24 February 2011, 10:26 | #201 |
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Hi all, heat sinking question:
I'm trying to remove the solder from the holes where extra RAM chips can be seated at the bottom of a rev 6A 500 mobo. Goal is to solder sockets there. I only have a relatively small solder station (can't remember how many watts), temperature can be set up to 450°C. I manage to remove solder from most holes using solder wick at 300°C, but some of them just won't melt. I've finally understood why: the solder points which don't want to melt are those connected to big fat tracks. Those big tracks sink all the heat and prevent proper and quick melting. I don't know what to do as I cannot prevent heat from going where it has to... Also, I'm afraid of applying heat to the board for too long. Any good advice on this matter? NOTE: I've also found that solder wick sinks a LOT of heat when you just unwind it and use the reel as a handle to hold it. What I actually do is cut a small piece of wick, lay it on the solder I need removing, and then apply heat only to that small, cut off portion of wick. Works much, much better that way -- solder melts and gets pumped in almost immediately. |
24 February 2011, 16:35 | #202 |
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Location: Thunder Bay, Canada
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Hi.
Use chipquik, it is like solder except has a very low melting point and it contaminates the solder it comes into contact with hence lowering the melting point to below 200 degs http://chipquik.com/ has info, videos etc |
24 February 2011, 16:59 | #203 |
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25 March 2011, 11:29 | #204 |
Ruler of the Universe
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@Eamoe, @kipper2k: Thanks to both. I've just bought a kit of chip quik. I was going to ask the same than Eamoe, as I've got to desolder the Rc outs and they are hard as stone.
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25 March 2011, 12:18 | #205 |
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Great to be of any use, usually others are... can you please tell me how you'll be doing with your kit? I haven't made the move yet.
EDIT: I meant to say I've been of use only INDIRECTLY... Last edited by Eamoe; 25 March 2011 at 13:38. |
25 March 2011, 14:31 | #206 |
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Location: PL?
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set 340°C, use normal non-ROHS solder - preheating of board with some hot air gun can help a lot.
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27 March 2011, 00:33 | #207 | |
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Quote:
If any can tell me... EDIT: Forget it, it's nozzles, isn't it? I'm going to buy one. Eamoe I don't know how I'll do, but I think I'll have to desolder first the solder (more or less), for what I've bought a cheap 50watts iron solder (4 or 5 € with sending cost included) just for it, as the good jbc one I've got has only 20 watts. Later I think I have to desolder the chip kit to get joined with the existing one, and later to suck all together. So... what will be better, the hot air gun with a 2mm nozzle or to try with a 50watts solder and the chip quik solution? Last edited by Retrofan; 30 March 2011 at 11:56. |
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27 March 2011, 04:09 | #208 |
I hate potatos and shirts
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Chip Quick and a large nozzle on the rework air station is your best approach.
Just set the air temp to as low as 100°C for start, it will not destroy your board, nor the near components. |
27 March 2011, 10:53 | #209 |
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Have the same worry here. I do have a hot air gun, but its purpose is more like removing wallpaper, scraping paint off things, fast drying paint and so on... it only has two temp settings (350 / 550 °C). Nothing I can do with this, right?
Also I have a general question about hot air reworking: sometimes I read people saying you should heat a large portion of the board, sometimes it is said you need to be very accurate and use small nozzles, even nozzles with adapted shape depending on the type of components you need desoldering. When is it that you want to be accurate and when to heat large portions of boards? |
27 March 2011, 21:10 | #210 | ||
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Quote:
Quote:
And are you saying to desolder it with the hot air gun or just to hot it first? |
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30 March 2011, 06:41 | #211 |
I hate potatos and shirts
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Chip Quik (the desoldering paste) will let the part get molten as low as 58°C, heating the surrounding area to near 80~100°C will not affect them, but the place where the Chip Quik was applied will melt and the SMD part will fall off easily.
