Separate the functions in the purchase list
Qnity’s laminate overview includes families serving different material functions. Its AP page describes an adhesiveless copper-clad laminate, while LF coverlay includes a separate adhesive coating. These are not competing descriptions of the same layer. Use the laminate guide for the base construction and the coverlay guide for protective insulation.
Information to retain from a product selection
| Decision | Define | Review |
|---|---|---|
| Product role | Laminate, coverlay or bonding layer | Correct position in the stack |
| Construction | Dielectric, copper and adhesive details | Available combination and ordering code |
| Property context | Method, frequency and conditioning | Relevance to the application |
| Change control | Approved product and alternatives | Requalification triggers |
Read a construction code with its sheet
Confirm dielectric thickness, copper selection, sidedness, and any adhesive thickness against current supplier documentation. Keep the supplier’s units and tolerances clear when transferring data to the stack drawing. Product-family property tables can be useful for screening, but they do not establish the exact finished-board dimensions or acceptance criteria. Ask which construction is being quoted and whether it matches your released material callout.
Resolve substitutions at the right level
When an alternate is proposed, compare the function it replaces first. Review the full layer sequence, assembly exposure, electrical geometry, and required qualification evidence. Do not accept an alternate because its marketing category sounds similar. Save the reviewed candidate and the reasons for approval in the project record so later procurement decisions do not reopen an undocumented material selection.
Before you release the design
- Use full product identifiers.
- Record the supplier-document revision.
- Separate typical properties from drawing limits.
- Ask for explicit deviations in the quotation.
Watch points
- One Pyralux family name does not define every material used in a flex assembly.
Practical questions
Can a brand requirement allow several grades?
Yes, if the drawing or approved-material list identifies the permitted constructions and the conditions under which each can be used.
Are AP and LF automatically interchangeable?
No. Their roles and constructions differ. Determine the actual layer being specified before comparing alternatives.
Technical references
References support the material or design context. Check the exact grade, part number, document revision and project conditions before release.Updated 27 September 2026 · Technical content policy · Engineering guidance supports project review; the agreed drawing defines the build.