Pre-formed Conductive Bumps on Bonding Pads for Probing
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Solution Overview
Problem
Probing of microelectronic bonding pads during testing often leaves marks or gouges, which can weaken the bond between the bonding pad and the conductive bump, leading to suboptimal intermetallic compound formation and reduced bonding strength.
Innovation Solution
Forming conductive bumps on bonding pads prior to probing and wire-bonding connections, with an insulating layer on the conductive bumps to protect and support them, ensuring a pristine surface for bonding and minimizing the impact of probe marks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If probing is performed on bonding pads during testing, then functionality and reliability can be tested, but marks or gouges are left on the bonding pad surface which weaken the bond between the bonding pad and conductive bump
Solution Approach 1:
The conductive bump is formed on the bonding pad surface before probing occurs. This preliminary formation of the bump creates a protective structure that prevents direct contact between the probe and the bonding pad surface, thereby avoiding marks or gouges while still allowing testing to proceed on the bump structure itself
Solution Approach 2:
The conductive bump acts as an intermediary element between the bonding pad and the probe. Instead of the probe directly contacting the bonding pad, it contacts the bump which serves as a mediator, transferring the testing function while protecting the bonding pad surface from damage
2Strength
If conductive bumps are formed on bonding pads before probing, then bond strength is improved by bonding to pristine surfaces, but additional manufacturing steps are required
Solution Approach 1:
The formation of the conductive bump is merged with the wire-bonding process itself. The bump is created as part of the standard wire-bonding operation rather than as a separate preprocessing step, thereby improving bond strength without significantly increasing manufacturing process complexity
Data Source
AI summary
Apparatuses including pre-forming conductive bumps on bonding pads for probing and wire-bonding connections and methods for making the same are disclosed. A method may include providing a microelectronic die including a conductive bump formed on a bonding pad, and an insulating layer formed on at least a portion of a surface of the conductive bump, and probing the conductive bump to test the microelectronic die. Other embodiments are also described.