A novel solid-liquid interdiffusion(SLID)bonding method with the assistance of temperature gradient(TG)was carried out to bonding Cu and Ni substrates with Sn as interlayer.The element distribution and grain morpholog...A novel solid-liquid interdiffusion(SLID)bonding method with the assistance of temperature gradient(TG)was carried out to bonding Cu and Ni substrates with Sn as interlayer.The element distribution and grain morphology of interfacial intermetallic compound(IMC)in Cu/Sn/Ni micro-joints during both SLID and TG-SLID bonding and in the final Cu/(Cu,Ni)_(6)Sn_(5)/Ni full IMC micro-joints were analyzed.Under the effect of Cu-Ni cross-interaction,interfacial(Cu,Ni)_(6)Sn_(5) dominated the IMC growth at all the interfaces.The morphology of the(Cu,Ni)_(6)Sn_(5) grains was closely related to Ni content with three levels of low,medium and high.The full IMC micro-joints consisted of L-(Cu,Ni)_(6) Sn_(5),M-(Cu,Ni)_(6)Sn_(5) and H-(Cu,Ni)_(6)Sn_(5) grains after SLID bonding or TG-SLID bonding with Ni as hot end,while only L-(Cu,Ni)_(6)Sn_(5) grains after TG-SLID bonding with Cu as hot end,showing that the direction of TG had a remarkably effect on the growth and morphology of the interfacial(Cu,Ni)_(6)Sn_(5) during TG-SLID bonding.Thermodynamic analysis revealed the key molar latent heat and critical Ni content between fine-rounded-like(Cu,Ni)_(6)Sn_(5) and block-like(Cu,Ni)_(6)Sn_(5) were 17,725.4 J and 11.0 at.%at 260℃,respectively.Moreover,the growth kinetic of the interfacial IMC was analyzed in detail during bonding with and without TG.Under the combination of TG and Cu-Ni cross-interaction,void-free full IMC micro-joints were fast formed by TG-SLID bonding with Cu as hot end.This bonding method may present a feasible solution to solve the problems of low formation efficiency and inevitable Cu_(3) Sn growth of full IMC joints for 3 D packaging applications.展开更多
Tensile strengths of QFP micro-joints with different pitches were tested by means of micro-joints tester. On the basis of those results, the effects of QFP pitches’ numbers on the mechanical properties were studied a...Tensile strengths of QFP micro-joints with different pitches were tested by means of micro-joints tester. On the basis of those results, the effects of QFP pitches’ numbers on the mechanical properties were studied and the microstructures of cracks of micro-joints were analyzed based on facts of SEM and EDS. The results indicate that of tensile strengths micro-joint of 48 pitches are lower than that of 100 pitches and the tensile strength of soldered joint is higher than that of solder itself. The fracture mechanism of QFP soldered joint with Sn-Pb solder acts as the interface cavity impair ductile rupture while the fracture mechanism of QFP soldered joint with lead-free solder shows trans-crystalline toughness rupture which belongs to micro-holes coalescence fracture.展开更多
Soldering experiments of quad flat package(QFP) devices were carried out by means of diode laser soldering system with Sn-Ag-Cu and Sn-Cu-Ni lead-free solders, and competitive experiments were also carried out not onl...Soldering experiments of quad flat package(QFP) devices were carried out by means of diode laser soldering system with Sn-Ag-Cu and Sn-Cu-Ni lead-free solders, and competitive experiments were also carried out not only with Sn-Pb eutectic solders but also with infrared reflow soldering method. The results indicate that under the conditions of laser continuous scanning mode as well as the fixed laser soldering time, an optimal power exists, while the optimal mechanical properties of QFP micro-joints are gained. Mechanical properties of QFP micro-joints soldered with laser soldering system are better than those of QFP micro-joints soldered with IR reflow soldering method. Fracture morphologies of QFP micro-joints soldered with laser soldering system exhibit the characteristic of tough fracture, and homogeneous and fine dimples appear under the optimal laser output power.展开更多
目的探讨对手足部骨折患者实施微型钢板内固定治疗的效果,分析该疗法对患者关节功能、疼痛程度的作用。方法选取71例手足部骨折患者进行回顾性研究,按照其治疗方法分为参照组(克氏针内固定术治疗患者35例)与研究组(微型钢板内固定手术...目的探讨对手足部骨折患者实施微型钢板内固定治疗的效果,分析该疗法对患者关节功能、疼痛程度的作用。方法选取71例手足部骨折患者进行回顾性研究,按照其治疗方法分为参照组(克氏针内固定术治疗患者35例)与研究组(微型钢板内固定手术治疗患者36例),对比两组患者治疗前后Broberg and Morrey手功能评分、Maryland足功能评分、疼痛程度,观察两组术后并发症发生率。结果术后,研究组手功能评分、足功能评分高于参照组(P<0.05);术后,研究组疼痛评分低于参照组(P<0.05);研究组术后并发症发生率低于参照组(P<0.05)。结论微型钢板内固定可显著减轻手足部骨折患者疼痛程度,并改善手功能、足功能,减少术后并发症的发生。展开更多
