{"id":11134,"date":"2026-11-02T15:23:30","date_gmt":"2026-11-02T07:23:30","guid":{"rendered":"https:\/\/www.umecpcb.com\/?p=11134"},"modified":"2026-11-02T15:23:30","modified_gmt":"2026-11-02T07:23:30","slug":"ceramic-pcb-thermal-conductivity-how-to-compare-datasheets","status":"publish","type":"post","link":"https:\/\/www.umecpcb.com\/pt\/ceramic-pcb-thermal-conductivity-how-to-compare-datasheets\/","title":{"rendered":"Ceramic PCB Thermal Conductivity: How to Compare Datasheets"},"content":{"rendered":"

\"96%<\/p>\n

A finished ceramic PCB – also called a ceramic circuit board – does not have one intrinsic W\/mK value that describes the entire assembly. Ceramic PCB thermal conductivity is primarily a property of the ceramic substrate material. The temperature rise of ceramic printed circuit boards also depends on substrate thickness, copper geometry, interfaces, mounting, heat spreading, and cooling.<\/p>\n

Before using a datasheet value in a thermal model or RFQ, identify what was measured and what the number cannot predict.<\/p>\n

What Does a Ceramic PCB Thermal Conductivity Value Mean?<\/b><\/strong><\/h2>\n

Thermal conductivity, usually represented by k<\/em>, describes how readily heat moves through a material under a temperature gradient. A value in W\/mK\u00a0is not a temperature, a heat-flow rating, or a guarantee that a complete PCB will stay below a particular operating temperature.<\/p>\n

For a ceramic PCB, the reported value most often applies to bulk alumina, aluminum nitride, silicon nitride, or another ceramic substrate. It may not describe a copper-clad substrate, a patterned ceramic circuit, a multilayer construction, a soldered assembly, or the complete path from device junction to ambient air.<\/p>\n

Material names alone are insufficient. Purity, grade, porosity, additives, and manufacturing route can affect the stated property. For an Al2O3 vs AlN PCB selection decision, use UMEC’s Al2O3 vs AlN PCB comparison<\/b><\/u><\/strong><\/a>\u00a0separately; the task here is to decide whether the datasheet numbers are comparable.<\/p>\n

Check What the Datasheet Value Applies To<\/b><\/strong><\/h2>\n

Start with the row label, table title, footnotes, and document scope. Confirm whether the value applies to raw ceramic, a fired substrate, a metalized substrate, or a named product construction. During ceramic circuit fabrication, metallization changes the structure but does not turn bulk conductivity into a complete-board rating. For AlN ceramic PCB production, establish whether the number describes incoming ceramic or the proposed metalized build. Then record the material grade, value type, temperature, method, and document revision.<\/p>\n

\"Example<\/p>\n

The values below show how one published datasheet lists several materials at 20 degC. They illustrate table reading, not universal specifications.<\/p>\n\n\n\n\n\n\n
Material entry<\/b><\/strong><\/td>\nListed thermal conductivity<\/b><\/strong><\/td>\nStated condition<\/b><\/strong><\/td>\nWhat still requires confirmation<\/b><\/strong><\/td>\n<\/tr>\n
Al2O3<\/td>\n24 W\/mK<\/td>\n20 degC<\/td>\nAlumina grade, purity, and whether the value is typical or controlled<\/td>\n<\/tr>\n
Si3N4<\/td>\n90 or 110 W\/mK<\/td>\n20 degC<\/td>\nExact grade and why two product variants differ<\/td>\n<\/tr>\n
AlN<\/td>\n170 W\/mK<\/td>\n20 degC<\/td>\nMaterial grade, tolerance, and applicability to the ordered substrate<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Separate explicit data from assumptions. The unit and temperature are stated; grade-level tolerances, test reports, and finished-board behavior may not be. An “AlN” value alone is not an acceptance criterion.<\/p>\n

When Are Two Ceramic PCB Thermal Conductivity Values Comparable?<\/b><\/strong><\/h2>\n

Two values are directly comparable only after the following fields are normalized:<\/p>\n