Advanced IC packaging for the future applications

Electrically conductive adhesives (ECAs) have been developed as an alternative to traditional Sn-Pb solders for electronic and optoelectronic applications. However, there are critical limitations such as the low conductivity, and unstable contact resistance. These limitations have seriously hindered the broad applications of ECAs. In order to overcome these limitations, a new formulation using Pb-free conducting filler particles was proposed. Our previous study proved that the metallurgical interconnections among conducting filler particles and between particles and the conducting pads were established by process control. In particular, it was found that the wetting behavior of conducting fillers in ECAs is one of the main mechanisms for the establishment of conduction paths. In this study, we propose the fundamental concept of an assembly process using fusible Pb-free conducting filler particles. Also, the effect of the reduction capability of base resin material on the solder wetting property was investigated. As candidates for ECA compositions, two types of resin materials and two lead-free solders were investigated. The reflow temperature profiles for each ECA formulation were determined using a differential scanning calorimeter (DSC) dynamic scan. The wettabilities of the lead-free solders were investigated using an optical microscope with a CCD camera and a microfocus Xray television system. It was found that the developed resin material with an intrinsic reduction capability shows good wettabilities in both leadfree candidates.

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“…1,2) Soldering technology using tin/lead solder alloys plays a crucial role in the manufacturing of electronics packaging.…”

Section: Introductionmentioning

confidence: 99%

The Effect of Reduction Capability of Resin Material on the Solder Wettability for Electrically Conductive Adhesives (ECAs) Assembly

Kim

Yasuda

et al. 2004

Mater. Trans.

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“…Since high performance IC's have increased in size over the years, the large die-pad, where the IC chip is bonded, more easily moves and tilts during the encapsulation process. Moreover, the IC packages are being made even thinner and smaller due to demands for smaller and lighter electronic apparatuses [2]. Therefore, any slight movement of the die-pad can result in various kinds of defects of the IC packages [3].…”

Section: Influences Of Molding Conditions On Die-pad Behavior In Ic Ementioning

confidence: 99%

Influences of molding conditions on die-pad behavior in IC encapsulation process analyzed by Hall element method

Sato

Yokoi

2000

IEEE Trans. Adv. Packag.

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It is important to analyze the dynamic die-pad behavior during the integrated circuit (IC) encapsulation process in order to reduce such defects caused by the die-pad movement as exposure of the IC chip on the package surface or breakage of bonding wires. In this study, experiments were carried out to investigate the influences of transfer time, internal pressure after the filling process, polyimide tapes pasted on lead frames, and viscosity of the resin on the die-pad behavior using the Hall element method developed in the previous study. The results showed that 1) the die-pad moved more when the transfer time was longer in this mold, 2) the internal pressure after the filling process had little influence on the die-pad behavior, 3) polyimide tapes restrained the die-pad movement along the thickness direction, and 4) the die-pad displaced larger with higher-viscosity resin.Index Terms-Die-pad behavior, Hall element, IC chip encapsulation, in-process measurement, molding conditions, permanent magnet, thermosetting resin, transfer molding.

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“…Therefore, the die-pad, which an IC chip is bonded on and is supported by thin leads easily, moves or tilts during the encapsulation process. On the other hand, due to the demands for smaller electronic apparatuses, IC packages are also growing smaller and thinner [2]. Consequently, slight die-pad movement, which did not pose any problems before, causes serious problems.…”

Section: Introductionmentioning

confidence: 95%

Development of measurement system for die-pad behavior in IC encapsulation process using Hall elements

Sato¹,

Yokoi²

2000

IEEE Trans. Adv. Packag.

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This paper describes a new method of measuring the die-pad behavior in the integrated circuit (IC) encapsulation process using Hall elements and a permanent magnet. The method enables us to measure the die-pad behavior along both the height and rotational directions during the melt filling and curing process. The measurement results were compared with that of the direct observation of the die-pad behavior using a high speed video camera and the static observation of the cross section of molding products, and the results obtained by Hall elements showed more or less good agreement with those of the other two methods. The experiments were carried out under three kinds of transfer times. The results showed that the die-pad moved more when the transfer time was longer, which suggested that the transfer time affected the die-pad behavior.Index Terms-Die-pad behavior, Hall element, IC encapsulation, in-process measurement, permanent magnet, thermosetting resin, transfer molding.

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Advanced IC packaging for the future applications

Cited by 24 publications

References 13 publications

The Effect of Reduction Capability of Resin Material on the Solder Wettability for Electrically Conductive Adhesives (ECAs) Assembly

The Effect of Reduction Capability of Resin Material on the Solder Wettability for Electrically Conductive Adhesives (ECAs) Assembly

Influences of molding conditions on die-pad behavior in IC encapsulation process analyzed by Hall element method

Development of measurement system for die-pad behavior in IC encapsulation process using Hall elements

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