Post by thread:[EE]: SMT Toaster Oven

Hi- Are you aware of the Easy-Bake egroup at http://au.egroups.com/group/E-Z_Bake ? Kind of quite now, but plans were to dedign a controller with temperature control to do this. Do you have any pictures of the results? David Roman Black wrote: {Quote hidden}> Hi Guys, we have successfully done a few boards > now with SMT PIC chips in a cheap toaster oven, > they are coming out quite good. > > Many thanks to Alexandre who sent me a temperature > vs time chart, and helpful "expert" tips. > > Just letting you know you can get a pretty good > result with a $35 US (second hand) toaster oven > and a stopwatch, and good solder paste of course. > > Each run it seems to be getting a bit better. > :o) > -Roman > > -- > http://www.piclist.com hint: PICList Posts must start with ONE topic: > [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

Hi David, I didn't see the group but had checked out a couple of amatuer SMT pages on the web. You really don't need a special controller, I just preheat the oven to about 150'C, put the boards in, wait 2 minutes, then turn the oven up full and watch the stopwatch. Works every time, just takes a little practice getting the boards placed well over the elements for even heating. I can take a picture and post it up if you like. :o) -Roman David Harris wrote: {Quote hidden}> > Hi- > Are you aware of the Easy-Bake egroup at > http://au.egroups.com/group/E-Z_Bake ? Kind of quite now, but plans were > to dedign a controller with temperature control to do this. Do you have > any pictures of the results? > David > > Roman Black wrote: > > > Hi Guys, we have successfully done a few boards > > now with SMT PIC chips in a cheap toaster oven, > > they are coming out quite good. > > > > Many thanks to Alexandre who sent me a temperature > > vs time chart, and helpful "expert" tips. > > > > Just letting you know you can get a pretty good > > result with a $35 US (second hand) toaster oven > > and a stopwatch, and good solder paste of course. > > > > Each run it seems to be getting a bit better. -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

>Hi Guys, we have successfully done a few boards >now with SMT PIC chips in a cheap toaster oven, >they are coming out quite good. >Just letting you know you can get a pretty good >result with a $35 US (second hand) toaster oven >and a stopwatch, and good solder paste of course. >Each run it seems to be getting a bit better. It's really nice, so bad we CAN'T find the proper solder in paste here in Brazil... :~( ---8<---Corte aqui---8<---- Alexandre Souza spam_OUTtaitoTakeThisOuTterra.com.br http://planeta.terra.com.br/lazer/pinball/ ---8<---Corte aqui---8<---- -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

How long do you cook it at full temp? ----- Original Message ----- From: "Roman Black" <.....fastvidKILLspam@spam@EZY.NET.AU> To: <PICLISTKILLspamMITVMA.MIT.EDU> Sent: Sunday, July 01, 2001 11:22 Subject: Re: [EE]: SMT Toaster Oven {Quote hidden}> Hi David, I didn't see the group but had checked > out a couple of amatuer SMT pages on the web. > > You really don't need a special controller, I > just preheat the oven to about 150'C, put the > boards in, wait 2 minutes, then turn the oven up > full and watch the stopwatch. Works every time, > just takes a little practice getting the boards > placed well over the elements for even heating. > > I can take a picture and post it up if you like. > :o) > -Roman > > > David Harris wrote: > > > > Hi- > > Are you aware of the Easy-Bake egroup at > > http://au.egroups.com/group/E-Z_Bake ? Kind of quite now, but plans were {Quote hidden}> > to dedign a controller with temperature control to do this. Do you have > > any pictures of the results? > > David > > > > Roman Black wrote: > > > > > Hi Guys, we have successfully done a few boards > > > now with SMT PIC chips in a cheap toaster oven, > > > they are coming out quite good. > > > > > > Many thanks to Alexandre who sent me a temperature > > > vs time chart, and helpful "expert" tips. > > > > > > Just letting you know you can get a pretty good > > > result with a $35 US (second hand) toaster oven > > > and a stopwatch, and good solder paste of course. > > > > > > Each run it seems to be getting a bit better. > > -- > http://www.piclist.com hint: PICList Posts must start with ONE topic: > [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads > > > -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

