Building a medical device runs through a defined set of manufacturing stages, from the first review of the design to the shipment of finished units. This article works through those stages in order, then covers what to look for in the partner running them.
The steps below describe a turnkey program, where the manufacturer buys the components as well as building the product. Under a consigned arrangement, the technical work is the same, and the OEM keeps the purchasing.
Before production starts, an engineering team reviews the design against what the factory can build. That covers
The manufacturer returns recommendations, and the OEM decides what to change. The review comes early for a reason: once a medical design has been through verification, altering it means verifying it again.
The bare board is made before any components go onto it, usually by a specialist fabricator rather than the assembly plant. Fabrication covers laminating the layers, drilling and plating the holes that connect them, etching the copper, and applying solder mask and a surface finish. Boards for high-reliability applications are built to IPC-6012 Class 3, which sets tighter limits on plating thickness and the copper left around each hole. They are electrically tested before they ship.
Assembly begins with solder paste, deposited through a stencil cut to match the board's pads. Placement machines then set the components onto the wet paste, and the board passes into a reflow oven, where the paste melts and forms the joints. Through-hole parts cannot take that heat profile, so they are fitted afterward and soldered selectively or by wave.
Reflow can leave defects that are not visible from above, so boards are inspected more than once. Automated optical inspection covers placement and the joints on exposed pads, while ball grid arrays, whose connections sit underneath the package, are checked by X-ray.
The standard those inspections work to is IPC-A-610, which defines three classes of workmanship. Class 3 is the most demanding, written for products that have to keep working and cannot be taken out of service, and medical programs commonly specify it. It’s a contractual requirement (rather than a regulatory one).
Once the boards pass test, they go into the product. Assemblers fit them to the enclosure and connect the harnesses, cabling, power supply, and display—along with any other mechanical parts the design calls for. How far this runs depends on the program. Some OEMs take a sub-assembly and integrate it themselves, while others receive a complete product ready to ship. In medical, the range is wide, covering everything from benchtop imaging and diagnostic systems to handheld and wearable devices.
Earlier tests could only confirm that the boards worked on their own. With the unit assembled, it can be run as a complete product, including the interactions between subsystems that were not testable while they sat apart. Electrical safety is verified at this point, with hi-pot testing applying voltage across the insulation to confirm it holds.
Packaging has to protect the device in transit and carry the information identifying it. Electrostatic protection and moisture barriers are chosen according to how sensitive the components inside are. The labeling is the regulated element, since medical devices carry unique device identifiers and the content of the label is the OEM's responsibility as legal manufacturer.
The paperwork that leaves with a shipment is what makes the units traceable later. Each batch is linked to the components used, the processes run, and the results recorded—so a problem reported from the field can be narrowed to a defined set of units. The shipping origin matters commercially too, as duties and transit times follow from the site that built the product.
Most providers run this process in broadly the same way. Where they differ is in where they can run it, at what volume, and under which certifications.
A provider's footprint determines where a program can be built and what options remain if one site becomes unavailable. Spreading production across regions (as Asteelflash does from 18 production facilities on four continents) lets output sit near demand while a qualified alternative stays in reserve.
The number of plants matters less than whether work can move between them. Transferring a validated medical process takes equivalent equipment, documentation good enough to travel, and requalification of the receiving line. It’s worth asking how a provider manages transfers.
Distance adds time and freight cost, and leaves a program exposed to changes in customs and tariffs. For devices supplied to hospitals or distributors under service commitments, producing within the region shortens replenishment and reduces the stock needed to cover transit.
A low unit price in one region does not always survive the cost of setting up there. Labor rates, freight, duties, and access to engineering support vary enough that the cheapest place to run sustained volume is often not the right place to launch.
ISO 13485 certification of the manufacturing site is the baseline for medical work. It certifies a quality management system and does not transfer regulatory approval, which stays with the OEM as legal manufacturer. Certification is granted facility by facility, so the question is which sites hold it.
Asteelflash's medical work is concentrated on medium-to-high-mix production at low to medium volumes. That distinction matters, because a plant built for very high volume and one built for medium mix at lower volume are set up differently and priced differently.
Asteelflash builds medical electronics at five ISO 13485-certified facilities, covering PCBA, box build, system integration, and final testing. If you are assessing manufacturing partners for a device program, contact our team to discuss your requirements.
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PCBA mounts and solders components onto a bare board to produce a working assembly. In medical devices, it is normally built to IPC Class 3 criteria within an ISO 13485 quality system.
PCBA produces the populated circuit board. Box build takes it from there, fitting the board into the enclosure with the harnesses, cabling, and mechanical parts (and can extend to full system integration).
IPC-A-610 defines three classes of workmanship. Class 3 is the most demanding, covering products that have to keep working and cannot be taken out of service. It applies by contract, not regulation.
Asteelflash's medical programs run through ISO 13485-certified facilities. Supplier qualification, incoming component checks, and inspection during assembly create the record tying a finished unit back to its inputs.
ISO 13485 is the quality management standard written for medical devices and the one that matters most. ISO 9001 and ISO 14001 often sit alongside it, and certification is granted per facility.