lead free solder again

Hello Robert,

Don't know, I should have said "if". Problem is, the Eurocrat don't know either. They seem to have just put up a new law and then hope and cross their fingers. If they really care much, that is.

Well, when you see the experience reported by Swatch and others the problem may be larger than we think. Reflowed SMT doesn't just consist of solder joints.

--
Regards, Joerg

http://www.analogconsultants.com

Hello Klaus,

Ok, that wasn't really the kind of paper I was looking for. I could dig through the 100+ references now. However, from a responsible legislative body I would have expected at least something like a watertight scientific long term test. Such as "Hey, we have soldered these boards. This is how we did it and these are the materials and temperature profiles. We then exposed them to various climate conditions for 15 years and here are the quality results".

--
Regards, Joerg

http://www.analogconsultants.com

According to the NASA site

3% Pb is enough to dramatically reduce whisker formation:

"Studies have shown that alloying tin with a second metal reduces the propensity for whisker growth. Alloys of tin and lead are generally considered to be acceptable where the alloy contains a minimum of 3% lead by weight. Although some experimenters have reported whisker growth from tin-lead alloys, such whiskers have also been reported to be dramatically smaller..."

So, why don't the Euro-folks just limit solder to 3-4% Pb as a first, safe step? That's a 10-fold reduction. Total Pb might be reduced over RoHS, as more devices might be included, and longer-lived consumer devices would be an environmental win too.

Curiously, James Arthur

(Alternatively, you could outlaw FR-4, epoxy, ...etc. In California they're considered hazardous waste.

It's all very strange. Hydrogenated fats kill far more people, and they're added to food deliberately.)

Because the precautionary principle deems that you can't have too little of a bad thing.

Hello James,

Could have many reasons. Possible ones:

a. They don't have a clue. b. They have poor technical advisers. c. They have no technical advisers. d. They don't care, they just want to look green.

CA can be strange. That's why some companies are now elsewhere. But now at least we have Arnold who can veto the stupidest attempts to kill businesses and jobs.

There is a lot of not-in-my-back-yard (NIMBY) behavior.

There is probably a huge difference in lobbying power. Lobbying power is measured in campaign contribution amounts.

--
Regards, Joerg

http://www.analogconsultants.com

[snip] [snip]

Yep. AZ now has Google and there was an announcement yesterday that we're also getting Ebay.

Three cheers for the Left Coast ;-)

...Jim Thompson

-- | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona Voice:(480)460-2350 | | | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | |

| 1962 | I love to cook with wine. Sometimes I even put it in the food.

That's what one woman, IIRC in Scotland, thought and vigorously shielded herself from any and all germs, bacteria and whatnot.

AFAIR she died from a simple cold.

--
Regards, Joerg

http://www.analogconsultants.com

...

Yes! Let's start a new campaign - RoHF: Reduction of Hydrogenated Fats. All food companies must comply by July 1, 2007. No imports to the United States or to the European Union of non-RoHF compliant food.

Michael

So, essentially, you're saying that they used about as much science as the EPA and their ilk to ramrod through all the antismokerist propaganda.

Thanks, Rich

A few germs are very good for you !

Excessive cleankliness has been suggested as one cause for ever increasing cases of allergies too btw.

Graham

Even if you could find someone crazy enough to insure against tin whisker failures, it is actually a company reputation problem. That can lead to lost sales or being excluded from the market. Disastrous for small companies!

Our boards are in a hermetically sealed package that can withstand a few hundred bars of pressure. Conformal coating only provides added costs and repair hassles for us. Can whiskers penetrate thru a polyurethane conformal coat?

--
Mark

Sure. Ban high fructose corn syrup (as used in American Coke products) as well. Good old fashioned cane sugar as used in Mexican and Canadian Coke tastes better and is better for you. Of course there's that corn lobby to deal with (one of the most subsidized crops)...

Best regards, Spehro Pefhany

--
"it\'s the network..."                          "The Journey is the reward"
speff@interlog.com             Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog  Info for designers:  http://www.speff.com

Hello Graham,

cases

That's probably why my forefathers reached almost biblical ages. It was a farming region, hog raising and all that. I can't remember a time when there wasn't piles of manure on the main road through town. They had a saying: "Where there is a stench, there it won't be cold. Lots of people froze to death but nobody died from a stench". And boy did it stink in them barns.

--
Regards, Joerg

http://www.analogconsultants.com

Hello Spehro,

Well, just don't drink any of that soft drink stuff. It's been years since I had one. Cerveza is healthier IMHO ;-).

--
Regards, Joerg

http://www.analogconsultants.com

Excellent--I'm in!

James Arthur

(The advantage to hydrogenating fats is that it creates permanent food-artifacts. Invaluable if you want to pass baked-good heirlooms on to your great-grandchildren, but really bad for arteries.)

Until recently, I used to point out that gasoline was cheaper than Coke as a measure of how cheap gasoline was. Odd that people are upset about the price of the useful and valuable commodity that provides all sorts of useful work, then happily pay as much or more for another, whose consumption is completely voluntary, and which gives them no value in return.

In my reading, yes, cerveza is healthier--an ounce or two of alchohol daily seems to increase HDL cholesterol ('good' cholesterol), and reduces risk of heart disease. Soft drinks make you fat, make LDL, and increase risk of diabetes and heart disease.

Best, James Arthur

Maybe not in this case. Because they were invented and in use before the Food and Drug Administration's creation, they're grandfathered -- exempt from regulation by same. So, they're immune.

Hydrogenation was thought quite a miracle when first invented around

1902, as the resultant artificially saturated fat ("trans fat") lasted a lot longer. They just didn't realize that evolution hadn't equipped us to metabolize this new plasticized-fat properly. It raises bad cholesterol, and lowers the good.

Lasting longer was important in the days before refrigeration, but had little impact on public health because most people still ate food fresh. Fast food has changed that -- nowadays, some people unknowingly eat a lot of it. My dad, for example. He was a doctor, fit, lean, brilliant, and very health-conscious, but inadvertently ate a lot of shortening/margarine/trans fats. He died suddenly, unexpectedly, in his prime, of heart disease. He was 65.

James Arthur

Yeah right - Measuring one of our ovens (max power draw is 100A at 208V 3 phase) it went from 12 to 15 kW when warm with a reasonable board load to about 17 to 20 kw draw with a lead free profile, with about half the productivity, maybe worse since we tend to run the oven slower then we need to with leaded boards. Nitrogen may also be needed in some cases, which means that at least 2 times as much nitrogen would be needed for the same amount of product processed.

Perhaps ypu did not *read* the conclusions: No matter what anybody did, as long as tin was persent, the results were highly variable from no tin whiskers to numerous tin whiskers. They have even been seen in electronic solder...