On Wed, Apr 07, 2010 at 11:36:49PM -0700, Chuck Guzis wrote: ... That can cut your via. Safer to use a sewing machine needle or pin. Heat the solder until it is molten, clean with needle/pin as the solder tends not to stick to the steel. In a pinch, the end of a capacitor/resistor lead will do if you are careful. You can 'capture' the solder in the via on the lead and simply snip off that piece to get it back through the hole. The solder pump works well normally. RoHS solder is going to be harder, unless you have to stay RoHS, I suggest diluting it down with tin/lead solder will help make it easier to clean. YMWV - 73 Diane VA3DB -- - db at FreeBSD.org db at db.net http://www.db.net/~db

That sounds a bit cool to me. I normally use a #8 tip (800 Fahrenheit) on my TCP for such work. Adding a bit of solder will genrally improve the heat conduction and make it a lot easier to get the solder in the hole molten. Also, if it deosn't cleaer the first time you use the sucker, it's notmally a wast of time to just try again. Resolder the joing with fresh solder and then suck it off. My method for removing ICs inteact without damaing the PCB is to suck off the oslder (as above), then free the pins on the solder side. They will normally be against ones side of the hole, use pliers or a small screwdrive to foce them towards the centre of the hole. You need ot know how much force you can reasonably apply without wreckign the via, this, alas, comes with experiece. If the pin won;t move, reolder it, resuck, and try again. Then on the component side of the board, use a small screwdriver to fuch the IC pins inwards (towards the body of the IC). Place the scrrewever as close to the PCB as posible. When they've all 'moved' the IC will normlly just lift out with no damage to PCB or chip. I've never had a hole/via that won't clear if heated wirh an adequate soldering iron from one side and sucked from the other. -tony

On 9 Apr 2010 at 0:05, Pete Turnbull wrote: I do keep an assortment of tips around; I think that the "one that comes in the box" is a PTA7, but for fine 63/37 SnPb solder, 700F is just too hot. I don't particularly care for RoHS solder; fortunately, the leaded stuff is easy enough to obtain in the US. It might not be the case in the EU. The last bit of plumbing I did (replacing a well pressure tank) was done with 50/50 solder and it's the solder that I use when working on brass musical instruments. It stays "plastic" longer than the eutectic variety (which has virtually no plastic phase) and can be tooled while still soft. The amount of lead-bearing surface exposed to the water supply or musician is very small if things have been done correctly. But since "plumber" comes from the Latin for lead, what does one call an RoHS pipefitter? Stanner? Indier? --Chuck

On Fri, Apr 9, 2010 at 14:17, Tony Duell <ard at p850ug1.demon.co.uk> wrote: Aaaaand just to play devil's advocate: The regulations are then discussed by people that don't actually know what's going on either (BTW no, I don't know either!) - What is the safe level of lead in drinking water? For what body mass? For what developmental stage? To what extent? You'd have to ask pediatricians, neurologists, and biochemists - search PubMed and you'll find they are arguing about it all the time. Officially, for children and infants there is _no_ safe level. That does not mean that every child exposed to x ppm lead in water will exhibit any symptoms - but perhaps one will. Is that acceptable risk? - How much lead is leeched into the water from a joint? Over what time frame? How much variation is there, based on the skill of a plumber? Will _all_ joints of even a good plumber be good? What is the pipes are disturbed in some way? I guess one could ask chemists, maybe get a fluid engineer as well. There are of course places in the world where people live and raise children with (from our POV) horrendous levels of environmental contamination (such as the 'electronic graveyard' places in third-world countries). But here, the cost of removing lead wherever possible is a relatively small detriment economically; in the scheme of things a minor inconvenience. (I for one prefer PEX pipes over copper anyways!) I think that eventually everyone will be as familiar with lead-free solder on circuit boards as "we" are with the older stuff. And wonder what the fuss was all about. Joe. -- Joachim Thiemann :: http://www.tsp.ece.mcgill.ca/~jthiem

Such pipes are not uncommon in the UK... I 've been using leaded solder and drinking water from pipes with lead solder joints (if not full elad pipes) for most of my life. I am still here. Not yet (but please don't give them ideas, I happen to like old stainded glass windows). On the other heand they did try to ban the use of lead alloys for organ pipes in orgnas with electronic action (on the grounds that this was then an electronic device and came under the RoHS directive). As somebody said 'Can you give one instance of somebody being poisoned by a church organ'. -tony