Roman wrote: >You really don't need a special controller, I >just preheat the oven to about 150'C, put the >boards in, wait 2 minutes, then turn the oven up >full and watch the stopwatch. Works every time, >just takes a little practice getting the boards >placed well over the elements for even heating. > >I can take a picture and post it up if you like. Roman, Are you kidding? You sure better post "everything" about this, otherwise someone will try to patent it out from under you. A toaster oven usually works by direct radiation. What temperature do you suppose the surface of the pcb gets up to? And is this allowable, regards the specs for the chips? And how does this compare to commercial smt cookers? - dan ============== -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

> Are you kidding? You sure better post "everything" about > this, otherwise someone will try to patent it out from > under you. > > A toaster oven usually works by direct radiation. What > temperature do you suppose the surface of the pcb gets up > to? And is this allowable, regards the specs for the chips? > And how does this compare to commercial smt cookers? I use a toaster oven too. I used to use a hot air gun and the results were pretty good but required a lot of operator skill and attention. Very easy to stuff it up. Then I tried experimenting with a pop-up toaster on its side, working on the theory that the smaller air volume would be better for control. The theory was OK but implementing it with a mass produced product wasn't all that practical. Because of the volume thing, I wasn't too sure how the toaster oven would go. I bought a fan forced toaster oven and after a bit of experimentation, found that putting the boards on the mica element formers from the previous toaster experiments was perfect as it forms a bit of a barrier between the top and bottom halves of the oven. I played around a bit with shelf height to get good even heat coverage. My procedure is also manual at this stage but it will be simple to automate as soon as I get time. I use a single thermocouple (as I know from experiments that it is representative) and the temp meter I use has time on the display. Put the boards in the oven. Set temp to max, top & bottom elements and fan on. When temp reads about 5 degrees below preheat, turn everything off. (the 5 degrees compenstates for the system lag so the temp will reach the setpoint and hold steady for around 30 sec). Wait the preheat period. Select grill and max temp. No fan. When temp reaches 200 degrees, turn off. The board temp will peak at 210-215 and drop off. At about 190 (solder solid again), turn the fan on with no elements (mixes in the slightly cooler air from below). I open the door a little at 160 degrees and fully at about 100 degrees. If I plot the temp and time it's almost exactly on the line provided by the solder manufacturer. The whole cycle is about 5 minutes from board in to board out and yield so far has been no failures in about 75 board/panels. Steve. ====================================================== Steve Baldwin Electronic Product Design TLA Microsystems Ltd Microcontroller Specialists PO Box 15-680, New Lynn http://www.tla.co.nz Auckland, New Zealand ph +64 9 820-2221 email: .....stevebKILLspam.....tla.co.nz fax +64 9 820-1929 ====================================================== -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

Has anyone thought of making something like what the pizza delivery places use? Put the board on a conveyer on one side, it goes through the oven at a set rate and comes out the other side nicely baked. Seems like it would be great for production work. Steve Baldwin wrote: {Quote hidden}> > > Are you kidding? You sure better post "everything" about > > this, otherwise someone will try to patent it out from > > under you. > > > > A toaster oven usually works by direct radiation. What > > temperature do you suppose the surface of the pcb gets up > > to? And is this allowable, regards the specs for the chips? > > And how does this compare to commercial smt cookers? > > I use a toaster oven too. I used to use a hot air gun and the results > were pretty good but required a lot of operator skill and attention. > Very easy to stuff it up. Then I tried experimenting with a pop-up > toaster on its side, working on the theory that the smaller air > volume would be better for control. The theory was OK but > implementing it with a mass produced product wasn't all that > practical. Because of the volume thing, I wasn't too sure how the > toaster oven would go. > > I bought a fan forced toaster oven and after a bit of experimentation, > found that putting the boards on the mica element formers from the > previous toaster experiments was perfect as it forms a bit of a > barrier between the top and bottom halves of the oven. I played > around a bit with shelf height to get good even heat coverage. > > My procedure is also manual at this stage but it will be simple to > automate as soon as I get time. > I use a single thermocouple (as I know from experiments that it is > representative) and the temp meter I use has time on the display. > Put the boards in the oven. > Set temp to max, top & bottom elements and fan on. > When temp reads about 5 degrees below preheat, turn everything > off. (the 5 degrees compenstates for the system lag so the temp > will reach the setpoint and hold steady for around 30 sec). > Wait the preheat period. > Select grill and max temp. No fan. > When temp reaches 200 degrees, turn off. > The board temp will peak at 210-215 and drop off. > At about 190 (solder solid again), turn the fan on with no elements > (mixes in the slightly cooler air from below). > I open the door a little at 160 degrees and fully at about 100 > degrees. > > If I plot the temp and time it's almost exactly on the line provided > by the solder manufacturer. The whole cycle is about 5 minutes > from board in to board out and yield so far has been no failures in > about 75 board/panels. > > Steve. > > ====================================================== > Steve Baldwin Electronic Product Design > TLA Microsystems Ltd Microcontroller Specialists > PO Box 15-680, New Lynn http://www.tla.co.nz > Auckland, New Zealand ph +64 9 820-2221 > email: EraseMEstevebspam_OUTTakeThisOuTtla.co.nz fax +64 9 820-1929 > ====================================================== > > -- > http://www.piclist.com hint: PICList Posts must start with ONE topic: > [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

