Proximity coupling interconnect packaging systems and methods

A semiconductor package assembly comprising:

• a substrate having bond pads;
• a first semiconductor die disposed adjacent the substrate, the first semiconductor die having a first coupling face that faces away from the substrate;
• a second semiconductor die disposed adjacent the substrate and spaced laterally apart from the first semiconductor die, the second semiconductor die having a second coupling face that faces away from the substrate;
• a third semiconductor die having a third coupling face and bond pads at the third coupling face, the third semiconductor die stacked on the first semiconductor die and the second semiconductor die such that the third coupling face faces the first coupling face and the second coupling face;
• a first proximity coupling interconnect between the first semiconductor die and the third semiconductor die, the first proximity coupling interconnect comprising a first conductive pad on the first coupling face and a third conductive pad on the third coupling face spaced from the first conductive pad by a first gap distance and aligned with the first conductive pad;
• a second proximity coupling interconnect between the second semiconductor die and the third semiconductor die, the second proximity coupling interconnect comprising a second conductive pad on the second coupling face and a fourth conductive pad on the third coupling face spaced from the second conductive pad by a second gap distance and aligned with the second conductive pad;
• and
• a spacer die having a height greater than a height of the first semiconductor die or the second semiconductor die, the spacer die positioned on the substrate and having a fourth coupling face that faces away from the substrate, the spacer die being spaced laterally from the first semiconductor die and the second semiconductor die, and the third semiconductor die being stacked over the spacer die such that the third coupling face overlaps a portion of the fourth coupling face.