Hi Peter,
Thanks for your comments.
I wish to put the step at the bottom of the stencil as we are using a ProFlow unit on a Dek265Lt. As I
understand it there should be a 1:36 keep out when using a stepped stencil (if I have a 3 thou step, then
I need a 108 thou keep out either side).
Thanks,
David
"" wrote:
> [This e-mail is confidential and may also be privileged. If you are not the
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> Hi, David,
>
> Your existing stencil manufacturer ought to be able to do it for you, or if
> not, talk to any local CM's about who they use.
>
> You want to step the bottom of the stencil - I take it you mean the step
> will contact the board not the paste squeegee? Be careful doing this unless
> you have a lot of real estate clearance on the board around the area of the
> step, as you won't get proper stencil contact with the board until the step
> "runs out". The board area between the edge of the step and the the end of
> the run-put will have "mutant" solder paste deposits - wrong thickness, out
> of shape, out of area, etc. The squeegee will also "form" the stencil over
> the step, deforming it quickly beyond use.
>
> The step should always be on the squeegee side, so that a uniform surface
> is presented to the board. Then you will get controllable solder paste
> thicknesses (that word again) wherever you want them.
>
> Regards
>
> Pete Duncan
>
> David Simmons
> <dave.simmons@T To: [log in to unmask]
> AIT.CO.NZ> cc: (bcc: DUNCAN Peter/Asst Prin Engr/ST Aero/ST Group)
> Sent by: Subject: [TN] Stepped Stencil
> TechNet
> <[log in to unmask]
> G>
>
> 08/23/01 08:53
> AM
> Please respond
> to "TechNet
> E-Mail Forum."
>
> Hi,
> We are considering the use of a stepped stencil.
> The base thickness is 5 thou and we would like the step to be 8 thou (3
> thou thicker).
> We would like the step to be on the bottom side of the stencil.
> The total stencil size is 20 by 20 inch.
> The size of the step would be about 50 * 50 mm.
> Does anyone have any contacts of stencil manufacturers who can do this
> for us?
> Thanks
> David
>
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