Pub Date : 2018-09-01DOI: 10.1109/IEMT.2018.8511655
J. Kong, B. E. Cheah, K. Yong
A novel and high-performance interconnect structure is the core of this work. This patent-pending [1] structure is termed Guided Interconnect (GI), as its basic principle is to “guide” the electromagnetic (EM) wave of highspeed signaling in a tightly-coupled manner. It is shown that, from the research work, up to 20% higher I/O density and 40% Z-height reduction can be achieved without jeopardizing signal integrity performance. The application is not limited to semiconductor packaging, but also for printed circuit board (PCB) and flexible printed circuit (FPC).
{"title":"A Novel Electromagnetic Field Guided Interconnect for High-Performance Applications","authors":"J. Kong, B. E. Cheah, K. Yong","doi":"10.1109/IEMT.2018.8511655","DOIUrl":"https://doi.org/10.1109/IEMT.2018.8511655","url":null,"abstract":"A novel and high-performance interconnect structure is the core of this work. This patent-pending [1] structure is termed Guided Interconnect (GI), as its basic principle is to “guide” the electromagnetic (EM) wave of highspeed signaling in a tightly-coupled manner. It is shown that, from the research work, up to 20% higher I/O density and 40% Z-height reduction can be achieved without jeopardizing signal integrity performance. The application is not limited to semiconductor packaging, but also for printed circuit board (PCB) and flexible printed circuit (FPC).","PeriodicalId":292144,"journal":{"name":"2018 IEEE 38th International Electronics Manufacturing Technology Conference (IEMT)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129372007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-09-01DOI: 10.1109/IEMT.2018.8511770
M. Tay, Yun Zhao, Ming Siong Lim, Raymond Kim Swee Goh
Striving next level of better package robustness reliability level, mold compound plays vital role of the overall package quality. Together with ADEGO specific requirement, formulation optimization on releasing agent, carbon black, flame retardant and ion trapper were introduced in the first phase of improvement. Second phase improvement started where facing challenge of mold releasing performance. This paper explained the extensive research bringing better effective solution. First was the implementation of releasing agent, polyethylene wax to eliminate package crack. Secondly, the study of fine carbon particle size of 90um to overcome particle short between lead and die pad as well as to reduce hard short risk. Third implementation was introduction of ion trapper hydrotalcite type “D”, purpose is to maintain pH level of 5–7 fulfilled ADEGO requirement of C1- content <20ppm. Fourth introduction is flame retardant from metal hydroxide to organic phosphorous in order to minimize leakage issue due to the product has poor ion barrier related to chip design. With these 4 types of composition changed, random runner stick and rough surface were observed during accumulative mold shot. By switching the flame retardant to inorganic material, the mold sticking issue was eliminated during continuous molding. Further research indicates that metal hydroxide contained OH- which act as free ion and easily move around within the compound compositions. In addition, organic phosphorus is soluble in resin and obstructed the cross linking of resin and catalyst. This shows that metal hydroxide will help to improve curability and prolong continuous molding duration.
