Printed Wiring Board Alignment Mark Positioning

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Solution Overview

Problem

Existing methods for manufacturing electronic modules with copper foil conductive layers face issues such as warping, which leads to wiring breakage and reduced connection reliability, making them less desirable in terms of productivity.

Innovation Solution

A method involving a laminate body with a conductive film and insulation layers, where alignment marks are used to precisely position and enclose electronic components, forming via holes and conductive circuits to connect components without direct contact with the conductive film, thereby minimizing warping and enhancing connection reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If copper foil is used as the conductive layer, then electrical conductivity is improved, but the copper foil warps during thermosetting, causing wiring breakage and reduced connection reliability

Engineering Contradiction:

Improveconnection reliabilityVSAvoidflatness of conductive layer

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent introduces a resin layer as an intermediary between the copper foil and the electronic component. This resin layer absorbs the dimensional changes and warping forces during thermosetting, preventing direct transmission of stress to the copper foil and electronic component, thereby maintaining connection reliability while allowing the use of copper foil for electrical conductivity

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent applies a protective resin coating on the copper foil before assembling the electronic module. This pre-applied cushioning layer compensates for upcoming warping during thermosetting, preventing wiring breakage and maintaining the flatness required for reliable connections

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

2Manufacturing precision

If thin copper foil is used, then fine-pitch wiring can be formed, but the copper foil becomes harder to use and more prone to warping

Engineering Contradiction:

Improvefine-pitch wiring capabilityVSAvoidhandling difficulty

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The resin layer serves as a mediator that supports thin copper foil during manufacturing processes. It provides mechanical stability and ease of handling while allowing the thin copper foil to maintain its fine-pitch wiring capability, resolving the contradiction between thickness and manufacturability

Inventive Principle:

Principle #24Intermediary (Mediator)

3Ease of manufacture

If thick copper foil is used, then handling is easier, but fine-pitch wiring cannot be formed by etching

Engineering Contradiction:

Improvehandling easeVSAvoidfine-pitch wiring capability

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent changes the physical state and properties of the copper foil by applying resin coatings and controlling the thermosetting process parameters. This allows the use of thicker copper foil that is easier to handle while still achieving fine-pitch wiring through controlled etching and resin support

Inventive Principle:

Principle #35Parameter changes

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 improves the alignment and connection reliability of electronic components, reduces defects like wiring breakage, and enhances the productivity of printed wiring boards by maintaining the flatness of the laminate substrate.

Implementation Method 1

An alignment mark is formed in the laminate body by removing at least a portion of the conductive film

Methodology Applied

Scientific EffectPhysical removal (etching):

Implementation Method 2

An adhesive layer is provided on a second surface of the first insulation layer opposite to the first surface

Methodology Applied

Scientific EffectAdhesion: Adhesive

Implementation Method 3

The via hole is formed at a position determined based on the alignment mark. A surface of the laminate body and a surface of the via hole are plated to form a via conductor in the via hole

Methodology Applied

Scientific EffectElectroplating: Electroplating

Data Source

PatentUS8613136B2Method of manufacturing printed wiring board with built-in electronic component

Publication Date: 2013.12.24 IBIDEN CO LTD

AI summary

A printed wiring board is manufactured by a method in which a laminate body having a first insulation layer and a conductive film is provided. An alignment mark is formed in the laminate body by removing at least a portion of the conductive film. An electronic component is placed on an adhesive layer provided on the first insulation layer at a position determined based on the alignment mark. After the electronic component is enclosed inside an opening of the second insulation layer, a via hole exposing a terminal of the electronic component is formed at a position determined based on the alignment mark used to determine the position of the electronic component. A via conductor is formed in the via hole, and a conductive layer is formed on the conductive film and patterned to form a conductive circuit connected to the via conductor.