US20090081390A1

US20090081390A1 - Cylinder structure

Info

Publication number: US20090081390A1
Application number: US11/862,191
Authority: US
Inventors: Yung-Hui Chen; Po-An Lin
Original assignee: Compal Electronics Inc
Current assignee: Compal Electronics Inc
Priority date: 2007-09-26
Filing date: 2007-09-26
Publication date: 2009-03-26
Also published as: CN101400230A; CN101400230B; TW200915957A

Abstract

A cylinder structure including a plastic cylinder, a metal cylinder, and a metal layer is provided. The plastic cylinder has a first flat on the top thereof. The metal cylinder has a second flat on the top thereof, and is partly inserted into the top of the plastic cylinder, wherein the second flat is higher than the first flat relative to the top of the plastic cylinder. The metal layer covers the exposed surface of the plastic cylinder and the exposed surface of the metal cylinder.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention generally relates to a housing and a cylinder structure thereof, in particular, to an electronic device housing and a cylinder structure thereof.
2. Description of Related Art
An electronic device housing mainly serves two purposes. First of all, the electronic device housing provides a base for the electronic components to be fixed thereon. Secondly, the electronic device housing offers physical protection to the electronic components disposed therein and prevents the electronic components from damage caused by electrostatic discharge (ESD) and electro-magnetic interference (EMI).
In order to perform the aforesaid two functions, the housing for electronic device usually comprises cylinder structures, onto which the electronic parts can be fastened, and a metal layer, shielding the electronic components from ESD and EMI.
FIG. 1A is a local cross-sectional view of a conventional electronic device housing. Referring to FIG. 1A, the electronic device housing 100 includes a wall 110, a metal cylinder 120, a plastic cylinder 130, and a metal layer 140. The plastic cylinder 130 is formed on the wall 110, and the plastic cylinder 130 has a first hole 132 and a plurality of burrs 134 on the top thereof, wherein the burrs 134 are resulted from inevitable defect of the molding process. The metal cylinder 120, which has a second hole 122 with an internal thread 122 a, is inserted into the first hole 132 and fixed therein. The metal layer 140 is a sputtered layer, which covers the exposed surface of the plastic cylinder 130, the exposed surface of the metal cylinder 120, and the inner surface of the wall 110.
FIG. 1B is a local cross-sectional view of a circuit board installed on the electronic device housing in FIG. 1A, and FIG. 1C is a local cross-sectional view of the electronic device housing in FIG. 1B with its burrs consumed. Referring to FIG. 1B, the circuit board 50 of the electronic device has a plurality of ground pads 52 ( only one is shown), a plurality of screws 54 ( only one is shown ), and a plurality of fixing hole 56 (only one is shown), through which the screws 54 are fastened in the second hole 122 of the metal cylinder 120, and thus the circuit board 50 is fixed on the burrs 134 (shown in FIG. 1A) on the top of the plastic cylinder 130, wherein the ground pads 52 are in contact with the metal layer 140. The contact between the metal layer 140 and the ground pads 52 provides the metal layer 140 with the function of electromagnetic shielding.
The burrs 134 and a portion of the metal layer 140 thereon, however, could be consumed by the friction between the circuit board 50 and the plastic cylinder 130, or by the pressure exerted on the burrs 134 when installing the circuit board. The damage of the contact between the ground pads 52 and the metal layer 140 produces an open 142 (shown in FIG. 1C) on the metal layer 140, which leads to higher resistance or open circuit therebetween, and hence diminishes the electromagnetic shielding performance of the electronic device housing 100.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a cylinder structure preventing the metal layer from being open-circuited by the damage of burrs.
The present invention also provides an electronic device housing using the aforementioned cylinder structure and thus insures the electromagnetic shielding performance.
The present invention provides a cylinder structure including a plastic cylinder, a metal cylinder, and a metal layer. The plastic cylinder has a first flat on the top thereof. The metal cylinder has a second flat on the top thereof, and is partly inserted into the top of the plastic cylinder, wherein the second flat is higher than the first flat relative to the top of the plastic cylinder.
According to an embodiment of the present invention, the plastic cylinder has a first hole having a first shoulder on the inner surface of the first hole, and the metal cylinder has a second shoulder supported by the first shoulder.
According to an embodiment of the present invention, the metal cylinder has a second hole having an internal thread on the inner surface of the second hole.
According to an embodiment of the present invention, the metal cylinder has a first segment and a second segment, and the joint between the first segment and the second segment forms the second shoulder.
According to an embodiment of the present invention, a part of the first segment protrudes from the first flat, and the part of the first segment has the second flat, and the first segment has a plurality of concaves spread on the outer surface thereof.
According to an embodiment of the present invention, the plastic cylinder has a burr formed on the outermost edge of the first flat.
According to an embodiment of the present invention, the plastic cylinder has a plurality of reinforcing ribs distributed on the outer side of the plastic cylinder.
The present invention further provides an electronic device housing including a wall, at least one plastic cylinder, at least one metal cylinder, and a metal layer. The plastic cylinder has a first flat on the top thereof, and the bottom of the plastic cylinder is attached to the wall. The metal cylinder has a second flat on the top thereof, and is partly inserted into the top of the plastic cylinder, wherein the second flat is higher than the first flat relative to the top of the plastic cylinder. The metal layer covers the exposed surface of the plastic cylinder, the exposed surface of the metal cylinder, and the inner surface of the wall.
According to an embodiment of the present invention, the plastic cylinder has a first hole having a first shoulder on the inner surface of the first hole, and the metal cylinder has a second shoulder supported by the first shoulder.
According to an embodiment of the present invention, the metal cylinder has a second hole having internal thread on the inner surface of the second hole.
According to an embodiment of the present invention, the metal cylinder has a first segment and a second segment, and the joint between the first segment and the second segment forms the second shoulder.
According to an embodiment of the present invention, a part of the first segment protrudes from the first flat, and the part of the first segment has the second flat, and the first segment has a plurality of concaves spread on the outer surface thereof.
According to an embodiment of the present invention, the plastic cylinder has a burr formed on the outermost edge of the first flat.
According to an embodiment of the present invention, the plastic cylinder has a plurality of reinforcing ribs distributed on the outer side of the plastic cylinder.
According to an embodiment of the present invention, the wall and the plastic cylinder are integrally formed.
As described above, in the present invention, the second flat is higher than the first flat relative to the top of the plastic cylinder. To paraphrase, a circuit board installed on the cylinder structure is supported by the metal cylinder instead of the burrs or the first flat of the plastic cylinder. Hence, even if the metal layer between the metal cylinder and the ground pads is consumed, the metal layer remains electrically connected with the ground pads via the metal cylinder thus insures the electromagnetic shielding performance of the electronic device housing.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

