Mohamad Firdaus Rosle - Academia.edu (original) (raw)
Papers by Mohamad Firdaus Rosle
This study focuses towards typical micromechanical properties such as strength, yield point, Youn... more This study focuses towards typical micromechanical properties such as strength, yield point, Young's Modulus, strain, shapes of fracture end and element analysis, atomic percentage of Ca of 4N gold (Au) wire using microstructures and composition observation, micro-tensile test and depth sensing indentation technique. A series of micro-tensile test were performed with different strain rate values of 10˚-10-4 min-1 on to a 25.4 µm diameter plain gold wire. The nanoindentation with 20 mN maximum load was indented on a near fracture end of a gold wire specimen, for which this test was carried out after the microtensile test. The stress-strain curves were used to characterize the 4N purity gold wire. The shapes of fracture end of gold wire after micro tensile test were carried out using Scanning Electron Microscopic (SEM). The finding showed that the mechanical properties of ultra-fine gold wire was in the proportional relationship with the increment of the strain rate value. It is suggested that micromechanical behaviour gave the effect for the wirebonding process in order to characterize the wire loop control and strengthen the wire loop to avoid the wire sweep.
Key Engineering Materials, 2011
In the last decade, failure of microelectronic devices has become a prominent field of research a... more In the last decade, failure of microelectronic devices has become a prominent field of research all across the world. The results of this of failure analysis allow an engineer to choose package geometries and materials which reduce the risk of failure. This paper is meant to relate the stress effect on material properties during Quad Flat No-Leads (QFN) stacked-die packages manufacturing processes. To achieve the study, the finite element technique was used to perform an extensive structural analysis on a QFN package design once it was verified by related experiments. A QFN unit was developed in three dimensional geometry with various materials be will simulated in order to determine the location of failure. The induced stress results were also measured in the maximum value, indicating the low modulus and coefficient of thermal expansion (CTE) in the packaging material were important for reducing high stress during the manufacturing stages. However, numerical simulation demonstrated...
Wire chemistry and bonding conditions are found to affect the Au-Al intermetallic compounds forma... more Wire chemistry and bonding conditions are found to affect the Au-Al intermetallic compounds formation and growth. Bonding achieved when these two metals come into intimate contact between each other by interactions of ultrasonic energy, force, temperature and time. Inter diffusion of the joining metals at the interface activated the formation of stoichiometric intermetallic. This paper investigates the effects of bonding parameter match (ultrasonic level and force) on the growth behaviours of gold aluminide compound during thermal aging. Samples were built with different combination of ultrasonic level and force for high temperature storage (HTS) test at certain elevated temperature and time. Measurements for bonded ball mechanical strength and observations on intermetallic compounds growth patterns were carried out. Discussions on these phenomena were based on the physical, thermal and atomic properties of the bonding elements. It is suggested that un-optimised ultrasonic level and...
Materials Today: Proceedings, 2019
This study focuses towards typical micromechanical properties such as strength, yield point, Youn... more This study focuses towards typical micromechanical properties such as strength, yield point, Young's Modulus, strain, shapes of fracture end and element analysis, atomic percentage of Ca of 4N gold (Au) wire using microstructures and composition observation, micro-tensile test and depth sensing indentation technique. A series of micro-tensile test were performed with different strain rate values of 10˚-10-4 min-1 on to a 25.4 µm diameter plain gold wire. The nanoindentation with 20 mN maximum load was indented on a near fracture end of a gold wire specimen, for which this test was carried out after the microtensile test. The stress-strain curves were used to characterize the 4N purity gold wire. The shapes of fracture end of gold wire after micro tensile test were carried out using Scanning Electron Microscopic (SEM). The finding showed that the mechanical properties of ultra-fine gold wire was in the proportional relationship with the increment of the strain rate value. It is suggested that micromechanical behaviour gave the effect for the wirebonding process in order to characterize the wire loop control and strengthen the wire loop to avoid the wire sweep.