{"title":"Challenges to Improve Packages Robustness and Elimination of Mold Compound Sticking on Power Leaded Package","authors":"M. Tay, Yun Zhao, Ming Siong Lim, Raymond Kim Swee Goh","doi":"10.1109/IEMT.2018.8511770","DOIUrl":"https://doi.org/10.1109/IEMT.2018.8511770","url":null,"abstract":"Striving next level of better package robustness reliability level, mold compound plays vital role of the overall package quality. Together with ADEGO specific requirement, formulation optimization on releasing agent, carbon black, flame retardant and ion trapper were introduced in the first phase of improvement. Second phase improvement started where facing challenge of mold releasing performance. This paper explained the extensive research bringing better effective solution. First was the implementation of releasing agent, polyethylene wax to eliminate package crack. Secondly, the study of fine carbon particle size of 90um to overcome particle short between lead and die pad as well as to reduce hard short risk. Third implementation was introduction of ion trapper hydrotalcite type “D”, purpose is to maintain pH level of 5–7 fulfilled ADEGO requirement of C1- content <20ppm. Fourth introduction is flame retardant from metal hydroxide to organic phosphorous in order to minimize leakage issue due to the product has poor ion barrier related to chip design. With these 4 types of composition changed, random runner stick and rough surface were observed during accumulative mold shot. By switching the flame retardant to inorganic material, the mold sticking issue was eliminated during continuous molding. Further research indicates that metal hydroxide contained OH- which act as free ion and easily move around within the compound compositions. In addition, organic phosphorus is soluble in resin and obstructed the cross linking of resin and catalyst. This shows that metal hydroxide will help to improve curability and prolong continuous molding duration.","PeriodicalId":292144,"journal":{"name":"2018 IEEE 38th International Electronics Manufacturing Technology Conference (IEMT)","volume":"163 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122625936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-09-01DOI: 10.1109/IEMT.2018.8511786
K. Julianous, P.Y. Chan, M. W. Chong
CF4/O2 microwave plasma widely used as an alternative method for mold compound decapsulation on copper wire technology devices as it has the capability to preserve wire surface and wire mechanical strength. However, some drawbacks with copper-silver bonding metallurgy system where plasma byproducts (F and O) react with copper (Cu), silver (Ag) and silicon (Si) when exposed to moist air producing undesired compound (AgCuF3, Cu2O, and SiO2) which accumulated at wedge surface that disrupted the inspection process. This reaction occurred right after taking out from microwave plasma chamber. These undesired compound formations led to wire strength degradation and resulting low wedge pull force. Therefore, prevention methods are introduced by using Ultra-High Vacuum (UHV) that able to prevent chemical reaction between plasma by-products with moist air. In addition, laser ablation able to permanently stop all the reactions. SEM inspection on wire surface after the decapped sample treatment in UHV chamber confirmed the absence of undesired compound formation and mechanical wire test shows consistent and repeatable wedge pull force results. This method is proven to provide genuine results in wire inspection analysis as well as mechanical wire test data without any influence by artifact from sample preparation process.
{"title":"Process Improvement for CF4/02 Microwave Plasma Decapsulation on Cu-Ag Bonding Metallurgy System","authors":"K. Julianous, P.Y. Chan, M. W. Chong","doi":"10.1109/IEMT.2018.8511786","DOIUrl":"https://doi.org/10.1109/IEMT.2018.8511786","url":null,"abstract":"CF4/O2 microwave plasma widely used as an alternative method for mold compound decapsulation on copper wire technology devices as it has the capability to preserve wire surface and wire mechanical strength. However, some drawbacks with copper-silver bonding metallurgy system where plasma byproducts (F and O) react with copper (Cu), silver (Ag) and silicon (Si) when exposed to moist air producing undesired compound (AgCuF3, Cu2O, and SiO2) which accumulated at wedge surface that disrupted the inspection process. This reaction occurred right after taking out from microwave plasma chamber. These undesired compound formations led to wire strength degradation and resulting low wedge pull force. Therefore, prevention methods are introduced by using Ultra-High Vacuum (UHV) that able to prevent chemical reaction between plasma by-products with moist air. In addition, laser ablation able to permanently stop all the reactions. SEM inspection on wire surface after the decapped sample treatment in UHV chamber confirmed the absence of undesired compound formation and mechanical wire test shows consistent and repeatable wedge pull force results. This method is proven to provide genuine results in wire inspection analysis as well as mechanical wire test data without any influence by artifact from sample preparation process.","PeriodicalId":292144,"journal":{"name":"2018 IEEE 38th International Electronics Manufacturing Technology Conference (IEMT)","volume":"133 S228","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120853347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-09-01DOI: 10.1109/IEMT.2018.8511745
Que Wei, Loo Shei Meng
Ag (Silver) wire is an emerging choice for packaging for its excellent mechanical properties and lower cost. The introduction of Ag alloy wire (~95% purity) in STMicroelectronics has been done to overcome the limitations of Cu (Copper) wire (hardness). A new development approach has been applied to ensure the highest manufacturing robustness. However, this also came with some challenges that were faced at the beginning to stabilize ramp up and manufacturing production. Design of Experiments was done using Robust Development approach: this had improved the process workability. One wire-bonding recipe is able to be used on multiple Front End technologies with this approach. This helped to simplify production management in the assembly lines. A strict quality control approach is used to minimize manufacturing variations and this has strong benefit in improving MTBA (Mean Time between Assist). FMEA (Failure Modes and Effects Analysis) methodology helped identify key risks for studies and analysis, while increasing the workability for wire bond process. Quick and long-term reliability were done on the weekly lots, to not only assess the production, but also protect our customer.
