Fan-Out Package Structure Using Staggered Pads to Eliminate Conductive Posts
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Solution Overview
Problem
Existing fan-out technologies require multiple redistribution layers and conductive holes/posts, leading to complex processes, increased costs, parasitic effects, and interference with signal transmission and heat dissipation.
Innovation Solution
A fan-out package structure and method that eliminates the need for conductive posts by using pads of different heights, with a first pad and a second pad, where the first wiring layer is fanned out from the lower pad and the second wiring layer from the higher pad, and dielectric layers are used to cover and protect these layers, simplifying the process and reducing parasitic and capacitive effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple redistribution layers and conductive holes are used to connect pads, then fan-out extension is achieved, but process complexity increases and manufacturing cost increases
Solution Approach 1:
The patent transitions from planar redistribution layers to a three-dimensional pad height differentiation approach. Pads are formed at different heights on the packaging element surface, allowing direct vertical connections to wiring layers without requiring multiple horizontal redistribution layers and conductive holes. This dimensional change eliminates complex wiring processes while achieving fan-out extension.
2Adaptability or versatility
If multiple redistribution layers and conductive holes are used to connect pads, then fan-out extension is achieved, but manufacturing cost increases
Solution Approach 1:
The patent extracts and eliminates the redundant redistribution layers and conductive holes from the traditional fan-out structure. By using pads of different heights that directly expose to the exterior, the design removes unnecessary intermediate connection structures, thereby simplifying manufacturing processes and reducing production costs.
3Reliability
If conductive holes are used in redistribution layers, then electrical connection is achieved, but parasitic effect and capacitive effect increase
Solution Approach 1:
The patent converts the traditional approach of using conductive holes (which create parasitic effects) into exposed pads of different heights. This transformation eliminates the harmful parasitic and capacitive effects associated with conductive holes while maintaining reliable electrical connections through direct pad-to-wiring-layer contacts.
4Reliability
If conductive holes are used in redistribution layers, then electrical connection is achieved, but heat dissipation effect deteriorates
Solution Approach 1:
The patent eliminates conductive holes that impede heat flow and replace them with exposed pads of different heights. This structural change removes thermal barriers, allowing improved heat dissipation while maintaining electrical connectivity through the pad-wiring layer interfaces.
Data Source
AI summary
Provided are fan-out package structure and fan-out packaging method. Structure includes packaging element, plastic package body, first dielectric layer, and second dielectric layer, packaging element has first pad and second pad, height of first pad is lower than that of second pad, plastic package body plastic-seals packaging element, and end surface of first pad is exposed from surface of plastic package body, one side of first pad away from packaging element has first wiring layer, and first wiring layer has first solder ball; first dielectric layer is provided on one side of first wiring layer away from packaging element, end surface of second pad is exposed from surface of first dielectric layer, one side of second pad away from packaging element has second wiring layer, and second wiring layer has second solder ball; and one side of second wiring layer away from first wiring layer has second dielectric layer.