0
Research Papers

Nondestructive Failure Analysis and Simulation of Encapsulated 0402 Multilayer Ceramic Chip Capacitors Under Thermal and Mechanical Loading

[+] Author and Article Information
B. Wunderle

 Fraunhofer Institut Zuverlässigkeit und Mikrointegration, Gustav-Meyer-Allee 25, 13355 Berlin, Germanybernhard.wunderle@izm.fraunhofer.de

T. Braun, D. May, B. Michel

 Fraunhofer Institut Zuverlässigkeit und Mikrointegration, Gustav-Meyer-Allee 25, 13355 Berlin, Germany

H. Reichl

Forschungsschwerpunkt Technologien der Mikroperipherik, Technische Universität Berlin, Gustav-Meyer-Allee 25, 13355 Berlin, Germany

J. Electron. Packag 131(1), 011012 (Feb 13, 2009) (6 pages) doi:10.1115/1.3078187 History: Received November 06, 2007; Revised September 26, 2008; Published February 13, 2009

The use of multilayer ceramic chip capacitors as integrated passive in, e.g., system in package applications needs methods to examine and predict their reliability. Therefore, a nondestructive failure analytical technique is described to detect cracks in the ceramic and the metallic layers within encapsulated 0402 surface mount device (SMD) capacitors. After choosing from techniques to reproducibly generate cracks, it is shown that an in situ capacitance measurement is a convenient method to detect these failures unambiguously. Finite element simulations support the experimental results. A reliability estimate for capacitor integrity under given loading conditions is given.

Copyright © 2009 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Schematic of a ceramic capacitor with typical flex-crack evolving at stress concentration due to thermomechanical loading. How can cracks be detected when an encapsulation is present?

Grahic Jump Location
Figure 2

(a) Cracks (arrows) for 0805 soldered SMD resistor and (b) glued 0402 capacitor after three-point bending

Grahic Jump Location
Figure 3

0402 SMD capacitor (1×0.5×0.5 mm3) fixed in a shear tester. Crack patterns in capacitors to the right.

Grahic Jump Location
Figure 4

Direct loading of the soldered capacitor by a blunted chisel applied in a testing machine. F=47±1 N (see Ref. 9).

Grahic Jump Location
Figure 5

Capacitor (arrow) soldered on board (0.8 mm thick) for concave three-point bending. Gap a=20 mm.

Grahic Jump Location
Figure 6

Damage induced after three-point bending

Grahic Jump Location
Figure 7

In situ capacitance measurements show a typical discontinuous decay from the nominal value C0 during mechanical loading. dc=0.85±0.1 mm on 0.8 mm board.

Grahic Jump Location
Figure 8

Thermal loading of capacitor on organic board with C-recording in intervals. Damage cannot be clearly identified.

Grahic Jump Location
Figure 9

Rate-dependent, viscoelastic behavior of molding compound represented as a master curve (Prony series). The high E-modulus indicates a highly filled epoxy resin.

Grahic Jump Location
Figure 10

FE simulation of molded capacitor (quarter symmetry). dboard=0.8 mm; dmold=1.75 mm. Around Tg of the mold, tensile stresses act on the cap (arrows).

Grahic Jump Location
Figure 11

Total force (in the x-direction) on the capacitor

Grahic Jump Location
Figure 12

Setup for thermal loading of the encapsulated capacitor. The IR image shows perfect temperature homogeneity across the package.

Grahic Jump Location
Figure 13

Typical temperature dependence of the capacitance of nondamaged capacitors

Grahic Jump Location
Figure 14

Unambiguous detection of failure in encapsulated capacitors by discontinuities in the curves (cf. b versus f)

Grahic Jump Location
Figure 15

Signs of minor damage after multiple loading

Grahic Jump Location
Figure 16

FE model for convex three-point bending as in Fig. 5. Depicted are σxx-stresses at the onset of damage (see Fig. 7). dc=0.9 mm. Material data as in Table 1.

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In