How to Solder SMD chips

smd-150x150 SMD soldering – At first, I tinned all the circuit board pads for the SMD chips before trying to mount them. That was a mistake. With both pads for chip tinned, heating up one end of the chip caused the situation in Figure 5. When heat was applied to the other end, the chip would not seat properly since the first end was frozen in place by the solder.

The trick was to tin only one circuit board pad of each SMD. Then, when the heat was applied at the tinned pad, it seated as shown in Figure 6A at the end of this article. Then solder was applied to the other end to get result shown in Figure 6B.

SMT (Surface-mount technology) is a method for constructing electronic circuits in which the components (SMC, or Surface Mounted Components) are mounted directly onto the surface of printed circuit boards (PCBs).
Electronic devices so made are called surface-mount devices or SMDs.

SMD soldering guide

Soldering SMD chips to the boards (surface mount soldering), you will need four things:

  • A good soldering iron. It is much easier with a 60W like Weller W60P temperature-controlled iron.
  • A suitable pair of tweezers is esential. Use a 4.5 inch curved pair.
  • A head-mounted binocular magnifier, the kind you can flip up or down as needed.
  • A board vise (or something similar) to hold the PCB securely while you are soldering on it.

Surface mount soldering videos

SMT Soldering no2

Advanced surface mount, vertical drag soldering at Washburn Computer Group by John Gammell, Certified IPC Trainer.

Before you start soldering the SMD, make sure you’ve separated them intro groups and tagged each group with its value. You can use something like a hinged plastic box that is divided intro compartments, but make sure the compartments can’t leak into each other.

Once you’ve tinned the pads (remember one pad per chip), you pick up a chip with the tweezers and position it onto its set of pads. While holding it in place with the tweezers, you heat the tinned end until the solder melts and adheres to the chip. Let this cool. Remove the tweezers and solder the other end. The chips are small, so don’t use too much solder. Don’t hold the iron on the chip too long. With a good iron, it should take just seconds.

smd soldering

It helps soldering SMD is you use an iron with a steel-clad instead of a solid copper tip. Be sure to keep the tip clean. The traditional damp-sponge cools oof the tip and can fuls the tip if the sponge burs. I much prefer a brass-wool pad. This is not the officially way to correctly apply SMD soldering but this worked for me.


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