HDI microsection testing examines a prepared cross-section of selected features. It can reveal layer geometry, copper interfaces and defects visible in that plane. Because the method samples particular locations and conditions, the report should state what was sectioned and avoid implying that every connection on every board was observed.
Make the sample representative
Identify the via arrangements and regions that the section needs to represent. Tie the coupon or sample location to the stackup and fabrication lot. A section of a simple connection may not represent a more demanding stacked path elsewhere in the board.
Specify the applicable method and acceptance requirements through the project's approved standards and procurement documents. The design owner and supplier should agree how preparation, evaluation and reporting will support the intended decision.
Read the report in context
| Report element | What it helps establish |
|---|---|
| Sample identity | Relationship to the production lot and released construction |
| Section location | Which interconnect and geometry were examined |
| Preparation and exposure | Conditions under which the observation was made |
| Measurements and findings | Observed dimensions and evaluated acceptance criteria |
Understand the limits
A physical section is useful evidence, but latent interface behavior can require another type of evaluation. IPC has specifically raised concerns about microvia failures that traditional microsection inspection alone may not detect. Discuss relevant electrical performance evidence under agreed thermal exposure rather than adding more photographs without a defined purpose.
The complementary test should also be documented. Record its specimen construction, exposure, measurement method and acceptance criterion. A test name without those details is not enough to compare results across suppliers or revisions.
Use findings for disposition
If a result is outside the agreed criteria, preserve the evidence and identify who can authorize the next step. Determine whether the issue affects the sampled unit, a defined lot or a broader construction concern through an appropriate investigation. Do not infer scope solely from one image.
For a later process change, review whether the previous sample still represents the new configuration. Maintain traceability between the accepted construction and the evidence retained with the order. This guide does not claim in-house laboratory equipment or a particular inspection capability; verified company details remain [NEEDS CLIENT INPUT].
Continue the engineering review
- Microvia reliability and thermal exposure
- HDI PCB prototype validation
- IPC-6016 replacement and procurement notes
- HDI PCB engineering hub
Source checked October 2, 2026: IPC microvia reliability warning. Supplier literature is context, not a claim of this site’s equipment or capabilities.
Review your HDI requirements
Share the board revision, proposed stackup, quantity and open questions. Include the requirements discussed in this guide so the project review starts with the same assumptions.