LSM-0.8-10-D12 C&D Technologies., LSM-0.8-10-D12 Datasheet - Page 17

• Manufacturer Part Number: LSM-0.8-10-D12
• Description: Non-isolated, 12vin, 0.75-5vo U T Dc/dc Converters
• Manufacturer: C&D Technologies.

Tape & Reel Surface Mount Package
Murata Power Solutions' LSM series DC/DC converters are the only higher-
current (10A) SMT DC/DC's that can be automatically "pick-and-placed" using
standard vacuum-pickup equipment (nozzle size and style, vacuum pressure
and placement speed may need to be optimized for automated pick and place)
and subsequently reflowed using high-temperature, lead-free solder.
assembled by their vendors with high-temperature solder (usually Sn96.5/Ag3.5
with a melting point +221°C) so that you may attach them to your board using
low-temperature solder (usually Sn63/Pb37 with a melting point of +183°C).
Conceptually straightforward, this "stepped" solder approach has its limita-
tions, and it is clearly out of step with an industry trending toward the broad
use of lead-free solders. Are you to experiment and develop reflow profiles
from other vendors that ensure the components on those DC/DC never exceed
215-216°C? If those components get too hot, "double-reflow" could compro-
mise the reliability of their solder joints. Virtually all these devices demand you
"cool down" the Sn63 profile you are likely using today.
Virtually all SMT DC/DCs today are unprotected "open-frame" devices
250
221
200
183
150
100
50
0
50
Sn96.5/Ag3.5 Melting Point
Sn63/Pb37 Melting Point
100
www.murata-ps.com
PCB TEMPERATURE INSIDE THE HEAT SHIELD
150
Figure 6. Reflow Solder Profile
Time (Seconds)
200
solders no one else has. We do have a simple and practical, straightforward
approach that works. We assemble our SMT DC/DC’s on a thermally-stable
plastic lead-frame (nylon 46, UL94V-0 flammability rated) using a high temper-
ature lead-free solder. In addition, the LSM is transitioning to RoHS (Reduction
of Hazardous Substances) construction and SAC 305 RoHS-approved solder.
The lead-frame ensures coplanarity (to within 0.004 in.) of the unit's copper
leads. These leads are gold-plated with a nickel underplate. See Mechanical
Data for additional information.
provides thermal insulation to internal components during reflow and doubles
as the vacuum pick-up location. The insulation properties of the heat shield are
so effective that temperature differentials as high as 50°C develop inside-to-
outside the shield. Oven temperature profiles with peaks of 250-260°C and
dwell times exceeding 2 minutes above 221°C are easily achieved. MPS's
new-generation SMT units are shipped in stackable, JEDEC-style plastic tray.
MPS is not exempted from the Laws of Physics. And we do not have magic
The disposable heat shield, with a cutaway exposing the package leads,
Non-Isolated, 12V
250
HEAT SHIELD OUTSIDE TEMPERATURE
Technical enquiries email: [e-mail], tel:
300
in
LSM-10A D12 Models
, 0.75-5V
MDC_LSM 10A D12 Models.B01 Page 17 of 18
Single Output
350
out
DC/DC Converters
400
[phone]