Sensors

8

Freescale Semiconductor

MMA7331L

MINIMUM RECOMMENDED FOOTPRINT FOR SURFACE MOUNTED APPLICATIONS

PCB Mounting Recommendations

MEMS based sensors are sensitive to Printed Circuit

Board (PCB) reflow processes. For optimal zero-g offset after

PCB mounting, care must be taken to PCB layout and reflow

conditions. Reference application note AN3484 for best

practices to minimize the zero-g offset shift after PCB

mounting.

Surface mount board layout is a critical portion of the total

design. The footprint for the surface mount packages must be

the correct size to ensure proper solder connection interface

between the board and the package.

With the correct footprint, the packages will self-align when

subjected to a solder reflow process. It is always

recommended to design boards with a solder mask layer to

avoid bridging and shorting between solder pads.

Figure 8. LGA 14-Lead, 5 x 3 mm Die Sensor

6x2

12x1

14x0.9

14x0.6

10x0.8

1

13

6

8