Currently,wire bonding is the most popular first-level interconnection technology used between the die and package terminals,but even with its long-term and excessive usage,the mechanism of wire bonding has not been c...Currently,wire bonding is the most popular first-level interconnection technology used between the die and package terminals,but even with its long-term and excessive usage,the mechanism of wire bonding has not been completely evaluated.Therefore,fundamental research is still needed.In this study,the mechanism of microweld formation and breakage during Cu-Cu wire bonding was investigated by using molecular dynamics simulation.The contact model for the nanoindentation process between the wire and substrate was developed to simulate the contact process of the Cu wire and Cu substrate.Elastic contact and plastic instability were investigated through the loading and unloading processes.Moreover,the evolution of the indentation morphology and distributions of the atomic stress were also investigated.It was shown that the loading and unloading curves do not coincide,and the unloading curve exhibited hysteresis.For the substrate,in the loading process,the main force changed from attractive to repulsive.The maximum von Mises stress increased and shifted from the center toward the edge of the contact area.During the unloading process,the main force changed from repulsive to attractive.The Mises stress reduced first and then increased.Stress concentration occurs around dislocations in the middle area of the Cu wire.展开更多
In the wire bonding process of microelectronic packaging,heat affect zone(HAZ)is an important factor governing the loop profile of bonding.The height of loop is affected by the length of the HAZ.Factors governing the ...In the wire bonding process of microelectronic packaging,heat affect zone(HAZ)is an important factor governing the loop profile of bonding.The height of loop is affected by the length of the HAZ.Factors governing the HAZ were studied.To investigate this relationship,experiments were done for various sizes of wire and free air ball(FAB).Electric flame-off(EFO)current, EFO time,EFO gap and recrystallization were also studied.The results show that as the size of FAB becomes larger,the length of HAZ increases.With the increase of EFO current and time,the length of HAZ becomes longer.When FAB forms at the same parameter the length of HAZ becomes shorter with the high temperature of recrystallization.展开更多
The physical and technological aspects of wire ball-wedge bonding in the assembly of integrated circuits are considered.The video camera and the pattern recognition system(PRS)of new bonder helps to provide accurate p...The physical and technological aspects of wire ball-wedge bonding in the assembly of integrated circuits are considered.The video camera and the pattern recognition system(PRS)of new bonder helps to provide accurate positioning of the bonding tool on the chip pads of integrated circuits.The formation of the loop wire cycle is ensured by the synchronous movement of the bonding head along the Z axis and the working table along the XY axes based on the servo drive.A feature of the bonder is that it can bond all the wire loops of the electronic device according to the pre-recorded program without needing to align the bonding points.展开更多
The temperature effect on bonding strength and ultrasonic transmission in a PZT transducer system was investigated. The results show that, the temperature change influences the material features of the bonding interfa...The temperature effect on bonding strength and ultrasonic transmission in a PZT transducer system was investigated. The results show that, the temperature change influences the material features of the bonding interface, such as elastic modulus, tensile strength of gold ball and Ag substrate, which results in different bonding strengths. Moreover, the temperature change also influences the impedance and dissipative ultrasonic energy in the PZT system. The current signal of PZT transducer was analyzed by join time-frequency analysis, which can reveal the current change in a bonding process more clearly and completely. The analysis shows that the bonding parameters influence mutually. These results can help build some criteria for parameter match and optimization in wire bonding processes.展开更多
