Structures and methods for providing electrical isolation in semiconductor devices

A method of forming a semiconductor structure, the method comprising:

• forming a plurality of semiconductor chips, each of the semiconductor chips comprising a substrate with one or more transistors or integrated circuits formed thereon;
• forming, on a top surface of each of the plurality of semiconductor chips, first solder bumps;
• flipping the plurality of semiconductor chips having the first solder bumps formed thereon;
• bonding the flipped plurality of semiconductor chips to a first side of an interposer through the first solder bumps in an arrangement that includes air gaps separating adjacent semiconductor chips, the air gaps abutting respective side surfaces of the adjacent semiconductor chips;
• and
• bonding the interposer to a printed circuit board (PCB) or package substrate through second solder bumps disposed on a second side of the interposer.

A method of forming a semiconductor structure, the method comprising:

• forming a plurality of semiconductor chips, each of the semiconductor chips comprising a substrate with one or more transistors or integrated circuits formed thereon;
• forming, on a top surface of each of the plurality of semiconductor chips, first solder bumps having a first pitch;
• flipping the plurality of semiconductor chips having the first solder bumps formed thereon;
• bonding the flipped plurality of semiconductor chips to a first side of an interposer through the first solder bumps in an arrangement that includes air gaps separating adjacent semiconductor chips, the air gaps abutting respective side surfaces of the adjacent semiconductor chips;
• bonding the interposer to a top surface of a package substrate through second solder bumps disposed on a second side of the interposer, the second solder bumps having a second pitch that is greater than the first pitch;
• and
• forming, directly on a bottom surface of the package substrate, third solder bumps.