Three-dimensional integrated circuit structures and methods of forming the same

A device, comprising:

• a board substrate comprising a first group of bumps and a second group of bumps thereon:
• a first semiconductor package disposed over and electrically connected to the board substrate through the first group of bumps;
• a first underfill layer surrounding the first group of bumps;
• a second semiconductor package disposed over and electrically connected to the board substrate through the second group of bumps;
• a second underfill layer surrounding the second group of bumps;
• first and second blocking walls arranged parallel to each other and located between the first and second semiconductor packages;
• and
• third and fourth blocking walls arranged parallel to each other and located outside of the first and second semiconductor packages,
• wherein from the top view, a central part of a first sidewall of the first blocking wall is in direct contact with the first underfill layer while an edge part of the first sidewall of the first blocking wall is exposed from the first underfill layer, and a central part of a first sidewall of the third blocking wall is in direct contact with the first underfill layer while an edge part of the first sidewall of the third blocking wall is exposed from the first underfill layer.

A method of forming a device, comprising:

• providing a board substrate;
• forming a first group of bumps and a second group of bumps on a first surface of the board structure;
• forming first and second blocking walls on the first surface of the board structure between the first group of bumps and the second group of bumps, wherein the first and second blocking walls are arranged parallel to each other, located between the first and second semiconductor packages, and in direct contact a first solder mask layer formed on the board substrate, wherein the first solder mask layer comprises silica, barium sulfate or epoxy resin;
• bonding a first semiconductor package to the board substrate through the first group of bumps;
• and
• forming a first underfill layer surrounding the first group of bumps and flowing to the first blocking wall,
• wherein from a top view, a central part of a first sidewall of the first blocking wall is in direct contact with the first underfill layer while an edge part of the first sidewall of the first blocking wall is exposed from the first underfill layer.