SCA3000 VTI [VTI technologies], SCA3000 Datasheet - Page 10

• Manufacturer Part Number: SCA3000
• Description: 3-axis accelerometer
• Manufacturer: VTI [VTI technologies]

5.8 Moisture sensitivity level (MSL) classification
5.9 Inspection
VTI Technologies Oy
www.vti.fi
Figure 8. Typical convection reflow soldering phases and profile.
The process window for lead-free soldering is narrower than for traditional eutectic SnPb solders.
Thus, caution has to be taken care when adjusting the reflow profiles. The reflow profile should be
measured using a thermo-couple measurement system. It is recommended that at least three
thermo-couples are used, depending on the application. As a general guide, one thermo-couple
should be placed under a component having the largest thermal mass, one next to the smallest
component, one should be in contact with SCA3000 component's solder joint, and others to the
appropriate spots on a circuit board, e.g. corner, center, bottom of the board etc. The reflow profile
should be adjusted according to the measured data so that each solder joint experiences an
optimal reflow profile. The temperature gradient should be as small as possible across the
circuit board and the components. Extreme caution has to be taken if the circuit board
contains components with vastly different thermal masses.
The Moisture Sensitivity Level of the SCA3000 component is Level 3 according to the IPC/JEDEC
J-STD-020C. The part is delivered in a dry pack. The manufacturing floor time (out of bag) at the
customer’s end is 168 hours. Maximum soldering peak temperature for the SCA3000 is
260°C/40sec, measured from the package body.
Optical and visual inspection of solder joints can be done only partly, since the solder joints are
located underneath the component itself. Therefore inspection of the solder joints with conventional
AOI (automatic optical inspection) system is not recommended. Figure 9 show photos of how the
soldered component on PWB looks from different directions.
Subject to changes
TN54
SCA3000 Assembly Instructions
Rev.C
10/15