Pub Date : 2021-09-13DOI: 10.23919/empc53418.2021.9585014
G. Pippione, S. Codato, A. Maina, A. Mirigaldi, M. Riva, R. Paoletti
Packaged high-power diode lasers have applications in many areas ranging from optoelectronic high density data storage, high power industrial laser for material processing, to medical (chirurgical/aesthetical) applications. The paper presents the development of families of laser modules which, using the same platform and assembly lines, can achieve a specific combination of power, brightness, compactness and cost effectiveness, depending on final application. Results for products emitting at 9XXnm and at 450 nm will be presented, describing the design, the realization and the production.
{"title":"Optimized Packaging Solutions for Multi-Emitter Laser Modules","authors":"G. Pippione, S. Codato, A. Maina, A. Mirigaldi, M. Riva, R. Paoletti","doi":"10.23919/empc53418.2021.9585014","DOIUrl":"https://doi.org/10.23919/empc53418.2021.9585014","url":null,"abstract":"Packaged high-power diode lasers have applications in many areas ranging from optoelectronic high density data storage, high power industrial laser for material processing, to medical (chirurgical/aesthetical) applications. The paper presents the development of families of laser modules which, using the same platform and assembly lines, can achieve a specific combination of power, brightness, compactness and cost effectiveness, depending on final application. Results for products emitting at 9XXnm and at 450 nm will be presented, describing the design, the realization and the production.","PeriodicalId":348887,"journal":{"name":"2021 23rd European Microelectronics and Packaging Conference & Exhibition (EMPC)","volume":"290 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":"116422485","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/empc53418.2021.9584981
Hoang-Vu Nguyen, Lisette Hernandez Gonzalez, K. Imenes, K. Aasmundtveit
Reworkable anisotropic conductive adhesives (ACAs) are of interest when the material is used for assembling electronic modules with high value, such as in medical devices. Adhesive matrices comprising a blend of a thermosetting epoxy and a thermoplastic polymer are selected because it has shown potential to ensure good electrical and mechanical integrity whilst still allowing reworkability for ACA assemblies. Our previous work demonstrated the feasibility of using blends of an epoxy and a thermoplastic polysulfone as an adhesive matrix for the reworkable ACAs. The rework temperature, however, is relatively high (190°C) which causes disadvantages for the rework process and safety of sensitive electronic components nearby. ACA material with lower rework temperature is thus of interest. This paper presents the findings of favorable mixing ratio between an epoxy compatible with ACA applications and a thermoplastic polymer that offers good mechanical strength combined with reworkability at a temperature as low as 100°C. The results show that the adhesive blends with a high concentration of thermoplastic polymer (35–65 wt%) exhibit satisfactory die shear strength at temperatures relevant for production/storage (23°C) and operation of medical devices (50°C). Furthermore, successful rework at temperature as low as 100°C is confirmed for such adhesive blends.
{"title":"Enabling Low-Temperature Reworkability for Anisotropic Conductive Adhesives","authors":"Hoang-Vu Nguyen, Lisette Hernandez Gonzalez, K. Imenes, K. Aasmundtveit","doi":"10.23919/empc53418.2021.9584981","DOIUrl":"https://doi.org/10.23919/empc53418.2021.9584981","url":null,"abstract":"Reworkable anisotropic conductive adhesives (ACAs) are of interest when the material is used for assembling electronic modules with high value, such as in medical devices. Adhesive matrices comprising a blend of a thermosetting epoxy and a thermoplastic polymer are selected because it has shown potential to ensure good electrical and mechanical integrity whilst still allowing reworkability for ACA assemblies. Our previous work demonstrated the feasibility of using blends of an epoxy and a thermoplastic polysulfone as an adhesive matrix for the reworkable ACAs. The rework temperature, however, is relatively high (190°C) which causes disadvantages for the rework process and safety of sensitive electronic components nearby. ACA material with lower rework temperature is thus of interest. This paper presents the findings of favorable mixing ratio between an epoxy compatible with ACA applications and a thermoplastic polymer that offers good mechanical strength combined with reworkability at a temperature as low as 100°C. The results show that the adhesive blends with a high concentration of thermoplastic polymer (35–65 wt%) exhibit satisfactory die shear strength at temperatures relevant for production/storage (23°C) and operation of medical devices (50°C). Furthermore, successful rework at temperature as low as 100°C is confirmed for such adhesive blends.","PeriodicalId":348887,"journal":{"name":"2021 23rd European Microelectronics and Packaging Conference & Exhibition (EMPC)","volume":"57 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":"126532210","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/empc53418.2021.9584989
A. Steenmann, Benjamin Schellscheidt, T. Licht
The change of solder materials is driven by ever new requirements and legislations. Thus, lead-free tin based solders like tin-silver-copper (SAC) have become a standard in the electrical industry, especially in high-power modules. In terms of processing and behavior, they are still different to lead-based solders. In order to obtain lead-free solders with the familiar behavior and proven performance of lead-based solders, their development continues. Micro-additives in conventionally used SAC solder can improve mechanical properties, processability and durability. To evaluate these properties, we soldered different solder alloys with three individual micro-additives each and compare them with standard SAC solder. Following shear tests and optical inspection of the solder joints provide information about the differences in reliability, durability and phase growth caused by the individual micro-additives. By comparing two solders with combined micro-additives, the interaction of the additives can be estimated. In conclusion, it is clear that micro-additives can improve the standard solder. By adding different micro-additives, solder can be adapted to the requirements of different applications.
