Post by thread:[EE] Cheap rework station?

I recently made my first electronics board with SMT components and found that I really liked working with them. The TQFP package was kind of a pain to solder, though, and I know it would be really difficult to solder LFCSP/LGA/QFN (no leads) packages. I would like to be able to solder these packages because a lot of sensors like accelerometers and gyroscopes use them and instead of paying $20-$50 for an evaluation board, I could make one myself for a few bucks. So I'm considering purchasing a hot air rework station. As I'm a student, I can't afford to purchase a name-brand station. I've been looking at the Aoyue 968: hackaday.com/2009/02/20/tools-aoyue-968-3-in-1-soldering-and-rework-station/ http://www.amazon.com/Aoyue-968-Digital-Rework-Station/dp/B000HDG0AO Has anyone had any experience with Aoyue products, or this station in particular? I would like to hear any advice you might have, thanks

{Quote hidden}> Date: Fri, 14 Jan 2011 11:34:50 -0500 > Subject: [EE] Cheap rework station? > From: spam_OUTnathanpiclistTakeThisOuTgmail.com > To: .....piclistKILLspam@spam@mit.edu > > I recently made my first electronics board with SMT components and > found that I really liked working with them. The TQFP package was kind > of a pain to solder, though, and I know it would be really difficult > to solder LFCSP/LGA/QFN (no leads) packages. I would like to be able > to solder these packages because a lot of sensors like accelerometers > and gyroscopes use them and instead of paying $20-$50 for an > evaluation board, I could make one myself for a few bucks. So I'm > considering purchasing a hot air rework station. > > As I'm a student, I can't afford to purchase a name-brand station. > I've been looking at the Aoyue 968: > > hackaday.com/2009/02/20/tools-aoyue-968-3-in-1-soldering-and-rework-station/ > www.amazon.com/Aoyue-968-Digital-Rework-Station/dp/B000HDG0AO > > Has anyone had any experience with Aoyue products, or this station in > particular? > > I would like to hear any advice you might have, thanks! > -- I have a couple different hot-air rework tools I've purchased from Madell (not be confused with Matel). Works fine. Their stereo microscope on a double arm boom is probably among the best tool investments I've ever made. I have also used a household electric skillet for smt soldering and desoldering of leadless parts but not BGAs. Also worked fine but a bit fiddly. I have a modified toaster oven I use for some SMT soldering if have lots of parts to deal with or more than just a few boards to make. Works quite well. You can get polyester film solder paste screens made quite cheaply but with the limitation on minimum pad size. Stainless steel screens are also reasonable, if not a bit more expensive. But last longer and can have much smaller pad sizes. Solder cream (paste), squeegees, pneumatic applicators are all available. The pneumatic applicator I have is used (brand escapes me right now) and was relatively cheap, less than $100. But I spent at least that much in plumbing and tubing to get it working again. Rob

I have an Aoyue 2738A and have had great luck with it. Not sure if I would go with another "heating element built-in to the soldering tip" model again, as replacement tips are expensive and a bit hard to find. http://www.sparkfun.com/products/609 <- cheaper sources are available but Sparkfun replaced a hot-air heating element that I deemed as failing too soon without question. I have heard that Aoyue's QC is hit or miss, but so far I have been happy. On Jan 14, 2011, at 09:34 AM, Nathan House wrote: {Quote hidden}> I recently made my first electronics board with SMT components and > found that I really liked working with them. The TQFP package was kind > of a pain to solder, though, and I know it would be really difficult > to solder LFCSP/LGA/QFN (no leads) packages. I would like to be able > to solder these packages because a lot of sensors like accelerometers > and gyroscopes use them and instead of paying $20-$50 for an > evaluation board, I could make one myself for a few bucks. So I'm > considering purchasing a hot air rework station. > > As I'm a student, I can't afford to purchase a name-brand station. > I've been looking at the Aoyue 968: > > hackaday.com/2009/02/20/tools-aoyue-968-3-in-1-soldering-and-rework-station/ > www.amazon.com/Aoyue-968-Digital-Rework-Station/dp/B000HDG0AO > > Has anyone had any experience with Aoyue products, or this station in > particular? > > I would like to hear any advice you might have, thanks! > -

