{"title":"Investigation of Thermosonic Wire Bonding Resistance of Gold Wire Onto Copper Pad","authors":"Y. Jeng, S. Chiu, P. Huang, Shiuh-Hwa Shyu","doi":"10.1109/TEPM.2009.2034467","DOIUrl":"https://doi.org/10.1109/TEPM.2009.2034467","url":null,"abstract":"This paper discusses the electric performance for thermosonic wire bonding of gold wire onto copper pads. Various methods normally used to improve bondability were investigated including the bare copper pads with argon shielding gas and the copper pads with cupric oxide film, cuprous oxide film, and silver film. The micro-contact theory was used to determine the effective contact area. The circuit contact resistance was measured for each sample and was presented in terms of ultrasound power and effective contact area. The results show that the increase in the effective contact area leads to a lower circuit contact resistance before reaching a minimum value, and further increase in the effective contact area would not have noticeable effect on the resistance.","PeriodicalId":55010,"journal":{"name":"IEEE Transactions on Electronics Packaging Manufacturing","volume":"11 1","pages":"65-70"},"PeriodicalIF":0.0,"publicationDate":"2010-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81590910","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}
H. Reynolds, J. Osenbach, G. Henshall, R. Parker, P. Su
{"title":"Tin Whisker Test Development—Temperature and Humidity Effects Part I: Experimental Design, Observations, and Data Collection","authors":"H. Reynolds, J. Osenbach, G. Henshall, R. Parker, P. Su","doi":"10.1109/TEPM.2009.2030179","DOIUrl":"https://doi.org/10.1109/TEPM.2009.2030179","url":null,"abstract":"The effects of temperature and humidity on tin whisker growth were investigated through a collaborative project sponsored by the International Electronics Manufacturing Initiative (iNEMI) and its member companies. A broad range of testing conditions was adopted to test a variety of components with matte tin (Sn) plating and copper (Cu)-based leadframes. The primary goal of the study was to collect data that could be used to develop mathematical models (acceleration functions) that describe the dependence of tin whisker growth and corrosion on temperature and humidity. This paper describes the background, experimental design, data collection and reports results. Part II of the study (J. W. Osenbach et a. ?Tin whisker test development-Temperature and humidity effects part II: Acceleration model development,? Electronics Packaging Manufacturing, Vol. 33, no. 1, pp., Jan. 2010) discusses in the data analyses and acceleration model development. Storage testing was performed over a wide range of temperature and humidity conditions from 30?C to 100?C and from 10% to 90% relative humidity (RH). Commercially produced components with both 3 ?m and 10 ?m thicknesses from three sources were evaluated. For components with the 10 ?m-plating, the plating was evaluated in both the as-plated and reflowed (260?C) conditions. These variations resulted in a large experimental matrix that included 13 different Sn platings, aged at ten different temperature and humidity combinations. Further, the aging test was done at five different laboratories with inspections performed at eight different laboratories. The data collected include 1) corrosion incubation time, 2) tin whisker incubation time, and 3) dependence of the maximum whisker length on storage time at each temperature/humidity condition. Data suggest that corrosion is not a unique driving force for whisker initiation and growth. Whisker formation differs in corroded and non-corroded regions. Due to the scope of this work, it is broken down into two papers. The data and experimental observations are discussed in this paper. The mathematical model development, discussion of results and conclusions are included in Part II of this study.","PeriodicalId":55010,"journal":{"name":"IEEE Transactions on Electronics Packaging Manufacturing","volume":"33 1","pages":"1-15"},"PeriodicalIF":0.0,"publicationDate":"2010-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80406433","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}
J. Osenbach, H. Reynolds, G. Henshall, R. Parker, P. Su
{"title":"Tin Whisker Test Development—Temperature and Humidity Effects Part II: Acceleration Model Development","authors":"J. Osenbach, H. Reynolds, G. Henshall, R. Parker, P. Su","doi":"10.1109/TEPM.2009.2032919","DOIUrl":"https://doi.org/10.1109/TEPM.2009.2032919","url":null,"abstract":"The incubation time for both whisker growth and corrosion in thin Sn platings (3-10 ¿m thick) on Cu-based alloys have been found to be well represented by an exponential function of humidity and an Arrhenius function of temperature for both as-deposited and reflowed tin platings. Furthermore, whisker growth was found to follow the same functionality in both corroded and non-corroded regions of the plating. The effective activation energies and humidity coefficients were found to depend upon plating thickness, exposure to reflow, and presence of