EMI Basics

A portable electronic device could include several components coupled to a circuit board for providing processing and other device operations. Some of the components can generate electromagnetic waves that interfere with the operation of other components of the device. For example, circuitry associate with connecting to a communications network could interfere with other device components (e.g., sensor arrays).

The Old Way of Integrating an EMI Shield

To protect the components from such interference, different approaches could be used. In one embodiment a conductive can shielding could be constructed around the components. For example, a frame can be soldered around the periphery of the components, and a cover can be attached to the frame.

The frame and cover approach, however, may require two distinct components, constructed from sheets of conductive material (e.g., from sheet metal) added to the circuit board supporting the electronic device components. This could in turn require additional space within the device for the EMI shield, which may place a limit on the device size.

Apple's New Way of Integrating an EMI Shield

Apple's invention covers the use of conformal coating for providing EMI shielding within an iOS device. In particular, this is directed to applying consecutive sheets of conformal coating over components of an iOS device circuit board to provide both a water-resistant coating and an EMI shield.

An iOS device could include at least one circuit board on which one or more components could be mounted. The board could be treated with a conformal coating, which provides a substantially continuous layer of material around the board and the components. The conformal coating could be constructed using any suitable non-conductive material such that contaminate is substantially prevented from leaking through the coating and shorting the electronic device components.

To provide EMI shielding to the device components, a second layer of conforming material could be applied to the circuit board. The material used for the second layer could be a conductive material, which could prevent electromagnetic waves from propagating from one component to another. The second layer could be electrically coupled to the circuit board to provide grounding. In particular, the second layer could be coupled to conductive pads of the circuit board through openings or apertures of the first (non-conductive) layer.

Apple's patent FIG. 4 is an exploded view of a conforming coating EMI shield applied to a circuit board; FIG. 5 is a schematic view of a portion of the assembled confirming coating EMI shield and circuit board of FIG. 4.

The inventors of Apple's patent application: Scott Myers and Douglas Weber. Here's a temporary link to the report (that's only good for 48 hours).

Apple Invents New Location Services System

Plain and simple, Apple has invented a new location services system. It's new because the patent clearly presents the system as extensively using WIMAX transmitters. The new geo-location services system that uses a known triangulation methodology will be used to deliver promotions, news and emergency notifications. Apple currently uses location services in conjunction with their MobileMe "Find My iPhone" feature.

Apple's patent FIG. 1 shows an example system including a computing device for providing location-based services to mobile devices in communication with the computing device; FIG. 4 shows a flow chart of an example process for generating a set of neighbors for a radio transmitter.

The sole inventor of Apple's patent application is Markus Fischer. For communication nerds who want to know more about this patent, check out patent application 20110084881. Here's a temporary link that's good for about 48 hours.

And lastly, beyond a number of continuation patents that have surfaced this morning which slightly update older 2004-2007 Apple patents, there's one last patent application of mild interest that's titled "Data Routing Accelleration."  Patent application 20110085549 generally relates to computer networks, and more particularly to improving computer network performance. Here's a temporary link good for about 48 hours.

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