Vertically stacked multichip modules

A circuit assembly apparatus comprising:

• a first semiconductor die;
• a second semiconductor die;
• a first substrate including:
• a first insulating layer;
• a first metal layer disposed on a first side of the first insulating layer, a first side of the first semiconductor die being disposed on and electrically coupled with the first metal layer;
• a second metal layer disposed on a second side of the first insulating layer, the second side of the first insulating layer being opposite the first side of the first insulating layer, a first side of the second semiconductor die being disposed on and electrically coupled with the second metal layer, the first insulating layer electrically isolating the first metal layer from the second metal layer;
• a third metal layer disposed on the second side of the first insulating layer, the third metal layer being electrically isolated from the second metal layer;
• and
• a conductive via disposed through the first insulating layer, the conductive via electrically coupling the first metal layer with the third metal layer,
• the first metal layer and the conductive via electrically coupling the first semiconductor die with the third metal layer;
• and
• a second substrate having:
• a second insulating layer;
• a fourth metal layer disposed on a first side of the second insulating layer, a second side of the second semiconductor die being disposed on and electrically coupled with the fourth metal layer, the second side of the second semiconductor die being opposite the first side of the second semiconductor die;
• a conductive connector being disposed between the third metal layer and the fourth metal layer, the conductive connector electrically coupling the third metal layer with the fourth metal layer, the first metal layer, the conductive via, the third metal layer, the conductive connector and the fourth metal layer electrically coupling the first semiconductor die with the second semiconductor die;
• and
• a fifth metal layer disposed on a second side of the second insulating layer, the second side of the second insulating layer being opposite the first side of the second insulating layer, the fifth metal layer being electrically isolated from the fourth metal layer by the second insulating layer.

A circuit assembly apparatus comprising:

• a first semiconductor die;
• a second semiconductor die;
• a first substrate;
• a second substrate;
• and
• a third substrate,
• the first semiconductor die having a first side coupled with a first side of the first substrate and a first side of the second substrate,
• the second semiconductor die having a first side coupled with a second side of the second substrate and a first side of the third substrate,
• the first substrate having a first electrically isolated metal layer disposed on a second side, the second side of the first substrate being opposite the first side of the first substrate,
• the third substrate having a second electrically isolated metal layer disposed on a second side, the second side of the third substrate being opposite the first side of the third substrate,
• the first substrate, the first semiconductor die, the second substrate, the second semiconductor die and the third substrate being arranged in a vertical stack, such that current flows in the circuit assembly apparatus from the first substrate to the third substrate through the first semiconductor die, the second substrate and the second semiconductor die.