Sona,

I guess I wrote the question wrong. I wasn't really interested in your
capabilities. I was curious as to what your CAM dept preference
would be. Would you rather get the soldermask features 1:1 and
let your CAM operators modify to achieve an acceptable product
or would you rather get your designs coming in the door with
soldermask features preset (larger some value) than your pad sizes.

I was asked by a CM who designs for many fabricators what
would be the proper way to do the design. My belief is 1:1 and
let "us" (fabricators) modify to meet our process. However I have
others in my staff that believe we should dictate a value coming
in (it'd be changed anyways).

Regards,

David Hoover  (aka. Groovy)

----- Original Message -----
From: "Fineline Circuits, Inc." <[log in to unmask]>
To: <[log in to unmask]>
Sent: Wednesday, November 05, 2003 8:51 AM
Subject: Re: [TN] Soldermask Clearance Question


> David:
>
> For standard technology and screened soldermask we prefer a soldermask
> clearance of .008mls
> For higher technology pcb's and liquid photoimageable mask we prefer a
mask
> clearance of .004mls although tighter clearances are achieved..
> A 1:1 will bleed mask on pads and or in the holes.
> These are general guidelines. Our CAM dept. generally check the design out
> for soldemask clearances making sure no adjacent traces/pads are exposed
> depending upon the thickness of the pcb and  soldermask.
>
> Sona Sitapara
> Fineline Circuits Inc.
>
>
>
> > David Hoover wrote:
> > > I am in the middle of a discussion/debate with assemblers on one side
> and
> > > designers on the other.
> > >
> > > The question is:
> > > What would your shop prefer to receive from the designer for
soldermask
> > > features?
> > >
> > > either
> > > A) 1:1?  (Soldermask clearance same as the holesize, padsize,
> > > surfacemount, or
> > >               clearanced feature size)
> > > or
> > > B) Soldermask Clearance set at some value over the pad/feature/SMT siz
e?
> > >     (Like 3 mils per side)
> > >
> > > Thanks for any and all responses,
> > >
> > > David Hoover
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