Flexmemsenabled heterointegration for monolithic fbar. This paper presents a method for integrating circuitry into the lid wafer to form a sub0. The filters are still using avagosmicrocap bonded wafer chip scale packaging csp technology with throughsilicon vias tsvs enabling electrical contacts and scandium. Advanced packaging, especially at the wafer level, is becoming increasingly important for mems and 3d stacking applications. A tactile sensor array may also consist of fbar devices, and gravimetric sensing can be based on fbar resonators. As with any mechanical resonator oscillator, a costeffective hermetic package combined with circuit technology are critical for commercial application. Billions of fbar duplexers have been fabricated using avago.
Wlcsp includes wafer bumping with or without pad layer redistribution or rdl, wafer level final test, device singulation and packing. Packaging for mems micro electro mechanical systems, which includes encapsulation and electrical interconnection, is indispensable for practical applications. Wafer level chip scale packaging wlcsp is a fanin wafer level package fiwlp that provides significant package footprint reductions, lower cost, improved electrical performance, and a relatively simpler construction over conventional wirebond or interposer packaging technologies. To suppress signal leakage, we have proposed a signal. The design, fabrication and packaging process of silicon resonators capable of the integration of lsi large scale integration have been. Waferscale packaging for fbarbased oscillators ieee xplore. Throughsilicon vias tsvs enable electrical contacts. Request pdf wafer scale packaging for fbarbased oscillators recent advances in temperaturecompensation for fbar film bulk acoustic resonators have brought this technology forward as a. Overview and outlook of threedimensional integrated. Us9343450b2 wafer scale packaging platform for transceivers. Wafer scale packaging of mems by using plasmaactivated. The 1spl times1mmsup 2 highq filter is hermetically sealed as two thin layers of silicon. Some of the first published investigations on wafer scale encapsulated resonators 8 indicated good stability, but measurements were of resonators only, not full oscillators, and were limited by experimental setup fluctuations to an accuracy of only 3. A method of wafer scale packaging acoustic resonator devices and an apparatus therefor.
Fbar cmos sensor design active cmos substrate the integrated circuit substrate was designed and fabricated in a 0. Waferscale integration, wsi for short, is a rarely used system of building verylarge integrated circuit networks that use an entire silicon wafer to produce a single superchip. Wcsp, also referred to as dsbga, is packaging technology that includes the following features. This allows a better coupling coefficient and better performance. Fabrication of an hermetically packaged silicon resonator on ltcc. The fbar operates in inductive mode in an oscillator so that its. There is an accelerating trend toward wafer level chip scale packaging, with estimates placing growth at 26% cagr for. Waferscale microoptics fabrication is based on technology established by the semiconductor industry. Flexmemsenabled heterointegration for monolithic fbarabove. Broadcom afem8200 pamid in the apple iphone 12 series. Thousands of components are fabricated in parallel on a wafer.
Heterogeneous integration, preprocessed soi fabrication, and wafer scale packaging are the main application topics. Wafer level packaging allows integration of wafer fab, packaging, test, and burnin at wafer level in order to streamline the manufacturing process undergone by a device from silicon start to customer shipment. In joint conference of the ieee international frequency control and the european frequency and time forum, san francisco, ca, 25 may 2011. Quartz mems oscillators for highperformance navigation and. Mems resonator, longterm stability, resonant frequency stability, encapsulation, hysteresis introduction resonators are one of the key elements in communication engineering. The method including providing a partially completed semiconductor substrate comprising a plurality of single crystal acoustic resonator devices, each having a first electrode member, a second electrode member, and an overlying passivation material. Wafer level packaging involves attaching the top and bottom outer layers of packaging and the solder bumps to integrated circuits while still in the wafer, and then dicing the wafer. Otis, journal2011 joint conference of the ieee international frequency control and the european frequency and. Compared to the previous generation, the fbar technology features some advances in the piezoelectric material.
Wafer scale packaging for fbar based oscillators more by brian otis recent advances in temperaturecompensation for fbar film bulk acoustic resonators have brought this technology forward as a serious contender in the oscillator marketplace. In joint conference of the ieee international frequency control and the european frequency and time forum. Discera making silicon mems oscillators from research to commercial products. Wafer level packaging wlp is the technology of packaging an integrated circuit while still part of the wafer, in contrast to the more conventional method of slicing the wafer into individual circuits dice and then packaging them. The suburban cdma use model is based on the phone being used at. Waferscale packaging for fbarbased oscillators ieee. Baw fbar, sapphire for tcsaw3, and metal package working as a heat sink plays an essential role in high power application16,17. Jun 01, 2016 the filters are still hermetically wafer level packaged with avagos microcap bonded wafer chip scale packaging csp technology. Silicon based bulkacousticwave baw filters utilize mainstream wafer processing and can create.