At 07:27 PM 7/1/01 -0400, Brandon Fosdick wrote: >Has anyone thought of making something like what the pizza delivery >places use? Put the board on a conveyer on one side, it goes through the >oven at a set rate and comes out the other side nicely baked. Seems like >it would be great for production work. It wouldn't be any huge deal to set up, the hard part would be to fab the belt. Steppers would control the rate through, and you could control the temperature profile as well. BTW: I started the easy-bake group :) -- Dave's Engineering Page: http://www.dvanhorn.org I would have a link to http://www.findu.com/cgi-bin/find.cgi?KC6ETE-9 here in my signature line, but due to the inability of sysadmins at TELOCITY to differentiate a signature line from the text of an email, I am forbidden to have it. -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

> At 07:27 PM 7/1/01 -0400, Brandon Fosdick wrote: > >Has anyone thought of making something like what the pizza delivery > >places use? Put the board on a conveyer on one side, it goes through the > >oven at a set rate and comes out the other side nicely baked. Seems like > >it would be great for production work. > > It wouldn't be any huge deal to set up, the hard part would be to fab the belt. Go to a Quizno's and check out their setup. I think they use a flexible wire rack. They drop a sandwich on one side and it travels thru the oven and comes out the other. > Steppers would control the rate through, and you could control the > temperature profile as well. > > BTW: I started the easy-bake group :) > > -- > Dave's Engineering Page: http://www.dvanhorn.org -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

Hi Fritz, i'm still learning here and that is one thing i'm playing with. It depends on the distance the boards are placed above the elements, and how many boards are in there. And obviously the element power. Currently I have the boards about 25mm above the element, it goes like this: * preheat oven to 150'C * insert boards, preheat for 2 to 3 minutes * turn oven up full (check stopwatch) * takes about 35 seconds for solder paste to melt * give it about 15 seconds after that * open door and gently slide rack out The results are reasonably good, but more importantly they are predictable each time. On the 28pin PIC there were maybe 2 legs dry and 2 legs bridged, I found by increasing the solder paste amount I now get no drys and maybe 2 or 3 bridged. All of the joints are excellent (I use 30x microscope) and removing a couple of bridges per board takes a few seconds manually with an iron and wick. It's good enough for small production now, and as I refine it it's getting better. I use a 19 gauge needle on the paste syringe, ground flat and only 10mm of needle length. I just need to practice laying down the correct amount of paste, each run it gets easier. I welcome any suggestions, and as usual I will probably end up putting my procedure and pictures on my web page. :o) -Roman Fritz Braun Jr. wrote: > > How long do you cook it at full temp? > > {Original Message removed}

David VanHorn wrote: > > At 07:27 PM 7/1/01 -0400, Brandon Fosdick wrote: > >Has anyone thought of making something like what the pizza delivery > >places use? Put the board on a conveyer on one side, it goes through the > >oven at a set rate and comes out the other side nicely baked. Seems like > >it would be great for production work. > > It wouldn't be any huge deal to set up, the hard part would be to fab the belt. > Steppers would control the rate through, and you could control the > temperature profile as well. I fixed a wire belt conveyor oven, it was used by a printer for drying special inks on business cards. They usually shake a lot, not good for melted solder. What about a slowly rotating platter, ie a rotary motion instead of a linear motion?? Or even rotate the heating elements over a flat metal table?? That has a lot of possibilities. With a cheap toaster oven we can do 4 boards in about 5 minutes, which is fine, but a continuous production would be excellent. -Roman -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

