Multi-Die Package Layout for Higher Creepage Insulation
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Solution Overview
Problem
Semiconductor devices with multiple elements in a single package face challenges in maintaining insulation withstand voltage due to differences in power supply voltages between conduction paths, leading to potential electrical insulation failures.
Innovation Solution
A semiconductor device design featuring conductive support members with die pads and insulating elements, where semiconductor elements are mounted on separate die pads with different potentials, and a sealing resin covers them to ensure insulation and reduce electric field strength, enhancing the insulation withstand voltage between conduction paths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple semiconductor elements are mounted in one package with different power supply voltages, then device integration is improved, but insulation withstand voltage between conduction paths deteriorates
Solution Approach 1:
The conductive support member is divided into multiple die pads (first die pad, second die pad, third die pad) that are separated from each other. Each die pad is assigned to different semiconductor elements requiring different power supply voltages, creating isolated conduction paths. This segmentation prevents voltage interference between elements while maintaining integration within a single package.
Solution Approach 2:
An insulating element is introduced as an intermediary between the first die pad and the second die pad. This insulating element has a first insulating surface facing the first die pad and a second insulating surface facing the second die pad, providing electrical isolation between conduction paths with different potentials while allowing signal transmission through capacitive coupling.
2Area of stationary object
If die pads are placed close together for compact design, then package size is reduced, but insulation withstand voltage between die pads deteriorates
Solution Approach 1:
The insulating element extends in the thickness direction (vertical dimension) between the first die pad and the second die pad. By utilizing the vertical dimension rather than only the horizontal plane, the patent achieves effective electrical isolation without increasing the lateral footprint of the package, thus maintaining compact size while improving insulation withstand voltage.
Solution Approach 2:
The insulating element is constructed with multiple materials having different properties: a first insulating layer with first dielectric constant and a second insulating layer with second dielectric constant. This composite structure optimizes both insulation performance and signal transmission characteristics, allowing compact design with maintained reliability.
3Reliability
If insulating element thickness is increased to improve insulation, then insulation withstand voltage is improved, but signal transmission capability deteriorates
Solution Approach 1:
The insulating element comprises a first insulating layer and a second insulating layer with different dielectric constants. The first insulating layer (closer to the first die pad) has a first dielectric constant optimized for insulation withstand voltage, while the second insulating layer (closer to the second die pad) has a second dielectric constant optimized for signal transmission. This composite structure resolves the trade-off between insulation and signal transmission.
Solution Approach 2:
Different regions of the insulating element are assigned different dielectric properties: the first insulating layer provides high insulation strength where voltage stress is highest, while the second insulating layer provides optimal signal coupling where transmission efficiency is critical. This local optimization of material properties simultaneously improves both insulation withstand voltage and signal transmission capability.
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
The design effectively improves the insulation withstand voltage between circuits with different power supply voltages, reducing the risk of electrical failures and enhancing the reliability of semiconductor devices in applications like electric vehicles and home appliances.
Implementation Method 1
a sealing resin that covers the first die pad, the second die pad, the first semiconductor element, the second semiconductor element, and the insulating element and insulates the first die pad and the second die pad from each other
Implementation Method 2
an insulating element that conducts to the first semiconductor element and the second semiconductor element and insulates the first circuit and the second circuit from each other
Implementation Method 3
when viewed along the thickness direction, a peripheral edge of the first die pad has a first near-angle portion including a first end portion in a second direction orthogonal to both the thickness direction and the first direction, and wherein the first near-angle portion is separated from the second die pad in the first direction toward the first end portion in the second direction
Data Source
AI summary
A semiconductor device includes a first die pad, a second die pad, a first semiconductor element, a second semiconductor element, an insulating element, first terminals, second terminals, and a sealing resin. The sealing resin has a top surface, a bottom surface, and first to third side surfaces. The first terminals include a first edge terminal located closest to the third side surface. The second terminals include a second edge terminal located closest to the third side surface. A first creepage distance, which is a shortest distance from the first edge terminal to the second edge terminal along the first side surface, the third side surface, and the second side surface, is shorter than a second creepage distance, which is a shortest distance from the first edge terminal to the second edge terminal along the first side surface, the bottom surface, and the second side surface.