Abstract: A circuit board assembly that makes use of a low-temperature co-fired ceramic (LTCC) substrate, and a process for producing the assembly. The substrate contains at least first and second regions formed by a plurality of first ceramic layers and at least one second ceramic layer, respectively, that are superimposed and bonded to each other. Conductor lines are present on at least some of the first ceramic layers so as to be between adjacent pairs of the layers. Electrically-conductive vias electrically interconnect the conductor lines on different first ceramic layers, and a surface-mount IC device is mounted to the substrate. The first ceramic layers are formed of electrically-nonconductive materials, while the one or more second ceramic layers contain thermally-conductive particles dispersed in a matrix of electrically-nonconductive materials, such that the one or more second ceramic layers are more thermally conductive than the first ceramic layers.

Abstract: A circuit board assembly having a laminate construction of multiple layers, such as a LTCC ceramic substrate, with conductor lines between adjacent pairs of layers. A heat sink is bonded to a first surface of the substrate, and a cavity is defined by and between the heat sink and the substrate such that a base wall of the cavity is defined by one of the layers with conductor lines thereof being present on the base wall. A surface-mount circuit device is received within the cavity, mounted to the base wall, and electrically connected to the conductor lines on the base wall. The device is received within the cavity such that a surface of the device contacts a surface region of the heat sink. The surface of the device is bonded to the surface region of the heat sink to provide a substantially direct thermal path from the device to the heat sink.

Abstract: A circuit board assembly that makes use of a low-temperature co-fired ceramic (LTCC) substrate, and a process for producing the assembly. The substrate contains at least first and second regions formed by a plurality of first ceramic layers and at least one second ceramic layer, respectively, that are superimposed and bonded to each other. Conductor lines are present on at least some of the first ceramic layers so as to be between adjacent pairs of the layers. Electrically-conductive vias electrically interconnect the conductor lines on different first ceramic layers, and a surface-mount IC device is mounted to the substrate. The first ceramic layers are formed of electrically-nonconductive materials, while the one or more second ceramic layers contain thermally-conductive particles dispersed in a matrix of electrically-non-conductive materials, such that the one or more second ceramic layers are more thermally conductive than the first ceramic layers.