Semiconductor Module Asymmetric Bonding Inspection
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Solution Overview
Problem
Existing stacked semiconductor modules face challenges in reliably judging the quality of bonding between upper and lower connection terminals due to similar shapes and sizes, making it difficult to distinguish between bonded and unbonded states during non-destructive inspections, particularly in transmissive inspections like X-ray or ultrasonic scans.
Innovation Solution
The semiconductor module design features a pad with an opening section on the substrate that has a different planar shape from the connection terminals, allowing the shape to protrude beyond the terminals during inspection, enabling clear differentiation between bonded and unbonded states through transmissive inspection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the same shape and size connection terminals are used for both upper and lower layers, then the manufacturing process is simplified and components are standardized, but it becomes extremely difficult to distinguish bonded locations from unbonded locations during transmissive inspection
Solution Approach 1:
The invention applies asymmetry by making the lower connection terminal have a different shape (larger diameter) compared to the upper connection terminal. This shape difference allows transmissive inspection to clearly distinguish between bonded and unbonded states: when bonded, the inspection beam passes through both terminals showing similar sizes; when unbonded, the size difference is visible, enabling reliable quality assessment without complicating the manufacturing process.
2Productivity
If electrical inspection is used to judge connection quality, then the inspection process is fast and automated, but it cannot reliably distinguish between temporary electrical contact and sound physical bonding
Solution Approach 1:
The invention introduces a shape difference as an intermediary visual marker that mediates between the fast automated electrical inspection and the need for reliable bonding quality judgment. The transmissive inspection method using X-ray or ultrasonic waves provides a non-contact visual indicator of bonding status through the shape difference, complementing electrical inspection and enabling reliable quality assessment without sacrificing inspection speed.
3Reliability
If transmissive inspection is used to verify bonding, then non-contact inspection is achieved, but visual judgment requires very long time and automatic judgment cannot set threshold values
Solution Approach 1:
The invention uses shape difference as a visual indicator that creates distinct imaging characteristics during transmissive inspection. The larger lower terminal and smaller upper terminal produce clearly distinguishable images when unbonded versus when bonded, enabling both rapid visual judgment and automated threshold-based detection, thereby reducing inspection time while maintaining non-contact reliability.
Data Source
AI summary
A pad (15) is provided on a surface connecting a first substrate (11) of a lower layer module with an upper layer module, the pad is partially covered by an insulating film (20) to form an opening section (3) exposing the pad (15), a first connection terminal (2) is formed on the lower surface of the first substrate (11) of the lower layer module, the planar shape of the opening section (3) is different from the planar shape of the first connection terminal (2), the outer shape of the opening section (3) is larger than the first connection terminal (2), and in a transmissive inspection from above, the shape of the lower end of a second connection terminal (30) spreading in the opening section (3) is not concealed by the other terminal. This configuration enables easy and reliable determination of whether bonding sections are satisfactory by a non-destructive inspection.