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Preserve the measurement method beside Tg

The regional manufacturer record distinguishes DSC, TMA and DMA transition measurements. For R-5725S it lists a DSC Tg of 200掳C and a DMA value of 215掳C. They describe different measurement techniques, not conflicting operating-temperature ratings.

Similarly, time-to-delamination results with copper and without copper are different tests. Keep the specimen and method with the result. Do not choose the larger number from a different condition to represent the finished board's assembly capability.

Construction decisions at a glance

Map the real thermal history

Record the expected lamination sequence, soldering exposure and permitted repair cycles. A thick board with fine plated holes can impose different interconnect demands from a simple thin board using the same resin system.

Identify the holes and interfaces that require evidence. A catalog property can inform material screening, but it does not replace the construction-specific acceptance plan or demonstrate that every hole survives the intended production history.

Use thickness expansion as a bounded illustration

The tool integrates two entered expansion coefficients across a simplified sharp transition. Its sample uses a 1.6 mm dielectric, heating from 25掳C to 200掳C, a transition at 150掳C and coefficients of 50 and 250 ppm per degree. The modeled free thickness change is 30 碌m.

Those are hypothetical values. The calculation excludes copper constraint, gradual transition behavior and plated-hole fatigue. It helps explain why the temperature interval matters; it cannot calculate the lifetime of a via or approve repeated reflow.

Piecewise free thickness expansion

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.

Compare neighboring materials for a stated task

The R-5735 route-length guide handles another mid-loss construction through an electrical allocation task. Similar application positioning does not imply identical thermal behavior or a common approved bonding recipe.

The HIPER D R-1755D page focuses on an automotive board's thermal expansion discussion. The difference in application context is not a certification boundary by itself. The actual mission profile and agreed board-level evidence remain essential.

Keep electrical suitability in the decision

Thermal screening should not obscure the required channel performance. Preserve the line geometry, copper and frequency used for the design input. A Tg comparison cannot establish loss, impedance or timing equivalence.

The MEGTRON series comparison is the appropriate entry when several families remain candidates. It compares complete channel needs and commercial scope without treating the generation number as an automatic recommendation.

Request a reviewed construction and evidence scope

Provide the exact R-5725S/R-5620S callout, layer map, board thickness, copper, hole sizes, assembly history and quantity. Include critical electrical requirements and the inspection or reliability evidence needed for release.

The cost worksheet accepts only your own allowances. Keep special coupons, testing and qualification work visible when comparing proposals. A useful quote identifies the material and construction assumptions, and does not convert a published Tg into a blanket promise of high-temperature service.

Close the material and construction decision together

The finished board combines a dielectric, copper patterns, holes, surface coatings and a manufacturing history. Its behavior cannot be inferred from a family name alone. State the supplied grade, reinforcement, thickness, copper and processing conditions that matter to the intended application.

Keep handling and assembly requirements with the fabrication drawing. A thin panel, punched outline or unusual support condition can change the production route even when the electrical circuit is simple. Ask the fabricator to review the actual features and panel format rather than assuming a dimensional example represents a production capability.

For cost comparison, hold the drawing, quantity, test scope and acceptance requirements constant. Record one-time tooling separately from recurring work, and distinguish raw material utilization from accepted-board yield. Any calculator on this page uses supplied assumptions; an actual quotation requires the files and an agreed scope.

A source-qualified table should be read alongside the exclusions and footnotes, not separated from them. If the supplier limits an application, identify whether that limitation affects the current design before requesting a price. A familiar family classification does not override an explicit restriction, and a positive calculator result cannot remove it.

For a repeat build, compare the newly proposed supply with the previously approved material record. Exact grade, manufacturing site where relevant, foil treatment, reinforcement and dimensional basis can matter. Define which changes require notification and which need technical approval. This avoids turning a purchasing substitution into an unnoticed design change.

Receiving records should support the agreed identity and traceability requirement. A certificate for a raw material, a finished-board inspection report and an assembly test result cover different boundaries. Request the records that actually answer the project questions rather than collecting unrelated certificates.

When a source contains conflicting values, keep the discrepancy visible until a controlled revision or written supplier response resolves it. Do not create a new table by combining the most favorable entries from several sources. The released drawing, material list and quotation should all describe the same accepted construction.