Surface mount information, Pick and place, Nozzle recommendations – GE Industrial Solutions Austin MegaLynx SMT User Manual

Page 26: Tin lead soldering

Advertising
background image

Data Sheet
September 10, 2013

Austin MegaLynx

TM

SMT: Non-Isolated DC-DC Power Modules:

4.5 – 5.5Vdc input; 0.8 to 3.63Vdc Output; 30A output current

6.0 – 14Vdc Input; 0.8Vdc to 3.63Vdc Output; 20/30A output

LINEAGE

POWER

26

Surface Mount Information

Pick and Place

The Austin MegaLynx

TM

SMT modules use an open

frame construction and are designed for a fully
automated assembly process. The modules are fitted
with a label designed to provide a large surface area
for pick and place operations. The label meets all the
requirements for surface mount processing, as well as
safety standards, and is able to withstand reflow
temperatures of up to 300

o

C. The label also carries

product information such as product code, serial
number and location of manufacture.

Figure 57. Pick and Place Location.

Nozzle Recommendations

The module weight has been kept to a minimum by
using open frame construction. Even so, these
modules have a relatively large mass when compared
to conventional SMT components. Variables such as
nozzle size, tip style, vacuum pressure and pick &
placement speed should be considered to optimize
this process. The minimum recommended inside
nozzle diameter for reliable operation is 3mm. The
maximum nozzle outer diameter, which will safely fit
within the allowable component spacing, is 5 mm
max.

Tin Lead Soldering

The Austin MegaLynx

TM

SMT 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.

REF

L

O

W

T

E

MP

C)

REFLOW TIME (S)

Figure 58. Reflow Profile for Tin/Lead (Sn/Pb)
process.

MAX

TE

MP

S

O

LD

ER

C)

Figure 59. Time Limit Curve Above 205

o

C Reflow

for Tin Lead (Sn/Pb) process.

0

50

100

150

200

250

300

Preheat zo ne
max 4

o

Cs

-1

Soak zo ne
30-240s

Heat zone
max 4

o

Cs

-1

Peak Temp 235

o

C

Co oling
zone
1-4

o

Cs

-1

T

lim

above

205

o

C

200

205

210

215

220

225

230

235

240

0

10

20

30

40

50

60

Advertising