Integrated circuits plastic packaging

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. 

Examples of conductive ABS polymer composites include electromagnetic shielding materials (56,57) and electrically conductive composite plastic sheets, which may be used for packaging of integrated circuit devices (58,59). 

PECVD of silicon nitride has been of commercial importance since 1976.1 The original motivation was to find a final passivation layer for an integrated circuit that would replace the doped silicon dioxide films then in use. The latter were not reliable enough to permit packaging of integrated circuits in plastic. Silicon nitride was recognized as a better final passivation film, but the only available technique for its deposition was the high-temperature thermal process. Since it had to cover an aluminum final metallization layer that would melt at 600°C, this clearly could not work. The solution was to use PECVD at 350° to 400°C. 

DIP (Dual Inline Package) A standard housing constructed of hard plastic commonly used to hold an integrated circuit. The circuit s leads are connected to two parallel rows of pins designed to fit snugly into a socket these pins may also be soldered directly to a printed-circuit board. If you try to install or remove dual inline packages, be careful not to bend or damage their pins. 

Studies on thermomechanical stresses in plastic packaged integrated circuits after molding and in encapsulation materials, show the resulting stress distribution on the surface of the die and clarify the fundamental mechanism in the generation of thermomechanical stresses in molding compounds. 

To avoid surface corrosion processes, the microelectronic industry takes three precautions it avoids the use of solvents and reagents that may leave an ionic residue on the microcircuits it encapsulates the integrated circuits and it packages the microcircuits in plastic containers. When used in weapons, in space, or in undersea communi... 

Solid state lasers have become ubiquitous in our society. Pulsed YAG Nd lasers are used for welding of metals and plastics. Among the applications are medical apparatus catheters where the weld size must be very small fiber optics communication systems and hermetic sealing of integrated circuit packages. 

Bare die such as integrated circuits may be assembled in plastic or ceramic carriers, called chip-scale packages, whose dimensions are slightly larger than the chip. CSPs are often defined as packages that are no larger than 1.5 times the area of the die or no more than 1.2 times the width or length of the die. If the carrier is a BGA type, an alternate definition is that the solder-ball pitch be less than 1 mm. The pitch of... 

The most signilieant application for conductive adhesives in the manufacture of microelectronics is the attachment of silicon chips to lead frames. Of the 40 billion integrated circuits (ICs) manufactured each year, approximately 90% are encapsulated in plastic-molded packages, and most of these are assembled with conductive adhesives [4]. A schematic illustration of a plastic-molded IC package is shown in Fig. 2. The conductive... 

Figure 2 Cross section of a plastic-molded integrated circuit package.

Molding Compound Delamination in Plastic SMT Packages. Plastic-packaged integrated circuits are generally transfer molded using a filled epoxy-based compound. 

Plastics in the form of epoxide moulding compounds have now almost completely dominated the packaging of integrated circuits which, when mounted on printed circuit boards, form the functional core of the latest technology equipment. 

Fig. 3. Most widely used method for packaging integrated circuits—low cost plastic packages called P-DIPs (plastic dual inline packages).

Figure 30 Main applications of adhesives in electronic and semiconductor industries (a) polyimide interlayer dielectric films in the fabrication of integrated circuits (b) die attachment in plastic packages (c) die attachment in ceramic packages (d) multichip module with flip chip and surface-mounted devices (e) flexible circuitry (f) tape automated bonding (g) liquid crystal display panels.

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