The Experts below are selected from a list of 477 Experts worldwide ranked by ideXlab platform
Zhen-guo Yang - One of the best experts on this subject based on the ideXlab platform.
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Preparation and characterization of printable Solder Resist inks based on hyperbranched polyester
Journal of Applied Polymer Science, 2014Co-Authors: Chao Yang, Yu Chang, Zhen-guo YangAbstract:Two novel Solder Resist inks containing hyperbranched epoxy resin (HBPE) for thermal curing and hyperbranched epoxy acrylate resin (HBPEA) for UV-curing were introduced in this work. Different generations of HBPE and HBPEA were synthesized and their chemical structures were determined by FT-IR. Both curing reactions were monitored under differential scanning calorimetry (DSC) and photo-DSC. For HBPE, the curing temperature of 7th generation was only 91°C and for HBPEA, the curing duration of 7th generation was under 10 s. The thermal stabilities of cured resins were much more stable than linear resin, as the decomposition temperatures of HBPE and HBPEA were both over 400°C. The ink containing HBPE or HBPEA jetted by piezoelectric printer showed excellent accuracy and consistency of linewidth and the morphologies of cured pattern were observed through a stereo microscope. Other performances of Solder masks were tested under China Printed Circuit Association (CPCA) standard (CPCA/JPCA 4306-2011), which satisfy all requirements of printed circuit board Soldering procedure. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41805.
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synthesis of low viscosity fast uv curing Solder Resist based on epoxy resin for ink jet printing
Journal of Applied Polymer Science, 2013Co-Authors: Chao Yang, Zhen-guo YangAbstract:A novel photosensitive low viscosity epoxy resin was synthesized by polyethylene glycol (PEG)-modified bisphenol-A epoxy resin (E51). The resin was modified by ethylene glycol, diethylene glycol, and different molecule weights (200,300,400) PEGs to optimize the minimum viscosity. FTIR was used to determine molecule structure. Cationic photoinitiator (UVI-6976) mixed with modified resin (10 wt %), was utilized to boost the resin curing under UV light. The curing degree was beyond 90% within 40 s and the whole process was monitored by photo-DSC. The modified resin diluted with ethylene glycol diglycidyl ether, was screen printed onto polyimide and polyethylene terephthalate substrate, and the properties of Solder mask were up to China printed circuit association standard. The Solder Resist also meet all requirements under ink-jet printing technology as the viscosity is under 60 mPa·s and the curing duration is <1 min. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
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Synthesis of low viscosity, fast UV curing Solder Resist based on epoxy resin for ink‐jet printing
Journal of Applied Polymer Science, 2012Co-Authors: Chao Yang, Zhen-guo YangAbstract:A novel photosensitive low viscosity epoxy resin was synthesized by polyethylene glycol (PEG)-modified bisphenol-A epoxy resin (E51). The resin was modified by ethylene glycol, diethylene glycol, and different molecule weights (200,300,400) PEGs to optimize the minimum viscosity. FTIR was used to determine molecule structure. Cationic photoinitiator (UVI-6976) mixed with modified resin (10 wt %), was utilized to boost the resin curing under UV light. The curing degree was beyond 90% within 40 s and the whole process was monitored by photo-DSC. The modified resin diluted with ethylene glycol diglycidyl ether, was screen printed onto polyimide and polyethylene terephthalate substrate, and the properties of Solder mask were up to China printed circuit association standard. The Solder Resist also meet all requirements under ink-jet printing technology as the viscosity is under 60 mPa·s and the curing duration is
Chao Yang - One of the best experts on this subject based on the ideXlab platform.
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Preparation and characterization of printable Solder Resist inks based on hyperbranched polyester
Journal of Applied Polymer Science, 2014Co-Authors: Chao Yang, Yu Chang, Zhen-guo YangAbstract:Two novel Solder Resist inks containing hyperbranched epoxy resin (HBPE) for thermal curing and hyperbranched epoxy acrylate resin (HBPEA) for UV-curing were introduced in this work. Different generations of HBPE and HBPEA were synthesized and their chemical structures were determined by FT-IR. Both curing reactions were monitored under differential scanning calorimetry (DSC) and photo-DSC. For HBPE, the curing temperature of 7th generation was only 91°C and for HBPEA, the curing duration of 7th generation was under 10 s. The thermal stabilities of cured resins were much more stable than linear resin, as the decomposition temperatures of HBPE and HBPEA were both over 400°C. The ink containing HBPE or HBPEA jetted by piezoelectric printer showed excellent accuracy and consistency of linewidth and the morphologies of cured pattern were observed through a stereo microscope. Other performances of Solder masks were tested under China Printed Circuit Association (CPCA) standard (CPCA/JPCA 4306-2011), which satisfy all requirements of printed circuit board Soldering procedure. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41805.