For micromirrors an 8 wafer level packaging process was developed using preprocessed borosilicate glass wafers. Waferlevelpackage for bulk acoustic wave baw filters. Chip scale packaging csp defines the logical end of ic package scaling in the package surface area 2d as package area and ic size converge, for example in direct chip attach dca applications. The efforts include developing novel resonator structures for highly stable oscillators, wafer level vacuum packaging at 110 mtorr level for volume production, and sophisticated mixedsignal circuits for temperature compensation and timing applications.
It is recognized that a major part of the mems cost is the packaging and testing. Billions of fbar duplexers have been fabricated using avago technologies wafer scale packaging process, whereby a silicon lid wafer is audiffusionbonded to a base fbar wafer to make a robust, hermetic package. Wafer scale packaging for fbarbased oscillators abstract. Pdf for some time, fbar technology has lagged behind ceramic technology and. Some more recent efforts have shown limited stability data of oscillators. Evidence of smaller 1f noise in alscn based oscillators compared to. Cap wafer process flow bonding and tsv process flow mems fbar fabrication unit active chips process active chips fabrication units fe module packaging process fe module packaging unit cost analysis fbar baw filter wafer frontend cost fbar baw filter wafer frontend cost per process steps fbar baw filter probe test. In a novel costeffective wafer level packaging concept reported for fbar devices, photoepoxy is laid. In the fabrication process, the substrate was initially cleaned using an rca cleaning op. Fci is an interesting company because they compete with larger players such as ase and amkor plus, a big part of their operations is in china. The process of packaging a wafer prior to dicing is called wafer level packaging.
Pdf a fully integrated waferscale submm3 fbarbased. Flipchip international fci, based in phoenix, arizona, is one of the service providers in this segment. Quartz mems oscillators for highperformance navigation. Avago afem9040 avagos new generation frontend module 2016. Wafer level packaging consists of extending the wafer fab processes to include device interconnection and device protection processes.
Wafer level packaging of mems institute of physics. Introduction w afer level packaging wlp of cmos imager sen. In particular, a silicon wafer is utilized as a platform interposer upon which all of the components. Here, an fbar is fabricated on one wafer while a second lid wafer contains circuitry with through wafer vias, au pads, sealing structures, and a recessed air cavity above the fbar. Wafer level packaging wlp scope the intent of this chapter is to provide a brief overview of wafer level packaging wlp, including wafer level chip scale packaging wlcsp and fan out packaging, as a background for a roadmap for these technologies going forward. Low loss and high isolation techniques for high power rf. Includes answers to questions about tis wcsp packaging technologys advantages and proper practices to work with wcsp devices. This is a vialast or viasafterbonding technique in which mems components are fabricated first. Billions of fbar duplexers have been fabricated using avago technologies wafer scale packaging process, whereby a silicon lid wafer is audiffusionbonded to a base fbar wafer to make a robust. Feb 07, 2002 highq fbar filters in a wafer level chip scale package abstract. Currently quartz is the most widely used resonator material. At vtt, wafer level packaging based on tapered partially electroplated copper filled tsvs has been developed for interconnection of mems components.
Film bulk acoustic resonator research papers academia. Based on recent mems market studies4,5, we estimate that approximately half of. Memsbased quartz oscillators and filters for onchip integration. Combining large size and reduced packaging, wsi was expected to lead to dramatically reduced costs for some systems, notably massively parallel supercomputers. Wafer level chip scale packaging wlcsp is a fanin wafer level package wlp that offers compelling advantages for cost and space constrained mobile devices and new applications such as wearable electronics. As with any mechanical resonator oscillator, a costeffective hermetic package combined with circuit technology. The transistor cycle is the basis of the most advanced chips, see figure 2. Index termslow loss, radio frequency microelectromechanical system rf mems, solder bonding, throughsiliconvia tsv, wafer level packaging wlp. As discrete components fbar technology based parts like basic resonators and filters are packaged in miniaturisedsmall form factor like wafer level packages. A wafer scale implementation of an optoelectronic transceiver assembly process utilizes a silicon wafer as an optical reference plane and platform upon which all necessary optical and electronic components are simultaneously assembled for a plurality of separate transceiver modules. The chip enables a 6 x 4 array of fbar based pierce oscillators. Jan 11, 2017 small m, ruby r, ortiz s, parker r, zhang f, shi j, otis b 2011 wafer scale packaging for fbar based oscillators. Aln based fbar resonators also show good potential on oscillator. Waferscale packaging for fbarbased oscillators request pdf.
