Methods of manufacturing stacked semiconductor die assemblies with high efficiency thermal paths

A method for packaging a semiconductor die assembly having a first semiconductor die coupled to a package substrate and a plurality of second semiconductor dies arranged in a stack on the first semiconductor die, wherein the first semiconductor die has a peripheral region extending laterally outward from the stack of second semiconductor dies, the method comprising:

• attaching a first support and a second support of an inner casing to the peripheral region of the first semiconductor die such that the second semiconductor dies are at least partially positioned within an inner cavity defined by the inner casing;
• attaching a top of the inner casing to an uppermost one of the second semiconductor dies in the stack;
• flowing an underfill material through the inner cavity from a first open side of the inner casing toward a second open side of the inner casing such that the underfill material (a) extends between the second semiconductor dies, (b) extends between a lowermost one of the second semiconductor dies in the stack and the first semiconductor die, (c) contacts an interior surface of the first support facing the stack of second semiconductor dies, and (d) contacts an interior surface of the second support facing the stack of second semiconductor dies;
• and
• attaching an outer casing to the package substrate such that the first semiconductor die, the second semiconductor dies, and the inner casing are enclosed within an outer cavity defined by the outer casing.

A method for packaging a semiconductor die assembly having a first semiconductor die coupled to a package substrate and a plurality of second semiconductor dies arranged in a stack on the first semiconductor die, wherein the first semiconductor die has a peripheral region extending laterally outward from the stack of second semiconductor dies, the method comprising:

• attaching a first support and a second support of an inner casing to the peripheral region of the first semiconductor die such that the second semiconductor dies are at least partially positioned within an inner cavity defined by the inner casing;
• flowing an underfill material through the inner cavity from a first open side of the inner casing toward a second open side of the inner casing such that the underfill material extends between the second semiconductor dies;
• and
• attaching an outer casing to the package substrate such that the first semiconductor die, the second semiconductor dies, and the inner casing are enclosed within an outer cavity defined by the outer casing.