Semiconductor Package Pillar Structure for Encapsulant Thinning
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Solution Overview
Problem
In semiconductor packages, thinning the encapsulant covering the semiconductor die through grinding can cause the encapsulant to fall off, exposing the die and compromising the package's integrity.
Innovation Solution
A semiconductor package structure that includes a semiconductor die and at least one pillar structure with a recess portion, where the pillar structure is electrically connected to the conductive pad of the semiconductor die and has a higher conductivity than the conductive pad, and an encapsulant that covers the die and a portion of the pillar structure, with the upper pad portion of the pillar structure being embedded in the encapsulant.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If the encapsulant thickness is reduced through grinding to decrease package thickness, then the package thickness is reduced, but the encapsulant may fall off from the semiconductor die
Solution Approach 1:
The pillar structure is formed on the semiconductor die before the encapsulant is applied. This preliminary structure provides a mechanical anchor that prevents the encapsulant from falling off during subsequent thinning operations, allowing the encapsulant to be ground down to the desired thickness without compromising adhesion
Solution Approach 2:
The pillar structure creates a localized reinforcement zone at specific positions on the semiconductor die where the encapsulant needs to be anchored. This localized approach provides enhanced adhesion only where needed, while allowing the rest of the encapsulant to be thinned uniformly
2Length of stationary object
If the encapsulant is thinned to a lower value to reduce package thickness, then the package thickness is reduced, but the semiconductor die becomes exposed
Solution Approach 1:
The pillar structure is formed in advance with a height that extends beyond the final desired encapsulant thickness. This preliminary structure serves as a depth reference during the grinding process, allowing precise control of the encapsulant thickness to prevent die exposure while achieving the target thickness
Solution Approach 2:
The pillar structure changes the physical parameters of the encapsulant-die interface by providing a stepped profile. This creates distinct height levels that serve as mechanical stops during grinding, enabling precise thickness control and preventing the encapsulant from being ground too thin and exposing the die
Data Source
AI summary
A semiconductor package structure includes a semiconductor die and at least one pillar structure. The semiconductor die has an upper surface and includes at least one conductive pad disposed adjacent to the upper surface. The pillar structure is electrically connected to the conductive pad of the semiconductor die, and defines a recess portion recessed from a side surface of the pillar structure. A conductivity of the pillar structure is greater than a conductivity of the conductive pad.