Surface mount information, Continued), Tin lead soldering – GE Industrial Solutions EVW020A0S6R0 Series (Eighth-Brick) User Manual

Page 11: Lead free soldering, Pb-free reflow profile, Msl rating, Storage and handling

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Data Sheet

March 3, 2011

EVW020A0S6R0 Series Eighth-Brick Power Modules

36–75Vdc Input; 6.0Vdc Output; 20A Output Current

LINEAGE

POWER

11

Surface Mount Information

(continued)

The CP is constructed from a solid copper pin with an
integral solder ball attached, which is composed of
tin/lead (Sn/Pb) solder for non-Z codes, or Sn/Ag

3

/Cu

(SAC) solder for –Z codes. The CP connector design
is able to compensate for large amounts of co-
planarity and still ensure a reliable SMT solder joint.
Typically, the eutectic solder melts at 183

o

C (Sn/Pb

solder) or 217-218

o

C (SAC solder), 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.

Tin Lead Soldering

The EVW020A0S6R0 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

P reheat zo ne
max 4

o

Cs

-1

So ak zo ne
30-240s

Heat zo ne
max 4

o

Cs

-1

P eak Temp 235

o

C

Co o ling
zo ne
1-4

o

Cs

-1

T

lim

above

205

o

C

REFLOW TIME (S)

Figure 23. Reflow Profile for Tin/Lead (Sn/Pb)
process

M

AX 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 24. Time Limit Curve Above 205

o

C for

Tin/Lead (Sn/Pb) process

Lead Free Soldering

The –Z version of the EVW020A0S6R0 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 25.

MSL Rating

The EVW020A0S6R0 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
minimum of 12 months from the bag seal date, when
stored at the following conditions: < 40° C, < 90%
relative humidity.

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