{"title":"Influence of Micro-Additives on Lead-Free Solder Joints","authors":"A. Steenmann, Benjamin Schellscheidt, T. Licht","doi":"10.23919/empc53418.2021.9584989","DOIUrl":"https://doi.org/10.23919/empc53418.2021.9584989","url":null,"abstract":"The change of solder materials is driven by ever new requirements and legislations. Thus, lead-free tin based solders like tin-silver-copper (SAC) have become a standard in the electrical industry, especially in high-power modules. In terms of processing and behavior, they are still different to lead-based solders. In order to obtain lead-free solders with the familiar behavior and proven performance of lead-based solders, their development continues. Micro-additives in conventionally used SAC solder can improve mechanical properties, processability and durability. To evaluate these properties, we soldered different solder alloys with three individual micro-additives each and compare them with standard SAC solder. Following shear tests and optical inspection of the solder joints provide information about the differences in reliability, durability and phase growth caused by the individual micro-additives. By comparing two solders with combined micro-additives, the interaction of the additives can be estimated. In conclusion, it is clear that micro-additives can improve the standard solder. By adding different micro-additives, solder can be adapted to the requirements of different applications.","PeriodicalId":348887,"journal":{"name":"2021 23rd European Microelectronics and Packaging Conference & Exhibition (EMPC)","volume":"468 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":"124934143","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/empc53418.2021.9584962
A. Velea, Joshua Wilson, A. Pak, M. Seckel, Sven Schmidt, Stefan Kosmider, Nasim Bakhshaee, W. Serdijn, V. Giagka
Our limited understanding of the nervous system forms a bottleneck which impedes the effective treatment of neurological disorders. In order to improve patient outcomes it is highly desirable to interact with the nervous tissue at the resolution of individual cells. As neurons number in the billions and transmit signals electrically, high-density, cellular-resolution microelectrode arrays will be a useful tool for both treatment and research.This paper investigates the advantages and versatility of laser-patterning technologies for the development of such high-density microelectrode arrays in flexible polymer substrates. In particular, it aims to elucidate the mechanisms involved in laser patterning of thin polymers on top of thin metal layers. For this comparative study, a pulsed picosecond laser (Schmoll Picodrill) with two separate wavelengths (1064 nm (infrared (IR)) and 355 nm (ultraviolet (UV))) was used. A 5 $mu$ m thick electroplated layer of gold (Au) was used to form the microelectrodes. Laser-patterning was investigated to expose the Au electrodes when encapsulated by two different thermoplastic polymers: thermoplastic polyurethane (TPU), and Parylene-C, with thicknesses of maximum 25 $mu$ m. The electrode diameter and the distance between electrodes were reduced down to 35 $mu$ m and 30 $mu$ m, respectively. The structures were evaluated using optical microscopy and white light interferometry and the results indicated that both laser wavelengths can be successfully used to create high-density microelectrode arrays in polymer substrates. However, due to the lower absorption coefficient of metals in the IR spectrum, a higher uniformity of the exposed Au layer was observed when IR-based lasers were used. This paper provides more insight into the mechanisms involved in laser-patterning of thin film polymers and demonstrates that it can be a reliable and cost-effective method for the rapid prototyping of thin-film neural interfaces.
