Check patentability & draft patents in minutes with Patsnap Eureka AI!

A varistor and production method

A varistor, electrode technology, applied in resistors, non-adjustable metal resistors, electrical components, etc., can solve problems such as difficulty in consistent control, loss of passivation coating discs, etc.

Active Publication Date: 2008-12-24
DONGGUAN LITTELFUSE ELECTRONICS CO LTD
View PDF1 Cites 2 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

These methods have the disadvantage of being difficult to control consistently
Additionally, handling and component adhesion can lead to defects in the passivation coating and even within the disc itself

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • A varistor and production method
  • A varistor and production method
  • A varistor and production method

Examples

Experimental program
Comparison scheme
Effect test

example

[0047] Traditionally, ceramic disc bodies are manufactured by sintering. The ceramic material is primarily ZnO, which contains bismuth, antimony, and other oxides required to achieve the desired electrical properties. The size of the disc is: diameter 20.5 mm, thickness ~ 2 mm. The electrodes are fired onto the surface in such a way that a silver paste material is printed on each flat side of the disc, containing binders, solvents suitable for the printing process and subsequent firing steps and glass raw materials. Then, it is subjected to a firing process at a peak temperature of 600-800° C. for a total time of 1.5-8 hours. The silver electrode was approximately 17 mm in diameter, thus leaving an exposed ceramic ring with a radial dimension of 1.75 mm on each planar surface. The thickness of the silver material is in the range of 4-18 μm. Exposed flats (ie, planar surface areas not covered by silver material) were passivated by loading the part into a nest similar to tha...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

A varistor has a disc (12) of ceramic material having opposed faces with face edges. There is an electrode (13) on each face with a gap between each electrode (13) and the edge of the face. Glass passivation (14) is on at least one face in the gap, the passivation (14) not extending from one electrode to the other electrode around the surface of the disc (12). Because the passivation is only on the planar opposed disc faces, it may be applied in a simple operation such as screen printing. Indeed, the screen printing may be performed while the discs are in the same nest plates as are used for printing of electrode paste. Even though the passivation does not extend from one electrode to the other, it nevertheless breaks a potentially conductive path between the electrodes caused by interaction between the ceramic and encapsulant materials.

Description

technical field [0001] The present invention relates to metal oxide varistors (MOVs). Background technique [0002] Typically, the manufacture of an MOV includes: sintering (sintering) metal oxide ceramic powder to provide a disk-shaped (optionally, square or other shape) body; firing (fire) electrodes on the disk-shaped body; typically, connecting leads by soldering; and packaging. It is well known that the choice of encapsulant is critical to ensure good electrical stability over time. Many packaging materials can cause defects, including increased leakage and / or a drop in nominal voltage, when subjected to a biased high temperature test, often referred to as an accelerated life test, such as maintaining 125°C at rated bias for 1000 Hour. [0003] The traditional approach to this problem has been to develop or select a specialized encapsulation material that does not exhibit this problem when used with a specific ceramic material. However, this is not always possible a...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): H01C7/102
CPCH01C7/102
Inventor N·麦克洛克林M·奥多诺万
Owner DONGGUAN LITTELFUSE ELECTRONICS CO LTD
Features
  • R&D
  • Intellectual Property
  • Life Sciences
  • Materials
  • Tech Scout
Why Patsnap Eureka
  • Unparalleled Data Quality
  • Higher Quality Content
  • 60% Fewer Hallucinations
Social media
Patsnap Eureka Blog
Learn More

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2025 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com