{"id":1740,"date":"2009-05-14T09:47:11","date_gmt":"2009-05-14T16:47:11","guid":{"rendered":"http:\/\/mightyohm.com\/blog\/?p=1740"},"modified":"2015-09-26T11:11:07","modified_gmt":"2015-09-26T18:11:07","slug":"book-review-hot-air-rises-and-heat-sinks-by-tony-kordyban","status":"publish","type":"post","link":"https:\/\/mightyohm.com\/blog\/2009\/05\/book-review-hot-air-rises-and-heat-sinks-by-tony-kordyban\/","title":{"rendered":"Book Review: Hot Air Rises and Heat Sinks, by Tony Kordyban"},"content":{"rendered":"<figure id=\"attachment_1742\" aria-describedby=\"caption-attachment-1742\" style=\"width: 330px\" class=\"wp-caption alignnone\"><a href=\"http:\/\/www.amazon.com\/gp\/product\/0791800741?ie=UTF8&amp;tag=mightyohm-20&amp;linkCode=as2&amp;camp=1789&amp;creative=9325&amp;creativeASIN=0791800741\"><img loading=\"lazy\" decoding=\"async\" data-attachment-id=\"1742\" data-permalink=\"https:\/\/mightyohm.com\/blog\/2009\/05\/book-review-hot-air-rises-and-heat-sinks-by-tony-kordyban\/hot-air-rises-and-heat-sinks\/\" data-orig-file=\"https:\/\/mightyohm.com\/blog\/wp-content\/uploads\/2009\/04\/hot-air-rises-and-heat-sinks.jpg\" data-orig-size=\"330,492\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;}\" data-image-title=\"Hot Air Rises and Heat Sinks\" data-image-description=\"\" data-image-caption=\"&lt;p&gt;Everything You Know About Cooling Electronics Is Wrong&lt;\/p&gt;\n\" data-large-file=\"https:\/\/mightyohm.com\/blog\/wp-content\/uploads\/2009\/04\/hot-air-rises-and-heat-sinks.jpg\" class=\"size-full wp-image-1742\" title=\"Hot Air Rises and Heat Sinks\" src=\"http:\/\/mightyohm.com\/blog\/wp-content\/uploads\/2009\/04\/hot-air-rises-and-heat-sinks.jpg\" alt=\"Everything You Know About Cooling Electronics Is Wrong\" width=\"330\" height=\"492\" \/><\/a><figcaption id=\"caption-attachment-1742\" class=\"wp-caption-text\">Everything You Know About Cooling Electronics Is Wrong!<\/figcaption><\/figure>\n<p>Working as an electrical engineer, I have often been faced with thermal design problems.  They are usually in the form of: &#8220;Given a maximum system temperature X, ensure that the maximum temperature of all devices in the design does not exceed Y.&#8221;\u00a0  Temperature X is usually a customer spec, while temperature Y is almost always driven by <a href=\"http:\/\/en.wikipedia.org\/wiki\/MTTF\">MTTF<\/a> constraints on the semiconductors used in the design.\u00a0 This sounds simple enough until you realize that:<\/p>\n<ul>\n<li>The system temperature is often not clearly defined.\u00a0 Is it the ambient air temperature?\u00a0 The temperature of the printed circuit board the part is mounted on?\u00a0 The temperature of a baseplate (usually a sizable piece of aluminum) that won&#8217;t even exist in the finished design?<\/li>\n<li>The MTTF spec is usually based on things you can&#8217;t measure directly (at least not easily or accurately), like the junction temperature of a transistor that is on a die you can&#8217;t even see, inside a package you don&#8217;t have a thermal model for.\u00a0 In addition, MTTF numbers are often wildly inaccurate, don&#8217;t account for duty cycle, etc.\u00a0 <em>Yikes.<\/em><\/li>\n<li>Chances are, the guy who worked on the part before you hasn&#8217;t checked the thermal readings in years, so it&#8217;s actually running way over the limits, and now you have to fix it.\u00a0 A small change in the design can drastically affect the numbers<\/li>\n<\/ul>\n<p>At the end of the day, numbers are scribbled on envelopes or entered into spreadsheets, <span style=\"text-decoration: line-through;\">guesses<\/span> estimates are made, and everyone resolves to develop a better thermal model next time, which of course never happens.