Pub Date : 2022-02-25DOI: 10.1108/ssmt-08-2021-0056
Chun-Sheng Chen, Hai Wang, Yung-Chin Kao, Po-Jen Lu, Wei-Ren Chen
Purpose This paper aims to establish the predictive equations of height, area and volume of printed solder paste during solder paste stencil printing (SPSP) process in surface mount technology (SMT) to better understand the effect of process parameters on the printing quality. Design/methodology/approach An experiment plan is proposed based on the response surface method (RSM). Experiments with 30 different combinations of process parameters are performed using a solder paste printer. After printing, the volume, area and height of the printed SAC105 solder paste are measured by a solder paste inspection machine. Using RSM, the predictive equations associated with the printing parameters and the printing quality of the solder paste are formed. Findings The optimal printing parameters are 175.08 N printing pressure, 250 mm/s printing speed, 0.1 mm snap-off height and 15.7 mm/s stencil snap-off speed if the target height of solder paste is 100 µm. As the target printing area of solder paste is 1.1 mm × 1.3 mm, the optimized values of the printing parameters are 140.29 N, 100.52 mm/s, 0.63 mm and 20.25 mm/s. When both the target printing height and area are optimized together, the optimal values for the four parameters are 86.67 N, 225.76 mm/s, 0.15 mm and 1.82 mm/s. Originality/value A simple RSM-based experimental method is proposed to formulate the predictive polynomial equations for height, area and volume of printed solder paste in terms of important SPSP parameters. The predictive equation model can be applied to the actual SPSP process, allowing engineers to quickly predict the best printing parameters during parameter setting to improve production efficiency and quality.
{"title":"Predictive model of the solder paste stencil printing process by response surface methodology","authors":"Chun-Sheng Chen, Hai Wang, Yung-Chin Kao, Po-Jen Lu, Wei-Ren Chen","doi":"10.1108/ssmt-08-2021-0056","DOIUrl":"https://doi.org/10.1108/ssmt-08-2021-0056","url":null,"abstract":"\u0000Purpose\u0000This paper aims to establish the predictive equations of height, area and volume of printed solder paste during solder paste stencil printing (SPSP) process in surface mount technology (SMT) to better understand the effect of process parameters on the printing quality.\u0000\u0000\u0000Design/methodology/approach\u0000An experiment plan is proposed based on the response surface method (RSM). Experiments with 30 different combinations of process parameters are performed using a solder paste printer. After printing, the volume, area and height of the printed SAC105 solder paste are measured by a solder paste inspection machine. Using RSM, the predictive equations associated with the printing parameters and the printing quality of the solder paste are formed.\u0000\u0000\u0000Findings\u0000The optimal printing parameters are 175.08 N printing pressure, 250 mm/s printing speed, 0.1 mm snap-off height and 15.7 mm/s stencil snap-off speed if the target height of solder paste is 100 µm. As the target printing area of solder paste is 1.1 mm × 1.3 mm, the optimized values of the printing parameters are 140.29 N, 100.52 mm/s, 0.63 mm and 20.25 mm/s. When both the target printing height and area are optimized together, the optimal values for the four parameters are 86.67 N, 225.76 mm/s, 0.15 mm and 1.82 mm/s.\u0000\u0000\u0000Originality/value\u0000A simple RSM-based experimental method is proposed to formulate the predictive polynomial equations for height, area and volume of printed solder paste in terms of important SPSP parameters. The predictive equation model can be applied to the actual SPSP process, allowing engineers to quickly predict the best printing parameters during parameter setting to improve production efficiency and quality.\u0000","PeriodicalId":49499,"journal":{"name":"Soldering & Surface Mount Technology","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2022-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47428603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-02-22DOI: 10.1108/ssmt-10-2021-0064
R. Shalaby
Purpose This study aims to summarize the effects of minor addition of Ho REE on the structure, mechanical strength and thermal stability of binary Sn- Ag solder alloys for high-performance applications. Design/methodology/approach This study investigates the effect of a small amount of holmium addition on the microstructure, thermal stability, mechanical behaviour and wettability of environmentally friendly eutectic melt-spun process Sn – Ag solder alloys. Dynamic resonance technique, X-ray diffraction (XRD) and scanning electron microscopy were carried to study stiffness, identification of the phases and the morphology features of the solder. Structure and microstructure analysis indicated that presence of rhombohedral ß-Sn phase in addition to orthorhombic IMC Ag3Sn phase dispersed in Sn-matrix. Also, the results showed that Ho rare earth addition at a small trace amount into Sn-Ag system reduces and improves the particle size of both rhombohedral ß-Sn and orthorhombic IMC Ag3Sn based on the adsorption effect of the active RE element. The adsorption of Ho at grain boundaries resulted in Ag3Sn more uniform needle-like