{"title":"Manufacturability of Ag Wire for Mass Production - Challenges and Robustness","authors":"Que Wei, Loo Shei Meng","doi":"10.1109/IEMT.2018.8511745","DOIUrl":"https://doi.org/10.1109/IEMT.2018.8511745","url":null,"abstract":"Ag (Silver) wire is an emerging choice for packaging for its excellent mechanical properties and lower cost. The introduction of Ag alloy wire (~95% purity) in STMicroelectronics has been done to overcome the limitations of Cu (Copper) wire (hardness). A new development approach has been applied to ensure the highest manufacturing robustness. However, this also came with some challenges that were faced at the beginning to stabilize ramp up and manufacturing production. Design of Experiments was done using Robust Development approach: this had improved the process workability. One wire-bonding recipe is able to be used on multiple Front End technologies with this approach. This helped to simplify production management in the assembly lines. A strict quality control approach is used to minimize manufacturing variations and this has strong benefit in improving MTBA (Mean Time between Assist). FMEA (Failure Modes and Effects Analysis) methodology helped identify key risks for studies and analysis, while increasing the workability for wire bond process. Quick and long-term reliability were done on the weekly lots, to not only assess the production, but also protect our customer.","PeriodicalId":292144,"journal":{"name":"2018 IEEE 38th International Electronics Manufacturing Technology Conference (IEMT)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132373223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-09-01DOI: 10.1109/IEMT.2018.8511722
Pedro Almazan, Chellamuthu Naveendran, Chai Ying Lee
Formation of Pb (Lead) flakes after die attach reflow process is a common concern when soldering packages with high temperature and soldering material with high in Lead components. Pb flakes are visually manifested on the chip bonding pad after the post Reflow cleaning process, general term as “flux cleaning process”. Small Pb solder spheres can leave behind stains on bonding pad and could reduce wire-bonding yields, with the failure mode of non-stick-on-pad. This Pb flakes formation was investigated and the findings from this phenomenon will be discussed in this paper since very few studies found in current literature. Hypothesis for Pb flakes formation could be attributed during solder Reflow process. Rapid temperature excursions caused the flux component within the solder paste to rapidly expand. Some of the ingredients within the flux component will reach their boiling temperature, at which small solder spheres will experience “popcorn effect” and re-deposited themselves to the bond pad. Hence, this paper also described the feasibility studies of different flux cleaning methods on how to effectively remove this Pb flakes. Process/Equipment and Materials were considered on these studies to validate the applicable solutions for Pb flakes removal on bonding pad. Considerations are the following for the flux cleaning evaluations; Equipment: Spray-in-Air (Water-based chemical), Centrifugal type (both Water-based & Solvent-based chemicals) and Ultrasonic (both Water-based & Solvent-based chemicals). Due to implications or risks identified from these feasibility considerations, the current Ultrasonic process + new cleaning Chemistry with better results were selected to precede further evaluation, including Reliability assessment.
