Motorola

About: Motorola is a company organization based out in Schaumburg, Illinois, United States. It is known for research contribution in the topics: Signal & Communications system. The organization has 27298 authors who have published 38274 publications receiving 968710 citations. The organization is also known as: Motorola, Inc. & Galvin Manufacturing Corporation.

Low profile exposed die chip carrier package

Abstract: An integrated circuit package (10) comprises a semiconductor die (12), and a substrate (14) having a through-cavity opening (22) for receiving the semiconductor die. The bottom side of the substrate has solder pads (24) arranged as a peripheral pad grid array. The semiconductor die is wire bonded (26) to the to the top side of the substrate. An encapsulant (16) seals the top surface of the semiconductor die and circuitry, and portions of the top side of the substrate. The bottom surface of the semiconductor die remains exposed to the atmosphere, eliminating moisture-related die attach delamination issues and improving heat transfer away from the semiconductor die. Furthermore, the reduced contribution of the semiconductor die to overall package height results in an ultra low profile package.

Configurable optical filter or display

Abstract: A configurable display comprising a distributed Bragg reflector having a plurality of flexible, compressible polymer layers is provided. The polymer layers are transparent and comprise alternating layers of differential index of refraction material so that a reflective surface is formed at each interface between the alternating layers. The polymer layers are sandwiched between a first electrode which is transparent and a second electrode. Thickness of each of the layers is designed such that light reflecting from the reflective surfaces interferes constructively at predetermined wavelengths. The thickness of each of the layers is altered by application of a static potential between the first and second electrodes which deforms the polymer layers thereby shifting the wavelength at which constructive interference occurs. In this manner wavelength and amplitude of reflective light can be modulated by a voltage applied between the first and second electrodes.

Stress-induced current in thin silicon dioxide films

Abstract: Low-field current following Fowler-Nordheim stress of thin gate oxides is studied The conduction mechanism is attributed to trap-assisted tunneling of electrons For oxides thicker than 100 AA, this stress-induced current is observed to decay as traps are filled without significant tunneling out of traps In thinner oxides, steady-state current flows when there is an equilibrium between trap filling and emptying processes This model is observed to be consistent with stress-induced current behavior in a wide range of oxide thicknesses (60 AA to 130 AA) and process technologies >

Moisture absorption and desorption predictions for plastic ball grid array packages

Abstract: Plastic electronic packages are known to absorb moisture when exposed to humid ambient conditions during storage in tape and reel in the factory. Reliability becomes a concern when packages are exposed to a humid environment for a prolonged time and then processed through a reflow oven. Thermo-mechanical and moisture induced interfacial stresses generated between the die attach and die may lead to die delamination and package cracking. Current package level moisture evaluation methods are based on experimental weight gain measurements and visual inspection after reflow for cracking or delamination. This study presents a finite element analysis (FEA) simulation of the moisture weight gain or loss in plastic ball grid array (PBGA) packages as a function of time including the effects of package geometry and material selection. Experimental weight gain and bakeout data for a 68 I/O PBGA package are shown to closely match FEA model predictions. Diffusivity and solubility property data for common packaging materials are given as a function of temperature ranging from 23/spl deg/C to 150/spl deg/C. Solder pot dip tests performed at 230/spl deg/C indicate that popcorn failures result when the moisture concentration in the die attach region exceeds 0.0048 g/cm/sup 3/ for the specific package tested.