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synthesis of low viscosity fast uv curing Solder Resist based on epoxy resin for ink jet printing
Journal of Applied Polymer Science, 2013Co-Authors: Chao Yang, Zhen-guo YangAbstract:A novel photosensitive low viscosity epoxy resin was synthesized by polyethylene glycol (PEG)-modified bisphenol-A epoxy resin (E51). The resin was modified by ethylene glycol, diethylene glycol, and different molecule weights (200,300,400) PEGs to optimize the minimum viscosity. FTIR was used to determine molecule structure. Cationic photoinitiator (UVI-6976) mixed with modified resin (10 wt %), was utilized to boost the resin curing under UV light. The curing degree was beyond 90% within 40 s and the whole process was monitored by photo-DSC. The modified resin diluted with ethylene glycol diglycidyl ether, was screen printed onto polyimide and polyethylene terephthalate substrate, and the properties of Solder mask were up to China printed circuit association standard. The Solder Resist also meet all requirements under ink-jet printing technology as the viscosity is under 60 mPa·s and the curing duration is <1 min. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
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Synthesis of low viscosity, fast UV curing Solder Resist based on epoxy resin for ink‐jet printing
Journal of Applied Polymer Science, 2012Co-Authors: Chao Yang, Zhen-guo YangAbstract:A novel photosensitive low viscosity epoxy resin was synthesized by polyethylene glycol (PEG)-modified bisphenol-A epoxy resin (E51). The resin was modified by ethylene glycol, diethylene glycol, and different molecule weights (200,300,400) PEGs to optimize the minimum viscosity. FTIR was used to determine molecule structure. Cationic photoinitiator (UVI-6976) mixed with modified resin (10 wt %), was utilized to boost the resin curing under UV light. The curing degree was beyond 90% within 40 s and the whole process was monitored by photo-DSC. The modified resin diluted with ethylene glycol diglycidyl ether, was screen printed onto polyimide and polyethylene terephthalate substrate, and the properties of Solder mask were up to China printed circuit association standard. The Solder Resist also meet all requirements under ink-jet printing technology as the viscosity is under 60 mPa·s and the curing duration is
Dongok Kwak - One of the best experts on this subject based on the ideXlab platform.
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Bi-directional homogenization equivalent modeling for the prediction of thermo-mechanical properties of a multi-layered printed circuit board (PCB)
Journal of Micromechanics and Microengineering, 2016Co-Authors: Sung-jun Joo, Dongok Kwak, Do-hyoung Kim, Buhm Park, Junhong Park, Hak-sung KimAbstract:Warpage of multi-layered printed circuit boards (PCB) during the reflow process is a serious problem which affects the reliability of Solder ball connections between the PCB and the mounted semi-conductor packages in electronic devices. It is essential to predict the warpage of the PCB accurately; however, the complicated copper patterns in multi-layered PCBs render a full modeling analysis impossible due to the excessive computing time required. To overcome this problem, we have developed analytical equations of three Cu patterns (line, square, and grid) for the application of thermo-mechanical properties simply by equivalent modeling of Cu patterns. In the proposed equations, the effect of thermo-viscoelastic properties as well as the influence of surrounding layers such as woven glass fabric/BT (bismaleimide triazine), composite laminate (BT core), and photoimageable Solder Resist (PSR) were considered. To verify the developed equations, vibration tests based on the wave propagation approach were performed at various temperatures. Good agreement was observed between the equivalent model and the experimental results.
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anisotropic viscoelastic shell modeling technique of copper patterns photoimageable Solder Resist composite for warpage simulation of multi layer printed circuit boards
Journal of Micromechanics and Microengineering, 2015Co-Authors: Dongok KwakAbstract:In this study, the warpage simulation of a multi-layer printed circuit board (PCB) was performed as a function of various copper (Cu) patterns/photoimageable Solder Resist (PSR) composite patterns and their anisotropic viscoelastic properties. The thermo-mechanical properties of Cu/PSR patterns were obtained from finite element analysis (virtual test) and homogenized with anisotropic composite shell models that considered the viscoelastic properties. The multi-layer PCB model was simplified based on the unit Cu/PSR patterns and the warpage simulation during the reflow process was performed by using ABAQUS combined with a user-defined subroutine. From these results, it was demonstrated that the proposed anisotropic viscoelastic composite shell simulation technique can be successfully used to predict warpage of multi-layer PCBs during the reflow process.
