IEEE Transactions on Parts, Hybrids, and Packaging最新文献

{"title":"The Reliability of Soldered or Epoxy Bonded Chip Capacitor Interconnections on Hybrids","authors":"G. Dreyer, A. Koudounaris, I. Pratt","doi":"10.1109/TPHP.1977.1135212","DOIUrl":"https://doi.org/10.1109/TPHP.1977.1135212","url":null,"abstract":"The influence of capacitor chip-to-substrate assembly variables on interconnect reliability was evaluated using several conventional environmental tests. The variables investigated included: capacitor chip size, capacitor end metallization, substrate pad size, substrate metallization, different solders, and a nonconduetive and a conductive epoxy. Environmental tests consisted of mechanical shock, temperature cycling, and high temperature storage. The test specimens included three capacitor sizes: 0.050 X 0.080 in, 0.080 X 0.180 in, and 0.080 X 0.270 in, all 0.050 in high; and three end terminations: silver, palladium-silver, and an Sn60-Pb36-Ag4 solder coating. Substrate pad sizes were varied to represent large, medium, and small bonding areas. Capacitors having all three end terminations were reflow soldered on Sn10-Pb88-Ag2 or Sn96-Ag4 tinned pads, by reflowing Sn62-Pb-36-2Ag paste, or by Silver conductive epoxy bonding with Ablefilm 606-2 (commonly used for bonding active devices). Also, capacitors with palladium-silver end terminations were bonded with nonconductive epoxy, while the electrical interc0nnection from substrate to chip was made by thermocompression bonded gold wire. Two types of substrate metallization were used: a) thin film nichrome, nickel, gold;b) thick film platinum-gold. Testing consisted of the sequential exposure:· i) to 3000-G mechanical shock (5 pulses), ii) temperature cycling from -65 to 150°C (100 cycles), iii) 3000-G mechanical shock (5 pulses), and iv) high temperature exposure at 150°°C for one week (168 h). All chips were visually and electrically checked after each test. Capacitor attachment was more reliable when small chips were bonded to thick f'dm metallization and when the bonding pads were large. Snl0 solder or nonconductive epoxy were the most reliable inter, connect materials. When soldering, the best electrical and mechanical end terminations were palladium-silver; the appearance of silver end terminations changed during environmental testing, but solder coated or palladium-silver terminations were visually unaffected. When conductive epoxy bonding, no differences were noted between silver or palladium-silver terminations. Visual examination was of minimal value in detecting marginal chip attachments. The most effective environmental test combination was thermal cycling followed by mechanical shock.","PeriodicalId":387212,"journal":{"name":"IEEE Transactions on Parts, Hybrids, and Packaging","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1977-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124217110","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":"Computerized Thermal Analysis of Hybrid Circuits","authors":"R. David","doi":"10.1109/TPHP.1977.1135213","DOIUrl":"https://doi.org/10.1109/TPHP.1977.1135213","url":null,"abstract":"A computer program was written to perform steady-state analysis for hybrid circuits. The output of the program gives the temperature of each power dissipating element in the hybrid. The program is based upon solution of Laplace's equation in three dimensions using Fourier techniques. The assumptions made are: no convection or radiation, constant and isotropic thermal conductivity for any single material, and constant temperature at the bottom of the hybrid package. Bessel's inequality allows one to input the desired accuracy and to determine where the infinite series should be truncated. Theoretically, the program will attain any desired accuracy less than 100 percent, but practical considerations of computer run times limit accuracies to the 90- to 95-percent region. The program has been tested by comparing computer results to known theoretical exact solutions and to actual measurements on sample hybrids. When compared to known theoretical exact solutions, the computer result accuracy is between 95 and 100 percent. When compared to actual measurements on sample hybrids, the computer result accuracy is between 90 and 95 percent. This program has been used successfully on over twenty circuit designs. It has also been used to evaluate simpler types of thermal anal- yses.","PeriodicalId":387212,"journal":{"name":"IEEE Transactions on Parts, Hybrids, and Packaging","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1977-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128932124","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 Foil Edge Modifications and Configurational Changes on Energy Storage Capacitor Weight","authors":"R. Parker","doi":"10.1109/TPHP.1977.1135204","DOIUrl":"https://doi.org/10.1109/TPHP.1977.1135204","url":null,"abstract":"Corona failure at foil edges is the principal failure mechanism in well-designed and manufactured high energy-density pulse-discharge capacitors. By forming the foil edge with laser cutting or spark discharge machining, a 25-percent increase in corona inception voltage (CIV) over untreated edges is obtained. Folded foil produces a larger increase. Weight minimization using peak edge field as the limiting factor suggests that a configuration where the foil and dielectric are of equal thickness produces the lightest capacitor. Typical designs are presented.","PeriodicalId":387212,"journal":{"name":"IEEE Transactions on Parts, Hybrids, and Packaging","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1977-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132404795","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":"Hybrid Microcircuit Tape Chip Carrier Materials/Processing Trade-Offs","authors":"J. Smith, S. Stuhlbarg","doi":"10.1109/TPHP.1977.1135197","DOIUrl":"https://doi.org/10.1109/TPHP.1977.1135197","url":null,"abstract":"This