Wafer-Level Vacuum-Packaged Translatory MEMS Actuator with Large Stroke for NIR-FT Spectrometers

We present a wafer-level vacuum-packaged (WLVP) translatory micro-electro-mechanical system (MEMS) actuator developed for a compact near-infrared-Fourier transform spectrometer (NIR-FTS) with 800–2500 nm spectral bandwidth and signal-nose-ratio (SNR) > 1000 in the smaller bandwidth range (1200–2500 nm) for 1 s measuring time. Although monolithic, highly miniaturized MEMS NIR-FTSs exist today, we follow a classical optical FT instrumentation using a resonant MEMS mirror of 5 mm diameter with precise out-of-plane translatory oscillation for optical path-length modulation. Compared to highly miniaturized MEMS NIR-FTS, the present concept features higher optical throughput and resolution, as well as mechanical robustness and insensitivity to vibration and mechanical shock, compared to conventional FTS mirror drives. The large-stroke MEMS design uses a fully symmetrical four-pantograph suspension, avoiding problems with tilting and parasitic modes. Due to significant gas damping, a permanent vacuum of ≤3.21 Pa is required. Therefore, an MEMS design with WLVP optimization for the NIR spectral range with minimized static and dynamic mirror deformation of ≤100 nm was developed. For hermetic sealing, glass-frit bonding at elevated process temperatures of 430–440 °C was used to ensure compatibility with a qualified MEMS processes. Finally, a WLVP MEMS with a vacuum pressure of ≤0.15 Pa and Q ≥ 38,600 was realized, resulting in a stroke of 700 µm at 267 Hz for driving at 4 V in parametric resonance. The long-term stability of the 0.2 Pa interior vacuum was successfully tested using a Ne fine-leakage test and resulted in an estimated lifetime of >10 years. This meets the requirements of a compact NIR-FTS.

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Low Temperature Al-Al Thermo-compression Bonding with Sn Oxidation Protect Layer for Wafer-level Hermetic Sealing

IEEJ Transactions on Sensors and Micromachines ◽

10.1541/ieejsmas.136.237 ◽

2016 ◽

Vol 136 (6) ◽

pp. 237-243 ◽

Cited By ~ 2

Author(s):

Shiro Satoh ◽

Hideyuki Fukushi ◽

Masayoshi Esashi ◽

Shuji Tanaka

Keyword(s):

Low Temperature ◽

Wafer Level ◽

Hermetic Sealing

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WLCSP Laminate Removal Using NIR Laser

10.31399/asm.cp.istfa2018p0486 ◽

2018 ◽

Author(s):

Chun Haur Khoo

Keyword(s):

Near Infrared ◽

Laser Energy ◽

Photon Emission ◽

Mechanical Damage ◽

Consumer Products ◽

Fault Isolation ◽

Wafer Level ◽

Isolation Technique ◽

Laminate Layer ◽

Nir Laser

Abstract Driven by the cost reduction and miniaturization, Wafer Level Chip Scale Packaging (WLCSP) has experienced significant growth mainly driven by mobile consumer products. Depending on the customers or manufacturing needs, the bare silicon backside of the WLCSP may be covered with a backside laminate layer. In the failure analysis lab, in order to perform the die level backside fault isolation technique using Photon Emission Microscope (PEM) or Laser Signal Injection Microscope (LSIM), the backside laminate layer needs to be removed. Most of the time, this is done using the mechanical polishing method. This paper outlines the backside laminate removal method of WLCSP using a near infrared (NIR) laser that produces laser energy in the 1,064 nm range. This method significantly reduces the sample preparation time and also reduces the risk of mechanical damage as there is no application of mechanical force. This is an effective method for WLCSP mounted on a PCB board.

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Strengthening Thermal Stability in V2O5-ZnO-BaO-B2O3-M(PO3)n Glass System (M = Al, Mg) for Laser Sealing Applications

Applied Sciences ◽

10.3390/app11104603 ◽

2021 ◽

Vol 11 (10) ◽

pp. 4603

Author(s):

Soyoung Kim ◽

Karam Han ◽

Seonhoon Kim ◽

Linganna Kadathala ◽

Jinhyeok Kim ◽

...

Keyword(s):

Thermal Stability ◽

Thermal Expansion ◽

Bond Strength ◽

Coefficient Of Thermal Expansion ◽

Glass Frit ◽

Glass System ◽

Fiber Types ◽

Hermetic Sealing ◽

Doped Glasses ◽

Glass Panels

Today, the most common way of laser sealing is using a glass frit paste and screen printer. Laser sealing using glass frit paste has some problems, such as pores, nonuniform height, imperfect hermetic sealing, etc. In order to overcome these problems, sealing using fiber types of sealant is attractive for packaging devices. In this work, (70-x)V2O5-5ZnO-22BaO-3B2O3-xM(PO3)n glasses (mol%) incorporated with xM(PO3)n concentration (where M = Mg, Al, n = 2, 3, respectively) were fabricated and their thermal, thermomechanical, and structural properties were investigated. Most importantly, for this type of sealing, the glass should have a thermal stability (ΔT) of ≥80 °C and the coefficient of thermal expansion (CTE) between the glass and panel should be 1.0 ppm/°C. The highest thermal stability ΔT of the order of 93.2 °C and 112.9 °C was obtained for the 15 mol% of Mg(PO3)2 and Al(PO3)3 doped glasses, respectively. This reveals that the bond strength and connectivity is more strongly improved by trivalent Al(PO3)3. The CTE of a (70-x)V2O5-5ZnO-22BaO-3B2O3-xAl(PO3)3 glass system (mol%) (where x = 5–15, mol%) is in the range of 9.5–15.5 (×10−6/K), which is comparable with the CTE (9–10 (×10−6/K)) of commercial DSSC glass panels. Based on the results, the studied glass systems are considered to be suitable for laser sealing using fiber types of sealant.

