- Joined
- Mar 27, 2011
- Location
- Soviet Mexico
So as some of you might know I recently bought a Hot Air Rework Station. For doing reflow soldering of SMD's and Reballing of BGA's. so heres my adventures and mistakes with it. So everyone can point, laugh and learn along with me if they are so incline (probably alot of laughing and the release of alot of magical smoke).
MIVE Repair
First Project On The table is my Asus Maximus IV Extreme, with a destroyed decoupling capacitor. Which has turned into a nightmare to remove.
The top of this cap was broken off accidently due to insulation/defect. As I have said before These things are really really fragile. They are a plastic case with a slight bottom metal backplane and several small plates inside that have an air gap between them. So if you break the top off and moisture, dirt, water hotglue gets in there your screwed and it will probably kick the bucket. If your me you get all 4 of those in there and then give it a shake and claim win (okay not win but fail). As i have learned today the case on these melt at around 170c. Which is kinda stupid cause you have to heat them to around 260-300c to get the solder to melt
The trick to remove one of these is to heat the underside of the board at the same time as your hitting the top with the hot air rework gun from the top. I don't have a Under board heater so I used the extreme overclockers companion, the hair dryer. Throw inside a Mac g4 power cube upside down (wow another use for a mac, and I though this thing was only useful as a trash can, which is actually what I use it for. Make sure to apply plenty of flux around the Capacitor itself. This helps keep the solder on the pads from bridging each other. Aswell as protect the surface from the heat your throwing at it some. Your gonna have to get the temperature in the 240c+ range to remove it. Its alot easier if you can heat the under side of the board close to the same temperature range as to much heat to the top of the cap just makes the plastic melt and crumble to the board. Also helps to throw some tinfoil over the VRM's and other stuff on the surface where you are blowing the hottest air. To prevent desoldering them or moveing them in the process.
A few shots of the underboard heater setup I rigged.
After much work and the need to crank the hot air rework station up to 500c to get enough heat to transfer (this board has alot of mass so it acts like a giant heatsink, this component also is in the middle of the power planes) I removed remains of the decoupling cap. Which I had pretty much Mutilated during the process. Also ended up tearing part of one of the pads by being hasty and aggressive, not enough that it should be a problem though.
Before (shot of the damage cap under the microscope)
After - but before cleanup
Torn Pad
Now I just need to finish cleaning up the pads and attempt to put the new capacitor in place which I sure is gonna end up being difficult, if i dont kill one or two in the process (these cost about 4$ a Cap, not to bad but not great either)
MIVE Repair
First Project On The table is my Asus Maximus IV Extreme, with a destroyed decoupling capacitor. Which has turned into a nightmare to remove.
The top of this cap was broken off accidently due to insulation/defect. As I have said before These things are really really fragile. They are a plastic case with a slight bottom metal backplane and several small plates inside that have an air gap between them. So if you break the top off and moisture, dirt, water hotglue gets in there your screwed and it will probably kick the bucket. If your me you get all 4 of those in there and then give it a shake and claim win (okay not win but fail). As i have learned today the case on these melt at around 170c. Which is kinda stupid cause you have to heat them to around 260-300c to get the solder to melt
The trick to remove one of these is to heat the underside of the board at the same time as your hitting the top with the hot air rework gun from the top. I don't have a Under board heater so I used the extreme overclockers companion, the hair dryer. Throw inside a Mac g4 power cube upside down (wow another use for a mac, and I though this thing was only useful as a trash can, which is actually what I use it for. Make sure to apply plenty of flux around the Capacitor itself. This helps keep the solder on the pads from bridging each other. Aswell as protect the surface from the heat your throwing at it some. Your gonna have to get the temperature in the 240c+ range to remove it. Its alot easier if you can heat the under side of the board close to the same temperature range as to much heat to the top of the cap just makes the plastic melt and crumble to the board. Also helps to throw some tinfoil over the VRM's and other stuff on the surface where you are blowing the hottest air. To prevent desoldering them or moveing them in the process.
A few shots of the underboard heater setup I rigged.
After much work and the need to crank the hot air rework station up to 500c to get enough heat to transfer (this board has alot of mass so it acts like a giant heatsink, this component also is in the middle of the power planes) I removed remains of the decoupling cap. Which I had pretty much Mutilated during the process. Also ended up tearing part of one of the pads by being hasty and aggressive, not enough that it should be a problem though.
Before (shot of the damage cap under the microscope)
After - but before cleanup
Torn Pad
Now I just need to finish cleaning up the pads and attempt to put the new capacitor in place which I sure is gonna end up being difficult, if i dont kill one or two in the process (these cost about 4$ a Cap, not to bad but not great either)
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