scholarly journals Wirebond Process Improvement through Silicon Die Polyimide Removal

2020 ◽  
pp. 33-37
Author(s):  
Anthony R. Moreno ◽  
Jonalyn E. Jaylo ◽  
Frederick Ray I. Gomez ◽  
Edwin M. . Graycochea Jr
Keyword(s):  
Shear Strength ◽  
Statistical Analysis ◽  
Sodium Hydroxide ◽  
Process Improvement ◽  
Etching Process ◽  
Ball Shear ◽  
Polyimide Coating ◽  
The Wire ◽  
Polyimide Layer

This study aims to develop polyimide etching process on the silicon die after decapsulation to resolve the wire shear issue during ball shear data gatherings. The shear strength of the ball is affected by the presence of polyimide insulator during ball shearing process, due to the polyimide layer of the silicon die being coplanar with the ball height of the wire. Experimentation and statistical analysis were done on units with and without polyimide coating, with Sodium Hydroxide (NaOH) used to remove the excess polyimide.  Results revealed that silicon dice without polyimide coating resulted to better reading in terms of ball shear.

An integrated statistical analysis for process improvement

2012 ◽  
Vol 3 (3) ◽  
pp. 184-193 ◽  
Author(s):  
V. Mariappan ◽  
Rajesh S. Prabhu Gaonkar ◽  
Milind Sakhardande ◽  
Mahesh Dhawalikar
Keyword(s):  
Statistical Analysis ◽  
Process Improvement

Slab avalanche measurements

1977 ◽  
Vol 14 (2) ◽  
pp. 206-213 ◽  
Author(s):  
R. Perla
Keyword(s):  
Shear Strength ◽  
Statistical Analysis ◽  
Failure Stress ◽  
In Situ Measurement ◽  
Failure Plane ◽  
Unresolved Problem ◽  
Shear Frame ◽  
Frame Device

From a study of 205 slab avalanches it is concluded that failure initiates where the slope is 25° or steeper, that slab failure stress is in the range 102–104 N/m2, and that the slab failure plane is most commonly at a temperature of −5 °C or warmer.The in situ measurement of shear strength is still an unresolved problem. A statistical analysis of a shear-frame device shows that the device is sensitive to the rate of pull and to the frame area. The larger the frame area, the smaller the measured shear strength. Approximately 10 measurements are required to sample a mean shear strength of a slab failure plane to within 15% accuracy at 90% confidence.

The Study on The Under Bump Metallurgy (Ubm) and 63SN-37PB Solder Bumps Interface for Flip Chip Interconnection

1998 ◽  
Vol 515 ◽  
Author(s):  
Se-Young Jang ◽  
Kyung-Wook Paik
Keyword(s):  
Shear Strength ◽  
Direct Contact ◽  
Flip Chip ◽  
Organic Substrates ◽  
Adhesion Properties ◽  
Ball Shear ◽  
Solder Bumps ◽  
Diffusion Barrier Layer ◽  
Solder Reflow ◽  
Ball Shear Strength

ABSTRACTIn the flip chip interconnection on organic substrates using eutectic Pb/Sn solder bumps, highly reliable Under Bump Metallurgy (UBM) is required to maintain adhesion and solder wettability. Various UBM systems such as l.tm Al/0.2 μm Ti/5 μm Cu, l μm A1/0.2 μm Ti/l μm Cu, 1 μm A1/0.2 μm Ni/1 μm Cu and 1 μm At/10.2μm Pd/l μm Cu, laid under eutectic Pb/Sn solder of low melting point, were investigated with regard to their interfacial reactions and adhesion properties. The effects of numbers of solder reflow and aging time on the growth of intermetallic compounds (IMC) and on the solder ball shear strength were investigated. Good ball shear strength was obtained with 1 μm AI/0.2μm Ti/5μm Cu and 1 μm Al/0.2 μm Ni/l μm Cu even after 4 solder reflows or 7 day aging at 150°C. In contrast, l μm Al/0.2 μm Ti/l μm Cu and l μm A1/0.21μm Pd/μm Cu shows poor ball shear strength. The decrease of the shear strength was mainly due to the direct contact between solder and nonwettable metal such as Ti and Al resulting in a delamination. Thin 1 μm Cu and 0.2 μm Pd diffusion barrier layer were completely consumed by Cu-Sn and Pd-Sn reaction.

scholarly journals Effect of Industrial Waste and Geopolymers on Stabilisation of Expansive Clay

2019 ◽  
Vol 9 (2) ◽  
pp. 5575-5577
Keyword(s):  
Shear Strength ◽  
Sodium Hydroxide ◽  
Clay Soil ◽  
Research Work ◽  
Expansive Soil ◽  
Industrial Wastes ◽  
Engineering Properties ◽  
Low Permeability ◽  
Expansive Clay ◽  
Strength Determination

Expansive clay soils are geotechnically problematic in nature as they possess less shear strength, high compressibility and low permeability. This research work was carried out with a view to improve index and engineering properties of expansive soil by stabilizing it with industrial wastes and geopolymers. The industrial wastes such as fly ash, silica fume and sodium-hydroxide were used for the stabilization of expansive soil. the virgin clay soil was tested for its index properties, compaction characteristics and shear strength determination. the stabilization of clay is made by adding and mixing those materials by varying its percentage. In the stabilization of soil with sodium hydroxide, an attempt has been made to study the effect of its molarity on the various properties of the soil. The clay soil stabilized with various materials was also tested for the same properties and that results were compared with that of virgin soil to find the effect of stabilization.