corrosion. The effective activation energies ranged from 0.23 eV to 0.41 eV and the humidity coefficients ranged from -0.012% to -0.031%. Corrosion enhanced whisker growth occurred by lowering the effective activation energy for whisker growth. A theory based on excess, non-creep relaxed, oxidation induced strain was developed to explain the corrosion induced energy barrier lowering. The data showed that 60°C/87%RH appears to be the optimal high temperature/high humidity test condition at this time for Sn over Cu substrates. Within the limits of the whisker and corrosion (incubation) acceleration functions developed in this study, it is concluded that the JEDEC tests can be used to indicate behavior at other temperature/humidity points that could be relevant storage or service conditions.","PeriodicalId":55010,"journal":{"name":"IEEE Transactions on Electronics Packaging Manufacturing","volume":"61 1","pages":"16-24"},"PeriodicalIF":0.0,"publicationDate":"2010-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82053085","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}
Hsien-Chie Cheng, Wan Hwang, K. Kao, J. Tsang, S. Yang, Chao-Chyun An, S.M. Chang
{"title":"Thermal-Mechanical Process Simulation of an Advanced NCF Technology","authors":"Hsien-Chie Cheng, Wan Hwang, K. Kao, J. Tsang, S. Yang, Chao-Chyun An, S.M. Chang","doi":"10.1109/TEPM.2009.2030958","DOIUrl":"https://doi.org/10.1109/TEPM.2009.2030958","url":null,"abstract":"The paper introduces an advanced nonconductive film (NCF) typed FC technology employing a novel compliant composite interconnect structure. The interconnect reliability and bondability of the technology are demonstrated through experimental thermal humidity (TH) test in conjunction with a two-point daisy chain resistance measurement. The alternative goal of the study aims to look into the insight of the thermal-mechanical behaviors of the novel packaging technology during NCF bonding process and thermal testing through numerical modeling and experimental validation. For effectively simulating the bonding process, a process-dependent finite-element (FE) simulation methodology is performed. The validity of the proposed methodology is verified through several experimental methods, including a Twyman-Green (T/G) interferometry technique for warpage measurement, and a four-point probe method for contact resistance measurement. At last, a design guideline for improved process-induced thermal-mechanical behaviors is presented through parametric FE analysis. Both numerical and experimental results demonstrate the feasibility in applying the novel compliant interconnects to achieve a proper contact stress at various temperature environments so as to hold a low and stable connection resistance at elevated temperature. Most importantly, the novel interconnects survive the 85degC/85%RH TH test for 500 hours.","PeriodicalId":55010,"journal":{"name":"IEEE Transactions on Electronics Packaging Manufacturing","volume":"19 1","pages":"301-310"},"PeriodicalIF":0.0,"publicationDate":"2009-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82542076","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}
O. M. Amirmajdi, R. Ashyer-Soltani, M. Clode, S. Mannan, Yunqi Wang, E. Cabruja, G. Pellegrini
{"title":"Cross-Section Preparation for Solder Joints and MEMS Device Using Argon Ion Beam Milling","authors":"O. M. Amirmajdi, R. Ashyer-Soltani, M. Clode, S. Mannan, Yunqi Wang, E. Cabruja, G. Pellegrini","doi":"10.1109/TEPM.2009.2029344","DOIUrl":"https://doi.org/10.1109/TEPM.2009.2029344","url":null,"abstract":"Mechanical cross-section polishing has traditionally been the method of choice for preparing samples to be examined by scanning electron microscopy (SEM). Although mechanical polishing, allied to selective chemical etching can reveal the most important characteristics of solder joint microstructure, subtle details may be lost. A relatively new cross section polishing method has been developed using an argon ion beam to prepare a flat surface with potentially less sample damage. In this study we compare these two methods of cross section polishing for solder-substrate couples, and for delicate MEMS type structures. Four solder samples were prepared, consisting of SAC (Sn-Ag-Cu) solder, SAC solder on copper substrate, SAC solder on nickel substrate and In-Sn solder on niobium substrate. SEM was used to examine the polished samples and it was found that features such as the internal structure of intermetallic compounds (IMCs) was more readily identified using the new technique. The ion beam milling technique was also found to be more suitable for simultaneous observation of multiple aspects of microstructure (e.g., identification of IMCs in relation to grain boundaries, substrate crystal structure or the eutectic solder structure). The MEMS device cross-sections could only be prepared by the ion beam method as mechanical polishing caused too much damage.","PeriodicalId":55010,"journal":{"name":"IEEE Transactions on Electronics Packaging Manufacturing","volume":"19 1","pages":"265-271"},"PeriodicalIF":0.0,"publicationDate":"2009-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85926747","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}