{"title":"UV and IR Laser-Patterning for High-Density Thin-Film Neural Interfaces","authors":"A. Velea, Joshua Wilson, A. Pak, M. Seckel, Sven Schmidt, Stefan Kosmider, Nasim Bakhshaee, W. Serdijn, V. Giagka","doi":"10.23919/empc53418.2021.9584962","DOIUrl":"https://doi.org/10.23919/empc53418.2021.9584962","url":null,"abstract":"Our limited understanding of the nervous system forms a bottleneck which impedes the effective treatment of neurological disorders. In order to improve patient outcomes it is highly desirable to interact with the nervous tissue at the resolution of individual cells. As neurons number in the billions and transmit signals electrically, high-density, cellular-resolution microelectrode arrays will be a useful tool for both treatment and research.This paper investigates the advantages and versatility of laser-patterning technologies for the development of such high-density microelectrode arrays in flexible polymer substrates. In particular, it aims to elucidate the mechanisms involved in laser patterning of thin polymers on top of thin metal layers. For this comparative study, a pulsed picosecond laser (Schmoll Picodrill) with two separate wavelengths (1064 nm (infrared (IR)) and 355 nm (ultraviolet (UV))) was used. A 5 $mu$ m thick electroplated layer of gold (Au) was used to form the microelectrodes. Laser-patterning was investigated to expose the Au electrodes when encapsulated by two different thermoplastic polymers: thermoplastic polyurethane (TPU), and Parylene-C, with thicknesses of maximum 25 $mu$ m. The electrode diameter and the distance between electrodes were reduced down to 35 $mu$ m and 30 $mu$ m, respectively. The structures were evaluated using optical microscopy and white light interferometry and the results indicated that both laser wavelengths can be successfully used to create high-density microelectrode arrays in polymer substrates. However, due to the lower absorption coefficient of metals in the IR spectrum, a higher uniformity of the exposed Au layer was observed when IR-based lasers were used. This paper provides more insight into the mechanisms involved in laser-patterning of thin film polymers and demonstrates that it can be a reliable and cost-effective method for the rapid prototyping of thin-film neural interfaces.","PeriodicalId":348887,"journal":{"name":"2021 23rd European Microelectronics and Packaging Conference & Exhibition (EMPC)","volume":"308 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":"132067299","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/empc53418.2021.9584993
A. Zehri, T. Nilsson, Yifeng Fu, Johan Liu
The current development of the electronics system requires capabilities beyond conventional heat transfer approaches. New solutions based on advanced materials are being developed to tackle the current challenges in the development of electronics systems and the nanoscale 2D materials such as graphene are at the centre of the effort to exploit the intrinsic properties of carbon nanomaterials. In this work, we introduce a new concept of graphene-coated copper nanoparticles (G-CuNPs) and explore their multifunctional potential applications in metallic based paste used in electronics. The nanoscale powder was found to present a core/shell structure with the copper particle at its core and a disordered multilayer graphene structure continuously coating its surface. The composition of the particles was analysed, and the presence of the coating was found to provide oxidation protection for the metallic core. Thermogravimetric analysis (TGA) showed an additional role of the G-CuNPs with a reduction effect without the use of an additional reducing agent. Furthermore, due to the combined effect of the size of the particles and the oxidation-free metallic core, Differential Scanning Calorimetry (DSC) analysis revealed a melting depression at temperatures as low as $155 ^{circ}mathrm{C}$. Finally, the mechanical properties of the nanocoating were investigated and the results showed an enhanced ductility at the surface of the particles due to the presence of the multi-layered graphene structure, which might be exploited for powder flow and lubrication effect.