which is distributed in the ß-Sn matrix. The fine and uniform microstructure leads to improvement of mechanical strength. The microstructure refinement is due to the high surface free energy of IMC Ag3Sn grains, and it prevents the dislocation slipping. This maybe enhance the micro-hardness and micro-creep hence delays the breaking point of the solder. Ho (RE) trace addition could enhance the melting temperature and contact angle up to 215°C and 31°, Respectively, compared with plain solder. All results showed that Ho trace addition element has an effective method to enhance new solder joints. Findings Effect of rare earth element Ho particles on the microstructure and mechanical behavior of eutectic Sn-3.5Ag solder alloy was studied. Some important conclusions are summarized in the following: microstructure investigations revealed that the addition of Ho particles to eutectic Sn-3.5Ag inhibited in reducing and refines the crystallite size as well as the Ag3Sn IMC which reinforced the strength of plain solder alloy. The mechanical properties values such as Young’s modulus, Vickers microhardness of Sn-3.5Ag solder alloy can be significantly improved by adding a trace amount of Ho particles compared with plain solder due to the existence of finer and higher volume fraction of Ag3SnIMC. These variations can be understood by considering the plastic deformation. The strengthening mechanism of the Sn-3.5Ag-Ho solder alloy could be explained in terms of Ho harden particles and finer IMC, which are distributed within eutectic regions because they act as pinning centres which inhibited the mobility of dislocation that concentrated around the grain boundaries. The results show that the best creep resistance is obtained when the addition of Ho 0.5 is compared to plain solder. The addition of Ho on Sn-3.5Ag lead-free solder alloy decrease
{"title":"Development of holmium doped eutectic Sn-Ag lead-free solder for electronic packaging","authors":"R. Shalaby","doi":"10.1108/ssmt-10-2021-0064","DOIUrl":"https://doi.org/10.1108/ssmt-10-2021-0064","url":null,"abstract":"\u0000Purpose\u0000This study aims to summarize the effects of minor addition of Ho REE on the structure, mechanical strength and thermal stability of binary Sn- Ag solder alloys for high-performance applications.\u0000\u0000\u0000Design/methodology/approach\u0000This study investigates the effect of a small amount of holmium addition on the microstructure, thermal stability, mechanical behaviour and wettability of environmentally friendly eutectic melt-spun process Sn – Ag solder alloys. Dynamic resonance technique, X-ray diffraction (XRD) and scanning electron microscopy were carried to study stiffness, identification of the phases and the morphology features of the solder. Structure and microstructure analysis indicated that presence of rhombohedral ß-Sn phase in addition to orthorhombic IMC Ag3Sn phase dispersed in Sn-matrix. Also, the results showed that Ho rare earth addition at a small trace amount into Sn-Ag system reduces and improves the particle size of both rhombohedral ß-Sn and orthorhombic IMC Ag3Sn based on the adsorption effect of the active RE element. The adsorption of Ho at grain boundaries resulted in Ag3Sn more uniform needle-like which is distributed in the ß-Sn matrix. The fine and uniform microstructure leads to improvement of mechanical strength. The microstructure refinement is due to the high surface free energy of IMC Ag3Sn grains, and it prevents the dislocation slipping. This maybe enhance the micro-hardness and micro-creep hence delays the breaking point of the solder. Ho (RE) trace addition could enhance the melting temperature and contact angle up to 215°C and 31°, Respectively, compared with plain solder. All results showed that Ho trace addition element has an effective method to enhance new solder joints.\u0000\u0000\u0000Findings\u0000Effect of rare earth element Ho particles on the microstructure and mechanical behavior of eutectic Sn-3.5Ag solder alloy was studied. Some important conclusions are summarized in the following: microstructure investigations revealed that the addition of Ho particles to eutectic Sn-3.5Ag inhibited in reducing and refines the crystallite size as well as the Ag3Sn IMC which reinforced the strength of plain solder alloy. The mechanical properties values such as Young’s modulus, Vickers microhardness of Sn-3.5Ag solder alloy can be significantly improved by adding a trace amount of Ho particles compared with plain solder due to the existence of finer and higher volume fraction of Ag3SnIMC. These variations can be understood by considering the plastic deformation. The strengthening mechanism of the Sn-3.5Ag-Ho solder alloy could be explained in terms of Ho harden particles and finer IMC, which are distributed within eutectic regions because they act as pinning centres which inhibited the mobility of dislocation that concentrated around the grain boundaries. The results show that the best creep resistance is obtained when the addition of Ho 0.5 is compared to plain solder. The addition of Ho on Sn-3.5Ag lead-free solder alloy decrease","PeriodicalId":49499,"journal":{"name":"Soldering & Surface Mount Technology","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2022-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44578670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-02-15DOI: 10.1108/ssmt-08-2021-0059
