Card Guide Recommendations
Card Guides are produced to accept either center or side mount cards. Card
guides are designed to accept printed circuit boards of a particular thickness. So card
guides need to be selected to accommodate the style of board used in the system. Common
sizes; 1/32", 1/16", 3/32", and 1/8" thick printed circuit boards.
Card guides may also be produced in either Plastic or Metal. Plastic card guides are
much cheaper than their more expensive metal counter-parts.
Plastic Card Guides: Plastic or Nylon card guides are available in a variety of
different colors. Including Red (system slot), Green (Power slot), Yellow, and Gray.
Some guides may be designed for use in IEEE1101.10 systems where ESD may need removal from the front panel of the plug-in
board, as well as from charged components on the board itself, during hot swapping.
These guides also include chambers in the front face for coding keys as specified in
IEC 60297-3-103 [Keying
Cards per Slot].
Metal Card Guides: Metal card guides may also be used to help ground the PWB
using the card slot. Circuit cards are some times designed with a metal (normally
copper) island that runs the length of the top and bottom of the card. This metal
island is connected to circuit ground which then helps to ground the card to the metal
card guide.
Also refer to Filler Panels or Slot Bypass Cards which will also
benefit from metal card rails by reducing card-to-card (slot-to-slot) noise.
Air flow blockers which close off the air coming from beneath the card cage may also be
used with some types of card guides [used in an empty slot].
Metal card guides may also be used as a Circuit Card Assembly (CCA) heat sinks when
copper bands are formed on the PCB. The board copper is terminated to a heat radiator,
or land located on the card and is then used to conduct heat out to the card guide.
This large contact area of the guide transfers the heat rapidly from the CCA to the
Guide and into the chassis or cold frame holding the guide. Normally spring fingered
card guides work best when the board guide is used as a conductor. Spring fingered
guides insure that the guide and the board are always in good contact.
Card Guide Clusters / Decks are also available in 1, 2, 3 or 4 slot clusters, having
all the board slot guides pre-connected.
Design Options; Metal, Plastic, white, multi-colored, Keyed, thickness [.063 is standard].
Card Guide Manufacturers
Atlee {Printed Circuit Board Holders, Card Guides}
Birtcher {Beryllium Copper retainers}
Hartmann Elektronik {Cardguide 4 HP, coding acc. to IEEE 1101.10, Material Polycarbonat UL94 V-0, Board thickness 1.6 to 2 mm, Colors: Red (CPU slot), Green (CompactPCI power supply 1/2 HP offset), Grey (peripheral slot)}
Richro {Card Guide Manufacturer, Tension, Vertical Mount, Metal, Plastic, Snap-In}
Pixus Technologies {Plastic Guide Rails, Air flow blockers}
Unitrack Industries {Nylon Slotted PC Card Guides; Vibration and Shock Damping Card Guides, ESD plastic, Metal Card Guides}
When to Define Chassis Card Keying, next chassis
design topic.
To prevent incorrect board insertion, in the incorrect slot.
How To Design an Embedded Equipment Chassis; Subject Index
