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Rugged AN-MCDU

Product description:

The product is an avionic Advanced Navigator-Multifunction Control & Display Unit (AN-MCDU) keypad assembly with a powder coated CNC metal bezel, individually backlit plastic keys with flange gasket seals, silicon rubber actuator, backlit metal dome array and PCBA with conformal coating for use in the cockpit of Boeing 737 aircraft for pilot and co-pilot use.

 

Technical challenge:

As an aviation device, the product must meet or exceed environmental conditions outlined in the RTCA/DO-160G guidelines and the stringent requirements of MIL Standards and Specification for all aspects of the design,

including materials and construction. It needed to meet or exceed an IP67 rating without using permanent seals. It needed to be modular to facilitate replacement and shop repair with fully interchangeable components.

 

How we did it:

We approached the design based on face side panel sealing, which met our client’s and the Mil Standards. The design incorporated floating backlit keycaps with an adhesive sealed silicone actuator pad supported by a PCBA. We addressed the tactile response, force and individual backlighting by using standard backlightable metal domes attached to a dome array fixed to the top face of the PCBA. Individual adhesive sealed plastic lenses were used for the light sensors and annunciators. The project required a CNC aluminum bezel incorporating dead stop posts to control the sealing compression

applied to the silicone pads during PCBA assembly. Due to space constraints, we split the electronics design into a main and daughter PCBA, where the Daughter is stacked on the rear face of the main PCBA.

 

Results:

The product meets all client requirements and specifications.

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