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Method for cooling a handheld or portable device

IP.com Disclosure Number: IPCOM000021726D
Publication Date: 2004-Feb-04
Document File: 4 page(s) / 77K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for cooling a handheld or portable device. Benefits include improved functionality, improved power performance, and improved reliability.

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Method for cooling a handheld or portable device

Disclosed is a method for cooling a handheld or portable device. Benefits include improved functionality, improved power performance, and improved reliability.

Background

         Thermal management is required for packages with increasing power in hand-held or portable device. The increasing power is higher than the power levels that the package and system can handle, resulting in high operation temperature and higher risk for product reliability.

Conventionally, reducing package junction-to-board thermal resistance (θjb) increases the package capability to handle higher power.

Ice coolers have been conventionally used for food storage. Ice pads are frozen. Then, they are placed inside the ice cooler. Heat from the food or the heat leakage through the ice cooler wall is absorbed by the ice pads. The food or drink inside the ice cooler is maintained at a lower temperature than the ambient air. When the ice pads reach their heat absorbing capacity, the ice cooler cannot maintain the low temperature any more and additional cold ice pads must be added.

         The packages inside the hand-held and portable device conventionally rely on the printed circuit board (PCB) to dissipate heat to ambient by natural convection or radiation. Cooling capability is very limited, and high power dissipation for an extended time can easily result in a device temperature exceeding the specification (see Figure 1).

General description

The disclosed method is a cooling solution for a hand-held or portable device. The concept is similar to the ice cooler and ice pads. The electronic devices and the ice-pad type of material are placed inside an enclosure with thermal insulation around it. A heat pipe or thermal-conductive metal rod inserted into the cooler acts as a thermal bridge between the cooler and the docking station. A very small amount of weight is added to the hand-held or portable device. The weight of solid-state refrigeration or the thermo-electrical cooler is located on the docking station.

During charge mode, the hand-held or portable device must be plugged into the docking station. The power supply or the AC/DC converter through the electrical connector and the electrical circuit supplies the electrical power to the battery. The solid-state refrigeration or thermo-electrical cooler, remove the heat from the ice-pad type of material to the ambient environment through the heat pipe, thermal conductive rod, or the thermal conductor. After charging is competed, the battery is full and the ice-pad material is cold and frozen.

During operation mode, the hand-held or portable device is removed from the docking station. The electronic device is powered by the battery. The heat generated by the electronic device is absorbed by the ice-pad material inside the cooler. An indicator provides the user with a charge warning whenever the battery is low, the heat absorbing capacity is reached, or the electronic device exceeds the tempe...