Development of a High Temperature Interconnect Solution as an Alternative to High Lead or Gold Content Solders

2016 ◽  
Vol 2016 (HiTEC) ◽  
pp. 000196-000206
Author(s):  
Martin Wickham ◽  
Kate Clayton ◽  
Ana Robador ◽  
Chris Hunt ◽  
Robin Pittson ◽  
...  
Keyword(s):  
High Temperature ◽  
Electronic Materials ◽  
Research Programme ◽  
National Physical Laboratory ◽  
Electrical Performance ◽  
Processing Temperature ◽  
Gold Content ◽  
Physical Laboratory ◽  
Electronic Assemblies ◽  
High Lead

AbstractA collaborative research programme between project partners Microsemi, the National Physical Laboratory (NPL) and Gwent Electronic Materials (GEM), has successfully developed innovative materials specifically designed to offer an alternative for high Pb or Au content materials to increase the operating temperature of electronic assemblies. Currently, for electronic assemblies to operate at high temperature, they must use a high lead solder or a very expensive gold based solder to withstand these temperatures. The ELCOSINT project has developed an inexpensive lead-free alternative for joining high temperature electronics suitable for operating at temperatures above 250°C utilising standard surface mount assembly processes. This paper summarises the work undertaken by the authors to develop and better understand this new family of electrical interconnection materials. The project brought together a materials supplier (GEM – Gwent Electronic Materials), an end-user (MSL - Microsemi) and an technology research organisation (NPL – National Physical Laboratory) to jointly develop, test and implement in production, the solution based on silver-loaded silicone materials. This paper focuses on the testing and materials evaluation undertaken at NPL to determine the long term performance of these alternative materials including high temperature ageing up to 300°C, thermal cycling and damp heat testing. Details of the shear strength and electrical performance of interconnects between the substrates and components during the test regimes are given. The manufacturing process is outlined including details of the test vehicles utilised. The processing temperature for the conductive adhesive is 250°C which offers additional advantages in potential improvements in component and substrate reliability compared to soldered solutions which would typically be processed at temperatures above 300°C.

HiTeMS: A Pan-European Project to Solve High Temperature Measurement Problems in Industry

2012 ◽  
Vol 45 (10) ◽  
pp. 315-318 ◽  
Author(s):  
Graham Machin
Keyword(s):  
High Temperature ◽  
Temperature Measurement ◽  
Temperature Scale ◽  
Research Programme ◽  
National Physical Laboratory ◽  
The European Union ◽  
Physical Laboratory ◽  
High Temperature Measurement ◽  
Metrology Research ◽  
High Temperature Fixed Points

In my previous article [1] I discussed some of the innovations that are taking place at the National Physical Laboratory (NPL) in improving high temperature measurement. Starting with the current defined temperature scale ITS-90 [2, 3], I introduced the concepts of high-temperature fixed points [4], new types of thermocouple for use to 1500°C [5, 6] and developments in self-validation for contact thermometry sensors [7] and showed that high temperature measurement is undergoing a quiet revolution throughout the measurement chain. Here I want to set the work at NPL in a broader context of developments in the European Union (EU), again led from NPL, through the European Metrology Research Programme project “HiTeMS: High Temperature Measurement Solutions for Industry”.

High Temperature Endurance of Packaged SOI Devices for Signal Conditioning and Processing Applications

2011 ◽  
Vol 2011 (HITEN) ◽  
pp. 000251-000254
Author(s):  
S T Riches ◽  
C Johnston ◽  
M Sousa ◽  
P Grant
Keyword(s):  
High Temperature ◽  
Electronic Materials ◽  
Silicon On Insulator ◽  
Electrical Performance ◽  
Research Centre ◽  
Signal Conditioning ◽  
Reliability Data ◽  
Die Attach ◽  
Soi Devices ◽  
Formed Part

Silicon on Insulator (SOI) device technology is fulfilling a niche requirement for electronics that functions satisfactorily at operating temperatures of >200°C. Most of the reliability data on the high temperature endurance of the devices is generated on the device itself with little attention being paid to the packaging technology around the device. Similarly, most of the reliability data generated on high temperature packaging technologies uses testpieces rather than real devices, which restricts any conclusions on long term electrical performance. This paper presents results of high temperature endurance studies on SOI devices combined with high temperature packaging technologies relevant to signal conditioning and processing functions for sensors in down-well and aero-engine applications. The endurance studies have been carried out for up to 7,056 hours at 250°C, with functioning devices being tested periodically at room temperature, 125°C and 250°C. Different die attach and wire bond options have been included in the study and the performance of multiplexers, transistors, bandgap voltage, oscillators and voltage regulators functional blocks have been characterised. This work formed part of the UPTEMP project which was set-up with support from UK Technology Strategy Board and the EPSRC. The project brought together a consortium of end-users (Sondex Wireline and Vibro-Meter UK), electronic module manufacturers (GE Aviation Systems Newmarket) and material suppliers (Gwent Electronic Materials and Thermastrate Ltd) with Oxford University-Materials Department, the leading UK high temperature electronics research centre.

