Binary Promoter Improving the Moderate-Temperature Adhesion of Addition-Cured Liquid Silicone Rubber for Thermally Conductive Potting
The strong adhesion of thermally conductive silicone encapsulants on highly integrated electronic devices can avoid external damages and lead to an improved long-term reliability, which is critical for their commercial application. However, due to their low surface energy and chemical reactivity, th...
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MDPI AG
2022-07-01
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| Series: | Materials |
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| Online Access: | https://www.mdpi.com/1996-1944/15/15/5211 |
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| author | Jia-Kai Wu Kai-Wen Zheng Qiong-Yan Wang Xin-Cheng Nie Rui Wang Jun-Ting Xu |
| author_facet | Jia-Kai Wu Kai-Wen Zheng Qiong-Yan Wang Xin-Cheng Nie Rui Wang Jun-Ting Xu |
| author_sort | Jia-Kai Wu |
| collection | DOAJ |
| description | The strong adhesion of thermally conductive silicone encapsulants on highly integrated electronic devices can avoid external damages and lead to an improved long-term reliability, which is critical for their commercial application. However, due to their low surface energy and chemical reactivity, the self-adhesive ability of silicone encapsulants to substrates need to be explored further. Here, we developed epoxy and alkoxy groups-bifunctionalized tetramethylcyclotetrasiloxane (D<sub>4</sub>H-MSEP) and boron-modified polydimethylsiloxane (PDMS-B), which were synthesized and utilized as synergistic adhesion promoters to provide two-component addition-cured liquid silicone rubber (LSR) with a good self-adhesion ability for applications in electronic packaging at moderate temperatures. The chemical structures of D<sub>4</sub>H-MSEP and PDMS-B were characterized by Fourier transform infrared spectroscopy. The mass percentage of PDMS-B to D<sub>4</sub>H-MSEP, the adhesion promoters content and the curing temperature on the adhesion strength of LSR towards substrates were systematically investigated. In detail, the LSR with 2.0 wt% D<sub>4</sub>H-MSEP and 0.6 wt% PDMS-B exhibited a lap-shear strength of 1.12 MPa towards Al plates when curing at 80 °C, and the cohesive failure was also observed. The LSR presented a thermal conductivity of 1.59 W m<sup>−1</sup> K<sup>−1</sup> and good fluidity, which provided a sufficient heat dissipation ability and fluidity for potting applications with 85.7 wt% loading of spherical α-Al<sub>2</sub>O<sub>3</sub>. Importantly, 85 °C and 85% relative humidity durability testing demonstrated LSR with a good encapsulation capacity in long-term processes. This strategy endows LSR with a good self-adhesive ability at moderate temperatures, making it a promising material requiring long-term reliability in the encapsulation of temperature-sensitive electronic devices. |
| first_indexed | 2024-03-09T05:15:49Z |
| format | Article |
| id | doaj.art-42d9c9b22e6e4f7eaec250f964b31b2a |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-09T05:15:49Z |
| publishDate | 2022-07-01 |
| publisher | MDPI AG |
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| spelling | doaj.art-42d9c9b22e6e4f7eaec250f964b31b2a2023-12-03T12:45:20ZengMDPI AGMaterials1996-19442022-07-011515521110.3390/ma15155211Binary Promoter Improving the Moderate-Temperature Adhesion of Addition-Cured Liquid Silicone Rubber for Thermally Conductive PottingJia-Kai Wu0Kai-Wen Zheng1Qiong-Yan Wang2Xin-Cheng Nie3Rui Wang4Jun-Ting Xu5MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science & Engineering, Zhejiang University, Hangzhou 310027, ChinaMOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science & Engineering, Zhejiang University, Hangzhou 310027, ChinaResearch and Development Center, Zhejiang Sucon Silicone Co., Ltd., Shaoxing 312088, ChinaResearch and Development Center, Zhejiang Sucon Silicone Co., Ltd., Shaoxing 312088, ChinaResearch and Development Center, Zhejiang Sucon Silicone Co., Ltd., Shaoxing 312088, ChinaMOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science & Engineering, Zhejiang University, Hangzhou 310027, ChinaThe strong adhesion of thermally conductive silicone encapsulants on highly integrated electronic devices can avoid external damages and lead to an improved long-term reliability, which is critical for their commercial application. However, due to their low surface energy and chemical reactivity, the self-adhesive ability of silicone encapsulants to substrates need to be explored further. Here, we developed epoxy and alkoxy groups-bifunctionalized tetramethylcyclotetrasiloxane (D<sub>4</sub>H-MSEP) and boron-modified polydimethylsiloxane (PDMS-B), which were synthesized and utilized as synergistic adhesion promoters to provide two-component addition-cured liquid silicone rubber (LSR) with a good self-adhesion ability for applications in electronic packaging at moderate temperatures. The chemical structures of D<sub>4</sub>H-MSEP and PDMS-B were characterized by Fourier transform infrared spectroscopy. The mass percentage of PDMS-B to D<sub>4</sub>H-MSEP, the adhesion promoters content and the curing temperature on the adhesion strength of LSR towards substrates were systematically investigated. In detail, the LSR with 2.0 wt% D<sub>4</sub>H-MSEP and 0.6 wt% PDMS-B exhibited a lap-shear strength of 1.12 MPa towards Al plates when curing at 80 °C, and the cohesive failure was also observed. The LSR presented a thermal conductivity of 1.59 W m<sup>−1</sup> K<sup>−1</sup> and good fluidity, which provided a sufficient heat dissipation ability and fluidity for potting applications with 85.7 wt% loading of spherical α-Al<sub>2</sub>O<sub>3</sub>. Importantly, 85 °C and 85% relative humidity durability testing demonstrated LSR with a good encapsulation capacity in long-term processes. This strategy endows LSR with a good self-adhesive ability at moderate temperatures, making it a promising material requiring long-term reliability in the encapsulation of temperature-sensitive electronic devices.https://www.mdpi.com/1996-1944/15/15/5211binary promoterliquid silicone rubberthermally conductivemoderate-temperature adhesion |
| spellingShingle | Jia-Kai Wu Kai-Wen Zheng Qiong-Yan Wang Xin-Cheng Nie Rui Wang Jun-Ting Xu Binary Promoter Improving the Moderate-Temperature Adhesion of Addition-Cured Liquid Silicone Rubber for Thermally Conductive Potting Materials binary promoter liquid silicone rubber thermally conductive moderate-temperature adhesion |
| title | Binary Promoter Improving the Moderate-Temperature Adhesion of Addition-Cured Liquid Silicone Rubber for Thermally Conductive Potting |
| title_full | Binary Promoter Improving the Moderate-Temperature Adhesion of Addition-Cured Liquid Silicone Rubber for Thermally Conductive Potting |
| title_fullStr | Binary Promoter Improving the Moderate-Temperature Adhesion of Addition-Cured Liquid Silicone Rubber for Thermally Conductive Potting |
| title_full_unstemmed | Binary Promoter Improving the Moderate-Temperature Adhesion of Addition-Cured Liquid Silicone Rubber for Thermally Conductive Potting |
| title_short | Binary Promoter Improving the Moderate-Temperature Adhesion of Addition-Cured Liquid Silicone Rubber for Thermally Conductive Potting |
| title_sort | binary promoter improving the moderate temperature adhesion of addition cured liquid silicone rubber for thermally conductive potting |
| topic | binary promoter liquid silicone rubber thermally conductive moderate-temperature adhesion |
| url | https://www.mdpi.com/1996-1944/15/15/5211 |
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