Patent Application
20090174985
1. Field of Invention
The present invention relates to a ceramic capacitor assembly, and more particularly to a ceramic capacitor assembly that comprises a capacitor with two legs and a cushion to prevent the ceramic capacitor from deforming or breaking and can be mounted securely on a printed circuit board by surface mount technology.
2. Description of the Related Art
Passive components, such as capacitors, resistors, inductors or the like, can be mounted on a printed circuit board (PCB) by two different ways.
In a first method, the PCB has an upper surface, a lower surface and two holes. The holes are defined through the PCB. The passive component has a body and two legs. The body is mounted on the upper surface of the PCB. The legs are mounted on the body, protrude through the holes of the PCB and before being bent and soldered onto the lower surface of the PCB. Therefore, mounting procedures of the passive component on the PCB using two legs comprises complex steps.
In a second method, the passive component is a surface mounted device (SMD) and has a body and two terminals. The body has two ends. The terminals are respectively mounted on the ends of the body. When the passive component is mounted on the PCB, the terminals are soldered on the PCB. The procedure to mount the passive component on the PCB directly is easy and fast. However, when the passive component is a ceramic capacitor, the PCB may warp or deform whilst the terminals are being soldered onto the PCB and the passive component may be damaged or even break. Thus, the passive components, especially ceramic passive components are easily damaged.
With reference to FIGS. 11 and 12, Taiwan patent No. M262821 discloses a capacitor assembly comprising a ceramic capacitor (40) and an insulating cover (50). The ceramic capacitor (40) has a body (42), two terminals (43) and two legs (41). The body (42) has two ends. The terminals (43) are respectively formed on the ends of the body (42). The legs (41) connect respectively to the terminals (43) and are soldered on an upper surface of the PCB.
The insulating cover (50) covers the body (42) and the terminals (43), allows the legs (41) to protrude from the insulating cover (50) and has a bottom and multiple supports (51). The supports (51) are formed on and protrude from the bottom of the insulating cover (50) and are mounted in contact with a PCB. Therefore the legs (41) can be bent under and mounted below the bottom of the insulating cover (50) and between the supports (51) so the ceramic capacitor (40) can be mounted securely on the PCB. Thus, the legs (41) and the insulating cover (50) prevent the body (42) and the terminals (43) from being mounted directly on the upper surface of the PCB.
However, the insulating cover (50) entirely covers the body (42) and the terminals (43), so much material is wasted raising costs.
To overcome the shortcomings, the present invention provides ceramic capacitor to mitigate or obviate the aforementioned.
The primary objective of the present invention is to provide a ceramic capacitor assembly comprising two legs and a cushion that allow the ceramic capacitor to be mounted securely on a print circuit board by surface mount technology (SMT) and prevent the ceramic capacitor from deforming or breaking.
To achieve the objective, the ceramic capacitor assembly in accordance with the present invention comprises a ceramic capacitor and a cushion. The ceramic capacitor has a body, two terminals and two legs. The body has a bottom. The terminals are formed respectively on the body. The legs connect to and protrude respectively from the terminals. The cushion is a resilient material and has an upper surface, a lower surface being mounted on the PCB, an outer edge and two fastening detents. The upper surface of the cushion corresponds to and is mounted adjacent to the ceramic capacitor. The detents correspond to the legs and are provided for legs to fasten to the cushion.
The ceramic capacitor and the cushion are easily assembled and the cushion can replace an insulating cover of a conventional ceramic capacitor assembly to reduce costs and complexity of manufacture.
Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
With reference to
The ceramic capacitor (20) may be rectangular (such as a multi-layer ceramic capacitor) or a disk-shape (parallel board capacitor) and has a body, two terminals and two legs (21, 21a, 21b, 21c). The body has a bottom. The terminals are formed on the body. With further reference to
The cushion (10) is made of resilient material, such as resin, may be rectangular, circular or other shapes, is mounted on the PCB and has an upper surface (11), a lower surface, an outer edge, two fastening detents.
The upper surface (11) corresponds to and is mounted adjacent to the ceramic capacitor (20) and may be flat.
The lower surface is flat and is opposite to the upper surface (11).
With further reference to
In a first embodiment, each fastening detent comprises a through hole (12, 12a) and a recess (13, 13a, 13b).
The through holes (12, 12a) are defined through the cushion (10), correspond to the legs (21, 21a, 21b, 21c) and allow the legs (21, 21a, 21b, 21c) to extend respectively through the through holes (12, 12a). Each through hole (12) may be circular, be larger than and correspond to the legs (21). Each through hole (12a) may be a slot and may correspond to the flattened segment (212) thereby only allowing the flattened segment (212) to extend through the through hole (12a) and may correspond to the protrusion (211b) of a parallelepiped leg (21b) thereby allowing the parallelepiped leg (21b) to be mounted securely in the slot (12a). Therefore, the capacitor (20) is held out of contact with the upper surface (11) of the cushion (10).
Each recess (13, 13a, 13b) is formed in the lower surface from the through hole (12, 12a), communicates with one of the through holes (12, 12a) and is mounted around a corresponding one of the legs (21, 21a, 21b, 21c).
In a first variant, the recess (13) is formed from the through holes (12, 12a) to the outer edge of the cushion (10) to allow the distal segment of the corresponding leg (21, 21a, 21b, 21c) to be mounted flush with the lower surface of the cushion (10) after being bent, thereby making mounting on the PCB easily.
In a second variant, the recess (13a) as
In a third variant, the recess (13b) as
In a preferred embodiment, the cushion (10) is rectangular and further has two ends. Each recess (13, 13a, 13b) is formed in the lower surface from one of the through hole (12, 12a) to a corresponding one of the ends of the cushion (10).
In a second embodiment, each fastening detent comprises a receiving notch (14) and a recess (13c). Each receiving notch (14) is formed in one of the outer edges from the upper surface to the lower surface and corresponds to and receives partially the proximal segment. The recess (13c) as
In a preferred embodiment, the cushion (10) is rectangular and further has two ends. The receiving notches (14) are formed respectively in the ends of the cushion (10).
Therefore, the legs (21, 21a, 21b, 21c) may hold the body and the terminals of the ceramic capacitor (20) out of contact with the cushion (10), so the ceramic capacitor (20) is not mounted directly on the PCB to prevent the ceramic capacitor (20) from being damaged during mounting and soldering.
Furthermore, the cushion (10) is mounted between the body and the terminals of the ceramic capacitor (20) and the PCB, so can support the whole body of the ceramic capacitor (20). Accordingly, the ceramic capacitor (20) can be mounted securely on the PCB.
Moreover, the ceramic capacitor (20) and the cushion (20) are easily assembled and the cushion (20) can replace an insulating cover of a conventional ceramic capacitor assembly to save money and manufacturing costs and complexity.
Even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only. Changes may be made in detail, especially in matters of shape, size and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