{"title":"Feasibility of Pb Flakes Reduction Post Reflow Cleaning Process","authors":"Pedro Almazan, Chellamuthu Naveendran, Chai Ying Lee","doi":"10.1109/IEMT.2018.8511722","DOIUrl":"https://doi.org/10.1109/IEMT.2018.8511722","url":null,"abstract":"Formation of Pb (Lead) flakes after die attach reflow process is a common concern when soldering packages with high temperature and soldering material with high in Lead components. Pb flakes are visually manifested on the chip bonding pad after the post Reflow cleaning process, general term as “flux cleaning process”. Small Pb solder spheres can leave behind stains on bonding pad and could reduce wire-bonding yields, with the failure mode of non-stick-on-pad. This Pb flakes formation was investigated and the findings from this phenomenon will be discussed in this paper since very few studies found in current literature. Hypothesis for Pb flakes formation could be attributed during solder Reflow process. Rapid temperature excursions caused the flux component within the solder paste to rapidly expand. Some of the ingredients within the flux component will reach their boiling temperature, at which small solder spheres will experience “popcorn effect” and re-deposited themselves to the bond pad. Hence, this paper also described the feasibility studies of different flux cleaning methods on how to effectively remove this Pb flakes. Process/Equipment and Materials were considered on these studies to validate the applicable solutions for Pb flakes removal on bonding pad. Considerations are the following for the flux cleaning evaluations; Equipment: Spray-in-Air (Water-based chemical), Centrifugal type (both Water-based & Solvent-based chemicals) and Ultrasonic (both Water-based & Solvent-based chemicals). Due to implications or risks identified from these feasibility considerations, the current Ultrasonic process + new cleaning Chemistry with better results were selected to precede further evaluation, including Reliability assessment.","PeriodicalId":292144,"journal":{"name":"2018 IEEE 38th International Electronics Manufacturing Technology Conference (IEMT)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131373423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-09-01DOI: 10.1109/IEMT.2018.8511665
Chu Wei
A method towards low cost chip assembly is by increase unit density per Leadframe with Top gate molding solution. In top gate molding, leadframe not require to dedicated space for mold runner in transfer process. That space will replace with more units by lower unit column-to-column pitch distance. Typical challenge of top gate molding is wire sweep especially on unit at Leadframe outer row. EMC injected into units on Leadframe outer row experiencing unbalance mold flow that challenging the molding process development. CAE simulation tool used to predict mold flow behavior and improvement runner design to minimize mold flow unbalance at end of transfer filling process. DOE experiment was perform to optimize transfer time range between 7.8s to 10.5s. Wire loop height optimization was perform as continuous improvement to improve wire sweep in QFP top gate molding from 10.47% to 7%.
{"title":"Top Gate Molding and Wire Sweep Improvement in Full Plastic QFP Packages","authors":"Chu Wei","doi":"10.1109/IEMT.2018.8511665","DOIUrl":"https://doi.org/10.1109/IEMT.2018.8511665","url":null,"abstract":"A method towards low cost chip assembly is by increase unit density per Leadframe with Top gate molding solution. In top gate molding, leadframe not require to dedicated space for mold runner in transfer process. That space will replace with more units by lower unit column-to-column pitch distance. Typical challenge of top gate molding is wire sweep especially on unit at Leadframe outer row. EMC injected into units on Leadframe outer row experiencing unbalance mold flow that challenging the molding process development. CAE simulation tool used to predict mold flow behavior and improvement runner design to minimize mold flow unbalance at end of transfer filling process. DOE experiment was perform to optimize transfer time range between 7.8s to 10.5s. Wire loop height optimization was perform as continuous improvement to improve wire sweep in QFP top gate molding from 10.47% to 7%.","PeriodicalId":292144,"journal":{"name":"2018 IEEE 38th International Electronics Manufacturing Technology Conference (IEMT)","volume":"172 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131610860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-09-01DOI: 10.1109/IEMT.2018.8511697
Younan Hua, Yue Shen, J. Goh, Y. Kee, Xiaomin Li
In wafer fab and assembly processes, non-stick on pad (NSOP) problem impacts seriously yields of the products as the electrical communication between the integrated circuit (IC) chips and other components taking place via the bondpad of the chip. NSOP (Non-Stick On pad) is a failure mode of the IC chip that occurs as a result of poor adhesion between the Aluminium (A1) bondpad and either the bond wire or solder contact. Such failures can be observed even for nanoscale chips such as the 65nm, 45nm, 40nm, and 28nm nodes and beyond. In order to eliminate NSOP problem to enhance the yield of products, process engineers from wafer fab and assembly house together with failure analysis engineers have to know what a good quality bondpad is and how to evaluate and qualify. On these common questions and concerns, in this paper, we will study and introduce Al bondpad qualification methodologies (OSAT and OSSD) and eliminate NSOP problem.