{"title":"Exploring Graphene Coated Copper Nanoparticles as a multifunctional Nanofiller for Micro-Scaled Copper Paste","authors":"A. Zehri, T. Nilsson, Yifeng Fu, Johan Liu","doi":"10.23919/empc53418.2021.9584993","DOIUrl":"https://doi.org/10.23919/empc53418.2021.9584993","url":null,"abstract":"The current development of the electronics system requires capabilities beyond conventional heat transfer approaches. New solutions based on advanced materials are being developed to tackle the current challenges in the development of electronics systems and the nanoscale 2D materials such as graphene are at the centre of the effort to exploit the intrinsic properties of carbon nanomaterials. In this work, we introduce a new concept of graphene-coated copper nanoparticles (G-CuNPs) and explore their multifunctional potential applications in metallic based paste used in electronics. The nanoscale powder was found to present a core/shell structure with the copper particle at its core and a disordered multilayer graphene structure continuously coating its surface. The composition of the particles was analysed, and the presence of the coating was found to provide oxidation protection for the metallic core. Thermogravimetric analysis (TGA) showed an additional role of the G-CuNPs with a reduction effect without the use of an additional reducing agent. Furthermore, due to the combined effect of the size of the particles and the oxidation-free metallic core, Differential Scanning Calorimetry (DSC) analysis revealed a melting depression at temperatures as low as $155 ^{circ}mathrm{C}$. Finally, the mechanical properties of the nanocoating were investigated and the results showed an enhanced ductility at the surface of the particles due to the presence of the multi-layered graphene structure, which might be exploited for powder flow and lubrication effect.","PeriodicalId":348887,"journal":{"name":"2021 23rd European Microelectronics and Packaging Conference & Exhibition (EMPC)","volume":"13 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":"132024637","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/empc53418.2021.9584978
S. Klengel, A. Krombholz, Olaf Schwedler, H. Busch
Additive manufacturing of copper structures with selective laser melting offers promising possibilities for prototyping or production of unconventional structures for electronic assemblies. There are various copper powders from different manufacturers available that are suitable for processing with SLM technology. Simple structures produced with copper powder in SLM technology are increasingly being used. However, more complex structures with small dimensions are still the exception. As part of a public funded project, we are researching the potentials and limits of the copper materials and processes currently used for additive manufacturing in electronic systems using the example of a heat sink for microelectronic assemblies. Within the project we focus on the aspects of microstructure formation after processing (e.g. particle sintering, pore formation, binder residues, etc.). In our paper we summarize the research results achieved so far. In comparison to reference assemblies from conventional production, we show impressive high-resolution microstructural results of SEM on copper powder in initial state and manufactured structures and correlate these results to each other. The result is a current state of the art for the use of copper materials and SLM processes in additive manufacturing in the field of electronic systems.
{"title":"Material characterization of copper structures for electronic systems manufactured by selective laser melting (SLM)","authors":"S. Klengel, A. Krombholz, Olaf Schwedler, H. Busch","doi":"10.23919/empc53418.2021.9584978","DOIUrl":"https://doi.org/10.23919/empc53418.2021.9584978","url":null,"abstract":"Additive manufacturing of copper structures with selective laser melting offers promising possibilities for prototyping or production of unconventional structures for electronic assemblies. There are various copper powders from different manufacturers available that are suitable for processing with SLM technology. Simple structures produced with copper powder in SLM technology are increasingly being used. However, more complex structures with small dimensions are still the exception. As part of a public funded project, we are researching the potentials and limits of the copper materials and processes currently used for additive manufacturing in electronic systems using the example of a heat sink for microelectronic assemblies. Within the project we focus on the aspects of microstructure formation after processing (e.g. particle sintering, pore formation, binder residues, etc.). In our paper we summarize the research results achieved so far. In comparison to reference assemblies from conventional production, we show impressive high-resolution microstructural results of SEM on copper powder in initial state and manufactured structures and correlate these results to each other. The result is a current state of the art for the use of copper materials and SLM processes in additive manufacturing in the field of electronic systems.","PeriodicalId":348887,"journal":{"name":"2021 23rd European Microelectronics and Packaging Conference & Exhibition (EMPC)","volume":"12 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":"134491017","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/empc53418.2021.9585003
Madadnia Behnam, Bossuyt Frederick, V. Jan
This paper presents a novel approach for removing out-of-plane deformation in metal interconnects by adding a fractional structure to the original meander shape and using the optimised fabrication stack. In thermoformed electronics in cases where copper is used as the conductor, the twisting of meander-shaped structures caused by excessive mechanical stress can cause a non-uniform surface, delamination of the metal interconnect from the substrate, and in some cases, a short circuit to the adjacent tracks. Typically, stretchable electronics designers use various shapes and widths of the copper interconnect to tackle this issue. Using conventional meander shapes such as horseshoes and U shapes is not universally practical, especially when stretching is higher than 30 percent leading to significant out-of-plane deformation. Limiting this out-of-plane deformation by reducing the track width is not always applicable, as a minimum width is needed from a technology and conductivity perspective. The presented approach is inspired by computational and experimental studies of multiple meander shapes and fabrication methods. A geometry-based and fabrication-based approach is presented, which can reduce the mechanical stress of almost all possible meander shapes by increasing the meander’s path length to accommodate the metal track’s produced torque during stretching. An analytical approach is provided for calculating the optimal meander parameters, and the optimal fabrication stack is achieved based on simulation results. Experiments and finite-element modeling for an industrial case study show the improvement in the stress distribution and reduction of out-of-plane.
