CMA3000 Datasheet, PDF (12/18 Pages) VTI technologies – 3-axis accelerometer

CMA3000 Assembly Instructions
Figure 10. Typical convection reflow soldering phases and profile (IPC/JEDEC J-STD-020C table
5-2 and figure 5-1).
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 CMA3000 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.
Underfilling of the CMA3000 is not recommended. This can affect on the component performance.
VTI Technologies Oy
www.vti.fi
PRELIMINARY
Subject to changes
TN68
12/18
Rev.09