Xinmeng Zhai, Yue Chen, Yuefeng Li, Jun Zou, Mingming Shi, Bobo Yang
Purpose This study aims to study the mechanical, photoelectric, and thermal reliability of SAC307 solder joints with Ni-decorated MWCNTs for flip-chip light-emitting diode (LED) package component during aging. By adding nanoparticles (Ni-multi-walled carbon nanotubes [MWCNTs]) to the solder paste, the shear strength and fatigue resistance of the brazed joint can be improved. However, the aging properties of Ni-modified MWCNTs composite solder joints have not been deeply studied. In this research, the mechanical, photoelectric and thermal reliability of SAC307 packaged flip-chip LEDs with Ni-MWCNTs added during aging were studied. Design/methodology/approach Compared with SAC solder alloys, the effects of different contents (0, 0.05, 0.1 and 0.2 Wt.%) of Ni-MWCNTs on the photoelectric and thermal properties of composite solder joints were examined. To study the aging characteristics of composite solder joints, the solder joints were aged at 85°C/85% relative humidity. Findings The addition of an appropriate amount of reinforcing agent Ni-MWCNTs reduces the density of the composite solder to 96% of the theoretical value of the SAC solder alloy. In addition, the microhardness increases and the wetting angle decreases. Two different phase compositions were observed in the solder joints with Ni-MWCNTs reinforcement: Cu3Sn and (Cu, Ni)6Sn5. The solder joints of SAC307-0.1Ni-MWCNTs exhibit the highest luminous flux and luminous efficiency of flip-chip LED filaments, the lowest steady-state voltage and junction temperature. And with the extension of the aging time, its aging stability is the best. In short, when the addition amount of Ni-MWCNTs is 0.1 Wt.%, the solder joints exhibit the best wettability and the thinnest intermetallic compound layer. And the shear strength of the tested solder joints is the best, and the void ratio is the lowest. At this time, the enhancement effect of Ni-MWCNTs on the composite solder has been best demonstrated. Research limitations/implications The content range of enhancer Ni-MWCNTs needs to be further reduced. Practical implications The authors have improved the performance of Ni-modified MWCNTs composite solder joints. Originality/value Composite solder with high performance has great practical application significance for improving the reliability and life of the whole device.
{"title":"Mechanical, photoelectric and thermal reliability of SAC307 solder joints with Ni-decorated MWCNTs for flip-chip LED package component during aging","authors":"Xinmeng Zhai, Yue Chen, Yuefeng Li, Jun Zou, Mingming Shi, Bobo Yang","doi":"10.1108/ssmt-08-2021-0059","DOIUrl":"https://doi.org/10.1108/ssmt-08-2021-0059","url":null,"abstract":"\u0000Purpose\u0000This study aims to study the mechanical, photoelectric, and thermal reliability of SAC307 solder joints with Ni-decorated MWCNTs for flip-chip light-emitting diode (LED) package component during aging. By adding nanoparticles (Ni-multi-walled carbon nanotubes [MWCNTs]) to the solder paste, the shear strength and fatigue resistance of the brazed joint can be improved. However, the aging properties of Ni-modified MWCNTs composite solder joints have not been deeply studied. In this research, the mechanical, photoelectric and thermal reliability of SAC307 packaged flip-chip LEDs with Ni-MWCNTs added during aging were studied.\u0000\u0000\u0000Design/methodology/approach\u0000Compared with SAC solder alloys, the effects of different contents (0, 0.05, 0.1 and 0.2 Wt.%) of Ni-MWCNTs on the photoelectric and thermal properties of composite solder joints were examined. To study the aging characteristics of composite solder joints, the solder joints were aged at 85°C/85% relative humidity.\u0000\u0000\u0000Findings\u0000The addition of an appropriate amount of reinforcing agent Ni-MWCNTs reduces the density of the composite solder to 96% of the theoretical value of the SAC solder alloy. In addition, the microhardness increases and the wetting angle decreases. Two different phase compositions were observed in the solder joints with Ni-MWCNTs reinforcement: Cu3Sn and (Cu, Ni)6Sn5. The solder joints of SAC307-0.1Ni-MWCNTs exhibit the highest luminous flux and luminous efficiency of flip-chip LED filaments, the lowest steady-state voltage and junction temperature. And with the extension of the aging time, its aging stability is the best. In short, when the addition amount of Ni-MWCNTs is 0.1 Wt.%, the solder joints exhibit the best wettability and the thinnest intermetallic compound layer. And the shear strength of the tested solder joints is the best, and the void ratio is the lowest. At this time, the enhancement effect of Ni-MWCNTs on the composite solder has been best demonstrated.\u0000\u0000\u0000Research limitations/implications\u0000The content range of enhancer Ni-MWCNTs needs to be further reduced.\u0000\u0000\u0000Practical implications\u0000The authors have improved the performance of Ni-modified MWCNTs composite solder joints.\u0000\u0000\u0000Originality/value\u0000Composite solder with high performance has great practical application significance for improving the reliability and life of the whole device.\u0000","PeriodicalId":49499,"journal":{"name":"Soldering & Surface Mount Technology","volume":"42 4","pages":""},"PeriodicalIF":2.0,"publicationDate":"2022-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41294583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-02-09DOI: 10.1108/ssmt-08-2021-0054