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Warpage characteristics of wafer-level package of MEMS with glass frit bonding

2013 14th International Conference on Electronic Packaging Technology ◽

10.1109/icept.2013.6756603 ◽

2013 ◽

Cited By ~ 1

Author(s):

Gaowei Xu ◽

Shuangfu Wang ◽

Chunsheng Zhu ◽

Jiaotuo Ye ◽

Wei Gai ◽

...

Keyword(s):

Glass Frit ◽

Wafer Level ◽

Wafer Level Package

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Non-Traditional Applications of near Infrared Spectroscopy Based on the Optical Characteristic Models for a Biological Material Having Cellular Structure

Journal of Near Infrared Spectroscopy ◽

10.1255/jnirs.119 ◽

1998 ◽

Vol 6 (1) ◽

pp. 41-46 ◽

Cited By ~ 6

Author(s):

Satoru Tsuchikawa

Keyword(s):

Biological Material ◽

Path Length ◽

Cellular Structure ◽

Process Model ◽

Near Infrared ◽

Traditional Approach ◽

Nir Spectroscopy ◽

Optical Path Length ◽

Optical Path ◽

The Mean

Non-destructive measurements, based on near infrared (NIR) spectroscopy, on biological material with a cellular structure like wood require a non-traditional approach. We have developed new concepts to model the optical properties of a sample having cellular structure, for the illumination conditions of the spectrometer available to us. A set of optical models, which consisted of the directional characteristics models, the light-path models and the equivalent surface roughness model was proposed to clarify the behaviour of light propagation in a wood sample. Furthermore, the mean optical path length, which was derived by incorporating the nth power cosine model of radiant intensity into the diffusion process model in consideration of the parallel beam component of incident light, was calculated. By introducing the concept of equivalent sample thickness, compatible with the mean optical path length, into the Kubelka–Munk theory, generalised input/output equations for radiation were constructed. In this non-traditional application of NIR spectroscopy, these optical concepts make it possible to analyse both the physical condition and chemical composition of a biological material with a cellular structure.

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Effect of Design Parameters on Drop Test Performance of Wafer Level Chip Scale Packages (WLCSP)

ASME 2011 Pacific Rim Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Systems, MEMS and NEMS: Volume 1 ◽

10.1115/ipack2011-52078 ◽

2011 ◽

Author(s):

Pushkraj Tumne ◽

Vikram Venkatadri ◽

Santosh Kudtarkar ◽

Michael Delaus ◽

Daryl Santos ◽

...

Keyword(s):

Flip Chip ◽

Bulk Solder ◽

Consumer Electronics ◽

Drop Test ◽

Design Parameters ◽

Mechanical Shock ◽

Wafer Level ◽

Cross Sectional ◽

Right Censored Data ◽

Solder Balls

Today’s consumer market demands electronics that are smaller, faster and cheaper. To cater to these demands, novel materials, new designs, and new packaging technologies are introduced frequently. Wafer Level Chip Scale Package (WLCSP) is one of the emerging package technologies that have the key advantages of reduced cost and smaller footprint. The portable consumer electronics are frequently dropped; hence the emphasis of reliability is shifting towards study of effects of mechanical shock loading increasingly. Mechanical loading typically induces brittle fractures (also known as intermetallic failures) between the solder bumps and bond pads at the silicon die side. This type of failure mechanism is typically characterized by the board level drop test. WLCSP is a variant of the flip-chip interconnection technique. In WLCSPs, the active side of the die is inverted and connected to the PCB by solder balls. The size of these solder balls is typically large enough (300μm pre-reflow for 0.5mm pitch and 250μm pre-reflow for 0.4mm pitch) to avoid use of underfill that is required for the flip-chip interconnects. Several variations are incorporated in the package design parameters to meet the performance, reliability, and footprint requirements of the package assembly. The design parameters investigated in this effort are solder ball compositions with different Silver (Ag) content, backside lamination with different thickness, WLCSP type –Direct and Re-Distribution Layer (RDL), bond pad thickness, and sputtered versus electroplated Under Bump Metallurgy (UBM) deposition methods for 8×8, 9×9, and 10×10 array sizes. The test vehicles built using these design parameters were drop tested using JEDEC recommended test boards and conditions as per JESD22-B11. Cross sectional analysis was used to identify, confirm, and classify the intermetallic, and bulk solder failures. The objective of this research was to quantify the effects and interactions of WLCSP design parameters through drop test. The drop test data was collected and treated as a right censored data. Further, it was analyzed by fitting empirical distributions using the grouped and un-grouped data approach. Data analysis showed that design parameters had a significant effect on the drop performance and played a vital role in influencing the package reliability.

