Ceramic Wiring Substrate Resin Layout for Accurate Resistor Trimming

Solution Overview

Problem

Existing methods for adjusting the resistance of a resistor on a wiring substrate covered with a resin layer face challenges due to thermal changes and difficulty in direct laser trimming, leading to inaccurate resistance values and potential damage from heat and pressure application.

Innovation Solution

A wiring substrate design with two resin layers, where the first resin layer is joined to the ceramic substrate before resistance adjustment, allowing lower heat application and reduced thermal impact, and a second resin layer covers the resistor to protect it from chemical and oxidative influences.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a resin layer is disposed on the resistor and heat and pressure are applied to join the resin layer to the ceramic substrate, then the resistor is protected from environmental factors, but the resistance of the resistor changes due to thermal impact

Engineering Contradiction:

Improveprotection of resistorVSAvoidresistance accuracy

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The resin layer is divided into two separate layers: a first resin layer joined to the ceramic substrate before resistor trimming, and a second resin layer formed after trimming to cover the resistor. This segmentation allows the first layer to provide mechanical support and protection during the critical trimming phase, while the second layer provides final environmental protection without exposing the resistor to high heat and pressure that would alter its resistance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The first resin layer is joined to the ceramic substrate before the resistor trimming operation. This preliminary action provides structural support and protection to the resistor during the subsequent laser trimming process, preventing damage from the trimming operation while allowing precise resistance adjustment to be performed.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If a resin layer is formed before trimming of the resistor, then the resistor is protected during formation, but adjustment of the resistance is difficult because the resistor cannot be viewed directly

Engineering Contradiction:

Improveprotection of resistorVSAvoidresistor trimming

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The resin layer is divided into two separate layers: a first resin layer joined to the ceramic substrate before resistor trimming, and a second resin layer formed after trimming to cover the resistor. This segmentation allows the first layer to provide mechanical support and protection during the critical trimming phase, while the second layer provides final environmental protection without exposing the resistor to high heat and pressure that would alter its resistance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The first resin layer is joined to the ceramic substrate before the resistor trimming operation. This preliminary action provides structural support and protection to the resistor during the subsequent laser trimming process, preventing damage from the trimming operation while allowing precise resistance adjustment to be performed.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If heat and pressure are applied to join the resin layer to the ceramic substrate after resistance adjustment, then the resistor is protected, but the resistance accuracy deteriorates due to thermal changes

Engineering Contradiction:

Improveprotection of resistorVSAvoidresistance accuracy

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The resin layer is divided into two separate layers: a first resin layer joined to the ceramic substrate before resistor trimming, and a second resin layer formed after trimming to cover the resistor. This segmentation allows the first layer to provide mechanical support and protection during the critical trimming phase, while the second layer provides final environmental protection without exposing the resistor to high heat and pressure that would alter its resistance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The first resin layer is joined to the ceramic substrate before the resistor trimming operation. This preliminary action provides structural support and protection to the resistor during the subsequent laser trimming process, preventing damage from the trimming operation while allowing precise resistance adjustment to be performed.

Inventive Principle:

Principle #10Preliminary action

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

The resistance accuracy of the resistor is enhanced, and thermal changes are minimized, ensuring precise resistance values while protecting the resistor from environmental factors.

Implementation Method 1

application of heat and pressure for joining the first resin layer to the ceramic substrate

Methodology Applied

Scientific EffectHeat and pressure joining:

Implementation Method 2

adjustment of the resistance of the resistor by means of laser trimming

Methodology Applied

Scientific EffectLaser trimming: Laser Ablation

Implementation Method 3

protect the resistor from influences of chemical solution, oxidation, etc.

Methodology Applied

Scientific EffectOxidation protection: Oxidation

Data Source

PatentUS12526918B2Wiring substrate and method for manufacturing wiring substrate

Publication Date: 2026.01.13 NITERRA CO LTD

AI summary

A wiring substrate includes a ceramic substrate, a thin-film resistor disposed on the ceramic substrate, a first resin layer formed of a resin and disposed in a region on the ceramic substrate where the resistor is not disposed, and a second resin layer formed of a resin and covering the resistor on the ceramic substrate.