As metal spray/thermal spray coatings are typically pure metallics with no binders, they are very well suited to applications in the electrical and electronic industry.
One of the very common applications that has been undertaken for over 4 decades is the spraying of capacitor ends. In the manufacture process of thin film capacitors, the end faces are commonly sprayed with zinc or tin/zinc alloys. The purpose of the coating is to connect the layers of the metallic foils together and also to give a sturdy, robust layer to make soldered wire connections to the capacitors. Coatings are often several hundred microns thick. One of the main benefits of the thermal sprayed coatings are that only small amounts of heat are transferred to the capacitors, meaning there is no damage to the plastic film part. Capacitors of varying sizes are commonly sprayed, from small lighting capacitors up to large, power capacitors.
The conductivity of thermal sprayed coatings is also used to help connection to resin resistors/insulators or graphite heating rods where aluminium or aluminium bronze coatings are very commonly applied.
Metal spray deposits are used extensively in the Electrical Industry for applications including electrically conductive coatings and resistance type heating circuits. As well as conductivity, thermal sprayed ceramic coatings can be used for their electrical insulation properties. Ceramics such as alumina can be applied by plasma spraying or powder flame spraying to create a non-conductive layer.
One further electrical application is to spray Faraday cages to protect against electro-magnetic emissions.
There are many applications of switch boxes being sprayed and more exciting is the use of electrical coatings in radio-rooms of mine-sweeping boats made from GRP.
Corrosion is also an issue in the electrical industry and commonly coatings of zinc, aluminium or their alloys are applied by flame spray or arc spray to steel electrical switch boxes or transformer housings to prevent from the onslaught of corrosion.
Carbon and ceramic resistors and carbon brushes are sprayed with a thin film of copper to provide an electrical connection of high conductivity.
Thick film electrical circuits carry higher currents than the printed type and are produced by spraying the metal onto a non-conductive substrate usually plastic, glass or ceramic.
|Electrically conductive coating on a Dielectric substrate||Capacitors|