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US 7,030,628 B2Granted
Method and device for evaluating charge potential
AssigneeAlps Electric Co., Ltd.
InventorSadao Kawata
Life of this patent
Estimating the term…
Abstract
In a charge potential evaluation device, the measured value of a potential difference Vc in a charged plate monitor (CPM) is converted into a potential difference Vh between the conductive pattern and load beam in a head gimbal assembly (HGA), using the following expression (1), V h = d h ɛ h · ɛ c d c V c [ Expression 1 ] where dh denotes the distance between the conductive pattern and the load beam in the HGA, dc denotes the distance between the conductive plate and a grounded surface in the CPM, εh denotes the relative permittivity of an insulating foundation layer in the HGA, and εc denotes the relative permittivity of the region between the conductive plate and the grounded surface in the CPM.
Claims21
A charge potential evaluation method comprising:
- (a) acquiring, in an object to be measured that has a first conductor and a second conductor opposed to each other with a dielectric therebetween, a value of a relative permittivity of the dielectric and a distance between the first and second conductors;
- (b) measuring, in a predetermined atmosphere, a potential Vc of a conductive plate facing a grounded surface with a predetermined distance therebetween;
- and
- (c) converting a potential difference Vh between the first conductor and the second conductor in the object to be measured in the atmosphere, using the following expression (1),
- V
- h
- =
- d
- h
- ɛ
- h
- ·
- ɛ
- c
- d
- c
-
- V
- c
- [
- Expression
-
-
- 1
- ]
- where dh denotes the distance between the first conductor and the second conductor in the object to be measured, dc denotes the distance between the conductive plate and the grounded surface, εh denotes a relative permittivity of the dielectric in the object to be measured, and εc denotes the relative permittivity between the conductive plate and the grounded surfaces,
- wherein ions are produced by an ionizer to form an atmosphere in which the conductive plate and the grounded surface are to be disposed.
24 more elements
A charge potential evaluation device comprising:
- a grounded surface;
- a conductive plate facing the grounded surface with a predetermined distance therebetween;
- potential measuring means for measuring a potential Vc of the conductive plate;
- input means for inputting, in an object to be measured that has a first conductor and a second conductor opposed to each other with a dielectric therebetween, a value of a relative permittivity of the dielectric and a distance between the first and second conductors;
- conversion means for converting a potential difference Vh between the first conductor and the second conductor in the object to be measured in the same atmosphere as that of the conductive plate, by calculating the following expression (2) based on the measured value of a potential Vc of the conductive plate,
- V
- h
- =
- d
- h
- ɛ
- h
- ·
- ɛ
- c
- d
- c
-
- V
- c
- [
- Expression
-
-
- 2
- ]
- where dh denotes a distance between the first conductor and the second conductor in the object to be measured, dc denotes the distance between the conductive plate and the grounded surface, εh denotes the relative permittivity of the dielectric in the object to be measured, and εc denotes a relative permittivity between the conductive plate and the grounded surface;
- and
- an ionizer that produces ions to provide a predetermined atmosphere for the conductive plate and the grounded surface.
26 more elements
A charge potential evaluation device comprising:
- a grounded surface;
- a conductive plate facing the grounded surface with a predetermined distance therebetween;
- potential measuring means for measuring a potential Vc of the conductive plate;
- and
- an ionizer that produces ions to provide a predetermined atmosphere for the conductive plate and the grounded surface,
- wherein the distance dc between the conductive plate and the grounded surface and a relative permittivity εc between the conductive plate and the grounded surface is set, or made adjustable so that a distance dh between a first conductor and a second conductor in an object to be measured that has the first and second conductors opposed to each other with a dielectric therebetween, a relative permittivity εh of the dielectric in the object to be measured, the distance dc, and the relative permittivity εc satisfy the relationship shown by the following expression (3),
- d
- h
- ɛ
- h
- ·
- ɛ
- c
- d
- c
- =
- 1
- ,
- [
- Expression
-
-
- 3
- ]
- and wherein the potential Vc can thereby be obtained as a potential difference Vh between the first conductor and the second conductor in the object to be measured.
