Alejandro,

I noticed that you did not state the stencil thickness you are currently
using.  I do not think you need to step the stencil, but should go with a
.125mm thick stencil.  The stencil should have smooth walls (Laser cut and
electropolished).  Just make sure you don't violate your area aspect ratio.
A .125mm stencil should apply adequate paste for most SMT components with
the exception of CCGA components- although you might need to tweak aperture
sizes on some components to ensure adequate solder volumes.
Step stencils, metal blades, and high density don't always work because of
the paste shadowing clearances that are necessary.

Steve A

> -----Original Message-----
> From: Becerra Alejandro [SMTP:[log in to unmask]]
> Sent: Wednesday,November 14,2001 7:42 AM
> To:   [log in to unmask]
> Subject:      [TN] Resistor Networks of 0.5 mm Pitch
>
> Hello to All,
> we are planning to start using resistor networks of 0.5 mm pitch
> in a normal reflow soldering process. The boards are FR-4 with HASL
> coating.
> Is there any special concern about this component?
> So far the smallest resistor network that we are using is a 0.8 mm pitch.
> Within my company it is being recommended a stepped stencil for this
> component. Is this necessary?
>
> Thanks,
>
> Alejandro Becerra
>

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