hi,

there may be no easy solution.  if indeed it is a defect associated with a specific lot, you should be able to come up with a test that would filter out subsequent parts at receiving inspection.  you may also need to create a specification control drawing to add this requirement to the vendor's specification.

this leaves you with a task of identifying and replacing those parts from the suspect lot that you have already attached.

can you consider a two stage reflow process?  the first stage would be your normal process without the capacitors.  the second stage would be a reflow process in which a low termperature solder is used.

good luck.

phil

-----Original Message-----
From: Howard Watson [mailto:[log in to unmask]]
Sent: Thursday, January 17, 2002 7:09 AM
To: [log in to unmask]
Subject: Re: [TN] Al Electrolytic Capacitors leaking



Thanks Phil.  I am wondering if the 218C is too high of a peak temperature for these type of components.  We use a lot of them, so hand soldering is not a popular recommendation here.  Can they get damaged without any visible defect?  I have isolated the problem to a specific lot, but then maybe it will show up again in the future.

Howard Watson
Manufacturing Engineer
AMETEK/Dixson



        "Crepeau, Phil" <[log in to unmask]>
Sent by: TechNet <[log in to unmask]>


01/16/02 04:45 PM
Please respond to "TechNet E-Mail Forum."; Please respond to "Crepeau, Phil"



        To:        [log in to unmask]
        cc:
        Subject:        Re: [TN] Al Electrolytic Capacitors leaking



hi,

definitely sounds like a job for hand soldering after mass reflow.  oh, and definitely, these parts are prone to failure at high temperature.  isn't everything?

phil
-----Original Message-----
From: Howard Watson [mailto:[log in to unmask]]
Sent: Wednesday, January 16, 2002 12:28 PM
To: [log in to unmask]
Subject: [TN] Al Electrolytic Capacitors leaking


Technetters,

Please help!  I have some Aluminum Electrolytic Capacitors that are leaking fluid on the top of the can after reflow.  My peak temperature on the top of the can is 218C, with a time above 183 at 53 seconds, which seem to be appropriate.  The manufacturer recommends the time above 200C to be 20 seconds maximum, which is too little on these boards to get good solder on all the components.  The boards are reflowed in a Vitronics 10 zone convection oven.  The part is Nichicon #2309369R25.  Is anyone familiar with this type of problem, and if so any suggestions will be greatly appreciated!   Are these type of parts prone to failure at high temperatures?

Howard Watson
Manufacturing Engineer
AMETEK/Dixson