A. Skwarek, Przemysław Ptak, K. Górecki, K. Witek, B. Illés
Purpose This paper aims to present the results of investigations that show the influence of ZnO composite soldering paste on the optical and thermal parameters of power light-emitting diodes (LEDs). Design/methodology/approach ZnO nanocomposite solder alloys were produced via the ball milling process from the solder paste Sn99Ag0.3Cu0.7 (SACX0307) and 1.0 wt% of ZnO nanoparticle reinforcements with different primary particle sizes (200 nm, 100 nm and 50 nm). Power LEDs were soldered onto a metal core printed circuit board. A self-designed LED test system was used to measure the thermal and optical characteristics of the LEDs. Findings The influence of the soldering paste on the thermal and optical parameters of LEDs was observed. In all solder alloys, ZnO ceramic reinforcement, at a level of 1 wt%, increased the thermal parameters of LEDs and decreased their luminous efficiency. Thermal resistance values were10% higher, and junction temperature change over ambient temperature was 20% higher for the samples soldered with composite solder pastes than the reference sample. At the same time, luminous efficiency dropped by 32%. Originality/value The results prove that ZnO ceramic reinforcement of solder paste influences the thermal properties of solder joints. As was proven, the quality of the solder joints influences the whole assembly.
{"title":"The influence of SACX0307-ZnO nanocomposite solder alloys on the optical and thermal properties of power LEDs","authors":"A. Skwarek, Przemysław Ptak, K. Górecki, K. Witek, B. Illés","doi":"10.1108/ssmt-08-2021-0054","DOIUrl":"https://doi.org/10.1108/ssmt-08-2021-0054","url":null,"abstract":"\u0000Purpose\u0000This paper aims to present the results of investigations that show the influence of ZnO composite soldering paste on the optical and thermal parameters of power light-emitting diodes (LEDs).\u0000\u0000\u0000Design/methodology/approach\u0000ZnO nanocomposite solder alloys were produced via the ball milling process from the solder paste Sn99Ag0.3Cu0.7 (SACX0307) and 1.0 wt% of ZnO nanoparticle reinforcements with different primary particle sizes (200 nm, 100 nm and 50 nm). Power LEDs were soldered onto a metal core printed circuit board. A self-designed LED test system was used to measure the thermal and optical characteristics of the LEDs.\u0000\u0000\u0000Findings\u0000The influence of the soldering paste on the thermal and optical parameters of LEDs was observed. In all solder alloys, ZnO ceramic reinforcement, at a level of 1 wt%, increased the thermal parameters of LEDs and decreased their luminous efficiency. Thermal resistance values were10% higher, and junction temperature change over ambient temperature was 20% higher for the samples soldered with composite solder pastes than the reference sample. At the same time, luminous efficiency dropped by 32%.\u0000\u0000\u0000Originality/value\u0000The results prove that ZnO ceramic reinforcement of solder paste influences the thermal properties of solder joints. As was proven, the quality of the solder joints influences the whole assembly.\u0000","PeriodicalId":49499,"journal":{"name":"Soldering & Surface Mount Technology","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2022-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44423781","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-02-01DOI: 10.1108/ssmt-10-2021-0063
Yangyang Lai, K. Pan, Yuqiao Cen, Junbo Yang, Chongyang Cai, Pengcheng Yin, Seungbae Park
Purpose This paper aims to provide the proper preset temperatures of the convection reflow oven when reflowing a printed circuit board (PCB) assembly with varied sizes of components simultaneously. Design/methodology/approach In this study, computational fluid dynamics modeling is used to simulate the reflow soldering process. The training data provided to the machine learning (ML) model is generated from a programmed system based on the physics model. Support vector regression and an artificial neural network are used to validate the accuracy of ML models. Findings Integrated physical and ML models synergistically can accurately predict reflow profiles of solder joints and alleviate the expense of repeated trials. Using this system, the reflow oven temperature settings to achieve the desired reflow profile can be obtained at substantially reduced computation cost. Practical implications The prediction of the reflow profile subjected to varied temperature settings of the reflow oven is beneficial to process engineers when reflowing bulky components. The study of reflowing a new PCB assembly can be started at the early stage of board design with no need for a physical profiling board prototype. Originality/value This study provides a smart solution to determine the optimal preset temperatures of the reflow oven, which is usually relied on experience. The hybrid physics–ML model providing accurate prediction with the significantly reduced expense is used in this application for the first time.
