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应用有限元方法分析了QFN形式的SiP封装器件在回流焊中的热应力与湿热合成应力。结果表明,在回流焊过程中,由于其结构特点与湿气的扩散不均引起湿热应力变化梯度加大,在其材料交界处应力集中现象明显。最大湿热应力是单纯考虑热应力的情况1.66倍左右。通过比较得知湿热环境对这种SiP器件的影响比一般的封装器件要大,更可能导致器件失效。 相似文献
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湿热环境与电子产品可靠性 总被引:8,自引:0,他引:8
彭骞 《电子产品可靠性与环境试验》2003,(5):57-60
阐述了湿热环境对电子产品质量寿命的影响,并重点介绍了目前湿热试验的热门话题:离子迁移失效的机理和试验方法。 相似文献
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本文仅阐述作为气候环境之一的湿热条件及其气候特征,分析了湿热因素对电子设备产生的劣化效应,并提出电子设备的防潮措施和考核方法,供工程设计时参考. 相似文献
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叙述了PbS薄膜的化学水浴制备方法及PbS薄膜形貌、性能测试及湿热环境(相对湿度95%)试验的过程,阐述了PbS探测器芯片经湿热环境试验后暗阻等性能参数的变化情况,分析了其原因和相关机理。短时间(1 h)内湿热环境下,其性能参数变化在5%以内,在持续24 h的潮湿环境后,PbS的暗阻增大50%以上。在之后的2×24 h、3×24 h、4×24 h、5×24 h湿热环境下,暗阻值增量随时间递增呈正比例关系。当潮湿试验进行到7×24 h后,部分试验样件无法测试出响应信号,样件失效。 相似文献
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采用Abaqus软件模拟了CPU和DDR双层芯片堆叠封装组件在85℃/RH85%湿热环境下分别吸湿5,17,55和168 h的相对湿气扩散分布和吸湿168 h后回流焊过程中湿应力、热应力和湿热应力分布,并通过吸湿和回流焊实验分析了该组件在湿热环境下的失效机理。模拟结果表明,在湿热环境下,分别位于基板和CPU、CPU和DDR之间的粘结层1和2不易吸湿,造成粘结层的相对湿度比塑封材料低得多,但粘结层1的相对湿度比粘结层2要高。吸湿168 h后,在回流焊载荷下湿应力主要集中在芯片DDR远离中心的长边上,而最大湿热应力和热应力一样位于底层芯片CPU的底角处,其数值是单纯热应力的1.3倍。实验结果表明,界面裂纹及分层集中在底层CPU芯片的边角处和芯片、粘结层和塑封材料的交界处,与模拟结果相一致。 相似文献
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We present here in this paper main results obtained during the first phase of a work plan which aim is to allow the use of plastic encapsulated devices (PED’S) in some military equipments. This phase (called feasibility) was conducted in order to evaluate the risk an equip-ment maker takes when using standard PED’S. TO do that a large number OF PED’S (about 1000) were characterized. Main features of performed tests are that they were se-quential file of tests and better suited to assessment of PED’S reliability. Moreover one file included an extremely severe damp heat test, at high temperature and high hu-midity, called HAST. Results we get show a large disparity in PED’S behaviour under rugged environments. Fine fail-ure analysis have shown what are major defect modes and indicated that classical corrosion is not the only failure mechanism which occurs at high temperature and high humidity conditions. Failure rate derived from these results can be compared favourably with those computed following reliability prediction models. 相似文献
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《Organic Electronics》2014,15(2):569-576
Two different types of aluminum-doped zinc oxide (AZO) thin films were fabricated using low cost sol–gel technique. By applying damp heat testing, the optical and electrical properties of those films were investigated under the influence of accelerated degradation from moisture or moisture vapor. Complementary measurements of optical transmittance, work function, and conductivity allowed exploring the degradation of AZO thin films and the corresponding OPV devices. We found that optical properties like transmittance, absorption coefficient, and band gap are not influenced by temperature and moisture. However, an increase in the work function, and a decrease in the conductivity of AZO films were observed upon damp heat exposure indicating the formation of a barrier or depletion layer at the metal oxide semiconductor interface. 相似文献
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Processability and reliability of epoxy adhesive used in microelectronic devices linked to effects of degree of cure and damp heat aging 总被引:1,自引:0,他引:1
In an effort to explicate the effects of degree of cure (conversion) and damp heat aging at 85 °C/85% RH on physical properties of the cured epoxy system consisting of diglycidyl ether of bisphenol F (DGBF) and imidazole as a curing agent, an experimental approach was systematically performed using a dynamic mechanical analyzer (DMA) and thermomechanical analyzer (TMA). Of interesting physical properties are the storage modulus, loss modulus, tan δ, glass transition temperature (Tg), and coefficient of thermal expansion (CTE). The die shear test was performed to evaluate changes in adhesion strength of the cured epoxy with and without an epoxy silane before and after the damp heat aging. We have found that the magnitude of storage modulus in a glass transition region and the onset temperature for degradation of storage modulus, DMA Tg, increase as the conversion of cure increases. Even though such benefits observed at ambient are lessened after extended exposure to the damp heat aging, higher conversion has less degradation than lower conversion. It is observed that Tg taken from DMA and TMA decreases approximately from 132 °C to 81 °C after 500 h of damp heat aging. Such large diminution is attributed to high moisture diffusivity of 2.0 × 10−8/cm2/s at 85 °C/85% RH and can cause large dimensional instability at the critical interface supported by the epoxy adhesive. We have also found that a 3-parameter exponential function is useful to predict the degradation of Tg under the given aging condition. Although the effect of an epoxy silane is negligible at ambient, it provides better adhesion strength after the damp heat aging. Finally, we intend to give process guidelines for the usage of DGBF/imidazole epoxy system to ensure stringent reliability in electronic device applications. 相似文献
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Nishida Y. Fujiura K. Hoshino K. Shimizu M. Yamada M. Nakagawa K. Ohishi Y. 《Photonics Technology Letters, IEEE》1999,11(12):1596-1598
We report reliability test results for a fluoride fiber module. We developed a sealed fluoride fiber module for practical optical fiber amplifier use. Trouble-free damp heat storage and low-temperature storage for 5000 h and trouble-free temperature cycling and temperature-humidity cycling tests revealed that our fluoride fiber module has long-term stability under practical environmental conditions 相似文献
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文章主要探讨不同的环境条件如低温、恒定湿热、冷热冲击等对LED背光源性能的影响,同时对LED背光源的主要应用领域进行了阐述,并期待LED背光源测试方法的标准尽早发布实施。 相似文献
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通过对ZnO压敏电阻器试验结果的分析,探讨其在稳态湿热试验中引起性能变化的因素,提出要提高产品的耐湿性能,必须在包封料选择和瓷体制作工艺上加以改进。 相似文献
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以某型模块热设计为例,首先按自然散热方式进行理论计算,然后应用FloTHERM软件对导航模块的散热性能进行仿真分析,为电子设备的散热设计提供了设计依据和参考,最后对仿真分析的结果进行了分析总结。 相似文献