This paper presents the recent study by investigating the vital responses of wire bonding with the application of conduction pre-heating. It is observed through literature reviews that, the effect of pre-heating has n...This paper presents the recent study by investigating the vital responses of wire bonding with the application of conduction pre-heating. It is observed through literature reviews that, the effect of pre-heating has not been completely explored to enable the successful application of pre-heating during wire bonding. The aim of wire bonding is to form quality and reliable solid-state bonds to interconnect metals such as gold wires to metalized pads deposited on silicon integrated circuits. Typically, there are 3 main wire bonding techniques applied in the industry;Thermo-compression, Ultrasonic and Thermosonic. This experiment utilizes the most common and widely used platform which is thermosonic bonding. This technique is explored with the application of conduction pre-heating along with heat on the bonding site, ultrasonic energy and force on an Au-Al system. Sixteen groups of bonding conditions which include eight hundred data points of shear strength at various temperature settings were compared to establish the relationship between bonding strength and the application of conduction pre-heating. The results of this study will clearly indicate the effects of applied conduction pre-heating towards bonding strength which may further produce a robust wire bonding system.展开更多
Manual process of creating bonding diagram is known to be time consuming and error prone. In comparison, offline programming (OLP) provides a much more viable option to reduce the wire bonding creation time and error....Manual process of creating bonding diagram is known to be time consuming and error prone. In comparison, offline programming (OLP) provides a much more viable option to reduce the wire bonding creation time and error. OLP is available in two versions, i.e., vendor specific OLP and direct integration offline pro- gramming (Di-OLP). Both versions utilize the bonding diagram and computer aided design data to speed up bonding program creation. However, the newly proposed Di-OLP is more flexible as it can be used to create bonding program for multiple machine platforms in microelectronics industry. Some special features of Di-OLP method are presented. The application of generic OLP however, is applicable to machines that recognize ASCII text file. The user needs to know the data format accepted by machine and convert the data accordingly to suit its application for different machine platforms. Di-OLP is also a practical method to replace the time consuming manual method in production line.展开更多
An 8-channel hybrid-integrated chip for 200 Gb/s(8×25 Gb/s)signal transmission has been demonstrated.The channels are all within the O-band,and with a spacing of 800 GHz.The core of this chip is a monolithic inte...An 8-channel hybrid-integrated chip for 200 Gb/s(8×25 Gb/s)signal transmission has been demonstrated.The channels are all within the O-band,and with a spacing of 800 GHz.The core of this chip is a monolithic integrated multi-wavelength laser array of 8 directly-modulated distributed feedback(DFB)lasers.By using the reconstruction equivalent chirp technique,multi-wavelength integration and asymmetric phase shift structures are achieved in the laser array.The output laser beams of the array are combined by a planar light-wave circuit,which is hybrid-integrated with the laser array by photonic wire bonding.Experiment results of this transmitter chip show good single-mode working of each unit laser,with a sidemode suppression ratio above 50 dB,and the modulation bandwidth is above 20 GHz.Clear eye diagrams are obtained in the lasers for 25 Gb/s non-return-to-zero modulation,which implies a total 200 Gb/s transmission rate for the whole chip.展开更多
Wire bonding is one of the main processes of the LED packaging which provides electrical interconnec- tion between the LED chip and lead frame. The gold wire bonding process has been widely used in LED packaging indus...Wire bonding is one of the main processes of the LED packaging which provides electrical interconnec- tion between the LED chip and lead frame. The gold wire bonding process has been widely used in LED packaging industry currently. However, due to the high cost of gold wire, copper wire bonding is a good substitute for the gold wire bonding which can lead to significant cost saving. In this paper, the copper and gold wire bonding processes on the high power LED chip are compared and analyzed with finite element simulation. This modeling work may provide guidelines for the parameter optimization of copper wire bonding process on the high power LED packaging.展开更多
Non-destructive detection of wire bonding defects in integrated circuits(IC)is critical for ensuring product quality after packaging.Image-processing-based methods do not provide a detailed evaluation of the three-dim...Non-destructive detection of wire bonding defects in integrated circuits(IC)is critical for ensuring product quality after packaging.Image-processing-based methods do not provide a detailed evaluation of the three-dimensional defects of the bonding wire.Therefore,a method of 3D reconstruction and pattern recognition of wire defects based on stereo vision,which can achieve non-destructive detection of bonding wire defects is proposed.The contour features of bonding wires and other electronic components in the depth image is analysed to complete the 3D reconstruction of the bonding wires.Especially to filter the noisy point cloud and obtain an accurate point cloud of the bonding wire surface,a point cloud segmentation method based on spatial surface feature detection(SFD)was proposed.SFD can extract more distinct features from the bonding wire surface during the point cloud segmentation process.Furthermore,in the defect detection process,a directional discretisation descriptor with multiple local normal vectors is designed for defect pattern recognition of bonding wires.The descriptor combines local and global features of wire and can describe the spatial variation trends and structural features of wires.The experimental results show that the method can complete the 3D reconstruction and defect pattern recognition of bonding wires,and the average accuracy of defect recognition is 96.47%,which meets the production requirements of bonding wire defect detection.展开更多