American Journal of Engineering and Applied Sciences, 2009
Problem statement: Repeated heat cure during assembly processes affected the Die Attach Film (DAF... more Problem statement: Repeated heat cure during assembly processes affected the Die Attach Film (DAF) material properties and the effectiveness touched area that leads to weak die bonding and delamination. Suitable die attached condition and DAF material selection had been evaluated to achieve required reliability performance in the manufacturing of the 3D Quad Flat No-Lead (QFN) stacked die package. Approach: During this study, special attention was given to the development of the residual stresses due to mismatch in the coefficients of thermal expansion of different DAF materials. Both experimental and finite element method were employed to gain a better understanding in a stress development induced between two different type of DAF, different die attach temperature and during the manufacturing process. Differential scanning calorimetry (DSC) was used to measure the changes of heat flow characteristics for both types of DAF. The die bond strength results measured using shear testing machine were compared with the finite element method prediction. Results: Although both DAF samples achieved good reliability performance and passed the Moisture Sensitivity Level 3 test (MSL3) at reflow 260°C without any sign of delamination, numerical simulation had demonstrated that the stress development were increased exponentially as the die attach temperature increased. It showed that different DAF gave different values of stresses but presented the same trend which the lowest die attached temperature (100°C in comparison with 125°C and 150°C) gave more stress to the die and possibility that the die will have weak adhesion to the substrate was high. Conclusions/Recommendations: Therefore for this case, stress can be relieved by having higher die attached temperature with an adequate bonding force and time, however die attached temperature for both DAF must be used above the glass transition temperature (128°C for DAF A and 165°C for DAF B) and being controlled not to exceed the crystallization temperature (203°C for DAF A and 204°C for DAF B) of both DAF.
Key Engineering Materials, 2011
In the last decade, failure of microelectronic devices has become a prominent field of research a... more In the last decade, failure of microelectronic devices has become a prominent field of research all across the world. The results of this of failure analysis allow an engineer to choose package geometries and materials which reduce the risk of failure. This paper is meant to relate the stress effect on material properties during Quad Flat No-Leads (QFN) stacked-die packages manufacturing processes. To achieve the study, the finite element technique was used to perform an extensive structural analysis on a QFN package design once it was verified by related experiments. A QFN unit was developed in three dimensional geometry with various materials be will simulated in order to determine the location of failure. The induced stress results were also measured in the maximum value, indicating the low modulus and coefficient of thermal expansion (CTE) in the packaging material were important for reducing high stress during the manufacturing stages. However, numerical simulation demonstrated...
There are several issues related to the mechanical and electrical wirebond failure during wirebon... more There are several issues related to the mechanical and electrical wirebond failure during wirebonding process. Major factors are associated with AuAl intermetallic system. AuAl intermetallic compounds (IMC) can easily form at room temperature and can be accelerated with the elevated temperature. In this paper, pattern of intermetallic compounds growth and potential degradation due to voids in thermosonic ball bonding were studied on AuAl intermetallic compounds. The thermosonic ball bonding process used 99.99% gold wire and aluminized pad of Si chip. Results after HTS at 150ºC for 500 hours demonstrated that voids were generated around the diffusion layer because of the Kirkendall effect and severe voids was clearly exhibited after thermal aging at 150ºC for 1000 hours. Prolong aging time can lead to bonding failure associate with Kirkendall voids.
2007 9th Electronics Packaging Technology Conference, 2007
The trend in the semiconductor industry is to develop more powerful components while decreasing t... more The trend in the semiconductor industry is to develop more powerful components while decreasing the component size. A suitable material set has to be obtained for the required reliability performance. The objective of this study is to evaluate the performance of different die attach film (DAF) and epoxy pastes for stacked die Quad Flat No-lead package. Both experimental and modeling works are resorted to analyze and refine the package design. Six combinations of die attach materials are evaluated to compare with current single die package. The strengths and weaknesses of the DAF and epoxy paste are compared in this paper. Die shear test is performed to study the adhesion condition between the die attach material and silicon die. Finite element model of the package is generated to determine the thermally induced stresses under different conditions. All the results show that it is robust to use the new epoxy paste and DAF.
