Abstract: A printed circuit board module consists of a first printed circuit board with a nonconductive panel connected to the foil side of the board. Extending parallel to and spaced from the first printed circuit board is a frame having a number of standoffs connected to the first printed circuit board and its insulating panel. A frame insert consisting of a nonconductive panel to which a second printed circuit board is fastened is removably positioned within the central opening of the frame. Two opposed inner edges of the frame have two sets of spaced support tabs. The two sets of tabs are parallel to one another and staggered so as to form a channel therebetween. The corresponding edges of the frame insert have a plurality of aligned locking tabs so dimensioned and positioned as to fit between adjacent locking tabs in one set and slide along the channel to retain the insert within the frame.

Abstract: A chassis for holding a plurality of printed circuit boards has a number of locations at which the printed circuit boards may be positioned. Each of the locations having opposed slotted tracks for holding opposite edges of the printed circuit board placed at that location. One of the locations holds a power supply for the chassis.A printed circuit board retaining mechanism has a first position in which a tab extends across the slots in one of the tracks for each of the printed circuit board locations and a second position in which the tabs do not extend across the slot. Each of the printed circuit boards has a notch along one edge. When the printed circuit board is fully inserted into one of the locations in the chassis, the tab corresponding to that track engages the notch preventing the removal of the printed circuit board from the chassis.