Chip-On-Board (COB) technology is very similar to MCM-L technology and has several advantages. It supports the use of both conventional soldered components and bare dies on a laminate dielectric substrate. It saves weight and volume compared to the conventional MCM technology with hermetic packages since it eliminates the intermediate substrate and pins of a MCM device.
When design parameters cannot be met by traditional assembly techniques, Chip-On-Board (COB) could be the solution. COB is an excellent choice for the miniaturization of your electrical circuit. In COB manufacturing, an unpackaged semiconductor die is attached directly onto the surface of a PCB substrate along with signal conditioning or support circuitry. Electrical connections are formed when the IC is attached to the corresponding substrate interconnects with wire bonding. A junction coating material (epoxy resin or a silicone coating) is then applied on top of the die to encapsulate and protect the die and wire bonds.
COBs primary advantage is that it reduces the weight and mass of the circuit. When this is a primary concern, Chip-On-Board technology is the choice for circuit miniaturization solution.Using conventional printed wiring boards (PWBs) and standard wire bonding technology, COB technology can yield a factor of at least 10 in weight and volume saving. COB provides high packing density, quick turnaround, can be adapted to high frequencies, can mix standard assembly technologies and is applicable to most substrates. COB technology also reduces the thermal resistance and the number of interconnects between an active die and thesubstrate, which can potentially improve the overall circuit speed and the reliability of the design.This is a manufacturing solution that allows fast modification of existing product designs, even where space is at a premium.
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