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2003-08-29 by mumin55555
hallo again! i read your answers, thanks a lot. but here, in israel there are almost no electronics stors, and the ones existing, do not have a lot of stuff. so what is flux? is "electronics solder" is the same as "solder paste" that i can get here?
2003-08-29 by Stefan Trethan
On Fri, 29 Aug 2003 13:12:32 -0000, mumin55555 <MUMIN55555@...> wrote: > hallo again! > i read your answers, thanks a lot. but here, in israel there are almost > no electronics stors, and the ones existing, do not have a lot of stuff. > so what is flux? is "electronics solder" is the same as "solder paste" > that i can get here? solder paste may be the stuff for plumbing etc. which corrodes metal. you need colophony/resin flux. you should get it in chemicals shops. also any electronics shop should have rosin/flux core solder. this already has a core of flux and you don't need anything else for most things. you may too think about buying abroad (mail order) if there is no other way. but i really think there are suppliers. maybe you can find a company which does repair / design of electronics with google in your country and ask them where they get their stuff. the smaller the company the better (bigger ones have connections to other countries and can import more easily). i am relatively sure there are sorces in your country which you only need to find. are there no mail order electronics suppliers where you are? st
> > > > Be sure to visit the group home and check for new Bookmarks and files: > http://groups.yahoo.com/group/Homebrew_PCBs > > To unsubscribe from this group, send an email to: > Homebrew_PCBs-unsubscribe@yahoogroups.com > > > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ > > >
2003-08-30 by JanRwl@AOL.COM
In a message dated 8/29/2003 8:14:12 AM Central Standard Time, MUMIN55555@HOTMAIL.COM writes: > i read your answers, thanks a lot. but here, in israel there are > almost no electronics stors, and the ones existing, do not have a > lot of stuff. so what is flux? is "electronics > solder" is the same as "solder paste" that i can get here? > Surely in Israel, "electronic solder" is readily available if you know how to FIND it! That little country is "High Tech"! "Flux" is the substance that makes solder "take" well. In "electronic solder" it is usually a "core" in the solder-wire itself, and is usually a rosin-based gooey light-brown stuff that is non-corrosive when room-temperature. BUT, it becomes mildly acidic when heated, and makes the solder flow nicely on bright terminals. "Solder paste" is a dark brown CORROSIVE substance one might use for, say, roofing or plumbing with copper pipes. It should ALWAYS be wiped off with soap and water after soldering is done. Else, its residue will CORRODE the base-metal and at least make things UGLY. It has the consistency of "axle grease" at room-temperature (20-21° C). "Solder paste" should NOT be used for electrical stuff unless that is the ONLY way you can make a particular soldering-job work, and in THAT case, it must be washed off CAREFULLY, immediately after use. The "acid" in "acid-core" solder is the flux for that kind of solder. It is very corrosive, and should be used ONLY for very difficult metals to solder, and VERY CAREFULLY washed off after cooling! Lotsa luck! Jan Rowland [Non-text portions of this message have been removed]
2003-08-30 by Leon Heller
----- Original Message -----
From: "mumin55555" <MUMIN55555@...> To: <Homebrew_PCBs@yahoogroups.com> Sent: Friday, August 29, 2003 2:12 PM Subject: [Homebrew_PCBs] but is "soldering paste" ok to use? > hallo again! > i read your answers, thanks a lot. but here, in israel there are > almost no electronics stors, and the ones existing, do not have a > lot of stuff. so what is flux? is "electronics > solder" is the same as "solder paste" that i can get here? Electronic solder is like wire (made from a tin/lead alloy- usually 60% tin and 40% lead) with a flux (typically resin) core. The flux core melts with the solder when the soldering iron is applied and cleans the metal of oxides etc. helping the solder to flow properly and wet the parts to be joined. Resin flux leaves a residue which can look a bit messy. It may be removed by scrubbing with a brush and solvent, like iso-propyl alcohol. You can also get 'low-residue' solder which uses a different flux, which mostly evaporates when soldering, and doesn't need cleaning. It doesn't work as well as resin, in my experience. Solder paste consists of solder powder mixed with flux and is applied to PCBs when assembling surface mount components. Leon -- Leon Heller, G1HSM leon_heller@... http://www.geocities.com/leon_heller
2003-08-30 by Stefan Trethan
