The document you probably are referring to is IPC7525. It describes stencil
design GUIDELINES. Because of all the variables in the printing process you
can not come up with design RULES.
If you design and assemble your own boards you can establish in-house rules
for stencil design, but for a contract manufacturer that is a different
story. He has to look at the board that is provided and choose the best
design rules that than fit his process.
As far as aperture reductions go, some assemblers (very few) reduce all
their apertures by 1mil, most reduce only some apertures to eliminate
bridging.
Look at your own assembly process, determine what works best and write a set
of "design rules" as your own addendum to IPC7525 to match that in order to
get to World Class production quality.
Good luck,
Ahne.
-----Original Message-----
From: TechNet [mailto:[log in to unmask]]On Behalf Of Bob Willis
Sent: Monday, November 19, 2001 04:52
To: [log in to unmask]
Subject: Re: [TN] Stencil Reductions
If you call Peter Swanson at Intertronics in the UK he can supply you the
IPC Standard document.
Many thanks
Bob Willis
Electronic Presentation Services
2 Fourth Ave, Chelmsford, Essex, CM1 4HA England
See us at APEX 2002 www.bobwillis.co.uk/workshops/apex/apex.htm
www.bobwillis.co.uk
Tel: (44) 01245 351502 Fax: (44) 01245 496123
Single solution to your seminar, conference or roadshow
www.seminar-registrations.com
----- Original Message -----
From: Cathy Killen
To: [log in to unmask]
Sent: Monday, November 19, 2001 9:16 AM
Subject: [TN] Stencil Reductions
Hi,
Does any standard/procedure exist in relation to stencil reductions on a
paste screen? If so, where can I source them. If there are no
standards/procedures what reductions would you recommend?
Thanks.
Cathy Killen
Training Instructor
Smtek Europe Ltd.
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