Resistive Film Lapping Detection Element for Magnetic Head Substrates
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for detecting the amount of lapping in thin film magnetic heads require large spacing portions for pad arrangement, limiting the number of sliders that can be produced from a single wafer and complicating the reduction of slider size, which hinders cost reduction and high-density integration.
Innovation Solution
A lapping detection element with a resistive film exposed on the lapping surface and connected to a single pad on a non-lapping surface, where one end of the resistive film is grounded to the substrate, reducing the need for two pads and allowing for a smaller pad area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If two pads are provided on spacing portions for measuring resistance of resistive films, then resistance measurement can be performed, but the area required for pad arrangement increases, limiting the number of sliders that can be produced from a single wafer
Solution Approach 1:
The invention extracts one of the two necessary electrical connection points from the pad structure and relocates it to the substrate ground potential. This allows resistance measurement to be performed with only one pad on the spacing portion, effectively halving the pad arrangement area requirement while maintaining full measurement functionality.
Solution Approach 2:
The substrate serves as an intermediary electrical connection, providing ground potential directly to the resistive film without requiring a separate pad. This mediator approach eliminates the need for the second pad, reducing spacing portion area while enabling complete resistance measurement capability.
2Measurement precision
If large spacing portions are provided for pad arrangement, then resistance measurement is enabled, but the number of sliders that can be produced from a single wafer decreases
Solution Approach 1:
By extracting one electrical connection point from the pad structure and assigning it to the substrate ground, the invention reduces the spacing portion area required for pad arrangement. This directly increases the number of sliders that can be produced from a single wafer while preserving lapping amount detection capability through resistance measurement.
Solution Approach 2:
The substrate is given the additional function of providing electrical ground connection for the resistive film, beyond its structural role. This multi-functionality eliminates the need for dedicated pad structures for grounding, thereby reducing spacing requirements and increasing slider density per wafer.
3Productivity
If slider size is reduced to increase density, then more sliders can be produced, but the area available for pad arrangement in spacing portions becomes insufficient
Solution Approach 1:
The invention extracts the ground connection function from the pad structure and assigns it to the substrate. This reduces the minimum spacing portion area required, enabling the use of smaller slider sizes and higher density arrangements while maintaining sufficient area for the reduced pad structures.
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 enables a significant reduction in the area required for pad arrangement, allowing for more sliders to be produced from a single wafer and improving lapping accuracy, especially in smaller slider sizes like femto-size sliders.
Implementation Method 1
the electric resistance of the resistive films changes as the cross section of the resistive films becomes small
Data Source
AI summary
An element for detecting an amount of lapping of a stacked structure that includes a substrate and a magnetic field detecting sensor is provided. The element comprises: a resistive film that is arranged on a lapping surface of the stacked structure, the resistive film being exposed at the lapping surface together with the magnetic field detecting sensor, wherein the resistive film has a resistance value that varies depending on the amount of lapping; and a pad for measuring the resistance value, wherein the pad is formed on a surface of the stacked structure, the surface being other than the lapping surface, and wherein the pad is electrically connected to one end of the resistive film. Another end of the resistive film is electrically connected to the substrate.