Semiconductor Device Thermal Isolation via Spacer Gaps

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In semiconductor devices, the heat generated by semiconductor chips conducts to control ICs via the main circuit board and printed circuit board, causing the control ICs to reach their guaranteed operating temperature before the semiconductor chips, thereby limiting the overall device's operating temperature and reliability.

Innovation Solution

A semiconductor device design featuring a semiconductor unit with a main circuit board and printed circuit board configuration, where the semiconductor unit is attached to a case with a gap between the printed circuit board and the case's bottom surface, reducing thermal interference by using spacers to isolate the printed circuit board from direct heat conduction, allowing for higher operating temperatures without damaging the control ICs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the printed circuit board is disposed adjacent to the main circuit board without spacing, then the device structure is compact and simple, but heat from the semiconductor chip conducts to the control ICs, limiting the operating temperature

Engineering Contradiction:
Improveoperating temperatureVSAvoiddevice structure
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent introduces a vertical spacing dimension between the printed circuit board and main circuit board by using spacers. Instead of arranging components in a flat plane, the solution creates a three-dimensional structure where the printed circuit board is positioned at a different vertical level, thereby reducing thermal conduction while maintaining compact horizontal footprint.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The spacers act as intermediary elements between the main circuit board and printed circuit board. These spacers physically separate the two boards and serve as thermal barriers, preventing direct heat conduction from the semiconductor chip to the control ICs while still allowing structural support and electrical connection.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If bonding material is used to attach the printed circuit board to the case, then the connection is strong and reliable, but manufacturing cost increases and the assembly process becomes more complex

Engineering Contradiction:
Improveconnection reliabilityVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent extracts and eliminates the bonding material from the assembly process. Instead of using adhesive or solder to attach the printed circuit board to the case, the design relies on the mechanical interference fit between the spacers and the case structure, thereby removing the need for additional bonding materials and simplifying manufacturing.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The spacers are designed to automatically provide both mechanical support and thermal isolation functions without requiring additional bonding materials. The self-aligning and self-supporting features of the spacer structure enable the assembly to be completed through simple insertion, making the system self-sufficient and eliminating complex bonding processes.

Inventive Principle:
Principle #25Self-service

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 enhances the operating temperature of the semiconductor device, improves reliability by reducing thermal interference with control ICs, and lowers manufacturing costs by eliminating the need for bonding materials and simplifying the assembly process.

Implementation Method 1

the printed circuit board being disposed in the control circuit area on the front surface of the bottom portion via a spacer, having a gap between the printed circuit board and the front surface of the bottom portion

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentUS11658151B2Semiconductor device
Publication Date: 2023.05.23 FUJI ELECTRIC CO LTD
  • US11658151B2 patent drawing
  • US11658151B2 patent drawing
  • US11658151B2 patent drawing

AI summary

A semiconductor device includes a semiconductor unit, a printed circuit board and a case, including a bottom portion formed in a plate-like shape and a side wall portion surrounding an outer periphery of the bottom portion of the case. The bottom portion has a main circuit area having an opening, and a control circuit area adjacent to the main circuit area in a plan view. The semiconductor unit is attached in the main circuit area from a rear surface of the bottom portion such that an insulating plate of the semiconductor unit is exposed to inside the case through the opening. The printed circuit board is disposed in the control circuit area on the front surface of the bottom portion via a spacer, having a gap between the printed circuit board and the front surface of the bottom portion.