{"id":10067,"date":"2019-04-17T15:50:28","date_gmt":"2019-04-17T19:50:28","guid":{"rendered":"http:\/\/www.qats.com\/cms\/?p=10067"},"modified":"2025-09-26T15:20:52","modified_gmt":"2025-09-26T19:20:52","slug":"industry-developments-extrusion-profile-heat-sinks","status":"publish","type":"post","link":"https:\/\/www.qats.com\/cms\/2019\/04\/17\/industry-developments-extrusion-profile-heat-sinks\/","title":{"rendered":"Industry Developments: Extrusion Profile Heat Sinks"},"content":{"rendered":"\n

By Norman Quesnel<\/strong>
Senior Member of Marketing Staff
Advanced Thermal Solutions, Inc. (ATS)<\/a><\/em><\/p>\n\n\n\n

Extruded metal heat sinks<\/a> are among the lowest cost, widest used heat spreaders in electronics thermal management. Besides their affordability, extruded heat sinks are lightweight, readily cut to size and shape, and capable of high levels of cooling.<\/p>\n\n\n\n

Metal\nChoices<\/strong><\/p>\n\n\n\n

Most extruded heat sinks are made from\naluminum alloys, mainly from the 6000 alloy series, where aluminum dominates. Trace\namounts of other elements are added, including magnesium and silicon. These\nalloys are easy to extrude and machine, are weldable, and can be hardened. <\/p>\n\n\n\n

Common alloys for extruded heat sinks are the 6063 metals. These can be extruded as complex shapes, with very smooth surfaces. 6061 aluminum is also used for extrusions. Its tensile strength (up to 240 MPa) is superior to 6063 alloys (up to 186 MPa). In addition to heat sinks, these aluminum alloys are popular for architectural applications such as window and door frames. [1]<\/p>\n\n\n

\n
\"Extrusion
Figure 1. An extruded aluminum heat sink with a black anodized finish. [2]<\/figcaption><\/figure>\n<\/div>\n\n\n

The surfaces of these metals can be anodized to replace their naturally occurring surface layer of aluminum oxide<\/a>. Anodizing provides more heat transfer, corrosion resistance and better adhesion for paint primers. It is an electrochemical process that increases surface emissivity, corrosion and wear resistance, and electrical isolation.<\/p>\n\n\n\n

The\nExtruding Process<\/strong><\/p>\n\n\n\n

Aluminum alloys are popular for extruding as heat sinks because they provide both malleability and formability. They can be easily machined<\/a> and are as little as one-third the density of steel. This results in extrusions that are both strong and stable, at a reduced cost relative to other materials. <\/p>\n\n\n

\n
\"\"
Figure 2. Heated aluminum alloy billets are pushed through a die to produce extruded length heat sinks and other parts. [3]<\/figcaption><\/figure>\n<\/div>\n\n\n

The aluminum extrusion process starts\nwith designing and creating the die that will shape the heat sink profile. Once\nthis has been done, a cylindrical billet of aluminum is heated up in a forge to\nhigh temperatures, generally between 800-925\u00b0<\/a>F\n(427-496\u00b0C). Next, a lubricant is added to the aluminum to prevent it from\nsticking to any of the machinery. It is then placed on a loader and pressure is\napplied with a ram to push heated aluminum through the die.<\/p>\n\n\n\n

During this process, nitrogen is added in order to prevent oxidation. The extruded part will pass completely through the die and out the other side. It has now been elongated in the shape of the die opening. The finished extrusion is then cooled, and if necessary, a process of straightening and hardening creates the finished product. <\/p>\n\n\n\n

They can be cut to the desired lengths, drilled and machined, and undergo a final aging process before being ready for market. [4]<\/p>\n\n\n\n

Finished heat sinks typically come\nwith anodized surfaces, which can enhance their thermal performance.\nAlternatively, a chromate finish provides some corrosion protection, or can be\nused as a primer before a final paint or powder coating is applied. [5]<\/p>\n\n\n\n

Shapes of\nExtruded Heat Sinks<\/strong><\/p>\n\n\n\n

Extruded heat sink profiles range\nfrom simple flat back fin structures to complex geometries for optimized\ncooling. They can be used for natural (passive) or forced convection (active)\nwith an added fan or blower. Extruded profiles can also include special\ngeometries and groove patterns for use with clip or push pin attachment\nsystems. [6]<\/p>\n\n\n

\n
\"\"
Figure 3. Extruded heat sinks are available in many shapes and lengths. [6]<\/figcaption><\/figure>\n<\/div>\n\n\n

Extrusions are also available in\nbulk lengths, e.g. 8 feet, which can be cut to different lengths per customer\nneeds.<\/p>\n\n\n\n

Optimizing\nThermal Performance<\/strong><\/p>\n\n\n\n

6063 aluminum alloy has a thermal conductivity<\/a> of 201-218 W\/(mK). Higher tensile strength 6061 aluminum\u2019s thermal conductivity ranges from 151-202 W\/(mK).<\/p>\n\n\n\n

Besides choosing the aluminum alloy, selecting an optimal extruded\nheat sink should factor in its overall dimensions and weight, the specified thermal\nresistance, and the extrusion shape (flat-back, flat-back with gap, hollow,\ndouble-sided, etc.). [7]<\/p>\n\n\n\n

Extruded heat sinks can be designed with very thin, and thus more, fins than other sink types. They can be extruded with aspect ratios of around 8:1, which can greatly optimize heat sink performance. A heat sink\u2019s aspect ratio is basically the comparison of its fin height to the distance between its fins. <\/p>\n\n\n\n

