Gold Bump Buffer for Wire Bonding Die Protection
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Solution Overview
Problem
The existing wire bonding structures face damage to the die and bond pad during the bonding process due to heat generated when forming ball bonds, leading to reduced yield and potential structural and functional issues.
Innovation Solution
A gold bump is positioned between the bond pad and the ball bond to act as a buffer, preventing direct contact and reducing the risk of damage, while also using a capillary to form the ball bond and bonding wire, improving the efficiency of the bonding process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If copper ball bond and bonding wire are used to reduce manufacturing cost, then manufacturing cost is reduced, but heat damage to die and bond pad occurs during bonding process
Solution Approach 1:
A gold bump is introduced as an intermediary element between the copper ball bond and the bond pad. The gold bump serves as a protective mediator that absorbs heat and prevents direct thermal damage to the bond pad and die during the bonding process, while still allowing electrical and mechanical connectivity to be maintained.
Solution Approach 2:
The gold bump is pre-formed on the bond pad before the copper ball bond is attached. This beforehand cushioning structure prepares the bonding interface in advance, creating a heat-resistant buffer zone that protects vulnerable components from thermal damage during subsequent bonding operations.
2Device complexity
If ball bond is formed directly on bond pad to simplify structure, then device complexity is reduced, but damage to die and bond pad occurs
Solution Approach 1:
The gold bump acts as an intermediary bonding interface between the ball bond and bond pad. This additional element increases structural reliability by providing a more robust bonding surface and heat sink, thereby improving yield despite the slight increase in structural complexity.
3Reliability
If distance between ball bond and bond pad is increased to improve yield, then reliability is improved, but manufacturing process complexity increases
Solution Approach 1:
Instead of increasing the horizontal distance between ball bond and bond pad, the solution adds a vertical dimension by introducing the gold bump as an intermediate layer. This dimensional change achieves the effect of separation and protection without requiring larger lateral spacing, thus avoiding increased manufacturing complexity.
Data Source
AI summary
The present invention relates to a wire bonding structure, and more particularly to a manufacturing method for said wire bonding structure. The wire bonding structure comprises a die that connects with a lead via a bonding wire. At least one bond pad is positioned on an active surface of the die, and a gold bump is provided on the bond pad; furthermore, a ball bond can be positioned upon the gold bump. The bond pad and the gold bump can separate the ball bond and the die, which can avoid damaging the die during the bonding process.