Influence of thermal cycling on reliability of solder joints executed on long and metal core PCBs

Sitek, J.; Araźna, A.; Janeczek, Kamil; Stęplewski, W.; Lipiec, K.; Futera, K.; Ciszewski, Piotr

doi:10.1108/ssmt-03-2015-0009

Cited by 5 publications

(2 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Nevertheless, greatly few literatures reported their precise correlations in solder joints, even less so in micro-joints of advanced packages. It was well-documented that micro-joints tend to experience greater thermally induced stress, and have more pronounced microstructure evolutions of the IMCs (Sitek et al, 2015;Li et al, 2017). Furthermore, Ni has been currently used as the metalized pad of chip side in advanced packages.…”

Section: Introductionmentioning

confidence: 99%

Intermetallics evolution and its reliability effects on micro-joints in flip chip assemblies

Tian

Fang

Ren

et al. 2020

View full text Add to dashboard Cite

Purpose This paper aims to assess precise correlations between intermetallic compounds (IMCs) microstructure evolutions and the reliability of micro-joints with a Cu/SAC305solder/Ni structure using thermal shock (TS) tests. Design/methodology/approach This paper uses 200-µm pitch silicon flip chips with nickel (Ni) pads and stand-off height of approximately 60 µm, assembled on substrates with copper (Cu) pads. After assembly, the samples were subjected to air-to-air thermal shock testing from 55 to 125 per cent. The transfer time was less than 5 s, and the dwell time at each temperature extreme was 15 min. To investigate the microstructure evolution and crack growth, two samples were removed from the thermal shock chamber at 0, 400, 1,200, 2,000, 5,800 and 7,000 cycles. Findings The results showed that one (Cu, Ni)6Sn5/(Ni, Cu)3Sn4 dual-layer structure formed at the Ni pad interface of chip side dominates the micro-joints failure. This is because substantial (Ni, Cu)3Sn4 grain boundaries provide a preferential pathway for the catastrophic crack growth. Other IMCs microstructure evolutions that cause the prevalent joints failure as previously reported, i.e. thickened interfacial (Cu, Ni)6Sn5 and Ni3P layer, and coarsened IMCs inside the solder matrix, only contributed to the occurrence of fine cracks. Moreover, the typical interfacial IMCs spalling triggered by thermally induced stress did not take place in this study, showing a positive impact in the micro-joint reliability. Originality/value As sustained trends toward multi-functionality and miniaturization of microelectronic devices, the joints size is required to be constantly scaled down in advanced packages. This arises a fact that the reliability of small-size joints is more sensitive to the IMCs because of their high volume proportion and greatly complicated microstructure evolutions. This paper evaluated precise correlations between IMCs microstructure evolutions and the reliability of micro-joints with a Cu/SAC305solder/Ni structure using TS tests. It found that one (Cu, Ni)6Sn5/(Ni, Cu)3Sn4 dual-layer structure formed at the Ni pad interface dominate the micro-joints failure, whereas other IMCs microstructure evolutions that cause the prevalent joints failure exhibited nearly negligible effects.

show abstract

Section: Introductionmentioning

confidence: 99%

Intermetallics evolution and its reliability effects on micro-joints in flip chip assemblies

Tian

Fang

Ren

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Among them, X-ray inspection, scanning acoustic microscopy (SAM), plasma or acid etching, laser ablation or thermo-mechanical milling can be mentioned (Ardebili and Pecht, 2009; Liu et al , 2012; Shannon et al , 2010; Sylvester et al , 2013; Tang et al , 2011; Ng et al , 2012). Conventional X-ray as a common non-destructive method used in electronic industry (Sylvester et al , 2013; Sitek et al , 2015; Shannon et al , 2010; Stęplewski et al , 2014; Neubauer, 1997) can be useful to reveal, e.g. component misalignments, solder joint bridges or large cracks and voids in solder joints, but it becomes unsuitable when multi-layer samples with smaller feature size are examined.…”

Section: Introductionmentioning

confidence: 99%

Failure analysis of epoxy molded IC packages

Janeczek

Araźna

Futera

et al. 2016

Self Cite

View full text Add to dashboard Cite

Purpose The aim of this paper is to present non-destructive and destructive methods of failure analysis of epoxy moulded IC packages on the example of power MOSFETs in SOT-227 package. Design/methodology/approach A power MOSFET in SOT-227 package was examined twice using X-ray inspection, at first as the whole component to check if it is damaged and then after removing the upper part of package by mechanical grinding. The purpose of the second X-ray inspection was to prepare images for estimation of the total number and approximate location of voids in soft solder layers. Finally, power MOSFETs were subjected to decapsulation process using a concentrated sulphuric acid to verify existence of damage areas noticed during X-ray analysis and to observe other possible failures such as cracks in aluminium metallization or wires deformation. Findings X-ray analysis was revealed to be adequate technique to detect damage (e.g. meltings) in power MOSFETs in SOT-227 package, but only when tested components were analysed in the side view. This type of analysis combined with a graphic software is also suitable for voids estimation in soft solder layers. Moreover, it was found that a single acid (concentrated sulphuric acid) at elevated temperature can be successfully used for decapsulation of power MOSFETs in SOT-227 package without damage of aluminium metallization and aluminium wires. Such decapsulation process enables analysis of defects in wire, die and package materials. Research limitations/implications Further investigations are required to examine if the presented methods of failures analysis can be used for other types of components (e.g. high power resistors) in similar packages. Practical/implications The described methods of failure analysis can find application in electronic industry to select components which are free of damage and in effect which allow to produce high reliable devices. Apart from it, the presented method is applicable to evaluate reasons of improper work of tested electronic devices and to identify faked components. Originality/value This paper contains valuable information for research and technical staff involved in the assessment of electronic devices who needs practical methods of failure analysis of epoxy moulded IC packages.

show abstract

Thermal test effect on fan-out wafer level package strength

Zhong

Choi

2017

2017 12th International Microsystems, Packaging, Assembly and Circuits Technology Conference (IMPACT)

View full text Add to dashboard Cite

Fan-out wafer level packaging technology becomes more and more popular and attractive of its flexibility for integration of diverse devices in a very small form factor and it is also a cost effective packaging solution. As fan-out wafer level package (FOWLP) is composed of various materials, the proper structural design and material selection are essential to achieve reliability requirements. In this study, FOWLP material especially the epoxy molding compound (EMC) thermal properties are evaluated to understand the effect of thermal factors on EMC strength. The long term thermal test is applied and the EMC flexure strength increases significantly after the high temperature storage test.

show abstract

Influence of thermal cycling on reliability of solder joints executed on long and metal core PCBs

Cited by 5 publications

References 4 publications

Intermetallics evolution and its reliability effects on micro-joints in flip chip assemblies

Intermetallics evolution and its reliability effects on micro-joints in flip chip assemblies

Failure analysis of epoxy molded IC packages

Thermal test effect on fan-out wafer level package strength

Contact Info

Product

Resources

About