scholarly journals National Physical Laboratory Radiocarbon Measurements II

Radiocarbon ◽  
1964 ◽  
Vol 6 ◽  
pp. 25-30 ◽  
Author(s):  
W. J. Callow ◽  
M. J. Baker ◽  
Daphne H. Pritchard
Keyword(s):  
Standard Deviation ◽  
Standard Error ◽  
Half Life ◽  
Research Programme ◽  
National Physical Laboratory ◽  
Reference Standard ◽  
Best Value ◽  
Physical Laboratory ◽  
The Difference ◽  
Absolute Age

The following list comprises measurements made since those reported in NPL I and is complete to the end of November 1963.Ages are relative to a.d. 1950 and are calculated using a half-life of 5568 yr. The measurements have been corrected for fractionation and referred to 0.950 times the activity of the NBS oxalic acid as a contemporary reference standard. The quoted uncertainty is one standard deviation derived from a proper combination of the parameter variances, viz. those of the standard and background measurements over a rolling twenty-week period, of the sample measurements from at least three independent fillings, of the δC13 measurements and of the de Vries effect (assumed to add an additional uncertainty equivalent to a standard deviation of 80 yr). Any uncertainty in the half-life has been excluded so that relative C14 ages may be correctly compared. Absolute age assessments, however, should be made using the accepted best value for the half-life and the appropriate uncertainty included. If the net sample activity is less than 4 times the standard error of the difference between the sample and background activities, a lower limit to the age is reported equivalent to a sample activity of 4 times the standard error of this difference.The description of each sample is based on information provided by the person submitting the sample to the Laboratory.The work reported forms part of the research programme of the Laboratory and is published by permission of the Director.

scholarly journals On the high temperature standards of the national physical laboratory: an account of a comparison of platinum thermometers and thermo-junctions with the gas thermo­meter.

1904 ◽  
Vol 73 (488-496) ◽  
pp. 217-219
Author(s):  
John Allen Harker ◽  
Richard Tetley Glazebrook
Keyword(s):  
High Temperature ◽  
Boiling Point ◽  
National Physical Laboratory ◽  
Temperature Standards ◽  
Physical Laboratory

This paper contains an account of a continuation of the work of Dr. P. Chappuis and the author,* on a comparison of the scale of the gas thermometer with that of certain specially-constructed platinum thermometers, from temperatures below zero up to the boiling point of sulphur, and in one case to a point close to 600° C.

Steels for Steam Power Plant

1953 ◽  
Vol 167 (1) ◽  
pp. 414-433
Author(s):  
A. M. Sage
Keyword(s):  
High Temperature ◽  
Power Plant ◽  
National Physical Laboratory ◽  
Research Association ◽  
Creep Tests ◽  
Steam Power ◽  
Iron And Steel ◽  
Steam Power Plant ◽  
Physical Laboratory ◽  
High Temperature Steam

