Semiconductor Package Sacrificial Pad Structure for Probe Reliability
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Solution Overview
Problem
The semiconductor industry faces challenges in achieving robust reliability and high yield in semiconductor package manufacturing due to issues with protrusions and smeared conductive materials during the packaging process, which can lead to manufacturing costs and reliability concerns.
Innovation Solution
The process involves forming aluminum pads with sacrificial pads for circuit probe testing, followed by encapsulation in a dielectric bond layer, singulation, and subsequent processing steps that include planarization and etching to remove smeared portions and reduce protrusion height, thereby improving the reliability and yield of the semiconductor package.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If circuit probe testing is performed on aluminum pads, then known good dies can be identified, but protrusions and smeared conductive materials are formed causing reliability issues
Solution Approach 1:
A sacrificial pad made of soft metal (e.g., copper) is introduced as an intermediary element during circuit probe testing. The probe contacts the sacrificial pad instead of the aluminum pad, preventing direct mechanical damage to the aluminum pad. The sacrificial pad absorbs the probing stress through deformation, eliminating protrusions and smeared conductive materials while maintaining die identification functionality.
2Reliability
If protrusions are removed through planarization and etching, then short circuits and parasitic capacitance are minimized, but manufacturing complexity increases
Solution Approach 1:
The sacrificial pad is designed to be consumed during the probing process itself, performing the function of protecting the aluminum pad before any damage occurs. This preliminary protective action eliminates the need for subsequent complex planarization and etching steps to remove protrusions, as the sacrificial pad deformation is intentional and functional rather than defective.
Data Source
AI summary
In an embodiment, a method includes attaching a first package component to a first carrier, the first package component comprising: an aluminum pad disposed adjacent to a substrate; a sacrificial pad disposed adjacent to the substrate, the sacrificial pad comprising a major surface opposite the substrate, a protrusion of the sacrificial pad extending from the major surface; and a dielectric bond layer disposed around the aluminum pad and the sacrificial pad; attaching a second carrier to the first package component and the first carrier, the first package component being interposed between the first carrier and the second carrier; removing the first carrier; planarizing the dielectric bond layer to comprise a top surface being coplanar with the protrusion; and etching a portion of the protrusion.