基金financially supported by the National Natural Science Foundation of China(No.52075072)the Fundamental Research Funds for the Central Universities(No.DUT20JC46)。
文摘A novel solid-liquid interdiffusion(SLID)bonding method with the assistance of temperature gradient(TG)was carried out to bonding Cu and Ni substrates with Sn as interlayer.The element distribution and grain morphology of interfacial intermetallic compound(IMC)in Cu/Sn/Ni micro-joints during both SLID and TG-SLID bonding and in the final Cu/(Cu,Ni)_(6)Sn_(5)/Ni full IMC micro-joints were analyzed.Under the effect of Cu-Ni cross-interaction,interfacial(Cu,Ni)_(6)Sn_(5) dominated the IMC growth at all the interfaces.The morphology of the(Cu,Ni)_(6)Sn_(5) grains was closely related to Ni content with three levels of low,medium and high.The full IMC micro-joints consisted of L-(Cu,Ni)_(6) Sn_(5),M-(Cu,Ni)_(6)Sn_(5) and H-(Cu,Ni)_(6)Sn_(5) grains after SLID bonding or TG-SLID bonding with Ni as hot end,while only L-(Cu,Ni)_(6)Sn_(5) grains after TG-SLID bonding with Cu as hot end,showing that the direction of TG had a remarkably effect on the growth and morphology of the interfacial(Cu,Ni)_(6)Sn_(5) during TG-SLID bonding.Thermodynamic analysis revealed the key molar latent heat and critical Ni content between fine-rounded-like(Cu,Ni)_(6)Sn_(5) and block-like(Cu,Ni)_(6)Sn_(5) were 17,725.4 J and 11.0 at.%at 260℃,respectively.Moreover,the growth kinetic of the interfacial IMC was analyzed in detail during bonding with and without TG.Under the combination of TG and Cu-Ni cross-interaction,void-free full IMC micro-joints were fast formed by TG-SLID bonding with Cu as hot end.This bonding method may present a feasible solution to solve the problems of low formation efficiency and inevitable Cu_(3) Sn growth of full IMC joints for 3 D packaging applications.
文摘Tensile strengths of QFP micro-joints with different pitches were tested by means of micro-joints tester. On the basis of those results, the effects of QFP pitches’ numbers on the mechanical properties were studied and the microstructures of cracks of micro-joints were analyzed based on facts of SEM and EDS. The results indicate that of tensile strengths micro-joint of 48 pitches are lower than that of 100 pitches and the tensile strength of soldered joint is higher than that of solder itself. The fracture mechanism of QFP soldered joint with Sn-Pb solder acts as the interface cavity impair ductile rupture while the fracture mechanism of QFP soldered joint with lead-free solder shows trans-crystalline toughness rupture which belongs to micro-holes coalescence fracture.
基金Project(CX07B_087z) supported by Jiangsu General Colleges and Universities Postgraduate Scientific Research Innovative Plan, ChinaProject(06-E-020) supported by the Six Kind Skilled Personnel Project of Jiangsu Province, China
文摘Soldering experiments of quad flat package(QFP) devices were carried out by means of diode laser soldering system with Sn-Ag-Cu and Sn-Cu-Ni lead-free solders, and competitive experiments were also carried out not only with Sn-Pb eutectic solders but also with infrared reflow soldering method. The results indicate that under the conditions of laser continuous scanning mode as well as the fixed laser soldering time, an optimal power exists, while the optimal mechanical properties of QFP micro-joints are gained. Mechanical properties of QFP micro-joints soldered with laser soldering system are better than those of QFP micro-joints soldered with IR reflow soldering method. Fracture morphologies of QFP micro-joints soldered with laser soldering system exhibit the characteristic of tough fracture, and homogeneous and fine dimples appear under the optimal laser output power.
文摘目的探讨对手足部骨折患者实施微型钢板内固定治疗的效果,分析该疗法对患者关节功能、疼痛程度的作用。方法选取71例手足部骨折患者进行回顾性研究,按照其治疗方法分为参照组(克氏针内固定术治疗患者35例)与研究组(微型钢板内固定手术治疗患者36例),对比两组患者治疗前后Broberg and Morrey手功能评分、Maryland足功能评分、疼痛程度,观察两组术后并发症发生率。结果术后,研究组手功能评分、足功能评分高于参照组(P<0.05);术后,研究组疼痛评分低于参照组(P<0.05);研究组术后并发症发生率低于参照组(P<0.05)。结论微型钢板内固定可显著减轻手足部骨折患者疼痛程度,并改善手功能、足功能,减少术后并发症的发生。
