散熱是保證電源器適配安全、可靠工作的重要條件。溫度過高,將引起電源適配器的性能指標發(fā)生變化,甚至引起電源適配器的失效,因此,控制好溫升,使其不超過可靠性規(guī)定的限值是散熱設(shè)計的根本任務(wù)。
Heat dissipation is an important condition to ensure the safe and reliable operation of the power adapter. If the temperature is too high, the performance index of the power adapter will change, even cause the failure of the power adapter. Therefore, the basic task of cooling design is to control the temperature rise well so that it does not exceed the reliability limit.
電源適配器的元器件都有一定的工作溫度范圍要求,如果超過其極限溫度,將引起電源工作狀態(tài)的改變,因而使電子設(shè)備不能穩(wěn)定、可靠地工作,縮短其使用壽命,甚至造成電子設(shè)備的損壞。
The components of power adapter have a certain range of operating temperature requirements. If the limit temperature is exceeded, the working state of power supply will be changed, so that the electronic equipment can not work stably and reliably, shorten its service life, and even cause damage to the electronic equipment.
1、散熱器的選用:散熱器選擇的原則是在保證充分散熱的前提下,應(yīng)盡量選用體積小、重量輕的散熱器,這樣可節(jié)省機內(nèi)空間,減少電源適配器的總重量。
1. Selection of radiator: The principle of radiator selection is to ensure sufficient heat dissipation, should try to choose a small, light weight radiator, so as to save space in the machine, reduce the total weight of the power adapter.
2、散熱器的安裝:安裝散熱器時應(yīng)盡量選用散熱熱阻小的安裝方式。
2, radiator installation: when installing the radiator, we should try to choose a small heat dissipation method.
3、盡量減小界面熱阻:散熱器表面應(yīng)平整、光潔,為減小散熱器與功率半導(dǎo)體的接觸熱阻,應(yīng)注意保持二者界面間的平整與光潔。如果界面既平整、光潔,又無氧化層時,其間可不加墊片,否則應(yīng)涂以硅脂或加裝導(dǎo)熱墊片。
3. Minimizing the thermal resistance of the interface: The surface of the radiator should be smooth and clean. In order to reduce the contact thermal resistance between the radiator and the power semiconductor, it is necessary to keep the interface smooth and clean. If the interface is smooth and clean, and there is no oxide layer, there is no gasket, otherwise it should be coated with silicone grease or heat conductive gasket.
4、散熱器的涂覆:為增加散熱器的輻射能力,散熱片表面應(yīng)涂一層黑色油漆或氧化物等高輻射系數(shù)的涂層,應(yīng)優(yōu)先選用具有黑色涂層的散熱器,并應(yīng)保護涂層不受損壞。
4. Radiator coating: In order to increase the radiation capacity of the radiator, the surface of the radiator should be coated with a high radiation coefficient coating, such as black paint or oxide. The radiator with black coating should be preferred and the coating should be protected from damage.
5、散熱器的安裝:在散熱器上安裝功率器件時,其安裝孔的尺寸應(yīng)與功率半導(dǎo)體固定孔的尺寸相符,孔不宜太大,也不宜太小。
5. Radiator installation: When installing power devices on the radiator, the size of the installation hole should be the same as the size of the power semiconductor fixed hole, the hole should not be too big or too small.
6、功率半導(dǎo)體的安裝位置:功率半導(dǎo)體應(yīng)安裝于散熱器的中心。若在同一散熱器上裝多個功率半導(dǎo)體時,可先近似的按半導(dǎo)體功耗的比例將散熱片分割成幾部分,每個半導(dǎo)體盡量放在相應(yīng)部分的中心位置,這樣可使散熱器均勻受熱,提高散熱效率。
6. Installation location of power semiconductor: power semiconductor should be installed in the center of radiator. If a plurality of power semiconductors are installed on the same radiator, the radiator can be divided into several parts approximately according to the power consumption ratio of the semiconductors. Each semiconductor should be placed in the center of the corresponding part as far as possible, so that the radiator can be heated evenly and the heat dissipation efficiency can be improved.
7、散熱器的安放位置:應(yīng)盡可能使散熱器直接接觸電源外部的空氣流,使環(huán)境溫度降低。同時可提高散熱器對流換熱的效果。
7. The location of the radiator: the radiator should be in direct contact with the air outside the power supply as far as possible to reduce the ambient temperature. At the same time, the effect of convection heat transfer of radiator can be improved.