Photo chemical machining of metal components.
EMC electromagnetic compatibility is an important aspect of metal component fabrication. Modern metal component
manufacture generally involves photo chemical machining, also known as photo chemical milling, photo fabrication
and chemical etching. The process involves creating a type of electronic blueprint using computer aided design
CADCAM equipment and using a laser plotter. Once the blueprint is ready it can be replicated many times to create a
double sided photo tool which will be used to create and etch the metal component.
To apply the design, the sheet of metal is inserted into the photo tool with a photo resist coating. Once this
coating has been removed the metal component will contain the image and any unwanted metal can be removed by using
a chemical solution. The etched metal component is then ready for any additional forming that has to be done.
One consideration for aerospace manufacturers of this type of metal forming is EMC, because there are
regulations to be complied with. In essence, a metal component should not be susceptible to too much
electromagnetic interference, nor should it give off too much electromagnetic interference. This is increasingly
important in a world full of electronic devices. Just within the household, most people have microwaves, cookers
and even fridges with circuit boards, as well as hi-fis, televisions and computers. All of these could be
vulnerable to electromagnetic interference, so taking care of EMC is essential.
Metal component etching produces components that are used not only for circuit boards, but also for circuits,
antenna and other technical applications.
Metal components are even used in television and computer screens. In order to have the appropriate shielding to
comply with EMC requirements, a fine metal mesh is used to provide a barrier to electromagnetic interference. Most
of us would not even realise it is there, as the metal mesh is finer than a strand of human hair. This type of
shielding can be used to protect anechoic chambers, rooms, buildings, windows, cables, gaskets and much more.
Photo chemical machining uses a wide range of metals, including copper, carbon steel, stainless steel, zinc, lead,
magnesium, silver, vanadium, manganese and many others. Whatever the metal used, EMC comes into play, with the
requirement that devices not absorb too much electromagnetic interference during the manufacturing process.
Both manufacturers and their customers find that photo etching for a metal component is a cost effective and quick
way of doing business. It bypasses the need for expensive hand casting and makes it easy to make changes if
necessary. Metal component etching also has other applications such as the creation of beautiful metal jewellery.
And the wearers of that jewellery probably never think about the need for EMC.
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