Could be an Alloy 42 leadframe, this will require a hotter reflow spike
to wet properly. If not Alloy 42, could be an issue with
contamination/oxidation related to the particular manufacturer (they
never make bad parts, hehehe). Check for leadframe metallurgy, then
solderability testing of component leads using your existing process
chemistry for flux selection. If contamination, you might be able to
address by going to a more active flux/paste for improved wetting.

Mike McMonagle
K*Tec Electronics
(281) 243-5639

> -----Original Message-----
> From: Thibodeau, Chad [SMTP:[log in to unmask]]
> Sent: Wednesday, August 05, 1998 1:28 PM
> To:   [log in to unmask]
> Subject:      [TN] 240 Pin PQFP Solderability Problems
>
> We are having difficulty in soldering a particular manufacturer's 240
> Pin
> (20 mil) PQFP using a standard reflow process.  The defect we are
> seeing is
> described as "pillowing effect" or "foot-in-the-mud effect" in which
> it
> appears that the there is a wettability issue.  The difficulty with
> this
> failure is that it is very random in nature, although supposedly not
> uncommon.  If anyone has experienced a similar type of problem, PLEASE
> respond with any information you can.  Your contribution will be very
> much
> appreciated.  Thank you.
>
> Chad Thibodeau
> EF Data
> Component Engineer
> 602 333-2138 Phone
> 602 921-9012 Fax
> [log in to unmask]
>
> ################################################################
> 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
################################################################