<\/p>\n<p>I stumbled upon this book at the <a href=\"http:\/\/www.bkstr.com\/webapp\/wcs\/stores\/servlet\/StoreCatalogDisplay?langId=-1&amp;storeId=10161&amp;demoKey=d&amp;catalogId=10001\">Stanford University Bookstore<\/a> a few months ago.\u00a0 Given my experience (frustration) with thermal design, I couldn&#8217;t help but pick it up and start reading.<\/p>\n<p>It&#8217;s a fairly quick read and thoroughly entertaining.\u00a0 Kordyban&#8217;s style is very informal.\u00a0 The chapters are in the form of several short stories about fictional characters at a made-up company called TeleLeap.\u00a0 These characters have to solve a series of design problems, which are used as examples to explain several concepts of thermal design.\u00a0 There are no lengthy derivations and the technical discussions are pretty understandable, even to someone who never took <a href=\"http:\/\/en.wikipedia.org\/wiki\/Thermodynamics\">thermodynamics<\/a> in college (like me).<\/p>\n<p>In particular, I found Kordyban&#8217;s discussions of the errors that can creep into <a href=\"http:\/\/en.wikipedia.org\/wiki\/Thermocouple\">thermocouple<\/a> measurements, the difficulty of measuring junction temperature directly, and the problem with <a href=\"http:\/\/images.google.com\/images?q=pin%20fin&amp;oe=utf-8&amp;rls=org.mozilla:en-US:official&amp;client=firefox-a&amp;um=1&amp;ie=UTF-8&amp;sa=N&amp;hl=en&amp;tab=wi\">pin-fin heatsinks<\/a> very interesting and educational.\u00a0 I won&#8217;t say that I am an expert in thermal design having read this book, but I do have just a little bit more insight into what&#8217;s going on (and what to avoid).<\/p>\n<p>Unfortunately, the book is out of print, so you&#8217;ll have to find a used copy and pay some big bucks &#8211; unless you get lucky like I did and find one that&#8217;s still sitting on the shelf.\u00a0 No, you can&#8217;t have mine!<\/p>\n<p><a href=\"http:\/\/www.amazon.com\/gp\/product\/0791800741?ie=UTF8&amp;tag=mightyohm-20&amp;linkCode=as2&amp;camp=1789&amp;creative=9325&amp;creativeASIN=0791800741\">Hot Air Rises and Heat Sinks: Everything You Know About Cooling Electronics Is Wrong<\/a><img loading=\"lazy\" decoding=\"async\" style=\"border:none !important; margin:0px !important;\" src=\"http:\/\/www.assoc-amazon.com\/e\/ir?t=mightyohm-20&amp;l=as2&amp;o=1&amp;a=0791800741\" border=\"0\" alt=\"\" width=\"1\" height=\"1\" \/><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Working as an electrical engineer, I have often been faced with thermal design problems. They are usually in the form of: &#8220;Given a maximum system temperature X, ensure that the maximum temperature of all devices in the design does not exceed Y.&#8221;\u00a0 Temperature X is usually a customer spec, while temperature Y is almost always &hellip; <a href=\"https:\/\/mightyohm.com\/blog\/2009\/05\/book-review-hot-air-rises-and-heat-sinks-by-tony-kordyban\/\" class=\"more-link\">Continue reading <span class=\"screen-reader-text\">Book Review: Hot Air Rises and Heat Sinks, by Tony Kordyban<\/span> <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"jetpack_post_was_ever_published":false},"categories":[40],"tags":[206,209,501,208,207],"class_list":["post-1740","post","type-post","status-publish","format-standard","hentry","category-books-and-resources","tag-book-review","tag-cooling","tag-electronics","tag-heatsinks","tag-thermal-design"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/pioCd-s4","jetpack_sharing_enabled":true,"jetpack_likes_enabled":true,"jetpack-related-posts":[{"id":52,"url":"https:\/\/mightyohm.com\/blog\/2008\/07\/pid\/","url_meta":{"origin":1740,"position":0},"title":"PID Controlled Solder Paste Fridge","author":"Jeff","date":"July 27, 2008","format":false,"excerpt":"I recently decided I needed to upgrade my garage electronics bench to include capability to work on surface mount components.