Complex instruments have historically been produced as metal boxes where the control of EMI and RFI is quite straightforward. However, with the desire and demand for more styling and customisation, low volume, plastic moulding solutions are growing ever stronger - forcing design departments to look at alternate manufacturing methods. This doesn't need to dramatically affect EMI and RFI requirements or increase your build cost.
With the development of metal-laden paints, thin coatings applied on the inside or even 100% coverage on plastic mouldings can provide a good level of protection and control for both EMI and RFI. Dependent on the requirements, specification can include nickel, copper or silver laden paint and with a typical thickness of 50 microns, there is negligible impact to space, assembly and finish. These products exhibit excellent environmental ageing stability with scratch resistance, whilst providing an aesthetically pleasing coating appearance with excellent long-term shielding and grounding properties. Combined with EMC gaskets, glues and mesh, complete solutions can be created with no compromise on style.
Although relatively expensive as an application, when carefully considered as part of the entire assembly, internal metal work assemblies can be greatly simplified as there is no need for internal Faraday boxes. This reduces Bill of Material lists, build time and ultimately cost and risk due to fewer parts.
At Midas, we can support you with all types of EMI coatings and apply it not only to your polyurethane mouldings but to subcontracted parts such as injection mouldings for the higher volume aspects of your assembly.
Contact me on r.sparkhall@midas-pattern.co.uk now to organise a review meeting.