1. Technical field
The disclosure generally relates to a capacitor and a multilayer circuit board using the capacitor.
2. Description of the Related Art
A capacitor on a circuit board may include two opposite metal layers and a dielectric layer positioned between the two opposite metal layers. Capacitance of the capacitor is proportional to an area of the metal layers, and is inversely proportional to a thickness of the dielectric layer. That is, capacitance of the capacitor can be improved by increasing the area of the metal layers or by decreasing thickness of the dielectric layer. However, increasing the area of the metal layers may cause the capacitor to occupy much more space, and decreasing the thickness of the dielectric layer may affect impedance matching with other circuits of the circuit board.
Therefore, there is room for improvement within the art.
Many aspects of an exemplary capacitor and multilayer circuit board can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the exemplary capacitor and multilayer circuit board. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. Wherever possible, the same reference numbers are used throughout the drawings to refer to the same or like elements of an embodiment.
Referring to
The first conductive layer 11 includes a first patterned conductive layer 113, a second patterned conductive layer 115, and a patterned dielectric layer 117. The first patterned conductive layer 113 includes a first connecting portion 1133 and a plurality of first branch portions 1134. The first connecting portion 1133 connects to the negative electrode 90 to receive the negative voltage, and the first connecting portion 1133 is strip shaped. The plurality of first branch portions 1134 radiate from two opposite sides of the first connecting portion 1133. The plurality of first branch portions 1134 may be spaced substantially evenly, and the plurality of the first branch portions 1134 are arc shaped. The first connecting portion 1133 and the plurality of first branch portions 1134 are coplanar. The first connecting portion 1133 and the plurality of first branch portions 1134 define a plurality of first openings 1131.
The second patterned conductive layer 115 has a shape corresponding to the first openings 1131 defined in the first patterned conductive layer 113. In detail, the second patterned conductive layer 115 includes a second connecting portion 1153 and a plurality of second branch portions 1154. The second connecting portion 1153 connects to the positive electrode 80 to receive the positive voltage, and the second connecting portion 1154 is strip shaped. The plurality of second branch portions 1154 radiate from two opposite sides of the second connecting portion 1153. The width of each of the plurality of second branch portions 1154 is a slightly less than the width of each of the plurality of first openings 1131. The plurality of first branch portions 1154 may be spaced substantially evenly. The second branch portions 1154 in the middle of the plurality of second branch portions 1154 is round, and the other second branch portions 1154 are arc shaped. The second connecting portion 1153 and the plurality of the second branch portions 1153 are coplanar. The second connecting portion 1153 and the plurality of second branch portions 1154 define a plurality of second openings 1151, and the width of each of the plurality of second openings 1151 is a slightly greater than the width of each of the plurality of first branch portions 1134.
The second patterned conductive layer 115 and the patterned dielectric layer 117 are located within the first openings 1131. The patterned dielectric layer 117 is sandwiched between the first patterned layer 113 and the second patterned layer 115. The first patterned conductive layer 113, the second patterned conductive layer 115 and the patterned dielectric layer 117 are in a same horizontal plane, thus those three elements together have a depth, or vertical displacement, which is not greater than the depth of a single one. In detail, each of the plurality of second branch portions 1154 is located to correspond to each of the first openings 1131, and each of the plurality of first branch portions 1134 is located to correspond to each of the second openings 1151. Therefore, a plurality of gaps exist between the first patterned conductive layer 113 and the second patterned conductive layer 115. The patterned dielectric layer 117 is positioned so as to infill the plurality of gaps to create a capacitive arrangement and capability between the first patterned conductive layer 113 and the second patterned conductive layer 115.
Referring to
The first conductive layer 11, the second conductive layer 12, the third conductive layer 13 and the fourth conductive layer 14 are stacked from top to bottom, in that order, with the dielectric layer 119 between coplanar conductive layers which are in close proximity. Each branch portion provided with the positive voltage of one patterned conductive layer is opposite to the branch portion provided with the negative positive voltage of the other adjacent patterned conductive layer. Each branch portion provided with the negative voltage of one patterned conductive layer is opposite to the branch portion provided with the positive voltage of the other adjacent patterned conductive layer (as shown in
Each of the patterned conductive layer includes a plurality of branch portions provided with the positive voltage interlaced with a plurality of branch portions provided with the negative voltage. There are electrical fields created between the branch portions provided with the positive voltage and the branch portions provided with the negative voltage in the same coplanar layer. Therefore, the capacitance of the capacitor is increased without changing the size of the capacitor. Furthermore, the capacitor is in itself a multilayer component, and can be located within a multilayer circuit board so the individual coplanar layers correspond to the multiple layers of the multilayer circuit board, hence a wiring and other space of the multilayer circuit board is saved.
It is to be understood, however, that even though numerous characteristics and advantages of the exemplary disclosure have been set forth in the foregoing description, together with details of the structure and function of the exemplary disclosure, the disclosure is illustrative only, and changes may be made in detail, especially in the matters of shape, size, and arrangement of parts within the principles of exemplary disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
Number | Date | Country | Kind |
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101126080 | Jul 2012 | TW | national |