I really don't think that a through hole via can work when you're

discussing via in pad. Too many manufacturing problems.

Blind and buried is the way to go.

Have you tried via HALF in pad ?

You can add a blind via at the end of the pad instead of the middle.

This takes care of many of the issues , but of course your board price

has gone up significantly...



Good Luck,



Andre Demers C.I.D.

Senior PCB Designer 



cmrsummit Technologies 

310-733 boulevard St-Joseph 

Gatineau (Québec) J8Y 4B6 

Canada 



Telephone: 819.205.1185 

Toll Free: 877.428.1229 

Fax: 514.428.5953 



[log in to unmask] 

www.cmrsummit.com













-----Original Message-----

From: DesignerCouncil [mailto:[log in to unmask]] On Behalf Of Ray Johnston

Sent: Thursday, January 29, 2009 10:43 AM

To: [log in to unmask]

Subject: Re: [DC] Via-In-Pad



Alexis,

If you use via-in-pad, it must be a filled via or it will leave a sink in 

the pad and even then manufacturing may have soldering issues. If the via is 

filled manufacturing will have soldering issues. we tried this technology in 

0603 and 0805 pads with a 10mil through hole and abandoned it because the 

cost of filled vias and the manufacturing soldering problems.



Ray Johnston

Rane Corporation

425-355-6000

rayj@rane,com





----- Original Message ----- 

From: "Alexis Meehan" <[log in to unmask]>

To: <[log in to unmask]>

Sent: Wednesday, January 28, 2009 6:59 PM

Subject: [DC] Via-In-Pad





> One of our engineers has asked if we can implement via-in-pad on a handful 

> of 0603 pads to facilitate routing of critical lines. We've never done it 

> here before, and I know that it increases both fab and assembly costs. I'm 

> also concerned about the risks involved (trapped solvents, rising via 

> plugs, etc). Has anyone out there used this technology on only a few 

> components with success (and minimal problems)? I'm not sure if we should 

> be doing this on a layout spin that needs to be our production version. 

> Thanks in advance for any feedback.

>

> Alexis Meehan

> Opnext Subsystems, Inc.

> Desk: 408-385-3040

>

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