Fabrication of piezoelectric aln thin film for fbars. Oscillators normally consist of a highq frequency reference tank, which determines the frequency and the stability of the oscillator, and a circuit that sustains the oscillation. Fbars can also be integrated with power amplifiers pa or low noise. Wafer scale packaging for fbar based oscillators recent advances in temperaturecompensation for fbar film bulk acoustic resonators have brought this technology forward as a serious contender in the oscillator marketplace. Semiconductoronpolymer wafer level chip scale packaging. Waferlevel chipscale package fanin wlp and fanout wlp. Manufacturing and reliability of chipscale packaged fbar. The next and current generation of resonator packaging, termed g2.
In this work, a monolithic oscillator chip is heterogeneously integrated by a film bulk acoustic resonator fbar and a complementary metaloxidesemiconductor cmos chip using flexmems technology. Filters in a wafer level chip scale package, submitted to isscc 2001. Recent advances in temperaturecompensation for fbar film bulk acoustic resonators have. Sensor fabrication and circuitrya technique for integrating active circuitry into the lid of the wafer scale hermetic fbar package was demonstrated in 8.
At least one of the devices to be configured with an. Piezoelectric transduction presents lower motional impedances at these frequencies, and piezoelectrically transduced film bulk acoustic wave resonator fbar 911 and contour mode resonator cmr 12, based oscillators operating at few ghz frequencies have been demonstrated. Pdf thinfilm bulkwave acoustic resonator fbar for wireless. Overview and outlook of threedimensional integrated circuit. Recent advances in temperaturecompensation for fbar film bulk acoustic resonators have brought this technology forward as a serious contender in the oscillator marketplace. With a wafer as the starting point, it involves epitaxial silicon. Closein phase noise is an important performance metric for a. Scale packaging wlcsp has enabled smaller and thinner semiconductor devices with greater functionality to be used in consumer mobile applications such as smart phones, tablets and hand held gps tracking devices. The semiconductor manufacturing process flow, when highly simplified, can be divided into two primary cycles of transistor and interconnect fabrication. Fabrication the quartz resonator fabrication process is illustrated in fig. Wafer scale packaging for fbar based oscillators m small, r ruby, s ortiz, r parker, f zhang, j shi, b otis 2011 joint conference of the ieee international frequency control and the, 2011.
Example of wafer level packaged silicon mems resonators. Wafer level chip scale packaged rf filters use thinfilm bulk acoustic resonator technology. Pdf waferscale packaging for fbarbased oscillators. Recent advances in 3d package reliability dfr solutions. Sep 01, 2019 the fbar has two resonant frequencies of the zero phase, i.
Wafer scale packaging of mems by using plasmaactivated wafer. Limited heat sinking solder based interconnects interconnects always surrounded by underfill. However, oscillators using mems resonator perform poorly compared to quartz based oscillators in terms of closein phase noise. Avago afem9040 avagos new generation frontend module. Tc fbar employing siof film is much attractive to improve tcf, which can also keep better coupling factor than that of sio2 based tc fbar 15. Vibrating rf mems for timing and frequency references rtt. Highq fbar filters in a waferlevel chipscale package. M small, r ruby, s ortiz, r parker, f zhang, j shi, b otis. Frequency control and selection in wireless frontend are relying on. New designs for memsmicromirrors and micromirror packaging. Microchip oscillators and clocks using microelectromechanical.
They are different and in general the throughsilicon via tsv separates 3d ic packaging from 3d siic integrations since the latter two use tsv but 3d ic packaging does not. Figure 3 from waferscale packaging for fbarbased oscillators. The stateoftheart of fabrication, testing and packaging technology is summarized. Wafer level package wlp technology differs from other ballgrid array bga and laminate based csps in that no bond wires or interposer connections are required. This thesis also contains results on research of different applications requiring direct wafer bonding.
An optimized design of an optical package is presented that avoids any stray. Compared to the previousgeneration, the fbar technology features some advances in the piezoelectric material. Wafer level transfer based heterogeneous integration. Scaling thickness is a key metric in packaging evolution. This stable low phase noise oscillator was used to acquire and track the gps signal in a commercial avionics system, the first demonstration of its kind for mems oscillators. Longterm stability of a hermetically packaged mems disk. With wlcsp, all of the manufacturing process steps are performed in parallel at the silicon wafer level rather than sequentially. Secondly, as final products, various mems oscillators from various companies are compared with quartz crystal oscillators in terms of jitter, power consumption, and temperature stability.
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