Materials Today: Proceedings, 2019
Wire chemistry and bonding conditions are found to affect the Au-Al intermetallic compounds forma... more Wire chemistry and bonding conditions are found to affect the Au-Al intermetallic compounds formation and growth. Bonding achieved when these two metals come into intimate contact between each other by interactions of ultrasonic energy, force, temperature and time. Inter diffusion of the joining metals at the interface activated the formation of stoichiometric intermetallic. This paper investigates the effects of bonding parameter match (ultrasonic level and force) on the growth behaviours of gold aluminide compound during thermal aging. Samples were built with different combination of ultrasonic level and force for high temperature storage (HTS) test at certain elevated temperature and time. Measurements for bonded ball mechanical strength and observations on intermetallic compounds growth patterns were carried out. Discussions on these phenomena were based on the physical, thermal and atomic properties of the bonding elements. It is suggested that un-optimised ultrasonic level and...
Intermetallic formation between gold wire and Al pad is well documented to represent mechanical s... more Intermetallic formation between gold wire and Al pad is well documented to represent mechanical strength of ballbond. Bonding achieved when these two metals come into intimate contact between each other by interactions of ultrasonic energy, force, temperature and time. Under elevated temperature and time, theoretically the intermetallic phase can thicken and growth due reactive diffusion activated by temperature. This paper presents effects on ultrasonic energy and force to the intermetallic growth patterns for gold wire with 99% composition of Au. Samples were prepared by different variables of ultrasonic energy and force with constants bonding temperature at 240°C. Investigation was carried out by baking the samples in the high thermal storage (HTS) chamber at 175 °C. Measurements for ballbond mechanical strength and observations on intermetallic growth patterns were carried out using ball shear and ball pull tester, optical microscope and scanning electron microscope (SEM). The r...
There are several issues related to the mechanical and electrical wirebond failure during wirebon... more There are several issues related to the mechanical and electrical wirebond failure during wirebonding process. Major factors are associated with AuAl intermetallic system. AuAl intermetallic compounds (IMC) can easily form at room temperature and can be accelerated with the elevated temperature. In this paper, pattern of intermetallic compounds growth and potential degradation due to voids in thermosonic ball bonding were studied on AuAl intermetallic compounds. The thermosonic ball bonding process used 99.99% gold wire and aluminized pad of Si chip. Results after HTS at 150ºC for 500 hours demonstrated that voids were generated around the diffusion layer because of the Kirkendall effect and severe voids was clearly exhibited after thermal aging at 150ºC for 1000 hours. Prolong aging time can lead to bonding failure associate with Kirkendall voids.
Intermetallic formation between gold wire and Al pad is well documented to represent mechanical s... more Intermetallic formation between gold wire and Al pad is well documented to represent mechanical strength of ballbond. Bonding achieved when these two metals come into intimate contact between each other by interactions of ultrasonic energy, force, temperature and time. Under elevated temperature and time, theoretically the intermetallic phase can thicken and growth due reactive diffusion activated by temperature. This paper presents effects on ultrasonic energy and force to the intermetallic growth patterns for gold wire with 99% composition of Au. Samples were prepared by different variables of ultrasonic energy and force with constants bonding temperature at 240°C. Investigation was carried out by baking the samples in the high thermal storage (HTS) chamber at 175 °C. Measurements for ballbond mechanical strength and observations on intermetallic growth patterns were carried out using ball shear and ball pull tester, optical microscope and scanning electron microscope (SEM). The r...
Advanced Materials Research, 2012
Dye sensitized solar cell (DSSC) is a new class of low-cost solar cell, that belongs to third gen... more Dye sensitized solar cell (DSSC) is a new class of low-cost solar cell, that belongs to third generation solar cells in thin film based. It is based on a semiconductor formed between a photo-sensitized anode and an electrolyte, known as photoelectrochemical system. A lot of research has been conducted due to their interesting potential for low-cost, lightweight, disposable and having cell efficiency up to 10%. This paper reports the fabrication of dye sensitized solar cells using TiO2 nanoparticles and chlorophyll as active layer. TiO2 nanoparticles were prepared by sol-gel method while the chlorophyll was extracted from Pandanus amaryllifolius (Pandan leaf). TiO2 film was prepared on ITO coated glass using dip coating technique and then immersed overnight in the chlorophyll solution. An electrolyte solution composed of PC-LiClO4 was injected into the cell before sealed using glass that was coated with Pt as top electrode. An active area of 4.48 cm2 was fabricated by black masking t...
