Roger,

I do not have anything to suggest for the .002 lines and spaces.
 
On the depth drilling and plating, depending on design constraints, 
you may be able to gain something if it is possible to depth drill 
the blind vias deeper than .016. 

We have been able to plate down to .015 but the vias had to be at 
least twice as deep for the vibration and hammering to work. In 
this approach, the bottom of the via did not plate but there was 
reliable connection to the interconnecting layers that fell within 
the .015 depth. 

In our case, we also we found it easier to nickel/gold plate the depth 
drilled and plated vias than to tin/lead plate. Again, this may or 
may not be possible due to design and cost considerations.

Good luck,

Luis Rivera
CompuRoute, Inc.
Dallas, TX
[log in to unmask]
(214) 340-0543


> Date: Tue, 11 Feb 1997 22:41:54 -0800
> From: [log in to unmask] ([log in to unmask])
> Organization: Home
> To: [log in to unmask]
> Subject: Blind vias & fine lines
> 
> Techneters,
>         Can anyone help? I am having two problem areas:
> 
>     1) Blind via holes 16 mil diameter 16 mil deep contacting with 4 
> inner layers. I cannot always plate copper into all holes. If I do copper 
> plate them I cannot tin plate all the holes. I have vibrators on the 
> cathode movement frame and a giant to clout the fight bars with a 2 pound 
> hammer. Is there anything else I can do?!?
> 
>     2) Circuits with 2 mil track and gaps. The finish required is 
> electroless nickel/immersion gold. How can this be done without causing 
> the tracks to short with nickel spikes?
> 
>         Thanks in advance,
>             Roger Hammond
> 
 

***************************************************************************
* TechNet mail list is provided as a service by IPC using SmartList v3.05 *
***************************************************************************
* To unsubscribe from this list at any time, send a message to:           *
* [log in to unmask] with <subject: unsubscribe> and no text.        *
***************************************************************************
* If you are having a problem with the IPC TechNet forum please contact   *
* Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask]      *
***************************************************************************