How to Use Air-Gaps to Insulate High-Voltage Semiconductor Chips
A design for semiconductor chips that uses empty air-filled trenches to provide better electrical insulation for high-voltage transistors without needing complex filling materials.
Original patent title: “USRE48450E1 - Semiconductor device and method for manufacturing the same”
A design for semiconductor chips that uses empty air-filled trenches to provide better electrical insulation for high-voltage transistors without needing complex filling materials. Granted to Renesas Electronics Corp in 2021 with 13 claims.
Key facts
Coverage
What does this patent actually cover?
This patent describes a way to isolate high-voltage transistors on a chip by surrounding them with a trench containing an air-gap. Instead of filling the entire trench with a solid insulating material, which can be difficult and expensive to do perfectly, the process uses an insulating film to cover the device and the trench in a way that leaves an empty space inside. This air-gap acts as a highly effective electrical barrier. The design ensures that the side of the trench at the bottom of the air-gap touches the semiconductor substrate directly, creating a robust isolation structure that prevents electrical leakage between components.
The gap
What does this patent NOT cover?
- Does not cover semiconductor devices that use solid dielectric materials to completely fill the isolation trenches.
- Does not cover designs where the air-gap does not extend through the specific semiconductor layers defined in the manufacturing process.
- Does not cover transistors that are not surrounded by a trench in a plan view.
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
What made this novel
The innovation lies in using the deposition process of the insulating film to intentionally create an air-gap that is trapped within the trench, turning a potential manufacturing defect into a functional, high-performance insulation feature.
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Where you've seen this
Real-world examples
Power management integrated circuits (PMICs)
High-voltage lateral MOS transistors in automotive control units
Why it matters
The bigger picture
In power electronics, managing high voltages on a tiny chip is a major challenge. If transistors are not properly isolated, they can interfere with each other or break down. This patent offers a simpler, more cost-effective way to achieve high-voltage isolation by leveraging the natural insulating properties of air, which helps manufacturers produce more reliable power-management chips for automotive and industrial applications.
Filed
March 13, 2018
Granted
February 23, 2021
Market context
Who's building on this
Companies in this space
Renesas Electronics, a major player in the automotive semiconductor market, holds this patent. They continue to focus on power-efficient designs for electric vehicles and industrial automation, where this type of high-voltage isolation is critical.
Market impact
This patent provides a specific manufacturing pathway for high-voltage power devices. By simplifying the isolation process, it helps manufacturers reduce production costs and improve the breakdown voltage capabilities of their chips, which is essential for the ongoing shift toward higher-efficiency power electronics in the automotive sector.
Claim 1 — Plain English
What this patent covers
This patent describes a way to isolate high-voltage transistors on a chip by surrounding them with a trench containing an air-gap. Instead of filling the entire trench with a solid insulating material, which can be difficult and expensive to do perfectly, the process uses an insulating film to cover the device and the trench in a way that leaves an empty space inside. This air-gap acts as a highly effective electrical barrier. The design ensures that the side of the trench at the bottom of the air-gap touches the semiconductor substrate directly, creating a robust isolation structure that prevents electrical leakage between components.
The clever bit
The innovation lies in using the deposition process of the insulating film to intentionally create an air-gap that is trapped within the trench, turning a potential manufacturing defect into a functional, high-performance insulation feature.
What it does not cover
- Does not cover semiconductor devices that use solid dielectric materials to completely fill the isolation trenches.
- Does not cover designs where the air-gap does not extend through the specific semiconductor layers defined in the manufacturing process.
- Does not cover transistors that are not surrounded by a trench in a plan view.
Patent timeline
Application submitted to the patent office
Application published, typically 18 months after filing
Patent officially issued
PatentBrief Score
Impact Score
Limited data
Citation count
0/40
No citations yet
Claim breadth
9/20
Moderate scope
Recency
10/20
Granted 5–10 years ago
Assignee scale
0/20
Independent or smaller assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
Heuristic Value Estimate
What this patent might be worth
$26K – $84K
Midpoint $53K · 11.7 yr remaining · industry ×1.4
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
The original legal language
Original claims
13 claims as filed with the patent office.
