X-ray diffraction imaging of fully packaged n–p–n transistors under accelerated ageing conditions

Abstract

X-ray diffraction imaging was used to monitor the local strains that developed around individual n–p–n bipolar transistors within fully encapsulated packages under conditions of extremely high forward bias to simulate accelerated ageing. Die warpage associated with the packaging was observed to relax systematically as the polymer became viscous due to the temperature rise associated with the dissipation of heat in the transistor. The direct image size and intensity from the individual transistors were interpreted in terms of a model in which local thermal expansion is treated as a cylindrical inclusion of distorted material, contrast arising principally from lattice tilt. The extension of the thermal strain image along the emitter with increasing power dissipation was ascribed to the effect of current crowding in the emitter region. Weaker large-area contrast associated with the base–collector region was interpreted as arising from the smaller change in effective misorientation at the high X-ray energy of thermal lattice dilation in the base region.

К вопросу о механизмах разогрева светодиодов на основе p-InAsSbP/n-InAs(Sb)

“…Вполне очевидно, что в зависимости от 3 В соотношении (3) не учитывается температурная зависимость коэффициента вывода излучения γ и инжекции. 4 В большинстве известных из литературы случаев значения ζ 77 K 300 K для СД на основе InAs находятся в пределах от 10 до 30 (см., например, [36]).…”

“…Изучение токового разогрева полупроводниковых p−n-структур представляет несомненный интерес как при создании и использовании мощных переключателей и (традиционных) светодиодов (СД), так и для исследований и разработок новых подходов к отводу тепла от работающих электронных компонент, например, за счет радиационного или термоэлектрического охлаждения [1][2][3]. Кроме этого, существует ряд задач, требующих анализа распределения температуры в многоэлементных устройствах, где растекание тепла от работающего элемента с p−n-переходом изменяет условия для работы соседних с ним элементов [4][5][6][7].…”

On heating mechanisms in LEDs based on p-InAsSbP/n-InAs(Sb)

“…The study of current heating of semiconductor p−n structures is of undoubted interest both in the creation and use of high-power switches and (traditional) LEDs, and for research and development of new approaches to heat removal from working electronic components, for example, through radiation or thermoelectric cooling [1][2][3]. In addition, there are a number of tasks that require analysis of the temperature distribution in multi-element devices, where the spreading of heat from a working element with a p−n junction changes the conditions for the operation of neighboring elements [4][5][6][7].…”

“…Ratio (3) doesn't not take into account the temperature dependence of the radiation-extraction efficiency γ and injection efficiency 4. In most cases known from the literature the values of ζ 77 K 300 K for InAsbased LEDs are in the range from 10 to 30 (see, for example,[36]).…”