{"id":931,"date":"2026-06-09T15:51:13","date_gmt":"2026-06-09T13:51:13","guid":{"rendered":"https:\/\/segdielectriques.com\/en\/non-classe\/choosing-optimising-thermal-fillers-selection-guide\/"},"modified":"2026-06-09T15:51:13","modified_gmt":"2026-06-09T13:51:13","slug":"choosing-optimising-thermal-fillers-selection-guide","status":"publish","type":"post","link":"https:\/\/segdielectriques.com\/en\/article\/choosing-optimising-thermal-fillers-selection-guide\/","title":{"rendered":"Choosing and Optimising Thermal Fillers: A Selection Guide"},"content":{"rendered":"<p>From filler selection to processing optimisation, every technical decision influences the final thermal conductivity of the composite. This guide summarises the selection criteria and best practices for dielectric insulation applications.<\/p>\n<h2>Ceramic filler selection table<\/h2>\n<figure class=\"wp-block-table\">\n<table>\n<thead>\n<tr>\n<th>Filler<\/th>\n<th>Therm. cond.<\/th>\n<th>Elec. insul.<\/th>\n<th>Cost<\/th>\n<th>Processing<\/th>\n<th>Recommended use<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>h-BN platelets<\/td>\n<td>High<\/td>\n<td>Excellent<\/td>\n<td>High<\/td>\n<td>Orientation req.<\/td>\n<td>Power electronics<\/td>\n<\/tr>\n<tr>\n<td>AlN (silane-treated)<\/td>\n<td>Very high<\/td>\n<td>Good<\/td>\n<td>Medium-high<\/td>\n<td>High rate req.<\/td>\n<td>SiC\/GaN modules<\/td>\n<\/tr>\n<tr>\n<td>Al\u2082O\u2083 alumina<\/td>\n<td>Moderate<\/td>\n<td>Very good<\/td>\n<td>Low<\/td>\n<td>Easy<\/td>\n<td>Transformers<\/td>\n<\/tr>\n<tr>\n<td>Hybrid BN + AlN<\/td>\n<td>High<\/td>\n<td>Good<\/td>\n<td>Medium<\/td>\n<td>Synergies to validate<\/td>\n<td>High performance<\/td>\n<\/tr>\n<tr>\n<td>Al(OH)\u2083<\/td>\n<td>Low<\/td>\n<td>Good<\/td>\n<td>Very low<\/td>\n<td>Critical viscosity<\/td>\n<td>Flame retardancy<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/figure>\n<h2>Typical industrial applications<\/h2>\n<p>High thermal conductivity and electrical insulation composites find applications in four main industrial sectors:<\/p>\n<ul>\n<li><strong>Transformers:<\/strong> Thermal dissipation + dielectric strength. Recommended filler: Al\u2082O\u2083 or h-BN.<\/li>\n<li><strong>SiC\/GaN modules:<\/strong> Critical thermal interfaces, flux &gt; 50 W\/cm\u00b2. Filler: silane-treated AlN.<\/li>\n<li><strong>Electric vehicles:<\/strong> Batteries and inverters. Weight and vibration constraints. Filler: h-BN platelets.<\/li>\n<li><strong>Aerospace:<\/strong> Extreme environments &gt; 200 \u00b0C. 3D printing. Filler: h-BN in high-Tg epoxy.<\/li>\n<\/ul>\n<h2>Optimisation methodology: 5 key steps<\/h2>\n<ul>\n<li><strong>Define application constraints:<\/strong> Target thermal conductivity, minimum dielectric strength, temperature range, mechanical requirements and cost constraint.<\/li>\n<li><strong>Select the filler and its morphology:<\/strong> Prefer platelets or cylinders for aspect ratio. Combine two complementary particle sizes to optimise network density (jar\/pebbles\/sand principle).<\/li>\n<li><strong>Treat surfaces (functionalisation):<\/strong> Silane for AlN, admicelle for h-BN. This treatment reduces interfacial thermal resistance and can double the effective conductivity of the composite.<\/li>\n<li><strong>Optimise volume fraction:<\/strong> Determine the percolation threshold. Target 50-60 vol.% for maximum performance while ensuring that the resin viscosity remains compatible with the processing method.<\/li>\n<li><strong>Validate dual-filler synergistic effects:<\/strong> Test dual-filler combinations (AlN + Al\u2082O\u2083, BN + AlN). Synergies can provide an additional gain of 20-40% on effective thermal conductivity.<\/li>\n<\/ul>\n<p><strong>Trends 2025-2026.<\/strong> The electrical insulation materials market is growing strongly (+6.6%\/year). Applications related to electric vehicles, energy management systems and renewable energies are driving demand towards high thermal conductivity composites combining hybrid fillers and advanced surface treatments.<\/p>\n<p><em>Do you want to choose and optimise the right thermal filler for your dielectric application? Contact our technical team at <a href=\"mailto:sales@segdielectriques.com\">sales@segdielectriques.com<\/a> for tailored support.<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"<p>A practical guide to selecting and optimising ceramic thermal fillers for dielectric insulation, from selection tables to a 5-step optimisation methodology.<\/p>\n","protected":false},"author":1,"featured_media":930,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"pdf_url":"","secteur":"","cta_label":"","footnotes":""},"categories":[16],"tags":[],"class_list":["post-931","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-article"],"_links":{"self":[{"href":"https:\/\/segdielectriques.com\/en\/wp-json\/wp\/v2\/posts\/931","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/segdielectriques.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/segdielectriques.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/segdielectriques.com\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/segdielectriques.com\/en\/wp-json\/wp\/v2\/comments?post=931"}],"version-history":[{"count":0,"href":"https:\/\/segdielectriques.com\/en\/wp-json\/wp\/v2\/posts\/931\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/segdielectriques.com\/en\/wp-json\/wp\/v2\/media\/930"}],"wp:attachment":[{"href":"https:\/\/segdielectriques.com\/en\/wp-json\/wp\/v2\/media?parent=931"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/segdielectriques.com\/en\/wp-json\/wp\/v2\/categories?post=931"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/segdielectriques.com\/en\/wp-json\/wp\/v2\/tags?post=931"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}