Pub Date : 2021-09-13DOI: 10.23919/empc53418.2021.9584956
R. Klengel, S. Klengel, J. Schischka, N. Araki, M. Eto, T. Haibara, Takashi Yamada
Silver (Ag) bonding wires are mainly used in consumer products as a reliable low-cost alternative to gold (Au) bonding wires. In automotive applications, the materials are exposed to particularly harsh environmental conditions. In order to understand the influence of these conditions in the electronic package on the silver-aluminum material system, we carried out extensive studies. 4N Ag wire, Pd alloyed Ag wire and a new Ag wire with innovative additives (GX2s) were encapsulated after wire bonding on Al chip metallization in a package with a chloride and sulfur-containing molding compound and subjected to corresponding reliability tests. Then, the material behavior of the different silver wires was compared to Au wire bonds after high temperature storage life test (HTSL) and unbiased highly accelerated stress test (uHAST). After broad ion beam cross sectioning the samples were investigated subsequently by Scanning Electron Microscopy (SEM). Additionally, high resolution transmission electron microscopy (TEM) investigations with nano-spot element analyses (EDS) and electron beam diffraction were done to characterize the intermetallic compounds formed and to specify the running corrosion mechanism in correlation to the alloying elements/additives used. The results show that similar degradation mechanisms take place in the Ag-Al system compared to the Au-Al system. Both material combinations show corrosion effects after testing. However, the reliability behavior of the Ag wires can be significantly optimized by adding alloying elements such as palladium or other innovative additives. Thus, the reliability behavior of electronic assemblies can be optimized even under low-cost conditions.
{"title":"Corrosion effects and reliability improvement of silver wire bonded contacts in automotive application","authors":"R. Klengel, S. Klengel, J. Schischka, N. Araki, M. Eto, T. Haibara, Takashi Yamada","doi":"10.23919/empc53418.2021.9584956","DOIUrl":"https://doi.org/10.23919/empc53418.2021.9584956","url":null,"abstract":"Silver (Ag) bonding wires are mainly used in consumer products as a reliable low-cost alternative to gold (Au) bonding wires. In automotive applications, the materials are exposed to particularly harsh environmental conditions. In order to understand the influence of these conditions in the electronic package on the silver-aluminum material system, we carried out extensive studies. 4N Ag wire, Pd alloyed Ag wire and a new Ag wire with innovative additives (GX2s) were encapsulated after wire bonding on Al chip metallization in a package with a chloride and sulfur-containing molding compound and subjected to corresponding reliability tests. Then, the material behavior of the different silver wires was compared to Au wire bonds after high temperature storage life test (HTSL) and unbiased highly accelerated stress test (uHAST). After broad ion beam cross sectioning the samples were investigated subsequently by Scanning Electron Microscopy (SEM). Additionally, high resolution transmission electron microscopy (TEM) investigations with nano-spot element analyses (EDS) and electron beam diffraction were done to characterize the intermetallic compounds formed and to specify the running corrosion mechanism in correlation to the alloying elements/additives used. The results show that similar degradation mechanisms take place in the Ag-Al system compared to the Au-Al system. Both material combinations show corrosion effects after testing. However, the reliability behavior of the Ag wires can be significantly optimized by adding alloying elements such as palladium or other innovative additives. Thus, the reliability behavior of electronic assemblies can be optimized even under low-cost conditions.","PeriodicalId":348887,"journal":{"name":"2021 23rd European Microelectronics and Packaging Conference & Exhibition (EMPC)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115549196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-13DOI: 10.23919/empc53418.2021.9584979
Luca Link, Ankit Sharma, V. Polezhaev, T. Huesgen, M. Vaas, G. Stohrer, F. Koch
The embedding of power electronics components into the PCB increases their thermal and electrical performance. Due to lower parasitic inductances and a lower thermal resistance, the overall power density of the system can be increased. However, there is a lack on studies about the reliability of PCB embedded power electronics, especially under humidity stress. This study uses test vehicles with functional diodes embedded into the PCB. The reliability of the test vehicles is studied under HV-H3TRB conditions. A critical leakage current is observed after 200h with a benzoxazine based prepreg and after 600h for an epoxy based prepreg. A root- cause analysis revealed lift-off of the polyimide layer and subsequent electrochemical corrosion as failure mechanism. The delamination is most likely triggered by the Au surface on the chips top metal pad. A second set of test samples was fabricated using an improved surface treatment before lamination. 75% of these samples passed the 1000h H3TRB test successfully.
