TECHNET Archives

September 2004

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:
Hal Winslow <[log in to unmask]>
Reply To:
Date:
Wed, 29 Sep 2004 14:55:07 -0400
Content-Type:
text/plain
Parts/Attachments:
text/plain (90 lines)
Also check for moisture sensitivity of the LEDs.  I seem to remember (from a
"past life") being surprised to find those little LEDs actually had a max
humidity exposure time...

-----Original Message-----
From: TechNet [mailto:[log in to unmask]]On Behalf Of Creswick, Steven
Sent: Wednesday, September 29, 2004 2:42 PM
To: [log in to unmask]
Subject: Re: [TN] Reliability issue in 0402 soldering


I propose that you are damaging the LED's .... Take a quick check of the
manufacturer's data sheet to confirm that the part will endure the reflow
profile that you are subjecting them to.

Temp cycle a few of the remaining "working" parts - I bet they die soon as
well.

Sorry,

Steve C

-----Original Message-----
From: Prasad AN [mailto:[log in to unmask]]
Sent: Wednesday, September 29, 2004 4:14 AM
To: [log in to unmask]
Subject: [TN] Reliability issue in 0402 soldering


Hi all

We are assembling around 750 # of 0402 size LEDs in small PCB of size 65mm X
65mm.

The problem we are having after reflow, when PCB is tested all the LEDs are
glowing.

But after some time the problem starts with 3-4 LEDs not glowing.

The PCB surface is of  Tin plating.

Let me know is the PCB surface is suitable for this type of board. If not
what type of surface is recommended for PCB with only 0402 LEDs.


Thanks with Warm regards

A.N.Prasad




---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 1.8e
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to
[log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to
[log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16
for additional information, or contact Keach Sasamori at [log in to unmask] or
847-509-9700 ext.5315
-----------------------------------------------------

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 1.8e
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to
[log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to
[log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16
for additional information, or contact Keach Sasamori at [log in to unmask] or
847-509-9700 ext.5315
-----------------------------------------------------

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 1.8e
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
-----------------------------------------------------

ATOM RSS1 RSS2