Three-Mask Fabrication and Optimized Design of First-Level Free-Standing Interconnect for Microelectronics Application

Author(s):  
Qi Zhu ◽  
Lunyu Ma ◽  
George Lo ◽  
Suresh K. Sitaraman

Advances in compliant off-chip interconnects have achieved great strides. G-Helix, an electroplated compliant chip-to-substrate interconnect has the potential for accomplishing low-cost, easy-to-fabricate, wafer-level packaging. In this work, the design, fabrication, optimization and reliability of the G-Helix compliant off-chip interconnects have been studied. A three-mask process was used to successfully fabricate the free-standing G-Helix compliant interconnect. The mechanical compliance and the electrical parasitics were studied through numerical and analytical models. Response Surface Methodology (RSM) was used to maximize the mechanical compliance and minimize the electrical parasitics as well as the stresses induced in the interconnect. It is also seen through the models that an array of interconnects will be able to withstand the die and the heat-sink weight without plastically yielding. Also, the G-Helix interconnect assembly on organic printed circuit board using lead-free solder will be able to withstand more than 1000 accelerated thermal cycles without the need for an underfill.

2000 ◽  
Author(s):  
John H. Lau ◽  
Stephen H. Pan ◽  
Chris Chang

Abstract In this study, time-temperature-dependent nonlinear analyses of lead-free solder bumped wafer level chip scale package (WLCSP) on printed circuit board (PCB) assemblies subjected to thermal cycling conditions are presented. Two different lead-free solder alloys are considered, namely, 96.5wt%Sn-3.5wt%Ag and 100wt%In. The 62wt%Sn-36wt%Pb-2wt%Ag solder alloy is also considered to establish a baseline. All of these solder alloys are assumed to obey the Garofalo-Arrhenius steady-state creep constitutive law. The shear stress and shear creep strain hysteresis loops, shear stress history, and shear creep strain history at the corner solder joint are presented for a better understanding of the thermal-mechanical behaviors of lead-free solder bumped WLCSP on PCB assemblies. Also, the effects of microvia build-up PCB on the WLCSP solder joint reliability are investigated.


2002 ◽  
Vol 124 (2) ◽  
pp. 69-76 ◽  
Author(s):  
John H. Lau ◽  
Stephen H. Pan ◽  
Chris Chang

In this study, time-temperature-dependent nonlinear analyses of lead-free solder bumped wafer level chip scale package (WLCSP) on printed circuit board (PCB) assemblies subjected to thermal cycling conditions are presented. Two different lead-free solder alloys are considered, namely, 96.5wt percent Sn-3.5wt percent Ag and 100wt percent In. The 62wt percent Sn-36wt percent Pb-2wt percent Ag solder alloy is also considered to establish a baseline. All of these solder alloys are assumed to obey the Garofalo-Arrhenius steady-state creep constitutive law. The shear stress and shear creep strain hysteresis loops, shear stress history, and shear creep strain history at the corner solder joint are presented for a better understanding of the thermal-mechanical behaviors of lead-free solder bumped WLCSP on PCB assemblies. Also, the effects of microvia build-up PCB on the WLCSP Solder joint reliability are investigated.


2014 ◽  
Vol 6 (3-4) ◽  
pp. 361-369 ◽  
Author(s):  
Abouzar Hamidipour ◽  
Reinhard Feger ◽  
Sebastian Poltschak ◽  
Andreas Stelzer

This paper proposes a fully integrated 160-GHz transmitter and receiver in package for millimeter-wave applications. The monolithic integrated circuits were designed with a harmonic approach and were fabricated using a SiGe:C HBT production technology with an fTand fmaxof 170 and 250 GHz, respectively. The manufactured 2006 × 1865 µm2bare dies were integrated in 6 × 6 mm2embedded wafer level ball grid array packages, where they were interconnected with highly directional antennas built on the redistribution layer of the packages. With a total frequency multiplication factor of 36 and an active balun at the first stage, the transmitter allows the use of a 4.5-GHz input signal driven from a single-ended signal source [1] and distributed on a standard low-cost printed circuit board. The receiver comprises a Gilbert-cell-based subharmonic mixer with a simulated 1-dB input compression point of −4 dBm, and a minimum double-sideband noise figure of 16.5 dB. The functionality of the proposed system was successfully demonstrated in a quasi-monostatic FMCW radar measurement with a 1-ms up-chirp frequency sweep from 157 to 160 GHz and in a forward-scatter imaging experiment with an 8-GHz frequency ramp from 157 to 165 GHz.


Author(s):  
Keyur Mahant ◽  
Hiren Mewada ◽  
Amit Patel ◽  
Alpesh Vala ◽  
Jitendra Chaudhari

Aim: In this article, wideband substrate integrated waveguide (SIW) and rectangular waveguide (RWG) transition operating in Ka-band is proposed Objective: In this article, wideband substrate integrated waveguide (SIW) and rectangular waveguide (RWG) transition operating in Ka-band is proposed. Method: Coupling patch etched on the SIW cavity to couple the electromagnetic energy from SIW to RWG. Moreover, metasurface is introduced into the radiating patch to enhance bandwidth. To verify the functionality of the proposed structure back to back transition is designed and fabricated on a single layer substrate using standard printed circuit board (PCB) fabrication technology. Results: Measured results matches with the simulation results, measured insertion loss is less than 1.2 dB and return loss is better than 3 dB for the frequency range of 28.8 to 36.3 GHz. By fabricating transition with 35 SRRs bandwidth of the proposed transition can be improved. Conclusion: The proposed transition has advantages like compact in size, easy to fabricate, low cost and wide bandwidth. Proposed structure is a good candidate for millimeter wave circuits and systems.


2021 ◽  
Vol 11 (15) ◽  
pp. 6885
Author(s):  
Marcos D. Fernandez ◽  
José A. Ballesteros ◽  
Angel Belenguer

Empty substrate integrated coaxial line (ESICL) technology preserves the many advantages of the substrate integrated technology waveguides, such as low cost, low profile, or integration in a printed circuit board (PCB); in addition, ESICL is non-dispersive and has low radiation. To date, only two transitions have been proposed in the literature that connect the ESICL to classical planar lines such as grounded coplanar and microstrip. In both transitions, the feeding planar lines and the ESICL are built in the same substrate layer and they are based on transformed structures in the planar line, which must be in the central layer of the ESICL. These transitions also combine a lot of metallized and non-metallized parts, which increases the complexity of the manufacturing process. In this work, a new through-wire microstrip-to-ESICL transition is proposed. The feeding lines and the ESICL are implemented in different layers, so that the height of the ESICL can be independently chosen. In addition, it is a highly compact transition that does not require a transformer and can be freely rotated in its plane. This simplicity provides a high degree of versatility in the design phase, where there are only four variables that control the performance of the transition.


Author(s):  
Hanh

In this work, ZnO nanorods (NRs) were successfully grown on printed circuit board substrates (PCBs) by utilizing a one-step, seedless, low-cost hydrothermal method. It was shown that by implementing a galvanic cell structure in an aqueous solution of 80 mM of zinc nitrate hexahydrate and hexamethylenetetramine, ZnO NRs can directly grow on the PCBs substrate without the assistance of a seed layer. The effect of hydrothermal time on the surface morphologies, and the crystallinity of the as-grown ZnO nanorods (NRs) was also investigated. The as-grown ZnO NRs also exhibited a significant enhancement in vertical growth and their crystallinity with 5 hour growth.


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