To main content

Environmental Stress Testing of Wafer-Level Au-Au Thermocompression Bonds Realized at Low Temperature: Strength and Hermeticity

Abstract

Hermeticity, reliability and strength of four laminates bonded at different temperatures by Au-Au thermocompression bonding have been investigated. Laminates with a diameter of 150 mm were realized by bonding a wafer containing membrane structures to a Si wafer with patterned bond frames. A bond tool pressure of 2266 mbar was applied for 15 minutes at temperatures ranging from 150–300°C. The hermetic properties were estimated by membrane deflection measurements applying white-light interferometry after bonding. Reliability was tested by exposing the laminates to a steady-state life test, a thermal shock test, and a moisture resistance test. Bond strength was estimated by pull test measurements. A dicing yield above 90% was obtained for all laminates. Laminates bonded at 200°C and above had significantly higher hermetic yield than the laminate bonded at 150°C. No degradation in hermeticity was observed after the reliability tests. The maximum leakage rate (MLR) was estimated from two measurements of membrane deflection executed at two different times and was below 10−11 mbar ⋅ l ⋅ s−1. The average bond strength ranged from 44 to 175 MPa.

Category

Academic article

Client

  • Research Council of Norway (RCN) / 210601

Language

English

Author(s)

  • Nishant Malik
  • Hannah Rosquist Tofteberg
  • Erik Poppe
  • Terje Finstad
  • Kari Schjølberg-Henriksen

Affiliation

  • University of Oslo
  • SINTEF Digital / Microsystems and Nanotechnology

Year

2015

Published in

ECS Journal of Solid State Science and Technology

ISSN

2162-8769

Volume

4

Issue

7

Page(s)

P236 - P241

View this publication at Cristin