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US 7,598,621 B2Granted
Device package, a printed wiring board, and an electronic apparatus with efficiently spaced bottom electrodes including intervals between bottom electrodes of different lengths
AssigneeRicoh Company, Ltd.
InventorAkira Yashiro
Life of this patent
Estimating the term…
Abstract
A device package, such as a BGA, to be mounted on a printed wiring board (PWB) is disclosed. The bottom electrodes of the device package are arranged in an array such that intervals between the edges of the bottom electrodes become different from place to place. The intervals may be set wider at the peripheral positions of the bottom electrodes. The PWB includes pads that are located at positions corresponding to the bottom electrodes.
Claims5
A device package to be mounted on the surface of a printed wiring board, comprising:
- a plurality of bottom electrodes arranged in a first row, which is an outermost row of the package, and a second row parallel and adjacent to the first row and, sizes of which bottom electrodes are different from place to place such that intervals between edges of the bottom electrodes in a section of the first row progressively increase in length from an end of the section of the first row toward a center of the first row such that an interval between a first electrode disposed at an end of the section of the first row and a second electrode in the first row, which is a next electrode closer to the center of the first row after the first electrode, is shorter than an interval between the second electrode and a third electrode, which is a next electrode after the second electrode within the first row, wherein
- the interval between the second electrode and third electrode is shorter than an interval between the third electrode and a fourth electrode, which is a next electrode after the third electrode within the first row, and
- the fourth electrode is closer to the center than is the third electrode.
Dependencies are inferred from the claim text.