{"title":"An intelligent system for reflow oven temperature settings based on hybrid physics-machine learning model","authors":"Yangyang Lai, K. Pan, Yuqiao Cen, Junbo Yang, Chongyang Cai, Pengcheng Yin, Seungbae Park","doi":"10.1108/ssmt-10-2021-0063","DOIUrl":"https://doi.org/10.1108/ssmt-10-2021-0063","url":null,"abstract":"\u0000Purpose\u0000This paper aims to provide the proper preset temperatures of the convection reflow oven when reflowing a printed circuit board (PCB) assembly with varied sizes of components simultaneously.\u0000\u0000\u0000Design/methodology/approach\u0000In this study, computational fluid dynamics modeling is used to simulate the reflow soldering process. The training data provided to the machine learning (ML) model is generated from a programmed system based on the physics model. Support vector regression and an artificial neural network are used to validate the accuracy of ML models.\u0000\u0000\u0000Findings\u0000Integrated physical and ML models synergistically can accurately predict reflow profiles of solder joints and alleviate the expense of repeated trials. Using this system, the reflow oven temperature settings to achieve the desired reflow profile can be obtained at substantially reduced computation cost.\u0000\u0000\u0000Practical implications\u0000The prediction of the reflow profile subjected to varied temperature settings of the reflow oven is beneficial to process engineers when reflowing bulky components. The study of reflowing a new PCB assembly can be started at the early stage of board design with no need for a physical profiling board prototype.\u0000\u0000\u0000Originality/value\u0000This study provides a smart solution to determine the optimal preset temperatures of the reflow oven, which is usually relied on experience. The hybrid physics–ML model providing accurate prediction with the significantly reduced expense is used in this application for the first time.\u0000","PeriodicalId":49499,"journal":{"name":"Soldering & Surface Mount Technology","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2022-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46428716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-26DOI: 10.1108/ssmt-05-2021-0018
Siang Miang Yeo, H. Yow, K. H. Yeoh
Purpose Semiconductor packaging industry has in recent years tightened the tolerance criteria for acceptable solder void size in the semiconductor packages due to the high usage in automotive applications. Semiconductor packaging component makers have strengthened the quality of the solder joint and its electrical conductivity by controlling the maximum solder void size reduction from 10-15% to 5% or below over die size. This paper aims to reduce the solder void size to minimum level that current industry could not achieve and introduce a new soldering processes by combining vacuum reflow and pressure cure to effectively reduce solder void. Design/methodology/approach This study is using the empirical data collection to prove the feasible in achieve the goal. It is an engineering approach. This research study is even considering sufficient data (>22 units) in each evaluation to represent the actual performance. Findings Successfully eliminate all the hollow solder void that current industry claimed as solder void. EDX analysis showed that the compressed solder voids remained in the solder are filled with solid carbon-based substances which could be originated from the trapped flux residues. It is empirical data proven in feasibility stage. Research limitations/implications The study is able to produce solder void-less. This method is suitable for high volume manufacturing process also. This may lead a new pave way for industry to resolve solder void problem. The current pressure cure machine could not apply more than 200°C temperature which limits medium and high temperature solder paste or alloy testing. Therefore, only low temperature solder alloy Pb37Sn63 was able to be evaluated. Originality/value This study is original and has not been published elsewhere to produce high efficiency product in semiconductor packaging performance in electrical path and heat dissipation. It also improves package reliability due to solder joint used as interconnect in semiconductor packaging.
{"title":"Solder void size reduction in semiconductor package by vacuum reflow and pressure cure processes","authors":"Siang Miang Yeo, H. Yow, K. H. Yeoh","doi":"10.1108/ssmt-05-2021-0018","DOIUrl":"https://doi.org/10.1108/ssmt-05-2021-0018","url":null,"abstract":"\u0000Purpose\u0000Semiconductor packaging industry has in recent years tightened the tolerance criteria for acceptable solder void size in the semiconductor packages due to the high usage in automotive applications. Semiconductor packaging component makers have strengthened the quality of the solder joint and its electrical conductivity by controlling the maximum solder void size reduction from 10-15% to 5% or below over die size. This paper aims to reduce the solder void size to minimum level that current industry could not achieve and introduce a new soldering processes by combining vacuum reflow and pressure cure to effectively reduce solder void.\u0000\u0000\u0000Design/methodology/approach\u0000This study is using the empirical data collection to prove the feasible in achieve the goal. It is an engineering approach. This research study is even considering sufficient data (>22 units) in each evaluation to represent the actual performance.\u0000\u0000\u0000Findings\u0000Successfully eliminate all the hollow solder void that current industry claimed as solder void. EDX analysis showed that the compressed solder voids remained in the solder are filled with solid carbon-based substances which could be originated from the trapped flux residues. It is empirical data proven in feasibility stage.\u0000\u0000\u0000Research limitations/implications\u0000The study is able to produce solder void-less. This method is suitable for high volume manufacturing process also. This may lead a new pave way for industry to resolve solder void problem. The current pressure cure machine could not apply more than 200°C temperature which limits medium and high temperature solder paste or alloy testing. Therefore, only low temperature solder alloy Pb37Sn63 was able to be evaluated.\u0000\u0000\u0000Originality/value\u0000This study is original and has not been published elsewhere to produce high efficiency product in semiconductor packaging performance in electrical path and heat dissipation. It also improves package reliability due to solder joint used as interconnect in semiconductor packaging.\u0000","PeriodicalId":49499,"journal":{"name":"Soldering & Surface Mount Technology","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2022-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49602485","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-14DOI: 10.1108/ssmt-07-2021-0043
Krzysztof Górecki, Przemysław Ptak, Barbara Dziurdzia
Purpose
This paper presents the results of the investigations of LED modules soldered with the use of different soldering pastes.
