Development of High Thermally Conductive Die Attach for TIM Applications

2019 ◽  
Vol 2019 (1) ◽  
pp. 000312-000315
Author(s):  
Maciej Patelka ◽  
Sho Ikeda ◽  
Koji Sasaki ◽  
Hiroki Myodo ◽  
Nortisuka Mizumura

Abstract High power semiconductor applications require a Thermal Interface Die Attach Material with high thermal conductivity to efficiently release the heat generated from these devices. Current Thermal Interface Material solutions such as thermal grease, thermal pads and silicones have been industry standards, however may fall short in performance for high temperature or high-power applications. This presentation will focus on development of a cutting-edge Die Attach Solution for Thermal Interface Management, focusing on Fusion Type epoxy-based Ag adhesive with an extremally low Storage Modulus and the Thermal Conductivity reaching up to 30W/mK, and also Very Low Modulus, Low-Temperature Pressureless Sintered Silver Die Attach with the Thermal Conductivity of 70W/mK.

2020 ◽  
Vol 17 (3) ◽  
pp. 106-109
Author(s):  
Maciej Patelka ◽  
Sho Ikeda ◽  
Koji Sasaki ◽  
Hiroki Myodo ◽  
Nortisuka Mizumura

Abstract High-power semiconductor applications require a thermal interface die attach material with high thermal conductivity to efficiently release the heat generated from these devices. Current thermal interface material solutions such as thermal grease, thermal pads, and silicones have been industry standards, however may fall short in performance for high-temperature or high-power applications. This article focuses on development of a cutting-edge die attach solution for thermal interface management, focusing on fusion-type epoxy-based Ag adhesive with an extremely low storage modulus and the thermal conductivity reaching up to 30 W/mK, and also very low-modulus, low-temperature pressureless sintering silver die attach with a thermal conductivity of 70 W/mK.


Author(s):  
R. Kempers ◽  
R. Frizzell ◽  
A. Lyons ◽  
A. J. Robinson

Typical thermal interface materials (TIMs) consist of high thermal conductivity solid particles dispersed in a continuous, low thermal conductivity organic compound. Despite using filler materials of very high thermal conductivity, the effective thermal conductivity of these TIMs is often two orders of magnitude lower than the pure filler materials. In addition, dispensing and flow of the particle-matrix composite results in voids being trapped within the bond. To address these issues, a novel metal micro-textured thermal interface material (MMT-TIM) has been developed. This material consists of a thin metal foil with raised micro-scale features that plastically deform under an applied pressure thereby creating a continuous, thermally conductive, path between the mating surfaces. Numerical tools have been developed that couple the mechanical and thermal properties and behaviour of MMT-TIMs as they undergo large-plastic deformation during assembly. This study presents the modelling approach and predictions of MMT-TIM performance based on these numerical techniques. The predictions show good agreement with experimental results, which were obtained using prototype MMT-TIMs and an advanced TIM characterization facility. Finally, a future outlook for this technology is presented based on these promising initial results.


2010 ◽  
Vol 132 (4) ◽  
Author(s):  
Hung-En Chou ◽  
Shang-Ray Yang ◽  
Sea-Fue Wang ◽  
James C. Sung

As a thermal interface material, thermal grease (TG) has been extensively applied to facilitate heat dissipation in electronic devices. Despite the superior thermal conductivity of diamond, researches on diamond-containing TGs remain rare. In this study, four kinds of TGs in which diamond served as essential filler were prepared and hot disk technique was applied to measure their thermal conductivity k(TG). After two unoverlapped particle sizes were selected, the volumetric filler content, terminal group, and viscosity of a polydimethylsiloxane (PDMS) matrix were modified in sequence. Based on the preferred recipe of a single-filler TG, two double-filler TG series were prepared by retaining the large diamonds and replacing the small ones by Al2O3 or ZnO, respectively. Depending on the content, it was found that diamond was not always the best choice for small filler. The highest k(TG), which was 23 times greater than the original k(PDMS), appeared in a ZnO-containing double-filler grease (=3.52 W/mK). The prediction for the maximum attainable thermal conductivity was preliminarily supported.


2005 ◽  
Vol 128 (1) ◽  
pp. 46-52 ◽  
Author(s):  
Jong-Jin Park ◽  
Minoru Taya

A thermal interface material (TIM) is a crucial material for transferring heat from a die to a heatsink. We developed a new TIM composed of carbon nanotubes, silicon thermal grease, and chloroform. The thermal impedance of the TIM was measured using a new device based on thermometer principles to measure thermal impedance and resistance. This device consists of an alumina substrate, titanium tungsten (TiW) layers, gold layers, and thin alumina layers. Then the measured thermal conductivity of the TIM was compared with predictions made by the thermal resistor network model, and the experimental results were found to be consistent with the predictions made by the model.


2018 ◽  
Vol 2018 (HiTEC) ◽  
pp. 000051-000055
Author(s):  
Maciej Patelka ◽  
Nicholas Krasco ◽  
Sho Ikeda ◽  
Toshiyuki Sato ◽  
Miguel Goni ◽  
...  