{"title":"Top side isolation investigation of PCB embedded 1.2kV dies","authors":"Luca Link, Ankit Sharma, V. Polezhaev, T. Huesgen, M. Vaas, G. Stohrer, F. Koch","doi":"10.23919/empc53418.2021.9584979","DOIUrl":"https://doi.org/10.23919/empc53418.2021.9584979","url":null,"abstract":"The embedding of power electronics components into the PCB increases their thermal and electrical performance. Due to lower parasitic inductances and a lower thermal resistance, the overall power density of the system can be increased. However, there is a lack on studies about the reliability of PCB embedded power electronics, especially under humidity stress. This study uses test vehicles with functional diodes embedded into the PCB. The reliability of the test vehicles is studied under HV-H3TRB conditions. A critical leakage current is observed after 200h with a benzoxazine based prepreg and after 600h for an epoxy based prepreg. A root- cause analysis revealed lift-off of the polyimide layer and subsequent electrochemical corrosion as failure mechanism. The delamination is most likely triggered by the Au surface on the chips top metal pad. A second set of test samples was fabricated using an improved surface treatment before lamination. 75% of these samples passed the 1000h H3TRB test successfully.","PeriodicalId":348887,"journal":{"name":"2021 23rd European Microelectronics and Packaging Conference & Exhibition (EMPC)","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131377310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-13DOI: 10.23919/empc53418.2021.9584980
Dániel Straubinger, A. Géczy
In this paper we focus on the effect of highly increased current density and resulting temperatures in the microstructure of lead-free solder joints of chip-scale components in order to investigate quality and reliability aspects of these widely used components in surface mount technology (SMT). We prepared a daisy chain of zero-ohm resistors, where the current loading was set to specific values (2 A, 2,5 A) for specific components (0402, 0603) and specific trace-to-pad connections. The substrate was RO4000 type epoxy-ceramic, to increase possible thermal load on the substrate. The assembly process was performed with batch-type SMT machinery and vapour phase soldering with classic SAC305 alloy. The loading was performed on ambient atmosphere, and in drying ovens on elevated temperatures for 2500 hours. We also prepared control samples without load on ambient atmosphere. We found with cross-sections, that dissolved intermetallic compound structures (Cu6Sn5) were found in specific regions of the meniscus of surface mounted components, in the possible route of the current from the pad to the functional resistive layer of the SM resistor. The cross-section analysis was also further extended with polarized optical image investigations, where different microstructures are presented in function of the sample types. The paper also presents joint quality aspects such as shear-strength analysis. It was found that due to the current and the increased load, the microstructure of the joint changed, but extensive proof of electromigration was not present.
在本文中，我们重点研究了高电流密度和由此产生的温度对芯片级元件无铅焊点微观结构的影响，以研究这些广泛应用于表面贴装技术(SMT)的元件的质量和可靠性。我们准备了一个零欧姆电阻的菊花链，其中电流负载被设置为特定的值(2 a, 2,5 a)，用于特定的组件(0402,0603)和特定的走线到焊盘连接。基板为RO4000型环氧陶瓷，以增加基板上可能的热负荷。装配过程采用批量式SMT机械，采用经典SAC305合金进行气相焊接。加载在环境气氛中进行，并在高温烘箱中进行2500小时的干燥。我们还制备了不加环境气氛负荷的对照样品。我们发现，在表面安装元件的半月板的特定区域发现了溶解的金属间化合物结构(Cu6Sn5)，在电流从焊盘到SM电阻器的功能电阻层的可能路径中。截面分析还进一步扩展了偏振光学图像调查，其中不同的微观结构呈现在样品类型的函数中。本文还对节理质量进行了分析，如抗剪强度分析。结果发现，由于电流和载荷的增加，接头的显微组织发生了变化，但没有广泛的电迁移证据。
{"title":"Effect of highly increased current density in the microstructure of lead-free solder joints","authors":"Dániel Straubinger, A. Géczy","doi":"10.23919/empc53418.2021.9584980","DOIUrl":"https://doi.org/10.23919/empc53418.2021.9584980","url":null,"abstract":"In this paper we focus on the effect of highly increased current density and resulting temperatures in the microstructure of lead-free solder joints of chip-scale components in order to investigate quality and reliability aspects of these widely used components in surface mount technology (SMT). We prepared a daisy chain of zero-ohm resistors, where the current loading was set to specific values (2 A, 2,5 A) for specific components (0402, 0603) and specific trace-to-pad connections. The substrate was RO4000 type epoxy-ceramic, to increase possible thermal load on the substrate. The assembly process was performed with batch-type SMT machinery and vapour phase soldering with classic SAC305 alloy. The loading was performed on ambient atmosphere, and in drying ovens on elevated temperatures for 2500 hours. We also prepared control samples without load on ambient atmosphere. We found with cross-sections, that dissolved intermetallic compound structures (Cu6Sn5) were found in specific regions of the meniscus of surface mounted components, in the possible route of the current from the pad to the functional resistive layer of the SM resistor. The cross-section analysis was also further extended with polarized optical image investigations, where different microstructures are presented in function of the sample types. The paper also presents joint quality aspects such as shear-strength analysis. It was found that due to the current and the increased load, the microstructure of the joint changed, but extensive proof of electromigration was not present.","PeriodicalId":348887,"journal":{"name":"2021 23rd European Microelectronics and Packaging Conference & Exhibition (EMPC)","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131610521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-13DOI: 10.23919/empc53418.2021.9585015
