Applications of adhesives in electronic

Fig. 2 shows one large application of adhesives in electronic goods that is now a very large market for high-performance adhesives and potting compounds. Fig. 3 shows an enlargement of the epoxy adhesive film on a bonded aluminum honeycomb. 

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.

This chapter describes the adhesive technologies used in the electrical industry with an introduction to the conduction mechanisms in adhesive joints, the specific requirements for the application of adhesives in electronics, and reliability evaluation methods. This chapter could be summarized with the following conclusions. 

Most applications of polymers in electronic packaging have a number of common requirements. Most pervasive is the moisture issue, but other important requirements are low dielectric constant, low dielectric losses (dissipation factor), and good adhesion to various substrates and metallizations. With the... 

Presently, significant work has been done to develop and optimize various LRP techniques. Commercial applications are still scarce. The general expectation is that the products of LRP will mainly be employed in high-value-added products. These may include specialty coatings, adhesives, personal care products, biomedical applications, and optoelectronical applications. Examples of biomedical applications can be foimd in the work of eg, Muller (128), Haddleton (129), and Wooley (130,131). For materials in optoelectronical applications it is of great importance that many of the techniques from FRP can be adopted to LRP. An example is surface grafting from or onto various substrates, like silica (132) and gold (133). Much of the work of Hawker and co-workers is dedicated to the application of LRP in electronical applications (134). 

Detailed information on the appropriate volumes, application, and use of adhesives in electronic manufacturing is beyond the scope of this chapter. The reader wishing further information is referred to Prasad. 

Adhesives have a wide range of applieations in packaging sports, shoes, furniture, applianee and houseware assembly, rug baeking, fabric combining, surgical, millwork manufacture, electronics, automotive, aircraft, space, transportation, and the building construction industries. Discussion of the application of adhesives in this chapter will be limited to the construction industry. 

There are numerous applications for adhesives in electronics manufacturing industries some bringing additional property requirements for adhesive formulators, particularly those of conductivity and heat and stress dissipation. Licari and Swanson (2005) give a complete exposition on the subject. 

Part IV of the book describes the applications of adhesives with respect to special adherends. Applications of adhesives in aerospace, electronic, and medical/dental have been described in separate chapters because of the importance and breadth of adhesion use in these industries. There are few, if any, adhesives that are not used by these industries, thus rendering the information in the chapters useful to nearly any other... 

Kristiansen H, Liu J. Overview of conductive adhesive interconnection technologies for display applications. Conductive Adhesives For Electronics Packaging. In Liu J, ed. Electrochemical Publications 1999. 

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. 

Melt blending poly(phenylene ether), poly-(styrene), and curable epoxy resins yield materials that are suitable for use as adhesives in electronics applications [78]. In particular, the composition of such adhesives is useful in laminating films for electronic applications. 

As more sophisticated adhesion models become available, it is obvious that they will greatly influence the applications of adhesion, from colloids, pastes and gels to aerospace, electronics and cells. It seems likely that, just as photocopying, food, and aerospace drove adhesion science forward in the last 50 years, electronics and bioadhesion will pnsh back the bonndaries in the new milleninm. We will move increasingly towards molecnlar applications. 

In addition, the structure of the uncured materials can be selected to fit a variety of industrial application processes. Thus, they are used in Aerospace applications, Automotive applications, as Adhesives in the textile industry and in building, electronic, healthcare, energy, medical, paper and personal care industries (see Adhesion in medicine). 

We will see in the chapter Robot Application of Adhesives and Sealants later in this Handbook that there are also robots, with two and three axes, that may use these syringes, for instance to apply adhesives at very high speeds in electronics, and also on revolution parts. The syringes offer a very low weight and therefore can be moved at very high speed with a small robot for fast and very accurate jobs in electronics (Fig. 10). 

Further discussion on robotic applications of adhesives and sealants are done in a separate chapter Robotic Application , and also in the chapters Adhesives for Electronics and Automotive Adhesives and Sealants later in the Handbook. 

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