Metal-ceramic Package Research Articles

Thermal Conductivity Gas Sensors for High-Temperature Applications.

This paper describes a fast and flexible microfabrication method for thermal conductivity gas sensors useful in high-temperature applications. The key parts of the sensor, the microheater and the package, were fabricated from glass-coated platinum wire and the combination of laser micromilling (ablation) of already-sintered monolithic ceramic materials and thick-film screen-printing technologies. The final thermal conductivity gas sensor was fabricated in the form of a complete MEMS device in a metal ceramic package, which could be used as a compact miniaturized surface-mounted device for soldering to standard PCB. Functional test results of the manufactured sensor are presented, demonstrating their full suitability for gas sensing applications and indicating that the obtained parameters are at a level comparable to those of standard industrially produced sensors. The results of the design and optimization principles of applied methods are discussed with regard to possible wider applications in thermal gas sensor prototyping in the future. The advantage of the developed sensors is their ability to operate in air environments under high temperatures of 900 °C and above. The sensor element material and package metallization were insensitive to oxidation compared with classical sensor-solution-based metal-glass packages and silicone MEMS membranes, which exhibit mechanical stress at temperatures above 700 °C.

Design, Analysis and Validation of MCP Package for GaAs Monolithic Microwave Integrated Circuits Packaging

This paper describes the design aspects of high reliable packages including package resonance, material selection, and feed-through design to match the die designer specifications. Design, simulation and thin film fabrication of 50Ω microstrip line on a 10 mil Al2O3 substrate suitable for MMIC assembly are also presented. Al2O3 substrate is taken because of lower transitional losses at the seal ring of the package, lower leakage and best suitable for hermiticity. Strip line design, study and the input-output transitions between two ports is analysed and optimized. Evidence of package self resonating mode study carried out theoretically and similar is simulated by using CST microwave studio. Package physical model analysis is carried out on a metal-ceramic package (MCP) which is suitable for embedding an amplifier of 20 dB gain and low power in c-band, 35 dB gain and low noise figure in s-band and 28 dB typical gain in x-band. Packaging effects in each case is analysed and optimised to meet the design requirements. With systematic ideas, the complete package modelling, characterization and MMICs packaging are carried out as per the reliability standards for space application. This package is sealed using the hermetic sealing technique to assure no leakage when subjected to the environmental test conditions like operating temperature test, active burn-in test for 240 h and steady-state life test for 1000 h to check MMIC behaviour under overstress conditions. Packaged module RF performances are noted at pre-subjected and post-subjected temperature conditions. Drifts are calculated at both temperature stages.

РАДИАЦИОННО СТОЙКАЯ ОПТОЭЛЕКТРОННАЯ ПАРА ДЛЯ ВТОРИЧНЫХ ИСТОЧНИКОВ ПИТАНИЯ

In this paper we present the results of development of the optocouplers for secondary power supplies. The dies of the optical radiation emitters are based on double heteroepitaxial AlGaAs structures, and the dies of the radiation receivers are based on silicon-on-sapphire. Dies were bonded to metal-ceramic packages using the optically clear silicone-organic adhesive. The results of the optocoupler testing showed the level of resistance to γ-neutron radiation, which meets the requirements for radiationresistant devices used in control and communication systems.

Тенденции развития металлокерамических корпусов

Тенденции развития металлокерамических корпусов

Металлокерамические корпуса и материалы АО «ТЕСТПРИБОР» для изделий микроэлектроники

Металлокерамические корпуса и материалы АО «ТЕСТПРИБОР» для изделий микроэлектроники

Перспективные типы металлокерамических корпусов для электронных компонентов производства АО "ЗПП"

Перспективные типы металлокерамических корпусов для электронных компонентов производства АО "ЗПП"

Diamond Schottky barrier diode for high-temperature, high-power, and fast switching applications

High-current vertically structured diamond Schottky barrier diodes (SBDs) with a thick field plate and a doping-controlled drift layer were fabricated. The fabricated vertical SBD (VSBD) realized forward currents and blocking voltages of more than 1 A and 300 V at 250 °C. The VSBD was mounted on a metal-ceramic package with a gold bonding wire and a high-temperature resistive resin. The switching behavior of the packaged diamond VSBD was characterized by a double-pulse method at elevated temperatures. The device showed a short turn-off time with a low switching charge of less than 5 nC, which remained almost constant even at 250 °C.

Multiphysics Modeling of RF and Microwave High-Power Transistors

In this paper, we present a multiphysics approach for the simulation of high-power RF and microwave transistors, in which electromagnetic, thermal, and nonlinear transistor models are linked together within a harmonic-balance circuit simulator. This approach is used to analyze a laterally diffused metal-oxide-semiconductor (LDMOS) transistor that has a total gate width of 102 mm and operates at 2.14 GHz. The transistor die is placed in a metal-ceramic package, with bond-wire arrays connecting the die to the package leads. The effects of three different gate bond-pad layouts on the transistor efficiency are studied. Through plots of the spatial distributions of the drain efficiency and the time-domain currents and voltages across the die, we reveal for the first time unique interactions between the electromagnetic effects of the layout and the microwave behavior of the large-die LDMOS power field-effect transistor.

Over 70% PAE packaged GaN HEMT through wideband internal matching at second harmonic in S-band

Reported is a design methodology to efficiently control source and load impedances of a power GaN HEMT at the second-harmonic frequency inside a metal ceramic package. Second-harmonic source control is more precisely investigated. A specific filter is implemented at the gate side within the package to transform external source impedances into negative reactances seen by the internal device at second-harmonic frequencies. Whatever the external source termination presented at second-harmonic frequencies, source impedances seen by the internal die are confined to high efficiency regions. This methodology is applied to a 20 W packaged GaN HEMT using internal control of input and output second-harmonic impedances to reach more than 70% of power-added-efficiency (PAE) on 30% relative bandwidth in S-band.

