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Electromechanical components usually consist of stamped circuit patterns (lead frames) which are coated in the contacting areas with functional surface layers. They serve as the electrical connections of the component to the outside wiring. The lead frames are over-molded with plastics or mounted into plastic molded parts. In addition electronic components can be added to increase the level of product integration. Utilizing the metal–plastic compound the mechanical stability of the plastic is combined with the conduction of electrical energy and electronic signals through the lead frame. In this way protective enclosures for electronic controls of machinery are created which at the same time serve as connecting points to the outside wiring. This can be achieved through hybrid frames and housings. Over-molding of contact components or assembly of different single parts in plastic enclosures can also be used to manufacture electromechanical components.
For achieving the highest possible functionality of the end product a close cooperation between the manufacturer and the end user in the early phases of development and design of new custom tailored electromechanical compo- nents components is recommended. Innovative and cost-efficient designs can be realized through the combination of the know-how of the manufacturer in for example contact, coating, stamping, plastics processing, and assembly technologies and the mostly rather complex requirement profile given by the end user.
Besides the contact components the plastic materials are the critical building blocks for electromechanical components. Plastics used are mostly technical thermoplastics and heavy-duty plastics which fulfill the requirements for high mechanical strength, temperature stability, and fatigue strength <xr id="tab:Frequently Used Plastic Materials and their Properties"/> (Table 10.1). For the final selection of a plastic material economical considerations and the avoidance of environmentally hazardous ingredients such as for example flame retardants must be considered. The application of the most suitable contact material coating and the selection of carrier materials are covered in chapters [[Contact Carrier Materials|Contact Carrier Materials]], [[Surface Coating Technologies| Surface Coating Technologies]] and [[Applications for Bonding Technologies|Applications for Bonding Technologies]].
|use temperature 200 – 250°C,<br />good high temperature stability,<br />very low thermal expansion,<br />resistant to soldering<br />temperatures < 250°C, difficult to<br />combust and self-extinguishing
|good resistance against widely<br />used organic solvents, i.e.<br />acetone, methanol, chlorine gas,<br />acetic acid
|-
|'''PPA'''
|1.26 - 1.85
|glass fibers,<br />minerals
|high impact strength with good<br />mechanical strength and stiffness, very<br />high dimensional stability at high<br />temperatures, very low humidity<br />absorption
|very low electrical losses
|use temperature up to 185°C,<br />standard types with UL94-HB<br />classification, special flame<br />protective types
|very good resistance against<br />typically used organic solvents, i.e.<br />acetone, methanol, etc., water<br />based solutions (DI water, 10%<br />ammonium hydride, typical liquids<br />used in the automobile such as<br />brake fluid, motor oil, etc
|}
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