Hi Michelle,

Do you know if the рroblem comes from the рrocess or comрonent itself? Your descriрtion is too generic to give an idea on the root cause.

One of our customers saw a similar рroblem but they narrow it down to the comрonent and then we did our рart to establish the root cause. 
Vladimir

SENTEC Testing Laboratory Inc.
11 Canadian Road, Unit 7.
Scarborough, ON M1R 5G1
Tel: (416) 899-1882
Fax: (905) 882-8812
www.sentec.ca

-----Original Message-----
From: Michelle Masaitis <[log in to unmask]>
Sender: TechNet <[log in to unmask]>
Date:         Thu, 18 Nov 2010 07:41:48 
To: <[log in to unmask]>
Reply-To: TechNet E-Mail Forum <[log in to unmask]>,
        Michelle Masaitis <[log in to unmask]>
Subject: [TN] Led Failures Please help

-   the through-hole LED in question is made by company "EOI ", and their 
part number is  "EOZ-ZARNCD0-DG " (s 
-   according to the component spec sheet  (enclosed), the maximum 
temperature for the component is 260℃ 
-   the maximum temp and wave contact time we initially used is  249℃ , 4-6 
seconds.  We saw some defects after first pass, usually about .2%, but one 
month as high as 1.5%.   After successful testing, there were then some 
latent defects that occurred at our customer or their end customer.  The 
defects are erratic, sometimes the LEDs work, and sometimes they don't 
-  the supplier recommended a lower temperature and shorter exposure profile 
so we used SAC305 solder with maximum temp of 244.4℃ and 3 seconds.  
There 
were no defects after first pass and testing, but again we had some latent 
defects occur at customer 
-   for reference, we run many similar LED from other manufacturers 
(OSRAM&Lumiled, also spec at 260℃) at temperatures of 251℃ and 4-7 
seconds 
and see no such problems. 

Attached is a wave profile.

Please let me know if you seen a similar issue and what caused it.


Thanks

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