Semiconductor Device Notched Substrate Adhesion
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Solution Overview
Problem
Conventional semiconductor devices face challenges in achieving high reliability in the attachment between the insulating substrate and the case, particularly under thermal stress, due to limited adhesive surface area and susceptibility to cracking.
Innovation Solution
The semiconductor device incorporates an insulating substrate with front-side and back-side notched portions on its side surface, creating a recess portion in the case for adhesive placement, which allows for increased adhesive coverage and improved thermal stress resistance by distributing the adhesive agent both above and below a central peak, enhancing the adhesion reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the insulating substrate is attached to the case using conventional methods with limited adhesive surface area, then the attachment structure is simple, but the reliability under thermal stress is insufficient due to susceptibility to cracking
Solution Approach 1:
The insulating substrate is segmented with notched portions that divide the substrate surface into multiple regions. This segmentation increases the adhesive surface area by creating additional interfaces between the substrate and case, allowing the adhesive to distribute thermal stress more effectively across multiple zones rather than a single continuous surface.
Solution Approach 2:
The notched portions extend in the thickness direction of the substrate, adding a vertical dimension to the adhesive interface. This dimensional extension creates overlapping adhesive zones that provide redundant bonding paths, improving reliability without significantly increasing lateral complexity.
2Reliability
If the adhesive surface area is increased to improve thermal stress resistance, then the reliability is enhanced, but the device complexity increases due to additional notched portions
Solution Approach 1:
The notched portions are strategically positioned at specific locations on the substrate where thermal stress concentration is most likely to occur. This localized approach concentrates the adhesive reinforcement where it is most needed, improving thermal stress resistance without adding unnecessary complexity to the entire substrate structure.
Solution Approach 2:
The notched portions create an excessive adhesive surface area beyond what would be minimally required, providing a margin of safety for thermal stress resistance. This partial redundancy ensures that even if some adhesive bonds degrade, sufficient bonding remains to maintain reliability.
3Reliability
If the insulating substrate is securely attached to the case, then the reliability is improved, but the manufacturing precision requirements increase due to the notched portion dimensions
Solution Approach 1:
The notched portions are designed with specific dimensional parameters (depth, width, spacing) that optimize the balance between attachment security and manufacturing feasibility. By carefully controlling these parameters, the design achieves reliable attachment while remaining compatible with standard manufacturing tolerances.
Data Source
AI summary
Provided is a semiconductor device including an insulating substrate on which a semiconductor chip is mounted and a case that is adhered to the insulating substrate. The case includes a recess portion that is provided with an adhesive agent and into which a front surface side of the insulating substrate is inserted. The insulating substrate includes, in a side surface along a thickness direction, a front-side notched portion formed on the front surface side and a back-side notched portion formed on a back surface side. Length from a peak located between the front-side notched portion and the back-side notched portion to the front surface in the thickness direction is greater than or equal to 30% of an less than or equal to 70% of length of the recess portion of the case in the thickness direction.