Printed circuit board with high heat dissipation

A printed wiring board assembly comprising an electrically nonconductive component carrier sheet, multiple electronic components mounted on said carrier sheet and electrical wiring printed on said carrier sheet and defining with said components an electronic circuit;

• at least one heat spreader formed of thermally conductive material connected-to said carrier sheet, at least one of said components being attached to a first part of said heat spreader;
• a housing enclosing said carrier sheet and said components, including a base housing portion and a cover housing portion, said housing portions being formed of thermally conductive material;
• and a second part of said heat spreader being disposed between said housing portions and defining therewith parallel heat flow paths between said heat spreader and both of said housing portions whereby said housing acts as a heat sink as thermal energy is transferred between said one component and said housing through said heat spreader;
• said carrier sheet comprising a plurality of conductive junction pads and wiring conductor elements;
• said first heat spreader part being secured by bonding metal to at least one of said conductor elements;
• said carrier sheet having a margin with at least one opening formed therein, said first heat spreader part being received and secured in said opening, said bonding metal surrounding said opening.