Thanks Steve for the good info. The procedures are very similar, and hopefully Alexandre from Africa will post some of his info too? I don't use a thermocouple, but I first put a ceramic block in the oven at different locations and times and measured it's temp with my non-contact thermometer. Surface mount production is much more gentle than rework, the boards are treated very well. With my setup the oven just brings the solder to melt and is turned off a few seconds later. Since I know the max rate the oven can heat, this ensures the total board heating never gets over the safe amount. According to my non-contact thermometer, the max temp of the chips and board is LESS than normal soldering with my temp controlled weller iron. The solder joints are very bright and nicely wetted, microscope inspection shows they are very high qualty soldered. I use the 2% silver solder paste that Alexandre suggested. -Roman Steve Baldwin wrote: {Quote hidden}> > > Are you kidding? You sure better post "everything" about > > this, otherwise someone will try to patent it out from > > under you. > > > > A toaster oven usually works by direct radiation. What > > temperature do you suppose the surface of the pcb gets up > > to? And is this allowable, regards the specs for the chips? > > And how does this compare to commercial smt cookers? > > I use a toaster oven too. I used to use a hot air gun and the results > were pretty good but required a lot of operator skill and attention. > Very easy to stuff it up. Then I tried experimenting with a pop-up > toaster on its side, working on the theory that the smaller air > volume would be better for control. The theory was OK but > implementing it with a mass produced product wasn't all that > practical. Because of the volume thing, I wasn't too sure how the > toaster oven would go. > > I bought a fan forced toaster oven and after a bit of experimentation, > found that putting the boards on the mica element formers from the > previous toaster experiments was perfect as it forms a bit of a > barrier between the top and bottom halves of the oven. I played > around a bit with shelf height to get good even heat coverage. > > My procedure is also manual at this stage but it will be simple to > automate as soon as I get time. > I use a single thermocouple (as I know from experiments that it is > representative) and the temp meter I use has time on the display. > Put the boards in the oven. > Set temp to max, top & bottom elements and fan on. > When temp reads about 5 degrees below preheat, turn everything > off. (the 5 degrees compenstates for the system lag so the temp > will reach the setpoint and hold steady for around 30 sec). > Wait the preheat period. > Select grill and max temp. No fan. > When temp reaches 200 degrees, turn off. > The board temp will peak at 210-215 and drop off. > At about 190 (solder solid again), turn the fan on with no elements > (mixes in the slightly cooler air from below). > I open the door a little at 160 degrees and fully at about 100 > degrees. > > If I plot the temp and time it's almost exactly on the line provided > by the solder manufacturer. The whole cycle is about 5 minutes > from board in to board out and yield so far has been no failures in > about 75 board/panels. -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

> >What about a slowly rotating platter, ie a rotary >motion instead of a linear motion?? Or even rotate >the heating elements over a flat metal table?? >That has a lot of possibilities. With a cheap toaster >oven we can do 4 boards in about 5 minutes, which is >fine, but a continuous production would be excellent. >-Roman You know.. There is a home-type pizza baker that works this way. Hmm :) -- Dave's Engineering Page: http://www.dvanhorn.org I would have a link to http://www.findu.com/cgi-bin/find.cgi?KC6ETE-9 here in my signature line, but due to the inability of sysadmins at TELOCITY to differentiate a signature line from the text of an email, I am forbidden to have it. -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

>Has anyone thought of making something like what the pizza delivery >places use? Put the board on a conveyer on one side, it goes through the >oven at a set rate and comes out the other side nicely baked. Seems like >it would be great for production work. Wait a minute...these are real. They are called convection reflow ovens and the only difference is they are longer. You can have "zones" and a temperature profile (curve) as the board goes through. It's the kind of thing you need if you ever get into BGA chips. Now I know the idea works in reverse--I always suggested running pizzas through the thing...then I read somewhere that someone was doing that and they found that the residues had an effect on the solder joints when they went back to using it to do boards...oh, well. Barry -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

