What an air quality monitor is made of
The front and rear housings are PC/ABS, injection moulded with a fine texture, vent louvres and a keyhole slot for the wall. A clear light pipe carries the status LED. A perforated mesh covers the sensor window.
Inside sit a laser-scattering PM2.5 sensor, a temperature and humidity sensor chip and an ESP32 Wi-Fi and Bluetooth module on a printed circuit board assembly. A micro-USB cable powers it, and a rating label and printed carton finish the product.
The process chain
The housings run through resin drying, injection moulding, trimming, pad printing and a colour check. The circuit board goes through solder paste printing and inspection, pick-and-place, reflow, automated optical inspection, firmware flashing and a functional test. Final assembly ends with a sensor warm-up, a Wi-Fi pairing test and a reading check against a reference.
Where India is strongest
Electronics assembly is strongest in Bengaluru, Chennai, Noida and Pune. Precision injection moulders cluster around Chennai, Bengaluru, Pune and Noida. Sheet-metal press shops in Faridabad and Pune make the mesh, Silvassa and Noida supply cables, and Sivakasi prints labels and cartons.
On the Woosh Air program we moved the circuit board assembly and the plastic parts from China to India. The filter manufacturing stayed in China, and everything ships to customers in the US. Savings: over USD 73,000 a month.
What drives the cost
The sensor and the Wi-Fi module are priced by their makers worldwide, so the savings sit in the circuit board assembly, the moulded parts and final assembly. Test time per unit, mould cost spread over volume, texture and colour work, and packaging and freight make up the rest.
What we inspect
First-article inspection of the board, AOI and X-ray on samples, and a functional test log for every serial number. On the plastics: colour match, sink marks and snap-fit engagement. On the finished monitor: readings against a reference, keyhole strength on a wall-hang test, and a pre-shipment inspection before the US shipment.
Example teardown for illustration. Standards named here are the ones we usually check against; your drawing and target market set the exact scope.