過熱焊點 的英文怎麼說
中文拼音 [guòrèhàndiǎn]
過熱焊點
英文
overheated solder connection-
To validate the formulated transition element for the calculation of the hot - spot stress and stress concentration factor in the welded components by experimental results, the stress concentration factor of the experimental welded specimens carried out in the research group is calculated by using the developed plane - transition element. the calculated stress concentration factor in the two types of tested welding components agrees well with that obtained from the experimental result. and the calculated result on the tendency of hot - spot stresses agrees well with that from the measured result
為了驗證文中構造的過渡單元模型用於分析焊接節點附近的應力集中問題的正確性和有效性，進一步又對過渡單元模型進行實驗結果驗證，採用平面過渡單元模型計算了本課題組進行的兩類焊接構件的應力集中系數，並與根據實測方法得到的應力集中系數進行了比較，計算結果與實驗測試得到的應力集中系數和相應的熱點應力變化趨勢比較吻合，為本文建立的過渡單元的實際應用提供了初步的基礎。As an electric current passes through, the joule heating and electromigration effects occur in the flip chip solder bumps
當電流通過焊點時，會伴隨產生焦耳熱效應和電遷移效應。The maximal power outputs of 37. 0 mw / cm2 and 30. 0 mw / cm2 for the p - and n - type laminated materials respectively at the temperature difference 490 have been experimentally obtained, which are about 2. 5 and 3. 0 times those of - fesi2. chemical analyses show that the interface failure between the bridge alloy and the semiconductor bi2te3 results mainly from the eutectic mixtures with low melting point and brittle compounds formed during welding and long time annealing at 190. it is found that the electrical properties of a laminated structure are mainly controlled by the wettability of the bridge alloy on the semiconductor surface
發現： 1 ）疊層材料具有明顯優于均質材料的熱電性能，在490溫差下， p -型和n -型疊層材料的最大輸出功率分別達到37 . 0和30 . 0 （ mw / cm ~ 2 ） ，是同類型均質- fesi _ 2的2 . 5和3倍； 2 ）在焊接過程和190長時間退火處理過程中，焊接過渡層合金和基體半導體（特別是bi _ 2te _ 3 ）之間存在明顯的元素相互擴散，從而在過渡層中形成一些低熔點共晶體和脆性化合物，這是導致疊層材料破壞的主要原因； 3 ）焊接過渡層合金與半導體基體之間的潤濕性是影響界面層電性能的主要因素。This study aims at the analysis on local hot spot stress in critical components of long - span steel bridges and numerical simulation on the accumulated fatigue damage for the purpose of providing an accurate assessment of the accumulated fatigue damage and fatigue life of the components
本文的研究工作是圍繞著大跨度橋梁在交通荷載作用下，關鍵焊接構件的局部熱點應力分析和相應的疲勞損傷累積分析而展開的，目的為了對這些焊接構件內的疲勞損傷累積的過程進行比較準確的評估。Zhang liji ( material physics and chemistry ) directed by professor xie xiaoming this paper is intended to solve problems for those who are designing, using pbgas. failure mechanism, as well as cycles to failure of two groups of pbga samples ( with / without underfill ) for thermal cycling conditions in the range of - 40 ~ 125, were presented. the experiment shows that solder ball in the samples without underfill cracked after 500 times cycle, no crack was found in the underfilled samples even after 2700 cycles
通過一系列的實驗，得到以下實驗結果： ?在本論文設定的溫度循環條件下，未充膠pbga樣品的熱疲勞品壽命在500周左右，充膠樣品的焊點壽命高於2700周； ?對于未充膠器件，中心距（ dnp ）是決定焊點應力、應變大小的最主要因素，裂紋總是從中心距較大處萌生並向中心處擴展； ?溫度循環的過程中焊盤附近焊料組織明顯粗化。Abstract : in the present paper the progress was reviewed in the active filler metals with different temperatures for ceramic to metal brazing and related brazing technique of reducing joining - gap residual stress. it was recommended that the key developing field for our country should be the high temperature active filler with heat - and oxidation - resisting properties. the brazing techniques to reduce joining - gap residual stress and the principles to select transition layers for the joining gap were also introduced
文摘:闡述了陶瓷/金屬釬焊用不同溫度的活性釬料及以降低焊縫殘余應力為中心的釬焊工藝進展；指出：在我國耐高溫、抗氧化性優良的高溫耐熱型活性釬料是重點發展方向；介紹了降低焊縫殘余應力的釬焊工藝和焊縫中間添加過渡層的選擇原則。分享友人