Public evidence

electrical.thermal.heatsink_rth

Machine-checked verification for calculation version 1.1.0 · tier internally_reviewed

Open calculator API Capability Download JSON CVP Manifest MCP Review policy

CVP status

Lumped steady-state Rθ; not Zth(t), CFD, or θCA+θSA (double-count)

Declared partition coverage: PASS · 4/4 declared partitions (ja, stack, required-sa, invalid-domain)
Versions: Calculation 1.1.0 · CVP protocol 1.0.0-proposed
CVP identity: 3/3 property · digest e84796291008

Verification

Legacy regression suite: 17/17 calculation tests · Production surface contract 6/6

Three distinct suites: educational examples on the calculator page, this legacy regression count (17/17 golden + boundary), and the CVP verification suite below. They are not the same number. Property, metamorphic, round-trip, O3, and interface statuses/checks are recorded in the CVP Manifest . SKIP (0/0) means that suite has no published vectors.

This calculator CURRENT · Public schema 1.1.0 matches · Semantic contract ✓ · Production attested · Public/cache ✓ · Origin ✓

CVP verification suite

Protocol checks from the Evidence Manifest. Distinct from the legacy regression suite above. Calculation version 1.1.0. CVP 1.0.0-proposed. 4/4 golden · 8/8 CVP boundary · 9/9 invalid · 3/3 property · 3/3 metamorphic · 2/2 round-trip · 3/3 cross-interface · 1/1 cross-calculator · 4/4 CVP contract. digest e84796291008.

Golden (oracle-backed) 4 / 4
CVP boundary 8 / 8
Invalid input 9 / 9
Property 3 / 3
Metamorphic 3 / 3
Round-trip 2 / 2
Cross-interface 3 / 3
Cross-calculator 1 / 1
CVP contract 4 / 4
Interfaces PASS · UI (SSR) / REST / MCP
Interface claim ui-ssr is query-result HTML, not a live browser session.
Assurance Engineering

release artifacts aligned PASS
schema output required declared PASS
schema valid input executes PASS
engine success output validates schema PASS
schema rejects incomplete input PASS
rest success payload validates schema PASS

Fingerprint sha256:4e5f89c5bbd8f444c91daa988c9085b4d4e159aff60af497e4dd5e180c4ce60a

Input schema sha256:e0368bf8a72142969285ce1e69ef710a5a43f00276ab16322c9e8cfc0061058d · Output schema sha256:ba3caefa631d7ec1c7571e9d97c0ffb097099dcfed5105f8dc46fb4d5086cc26 · Build-time SHA-256 digests prove published artifacts agree with each other (release_integrity.scope=workspace). Production attestation GETs canonical URLs twice (public/cached view and origin), including Capability HTML, via npm run attest:production --write (published at /.well-known/calculatorx-production-attestation.json) and fails if the public Capability page advertises a different calculation_version. This is artifact consistency, not an independent immutable release log.

Build & scope

Engine identity and declared limitations.

Tool: heatsink-rth
Engine: heatsink-rth
Engine build: 2026-09-13
Evidence core: 2026-09-13T22:54:03.327Z
Rendered: 2026-11-10T05:18:41.887Z
Last reviewed: 2026-09-14

Assumptions

Steady-state lumped thermal resistance
Rθ constant (not Zth(t))
θJA is an effective / application value, not a JEDEC-board package constant
θJC+θCS+θSA is a single series path; parallel PCB/package paths are ignored
P is device dissipation converted to heat

Limitations

Steady-state lumped Rθ only; not Zth(t) or CFD
θJA and θJC+θCS+θSA are exclusive models — mixing them is CONFLICTING_INPUTS
Required mode reports θSA,max, not total θJA
θCA / Rth_HS are rejected: θCA already includes the ambient-side path
Parallel PCB/package heat-flow paths are ignored on the explicit stack
P is device dissipation converted to heat, not load or output power
θSA,max ≤ 0 returns HEATSINK_INFEASIBLE and is not a purchasable heatsink

Sources

Standards and references supporting this tool specification. Methods are listed separately — they are algorithms, not bibliographic sources.

JEDEC JESD51 series — Integrated Circuits Thermal Measurement Method — Junction-to-ambient and junction-to-case thermal metrics on specified test boards
Supports: Tj = Ta + P·θJA as a thermal-metric estimate; θJA is test-condition specific
Analog Devices — Practical Design Techniques for Power and Thermal Management — Section 8, Fig. 8.50 — junction → case → case-to-sink → sink-to-ambient
Supports: θJA = θJC + θCS + θSA; required θSA,max = (Tj,max−Ta)/P − θJC − θCS
Texas Instruments SPRA953 — Semiconductor and IC Package Thermal Metrics — RθJA, RθJC, and application dependence of junction-to-ambient metrics
Supports: θJA is not a universal equivalent of the explicit case/heatsink stack
Analog Devices — Thermal Characterization of IC Packages — θCA is case-to-ambient (all case-to-ambient paths); θJA = θJC + θCA
Supports: Do not add θCA to θSA — θCA already includes the ambient-side path

Verification disclosure

Aggregate outcomes, scope and artifact commitments are public. Complete test inputs, expected values, execution records and oracle infrastructure are retained privately. This summary does not independently reproduce the full verification run.