On Sat, 30 Aug 2003 08:34:08 +0100, Leon Heller <leon_heller@...> wrote: > > ----- Original Message ----- From: "mumin55555" <MUMIN55555@...> > To: <Homebrew_PCBs@yahoogroups.com> > Sent: Friday, August 29, 2003 2:12 PM > Subject: [Homebrew_PCBs] but is "soldering paste" ok to use? > > >> hallo again! >> i read your answers, thanks a lot. but here, in israel there are >> almost no electronics stors, and the ones existing, do not have a >> lot of stuff. so what is flux? is "electronics >> solder" is the same as "solder paste" that i can get here? > > Electronic solder is like wire (made from a tin/lead alloy-usually 60% > tin > and 40% lead) with a flux (typically resin) core. The flux core melts > with > the solder when the soldering iron is applied and cleans the metal of > oxides > etc. helping the solder to flow properly and wet the parts to be joined. > Resin flux leaves a residue which can look a bit messy. It may be removed > by > scrubbing with a brush and solvent, like iso-propyl alcohol. You can also > get 'low-residue' solder which uses a different flux, which mostly > evaporates when soldering, and doesn't need cleaning. It doesn't work as > well as resin, in my experience. > > Solder paste consists of solder powder mixed with flux and is applied to > PCBs when assembling surface mount components. > > Leon > -- > Leon Heller, G1HSM > leon_heller@... > http://www.geocities.com/leon_heller but washing of proper flux (colophony) is only for making it look better. it doesn't corrode the metals and it is not conductive (at least with non- critical circuits). maybe when doing hf work of very sensitive high impedance circuits wash it off. most time when i make boards only for me i don't wash it of. too lazy. it may be a good idea to test the circuit before cleaning it. (to avoid recleaning). i have also seen big differences in flux used. sometimes it makes a real mess, dark brown stuff everywhere, sometimes it is not darker than the pcb. this depends of soldering speed, flux type used in the wire, amount of flux, and also it depends very of the iron temperature. if it is too hot you get darker (more burnt) flux residue. if i make a nice clean circuit on a fresh pcb with new components there is not too much mess. if you solder it quick and have the right temperature is doesn't get ugly. but when doing repairs (desoldering components, solder another in again etc.) most time it needs cleaning afterwards. i think the flux residue is no disadvantage. it prevents corrosion and helps when you need to get the part out of the pcb again... i hope you find a supplier for what you need. Austria is a small country too but within the EU i can get things easy. most time from germany if i can't find them here. but there are plenty of mail order companies and even some small stores in big cities which carry these things. st
> > > Be sure to visit the group home and check for new Bookmarks and files: > http://groups.yahoo.com/group/Homebrew_PCBs > > To unsubscribe from this group, send an email to: > Homebrew_PCBs-unsubscribe@yahoogroups.com > > > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ > > >
2003-08-30 by JanRwl@AOL.COM
In a message dated 8/30/2003 2:36:12 AM Central Standard Time, leon_heller@... writes: > Solder paste consists of solder powder mixed with flux and is applied to > PCBs when assembling surface mount components. > Now, THIS is NEW! SMT has caused "invention" of some new preparations, and, yes, probably the word "paste" has been newly adopted to describe solder/flux "powder" mixes which are "blobbed on" where a joint is to be made when EVERYTHING is heated, as is done in SMT work. HOWEVER, the original inquiry here was using the OLD term, "solder paste" which is a kind of FLUX which is very effective for roofing copper, galvanized duct-work, and plumbing copper, but it is CORROSIVE if not washed off, once soldering is done! Jan Rowland [Non-text portions of this message have been removed]
2003-08-31 by Stuart Winsor
In article <22.3d3bf382.2c819b2e@...>, <JanRwl@...> wrote: > "Solder paste" is a dark brown CORROSIVE substance one might use for, > say, roofing or plumbing with copper pipes. Perhaps it should be mentioned that there are solder pastes specifically for electronic work. See the example given. http://uk.farnell.com/jsp/search/searchresultstwo.jsp?action=0&ImgDisp=Y&QText=Solder+paste>> If you go to that company's home page there seem to be lot of options for selecting your country so maybe you can buy from them. For all my work I now use "Low mwlting point solder" also available from the above, who are a major supplier of electronic components of all sorts. Interestingly they have a kit for a CNC PCB drill that is made of wood! Stuart. No connection with the above company other than as a satisfied customer. -- __ __ __ __ __ ___ _____________________________________________ |__||__)/ __/ \|\ ||_ | / | || \\__/\__/| \||__ | /...Internet access for all Acorn RISC machines ___________________________/ stuartwinsor@... 101 uses for a Pentium: No1 - A slow cooker.