22 more elements
A charge potential evaluation method comprising:
- (a) acquiring, in an object to be measured that has a first conductor and a second conductor opposed to each other with a dielectric therebetween, a value of a relative permittivity of the dielectric and a distance between the first and second conductors;
- (b) measuring, in a predetermined atmosphere, a potential Vc of a conductive plate facing a grounded surface with a predetermined distance therebetween;
- and
- (c) converting a potential difference Vh between the first conductor and the second conductor in the object to be measured in the atmosphere, using the following expression (1),
- V
- h
- =
- d
- h
- ɛ
- h
- ·
- ɛ
- c
- d
- c
-
- V
- c
- [
- Expression
-
-
- 1
- ]
- where dh denotes the distance between the first conductor and the second conductor in the object to be measured, dc denotes the distance between the conductive plate and the grounded surface, εh denotes a relative permittivity of the dielectric in the object to be measured, and εc denotes the relative permittivity between the conductive plate and the grounded surface,
- wherein the object to be measured is a head gimbal assembly (HGA) in which a first conductor to which a magnetic head is connected and a load beam serving as a second conductor, are opposed to each other with an insulating foundation layer serving as a dielectric therebetween.
24 more elements
A charge potential evaluation device comprising:
- a grounded surface;
- a conductive plate facing the grounded surface with a predetermined distance therebetween;
- potential measuring means for measuring a potential Vc of the conductive plate;
- input means for inputting, in an object to be measured that has a first conductor and a second conductor opposed to each other with a dielectric therebetween, a value of a relative permittivity of the dielectric and a distance between the first and second conductors;
- and
- conversion means for converting a potential difference Vh between the first conductor and the second conductor in the object to be measured in the same atmosphere as that of the conductive plate, by calculating the following expression (2) based on the measured value of a potential Vc of the conductive plate,
- V
- h
- =
- d
- h
- ɛ
- h
- ·
- ɛ
- c
- d
- c
-
- V
- c
- [
- Expression
-
-
- 2
- ]
- where dh denotes a distance between the first conductor and the second conductor in the object to be measured, dc denotes the distance between the conductive plate and the grounded surface, εh denotes the relative permittivity of the dielectric in the object to be measured, and εc denotes a relative permittivity between the conductive plate and the grounded surface,
- wherein the object to be measured is a head gimbal assembly (HGA) in which a first conductor to which a magnetic head is connected and a load beam serving as a second conductor, are opposed to each other with an insulating foundation layer serving as a dielectric therebetween.
26 more elements
A charge potential evaluation device comprising:
- a grounded surface;
- a conductive plate facing the grounded surface with a predetermined distance therebetween;
- and
- potential measuring means for measuring a potential Vc of the conductive plate,
- wherein the distance dc between the conductive plate and the grounded surface and a relative permittivity εc between the conductive plate and the grounded surface is set, or made adjustable so that a distance dh between a first conductor and a second conductor in an object to be measured that has the first and second conductors opposed to each other with a dielectric therebetween, a relative permittivity εh of the dielectric in the object to be measured, the distance dc, and the relative permittivity εc satisfy the relationship shown by the following expression (3),
- d
- h
- ɛ
- h
- ·
- ɛ
- c
- d
- c
- =
- 1
- ,
- [
- Expression
-
-
- 3
- ]
- wherein the potential Vc can thereby be obtained as a potential difference Vh between the first conductor and the second conductor in the object to be measured, and
- wherein the object to be measured is a head gimbal assembly (HGA) in which a first conductor to which a magnetic head is connected and a load beam serving as a second conductor, are opposed to each other with an insulating foundation layer serving as a dielectric therebetween.
22 more elements
Dependencies are inferred from the claim text.