Describe the circuit's role in the device
A handheld imaging accessory and a patient connected measurement module should not inherit the same generic board checklist. Identify what the board measures, controls and communicates, and record the consequences of missing, delayed or incorrect behavior. Use the project's responsible engineering team to translate those consequences into review and test requirements.
TI's medical design resources cover several distinct equipment families. This breadth is a useful reminder to start with the intended device architecture instead of treating medical electronics as one uniform electrical load.
Protect boundaries while increasing density
Show isolation regions, sensitive analog inputs, shielding and accessible connectors in the layout review. A new microvia escape or copper pour must be checked against these boundaries on all layers, including layers that are not visible in an assembly drawing.
For a measurement channel, create an error budget that includes the board's contribution. Reserve prototype access that can distinguish sensor behavior from interference introduced by digital activity, power conversion or the enclosure. Assign a reviewer to each unresolved assumption.
Specify evidence before ordering
The procurement package should state the required material records, board identification, inspection reports and handling information. Agree on the relevant construction qualification and acceptance documents with the supplier. Do not rely on a broad industry label to define a test method or a traceability depth.
- Tie each critical board requirement to a drawing or specification revision.
- Define which substitutions require engineering review.
- Specify how lots and inspection results will be linked.
- Identify assembly and rework exposures in the validation plan.
Maintain the link from prototype to production
Retain the construction and process assumptions used during verification. If the laminate, via structure, assembly site or protective treatment changes, review whether the earlier evidence remains applicable. Record the reasoning behind the decision rather than treating an unchanged schematic as proof of equivalence.
For field investigations, a searchable build history is more useful than a folder of disconnected certificates. Make the board revision, approved deviations and inspection records retrievable by the identifier carried on the hardware.
Adjacent-layer access, one connection at a time
Dielectric · geometry + material
Core or build-up dielectric
Illustrative only. Copper thickness, dielectric construction and via spans require a reviewed stackup.
Common questions
Does using HDI make a PCB medical grade?
No. HDI describes an interconnection approach. Product suitability depends on specified requirements, manufacturing controls and the device's applicable verification and qualification work.
Should a purchasing specification simply request the strictest class?
Define the actual performance and acceptance requirements with the responsible team. A class label without an applicable standard, revision and agreed details can leave important questions unanswered.
References & further reading
Method & assumptions · General design guidance. Validate the proposed construction and acceptance criteria for your project.