In typical heat sinks the aspect ratio is between 3:1 and 5:1. A high aspect ratio heat sink has taller fins with a smaller distance between them for a ratio that can be 8:1 to 16:1 or greater.<\/p>\n\n\n\n

Thus,\na high aspect ratio heat sink provides greater density of fins in a given\nfootprint than with a more common size sink. The great benefit is the increased\namount of heat dissipating surface area it provides due to its additional fins.\nFurther, these heat sinks do not occupy any more length or width. The result is\na more efficient heat sink with higher performance per gram in the same\nfootprint. [9]<\/p>\n\n\n\n

Applications<\/strong><\/p>\n\n\n\n

An extruded heat sink is used mainly to increase the surface area\navailable for heat transfer from high-power semiconductor devices, thus\nreducing a given semiconductor\u2019s external case temperature, as well as its\ninternal junction temperature. <\/p>\n\n\n

\n
\"\"
Figure 4. Extruded heat sinks mounted on processors by clips (left) and push pins (right). [10]<\/figcaption><\/figure>\n<\/div>\n\n\n

This allows the semiconductor devices to perform at their highest\nlevel, with maximum reliability. Such semiconductor devices include (but are\nnot limited to) RF power transistors, RF power amplifiers, Power MOSFETs,\nIGBTs, inverter power modules, and thyristor modules.<\/p>\n\n\n

\n
\"\"
Figure 5. Extruded heat sinks screwed onto a brick DC-DC converter. [11]<\/figcaption><\/figure>\n<\/div>\n\n\n

In some power conversion circuit applications, large diodes, rectifiers, diode modules and even high-power resistors (thick film, etc.) can also require thermal contact with an extruded heat sink. For cooling DC-DC power converters and power modules<\/a>, extruded heat sinks are available for full, half, quarter and one-eighth brick sizes <\/p>\n\n\n\n

References<\/strong><\/p>\n\n\n\n

    \n
  1. https:\/\/en.wikipedia.org\/wiki\/6063_aluminium_alloy<\/a><\/li>\n\n\n\n
  2. http:\/\/www.aluminumextrusionsprofiles.com\/sale-7552970-black-anodized-aluminium-heat-sink-profiles-extruded-aluminum-heatsink-radiators.html<\/a>
    <\/li>\n\n\n\n
  3. https:\/\/www.aec.org\/page\/basics_basics<\/a><\/li>\n\n\n\n
  4. https:\/\/www.clintonaluminum.com\/6061-aluminum-vs-6063-in-extrusion-applications<\/a>
    <\/li>\n\n\n\n
  5. http:\/\/www.wakefield-vette.com\/products\/natural-convection\/thermal-extrusions-overview\/CategoryID\/15\/Default.aspx<\/a><\/li>\n\n\n\n
  6. https:\/\/www.boydcorp.com\/thermal\/heat-sinks\/extruded.html<\/a>
    <\/li>\n\n\n\n
  7. http:\/\/www.richardsonrfpd.com\/Pages\/Product-End-Category.aspx?productCategory=10188<\/a><\/li>\n\n\n\n
  8. http:\/\/www.getecna.com\/products\/heat-sinks\/<\/a><\/li>\n\n\n\n
  9. https:\/\/www.qats.com\/cms\/2013\/04\/11\/increased-performance-from-high-aspect-ratio-heat-sinks\/<\/a><\/li>\n\n\n\n
  10. https:\/\/www.qats.com\/Heat-Sink\/Attachments<\/a><\/li>\n\n\n\n
  11. https:\/\/www.powerelectronics.com\/thermal-management\/heat-sinks-cool-brick-dc-dc-converters<\/a><\/li>\n<\/ol>\n\n\n\n
    \n\n\n\n

    For more information about Advanced Thermal Solutions, Inc. (ATS) thermal management consulting and design services, visit <\/em>https:\/\/www.qats.com\/consulting<\/em><\/a> or contact ATS at 781.769.2800 or <\/em>ats-hq@qats.com<\/em><\/a>. To register for Qpedia and to get access to its archives, visit <\/em>
    https:\/\/www.qats.com\/Qpedia-Thermal-eMagazine<\/em><\/a>.\ufeff<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"

    By Norman QuesnelSenior Member of Marketing StaffAdvanced Thermal Solutions, Inc. (ATS) Extruded metal heat sinks are among the lowest cost, widest used heat spreaders in electronics thermal management. Besides their affordability, extruded heat sinks are lightweight, readily cut to size … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":1001004,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[30],"tags":[797,101,231],"class_list":["post-10067","post","type-post","status-publish","format-standard","hentry","category-heat-sinks","tag-extrusions","tag-heat-sinks-2","tag-manufacturing-2"],"_links":{"self":[{"href":"https:\/\/www.qats.com\/cms\/wp-json\/wp\/v2\/posts\/10067","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.qats.com\/cms\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.qats.com\/cms\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.qats.com\/cms\/wp-json\/wp\/v2\/users\/1001004"}],"replies":[{"embeddable":true,"href":"https:\/\/www.qats.com\/cms\/wp-json\/wp\/v2\/comments?post=10067"}],"version-history":[{"count":5,"href":"https:\/\/www.qats.com\/cms\/wp-json\/wp\/v2\/posts\/10067\/revisions"}],"predecessor-version":[{"id":12475,"href":"https:\/\/www.qats.com\/cms\/wp-json\/wp\/v2\/posts\/10067\/revisions\/12475"}],"wp:attachment":[{"href":"https:\/\/www.qats.com\/cms\/wp-json\/wp\/v2\/media?parent=10067"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.qats.com\/cms\/wp-json\/wp\/v2\/categories?post=10067"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.qats.com\/cms\/wp-json\/wp\/v2\/tags?post=10067"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}