Integrated-circuit encapsulation

C. P. Wong, Improved Eoom-Temperature Wulconicyed Silicone Elastomers as Integrated Circuit Encapsulants, Polymer Materials for Electronics Applications, American Chemical Society Symposium Series, Washington, D.C., Nos. 184, 171, 1982. 

When phosphorus is added to Si02, in addition to gettering mobile alkali ions, it tends to reduce the intrinsic tensile stress in such films, thereby reducing their tendency to crack. Both functions are important when the film is used as a final passivation film for integrated circuits encapsulated in plastic. Phosphorus additions of 7 weight percent seem to be optimum in order to produce the above desirable film characteristics. 

Manzione et al. (1988) presented an empirical model for transfer moulding of filled epoxyresin systems for integrated-circuit encapsulation. The following chemorheological model (combining temperature, shear and cure effects) was used to aid flow-balancing calculations ... 

Nguyen et al. (1992, 1993) highlighted a full process model for transfer moulding of highly filled epoxies in integrated-circuit encapsulation. This model used the following kinetic and chemorheological models ... 

Heterogeneous Conduction Processes in Integrated-Circuit Encapsulation... 

The typical TP encapsulation process is an insert injection molding or liquid injection molding operation. The insert, a coil, or an integrated circuit, for example, is placed in a mold equipped with either fixed spider type supports or retractable pins or other features to support it when molten TP is injected. 

The acoustic microscopy s primary application to date has been for failure analysis in the multibillion-dollar microelectronics industry. The technique is especially sensitive to variations in the elastic properties of semiconductor materials, such as air gaps. SAM enables nondestructive internal inspection of plastic integrated-circuit (IC) packages, and, more recently, it has provided a tool for characterizing packaging processes such as die attachment and encapsulation. Even as ICs continue to shrink, their die size becomes larger because of added functionality in fact, devices measuring as much as 1 cm across are now common. And as die sizes increase, cracks and delaminations become more likely at the various interfaces. 

Improved Room-Temperature Vulcanized (RTV) Silicone Elastomers as Integrated Circuit (IC) Encapsulants... 

Thin films (qv) of vitreous silica have been used extensively in semiconductor technology. These serve as insulating layers between conductor stripes and a semiconductor surface in integrated circuits, and as a surface passivation material in planar diodes, transistors, and injection lasers. They are also used for diffusion masking, as etchant surfaces, and for encapsulation and protection of completed electronic devices. Thin films serve an important function in multilayer conductor insulation technology where a variety of conducting paths are deposited in overlay patterns and insulating layers are required for separation. 

A number of polymeric coatings, primarily polyimides, epoxies, and silicones, are used as adhesives and in other aspects of packaging, as well as for final encapsulation and protection of the integrated circuit. 

Evolution of Epoxy Encapsulation Compounds for Integrated Circuits A User s Perspective... 

The commercial integrated circuit (chip) is normally encapsulated in a thermoset plastic molding compound to protect the chip and permit handling and subsequent assembling without loss of circuit integrity. However, the increasing complexity of the chip has... 

K. Miyake et al., Thermal Stress Analysis of Plastic Encapsulated Integrated Circuits by FEM, lECE Proc., Japan, 1984, p. 2833. 

JL olymers are increasingly being used in a wide variety of applications in electronics and photonics, most of which use polymers in their traditional role as engineering materials (e.g., circuit boards, molded products, wire and cable insulation, encapsulants, and adhesives). In addition, many other unique applications require material properties that only polymers can provide. Examples include resist materials for the lithographic fabrication of integrated circuits (1C) and polymers for optical recording. These types of applications may be considered passive in the sense that the polymer does not play an active role in the operation of the device or circuit. Rather, it serves some other function such as mechanical support, electrical insulation, or in the case of resists, some intermediate function in the fabrication of the device. 

In this second example we demonstrate the applicability of the automatic design methodology to the design of polymers with desired properties. The problem is to design polymers for use as integrated-circuit (IC) encapsulants. 

Glass films are used in the semiconductor industry because of their dielectric properties, and are used for encapsulating integrated circuits and other electronic devices because they provide a hermetic seal. Glass films are formed by both reactive and non reactive deposition methods, (e.g., evaporation, sputtering, and ion implantation or ion platting for the latter). 

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