Package Board Cavity Design for Thin PoP Bridge Defect Reduction
Solution Overview
Problem
Existing package boards face challenges in reducing the overall thickness of package on package structures and minimizing bridge defects in external connection terminals, particularly in implementing fine pitch connections.
Innovation Solution
A package board design featuring a first insulating layer with a penetrating cavity, a first connection pad with a metal post and barrier layer, and a second connection pad with a larger diameter, which reduces the overall thickness and enhances connection reliability by increasing the bonded area with external terminals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If a conventional package board structure is used, then the overall thickness of the package on package is reduced, but bridge defects in external connection terminals increase
Solution Approach 1:
The external connection terminal structure is segmented into multiple parts: a first external connection terminal extending from the first surface, a second external connection terminal extending from the second surface, and a bridge portion connecting them. This segmentation allows each part to be independently optimized for its specific function, reducing bridge defects while maintaining thin profile.
Solution Approach 2:
The external connection terminal is designed to extend in multiple directions (upward from first surface, downward from second surface, and laterally as bridge portion), utilizing three-dimensional space efficiently. This dimensional approach allows the terminal to achieve both thin overall thickness and reliable connections without bridge defects.
2Length of stationary object
If a conventional package board structure is used, then the overall thickness of the package on package is reduced, but implementation of fine pitch connections becomes difficult
Solution Approach 1:
The connection structure is divided into distinct segments (first external connection terminal, second external connection terminal, and bridge portion) that can be independently formed and controlled. This segmentation enables precise control over pitch dimensions while maintaining thin overall thickness.
Solution Approach 2:
The design allows independent control of critical parameters including the pitch between first and second external connection terminals, the dimensions of the bridge portion, and the thickness of the package board. This parameter control enables fine pitch implementation while maintaining thin profile.
3Reliability
If the diameter of connection pads is increased to reduce bridge defects, then connection reliability improves, but the interval between package boards increases
Solution Approach 1:
The external connection terminal utilizes three-dimensional routing with vertical extensions from both surfaces and lateral bridge portions. This allows the terminal to achieve large bonded areas for reliable connections while maintaining small horizontal footprint, thus reducing the interval between package boards.
Solution Approach 2:
The connection structure has different dimensions optimized for different functions: large diameter at the bonded areas for reliability, but compact horizontal dimensions for the bridge portion to minimize interval between package boards.
Data Source
AI summary
There are provided a package board, a method for manufacturing the same, and a package on package having the same. The package board according to an exemplary embodiment of the present disclosure includes a first insulating layer formed with a cavity having a penetrating shape; and a first connection pad formed to penetrate through the first insulating layer and formed at one side of the cavity.