LISTSERV - TECHNET Archives - LISTSERV.IPC.ORG

TECHNET Archives

March 2002

TechNet@IPC.ORG

	LISTSERV Archives
	TECHNET Home
	TECHNET March 2002

	Log In
	Register

	Subscribe or Unsubscribe

	Search Archives

Options:	Use Monospaced Font Show Text Part by Default Show All Mail Headers
Message:	[<< First] [< Prev] [Next >] [Last >>]
Topic:	[<< First] [< Prev] [Next >] [Last >>]
Author:	[<< First] [< Prev] [Next >] [Last >>]

Subject:	Re: Via in Pad? Need Help!!!
From:	Earl Moon <[log in to unmask]>
Reply To:	TechNet E-Mail Forum.
Date:	Tue, 5 Mar 2002 23:56:06 -0600
Content-Type:	text/plain
Parts/Attachments:	text/plain (40 lines)

Seth,

There are two basic ways to do it. One is, when necessary, to use sequential
lamination that forces resin up the "standard" size (not micro via) hole
leaving it relatively flat or flush to the surface. Then, the hole is
electrolessly deposited and electroplated over. The second is to fill the
holes with conductive material/resin and do the same. The conductive resin
usually is silver and does a nice job as well.

Flatness, to some, can be an issue. I'll post an image, showing a typical
condition, on Steve's site if he will be so kind. However, the surfaces are
suitable for BGA type devices because of their self aligning tendencies.
Haven't used it for others but chip components that don't find the surfaces
a problem especially compared to vias that are disastrous.

This whole issue, for me, revolves around some R/F folks, and their designs,
not recalculating the electrical requirements to get rid of vias in holes.
As you know, touching these parts up is not feasable as the solder still
keeps draining down the holes and chip cracking occurs during the process.
Chip devices just can't take to much thermal and shouldn't with good designs.

Oh Seth, before I forget, I forgot how to get either myself or other folks
into your ftp site. Some folks are asking me how and I need to know as well
as I'm on a different computer now and lost the info.

Thanks,

Earl

---------------------------------------------------------------------------------
Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL
To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives
Please visit IPC web site http://www.ipc.org/html/forum.htm for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
---------------------------------------------------------------------------------

ATOM RSS1 RSS2

LISTSERV.IPC.ORG