Design/methodology/approach
The tested power LED modules are soldered using different solder pastes and soldering processes. Thermal parameters of the performed modules are tested using indirect electrical methods. The results of measurements obtained for different modules are compared and discussed.
Findings
It was shown that the soldering process visibly influences the results of measurements of optical and thermal parameters of LED modules. For example, values of thermal resistance of these modules and the efficiency of conversion of electrical energy into light differ between each other even by 15%.
Practical implications
The obtained results of investigations can be usable for designers of the assembly process of power LED modules.
Originality/value
This paper shows the investigations results in the area of effective assembly of power LEDs to the metal core printed circuit board (MCPCB) using different soldering pastes (REL22, REL61, LMPA-Q6, OM-5100, OM-338-PT, M8, OM-340, CVP-390). It was shown that the best thermal and optical properties of these modules are obtained for the OM5100 paste by Alpha Assembly.
{"title":"Influence of the soldering paste type on optical and thermal parameters of LED modules","authors":"Krzysztof Górecki, Przemysław Ptak, Barbara Dziurdzia","doi":"10.1108/ssmt-07-2021-0043","DOIUrl":"https://doi.org/10.1108/ssmt-07-2021-0043","url":null,"abstract":"<h3>Purpose</h3>\u0000<p>This paper presents the results of the investigations of LED modules soldered with the use of different soldering pastes.</p><!--/ Abstract__block -->\u0000<h3>Design/methodology/approach</h3>\u0000<p>The tested power LED modules are soldered using different solder pastes and soldering processes. Thermal parameters of the performed modules are tested using indirect electrical methods. The results of measurements obtained for different modules are compared and discussed.</p><!--/ Abstract__block -->\u0000<h3>Findings</h3>\u0000<p>It was shown that the soldering process visibly influences the results of measurements of optical and thermal parameters of LED modules. For example, values of thermal resistance of these modules and the efficiency of conversion of electrical energy into light differ between each other even by 15%.</p><!--/ Abstract__block -->\u0000<h3>Practical implications</h3>\u0000<p>The obtained results of investigations can be usable for designers of the assembly process of power LED modules.</p><!--/ Abstract__block -->\u0000<h3>Originality/value</h3>\u0000<p>This paper shows the investigations results in the area of effective assembly of power LEDs to the metal core printed circuit board (MCPCB) using different soldering pastes (REL22, REL61, LMPA-Q6, OM-5100, OM-338-PT, M8, OM-340, CVP-390). It was shown that the best thermal and optical properties of these modules are obtained for the OM5100 paste by Alpha Assembly.</p><!--/ Abstract__block -->","PeriodicalId":49499,"journal":{"name":"Soldering & Surface Mount Technology","volume":"11 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2022-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138533809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-07DOI: 10.1108/ssmt-10-2021-0065
Madhuri Chandrashekhar Deshpande, Rajesh Chaudhari, Ramesh Narayanan, Harishwar Kale
Purpose
This study aims to develop indium-based solders for cryogenic applications.
Design/methodology/approach
This paper aims to investigate mechanical properties of indium-based solder formulations at room temperature (RT, 27 °C) as well as at cryogenic temperature (CT, −196 °C) and subsequently to find out their suitability for cryogenic applications. After developing these alloys, mechanical properties such as tensile and impact strength were measured as per American Society for Testing and Materials standards at RT and at CT. Charpy impact test results were used to find out ductile to brittle transition temperature (DBTT). These properties were also evaluated after thermal cycling (TC) to find out effect of thermal stress. Scanning electron microscope analysis was performed to understand fracture mechanism. Results indicate that amongst the solder alloys that have been studied in this work, In-34Bi solder alloy has the best all-round mechanical properties at RT, CT and after TC.
