TECHNET Archives

February 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:
Jorge Engenharia <[log in to unmask]>
Reply To:
TechNet E-Mail Forum.
Date:
Wed, 2 Feb 2000 06:45:50 -0500
Content-Type:
text/plain
Parts/Attachments:
text/plain (75 lines)
Thomas

   I have seen problems with PLCC socket when they run inside IR oven due to
shadow effect caused by the walls of the socket, the peak temperature
achieved were the lowest in the board that contribute to a weak solder
joint. Using forced convection oven they had better performance.I always
measure temperature inside the socket to check the oven profile. Besides
that they are hard to inspect, difficult to rework and not easy at placement
machines ( vision system )
  Other problem could be component insertion inside the socket, some
operators didn't realize the force that they have ...
  Other problem could be in handling ( magazine insertion, packing, etc .. )
due the height and location of the socket it could crash somewhere
   I try to avoid using this parts and when is possible I put the component
direct in the board without the socket !!!

Thanx
Jorge Dourado de Santana
Maintenance / Process Engr
Microtec - Brazil


> -----Original Message-----
> From: Thomas Han [SMTP:[log in to unmask]]
> Sent: 1 de Fevereiro de 2000 22:17
> To:   [log in to unmask]
> Subject:      [TN] SMD PLCC Socket
>
> We ran a batch of boards that had surface mount PLCC84pin sockets.  PLCC
> components are placed prior to shippment.  Our customer have noticed that
> few boards had disconnected socket pins(one per socket).  Only thing that
> I
> could think of that would cause this to happen is, installation of PLCCs
> into its socket, creating enough  shear force on the connector to break
> the
> solder joint.  I didn't get a chance to look at the broken solder joint
> itself, but I took a look at some of the finished goods in house, and the
> plastic housing on the sockets bow out a little bit upon insertion of
> PLCC.
>  Has anyone seen this before?  What else might cause this to happen.
> Customer had stated that the solder joints are well wetted.  Any input is
> greatly appreciated.
>
> Tom
>
> ##############################################################
> 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
##############################################################

ATOM RSS1 RSS2