CMA3000 VTI Hamlin, CMA3000 Datasheet - Page 16

• Manufacturer Part Number: CMA3000
• Description: Cma3000 Series 3-axis Accelerometer
• Manufacturer: VTI Hamlin

6.6 Component placement
6.7 Reflow soldering
7
8
9
VTI Technologies Oy
www.vti.fi
Hand Soldering Guidelines
Environmental Aspects
Effect of the Reflow Soldering
An accurate alignment of the component is an important process step although the surface tension
of the solder during the reflow step will help with the self-alignment. The use of a split-vision
alignment system is recommended to ensure the precise alignment of the component to the PWB.
The Z placement force should be carefully controlled in order to prevent the solder bridging,
component damage and misalignment.
The same reflow profile, as for the component removal, can be used for the re-attachment of the
replacement component as long as all solder joints will fully melt and properly wet the contact
areas. Otherwise, a new and proper reflow profile must be developed and measured from the
solder joints. Note that the reflow profile is always solder paste and flux dependent. The reworked
PWBs should be allowed to cool to the room temperature. The PWBs and the components should
be inspected after the rework process for possible defects. The use of X-ray inspection techniques
can be used to verify the success of the rework process.
Hand soldering of the CMA3000 component with soldering iron is not recommended. For proto-
uses of the CMA3000 component, VTI can provide pre-assembled component on a PWB. For
more information on this, please find the document CMA3000-D0X PWB specification 8287500A
and CMA3000-D0X PWB specification 8287600A. These can be found from the Internet at
www.vti.fi.
VTI Technologies respects environmental values and thus its CoM packaged accelerometer
sensors are lead-free and RoHS compatible. VTI Technologies’ sensors should be soldered with
lead-free solders in order to guarantee full RoHS compatibility.
CMA3000 is a factory calibrated three-axis accelerometer. However, reflow soldering may cause
acceleration offset shift due to thermal stress induced to the component. Offset shift depends e.g.
on the used layout design, circuit board material and the manufacturing process. Offset shift
stabilizes typically in 6 h after the reflow and is typically less than 150 mg (1σ). Calibration is not
recommended prior the offset has settled.
Typical offset settling behavior after the soldering can be seen in Figure 14 below.
Subject to changes
PRELIMINARY
TN68
CMA3000 Assembly Instructions
Rev.09
16/18