Concepts involved
Citations
Patent lineage
Cite this patent
Yanagi, S., Otsu, Y., Nitta, T., ONISHI, K., Morii, K., & Kimura, H. (2021). How to Use Air-Gaps to Insulate High-Voltage Semiconductor Chips (U.S. Patent No. RE48,450). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/RE48450/android-operating-system
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
Embed
Add this patent to your site
Drop this plain-English patent card into any blog post or article — free, no signup. It always links back to the full breakdown here.
<div data-patentlens-widget data-patent-number="USRE48450"></div> <script src="https://patentbrief.org/embed.js" async></script>
Stay in the loop
Get a weekly digest of new patents.
One email per week. No spam. Unsubscribe anytime.
Keep exploring
Related patents you should know
US 4683195 · 1987
How to Make Billions of Copies of a DNA Segment
This patent describes the Polymerase Chain Reaction (PCR), a method to rapidly create many copies of a specific piece of DNA or RNA, enabling its detection and analysis.
Cetus Corp
US 8697359 · 2014
How to Edit Genes in Human Cells Using an Engineered CRISPR System
This patent describes an engineered CRISPR-Cas9 system for precisely cutting DNA in eukaryotic cells to change how genes work, opening the door for gene editing in complex organisms.
Massachusetts Institute of Technology
US 7657849 · 2010
How the iPhone's Slide-to-Unlock Gesture Works
Apple's 2010 patent describes unlocking a device by dragging a specific graphical image across the touchscreen along a predefined path, a gesture that became iconic with the original iPhone.
Apple Inc
US 4733665 · 1988
How Doctors Implant a Permanent Stent Using a Balloon
This patent describes the method for placing a permanent, expandable wire mesh tube inside a blood vessel or other body tube using a balloon-tipped catheter to widen it and keep it open.
Expandable Grafts Partnership
US 4965188 · 1990
How to Make Many Copies of a DNA Piece with Heat
This patent describes the Polymerase Chain Reaction (PCR) method, a technique to make millions of copies of a specific DNA segment using a heat-resistant enzyme and repeated temperature changes.
Cetus Corp
US 4235871 · 1980
How to Encapsulate Active Materials in Lipid Bubbles Efficiently
This patent describes a method for trapping biologically active substances inside tiny, multi-layered fat bubbles called liposomes, using a specific water-in-oil emulsion and gel-forming process to improve how much material gets captured.
Individual
More to explore
More in Semiconductors & Chips
US 5563422 · 1996 · Nichia Chemical Industries Ltd
How Nichia Created the First Practical Blue LED Electrodes
US 10373050 · 2019 · Qualcomm Inc
How to Make AI Run Faster on Smaller Computer Chips
US 2981877 · 1961 · Fairchild Semiconductor Corp
How Robert Noyce Invented the Modern Integrated Circuit
US 2569347 · 1951 · Bell Telephone Laboratories Inc
The Invention of the Junction Transistor
New to patents?
Common Questions
Frequently Asked Questions
What does How to Use Air-Gaps to Insulate High-Voltage Semiconductor Chips cover?
A design for semiconductor chips that uses empty air-filled trenches to provide better electrical insulation for high-voltage transistors without needing complex filling materials.
Who owns patent US RE48450?
Renesas Electronics Corp owns this patent, granted in 2021.
When does this patent expire?
This patent is expected to expire on February 23, 2041, when the invention enters the public domain.
What problem does this patent solve?
In power electronics, managing high voltages on a tiny chip is a major challenge. If transistors are not properly isolated, they can interfere with each other or break down. This patent offers a simpler, more cost-effective way to achieve high-voltage isolation by leveraging the natural insulating properties of air, which helps manufacturers produce more reliable power-management chips for automotive and industrial applications.
What does this patent NOT cover?
Does not cover semiconductor devices that use solid dielectric materials to completely fill the isolation trenches.
Patent monitoring