The ultrasonic wedge bonding with d25 μm copper wire was achieved on Au/Ni plated Cu substrate at ambient temperature.Ultrasonic wedge bonding mechanism was investigated by using SEM/EDX,pull test,shear test and micr...The ultrasonic wedge bonding with d25 μm copper wire was achieved on Au/Ni plated Cu substrate at ambient temperature.Ultrasonic wedge bonding mechanism was investigated by using SEM/EDX,pull test,shear test and microhardness test.The results show that the thinning of the Au layer occurs directly below the center of the bonding tool with the bonding power increasing.The interdiffusion between copper wire and Au metallization during the wedge bonding is assumed negligible,and the wedge bonding is achieved by wear action induced by ultrasonic vibration.The ultrasonic power contributes to enhance the deformation of copper wire due to ultrasonic softening effect which is then followed by the strain hardening of the copper wedge bonding.展开更多
The influences of additive elements on properties of gold wire and the technology of homogeneously adding those elements to gold matrix were studied. A BJ-type gold bonding wire for automatic bonders was developed, wh...The influences of additive elements on properties of gold wire and the technology of homogeneously adding those elements to gold matrix were studied. A BJ-type gold bonding wire for automatic bonders was developed, which has high bond strength and stable uniform mechanical properties and is capable of forming good spherical shape of melting-ball observed by SEM. The bonding wire is fully suitable to the requirements of the automatic bonding technology and satisfies the performance requirement of IC products.展开更多
铜线表面钯层特征是影响芯片封装过程中烧球和键合质量的重要因素。采用无卤直接涂镀工艺,制备了不同涂镀速度和涂镀温度下的镀钯铜线,研究了涂镀速度对镀层形貌和无空气焊球(free air ball,FAB)特征的影响。结果表明:随着涂镀速度增加...铜线表面钯层特征是影响芯片封装过程中烧球和键合质量的重要因素。采用无卤直接涂镀工艺,制备了不同涂镀速度和涂镀温度下的镀钯铜线,研究了涂镀速度对镀层形貌和无空气焊球(free air ball,FAB)特征的影响。结果表明:随着涂镀速度增加,涂镀时间减少,钯颗粒在铜线表面分布的均匀性变差,局部分布不均匀的钯颗粒团聚引起钯颗粒浓度较高,镀层表面钯颗粒团聚区域增加。在涂镀速度50 m/min下,镀层表面钯分布较为均匀。随着涂镀速度的增加,FAB球直径逐渐减小;镀钯铜线表面Pd颗粒团聚区域和未团聚区域的钯含量差增大,FAB球尺寸的一致性逐渐下降。在较低涂镀速度50 m/min下,FAB球表面钯分布比较均匀;在较高的涂镀速度100 m/min下,镀层表面大量团聚的钯颗粒重熔后在FAB球表面呈大面积连续的富钯区,钯再分布的均匀性较差。从FAB球尺寸的一致性和表面钯再分布的均匀性方面考虑,涂镀速度50 m/min和涂镀温度400℃为镀钯铜线涂镀较佳的工艺参数。展开更多
Copper wire, serving as a cost-saving alternative to gold wire, has been used in many high-end thermosonic ball bonding applications. In this paper, the bond shear force, bond shear strength, and the ball bond diamete...Copper wire, serving as a cost-saving alternative to gold wire, has been used in many high-end thermosonic ball bonding applications. In this paper, the bond shear force, bond shear strength, and the ball bond diameter are adopted to evaluate the bonding quality. It is concluded that the ef/~cient ultrasonic power is needed to soften the ball to form the copper bonds with high bonding strength. However, excessive ultrasonic power would serve as a fatigue loading to weaken the bonding. Excessive or less bonding force would cause cratering in the silicon.展开更多
Eleven groups of wire bonding experiments are carried out on an experiment platform （restructured with a U3000 heavy aluminum wedge wire bonder）. Pure silicon aluminum wire （300 μm in diameter, 2.94-3.92 N in aver...Eleven groups of wire bonding experiments are carried out on an experiment platform （restructured with a U3000 heavy aluminum wedge wire bonder）. Pure silicon aluminum wire （300 μm in diameter, 2.94-3.92 N in average pull force） and nickel coated aluminum substrates are used in the experiments. During the experiment process, only ultrasonic power rate parameter is changed and the other bonding parameters are kept as constant, The bonding force and time are 4.90 N and 100 ms respectively. After the bonding experiments, shear strength tests are carried out on the bonds as the bonding strength criterion. From those experiments and test results, some conclusions are obtained： In the small ultrasonic power rate conditions （about 20%-30%）, with the power increasing, the bonding strength enhances accordingly; However, in the large ultrasonic power rate conditions （about 45%-70%）, the bonding strength decreases accordingly and over bonding happens. Only when the ultrasonic power rate is in a moderate condition （about 35%-40%） can good and stabilized bonding strength be acquired.展开更多
基金the National Key R&D Program of China(Grant No.2019YFB1704600)the Hubei Provincial Natural Science Foundation of China(Grant No.2020CFA032).