FIG. 1A is a local cross-sectional view of a conventional electronic device housing.

FIG. 1B is a local cross-sectional view of a circuit board installed on the electronic device housing in FIG. 1A.

FIG. 1C is a local cross-sectional view of the electronic device housing in FIG. 1B with its burrs consumed.

FIG. 2A is a local top view of the electronic device housing according to an embodiment of the present invention.

FIG. 2B is a local cross-sectional view taken along line A-A in FIG. 2A.

FIG. 2C is a magnified view of the area circle A in FIG. 2A.

FIG. 3 is a local cross-sectional view of a circuit board installed on the electronic device housing in FIG. 2A.

FIG. 4 is a local cross-sectional view of a circuit board installed on the electronic device housing according to another embodiment of the present invention.

FIG. 5A is a top view of the metal cylinder in FIG. 4.

FIG. 5B is a cross-sectional view taken along line B-B in FIG. 5A.

DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.
FIG. 2A is a local top view of the electronic device housing according to an embodiment of the present invention, FIG. 2B is a local cross-sectional view taken along line A-A in FIG. 2A, and FIG. 2C is a magnified view of the circle A in FIG. 2A. Referring to FIG. 2A, FIG. 2B, and FIG. 2C, the electronic device housing 300 includes a wall 310 and a cylinder structure 200. The cylinder structure 200 includes a plastic cylinder 210, a metal cylinder 220, and a metal layer 230, wherein the plastic cylinder 210 has a first flat 212 on the top thereof. The bottom of the plastic cylinder 210 is attached to the wall 300, wherein the wall 300 and the plastic cylinder 210 may be integrally formed. The metal cylinder 220 has a second flat 222, and is partly inserted into the top of the plastic cylinder 210 and fixed therein, wherein the second flat 222 is higher than the first flat 212 relative to the top of the plastic cylinder 210. In the present embodiment, the plastic cylinder 210 has a first hole 214, wherein the first hole 214 has a first shoulder 214 a on the inner surface thereof. The metal cylinder 220 is partly inserted into the first hole 214 and has a second shoulder 224, which is supported by the first shoulder 214 a. The metal layer 230 maybe a sputtered layer, which covers the exposed portion of the inner surface of the wall 300, the exposed surface of the plastic cylinder 210 and the exposed surface of the metal cylinder 220. What is more, the cylinder structure 200 may further include a plurality of reinforcing ribs 218, which are distributed on the outer surface of the plastic cylinder 210 and strengthen the structure of the plastic cylinder 210.
FIG. 3 is a local cross-sectional view of a circuit board installed on the cylinder structure in FIG. 2A. Referring to FIG. 2A and FIG. 3, it should be noticed that, although a circuit board 50 is described, any electronic elements suitable for being installed on an electronic device housing is applicable. The circuit board 50 is supported by the metal cylinder 220 instead of the plastic cylinder 210, since the second flat 222 is higher than the first flat 212. Thus, even if the metal layer 230 between the metal cylinder 220 and the circuit board 50 is consumed by friction, the ground pad 52 will still be in contact with the metal cylinder 220, hence the electromagnetic shielding performance of the metal layer 230 is ensured.
FIG. 4 is a local cross-sectional view of a circuit board installed on the cylinder structure according to another embodiment of the present invention. The present embodiment is similar to the aforesaid embodiment, and in these two embodiments, like reference numerals refer to like elements. Referring to FIG. 4, the cylinder structure 200′ has a plurality of burrs 216 formed on the outermost edge of the first flat 212′. The circuit board 50 is supported by the metal cylinder 220, which is higher than the burrs 216 relative to the top of the plastic cylinder 210′, thus the circuit board 50 is not in contact with the burrs 216, therefore prevents the circuit board 50 from damaging the burrs 216 and maintains the electromagnetic shielding performance of the metal layer 230.
FIG. 5A is a top view of the metal cylinder in FIG. 4, and FIG. 5B is a cross-sectional view taken along line B-B in FIG. 5A. Referring to FIG. 4, FIG. 5A and FIG. 5B, the metal cylinder 220 may have a second hole 226 having an internal thread 226 a on the inner surface of the second hole 226. The circuit board 50 may be fixed on the cylinder structure 200′ by use of fastening the screw 54 in the second hole 226 through a fixing hole 56 on the circuit board 50. In the present embodiment, the metal cylinder 220 may have a first segment 220 a and a second segment 220 b, wherein the joint between the first segment 220 a and the second segment 220 b forms the aforesaid second shoulder 224. Furthermore, one part of the first segment 220 a may protrude from the first flat 212′, and the second flat 222 is located on the top of the aforementioned part of the first segment 220 a, hence the ground pad 52 of the circuit board 50 is in contact with the first segment 220 a. Moreover, the first segment 220 a may have a plurality of concaves 228 spread on the outer surface thereof. The concaves 228 further enhance the fixation between the metal cylinder 220 and the plastic cylinder 210′.
In summary, in the present invention, the second flat is higher than the first flat relative to the top of the plastic cylinder. To restate, a circuit board installed on the cylinder structure or the electronic device housing is not in contact with the metal layer on the burrs or on the plastic cylinder, alternatively, the circuit board is in contact with the metal layer on the metal cylinder. Hence, even if the metal layer between the metal cylinder and the ground pads is consumed, the metal layer remains its electrical connection with the ground pads through the metal cylinder. Thus the electromagnetic shielding performance of the electronic device housing in the present invention is assured.
Furthermore, the plastic cylinder has a plurality of concaves spread on the outer surface thereof, which enhances the fixation between the plastic cylinder and metal cylinder.
It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.