B. Illés, A. Skwarek, O. Krammer, T. Hurtony, Dániel Straubinger, J. Ratajczak, G. Harsányi, K. Witek
In the present study, SACX0307-ZnO and SACX0307-TiO2 nano-composite solder pastes were fabricated. The ceramic reinforcements were used in 1wt% and with different primary particle sizes between 50-200nm. The soldering properties and microstructure of the solder joints were investigated. The nano-particles were mixed into the solder paste by standard ball milling process. Reflow soldering technology has been applied to prepare solder joints and spreading tests from the different solder alloys. The solder joints were evaluated by shear test, and cross-sections were prepared to investigate the metallographic properties by Scanning Electron Microscopy (SEM). The different ceramic nano-particles had different effects on the solderability of solder alloys. Best results were observed in the case of TiO2 nano-particles with improved wetting and mechanical strength. The microstructural investigations showed considerable grain refinement and the modified grain boundary/interfacial properties, which could cause the increase of the mechanical parameters.
{"title":"Properties of nano-composite SACX0307-(ZnO, TiO2) solders","authors":"B. Illés, A. Skwarek, O. Krammer, T. Hurtony, Dániel Straubinger, J. Ratajczak, G. Harsányi, K. Witek","doi":"10.23919/empc53418.2021.9585015","DOIUrl":"https://doi.org/10.23919/empc53418.2021.9585015","url":null,"abstract":"In the present study, SACX0307-ZnO and SACX0307-TiO2 nano-composite solder pastes were fabricated. The ceramic reinforcements were used in 1wt% and with different primary particle sizes between 50-200nm. The soldering properties and microstructure of the solder joints were investigated. The nano-particles were mixed into the solder paste by standard ball milling process. Reflow soldering technology has been applied to prepare solder joints and spreading tests from the different solder alloys. The solder joints were evaluated by shear test, and cross-sections were prepared to investigate the metallographic properties by Scanning Electron Microscopy (SEM). The different ceramic nano-particles had different effects on the solderability of solder alloys. Best results were observed in the case of TiO2 nano-particles with improved wetting and mechanical strength. The microstructural investigations showed considerable grain refinement and the modified grain boundary/interfacial properties, which could cause the increase of the mechanical parameters.","PeriodicalId":348887,"journal":{"name":"2021 23rd European Microelectronics and Packaging Conference & Exhibition (EMPC)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114874526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-13DOI: 10.23919/empc53418.2021.9584992
H. Xia, A. Roy, E. Bardalen, Hoang-Vu Nguyen, K. Aasmundtveit, P. Ohlckers
Copper-tin Solid-Liquid Interdiffusion (Cu-Sn SLID) bonding has shown potential for packaging of microelectromechanical system (MEMS) devices such as microbolometers due to its low cost and high-temperature stability. A thin micromachined silicon cap is desired in the packaging of microbolometers to minimize the infrared light absorption. In the preferred fabrication process flow, the Cu-Sn sealing frames are deposited on both the cap and device wafers prior to micromachining the cap wafer. This method greatly simplifies the process compared to when the metal layers are deposited after the cap etching process. However, such an approach might affect the bonding quality due to the Cu-Sn sealing frame being used directly as a mask for the cap etching. The present work addresses this concern using a cap wafer (with and without micromachining process) bonded to a device wafer using the Cu-Sn SLID technique. A dicing yield at or near 100% is achieved for both samples. The interface of Cu-Sn bonds shows a similar Cu/Cu3Sn/Cu structure between the samples without cavity and with a cavity, which indicates that the micromachining process has a minor impact on the Cu-Sn bonds. However, the measured die shear strengths of the samples with and without cavity are relatively low due to fracture at the Cu/Cu3 Sn interface and adhesion fracture at the TiW layer. The bond strength can be further improved by optimizing the Cu/Sn electroplating process and improving the adhesion layer.
