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Title: Joule heating induced thermomigration failure in un-powered microbumps due to thermal crosstalk in 2.5D IC technology

Abstract

Thermal-crosstalk induced thermomigration failure in un-powered microbumps has been found in 2.5D integrated circuit (IC) circuit. In 2.5D IC, a Si interposer was used between a polymer substrate and a device chip which has transistors. The interposer has no transistors. If transistors are added to the interposer chip, it becomes 3D IC. In our test structure, there are two Si chips placed horizontally on a Si interposer. The vertical connections between the interposer and the Si chips are through microbumps. We powered one daisy chain of the microbumps under one Si chip; however, the un-powered microbumps in the neighboring chip are failed with big holes in the solder layer. We find that Joule heating from the powered microbumps is transferred horizontally to the bottom of the neighboring un-powered microbumps, and creates a large temperature gradient, in the order of 1000 °C/cm, through the un-powered microbumps in the neighboring chip, so the latter failed by thermomigration. In addition, we used synchrotron radiation tomography to compare three sets of microbumps in the test structure: microbumps under electromigration, microbumps under thermomigration, and microbumps under a constant temperature thermal annealing. The results show that the microbumps under thermomigration have the largest damage. Furthermore, simulation ofmore » temperature distribution in the test structure supports the finding of thermomigration.« less

Authors:
;  [1]; ;  [2]; ;  [3]
  1. Department of Materials Science and Engineering, UCLA, Los Angeles, California 90095-1595 (United States)
  2. Qualcomm, San Diego, California 92121 (United States)
  3. Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)
Publication Date:
OSTI Identifier:
22598867
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 120; Journal Issue: 7; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ANNEALING; COMPARATIVE EVALUATIONS; COMPUTERIZED SIMULATION; DAMAGE; ELECTROPHORESIS; FAILURES; INTEGRATED CIRCUITS; JOULE HEATING; LAYERS; POLYMERS; SILICON; SUBSTRATES; SYNCHROTRON RADIATION; SYNCHROTRONS; TEMPERATURE DISTRIBUTION; TEMPERATURE GRADIENTS; TOMOGRAPHY; TRANSISTORS

Citation Formats

Li, Menglu, Tu, K. N., E-mail: kntu@ucla.edu, Kim, Dong Wook, Gu, Sam, Parkinson, Dilworth Y., and Barnard, Harold. Joule heating induced thermomigration failure in un-powered microbumps due to thermal crosstalk in 2.5D IC technology. United States: N. p., 2016. Web. doi:10.1063/1.4961219.
Li, Menglu, Tu, K. N., E-mail: kntu@ucla.edu, Kim, Dong Wook, Gu, Sam, Parkinson, Dilworth Y., & Barnard, Harold. Joule heating induced thermomigration failure in un-powered microbumps due to thermal crosstalk in 2.5D IC technology. United States. doi:10.1063/1.4961219.
Li, Menglu, Tu, K. N., E-mail: kntu@ucla.edu, Kim, Dong Wook, Gu, Sam, Parkinson, Dilworth Y., and Barnard, Harold. Sun . "Joule heating induced thermomigration failure in un-powered microbumps due to thermal crosstalk in 2.5D IC technology". United States. doi:10.1063/1.4961219.
@article{osti_22598867,
title = {Joule heating induced thermomigration failure in un-powered microbumps due to thermal crosstalk in 2.5D IC technology},
author = {Li, Menglu and Tu, K. N., E-mail: kntu@ucla.edu and Kim, Dong Wook and Gu, Sam and Parkinson, Dilworth Y. and Barnard, Harold},
abstractNote = {Thermal-crosstalk induced thermomigration failure in un-powered microbumps has been found in 2.5D integrated circuit (IC) circuit. In 2.5D IC, a Si interposer was used between a polymer substrate and a device chip which has transistors. The interposer has no transistors. If transistors are added to the interposer chip, it becomes 3D IC. In our test structure, there are two Si chips placed horizontally on a Si interposer. The vertical connections between the interposer and the Si chips are through microbumps. We powered one daisy chain of the microbumps under one Si chip; however, the un-powered microbumps in the neighboring chip are failed with big holes in the solder layer. We find that Joule heating from the powered microbumps is transferred horizontally to the bottom of the neighboring un-powered microbumps, and creates a large temperature gradient, in the order of 1000 °C/cm, through the un-powered microbumps in the neighboring chip, so the latter failed by thermomigration. In addition, we used synchrotron radiation tomography to compare three sets of microbumps in the test structure: microbumps under electromigration, microbumps under thermomigration, and microbumps under a constant temperature thermal annealing. The results show that the microbumps under thermomigration have the largest damage. Furthermore, simulation of temperature distribution in the test structure supports the finding of thermomigration.},
doi = {10.1063/1.4961219},
journal = {Journal of Applied Physics},
number = 7,
volume = 120,
place = {United States},
year = {Sun Aug 21 00:00:00 EDT 2016},
month = {Sun Aug 21 00:00:00 EDT 2016}
}
  • Cited by 1
  • The electromigration of flip chip solder joints consisting of 97Pb-3Sn and 37Pb-63Sn composite solders was studied under high current densities at room temperature. The mean time to failure and failure modes were found to be strongly dependent on the change in current density. The composite solder joints did not fail after 1 month stressed at 4.07x10{sup 4} A/cm{sup 2}, but failed after just 10 h of current stressing at 4.58x10{sup 4} A/cm{sup 2}. At a slightly higher current stressing of 5.00x10{sup 4} A/cm{sup 2}, the composite solder joints failed after only 0.6 h due to melting. Precipitation and growth ofmore » Cu{sub 6}Sn{sub 5} at the cathode caused the Cu under bump metallurgy to be quickly consumed and resulted in void formation at the contact area. The void reduced the contact area and displaced the electrical path, affecting the current crowding and Joule heating inside the solder bump. Significant Joule heating inside solder bumps can cause melting of the solder and quick failure. The effect of void propagation on current crowding and Joule heating was confirmed by simulation.« less
  • Empirical scaling factors between the height-integrated joule heating rate deduced from measurements of the Chatanika incoherent scatter radar and the square of magnetic perturbation at College are derived. These relationships, calculated for different situations (the eastward and westward electrojects and daytime) are then used to estimate the joule heating rate along the latitudinal extent of the auroral oval on the basis of magnetometer data from the IMS Alaska meridian chain of observations. The total heat input for a disturbed day (April 12, 1978) is estimated to be 2.8 x 10/sup 15/ J.
  • Empirical scaling factors between the height-integrated joule heating rate deduced from measurements of the Chatanika incoherent scatter radar and the square of magnetic perturbation at College are derived. These relationships, calculated for different situations (the eastward and westward electrojects and daytime) are then used to estimate the joule heating rate along the latitudinal extent of the auroral oval on the basis of magnetometer data from the IMS Alaska meridian chain of observations. The total heat input for a disturbed day (April 12, 1978) is estimated to be 2.8 x 10/sup 15/ J.