The ones I was involved in that weren't MEMS were mixed signal. The digital side was always a fairly mundane geometry. IIRC the smallest was
0.35um which processor guys would probably consider ancient. We wouldn't have had a choice because we needed higher voltage capability for the analog side and didn't have space for MCM.-- Regards, Joerg http://www.analogconsultants.com/
Jim - do you know by any chance what solder GM uses on their Alumina boards? I tried working on one board with 60/40 lead tin solder with no luck. The solder on the board had to be removed to get to copper. I was guessing the initial solder was incompatible and/or worked at a higher temperature.
Hul
Jim Thomps> > >> >> > >>
[snip]
I have no idea what is used now. I last ran a hybrid (alumina/beryllia substrates) facility in 1970-73. Back then we were using a solder with gold in it to avoid leaching the gold traces. Alumina boards with copper traces came after I left that part of the semiconductor biz.
I would hazard a guess that the present solder has some silver in it. ...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 Skype: skypeanalog | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
I can't read it - or at least I'm not prepared to pay to access the full text - but it does seem to be a recent (2010) snap-shot of what's going on.
-- Bill Sloman, Sydney
"Jim Thompson" wrote in message news: snipped-for-privacy@4ax.com...
I suppose pure lead is a possibility (higher temp performance? RoHS exempt?), or bismuth (rather brittle to use pure, though?).
Anything tin-based should be regular RoHS style alloys (aside from the aforementioned gold $$$), which should be fine if you turn up the iron a bit. The substrate is probably doing a good job of heatsinking too, so you probably want to preheat it.
Tim
-- Seven Transistor Labs, LLC Electrical Engineering Consultation and Contract Design Website: http://seventransistorlabs.com
Gold itself is a pretty good solder. I suppose if you heat it locally with infra-red laser, it could be welded to silicon.
Crap! Even 0.18um is no big deal. This snipped-for-privacy@gmail.com is nothing but a bloviator. What don't you declare your credentials Edward? Degree? Company? Position? Preferred broom style ?>:-} ...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 Skype: skypeanalog | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
Not interested in fame war.
Your "contributions" to this thread have never exceeded Popular Science level and have confused those seeking accurate information on making their own chips.
You have been dismissed from class. ...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 Skype: skypeanalog | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
blue laser may work better, gold's reflective in the IR.
-- umop apisdn
ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.