The sealed chassis of a typical use in harsh environmental conditions of the design practice, described the structure of the thermal design of the design ideas and specific heat structure, while the application of state-of-the-art thermal analysis software structure of thermal design verification and optimization.
Thermal design occupies an important position in the radio structure design, practice shows that the 30w led failure rate of electronic components with the device temperature is increased exponentially relationship and increase the performance of electronic equipment lines and is inversely proportional to the temperature change more demanding environmental conditions under thermal design required careful analysis and calculation here Monopolizing sealed chassis design with their peers, in respect of a project.
30w led Electronic equipment cooling method the total heat loss depends on the device and its concentration device (or device) allow the ambient temperature of the temperature and device (or devices) to select the appropriate cooling methods depending on the specific circumstances of a device environment is more demanding applications, case saddled portable, field work unattended equipment requirements miniaturization, light weight, water-resistant, anti-high-low-temperature, heat-resistant, high strength. following a device technical indicators excerpt:
Operating Temperature: -25 ℃ ~ +55 ℃
Vibration: Sine 55 ~~ 5Hz acceleration amplitude 1.5g
Chatter: 15g
Humidity: 95 ± 3% (ambient temperature: 30 ℃ ± 2 ℃)
Weight <25kg
Analysis above indicators, the humidity over large field equipment for long-term work environment, which determines the chassis fully sealed chassis. Fever devices such as power supply, CPU box, therefore the thermal design of the chassis to become the device can work The key in the design process of argumentation first denied the chassis fan installed outside the program, although more rapidly away chassis surface heat forced air cooling but installed fan is bound to increase the power output power, increase the heat consumption, but also the main reason is high heat, high humidity environment can not guarantee that the fan is working properly. thus the thermal design of the chassis can be set to conduction cooling.
From start to determine the various design aspects:
· PCB optimal design in the completed function under the premise of the rational layout of components, heat evenly shed conducive to consumption and cooling measures conducive to take the structure.
· Thermal conduction plate design of one end and the heating device into close contact, and the other end is brought into close contact with the chassis wall. Two heat conduction of 30w led lights: the heat generating element → thermal conduction plate → tank wall.
The thermal design of the chassis shell.
1 PCB board design
Optimal design for PCB circuit design in accordance with the first principle, first select the better high temperature performance, industrial-grade devices take cooling measures to facilitate the structure, the key lies in the component layout neatly arranged in rows. Centre emplaced heat loss device dual in-line devices, peripheral devices emplaced relatively large heat loss. use more. well it is the overall thermal design and lay a good foundation.
2 thermally conductive plate design
Thermally conductive plate to select a large copper plate of the heat transfer coefficient. General chip pin at fever neatly dual in-line devices, device pins through the thermally conductive plate device underside closely with insulation film the thermal conductivity of the plate surface