Bottom side / first side assembly, Tin lead soldering, Lead free soldering – GE Industrial Solutions FLT012A0-SZ User Manual

Page 8: Msl rating, Storage and handling

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Data Sheet
February 9, 2012

FLT012A0Z/FLT012A0-SZ Input Filter Modules

75Vdc Input Voltage Maximum, 12A Output Current Maximum

LINEAGE

POWER

8

Bottom Side / First Side Assembly

This module is not recommended for assembly on the
bottom side of a customer board. If such an assembly
is attempted, components may fall off the module
during the second reflow process.

Tin Lead Soldering

The FLT012A0-SZ power modules are lead free
modules and can be soldered either in a lead-free
solder process or in a conventional Tin/Lead (Sn/Pb)
process. It is recommended that the customer review
data sheets in order to customize the solder reflow
profile for each application board assembly. The
following instructions must be observed when
soldering these units. Failure to observe these
instructions may result in the failure of or cause
damage to the modules, and can adversely affect
long-term reliability.

In a conventional Tin/Lead (Sn/Pb) solder process
peak reflow temperatures are limited to less than
235

o

C. Typically, the eutectic solder melts at 183

o

C,

wets the land, and subsequently wicks the device
connection. Sufficient time must be allowed to fuse
the plating on the connection to ensure a reliable
solder joint. There are several types of SMT reflow
technologies currently used in the industry. These
surface mount power modules can be reliably
soldered using natural forced convection, IR (radiant
infrared), or a combination of convection/IR. For
reliable soldering the solder reflow profile should be
established by accurately measuring the modules CP
connector temperatures.

R

E

FLOW

TEM

P

C)

0

50

100

150

200

250

300

Preheat zo ne
max 4

o

Cs

-1

So ak zo ne
30-240s

Heat zone
max 4

o

Cs

-1

Peak Temp 235

o

C

Co o ling
zo ne
1-4

o

Cs

-1

T

lim

above

205

o

C

REFLOW TIME (S)

Figure 13. Reflow Profile for Tin/Lead (Sn/Pb)
process.

MAX

TE

M

P

S

O

LD

ER

C)

200

205

210

215

220

225

230

235

240

0

10

20

30

40

50

60

Figure 14. Time Limit Curve Above 205

o

C Reflow

for Tin Lead (Sn/Pb) process.

Lead Free Soldering

The FLT012A0-SZ SMT modules are lead-free (Pb-
free) and RoHS compliant and are both forward and
backward compatible in a Pb-free and a SnPb
soldering process. Failure to observe the instructions
below may result in the failure of or cause damage to
the modules and can adversely affect long-term
reliability.


Pb-free Reflow Profile

Power Systems will comply with J-STD-020 Rev. C
(Moisture/Reflow Sensitivity Classification for
Nonhermetic Solid State Surface Mount Devices) for
both Pb-free solder profiles and MSL classification
procedures. This standard provides a recommended
forced-air-convection reflow profile based on the
volume and thickness of the package (table 4-2). The
suggested Pb-free solder paste is Sn/Ag/Cu (SAC).
The recommended linear reflow profile using
Sn/Ag/Cu solder is shown in Figure. 15. Soldering
outside of the recommended profile requires testing to
verify results and performance.

MSL Rating

The FLT012A0-SRZ SMT modules have a MSL rating
of 2a.

Storage and Handling

The recommended storage environment and handling
procedures for moisture-sensitive surface mount
packages is detailed in J-STD-033 Rev. A (Handling,
Packing, Shipping and Use of Moisture/Reflow
Sensitive Surface Mount Devices). Moisture barrier
bags (MBB) with desiccant are required for MSL
ratings of 2 or greater. These sealed packages
should not be broken until time of use. Once the
original package is broken, the floor life of the product
at conditions of <= 30°C and 60% relative humidity
varies according to the MSL rating (see J-STD-033A).
The shelf life for dry packed SMT packages will be a

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