{"id":4817,"date":"2012-04-04T08:00:03","date_gmt":"2012-04-04T12:00:03","guid":{"rendered":"http:\/\/www.engineeringradio.us\/blog\/?p=4817"},"modified":"2023-04-29T09:04:19","modified_gmt":"2023-04-29T13:04:19","slug":"rohs-and-electronics-reliability","status":"publish","type":"post","link":"https:\/\/www.engineeringradio.us\/blog\/2012\/04\/rohs-and-electronics-reliability\/","title":{"rendered":"RoHS and Electronics Reliability"},"content":{"rendered":"\n

ROHS stands for Restriction of Hazardous Substances<\/a> Directive. It is a mainly European effort to reduce lead (Pb), Mercury (Hg), Cadmium (Cd), Hexavalent Chromium (Cr+6<\/sup>), Polybrominated Biphenyl (PBB), Polybrominated diphenyl ethers (PBDE) and Acrylamide in electronics and consumer goods.<\/p>\n\n\n\n

The main effort appears to be in the reduction of lead in circuit boards and solder.\u00a0 Generally speaking, the reduction of pollutants is a good thing.\u00a0 Lead is toxic, especially to young children. Mercury is a potent neurotoxin.\u00a0 Those other elements and chemicals don’t sound good either.<\/p>\n\n\n\n

There are all sorts of green logos and other nice-looking things attached to products that meet the standard.<\/p>\n\n\n\n

\"Typical<\/a>
Typical ROHS label<\/figcaption><\/figure>\n\n\n\n

I feel better, don’t you?<\/p>\n\n\n\n

Now for the other side of ROHS.  According to Lead Free Electronics Reliability<\/a> (large .pdf) by Dr. Andrew Kostic, the effort had been hugely expensive with very limited results:<\/p>\n\n\n\n

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A huge (~ $14B annual revenue) semiconductor manufacturer estimated the annual worldwide Pb reduction per 1,000,000,000 integrated circuits was only equivalent to ~100 automobile batteries.<\/p>\n<\/blockquote>\n\n\n\n

Wow!  That is simply amazing on the face of it.  Over the years, I have probably found and carted at least 10 old car batteries to the recycling center for a few dollars each.  According to the Kostic paper:<\/p>\n\n\n\n

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(Computer chip manufacturer) Intel’s efforts to remove lead from its chips have so far cost the company more than $100 million and there is no clear end in sight to the project’s mounting costs<\/p>\n<\/blockquote>\n\n\n\n

Wouldn’t $100m be better spent on other, more pressing pollution issues?  Fukushima<\/a>, springs to mind.<\/p>\n\n\n\n

Further, the replacement metals used in electronics have some problems of their own.  They may be better for the environment, however, they lack testing and are<\/p>\n\n\n\n

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Not optimized for high reliability, severe stress, long life applications<\/p>\n<\/blockquote>\n\n\n\n

Further, replacing parts in legacy equipment using ROHS parts and solder may present problems with bonds between dissimilar metals.  Thus, making field repairs, or any repairs impossible.<\/p>\n\n\n\n

Many of the newer solders and circuit boards use Tin (Sn) as the finishing metal.  There is a problem with tin, known as Tin whiskers<\/a>.  This was first noted at the Bell Labs in 1947.  Small hairs grow out of the surface of the metal, acting as short circuits, and at higher (above 6 GHz) frequency RF, antennas.   This happens with other metals such as Zinc, Silver, and Gold.<\/p>\n\n\n\n

\"Silver<\/a>
Silver Sulfide Whiskers on circuit board<\/figcaption><\/figure>\n\n\n\n

As you can probably deduce, this can have certain detrimental effects<\/a> on the performance of the circuits in question.  I can imagine all sorts of strange behavior from controllers and other bits and parts of equipment.<\/p>\n\n\n\n

I don’t know how prevalent this is in Europe where the directive has been in effect for 6 years or so.\u00a0 It would be interesting to find out.\u00a0 I also wonder how many US manufacturers are adopting RoHS as the de facto standard in order to do business in Europe.<\/p>\n","protected":false},"excerpt":{"rendered":"

ROHS stands for Restriction of Hazardous Substances Directive. It is a mainly European effort to reduce lead (Pb), Mercury (Hg), Cadmium (Cd), Hexavalent Chromium (Cr+6), Polybrominated Biphenyl (PBB), Polybrominated diphenyl ethers (PBDE) and Acrylamide in electronics and consumer goods. The main effort appears to be in the reduction of lead in circuit boards and solder.\u00a0 … Continue reading RoHS and Electronics Reliability<\/span><\/a><\/p>\n","protected":false},"author":4,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3,4],"tags":[46],"class_list":["post-4817","post","type-post","status-publish","format-standard","hentry","category-general","category-tech-stuff","tag-repair-work"],"_links":{"self":[{"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/posts\/4817","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/comments?post=4817"}],"version-history":[{"count":16,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/posts\/4817\/revisions"}],"predecessor-version":[{"id":11621,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/posts\/4817\/revisions\/11621"}],"wp:attachment":[{"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/media?parent=4817"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/categories?post=4817"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/tags?post=4817"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}