文摘Currently,wire bonding is the most popular first-level interconnection technology used between the die and package terminals,but even with its long-term and excessive usage,the mechanism of wire bonding has not been completely evaluated.Therefore,fundamental research is still needed.In this study,the mechanism of microweld formation and breakage during Cu-Cu wire bonding was investigated by using molecular dynamics simulation.The contact model for the nanoindentation process between the wire and substrate was developed to simulate the contact process of the Cu wire and Cu substrate.Elastic contact and plastic instability were investigated through the loading and unloading processes.Moreover,the evolution of the indentation morphology and distributions of the atomic stress were also investigated.It was shown that the loading and unloading curves do not coincide,and the unloading curve exhibited hysteresis.For the substrate,in the loading process,the main force changed from attractive to repulsive.The maximum von Mises stress increased and shifted from the center toward the edge of the contact area.During the unloading process,the main force changed from repulsive to attractive.The Mises stress reduced first and then increased.Stress concentration occurs around dislocations in the middle area of the Cu wire.
基金Project(50705027)supported by the National Natural Science Foundation of ChinaProject(2007AA04Z315)supported by the National High-Tech Research and Development Program of China。
文摘In the wire bonding process of microelectronic packaging,heat affect zone(HAZ)is an important factor governing the loop profile of bonding.The height of loop is affected by the length of the HAZ.Factors governing the HAZ were studied.To investigate this relationship,experiments were done for various sizes of wire and free air ball(FAB).Electric flame-off(EFO)current, EFO time,EFO gap and recrystallization were also studied.The results show that as the size of FAB becomes larger,the length of HAZ increases.With the increase of EFO current and time,the length of HAZ becomes longer.When FAB forms at the same parameter the length of HAZ becomes shorter with the high temperature of recrystallization.
基金The 2019 Ministry of Education industry-university cooperation collaborative education project“Research on the Construction of Economics and Management Professional Data Analysis Laboratory”(Project number:201902077020)。
文摘The physical and technological aspects of wire ball-wedge bonding in the assembly of integrated circuits are considered.The video camera and the pattern recognition system(PRS)of new bonder helps to provide accurate positioning of the bonding tool on the chip pads of integrated circuits.The formation of the loop wire cycle is ensured by the synchronous movement of the bonding head along the Z axis and the working table along the XY axes based on the servo drive.A feature of the bonder is that it can bond all the wire loops of the electronic device according to the pre-recorded program without needing to align the bonding points.
基金Projects(50390064 50575230) supported by the National Natural Science Foundation of China Project(2003CB736202) supported by the National Basic Research Program of China
文摘The temperature effect on bonding strength and ultrasonic transmission in a PZT transducer system was investigated. The results show that, the temperature change influences the material features of the bonding interface, such as elastic modulus, tensile strength of gold ball and Ag substrate, which results in different bonding strengths. Moreover, the temperature change also influences the impedance and dissipative ultrasonic energy in the PZT system. The current signal of PZT transducer was analyzed by join time-frequency analysis, which can reveal the current change in a bonding process more clearly and completely. The analysis shows that the bonding parameters influence mutually. These results can help build some criteria for parameter match and optimization in wire bonding processes.
