Flexible circuit board and method of fabricating the same
A flexible circuit board and a method of fabricating the same are provided. The flexible circuit board includes a flexible substrate, in which the flexible substrate includes a first portion, two second portions, two third portions, two first bending portion and two second bending portions. The flexible circuit board includes first connecting circuit layers extending from an upper surface of the first portion through the first portions to upper surfaces of the second portions, second connecting circuit layers extending from lower surfaces of the second portions through the third portions to lower surfaces of the third portions, first circuit layers disposed on the upper surface of the first portion and second circuit layers disposed on the lower surfaces of the third portions. Therefore, the flexible circuit board can achieve no-via-hole and high density for circuit board.
1 . A flexible circuit board, comprising:
a flexible substrate, comprising a first portion, two second portions, two third portions, two first bending portions and two second bending portions, wherein the second portions are located above the third portions, and the first portion is located above the second portions,
wherein the two first bending portions are connected to the first portion and the two second portions, respectively, and the first portion and the second portions are located between the two first bending portions,
wherein the two second bending portions are connected to the two second portions and the two third portions, respectively, and the two second bending portions are located between the second portions,
a plurality of first connecting circuit layers, extending from an upper surface of the first portion of the flexible substrate through the first portion to upper surfaces of the second portions;
a plurality of second connecting circuit layers, extending from lower surfaces of the second portions of the flexible substrate through the third portion to lower surfaces of the third portions;
a plurality of first circuit layers, disposed over the upper surface of the first portion of the flexible substrate;
a plurality of second circuit layers, disposed over the lower surfaces of the third portions of the flexible substrate;
a third circuit layer, disposed over a lower surface of the first portion of the flexible substrate and between the two second bending portions; and
at least an embedded electronic component, disposed on the third circuit layer, and one of the at least an embedded electronic component is closer to the two second bending portions than to the two second portions.
2 . The flexible circuit board of claim 1 , further comprising:
a plurality of third circuit layers, disposed over a lower surface of the first portion and the two second bending portions of the flexible substrate, respectively; and
a plurality of embedded electronic components, disposed on the third circuit layers.
3 . The flexible circuit board of claim 1 , further comprising:
at least an electronic component, disposed on the first circuit layers and/or the second circuit layers of the flexible substrate.
4 . The flexible circuit board of claim 1 , further comprising:
a plurality of fixing pins, disposed on ends of the second portions of the flexible substrate near the first bending portions and the second bending portions, respectively.
5 . The flexible circuit board of claim 1 , wherein the first connecting circuit layers and the second connecting circuit layers comprises:
a plurality of conductive pillars, extending through the flexible substrate; and
a plurality of metal layers, disposed on the conductive pillars.
6 . A flexible circuit board, comprising:
a flexible substrate, comprising a first portion, two second portions, two third portions, two first bending portions and two second bending portions,
wherein the two first bending portions are connected to the first portion and the two second portions below the first portion, respectively, and the first portion and the second portions are located between the two first bending portions,
wherein the two second bending portions are connected to the two second portions and the two third portions below the second portions, respectively, and the two second bending portions are located between the second portions,
a plurality of first conductive pillars, extending from an upper surface of the first portion of the flexible substrate through the first portion toward the second portions, wherein the first conductive pillars are formed by inserting into first openings on the first portion of the flexible substrate;
a plurality of first metal layers, disposed on upper surfaces of the second portions of the flexible substrate and connected to the first conductive pillars;
a plurality of second conductive pillars, extending from lower surfaces of the second portions of the flexible substrate through the third portions toward the third portions, wherein the second conductive pillars are formed by inserting into second openings on the third portion of the flexible substrate;
a plurality of second metal layers, disposed on the lower surfaces of the second portions of the flexible substrate and connected to the second conductive pillars;
a plurality of first circuit layers, disposed over the upper surface of the first portion of the flexible substrate; and
a plurality of second circuit layers, disposed over the lower surfaces of the third portions of the flexible substrate.
7 . The flexible circuit board of claim 6 , further comprising:
a third circuit layer, disposed over a lower surface of the first portion of the flexible substrate and between the two second bending portions; and
at least an embedded electronic component, disposed on the third circuit layer.
8 . The flexible circuit board of claim 6 , further comprising:
a plurality of third circuit layers, disposed over lower surfaces of the first portion and the two second bending portions of the flexible substrate; and
a plurality of embedded electronic components, disposed on the third circuit layers.
9 . The flexible circuit board of claim 6 , further comprising:
a first electronic component, disposed on the upper surface of the first portion and electrically connected to the first circuit layers.
10 . The flexible circuit board of claim 6 , further comprising:
at least a second electronic component, disposed on the lower surfaces of the third portions and electrically connected to the second circuit layers.
11 . The flexible circuit board of claim 6 , further comprising:
a plurality of fixing pins, disposed on ends of the second portions of the flexible substrate near the first bending portions and the second bending portions, respectively.
12 . The flexible circuit board of claim 6 , further comprising:
a plurality of cover films, disposed on the first bending portions and the second bending portions.
13 . The flexible circuit board of claim 12 , further comprising:
a plurality of adhesive layers, disposed between the first portion and the second portions, between the second portions and the third portions, and between the two second bending portions of the flexible substrate.