Study of Low-Temperature Thermocompression Bonding in Ag-In Solder for Packaging Applications

Made, Riko I; Gan, Chee Lip; Yan, Li Ling; Yu, Aibing; Yoon, Seung Wook; Lau, John H.; Lee, Chengkuo

doi:10.1007/s11664-008-0555-8

Cited by 47 publications

(18 citation statements)

References 11 publications

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“…I, we should notice that the melting point of IMCs increases with the silver content, i.e. eutectic composition (144°C) < Agln2 (166°C) < 1 (300°C) <~(670°C) <~(695°C) [7,8].…”

Section: Experimental Designmentioning

confidence: 91%

Bonding interface materials evolution of intermediate In/Ag layers for low temperature fluxless solder based MEMS wafer level packaging

Lee

Yan

et al. 2008

2008 International Conference on Electronic Materials and Packaging

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In this paper, we proposed new intermediate bonding layers (IBLs) of Ag-rich composition in In-Ag solder systems in contrast to previous studies mainly based on eutectic composition. The intermetallic compounds (lMCs) at the bonding interface were investigated with respect to the bonding condition, post-bonding room temperature storage and post-bonding heat treatment. The IMCs of Ag 2 1n and Ag9114 with high temperature resist to postbonding process are derived under process condition of wafer bonding at 180°C, 40mins and subsequent 120°C-130°C annealing for 24 hours. Based on our results, we can design proper packaging process flow so as to get reliable wafer level packaged MEMS devices.

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“…I, we should notice that the melting point of IMCs increases with the silver content, i.e. eutectic composition (144°C) < Agln2 (166°C) < 1 (300°C) <~(670°C) <~(695°C) [7,8].…”

Section: Experimental Designmentioning

confidence: 91%

Bonding interface materials evolution of intermediate In/Ag layers for low temperature fluxless solder based MEMS wafer level packaging

Lee

Yan

et al. 2008

2008 International Conference on Electronic Materials and Packaging

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“…Since solid liquid interdiffusion bonding has the merits of a low bonding temperature process and high temperature application, it has been applied in the past few decades to the manufacturing of microwave packages, high power devices, thick-film resistors, GaAs/Si wafer packages, and even gold jewelry. Recently, diffusion soldering has also been employed for ceramic multichip modules [2,3], MEMS packaging [4], semiconductor packaging [5], hybrid joining [6], and hermetic package sealing [7].…”

Section: Introductionmentioning

confidence: 99%

Low Temperature Bonding of Pd/Ni Assembly for Hydrogen Purifier

Lin¹,

Chuang²,

Tsai³

et al. 2016

World Congress on Mechanical, Chemical, and Material Engineering

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-For manufacturing a Pd cell for hydrogen purification, a key technology is the bonding of a Pd fine tube with a stainless steel grasp. In this study, the SLID method has been employed to join Pd sheet and Ni plate to evaluate the bendability between a Pd tube and a Ni coated stainless steel grasp. The results indicated that directly inserting a Sn interlayer with a thickness of 8.5μm between the Pd sheet and Ni plate caused the formation of Ni3Sn4 and PdSn4 intermetallic compounds, respectively. However, certain Sn interlayer remained after SLID bonding and low shear strength of 5.3 MPa was obtained. Furthermore, the remaining of low melting point Sn interlayer cannot withstand the operating temperature (above 350 ºC) of SLID assembled Pd cell for hydrogen purification. Reducing the Sn interlayer thickness to 3 μm led to the complete exhausting of Sn interlayer. Unfortunately, a long crack appeared at the Ni3Sn4/PdSn4 interface and a low bonding strength was resulted. Adding an Ag thin layer between the Sn coated Pd sheet and Ni plate caused an Ag3Sn intermetallic compound to form between the Ni3Sn4 and PdSn4 layers, and cracking of the Pd/Ni joint was prevented. This improvement led to satisfactory bonding strengths ranging from 10.6 to 17.3 MPa. High temperature storage at 400ºC for 100 hr did not degrade the bonding interfaces or bonding strengths.

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“…Ag-rich alloys, i.e., with high Ag composition, had seldom been attempted for bonding applications. Over the past many years, several fluxless bonding processes have been developed for which the resulting joints are Ag-rich alloys having melting temperature higher than 695°C [4,5,6]. A typical bonding temperature is 180°C, above the horizontal isotherm of 166ºC.…”

Section: Introductionmentioning

confidence: 99%

Chemical reactions of silver and indium at 180°C annealing

Lin

Lee

2012

2012 IEEE 62nd Electronic Components and Technology Conference

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Since Ag and In react to form compound at room temperature was investigated, but the chemical reactions during bonding are not well understood. The Ag-In phase diagram shows two dominating intermetallic compounds (IMC), AgIn 2 and Ag 2 In. Therefore, based on the following systematic experiments to study the chemical reactions of AgIn system and compound formation. Copper (Cu) substrates were electroplated with 40 µm thick Ag layer, followed by indium layer of 1, 5, 10, and 15 µm, respectively. Thick Ag layer is chosen to prevent In reaction with underlying Cu substrate. The samples were annealed at 180°C in 100 millitorr for 5 minutes to emulate the bonding conditions. The microstructure and the composition on the surface of the samples were evaluated using scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX). Xray diffraction (XRD) was also employed to identify the IMC on the surface. The samples were then cut in cross section, polished, and studied also by SEM and EDX. The results show that, for the sample with 1µm thick indium, the In layer converts to Ag 2 In entirely after annealing. For sample with In layer thickness of 5 µm, AgIn 2 , Ag 2 In, and silver solid solution (Ag) all exist after annealing. No indium was identified. For sample having 10, and 15µm thick indium, In was detected on the surface, but was not found on the cross section. The polishing process probably bevels the thin In layer on the surface, making it invisible. We next studied what would happen if the Ag was annealed first before plating In. After plating the Ag layer, samples were annealed at 450°C for 3 hours to grow Ag grains. This was followed by plating 10µm In and annealing at 180°C. The result shows AgIn 2 , Ag 2 In as well as In. Significant In remains on the surface. The thicknesses of AgIn 2 and Ag 2 In layers are thinner than the sample whose Ag is not annealed.

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Study of Low-Temperature Thermocompression Bonding in Ag-In Solder for Packaging Applications

Cited by 47 publications

References 11 publications

Bonding interface materials evolution of intermediate In/Ag layers for low temperature fluxless solder based MEMS wafer level packaging

Bonding interface materials evolution of intermediate In/Ag layers for low temperature fluxless solder based MEMS wafer level packaging

Low Temperature Bonding of Pd/Ni Assembly for Hydrogen Purifier

Chemical reactions of silver and indium at 180°C annealing

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Study of Low-Temperature Thermocompression Bonding in Ag-In Solder for Packaging Applications

Cited by 47 publications

References 11 publications

Bonding interface materials evolution of intermediate In/Ag layers for low temperature fluxless solder based MEMS wafer level packaging

Bonding interface materials evolution of intermediate In/Ag layers for low temperature fluxless solder based MEMS wafer level packaging

Low Temperature Bonding of Pd/Ni Assembly for Hydrogen Purifier

Chemical reactions of silver and indium at 180&#x00B0;C annealing

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Chemical reactions of silver and indium at 180°C annealing