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

CMA3000 Assembly Instructions
1 Objective
This document describes guidelines for Printed Wiring Board (PWB) design and assembly of the
CMA3000 3-axis Accelerometer. It also aims to help customers achieve the optimum soldering
process.
2 VTI's 3D Stacked Wafer Level Chip-on-MEMS Package (CoM)
CMA3000 features a novel packaging concept, which is called Chip-on-MEMS (CoM). Its approach
has been to maintain the benefits of manufacturing the MEMS devices and ASICs on separate
wafers. For this Chip-on-MEMS concept, ASIC chips are flip-chipped onto the MEMS wafer in
known good locations. Redistribution and isolation layers are applied to the MEMS wafer, solder
spheres are provided for external connection before the ASICs are added and the MEMS and
ASIC chips are then isolated using a passivation layer. The concept is illustrated in Figure 1.
Figure 1. The concept of the CMA3000 component.
CoM-technology offers a variety of benefits including reduced lead inductance, an extremely small
sized chip scale package, less than 1mm thin profile, low weight, excellent solderability and
reworkability due to solder spheres. Because the CoM-technology represents the latest in the
surface mount packaging technology, it is important that the design of the printed wiring board, as
well as the assembly process, follow the suggested guidelines outlined in this document.
It should be emphasized that these guidelines are general in nature and should only be considered
as a starting point. The user must employ their actual experiences and development efforts to
optimize designs and processes for their manufacturing practices and the needs of varying end-
use applications.
VTI Technologies Oy
www.vti.fi
PRELIMINARY
Subject to changes
TN68
3/18
Rev.09