/g/ - Technology

Computers, Software, Technology

Posting Mode: Reply Return

Max message length: 5000


(used to delete files and postings)


  • Supported file types: GIF, JPG, PNG, WebM, OGG, and more
  • Max files: 5
  • Max file size: 50.00 MB
  • Read the global rules before you post, as well as the board rules found in the sticky.

02/27/20 IRC/Matrix/and Discord servers are now available, join here.
02/09/20 /ausneets/ has been added!
11/23/19 Donations can now be made via PayPal, thank you for all of your support!
11/21/19 We have successfully migrated to LynxChan 2.3.0, to see all of the changes to 16chan, click here.

[Index] [Catalog] [Archive] [Bottom] [Refresh]

(61.50 KB 579x575 E3PWwB9qSK.jpg)
Okay! How do I use this shit!? Anonymous 07/19/2020 (Sun) 23:26:18 No. 1171
A time ago my brother brought me a SMD Rework Station, to help me on repair our things. But, HOLY SHIT! WHY IS SO HARD?! Everytime I tried ended up with me burning the component or the board, or both. I tried to decrease the air or the temperature but the result end being the same. I know that I'm doing something wrong, but I don't know what is.
(29.69 KB 601x583 smd-bottom-preheat.jpeg)
>>1171 Soldering is based and redpilled. Anyways if you can't yet solder with an iron, get a Hakko 888D and learn to use it first. Hot-air soldering is much harder and it helps to pick up practice with direct conduction to get a feel for it. With SMD having a good workstation setup is important. You can bodge shitty repairs but if you want to do something tough like a BGA replace, reball etc you're going to want a preheater/underboard heater like pic related. This heats the whole board up evenly so you don't waste a bunch of heat through conduction on the large copper planes and will reduce your chance of burning stuff. Also you should be masking off the entirety of the top side of the board with kapton tape followed by a copper tape layer, only cut out a tiny window above the component you're working on. You will also need at least a non-contact thermometer at minimum, and maybe like 2-4 K-type thermocouples as well so you can actually measure temperatures on the board. >t. solder man
(71.45 KB 633x730 FILE2926.JPG)
>>1172 How much time I need to remove a SMD? It doesn't hurt the component?
usually like 20-30 seconds if you have a good setup. if you don't have a good setup you should do a ghetto preheat by waving the gun around quickly all over the board. like I said, you want the board to be nice and warm (~70-80C) all over so you won't waste as much of your heat into the big copper pours on the inner layers. if you just jam the heat on full blast to a cold board you can end up with the top of the component scorched at ~400C while the solder is still only like 170C (SAC305 needs 220C-245C to melt) on the connections to the board since the heat just keeps bleeding away into the copper. you will learn to hate ground planes with a fiery passion, seriously fuck emc compliance and all that garbage, fuck controlled impedance, fuck dcr. components are typically packaged in some sort of plastic package. if you solder it fast enough you can get the terminations up to 220/245C while keeping the silicon on the inside under it's critical temperature. like 140-160C or some shit maybe, forget exactly at the moment and it varies per-component.
>>1171 Hi I work in a smartphone repair shop. Depending on the size of the board, sometimes you need to hold the hot air a FEW MINUTES on the board just to heat it up enough to melt the solder. and don't worry about overheating; if the solder isn't melted yet, that means the board hasn't even reached solder's melting point temperature. I suggest setting your hot air temperature around 350C, watching tutorials on youtube and PRACTICING on garbage dead PCBs.
>>1187 Thanks bro


no cookies?