Semiconductor Package Recessed Conductive Post Adhesion
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Solution Overview
Problem
The existing methods for manufacturing semiconductor packages, which involve exposing conductive posts encapsulated by an encapsulant, often result in rough surfaces leading to cracks or delamination between the circuit layer and the conductive post, and residual particles from grinding operations can cause adhesion issues.
Innovation Solution
A semiconductor package design that includes a first dielectric layer with a recessed conductive post and a sacrificial element, where the encapsulant and sacrificial element are removed using sandblasting to create a rough surface, enhancing adhesion and preventing delamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the encapsulant is removed by a grinding technique to expose the conductive post, then the conductive post is exposed for electrical connection, but the roughness of the conductive post surface is relatively small which leads to cracks or delamination between the circuit layer and the conductive post
Solution Approach 1:
A roughening layer is formed on the conductive post surface before the encapsulant is removed. This preliminary action ensures that when the circuit layer is subsequently formed, it adheres to a roughened surface that provides mechanical interlocking, preventing cracks and delamination while the encapsulant is still present during manufacturing
Solution Approach 2:
The roughening layer is applied specifically to the surface of the conductive post that will contact the circuit layer, while leaving other portions of the conductive post smooth. This localized roughening provides enhanced adhesion exactly where needed without affecting other functional areas of the conductive post
2Manufacturing precision
If the encapsulant is removed by a grinding technique, then the conductive post is exposed, but particles of the conductive post remain on the encapsulant and particles of the encapsulant remain on the conductive post
Solution Approach 1:
A sacrificial layer is introduced as an intermediary between the encapsulant and the conductive post. During removal, the sacrificial layer is selectively removed along with the encapsulant, acting as a mediator that protects the conductive post from direct contact with grinding tools and prevents particle generation and adhesion issues
Solution Approach 2:
The harmful particle generation and adhesion problems are extracted by introducing a sacrificial layer that can be selectively removed. This layer takes on the role of being the sacrificial element that protects the conductive post surface from contamination during the encapsulant removal process
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method effectively prevents cracks and delamination by creating a rough surface on the dielectric layer, improving adhesion between the circuit layer and the conductive post, while also removing residual particles, thus enhancing the reliability of the semiconductor package.
Implementation Method 1
removing a top portion of the encapsulant and the sacrificial element to expose the conductive post such that a top surface of a remaining portion of the encapsulant is rough
Data Source
AI summary
A semiconductor package includes a dielectric layer and a conductive post. The dielectric layer has a first surface and a second surface opposite to the first surface. The conductive post is disposed in the dielectric layer. The conductive post includes a first portion and a second portion disposed above the first portion. The second portion of the conductive post is recessed from the second surface of the dielectric layer.