Multilayer film piezoelectric element of micro-actuator for hard disk and method for making same

A piezoelectric element and micro-actuator technology, which is applied in the manufacture/assembly of electrical components, piezoelectric/electrostrictive devices, piezoelectric/electrostrictive/magnetostrictive devices, etc., and can solve the existing technology of position accuracy It is difficult to realize and other problems, and achieves the effect of structural innovation, convenient processing and excellent performance.

CN1571181AInactive Publication Date: 2005-01-26TSINGHUA UNIV
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2005-01-26
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention relates to a multifilm piezoelectric element in harddisk micro-actuator and its preparing method. It makes piezoelectric ceramic film by casting method or web printing technique, etc., and makes medium electrode layer by web printing technique, etc. It adopts Ag / Pd electrode and PMN-PZT material to realize low- temperature coburn (reducing from >1300 deg.C to 1030-1190 deg.C). The invention increases the free-end displacement of magnetic head cantilever installed with piezoelectric micro-actuator to >=0.80 mum and resonance frequency to >15KHz (at the condition of external voltage <=40V) to make the micro-actuator have the characters of excellent displacement / voltage sensitivity, resonance frequency, driving force, etc., thus applied to accurate addressing and path location of secondary micro- actuator of a computer harddisk double-stage servo system. It can be widely applied to other technical fields of micro-actuation and position control.
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Description

technical field

[0001] The invention relates to a multilayer film piezoelectric element in a novel microactuator and a preparation method thereof, belonging to the technical field of microelectromechanical systems. Background technique

[0002] With the rapid development of information technology, the density of magnetic storage is increasing year by year. In recent years, the maximum areal density (MAD) of hard disks is increasing at an annual rate of 100%, and it is expected that the track pitch will drop below 0.25 μm after 5 years. Therefore, the track positioning accuracy must be less than 10% of the track pitch (0.025μm), and the servo bandwidth must be >3kHz to meet the track pitch requirements. Obviously, such a high position accuracy is difficult to achieve with the existing technology, and it is necessary to rely on the micro-actuator for the second-level control. In recent years, the application of dual-stage servo system (DSA) in hard disks has attracted wid...

Examples

Embodiment 1

[0030] First configure the PMN-PZT casting slurry, that is, Pb 3 o 4 , ZrO 2 、Ti 3 o 4 and MgNb 2 o 6 The powder (with a particle size of 0.8-2 μm) and the oily binder polyvinyl butyral (PVB) powder are mixed evenly in proportion (70:30), and the organic solvent isobutanol and n-propyl acetate (the mass ratio of which is 9 / 90), stir well. Ball mill on a planetary ball mill for 4 hours at a speed of 500 r / min. After ball milling, the viscosity can be vacuumed accordingly, and finally a uniformly dispersed and stable slurry can be obtained. Then put the slurry in the hopper on the tape casting machine for casting, that is, cast four layers of PMN-PZT ceramic green film with a thickness of 25 μm on the steel template and screen print three layers of 70Ag-30Pd electrodes with a thickness of 4 μm layer slurry. After cutting the multilayer ceramic green body into a number of multilayer ceramic element green bodies according to the element size requirements, put pure Al toge...

Embodiment 2

[0032] First configure the PMN-PZT casting slurry, that is, Pb 3 o 4 , ZrO 2 、Ti 3 o 4 and MgNb 2 o 6The powder (with a particle size of 0.8-2 μm) and the oily binder dioctyl phthalate (DOP) powder are mixed evenly according to the mass ratio (100:14.5), and the organic solvent isobutanol and n-propyl acetate are added at the same time, and stirred Uniform, wherein the mass ratio of solute powder, binder powder and solvent is (100:14.5:99), while the mass ratio of isobutanol and n-propyl acetate is (9 / 90). Then ball mill on a planetary ball mill for 4 hours at a speed of 500r / min. After ball milling, the viscosity can be vacuumed accordingly, and finally a uniformly dispersed and stable slurry can be obtained. Then put the slurry on a screen printing machine for brush plating, that is, brush-plate eight layers of PMN-PZT ceramic blank film with a thickness of 5 μm and brush-plate seven layers of Ag electrode layer slurry with a thickness of 2 μm on the steel template. ...

Embodiment 3

[0034] First configure the PMN-PZT casting slurry, and then ball mill it on a planetary ball mill for 4 hours at a speed of 500r / min. After ball milling, the viscosity can be vacuumed accordingly, and finally a uniformly dispersed and stable slurry can be obtained. Then put the slurry in the hopper on the tape casting machine for casting, that is, cast two layers of PMN-PZT ceramic green film with a thickness of 50 μm on the steel template and screen print a layer of 45Ag-55Pd electrode with a thickness of 8 μm layer slurry. After cutting the multilayer ceramic green body into a number of multilayer ceramic element green bodies according to the element size requirements, put pure Al together 2 o 3 The plastic is slowly discharged in the crucible, and then sealed and sintered (the specific temperature is 1130°C), low-temperature co-fired and annealed at 850°C to obtain a multilayer film element. After the two surfaces and two sides of the component are covered with external ...