Security & building automation
An access controller or a building gateway is installed once and then expected to be orderable for a decade. That makes the bus interface, the coating and the component lifecycle the real design constraints, not the feature list.
What the installation does to a board
Riser cupboards, plant rooms and air-handling spaces are not laboratories. The three failure modes below are why this industry buys build class and coating rather than the board that merely works on a bench.
A controller in a riser or a plenum chamber sees −20…+70 °C with condensation, not a clean bench. Moisture on a biased board is an electrochemical migration path, and the failure arrives as creeping leakage or intermittent resets long before anything looks burnt.
KNX, RS-485 and 24 V field wiring leaves the enclosure, so surge and ESD arrive on the connector rather than on the mains. Without isolation, a partitioned ground and IEC 61000-4-5 surge protection at the interface, the transceiver is the fuse, and the relay drive is next.
A reader listed in year one is expected to be re-orderable in year ten. In between, the microcontroller, an optocoupler or a connector goes end-of-life, and a board that cannot be re-built is a product that cannot be sold, whatever the field population needs.
Interface and environment
The build class follows the listing, not the budget. A Grade 3 or LL 294 listed controller is ordered at Class 3 with the full documentation set; readers and cameras are usually ordered at Class 2, where that is what the file calls for.
| Requirement | How we build it |
|---|---|
| Bus interfaces | KNX, RS-485 / BACnet MS/TP and 24 V field interfaces laid out as isolated zones, with the barrier held through the inner layers rather than only on the surface. |
| Surge and ESD at the connector | Space and routing reserved at the interface for the protection network you specify to IEC 61000-4-5, with the field side separated from logic ground. |
| Creepage and clearance | Partitioned routing and gap design to the limits in your safety file. We do not publish fixed millimetre values, because they follow from the standard your product is listed to. |
| Board thickness | 0.4 – 3.2 mm; 2.0 mm and above for DIN-rail carriers, terminal blocks and boards that are handled during installation. |
| Laminate | High-Tg FR-4 at Tg ≥ 170 °C as the floor, so the assembly survives lead-free reflow and the temperature swing of an unventilated enclosure. |
| Copper weight | 0.5 – 20 oz; 2 oz on relay drivers, 24 V distribution and any path that carries contact inrush instead of steady current. |
| Connectors and terminals | Press-fit, through-hole and terminal-block assembly with wave and selective soldering, plus hand soldering where a connector cannot take the wave. |
Supply over ten years
Long-term supply only means something if it is written down as steps with triggers. This is the sequence we run on every programme that has to stay orderable for ten years, and it is the sequence we will put in the supply agreement.
Every BOM line is recorded with manufacturer, part number, package and the authorised-distribution sources it can be bought from.
The approved list is re-checked against manufacturer lifecycle status on a rolling basis, not only when a purchase order arrives.
When a line goes NRND or end-of-life we propose a validated alternative with a parameter comparison, before the last order window closes.
We size the last-time buy against your forecast, hold it as your stock and report on it with a dated balance while the programme runs.
A change to a part, a process, a laminate or a production site triggers a written product change notification before the changed board ships.
Coatings and cleaning
Boards are cleaned ultrasonically and with DI water, coated selectively to IPC-CC-830B, and re-inspected after coating so that a covered test point or a bridged connector is caught before the unit is packed, not after it is installed.
Build class, listing and documentation
Access control and building automation carries two separate compliance stories. The badges below name the standards our build class and documentation are written against. UL 2043 plenum rating matters whenever a device sits in an air-handling space, and a Grade 3 controller is ordered at Class 3. The cards underneath name what the plant itself holds.
Quality system certified to ISO 9001:2015 and audited annually by SGS. Long-life building hardware adds unit serialisation so a controller installed years ago can still be traced to its panel, its lot and its test record.
Recognised printed wiring board manufacturing, held with LL for the fabrication process behind your listed end product.
Compliant lead-free lines, with supplier declarations of conformity held on file for the laminate and the components.
Compliant, with a per-board material declaration report available for your chemical-compliance file.
The final visual inspection standard applied on the floor, worked alongside IPC-A-600 and J-STD-001.
The qualification and performance specification for the rigid boards themselves; Class 3 orders are documented with microsections on request.
Environmental management practices followed in the plant, covering plating chemistry, effluent handling and waste routing.
Full scanned certificate package released on request.
Application case
A familiar project family: access controllers, building gateways and eight-channel 24 V distribution boards that have to mount on a DIN rail, take field wiring at a terminal block and stay orderable for a decade.
Quotation in 24 hours
Tell us which bus interfaces the board carries, the build class the listing requires and the annual volume you expect over the product life. We will answer with the ten-year supply plan alongside the price.
Send your Gerber, BOM or a plain description. An engineer, not a sales script, reviews it and replies within one working day. NDA on request.
