Extending WLCSP Packaging Technology Capabilities to Enable Miniaturized Sensor and MEMS Packaging Applications

WLCSP has been widely deployed in portable computing and communication devices for efficient die level packaging of integrated semiconductor and integrated passive applications. More recently with the proliferation of smart phone capabilities and applications as well as the emergence of Internet of Things and Wearable Electronics, MEMS and sensor devices in minimized package formats have become increasingly pervasive. These include image sensors, light sensors, finger print sensors as well as accelerometer, gyroscope and other MEMS motion sensing devices. It is predicted that the widespread adoption of WLCSP packaging for sensing applications will accelerate the proliferation of the incorporation of multiple sensor technologies within future communication devices. A number of these MEMS/Sensor applications have been able to leverage the existing WLCSP technology infrastructure and has led to opportunities to packaging and cost-effective standardization and miniaturization. On the other hand, some significant new changes to WLCSP process flows have also emerged that have had to be addressed. This paper will provide an overview of MEMS and Sensor applications that are currently or will use 2D, 2.5D or 3D wafer level packaging formats. Process enhancements including the ability to process thinner substrates with the adoption of temporary carrier technologies will also be highlighted.

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Rapid Silicon-to-Steel Bonding via Inductive Heating

Microelectromechanical Systems ◽

10.1115/imece2006-15456 ◽

2006 ◽

Cited By ~ 1

Author(s):

Brian D. Sosnowchik ◽

Liwei Lin ◽

Albert P. Pisano

Keyword(s):

Bonding Temperature ◽

Surface Preparation ◽

Fatigue Tests ◽

Bonding Process ◽

Inductive Heating ◽

Sensor Applications ◽

Mems Sensor ◽

Sensing Applications ◽

Minimal Damage ◽

Point Bend

In this work, we present a rapid, low temperature process for the bonding of silicon to steel through the use of inductive heating for MEMS sensor applications. The bonding process takes as short as three seconds with a maximum bonding temperature as low as 230°C at the steel surface. The bonding strength is strong, and causes minimal damage to steel. The process has also been shown to work using leaded and leadfree bonding solder with minimal surface preparation to the steel. Four characterization experiments – tensile and compressive 4-point bend, axial extension, and fatigue tests – have been performed to validate the bonding process and materials. As such, this work illustrates the promise of applying inductive heating for the rapid silicon bonding to steel components for MEMS sensing applications.

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Large-Area Thermal Distribution Sensor Based on Multilayer Graphene Ink

Sensors ◽

10.3390/s20185188 ◽

2020 ◽

Vol 20 (18) ◽

pp. 5188

Author(s):

Tomi Koskinen ◽

Taneli Juntunen ◽

Ilkka Tittonen

Keyword(s):

Signal To Noise Ratio ◽

Graphene Film ◽

Multilayer Graphene ◽

Wearable Electronics ◽

Large Area ◽

Sensor Applications ◽

Thermal Distribution ◽

Sensing Applications ◽

Detection Of Objects ◽

Distribution Mapping

Emergent applications in wearable electronics require inexpensive sensors suited to scalable manufacturing. This work demonstrates a large-area thermal sensor based on distributed thermocouple architecture and ink-based multilayer graphene film. The proposed device combines the exceptional mechanical properties of multilayer graphene nanocomposite with the reliability and passive sensing performance enabled by thermoelectrics. The Seebeck coefficient of the spray-deposited films revealed an inverse thickness dependence with the largest value of 44.7 μV K−1 at 78 nm, which makes thinner films preferable for sensor applications. Device performance was demonstrated by touch sensing and thermal distribution mapping-based shape detection. Sensor output voltage in the latter application was on the order of 300 μV with a signal-to-noise ratio (SNR) of 35, thus enabling accurate detection of objects of different shapes and sizes. The results imply that films based on multilayer graphene ink are highly suitable to thermoelectric sensing applications, while the ink phase enables facile integration into existing fabrication processes.

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Advanced 3D eWLB-SiP (embedded Wafer Level Ball Grid Array – System in Package) Technology

Additional Conferences (Device Packaging HiTEC HiTEN & CICMT) ◽

10.4071/2017dpc-tp2_presentation5 ◽

2017 ◽

Vol 2017 (DPC) ◽

pp. 1-20

Author(s):

Seung Wook Yoon

Keyword(s):

