Understanding the use of silicone gels for non-hermetic plastic packaging

Wong, Ching‐Ping; Segelken, J.M.; Balde, J.W.

doi:10.1109/ecc.1989.77838

“…Typical encapsulation materials are silicone gel, epoxy and parylene with the later showing high working temperatures more than 200°C. Several encapsulants claim to have working temperatures more than 250°C [171][172][173][174][175][176][177][178][179][180][181]; however, reliability studies claim encapsulants slowly degrade before reaching 250°C [137,182].…”

Section: Encapsulantmentioning

confidence: 99%

Integrated motor drives: state of the art and future trends

Abebe

¹

,

Vakil

²

,

Calzo

³

et al. 2016

IET Electric Power Applications

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With increased need for high power density, high efficiency and high temperature capabilities in aerospace and automotive applications, integrated motor drives (IMD) offers a potential solution. However, close physical integration of the converter and the machine may also lead to an increase in components temperature. This requires careful mechanical, structural and thermal analysis; and design of the IMD system. This study reviews existing IMD technologies and their thermal effects on the IMD system. The effects of the power electronics position on the IMD system and its respective thermal management concepts are also investigated. The challenges faced in designing and manufacturing of an IMD along with the mechanical and structural impacts of close physical integration is also discussed and potential solutions are provided. Potential converter topologies for an IMD like the matrix converter, two-level bridge, three-level neutral point clamped and multiphase full bridge converters are also reviewed. Wide band gap devices like silicon carbide and gallium nitride and their packaging in power modules for IMDs are also discussed. Power modules components and packaging technologies are also presented.

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“…Therefore, they do not intrinsically perform as well as hermetic packaging, especially in aggressive in vivo environments. Polymeric materials, such as silicones (Lachhman, Zorman, & Ko, 2012; Wang et al, 2015; Wong, Segelken, & Balde, 1989), LCP(Ha et al, 2010; Lee, Min, Jeong, Kim, & Kim, 2011; Lee, Min, Jeong, Kim, & Kim, 2011; Yun et al, 2019), polyimide (Palopoli‐Trojani, Woods, Chiang, Trumpis, & Viventi, 2016; Rubehn & Stieglitz, 2010; Woods et al, 2018) and parylene (Agarwal et al, 2018; Chang, Liu, Kang, & Tai, 2013; Lecomte, Degache, Descamps, Dahan, & Bergaud, 2017; Rodger, Weiland, Humayun, & Tai, 2006; Shapero, Liu, & Tai, 2016), are commonly used as non‐hermetic encapsulation materials for medical implants. These polymeric materials provide low weight, small size packaging options that if designed, manufactured and tested properly, offer the promise of a reliable substitute for a hermetic encapsulation.…”

Section: Introductionmentioning

confidence: 99%

Non‐hermetic packaging of biomedical microsystems from a materials perspective: A review

Chong

¹

,

Majerus

²

,

Bogie

³

et al. 2020

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Traditionally, implantable electronic devices have used metal-based hermetic encapsulation to protect the internal components from damage by the aggressive in vivo environment. Concurrently, hermetic encapsulation protects the surrounding tissue from harmful substances that might be leached from the packaged components (Bazaka & Jacob, 2012). In some cases, however, there is risk of electrochemical corrosion on the metallic surfaces because of the presence of various ions, amino acids, proteins and dissolved oxygen (Eliaz, 2019). Hermeticity is defined as the ability of sealed packages to resist foreign gases and liquids from penetrating the seal or encapsulating material (Madduri, Sammakia, Infantolino, & Chaparala, 2008). Hermetic packages are conventionally made from glass, metal or ceramic materials whereby the gas and moisture permeability through the material is negligible (Madduri et al., 2008; Schuettler, Schatz, Ordonez, & Stieglitz, 2011). Hermetic materials have been successfully used to package devices for chronic applications, some of the most notable being cochlear implants and cardiac pacemakers (Kirsten, Wetterling, Uhlemann, Wolter, & Zigler, 2013). Titanium is the most commonly used metal for hermetic encapsulation because of its biocompatibility, low permeability for ions and moisture, mechanical durability and the ability to create viable hermetic seals by laser welding (Amanat, James, & McKenzie, 2010). Ceramics have also been used for implants for wireless devices to address issues related to attenuation of electromagnetic transmission by metallic packaging (El Khatib, Pothier, Crunteanu, & Blondy, 2007; Schubring & Fujita, 2007; Shen & Maharbiz, 2019). Driven by the increased functionality and scalability offered by innovations in application-specific integrated circuits (ASICs) and the desire to create highly miniaturized devices on flexible polymer substrates, significant efforts have been made in creating miniaturized implants by integrating the majority of components on a single chip. As the

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“…Typical encapsulation materials are silicone gel, epoxy and parylene with the later showing high working temperatures more than 200°C. Several encapsulants claim to have working temperatures more than 250°C [171][172][173][174][175][176][177][178][179][180][181]; however, reliability studies claim encapsulants slowly degrade before reaching 250°C [137,182].…”

Section: Encapsulantmentioning

confidence: 99%

Integrated motor drives: state of the art and future trends

2017

IET Electric Power Applications

1

0

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With increased need for high power density, high efficiency and high temperature capabilities in aerospace and automotive applications, integrated motor drives (IMD) offers a potential solution. However, close physical integration of the converter and the machine may also lead to an increase in components temperature. This requires careful mechanical, structural and thermal analysis; and design of the IMD system. This study reviews existing IMD technologies and their thermal effects on the IMD system. The effects of the power electronics position on the IMD system and its respective thermal management concepts are also investigated. The challenges faced in designing and manufacturing of an IMD along with the mechanical and structural impacts of close physical integration is also discussed and potential solutions are provided. Potential converter topologies for an IMD like the matrix converter, two-level bridge, three-level neutral point clamped and multiphase full bridge converters are also reviewed. Wide band gap devices like silicon carbide and gallium nitride and their packaging in power modules for IMDs are also discussed. Power modules components and packaging technologies are also presented. IntroductionOver the last two decades there has been a shift from traditional physically separated motor and drive systems to more compact, power dense, motor-drive combinations [1]. This new power-dense motor-drive structure combines both the motor and its associated control and drive circuitry within a single enclosure. The earliest records of commercially available motor-drive systems were manufactured by Grundfos in 1991 and Franz Morat KG in 1993 [2].These compact systems have been called a variety of names from 'smart motors' to 'integrated motors', the latter forming the foundation for the new moniker currently identified with these systems [3]. The term 'integrated motor drive (IMD)' is the latest associated with this class of products and is as a result of the success of a TB Woods Inc. manufactured motor-drive registered under the same name [3].IMDs are increasingly being developed and produced by machine manufacturers due to the significant potential benefits they offer. The most significant of these benefits include direct replacement of inefficient direct on line motors, increased power density, lower losses and lower costs compared with separate motor and drive solutions. Technological advancements over the last decade have led to the development of robust electronic components able to withstand the harsh environments required by some forms of integration [4]. By eliminating separate enclosures and long cable runs, the integrated approach promises to lower system costs by 20 to 40% [5].Elimination of transmission cables has economic advantages, including increased reliability due to the removal of the output filter commonly required for long cables. Removal of long cable runs and integration into a single package will also significantly reduce potential electromagnetic interference (EMI). This a...

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Understanding the use of silicone gels for non-hermetic plastic packaging

Cited by 11 publications

References 10 publications

Integrated motor drives: state of the art and future trends

Integrated motor drives: state of the art and future trends

Non‐hermetic packaging of biomedical microsystems from a materials perspective: A review

Integrated motor drives: state of the art and future trends

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