文摘This paper presents the recent study by investigating the vital responses of wire bonding with the application of conduction pre-heating. It is observed through literature reviews that, the effect of pre-heating has not been completely explored to enable the successful application of pre-heating during wire bonding. The aim of wire bonding is to form quality and reliable solid-state bonds to interconnect metals such as gold wires to metalized pads deposited on silicon integrated circuits. Typically, there are 3 main wire bonding techniques applied in the industry;Thermo-compression, Ultrasonic and Thermosonic. This experiment utilizes the most common and widely used platform which is thermosonic bonding. This technique is explored with the application of conduction pre-heating along with heat on the bonding site, ultrasonic energy and force on an Au-Al system. Sixteen groups of bonding conditions which include eight hundred data points of shear strength at various temperature settings were compared to establish the relationship between bonding strength and the application of conduction pre-heating. The results of this study will clearly indicate the effects of applied conduction pre-heating towards bonding strength which may further produce a robust wire bonding system.
文摘Manual process of creating bonding diagram is known to be time consuming and error prone. In comparison, offline programming (OLP) provides a much more viable option to reduce the wire bonding creation time and error. OLP is available in two versions, i.e., vendor specific OLP and direct integration offline pro- gramming (Di-OLP). Both versions utilize the bonding diagram and computer aided design data to speed up bonding program creation. However, the newly proposed Di-OLP is more flexible as it can be used to create bonding program for multiple machine platforms in microelectronics industry. Some special features of Di-OLP method are presented. The application of generic OLP however, is applicable to machines that recognize ASCII text file. The user needs to know the data format accepted by machine and convert the data accordingly to suit its application for different machine platforms. Di-OLP is also a practical method to replace the time consuming manual method in production line.
基金supported by the National Key Research and Development Program of China(Nos.2018YFA0704402,2018YFB2201801,2018YFE0201200,and 2020YFB2205800)National Natural Science Foundation of China(Nos.61975075,61975076,and 62004094)+1 种基金Natural Science Foundation of Jiangsu Province(No.BK20200334)Jiangsu Science and Technology Project(No.BE2017003-2)。
文摘An 8-channel hybrid-integrated chip for 200 Gb/s(8×25 Gb/s)signal transmission has been demonstrated.The channels are all within the O-band,and with a spacing of 800 GHz.The core of this chip is a monolithic integrated multi-wavelength laser array of 8 directly-modulated distributed feedback(DFB)lasers.By using the reconstruction equivalent chirp technique,multi-wavelength integration and asymmetric phase shift structures are achieved in the laser array.The output laser beams of the array are combined by a planar light-wave circuit,which is hybrid-integrated with the laser array by photonic wire bonding.Experiment results of this transmitter chip show good single-mode working of each unit laser,with a sidemode suppression ratio above 50 dB,and the modulation bandwidth is above 20 GHz.Clear eye diagrams are obtained in the lasers for 25 Gb/s non-return-to-zero modulation,which implies a total 200 Gb/s transmission rate for the whole chip.
基金Project supported by the National Natural Science Foundation of China(Nos.50876038,50835005)the National High Technology Research and Development Program of China(No.2009AA03A1A3)
文摘Wire bonding is one of the main processes of the LED packaging which provides electrical interconnec- tion between the LED chip and lead frame. The gold wire bonding process has been widely used in LED packaging industry currently. However, due to the high cost of gold wire, copper wire bonding is a good substitute for the gold wire bonding which can lead to significant cost saving. In this paper, the copper and gold wire bonding processes on the high power LED chip are compared and analyzed with finite element simulation. This modeling work may provide guidelines for the parameter optimization of copper wire bonding process on the high power LED packaging.
