Electronics Assembly and Packaging
- (Blair Arch, Princeton University - Kimberly Chen)
- Electronic Packaging
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. Packaging of an electronic system must consider protection from mechanical damage, cooling, radio frequency noise emission and electrostatic discharge. Product safety standards may dictate particular features of a consumer product, for example, external case temperature or grounding of exposed metal parts. Prototypes and industrial equipment made in small quantities may use standardized commercially available enclosures such as card cages or prefabricated boxes. Mass-market consumer devices may have highly specialized packaging to increase consumer appeal. Electronic packaging is a major discipline within the field of mechanical engineering.
- Electronic Packaging Design
Electronic packaging can be organized by levels:
- Level 0 - "Chip", protecting a bare semiconductor die from contamination and damage.
- Level 1 - Component, such as semiconductor package design and the packaging of other discrete components.
- Level 2 - Etched wiring board (printed circuit board).
- Level 3 - Assembly, one or more wiring boards and associated components.
- Level 4 - Module, assemblies integrated in an overall enclosure.
- Level 5 - System, a set of modules combined for some purpose.
The same electronic system may be packaged as a portable device or adapted for fixed mounting in an instrument rack or permanent installation. Packaging for aerospace, marine, or military systems imposes different types of design criteria.
Electronic packaging relies on mechanical engineering principles such as dynamics, stress analysis, heat transfer and fluid mechanics. 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 light), salt spray, explosive shock, and many more. These requirements extend beyond and interact with the electrical design.
- Electronics Assembly
An electronics assembly consists of component devices, circuit card assemblies (CCAs), connectors, cables and components such as transformers, power supplies, relays, switches, etc. that may not mount on the circuit card.
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. The design of these products depends on the production method and require careful consideration of dimensions and tolerances and tooling design. Some parts may be manufactured by specialized processes such as plaster- and sand-casting of metal enclosures.
- Electronics Equipment Assembler
An electronic equipment assembler, also known as a fabricator, mounts, connects, assembles and secures parts and components of electronic equipment. The assembler works behind the scenes to bring together the pieces of equipment we use every day, such as computers, electronic devices, toys and engines. A wide range of electronics are involved: computer circuit boards, transmitters, receivers, medical equipment, measuring devices, and automotive mechanisms.
Opening up the inside of a home computer provides a sense of the complexity of the job. A computer motherboard, for example, is a small circuit board that consists of dozens and dozens of individual components: resisters, transistors, wires, connectors, CPU sockets, battery connectors, and power connectors, just to mention a few. All of these tiny parts need to be fixed to the board and connected in order for the computer to function. Many large manufacturers outsource things like circuit boards to companies in China and India. However, these pre-assembled components still must be put together manually.
With new technological advancements requiring smaller and smaller micro electronics, mass production technology has become more automated. Changes in technology have transformed the way electronic equipment is made, and modern manufacturing systems use robots, programmable motion-control devices, sensing technologies and computers. Increasingly, companies are using lean manufacturing techniques, with teams of workers producing the entire device. The nature of the electronic equipment assembler's job has been transformed accordingly. Regardless of how or where, however, almost every piece of modern electronic equipment has at some point been in the hands of an electronic equipment assembler.
[More to come ...]
