PPM-C412/Best Practices
v1.0
www.winsystems.com
Page 56
I/O Connections OFF
—I/O Connections should also be off before connecting them to
the embedded computer modules or any I/O cards. Connecting hot signals can cause
damage whether the embedded system is powered or not.
Mounting and Protecting the I/O Module
The PPM-C412 must be mounted properly to avoid damage. Standoff kits are available
and recommended for use with the PPM-C412. See Table 21 on page 54 for details.
Placing the PPM-C412 on Mounting Standoffs
—Be careful when placing the PPM-
C412 on the mounting standoffs. Sliding the board around until the standoffs are visible
from the top can cause component damage on the bottom of the board.
Do Not Bend or Flex the PPM-C412
—Bending or flexing can cause irreparable damage.
Embedded computer modules are especially 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 and are connected to the embedded computer module’s ground plane.
Traces are often routed in the inner layers right below, above or around the mounting
holes.
•
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 contact 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 pro-
vide the support the embedded computer module needs to prevent bending or flex-
ing.
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 PPM-C412
—Never use star washers or any fastening hardware that
cut into the PPM-C412.
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.
