SMD removal.
SMD removal.
(OP)
Check this out...
It is supposed to ease SMD component removal/rework by use of a "magic" solution that causes the solder's melting point to plunge. !!
Has anyone tried this stuff? Does it actually work?
http://www.chipquikinc.com/
Keith Cress
Flamin Systems, Inc.- <http://www.flaminsystems.com>
It is supposed to ease SMD component removal/rework by use of a "magic" solution that causes the solder's melting point to plunge. !!
Has anyone tried this stuff? Does it actually work?
http://www.chipquikinc.com/
Keith Cress
Flamin Systems, Inc.- <http://www.flaminsystems.com>





RE: SMD removal.
Dan
Owner
http://www.Hi-TecDesigns.com
RE: SMD removal.
And what happens to all the neighboring parts with this stuff slopped on them?
Keith Cress
Flamin Systems, Inc.- <http://www.flaminsystems.com>
RE: SMD removal.
"Chip Quik consists of a low temperature removal alloy in wire form with excellent wetting ability that melts at 136°F (58°C)."
Common Fusible/Low Melting Alloys usually contain bismuth, lead, tin, cadmium or indium. Some eutectic alloys and their m.p.'s (omitted any with Cd or Pb):
In66.3Bi33.7 72oC
Bi57In26Sn17 79oC
In52.2Sn46Zn1.8 108oC
Adding Gallium, m.p. 30oC will further lower the alloy m.p.
Perhaps someone who removes SMD's can buy the stuff, or get a free sample as offered on the website, and report the Patent No. and any MSDS info re composition.
RE: SMD removal.
I guess that's what's bothering me. You have a solid material that melts at 400C.. I don't see why a material that melts at 58C would affect the high MP material WHATSOEVER. That's like saying put this molten lead against this steel bar and the steel will now melt at 400C. I don't understand. I can easily see that mixing the various alloys while they are both in liquid form would lower the MP of the final alloy.
Keith Cress
Flamin Systems, Inc.- <http://www.flaminsystems.com>
RE: SMD removal.
I too have wondered about the melting point. From what I remember from materials and chemistry: with heat applied the material will rise in temperature until the melting point is hit and it begins to melt. Once all of it has melted, the temperature can begin to rise again until the boiling point is reached. So, even though it melts at a low temperature, it can be heated up enough to melt solder. It probably also has a very high thermal mass and high conductivity, meaning it stays hot so that solder that it is in contact with melts and stays melted long enough to remove the device.
RE: SMD removal.
RE: SMD removal.
I'm open to corrections if I missed a day at class.
RE: SMD removal.
Think of putting salt on the road in winter.
Water melts at 32 degrees F.
Salt melts at some very high temperature.
Salt water melts at 0 degrees F.
Jim
RE: SMD removal.
I understand that totally. But in that case applying NaCl a dis-solvable solid onto snow.. Hmmmm on a microscopic level... The snow is solid water... What if you have 5F snow and throw 3F salt on it, does the snow still melt? How/why does the snow melt enough to allow the NaCl to start dissolving. Now you've gone and caused me more perplexity!! If this can be explained then I guess the chipquik can be.
I was rather thinking that you were flat going to have to heat every speck of existing solder up to its original temperature at least briefly enough for it to liquefy thereby allowing the alloying to be changed albeit quickly. If this supposition is correct their "remove parts at 300F" would seem misleading, as in the solder will remain liquid at lower temperatures once its melting point has been altered.
Keith Cress
Flamin Systems, Inc.- <http://www.flaminsystems.com>
RE: SMD removal.
In that regard, this makes sense to me for removal. But as I mentioned before, you would have to clean the board quite thoroughly to prevent the next solder attempt to continue creating more alloy (and killing off any industrial/military spec for the board).
Potentially useful, with care...
Dan
Owner
http://www.Hi-TecDesigns.com
RE: SMD removal.
When the highways department uses salt it is often colder than the snow. In many ares the salt is stored in open front sheds.
It will eventually be at the ambient temperature. When snow is forming, both the latent heat of vaporization and the latent heat of fusion are released into the atmosphere. It is fairly common for the temperature to rise when it is snowing. A snow storm is often the end of a cold spell. At this point the snow is probably warmer than the salt.
respectfully
RE: SMD removal.
The alloy absorbing the tin-lead? Maybe. When a part is soldered to an ENIG board, the gold just gets dissolved into the solder, even though the gold has a higher melting point than tin-lead. So maybe that the same thing happens here.
Using a syringe of solder paste to resolder a new part? Yeuk.
The process of cleaning the pads and reapplying the new solder can be more time consuming than just replacing the part the old fashioned way.
RE: SMD removal.
You don't need to melt salt to get it to dissolve in water.
- or am I missing the point?
A.
RE: SMD removal.
Zeusfaber.... You might be onto something there. I hadn't thought of that! Nice comparison. I certainly don't think of a metal dissolving into a liquid. I haven't seen any re-bar dissolving in the rain but that is just the common experience. Nice.
Keith Cress
Flamin Systems, Inc.- <http://www.flaminsystems.com>
RE: SMD removal.
RE: SMD removal.
I guess I never heard the name of the process. lolo
Keith Cress
Flamin Systems, Inc.- <http://www.flaminsystems.com>
RE: SMD removal.
Noway2, did you get an MSDS with the composition, or a Patent No.?
felixc, of course the concerns about contamination are real – you don't want an extremely low melting solder that melts or creeps during use!
A recent article “High-strength and High-fatigue-resistant Lead-free Solder” based upon the Sn/Cu/In/Ga system includes some metallurgy; note the Ga-In phase diagram. Within a certain alloy range, increasing In content lowered mp by 2oC per 1%In, and adding 0.5%Ga lowered the mp by 2.5oC. ht
A very low melting quaternary eutectic is Indalloy® 46L, 61Ga-25In-13Sn-1Zn, an alloy with mp 7-8oC, developed to replace mercury in liquid switches. http
The recent 2006 TMS Annual Meeting's Symposium on “Lead Free Solder Implementation: Reliability, Alloy Development, and New Technology” included a paper “Thermodynamic Models for the Bi-Ga-In-Sn-Zn Lead-Free System.” (They studied addition of Ga to the Bi-In-Sn-Zn system). http://
John R. Barnes' website “Designing Lead-Free, RoHS-Compliant, and WEEE-Compliant Electronics,” with lots of information on elements and solder alloys, regulations in Europe, California, China and elsewhere, and lots of links, seems very useful: http://www.dbicorporation.com/rohs.htm
RE: SMD removal.
Can you shed any descriptive light on the molecular action that takes place allowing 300C solid to melt in the presence of a eutectic mate at only 150C before they have been combined?
Keith Cress
Flamin Systems, Inc.- <http://www.flaminsystems.com>
RE: SMD removal.
This is similar to ladle metallurgy: Small pieces of (sometimes higher mp.) alloying element, usually as a 'master alloy' rather than elemental, are added to the melt prior to pouring the casting(s). The addition dissolves rather than melts, e.g., Si into Al(l) as an extreme case (done perhaps 400-500 C below the Si mp).
RE: SMD removal.
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com