On 14/01/2011 16:34, Nathan House wrote: > As I'm a student, I can't afford to purchase a name-brand station. > I've been looking at the Aoyue 968: If you've got the cash, a rework station would be great. If not, consider a fry pan. This is how I get the majority of SMD components onto boards. http://edeca.net/wp/2010/05/cooking-with-gas-my-first-smd-board/ I have made about 10 so far. Once you get the hang of how much paste to apply, it really isn't hard. One day I'll invest in a hot air station, until then the fry pan and copper braid (to remove occasional bridges) are enough. Davi

I was actually going to try that, except I was going to follow the Sparkfun method with a skillet: http://www.sparkfun.com/tutorials/59. I even bought an IR thermometer to measure the surface temps so that I could roughly follow a reflow profile. I accidentally bought the wrong kind of solder paste though, and so I soldered the board with my iron. The problem with this method is that you can't desolder stuff, right? So a board with a leadless package (or even TQFP) that might need to be replaced would have to be trashed. I'm still planning on trying this method sometime, though.. -Nathan P.S. Where do you get your solder paste, and how do you store it

{Quote hidden}> Date: Fri, 14 Jan 2011 17:43:43 -0500 > Subject: Re: [EE] Cheap rework station? > From: nathanpiclistKILLspamgmail.com > To: .....piclistKILLspam.....mit.edu > > I was actually going to try that, except I was going to follow the > Sparkfun method with a skillet: http://www.sparkfun.com/tutorials/59. > I even bought an IR thermometer to measure the surface temps so that I > could roughly follow a reflow profile. I accidentally bought the wrong > kind of solder paste though, and so I soldered the board with my iron. > > The problem with this method is that you can't desolder stuff, right? > So a board with a leadless package (or even TQFP) that might need to > be replaced would have to be trashed. > > I'm still planning on trying this method sometime, though.. > > -Nathan > > P.S. Where do you get your solder paste, and how do you store it? Yes, you can de-solder with this method. You need to get some liquid flux or flux pens. However, keep in mind that you may be damaging other parts on the board due to over heating. However on a small board, say one you made to adapt an LCC accelerometer to the 4 or 5 pins you need for serial interface, this works great. The LCC can be removed and maybe you have to replace a few caps or maybe a voltage regulator in the process. I've bought solder paste from numerous sources over the years. Digikey sells it (not the cheapest), or did anyway. I store it in an extra refrigerator I have. Its a "bar" fridge that I traded some other stuff to get. In there lives my solder paste and film. No food or drink. As for removing leaded packages, even big 288 lead TQFPs I ask myself if I'm more interested in preserving the part or the board. If I'm out to keep the board intact I've often used a Dremmel tool with a thin cut-off wheel to just buzz through pins being very careful to NOT NICK THE BOARD. Since there is a chance of shattering the cut-off wheel and you will likely be working with your face close to the board BE VERY CAREFUL. I take no responsibility for your trying this method and failing in any fashion! I've also done this on PLCCs that were soldered down. Then carefully "scrub" off the leftover cut pins from the pads with a hot soldering iron and lots of flux. Another trick is to thread a very fine wire behind all the pins on a side of a TQFP. 30 gauge usually works but not always. Then you flux the dickens out of the pins. Fix down one end of the fine wire and slowly pull forward on the other end as you heat pins with a fine tip iron. You can use the wire to lift pins from pads. I've done this a few times and with limited success. Mostly I've had problems getting the wire fed behind the pins or with accidentally lifting pads. Good luck. There are lots and lots of little tricks for removing parts from boards. Rob