Electronic device

Abstract

In an electronic device, a QFN is surface-mounted on a printed board. The QFN includes a main body containing an IC chip, a reinforcement portion, and multiple terminal portions. The reinforcement portion is exposed from a bottom portion of the main body and mechanically coupled with multiple reinforcement lands on the printed board. The multiple terminal portions are exposed from a peripheral of the main body and electrically coupled with multiple lands on the printed board. In the printed board, the multiple lands are connected with multiple conductive wires. Some of the multiple conductive wires are outside of the surface-mounted area. The others are inside of the surface-mounted area to face the reinforcement lands. This enhances a mounting efficiency in the printed board.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features, and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings. In the drawings:

FIG. 1 is an exploded view illustrating an overall structure of an electronic device according to a first embodiment of the present invention;

FIG. 2 is a view illustrating a cross-sectional structure of a QFN in the electronic device of the first embodiment;

FIG. 3A is a view illustrating a printed board of the first embodiment;

FIG. 3B is a cross-sectional view of the electronic device of the first embodiment;

FIG. 4 is a view illustrating a printed board of an electronic device as a modification 1;

FIG. 5 is a view illustrating a printed board of an electronic device as a modification 2;

FIG. 6 is a view illustrating a printed board of an electronic device as a modification 3;

FIG. 7 is a view illustrating a printed board of an electronic device as a modification 4;

FIG. 8 is a view illustrating a printed board of an electronic device as a modification 5;

FIG. 9A is a view illustrating a printed board of an electronic device as a modification 5;

FIG. 9B illustrates an enlarged view of wires;

FIG. 10A is a view illustrating a printed board of a comparative example; and

FIG. 10B illustrates an enlarged view of wires.

Claims

1. An electronic device comprising: an electronic component including a main body,an IC chip contained in the main body, anda plurality of terminal portions exposed from the main body; anda printed board, to which the main body of the electronic component is mounted, the printed board including a plurality of lands electrically coupled with the terminal portions of the electronic component,a plurality of conductive wires electrically coupled with the lands, anda connection member, which mechanically connects the printed board with a surface of the main body, the surface facing the printed board, to thereby mount the electronic component to the printed board,wherein the conductive wires include a first conductive wire, which is arranged within a surface area of the printed board, the surface area facing the main body of the electronic component, andwherein the connection member is configured to have a shape to correspond to the first conductive wire arranged within the facing area of the printed board.

2. The electronic device of claim 1, wherein the conductive wires include a plurality of first conductive wires, which are arranged inside of the facing area, and a plurality of second conductive wires, which are arranged outside of the facing area.

3. The electronic device of claim 2, wherein the first conductive wires and the second conductive wires are alternately arranged along a peripheral line of the facing area.

4. The electronic device of claim 2, wherein an elemental component for decreasing noises is electrically mounted to bridge the adjacent second conductive wires.

5. The electronic device of claim 2, wherein the electronic component includes a reinforcement portion, which supports the IC chip and is exposed from the main body and mechanically connected with the connection member in the printed board.

6. The electronic device of claim 5, wherein the connection member includes four corner connection sub-members, which are arranged to individually face four corners of the reinforcement portion of the electronic component,the second conductive wires include corner outside conductive wires, which are arranged to oppose each corner connection sub-member via a peripheral line of the facing area with no first conductive wires intervening.

7. The electronic device of claim 6, wherein an interval between adjacent two wires of the corner outside conductive wires is larger than an interval between two adjacent conductive wires other than the corner outside conductive wires.

8. The electronic device of claim 6, wherein one of the corner outside conductive wires is electrically coupled with at least two lands for large current to flow.

9. The electronic device of claim 6, wherein the connection member further includes a central connection sub-member arranged in a central portion of the facing area, andfirst conductive wires are arranged in the facing area to intervene between the central connection sub-member and a peripheral line of the facing area.

10. The electronic device of claim 9, wherein the central connection sub-member is electrically coupled with a ground.

11. The electronic device of claim 1, wherein all of the conductive wires are first conductive wires, which are arranged within the facing area.

12. The electronic device of claim 1, wherein the conductive wires include a plurality of first conductive wires, which are arranged in the facing area to adjoin each other.

13. The electronic device of claim 1, wherein wherein the connection member includes a reinforcement land and a solder resist.

14. The electronic device of claim 1, wherein the facing area is approximately rectangular.

15. The electronic device of claim 14, wherein each of the lands is arranged to cross a peripheral line of the facing area.