Len's SMD soldering tips

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Len Spyker
Posts: 147
Joined: Sat Apr 28, 2018 6:48 pm

Len's SMD soldering tips

Post by Len Spyker » Thu Jun 11, 2015 11:38 am

(1)    Always use a x3 head band goggle. (2)    Have  a small DC PC fan to remove smoke fumes away from your lungs and eyes. (3)    A large x3-5 magnifying inspection LED lamp close to hand and a x20 watch maker type or x 400 USB microscope just in case(4)    Good SMD soldering station 40W+ and all the tiny tips you can afford.(5)    An assortment of best quality solder braid sizes(6)    Practise on a broken PC mother board. Wax on, wax Off, Solder on, solder Off. …  The SMD kid.  For even the tiniest SMD chips I do NOT fuss about shorting the IC pins when soldering, quite the opposite!  First I use some solder flux then start soldering the pins adding a tiny bit of solder at each pin/pad Often this soldering phase rapidly turns into a large solder blob floating along the pins and most are now shorted !!  No worries mate. She will be right. Trust me, I am a  ….etc.  With the smallest solder braid I then start to clean up the shorted pins starting at the top level of the pins.Gently start to slide the hot braid along with the iron tip slowly along the row of shorted pins. Slowly work down to the level of the pins/pads until the shorts look like they are gone. Do the minimum good solder removal.I used this technique for soldering 25 Cypress CPU chips and even smaller logic ICs.  And Oh Yes. You can do such a great solder removal job that there are now OPEN circuits at the pin/pad interface.This is where all the magnifying gear comes into place—for the QA phase. Magically change hats from a dumb PCB assembler to a whip cracking sigma 6 QA inspector with the eagle eye for a dry joint.And look for the hidden short, especially ones UNDER the IC at the back of the pins/pads!  If in doubt about any pin/pad joint: With a tiny pin GENTLY try to move the pin at the pad level. Note: If you push too hard you may bend/fracture the pin at the IC base (un-repairable damage) and of course you find there are no spare ICs.  I confess I spent a few times standing in the fools corner complete with an “Solder Dunce” pointy cap, cursing myself.  But I am told “Practice makes perfect”. (Hah!). Have fun. Len Spyker Perth Australia.  

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