Form Factor ◽

Power Efficiency ◽

High Performance ◽

Electrical Characterization ◽

Cost Effective ◽

Electrical Performance ◽

Wearable Electronics ◽

Wafer Level ◽

Low Profile ◽

Line Spacing

FO-WLP (Fan-Out Wafer Level Packaging) has been established as one of the most versatile packaging technologies in the recent past and is already accounting for a market value of over 1 billion USD due to its unique advantages. The technology combines high performance, increased functionality with a high potential for heterogeneous integration and reduce the total form factor as well as cost-effectiveness. The emerging of advanced of silicon node technology down to 10 nanometer (nm) in support of higher performance, bandwidth and better power efficiency in mobile products pushes the boundaries of emerging packaging technologies to smaller form-factor packaging designs with finer line/spacing as well as improved thermal electrical/performance and integration of SiP or 3D capabilities. Advanced eWLB FO-WLP technology provides a versatile platform for the semiconductor industry's technology evolution from single or multi-die 2D package designs to 2.5D interposers and 3D System-in-Package (SiP) configurations. This paper reports developments that extend multi-die and 3D SiP applications with eWLB technology, including ultra thin devices or/and with an interposer substrate attachment. Test vehicles have been designed and fabricated to demonstrate and characterize integrated packaging solutions for network, mobile products including IoT and wearable electronics. The test vehicles have ranged from ~30mm2 to large sizes up to ~230mm2 and 0.4mm ball pitch. Assembly process details including 3D vertical interconnect, laser ablation, RDL processes and mechanical reliability characterizations are to be discussed with component and board level reliability results. In addition, warpage behavior and the PoP stacking process will also be presented. Innovative structure optimization that provides dual advantages of both height reduction and enhanced package reliability are reported. To enable higher interconnection density and signal routing, packages with multiple redistribution layers (RDL) and fine line/width spacing are fabricated and implemented on the eWLB platform. Successful reliability and electrical characterization results on multi-die and 3D eWLB-SiP configurations are reported as an enabling technology for highly integrated, miniaturized, low profile and cost effective solutions.

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Pyroelectric Energy Conversion and Its Applications—Flexible Energy Harvesters and Sensors

Sensors ◽

10.3390/s19092170 ◽

2019 ◽

Vol 19 (9) ◽

pp. 2170 ◽

Cited By ~ 15

Author(s):

Atul Thakre ◽

Ajeet Kumar ◽

Hyun-Cheol Song ◽

Dae-Yong Jeong ◽

Jungho Ryu

Keyword(s):

Energy Harvesting ◽

Energy Conversion ◽

Thermal Energy ◽

Cost Effective ◽

Electrical Energy ◽

Energy Scavenging ◽

Hybrid Energy ◽

Energy Harvesters ◽

Sensor Applications ◽

Sensing Applications

Among the various forms of natural energies, heat is the most prevalent and least harvested energy. Scavenging and detecting stray thermal energy for conversion into electrical energy can provide a cost-effective and reliable energy source for modern electrical appliances and sensor applications. Along with this, flexible devices have attracted considerable attention in scientific and industrial communities as wearable and implantable harvesters in addition to traditional thermal sensor applications. This review mainly discusses thermal energy conversion through pyroelectric phenomena in various lead-free as well as lead-based ceramics and polymers for flexible pyroelectric energy harvesting and sensor applications. The corresponding thermodynamic heat cycles and figures of merit of the pyroelectric materials for energy harvesting and heat sensing applications are also briefly discussed. Moreover, this study provides guidance on designing pyroelectric materials for flexible pyroelectric and hybrid energy harvesting.

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A Novel Handheld Electrochemical Analyzer System Interfaced to a Smartphone

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.543.47 ◽

2013 ◽

Vol 543 ◽

pp. 47-50 ◽

Cited By ~ 3

Author(s):

Vijayalakshmi Velusamy ◽

Khalil Arshak ◽

Olga Korostynska ◽

Ahmed Al-Shamma'a

Keyword(s):

Real Time ◽

Electrochemical Cell ◽

Specific Binding ◽

Smart Phone ◽

Cost Effective ◽

Dna Biosensor ◽

Effective Solution ◽

Minimum Level ◽

Sensing Applications ◽

Electrochemical Analyzer

Detailed in this paper is the design of a novel handheld electrochemical analyzer system interfaced to a smart phone, which provides versatile and cost-effective solution for real-time sensing applications. It was characterised for electron transfer events associated with chemical and biological samples. The presented design is implemented based on the Arduino nanoopen source electronics prototyping platform. The versatility of the instrument is further demonstrated by employing the electrochemical analyser to a modified electrochemical cell which formed the basis of a DNA biosensor. Cyclic voltammetry technique was used to impose a triangular waveform on an electrochemical cell and the resulting current through the cell was then monitored. The DNA biosensor generated unique electrical signals in real-time between complementary and non-complementary oligonucleotides sequences of the Bacillus cereus DNA. The effects of hybridization and non-specific binding were compared when the probe DNA molecules were immobilized on a conducting polymer matrix. The results showed that the probe DNA immobilized using electrochemical adsorption yielded better hybridization signals compared to other immobilization methods. The performance of the DNA sensor proved to be effective in terms of selectivity, sensitivity and reproducibility of hybridization events. Analysis of these DNA probes showed that the minimum level of detection was 33.3 pg/ml.

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Rapid Growth of TiO2 Nanoflowers via Low-Temperature Solution Process: Photovoltaic and Sensing Applications

Materials ◽

10.3390/ma12040566 ◽

2019 ◽

Vol 12 (4) ◽

pp. 566 ◽

Cited By ~ 7

Author(s):

M. Akhtar ◽

Ahmad Umar ◽

Swati Sood ◽

InSung Jung ◽

H. Hegazy ◽

...

