Sensors

Freescale Semiconductor

29

MMA7455L

MINIMUM RECOMMENDED FOOTPRINT FOR SURFACE MOUNTED APPLICATIONS

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.

SOLDERING AND MOUNTING GUIDELINES FOR THE LGA ACCELEROMETER SENSOR TO A PC BOARD

These guideline are for soldering and mounting the LGA package inertial sensors to printed circuit boards (PCBs). The purpose

is to minimize the stress on the package after board mounting. The MMA7455L digital output accelerometer uses the Land Grid

Array (LGA) package platform. This section describes suggested methods of soldering these devices to the PC board for con-

sumer applications. Figure 18 shows the recommended PCB land pattern for the package.

Figure 18. Recommended PCB Land Pattern for the 5 x 3 mm LGA Package