{"title":"Impact of Micromachining Process on Cu-Sn Solid-Liquid Interdiffusion (SLID) Bonds","authors":"H. Xia, A. Roy, E. Bardalen, Hoang-Vu Nguyen, K. Aasmundtveit, P. Ohlckers","doi":"10.23919/empc53418.2021.9584992","DOIUrl":"https://doi.org/10.23919/empc53418.2021.9584992","url":null,"abstract":"Copper-tin Solid-Liquid Interdiffusion (Cu-Sn SLID) bonding has shown potential for packaging of microelectromechanical system (MEMS) devices such as microbolometers due to its low cost and high-temperature stability. A thin micromachined silicon cap is desired in the packaging of microbolometers to minimize the infrared light absorption. In the preferred fabrication process flow, the Cu-Sn sealing frames are deposited on both the cap and device wafers prior to micromachining the cap wafer. This method greatly simplifies the process compared to when the metal layers are deposited after the cap etching process. However, such an approach might affect the bonding quality due to the Cu-Sn sealing frame being used directly as a mask for the cap etching. The present work addresses this concern using a cap wafer (with and without micromachining process) bonded to a device wafer using the Cu-Sn SLID technique. A dicing yield at or near 100% is achieved for both samples. The interface of Cu-Sn bonds shows a similar Cu/Cu3Sn/Cu structure between the samples without cavity and with a cavity, which indicates that the micromachining process has a minor impact on the Cu-Sn bonds. However, the measured die shear strengths of the samples with and without cavity are relatively low due to fracture at the Cu/Cu3 Sn interface and adhesion fracture at the TiW layer. The bond strength can be further improved by optimizing the Cu/Sn electroplating process and improving the adhesion layer.","PeriodicalId":348887,"journal":{"name":"2021 23rd European Microelectronics and Packaging Conference & Exhibition (EMPC)","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124328275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-13DOI: 10.23919/empc53418.2021.9585006
Chengqun Yu, Fei Yang, Johan Liu, Yong Zhang
In recent years, laser-reduced graphene oxide (LRGO) has received widespread interest, however, the thermal properties of graphene films obtained by laser reduction of GO are rarely reported. In this paper, a pulsed laser was used to reduce the prepared GO films. The obtained LRGO films were characterized by scanning electron microscopy (SEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS). The thermal diffusivity of the LRGO was measured as 7.3 mm2/s, higher than that of GO measured as 5.9 mm2/s. The heating performance of LRGO was performed under different DC voltages and the results show that the temperature can reach up to 91 °C with a response time of 14 s under the voltage of 18 V. The excellent electrothermal performance of LRGO films indicate that the LRGO films are promising as heating elements for various application such as defoggers.
