TECHNET Archives

March 2000

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:
From:
Phil Crepeau <[log in to unmask]>
Reply To:
TechNet E-Mail Forum.
Date:
Tue, 7 Mar 2000 11:46:12 -0800
Content-Type:
text/plain
Parts/Attachments:
text/plain (105 lines)
hi,

in our particular case, the pwbs are 10 layer/48 mils thick and 8 layer/39 mils thick; the smallest via is 13 mils.  we have experienced no via failures with copper in the vias.  some people would add nickel plating if they thought there were going to be z-axis expansion problems.

phil

-----Original Message-----
From: Louis, Edwin @ CSE [mailto:[log in to unmask]]
Sent: Tuesday, March 07, 2000 11:28 AM
To: [log in to unmask]
Subject: Re: [TN] Alloy 42 Leaded TSOPS


Do you know how to over come the enhanced Z-axis CTE and the problem of
cracked vias?

-----Original Message-----
From: Phil Crepeau [mailto:[log in to unmask]]
Sent: Friday, February 18, 2000 4:41 PM
To: [log in to unmask]
Subject: Re: [TN] Alloy 42 Leaded TSOPS


hi,

i think that thermount (random kevlar fiber) reinforced epoxy or polyimide
laminate would be a reasonable choice.  there's no weight penalty to pay.
does your design have other parts that are plastic packaged?  if so, what
would you do about them?

phil

-----Original Message-----
From: Louis, Edwin @ CSE [mailto:[log in to unmask]]
Sent: Friday, February 18, 2000 11:11 AM
To: [log in to unmask]
Subject: [TN] Alloy 42 Leaded TSOPS


We have a sole source for  TSOP components, in which, they are only
available with alloy 42 leads. The vendor refuses to build the parts with
Copper leads because the  CTE of alloy 42 better matches the die CTE and as
result they have fewer component failures and defects.

Does any one know of a PWB material that would better match the CTE of alloy
42 leaded TSOPs?

##############################################################
TechNet Mail List 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 web site (http://www.ipc.org/html/forum.htm) for additional
information.
If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or
847-509-9700 ext.5365
##############################################################

##############################################################
TechNet Mail List 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 web site (http://www.ipc.org/html/forum.htm) for additional
information.
If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or
847-509-9700 ext.5365
##############################################################

##############################################################
TechNet Mail List 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 web site (http://www.ipc.org/html/forum.htm) for additional
information.
If you need assistance - contact Keach Sasamori at [log in to unmask] or
847-509-9700 ext.5315
##############################################################

##############################################################
TechNet Mail List 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 web site (http://www.ipc.org/html/forum.htm) for additional
information.
If you need assistance - contact Keach Sasamori at [log in to unmask] or
847-509-9700 ext.5315
##############################################################

ATOM RSS1 RSS2