Microelectronic die having CMOS ring oscillator thereon and method of using same

A microelectronic die comprising:

• a die substrate;
• and
• a plurality of CMOS ring oscillators on the die substrate, the ring oscillators being disposed at regions of the die substrate that are adapted to exhibit differing strain responses to package-induced stress with respect to one another;
• wherein the die substrate includes die humps thereon, and wherein the plurality of ring oscillators includes:
• a first ring oscillator disposed at a first region of the die substrate at an edge region of a first die hump or on the first die bump;
• a second ring oscillator disposed at the first region at a proximity of the first die bump;
• a third ring oscillator disposed at a second region of the die substrate at an edge region of a second die bump or on the second die bump;
• and
• a fourth ring oscillator disposed at the second region of the die substrate at a proximity of the second die bump, wherein the first region and the second region are adapted to exhibit differing strain responses to package-induced stress with respect to one another.

A microelectronic die comprising:

• a die substrate;
• and
• a plurality of CMOS ring oscillators on the die substrate, the ring oscillators being disposed at regions of the die substrate that are adapted to exhibit differing strain responses to package-induced stress with respect to one another;
• wherein at least one of the ring oscillators is NMOS weighed, and at least one of the ring oscillators is PMOS weighed;
• wherein the die substrate includes die bumps thereon, and wherein the plurality of ring oscillators includes:
• a first NMOS weighed ring oscillator disposed at an edge of a die bump;
• a first PMOS weighed ring oscillator disposed at an edge of the die bump;
• a second NMOS weighed ring oscillator disposed at a proximity of the die bump;
• and
• a second PMOS weighed ring oscillator disposed at a proximity of the die bump.

A microelectronic die comprising;

• a die substrate;
• and a plurality of CMOS ring oscillators on the die substrate, the ring oscillators being disposed at regions of the die substrate that are adapted to exhibit differing strain responses to package-induced stress with respect to one another;
• wherein the die substrate includes die bumps thereon, and wherein the plurality of ring oscillators includes:
• a first ring oscillator disposed at an edge of a center region die bump or on the center region die bump;
• a second ring oscillator disposed at a proximity of the center region die bump;
• a third ring oscillator disposed at an edge of a horizontal edge region die bump or on the horizontal region die bump;
• a fourth ring oscillator disposed at a proximity of the horizontal edge region die bump;
• a fifth ring oscillator disposed at an edge of a vertical edge region die bump or on the vertical edge region die bump;
• a sixth ring oscillator disposed at a proximity of the vertical edge region die bump;
• a seventh ring oscillator disposed at an edge of a corner region die bump or on the corner region die bump;
• and an eighth ring oscillator disposed at a proximity of the corner region die bump.

A microelectronic die comprising:

• a die substrate;
• and
• a plurality of CMOS ring oscillators on the die substrate, the ring oscillators being disposed at regions of the die substrate that are adapted to exhibit differing strain responses to package-induced stress with respect to one another;
• wherein at least one of the ring oscillators is NMOS weighed, and at least one of the ring oscillators is PMOS weighed;
• wherein the die substrate includes die bumps thereon, and wherein the plurality of ring oscillators includes:
• a first NMOS weighed ring oscillator disposed at an edge of a center region die bump or on the center region die hump;
• a first PMOS weighed ring oscillator disposed at an edge of the center region die hump or on the center region die hump;
• a second NMOS weighed ring oscillator disposed at a proximity of the center region die hump;
• a second PMOS weighed ring oscillator disposed at a proximity of the center region die bump;
• a third NMOS weighed ring oscillator disposed at an edge of a horizontal edge region die hump or on the horizontal edge region die hump;
• a third PMOS weighed ring oscillator disposed at an edge of the horizontal edge region die bump or on the horizontal edge region die bump;
• a fourth NMOS weighed ring oscillator disposed at a proximity of the horizontal edge region die bump;
• a fourth PMOS weighed ring oscillator disposed at a proximity of the horizontal edge region die bump;
• a fifth NMOS weighed ring oscillator disposed at an edge of a vertical edge region die bump or on the vertical edge region die bump;
• a fifth PMOS weighed ring oscillator disposed at an edge of the vertical edge region die bump or on the vertical edge region die bump;
• a sixth NMOS weighed ring oscillator disposed at a proximity of the vertical edge region die bump;
• a sixth PMOS weighed ring oscillator disposed at a proximity of the vertical edge region die bump;
• a seventh NMOS weighed ring oscillator disposed at an edge of a corner region die bump or on the corner region die bump;
• a seventh PMOS weighed ring oscillator disposed at an edge of the corner region die bump or on the corner region die bump;
• an eighth NMOS weighed ring oscillator disposed at a proximity of the corner region die bump;
• and
• an eighth PMOS weighed ring oci1Iator disposed at a proximity of the corner region die hump.

A method of determining mechanical stress on a die comprising:

• providing a microelectronic die comprising:
• a die substrate;
• a CMOS ring oscillator on the die substrate;
• providing a frequency counter coupled to the ring oscillator to measure a frequency of the ring oscillator and to generate a frequency data signal therefrom;
• wherein the ring oscillator includes a plurality of ring oscillators on the die substrate, the ring oscillators being disposed at regions of the die substrate that are different from one another with respect to respective strain responses thereof;
• and using the frequency data signal from each of the plurality of ring oscillators to determine the mechanical stress on the die at a location of the ring oscillator, wherein at least one of the ring oscillators is disposed at a first region of the die substrate where one of three principal stress components may be assumed to be at its maximum value, and at least one of the ring oscillators is disposed at a second region of the die substrate where another one of the three principal stress components may be assumed to be at its maximum value.