As semiconductor packaging technologies continue to scale, it drives the use of existing and new materials in thin layer form factors. Increasing packaging complexity implies that materials in thin layers are subject to nontrivial loading conditions, which may exceed the toughness of the material, leading to cracks. It is important to ensure that the reliability of these low-cost materials is at par or better than currently used materials. This in turn leads to significant efforts in the area of material characterization at the lab level to speed up the development process. Methods for testing and characterizing fracture-induced failures in various material systems in electronic packaging are investigated in this paper. The learnings from different test methods are compared and discussed here. More specifically, different fracture characterization techniques on (a) freestanding “thin” solder-resist films and (b) filled “bulk” epoxy materials such as underfills and epoxy mold compounds are investigated. For thin films, learnings from different test methods for measuring fracture toughness, namely, uniaxial tension (with and without an edge precrack) and membrane penetration tests, are discussed. Reasonably good agreement is found between the various thin film toughness test methods; however, ease of sample preparation, fixture, and adaptability to environmental testing will be discussed. In the case of filled epoxy resin systems, the single-edge-notched bending (SENB) technique is utilized to obtain the fracture toughness of underfills and mold compounds with filler materials. Learnings on different methods of creating precracks in SENB samples are also investigated and presented.

References

References
1.
Zhu
,
X.
, and
Joyce
,
J.
,
2012
, “
Review of Fracture Toughness (G, K, J, CTOD, CTOA) Testing and Standardization
,”
Eng. Fract. Mech.
,
85
, pp.
1
46
.
2.
Damani
,
R.
,
Schuster
,
C.
, and
Danzer
,
R.
,
1997
, “
Polished Notch Modification of SENB-S Fracture Toughness Testing
,”
J. Eur. Ceram. Soc.
,
17
(
14
), pp.
1685
1689
.
3.
Peres
,
F.
,
Schon
,
C.
, and
Tarpani
,
J.
,
2010
, “
Effect of Precracking Method on KIc Results for Medium-Density Polyethylene Tested Under Cryogenic Condition
,”
Polym. Test.
,
29
(
6
), pp.
667
673
.
4.
de Souza
,
J.
,
Yoshimura
,
H.
,
Peres
,
F.
, and
Schon
,
C.
,
2012
, “
Effect of Sample Pre-Cracking Method and Notch Geometry in Plane Strain Fracture Toughness Tests as Applied to a PMMA Resin
,”
Polym. Test.
,
31
(
6
), pp.
834
840
.
5.
Salazar
,
A.
,
Patel
,
Y.
, and
Williams
,
J.
,
2013
, “
Influence of Crack Sharpness on the Fracture Toughness of Epoxy Resins
,”
13th International Conference on Fracture
(
ICF
), Beijing, China, June 16–21, pp. 4057–4066.
6.
Zhang
,
S.
,
Sun
,
D.
,
Fu
,
Y.
, and
Du
,
H.
,
2005
, “
Toughness Measurement of Thin Films: A Critical Review
,”
Surf. Coat. Technol.
,
198
(
1–3
), pp.
74
84
.
7.
Hinkley
,
J.
, and
Mings
,
S.
,
1990
, “
Fracture Toughness of Polyimide Films
,”
Polymer
,
31
(
1
), pp.
75
77
.
8.
Daly
,
S.
,
Miller
,
A.
,
Ravichandran
,
G.
, and
Bhattacharya
,
K.
,
2007
, “
An Experimental Investigation of Crack Initiation in Thin Sheets of Nitinol
,”
Acta Mater.
,
55
(
18
), pp.
6322
6330
.
9.
Rice
,
J.
,
1968
, “
A Path Independent Integral and the Approximate Analysis of Strain Concentration by Notches and Cracks
,”
ASME J. Appl. Mech.
,
35
(
2
), pp.
379
386
.
10.
Singh
,
R.
, and
Parihar
,
K.
,
1986
, “
The J-Integral as Fracture Criterion for Polycarbonate Thermoplastic
,”
J. Mater. Sci.
,
21
(
11
), pp.
3921
3926
.
11.
Rink
,
M.
,
Andena
,
L.
, and
Marano
,
C.
,
2014
, “
The Essential Work of Fracture in Relation to J-Integral
,”
Eng. Fract. Mech.
,
127
, pp.
46
55
.
12.
Pardeon
,
T.
,
Marchal
,
Y.
, and
Delannay
,
F.
,
2002
, “
Essential Work of Fracture Compared to Fracture Mechanics—Towards a Thickness Independent Plane Stress Toughness
,”
Eng. Fract. Mech.
,
69
(5), pp.
617
631
.
13.
Martinez
,
A.
,
Gamez-Perez
,
J.
,
Sanchez-Soto
,
M.
,
Velasco
,
J.
,
Santana
,
O.
, and
Maspoch
,
M.
,
2009
, “
The Essential Work of Fracture (EWF) Method-Analyzing the Post-Yielding Fracture Mechanics of Polymers
,”
Eng. Failure Anal.
,
16
(
8
), pp.
2604
2617
.
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