Security hardware is a mixed-signal problem in a sealed box. An antenna, an image sensor, an infrared illuminator and a power over Ethernet front end sit within a few centimetres of each other, and the unit is expected to run unattended for years in a place nobody visits. The board set has to be designed, built and recorded as one system.
Radio, imaging and power on one board set
A wireless reader needs a defined impedance, an image sensor needs a clean analogue front end, and the PoE stage brings both heat and switching noise. When those sections are fabricated and assembled in the same plant, the stack-up, finish and shielding decisions are made together, and a fault found at functional test is traced to the board, the part or the fit without a second supplier in the loop.
Thermal management inside a sealed housing
A sealed dome has almost no convection, so heat has to leave through the board. Metal-core laminate and heavy copper planes carry heat from the IR illuminator and the PoE stage into the housing wall, thermal vias move it between layers, and conformal coating protects the surface where condensation forms. The mix follows the thermal model agreed with engineering, with the published process limits on the capability page.
Unattended service life is an inspection question
A device that nobody services has to be right the first time. Incoming material is inspected at IQC, paste deposits are checked by SPI before placement, both sides are inspected by AOI after reflow, hidden joints are X-rayed, the first article is measured against the CAD data and every board is electrically tested before it is packed. Once the unit is assembled, functional and burn-in test confirm the whole device, not just the board.
Where a security programme stops being a board problem
A camera does not decide whether a scene is lit well enough; the sensor, the lens and the infrared illuminator do, and the board's share is reaching all three with clean power and a stable clock. An alarm panel does not decide what counts as an event either — that is the sensing chain and the algorithm together. An enquiry that arrives with a stack-up and a housing outline but no low-light figure and no false-alarm target leaves the board side guessing at which constraint it is being asked to hold, so the noise budget is spent inside a housing that was already chosen, and the gap shows up in an acceptance test or in the false alarms of a first season rather than on the drawing.
Certification belongs to the assembled device, not to the bare board. Electromagnetic and radio approval are granted to a unit with its cable, its shield can and its firmware, so what the fabrication side can offer is the precondition: a defined reference, filtering and grounding that hold from batch to batch, and a coating that keeps the surface the design called for inside a damp enclosure. A programme that buys a certified board and stops there has bought the paperwork without the unit that produced it.
The install base is the third boundary. A security device is bought once and stays on the wall for years, so a change of laminate, board thickness or connector footprint moves the electrical and thermal result of everything built afterwards, while units already installed keep running on the older construction. Settle which properties a replacement batch has to reproduce, and how they will be shown, before the stack-up is frozen; every later build is then a repeat rather than a re-qualification.
Built units, firmware and serial numbers
A camera or panel usually ships complete. Cable and harness work, firmware loading, functional and burn-in test, packing and serial-number traceability run in the same plant as the boards, so the device can leave as one built unit whose serial number maps back to the lot that produced it — and to the inspection record for that lot.
What a security quotation is actually pricing
Two quotations for the same Gerber set rarely differ by board area. They differ by how much of the unattended lifetime has been turned into a measurable step, and that work is priced alongside the fabrication.
- Making the thermal path and the noise floor measurable. Copper weight, dielectric thickness, via fill and the coating are checked against the agreed model and shown on a coupon and a micro-section taken from the production panel, so the board side can prove that the path it was asked to build is the path it built. Low-light behaviour and radio range stay with the assembled unit and the test house, and the two records together say which part of the device was verified where.
- Building a product family as one construction. Rows that share a stack-up can be pressed and sampled together, so variants keep their differences in the population, the coating and the test coverage rather than in the laminate, and a small reader does not need its own coupon round. The sequence behind that coverage is described under PCBA testing and quality assurance.
- Re-confirmation after a change. A new laminate, a different board thickness, a revised connector footprint or a heavier coating moves the thermal and electromagnetic premises, so a revision returns to the confirmed state and is re-run and re-recorded, instead of being released as a drawing update and found out at certification.
Price and evidence move together here as well. An order that carries less of the second is not cheaper in total; it moves the assembled-unit and certification work back into the customer's programme, where it is paid for again after a failed acceptance test or a first season of false alarms. A quotation that states which checks and which records are included lets the difference be read as a difference in proof rather than as a markup.
Next step
Send the Gerber set, the BOM and pick-and-place file, the quantity and the target date; a complete package is quoted within 24 to 48 hours. Board families used in security work have their own pages — high-frequency, HDI and aluminium metal-core — and box build covers the finished device. Lighting and IR heat problems are described under LED lighting PCBs, the rest of the industries we serve are on the industries page, and a quote can be requested on the contact page.