----- Original Message ----- From: Barry Gershenfeld <RemoveMEbarryTakeThisOuTZMICRO.COM> > Now I know the idea works in reverse--I always suggested running pizzas > through the thing...then I read somewhere that someone was doing > that and they found that the residues had an effect on the solder > joints when they went back to using it to do boards...oh, well. Hmmm... Pepperoni grease doesn't make a good fluxing agent? Maybe an enterprising sort could come up with a pepperoni that has a more compatible "organic flux", so the dream of a pizza shop by day/electronics production house at night could be a reality. :) Along a similar thought, there's a new business that opened across town that's a Laundromat + pub, called Suds and Duds. I could imagine some of the opening lines that go on in that bar. Stray animal pound + lunch meat company? -Dal -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

My dad was an engineer at Hughes Aircraft in the semiconductor division (did you know they had one?) and had to troubleshoot a number of problems. The worst one was when the metallic vapors that were deposited on the wafers stopped sticking to the surface. After much investigating, dad found out that the night crew was using the ovens to heat up their chicken, burritos, etc... and the microscopic volume of grease was plating onto the inside and then coating the wafers along with the metals during production. No metal vapor in the kitchen, no food in the clean room. James Newton, PICList Admin #3 spamBeGonejamesnewtonspamBeGonepiclist.com 1-619-652-0593 phone http://www.piclist.com {Original Message removed}

James Newton. Admin 3 wrote: > > My dad was an engineer at Hughes Aircraft in the semiconductor division (did > you know they had one?) and had to troubleshoot a number of problems. The > worst one was when the metallic vapors that were deposited on the wafers > stopped sticking to the surface. After much investigating, dad found out > that the night crew was using the ovens to heat up their chicken, burritos, > etc... and the microscopic volume of grease was plating onto the inside and > then coating the wafers along with the metals during production. > > No metal vapor in the kitchen, no food in the clean room. Ha ha! Now I know why PICs fail sometimes! Traces of Burrito in the die... ;o) -Roman -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

On Mon, 2 Jul 2001 17:59:03 +1000 Roman Black <TakeThisOuTfastvidEraseMEspam_OUTEZY.NET.AU> writes: > It's good enough for small production now, and > as I refine it it's getting better. I use a 19 gauge > needle on the paste syringe, ground flat and only > 10mm of needle length. I just need to practice > laying down the correct amount of paste, each run > it gets easier. Anyone having their board house silkscreen on the solder paste? I know there's an issue with the amount of time after paste placement before component placement. Can boards be refrigerated or something to extend this time? Harold FCC Rules Online at http://hallikainen.com/FccRules Lighting control for theatre and television at http://www.dovesystems.com ________________________________________________________________ GET INTERNET ACCESS FROM JUNO! Juno offers FREE or PREMIUM Internet access for less! Join Juno today! For your FREE software, visit: dl.http://www.juno.com/get/tagj. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

At 03:33 PM 7/5/01 -0500, you wrote: >You paid too much. My toaster ovens cost $35 new. Buy one online at >http://www.toastmaster.com > >[Shameless plug, toungue in cheek] I've seen some with (some kind of) electronic controls for around US$70, IIRC. LCD display. Best regards, =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= Spehro Pefhany --"it's the network..." "The Journey is the reward" RemoveMEspeffTakeThisOuTinterlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com Contributions invited->The AVR-gcc FAQ is at: http://www.bluecollarlinux.com =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= -- http://www.piclist.com hint: To leave the PICList piclist-unsubscribe-requestEraseME.....mitvma.mit.edu

At 04:00 PM 7/5/01 -0500, Lawrence Lile wrote: >They also fail to mention you can hack a standard Handi-Pan and use it to >make a nice bulk soldering pot. I did this for a dip-soldering "wave >solder" machine before I discovered SMT toaster ovens. You hold the board >with a pair of vice grips, and dunk the solder side into the molten solder, >holding it for 15 seconds and jiggling it a little. > ><Begin Legal Notice> >Do not try using a toaster oven for SMT soldering nor use a handi-pan for >melting bulk solder. Doing so voids your warrantee. Toastmaster does not >condone nor endorse such abuse of our products nor are we going to be >responsible when you dump molten solder in your lap. </Notice> I'd like to try that rotary pizza thing, but at $88 locally, it's a bit pricey. -- Dave's Engineering Page: http://www.dvanhorn.org I would have a link to http://www.findu.com/cgi-bin/find.cgi?KC6ETE-9 here in my signature line, but due to the inability of sysadmins at TELOCITY to differentiate a signature line from the text of an email, I am forbidden to have it. -- http://www.piclist.com hint: To leave the PICList EraseMEpiclist-unsubscribe-requestmitvma.mit.edu

