SCA3000 Datasheet, PDF (11/15 Pages) VTI technologies – 3-axis accelerometer

SCA3000 Assembly Instructions
Figure 9. Solder pads, component leads and the solder joints are located under the component
itself.
X-ray inspection is a recommended inspection method for being able to check the complete solder
joint area for solder bridges or short-circuits between solder pads. The X-ray inspection systems
vary from manual to fully automated optical inspection systems. X-ray can be used for sample
based process control, but it can also be implemented as an automatic in-line control. X-ray
inspection can also be used to establish and optimize the component assembly process
parameters.
Cross-sectional analysis is also an approved method to inspect how well solder has wetted the
pads of component. Cross-sectional analysis is not used for production inspection, but if required, it
can be used to establish and optimize the component assembly process parameters. Cross-
sectioning is a destructive inspection method. An example of a SCA3000 solder joint cross-section
in presented in figure 10.
Outer
surface of
solder pad
Inner surface
of solder pad
Figure 10. Wetting of solder is different on the inner and outer surface of the solder pad.
VTI Technologies Oy
www.vti.fi
Subject to changes
TN54
11/15
Rev.C