Over-voltage protection device and method for preparing the same

• US 9,099,861 B2
• Filed: 05/23/2013
• Issued: 08/04/2015
• Est. Priority Date: 05/23/2013
• Status: Active Grant

• Current Assignee: INPAQ Technology Co., Ltd.
• Original Assignee: INPAQ Technology Co., Ltd.
• Inventors: Chang, Yu Chia, Yeh, Hsiu Lun, Liu, Tze Chun, Hsu, Hsiu Mei
• Primary Examiner(s): Tran, Thienvu
• Assistant Examiner(s): BROOKS, ANGELA D
• Application Number:
  US13/900,824
• Publication Number:
  US 20140347772A1
• Time in Patent Office: 803 Days
• Field of Search: 361/56, 361/57, 361/112
• US Class Current: 1/1
• CPC Class Codes: H01L 27/0288 using passive elements as protective elements, e.g. resistors, capacitors, inductors, spark-gaps
• CPC Class Codes: H02H 9/044 Physical layout, materials not provided for elsewhere varistors H01C7/12; spark-gaps H01T; Ovshinsky devices H10N70/00

Abstract

An over-voltage protection device includes a substrate, an insulation layer having a depression over the substrate, a conductor layer having a first electrode and a second electrode over the insulation layer, wherein the first electrode and the second electrode form a discharge path, and the depression is under the discharge path. A method for preparing the over-voltage protection device includes the steps of forming an insulation layer over a substrate; forming a depression in the insulation layer; forming a photoresist pattern filling the depression and protruding the insulation layer; forming a conductor layer over the insulation layer; and removing the photoresist pattern, wherein the photoresist pattern divides the conductor layer into a first electrode and a second electrode that form a discharge path, and the depression is under the discharge path after the removal of the photoresist pattern.

Claims

1. An over-voltage protection device, comprising:

a substrate;

an insulation layer directly disposed over the substrate, wherein the insulation layer has a depression over the substrate; and

a conductor layer disposed over the insulation layer, wherein the conductor layer has a first electrode and a second electrode over the insulation layer, the first electrode and the second electrode form a discharge path, and the depression is under the discharge path and further comprising a gasket layer disposed over the conductor layer, wherein the gasket layer has an opening exposing at least a portion of the first electrode and the second electrode.

2. The over-voltage protection device of claim 1, wherein the substrate comprises aluminum oxide or ceramic, the insulation layer comprises polyimide or epoxy resin, and the conductor layer comprises copper.

3. The over-voltage protection device of claim 1, wherein the gasket layer comprises epoxy resin or polyimide.

4. The over-voltage protection device of claim 1, wherein a cross-sectional width of the opening is larger than a cross-sectional width of the depression.

5. The over-voltage protection device of claim 1, further comprising a protection layer disposed over the gasket layer, wherein the protection layer shields the opening.

6. The over-voltage protection device of claim 5, wherein the protection layer comprises epoxy resin or polyimide.

7. The over-voltage protection device of claim 1, wherein the first electrode has a first tip and the second electrode has a second tip facing the first tip.

8. The over-voltage protection device of claim 7, wherein the first tip and the second tip are disposed over the depression.

9. A method for preparing an over-voltage protection device, comprising steps of:

forming an insulation layer directly over a substrate;

forming a depression in the insulation layer;

forming a photoresist pattern filling the depression and protruding the insulation layer;

forming a conductor layer over the insulation substrate, wherein the photoresist pattern separates the conductor layer to form a first electrode and a second electrode; and

removing the photoresist pattern to form a discharge path between the first electrode and the second electrode with the depression being under the discharge path, and further comprising steps of;

forming a gasket layer over the conductor layer, wherein the gasket layer has an opening exposing at least a portion of the first electrode and the second electrode; and

forming a protection layer over the gasket layer, wherein the protection layer shields the opening.

10. The method for preparing an over-voltage protection device of claim 9, wherein a cross-sectional width of the opening is larger than a cross-sectional width of the depression.

11. The method for preparing an over-voltage protection device of claim 9, wherein the photoresist pattern has a tapered profile, the first electrode has a first tip, the second electrode has a second tip, and the first tip and the second tip are disposed over the depression.