Electronic Package Pad Protection for Oxidation-Free Hybrid Bonding
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Solution Overview
Problem
In hybrid-bonded packages of different die sizes, the external contact pads on the smaller die are prone to oxidation due to direct exposure, leading to reduced bonding capability with conductive wires or bumps, and the formation of a continuous conductive layer is hindered by the morphology modifier's thickness, causing conductive layer discontinuity and planarization issues in photolithography.
Innovation Solution
A protection layer is electroplated over the external contact pads to prevent oxidation and facilitate conductive wire bonding, using electroless plating operations to avoid conductive layer discontinuity issues, which do not require a seed layer and can handle the morphology modifier's thickness, ensuring a uniform conductive layer formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a continuous conductive layer is formed over the entire surface of hybrid-bonded packages, then oxidation protection is improved, but the morphology modifier's thickness hinders formation causing conductive layer discontinuity
Solution Approach 1:
The patent applies local quality by selectively forming the conductive layer only on the contact pads rather than uniformly over the entire surface. The conductive layer is localized to specific regions where oxidation protection is needed (the contact pads), while avoiding areas where the morphology modifier creates thickness issues. This selective formation resolves the contradiction by providing oxidation protection precisely where required without being hindered by the morphology modifier's thickness in other areas.
2Manufacturing precision
If the morphology modifier's thickness is increased, then planarization in photolithography is improved, but conductive layer discontinuity occurs
Solution Approach 1:
The patent resolves this contradiction by applying local quality through selective conductive layer formation. Instead of requiring uniform planarization across the entire surface, the conductive layer is formed only on the contact pads where it is needed. This localized approach allows the morphology modifier to have varying thickness without causing conductive layer discontinuity, as the conductive layer formation is confined to regions where the substrate provides adequate planarization support.
3Strength
If external contact pads are exposed on smaller die, then bonding capability is improved, but oxidation resistance deteriorates
Solution Approach 1:
The patent applies preliminary action by forming the conductive layer on the contact pads before the bonding process. This pre-formed conductive layer serves as a protective barrier that prevents oxidation during subsequent handling and bonding operations. The contact pads are prepared with this protective layer in advance, ensuring both bonding capability is maintained and oxidation resistance is provided before the pads are exposed to the ambient environment.
Solution Approach 2:
The patent employs composite materials by creating a multi-layer structure on the contact pads consisting of the base pad material combined with the conductive layer. This composite structure provides both the bonding capability of the original pad material and the oxidation resistance of the conductive layer, effectively resolving the contradiction between maintaining bonding strength and providing oxidation protection.
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 protection layer effectively delays oxidation of I/O terminals, enhances bonding capability, and mitigates conductive layer discontinuity problems, improving the reliability of hybrid-bonded packages by ensuring a continuous and uniform conductive layer even with thicker morphology modifiers.
Implementation Method 1
A protection layer is electroplated over the external contact pads to prevent oxidation and facilitate conductive wire bonding
Implementation Method 2
using electroless plating operations to avoid conductive layer discontinuity issues, which do not require a seed layer and can handle the morphology modifier's thickness, ensuring a uniform conductive layer formation
Data Source
AI summary
An electronic structure, an electronic package structure and method of manufacturing an electronic device are provided. The electronic structure includes a carrier and a protection layer. The carrier includes a first pad, a second pad and a first dielectric layer. The first pad is at a side of the carrier and configured to bond with a conductive pad. The second pad is at the side of carrier and configured to electrically connect an exterior circuit. The first dielectric layer includes a first portion around the first pad and a second portion around the second pad, wherein a top surface of the first portion and a top surface of the second portion are substantially coplanar. The protection layer is on the second pad and covers the second pad.