Damage Mechanics Approach for the Strength Evaluation of Solder Joint with Voids.

具有空洞焊点强度评估的损伤力学方法。

• 批准号: 12650097
• 负责人: MASANORI Kikuchi
• 金额: $ 2.18万
• 依托单位: Faculty of Science and Technology, Science University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12650097/
• 关键词: Damage Mechanics; Solder Joint; Thermal Fatigue; Voids; Fatigue Life; 混合モード; 損傷解析

The effect of voids, which is nucleated in solder joint by re-flow method, on the fatigue strength is studied expermentally and numerically. Follwing results are obtained.(1)Voids are meausured expermantally by changing the solder, flux in three cases. It was found that large voids are nucleared for solder with large flux content. For small flux content solder many small voids are observed. It is impossible to avoid void nucleation during solder joint process.(2)The faitgue life is measured expermentally, and it is found that it is affected the existence of voids. Larger void rate decreaces tha fatigue life of solder joint.(3)On the fatigue fracture, many cracks are observed. They are branched fatigue cracks, which grow to the phase boundary of solder and pat, and terminate at the boundary.(4)The fatigue crack behavior is simulated by FEM applying the damage mechanics approach. The effect of the existence of voids on the fatigue life is estimated based on these numerical simulations. It is concluded that lager voids decrease the fatigue strength. Finally it is recommented to decrease the flux content in solder to decrease the voids nucleation.

通过实验和数值模拟研究了再流法在焊点中形核的空洞对焊点疲劳强度的影响。获得了以下结果。（1）在三种情况下，通过改变焊料、助焊剂，对空洞进行了实验测量。结果表明，助焊剂含量大的钎料易形成大的空洞。对于小焊剂含量焊料许多小空隙观察。在焊点过程中，空洞形核是不可能避免的。（2）实验测量了材料的疲劳寿命，发现空洞的存在对材料的疲劳寿命有影响。较大的空洞率会降低焊点的疲劳寿命。(3)On疲劳断裂时，观察到许多裂纹。它们是分叉疲劳裂纹，扩展到焊料和焊点的相界，并终止于边界处。（4）采用损伤力学方法对疲劳裂纹行为进行了有限元模拟。基于这些数值模拟的疲劳寿命上的空洞的存在的影响估计。结果表明，较大的孔洞会降低疲劳强度。最后提出了降低焊料中助焊剂含量以减少空洞形核的建议。

项目成果

M.Kikuchi and M.Geni: "A Damage Model for Voil Configuration and Failure under Different Constratint Deformation Region in Ductle Matrix"Key Engineering Materials. Vols.183-187. 625-630 (2000)

M.Kikuchi和M.Geni：“导管基体中不同约束变形区域下的Voil配置和失效的损伤模型”关键工程材料。

菊池, 高橋: "異なる負荷形式下のディンプル破壊ュレーション"日本機械学会論文集. A67,656. 665-670 (2001)

Kikuchi, Takahashi：“不同载荷类型下的凹坑断裂”，日本机械工程师学会汇刊 A67,656 (2001)。

M.Kikuchi, D.Katagiri: "Study on the Mixed Mode Fatigue Crack Growth Behavior"Adavances in Computational Engineering & Science. vol.1. 1065-1070 (2000)

M.Kikuchi、D.Katagiri：“混合模式疲劳裂纹扩展行为的研究”计算工程进展

M.Geni and M.Kkuchi: "A Micro Damage Model for Local Void Coalesence in Ductile Matrix"Advances in Computational Engineering & Science. Vol.II. 1098-1103 (2000)

M.Geni 和 M.Kkuchi：“延性基体中局部空洞合并的微损伤模型”计算工程进展

M.Kikuchi: "Fatiguecrack growth simulation under Mode I+IIMixed Mode Condition"Vol.G. #1127 (2001)

M.Kikuchi：“模式 I II 混合模式条件下的疲劳裂纹生长模拟”Vol.G。