基金Intelligent Manufacturing and Robot Technology Innovation Project of Beijing Municipal Commission of Science and Technology and Zhongguancun Science and Technology Park Management Committee,Grant/Award Number:Z221100000222016National Natural Science Foundation of China,Grant/Award Number:62076014Beijing Municipal Education Commission and Beijing Natural Science Foundation,Grant/Award Number:KZ202010005004。
文摘Non-destructive detection of wire bonding defects in integrated circuits(IC)is critical for ensuring product quality after packaging.Image-processing-based methods do not provide a detailed evaluation of the three-dimensional defects of the bonding wire.Therefore,a method of 3D reconstruction and pattern recognition of wire defects based on stereo vision,which can achieve non-destructive detection of bonding wire defects is proposed.The contour features of bonding wires and other electronic components in the depth image is analysed to complete the 3D reconstruction of the bonding wires.Especially to filter the noisy point cloud and obtain an accurate point cloud of the bonding wire surface,a point cloud segmentation method based on spatial surface feature detection(SFD)was proposed.SFD can extract more distinct features from the bonding wire surface during the point cloud segmentation process.Furthermore,in the defect detection process,a directional discretisation descriptor with multiple local normal vectors is designed for defect pattern recognition of bonding wires.The descriptor combines local and global features of wire and can describe the spatial variation trends and structural features of wires.The experimental results show that the method can complete the 3D reconstruction and defect pattern recognition of bonding wires,and the average accuracy of defect recognition is 96.47%,which meets the production requirements of bonding wire defect detection.
基金Prpject(E052104/50705021)supported by the National Natural Science Foundation of ChinaProject(2006:01504489)supported by the Development Program for Outstanding Young Teachers in HIT
文摘The ultrasonic wedge bonding with d25 μm copper wire was achieved on Au/Ni plated Cu substrate at ambient temperature.Ultrasonic wedge bonding mechanism was investigated by using SEM/EDX,pull test,shear test and microhardness test.The results show that the thinning of the Au layer occurs directly below the center of the bonding tool with the bonding power increasing.The interdiffusion between copper wire and Au metallization during the wedge bonding is assumed negligible,and the wedge bonding is achieved by wear action induced by ultrasonic vibration.The ultrasonic power contributes to enhance the deformation of copper wire due to ultrasonic softening effect which is then followed by the strain hardening of the copper wedge bonding.
文摘The influences of additive elements on properties of gold wire and the technology of homogeneously adding those elements to gold matrix were studied. A BJ-type gold bonding wire for automatic bonders was developed, which has high bond strength and stable uniform mechanical properties and is capable of forming good spherical shape of melting-ball observed by SEM. The bonding wire is fully suitable to the requirements of the automatic bonding technology and satisfies the performance requirement of IC products.
文摘Copper wire, serving as a cost-saving alternative to gold wire, has been used in many high-end thermosonic ball bonding applications. In this paper, the bond shear force, bond shear strength, and the ball bond diameter are adopted to evaluate the bonding quality. It is concluded that the ef/~cient ultrasonic power is needed to soften the ball to form the copper bonds with high bonding strength. However, excessive ultrasonic power would serve as a fatigue loading to weaken the bonding. Excessive or less bonding force would cause cratering in the silicon.
基金This project is supported by National Natural Science Foundation of China (No.50390064)National Basic Research Program of China(973 Program,No.2003CB716202).
文摘Eleven groups of wire bonding experiments are carried out on an experiment platform （restructured with a U3000 heavy aluminum wedge wire bonder）. Pure silicon aluminum wire （300 μm in diameter, 2.94-3.92 N in average pull force） and nickel coated aluminum substrates are used in the experiments. During the experiment process, only ultrasonic power rate parameter is changed and the other bonding parameters are kept as constant, The bonding force and time are 4.90 N and 100 ms respectively. After the bonding experiments, shear strength tests are carried out on the bonds as the bonding strength criterion. From those experiments and test results, some conclusions are obtained： In the small ultrasonic power rate conditions （about 20%-30%）, with the power increasing, the bonding strength enhances accordingly; However, in the large ultrasonic power rate conditions （about 45%-70%）, the bonding strength decreases accordingly and over bonding happens. Only when the ultrasonic power rate is in a moderate condition （about 35%-40%） can good and stabilized bonding strength be acquired.