ELECTROMAGNETIC SIMULATION AND CHARACTERIZATION A METAL CERAMIC PACKAGE FOR PACKAGING OF HIGH ISOLATION SWITCHES

Packaging of planar MMICs poses a unique challenge at microwave frequencies as the dimensions of the encapsulating cavity are comparable to wavelength at the operational frequencies. In addition, the efiect of ground loops (caused by bond wires exposed to ground over extended length due to gaps between interconnects) deteriorates the situation even further in circuits like MMIC switches requiring high isolation between ports. The ground loops cause re∞ections thereby deteriorating the insertion loss flgure of merit. This paper presents optimization of design of a metal ceramic package used for packaging an SPDT MMIC switch working in the frequency range of 5{6GHz. The microwave performance of the package was simulated using EM simulation with parameters including cavity dimensions, port placement, gaps between interconnect lines, package feed-thrus and MMIC chip pads. Detailed characterization of the bare package and packaged SPDT MMIC done later shows a good match between the simulated and measured performance. The SPDT MMIC performance degradation was arrested by improvement in the package structure and it showed insertion loss of i1.6dB and input/output (I/O) return losses of »16dB in the new package as compared to the values of i2.1dB insertion loss and i12dB I/O return losses in the original package. The port-to-port isolation remained unchanged (»40dB in both cases) as it is governed by the MMIC assembly inside the package rather than the conditions at the I/O interfaces in this kind of large sized packages.

Equivalent-circuit modeling and verification of metal-ceramic packages for RF and microwave power transistors

A modeling procedure was developed to generate electrical package models for metal-ceramic packages. These models are capable of accounting for package effects associated with the package lead capacitance, the self and mutual inductances of the bond wires, and the coupling between the input and output of the package. A combination of full-wave electromagnetic simulation and equivalent-circuit model extraction allows accurate model generation and efficient circuit simulation. Measured S-parameters were used to verify the overall modeling methodology. It has been demonstrated that the package effects play an important role in the accurate prediction of the packaged transistor performance.

Growth of GaN on lithium gallate substrates for development of a GaN thin compliant substrate

Since we have found that an entire substrate can be chemically removed in less than 5 min and since GaN is impervious to chemical etching, the GaN on lithium gallate (LGO) system is an excellent template (due to near infinite etch selectivity) for developing a thin film/compliant GaN substrate. Here we report on our efforts to grow GaN on LGO, including improvement of the atomic surface morphology using pregrowth pretreatments. We also report the first transferred thin film GaN substrate grown on LGO, transferred off of LGO and mounted on GaAs. With this approach, (InAl)GaN alloys can be grown on thin GaN films, implementing a “compliant” substrate for the nitride alloy system. In addition, the flexibility of bonding to low cost Si, metal or standard ceramic IC packages is an attractive alternative to SiC and hydride vapor phase epitaxy GaN substrates for optimizing cost verses thermal conductivity concerns. We have demonstrated high quality growth of GaN on LGO. X-ray rocking curves of 145 arcsec are shown on a 0.28 μm thick films. For the first time, we present data on the out-of-plane crystalline quality of GaN/LGO material. Likewise, we show two orders of magnitude improvement in residual doping concentration and factors of 4 improvement in electron mobility. We show substantial vendor to vendor and intravendor LGO material quality variations. We have quantified the desorption of Ga and Li from the surface of LGO at typical growth temperatures using in situ desorption mass spectroscopy and x-ray photoelectron spectroscopy.

Growth of GaN on Lithium Gallate Substrates for Development of a GaN Thin Compliant Substrate

AbstractThe GaN on LGO system is the near perfect template (due to extremely high etch selectivity) for developing a viable thin film/compliant GaN substrate. Herein, we report on our efforts to grow GaN on LGO, including improvement of the microscopic surface morphology using pre-growthpretreatments. We also report on the first transferred thin film GaN substrate grown on LGO, transferred off of LGO, and mounted on GaAs. With this approach, (InAl)GaN alloys can be grown on thin GaN films, implementing a truly “compliant” substrate for the nitride alloy system. In addition, the flexibility of bonding to low cost Si, metal or standard ceramic IC packages is an attractive alternative to SiC and HVPE GaN substrates for optimizing cost verses thermal conductivity concerns. We have demonstratedhigh quality growth of GaN on LGO. X-Ray rocking curves of 145 arc-seconds are obtained with only a 0.28 μm thick film. We present data on the out of plane crystalline quality of GaN/LGO material. Likewise, we show 2 orders of magnitude improvement in residual doping concentration and factors of 4 improvement in electron mobility as compared to the only previously reported electrical data. We show substantial vendor to vendor and intra-vendor LGO material quality variations. We have also quantified the desorption of Ga and Li from the surface of LGO at typical growth temperatures using in situ desorption mass spectroscopy and XPS.

Computer Simulation of Small-Signal and Noise Behavior of Microwave Bipolar Transistors Up to 12 GHz

Computer-aided determination and optimization of lumped elements of equivalent circuits based on experimental data, application to the lumped equivalent circuit including noise sources of microwave bipolar transistors, and calculation of gain, noise, and stability from the said computer simulation are dealt with. As an example, a special microwave transistor mount and aspects of a new rugged metal-ceramic package are considered.