Packaging technologies adhesive requirements

Table 5,9 Adhesives requirements for various packaging technologies ...

Packaging technology Typical adhesive requirements Examples of adhesives... 

Packaging Technology Typical Adhesive Requirements Examples of Adhesives... 

Adhesives are also tailored to meet specific requirements of the packaging or assembly technology used (Table 5.9). Thus, the requirements for single-chip packaging in hermetically sealed ceramic packages such as CERDIPs will be somewhat different from those of plastic dual-in-line packages (PDIPs) and plastic-encapsulated microcircuits (PEMs). 

In recent years a technique has been developed in which large quantities of adhesive resins called compatibilizers are used between layers of noncompatible extruded films, primarily in packaging applications. With this technology, up to seven layers of film (foil, paper, or plastic), up to three of which may be adhesive, may be combined to offer properties unlike that of any single-film material. The adhesive layer(s) may also contribute special properties to the multilayer composite film, in addition to acting as the compatibilizer. It is interesting to note that a particular plastic resin with adhesive properties may be used alone as an extruded plastic film, or in a multilayer composite film, where no compatibilizer is required, in which case it should not be counted in the adhesive statistics. This example is just one of hundreds where an intermediate or final user... 

Adhesion of metals to polymers has been an intensively studied subject over the past decades This is due to the wide application of polymers to electronic packaging and, to a lesser extent, to device inter-connect The increasing demand in density for devices and speed for packaging, in turn, prompts searches for polymers with reduced dielectric constants than that of the widely used polyimide. Some fluorocarbon polymers, notably Teflon, have lower dielectric constants, 2.1, vis-i-vi the values of 3.0-3.5 for polyimides. The fluorocarbon polymers, however, have very weak adhesion to metals. An enhancement in adhesion is thus a primary requirement for the application of such polymers to technologies. A wide range of studies have been made in the past to understand and enhance the adhesion between metals and fluorocarbon polymers In this paper we review some of our earlier work, and present new observations related to the enhanced adhesion between metals and fluorocaiton polymers. We present results address three contributions to enhanced adhesion between metals and fluorocarbon polymers chemical, mechanical, and thermal. 

The equipment required for an investment in UV technology is affordable for smaller companies. Up to one 2ooW/cm El-bulb per som/min line speed is needed, depending on the adhesive formulation. The size of the installation then depends on the desired lamination speed. Some films, including printed films, are not transparent to UV rays. This can be a limitation, if the adhesive open time is too short and the irradiation stage needs to take place after the lamination stage. On the other hand the UV lamination process has no influence on most films used in the manufacture of packaging materials. 

Summary The broad objectives of technology developments in radiation-curable adhesives are to achieve the required mix of cohesive and adhesive properties, reduced odour and addressing toxicity and safety concerns. Recently, various players have focused on developing technology for laminating adhesives and PSAs, specifically for flexible packaging. 

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