WIRING BOARD WITH DUAL WIRING STRUCTURES INTEGRATED TOGETHER AND METHOD OF MAKING THE SAME
A wiring board with integrated dual wiring structures is characterized in that first and second wiring structures are positioned within and beyond a through opening of a stiffener, respectively. The mechanical robustness of the stiffener can prevent the wiring board from warping. The first wiring structure, positioned within the through opening of the stiffener, can provide primary fan-out routing, whereas the second wiring structure not only provides further fan-out wiring structure for the first wiring structure, but also mechanically binds the first wiring structure with the stiffener.
1 . A wiring board with dual wiring structures integrated together, comprising:
a stiffener having a through opening that extends through the stiffener;
a first wiring structure having a multi-layered routing circuitry and positioned within the through opening of the stiffener; and
a second wiring structure that is electrically coupled to the first wiring structure and includes at least one conductive trace laterally extending over a surface of the stiffener.
2 . The wiring board of claim 1 , wherein the first wiring structure has a smaller exposed surface area than that of the second wiring structure.
3 . The wiring board of claim 2 , wherein the stiffener extends beyond the exposed surface of the first wiring structure to form a cavity in the through opening of the stiffener.
4 . The wiring board of claim 1 , wherein the second wiring structure is electrically coupled to the first wiring structure through conductive vias.
5 . The wiring board of claim 1 , wherein both the first and the second wiring structures are buildup routing circuitries without a core layer.
6 . The wiring board of claim 1 , further comprising an anti-warping controller that is attached on the second wiring structure.
7 . A method of making a wiring board with dual wiring structures integrated together, comprising:
forming a first wiring structure on a detachable sacrificial carrier;
providing a stiffener that has a through opening extending through the stiffener;
inserting the first wiring structure and the sacrificial carrier into the through opening of the stiffener;
forming a second wiring structure that is electrically coupled to the first wiring structure and includes at least one conductive trace laterally extending over a surface of the stiffener; and
removing the sacrificial carrier to expose the first wiring structure.
8 . The method of claim 7 , wherein the step of removing the sacrificial carrier includes a chemical etching process or a mechanical peeling process.
9 . The method of claim 7 , further comprising a step of attaching an anti-warping controller on the second wiring structure before the step of removing the sacrificial carrier.