Journal of Electronic Packaging, 2010
Relatively little information is available on the growth patterns of gold aluminide compound in a... more Relatively little information is available on the growth patterns of gold aluminide compound in accurate 3D measurement as compared with 2D images of the projected surface. A 3D surface imaging technique by using infinite focus microscope (IFM) was proposed in this study to observe and explain the effects of bonding parameters on growth pattern of gold aluminide compound formed between a 25.48 μm 4N gold wire and an aluminum pad metallization. Two bonding factors, which were varied, were ball bonding force and ultrasonic current while bonding time and temperature were kept constant. The 3D surface measurement provides topographical and color information of the bonded region, which indicates that optimum bonding condition has a significant effect on uniform growth and wide coverage area of gold aluminide compound. Results illustrated by this technique were used as additional information to the results produce by the conventional methods such as cross section optical image and scannin...
wseas.us
Consumer demand for smaller and lighter products in wiresless application with maximum functional... more Consumer demand for smaller and lighter products in wiresless application with maximum functionality had drive the semiconductor industries toward the developement of 3-dimensional stacked die. One of the key technology is relies on die stacking process. A suitable bonding condition and material set are essential to achieve required reliability performance. This study is to relate the effects of variables bonding parameter on the mechanical adhesion and delamination of the die attach film in QFN stacked die. Samples are deliberately built with nine combination sets of die attach parameters including bonding temperature, force and time to achieve a minimum reliability performance under IPC/JEDEC Moisture Sensitivity Level 3 at reflow 260°C. Characterisation of die attach film was carried out using differential scanning calorimetry whereas it performance was carried out using shear testing machine and scanning acoustic test (SAT) is used to detect the interfacial delamination between DAF and die. The best die attach process is characterized by stable values of die attach film thermal resistance properties and optimum touch area between die/die attach film and die attach film/die.
This study focuses towards typical micromechanical properties such as strength, yield point, Youn... more This study focuses towards typical micromechanical properties such as strength, yield point, Young's Modulus, strain, shapes of fracture end and element analysis, atomic percentage of Ca of 4N gold (Au) wire using microstructures and composition observation, micro-tensile test and depth sensing indentation technique. A series of micro-tensile test were performed with different strain rate values of 10˚-10-4 min-1 on to a 25.4 µm diameter plain gold wire. The nanoindentation with 20 mN maximum load was indented on a near fracture end of a gold wire specimen, for which this test was carried out after the microtensile test. The stress-strain curves were used to characterize the 4N purity gold wire. The shapes of fracture end of gold wire after micro tensile test were carried out using Scanning Electron Microscopic (SEM). The finding showed that the mechanical properties of ultra-fine gold wire was in the proportional relationship with the increment of the strain rate value. It is suggested that micromechanical behaviour gave the effect for the wirebonding process in order to characterize the wire loop control and strengthen the wire loop to avoid the wire sweep.
Key Engineering Materials, 2011
In the last decade, failure of microelectronic devices has become a prominent field of research a... more In the last decade, failure of microelectronic devices has become a prominent field of research all across the world. The results of this of failure analysis allow an engineer to choose package geometries and materials which reduce the risk of failure. This paper is meant to relate the stress effect on material properties during Quad Flat No-Leads (QFN) stacked-die packages manufacturing processes. To achieve the study, the finite element technique was used to perform an extensive structural analysis on a QFN package design once it was verified by related experiments. A QFN unit was developed in three dimensional geometry with various materials be will simulated in order to determine the location of failure. The induced stress results were also measured in the maximum value, indicating the low modulus and coefficient of thermal expansion (CTE) in the packaging material were important for reducing high stress during the manufacturing stages. However, numerical simulation demonstrated...
