Die Attach for High Temperature Electronics Packaging (original) (raw)
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High-temperature die-attaches for SiC power devices
2011
SiC devices have been substituted to Si dies for high temperature applications. However, classical packagings are not adapted for harsh environment and new solutions for back-side die attach must be envisaged. In this paper, theoretical basis and results for nano-silver sintering Transient Liquid Phase Bonding will be presented.
Evaluation of High Temperature Joining Technologies for Semiconductor Die Attach
Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT), 2017
The development of novel high temperature die attach methods for semiconductor packaging enables use in harsh environments and unique opportunities for demanding industrial applications such as controls and monitoring for next generation engine and airframe platforms. Traditional die attach materials including lead solders and conductive adhesives cannot meet requirements of operation temperatures up to and exceeding 300°C due to their limited melting and glass transition temperatures [1]. The Manufacturing Technology Centre Ltd (MTC) has evaluated a range of high temperature die attach materials and processes for silicon and silicon carbide (SiC) semiconductors. Assembly processes were explored for bonding components with and without a back metallisation and with capability to support electrical back contact if required. Die attach methods evaluated include:Sinterable silver materials for back metallised semiconductor componentsSilver glass for non-back metallised semiconductor com...
SiC die-substrate connections for high temperature applications
2009
Silicon carbide (SiC) became very attractive material for high temperature and high power electronics applications due to its physical properties, which are not attainable in conventional Si semiconductor. However, the reliability of SiC devices is limited by assembly processes comprising die attachment and interconnections technology as well as the stability of ohmic contacts at high temperatures. The investigations of a die to substrate connection methods which can fulfill high temperature and high power requirements are the main focuses of the paper. In our researches following die attach technologies were applied: adhesive bonding with the use of organic and inorganic conductive compositions, solder bonding by means of gold germanium alloys, die bonding with the use of thermal conductive adhesive foil and joining technology based on low temperature sintering of silver nanoparticles. The applied bonding technologies are described and obtained results are presented.
A Review on Die Attach Materials for SiC-Based High-Temperature Power Devices
Metallurgical and Materials Transactions B, 2010
SHUN CHIN, KUAN YEW CHEONG, and AHMAD BADRI ISMAIL Recently, high-temperature power devices have become a popular discussion topic because of their various potential applications in the automotive, down-hole oil and gas industries for well logging, aircraft, space exploration, nuclear environments, and radars. Devices for these applications are fabricated on silicon carbide-based semiconductor material. For these devices to perform effectively, an appropriate die attach material with specific requirements must be selected and employed correctly. This article presents a review of this topic, with a focus on the die attach materials operating at temperatures higher than 623 K (350°C). Future challenges and prospects related to high-temperature die attach materials also are proposed at the end of this article.
Die-attachment solutions for SiC power devices
Microelectronics Reliability, 2009
Silicon carbide has become a very attractive material for high temperature and high power electronics applications due to its physical properties, which are different than those of conventional Si semiconductors. However, the reliability of SiC devices is limited by assembly processes comprising die attachment and interconnections technology as well as the stability of ohmic contacts at high temperatures. The investigations of die to substrate connection methods which can fulfill high temperature and high power requirements are the main focuses of the paper. This work focuses on die attach technologies: solder bonding by means of gold-germanium alloys, adhesive bonding with the use of organic and inorganic conductive compositions, as well as die bonding with the use of low temperature sintering with silver nanoparticles. The applied bonding technologies are described and obtained results are presented. Of the methods tested, the best solutions for high temperature application are two die attach technologies: silver glass die attach and die bonding with the use of low temperature sintered Ag nanopowders.
