Semiconductor Die Testing With Temporary Pads
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Solution Overview
Problem
Conventional KGD testing methods damage semiconductor die pads, rendering them unsuitable for subsequent solder bump connections and reducing the available area for components due to the need for sacrificial pads or contactless testing limitations.
Innovation Solution
Applying a temporary pad to the semiconductor die pad for testing, which is softer than the probe, allowing for non-damaging contact and subsequent removal to enable solder bump application, thus preserving pad functionality and area for connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a probe contacts a semiconductor die pad for testing, then testing can be performed, but the pad is damaged and becomes unsuitable for subsequent solder bump connections
Solution Approach 1:
A temporary pad made of softer material is introduced as an intermediary between the probe and the conductive pad. The probe contacts the temporary pad instead of the conductive pad, preventing damage to the conductive pad while enabling testing. The temporary pad absorbs the mechanical stress and damage from probe contact.
Solution Approach 2:
The temporary pad is designed as a disposable, sacrificial element that is removed after testing. It serves its purpose during testing and is then discarded, allowing the conductive pad to remain intact for subsequent solder bump connections. This follows the principle of using a cheap, temporary solution to protect a valuable permanent component.
2Manufacturing precision
If a sacrificial pad is used for testing, then pad damage is avoided on functional pads, but the available area for components is reduced
Solution Approach 1:
The temporary pad is discarded after serving its testing purpose, and the original conductive pad is recovered for its intended function with solder bumps. This allows the full area of the conductive pad to be utilized without permanent sacrifice, maximizing the usable die area while still enabling testing.
3Manufacturing precision
If contactless testing is used, then pad damage is avoided, but testing power is limited and complexity increases
Solution Approach 1:
The temporary pad serves as a simple mechanical intermediary that enables conventional contact-based testing without the complexity of contactless testing systems. It provides a straightforward solution that maintains probe-based testing simplicity while avoiding pad damage, without requiring antennas, wireless communication protocols, or other complex contactless testing infrastructure.
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
Enables reliable KGD testing without damaging the conductive pads, allowing for increased pad usage and extending probe life by protecting both the pad and probe from damage during testing.
Implementation Method 1
Applying a temporary pad to the semiconductor die pad for testing, which is softer than the probe, allowing for non-damaging contact
Data Source
AI summary
A method includes applying a temporary pad to a conductive pad of a semiconductor die. After testing the semiconductor die, the temporary pad is removed from the conductive pad.