Wire chemistry and bonding conditions are found to affect the Au-Al intermetallic compounds forma... more Wire chemistry and bonding conditions are found to affect the Au-Al intermetallic compounds formation and growth. Bonding achieved when these two metals come into intimate contact between each other by interactions of ultrasonic energy, force, temperature and time. Inter diffusion of the joining metals at the interface activated the formation of stoichiometric intermetallic. This paper investigates the effects of bonding parameter match (ultrasonic level and force) on the growth behaviours of gold aluminide compound during thermal aging. Samples were built with different combination of ultrasonic level and force for high temperature storage (HTS) test at certain elevated temperature and time. Measurements for bonded ball mechanical strength and observations on intermetallic compounds growth patterns were carried out. Discussions on these phenomena were based on the physical, thermal and atomic properties of the bonding elements. It is suggested that un-optimised ultrasonic level and...
Materials Today: Proceedings, 2019
This study focuses towards typical micromechanical properties such as strength, yield point, Youn... more This study focuses towards typical micromechanical properties such as strength, yield point, Young's Modulus, strain, shapes of fracture end and element analysis, atomic percentage of Ca of 4N gold (Au) wire using microstructures and composition observation, micro-tensile test and depth sensing indentation technique. A series of micro-tensile test were performed with different strain rate values of 10˚-10-4 min-1 on to a 25.4 µm diameter plain gold wire. The nanoindentation with 20 mN maximum load was indented on a near fracture end of a gold wire specimen, for which this test was carried out after the microtensile test. The stress-strain curves were used to characterize the 4N purity gold wire. The shapes of fracture end of gold wire after micro tensile test were carried out using Scanning Electron Microscopic (SEM). The finding showed that the mechanical properties of ultra-fine gold wire was in the proportional relationship with the increment of the strain rate value. It is suggested that micromechanical behaviour gave the effect for the wirebonding process in order to characterize the wire loop control and strengthen the wire loop to avoid the wire sweep.
American Journal of Engineering and Applied Sciences, 2009
Problem statement: Repeated heat cure during assembly processes affected the Die Attach Film (DAF... more Problem statement: Repeated heat cure during assembly processes affected the Die Attach Film (DAF) material properties and the effectiveness touched area that leads to weak die bonding and delamination. Suitable die attached condition and DAF material selection had been evaluated to achieve required reliability performance in the manufacturing of the 3D Quad Flat No-Lead (QFN) stacked die package. Approach: During this study, special attention was given to the development of the residual stresses due to mismatch in the coefficients of thermal expansion of different DAF materials. Both experimental and finite element method were employed to gain a better understanding in a stress development induced between two different type of DAF, different die attach temperature and during the manufacturing process. Differential scanning calorimetry (DSC) was used to measure the changes of heat flow characteristics for both types of DAF. The die bond strength results measured using shear testing machine were compared with the finite element method prediction. Results: Although both DAF samples achieved good reliability performance and passed the Moisture Sensitivity Level 3 test (MSL3) at reflow 260°C without any sign of delamination, numerical simulation had demonstrated that the stress development were increased exponentially as the die attach temperature increased. It showed that different DAF gave different values of stresses but presented the same trend which the lowest die attached temperature (100°C in comparison with 125°C and 150°C) gave more stress to the die and possibility that the die will have weak adhesion to the substrate was high. Conclusions/Recommendations: Therefore for this case, stress can be relieved by having higher die attached temperature with an adequate bonding force and time, however die attached temperature for both DAF must be used above the glass transition temperature (128°C for DAF A and 165°C for DAF B) and being controlled not to exceed the crystallization temperature (203°C for DAF A and 204°C for DAF B) of both DAF.
Key Engineering Materials, 2011
In the last decade, failure of microelectronic devices has become a prominent field of research a... more In the last decade, failure of microelectronic devices has become a prominent field of research all across the world. The results of this of failure analysis allow an engineer to choose package geometries and materials which reduce the risk of failure. This paper is meant to relate the stress effect on material properties during Quad Flat No-Leads (QFN) stacked-die packages manufacturing processes. To achieve the study, the finite element technique was used to perform an extensive structural analysis on a QFN package design once it was verified by related experiments. A QFN unit was developed in three dimensional geometry with various materials be will simulated in order to determine the location of failure. The induced stress results were also measured in the maximum value, indicating the low modulus and coefficient of thermal expansion (CTE) in the packaging material were important for reducing high stress during the manufacturing stages. However, numerical simulation demonstrated...