scholarly journals Statistical Analysis on Shear Strength Parameter from Index Properties of Fine-grained Soils

2021 ◽  
pp. 15-28
Author(s):  
Tariku Tafari Bakala ◽  
Emer Tucay Quezon ◽  
Mohammed Yasin
Keyword(s):  
Shear Strength ◽  
Statistical Analysis ◽  
Linear Regression ◽  
Statistical Models ◽  
Undrained Shear Strength ◽  
Strength Parameter ◽  
Index Properties ◽  
Fine Grained ◽  
Shear Strength Parameter ◽  
Undrained Shear

Shear strength is the essential engineering property of soil required to analyze and design foundations, retaining walls, bridges, embankment, and related infrastructure. The laboratory equipment and field instruments are not sufficient in developing countries to obtain soil engineering properties, especially strength properties. Thus, Geotechnical engineers usually endeavor to develop statistical models that best fit a particular area and soil type, especially for analysis and design purposes. In this research, a Statistical Analysis on the Shear Strength parameter from the Index Properties of Fine-Grained Soils was studied. For predicting the undrained shear strength parameter, single linear regression (SLR) and multiple linear regressions (MLR) analyses were developed. To develop the intended statistical models for a study, SAS JMP Pro 13, SPSS v22, and Microsoft Excel-2013 software were introduced. The results of a  study indicated that undrained shear strength(Cu) was significantly correlated with liquid limit(LL), plastic limit(PL), bulk density (ρbulk), dry density(ρdry), natural moisture content(NMC), and plasticity index(PI). While it was not significantly correlated with a specific gravity (Gs) and liquidity index (LI) of study area soil. Finally, a strong Model of Cu with a coefficient of determination (R2 = 0.806), good significance level, and less Std. error was obtained from multiple linear regression (MLR) analysis. The developed model can figure undrained shear strength parameter and wide application in the construction industry to minimize the cost, effort, and time for laboratory tests of shear strength parameter of a study area.

Reliability Study of Silver, Copper and Gold Wire Bonding on IC Device

2014 ◽  
Vol 2014 (1) ◽  
pp. 000850-000855
Author(s):  
Hongtao Gao ◽  
Jun Lu ◽  
Richard Lu ◽  
Wei Xin ◽  
Xiaojing Xu ◽  
...  
Keyword(s):  
Shear Strength ◽  
Copper Wire ◽  
Gold Wire ◽  
Wire Bonding ◽  
Silver Wire ◽  
Ball Shear ◽  
Significant Difference ◽  
Copper Wire Bonding ◽  
Bonding Wires ◽  
Ball Shear Strength

Copper wire bonding in IC packages is not always suitable for devices with active circuit under bonding pad because higher bonding power required for copper wire bonding may cause top aluminum metal splash and mechanically impact the circuit underneath. Silver wire is an alternative solution to this problem based on its physical properties and lower cost compared to gold wire. Ag88%Au8.5%Pd2.5%X1% and Ag95%Au1.5%Pd2.5%X1% alloyed silver wires are used in the study to compare with copper and gold wires of 99.99% in purity. As bonding power plays a dominating role in wire bonding, we focused on the effects of silver, copper and gold bonding wires with different bonding power on the top aluminum metal splash of power device by Optical Microscope(OM) and Scanning Electron Microscope(SEM). The ball shear strength of the bonding wires with different bonding power in samples without mold compound encapsulation was investigated before and after 24, 48, 96 and 192 hours of pressure cooker test (PCT). The intermetallic compound (IMC) formed between silver and aluminum was confirmed by focus ion beam (FIB) and transmission electron microscope (TEM). Although the top surface of the silicon device shows no significant difference after aluminum layer removal for all three wire types, the severity level of vertical deformation and side splash of aluminum layer due to copper wire bonding is much more than silver or gold wire using same amount of bonding power. Ball shear strength of non-encapsulated silver wire decreases dramatically after PCT aging compared with copper wire or gold wire and some samples show zero shear strength after PCT 96 hours and PCT 192 hours for silver wires doped with Pd/Au. Furthermore, larger bonding power induces higher ball shear strength. The major IMC compositions between silver and aluminum are Ag3Al and Ag2Al. A thermo dynamic model was built to explain why silver wire is prone to corrosion compared with copper wire by humidity although copper is easier to be ionized than silver. No electrical test was performed as the samples cannot be tested without package encapsulation and singulation. Furthermore, silver wire samples in SO8 package with mold compound encapsulation were subjected to highly accelerated stress test (HAST), PCT, temperature cycle test (TCT) after MSL1 preconditioning test as well as high temperature operation life test (HTOL) according to JEDEC procedures. The encapsulated samples using either Ag 88wt% or Ag95wt% alloys all passed MSL1 and PCT/HAST/TCT/HTOL. Drain to source on-resistance (Rdson) of the device including package parasitics was measured and it has no significant difference between silver wire and gold wire. The results from this study shows promising data using silver alloy wires but care should be taken to further understand the degradation of silver-aluminum interface under severe humidity condition. Using other metallization on silicon top surface such as NiAu or CuAu can significantly alleviate the interface problem related to AgAl.

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