Reflow Channel for Detecting Interconnect Continuity
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Solution Overview
Problem
Conventional methods face difficulties in detecting electrical interconnect failures between semiconductor die bumps and substrate conductive traces, as visual and X-ray inspections are inadequate for identifying non-contacting bumps and interconnects.
Innovation Solution
A method involving the formation of a conductive trace with an open channel on a substrate, where semiconductor die bumps or interconnect structures are aligned to flow into the channel during reflow, allowing for the detection of electrical continuity by the presence or absence of the bump material within the channel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If visual inspection or X-ray inspection is used to detect electrical interconnect failures, then the inspection process is simple and non-intrusive, but the detection capability is insufficient to identify non-contacting bumps and interconnect failures
Solution Approach 1:
The patent applies preliminary action by forming open channels in the conductive trace before the bumping process. These channels are pre-positioned to receive molten bump material during reflow, enabling subsequent visual detection of successful interconnect formation. This preliminary structuring allows simple inspection methods to achieve high detection capability.
Solution Approach 2:
The open channel acts as an intermediary element between the bump and the conductive trace. It provides a visible pathway that mediates the detection process, allowing inspection systems to observe whether molten bump material has successfully flowed into the conductive trace through the channel, thereby indicating proper interconnect formation.
2Reliability
If conventional bonding processes are used without open channels, then the manufacturing process is simpler, but electrical continuity cannot be reliably detected
Solution Approach 1:
The conductive trace is pre-formed with open channels before the bumping and reflow processes. This preliminary action creates a built-in detection mechanism that will capture molten bump material if proper contact is made, providing reliable verification of interconnect quality without adding complex post-bonding testing equipment.
Solution Approach 2:
The open channel creates a visual contrast or detectable feature when filled with bump material. This change in the channel's state (empty vs. filled) provides a reliable visual or X-ray detectable signal that indicates successful electrical interconnect formation, enhancing reliability through observable verification.
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 detection of electrical continuity or failure between semiconductor die and substrate interconnects, enhancing manufacturing quality control by visual or X-ray inspection.
Implementation Method 1
a portion of the first conductive cap flows into the first open channel
Data Source
AI summary
A semiconductor device has a semiconductor die with composite bump structures over a surface of the semiconductor die. A conductive layer is formed over the substrate. The conductive layer has a channel in an interconnect site of the conductive layer. The channel extends beyond a footprint of the composite bump structures. The semiconductor die is disposed over the substrate. The bump material of the composite bump structures is melted. The composite bump structures are pressed over the interconnect site of the conductive layer so that the melted bump material flows into the channel. Electrical continuity between the composite bump structures and conductive layer is detected by a presence of the bump material in the channel. No electrical continuity between the composite bump structures and conductive layer is detected by an absence of the bump material in the channel. The electrical continuity can be detected by visual inspection or X-ray.