\u00a0 I ordered a hot air reflow station and some no-clean solder paste from SRA. Solder paste is a little tricky to handle, because most solder paste needs to be refrigerated\u2026","rel":"","context":"In &quot;Electronics&quot;","block_context":{"text":"Electronics","link":"https:\/\/mightyohm.com\/blog\/category\/electronics\/"},"img":{"alt_text":"PID Controller closeup","src":"https:\/\/i0.wp.com\/mightyohm.com\/files\/flickr\/2706936015_5d8ef1cfd5_m.jpg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":2115,"url":"https:\/\/mightyohm.com\/blog\/2009\/09\/coombs-printed-circuits-handbook\/","url_meta":{"origin":1740,"position":1},"title":"Coombs: Printed Circuits Handbook","author":"Jeff","date":"September 24, 2009","format":false,"excerpt":"If The Art of Electronics is the bible of electronic circuit design, then the Printed Circuits Handbook is almost certainly the bible of printed circuit board (PCB) technology. I say this because even if you disregard the volumes of useful information inside (much of which I have never seen elsewhere\u2026","rel":"","context":"In &quot;Books and Resources&quot;","block_context":{"text":"Books and Resources","link":"https:\/\/mightyohm.com\/blog\/category\/books-and-resources\/"},"img":{"alt_text":"Printed Circuits Handbook","src":"https:\/\/i0.wp.com\/mightyohm.com\/blog\/wp-content\/uploads\/2009\/07\/41b213YFWHL.jpg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":979,"url":"https:\/\/mightyohm.com\/blog\/2009\/01\/gerbv\/","url_meta":{"origin":1740,"position":2},"title":"gerbv &#8211; A free, open source gerber viewer for Linux \/ OS X","author":"Jeff","date":"January 5, 2009","format":false,"excerpt":"When you finish a PCB design, you typically use the CAM export function of your layout tool to generate a set of gerber files to send to the PCB manufacturer.\u00a0 To avoid errors in the finished board, it's usually a good idea to review the files before you click send.\u2026","rel":"","context":"In &quot;Books and Resources&quot;","block_context":{"text":"Books and Resources","link":"https:\/\/mightyohm.com\/blog\/category\/books-and-resources\/"},"img":{"alt_text":"gerbv screenshot","src":"https:\/\/i0.wp.com\/gerbv.sourceforge.net\/GerbvScreenshot.png?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":3190,"url":"https:\/\/mightyohm.com\/blog\/2010\/10\/diy-integrated-circuit-design-with-mosis\/","url_meta":{"origin":1740,"position":3},"title":"DIY Integrated Circuit Design with MOSIS","author":"Jeff","date":"October 25, 2010","format":false,"excerpt":"MOSIS, short for Metal Oxide Semiconductor Implementation Service,\u00a0is to integrated circuits what BatchPCB is to printed circuit boards. \u00a0That is, it's a batch order service that makes getting your own custom ICs fabricated more affordable by allowing lots of designers to contribute their designs and share the costs of a\u2026","rel":"","context":"In &quot;Electronics&quot;","block_context":{"text":"Electronics","link":"https:\/\/mightyohm.com\/blog\/category\/electronics\/"},"img":{"alt_text":"Photo: SATRE