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Solid Capacitor Motherboards Introduced
jckrbbt writes with news that Gigabyte has introduced solid capacitor motherboards in its Intel 945 chipset products. From the article: "[S]olid capacitors have a higher tolerance for higher temperatures and they also perform better with higher frequencies and higher current than electrolytic capacitors. The superior heat resistance and better electric conductivity will allow PC enthusiasts to tweak the highest levels of performance from their system without fear of excessive capacitor wear or exploding capacitors."
Capacitors having the shortest lifespan of most electrical components means if this catches on there will be less electronic waste, and more reliable machines. Although I bet these cost twice as much....
I have seen them last less than a year. All you have to do is check where the capacitor is from. If it is from China (which is likely), then it has a high probability of failing very quickly. This is due to their stealing the formula from a Japanese company who became aware of the attempted theft and fed the women a recipe from the early 60's (and well known to hold up for only a year).
Motherboards may get obsolete fast, but I still would expect a longer life than just three years.
If this is true, I'm amazed so many old computers work so well. Maybe this is a bit off. In either case, it seems with such a huge difference in life span, unless there's a huge change in cost, the extra reliability offered by solid capacitors should make them standard in every motherboard. I'm not an electrical engineer though (or an economist).
The standard life test for an electrolytic capacitor is 1000hr at rated temperature. For most consumer equipment, this is 85C oe 105C depending on which electrolyte is used (and price paid). The life of electronic components doubles for every 10C reduction in temperature. At end of life, an electrolytic caacitor is allowed a 50% loss of capacitance and doubled ESR. For most cases these caps work fine (provided the designer included margin). In a PC application, it is reasonable to expect operating temperatures of about 45C to 55C. This would mean lives between 8000hr and 32,000hr.
I find it interesting that the solid electrolyte caps have finally found a home. These have been around fo about 20 years in one form or another. Maybe now the price will start falling and the small wet electrolytics will go the way of the vacuum tube.
As someone who has painstakingly replaced all the capacitors on two separate motherboards, I can definitely see why this is a good idea. The most recent was my Epox 8kra2+ board (with an Athlon XP 2600+, not over clocked.) I noticed the caps beginning to bulge slightly on top and develop some crusty electrolyte "dandruff" on the heads after 2 years of use, but I decided to hold off on major surgery until I began to notice any problems.
About a year later the system began to lock up mysteriously, and after ruling everything else out (this was my main system after all) I grabbed my soldering iron and began an hour or so of some rather nerve wrecking soldering. Every single 1000F and 1500F cap on the board needed replacement, so an old PIII board became the donor.
I measured the bad caps after removing them and most of them were off by about 300-700F, way outside of tolerance. After I finished I booted the system up, ran memtest for a few hours successfully, and never had a lockup since.
I see VERY few computers failed due to a cap problem before they are retired on account of being too old to be useful anymore. The most common component I see fail is the HD, which is no surprise given that it's mechanical. This could be useful for devices that are good for 25 years, but comptuers tend to get thrown out after 5.
Agreed. Tantalum capacitors have much better performance than electrolytics in most circumstances. However, there is outstanding debate about whether the use of tantalum capacitors is ethical, as tantalum is just about the rarest element that's actually used in the electronics industry and most of the deposits are in developing countries. Accusations have been levelled that electronics manufacturers are going to inordinate lengths to secure tantalum deposits, and the people who live there are the losers (especially since the by-products of processing tantalum ore are decidedly unpleasant).
I try to avoid using tantalum capacitors in my own designs as far as possible, trying to keep to NASA's guidelines for component derating when using electrolytics. Where I need precision capacitances I design the circuit so that a ceramic NP0 or similar EIA Class 1 capacitor can be used instead. I haven't had any capacitors fail yet.
Pirate Party UK
Compared to tantalum capacitors, these capacitors reach much higher capacities at the same physical volume, and the same or better ESL/ESR.
See for example here:
These aluminium electrolytic capacitors, with a solid conductive polymer electrolytic find their way even on most current mainboards, most often in the CPU DC-DC convertor circuits. They're usually easily recognizable from classic electrolytics by their small size and metal casing without a plastic sleeve.
A benefit from an all-solid-polymer capacitor mainboard is dubious, since classic alimuium electrolytic capacitors work just fine in many roles they're needed for, particularly in low-ripple-current situations.