{"title":"Effect of Lead-Free Soldering on Key Material Properties of FR-4 Printed Circuit Board Laminates","authors":"R. Sanapala, B. Sood, D. Das, M. Pecht","doi":"10.1109/TEPM.2009.2029566","DOIUrl":"https://doi.org/10.1109/TEPM.2009.2029566","url":null,"abstract":"The transition to lead-free soldering of printed circuit boards (PCBs) using solder alloys such as SnAgCu has resulted in higher temperature exposures during assembly compared with eutectic SnPb solders. The knowledge of PCB laminate material properties and their dependence on the material constituents, combined with their possible variations due to lead-free soldering temperature exposures, is an essential input in the laminate selection process. This paper provides laminate selection guidelines that were arrived at by assessing key material properties (glass transition temperature, coefficient of thermal expansion, decomposition temperature, and water absorption), and their responses to lead-free soldering assembly conditions. A range of commercially available FR-4 PCB laminate materials, classified on the basis of glass transition temperature (high, mid, and low), curing agents (dicyandiamide and phenolic), flame retardants (halogenated and halogen-free), and fillers (presence or absence) were studied. The laminate material properties under investigation were measured as per the IPC-TM-650 test methods before and after exposure to multiple lead-free soldering cycles. Combinatorial property analysis was conducted to investigate the causes behind variations in material properties.","PeriodicalId":55010,"journal":{"name":"IEEE Transactions on Electronics Packaging Manufacturing","volume":"6 1","pages":"272-280"},"PeriodicalIF":0.0,"publicationDate":"2009-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79543526","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}
{"title":"Chemical and Mechanical Analysis of PCB Surface Treated by Argon Plasma to Enhance Interfacial Adhesion","authors":"D. Shin, Hyosug Lee, J. Im","doi":"10.1109/TEPM.2009.2029700","DOIUrl":"https://doi.org/10.1109/TEPM.2009.2029700","url":null,"abstract":"Plasma treatment of printed circuit board (PCB) is a common step in the electronic packaging processes in order to modify the surface and enhance its adhesion to molding compound. In this paper, PCB surface modifications resulting from plasma treatment were investigated by chemical and mechanical analysis methods. The PCB substrate in consideration was for multichip package, consisting of a core layer sandwiched by solder resist (SR) material, which in turn was composed of epoxy, acryl resins, and several kinds of fillers. Argon was employed as a plasma gas and the number of times that the plasma treatment was applied was chosen as a variable to estimate the effect of repeated exposure to the SR surface during the manufacturing process. The resulting surface conditions were analyzed using roughness measurement, water contact angle measurement, X-ray photoelectron spectroscopy (XPS), nano-indentation, and nano-scratch test method. Comprehensive analyses made it possible to understand the characteristics of the effect of plasma on the PCB surface, i.e., SR material. It was found that the surface roughness after the one-time plasma treatment increased from ~ 62 to ~ 90nm, then decreased more or less to the initial level after three and eight times of repeated treatments. These roughness trends were explained by cleaning out contaminants accumulated in the surface crevices and then preferentially removing or melting away a thin resin layer from the peaks on the surface. The plasma treatment decreased the contact angle significantly and increased work of adhesion. Chemical analysis of these surfaces by XPS showed that the C-C bonds in SR were broken, the population of the polar groups such as O-H, C=O, and COOH increased, and the oxygen content increased. The polar groups increased surface energy, and resulted in increased PCB adhesion with the epoxy molding compound (EMC). Mechanical analysis by nano-indentation and nano-scratch test showed that the surface became soft and weak if plasma treatment was too excessive. In this case, a plasma affected zone corresponding to the severe C-C bond breakage was formed near the surface and the adhesion with EMC suffered. Therefore, caution should be exercised in determining the degree of plasma treatment needed.","PeriodicalId":55010,"journal":{"name":"IEEE Transactions on Electronics Packaging Manufacturing","volume":"52 1","pages":"281-290"},"PeriodicalIF":0.0,"publicationDate":"2009-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83298846","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}
