Solder Joints Repair, Write-up?
12-28-2003, 09:35 AM
#1
Junior Member
Thread Starter
Join Date: Dec 2003
Posts: 5
I did a little search, but didn't find a topic on the solder joints on what is needed to be removed and maybe pics of what exactly and were to fix the issue with the clock, sun roof and other items effected by these soldered circuit boards.
12-29-2003, 02:24 AM
#3
Senior Member
Join Date: Nov 2002
Posts: 3,108
U will need the following:
then this
this also
and finally this
(60/40 lead to tin
and also flux cleaner, however some people do not like the flux cleaner, it may remove the solder mask thus leaving shorts everywhere, i have tried using ISOPROPAL alchol (rubbing alchol) to clean the flux with a Q-tip. Word of caution, most drug store rubbing alchol contains water, so make sure you let your PCB sit for an hour to ensure 100% that all the moisture is gone before applying voltage.
Desoldering methods
A soldered joint which is improperly made will be electrically "noisy", unreliable and is likely to get worse in time. It may even not have made any electrical connection at all, or could work initially and then cause the equipment to fail at a later date! It can be hard to judge the quality of a solder joint purely by appearances, because you cannot say how the joint actually formed on the inside, but by following the guidelines there is no reason why you should not obtain perfect results.
A joint which is poorly formed is often called a "dry joint". Usually it results from dirt or grease preventing the solder from melting onto the parts properly, and is often noticeable because of the tendency of the solder not to "spread" but to form beads or globules instead, perhaps partially. Alternatively, if it seems to take an inordinately long time for the solder to spread, this is another sign of possible dirt and that the joint may potentially be a dry one.
There will undoubtedly come a time when you need to remove the solder from a joint: possibly to replace a faulty component or fix a dry joint. The usual way is to use a desoldering pump which works like a small spring-loaded bicycle pump, only in reverse! (More demanding users using CMOS devices might need a pump which is ESD safe.) A spring-loaded plunger is released at the push of a button and the molten solder is then drawn up into the pump. It may take one or two attempts to clean up a joint this way, but a small desoldering pump is an invaluable tool especially for p.c.b. work.
Sometimes, it's effective to actually add more solder and then desolder the whole lot with a pump, if the solder is particularly awkward to remove. Care is needed, though, to ensure that the boards and parts are not damaged by excessive heat; the pumps themselves have a P.T.F.E. nozzle which is heat proof but may need replacing occasionally.
An excellent alternative to a pump is to use desoldering braid, including the famous American "Soder-Wick" (sic) or Adcola "TISA-Wick" which are packaged in small dispenser reels. This product is a specially treated fine copper braid which draws molten solder up into the braid where it solidifies. The best way is to use the tip of the hot iron to press a short length of braid down onto the joint to be de-soldered. The iron will subsequently melt the solder, which will be drawn up into the braid. Take extreme care to ensure that you don't allow the solder to cool with the braid adhering to the work, or you run the risk of damaging p.c.b. copper tracks when you attempt to pull the braid off the joint.
I recommend buying a small reel of de-soldering braid, especially for larger or difficult joints which would take several attempts with a pump. It is surprisingly effective, especially on difficult joints where a desoldering pump may prove a struggle.
then this
this also
and finally this
(60/40 lead to tin
and also flux cleaner, however some people do not like the flux cleaner, it may remove the solder mask thus leaving shorts everywhere, i have tried using ISOPROPAL alchol (rubbing alchol) to clean the flux with a Q-tip. Word of caution, most drug store rubbing alchol contains water, so make sure you let your PCB sit for an hour to ensure 100% that all the moisture is gone before applying voltage.
Desoldering methods
A soldered joint which is improperly made will be electrically "noisy", unreliable and is likely to get worse in time. It may even not have made any electrical connection at all, or could work initially and then cause the equipment to fail at a later date! It can be hard to judge the quality of a solder joint purely by appearances, because you cannot say how the joint actually formed on the inside, but by following the guidelines there is no reason why you should not obtain perfect results.
A joint which is poorly formed is often called a "dry joint". Usually it results from dirt or grease preventing the solder from melting onto the parts properly, and is often noticeable because of the tendency of the solder not to "spread" but to form beads or globules instead, perhaps partially. Alternatively, if it seems to take an inordinately long time for the solder to spread, this is another sign of possible dirt and that the joint may potentially be a dry one.
