Power Module Insulating Film Layout for Edge Discharge Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Discharge occurs from the conductor layer of power modules due to incomplete coverage by sealing material or air bubbles, especially at the periphery edge and exposed edges, leading to potential electrical failures.
Innovation Solution
A power module design that covers the conductor layer's periphery edge and exposed areas with an insulating film, forms device openings matching the semiconductor shape, and includes a plating layer with a thickness equal to or less than the recessed portion depth, along with columnar connection terminals inserted into ceramic insulation cylinders.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If sealing material is applied to cover the conductor layer periphery edge, then discharge suppression is improved, but air bubbles form in the sealing material causing discharge
Solution Approach 1:
An insulating film is introduced as an intermediary layer between the conductor layer and the sealing material. This insulating film completely covers the periphery edge of the conductor layer, preventing air bubbles from forming in the sealing material while maintaining discharge suppression. The insulating film acts as a barrier that eliminates the harmful effect of air bubbles without compromising the sealing function.
Solution Approach 2:
The insulating film is applied in advance before the sealing material, creating a pre-prepared protective layer on the conductor layer periphery. This preliminary action ensures that when the sealing material is subsequently applied, air bubbles cannot form at the conductor layer interface, thus preventing discharge while maintaining reliable sealing.
2Reliability
If high-insulative resin is applied on the side surface of the conductor layer edge, then discharge suppression is improved, but the upper edge of the conductor layer remains exposed causing discharge
Solution Approach 1:
The solution transitions from one-dimensional side surface coating to two-dimensional top surface coverage. The insulating film is applied on the front surface of the conductor layer to completely cover the periphery edge including the upper edge, not just the side surface. This dimensional change ensures full coverage of the conductor layer edge, eliminating exposed areas that would cause discharge.
Solution Approach 2:
The insulating film provides localized insulation precisely where needed - on the front surface of the conductor layer at its periphery edge. This local quality enhancement targets the specific area where discharge occurs, ensuring complete coverage of the upper edge and periphery without affecting other areas of the conductor layer.
3Reliability
If the periphery edge of the conductor layer is completely covered by insulating film, then electric field concentration is suppressed, but the mounting region must be exposed
Solution Approach 1:
The insulating film structure is segmented into distinct functional zones: a device opening region where the mounting area is exposed for semiconductor device attachment, and a periphery coverage region where the conductor layer edge is completely covered. This segmentation allows the insulating film to simultaneously provide mounting access and discharge suppression, managing the complexity through functional division.
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
Suppresses discharge from the conductor layer by reducing electric field concentration at the periphery edges and non-filled spaces, effectively preventing electrical failures.
Implementation Method 1
concentration of an electric field in the recessed portion and the projecting portion at the periphery edge of the conductor layer is suppressed so that discharge from the recessed portion and the projecting portion can be suppressed
Data Source
AI summary
A conductor layer formed on a front surface of an insulating substrate occasionally discharges. A power module includes an insulating substrate, a semiconductor device mounted on the insulating substrate, a casing that houses the insulating substrate together with the semiconductor device, and a sealing material that seals the semiconductor device inside the casing. On the front surface of the insulating substrate, a conductor pattern is formed, the conductor pattern including at least a conductor layer where the semiconductor device is mounted, and on a front surface of the conductor layer, the front surface of the insulating substrate, together with a periphery edge of the conductor layer, is covered by an insulating film so as to expose a mounting region where the semiconductor device is mounted.