Resist Member Placement for Insulation in Semiconductor Devices
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional semiconductor devices face issues with insulation breakdown due to short insulation distances between conductive patterns and solder extrusions, leading to increased size and reduced reliability, as well as voids in solder joints that reduce thermal conductivity.
Innovation Solution
The semiconductor device incorporates resist members formed in a stripe shape on the metal base plate, strategically positioned to prevent solder flow-out and ensure adequate insulation distances between conductive patterns and solder, thereby reducing creepage distances and minimizing device size while maintaining reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the amount of solder is increased to prevent voids and ensure adequate coverage, then the reliability of the solder joint is improved, but the insulation distance between conductive patterns and solder extrusions is reduced, leading to insulation breakdown
Solution Approach 1:
A resist member is introduced as an intermediary substance between the solder and the conductive pattern. This resist member prevents direct contact between the solder extrusion and the conductive pattern, thereby maintaining insulation even when solder protrudes. The resist member acts as a barrier that allows the solder to fulfill its joining function while preventing the harmful effect of electrical conduction to the conductive pattern.
2Reliability
If the insulation distance is increased to prevent insulation breakdown, then the reliability is improved, but the substrate size must be enlarged, increasing the device size
Solution Approach 1:
The solution moves from a two-dimensional planar insulation approach to a three-dimensional approach by adding the resist member vertically between the solder and conductive pattern. Instead of increasing the horizontal insulation distance on the substrate surface, the resist member provides insulation in the vertical dimension, allowing shorter creepage distances on the substrate while maintaining adequate insulation protection.
3Reliability
If the creepage distance is increased to maintain insulation, then the insulation reliability is improved, but the substrate area must be increased, leading to larger device size
Solution Approach 1:
The resist member serves as a mediator that allows the conductive pattern to be positioned closer to the solder extrusion without compromising insulation reliability. By providing the necessary insulation function vertically, the resist member enables reduction of the horizontal creepage distance on the substrate, thereby reducing the overall substrate area 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 configuration effectively reduces creepage distances, minimizes semiconductor device size, and enhances insulation reliability by preventing solder flow-out and ensuring sufficient insulation distances, thus addressing the challenges of insulation breakdown and thermal conductivity.
Implementation Method 1
a metal plate 12 disposed on a rear surface of the electrical insulating board 11, and a base plate 15 having a front surface to which the metal plate 12 in the substrate 14 is joined by solder 16
Data Source
AI summary
In a semiconductor device, the marginal edge of a resist member on the side closer to a substrate is between first and third positions on a metal base plate. The third position is directly under an outer side surface of a metal plate. The first position is outside the third position and is away from a second position on the metal base plate directly under an outer side surface of the electrical insulating board, by a distance calculated by dividing “the height from a principal surface of the metal base plate to the front surface of the electrical insulating board” by “the tangent of the contact angle of solder created by the marginal edge stopping solder flow”. This makes it possible to ensure sufficient insulation distances between conductive patterns and the solder and to reduce creepage distances of the conductive patterns over the electrical insulating board.