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Preserve each electrical pair and its method

The cited CN-TDS2005-10 sheet gives Dk/Df pairs of 3.41/0.0013 at 1 GHz using IPC 2.5.5.9, 3.35/0.0021 at 10 GHz using IPC 2.5.5.5, and 3.52/0.0026 at 10 GHz using IEC 61189-2-721. These are typical values in a 0.76 mm, six-ply 2116 specimen context.

Do not take Dk from one row and Df from another to create an apparently better material. A model should record why a particular method and construction are appropriate. Differences between reported values are not automatically evidence of defective material; they can reflect the measurement and extraction boundary.

Source-qualified material review

Connect the design value to the actual stackup

The finished transmission line includes a dielectric distribution, copper geometry and surface treatment. A thin core or prepreg-rich interval can differ from the source specimen. Ask for the construction-specific electrical information used by the fabricator or simulation workflow.

Keep the proposed trace geometry with the material and copper selection. If an alternative glass style or resin content is proposed, review the effect on impedance and loss instead of preserving an old width without analysis. The stackup approval should include the relevant model assumptions.

Understand the dielectric-only calculation

The tool uses a small-loss homogeneous TEM approximation, with relative permeability assumed to be one. It accepts frequency, bulk relative permittivity, loss tangent and uniform path length. Its output is dielectric attenuation only, not total insertion loss.

The example uses hypothetical Dk 4 and Df 0.01 at 10 GHz over 100 mm. It is deliberately not a preloaded Synamic 6N specification. Copper roughness, conductor resistance, radiation, vias and connectors are excluded, so the result should never be compared directly with a complete measured channel without accounting for those contributions.

Compare material changes on a common boundary

For a meaningful alternative assessment, use the same frequency, routing length, reference planes and copper assumptions. A lower Df can reduce one part of loss while a different copper treatment changes another. Geometry adjustments needed to preserve impedance can also affect the comparison.

The Synamic 8G page addresses remaining routing-length allocation from a complete loss budget. Do not rank 6N and 8G only by their names or one headline number. Obtain the applicable construction data and evaluate the actual channel requirements.

Homogeneous TEM dielectric loss illustration

Optional cost comparison from your own allowances

Use a quotation or a clearly labeled internal assumption for each input. Keep the quantity, construction and inspection scope the same when comparing alternatives. This uncalibrated planning model adds entered values; it contains no current market rates and does not issue a 吃瓜tv quotation. You can contact the team without completing it.

Keep the paired material and suffix explicit

The cited technical sheet identifies Synamic 6N and 6NB. Laminate and prepreg have different roles, and the actual supply description should state which is required. An ambiguous Synamic 6BF callout cannot inherit the 6N table merely because the names share a digit.

Record the complete designation, source revision, foil type and thickness basis in the fabrication package. Identify any permitted alternatives and the approval owner. This protects a repeat build from an unnoticed change to the electrical construction.

Make the inquiry useful to both RF and purchasing teams

Send the stackup, operating frequency range, controlled-impedance requirements, routing-loss assumptions, copper and relevant test requirements. Include quantity, board dimensions and whether the exact material is fixed. State which data gaps need a supplier response before geometry is finalized.

Use the optional budget worksheet only with your own allowances or actual quote inputs. It does not price a decibel or determine the economic value of a material change. A quotation should identify the proposed construction and evidence scope so that the electrical and commercial decisions refer to the same board.

Tie the exact grade to an electrical construction

State the channel reference planes, frequency range, routing length, copper construction, transitions and interface assumptions together. A laminate loss-tangent value is one input to that system. It is not a complete insertion-loss measurement or a guarantee that a data rate will work.

Use comparable measurement or modeling conditions when screening alternatives. Material changes can require geometry changes to preserve impedance, and copper roughness can alter the result independently of the resin system. Keep the proposed stackup and the channel analysis synchronized through fabrication review.

For procurement, identify the properties that are fixed and the alternatives that can be evaluated. Request evidence at the relevant construction and frequency rather than a broad low-loss label. Compare total delivered scope and validation effort alongside material price. A shorter or better-routed channel may change the tradeoff more than replacing a material name alone.

A useful design-data record retains both the material value and the reason it was selected. State whether the value is supplier characterization, a construction-specific design input, a measured coupon extraction or an early assumption. These sources are not interchangeable. Keep frequency, method and specimen information visible when a comparison uses more than one document.

The tool on this page starts empty because a plausible default can otherwise be mistaken for a verified grade profile. Use the example to understand the units, then replace it with project inputs. A result with many decimal places does not imply that the material or routing-loss input is known to that precision.

For a high-speed design, plan how the model will be checked. Reference planes, coupon geometry, fixtures and the acceptance boundary determine what a measurement means. A coupon that characterizes one line construction does not automatically qualify every route or transition on the board.

Keep the commercial comparison aligned with the engineering one. Quantity, copper, layer structure, test deliverables and qualification effort should be comparable. A lower material allowance can be irrelevant if the proposed construction cannot meet the channel requirement, while a premium grade may be unnecessary if the actual route already has sufficient validated margin.