共查询到20条相似文献,搜索用时 156 毫秒
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倒装焊器件与常规的引线键合结构不同,现行的DPA标准不能完全适用于倒装焊结构.结合现有标准和倒装焊器件结构特点,以某塑封倒装焊集成电路器件为例,提出一套经过试验验证的、实用性强的倒装焊器件DPA试验流程.在原来标准的基础上提出了对BGA焊球材料成分分析、底充胶检查的超声扫描要求、芯片凸点结构检查等一些新的DPA要求.BGA焊球材料成分分析是使用能谱分析实现的,而芯片凸点结构检查则是通过对器件进行研磨开封实现的.经过试验验证,该流程方案可用于倒装焊集成电路器件的实际DPA工作. 相似文献
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倒装焊技术已被广泛地用于电子领域.对倒装焊而言,其焊点的可靠性、密封填充物与芯片或基板间的分层一直是特别重要的课题.介绍了一种加速环境试验--HAST,用于快速评价倒装焊接在FR-4基板上面阵列分布焊点的可靠性,试验结果说明HAST能够作为一个有效的可靠性试验评价工具用于倒装焊技术领域. 相似文献
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Kwang‐Seong Choi Haksun Lee Hyun‐Cheol Bae Yong‐Sung Eom Jin Ho Lee 《ETRI Journal》2015,37(2):387-394
A novel interconnection technology based on a 52InSn solder was developed for flexible display applications. The display industry is currently trying to develop a flexible display, and one of the crucial technologies for the implementation of a flexible display is to reduce the bonding process temperature to less than 150°C. InSn solder interconnection technology is proposed herein to reduce the electrical contact resistance and concurrently achieve a process temperature of less than 150°C. A solder bump maker (SBM) and fluxing underfill were developed for these purposes. SBM is a novel bumping material, and it is a mixture of a resin system and InSn solder powder. A maskless screen printing process was also developed using an SBM to reduce the cost of the bumping process. Fluxing underfill plays the role of a flux and an underfill concurrently to simplify the bonding process compared to a conventional flip‐chip bonding using a capillary underfill material. Using an SBM and fluxing underfill, a 20 μm pitch InSn solder SoP array on a glass substrate was successfully formed using a maskless screen printing process, and two glass substrates were bonded at 130°C. 相似文献
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A cost‐effective and simple solder on pad (SoP) process is proposed for a fine‐pitch microbump interconnection. A novel solder bump maker (SBM) material is applied to form a 60‐μm pitch SoP. SBM, which is composed of ternary Sn3.0Ag0.5Cu (SAC305) solder powder and a polymer resin, is a paste material used to perform a fine‐pitch SoP through a screen printing method. By optimizing the volumetric ratio of the resin, deoxidizing agent, and SAC305 solder powder, the oxide layers on the solder powder and Cu pads are successfully removed during the bumping process without additional treatment or equipment. Test vehicles with a daisy chain pattern are fabricated to develop the fine‐pitch SoP process and evaluate the fine‐pitch interconnection. The fabricated Si chip has 6,724 bumps with a 45‐μm diameter and 60‐μm pitch. The chip is flip chip bonded with a Si substrate using an underfill material with fluxing features. Using the fluxing underfill material is advantageous since it eliminates the flux cleaning process and capillary flow process of the underfill. The optimized bonding process is validated through an electrical characterization of the daisy chain pattern. This work is the first report on a successful operation of a fine‐pitch SoP and microbump interconnection using a screen printing process. 相似文献
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Thorpe R. Baldwin D.F. Smith B. McGovern L. 《Electronics Packaging Manufacturing, IEEE Transactions on》2001,24(2):123-135
As a concept to achieve low-cost, high-throughput flip chip on board (FCOB) assembly, a new process has been developed implementing next generation flip chip processing based no-flow fluxing underfill materials. The low-cost, high throughput flip chip process implements large area underfill printing, integrated chip placement and underfill flow and simultaneous solder interconnect reflow and underfill cure. The goals of this study are to demonstrate feasibility of no flow underfill materials and the high throughput flip chip process over a range of flip chip configurations, identify the critical process variables affecting yield, analyze the yield of the high throughput flip chip process, and determine the impact of no-flow underfill materials on key process elements. Reported in this work is the assembly of a series of test vehicles to assess process yield and process defects. The test vehicles are assembled by depositing a controlled mass of underfill material on the chip site, aligning chip to the substrate pads, and placing the chip inducing a compression type underfill flow. The assemblies are reflowed in a commercial reflow furnace in an air atmosphere to simultaneously form the solder interconnects and cure the underfill. A series of designed experiments identify the critical process variables including underfill mass, reflow profile, placement velocity, placement force, and underfill material system. Of particular interest is the fact that the no-flow underfill materials studied exhibit an affinity for unique reflow profiles to minimize process defects 相似文献