{"title":"Reducing out-of-plane deformation of metal interconnects in structural electronics","authors":"Madadnia Behnam, Bossuyt Frederick, V. Jan","doi":"10.23919/empc53418.2021.9585003","DOIUrl":"https://doi.org/10.23919/empc53418.2021.9585003","url":null,"abstract":"This paper presents a novel approach for removing out-of-plane deformation in metal interconnects by adding a fractional structure to the original meander shape and using the optimised fabrication stack. In thermoformed electronics in cases where copper is used as the conductor, the twisting of meander-shaped structures caused by excessive mechanical stress can cause a non-uniform surface, delamination of the metal interconnect from the substrate, and in some cases, a short circuit to the adjacent tracks. Typically, stretchable electronics designers use various shapes and widths of the copper interconnect to tackle this issue. Using conventional meander shapes such as horseshoes and U shapes is not universally practical, especially when stretching is higher than 30 percent leading to significant out-of-plane deformation. Limiting this out-of-plane deformation by reducing the track width is not always applicable, as a minimum width is needed from a technology and conductivity perspective. The presented approach is inspired by computational and experimental studies of multiple meander shapes and fabrication methods. A geometry-based and fabrication-based approach is presented, which can reduce the mechanical stress of almost all possible meander shapes by increasing the meander’s path length to accommodate the metal track’s produced torque during stretching. An analytical approach is provided for calculating the optimal meander parameters, and the optimal fabrication stack is achieved based on simulation results. Experiments and finite-element modeling for an industrial case study show the improvement in the stress distribution and reduction of out-of-plane.","PeriodicalId":348887,"journal":{"name":"2021 23rd European Microelectronics and Packaging Conference & Exhibition (EMPC)","volume":"27 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":"134375122","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/empc53418.2021.9584977
Prabjit Singh, L. Palmer, Chen Xu, M. Pudas, J. Keeping, M. M. Khaw, Kok Lieh Tan, H. Fu
Conformal coatings are applied to protect printed circuit boards and components mounted on them from the deleterious effects of moisture, particulate matter and corrosive gases. The conventional method of testing the effectiveness of these coatings is to expose the conformally coated hardware to a corrosive environment for extended periods of time — often lasting many months — and determine the mean time to failure. iNEMI’s Conformal Coating Evaluation for Improved Environmental Protection project team is recommending a quicker test method that takes less than a week to evaluate conformal coatings. This method uses the corrosion rates of conformally coated thin films of copper and silver exposed to a sulfur gas environment as a measure if the coating performance. The project team investigated how temperature and humidity impact the corrosion rates of conformally coated copper and silver thin films compared to uncoated films. Performances of acrylic, silicone and atomic layer deposited (ALD) coatings were studied as a function of temperature and relative humidity. The team found that temperature affected the corrosion rates of conformally coated copper and silver thin films, whereas relative humidity had a lesser influence. The team also discovered significant differences in corrosion protection provided by the three coatings that were tested.
