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Such electronlc is important to prevent immediate or premature electronic product failures. Potting can be rigid or soft. See Conformal coatingParylene. From Wikipedia, the free encyclopedia. They are fairly common in microwave assemblies for aerospace use, where precision transmission lines require complex metal shapes, in combination with hermetically sealed housings. This article needs additional citations for verification.
Electronic packaging is the design and production of enclosures for electronic devices ranging from individual semiconductor devices up to complete systems such herimticity a mainframe computer. It prevents ionization from forming between closely spaced live surfaces and initiating failure.
A designer must balance many objectives and practical considerations when selecting packaging methods. Prototypes and industrial equipment made in small quantities may use standardized commercially available enclosures such as card cages or prefabricated boxes.
Views Read Edit View history. The same electronic system may be packaged as a portable device or adapted electronnic fixed mounting in an instrument rack or permanent installation.
In the design of electronic products, electronic packaging engineers perform analyses to estimate such things as maximum temperatures for components, structural resonant frequencies, and dynamic stresses and deflections under worst-case environments.
It consists of a drop of specially formulated epoxy  or resin deposited over a semiconductor chip and its wire bonds, to provide mechanical support and exclude contaminants such as fingerprint residues which could disrupt circuit operation. Today, glass-seal packages are used mostly in critical components and assemblies for aerospace use, where leakage must be prevented even under extreme changes in temperature, pressure, and humidity.
Today it is most widely used to protect semiconductor components from moisture and mechanical damage, and to serve as a mechanical structure holding the lead frame and the chip together. In these, the individual diodes are mounted in an array that allows the device to produce a greater amount of luminous flux with greater ability to dissipate the resulting heat in an overall smaller package than can be accomplished by mounting LEDs, even surface mount types, individually on a circuit board.
It is also commonly used in high voltage products to allow live parts to be placed closer together, so that the product can be smaller. Product safety standards may dictate particular features of a consumer product, for example, external case temperature or grounding of exposed metal parts. The design of these products depends on the production method and require careful consideration of dimensions and tolerances and tooling design.
The pressure above the fluid is lowered to a full vacuum. Electronic packaging relies on mechanical engineering principles such as dynamics, stress analysis, heat transfer and fluid mechanics. Conformal coating is a thin insulating coating applied by various methods.
Printed circuits are primarily a technology for connecting components together, but they also provide mechanical structure. Some parts may be manufactured by specialized processes such as plaster- and sand-casting of metal enclosures. The tool of choice is a numerically controlled vertical milling machine, with automatic translation of computer-aided design CAD files to toolpath command files.
When void-free potting is required, it is common practice to place the product in a vacuum chamber while the resin is still liquid, hold a vacuum for several minutes to draw the air out of internal cavities and the resin itself, then release the vacuum.
Please help improve this article by adding citations to reliable sources. December Learn how and when to remove this template message. It provides hermiticitu and chemical protection of delicate components. Mass-market consumer devices may have highly specialized packaging to increase consumer appeal. Necessary cookies are absolutely essential for the website to function properly.
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HERMITICITY OF ELECTRONIC PACKAGES PDF
The author explains how to predict the reliability and the longevity of the packages based on leak rate measurements and the assumptions of impurities. Non-specialists in particular will benefit from the author's long involvement in the technology. Hermeticity is a subject that demands practical experience, and solving one problem does not necessarily give one the background to solve another. Thus, the book provides a ready reference to help deal with day to day issues as they arise. How to define the ""goodness"" of a seal? How is that seal measured?
Hermeticity of Electronic Packages
Electronic packaging is the design and production of enclosures for electronic devices ranging. Potting can be done in a pre-molded potting shell, or pacoages in a mold. In earlier times it was often used to discourage reverse engineering of proprietary products built as printed circuit modules. Views Read Pcakages View history.