{"title":"Optimizing SMT Performance Using Comparisons of Efficiency Between Different Systems Technique in DEA","authors":"A. Al-Refaie","doi":"10.1109/TEPM.2009.2029238","DOIUrl":"https://doi.org/10.1109/TEPM.2009.2029238","url":null,"abstract":"Surface-mount-technology (SMT) enables production of reliable printed circuit board at a reduced weight, volume, and cost. Nevertheless, SMT defects increase quality costs and deteriorate performance. In reality, defects are not equally important and their corresponding quality costs vary. In these regards, this research divides SMT defects into three classes; minor, major, and serious. Eight key factors from SMT processes are investigated concurrently with L18(21 times 37) array. Taguchi's accumulation analysis method is first applied and it provides incomplete optimal levels for some factor. In this research, each experiment is treated as a decision making unit (DMU) with defect counts set as inputs. Comparisons of efficiency between different systems (CEBDS) technique in data envelopment analysis (DEA) is then adopted to optimized SMT performance. The corresponding actual improvements in minor, major, and serious defect counts are found 0.352, 2.153, and 4.154 dB, respectively. Analysis of variance (ANOVA) is finally performed to determine significant factor effects. It is found that conveyor speed and reflow temperature are the most influential factors on SMT performance. In conclusion, the CEBDS technique turns out to be an efficient approach for optimizing process performance with categorical data.","PeriodicalId":55010,"journal":{"name":"IEEE Transactions on Electronics Packaging Manufacturing","volume":"77 1","pages":"256-264"},"PeriodicalIF":0.0,"publicationDate":"2009-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79294035","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}
{"title":"Constitutive and Aging Behavior of Sn3.0Ag0.5Cu Solder Alloy","authors":"K. Mysore, G. Subbarayan, V. Gupta, Ron Zhang","doi":"10.1109/TEPM.2009.2024119","DOIUrl":"https://doi.org/10.1109/TEPM.2009.2024119","url":null,"abstract":"We describe double-lap shear experiments on Sn3.0Ag0.5Cu solder alloy, from which fits to Anand's viscoplastic constitutive model, power-law creep model, and to time-hardening primary-secondary creep model are derived. Results of monotonic tests for strain rates ranging from 4.02E-6 to 2.40E-3 s-1, and creep response at stress levels ranging from 19.5 to 45.6 MPa are reported. Both types of tests were conducted at temperatures of 25degC, 75degC , and 125degC. Following an earlier study where Anand model and time hardening creep parameters for Sn3.8Ag0.7Cu and Sn1.0Ag0.5Cu solder alloys were reported, here we report power law model parameters so as to enable a comparison between all three alloys. Primary creep in Sn3.0Ag0.5Cu solder alloy is shown to be significant and are considered in addition to secondary creep and monotonic behavior. Aging influence on behavior is also shown to be significant. On the basis of experimental data, the following four aspects are discussed: 1) difference between testing on bulk versus joint specimen; 2) consistency between the creep and monotonic behaviors; 3) comparison against behaviors of Sn1.0Ag0.5Cu and Sn3.8Ag0.7Cu alloys as well as aganist Sn40Pb, 62Sn36Pb2Ag and 96.5Sn3.5Ag alloys; and 4) comparison of Sn3.0Ag0.5Cu and Sn3.8Ag0.7Cu relative to their aging response.","PeriodicalId":55010,"journal":{"name":"IEEE Transactions on Electronics Packaging Manufacturing","volume":"4 1","pages":"221-232"},"PeriodicalIF":0.0,"publicationDate":"2009-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87994387","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}
{"title":"Effects of Defects on the Thermal and Optical Performance of High-Brightness Light-Emitting Diodes","authors":"Liuxi Tan, Jia Li, Kai Wang, Sheng Liu","doi":"10.1109/TEPM.2009.2027893","DOIUrl":"https://doi.org/10.1109/TEPM.2009.2027893","url":null,"abstract":"Defects in terms of voids, cracks, and delaminations are often generated in light-emitting diodes (LEDs) devices and modules. During various manufacturing processes, accelerated testing, inappropriate handling, and field applications, defects are most frequently induced in the early stage of process development. One loading is due to the nonuniform loads caused by temperature, moisture, and their gradients. In this research, defects in various cases are modeled by a nonlinear finite-element method (FEM) to investigate the existence of interfaces, interfacial open and contacts in terms of thermal contact resistance, stress force nonlinearity, and optical discontinuity, in order to analyze their effects on the LED's thermal and optical performance. The simulation results show that voids and delaminations in the die attachment would enhance the thermal resistance greatly and decrease the LED's light extraction efficiency, depending on the defects' sizes and locations generated in packaging.","PeriodicalId":55010,"journal":{"name":"IEEE Transactions on Electronics Packaging Manufacturing","volume":"1 1","pages":"233-240"},"PeriodicalIF":0.0,"publicationDate":"2009-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90761082","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}