{"title":"Thermal Properties of Laser Reduced Graphene Oxide Films","authors":"Chengqun Yu, Fei Yang, Johan Liu, Yong Zhang","doi":"10.23919/empc53418.2021.9585006","DOIUrl":"https://doi.org/10.23919/empc53418.2021.9585006","url":null,"abstract":"In recent years, laser-reduced graphene oxide (LRGO) has received widespread interest, however, the thermal properties of graphene films obtained by laser reduction of GO are rarely reported. In this paper, a pulsed laser was used to reduce the prepared GO films. The obtained LRGO films were characterized by scanning electron microscopy (SEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS). The thermal diffusivity of the LRGO was measured as 7.3 mm2/s, higher than that of GO measured as 5.9 mm2/s. The heating performance of LRGO was performed under different DC voltages and the results show that the temperature can reach up to 91 °C with a response time of 14 s under the voltage of 18 V. The excellent electrothermal performance of LRGO films indicate that the LRGO films are promising as heating elements for various application such as defoggers.","PeriodicalId":348887,"journal":{"name":"2021 23rd European Microelectronics and Packaging Conference & Exhibition (EMPC)","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121572417","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-13DOI: 10.23919/empc53418.2021.9584999
{"title":"[EMPC 2021 Front cover]","authors":"","doi":"10.23919/empc53418.2021.9584999","DOIUrl":"https://doi.org/10.23919/empc53418.2021.9584999","url":null,"abstract":"","PeriodicalId":348887,"journal":{"name":"2021 23rd European Microelectronics and Packaging Conference & Exhibition (EMPC)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123156684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-13DOI: 10.23919/empc53418.2021.9584943
S. Klengel, R. Klengel, T. Stephan, Bolko Mühs-Portius, D. Wilke, Michael Hahn
Corrosion occurs on metallic materials in the presence of moisture and reactive gases, such as H2 S, SO2 or NO2 and is enhanced by different substances like e.g. chlorides. Particularly electronic materials and components are affected, because they are exposed to increasingly harsh environmental conditions, resulting in damage to corrosive media (e.g. off-shore systems, electronic components in engine compartment of automobiles). Especially for the materials and contacts of micro-and power electronic components, corrosion induced processes are significant reliability limiting. Additionally, depending on process parameters, corrosion can also be induced during manufacturing (e.g. nickel corrosion in pad metallization). We developed an innovative method, based on electrochemical measurements by a local measuring cell that allows corrosion sensitivity analyses of typical metallization systems for substrates and electrical contacts in a very short time. In this paper, we present and discuss the results for electrochemical corrosion testing by the new method in correlation to standard reliability tests, like mixed flow gas testing (MFG) and neutral salt spray testing as well as standardized electrochemical testing for metallization systems pf printed circuit boards. High resolution microstructural analyses after standard testing as well as after miniaturized cyclovoltammetric testing are giving evidence for the running corrosion mechanism. The investigations carried out in this study show the application potential of the new local electrochemical test method and the usability for quality inspection of PCBs.
{"title":"A new method for local electrochemical measurements at PCBs","authors":"S. Klengel, R. Klengel, T. Stephan, Bolko Mühs-Portius, D. Wilke, Michael Hahn","doi":"10.23919/empc53418.2021.9584943","DOIUrl":"https://doi.org/10.23919/empc53418.2021.9584943","url":null,"abstract":"Corrosion occurs on metallic materials in the presence of moisture and reactive gases, such as H2 S, SO2 or NO2 and is enhanced by different substances like e.g. chlorides. Particularly electronic materials and components are affected, because they are exposed to increasingly harsh environmental conditions, resulting in damage to corrosive media (e.g. off-shore systems, electronic components in engine compartment of automobiles). Especially for the materials and contacts of micro-and power electronic components, corrosion induced processes are significant reliability limiting. Additionally, depending on process parameters, corrosion can also be induced during manufacturing (e.g. nickel corrosion in pad metallization). We developed an innovative method, based on electrochemical measurements by a local measuring cell that allows corrosion sensitivity analyses of typical metallization systems for substrates and electrical contacts in a very short time. In this paper, we present and discuss the results for electrochemical corrosion testing by the new method in correlation to standard reliability tests, like mixed flow gas testing (MFG) and neutral salt spray testing as well as standardized electrochemical testing for metallization systems pf printed circuit boards. High resolution microstructural analyses after standard testing as well as after miniaturized cyclovoltammetric testing are giving evidence for the running corrosion mechanism. The investigations carried out in this study show the application potential of the new local electrochemical test method and the usability for quality inspection of PCBs.","PeriodicalId":348887,"journal":{"name":"2021 23rd European Microelectronics and Packaging Conference & Exhibition (EMPC)","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130290542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-13DOI: 10.23919/empc53418.2021.9584958
Jacob Maxa, M. Nowottnick
An active power cycling test-bed for a power MOSFET is presented in this publication. This setup is used to create temperature dependent load cycles of 24 parallel devices. After a passive calibration step the drain-to-source voltage is used to estimate the junction temperature. The devices are then heated until a predefined value is reached. The setup is power cycled until at least 20 channels failed and then analysed using metallographic cross-sections. Furthermore, this setup records the thermal impedance of each channel over time. With these data it is possible to detect and predict a solder fatigue (crack, void) during operation. Finally after all load cycles the results were evaluated by Weibull plots and a lifetime estimation for other temperatures is given in the way of a stress-life curve. The results suggest a comparable lifetime compared to ceramic-based components, if the substrate does not have an influence as a source of faults.
