HAMR Head NFT Structure With Stable Material for Thermal Deformation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The challenge in achieving higher recording densities in magnetic recording media is the deformation of near-field transducers (NFTs) due to high temperatures, which limits the effectiveness of heat-assisted magnetic recording (HAMR) heads, as gold, commonly used for NFTs, has a low melting point and deforms under operational conditions.

Innovation Solution

A magnetic recording head design featuring a near-field transducer (NFT) recessed from the media-facing surface, with a thermal shunt and a stable material spaced from the NFT, composed of different materials, and optionally comprising multiple layers, to manage heat and prevent deformation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If gold is used for the near-field transducer (NFT) material to achieve high optical efficiency, then optical efficiency is improved, but the NFT deforms due to low melting point and high temperature operation

Engineering Contradiction:

Improveoptical efficiencyVSAvoidNFT thermal stability

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The NFT is divided into multiple functional layers: a gold layer for optical efficiency, a thermally stable material layer for structural integrity, and a thermal shunt layer for heat management. This segmentation allows each layer to perform its specific function without compromising the others.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The NFT is constructed as a composite structure combining gold (for optical efficiency) with thermally stable materials (for dimensional stability). This composite approach enables the NFT to simultaneously achieve high optical efficiency and thermal stability, resolving the contradiction between these two properties.

Inventive Principle:

Principle #40Composite materials

2Productivity

If the main pole size is decreased to achieve higher recording density, then recording density is improved, but the recording field becomes smaller and effectiveness is limited

Engineering Contradiction:

Improverecording densityVSAvoidrecording field strength

Core Design Contradiction:

ProductivityVSPower

Solution Approach 1:

The patent introduces a vertical dimension to heat delivery by positioning the laser source and waveguide above the main pole, allowing the main pole to remain small for high density while the laser delivers energy from a different spatial dimension to compensate for the reduced magnetic field strength.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The waveguide acts as an intermediary that couples the laser energy to the NFT and magnetic medium, enabling enhanced heating effect without requiring a larger main pole. The waveguide mediates between the laser source and the recording medium, allowing energy delivery that compensates for the reduced magnetic field.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Power

If the NFT temperature is increased to improve recording capability, then recording effectiveness is improved, but the NFT deforms due to exceeding operational temperature

Engineering Contradiction:

Improverecording effectivenessVSAvoidNFT dimensional stability

Core Design Contradiction:

PowerVSStability of the object's composition

Solution Approach 1:

Different regions of the NFT structure have different thermal properties: the gold layer provides optical absorption and heat generation, while the thermally stable material layer provides dimensional stability and heat dissipation pathways. This local differentiation of material properties allows the NFT to withstand high temperatures without deformation.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The thermal shunt layer converts the harmful effect of excessive heat into a beneficial cooling mechanism by providing a controlled thermal pathway that dissipates heat away from the critical NFT regions, allowing high-temperature operation without deformation.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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 enhances the thermal stability of NFTs, improving their lifetime and allowing for increased areal recording density by reducing thermal gradients and maintaining the optical near-field confinement.

Implementation Method 1

a thermal shunt disposed on the NFT

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

a stable material disposed between the NFT and the MFS... reducing thermal gradients

Methodology Applied

Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentUS20260088043A1Heat Assisted Magnetic Recording Head Comprising A Thermally Stable Material

Publication Date: 2026.03.26 WESTERN DIGITAL TECHNOLOGIES INC

AI summary

The present disclosure generally relates to a magnetic recording head for a magnetic media drive. The magnetic recording head comprises a main pole, a waveguide disposed adjacent to the main pole, a near field transducer (NFT) coupled between the main pole and the waveguide, the NFT being recessed from a media facing surface (MFS), a thermal shunt disposed on the NFT, the thermal shunt being recessed from the MFS, and a stable material disposed between the NFT and the MFS. The stable material is spaced from the thermal shunt, and the stable material and the NFT comprise different materials. In some embodiments, a surface of the stable material facing the waveguide is tapered. The stable material may comprise two or more layers, the two or more layers comprising different materials.