Even using two soldering irons at a time, we couldn’t get consistent, thorough, solder-wetting of that thermal pad. We actually stumbled onto the skillet method by accident, after having problems doing hand-soldering of a chip with an exposed back-side thermal pad. Depending on size (obviously!) there is room in the skillet for 2 to 8 boards at a time. We typically do boards in batches of 5 to 20 units. (But it is MUCH easier to work with 50 mils and 0.95mm.) Hand-placed parts want to have a larger courtyard area than automated placement. Passives are 0805 or 1206 semiconductor packages have lead pitch down to 25 mils or 0.65mm. Our boards range from about a dozen parts, up to around 100 parts. (Our skillet was US$5.00 in a second-hand store.) ( Here’s one, of several, online pages discussing the method.) There has been a fair amount of cut-and-try to the process, but we made it work and you can’t beat the price. I currently work for a (very) small manufacturer, about a dozen employees in total.įor several years we have successfully used an electric skillet as our “tabletop reflow oven”. Also, for proper reflow soldering you will need solder paste.For batch production of say 10’s of boards, whats going to work better? A hot plate or an oven? Big mistake as excess solder will cause a big short and very likely RUIN either your mobo or GPU (or both). Reballed means he will add solder balls that are bigger for proper reflow process. This can easily nick a component and you will be screwed. When hot, solder is very weak as it went from solid to liquid and is trying to cooldown. Components being damaged due to heat are not much of a concern as long as they are within the proper reflow temperatures.īe careful not to damage underside SMT/Thru-Hole components in your oven. Second, components such as BGAs will suffer from warpage, which is why a cooldown zone is required in many ovens has it will lessen this. In a nutshell, you need flux in there or you will permanently damage the state of the solder and cause oxidation which is a huge no-no. Look, there is a whole science behind Reflow Soldering (which what you are trying to do achieve when baking). (not to mention the warpage BGA packages go thru when n ot properly soldered). In most cases a simple X-Ray machine is required to check that each BGA contact point is properly made. BGAs are the trickiest things to rework when it comes down to SMT components. Either way, careful when trying to rework this. Either there where left over solder balls which were violating the minimum spacing between contacts (which in turn cause a short) or there was excess solder which smeared around contact points and hence created a short. I might add that the initial soldering process might have caused one of two defects in the GPU's BGA contacts. Moreover, be sure to add flux in there, I have a suspicion that doing a second reflow soldering cycle will definitely cause corrosion to the solder since the original flux should be long since evaporated or consumed by the initial reflow solder process. In this case, the board should be subjected to either a Soak or Ramp style profile which go over 217*C Although to achieve correct reflow soldering, you need the adequate temperature or reflow profile. There are companies based in the US that do component based repair if this doesn't work out for you. This MAY work, but it may not either depending on if there is an encoder chip, fuse issue, video memory issue, and well, a many number of other things. When using a heat gun for reflow, you want to go around the board about 4 inches above it and move in a smooth fashion, quickly, back and forth to heat the board up and prevent any kind of heat stress, then once the board starts to get hot to the touch (uncomfortable hot), start focusing on the GPU in a swirling motion about 4 inches above the board for about 30 seconds to a minute trying not to focus too much heat on any one area.Īnd before you proceed, I do not take any responsibility if you break your board. Generally temps of around 500-600 degrees F is enough to get the solder to become soft and "reflow (don't move the board till it has cooled down!!!!). A hair dryer will not get the board hot enough to properly reflow the solder.
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