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SMT electronics assembly manufacturing forum.


Soldering of smt Resistor Networks

#33325

Soldering of smt Resistor Networks | 21 March, 2005

Help

We are having trouble soldering the above we have changed pad size but still have problems ???????

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Rob

#33327

Soldering of smt Resistor Networks | 21 March, 2005

Hi Colin,

Are you using the 1206 package with 4 elements or one of the higher density smaller packages? With the first type you can get them in both Convex or Concave terminations, with most of the solderability problems associated with using the Concave terminations.

Another common problem is where bridges occur due to excessive paste - usually resolved by aperture reduction on your stencil.

Rob.

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#33334

Soldering of smt Resistor Networks | 21 March, 2005

What is the specific problem?

Tell about: * Resistor pack * Board layout * Stencil aperatures

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#33347

Soldering of smt Resistor Networks | 22 March, 2005

The size is 1206 approx

with concave terminals

and we are using 1 to 1 appertures on 5thou screen

Thanks for reply

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Rob

#33351

Soldering of smt Resistor Networks | 22 March, 2005

Hi Colin,

If it's easy for you to swap to Convex try the Rohm MNR14 series, Bourns CAY series or Eurohm NC Series.

Else try a 10% apperture reduction - however we usually had a 6 thou stencil when we did this.

Cheers,

Rob.

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