Dual-Side RDL Package Structure for Thickness Reduction
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Solution Overview
Problem
Semiconductor packaging technology faces challenges in miniaturizing package structures while maintaining high integration and reducing thickness, as existing methods struggle to efficiently utilize both sides of a redistribution layer (RDL) for die placement and encapsulation.
Innovation Solution
A package structure and manufacturing method that includes a redistribution layer (RDL) with dies on both sides, where the first die is encapsulated and exposed conductive terminals are connected to solder balls, allowing for the elimination of a thick substrate and enabling the first die to be ground to any thickness, thus reducing the overall package thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a thick substrate is used to support dies, then structural stability is improved, but package thickness increases
Solution Approach 1:
The patent transitions from a single-sided die arrangement to a dual-sided die arrangement on the RDL. Dies are mounted on both the first surface and second surface of the RDL, effectively utilizing three-dimensional space. This dimensional change allows the package to achieve high integration without increasing the substrate thickness, as the vertical stacking of dies on opposite surfaces compensates for the eliminated thick substrate.
2Productivity
If dies are mounted on both sides of RDL, then integration density is improved, but manufacturing complexity increases
Solution Approach 1:
The patent divides the die mounting process into two separate encapsulation stages. First, dies on the first surface are encapsulated with a first encapsulant. Then, after separating the RDL from the carrier, dies on the second surface are encapsulated with a second encapsulant. This segmentation of the manufacturing process simplifies each individual step while achieving high integration density through dual-sided mounting.
3Length of stationary object
If the first die is ground to reduce thickness, then package miniaturization is improved, but die strength decreases
Solution Approach 1:
The patent applies encapsulants to both surfaces of the RDL before the thinning process. The first encapsulant protects dies on the first surface, and the second encapsulant protects dies on the second surface. This beforehand cushioning provides mechanical support and protection to the dies during and after the grinding process, preventing die damage even when the package is thinned to achieve miniaturization.
Data Source
AI summary
A package structure and a manufacturing method thereof are provided. The package structure includes a redistribution layer (RDL), at least one first die, a plurality of conductive terminals and solder balls, a first encapsulant, a plurality of second dies, and a second encapsulant. The RDL has a first surface and a second surface opposite to the first surface. The first die and the conductive terminals are electrically connected to the RDL and are located on the first surface of the RDL. The first encapsulant encapsulates the first die and the conductive terminals. The first encapsulant exposes part of the conductive terminals. The solder balls are electrically connected to the conductive terminals and are located over the conductive terminals exposed by the first encapsulant. The second dies are electrically connected to the RDL and are located on the second surface of the RDL. The second encapsulant encapsulates the second dies.