A review of the work carried out for the Steels for High Temperature committee of the British Electrical and Allied Industries Research Association between 1930 and 1952.† In this paper the achievements of the J/E committee between the years 1930 and 1952 are reported. Development of steam power plant largely depends on the physical properties of the materials. Realization of the effects of creep in metals has caused creep data to supersede Hooke's law in the determination of design methods for steam power plant. The study of the effects of creep properties in different steels led to the adoption of chromium- molybdenum, and chromium-molybdenum-silicon and, to a less extent, molybdenum-vanadium steel for the high-temperature components; superheater tubes, steam pipes, and superheater headers for plant using temperatures above 900 deg. F. From creep tests made, the stress-time relation for each component was obtained. Methods of creep testing are compared, and abnormally high creep rates are investigated. The testing of the reliability of long-time creep tests deduced from short-time creep tests is described. Relaxation tests carried out enabled a mathematical relation between relaxation time and stress to be derived. Investigations into the effects on the properties of the steel, of the presence of minor elements in the steel, and the method of manufacture, are described, and also the cause and effects of grain growth. The causes of, and means of avoiding, cracking of steel are studied. Future developments are outlined. FOREWORD C. H. Desch, D.Sc, Ph.D., F.R.S. Chairman of the Steels for High Temperature Committee of B.E.A.I.R.A. Since 1930 the Steels for High Temperature committee of the British Electrical and Allied Industries Research Association has fostered work on the properties of steels used in steam power plant. The committee was formed from the committee of the Department of Scientific and Industrial Research on the behaviour of materials at high temperatures, at a time when the importance of the phenomenon of creep in designing high-temperature steam power plant was being realized. The committee has always included in its membership representatives of leading steel makers, tube manufacturers, turbine builders, and boiler makers. The Admiralty has also been well represented and, also since their formation, the British Electricity Authority and the British Iron and Steel Research Association. The views of metallurgists and engineers concerned with the production and use of high-temperature steels have thus been combined in furthering co-operative work which has effectively contributed to advances in the design and efficiency of British steam power plant. The work of this committee has thus formed an integral part of the development of high-temperature steels which has been made by British industry over the last twenty years. The committee has throughout the work had the co-operation of the Engineering and Metallurgy Divisions of the National Physical Laboratory where most of the investigational work has been carried out. This work has been supported financially by the steel-making and the appropriate user industries. Since the inception of the committee in 1930 a number of detailed technical reports have been issued on various problems which it has investigated. The following report has been prepared to provide an overall picture of the major achievements of the committee. Although he has not been concerned with experimental work, Mr. Sage has had access to all reports and papers connected with the research. The value of the contributions of numerous investigators at the National Physical Laboratory is acknowledged, and Dr. Jenkins and Mr. Tapsell should be specially mentioned as having taken a leading part in the investigation since its inception.

Properties of Steels as a Basis for Design for High-Temperature Service. Part I: Carbon Steels

1940 ◽  
Vol 144 (1) ◽  
pp. 97-106 ◽  
Author(s):  
H. J. Tapsell ◽  
A. E. Johnson
Keyword(s):  
High Temperature ◽  
Carbon Content ◽  
Elevated Temperatures ◽  
National Physical Laboratory ◽  
Carbon Steels ◽  
Research Association ◽  
Physical Laboratory

The paper gives a brief account of the influence of stress, temperature, and time on the behaviour of carbon steels of about 0·15 to 0·50 per cent carbon content, and provides data as a basis for design purposes. The data given are derived from investigations carried out at the National Physical Laboratory, largely on behalf of the British Electrical and Allied Industries Research Association. Although practice has established satisfactory working stresses for carbon steels at moderately elevated temperatures—possibly up to 425 deg. C. (800 deg. F.)—it may serve a useful purpose to include herein particulars of the strength of carbon steels up to 800 deg. F. The chief purpose of the paper, however, is to assist the reader in appreciating the factors involved in estimating the useful strength of steels at higher temperatures extending to about 1,000 deg. F.

316. Temperature control in the H.T.S.T. pasteurization process

1945 ◽  
Vol 14 (1-2) ◽  
pp. 1-20 ◽  
Author(s):  
J. A. Hall
Keyword(s):  
Temperature Measurement ◽  
Temperature Control ◽  
Vapour Pressure ◽  
Research Programme ◽  
National Physical Laboratory ◽  
Experimental Results ◽  
The Other ◽  
Measuring Instruments ◽  
Speed Of Response ◽  
Physical Laboratory

An investigation has been made into the accuracy and speed of response of temperature-measuring instruments suitable for use in the control of H.T.S.T. pasteurization. Thermocouples used in conjunction with a ‘d.c. amplifier’ recorder system are shown to be markedly superior to both vapour-pressure and mercury-in-steel thermometers. The accuracy of temperature measurement is about ±0.3°F. as against ±1°., while the lag constant is about 0.2 sec. as against about 3 sec. Response to small, rapid and transient changes of temperature is also shown to be greatly improved. The operation of control contacts by the thermocouple recorder was found to be reliable to well within the limit of accuracy of calibration, but the other types showed variations of the order of ±1°F., in addition to the uncertainties of calibration.The work described in this paper was undertaken at the request of the National Institute for Research in Dairying as part of the research programme of the National Physical Laboratory, and is published by permission of the Director of the Laboratory. The author wishes to acknowledge the help he has received from Dr A. T. R. Mattick and Miss E. R. Hiscox of the National Institute for Research in Dairying and from his colleagues Mr C. Wigley and Miss V. M. Leaver. Dr Mattick and Miss Hiscox supplied the experimental results given in the introduction, for the drafting of which they are largely responsible. Mr Wigley derived the equations used in computing the theoretical curves of Text-fig. 6 and Miss Leaver assisted with the observational work.

scholarly journals Government science and the Royal Society: the control of the National Physical Laboratory in the inter-war years