Findings
It can be concluded from the results of this work that In-34Bi solder alloy has best all-round mechanical properties at RT, CT and after TC and therefore is the most appropriate solder alloy amongst the alloys that have been studied in this work for cryogenic applications
Originality/value
DBTT of indium-based solder alloys has not been found out in the work done so far in this category. DBTT is necessary to decide safe working temperature range of the alloy. Also the effect of TC, which is one of the major reasons of failure, was not studied so far. These parameters are studied in this work.
{"title":"Study of mechanical properties of indium-based solder alloys for cryogenic applications","authors":"Madhuri Chandrashekhar Deshpande, Rajesh Chaudhari, Ramesh Narayanan, Harishwar Kale","doi":"10.1108/ssmt-10-2021-0065","DOIUrl":"https://doi.org/10.1108/ssmt-10-2021-0065","url":null,"abstract":"<h3>Purpose</h3>\u0000<p>This study aims to develop indium-based solders for cryogenic applications.</p><!--/ Abstract__block -->\u0000<h3>Design/methodology/approach</h3>\u0000<p>This paper aims to investigate mechanical properties of indium-based solder formulations at room temperature (RT, 27 °C) as well as at cryogenic temperature (CT, −196 °C) and subsequently to find out their suitability for cryogenic applications. After developing these alloys, mechanical properties such as tensile and impact strength were measured as per American Society for Testing and Materials standards at RT and at CT. Charpy impact test results were used to find out ductile to brittle transition temperature (DBTT). These properties were also evaluated after thermal cycling (TC) to find out effect of thermal stress. Scanning electron microscope analysis was performed to understand fracture mechanism. Results indicate that amongst the solder alloys that have been studied in this work, In-34Bi solder alloy has the best all-round mechanical properties at RT, CT and after TC.</p><!--/ Abstract__block -->\u0000<h3>Findings</h3>\u0000<p>It can be concluded from the results of this work that In-34Bi solder alloy has best all-round mechanical properties at RT, CT and after TC and therefore is the most appropriate solder alloy amongst the alloys that have been studied in this work for cryogenic applications</p><!--/ Abstract__block -->\u0000<h3>Originality/value</h3>\u0000<p>DBTT of indium-based solder alloys has not been found out in the work done so far in this category. DBTT is necessary to decide safe working temperature range of the alloy. Also the effect of TC, which is one of the major reasons of failure, was not studied so far. These parameters are studied in this work.</p><!--/ Abstract__block -->","PeriodicalId":49499,"journal":{"name":"Soldering & Surface Mount Technology","volume":"116 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2022-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138533819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-03DOI: 10.1108/ssmt-06-2021-0039
Dániel Straubinger, A. Tóth, Viktor Kerek, Zsolt Czeczei, A. Szabó, A. Géczy
Purpose The purpose of this paper is to study the solder beading phenomenon (referring to larger-sized solder balls) of surface-mounted electrolytic capacitors. Solder beading could induce failures by violating the minimal electrical clearance on the printed circuit board (PCB). In modern lead-free reflow soldering, especially in high-reliability industries, such as automotive, aeroplane and aerospace, detecting and preventing such defects is essential in reliable and cost-effective manufacturing. Design/methodology/approach The large size of the involved components may block the view of automatic optical inspection; therefore, X-ray inspection is necessary. To detect the failure mode, X-ray imaging, cross-section grinding, optical microscopy and Fourier transformed infrared spectroscopy were used. High-resolution noncontact profilometry and optical microscopy were used to analyse component designs. The surface mounting process steps were also analysed to reveal their dependence on the issue. Test methods were designed and performed to reveal the behaviour of the solder paste (SP) during the reflow soldering process and to emphasise the component design relevance. Findings It was found that the reduction of SP volume only reduces the failure rate but does not solve the problem. Results show that excessive component placement pressure could induce solder beading. Statistical analysis revealed that differences between distinct components had the highest effect on the solder beading rate. Design aspects of solder beading-prone components were identified and discussed as the primary source of the problem. Practical implications The findings can be applied in surface-mount technology production, where the total failure count and resulting failure costs could be reduced according to the findings. Originality/value This paper shows that component design aspects such as the low distance between the underside of the component and the PCB and blocked proper outgassing of volatile compounds of the SP can be root causes of solder beading under surface-mounted electrolytic capacitors.
