Weibull analysis of soldered MLC under bending load stress

Franken, Klaus; Maier, Henning

doi:10.1016/s0955-2219(98)00425-7

Cited by 10 publications

(6 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…While tensile residual stresses develop normal to the plane of the electrode array (the L – W plane of Fig. ), they are small relative to the in‐plane bending stresses . Moreover, the fracture surfaces in this work (Figs.…”

Section: Resultsmentioning

confidence: 69%

“…1), 11,14 they are small relative to the in-plane bending stresses. [10][11][12][13][14][15][16] Moreover, the fracture surfaces in this work ( Figs. 4-8) show that the cracks are initiated and propagated in Mode I (i.e., the fracture surfaces are normal to the in-plane tensile bending stress and parallel to the T-W plane as shown in Fig.…”

Section: Resultsmentioning

confidence: 95%

“…These studies attribute the higher strength to crack tip shielding (e.g., crack deflection, blunting, or bridging) by the ductile, metallic electrodes. A separate body of literature has established that the mismatch in coefficient of thermal expansion between the electrode and dielectric layers gives rise to residual stresses that effect the electrical performance of MLCCs . However, recent findings that MLCC fracture begins at the device surface call into question the notion that an electrode‐localized strengthening mechanism like crack tip shielding is the determining factor in MLCC fracture strength .…”

Section: Introductionmentioning

confidence: 99%

“…A separate body of literature has established that the mismatch in coefficient of thermal expansion between the electrode and dielectric layers gives rise to residual stresses that effect the electrical performance of MLCCs. [10][11][12][13][14][15][16] However, recent findings that MLCC fracture begins at the device surface 17 call into question the notion that an electrode-localized strengthening mechanism like crack tip shielding is the determining factor in MLCC fracture strength. [8][9][10] Previous studies have shown that capacitance is increased by residual stress and probed this effect using uniaxial compression with in situ electrical measurements.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Strengthening Mechanisms in MLCCs: Residual Stress Versus Crack Tip Shielding

Lanning

Muhlstein

2013

J. Am. Ceram. Soc.

View full text Add to dashboard Cite

Failure by fracture is a serious problem with multilayer ceramic capacitors (MLCCs), and the interior electrodes are known to strengthen MLCCs. Historically, it has been assumed that the dominant strengthening mechanism is crack tip shielding via direct crack tip‐electrode interactions. However, we have found that residual stresses arising from differential thermal contraction after device sintering are actually responsible for the observed increase in strength. In addition, the fracture initiation sites in MLCCs are located outside of the electrode array, so the established idea that the electrical and mechanical failure controlling flaw populations are one and the same cannot be true. Weibull distributions were compared from the bending fracture of two populations of MLCCs with barium titanate (X7R) dielectric, nickel electrodes, and the same exterior geometries (but different electrode array configurations). MLCCs had characteristic strengths of 236 MPa versus a strength of 190 MPa for 19‐ and 3‐electrode MLCCs, respectively. Fractography, a critical flaw size computation, an analytical residual stress approximation, and in situ electrical measurements taken during bending were also used to examine the fracture process and demonstrate that residual stress and not crack tip shielding is an important strengthening mechanism in MLCCs.

show abstract

Section: Resultsmentioning

confidence: 69%

Section: Resultsmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Strengthening Mechanisms in MLCCs: Residual Stress Versus Crack Tip Shielding

Lanning

Muhlstein

2013

J. Am. Ceram. Soc.

View full text Add to dashboard Cite

show abstract

“…scientific and technological interests in MLCCs technology because of the increasing use of MLCCs in surface mount applications and the continued reduction of active layer thickness for higher capacitance MLCCs (Kahn et al, 1988;de With, 1993;Franken and Maier, 1999;Wereszczak et al, 1998;de With and Sweegers, 1995;Shin et al, 2003). A study of residual stress should aim to develop next generation devices that can be further miniaturized and show a higher capacitance.…”

Section: Introductionmentioning

confidence: 99%