This customer came to us with an idea. They wanted to produce a modular, configurable WiFi hot spot. The target market was businesses, manufacturing, hospitals, schools and airports. With a network of configurable hot spots their customers could have different radios (802.11 abg, Bluetooth, etc) in different parts of a facility configured with just the standards that were needed. They wanted each module to snap together like Lego. They were developing more sophisticated antennas so as not to use the typical “rubber ducky” antenna. They had an affinity for something of a waveform as in radio waves.
Our industrial designer put together a number of renderings for discussion and soon we were on our way. Their production forecast pointed toward injection molded plastics. There were several modules needed; Ethernet ports with distributed power and cooling, several radios and antenna modules. Each radio could snap onto the PSU/Ethernet base or onto another radio with antennas on top. Each radio could snap together in any order. Airflow came in through the PSU/Ethernet module. There were 4 airflow plenums, one in each corner distributing air to each of the module above. We developed several mounting brackets for wall, ceiling, etc. and a security feature.
The PSU/Ethernet module and radios needed to pass FCC for emissions and immunity making EMI containment critical. Frequently, plastic products will be coated with either a vacuum metalized coating or sprayed copper. Both of these require secondary operations and masking fixtures. We chose to use a plastic resin containing chopped stainless steel fibers that during the injection molding process “knit” together to form a Faraday cage. This worked well by keeping costs lower and meeting regulatory compliance.