Methods of forming integrated circuit package

A method for forming integrated circuit packages, the method comprising:

• mounting a plurality of first tier stacks to a substrate, the substrate having a first side and a second side, the substrate having a plurality of first contact pads and a plurality of probe pads on the first side, the substrate having a plurality of second contact pads on the second side, the plurality of first tier stacks being coupled to the plurality of first contact pads;
• electrically testing each of the first tier stacks using the probe pads to identify known good first tier stacks and known bad first tier stacks;
• mounting a first plurality of stacking substrates to the known good first tier stacks, and mounting a first plurality of dummy substrates to the known bad first tier stacks, thereby forming a plurality of second tier stacks;
• and
• electrically testing a subset of second tier stacks using the probe pads, the subset of second tier stacks being those stacks that do not comprise a dummy substrate, and identifying known good second tier stacks and known bad second tier stacks.

A method for forming integrated circuit packages, the method comprising:

• mounting a first tier stack to a substrate, wherein the substrate has one or more probing pads associated with the first tier stack;
• electrically testing the first tier stack using the one or more probing pads to obtain a first test result;
• identifying the first tier stack as a known good first tier stack or a known bad first tier stack based on the first test result;
• mounting a first stacking substrate to the first tier stack when the first tier stack is identified as the known good first tier stack, thereby forming a second tier stack;
• electrically testing the second tier stack using the one or more probing pads to obtain a second test result;
• identifying the second tier stack as a first known good second tier stack or a first known bad second tier stack based on the second test result;
• and
• mounting a second stacking substrate to the second tier stack when the second tier stack is identified as the first known good second tier stack, thereby forming a third tier stack.