{"title":"Qualification of Microchip Al Bondpad and Elimination of NSOP","authors":"Younan Hua, Yue Shen, J. Goh, Y. Kee, Xiaomin Li","doi":"10.1109/IEMT.2018.8511697","DOIUrl":"https://doi.org/10.1109/IEMT.2018.8511697","url":null,"abstract":"In wafer fab and assembly processes, non-stick on pad (NSOP) problem impacts seriously yields of the products as the electrical communication between the integrated circuit (IC) chips and other components taking place via the bondpad of the chip. NSOP (Non-Stick On pad) is a failure mode of the IC chip that occurs as a result of poor adhesion between the Aluminium (A1) bondpad and either the bond wire or solder contact. Such failures can be observed even for nanoscale chips such as the 65nm, 45nm, 40nm, and 28nm nodes and beyond. In order to eliminate NSOP problem to enhance the yield of products, process engineers from wafer fab and assembly house together with failure analysis engineers have to know what a good quality bondpad is and how to evaluate and qualify. On these common questions and concerns, in this paper, we will study and introduce Al bondpad qualification methodologies (OSAT and OSSD) and eliminate NSOP problem.","PeriodicalId":292144,"journal":{"name":"2018 IEEE 38th International Electronics Manufacturing Technology Conference (IEMT)","volume":"23 10","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120910422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-09-01DOI: 10.1109/IEMT.2018.8511774
Liew Soon Lee, Ruel Aranda, Rasydan Tahir
As technology grows, semiconductor industry is developing towards thinner & smaller packages to meet market demand. Uneven package shrinkage during manufacturing of Molded Matrix Array Package affects the assembly yield and the yield of succeeding processes including test. Thin Small Leadless Package is no exception to this matter and has experienced a high yield loss above 6.58% at test process for one of its packages. This paper discusses and investigates in details some of the factors which might lead to the uneven volumetric shrinkage of the mold across the panel. There are two factors which are investigated thoroughly in this study, namely: the effect of leadframe design; and the effect of assembly processes (molding, post mold cure PMC and reflow process) towards molding compound material characteristics. Thermomechanical simulation is set up to give a better insight on the first factor, meanwhile the latter is addressed via material characterization as well as physical assessment under actual process conditions. After evaluating the results, it is determined that the leadframe geometry gives a more dominant impact on the uneven volumetric shrinkage of the molding compound issue as compared to the process conditions. This brings to a final recommendation to mitigate the shrinkage by balancing the metal content on the vent and gate area of the leadframe.
{"title":"Title: Package Shrinkage on Thin Package","authors":"Liew Soon Lee, Ruel Aranda, Rasydan Tahir","doi":"10.1109/IEMT.2018.8511774","DOIUrl":"https://doi.org/10.1109/IEMT.2018.8511774","url":null,"abstract":"As technology grows, semiconductor industry is developing towards thinner & smaller packages to meet market demand. Uneven package shrinkage during manufacturing of Molded Matrix Array Package affects the assembly yield and the yield of succeeding processes including test. Thin Small Leadless Package is no exception to this matter and has experienced a high yield loss above 6.58% at test process for one of its packages. This paper discusses and investigates in details some of the factors which might lead to the uneven volumetric shrinkage of the mold across the panel. There are two factors which are investigated thoroughly in this study, namely: the effect of leadframe design; and the effect of assembly processes (molding, post mold cure PMC and reflow process) towards molding compound material characteristics. Thermomechanical simulation is set up to give a better insight on the first factor, meanwhile the latter is addressed via material characterization as well as physical assessment under actual process conditions. After evaluating the results, it is determined that the leadframe geometry gives a more dominant impact on the uneven volumetric shrinkage of the molding compound issue as compared to the process conditions. This brings to a final recommendation to mitigate the shrinkage by balancing the metal content on the vent and gate area of the leadframe.","PeriodicalId":292144,"journal":{"name":"2018 IEEE 38th International Electronics Manufacturing Technology Conference (IEMT)","volume":"32 10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125705646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-09-01DOI: 10.1109/IEMT.2018.8511724