There are several issues related to the mechanical and electrical wirebond failure during wirebon... more There are several issues related to the mechanical and electrical wirebond failure during wirebonding process. Major factors are associated with AuAl intermetallic system. AuAl intermetallic compounds (IMC) can easily form at room temperature and can be accelerated with the elevated temperature. In this paper, pattern of intermetallic compounds growth and potential degradation due to voids in thermosonic ball bonding were studied on AuAl intermetallic compounds. The thermosonic ball bonding process used 99.99% gold wire and aluminized pad of Si chip. Results after HTS at 150ºC for 500 hours demonstrated that voids were generated around the diffusion layer because of the Kirkendall effect and severe voids was clearly exhibited after thermal aging at 150ºC for 1000 hours. Prolong aging time can lead to bonding failure associate with Kirkendall voids.
2007 9th Electronics Packaging Technology Conference, 2007
The trend in the semiconductor industry is to develop more powerful components while decreasing t... more The trend in the semiconductor industry is to develop more powerful components while decreasing the component size. A suitable material set has to be obtained for the required reliability performance. The objective of this study is to evaluate the performance of different die attach film (DAF) and epoxy pastes for stacked die Quad Flat No-lead package. Both experimental and modeling works are resorted to analyze and refine the package design. Six combinations of die attach materials are evaluated to compare with current single die package. The strengths and weaknesses of the DAF and epoxy paste are compared in this paper. Die shear test is performed to study the adhesion condition between the die attach material and silicon die. Finite element model of the package is generated to determine the thermally induced stresses under different conditions. All the results show that it is robust to use the new epoxy paste and DAF.
Materials Today: Proceedings, 2019
Wire chemistry and bonding conditions are found to affect the Au-Al intermetallic compounds forma... more Wire chemistry and bonding conditions are found to affect the Au-Al intermetallic compounds formation and growth. Bonding achieved when these two metals come into intimate contact between each other by interactions of ultrasonic energy, force, temperature and time. Inter diffusion of the joining metals at the interface activated the formation of stoichiometric intermetallic. This paper investigates the effects of bonding parameter match (ultrasonic level and force) on the growth behaviours of gold aluminide compound during thermal aging. Samples were built with different combination of ultrasonic level and force for high temperature storage (HTS) test at certain elevated temperature and time. Measurements for bonded ball mechanical strength and observations on intermetallic compounds growth patterns were carried out. Discussions on these phenomena were based on the physical, thermal and atomic properties of the bonding elements. It is suggested that un-optimised ultrasonic level and...
Intermetallic formation between gold wire and Al pad is well documented to represent mechanical s... more Intermetallic formation between gold wire and Al pad is well documented to represent mechanical strength of ballbond. Bonding achieved when these two metals come into intimate contact between each other by interactions of ultrasonic energy, force, temperature and time. Under elevated temperature and time, theoretically the intermetallic phase can thicken and growth due reactive diffusion activated by temperature. This paper presents effects on ultrasonic energy and force to the intermetallic growth patterns for gold wire with 99% composition of Au. Samples were prepared by different variables of ultrasonic energy and force with constants bonding temperature at 240°C. Investigation was carried out by baking the samples in the high thermal storage (HTS) chamber at 175 °C. Measurements for ballbond mechanical strength and observations on intermetallic growth patterns were carried out using ball shear and ball pull tester, optical microscope and scanning electron microscope (SEM). The r...
There are several issues related to the mechanical and electrical wirebond failure during wirebon... more There are several issues related to the mechanical and electrical wirebond failure during wirebonding process. Major factors are associated with AuAl intermetallic system. AuAl intermetallic compounds (IMC) can easily form at room temperature and can be accelerated with the elevated temperature. In this paper, pattern of intermetallic compounds growth and potential degradation due to voids in thermosonic ball bonding were studied on AuAl intermetallic compounds. The thermosonic ball bonding process used 99.99% gold wire and aluminized pad of Si chip. Results after HTS at 150ºC for 500 hours demonstrated that voids were generated around the diffusion layer because of the Kirkendall effect and severe voids was clearly exhibited after thermal aging at 150ºC for 1000 hours. Prolong aging time can lead to bonding failure associate with Kirkendall voids.
