LiTaO3 Capping Technology for Wafer Level Chip Size Packaging of SAW Filters

Zoschke, Kai; Wegner, Matthias; Lopper, Christina; Klein, M.J.K.; Gruenwald, R.; Schoenbein, Clemens; Lang, Klaus‐Dieter

doi:10.1109/ectc.2016.291

Cited by 5 publications

(3 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Since p prim and p sec have opposite signs, the estimated absolute value of the total pyroelectric coefficient increases only up to | p σ | = 2.3 μC m −2 K −1 . This is substantially lower than for LiTaO 3 (| p σ | = 176 μC m −2 K −1 ) or for LiNbO 3 (| p σ | = 40 μC m −2 K −1 –80 μC m −2 K −1 ), which are commonly used for SAW devices . Moreover, based on our calculations, p clamp is the main contributor to p eff .…”

Section: Resultsmentioning

confidence: 54%

Temperature Dependence of the Pyroelectric Coefficient of AlScN Thin Films

Kurz

Kirste

et al. 2018

Physica Status Solidi (a)

View full text Add to dashboard Cite

The piezoelectric and pyroelectric properties of aluminum nitride (AlN) can be further enhanced by alloying AlN with scandium nitride (ScN). However, while the pyroelectric effect can strongly affect the performance of electroacoustic devices such as surface acoustic wave (SAW) resonators, the pyroelectric properties of aluminum scandium nitride (AlScN) and their thermal dependence are not well known. In this work, the crystallographic, microstructural, and pyroelectric properties of 900 nm thick pyroelectric Al 1Àx Sc x N thin films (x ¼ 0 to 0.3) are investigated. All films have wurtzitetype crystal structure and are highly c-axis oriented. The pyroelectric coefficient in the temperature range of 20-80 C is determined by measuring the generated current as a function of sinusoidal temperature excitation. The effective pyroelectric coefficient of AlScN increases by approximately 85% in the investigated composition range. Moreover, no temperature dependence of the effective pyroelectric coefficient is observed for all samples. The increase of the effective pyroelectric coefficient is explained qualitatively by considering the contribution of primary and secondary pyroelectric effect as well as the substrate clamping.

show abstract

Section: Resultsmentioning

confidence: 54%

Temperature Dependence of the Pyroelectric Coefficient of AlScN Thin Films

Kurz

Kirste

et al. 2018

Physica Status Solidi (a)

View full text Add to dashboard Cite

show abstract

“…This WLP technique is a real chip-scale packaging method that enables packages to maintain the same size as a die. A new efficient WLP technique created a gas-filled cavity structure for SAW filter packages, using non-photosensitive film lamination technology, with high strength and a high elastic modulus [ 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 19 ].…”

Section: Process Flow Of the Saw Device’s Wlp And The Typical Failure...mentioning

confidence: 99%

“…WLP is the next step in miniaturization and cost reduction [ 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ]. In WLP, one or two organic or inorganic layers on top of the piezoelectric crystal, such as a lithium (LiTaO 3 , LT) piezoelectric substrate, form cavities above the active portions of the chip, which can protect the susceptible SAW device structure from probable injuries, such as dust or corrosion.…”

Section: Introductionmentioning

confidence: 99%

Development of a Reliable High-Performance WLP for a SAW Device

Chen

2022

Sensors

View full text Add to dashboard Cite

In this paper, we present wafer-level packaging technology for surface acoustic wave (SAW) filters with higher long-term reliability and better electrical performance. This article focuses on the package structure, fabrication processes, and reliability for the SAW filter wafer-level package (WLP). The key processes, including cavity wall (CW) dam formation through non-photosensitive film vias development using a laser drilling process, a redistribution layer (RDL), and ball-grid array formation are developed. In addition, a numerical study based on the finite element model has been conducted to analyze the stress distribution of Cu RDL traces. In addition, the CW dam and the roof layer are covered with polymer, which solves the delamination problem between the CW dam and the substrate. Meanwhile, after practical verification, the SAW filter WLP was resistant to encapsulating pressure using a high elastic modulus capping material, which solved the collapse problem. Additionally, a comparison of the RF filter package’s electrical performance following the preconditional level 3 and unbiased highly accelerated stress test revealed no differences in insertion attenuation across the passband (<0.2 dB, standard value: 1 dB). The final packages passed the reliability tests in the field of consumer electronics.

show abstract

Fan-In Wafer/Panel-Level Chip-Scale Packages

Lau

2021

Semiconductor Advanced Packaging

View full text Add to dashboard Cite

LiTaO3 Capping Technology for Wafer Level Chip Size Packaging of SAW Filters

Cited by 5 publications

References 17 publications

Temperature Dependence of the Pyroelectric Coefficient of AlScN Thin Films

Temperature Dependence of the Pyroelectric Coefficient of AlScN Thin Films

Development of a Reliable High-Performance WLP for a SAW Device

Fan-In Wafer/Panel-Level Chip-Scale Packages

Contact Info

Product

Resources

About