1980 ◽  
Vol 35 (2) ◽  
pp. 167-193
Keyword(s):  
Royal Society ◽  
National Laboratory ◽  
Research Programme ◽  
National Physical Laboratory ◽  
Public Institution ◽  
Committee Report ◽  
Physical Laboratory ◽  
Scientific Reputation ◽  
The Government ◽  
Important Position

Throughout the inter-war years attempts by government to stimulate civil industry through the encouragement and application of scientific research were dominated by the activities of the Department of Scientific and Industrial Research (DSIR). During this period the National Physical Laboratory (NPL) enjoyed a particularly important position among the DSIR’s research establishments, both by virtue of its annual budget and its scientific reputation. The latter was in many respects attributable to the Laboratory’s close and long-standing links with the Royal Society which, in principle, was responsible for the direction of the NPL’s research programme. In practice, the control of Britain’s premier national laboratory was a complex matter, and the events of the in ter-war years provide an illustration of the difficulties involved in directing and administering research at a time when policies for science were undergoing a fundamental transformation. The NPL was established in 1900 following sustained pressure exerted through both the Royal Society and the British Association for the Advancement of Science. The Treasury Committee report which recommended that a national laboratory be founded suggested that its functions should be to standardize instruments, to determine physical constants, and to undertake investigations ‘of great importance in connection with the industrial interests of this country, and which would fall very properly among the duties of a public institution’ (1). As a result the Government agreed to provide £4000 per annum, for five years in the first instance, as a grant in aid, and £12,000 for buildings and equipment. The Royal Society was asked to accept responsibility for the control of the laboratory and, despite some reservations concerning the inadequate scale of financial support, agreed to do so (2).

Perspectives of High-Temperature Pb-Free Bonding Materials

2018 ◽  
Vol 2018 (1) ◽  
pp. 000088-000098
Author(s):  
Hongwen Zhang ◽  
Ning-Cheng Lee
Keyword(s):  
High Temperature ◽  
High Power ◽  
Temperature Cycling ◽  
Processing Temperature ◽  
Potential Candidate ◽  
High Porosity ◽  
Solder Paste ◽  
Material Cost ◽  
Die Attach ◽  
High Lead

Abstract High lead solders have been used as die-attach and interconnect materials in discrete power packages. Due to the demand of SiC devices serving the high-power market and the harmful effects of Pb to human health and the environment, alternative Pb-free solders, novel bonding materials, as well as solutions have been studied extensively in recent years. The exemption of using high-Pb solders has been extended again to 2021, although it could be terminated at any time if a new technology or material were to be accepted by the industry. This paper presents potential materials and technologies for high-temperature Pb-free die-attachment, focusing on alternative solders. Sintering materials and transient liquid phase bonding (TLPB) materials have been briefly covered as well. AuSn, AuSi, and AuGe solders have shown to be exceptionally high in cost, which limited their application. BiAg- and BiCu-based solders—the BiAgX® family including solder paste, solder wire, and solder preform—improved wetting and exhibited remelting temperatures of 262°C and 270°C, respectively. The acceptable reliability performance on temperature cycling and thermal aging, as well as low material cost, has made them the most competitive candidates for low-power discrete die-attach devices. SnSbAgCu, with well-designed compositions in recent studies, offers a remelting temperature above 320°C. SnSbAgCu is targeted in markets for mid-to-high power devices. Reliability testing for other recently designed SnSbAgCu pastes for various die-attach vehicles is being studied. ZnAl has a remelting temperature above 380°C and an extremely low material cost (comparable to or even lower than the high-lead solders). Although the bonding process is stringent, the excellent thermomechanical behavior and the superior thermal/electrical conductivity have allowed ZnAl to be a potential candidate for high-temperature/high-power die-attach that is competitive with AuSi and AuGe solders. Sintering materials form bonds through solid state interdiffusion, while TLPB materials create a joint through solid-liquid interdiffusion, in which the remelting temperature is enhanced by forming massive IMCs. The desired high thermal/electrical/mechanical/melting performances, as well as the relatively low processing temperature (<350°C), are shining the sintering materials (especially Ag-sintering materials). The intrinsic high porosity (>20%) and the evolution of pores from pressureless sintering may overshadow the reliability. In addition, the immaturity of the processing (time/temperature/pressure/atmosphere/equipment availability, etc.) may deter the industrial adoption of sintering materials. So far, none of these materials or technologies is ideal to satisfy all the requirements of the variety of high-temperature, Pb-free die-attach applications in terms of processing, reliability, and cost. However, each material and solution has the potential to be a niche within this broader categorization.

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