Intermetallic formation between gold wire and Al pad is well documented to represent mechanical s... more Intermetallic formation between gold wire and Al pad is well documented to represent mechanical strength of ballbond. Bonding achieved when these two metals come into intimate contact between each other by interactions of ultrasonic energy, force, temperature and time. Under elevated temperature and time, theoretically the intermetallic phase can thicken and growth due reactive diffusion activated by temperature. This paper presents effects on ultrasonic energy and force to the intermetallic growth patterns for gold wire with 99% composition of Au. Samples were prepared by different variables of ultrasonic energy and force with constants bonding temperature at 240°C. Investigation was carried out by baking the samples in the high thermal storage (HTS) chamber at 175 °C. Measurements for ballbond mechanical strength and observations on intermetallic growth patterns were carried out using ball shear and ball pull tester, optical microscope and scanning electron microscope (SEM). The r...
Advanced Materials Research, 2012
Dye sensitized solar cell (DSSC) is a new class of low-cost solar cell, that belongs to third gen... more Dye sensitized solar cell (DSSC) is a new class of low-cost solar cell, that belongs to third generation solar cells in thin film based. It is based on a semiconductor formed between a photo-sensitized anode and an electrolyte, known as photoelectrochemical system. A lot of research has been conducted due to their interesting potential for low-cost, lightweight, disposable and having cell efficiency up to 10%. This paper reports the fabrication of dye sensitized solar cells using TiO2 nanoparticles and chlorophyll as active layer. TiO2 nanoparticles were prepared by sol-gel method while the chlorophyll was extracted from Pandanus amaryllifolius (Pandan leaf). TiO2 film was prepared on ITO coated glass using dip coating technique and then immersed overnight in the chlorophyll solution. An electrolyte solution composed of PC-LiClO4 was injected into the cell before sealed using glass that was coated with Pt as top electrode. An active area of 4.48 cm2 was fabricated by black masking t...
Journal of Electronic Packaging, 2010
Relatively little information is available on the growth patterns of gold aluminide compound in a... more Relatively little information is available on the growth patterns of gold aluminide compound in accurate 3D measurement as compared with 2D images of the projected surface. A 3D surface imaging technique by using infinite focus microscope (IFM) was proposed in this study to observe and explain the effects of bonding parameters on growth pattern of gold aluminide compound formed between a 25.48 μm 4N gold wire and an aluminum pad metallization. Two bonding factors, which were varied, were ball bonding force and ultrasonic current while bonding time and temperature were kept constant. The 3D surface measurement provides topographical and color information of the bonded region, which indicates that optimum bonding condition has a significant effect on uniform growth and wide coverage area of gold aluminide compound. Results illustrated by this technique were used as additional information to the results produce by the conventional methods such as cross section optical image and scannin...
wseas.us
Consumer demand for smaller and lighter products in wiresless application with maximum functional... more Consumer demand for smaller and lighter products in wiresless application with maximum functionality had drive the semiconductor industries toward the developement of 3-dimensional stacked die. One of the key technology is relies on die stacking process. A suitable bonding condition and material set are essential to achieve required reliability performance. This study is to relate the effects of variables bonding parameter on the mechanical adhesion and delamination of the die attach film in QFN stacked die. Samples are deliberately built with nine combination sets of die attach parameters including bonding temperature, force and time to achieve a minimum reliability performance under IPC/JEDEC Moisture Sensitivity Level 3 at reflow 260°C. Characterisation of die attach film was carried out using differential scanning calorimetry whereas it performance was carried out using shear testing machine and scanning acoustic test (SAT) is used to detect the interfacial delamination between DAF and die. The best die attach process is characterized by stable values of die attach film thermal resistance properties and optimum touch area between die/die attach film and die attach film/die.