Disk Drive Gimbal Zig-Zag Traces Residual Stress

Solution Overview

Problem

The existing disk drive suspensions face issues with creep due to the low creep resistance of pure copper used in additive manufacturing processes, leading to longer settling times and variations in pitch and roll static attitudes, which affect manufacturing throughput and precision.

Innovation Solution

The implementation of a gimbal with zig-zag shaped traces in the conducting layer, which provides stress relief and reduces residual stress, thereby minimizing creep and maintaining the adjusted pitch static attitude over time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If pure copper is used in additive manufacturing processes, then manufacturing capability and design flexibility are improved, but creep resistance deteriorates leading to longer settling times and variations in pitch and roll static attitudes

Engineering Contradiction:

Improveadditive manufacturing capabilityVSAvoidcreep resistance

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The conducting layer is segmented into multiple traces with zig-zag patterns rather than a single continuous trace. This segmentation creates multiple independent paths that collectively provide stress relief while maintaining electrical connectivity, allowing the use of pure copper in additive manufacturing while reducing creep effects.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The trace geometry is changed from a straight line to a zig-zag pattern with specific dimensions (width, spacing, and angle). This parameter change in the trace configuration provides stress relief and reduces residual stress, thereby minimizing creep and maintaining static attitude stability over time.

Inventive Principle:

Principle #35Parameter changes

2Device complexity

If traditional straight traces are used in the conducting layer, then manufacturing simplicity is maintained, but residual stress increases leading to greater creep and pitch static attitude variations

Engineering Contradiction:

Improvetrace geometry complexityVSAvoidpitch static attitude consistency

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The trace geometry is changed from a straight line to a zig-zag pattern with specific dimensions (width, spacing, and angle). This parameter change in the trace configuration provides stress relief and reduces residual stress, thereby minimizing creep and maintaining static attitude stability over time.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The trace design incorporates a zig-zag pattern that adds geometric complexity in the planar dimension, creating multiple segments that provide stress relief pathways. This dimensional change in trace configuration reduces residual stress while maintaining electrical functionality.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Reliability

If zig-zag shaped traces are implemented, then stress relief and creep reduction are achieved, but trace manufacturing complexity increases

Engineering Contradiction:

Improvecreep resistanceVSAvoidtrace pattern complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The trace geometry is changed from a straight line to a zig-zag pattern with specific dimensions (width, spacing, and angle). This parameter change in the trace configuration provides stress relief and reduces residual stress, thereby minimizing creep and maintaining static attitude stability over time.

Inventive Principle:

Principle #35Parameter changes

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 zig-zag shaped traces enhance the mechanical stability of the gimbal by reducing creep, ensuring consistent pitch and roll static attitudes, and improving manufacturing precision without significantly impacting electrical performance.

Implementation Method 1

The zig-zag shape is configured to provide a level of stress relief to the conducting material that is included in the trace

Methodology Applied

Scientific EffectStress relief: Stress Relaxation

Implementation Method 2

the low creep resistance of pure copper used in additive manufacturing processes, leading to longer settling times

Methodology Applied

Scientific EffectCreep: Creep

Data Source

PatentUS7957100B1Disk drive gimbal having reduced residual stress and related method of manufacture

Publication Date: 2011.06.07 MAGNECOMP CORP

AI summary

A disk drive gimbal, an apparatus, and a related method of manufacture, wherein the disk drive gimbal includes a strut having a trace with a zig-zag shape. The trace is made from conducting material, and the zig-zag shape is configured to provide a level of stress relief to the conducting material that is included in the trace.