Wai Shan Liau, Tek Keong Gan
The common problem vespel collet; the eutectic die bonding process pick up tool; is a short lifespan. The collet tip dimension is similar to shrink chip (size<0.05mm2), which causes an aggressive rubbing effect during die pick and bond cycle. Debris is generated and then accumulated the surrounding of the collet tip surface gradually. Clogged vespel collet tip will result in die pickup issue and accummulated debris will also damage the protruded guard ring design on the chip surface. As such, the vespel collet is then controlled at few ten thousand touchdown. Extending vespel collet lifespan by optimizing die bonding process parameter, changing collet tip dimension and material are not feasible in this situation. The current vespel collet is the hardest material and the smallest tip dimension that can be used in the application. Removing the damaged vespel collet tip by the cleaning process would then be a solution from other perspective. Conventional method is to have manual collet cleaning process offline by human, which lead to high machine idling time and inconsistent collet cleaning quality. An innovative smart manufacturing concept known as “collet auto clean system” is established. It is a programmable fixture that mounted on the die bonding machine to clean vespel collet tip automatically at every predefine touchdown before reaching of the total vespel collet touch down setting. The challenges face are (1) vespel collet tip shape & dimension design to maintain the same tip shape and to withstand the turning force without any broken tip after cleaning, (2) polishing paper grading selection; cleaning parameters definition and cleaned collet tip in-line buyoff for an effective cleaning process. With the implementation of “collet auto clean system”, the vespel collet lifespan is then improved from few ten thousand to few hundred thousand touchdown. Few hundred million parts are delivered without comprising process stability and quality deviation. Vespel collet material consumption has improved from few hundreds pcs to few ten pcs yearly. Also, 3 % collet changing schedule downtime is gained from collet changing interval before every 3 hours to after every 1.2 days.
{"title":"‘Collet Auto Clean System’, A Smart Automatic Solution for Die Bonding Pick Up Tool Lifespan & Throughput Enhancement","authors":"Wai Shan Liau, Tek Keong Gan","doi":"10.1109/IEMT.2018.8511724","DOIUrl":"https://doi.org/10.1109/IEMT.2018.8511724","url":null,"abstract":"The common problem vespel collet; the eutectic die bonding process pick up tool; is a short lifespan. The collet tip dimension is similar to shrink chip (size<0.05mm2), which causes an aggressive rubbing effect during die pick and bond cycle. Debris is generated and then accumulated the surrounding of the collet tip surface gradually. Clogged vespel collet tip will result in die pickup issue and accummulated debris will also damage the protruded guard ring design on the chip surface. As such, the vespel collet is then controlled at few ten thousand touchdown. Extending vespel collet lifespan by optimizing die bonding process parameter, changing collet tip dimension and material are not feasible in this situation. The current vespel collet is the hardest material and the smallest tip dimension that can be used in the application. Removing the damaged vespel collet tip by the cleaning process would then be a solution from other perspective. Conventional method is to have manual collet cleaning process offline by human, which lead to high machine idling time and inconsistent collet cleaning quality. An innovative smart manufacturing concept known as “collet auto clean system” is established. It is a programmable fixture that mounted on the die bonding machine to clean vespel collet tip automatically at every predefine touchdown before reaching of the total vespel collet touch down setting. The challenges face are (1) vespel collet tip shape & dimension design to maintain the same tip shape and to withstand the turning force without any broken tip after cleaning, (2) polishing paper grading selection; cleaning parameters definition and cleaned collet tip in-line buyoff for an effective cleaning process. With the implementation of “collet auto clean system”, the vespel collet lifespan is then improved from few ten thousand to few hundred thousand touchdown. Few hundred million parts are delivered without comprising process stability and quality deviation. Vespel collet material consumption has improved from few hundreds pcs to few ten pcs yearly. Also, 3 % collet changing schedule downtime is gained from collet changing interval before every 3 hours to after every 1.2 days.","PeriodicalId":292144,"journal":{"name":"2018 IEEE 38th International Electronics Manufacturing Technology Conference (IEMT)","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124374315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-09-01DOI: 10.1109/IEMT.2018.8511626
