HERMITICITY OF ELECTRONIC PACKAGES PDF
Six Sigma: Hermeticity Testing (Fine and Gross Leak) is used to determine the 1] H. Greenhouse, Hermeticity of Electronic Packages (William Andrew. As early as the s, SCHOTT’s Business Unit Electronic Packaging .. glass seal, for instance, hermeticity or seal strength, do not change as a result of. Electronic packaging is the design and production of enclosures for electronic devices ranging . Burn-in · Temperature cycling · Thermal shock · Solderability · Autoclave; Visual inspection; Hermeticity/moisture resistance.
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Molded hermitixity cases and structural parts can be made by a variety of methods, offering tradeoffs in piece part cost, tooling cost, mechanical and electrical properties, and ease of assembly. Many electrical products require the manufacturing of high-volume, low-cost parts such as enclosures or covers by techniques such as injection molding, die casting, investment casting, and so on.
Examples are integrated circuit chips in ceramic Dual In-line Package form, or complex hybrid assemblies of chip components on a ceramic base plate. This industry developed the glass-seal electrical feedthrough, using alloys such as Kovar to match the coefficient of expansion of the sealing glass so as to minimize mechanical stress on the critical metal-glass bond as the tube warmed up.
Six Sigma: Hermeticity Testing
It’s relatively common to find packages that contain other components than their designated ones, such as diodes or voltage regulators in transistor packages, etc.
It prevents ionization from forming between closely spaced live surfaces and initiating failure. Electronic packaging is a major discipline within the field of mechanical engineering. This page was last edited on 31 December hsrmiticity, at Such knowledge is important to prevent immediate or premature electronic product failures.
Curing can consist of polymerizing the internal resin or evaporating the solvent, which leaves an insulating dielectric material between different voltage components. A designer must balance many objectives and practical considerations when selecting hermticity methods.
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This method is used mostly in very large electrical equipment such as utility transformers, to increase breakdown voltage. Pl can be post-processed to provide conductive surfaces.
Hermetic metal packaging began life in the vacuum tube industry, where a totally leak-proof housing was essential to operation.
High-reliability equipment often must survive drop tests, loose cargo vibration, secured cargo vibration, extreme temperatures, humidity, water immersion or spray, rain, sunlight UV, IR and visible lightsalt spray, explosive shock, and packxges more.
It can also be used to improve heat transfer, electronlc if allowed to circulate by natural convection or forced convection through a heat exchanger. In earlier times it was often used to discourage reverse engineering of proprietary products built as printed circuit modules. Please help improve this article by adding citations to electeonic sources. Electronic packaging Integrated circuit packaging Package of integrated circuit packaging types Printed circuit board Surface-mount technology Through-hole technology.
It provides mechanical and chemical protection of delicate components. Quantities tend to be small; sometimes only one unit of a custom design is required. December Learn how and when to remove this template message.
Electronic packaging – Wikipedia
Prototypes and industrial equipment made in small quantities her,iticity use standardized commercially available enclosures such as card cages or prefabricated boxes. They are fairly common in microwave assemblies for aerospace use, where precision transmission lines require complex metal shapes, in combination with hermetically sealed housings.
It’s usually hermlticity dielectric fluid, chosen for chemical compatibility with the other materials present. This type of packaging can also be divided into two main types: Mass-market consumer devices may have highly specialized packaging to increase consumer appeal.
Piece part costs are high, but there is little or no cost for custom tooling, and first-piece deliveries can take as little as half a day. This also excludes dirt and conductive contaminants such as impure water from sensitive areas.
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. Gasketed metal castings are sometimes used to package electronic equipment for exceptionally severe environments, such as in heavy industry, aboard ship, or deep under water. Porosity Sealing or Resin Impregnation is similar to potting, but doesn’t use a shell or a mold. Another use is to protect deep-submergence items such as sonar transducers from collapsing under extreme pressure, by filling all voids.
Liquid filling can be removed for repair much more easily than potting. Punched and formed sheet metal is one of the oldest types of electronic packaging. Conformal coating is a thin insulating coating applied by various methods. Electronic packaging is the design and production of enclosures for electronic devices ranging from individual semiconductor devices up to complete systems such as a mainframe computer.
This makes them part of the universe of electronic packaging.
Electronic packages are sometimes made by machining solid blocks of metal, usually aluminum, into complex shapes. These requirements extend beyond and interact with the electrical design. Packaging of an electronic system must consider protection from mechanical damage, cooling, radio frequency noise emission and electrostatic discharge. The tool of choice is a numerically controlled vertical milling machine, with automatic translation of computer-aided design CAD files to toolpath command files.
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. It can be mechanically strong, provides electromagnetic shielding when the product requires that feature, and is easily made for prototypes and small production runs with little custom tooling expense. Potting can be rigid or soft. Packaging for aerospace, marine, or military systems imposes different types of design criteria.
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.
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