Hi Lawrence, I just went and looked at your toaster oven products at: http://www.toastmaster.com Cool! Your other post to the list about the use of your toaster ovens voiding the warranty worries me. Surely using toaster ovens for SMT work is quite gentle and controlled, compared to most other kitchen type use?? And maybe if you could build a data set of temps and heating times you could sell a lot of toaster ovens for SMT use?? I'm just guessing that there is a waiting market of people ready to do home SMT if they could get an oven and data on how to use it. We have just started doing SMT, and it really is not that hard. People are scared of investing in hardware and trying something new and unproven. Maybe the first toaster oven maker that has the guts to approach this market will sell thousands of toaster ovens?? -Roman {Quote hidden}> Lawrence Lile wrote: > > > > You paid too much. My toaster ovens cost $35 new. Buy one online at > > http://www.toastmaster.com > > > > [Shameless plug, toungue in cheek] > > Umm, but mine is full stainless steel body, inside > and out, 4 elements, 2500 watts. New they cost about > $85 US. I thought $35 for a used one in top condition > was quite ok. >:o) > -Roman -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

Had'nt occurred to me, but 1500W toaster ovens are what you see here - 120V vs 240V mains? Something to keep in mind per the reflow times quoted, perhsps. Jack Roman Black wrote: {Quote hidden}> > Lawrence Lile wrote: > > > > You paid too much. My toaster ovens cost $35 new. Buy one online at > > http://www.toastmaster.com > > > > [Shameless plug, toungue in cheek] > > Umm, but mine is full stainless steel body, inside > and out, 4 elements, 2500 watts. New they cost about > $85 US. I thought $35 for a used one in top condition > was quite ok. -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

At 10:30 AM 7/6/01 -0500, Lawrence Lile wrote: >Ya, maybe. 1000 customers just gets a yawn from our marketing department >They pay no attention to products with less than a million pieces potential >sales. That's why we make George Foreman Grills instead of soldering >equipment. I just bought one of those. For food though. -- Dave's Engineering Page: http://www.dvanhorn.org I would have a link to http://www.findu.com/cgi-bin/find.cgi?KC6ETE-9 here in my signature line, but due to the inability of sysadmins at TELOCITY to differentiate a signature line from the text of an email, I am forbidden to have it. -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

Hi, Everyone > Hi Guys, we have successfully done a few boards > now with SMT PIC chips in a cheap toaster oven, > they are coming out quite good. > > Many thanks to Alexandre who sent me a temperature > vs time chart, and helpful "expert" tips. You are welcome Roman. I have been out for a while so I will post some details so that everyone can see that the crazy idea of soldering SMT on toaster ovens works quite nicely... I am doing about 500 boards a month with 200 '0805' components and one SOIC avr Cpu and have not problems at all. The oven is a small 800w toaster oven with infrared "burners". The temperature profile is controlled by a comercial temperature controller that can do 'ramps'. The full cycle for a board is 6 minutes because I prefer to start the temperature slowly and keep it for a while bellow the flux activation phase just to make sure the board temperature equalizes all over. We have produced more than 4000 boards and had no problems at all with the soldering procedure. I even have SMD components on BOTH SIDES of the board and solder them all at the same time. The tension of the solder paste keeps the components from falling down. I would never try to build a moving conveyor !! It would make things much harder to control. I got the temperature profile from my setup and it beats a 3 zone oven by much. It is almost as good as a 7 zone oven. You get many more problems when you move the boards. If you have big production needs just go and buy a big oven or have the boards made by someone else. I got some of my board analysed with xray and all is really fine... If you want to try the toaster oven go ahead, it works nicely.... Be carefull with the temperature profile, use 2% silver solder paste and use only evens that have mostly infrared heating. I could not get repeatable results without a nice temperature controller. If anyone have any questions I would be happy to help in all I can.. PS: I am not in Africa, Roman... I am down in Brazil. It seems that we have 2 brazilian Alexandres on the Piclist. Best regards, Alexandre Guimaraes RemoveMEalexgEraseMEEraseMEiis.com.br -- http://www.piclist.com hint: To leave the PICList RemoveMEpiclist-unsubscribe-requestspam_OUTKILLspammitvma.mit.edu

