PPC3-12-413/Best Practices
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sensitive to flexing or bending around ball grid array (BGA) devices. BGA
devices are extremely rigid by design, and flexing or bending the
embedded computer module can cause the BGA to tear away from the
printed circuit board.
Mounting holes
—The mounting holes are plated on the top, bottom, and
through the barrel of the hole. The mounting holes are connected to the
embedded computer module’s ground plane.
• Never use a drill or any other tool in an attempt to make the holes
larger.
• Never use screws with oversized heads. The head could come in con-
tact with nearby components causing a short or physical damage.
• Never use self-tapping screws; they compromise the walls of the
mounting hole.
• Never use oversized screws that cut into the walls of the mounting
holes.
• Always use all of the mounting holes. By using all of the mounting
holes, you provide the support the embedded computer module
needs to prevent bending or flexing.
Plug or unplug connectors only on fully mounted boards
—Never plug
or unplug connectors on a board that is not fully mounted. Many of the
connectors fit rather tightly and the force needed to plug or unplug them
could cause the embedded computer module to be flexed.
Avoid cutting the EBC-C413
—Never use star washers or any fastening
hardware that cut into the EBC-C413.
Avoid over-tightening of mounting hardware
—Causing the area
around the mounting holes to compress could damage interlayer traces
around the mounting holes.
Use appropriate tools
—Always use tools that are appropriate for
working with small hardware. Large tools can damage components
around the mounting holes.
Avoid conductive surfaces
—Never allow the embedded computer
module to be placed on a conductive surface. Many embedded systems
use a battery to back up the clock-calendar and CMOS memory. A
conductive surface such as a metal bench can short the battery causing
premature failure.
Adding PC/104 Boards to Your Stack
Be careful when adding PC/104 boards to your stack
—Never allow the
power to be turned on when a PC/104 board has been improperly
plugged onto the stack. It is possible to misalign the PC/104 card and leave
a row of pins on the end or down the long side hanging out of the