Power Module Ceramic Substrate Integration for Thermal Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current circuit boards for power supply and control circuits in power conversion portions are not compatible for integration, as they either lack heat dissipation efficiency or structural integrity, leading to increased size and potential malfunctions due to thermal issues and stress from thermal expansion differences.
Innovation Solution
A power module with a highly heat-conductive ceramic substrate and a glass ceramic multilayer substrate integrated together, where the power wiring line is on the ceramic substrate and the control element is on the multilayer substrate, with direct contact and no resin layer, allowing efficient heat dissipation and suppression of heat transfer to the control circuit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a resin substrate is used for the circuit board, then the circuit board is easy to manufacture and inexpensive, but the heat dissipation efficiency is insufficient and the substrate cannot withstand high temperatures
Solution Approach 1:
The patent employs a composite substrate structure combining glass ceramic material with metal wiring layers. The glass ceramic provides high temperature resistance and appropriate thermal conductivity, while the metal layers provide electrical conductivity and additional heat dissipation pathways, resolving the contradiction between ease of manufacture and heat dissipation efficiency
Solution Approach 2:
The patent changes the material parameters of the substrate by using glass ceramic instead of resin, which has higher temperature resistance and different thermal conductivity characteristics. This parameter change enables the substrate to withstand high temperatures while maintaining manufacturability through established ceramic processing techniques
2Reliability
If a glass ceramic substrate is used for the circuit board, then the firing temperature is low and signal transmission loss is reduced, but the thermal conductivity is insufficient for efficient heat dissipation
Solution Approach 1:
The patent creates a composite structure where glass ceramic serves as the base substrate providing low firing temperature and low signal loss, while embedded metal wiring layers and thermal conduction paths provide enhanced thermal conductivity for heat dissipation from power elements
Solution Approach 2:
The patent segments the substrate into functional regions: glass ceramic areas for low-loss signal transmission and metal-rich areas for heat dissipation. This segmentation allows each region to optimize its performance for its specific function while being part of an integrated circuit board
3Volume of moving object
If power supply circuit and control circuit are integrated on the same circuit board, then the size of the power conversion portion is reduced, but the heat from power elements may affect the control elements
Solution Approach 1:
The patent applies local quality by creating different thermal zones on the same circuit board: areas with high thermal conductivity materials near power elements for heat dissipation, and areas with lower thermal conductivity near control elements to protect them from heat. This localized material property variation enables compact integration while preventing thermal interference
Solution Approach 2:
The patent uses thermal barriers and heat sinks as intermediary elements between power elements and control elements. These intermediaries manage heat flow, allowing close integration of power and control circuits while preventing direct thermal coupling that would cause interference
4Temperature
If a DCB substrate is used for the power supply circuit, then the heat dissipation capability is improved, but the wiring lines cannot be made thin and fine wiring cannot be formed
Solution Approach 1:
The patent combines DCB (direct copper bonding) technology for heat dissipation with modern thin-film wiring techniques. The DCB substrate provides excellent thermal conductivity through thick copper layers bonded to the ceramic, while separate thin-film wiring layers are deposited on the surface for fine, precise routing of control signals
Solution Approach 2:
The patent separates the thermal conduction function into the thickness dimension (using thick copper bonding layers in the DCB structure) and the wiring function into the surface plane (using thin-film deposited patterns). This dimensional separation allows independent optimization of heat dissipation and wiring precision
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 enables a compact, efficient heat dissipation system that maintains the reliability of both power and control circuits, even at high temperatures, by using a highly heat-conductive ceramic substrate with a glass ceramic multilayer substrate to manage thermal conductivity and expansion differences.
Implementation Method 1
a highly heat-conductive ceramic substrate composed of a ceramic material having higher thermal conductivity than a glass ceramic contained in the glass ceramic multilayer substrate
Implementation Method 2
a glass ceramic multilayer substrate disposed directly on the highly heat-conductive ceramic substrate... having lower thermal conductivity than the highly heat-conductive ceramic substrate
Implementation Method 3
the glass ceramic multilayer substrate is disposed directly on the highly heat-conductive ceramic substrate... allowing efficient heat dissipation and suppression of heat transfer to the control circuit
Data Source
Figure 1~2(d)
Figure 3(a)~4
Figure 5
AI summary
A power module according to the present invention includes a power wiring line provided with a power element, a glass ceramic multilayer substrate provided with a control element to control the power element, and a highly heat-conductive ceramic substrate composed of a ceramic material having higher thermal conductivity than a glass ceramic contained in the glass ceramic multilayer substrate, wherein the power wiring line is disposed on the highly heat-conductive ceramic substrate, and the glass ceramic multilayer substrate is disposed directly on the highly heat-conductive ceramic substrate.