Wired circuit board

Abstract

[Object] To provide a wired circuit board in which charged static electricity can be efficiently removed before mounting of electronic components and electrical stability of a wired circuit body portion can be reliably secured after the mounting of the electronic components.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[FIG. 1] A schematic plan view illustrating a suspension board with circuit as an embodiment of a wired circuit board according to the present invention;

[FIG. 2] An enlarged plan view of an electrostatic charge removing portion of the suspension board with circuit shown in FIG. 1;

[FIG. 3] A sectional view of the suspension board with circuit shown in FIGS. 1 and 2, in which the left-side figure is a sectional view thereof in a direction along the longitudinal direction of a conductive pattern, and the right-side figure is a sectional view of an electrostatic charge removing portion in a direction along the widthwise direction of the suspension board with circuit, taken along the line A-A in FIG. 2;

[FIG. 4] A sectional view illustrating the steps of producing a suspension board with circuit shown in FIG. 3, (a) showing the step of preparing a metal supporting layer, (b) showing the step of forming an insulating base layer on the metal supporting layer to provide a pattern in which a base opening is formed, (c) showing the step of simultaneously forming a conductive pattern and a ground connecting portion, (d) showing the step of forming a semiconductive layer so as to be continuous with all of the surface of a conductive pattern, the surface of an upper part of the ground connecting portion, the surface of the insulating base layer, and the surface of the metal supporting layer, and (e) showing the step of forming a first insulating cover layer on the semiconductive layer of an electrostatic charge removing portion (except for a front end portion thereof) in a pattern;

[FIG. 5] A sectional view illustrating the steps, subsequent to FIG. 4, of producing the suspension board with circuit shown in FIG. 3, (f) showing the step of removing the semiconductive layer exposed from the first insulating cover layer, (g) showing the step of forming a second insulating cover layer on the insulating base layer in a pattern so as to cover the first insulating cover layer and the conductive pattern, (h) showing the step of forming a metal opening in the metal supporting layer and (i) showing the step of forming a notch in a conduction cut-off portion;

[FIG. 6] A sectional view illustrating another process of producing a suspension board with circuit shown in FIGS. 4 and 5, (a) showing the step of forming an etching resist on a semiconductive layer of an electrostatic charge removing portion (except for a front end portion thereof) in a pattern, (b) showing the step of removing the semiconductive layer exposed from the etching resist, (c) showing the step of removing the etching resist; and (d) showing the step of forming an insulating cover layer on an insulating base layer in a pattern so as to cover the semiconductive layer and a conductive pattern;

[FIG. 7] A sectional view corresponding to FIG. 3, showing a suspension board with circuit as another embodiment (an embodiment in which a semiconductive layer directly contacts a metal supporting layer, and the semiconductive layer is interposed between an auxiliary wired circuit and an insulating cover layer) of a wired circuit board according to the present invention;

[FIG. 8] A sectional view corresponding to FIG. 3, showing a suspension board with circuit as another embodiment (an embodiment in which a semiconductive layer directly contacts a metal supporting layer, and the semiconductive layer is interposed between an auxiliary wired circuit and an insulating base layer) of a wired circuit board according to the present invention;

[FIG. 9] A sectional view corresponding to FIG. 3, showing a suspension board with circuit as another embodiment (an embodiment in which a semiconductive layer directly contacts a metal supporting layer, and the semiconductive layer is formed on the surface of an insulating cover layer) of a wired circuit board according to the present invention;

[FIG. 10] A sectional view corresponding to FIG. 3, showing a suspension board with circuit as another embodiment (an embodiment in which a semiconductive layer directly contacts a metal supporting layer, and the semiconductive layer is formed on the surface of an insulating base layer and the surface of an auxiliary wiring circuit, and also formed on the surface of an insulating cover layer) of a wired circuit board according to the present invention;

[FIG. 11] An enlarged plan view corresponding to FIG. 2, showing an electrostatic charge removing portion in a suspension board with circuit as another embodiment (an embodiment in which two conduction cut-off portions are formed) of a wired circuit board according to the present invention;

[FIG. 12] A sectional view corresponding to FIG. 3, showing a suspension board with circuit shown in FIG. 11, in which the left-side figure is a sectional view in a direction along a conductive pattern, and the right-side figure is a sectional view of a semiconductive layer forming portion in a direction along the widthwise direction of the suspension board with circuit; and

[FIG. 13] A sectional view corresponding to the left-side figure of FIG. 3, showing a suspension board with circuit in a direction along a conductive pattern.

DESCRIPTION OF REFERENCE NUMERALS

• • 1 suspension board with circuit
  • 2 the wired circuit body portion
  • 3 electrostatic charge removing portion
  • 4 conduction cut-off portion
  • 5 main wired circuit
  • 7 magnetic-head-side connecting terminal portion
  • 8 external connecting terminal portion
  • 9 semiconductive layer
  • 10 test-side connecting terminal portion
  • 11 auxiliary wired circuit
  • 12 metal supporting layer
  • 13 the insulating base layer
  • 15 insulating cover layer
  • 18 notch
  • 26 auxiliary conduction cut-off portion
  • 27 test-side connecting terminal portion
  • forming portion
  • 28 semiconductive layer forming portion

Claims

1. A wired circuit board comprising: a wired circuit body portion having a wired circuit;an electrostatic charge removing portion conducted with the wired circuit body portion and having a semiconductive layer; anda conduction cut-off portion arranged between the wired circuit body portion and the electrostatic charge removing portion to cut off electrical conduction therebetween.

2. The wired circuit board according to claim 1, wherein the electrostatic charge removing portion is arranged adjacent to a peripheral end portion of the wired circuit body portion.

3. The wired circuit board according to claim 1 or 2, wherein the wired circuit body portion comprisesa first terminal portion connected to the wired circuit and arranged on one side of the wired circuit body portion, anda second terminal portion connected to the wired circuit and arranged on the other side of the wired circuit body portion, andthe electrostatic charge removing portion is arranged on an outer side of a direction along the wired circuit with respect to the wired circuit between the first terminal portion and the second terminal portion.

4. The wired circuit board according to any of claim 1 through 3, wherein the electrostatic charge removing portion is separable from the wired circuit body portion at the conduction cut-off portion as a boundary.

5. The wired circuit board according to claim 4, wherein a notch is formed in the conduction cut-off portion.

6. The wired circuit board according to any of claim 1 thorough 5, wherein the electrostatic charge removing portion comprises a conductive layer connected to the wired circuit and an insulating layer laminated on the conductive layer, andthe semiconductive layer is formed on the conductive layer and/or the insulating layer.

7. The wired circuit board according to claim 6, wherein the electrostatic charge removing portion further comprises a metal supporting layer, andthe semiconductive layer is electrically connected with the metal supporting layer.

8. The wired circuit board according to claim 6 or 7, wherein the electrostatic charge removing portion comprises a third terminal portion connected to the conductive layer.

9. The wired circuit board according to claim 8, wherein the electrostatic charge removing portion comprisesa third terminal portion forming portion having the third terminal portion formed thereon,a semiconductive layer forming portion arranged between the third terminal portion forming portion and the conduction cut-off portion to form the semiconductive layer thereon, andan auxiliary conduction cut-off portion arranged between the third terminal portion forming portion and the semiconductive layer forming portion to cut off the electrical conduction therebetween.

10. The wired circuit board according to claim 9, wherein the third terminal portion forming portion is separable from the semiconductive layer forming portion at the auxiliary conduction cut-off portion as a boundary.

11. The wired circuit board according to claim 9 or 10, wherein a notch is formed in the auxiliary conduction cut-off portion.