Packaging mechanical stress

These advantages can only be significant if the tablets are considerably stable and hard. They must be hard enough to withstand mechanical stress by packag-... 

The packaging must physically protect the product from the mechanical stresses of warehousing, handling and distribution. Mechanical stress may take a variety of forms, from impact through to vibration in transit and compression forces on stacking. The demands for mechanical protection will vary with product type glass ampoules will require greater protection than plastic eye drop bottles, for example. 

Polyimides, both photodefinable and nonphotodefinable, are coming into increased use. Applications include planarizing interlayer dielectrics on integrated circuits and for interconnects, passivation layers, thermal and mechanical stress buffers in packaging, alpha particle barriers on memory devices, and ion implantation (qv) and dry etching masks. 

The primary packaging must physically protect the product from the mechanical stresses of warehousing, handling, and distribution. Mechanical stress may take a... 

Lead-tin alloys are the most commonly used solder materials for microelectronic packaging. Pb and Pb-rich alloys have one of the most desirable characteristics of C4 solders in that they are soft and compliant. The compliant nature of these alloys act a cushion for absorbing thermal and mechanical stresses and transfer minimum stresses to the die during microprocessor assembly processes. On the other hand, the melting... 

The outer casing (which gives protection against mechanical stress and contains the inner packaging and absorbent materials)... 

In recent years liquid crystalline thermosetting polymers have been the object of extensive research and patent activity (1-8). The interest in these materials lies in their challenging theoretical implications and in the noticeable potential applications. Highly crosslinked liquid crystalline thermosets turned out to be promising candidates for thin film applications in electronic packaging and as matrix materials for advanced composites due to their superior mechanical properties and heat resistance (4-6) on the other hand, lightly crosslinked networks can be easily oriented by mechanical stress and this results in a change of their optical properties (9). Applications as... 

PP reacts with oxygen in several ways, causing chain scission and brittleness that is associated with the loss in molecular weight. This action is promoted by high temperatures, light, or mechanical stress. A wide variety of stabilization packages are added for protection, depending on the application (157). 

Use of silicone gel in this way is illustrated in Fig. 3.5. Chip carriers to JEDEC design are filled with the uncured liquid gel by meter-mix application in-line and heated in a tunnel through which the conveyor strip passes to cure the gel. This then provides protection to the chip and its leads against both corrosion and mechanical stress caused by differential thermal expansion of the package components. 

The outstanding advantage the thermoplastics have over cellulose-based packaging materials is their very good barrier properties. The advantage of polyethylene in foodwrapping is without parallel over traditional wrapping materials, such as paper or metal foil, due to its resistance to moisture and mechanical stress. 

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