Keyword(s):

Low Temperature ◽

Anatase Phase ◽

Three Dimensional ◽

Solution Process ◽

Dye Sensitized Solar Cell ◽

Sensor Applications ◽

Dye Sensitized ◽

Sensing Applications ◽

Density Growth ◽

Temperature Solution

This paper reports the rapid synthesis, characterization, and photovoltaic and sensing applications of TiO2 nanoflowers prepared by a facile low-temperature solution process. The morphological characterizations clearly reveal the high-density growth of a three-dimensional flower-shaped structure composed of small petal-like rods. The detailed properties confirmed that the synthesized nanoflowers exhibited high crystallinity with anatase phase and possessed an energy bandgap of 3.2 eV. The synthesized TiO2 nanoflowers were utilized as photo-anode and electron-mediating materials to fabricate dye-sensitized solar cell (DSSC) and liquid nitroaniline sensor applications. The fabricated DSSC demonstrated a moderate conversion efficiency of ~3.64% with a maximum incident photon to current efficiency (IPCE) of ~41% at 540 nm. The fabricated liquid nitroaniline sensor demonstrated a good sensitivity of ~268.9 μA mM−1 cm−2 with a low detection limit of 1.05 mM in a short response time of 10 s.

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Anisotropic, Wrinkled, and Crack-Bridging Structure for Ultrasensitive, Highly Selective Multidirectional Strain Sensors

Nano-Micro Letters ◽

10.1007/s40820-021-00615-5 ◽

2021 ◽

Vol 13 (1) ◽

Author(s):

Heng Zhang ◽

Dan Liu ◽

Jeng-Hun Lee ◽

Haomin Chen ◽

Eunyoung Kim ◽

...

Keyword(s):

Rational Design ◽

Full Range ◽

Human Motion ◽

Strain Sensors ◽

Gauge Factor ◽

Wearable Electronics ◽

Trade Off ◽

Human Motion Detection ◽

Sensing Applications ◽

Anisotropic Structures

AbstractFlexible multidirectional strain sensors are crucial to accurately determining the complex strain states involved in emerging sensing applications. Although considerable efforts have been made to construct anisotropic structures for improved selective sensing capabilities, existing anisotropic sensors suffer from a trade-off between high sensitivity and high stretchability with acceptable linearity. Here, an ultrasensitive, highly selective multidirectional sensor is developed by rational design of functionally different anisotropic layers. The bilayer sensor consists of an aligned carbon nanotube (CNT) array assembled on top of a periodically wrinkled and cracked CNT–graphene oxide film. The transversely aligned CNT layer bridge the underlying longitudinal microcracks to effectively discourage their propagation even when highly stretched, leading to superior sensitivity with a gauge factor of 287.6 across a broad linear working range of up to 100% strain. The wrinkles generated through a pre-straining/releasing routine in the direction transverse to CNT alignment is responsible for exceptional selectivity of 6.3, to the benefit of accurate detection of loading directions by the multidirectional sensor. This work proposes a unique approach to leveraging the inherent merits of two cross-influential anisotropic structures to resolve the trade-off among sensitivity, selectivity, and stretchability, demonstrating promising applications in full-range, multi-axis human motion detection for wearable electronics and smart robotics.

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Utilising Commercially Fabricated Printed Circuit Boards as an Electrochemical Biosensing Platform

Micromachines ◽

10.3390/mi12070793 ◽

2021 ◽

Vol 12 (7) ◽

pp. 793

Author(s):

Uroš Zupančič ◽

Joshua Rainbow ◽

Pedro Estrela ◽

Despina Moschou

Keyword(s):

Printed Circuit Boards ◽

Electrochemical Sensors ◽

Cost Effective ◽

Electrochemical Sensing ◽

Label Free ◽

Circuit Boards ◽

Printed Circuit ◽

Sensing Applications ◽

Electrochemical Biosensing ◽

Pre Treatment

Printed circuit boards (PCBs) offer a promising platform for the development of electronics-assisted biomedical diagnostic sensors and microsystems. The long-standing industrial basis offers distinctive advantages for cost-effective, reproducible, and easily integrated sample-in-answer-out diagnostic microsystems. Nonetheless, the commercial techniques used in the fabrication of PCBs produce various contaminants potentially degrading severely their stability and repeatability in electrochemical sensing applications. Herein, we analyse for the first time such critical technological considerations, allowing the exploitation of commercial PCB platforms as reliable electrochemical sensing platforms. The presented electrochemical and physical characterisation data reveal clear evidence of both organic and inorganic sensing electrode surface contaminants, which can be removed using various pre-cleaning techniques. We demonstrate that, following such pre-treatment rules, PCB-based electrodes can be reliably fabricated for sensitive electrochemical biosensors. Herein, we demonstrate the applicability of the methodology both for labelled protein (procalcitonin) and label-free nucleic acid (E. coli-specific DNA) biomarker quantification, with observed limits of detection (LoD) of 2 pM and 110 pM, respectively. The proposed optimisation of surface pre-treatment is critical in the development of robust and sensitive PCB-based electrochemical sensors for both clinical and environmental diagnostics and monitoring applications.

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