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Anisotropic viscoelastic shell modeling technique of copper patterns/photoimageable Solder Resist composite for warpage simulation of multi-layer printed circuit boards
Journal of Micromechanics and Microengineering, 2015Co-Authors: Do-hyoung Kim, Dongok Kwak, Sung-jun Joo, Hak-sung KimAbstract:In this study, the warpage simulation of a multi-layer printed circuit board (PCB) was performed as a function of various copper (Cu) patterns/photoimageable Solder Resist (PSR) composite patterns and their anisotropic viscoelastic properties. The thermo-mechanical properties of Cu/PSR patterns were obtained from finite element analysis (virtual test) and homogenized with anisotropic composite shell models that considered the viscoelastic properties. The multi-layer PCB model was simplified based on the unit Cu/PSR patterns and the warpage simulation during the reflow process was performed by using ABAQUS combined with a user-defined subroutine. From these results, it was demonstrated that the proposed anisotropic viscoelastic composite shell simulation technique can be successfully used to predict warpage of multi-layer PCBs during the reflow process.
Hak-sung Kim - One of the best experts on this subject based on the ideXlab platform.
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Bi-directional homogenization equivalent modeling for the prediction of thermo-mechanical properties of a multi-layered printed circuit board (PCB)
Journal of Micromechanics and Microengineering, 2016Co-Authors: Sung-jun Joo, Dongok Kwak, Do-hyoung Kim, Buhm Park, Junhong Park, Hak-sung KimAbstract:Warpage of multi-layered printed circuit boards (PCB) during the reflow process is a serious problem which affects the reliability of Solder ball connections between the PCB and the mounted semi-conductor packages in electronic devices. It is essential to predict the warpage of the PCB accurately; however, the complicated copper patterns in multi-layered PCBs render a full modeling analysis impossible due to the excessive computing time required. To overcome this problem, we have developed analytical equations of three Cu patterns (line, square, and grid) for the application of thermo-mechanical properties simply by equivalent modeling of Cu patterns. In the proposed equations, the effect of thermo-viscoelastic properties as well as the influence of surrounding layers such as woven glass fabric/BT (bismaleimide triazine), composite laminate (BT core), and photoimageable Solder Resist (PSR) were considered. To verify the developed equations, vibration tests based on the wave propagation approach were performed at various temperatures. Good agreement was observed between the equivalent model and the experimental results.
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Anisotropic viscoelastic shell modeling technique of copper patterns/photoimageable Solder Resist composite for warpage simulation of multi-layer printed circuit boards
Journal of Micromechanics and Microengineering, 2015Co-Authors: Do-hyoung Kim, Dongok Kwak, Sung-jun Joo, Hak-sung KimAbstract:In this study, the warpage simulation of a multi-layer printed circuit board (PCB) was performed as a function of various copper (Cu) patterns/photoimageable Solder Resist (PSR) composite patterns and their anisotropic viscoelastic properties. The thermo-mechanical properties of Cu/PSR patterns were obtained from finite element analysis (virtual test) and homogenized with anisotropic composite shell models that considered the viscoelastic properties. The multi-layer PCB model was simplified based on the unit Cu/PSR patterns and the warpage simulation during the reflow process was performed by using ABAQUS combined with a user-defined subroutine. From these results, it was demonstrated that the proposed anisotropic viscoelastic composite shell simulation technique can be successfully used to predict warpage of multi-layer PCBs during the reflow process.
J.l. Jarvis - One of the best experts on this subject based on the ideXlab platform.
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Failure analysis and stress simulation in small multichip BGAs
2000 IEEE International Reliability Physics Symposium Proceedings. 38th Annual (Cat. No.00CH37059), 1Co-Authors: T. Moore, J.l. JarvisAbstract:This paper examines one of the common modes of structural failure in multichip BGAs, determines its locations within the package structure, relates it to the stresses generated in the reliability tests under which it occurs, and by Finite Element simulations, determines an explanation for the failure, and finally proposes a method to avoid this failure mechanism. Several designs of multichip BGA substrates were manufactured and production silicon assembled into them. These were all 14/spl times/22 mm 119 ball PBGA. These were subjected to a set of package reliability tests, until some units failed electrical test. The failed units were analysed and the physical location and shape of the failure was determined in many cases. From this information, the mechanical mode of failure for each unit was determined. In addition there was sufficient information in some of the analyses to provide definite suggestions as to the mechanism of failure. Meanwhile, Finite Element Analysis was performed using simplified representations of the multichip BGAs, in order to find the locations of highest stress, and the expected modes of failure. This data was matched to the failure modes found in the physical analysis. Some novel failure analysis techniques were used to expose the damage in the failed units. A particular failure mode occurred frequently in temperature cycle, and the sites of failure were located by failure analysis. The failure was due to open circuit in the copper tracks in the top layer of the substrate caused by cracking in the Solder Resist directly underneath the edge of the die attach fillet. Finite element analysis was carried out and the location of the actual failures was found to be a local zone of high tensile stress in the Solder Resist.