Fan-out packaging structure and method for manufacturing same
A fan-out packaging structure and a method for manufacturing the same are provided. The structure comprises: a fan-out substrate unit, and a secondary fan-out unit; an effective electrical connection between a second top surface of the fan-out substrate unit and a third bottom surface of the secondary fan-out unit is formed through a second solder array, and the fan-out substrate unit comprises a first wiring layer and a second wiring layer connected by conductive posts. By having a fan-out substrate unit with a double-layer wiring layer as the substrate of the fan-out wiring layer, the present disclosure reduces the achievable minimum line width, thereby increasing the achievable line density of the fan-out package. Meanwhile, replacing the traditional substrate with the double-layer wiring layer, and preparing the fan-out substrate unit and the secondary fan-out unit separately and then combining the two, shortens the time required to prepare the whole structure.
1 . A method for manufacturing a fan-out packaging structure, comprising:
providing a first temporary substrate; forming a first separation layer on the first temporary substrate; and forming a second wiring layer on the first separation layer, wherein the second wiring layer comprises a second circuit layer and a second dielectric layer, a second bottom surface and a second top surface opposite to the second bottom surface, wherein the second circuit layer is exposed from the second wiring layer, and wherein the first separation layer is in contact with the second top surface;
forming a plurality of conductive posts over the second bottom surface, wherein bottom surfaces of the plurality of conductive posts are facing away from the second bottom surface; filling gaps between the plurality of conductive posts with a first encapsulation layer; grinding the first encapsulation layer until the bottom surfaces of the plurality of conductive posts are exposed; forming a first wiring layer over the first encapsulation layer, wherein the first wiring layer comprises a first bottom surface and a first top surface opposite to the first bottom surface, wherein an effective electrical connection is formed between the first top surface and the plurality of conductive posts;
disposing a first solder array over the first bottom surface, wherein the first solder array is electrically connected to the first bottom surface; removing the first temporary substrate by removing the first separation layer;
forming an oxidation-resistant layer over the second circuit layer exposed from the second top surface of the second wiring layer, and obtaining a fan-out substrate;
cutting the fan-out substrate to form a plurality of fan-out substrate units;
providing a second temporary substrate, forming a second separation layer on the second temporary substrate; and forming a third wiring layer over the second separation layer, wherein the third wiring layer comprises a third bottom surface and a third top surface opposite to the third bottom surface, and wherein the third bottom surface is in contact with the second separation layer;
removing the second temporary substrate by removing the second separation layer;
forming a second solder array over the third bottom surface, wherein the second solder array is electrically connected to the third bottom surface to obtain a secondary fan-out structure;
cutting the secondary fan-out structure to form a plurality of secondary fan-out units; and
fixing and electrically connecting the third bottom surface to the second top surface through the second solder array.
2 . The method according to claim 1 , further comprising:
after forming the third wiring layer, disposing a semiconductor chip set over the third top surface, wherein the semiconductor chip set comprises one or more chips, a solder surface and an external connection surface, wherein an effective electrical connection between the solder surface and the third top surface is formed by an electrical connection structure;
filling gaps inside the electrical connection structure by a second filler layer;
encapsulating the semiconductor chip set with a second encapsulation layer to form an encapsulation body, wherein the second encapsulation layer encapsulates the third wiring layer, the semiconductor chip set, and the electrical connection structure;
grinding the second encapsulation layer until the external connection surface of the semiconductor chip set is exposed;
forming a third separation layer over the external connection surface, providing a third temporary substrate on the third separation layer;
removing the second temporary substrate by removing the second separation layer;
forming a second solder array over the third bottom surface;
removing the third temporary substrate by removing the third separation layer; and
obtaining the secondary fan-out structure.
3 . The method according to claim 1 , further comprising:
forming a support layer on a side of the first temporary substrate facing away from the second top surface after the first temporary substrate is removed; and
after forming the oxidation-resistant layer and cutting the fan-out substrate to obtain the plurality of fan-out substrate units, removing the support layer.
4 . The method according to claim 1 , further comprising: filling gaps of the second solder array with a first filler layer, wherein the first filler layer encapsulates the second solder array.