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Advent of 2.5/3Dimensional (2.5/3D) integration using through-silicon vias (TSVs) enables the formation of high signal bandwidth, fine pitch, and short-distance interconnections in stacked dies but the new package configuration poses technical challenges in package assembly process. To pace industry demands, a new alternative, Thermal Compression Bonding (TCB), to the conventional Flip Chip on Board (FCOB) process has been being developed for the 3D stacking. Among process materials, epoxy flux (or no-flow underfill) draws high attention again due to its technical advantages in both TCB and mass reflow process. The conventional mass reflow with epoxy flux could provide outstanding benefits to 2.5D package assembly process. The new Low Cost High Throughput Flip Chip Assembly process is one such process requiring fewer processing steps, lower cycle times, and lower cost. In this new process, underfill is dispensed prior to chip placement, and solder reflow and underfill cure occur simultaneously. This reduces the cycle time required for manufacture; however, the presence of a viscous underfill affects the chips' capacity for self-alignment. In a companion study, self-alignment for a flip chip undergoing rectilinear translation was analyzed. This paper applies an equivalent analysis process to a flip chip undergoing rotation in the presence of a viscous underfill. Details of the modeling process are presented along with parametric studies and contrasted against pure translation case. Conditions and process parameters which are more conducive to realignment and those hampering realignment are presented. 相似文献
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Thermal fatigue damage of flip chip solder joints is a serious reliability concern, although it usually remains tolerable
with the flip chip connections (of smaller chips) to ceramic boards as practiced by IBM for over a quarter century. However,
the recent trend in microelectronics packaging towards bonding large chips or ceramic modules to organic boards means a larger
differential thermal expansion mismatch between the board and the chip or ceramic module. To reduce the thermal stresses and
strains at solder joints, a polymer underfill is customarily added to fill the cavity between the chip or module and the organic
board. This procedure has typically at least resulted in an increase of the thermal fatigue life by a factor of 10, as compared
to the non-underfilled case. In this contribution, we first discuss the effects of the underfill to reduce solder joint stresses
and strains, as well as underfill effects on fatigue crack propagation based on a finite element analysis. Secondly, we probe
the question of the importance of the effects of underfill defects, particularly that of its delamination from the chip side,
on the effectiveness of the underfill to increase thermal fatigue life. Finally, we review recent experimental evidence from
thermal cycling of actual flip chip modules which appears to support the predictions of our model. 相似文献
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为了增加在有机基板上倒装芯片安装的可靠性,在芯片安装后,通常都要进行下填充。下填充的目的是为了重新分配由于硅芯片和有机衬底间热膨胀系数失配产生的热应力。然而,仅仅依靠填充树脂毛细管流动的传统下填充工艺存在一些缺点。为了克服这些缺点,人们研究出了一些新的材料和开发出了一些新的工艺。 相似文献
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倒装芯片下填充工艺的新进展(一) 总被引:1,自引:0,他引:1
为了增加在有机基板上倒装芯片安装的可靠性,在芯片安装后,通常都要进行下填充。下填充的目的是为了重新分配由于硅芯片和有机衬底间热膨胀系数失配产生的热应力。然而,仅仅依靠填充树脂毛细管流动的传统下填充工艺存在一些缺点。为了克服这些缺点,人们研究出了一些新的材料和开发出了一些新的工艺。 相似文献
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Tran S.K. Questad D.L. Sammakia B.G. 《Components and Packaging Technologies, IEEE Transactions on》1999,22(4):519-524
Flip chip attach on organic carriers is a novel electronic packaging assembly method which provides advantages of high input/output (I/O) counts, electrical performance and thermal dissipation. In this structure, the flip chip device is attached to organic laminate with predeposited eutectic solder. Mechanical coupling of the chip and the laminate is done via underfill encapsulant materials. As the chip size increases, the thermal mismatch between silicon and its organic carrier becomes greater. Adhesion becomes an important factor since the C4 joints fail quickly if delamination of the underfill from either chip or the solder mask interface occurs. Newly developed underfills have been studied to examine their properties, including interfacial adhesion strength, flow characteristics, void formation and cure kinetics. This paper will describe basic investigations into the properties of these underfills and also how these properties related to the overall development process. In addition, experiments were performed to determine the effects on adhesion degradation of flip chip assembly processes and materials such as IR reflow profile, flux quantity and residues. Surface treatment of both the chip and the laminate prior to encapsulation were studied to enhance underfill adhesion. Accelerated thermal cycling and highly accelerated stress testing (HAST) were conducted to compare various underfill properties and reliability responses 相似文献