If you have a glass door on your unit, you can just put a blob of solder paste in each of the 4 corners of the PCB. In general you will get a better result spending longer at preheat (160C) and shorter at peak, 30sec at (205C) Might be helpful also to wipe the pcb with some liquid flux between passes. Use the quickest / lowest profile, expect some of the SMD electros and large coils to need touch up with a soldering iron, these big components need longer / hotter profiles usually, (having a longer preheat may be helpful). So 3 passes leaded is about the same as one pass of unleaded. The simple solution is to use leaded solder paste, this gives you longer effective oven time because your peak oven times are lower. and I probably won't be doing 2 passes once I get the hang of it and build confidence. hopefully it won't suffer for going thru the oven two times. here's what the board looks like when its done and in its case (this one was hand soldered by me a week or two ago): as you can see, its not a 'difficult' board and nothing is very dense (the cpu is the 'hardest' part on the board to hand solder) and its just a simple 2 layer board with reasonably thick traces and nothing too challenging imho. before I start doing this en-masse, I'll test the hell out of this first-time baked board and see if it works as well as my hand-soldered boards. the analog parts are all TH and those will get sockets and be done by hand at the final stage. (I wonder if the resonator would also work on a small remote board that connects via pogo pins, saving me from having to temp-solder it and then unsolder later on?) all the parts that I'm using (that are smd) are digital parts and nothing is analog. eventually, I'll get some pogopins setup to do this and avoid having to solder any connectors on just to test the cpu system and get it initially loaded.
#Pcb reflow oven software#
I'll resolder the 6pin inline ftdi connector since this needs to be able to take software updates but the isp connector is no longer needed once you do the initial BL. 1" headers (isp and ftdi) since those have plastic spacer insulators on them and those did not look like they'd be happy to be baked. after I BL'd the system, I unsoldered the resonator (it does not seem like that would be a good thing to send thru the oven, but maybe its ok, I don't know yet) and I did unsolder the. just to boot the system, I did have to hand solder the 6pin ISP connector and also the 6 pin 'ftdi' inline connector, as well as a TH 16mhz resonator. I'll do one more placement of the remaining smd parts, do one more bake and then place the rest of the TH parts by hand. next time I get boards, I do plan to get a metal stencil but I didn't with this board run. after I brushed away the residue solder balls that were left over from the process, the job looked ok visually, at least. I did not have a stencil and just painted on some leaded paste (MG chem.
#Pcb reflow oven download#
it worked! was able to BL it and then download a sketch. 1uF and some 10k's so that I could try loading the bootloader into it. for the heck of it, I tried my first pass on the atmega 328, some. he was able to solder a pretty high density chip that few would attempt to solder by hand. My friend used a pretty common arduino system and a thermocouple (that I placed right on the pcb, touching an unused pad). the board was done in a cheap china pcb house (pcbway) and I've hand soldered this board in previous builds and it holds up well, but it IS a budget pcb service and so I'm not sure if I would weaken the solder mask or even the traces/vias if I did multiple bakes. can you guys advise me on this? once I get the hang of it and gain confidence, I will likely load the board fully and do the baking just once, but I'd like to take it in stages and if I get it wrong on the first try, I don't want to waste good chips and have to throw the whole thing away, etc. 1" header pins and any other plastic parts (I wonder, how tolerant are smd leds to reflowing?). obviously I will not solder electrolytics and plastic. if it takes firmware ok, then I can finish the board with the final baking of the more expensive parts. leave off the expensive smd chips and test the board to see if I can load firmware to it (arduino based using smd atmega 328). what I'm thinking of is to solder all the simple parts (caps and resistors) first and see how well that goes. but I'm not sure how bad it would be if I tried to do 2 or even 3 passes on the board. I'd like to try this out in stages and see how well it goes. I borrowed a friend's DIY oven (which is known to work) and I'm about to try loading my first set of parts on a 2 layer (fairly simple) pcb.
0 kommentar(er)