C.L Cha, H.J Chong, HG Yaw, M. Chong, C. Tea
Copper (Cu) wire always gains the population in semiconductor industry for its superior thermal and electrical performance with increase of gold wire price in the market. The expanding use of electronics components in automotive electronics and rising in high reliability requirement are stimulating vigorous research and development on intermetallic (IMC) growth at the interface between Cu wire bonded ball and Aluminum (Al) bond pad metallization. In microelectronics packaging, IMC is an essential for interconnect formation between bonding wire and bond pad metallization. It grows during other assembly processes. Cu-Al intermetallic grows slowly and perceived higher reliability performance compare to Au-Al system especially during high temperature storage stress test. However, Cu wire with Al pad metallization formed type of IMC with no or very narrow range of solubility and this type of compound is very strong but very brittle. This study evaluates bare Cu wire bonding on Al pad metallization. As Cu wire IMC is known hardly observed at T0 after wire bonded, evaluation samples were subject to thermal aging to promote the IMC growth in un-molded strip form. Preliminary responses e.g wire pull, ball shear strength were collected. IMC coverage were analyzed and its growth thickness were examined from cross section sample by scanning electron microscopy (SEM) method. The stability of Cu-Al IMC in molded package form was studied under different high temperature storage stress test condition include both 150°C@2000hrs and 175°C@1000hrs. SEM based analysis technique - energy dispersive x-ray spectroscopy (EDX) is used to identify the IMC phases. Aside, transmission electron microscopy (TEM) analysis is adopted to understand IMC growth behavior and phase in depth. IMC thermal driven degradation mechanism was analyzed and discussed. (literature study, bench mark other study)
{"title":"Cu-Al Intermetallic Growth Behaviour Study Under High Temperature Thermal Aging","authors":"C.L Cha, H.J Chong, HG Yaw, M. Chong, C. Tea","doi":"10.1109/IEMT.2018.8511626","DOIUrl":"https://doi.org/10.1109/IEMT.2018.8511626","url":null,"abstract":"Copper (Cu) wire always gains the population in semiconductor industry for its superior thermal and electrical performance with increase of gold wire price in the market. The expanding use of electronics components in automotive electronics and rising in high reliability requirement are stimulating vigorous research and development on intermetallic (IMC) growth at the interface between Cu wire bonded ball and Aluminum (Al) bond pad metallization. In microelectronics packaging, IMC is an essential for interconnect formation between bonding wire and bond pad metallization. It grows during other assembly processes. Cu-Al intermetallic grows slowly and perceived higher reliability performance compare to Au-Al system especially during high temperature storage stress test. However, Cu wire with Al pad metallization formed type of IMC with no or very narrow range of solubility and this type of compound is very strong but very brittle. This study evaluates bare Cu wire bonding on Al pad metallization. As Cu wire IMC is known hardly observed at T0 after wire bonded, evaluation samples were subject to thermal aging to promote the IMC growth in un-molded strip form. Preliminary responses e.g wire pull, ball shear strength were collected. IMC coverage were analyzed and its growth thickness were examined from cross section sample by scanning electron microscopy (SEM) method. The stability of Cu-Al IMC in molded package form was studied under different high temperature storage stress test condition include both 150°C@2000hrs and 175°C@1000hrs. SEM based analysis technique - energy dispersive x-ray spectroscopy (EDX) is used to identify the IMC phases. Aside, transmission electron microscopy (TEM) analysis is adopted to understand IMC growth behavior and phase in depth. IMC thermal driven degradation mechanism was analyzed and discussed. (literature study, bench mark other study)","PeriodicalId":292144,"journal":{"name":"2018 IEEE 38th International Electronics Manufacturing Technology Conference (IEMT)","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132652800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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