Flexible h-BN foam sheets for multifunctional electronic packaging materials with ultrahigh thermostability

Soft Matter ◽  
2018 ◽  
Vol 14 (20) ◽  
pp. 4204-4212 ◽  
Author(s):  
Deul Kim ◽  
Artavazd Kirakosyan ◽  
Jae Woong Lee ◽  
Jong-Ryul Jeong ◽  
Jihoon Choi

Flexible and robust h-BN foam sheets with a three-dimensional network structure exhibit a much enhanced thermal conductivity as well as thermo-stability at high temperature.

2019 ◽  
Vol 2019 (HiTen) ◽  
pp. 000075-000084
Author(s):  
Hongyan Xu ◽  
Yaochun Shen ◽  
Yihua Hu ◽  
Jianqiang Li ◽  
Ju Xu

Abstract A highly reliable three-dimensional network structure joint was fabricated based on Cu@Ni@Sn core-shell powder and transient liquid phase bonding (TLPB) technology for high temperature application. Cu@Ni@Sn joint is characterized by Cu metal particles embedded in the matrix of (Cu,Ni)6Sn5/Ni3Sn4 intermetallics (IMCs), low level of voiding is achieved, they can be reflowed at a low temperatures (<260°C), but reliably working at high temperature up to 415°C. Cu@Ni@Sn double-layer microparticles with different Sn layer and Ni layer thickness were fabricated and compressed as preform used for TLPB joint bonding, the microstructure and phase composition evolution for Cu@Sn and Cu@Ni@Sn system were comparatively studied during reflowing and aging process. Different kinds of interfacial structure designs were made, interfacial microscopic morphology was analyzed and compared under once and twice reflowing soldering process. Results indicated that Sn coating layer was completely consumed to form (Cu,Ni)6Sn5/Ni3Sn4 IMCs, Cu@Ni@Sn bondline have lower void rate and higher shear strength than that of Cu@Sn. The mechanism of Ni coating layer inhibit Cu atom diffusing towards Cu6Sn5 to form Cu3Sn was studied. The high reliable three-dimensional network structure joint based on Cu@Ni@Sn double-layer powder was fabricated for high temperature application.


2019 ◽  
Vol 16 (4) ◽  
pp. 188-195 ◽  
Author(s):  
Hongyan Xu ◽  
Yaochun Shen ◽  
Yihua Hu ◽  
Jianqiang Li ◽  
Ju Xu

Abstract A highly reliable three-dimensional network structure joint was fabricated based on Cu/Ni/Sn powder with double-layer coatings and transient liquid phase bonding (TLPB) technology for high temperature application. The Cu/Ni/Sn joint is characterized by Cu metal particles embedded in the matrix of (Cu,Ni)6Sn5/Ni3Sn4 intermetallic compounds (IMCs), with a low void ratio, and can be reflowed at low temperatures (<260°C), but it can reliably work at a high temperature up to 415°C. Cu/Ni/Sn double-layer powders with different Sn layer and Ni layer thickness were was fabricated and compressed as preform used for TLPB joint bonding. The microstructure and phase composition evolution for Cu/Sn and Cu/Ni/Sn systems during reflow and aging were comparatively studied. Two kinds of interfacial structure designs were made, and corresponding interfacial microscopic morphology was analyzed and compared under once and twice reflow soldering processes. The results indicated that the Sn-coating layer was completely consumed to form (Cu,Ni)6Sn5/Ni3Sn4 IMCs, and the Cu/Ni/Sn joint had a lower void ratio and a higher shear strength than those of Cu/Sn. The mechanism of the Ni-coating layer inhibiting phase transformation was studied. The high reliable three-dimensional network structure joint based on Cu/Ni/Sn double-layer powder was fabricated for high temperature application.


RSC Advances ◽  
2021 ◽  
Vol 11 (33) ◽  
pp. 20446-20456
Author(s):  
Xi Ma ◽  
Ziwei Wang ◽  
Haoguo Yang ◽  
Yiqiu Zhang ◽  
Zizhong Zhang ◽  
...  

Compared with traditional layered graphene, graphene hydrogels have been used to construct highly efficient visible light-excited photocatalysts due to their particular three-dimensional network structure and efficient electron transport capacity.


Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4752
Author(s):  
Xiaoqing Qu ◽  
Yuliya Nazarenko ◽  
Wei Yang ◽  
Yuanyang Nie ◽  
Yongsheng Zhang ◽  
...  

The oat β-glucan (OG) was added into set-type yogurt as a functional ingredient, in order to evaluate effects on the rheological characteristics and microstructure of set-type yogurt. When the OG concentration increased from 0 to 0.3%, the WHC gradually increased. At 0.3% OG, the set-type yogurt had the highest WHC of 94.67%. Additionally, the WHC continuously decreased, reaching the lowest WHC (about 80%) at 0.5% OG. When 0.3% OG was added, the highest score of sensory evaluation was about 85. The rheological result showed that the fermentation process went through the changes as follows: solid → liquid → solid → liquid. The addition of 0.3% OG decreased the fermentation time of set-type yogurt by about 16 min, making yogurt more inclined to be liquid. The acidity of set-type yogurt with OG was slightly higher. The result of microstructure showed that the addition of OG destroyed the three-dimensional network structure of yogurt, and some spherical aggregate particles could be clearly observed at 0.3% OG. Overall, this study provided a theoretical basis for the application of OG in set-type yogurt.


Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1302
Author(s):  
Younggi Hong ◽  
Munju Goh

Epoxy resin (EP) is one of the most famous thermoset materials. In general, because EP has a three-dimensional random network, it possesses thermal properties similar to those of a typical heat insulator. Recently, there has been substantial interest in controlling the network structure of EP to create new functionalities. Indeed, the modified EP, represented as liquid crystalline epoxy (LCE), is considered promising for producing novel functionalities, which cannot be obtained from conventional EPs, by replacing the random network structure with an oriented one. In this paper, we review the current progress in the field of LCEs and their application to highly thermally conductive composite materials.


1986 ◽  
Vol 59 (4) ◽  
pp. 541-550 ◽  
Author(s):  
Kyung-Do Suh ◽  
Hidetoshi Oikawa ◽  
Kenkichi Murakami

Abstract From the experimental results of the present investigation, it is apparent that two kinds of networks which have a different three-dimensional network structure give quite different behavior of chemical stress relaxation, even if both networks have the same network chain density. The difference in three-dimensional network structure for the two kinds of rubber arises from the degree of entanglement, which changes with the concentration of the polymer chains prior to the crosslinking process. The direct cause of chemical relaxation is due to the scission of network chains by degradation, whereas the total relaxation is caused by the change of geometrical conformation of network chains. This then casts doubt on the basic concept of chemorheology which is represented by Equation 2.


Nanoscale ◽  
2021 ◽  
Author(s):  
Shaoyang Xiong ◽  
Yue Qin ◽  
Linhong Li ◽  
Guoyong Yang ◽  
Maohua Li ◽  
...  

In order to meet the requirement of thermal performance with the rapid development of high-performance electronic devices, constructing a three-dimensional thermal transport skeleton is an effective method for enhancing thermal...


Sign in / Sign up

Export Citation Format

Share Document