Re: Soldering 402 chip R's

On Wed, 19 Sep 2007 13:21:28 -0700, Paul <energymover@xxxxxxxxx>
wrote:

On Sep 19, 1:08 pm, Spehro Pefhany <speffS...@xxxxxxxxxxxxxxxxxxxxxxx>
wrote:
On Wed, 19 Sep 2007 13:02:21 -0700, Paul <energymo...@xxxxxxxxx>
wrote:

Does anyone have any advice on soldering 402 size chip resistors to a
PCB? I thought perhaps some liquid solder that would slowly dry when
heat is applied from a heat gun.

I just use an iron. You need to actively hold them down or they'll get
sucked into the solder blob by surface tension. I tin one side, attach
the resistor then resolder both sides to make it pretty. A bit slow,
and you can expect to lose (as in never see again) some percentage of
the part.


Sounds like you're rather skillful. I can hardly see these buggers
with the naked eye. They're about the size of a grain of sand. So you
remove them from the paper, place it on the PCB, then place an iron
across the entire R? What percentage of R's will stick to the iron?


No.

Get an illuminated magnifier or some 2.5x granny glasses.

Small-tip soldering iron.

Blob a little solder onto one pad.

Place resistor with tweezers, and reheat that pad to solder one side.

Solder the other side.

Touch up as required.

Practice.


Or design with huge parts, like 0805's.

John


.

Relevant Pages

  • Re: Soldering/Desoldering temperatures
    ... >>Raising the iron temperature helps because the tip can cool somewhat ... >>and still melt solder. ... >>of conducting away the heat you apply. ... Another thing that sometimes works is a heat gun. ...
    (sci.electronics.repair)
  • Re: Hot air smd rework station. SMD removal??? Defective Machines???
    ... study of thermodynamics and heat transfer. ... think that a higher temperature is better for soldering. ... The raising of the temperature to the melting point of the solder ... A clean iron, well tinned, clean circuit board and component lead, fluxed. ...
    (sci.electronics.repair)
  • Re: Soldering surface mount components
    ... 1.You need a good HANDS FREE magnifier, one of them geeky head set ... Get a low wattage iron, 10-20 Watts, or so. ... Tack solder the chip on 1 corner. ... CHECK ALL PINS ...
    (sci.electronics.misc)
  • Re: Soldering surface mount components
    ... 1.You need a good HANDS FREE magnifier, one of them geeky head set ... Get a low wattage iron, 10-20 Watts, or so. ... Tack solder the chip on 1 corner. ... CHECK ALL PINS ...
    (sci.electronics.equipment)
  • Re: Soldering surface mount components
    ... 1.You need a good HANDS FREE magnifier, one of them geeky head set ... Get a low wattage iron, 10-20 Watts, or so. ... Tack solder the chip on 1 corner. ... CHECK ALL PINS ...
    (sci.electronics.design)