Abstract High power semiconductor applications require a die attach material with high thermal conductivity to efficiently release the heat generated from these devices. Current die attach solutions such as eutectic solders and high thermal conductive silver epoxies and sintered silver adhesives have been industry standards, however may fall short in performance for high temperature or high stress applications. This presentation will focus on development of a reinforced, sintered silver die attach solution for high power semiconductor applications with focus on a pressure-less, low temperature sintering technology that offers high reliability for high temperature (250°C) applications. The electronic, optoelectronic, and semiconductor industries have the need for high performance adhesives, in particular, high power devices require low-stress, high thermal conductivity, thermally stable, and moisture resistant adhesives for the manufacture of high reliability devices. This paper introduces a new reinforced sintered silver adhesive based on the “resin-free” Conductive Fusion Technology. The high performance adhesive offers a robust solution for high temperature, high reliability applications. Conductive Fusion Technology consists of a high thermal conductivity silver component blended with a non-conductive, low-modulus powder component. The non-conductive powder component comprises an organically modified inorganic material that exhibits excellent thermal stability at temperatures exceeding 250°C. Properties of the sintered silver adhesive, such as storage modulus, can be modified by varying the content of the non-conductive component.


2019 ◽  
Vol 10 ◽  
pp. 95-104 ◽  
Author(s):  
Idan Levy ◽  
Eyal Merary Wormser ◽  
Maxim Varenik ◽  
Matat Buzaglo ◽  
Roey Nadiv ◽  
...  

The substantial heat generation in highly dense electronic devices requires the use of materials tailored to facilitate efficient thermal management. The design of such materials may be based on the loading of thermally conductive fillers into the polymer matrix applied – as a thermal interface material – on the interface between two surfaces to reduce contact resistance. On the one hand, these additives enhance the thermal conductivity of the composite, but on the other hand, they increase the viscosity of the composite and hence impair its workability. This in turn could negatively affect the device–matrix interface. To address this problem, we suggest a tunable composite material comprising a combination of two different carbon-based fillers, graphene nanoplatelets (GNPs) and graphite. By adjusting the GNP:graphite concentration ratio and the total concentration of the fillers, we were able to fine tune the thermal conductivity and the workability of the hybrid polymer composite. To facilitate the optimal design of materials for thermal management, we constructed a ‘concentration–thermal conductivity–viscosity phase diagram’. This hybrid approach thus offers solutions for thermal management applications, providing both finely tuned composite thermal properties and workability. We demonstrate the utility of this approach by fabricating a thermal interface material with tunable workability and testing it in a model electronic device.


Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1699
Author(s):  
Sriharsha Sudhindra ◽  
Fariborz Kargar ◽  
Alexander A. Balandin

We report on experimental investigation of thermal contact resistance, RC, of the noncuring graphene thermal interface materials with the surfaces characterized by different degree of roughness, Sq. It is found that the thermal contact resistance depends on the graphene loading, ξ, non-monotonically, achieving its minimum at the loading fraction of ξ ~15 wt %. Decreasing the surface roughness by Sq~1 μm results in approximately the factor of ×2 decrease in the thermal contact resistance for this graphene loading. The obtained dependences of the thermal conductivity, KTIM, thermal contact resistance, RC, and the total thermal resistance of the thermal interface material layer on ξ and Sq can be utilized for optimization of the loading fraction of graphene for specific materials and roughness of the connecting surfaces. Our results are important for the thermal management of high-power-density electronics implemented with diamond and other wide-band-gap semiconductors.


2021 ◽  
pp. 002199832110595
Author(s):  
Weontae Oh ◽  
Jong-Seong Bae ◽  
Hyoung-Seok Moon

The microstructural change of graphite was studied after ultrasonic treatment of the graphite. When the graphite solution was treated with varying ultrasonic power and time, the microstructure changed gradually, and accordingly, the thermal conductivity characteristics of the composite containing the as-treated graphite was also different with each other. Thermal conductivity showed the best result in the silicone composite containing graphite prepared under the optimum condition of ultrasonic treatment, and the thermal conductivity of the composite improved proportionally along with the particle size of graphite. When the silicone composite was prepared by using a mixture of inorganic oxides and graphite rather than graphite alone, the thermal conductivity of the silicone composite was further increased. A silicone composite containing graphite was used for LED (light emitting diode) lighting system as a thermal interface material (TIM), and the temperature elevation due to heat generated, while the lighting was actually operated, was analyzed.


2018 ◽  
Vol 7 (4.33) ◽  
pp. 530
Author(s):  
Mazlan Mohamed ◽  
Mohd Nazri Omar ◽  
Mohamad Shaiful Ashrul Ishak ◽  
Rozyanty Rahman ◽  
Zaiazmin Y.N ◽  
...  

Epoxy mixed with others filler for thermal interface material (TIM) had been well conducted and developed. There are problem occurs when previous material were used as matrix material likes epoxy that has non-uniform thickness of thermal interface material produce, time taken for solidification and others. Thermal pad or thermal interface material using graphene as main material to overcome the existing problem and at the same time to increase thermal conductivity and thermal contact resistance. Three types of composite graphene were used for thermal interface material in this research. The sample that contain 10 wt. %, 20 wt. % and 30 wt. % of graphene was used with different contain of graphene oxide (GO).  The thermal conductivity of thermal interface material is both measured and it was found that the increase of amount of graphene used will increase the thermal conductivity of thermal interface material. The highest thermal conductivity is 12.8 W/ (mK) with 30 w. % graphene. The comparison between the present thermal interface material and other thermal interface material show that this present graphene-epoxy is an excellent thermal interface material in increasing thermal conductivity.  


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