Glass Substrate Insulating Film Structure for Dicing Crack Resistance
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Solution Overview
Problem
Glass substrates used in semiconductor devices face stress-related cracking issues during the dicing process due to resin shrinkage, which can compromise the reliability of components like CMOS image sensors.
Innovation Solution
A semiconductor device design featuring continuous insulating films on the glass substrate's surfaces and side surfaces, along with a frame and through-hole structures, to distribute stress uniformly and protect the glass substrate from cracking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If vias and wiring layers are formed in a glass substrate in panel state and then divided into individual pieces, then manufacturing efficiency is improved, but stress concentration occurs at the end portions causing cracks
Solution Approach 1:
The insulating film is formed to extend beyond the end portions of the glass substrate before dicing occurs. This preliminary protective action ensures that when the substrate is later divided into individual pieces, the insulating film already exists to protect against stress concentration and cracking at the newly created end surfaces.
Solution Approach 2:
The insulating film acts as a cushioning layer that absorbs and distributes the residual stress from the cured resin before the dicing process occurs. By having this protective layer in place beforehand, the harmful stress concentration that would normally cause cracks at the end portions is mitigated.
2Reliability
If resin is used for wiring layers and cured, then electrical insulation is improved, but resin shrinkage causes large stress leading to cracks
Solution Approach 1:
The insulating film serves as an intermediary layer between the glass substrate and the resin wiring layers. This intermediate layer helps distribute the stress generated by resin shrinkage during curing, preventing the concentration of stress at the end portions of the glass substrate that would lead to cracking.
Solution Approach 2:
The insulating film changes the stress distribution parameters by providing a compliant interface that can accommodate the volume changes associated with resin curing. This allows the resin to be cured with proper electrical insulation properties while the insulating film absorbs the mechanical stress.
3Reliability
If the glass substrate is protected with insulating films extending beyond end portions, then crack resistance is improved, but material usage increases
Solution Approach 1:
The insulating film is designed with local quality by extending specifically beyond the end portions of the glass substrate where stress concentration and cracking are most likely to occur. Rather than uniformly increasing material throughout the entire substrate, the additional material is strategically placed only where it provides the most protective benefit.
Data Source
AI summary
Provided is a semiconductor device capable of maintaining the flatness of a glass substrate and sufficiently protecting an end portion of the glass substrate. The semiconductor device includes a glass substrate including a first surface, a second surface opposite to the first surface, and a first side surface between the first surface and the second surface. The semiconductor device further includes wirings provided provided on the first and second surfaces, a first insulating film that covers the first surface, a second insulating film that covers the second surface, and a third insulating film that covers the first side surface, the third insulating film being continuous with at least one of the first or second insulating films.