ELECTRONICS","src":"https:\/\/i0.wp.com\/mightyohm.com\/blog\/wp-content\/uploads\/2010\/10\/EC101_Layout_50-500x363.jpg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":1010,"url":"https:\/\/mightyohm.com\/blog\/2009\/01\/diy-pid-controlled-soldering-hotplate\/","url_meta":{"origin":1740,"position":4},"title":"DIY PID Controlled Soldering Hotplate","author":"Jeff","date":"January 17, 2009","format":false,"excerpt":"In preparation for my Arduino-based AVR HV Programmer boards coming back, I decided to step up my home lab surface mount soldering capabilities. Step one was to find a cheap stereo zoom microscope on ebay, with 7-32X magnification, perfect for working on surface mount devices.\u00a0 One of my biggest frustrations\u2026","rel":"","context":"In &quot;Electronics&quot;","block_context":{"text":"Electronics","link":"https:\/\/mightyohm.com\/blog\/category\/electronics\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/mightyohm.com\/blog\/wp-content\/uploads\/2009\/01\/3201234462_c0a761b898_o.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/mightyohm.com\/blog\/wp-content\/uploads\/2009\/01\/3201234462_c0a761b898_o.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/mightyohm.com\/blog\/wp-content\/uploads\/2009\/01\/3201234462_c0a761b898_o.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/mightyohm.com\/blog\/wp-content\/uploads\/2009\/01\/3201234462_c0a761b898_o.jpg?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/mightyohm.com\/blog\/wp-content\/uploads\/2009\/01\/3201234462_c0a761b898_o.jpg?resize=1050%2C600&ssl=1 3x, https:\/\/i0.wp.com\/mightyohm.com\/blog\/wp-content\/uploads\/2009\/01\/3201234462_c0a761b898_o.jpg?resize=1400%2C800&ssl=1 4x"},"classes":[]},{"id":3655,"url":"https:\/\/mightyohm.com\/blog\/2011\/02\/surplusgizmos\/","url_meta":{"origin":1740,"position":5},"title":"SurplusGizmos","author":"Jeff","date":"February 17, 2011","format":false,"excerpt":"While I was visiting Portland last month, I made a quick stop at\u00a0SurplusGizmos in Hillsboro. SurplusGizmos is what an electronics store should be, and it's the kind of place that I love to visit. \u00a0It's also the kind of electronics store that is completely nonexistant in Austin (oh, my beloved\u00a0HSC,\u2026","rel":"","context":"In &quot;Electronics&quot;","block_context":{"text":"Electronics","link":"https:\/\/mightyohm.com\/blog\/category\/electronics\/"},"img":{"alt_text":"SurplusGizmos","src":"https:\/\/i0.wp.com\/mightyohm.com\/files\/flickr\/5439327183_2955aa7d1b.jpg?resize=350%2C200","width":350,"height":200},"classes":[]}],"_links":{"self":[{"href":"https:\/\/mightyohm.com\/blog\/wp-json\/wp\/v2\/posts\/1740","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mightyohm.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mightyohm.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mightyohm.com\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/mightyohm.com\/blog\/wp-json\/wp\/v2\/comments?post=1740"}],"version-history":[{"count":14,"href":"https:\/\/mightyohm.com\/blog\/wp-json\/wp\/v2\/posts\/1740\/revisions"}],"predecessor-version":[{"id":1809,"href":"https:\/\/mightyohm.com\/blog\/wp-json\/wp\/v2\/posts\/1740\/revisions\/1809"}],"wp:attachment":[{"href":"https:\/\/mightyohm.com\/blog\/wp-json\/wp\/v2\/media?parent=1740"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mightyohm.com\/blog\/wp-json\/wp\/v2\/categories?post=1740"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mightyohm.com\/blog\/wp-json\/wp\/v2\/tags?post=1740"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}