Semiconductor Tape Substrate Surface Roughness for Wire Bonding Reliability
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Solution Overview
Problem
The bleeding phenomenon during the heat treatment of die bond material in semiconductor device manufacturing leads to low molecular components oozing out and attaching to land pads, causing bonding failures in wire bonding, especially in substrate-type semiconductor devices with limited height and standardized external sizes, where the existing technologies fail to prevent the bleed from encroaching on land pads.
Innovation Solution
A method of manufacturing semiconductor devices involves modifying the surface roughness of the wiring board by creating a first region with a smaller average distance between local peaks between the land pad and the semiconductor chip, allowing the bleed to run along this region and preventing it from reaching the land pad, thereby stabilizing wire bonding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the die bond material is applied close to the land pad to maximize chip mounting area, then the productivity and space utilization are improved, but the bleeding phenomenon causes the low molecular component to encroach on the land pad, worsening the bonding reliability
Solution Approach 1:
The patent applies a surface treatment to create a first region with different surface properties (lower surface energy) between the land pad and the semiconductor chip. This local quality change causes the bleed to preferentially wet and spread on the treated region rather than on the land pad, resolving the contradiction by allowing close mounting while preventing contamination through differential surface wettability
Solution Approach 2:
The surface-treated first region acts as an intermediary barrier between the die bond material and the land pad. This intermediate layer with modified surface properties redirects the bleed flow away from the land pad, enabling close placement while maintaining bonding reliability through the mediating effect of the treated surface
2Adaptability or versatility
If the semiconductor device height is limited to meet standardized dimensions, then the adaptability to standardized applications is improved, but the bleed has a shorter distance to travel before reaching the land pad, worsening the manufacturing precision
Solution Approach 1:
The surface treatment creates a localized region with controlled wettability characteristics that actively manages bleed flow direction. This local quality modification compensates for the reduced travel distance caused by standardized height constraints, maintaining manufacturing precision through surface property control rather than relying solely on geometric distance
3Manufacturing precision
If a groove structure is added to prevent die bond material flow-out, then the manufacturing precision is improved, but the device complexity and fabrication difficulty increase
Solution Approach 1:
Instead of adding geometric structures like grooves, the patent changes the surface energy parameter of the substrate through surface treatment. This parameter change creates a virtual barrier that controls bleed flow through wettability differences, achieving manufacturing precision while avoiding the structural complexity and fabrication difficulty associated with physical grooves
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
This approach effectively prevents the bleed from attaching to the land pad, reducing the likelihood of bonding failures and improving the quality of semiconductor devices by utilizing capillary action to direct the bleed away from critical bonding areas.
Implementation Method 1
allowing the bleed to run along this region and preventing it from reaching the land pad, thereby stabilizing wire bonding
Data Source
AI summary
To provide a semiconductor device having an improved quality. The semiconductor device of the invention has a tape substrate having a semiconductor chip thereon, a plurality of land pads placed around the semiconductor chip, a plurality of wires for electrically coupling the electrode pad of the semiconductor chip to the land pad, and a plurality of terminal portions provided on the lower surface of the tape substrate. An average distance between local peaks of the surface roughness of a first region between the land pad of the tape substrate and the semiconductor chip is smaller than an average distance of local peaks of the surface roughness of a second region between the land pad of the tape substrate and the first region.