Define the electrical comparison
Specify frequency range or interface, length, allowable loss, impedance requirements, and connector transitions. Kuraray identifies low moisture absorption and low dielectric dissipation as VECSTAR film features. Apply those statements only to the described material. Compare proposed laminates using matching test conditions, then include copper roughness, trace geometry, bonding layers, and protective materials in the channel model.
Questions for an LCP and polyimide review
| Decision | Define | Review |
|---|---|---|
| Dielectric data | Frequency, method and conditioning | Comparable material measurements |
| Copper interface | Foil and surface treatment | Loss model assumptions |
| Bonding system | Bonding and cover materials | Whole-stack compatibility |
| Qualification | Product environment and channel limits | Evidence needed to approve a change |
Include processing and availability
Ask which exact copper-clad construction can be supplied and processed for your outline, vias, cover materials, and assembly profile. A material change can alter more than the dielectric in a solver. Use the low-loss selection guide to keep the system comparison complete, and request the fabricator’s proposed stack before committing critical routing dimensions.
Test the value of the change
Use a comparison coupon or representative interconnect that retains the real connector and reference geometry. Define humidity conditioning only where it answers the product requirement, and record its effect separately from dry measurements. The impedance stackup guide helps document geometry. Decide in advance what improvement would justify added sourcing or process qualification effort; otherwise the comparison can continue without resolving a product decision.
Before you release the design
- State the channel performance target.
- Request exact candidate laminate constructions.
- Compare conditioned and unconditioned data consistently.
- Include transitions in the validation plan.
Watch points
- A low-loss film cannot compensate for an undefined return path or incompatible connector interface.
Practical questions
Is LCP always lower loss?
Compare the named grades and complete geometry at relevant frequencies. A general material-family comparison cannot determine every finished channel.
Can it replace polyimide without layout changes?
Do not assume so. Recheck stack thickness, processing, copper choices, impedance geometry, and mechanical qualification.
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.