TECHNET Archives

June 2016

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:
George Wenger <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, [log in to unmask]
Date:
Wed, 22 Jun 2016 00:30:54 +0000
Content-Type:
text/plain
Parts/Attachments:
text/plain (43 lines)
Hi Mumtaz, 

Your statements are a little confusing. You indicated you fail solderability when you Dip-&-Look test the QFN with Sn63/Pb37 solder paste but pass solderability when you Surface Mount Process Simulation test the QFN with SAC305 solder paste. The Dip-&-Look test is supposed to be conducted by applying flux to the QFN pads and then dipping it into molten solder. This test is not intended to be done using solder paste. If you really meant that the QFN fails Dip-&-Look testing with Sn63/Pb37 solder but passes Surface Mount Process Simulation testing with SAC305 solder paste then my comment would be that it is not surprising that the QFN fails the Dip-&-Look testing because this is an inappropriate test for QFN packages. If you look at Section 5.3 in the JEDEC standard you will see that it indicates " The Dip and Look test is also inappropriate for BGA’s." This section should really indicate that the Dip-&-Look test is inappropriate for BGS's, QFN's and similar surface mount components. The solderability failures of these packages is due to physical issues associated with the Dip-&-Look test and not necessarily because the interconnection parts are not solderable. What I would do is to perform a Surface Mount Process Simulation test on the QFN using Sn63/Pb37 solder paste and I think you will see that the results will be completely different then the Dip-&-Look test. 

Regards, 

George 

George M. Wenger 
Failure Signature & Characterization Lab LLC 
609 Cokesbury Road, High Bridge, NJ 08829 
(908) 638-8771 (Home) (732)-309-8964 (Cell) 
[log in to unmask] 

----- Original Message -----

From: "Mumtaz Bora" <[log in to unmask]> 
To: [log in to unmask] 
Sent: Tuesday, June 21, 2016 7:42:26 PM 
Subject: [TN] laminate package wetting issues on ENIG surface 

Hello Technet team, 

We have a laminate based QFN package with ENIG plating on terminations. Using lead based paste Sn63/Pb37, we fail solderability test per JESD22B102E (dip and Look test) and also per J-STD-002 method B (dip and Look test). However, we passed reflow solderability test using lead free paste (SAC 305) per method JESD22B102E . Due to product requirements, we have to use eutectic Sn63/Pb37 solder paste. The reflow oven is convection air . If anyone had this issue and can share some insight or inputs will be much appreciated. 


Thank-you, 
Mumtaz 
858-795-0112 

CONFIDENTIALITY NOTE: The information transmitted, including attachments, is intended only for the person(s) or entity to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon this information by persons or entities other than the intended recipient is prohibited. If you received this in error, please contact the sender and destroy any copies of this information. 

______________________________________________________________________ 
This email has been scanned by the Symantec Email Security.cloud service. 
For more information please contact helpdesk at x2960 or [log in to unmask] 
______________________________________________________________________ 


______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask] 
______________________________________________________________________

ATOM RSS1 RSS2