2003-08-31 by kok@surfbest.net
There is perhaps some confusion about what the term \ufffdsolder(ing) paste\ufffd means. \ufffdSolder paste\ufffd is solder powder in a paste form, generally including some flux. It is used for mounting surface-mount parts onto PC boards. Ideally it is thixotropic which means it doesn\ufffdt flow when the pressure applied to it (such as from gravity) is below a certain threshold. It is also sticky, so it holds SMT parts onto the PCB before the parts are heated to melt the paste and create a solder joint. \ufffdSolderING paste\ufffd generally refers to a type of flux, and doesn\ufffdt contain solder powder. Flux: 5 : a substance used to promote fusion (as of metals or minerals); especially : one (as rosin) applied to surfaces to be joined by soldering, brazing, or welding to clean and free them from oxide and promote their union (definition from m-w.com) There are many types of flux, some more corrosive than others. Acid flux is definitely to be avoided for electronics work. I have used sal ammoniac paste (ammonium chloride in petroleum grease, brown colored stuff) for electronics tinkering in high school. I don\ufffdt recall it being very corrosive. However, there are better types of flux available for electronics use, so I don\ufffdt recommend the sal ammoniac paste, either. Rosin (resin from pine trees) is the traditional flux used for electronics work. There is also water-soluable flux available, however this should be washed off within a few hours of use. See http://www.kester.com/faq_ts.html and http://www.kester.com/flux.html . Recommendations: use rosin core solder for general electronic use. Use rosin core solder or solder paste for surface mount parts. Bare copper oxidizes and becomes hard to solder. To improve solderability, - solder your parts to the board soon after the board is made and cleaned - dip the PCB in etchant for a few seconds and then rinse thoroughly to brighten up the copper before stuffing parts and soldering - clean the copper with an abrasive cleaning pad (some people on this list have warned against using steel wool because it leaves iron particles in the copper which then rust) - if you use photosensitive boards, leave the photosensitive mask on until you want to solder to the board. Some people have reported that photosensitive mask material can be left on the board, and need not be removed before soldering. - Tin plate the board immediately after etching, using for example Tinnit electroless tin plating solution: http://jameco.com/cgi-bin/ncommerce3/ExecMacro/jameco/searchResult.d2w/report?sort=BKW&search=tinnit - Apply rosin-based flux to the areas to be soldered. I\ufffdve avoided that because it would be a hassle to clean up, or would be messy if left on the board. Cheers, - Jan
-----Original Message----- From: Stuart Winsor [mailto:stuartwinsor@...] Sent: Sunday, August 31, 2003 7:23 AM To: Homebrew_PCBs@yahoogroups.com Subject: Re: [Homebrew_PCBs] but is "soldering paste" ok to use? In article <22.3d3bf382.2c819b2e@...>, <JanRwl@...> wrote: > "Solder paste" is a dark brown CORROSIVE substance one might use for, > say, roofing or plumbing with copper pipes. Perhaps it should be mentioned that there are solder pastes specifically for electronic work. See the example given. http://uk.farnell.com/jsp/search/searchresultstwo.jsp?action=0&ImgDisp=Y&QText=Solder+paste>> If you go to that company's home page there seem to be lot of options for selecting your country so maybe you can buy from them. For all my work I now use "Low mwlting point solder" also available from the above, who are a major supplier of electronic components of all sorts. Interestingly they have a kit for a CNC PCB drill that is made of wood! Stuart. No connection with the above company other than as a satisfied customer. -- __ __ __ __ __ ___ _____________________________________________ |__||__)/ __/ \|\ ||_ | / | || \\__/\__/| \||__ | /...Internet access for all Acorn RISC machines ___________________________/ stuartwinsor@... 101 uses for a Pentium: No1 - A slow cooker.