paper surveys and compares several metallurgical structures and compositions used in the various reel-to-reel gang bonding processes now being implemented by high-volume semiconductor manufacturers. Various gang bonding techniques are reviewed briefly as background. Thermocompression (TC), hard solder, and soft solder inner lead bonding processes are compared, as well as TC, welding, and solder processes for outer lead bonding to lead frames or alumina-based networks. The characteristics, advantages and disadvantages of 1, 2, 3 layer interconnect metallizations, different bump structures, TC and solder bonding processes, and various carrier materials are discussed and compared.","PeriodicalId":387212,"journal":{"name":"IEEE Transactions on Parts, Hybrids, and Packaging","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1977-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115275528","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":"Obtaining High Reliability Performance from Commercial Quality Opto-Isolators","authors":"I. Doshay, M. Kalashian","doi":"10.1109/TPHP.1977.1135208","DOIUrl":"https://doi.org/10.1109/TPHP.1977.1135208","url":null,"abstract":"Techniques are presented for effectively screening plastic DIP opto-isolators for latent dark current leakage and premature current transfer end of life, with resultant low laboratory field failure rates. Investigations are described which included long life tests conducted at TRW Components Laboratories and vendor test laboratories, and field experience with TRW/Data Systems and TRW/VIDAR/Digital Products equipment. Resultant from these investigations were discovery of environmental stress conditions for predictable rates of dark current leakage acceleration and annealing, and for criteria and test conditions to identify latent premature end-of life current transfer characteristics. These findings were instrumental in the development of customized burn-in and screening techniques to effectively surface parts with latent infant mortality characteristics. Field failure rates were improved to less than eleven failures per billion hours. Laboratory test experience projects to failure rates of less than 13 failures in 109device-operating h at 25°C for these specially screened devices. This is approximately 100 times improvement over prior life experience of similar commercial and \"high rel\" devices, thus resulting in significant maintenance cost savings.","PeriodicalId":387212,"journal":{"name":"IEEE Transactions on Parts, Hybrids, and Packaging","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1977-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127219008","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":"Tab Lead Capacitor","authors":"G. Love, E. McLaurin, W. Hucks","doi":"10.1109/TPHP.1977.1135215","DOIUrl":"https://doi.org/10.1109/TPHP.1977.1135215","url":null,"abstract":"Differential thermal expansion between a monolithic chip capacitor and the common hybrid substrate materials gives rise to significant stresses in the chip. For conventional attach techniques and conventional chips, these stresses may exceed the strength of one or more of the components, chip, termination, substrate metallization, or solder, in the assembly with disastrous effects. Further, common choices of materials aggravate the basic problem by \"building-in\" opportunities for delayed failure due to slow formation of brittle intermetallies in the assembly. We have examined this problem in detail, and we offer a solution that incorporates material, process, and design innovations which essentially eliminate these problems as sources of device failure.","PeriodicalId":387212,"journal":{"name":"IEEE Transactions on Parts, Hybrids, and Packaging","volume":"217 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1977-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127124057","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":"Design of a Single Stress-Relaxation Test for Pressure Connections","authors":"R. Goel","doi":"10.1109/TPHP.1977.1135210","DOIUrl":"https://doi.org/10.1109/TPHP.1977.1135210","url":null,"abstract":"Pressure connections, for example, solderless wrap, sprit beam type, etc., have a common design principle of maintaining a high pressure at the interface of the wire and the terminal. Because of the creep characteristics of all materials, such connections can lose their pressure sustaining ability with time and temperature. Considering the long expected life of a connection, usually 40 years, and the ever in· creasing operating temperatures, made necessary by miniaturization of telephone equipment, the loss of force in a connection may become exceedingiy large and may make the connection vulnerable to mechanical disturbances and attacks from the pollutants in the environment. A method of extrapolating force loss at the contact interface from short-term data to long-term expectation is discussed. Based on the concept of thermally activated processes, an accelerated stress-relaxation test is designed that would cause the expected service rife relaxation to occur in a shorter period. Finally, it is shown that, to simulate a given service condition for all alloys of a common base metal, it is possible to choose a metal system among them that will yield a severe test condition for all alloys in that group. For example, it is shown that the 118°C-33 day stress-relaxation test used for simulating service conditions of 57°C for 40 years of copper C102 (OF copper) would induce as much or more relaxation than would occur in 40 years at 57°C in any copper-based alloy used as a spring material.","PeriodicalId":387212,"journal":{"name":"IEEE Transactions on Parts, Hybrids, and Packaging","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1977-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125568991","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":"Reduced