When a dry-film pattern fails near a change in surface geometry, immediately increasing exposure can confuse the investigation. First determine whether the resist was in the intended condition before imaging. Preserve evidence of the laminated film and the underlying feature rather than beginning with the final etched defect alone.
Define the film and its intended process
Qnity’s Riston DI7600 information specifically discusses wet-lamination conformation in a flex application. This is a product-specific capability; it does not establish that every dry film or lamination method will conform identically to the same panel.
Record the exact film, thickness designation, substrate condition and approved lamination procedure. Identify the elapsed time and handling between surface preparation, lamination and imaging, using the material supplier’s applicable instructions.
Map defects to physical features
| Observation | Comparison to make |
|---|---|
| Repeated location | Does it follow the same copper or substrate geometry? |
| Panel region | Is the concern concentrated near an edge or across a band? |
| Process stage | When can the condition first be observed? |
| Reference area | What differs in an unaffected but comparable feature? |
Retain orientation and transport direction. If the same design is rotated for a trial, record that explicitly so a geometry-related pattern can be distinguished from one fixed to the equipment direction.
Use a staged comparison
Under the process owner’s control, select samples after the relevant preparation, lamination and development stages. Mark them as investigation material. A defect that already exists before exposure should not be explained solely by an exposure setting.
For example, compare an affected step in the surface geometry with a nearby flat region on the same panel. Then repeat with a matched panel using the controlled change. This narrows the question without changing every process variable together.
Validate the complete patterning result
- State the proposed cause and supporting observation.
- Review the trial with the resist and equipment specialists.
- Keep unrelated imaging and development variables fixed.
- Inspect the final required conductor features.
- Record the approved process boundary and remaining unknowns.
Do not infer production readiness from a visually smooth film alone. The relevant result is a repeatable pattern meeting the defined geometry after its intended processing.
Keep photographs from intermediate stages with the trial report. They make it possible to distinguish a resolved lamination issue from an unrelated defect that appears later.
Include the observation method in each photograph record. A reflected-light view and a section through the resist answer different questions; neither should be presented as a direct repeat of the other when assessing a small local gap.
The etch-compensation guide covers the digital geometry boundary, while imaging traceability helps retain the setup used after lamination.
Move from reading to a build-ready project
Use the fabrication and assembly checklists to prepare drawings, production files and test requirements.
Open the DFM checklist