Corrosion-Resistant Chip Package Adhesion via Sulfur-Free Compound
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Solution Overview
Problem
Copper and silver bond wires in chip packages are prone to corrosion, especially when exposed to elevated temperatures and moisture, leading to weakened adhesion and mechanical strength, which can result in electrical failures before the anticipated end of life, due to sulfur-induced corrosion reactions.
Innovation Solution
A chemical compound is used that is free from sulfur, selenium, or tellurium functional groups to enhance adhesion between metal contact structures and packaging materials, preventing corrosion by forming strong bonds without creating 3-dimensional reaction products that undergo creep corrosion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If copper or silver bond wires are used instead of gold wire, then cost is reduced, but corrosion resistance deteriorates
Solution Approach 1:
A chemical compound is introduced as an intermediary substance between the packaging material and the metal contact structure. This compound forms a protective interface that prevents direct contact between corrosive elements in the packaging material and the copper or silver bond wires, thereby providing corrosion resistance while maintaining cost advantages of non-gold materials.
Solution Approach 2:
The solution creates a composite structure consisting of the packaging material, the chemical compound layer, and the metal contact structure. This multi-layer composite provides both the mechanical function of packaging and the chemical protection needed to prevent corrosion of the metal interconnects.
2Strength
If sulfur-containing adhesion promoters are used to improve bonding, then adhesion strength is improved, but corrosion resistance deteriorates
Solution Approach 1:
The chemical compound changes the chemical composition parameters by being essentially free from sulfur, selenium, and tellurium functional groups. This parameter change maintains adhesion strength through alternative chemical mechanisms while eliminating the harmful corrosive reactions that would otherwise occur with traditional sulfur-containing adhesion promoters.
3Object-affected harmful factors
If noble metal coatings are applied to improve corrosion resistance, then corrosion protection is improved, but adhesion strength deteriorates
Solution Approach 1:
The chemical compound serves as an intermediary layer between the noble metal coating and the packaging material. It provides the adhesion function that the noble metal coating cannot provide alone, while the noble metal coating continues to provide corrosion protection. The compound chemically bonds to both surfaces, creating a functional bridge.
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 use of these chemical compounds significantly reduces or eliminates corrosion risks for bond wires and metal surfaces, even when coated with noble metals, thereby improving the reliability and longevity of chip packages by maintaining strong bonding and mechanical integrity.
Implementation Method 1
the chemical compound may be configured to improve an adhesion between the metal contact structure and the packaging material and/or between the chip metal surface and the packaging material
Implementation Method 2
The use of these chemical compounds significantly reduces or eliminates corrosion risks for bond wires and metal surfaces, even when coated with noble metals
Data Source
AI summary
In various embodiments, a chip package is provided. The chip package may include a chip comprising a chip metal surface, a metal contact structure electrically contacting the chip metal surface, a packaging material at least partially encapsulating the chip and the metal contact structure, and a chemical compound physically contacting the packaging material and at least one of the chip metal surface and the metal contact structure, wherein the chemical compound may be configured to improve an adhesion between the metal contact structure and the packaging material and/or between the chip metal surface and the packaging material, as compared with an adhesion in an arrangement without the chemical compound, wherein the chemical compound is essentially free from functional groups comprising sulfur, selenium or tellurium.