{"title":"Development of a Quick Test for Conformal Coatings","authors":"Prabjit Singh, L. Palmer, Chen Xu, M. Pudas, J. Keeping, M. M. Khaw, Kok Lieh Tan, H. Fu","doi":"10.23919/empc53418.2021.9584977","DOIUrl":"https://doi.org/10.23919/empc53418.2021.9584977","url":null,"abstract":"Conformal coatings are applied to protect printed circuit boards and components mounted on them from the deleterious effects of moisture, particulate matter and corrosive gases. The conventional method of testing the effectiveness of these coatings is to expose the conformally coated hardware to a corrosive environment for extended periods of time — often lasting many months — and determine the mean time to failure. iNEMI’s Conformal Coating Evaluation for Improved Environmental Protection project team is recommending a quicker test method that takes less than a week to evaluate conformal coatings. This method uses the corrosion rates of conformally coated thin films of copper and silver exposed to a sulfur gas environment as a measure if the coating performance. The project team investigated how temperature and humidity impact the corrosion rates of conformally coated copper and silver thin films compared to uncoated films. Performances of acrylic, silicone and atomic layer deposited (ALD) coatings were studied as a function of temperature and relative humidity. The team found that temperature affected the corrosion rates of conformally coated copper and silver thin films, whereas relative humidity had a lesser influence. The team also discovered significant differences in corrosion protection provided by the three coatings that were tested.","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":"114564618","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/empc53418.2021.9584983
T. Huesgen, V. Polezhaev, Ankit Sharma, Chunlei Liu, M. Montazerian, P. Stadler, N. Pavliček, G. Salvatore
PCB embedding in combination with direct-bonded copper (DBC) substrates is an attractive approach for packaging of power semiconductors facilitating low-inductive designs while relying on a proven insulating material. However, the CTE mismatch of these materials could cause reliability issues. This study presents an initial reliability screening using simple IGBT prepackages with alumina-based DBC as test vehicles. After -40/150 °C temperature cycles, fracture of the substrate and the chip is observed, resulting in an increased on-state resistance. Literature data suggest that the substrate failure is independent from the embedding. To gain a deeper understanding of the limitations of the technology, further research with optimized DBC substrates is required.
{"title":"Reliability Screening of a Hybrid DBC/PCB power semiconductor prepackage","authors":"T. Huesgen, V. Polezhaev, Ankit Sharma, Chunlei Liu, M. Montazerian, P. Stadler, N. Pavliček, G. Salvatore","doi":"10.23919/empc53418.2021.9584983","DOIUrl":"https://doi.org/10.23919/empc53418.2021.9584983","url":null,"abstract":"PCB embedding in combination with direct-bonded copper (DBC) substrates is an attractive approach for packaging of power semiconductors facilitating low-inductive designs while relying on a proven insulating material. However, the CTE mismatch of these materials could cause reliability issues. This study presents an initial reliability screening using simple IGBT prepackages with alumina-based DBC as test vehicles. After -40/150 °C temperature cycles, fracture of the substrate and the chip is observed, resulting in an increased on-state resistance. Literature data suggest that the substrate failure is independent from the embedding. To gain a deeper understanding of the limitations of the technology, further research with optimized DBC substrates is required.","PeriodicalId":348887,"journal":{"name":"2021 23rd European Microelectronics and Packaging Conference & Exhibition (EMPC)","volume":"104 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":"127988466","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/empc53418.2021.9585002
Xinjian Gong, Jin Chen, Yong Zhang, Xiuzhen Lu, Johan Liu
A flexible graphene and polyimide composite film was designed and fabricated in this study. A polyimide solution was used as an adhesive layer to connect graphene film and polyimide film by hot-pressing. Laser flash thermal analysis method was carried out to evaluate the thermal diffusion coefficient of different thicknesses of the fabricated films at various temperatures. Bending test was carried out to evaluate the stability and reliability of the composite film. Scanning electron microscopy was applied to characterize the cross-section of the composite film before and after the peel test. IR imaging was employed to compare the heat diffusion of the composite film and traditional flexible copper clad laminate. The results show that the composite film has significantly better thermal diffusion capacity than traditional flexible copper clad laminate.
{"title":"Fabrication and Characterization of Graphene/polyimide Composite Film","authors":"Xinjian Gong, Jin Chen, Yong Zhang, Xiuzhen Lu, Johan Liu","doi":"10.23919/empc53418.2021.9585002","DOIUrl":"https://doi.org/10.23919/empc53418.2021.9585002","url":null,"abstract":"A flexible graphene and polyimide composite film was designed and fabricated in this study. A polyimide solution was used as an adhesive layer to connect graphene film and polyimide film by hot-pressing. Laser flash thermal analysis method was carried out to evaluate the thermal diffusion coefficient of different thicknesses of the fabricated films at various temperatures. Bending test was carried out to evaluate the stability and reliability of the composite film. Scanning electron microscopy was applied to characterize the cross-section of the composite film before and after the peel test. IR imaging was employed to compare the heat diffusion of the composite film and traditional flexible copper clad laminate. The results show that the composite film has significantly better thermal diffusion capacity than traditional flexible copper clad laminate.","PeriodicalId":348887,"journal":{"name":"2021 23rd European Microelectronics and Packaging Conference & Exhibition (EMPC)","volume":"37 8","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120969013","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}
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