At one time, many device components were made of metal for electromagnetic interference (EMI) protection, but the move to plastic offers a suitable alternative. To overcome the biggest weakness of plastic in attenuating electromagnetic interference, the lack of electrical conductivity, engineers began to look for ways to metallize the surface of plastic. To learn the difference between the four most common plastic plating methods, read our guide to each method.
First, vacuum plating applies evaporated metal particles to an adhesive layer on plastic parts. This occurs after thorough cleaning and surface treatment to prepare the substrate for application. Vacuum metallized plastic has a number of advantages, the main of which is that it can be safely kept in a particular cell. This makes it more environmentally friendly than other methods while applying an effective EMI shielding coating.
Chemical coating also prepares the surface of the plastic, but by etching it with an oxidizing solution. This drug promotes the binding of nickel or copper ions when the part is placed in a metal solution. This process is more dangerous for the operator, but guarantees complete protection against electromagnetic interference.
Another common method of plating plastics, electroplating, has similarities to chemical deposition. It also involves immersing the part in a metal solution, but the general mechanism is different. Electroplating is not oxidative deposition, but the coating of plastic in the presence of an electric current and two electrodes. However, before this can happen, the surface of the plastic must already be conductive.
Another metal deposition method that uses a unique mechanism is flame spraying. As you might have guessed, flame spraying uses combustion as the medium for coating plastics. Instead of vaporizing the metal, the Flame Atomizer turns it into a liquid and sprays it onto the surface. This creates a very rough layer that lacks the uniformity of other methods. However, it is a quick and relatively simple tool for working with hard-to-reach areas of components.
In addition to firing, there is a method of arc spraying, in which electric current is used to melt the metal.
Post time: Aug-12-2022