{"title":"Investigation of solder beading phenomenon under surface-mounted electrolytic capacitors","authors":"Dániel Straubinger, A. Tóth, Viktor Kerek, Zsolt Czeczei, A. Szabó, A. Géczy","doi":"10.1108/ssmt-06-2021-0039","DOIUrl":"https://doi.org/10.1108/ssmt-06-2021-0039","url":null,"abstract":"\u0000Purpose\u0000The purpose of this paper is to study the solder beading phenomenon (referring to larger-sized solder balls) of surface-mounted electrolytic capacitors. Solder beading could induce failures by violating the minimal electrical clearance on the printed circuit board (PCB). In modern lead-free reflow soldering, especially in high-reliability industries, such as automotive, aeroplane and aerospace, detecting and preventing such defects is essential in reliable and cost-effective manufacturing.\u0000\u0000\u0000Design/methodology/approach\u0000The large size of the involved components may block the view of automatic optical inspection; therefore, X-ray inspection is necessary. To detect the failure mode, X-ray imaging, cross-section grinding, optical microscopy and Fourier transformed infrared spectroscopy were used. High-resolution noncontact profilometry and optical microscopy were used to analyse component designs. The surface mounting process steps were also analysed to reveal their dependence on the issue. Test methods were designed and performed to reveal the behaviour of the solder paste (SP) during the reflow soldering process and to emphasise the component design relevance.\u0000\u0000\u0000Findings\u0000It was found that the reduction of SP volume only reduces the failure rate but does not solve the problem. Results show that excessive component placement pressure could induce solder beading. Statistical analysis revealed that differences between distinct components had the highest effect on the solder beading rate. Design aspects of solder beading-prone components were identified and discussed as the primary source of the problem.\u0000\u0000\u0000Practical implications\u0000The findings can be applied in surface-mount technology production, where the total failure count and resulting failure costs could be reduced according to the findings.\u0000\u0000\u0000Originality/value\u0000This paper shows that component design aspects such as the low distance between the underside of the component and the PCB and blocked proper outgassing of volatile compounds of the SP can be root causes of solder beading under surface-mounted electrolytic capacitors.\u0000","PeriodicalId":49499,"journal":{"name":"Soldering & Surface Mount Technology","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2022-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45018729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-15DOI: 10.1108/ssmt-08-2021-0055
Fei Chong Ng, A. Abas, M. N. Nashrudin, M. Y. Tura Ali
Purpose This paper aims to study the filling progression of underfill flow and void formation during the flip-chip encapsulation process. Design/methodology/approach A new parameter of filling progression that relates volume fraction filled to filling displacement was formulated analytically. Another indicative parameter of filling efficiency was also introduced to quantify the voiding fraction in filling progression. Additionally, the underfill process on different flip-chips based on the past experiments was numerically simulated. Findings All findings were well-validated with reference to the past experimental results, in terms of quantitative filling progression and qualitative flow profiles. The volume fraction filled increases monotonically with the filling displacement and thus the filling time. As the underfill fluid advances, the size of the void decreases while the filling efficiency increases. Furthermore, the void formed during the underfilling flow stage was caused by the accelerated contact line jump at the bump entrance. Practical implications The filling progression enabled manufacturers to forecast the underfill flow front, as it advances through the flip-chip. Moreover, filling progression and filling efficiency could provide quantitative insights for the determination of void formations at any filling stages. The voiding formation mechanism enables the prompt formulation of countermeasures. Originality/value Both the filling progression and filling efficiency are new indicative parameters in quantifying the performance of the filling process while considering the reliability defects such as incomplete filling and voiding.
{"title":"Analytical and numerical analyses of filling progression and void formation in flip-chip underfill encapsulation process","authors":"Fei Chong Ng, A. Abas, M. N. Nashrudin, M. Y. Tura Ali","doi":"10.1108/ssmt-08-2021-0055","DOIUrl":"https://doi.org/10.1108/ssmt-08-2021-0055","url":null,"abstract":"\u0000Purpose\u0000This paper aims to study the filling progression of underfill flow and void formation during the flip-chip encapsulation process.\u0000\u0000\u0000Design/methodology/approach\u0000A new parameter of filling progression that relates volume fraction filled to filling displacement was formulated analytically. Another indicative parameter of filling efficiency was also introduced to quantify the voiding fraction in filling progression. Additionally, the underfill process on different flip-chips based on the past experiments was numerically simulated.\u0000\u0000\u0000Findings\u0000All findings were well-validated with reference to the past experimental results, in terms of quantitative filling progression and qualitative flow profiles. The volume fraction filled increases monotonically with the filling displacement and thus the filling time. As the underfill fluid advances, the size of the void decreases while the filling efficiency increases. Furthermore, the void formed during the underfilling flow stage was caused by the accelerated contact line jump at the bump entrance.\u0000\u0000\u0000Practical implications\u0000The filling progression enabled manufacturers to forecast the underfill flow front, as it advances through the flip-chip. Moreover, filling progression and filling efficiency could provide quantitative insights for the determination of void formations at any filling stages. The voiding formation mechanism enables the prompt formulation of countermeasures.\u0000\u0000\u0000Originality/value\u0000Both the filling progression and filling efficiency are new indicative parameters in quantifying the performance of the filling process while considering the reliability defects such as incomplete filling and voiding.\u0000","PeriodicalId":49499,"journal":{"name":"Soldering & Surface Mount Technology","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2021-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43246093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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