{"title":"Accelerated Ageing Test and Lifetime Prediction of MOSFETs","authors":"Jacob Maxa, M. Nowottnick","doi":"10.23919/empc53418.2021.9584958","DOIUrl":"https://doi.org/10.23919/empc53418.2021.9584958","url":null,"abstract":"An active power cycling test-bed for a power MOSFET is presented in this publication. This setup is used to create temperature dependent load cycles of 24 parallel devices. After a passive calibration step the drain-to-source voltage is used to estimate the junction temperature. The devices are then heated until a predefined value is reached. The setup is power cycled until at least 20 channels failed and then analysed using metallographic cross-sections. Furthermore, this setup records the thermal impedance of each channel over time. With these data it is possible to detect and predict a solder fatigue (crack, void) during operation. Finally after all load cycles the results were evaluated by Weibull plots and a lifetime estimation for other temperatures is given in the way of a stress-life curve. The results suggest a comparable lifetime compared to ceramic-based components, if the substrate does not have an influence as a source of faults.","PeriodicalId":348887,"journal":{"name":"2021 23rd European Microelectronics and Packaging Conference & Exhibition (EMPC)","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121413511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-13DOI: 10.23919/empc53418.2021.9585004
Nihesh Mohan, Sri Krishna Bhogaraju, M. Łysień, Ludovic Schneider, F. Granek, Kerstin Lux, G. Elger
This paper presents results of an empirical investigation on drop feature optimization, subsequent fine trace printing and influence of sintering atmosphere on printed traces on polyimide substrate with Ag nanoparticle ink. The impact of printing parameters such as waveform features, jetting voltage and printhead height on drop formation and fine trace printing is investigated. The experiments revealed that drop diameter decreased by 33% after decreasing jetting voltage and overall waveform duration to a minimum functional range. From further studies, it is found that to print accurate fine traces an optimum drop spacing value in consideration with drop count should be selected which prints traces close to the required trace width dimensions. Based on these optimizations, trace width of 30 ± 2 μm can be printed with minimum pitch of 35 μm. Sintering progresses faster under air compared to nitrogen due to the efficient removal of the organic capping agents. The resulting sheet resistance under air and nitrogen were 0.1312 Ω/π and 1.8586 Ω/π respectively.
{"title":"Drop feature optimization for fine trace inkjet printing","authors":"Nihesh Mohan, Sri Krishna Bhogaraju, M. Łysień, Ludovic Schneider, F. Granek, Kerstin Lux, G. Elger","doi":"10.23919/empc53418.2021.9585004","DOIUrl":"https://doi.org/10.23919/empc53418.2021.9585004","url":null,"abstract":"This paper presents results of an empirical investigation on drop feature optimization, subsequent fine trace printing and influence of sintering atmosphere on printed traces on polyimide substrate with Ag nanoparticle ink. The impact of printing parameters such as waveform features, jetting voltage and printhead height on drop formation and fine trace printing is investigated. The experiments revealed that drop diameter decreased by 33% after decreasing jetting voltage and overall waveform duration to a minimum functional range. From further studies, it is found that to print accurate fine traces an optimum drop spacing value in consideration with drop count should be selected which prints traces close to the required trace width dimensions. Based on these optimizations, trace width of 30 ± 2 μm can be printed with minimum pitch of 35 μm. Sintering progresses faster under air compared to nitrogen due to the efficient removal of the organic capping agents. The resulting sheet resistance under air and nitrogen were 0.1312 Ω/π and 1.8586 Ω/π respectively.","PeriodicalId":348887,"journal":{"name":"2021 23rd European Microelectronics and Packaging Conference & Exhibition (EMPC)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131499189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：