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30 March 2011, 11:56 | #212 |
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Yesterday I received the chip Quick and tried with the hot air gun and my 20watts jbc iron solder. It wasn't so easy as I desoldered a socket with 40 pins very hard to desolder. I did what the instructions say:
1) Apply tack flux (Chip Quick) 2) With iron melt Chip Quik alloy on all pins 3) Maintain alloy in molten state long enough to release chip I did step 3 with the hot air gun, but the socket I wanted to release didn't want to come out. Then I sucked all the tin plus the chip quik alloy of the pins, but it wasn't coming out either. Then I went applying the tack flux alone and with the jbc desoldering the remaining tin and sucking it. Finally I had to use the solder braid and then it came out. I think the chip quick is better to release chips than big things... but it worked. This is what I did: It's an Acard. You know how it comes, with each socket looking each side, and it's very difficult to use it that way, as it takes a lot of room. So I changed one of the sockets so be angled and in the same side as the other. The thing is that I didn't find an angled socket, so I had to make it using angled pins, and for the upper ones cutting and soldering angled pins to the existing ones. Later I changed the power connector to be angled too. Last edited by Retrofan; 30 March 2011 at 12:32. |
15 November 2015, 05:37 | #213 |
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After years of mucking about with cheap-ish solutions, I pulled the trigger earlier this year and got a Weller soldering station (WESD51), tip set, and a soldapullit sucker. The combination of these is, for a hobbyist, awesome and I can heartily recommend this to anyone. It's not $20-iron cheap but it doesn't break the bank either.
I've (de)soldered many DIP-style IC's with it since then, and replaced them with sockets. Most legs can be desoldered/soldered at 650-700F, for the bigger heat-absorbing traces (GND, VCC) 800F works better. The soldapullit sucks like nobody's business and makes this a very fast process. The next step up would be an actual desoldering station, but with this setup it will only take you about 10 minutes to desolder up to DIP-48. Without breaking traces or destroying through-holes with heat. Before I used a cheap-ish temperature-controlled station that didn't control the tip's temperature, and one of those <$5 solder suckers. It was a nightmare. Chips soldered to the pcb on both sides? Good chance you'd rip a trace because the temperature would drop too fast, OR you'd overheat and the through-hole connector would fall out. Seriously, don't be stupid like me and skimp on the good stuff even if you don't do this too often. It's a world of difference. |
15 November 2015, 09:19 | #214 |
CaptainM68K-SPS France
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I use personally a thermo-regulated iron station, a 5$ solder sucker, AND a flux pen, with normal electronic solder (non-rohs).
With the flux pen applied, i then use the solder, and my iron is always at 400°C (Celsius). I work out anything, amiga, Atari ST, consoles, arcade boards, with no problem, i don't even use the solder braid. The main key is to not keep the iron tip too long. If enough flux has been applied it must come quick and easy. |
16 November 2015, 09:01 | #215 |
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Join Date: Jul 2003
Location: Helsinki / Finland
Age: 43
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The soldapullit looks like it's 100% plastic.
I would recommend an aluminium cased one. I use a generic one like this: https://d1gd7xtq3dij0r.cloudfront.net/d_4986.gif Never a problem. :-) |
16 November 2015, 10:10 | #216 |
CaptainM68K-SPS France
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it's the model i own
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08 July 2016, 18:39 | #217 |
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Location: Morwell Victoria Australia
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best tips I can give is always reflow the pins of the component you wish to remove with fresh solder before removing once the new part is fitted and soldered in clean off any flux with cue tips and Isopropyl alcohol or nail polish remover if left over time it will turn black and become conductive
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08 August 2016, 13:03 | #218 |
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Location: Oslo/Norway
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Need a bit of help here, as I have 2 GVP Geforce boards, where the one I will be using has broken ram sockets, while the other doesn't so I decided to to swap, as I couldn't find anyone who stills sells these things.
I have ZD-987 so it went easy enough. A few of the pins where stuck on both boards, but because of the design it was easy enough to desolder them after the sockets where removed, and put them back in place. Now to the issue at hand. There are a few of the pin holes that still have solder "in the middle" for lack of better word. And no matter what I try, I can't get rid off it. I've tried adding more solder, from both sides together with plenty of flux, and even tried with Chipquick. It makes no difference. It is as if the left over solder will not melt. I've tried it with ZD-987, braid and manual solder pump. But no, the solder still there. I've gone up to around 350c I think(normally I stay around 300c), but dear not go above that in fear of lift pads or destroy something. So I am out of ideas, so any would be welcome. |
08 August 2016, 14:12 | #219 |
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Location: Stockholm
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350° is the normal soldering temperatur for my soldering station. I'm surprised you managed to remove an entire SIMM socket at only 300°.
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08 August 2016, 14:51 | #220 |
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Location: Oslo/Norway
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I've had no problems with it, but I have lifted pads on higher tempratures. So I turned it down to be more careful.
The problem now is that the holes are so small, I can't get to the solder to melt it, or that is what I assume is the problem. |
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