Electronics technology has been developing rapidly since the first transistor was invented. Semiconductor technology is the most significant part for electronics technology development. At the first time one transistor with very small size could replace cathode tube. Now, thousand or even million transistors can be operated in one single chip. However, electronics have maximum temperature to be operated properly. A survey showed that the most cause of electronic failure is temperature. Thus electronics cooling cannot be separated in electronics technology.
Many types of cooling system for electronics have been introduced. The most common electronics cooling system is heat sink. Heat sink system can be divided into two parts, forced convection and natural convection.
Natural convection is convection heat transfer without any force applied to heat sink. This convection occurs because of buoyancy force naturally. Fluid (e.g air) has lower density if its temperature is high, this causes air moves up. In electronics, heat dissipated from chip causes increasing temperature surrounding then air density becomes low, thus air moves up. Since natural convection only uses buoyancy force, usually natural convection heat sink is attached vertically.
Forced convection need additional force to move air flows on heat sink. Fan is usually used to support air flow on heat sink. Heat transfer rate at this heat sink is bigger than natural convection. Many electronic equipments use this type.
Heat sink is attached to heat source to enhance heat transfer rate. When heat dissipated from electronic device cannot be overcome by heat sink, it needs additional system or even different cooling system. Heat pipes or thermoelectric cooler may be an option for additional system in heat sink.
No comments:
Post a Comment