I haven't done a lot or research on this... so I may be wrong... but I think I've experienced the woes of (at least first generation) laptops built to RoHS standards. We have a number of Dell laptops at work... we started out (unfortunately) with Inspiron 5100s, and when I came on board, I standardized on Latitudes (D500, a couple of D505, and D600). When those were no longer available we moved to D610s. Then onto D520s, then D530s. We don't have a current standard now.... As best as I know (which is the "I may be wrong" part above), the D500, D505, and D610 used regular lead solder. The D610 is RoHS (again, I may be wrong, but this is what I recall from back when we purchased these eons ago). The failure rate in the Inspirons was't to be proud of.... but that was due to a chassis with too much flex and screws would come loose and short out the mainboard. The failure rate in the Latitude D500s was zero, as with the D505s. We had one D600 that I retired to being flaky that seemed to originate with the mainboard or CPU, that at the time it was old enough not to merit more investment of time. Other than that, no D600s have failed (and I still use one daily at work). The D610s however.... I've got 2-3 flaky units, another unit that I retired due to broken solder joints on a connector on the mainboard, and one dead one that I don't recall what went wrong now. That is like 5 dead machines.... around 500% more than the D500/505/D600 series units ... The D520s/D530s haven't failed yet... but they aren't as old as the D610s yet so we'll see in another year or so..... W/o researching to verify, I attributed this to the lead free solder. It being more brittle I think has lead to breaking of connections due to mechanical and thermal stresses over time. I only hope they improved over time, as I have many systems and a laptop that I personally own that I don't want to die due to brittle solder joints or tin wiskers.... grrr.... Anyone feel free to correct me if I'm wrong on the lead/lead free solder changover at the D500/505/600 to D610 line in the Latitudes.... I have not researched it to verify the hypothesis and am simply going by memory. (which I've learned sometimes can be hazardous :-) ) -- Curt dwight elvey wrote:

I work in the communications industry, and most of the radio products made now are RoHS. Many of the troubles I see in equipment made in last few years are solder related: Improper re-flow, insufficeint solder, cracked joints, etc. The problem with the whole RoHS thing is that the typical solder formulation (60/40 tin/lead, for example) was chosen because it's formulation was optimal for the job. The stuff they have to use now obviously isn't. We'll have a clean environment, but crappy electronic products.

No. The little solder ball blob (the B in BGA) is there specifically to act as a cantilever to absorb stresses. IBM figured this out when they pioneered the technology in the 1960s. Without the tiny amount of give that the ball gives, failures would be so frequent that the devices would be useless, especially in today's world of relatively high power, small outline devices that are constantly going to sleep and waking up. PCBs? They have pretty much been out of the picture for a long time. Scrap plastic cases are now a resource - in China, scrap plastic is currently worth more than scrap steel. For all the pissing and moaning about RoHS solder, the reliability numbers really do not show a sky-is-falling disaster. If it did, world economies would be collapsing. Chill... -- Will

On 10 Apr 2010 at 17:57, William Donzelli wrote: Well, yes and no. The web (and IEEE's transactions on semicondutor packaging) is littered with papers comparing eutectic Sn-Pb solder with RoHS lead free and the results seem to be in favor of leaded solder. In particular, Pb-free solder seems to exhibit some brittleness that Pb solders do not. For example, here's a paper comparing shock (drop) tests: http://www.europeanleadfree.net/SiTE/UPLOAD/DOCUMENT/Projects/Drop_Tes t_Failure_Analysis_of_BgA_Packages.pdf It's not as if we can compare 70's era IBM BGAs with today's material, either. Today's BGAs tend to be larger and dissipate more power. When done badly, as in the Xbox "Red Ring of Death", failure results. When done well with careful design, RoHS BGA work is probably quite durable. --Chuck

----- Original Message ----- From: "Philip Pemberton" <classiccmp at philpem.me.uk> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Sent: Sunday, April 11, 2010 2:03 AM Subject: Re: RoHS nonsense, was: Desoldering Chips, was Re: Can someone, Whilst that is all true, alot of dust gets inside the games console, and the fan sometimes fails making the problem worse. There are mods that people do to help with the heat problem and keep the chips seated. After all, it is essentially a PC in a consoles shell. Regards, Andrew B aliensrcooluk at yahoo.co.uk

N0body H0me wrote: The screwed up thing with this mentality is that, if a machine is worth saving, it won't wind up in a landfill, therefore the lead will never get a chance to leech into the water. Of course this doesn't apply to everything, but the whole idea disposable electronics is bad from the start. Perhaps this is just another "advantage" to the manufacturers towards electronics that we're meant to discard after a year or so. A lot of stuff has unnecessarily incompatible custom plugs, power supplies with ROMs inside of them designed so the device refuses third party chargers, non-user replaceable batteries that last around a year, cheap materials used for their cases and displays that easily scratch, and the guarantee of a yearly newer model sporting more flash memory, also non-user upgradeable. :-( Not to mention the rent seeking closed operating systems and custom "stores" from which you can only buy approved apps. There'd be exponentially far less damage to the environment if these shiny e-turds were instead built to last, upgradeable, and built open standards. Even if leaded solder was used.

dwight elvey wrote: I'm most certainly dreading that. I have 3 G4 towers, a G4 mini, a G3 imac and an emac. :( I'd like to keep these boxes alive. So far the only dead machines I've had were due to bulging caps. These were older P3/Celeron x86 boxes that I didn't care to bother fixing the caps on. But the G4's are a lot more interesting and useful to me.