Hy, Alexandre Yes we have solder paste down here in Brazil !! We even have a Kester factory down here ! Anyone that needs it can send me a private mail and I will grab the phone number. I use Kester R276 with 2% silver. Works beautifully... Best regards, Alexandre Guimaraes RemoveMEalexgTakeThisOuTspamiis.com.br > >Hi Guys, we have successfully done a few boards > >now with SMT PIC chips in a cheap toaster oven, > >they are coming out quite good. > >Just letting you know you can get a pretty good > >result with a $35 US (second hand) toaster oven > >and a stopwatch, and good solder paste of course. > >Each run it seems to be getting a bit better. > > It's really nice, so bad we CAN'T find the proper solder in paste here in Brazil... :~( -- http://www.piclist.com hint: To leave the PICList EraseMEpiclist-unsubscribe-requestspamspamBeGonemitvma.mit.edu

Tony Nixon wrote: > I am finishing up a project I started awhile back that uses SM parts on > a small fiddly PCB. I'd be interested knowing how the oven and paste > work out. I might have to set up something like that myself. I takes me > about an hour to solder the parts on this small PCB and the result is > not very professional looking and is bound to lead to problems. > > Is the Farnell Part number - 149-968 > What oven brand do you use? > Does this method work on double sided SM components? Hi Tony, some good posts so far on this hey! I'm a real beginner with this and learning as much as anyone from the expert SMT guys posts. :o) The oven we use is a Ronson combi-oven, it has 2 bar elements on the bottom and two on the top. It was cheap and 1500w, and works great. We do 4 boards in 5 minutes with good repeatability. I could put 8 boards in, but can't be bothered, we only need to make small batches of 12 or 16 boards anyway. Heating is very localised above the elements, but our boards have all the chips within a 2" square so this works fine. I don't think we could solder a large board, not in one go anyway. It's working great for this particular project, a 28 pin SMT PIC and a few 8-pin SMT chips all close to each other. We then hand solder the PTH components (my preferred method). It heats the small boards completely, so would work on all SMT components top or bottom, but it sounds scary putting parts on the bottom! Alex G said he was going to put up some pictures of his equipment soon. -Roman -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

Hi everyone, Just to put in my two cents, I've started experimenting with this as well and I have the paste from Prime Electronics. "Multicore RM10" that someone mentioned earlier.. I've been talking with Alexandre G about this stuff and we have just started designing a temperature controller to adapt a toaster oven to a completely controllable SMT oven :) It will have the ability to define temperature profiles on a PC and download them into the controller then select them and run them standalone. Probably have the ability to log temperature to the PC as well just 'cause we can :) LCD and a few buttons for the interface. Temperature sensing using a thermocouple probably.. The intention is to release it for all to use. I'll keep everyone informed as we progress over the next several weeks. The questions is: do we make the SMT oven controller all surface mount components :) Chicken and Egg, which came first :P Cheers, Ash. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

Hi, Everyone > I've been talking with Alexandre G about this stuff and we have just started > designing a temperature controller to adapt a toaster oven to a completely > controllable SMT oven :) > The questions is: do we make the SMT oven controller all surface mount > components :) Chicken and Egg, which came first :P My vote is to make it all SMT ! Let's let everybody have some fun with small parts and tweezers and let's start to train them to make the necessary rework task they will have once they have the oven working. :-) About the solder paste I prefer to use it with 2% silver because on may capacitors the contact points have silver on them and it migrates to the solder if you use plain tin/lead paste. At least that is what AVX and some other capacitor manufacturers recommend. Try Kester, they are very reponsive to costumers, at least here in Brazil. They send me samples and sold me small quantities without any trouble at all. Remember always to store the paste in the refrigerator and take it out at least one hour before using it. If you don't store it at the fridge it will be bad really soon and if you do not let it warm to room temperature it does not stick to the pads or to the components. Best regards, Alexandre Guimaraes RemoveMEalexgKILLspamiis.com.br -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.