Gold-Plating on Copper Leads for Thermocompression Bonding-Part I: Initial Characterization","authors":"N. Panousis, P. Hall","doi":"10.1109/TPHP.1977.1135201","DOIUrl":"https://doi.org/10.1109/TPHP.1977.1135201","url":null,"abstract":"In this two part series, Au-plated Cu leads with reduced Au thicknesses are evaluated for thermocompression (TC) bonding. Part I is concerned with initial characterization, which makes use of recent measurements of grain boundary diffusion coefficients (D') of Cu through Au. Part II considers the problem of predicting the long term reliability (40 years at 50°C) of these TC bonds, using recent measurements of the volume interdiffusion coefficients (D). Oxygen-free Cu leads plated with as little as 0.7 µm Au were compared to the more typical plating thickness of about 2.5 µm. The properties evaluated in Part I are: 1) initial TC bondability; and 2) prebond shelf life, i.e., TC bondability after storage of the Au-plated leads. Results of these evaluations are the following. 1) Leads plated with as little as 0.7 µm Au can have acceptable initial TC bond strengths especially when bonded at 30 to 50 percent deformation. 2) High-temperature storage of the leads followed by TC bonding indicates a shelf life of greater than two years at 50°C. This is in agreement with predictions based on grain boundary diffusion of Cu through Au: D' = 8 x 10-5exp (-0.91 eV/kT) [cm2/s]. Thus the initial characterization was successful for Au thicknesses down to 0.7 µm.","PeriodicalId":387212,"journal":{"name":"IEEE Transactions on Parts, Hybrids, and Packaging","volume":"43 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1977-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120994791","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":"Performance of New Copper Based Metallization Systems in an 85°C 80-Percent RH Cl 2 Contaminated Environment","authors":"N. Sbar, L. Feinstein","doi":"10.1109/TPHP.1977.1135194","DOIUrl":"https://doi.org/10.1109/TPHP.1977.1135194","url":null,"abstract":"The performance of TPCNA (Ti-Pd-Cu-Ni-Au) and TCN+A (Ti-CuoNi+Au in selected areas only) meta!lizations in 85°C, 80-percent RH, with 0.5 to 1.8 ppm Cl 2 was compared with that of the standard TPA (Ti-Pd-Au) metallization. Encapsulated (RTV silicone rubber) and unencapsulated triple track conductor test specimens were used. Electrolytic corrosion was studied by biasing the specimens in the high humidity corrosive environment and measuring in situ leakage currents as a function of time. For the unencapsulated specimens, leakage currents increased and all samples failed by 600 h. The failure rates for TPCNA and TCN+A samples due to the formation of Cu and Ni dendrites between oppositely biased conductors were the same as for TPA which had Au and Pd dentrites. None of the encapsulated samples showed dendrite growth after ~ 1000 h. Unencapsulated TPCNA and TCN+A were less resistant to galvanic corrosion in the moist Cl 2 contaminated environment than were the TPA specimens. TCN+A failed first by Ti-Cu delamination and later by delamination of the Au due to corrosive oxidation of the underlying Ni. This latter failure mode was predominant for TPCNA. TPA conductors eventually failed at Ti-Pd interfaces. At 85°C, 80-percent RH, 1.6 ppm C!2, unencapsulated TCN+A degraded at the Ti-Cu interface ~10 times faster than unencapsulated TPA at the Ti-Pd interface. The corrosion product found on unencapsulated TPCNA and TCN+A and on Cu-NiAu external leads was identified as Cu, NiCl 2 . 3 [Cu, Ni(OH) 2 ]. The encapsulant was extremely effective in retarding galvanic corrosion. For encapsulated TCN+A and TPCNA, eventual bond failures were the result of penetration of the corrosive environment under the edges of the encapsulant. For TCN+A, encapsulation retarded the time to failure by a factor of >10. The relative resistance to galvanic corrosion in moist Cl 2 may be ranked TPA > TPCNA > TCN+A.","PeriodicalId":387212,"journal":{"name":"IEEE Transactions on Parts, Hybrids, and Packaging","volume":"304 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1977-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129293277","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":"Reliability Study of a High-Precision Thick Film Resistor Network","authors":"Y. Nakada, T. L. Schock","doi":"10.1109/TPHP.1977.1135207","DOIUrl":"https://doi.org/10.1109/TPHP.1977.1135207","url":null,"abstract":"This investigation was undertaken to determine the reliability of a thick film resistor network, comprised of 4 matched 1.1 M Omega resistors. The objectives of the program were: 1) to define any potential failure mechanism and 2) to determine the end-of-life (20 years) resistot properties. These objectives were achieved by a simulated life-testing of the resistor networks through the use of accelerated aging tests in various environments. Four resistor network properties were measured in this study: 1) resistance of individual resistor; 2) bridge imbalance voltage; 3) resistor noise; and 4) temperature coefficient of resistance. Evaluation of the data obtained in the present investigation resulted in the following conclusions. l)There is no potential failure mechanism that will cause the resistor network to degrade outside its end-of-life requirements during its lifetime. 2) The extrapolation of the high-temperature aging data to maximum operating temperature (70°C) indicates that the resistance value will not increase more than 0.5 percent in 20 years. 3) Other properties such as noise, stability against lightning surge, and temperature coefficient of resistance were insensitive to any aging treatments.","PeriodicalId":387212,"journal":{"name":"IEEE Transactions on Parts, Hybrids, and Packaging","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1977-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130470849","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}