IEEE Transactions on Power Electronics, 2000
Currently, the demand by new application scenarios of increasing operating device temperatures in power systems is requiring new die-attach materials with higher melting points and suitable thermomechanical properties. This makes the die-attach material selection, die-attaching process, and thermomechanical evaluation a real challenge in nowadays power packaging technology. This paper presents a comparative analysis of the thermomechanical performance of high-temperature die-attach materials (sintered nano-Ag, AuGe, and PbSnAg) under harsh thermal cycling tests. This study is carried out using a test vehicle formed by four dice (considering Si and SiC semiconductors) and Cu substrates. Thermally cycled test vehicles have been thermomechanically evaluated using die-shear tests and acoustic microscopy inspections. Besides, special attention is paid to set up a nano-Ag sintering process, in which the effects of sintering pressure or substrate surface state (roughness and surface activation) on the die-attach layer are analyzed. As a main result, this study shows that the best die-attach adherence is obtained for nano-Ag when pressure is applied on the dice (using a specifically designed press) during the sintering process (11 MPa provided die-shear forces of 53 kgf). However, this die-attach presents a faster thermomechanical degradation under harsh thermal cycling tests than other considered high-temperature die-attach materials (AuGe and PbSnAg) and PbSnAg shows the best thermomechanical performances.
Adhesion strength of die attach film for thin electronic package at elevated temperature
Microelectronics Reliability, 2018
Adhesion strength of a thin film for electronic packaging was investigated. The effects of temperature and loading rate on the adhesion were observed considering the viscoelasticity of adhesive. Various temperature conditions over the glass transition temperature of the adhesive were applied with controlled loading rates. A small hot plate was specially designed to control the temperature. Loading rate was controlled by a servo motor. A cantilever specimen was fabricated by two rectangular silicon chips. The adhesion was measured by a modified single cantilever beam method. Bending force was applied to the cantilever using rotatable jig. Adhesion strength was found to strongly depend on the temperature and loading rate. Below the glass transition temperature (T g), the adhesion strength was increased with increasing loading rate. Near the Tg, the adhesion strength was decreased with increasing loading rate. Above the T g , the adhesion strength did not significantly depend on the loading rate.
Bonding strength of multiple SiC die attachment prepared by sintering of Ag nanoparticles
Journal of Materials Processing Technology, 2015
a b s t r a c t 3 mm × 3 mm dummy SiC dies with 100\200\200 nm thick Ti\W\Au metallization have simultaneously been attached using sintering of Ag nanoparticle paste on AlN-based direct bonded copper substrates with 5\0.1 m thick NiP\Au finish. The effect of preparation and sintering parameters including time of drying the printed paste, sintering temperature and time, and pressure, on the average shear strength for multiple die attachments was investigated. The surfaces of the die attachments after the shear tests were observed and the individual shear strength values correlated with the "apparent" porosity and thicknesses of the corresponding die attachments (sintered layer). The results obtained are further discussed and compared with typical data reported in existing literature. Main conclusions include: (i) the present shear strength values and their variations are comparable with those reported for single die attachment samples, (ii) the effects of sintering parameters can be ascribed to the effectiveness of the organic content burnout and appropriate rate of growth and coalescence of the Ag nanoparticles during the sintering process, and (iii) thickness values of the sintered Ag die attachments may be taken as nondestructive measurements to monitor/evaluate the quality of die attachment during power electronic module manufacturing/assembly process.
Journal of Materials Science: Materials in Electronics, 2018
Low-stress design of bonding technology with a sandwich structure of sintered Ag and tungsten (W) thin film was developed for SiC power die-attached modules. The die-attached bonding layer was designed as sintered Ag/W/sintered Ag structure. Experiment results show that the initial bonding strength was larger than 65 MPa for this die-attached structure and larger than 35 MPa with a thermal shock test from − 50 to 250 °C for 1000 cycles. These results are largely better than that almost all sintering Ag technology reported in previous studies. Furthermore, the sandwich structure also compared with the sintered Ag structure which just using sintered Ag paste as bonding layer. The thickness of Ag paste is set as 100, 200 and 500 µm in the sintered Ag structure. The results show that the initial bonding strength of sintered Ag structure was about 60-70% of the value of W sandwich structure and about one-third of that after 1000 cycles. X-ray and SEM observation revealed that sandwich structure significantly decreased the size of crack extension in the sintered Ag layer during the thermal shock test. Finite element analysis reveal that the shear stress at the pore location of sandwich structure decreased to almost half values of the sintered Ag structure with the thickness of sintered Ag of 500 µm, and decreased almost 20% compared with the thickness of sintered Ag of 100 µm. The bonding technology with the W sandwich structure should be an attractive for low stress design in SiC power die-attached modules, which significantly increased its function for long-term high temperature applications.