are positioned one on top of the other between the top plate 12 and bottom plate 16 a gasket 22 a d is provided between the top plate 12 each of the substrates 20 a c and the bottom plate 16 respectively a plurality of electrical leads 24 extend from the outer periphery of substrate 20a outside the module housing the leads 24 are used for electrically coupling the chips in the module to external electrical components the module 10 is held together by a plurality of screws 26 and bolts 28 the screws pass through the top plate 12 the substrates 20 a c and gaskets 22 a d and bottom plate 16 when clamped together by a tightening of the screws and bolts the module 10 is liquid tight each substrate 20 includes a top surface 30 a bottom surface 32 and an open region or hole 34 formed through the substrate an attach area 36 is provided within the hole 34 and is used to attach a semiconductor chip package thereto note that the chip packages intended to be housed within the module and various electrical features present on each substrate are not shown in fig1 a and 1b for the sake of clarity but are described below in detail the bottom surface 32 of each substrate 20 includes a conduit 38 formed therein the conduit 38 acts as a channel for controlling the direction of the flow of the coolant it is useful to note that the conduit 38 encompasses the hole 34 and the attach area 36 of the substrate 20 the substrate 20 includes two coolant flow passage holes 40 the coolant passage holes 40 permit coolant to flow from the top surface 30 and into the conduit.