Semiconductor Device Stress Relief Coating Groove Adhesion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing resin-sealed semiconductor devices face issues with peeling between the mold resin and ceramic substrate, particularly due to stress, and existing solutions like grooves or protrusions in metal base plates are complex or require extensive rework for non-metallic structures.
Innovation Solution
A semiconductor device design featuring an insulating substrate with a circuit pattern and cooling body, where a coating film with lower hardness than the resin alleviates stress, and at least one of the circuit pattern or cooling body includes grooves or protrusions to enhance adhesion and prevent peeling, without the need for full-coating inspection and rework.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a groove or protrusion is provided in the metal base plate to enhance adhesion to resin, then adhesion strength is improved, but the metal base plate has a complicated shape and this technique is not applicable to structures without metal base plate
Solution Approach 1:
The patent applies local quality by providing grooves or protrusions only in specific regions where adhesion is needed, rather than modifying the entire base plate structure. The coating film is applied selectively to portions requiring stress relief, while other portions maintain direct contact between the resin and the circuit pattern or cooling body for mechanical interlocking.
2Reliability
If a coating film is provided over the entire region of the interface with mold resin to alleviate stress, then stress is reduced, but inspection of uncoated portions and rework are required resulting in difficult manufacturing
Solution Approach 1:
The patent applies partial action by providing the coating film only in specific regions where stress relief is needed, rather than coating the entire interface. The coating is applied to portions of the insulating substrate that require stress management, while other portions are left uncoated to allow direct resin contact for adhesion.
3Temperature
If the insulating substrate has higher thermal conductivity than the coating film, then heat dissipation is improved, but the coating film must be applied over thermally conductive surfaces requiring precise coating control
Solution Approach 1:
The patent applies local quality by providing the coating film only in specific regions where thermal management and stress relief are needed, rather than coating the entire insulating substrate. This selective coating approach maintains thermal conductivity in critical areas while providing stress relief and adhesion where required.
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 design effectively prevents peeling, improves long-term reliability, and simplifies manufacturing by reducing the need for extensive coating inspections and rework, while maintaining high thermal conductivity and heat dissipation properties.
Implementation Method 1
the coating film has lower hardness than the resin and alleviates stress applied from the resin to the insulating substrate
Implementation Method 2
the insulating substrate has higher thermal conductivity than the coating film
Implementation Method 3
at least one of the circuit pattern and the cooling body includes a groove or a protrusion contacting the resin without being covered with the coating film
Data Source
AI summary
A circuit pattern is bonded to a top surface of a ceramic substrate. A cooling body is bonded to an undersurface of the ceramic substrate. An IGBT and a FWD are provided on the circuit pattern. A coating film covers a junction between the ceramic substrate and the circuit pattern, and a junction between the ceramic substrate and the cooling body. A mold resin seals the ceramic substrate, the circuit pattern, the IGBT, the FWD, the cooling body, and the coating film etc. The ceramic substrate has higher thermal conductivity than the coating film. The coating film has lower hardness than the mold resin and alleviates stress applied from the mold resin to the ceramic substrate. The circuit pattern and the cooling body includes a groove contacting the mold resin without being covered with the coating film.