Head Suspension Laser Correction Intersecting Lines

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Solution Overview

Problem

Existing methods for correcting the load and attitude angle of head suspensions in hard disk drives face challenges with precision and accuracy, especially when repeated corrections are necessary, due to residual thermal stress from initial laser beam irradiation, leading to correction errors.

Innovation Solution

A method involving the use of a laser beam to draw intersecting straight lines on the head suspension, with each line forming a predetermined angle with the previous one, to minimize overlapping areas and maintain precision across multiple corrections, thereby avoiding thermal stress concentration and correction errors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a laser beam is used to correct the head suspension, then the correction precision is improved, but residual thermal stress causes errors in repeated corrections

Engineering Contradiction:

Improvecorrection precisionVSAvoidrepeated correction accuracy

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The correction process is divided into multiple sequential laser irradiation steps, where each step addresses a specific portion of the required correction. The total correction is segmented into manageable increments, allowing the system to achieve high precision through cumulative small adjustments rather than a single large correction that would create excessive thermal stress.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The laser beam is applied periodically with controlled intervals between irradiation steps. This periodic action allows thermal stress to dissipate between corrections while maintaining the cumulative correction effect, thereby preserving accuracy in repeated corrections without accumulating harmful residual thermal stress.

Inventive Principle:

Principle #19Periodic action

2Ease of manufacture

If mechanical displacement or bending methods are used to correct the head suspension, then the correction process is simpler, but the time required and device complexity increase

Engineering Contradiction:

Improvecorrection process simplicityVSAvoidcorrection time

Core Design Contradiction:

Ease of manufactureVSLoss of time

Solution Approach 1:

The patent replaces mechanical displacement and bending methods with laser beam irradiation. Instead of using physical jigs, fixtures, or mechanical tools to manually adjust the head suspension, a laser beam is used to induce controlled thermal deformation, achieving correction without complex mechanical systems or time-consuming manual operations.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Adaptability or versatility

If the same area is irradiated multiple times with a laser beam, then the correction can be repeated, but thermal stress concentration causes correction errors

Engineering Contradiction:

Improverepeated correction capabilityVSAvoidcorrection accuracy

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent applies different irradiation conditions to different local areas of the head suspension. By controlling the laser beam parameters (such as power, duration, and position) according to the specific requirements of each region, the system achieves accurate repeated corrections without concentrating excessive thermal stress in any single area, thereby maintaining precision throughout the correction process.

Inventive Principle:

Principle #3Local quality

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 approach allows for precise correction of the load and attitude angle of head suspensions even after multiple iterations, ensuring accurate alignment and reducing errors associated with thermal stress, thus improving the reliability and precision of the correction process.

Implementation Method 1

a technique of irradiating a head suspension with a laser beam, to thermally deform the head suspension and thereby correct the load and attitude angle of the head suspension

Methodology Applied

Scientific EffectLaser heating: Laser

Implementation Method 2

irradiating the irradiation area with a laser beam, to draw a pattern of predetermined length and shape with the laser beam in the irradiation area and thereby correct the load and attitude angle of the head suspension. This technique bends an objective part of the head suspension by drawing a specific irradiation pattern in the part with a laser beam

Methodology Applied

Scientific EffectThermal deformation: Thermal Expansion

Data Source

PatentUS10109306B2Method of correcting head suspension, method of manufacturing head suspension, head suspension and method of processing thin plate

Publication Date: 2018.10.23 NHK SPRING CO LTD

AI summary

A method corrects a head suspension by irradiating an objective part of the head suspension with a laser beam before or after mounting a read/write head on the head suspension. The method can precisely correct the head suspension even when correcting the head suspension a plurality of times. The method includes drawing, with the laser beam, a straight line of predetermined length on the objective part and repeating this process a plurality of times in such a way that the direction of a straight line drawn this time crosses the direction of a straight line drawn last time.