Ceramic Circuit Board Resist Film for Precise Etched Patterns

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Solution Overview

Problem

Existing methods for producing ceramic circuit boards, such as photolithography, screen printing, and inkjet printing, face inefficiencies in production efficiency, edge bonding issues, and difficulty in forming high-precision resist patterns due to low resistance to etching solutions and the need for form plate fabrication in screen printing.

Innovation Solution

A method using an inkjet printing process to form a multilayer resist cured film with uniform thickness, ensuring high resistance and precision, which includes stacking a ceramic substrate, a titanium nitride layer, a silver-containing brazing material layer, and a conductive metal plate, with the resist film applied using an inkjet device and cured to achieve precise circuit patterns.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If photolithography process is used to form resist pattern, then precision of circuit pattern is improved, but production efficiency deteriorates due to many steps including exposure and development

Engineering Contradiction:
Improveprecision of circuit patternVSAvoidproduction efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The invention extracts and eliminates the exposure and development steps from the photolithography process by using a screen printing process with a form plate that directly transfers the resist pattern through printing, thereby maintaining pattern precision while improving production efficiency

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention uses a form plate as a physical copy or template of the desired circuit pattern, which is printed onto the metal sheet using screen printing. This copying approach allows direct pattern transfer without requiring exposure and development steps

Inventive Principle:
Principle #26Copying

2Productivity

If screen printing process is used to form resist pattern, then production efficiency is improved, but fabrication time of form plate increases due to fine regulation needed in sizing

Engineering Contradiction:
Improveproduction efficiencyVSAvoidfabrication time of form plate
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The form plate is prepared in advance with the exact circuit pattern dimensions and geometry required. This preliminary fabrication of the form plate allows for rapid production of multiple circuit boards without repeated adjustments, as the pattern is already precisely defined in the form plate design

Inventive Principle:
Principle #10Preliminary action

3Productivity

If inkjet printing process is used to apply resist ink, then production efficiency is improved, but manufacturing precision deteriorates due to low resistance of resist ink to etching solutions

Engineering Contradiction:
Improveproduction efficiencyVSAvoidprecision of resist pattern
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The invention uses a disposable form plate made of inexpensive material that can be easily replaced. This allows for rapid production cycles where the form plate is used multiple times until wear occurs, then replaced without affecting the precision or resistance of the resist pattern, as each new form plate provides fresh, high-quality pattern transfer

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 efficiently produces ceramic circuit boards with high resistance to etching solutions and precise circuit patterns, enabling size reduction and output enhancement of power modules, while avoiding the limitations of traditional methods.

Implementation Method 1

a method for producing a ceramic circuit board with a resist cured film by using an inkjet device

Methodology Applied
Scientific EffectInkjet printing:

Implementation Method 2

curing to form a single-layer resist cured film

Methodology Applied
Scientific EffectCuring: Photopolymerisation

Data Source

PatentEP4131345B1Ceramic circuit board with resist cured film, manufacturing method therefor, and ceramic circuit board manufacturing method
Publication Date: 2024.10.23 DENKA CO LTD

AI summary

The method for producing a ceramic circuit board with a resist cured film having a predetermined circuit pattern according to the present invention includes a step of providing a metal-ceramic bonded body having a ceramic substrate, a layer containing titanium nitride, a brazing material layer containing silver, and a metal plate having electroconductivity stacked in this order, a step of applying a resist ink along the circuit pattern on the metal plate by an inkjet printing process, followed by curing to form a single-layer resist cured film, and repeating the formation a plurality of times to thereby form a multilayer resist cured film, and a step of etching the layer containing titanium nitride, the brazing material layer containing silver and the metal plate excluding the portions thereof present underneath the multilayer resist cured film by using an etching solution.