Magnetic Recording Head Bonding Pads Solder Nonwettable Coating

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Solution Overview

Problem

Conventional magnetic recording heads face limitations in adjusting flying height due to the placement of bonding pads outside the head, leading to performance issues and a risk of short circuits due to the small size and crowded arrangement of pads.

Innovation Solution

The magnetic recording head features a trailing surface with a plurality of bonding pads, each coated with an electrically conductive solder nonwettable material to prevent short circuits and allow for additional pads, enhancing connectivity and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If bonding pads are placed outside the head to allow for additional pads, then connectivity and functionality are improved, but the risk of short circuits increases due to crowded arrangement and small size

Engineering Contradiction:

ImproveconnectivityVSAvoidshort circuit risk

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent introduces a solder nonwettable coating as an intermediary layer on the bonding pads. This coating prevents solder from spreading to adjacent pads during the bonding process, thereby eliminating the short circuit risk while allowing additional bonding pads to be placed in close proximity for enhanced connectivity and functionality.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the surface property parameter of the bonding pads by applying a solder nonwettable coating. This parameter change prevents solder wetting and spreading, enabling safe placement of multiple bonding pads in a crowded arrangement without short circuit risks, thus improving connectivity while maintaining reliability.

Inventive Principle:

Principle #35Parameter changes

2Volume of moving object

If the size of the head is reduced to improve disk drive miniaturization, then productivity and compactness are improved, but the area available for bonding pads is reduced, limiting functionality

Engineering Contradiction:

Improvehead sizeVSAvoidbonding pad capacity

Core Design Contradiction:

Volume of moving objectVSAdaptability or versatility

Solution Approach 1:

The patent resolves the space constraint by utilizing the vertical dimension through the solder nonwettable coating. This allows bonding pads to be placed in close proximity on the limited head surface area without causing short circuits, effectively increasing the bonding pad capacity within the reduced head volume.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Adaptability or versatility

If multiple bonding pads are arranged in a crowded space to maximize connectivity, then adaptability is improved, but manufacturing precision requirements increase due to the risk of short circuits

Engineering Contradiction:

Improvefunctional connectionsVSAvoidpad placement precision

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The solder nonwettable coating acts as a protective intermediary that eliminates the need for precise spacing between bonding pads. By preventing solder spread, it allows pads to be placed in a crowded arrangement without increasing manufacturing precision requirements, thus maximizing functional connections.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 configuration improves the reading and writing performance by preventing short circuits and allowing for more functional connections, thereby stabilizing the flying height and enhancing the overall disk drive unit's performance.

Implementation Method 1

Each of the bonding pads has an electrically conductive solder nonwettable coat coating on one side portion thereof to prevent short circuit between the adjacent bonding pads

Methodology Applied

Scientific EffectSolder nonwetting: Wetting

Implementation Method 2

When the disk drive device operates, a lift force is generated by the aerodynamic interaction between the magnetic recording head 103 and the spinning magnetic disks 101

Methodology Applied

Scientific EffectAerodynamic lift: Aerofoil

Data Source

PatentUS8320081B2Magnetic recording head, head gimbal assembly, and disk drive unit with the same

Publication Date: 2012.11.27 SAE MAGNETICS (HK) LTD

AI summary

A magnetic recording head includes a trailing surface and a plurality of bonding pads arranged on the trailing surface and in a row adapted for both bonding and testing. Each of the bonding pads has at least one side portion being coated with electrically conductive solder nonwettable coat to prevent short circuit between the adjacent bonding pads. The invention also discloses a head gimbal assembly with the magnetic recording head and a disk drive unit having such head gimbal assembly.