An experimental study of carbonyl powder power inductor cracking during reflow process

IF 1.7 4区材料科学 Q3 ENGINEERING, ELECTRICAL & ELECTRONIC

Soldering & Surface Mount Technology Pub Date : 2020-07-13 DOI:10.1108/ssmt-10-2019-0033

Faisal Rehman, Rafiq Asghar, Kashif Iqbal, Ali Aman, Agha Ali Nawaz

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引用次数: 1

Abstract

Purpose In surface mount assembly (SMA) process, small components are subjected to high temperature variations, which result in components’ deformation and cracking. Because of this phenomenon, cracks are formed in the body of carbonyl powder ceramic inductor (CPCI) in the preheat and cooling stages of the reflow oven. These cracks become the main cause of board failure in the ageing process. The purpose of this paper is to ascertain the thermal stress, thermal expansion of carbonyl iron ceramics and its effects on crack commencement and proliferation in the preheat stage of reflow oven. Moreover, this paper also categorized and suggested important parameters of reflow profile that could be used to eliminate these thermal shock failures. Design/methodology/approach In this paper, two different reflow profiles were studied that evaluate the thermal shock of CPCI during varying ΔT at the preheat zone of the reflow oven. In the first profile, the change in temperature ΔT at preheat zone was set to 3.26°C/s, which has resulted in a number of device failures because of migration of micro cracks through the CPCI. In the second profile, this ΔT at preheat stage is minimized to 2.06°C/s that eliminated the thermal stresses; hence, the failure rates were significantly reduced. Findings TMPC0618H series lead (Pb)-free CPCI is selected for this study and its thermal expansion and thermal shock are observed in the reflow process. It is inferred from the results that high ΔT at preheat zone generates cracks in the carbonyl powder-type ceramics that cause device failure in the board ageing process. Comparing materials, carbonyl powder ceramic components are less resistant to thermal shock and a lower rate of temperature change is desirable. Originality/value The proposed study presents an experimental analysis for mitigating the thermal shock defects. The realization of the proposed approach is validated with experimental data from the printed circuit boards manufacturing process.

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羰基粉末功率电感在回流过程中开裂的实验研究

目的在表面安装组件（SMA）工艺中，小部件受到高温变化的影响，导致部件变形和开裂。由于这种现象，在回流炉的预热和冷却阶段，羰基粉末陶瓷电感器（CPCI）的本体会形成裂纹。这些裂纹成为板材在老化过程中失效的主要原因。本文的目的是确定羰基铁陶瓷在回流炉预热阶段的热应力、热膨胀及其对裂纹萌生和扩展的影响。此外，本文还对回流剖面的重要参数进行了分类，并提出了可以用来消除这些热冲击故障的重要参数。设计/方法/方法本文研究了两种不同的回流剖面，以评估在回流炉预热区ΔT变化期间CPCI的热冲击。在第一个剖面中，预热区的温度变化ΔT设置为3.26°C/s，由于微裂纹通过CPCI迁移，这导致了许多设备故障。在第二个剖面中，预热阶段的ΔT最小化至2.06°C/s，消除了热应力；因此，故障率显著降低。本研究选用TMPC0618H系列无铅CPCI，在回流过程中观察到其热膨胀和热冲击。结果表明，预热区的高ΔT在羰基粉末型陶瓷中产生裂纹，导致器件在板老化过程中失效。与材料相比，羰基粉末陶瓷部件对热冲击的抵抗力较低，并且需要较低的温度变化率。独创性/价值所提出的研究提出了减轻热冲击缺陷的实验分析。通过印刷电路板制造过程的实验数据验证了所提出方法的实现。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Soldering & Surface Mount Technology 工程技术-材料科学：综合

CiteScore

4.10

自引率

15.00%

发文量

审稿时长

>12 weeks

期刊介绍： Soldering & Surface Mount Technology seeks to make an important contribution to the advancement of research and application within the technical body of knowledge and expertise in this vital area. Soldering & Surface Mount Technology compliments its sister publications; Circuit World and Microelectronics International. The journal covers all aspects of SMT from alloys, pastes and fluxes, to reliability and environmental effects, and is currently providing an important dissemination route for new knowledge on lead-free solders and processes. The journal comprises a multidisciplinary study of the key materials and technologies used to assemble state of the art functional electronic devices. The key focus is on assembling devices and interconnecting components via soldering, whilst also embracing a broad range of related approaches.