Sun Microsystems, Inc.

Valerie St Cyr

Istvan Novak

Merle Tetreault

Daniel C Irish

A method of direct plane attachment of capacitors is disclosed. In one embodiment, a printed circuit board (PCB) having a signal layer, a first conductive plane, and a second conductive plane is provided. The signal layer may be the outermost layer of the PCB, while the first conductive layer may be arranged between the signal layer and the second conductive layer. A cavity may be formed in the printed circuit board, wherein the cavity extends from the signal layer down to the first conductive plane. The cavity may be large enough to accommodate one or more capacitors. A first terminal of the capacitor may be attached to the first conductive plane. The second terminal of the capacitor may be mounted within an opening in the first conductive plane. The method may allow a bypass capacitor to be directly coupled to a power or reference plane.

Direct plane attachment for capacitors

The problems outlined above may in large part be solved by a system and method for testing integrated passive components in a printed circuit board. In one embodiment, testing of integrated passive components may be conducted prior to completing the final lamination of the printed circuit board. The testing may be conducted on a tester having movable test probes. The method may include connecting a first test probe to a conductive plane, which may be electrically connected to the first terminals of two or more components. The conductive plane may be a ground plane, a power plane, or a signal plane. The first test probe may remain in a fixed position throughout the testing. A second test probe may be electrically connected to the second terminal of the first component. Following the connection of the second test probe, an electrical characteristic of the first component may be measured. Following the measurement of an electrical characteristic of the first component, the second test probe may then be repositioned in order to be electrically connected to the second terminal of a second component. After repositioning and electrically connecting the second test probe to the second terminal of the second component, an electrical characteristic of the second component may be measured. This may be repeated for any number of components to be tested. The first test probe, which is electrically connected to a conductive plane to which each of the tested components is electrically connected, may remain in a fixed position throughout the testing, while the second test probe moves from component to component.

System and method for testing integrated passive components in a printed circuit board

Apparatus and methods for achieving a desired value of electrical impedance between parallel planar conductors of an electrical power distribution structure by electrically coupling multiple bypass capacitors and corresponding electrical resistance elements in series between the planar conductors. The methods include bypass capacitor selection criteria and electrical resistance determination criteria based upon simulation results. An exemplary electrical power distribution structure produced by one of the methods includes a pair of parallel planar conductors separated by a dielectric layer, n discrete electrical capacitors, and n electrical resistance elements, where n&gE;2. Each of the n discrete electrical resistance elements is coupled in series with a corresponding one of the n discrete electrical capacitors between the planar conductors. The n capacitors have substantially the same capacitance C, mounted resistance R , mounted inductance L , and mounted resonant frequency f . The mounted resistance R of each of the n capacitors includes an electrical resistance of the corresponding electrical resistance element. The electrical power distribution structure achieves an electrical impedance Z at the resonant frequency f of the capacitors. The mounted resistance R of each of the n capacitors is substantially equal to (n&middot;Z). The mounted inductance L of each of the n capacitors is less than or equal to (0.2&middot;n&middot;&mgr; &middot;h), where &mgr; is the permeability of free space, and h is a distance between the planar conductors.

Adding electrical resistance in series with bypass capacitors to achieve a desired value of electrical impedance between conducts of an electrical power distribution structure

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Lincoln, MA, United States of America

Valerie St Cyr