Microstructured Surfaces for Disk Drive Head Suspension Adhesion

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Solution Overview

Problem

Existing disk drive integrated lead head suspensions face issues with interlayer adhesion, tool wear, vision system inspection characteristics, and mechanical, thermal, and aerodynamic performance, requiring improved manufacturing efficiency and performance.

Innovation Solution

The method involves creating microstructured surfaces on conductor, insulating, and cover layers using photolithography and subtractive/additive manufacturing processes, with features sized between 1 μm and 10 μm, to enhance adhesion, reduce tool wear, and improve aerodynamic performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If smooth surfaces are used on conductor and insulating layers, then manufacturing is simpler, but interlayer adhesion is poor

Engineering Contradiction:

Improveinterlayer adhesionVSAvoidsurface preparation complexity

Core Design Contradiction:

StrengthVSEase of manufacture

Solution Approach 1:

The patent applies microstructured surfaces with porous or textured topography on conductor and insulating layers. These microstructures increase surface area and provide mechanical interlocking between layers, significantly improving interlayer adhesion without requiring complex additional manufacturing steps beyond standard photolithography and etching processes.

Inventive Principle:

Principle #31Porous materials

2Ease of manufacture

If smooth surfaces are used on conductor layers, then manufacturing is easier, but tool wear increases

Engineering Contradiction:

Improveprocessing easeVSAvoidtool wear

Core Design Contradiction:

Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

Microstructured surfaces with controlled porosity and texture are implemented on conductor layers. These structures reduce tool wear during ultrasonic bonding and other joining processes by distributing contact stresses and reducing galling, while still allowing standard manufacturing processes to be used.

Inventive Principle:

Principle #31Porous materials

3Difficulty of detecting and measuring

If smooth surfaces are used on surfaces, then vision system inspection is simpler, but inspection characteristics are poor

Engineering Contradiction:

Improveinspection difficultyVSAvoidinspection characteristics

Core Design Contradiction:

Difficulty of detecting and measuringVSReliability

Solution Approach 1:

The microstructured surfaces provide enhanced light scattering and contrast characteristics that improve vision system inspection capabilities. The controlled porosity and surface texture create optical signatures that make defects more detectable while maintaining manageable inspection complexity through standard optical inspection systems.

Inventive Principle:

Principle #31Porous materials

4Productivity

If smooth surfaces are used on suspension components, then manufacturing is simpler, but aerodynamic performance is reduced

Engineering Contradiction:

Improvemanufacturing efficiencyVSAvoidaerodynamic drag

Core Design Contradiction:

ProductivityVSObject-generated harmful factors

Solution Approach 1:

Microstructured surfaces with porous or textured topography are applied to suspension components that interface with air flow. These structures reduce aerodynamic drag by controlling boundary layer transition and reducing pressure drag, while being integrated into standard manufacturing processes for the suspension components.

Inventive Principle:

Principle #31Porous materials

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 microstructured surfaces improve adhesion between layers, reduce tool wear, enhance mechanical properties, and increase aerodynamic performance, making the components more efficient and commercially viable.

Implementation Method 1

depositing a layer of photoimageable polymer having an associated set of process parameters including a minimum resolution and exposing the photoimageable polymer through a photomask

Methodology Applied

Scientific EffectPhotolithography: Photopolymerisation

Data Source

PatentUS10783908B1Microstructure patterned surfaces for integrated lead disk drive head suspensions

Publication Date: 2020.09.22 HUTCHINSON TECH INC

AI summary

Disk drive head suspension components having microstructured surfaces and a method for making the components. One embodiment of the method includes depositing a layer of photoimageable polymer having an associated set of process parameters including a minimum resolution and exposing the photoimageable polymer through a photomask having a microstructure-producing region with features below the minimum resolution for the photoimageable polymer. The exposed photoimageable polymer is developed to produce a layer of polymer having a thickness and a microstructured surface region with depressions that are less than the thickness of the polymer. In one embodiment the photomask has a microstructure-producing region with features sized and spaced between about 1 μm and 10 μm. Microstructured surfaces on structures such as flying leads, flying termination pads, cover coat layers and at insulating layer-trace interfaces and insulating layer-cover coat interfaces can be manufactured.