonly used in mass production of extremely hard materials. Electrochemical milling can cut odd or small shapes into very hard steels such as carbide, kovar, inconel and titanium, and is also often used as an effective deburring process.
In processing, pieces can be supplied with loose sheets or eyelashes, with tabulations which facilitate lower coating costs and reduce packaging.
The thickness of the material is another important cost consideration, because the thicker the part, the longer the carving. Components with a thickness of more than 1.5 mm are generally considered inexpensive for chemical etching.
The main element of the final cost, like all competition machining processes, is volume, and prices are drastically reduced when the number of sheets reaches 10 or 100.
It should be noted that the cost of chemical etching can be very competitive compared to other processes, such as stamping or laser profiles. Unlike stamping, it requires hard tools; Chemical etching is based on digital tools that are cheaper and faster to produce. Digital photography tools are a unique cost for traditional photographic engraving, but now with Laser Direct Imaging, there is no need for photography tools in a large number of projects.
You should also be aware that laser profiles are linear processes that are loaded by time and, therefore, by inches, engraving is only loaded with sheets. Simultaneous machining of components means that photogravure handles greater complexity without additional costs and also allows the creation of several prototypes on a sheet of paper.
In short, the costing process is a difficult process, but if it provides five variables, material, thickness, section size, tolerance and quantity, the chemical etching process can provide the most economical way to make its components.