TECHNET Archives

October 1998

TechNet@IPC.ORG
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 >>]

Print Reply
Subject:
Re: Vias in chip components pads?
From:
Lum Wee Mei <[log in to unmask]>
Reply To:
TechNet E-Mail Forum.
Date:
Fri, 2 Oct 1998 10:31:13 +0800
Content-Type:
text/plain
Parts/Attachments:
text/plain (45 lines) 
I am very curious to know:

1. Is it true that solder will definitely flow through a PTH via?
2. What if the via hole is small enough to prevent this capillary effect? Does that means PTH via is still
OK?
3. How small a via hole will be for (2)?



Kelly M. Schriver wrote:

> Hi Scott -
>
> The via in pad is a problem UNLESS it's a microvia which only goes a layer or
> two deep in the board.  Vias which go all the way thru the board will steal
> solder from the connection you're trying to make on one side, then turn that
> same solder into a nice spherical bead on the opposite side.
>
> The inspectors and touch up people, in turn, have lifetime job security.
>
> Regards - Kelly
>
> ################################################################
> TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c
> ################################################################
> To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body:
> To subscribe:   SUBSCRIBE TechNet <your full name>
> To unsubscribe:   SIGNOFF TechNet
> ################################################################
> Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information.
> For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312
> ################################################################

################################################################
TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c
################################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body:
To subscribe:   SUBSCRIBE TechNet <your full name>
To unsubscribe:   SIGNOFF TechNet 
################################################################
Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information.
For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312
################################################################

ATOM RSS1 RSS2