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Company focus Feb 01, 2023

Assuring quality, the Reliable Controls way

In 2020 Reliable Controls shipped 142,753 units of controllers and sensors across all product families. Less than 1 percent were returned to us. In other words, 99.42 percent of the time, you received high-quality product. That low warranty return is the direct result of a production process streamlined with integrated quality checks—from the moment raw components enter our facility to the shipment of our final products.

Minimal motion between the surface-mount technology (SMT) machine, through-hole stations, and bed of nails speeds up the production process. This is an example of lean manufacturing.




Our quality control starts by verifying our suppliers sent us the correct parts and quantities and that each unit meets our criteria. This is particularly important for our custom-designed components, where we set the dimensions and tolerances. This incoming inspection—a step that is accelerated as our confidence in a supplier grows—helps to ensure quality down the line.

Reliable Controls sources RC-FLEXair parts from 22 longstanding qualified suppliers.



Each circuit board requires a specific number of components—several hundred, on average. The production team meticulously compiles, documents, and tracks the kit of parts so they can trust they have what they need to start building. They then load this kit into the SMT machine.

One RC-FLEXair unit comprises 554 pieces, 184 of which are unique components that populate the circuit boards.


SMT assembly

The SMT process is three-fold—printing, placement, and inspection, which are all executed and controlled by the latest technology. Our jet printer can print up to a million dots of solder per hour, varying the amount of solder to ensure high-quality joints across the circuit board. An automated optical inspection occurs with every dot dispensed. After verifying the correct parts have been loaded, the placement machine (a robotic arm) can place 16,000 components per hour.

The RC-FLEXair has three PCBs: a mezzanine board, a main board, and an inputs/outputs board.


AOI inspection

Every circuit board we make undergoes an automated optical inspection (AOI), which ensures 100 percent accuracy of each solder joint and placement by comparing the board to a golden sample. Seven cameras inspect a board with unparalleled accuracy in 30–60 seconds, catching errors that would take a person far longer. This keeps our quality high and helps streamline production so products reach you quicker.

The AOI inspection helps keep the defect rate of Reliable Controls products below 1 percent.



Nobody likes waste. It’s inefficient and costs money. Lean manufacturing eliminates excess, resulting in reduced cycle time and faster build times. We keep inventory as low as possible, with enough stock ready to work on demand. We continually analyze our production forecasts and scheduling, ensuring we meet your needs in a timely manner. Once boards have undergone the inspection process, we stock them in our “supermarket” until they need to be kitted for through-hole (TH) assembly.

All Reliable Controls products, including the RC-FLEXair, are built to order.


TH assembly

Through-hole building continues the process of populating the board with components that fit through the holes and are soldered on the back, either by hand or in the wave-soldering machine. Imagine molten lava streaming from a volcano, bright red until it crusts over as it cools and oxidizes, gathering impurities. Molten solder is essentially the same, just silver. A wave-soldering machine is a 1,000-kilogram bath of solder with a pump that churns impurities to the side so the board rides a wave of clean solder that wicks up into the board—yet another automated and controlled process.

RC-FLEXair circuit boards are completely populated in the SMT; no TH assembly required.


Visual inspection

All our operators are trained to Institute of Printed Circuits (IPC) standards, and we visually inspect our soldering to ensure it meets the IPC-610-A quality requirements. Any variances or defects are identified during the detailed visual inspection if not already caught while our operators build the boards. We inspect 100 percent of our boards before they pass to testing.

This job takes having an “eye for detail” to a whole new level.


Bed of nails testing

Part of our goal to have the most satisfied customers means selling you products that do exactly what you expect them to. By testing every board on a bed of nails (designed by us and specific to each model), any defects are caught by us instead of the customer, resulting in very low returns. The bed of nails activates every point on the board, stimulating and measuring inputs and outputs by interfacing with a suite of sensors and RC-Studio®. This is a full quality check that ensures only the best units reach the end of the line.

Multiple beds of nails test the three RC-FLEXair circuit boards, independently and together.


Final assembly

We have more than 1,650 products in our catalog. Everyone on the production team is able to build them all. The flexibility among the team—their in-depth knowledge of our products, eye for detail, and quality mindset—is our biggest asset. The machines enhance rather than replace what we do with our own skills. In the final assembly stage, the team mounts boards in their enclosures, adds connectors, and carefully prepares labels. They then package the product and corresponding documents, ready for shipping.

The final assembly of an RC-FLEXair, from prep work to testing and boxing for shipment, takes roughly 10 minutes per controller.



Our average turnaround from order to shipping is 1.4 days. Many products don’t even make it onto a shelf because we build to order—they go from final assembly straight to shipping, where someone verifies the order has all the correct products and amounts. The shipper scans barcodes, updates our files, and cross-references paperwork, and away they go!