solder paste type
Cree strongly recommends using “no clean” solder paste with XLamp ML LeDs so that cleaning the PCB after soldering is not required.
Cree uses
internally.
Cree recommends the following solder paste compositions: SnAgCu (tin/silver/copper) and SnAg (tin/silver).
solder paste thickness
The choice of solder and the application method will dictate the specific amount of solder. For the most consistent results, an automated
dispensing system or a solder stencil printer is recommended. Cree has seen positive results using solder thickness that results in a 4-mil
(102-μm) bond line, i.e., the solder joint thickness after reflow soldering.
after soldering
After soldering, allow XLamp ML family LeDs to return to room temperature before subsequent handling. Premature handling of the
device could result in damage to the LeD.
Cree recommends verifying the solder process by checking the consistency of the solder bond of several trial PCBs after reflow. After
shearing selected devices from the circuit board the solder should appear completely re-flowed (no solder grains evident). The solder
areas should show minimum evidence of voids on the backside of the package and the PCB.
Cleaning pCbs after soldering
Cree recommends using “no clean” solder paste so that flux cleaning is not necessary after reflow soldering. If PCB cleaning is necessary,
Cree recommends the use of isopropyl alcohol (IPA).
Do not use ultrasonic cleaning.
Moisture sensitivity
XLamp ML Family LeDs are shipped in sealed, moisture-barrier bags
(MBB) designed for long shelf life. If XLamp ML Family LeDs are
exposed to moist environments after opening the MBB packaging but
before soldering, damage to the LeD may occur during the soldering
operation. The derating table at right defines the maximum exposure
time (in days) for an XLamp ML Family LeD in the listed humidity and
temperature conditions. LeDs with exposure time longer than the time
specified below must be baked according to the baking conditions listed below.
P
CorrECt
X
Wrong
temp.
Maximum percent relative Humidity
30%
40%
50%
60%
70%
80%
90%
35 ºC
-
-
-
17
1
.5
.5
30 ºC
-
-
-
28
1
1
1
25 ºC
-
-
-
-
2
1
1
20 ºC
-
-
-
-
2
1
1
55
Copyright © 2010-2018 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree
®
, the Cree logo and XLamp
®
are registered trademarks of Cree, Inc. Other
trademarks, product and company names are the property of their respective owners and do not imply specific product and/or vendor endorsement, sponsorship or association. This document is provided
for informational purposes only and is not a warranty or a specification. For product specifications, please see the data sheets available at www.cree.com. For warranty information, please contact Cree
Sales at [email protected].
5
XLamp
®
mL FamiLy LED SoLDEring & HanDLing