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Study on Process Induced out-of-plane deformation for Fan-Out Wafer Level Packaging

2020 IEEE 8th Electronics System-Integration Technology Conference (ESTC) ◽

10.1109/estc48849.2020.9229783 ◽

2020 ◽

Author(s):

A. Salahouelhadj ◽

M. Gonzalez ◽

A. Podpod ◽

E. Beyne

Keyword(s):

Plane Deformation ◽

Wafer Level ◽

Wafer Level Packaging ◽

Out Of Plane

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Validation of nine years of MOPITT V5 NIR using MOZAIC/IAGOS measurements: biases and long-term stability

Atmospheric Measurement Techniques ◽

10.5194/amt-7-3783-2014 ◽

2014 ◽

Vol 7 (11) ◽

pp. 3783-3799 ◽

Cited By ~ 8

Author(s):

A. T. J. de Laat ◽

I. Aben ◽

M. Deeter ◽

P. Nédélec ◽

H. Eskes ◽

...

Keyword(s):

Near Infrared ◽

Transport Model ◽

A Priori ◽

Validation Data ◽

Chemistry Transport Model ◽

Large Variability ◽

Long Term Stability ◽

Spatio Temporal ◽

Good Agreement

Abstract. Validation results from a comparison between Measurement Of Pollution In The Troposphere (MOPITT) V5 Near InfraRed (NIR) carbon monoxide (CO) total column measurements and Measurement of Ozone and Water Vapour on Airbus in-service Aircraft (MOZAIC)/In-Service Aircraft for a Global Observing System (IAGOS) aircraft measurements are presented. A good agreement is found between MOPITT and MOZAIC/IAGOS measurements, consistent with results from earlier studies using different validation data and despite large variability in MOPITT CO total columns along the spatial footprint of the MOZAIC/IAGOS measurements. Validation results improve when taking the large spatial footprint of the MOZAIC/IAGOS data into account. No statistically significant drift was detected in the validation results over the period 2002–2010 at global, continental and local (airport) scales. Furthermore, for those situations where MOZAIC/IAGOS measurements differed from the MOPITT a priori, the MOPITT measurements clearly outperformed the MOPITT a priori data, indicating that MOPITT NIR retrievals add value to the MOPITT a priori. Results from a high spatial resolution simulation of the chemistry-transport model MOCAGE (MOdèle de Chimie Atmosphérique à Grande Echelle) showed that the most likely explanation for the large MOPITT variability along the MOZAIC-IAGOS profile flight path is related to spatio-temporal CO variability, which should be kept in mind when using MOZAIC/IAGOS profile measurements for validating satellite nadir observations.

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Distinct Difference in Sensitivity of NIR vs. IR Bands of Melamine to Inter-Molecular Interactions with Impact on Analytical Spectroscopy Explained by Anharmonic Quantum Mechanical Study

Molecules ◽

10.3390/molecules24071402 ◽

2019 ◽

Vol 24 (7) ◽

pp. 1402 ◽

Cited By ~ 9

Author(s):

Justyna Grabska ◽

Krzysztof B. Beć ◽

Christian G. Kirchler ◽

Yukihiro Ozaki ◽

Christian W. Huck

Keyword(s):

Vibrational Spectroscopy ◽

Molecular Interactions ◽

Near Infrared ◽

Three Dimensions ◽

Quantum Mechanical ◽

Quantum Mechanical Calculations ◽

Spectral Simulation ◽

Analytical Spectroscopy ◽

Quality Control Tool ◽

Out Of Plane

Melamine (IUPAC: 1,3,5-Triazine-2,4,6-triamine) attracts high attention in analytical vibrational spectroscopy due to its misuse as a food adulterant. Vibrational spectroscopy [infrared (IR) and Raman and near-infrared (NIR) spectroscopy] is a major quality control tool in the detection and quantification of melamine content. The physical background for the measured spectra is not interpreted in analytical spectroscopy using chemometrics. In contrast, quantum mechanical calculations are capable of providing deep and independent insights therein. So far, the NIR region of crystalline melamine has not been studied by quantum mechanical calculations, while the investigations of its IR spectra have remained limited. In the present work, we employed fully anharmonic calculation of the NIR spectrum of melamine based on finite models, and also performed IR spectral simulation by using an infinite crystal model—periodic in three dimensions. This yielded detailed and unambiguous NIR band assignments and revised the previously known IR band assignments. We found that the out-of-plane fundamental transitions, which are essential in the IR region, are markedly more sensitive to out-of-plane inter-molecular interactions of melamine than NIR transitions. Proper description of the chemical surrounding of the molecule of melamine is more important than the anharmonicity of its vibrations. In contrast, the NIR bands mostly arise from in-plane vibrations, and remain surprisingly insensitive to the chemical environment. These findings explain previous observations that were reported in IR and NIR analytical studies of melamine.

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