There will undoubtedly come a time when you need to remove the solder from a joint: possibly to replace a faulty component or fix a dry joint. The usual way is to use a desoldering pump which works like a small spring-loaded bicycle pump, only in reverse! (More demanding users using CMOS devices might need a pump which is ESD safe.) A spring-loaded plunger is released at the push of a button and the molten solder is then drawn up into the pump. It may take one or two attempts to clean up a joint this way, but a small desoldering pump is an invaluable tool especially for p.c.b. work.
Sometimes, it's effective to actually add more solder and then desolder the whole lot with a pump, if the solder is particularly awkward to remove. Care is needed, though, to ensure that the boards and parts are not damaged by excessive heat; the pumps themselves have a P.T.F.E. nozzle which is heat proof but may need replacing occasionally.
An excellent alternative to a pump is to use desoldering braid, including the famous American "Soder-Wick" (sic) or Adcola "TISA-Wick" which are packaged in small dispenser reels. This product is a specially treated fine copper braid which draws molten solder up into the braid where it solidifies. The best way is to use the tip of the hot iron to press a short length of braid down onto the joint to be de-soldered. The iron will subsequently melt the solder, which will be drawn up into the braid. Take extreme care to ensure that you don't allow the solder to cool with the braid adhering to the work, or you run the risk of damaging p.c.b. copper tracks when you attempt to pull the braid off the joint.
I recommend buying a small reel of de-soldering braid, especially for larger or difficult joints which would take several attempts with a pump. It is surprisingly effective, especially on difficult joints where a desoldering pump may prove a struggle.
12-29-2003, 12:10 PM
#4
Junior Member
Thread Starter
Join Date: Dec 2003
Posts: 5
Thanks for the input, I was hoping for more pics related to the FC items that need to be re-soldered. I do actually know how to solder and remove it, just curious about locations of the parts that need the re-work.
I have an idea what/where they are, but no actual picture of where it is behind in the center consel.
I have an idea what/where they are, but no actual picture of where it is behind in the center consel.
12-29-2003, 12:33 PM
#5
Senior Member
Join Date: Nov 2002
Posts: 3,108
you have to remove the logicon, take out the instrumentation cluster, then you can unhook the cable that the logicon connects to. Once you have hte logicon connections out just remove the unit and open it up.
Replace every single solder joint, there aren't that many to do anyways.
Replace every single solder joint, there aren't that many to do anyways.
12-29-2003, 04:05 PM
#6
Senior Member
Join Date: Oct 2003
Location: Boston Ma.
Posts: 1,420
On the cpu(NOT ECU) I just resoldered the prongs for the harness and the relays/flashers. My clock and warning lights only worked intermittently. I then resoldered the warning light cluster/clock. Again the prongs for the harness and the ribbon wire looked like the weak link, I soldered them and no problems since. Its best to do all of them, but it require time.
12-30-2003, 05:09 AM
#7
Junior Member
Join Date: Dec 2003
Posts: 2
Try this link
http://www.teamfc3s.org/faq/
Two quick warnings about soldering.
1. Do not use acid core, water soluble, RA, SA, RSA or no clean flux.
Use RMA flux only. Improper heating and or cleaning of the others can lead to corrosion anf failures worse than cold solder joints.
RMA and isopropyl alcohol is idiot proof (and I have 25+ years of training to prove it) Use a minimum of flux. More is NOT better.
Electronics grade solder is Sn60 or Sn63 (Tin=60 or 63%, balance Lead).
2. Do not use the solder sucker, the solder wick is safer as well. Use a soldering iron, not a pistol grip soldering gun. Make sure you iron has a three prong plug and uses a grounded tip. Do not use the thing from your wood burning crafts set. Your soldering iron should say it is ESD safe.
Good luck
http://www.teamfc3s.org/faq/
Two quick warnings about soldering.
1. Do not use acid core, water soluble, RA, SA, RSA or no clean flux.
Use RMA flux only. Improper heating and or cleaning of the others can lead to corrosion anf failures worse than cold solder joints.
RMA and isopropyl alcohol is idiot proof (and I have 25+ years of training to prove it) Use a minimum of flux. More is NOT better.
Electronics grade solder is Sn60 or Sn63 (Tin=60 or 63%, balance Lead).
2. Do not use the solder sucker, the solder wick is safer as well. Use a soldering iron, not a pistol grip soldering gun. Make sure you iron has a three prong plug and uses a grounded tip. Do not use the thing from your wood burning crafts set. Your soldering iron should say it is ESD safe.
Good luck
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