Claims

1. A cylinder structure, comprising:

a plastic cylinder having a first flat on the top thereof;

a metal cylinder partly inserted into the top of the plastic cylinder, and having a second flat on the top of the metal cylinder, wherein the second flat is higher than the first flat relative to the top of the plastic cylinder; and

a metal layer covering the exposed surface of the plastic cylinder and the exposed surface of the metal cylinder.

2. The cylinder structure according to claim 1, wherein the plastic cylinder has a first hole having a first shoulder on the inner surface of the first hole, and the metal cylinder has a second shoulder supported by the first shoulder.

3. The cylinder structure according to claim 2, wherein the metal cylinder has a second hole having an internal thread on the inner surface of the second hole.

4. The cylinder structure according to claim 2, wherein the metal cylinder has a first segment and a second segment, and the joint between the first segment and the second segment forms the second shoulder.

5. The cylinder structure according to claim 4, wherein a part of the first segment protrudes from the first flat, and the part of the first segment has the second flat, and the first segment has a plurality of concaves spread on the outer surface thereof.

6. The cylinder structure according to claim 1, wherein the plastic cylinder has a burr formed on the outermost edge of the first flat.

7. The cylinder structure according to claim 1, wherein the plastic cylinder has a plurality of reinforcing ribs distributed on the outer side of the plastic cylinder.

8. An electronic device housing, comprising:

a wall;

at least one plastic cylinder, having a first flat on the top thereof, and the bottom of the plastic cylinder attached to an inner surface of the wall;

at least one metal cylinder, partly inserted into the top of the plastic cylinder, and having a second flat on the top of the metal cylinder, wherein the second flat is higher than the first flat relative to the top of the plastic cylinder; and

a metal layer, covering the exposed portion of the inner surface of the wall, the exposed surface of the plastic cylinder, and the exposed surface of the metal cylinder.

9. The electronic device housing according to claim 8, wherein the plastic cylinder has a first hole having a first shoulder on the inner surface of the first hole, and the metal cylinder has a second shoulder supported by the first shoulder.

10. The electronic device housing according to claim 9, wherein the metal cylinder has a second hole having internal thread on the inner surface of the second hole.

11. The electronic device housing according to claim 9, wherein the metal cylinder has a first segment and a second segment, and the joint between the first segment and the second segment forms the second shoulder.

12. The electronic device housing according to claim 11, wherein a part of the first segment protrudes from the first flat, and the part of the first segment has the second flat, and the outer surface of the first segment has a plurality of concaves spread on the outer surface thereof.

13. The electronic device housing according to claim 8, wherein the plastic cylinder has a burr formed on the outermost edge of the first flat.

14. The electronic device housing according to claim 8, wherein the plastic cylinder has a plurality of reinforcing ribs distributed on the outer side of the plastic cylinder.

15. The electronic device housing according to claim 8, wherein the wall and the plastic cylinder are integrally formed.