Glide head assembly and method therefor

A test device for testing moving surfaces on a rotating disk to determine a presence of asperities thereon, comprising:

• (a) a support structure;
• (b) a rotary drive operative to rotate a disk thereon relative to said support structure;
• (c) a first glide head assembly supported on said support structure, said first glide head assembly including:
• (1) a flexure extending along a longitudinal axis and including a proximal end portion secured to said support structure and a distal end portion positioned in proximity to one said moving surfaces;
• (2) a slider secured to said distal end portion;
• (3) a piezoelectric transducer disposed in a region between said slider and said distal end position so that said transducer is sandwiched therebetween, said transducer configured as a flat plate and including an exposed free end portion which projects outwardly from the region between said distal end portion and said slider to define a cantilever having a selected length, said transducer operative to vibrate in response to the presence of an asperity moving past said slider to generate an electronic signal;
• (d) signal processing electronics operative to process the electronic signal;
• and
• (e) electrical interconnects establishing electrical communication between said transducer and said signal processing electronics.

A method of producing a glide head assembly for use in a system that is operative to test moving surfaces to determine a presence of asperities thereon, wherein the system includes signal processing circuity operative to process an electronic signal generated in response to the presence of an asperity and wherein said glide head assembly includes a flexure having a proximal end portion adapted to be secured to a support structure and a distal end portion adapted to be positioned in proximity to one of the moving surfaces and including a slider disposed on the distal end portion of said flexure and operative to respond to the presence of the asperity, comprising the steps of:

• (a) providing a piezoelectric transducer that, when secured to the distal end portion of said flexure, will vibrate with a dominant mode of vibration relative to all vibrational modes of said flexure and said slider thereby to produce a signal having a dominant signal component at a selected dominant frequency;
• (b) securing said transducer to the distal end portion of said flexure;
• (c) electrically interconnecting said transducer to said signal processing circuitry such that said signal processing circuitry receives said signal;
• and
• (d) filtering said signal to suppress components thereof that are at frequencies not within a selected bandwidth range that includes the dominant frequency.