Epoxy Molding Compounds as Encapsulation Materials for Microelectronic Devices

Abstract. This research studied about an epoxy molding compound (EMC) floor life to reliability performance of integrated circuit (IC) package. Molding is the process for protecting the die of IC package form mechanical and chemical reaction from external environment by shaping EMC. From normal manufacturing process, the EMC is stored in the frozen at 5oC and left at around room temperature for aging time or floor life before molding process. The EMC floor life effect to its properties and reliability performance of IC package. Therefore, this work interested in varied the floor life of EMC before molding process to analyze properties of EMC such as spiral flow length, gelation time, and viscosity. In experiment, the floor life of EMC was varied to check the effect of its property to reliability performance. The EMC floor life were varied from 0 hours to 60 hours with a step of 12 hours and observed wire sweep, incomplete EMC, and delamination inside the packages for 3x3, 5x5 and 8x8 mm2 of QFN packages. The evaluation showed about clearly effect of EMC floor life to IC packaging reliability. EMC floor life is not any concern for EMC property, moldabilty, and reliability from 0 hours to 48 hours for molding process of 3x3,5x5 and 8x8 mm2 QFN packaging manufacturing

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“…The results of wire sweep and incomplete mold used for observing moldability of 3x3,5x5 and 8x8 mm 2 …”

Section: Moldabilitymentioning

confidence: 99%

The Effect of Epoxy Molding Compound Floor Life to Reliability Performance and mold ability for QFN Package

Peanpunga

Ugsornrat

Thorlor

et al. 2017

J. Phys.: Conf. Ser.

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“…g(a)= f ::) = f kdt (2) where is the rate of reaction; a is the fractional conversion at any time t; k, the Arrhenius rate constant, and f(a), a function form of a that depends on the reaction mechanism.…”

Section: Theoretical Analysismentioning

confidence: 99%

Thermal Reaction Characterization of an Epoxy Molding Compound

Choi²,

Lee

et al. 2001

Polym J

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ABSTRACT:A novel epoxy molding compound for electronic industry application was used to conduct thermal analysis characterization using differential scanning calorimetry (DSC) and thermogravimetric analyzer (TGA). The reaction kinetics of cure and thermal degradation have been analyzed based on a proposed iso-conversional model. The kinetic results showed that the cure and decomposition process are complex, and the values of activation energy are dependent on the degree of conversion.KEY WORDS Epoxy Molding Compound / Iso-Conversional Model / Cure Kinetics / Thermal Degradation/ Electrical and electronic devices have been encapsulated in a variety of resinous materials, including epoxy, silicone and phenolic materials. Epoxy molding compounds for the encapsulation of electronic components are considered a specialty market by the epoxy manufactures. The worldwide consumption of electronic grade molding compounds is approximately 100000000 metric tons (1997) and growing. The amount of epoxy resin used in these compounds is approximately 10% of that figure. The electronic grade epoxy resins must have a higher degree of purity than the commodity epoxy resins. The halogen content of these resins is usually less than 800 ppm and are much more difficult to manufacture than the standard resins. 1 The useful properties of epoxy resins appear only after curing. The curing step transforms the epoxy from a lowmolecular-weight material to a highly crosslinked space network. The properties of the cured resin depend on either the type of epoxide and the curing system used or the extent of cure. Recently, epoxy molding compounds have been widely used in the electronic industry and encapsulation of integrated circuits by means of transfer molding.2 Only limited information, however, may be found in the literature concerning the cure and degradation characterization of these molding compounds. Therefore, kinetic characterization of thermoset systems is necessary for a better understanding of structureproperty relationships. 3 The attractive feature of isothermal experiments is that the rate constants at each temperature are better defined and the constants obtained at different temperatures would permit the determination of the activation energy associated with the thermal degradation. 4 • 5 However, the nature of the reactions and the final products may differ at different temperatures, and the kinetic parameters thus obtained are not without ambiguity. 6 Dynamic experiments, conducted at a specified heating rate using DSC, will yield conversion-timetemperature data that are comprehensive enough to permit direct evaluations of the kinetic parameters. A single dynamic run gives as much information as do several isothermal runs. Furthermore, dynamic measurements can provide kinetic information over a larger temperature range and there is no preheating problems as is the case with isothermal experiments in which the sample must be first heated to the isothermal hold temperature during which thermal reactions may take place. It is v...

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“…The relatively high thermal conductivity and low thermal capacity of the thin bare-die silicon chips, enables photonic flash soldering at very short time scales and relatively low pulse energies as reported before [8][9][10]. For packaged components, however, the mold epoxy and other polymers used in the packaging, normally have orders of magnitude lower thermal conductivity compared to silicon [11]. This combined with the fact that packaged components are generally thicker and bulkier than baredie chips, makes photonic soldering of such components more challenging.…”

Section: Introductionmentioning

confidence: 97%

Hybrid integration on low-cost flex foils using photonic flash soldiering

Pakazad

Barink

Arutinov

et al. 2016

2016 6th Electronic System-Integration Technology Conference (ESTC)

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Soldering of packaged electronic components using industry standard Sn-Ag-Cu (SAC) lead-free solders on low-cost foils, which are often the substrate of choice for flexible electronics, is challenging. This is mainly originating from the fact that the reflow temperatures of these solder alloys are normally higher than the maximum processing temperature of the low-cost flex foils. To enable component integration on the low-cost foils a novel method for soldering has been introduced by Holst Centre as an alternative to oven reflow, termed "photonic soldering". In this method high intensity photonic flashes are used to deliver the thermal energy required for soldering. By taking advantage of the selectivity of light absorption, the required energy for soldering is delivered to the components and circuit tracks while excessive heating of the foils is avoided. This paper presents successful photonic flash soldering of packaged LED components on low-cost polyethylene terephthalate (PET) foils using conventional SAC solders as a demonstration of the capabilities of this novel soldering technology. IntroductionReliable integration of conventional electronic chips and passive components next to printed electronics on flexible foils enables realization of smart flexible systems with complex functionality [1,2]. To reduce the cost of such systems, low-cost flexible foils are preferred as the base substrate. However, reliable bonding of components on low-cost foils is generally challenging, due to limited processing temperature range of the foils. Conductive adhesives with relatively low curing temperatures (typically 120-150 °C) are commonly used for component bonding on such foils [3][4][5]. While for a variety of applications conductive adhesives provide sufficient reliability, for more demanding applications such as automotive or wearables higher quality bonds are required.Soldering has been commonly used in electronic industry for reliable component bonding on printed circuit boards (PCBs). However, the melting temperature of industry standard solder alloys such as lead-free Sn-AgCu (SAC) is above the maximum processing temperature range of low-cost foils such as polyester foils, which renders oven solder reflow on these foils practically impossible. Low-temperature solder alloys with melting temperatures below 150 °C such as SnBi alloys can be used as alternatives to SAC solders; however there are reliability challenges associated with low-temperature

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Epoxy Molding Compounds as Encapsulation Materials for Microelectronic Devices

Cited by 187 publications

References 66 publications

The Effect of Epoxy Molding Compound Floor Life to Reliability Performance and mold ability for QFN Package

The Effect of Epoxy Molding Compound Floor Life to Reliability Performance and mold ability for QFN Package

Thermal Reaction Characterization of an Epoxy Molding Compound

Hybrid integration on low-cost flex foils using photonic flash soldiering

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