Hello

We have been desining PCB's with Components of 20mil and 25mil pitch. For
Good reasons and requirements of my customers Fabrication capabilities and
or requirements, we have been providing Solder Masks in between these
pins. Ofcourse no routing between the pins. I really have'nt explored the
success and or failure rate or statistics, but now I am interested in
knowing and probably I will put them on the Technet, once I collect
them. 

tks

k.varadaraj

Fm: K.Varadaraj, Chief Executive, CADET Automation Systems, India.
    Ph: 91-80-665 7215 , Fax: 91-80-528 0101
    email: [log in to unmask]



On Thu, 13 Mar 1997, Wander, Nicholas G wrote:

> Andy, we normally do not put solder mask between surface mount pads on
> 20 and 25 mil pitch. We just have a continuous window around all the
> pads on each side of the part. You really do not need solder mask
> between the pads as long as there are no traces between the pads.
> 
> Nick Wander
> Unisys, Roseville, MN 
> 
> >----------
> >From: 	Andy[SMTP:[log in to unmask]]
> >Sent: 	Wednesday, March 12, 1997 7:38 PM
> >To: 	'Technet'
> >Subject: 	Solder Mask on fine pitch SMT component
> >
> >Hello
> >
> >I am facing a problem with fine pitch SMT component of 20mils. How can the
> >soldermask be applied in between the pads without covering them? My supplier
> >claims that their process capability is restricted.
> >
> >Another Question:
> >Which PCB manufacturing house in Singapore can produce 6mils trace/air-gap
> >(for internal layers as well) specifications?
> >
> >
> >Please Advice...Thanks
> >
> >
> 
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