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→Assembled Contact Components
Plastic molded or encapsulated components are of increasing importance due to rising requirements for smaller, lighter and more compact designs with cost efficient pricing. Wherever mechanics and electronics meet, electromechanical components can be used in a multitude of applications, such as in automotive, communications, appliance and consumer electronics engineering.
In automotive applications, such components are used in ever increasing volumes. In hybrid housings, electronic components are integrated into components for increasingly more complex engine management functions. Strip-molded contact parts are, for example, used for seat adjustment and airbag sensors; assembled contact parts are important functional components among others for memory mirror positioning units.
<figtable id="tab:Frequently Used Plastic Materials and their Properties">
<caption>'''<!--Table 10.1:-->Frequently Used Plastic Materials and their Properties'''</caption>
{| class="twocolortable" style="text-align: left; font-size: 12px"
|-
!rowspan="2" style="text-align:center;"| Type of Plastics:<br />Poly-condensate<br />Sub-Type: Thermo-<br />plastics Abbrev.!colspan="6" style="text-align:center; padding:2px"| Properties
|-
!Density<br />[g/cm<sup>3</sup>]
!Reinforcement<br />Materials
|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
|}
</figtable>
== Hybrid Frames and Housings==
Hybrid frames and housings serve as the connecting points between mechanics and electronics (<xr id="fig:Component with hybrid housing for use in automobiles"/> <!--(Fig. 10.1)-->). They allow the transmission of signals or electrical energy. The connection to the current paths inside the housing is mostly done by bonding with aluminum wires. The over-molded lead frames are typically manufactured from aluminum clad strip materials , which are well suited for bonding. The connectors integrated into the housing for transferring the current paths to the outside , are coated with tin, silver, or gold, depending on specific requirements.
<figure id="fig:Component with hybrid housing for use in automobiles">
[[File:Component with hybrid housing for use in automobiles.jpg|rightleft|thumb|Figure 1: Component with hybrid housing for use in automobiles]]
</figure>
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== Continuous Strip Over-Molding==
In strip form , over-molded contact parts reduce the complexity of assembly of the finished product. This complexity constantly increases with adding additional subcomponents (<xr id="fig:Examples of strip over molded contact components"/> <!--(Fig. 10.2)-->).
The strip over-molded contact parts can be tested for various quality parameters during manufacturing , to continuously ensure the ever increasing reliability requirements of the end components.
Combining stamping and molding techniques in an automated production line allows the stamped contact parts to be molded into plastics as a complete functional unit. This also allows enables to reduce manufacturing tolerances to levels below those achievable with conventional assembly methods.
<figure id="fig:Examples of strip over molded contact components">
[[File:Examples of strip over molded contact components.jpg|rightleft|thumb|Figure 2:Examples of strip over molded contact components]]
</figure>
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==Assembled Contact Components==
For applications and materials which do not allow strip over-molding, semi or fully automated assembly processes can be utilized. Different single parts, like printed circuit boards, stamped parts or contact components are assembled together with plastic molded parts on specialized equipment to complete functional components with low tolerances and high levels of functionality (<xr id="fig:Examples of assembled contact components"/><!--(Fig. 10.3)-->). This also allows to integrate components which otherwise are difficult to mount onto circuit boards or carriers, such as capacitors, coils or sensor elements into the functional component assembly. Contact parts used in these components are already tested on the assembly machine for quality parameters and functionality.
<figure id="fig:Examples of assembled contact components">
[[File:Examples of assembled contact components.jpg|rightleft|thumb|Figure 3: Examples of assembled contact components]]
</figure>