Multilayer Coil Component Breaking Process for Stable Plating

Solution Overview

Problem

The existing methods for manufacturing coil components often result in increased surface resistance due to breakage or elongation of metal magnetic powder during cutting, leading to abnormal plating growth and poor quality due to short-circuiting between outer electrodes.

Innovation Solution

A coil-component manufacturing method involving the production of an unfired multilayer body block with unsintered magnetic and coil conductor layers, followed by pressure application, firing, resin impregnation, scribing to form a break start point, and breaking into individual chip units, which reduces surface resistance by propagating the fracture face along the interface between metal magnetic particles and resin, preventing abnormal plating growth.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If cutting pressure-bonded green sheets into individual chip units by use of a dicer, force-cutting, or other methods, then individual chip units are produced, but breakage or elongation of metal magnetic powder at the cut face occurs, causing reduced surface resistance

Engineering Contradiction:

Improveproduction efficiencyVSAvoidsurface resistance

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by forming a V-shaped groove (break start point) at the intended cut location before breaking the green sheets. This pre-formed groove concentrates stress and guides the fracture to propagate along a predetermined path through the magnetic layers, preventing random breakage and elongation of metal magnetic powder that would otherwise occur during cutting operations. The break starts at the V-shaped groove and propagates downward, ensuring clean separation without damaging the magnetic powder structure.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent replaces mechanical cutting systems (dicer, force-cutting) with a breaking mechanism that utilizes controlled fracture propagation. Instead of applying cutting force that shears through the material and damages metal magnetic powder, the method uses a pre-formed V-shaped groove to initiate and guide a clean break, substituting the cutting action with a controlled fracture process that preserves surface resistance.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Productivity

If cutting green sheets into individual chip units, then individual components are obtained, but abnormal growth of plating occurs during outer electrode formation, leading to short-circuiting

Engineering Contradiction:

Improveproduction efficiencyVSAvoidelectrical insulation

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent applies preliminary action by forming a V-shaped groove (break start point) at the intended cut location before breaking the green sheets. This pre-formed groove concentrates stress and guides the fracture to propagate along a predetermined path through the magnetic layers, preventing random breakage and elongation of metal magnetic powder that would otherwise occur during cutting operations. The break starts at the V-shaped groove and propagates downward, ensuring clean separation without damaging the magnetic powder structure.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent replaces mechanical cutting systems (dicer, force-cutting) with a breaking mechanism that utilizes controlled fracture propagation. Instead of applying cutting force that shears through the material and damages metal magnetic powder, the method uses a pre-formed V-shaped groove to initiate and guide a clean break, substituting the cutting action with a controlled fracture process that preserves surface resistance.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This method effectively reduces surface resistance and prevents poor quality issues such as short-circuiting between outer electrodes, ensuring higher reliability and performance of the coil components.

Implementation Method 1

impregnating the fired multilayer body block with resin

Methodology Applied

Scientific EffectImpregnation: Absorption (physical)

Implementation Method 2

by firing the unfired multilayer body block, producing a fired multilayer body block including a stack of a magnetic layer and a coil conductor layer, the magnetic layer including the metal magnetic particles

Methodology Applied

Scientific EffectFiring: Sintering

Implementation Method 3

applying pressure to the unfired multilayer body block

Methodology Applied

Scientific EffectPressure application: Compression

Data Source

PatentUS20230420182A1Coil-component manufacturing method and coil component

Publication Date: 2023.12.28 MURATA MFG CO LTD

AI summary

A coil-component manufacturing method includes producing an unfired multilayer body block including a stack of an unsintered magnetic layer and an unsintered coil conductor layer; applying pressure to the unfired multilayer body block; and by firing the unfired multilayer body block, producing a fired multilayer body block including a stack of a magnetic layer and a coil conductor layer. The method also includes impregnating the fired multilayer body block with resin; by scribing a surface of the fired multilayer body block impregnated with the resin, forming a break start point in the surface of the fired multilayer body block; by breaking the fired multilayer body block impregnated with the resin into individual chip units, producing a multilayer body; and by plating, forming an outer electrode on an outer surface of the multilayer body or on an outer surface of the fired multilayer body block.