Substrate Board Local Reinforcing Layer for Planarity Control

Solution Overview

Problem

Substrate boards with irregularly distributed metal portions cause electromagnetic interference and planarity defects, leading to defective or missing electrical connections between integrated-circuit chips and the substrate, due to warping or sagging.

Innovation Solution

A non-metallic local reinforcing or balancing layer is added to zones on the substrate board free from metal portions, which can be in the form of points, lines, or films, to compensate for irregularities and prevent warping, ensuring coplanarity and proper chip mounting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If metal portions are irregularly distributed to form electrical connection networks, then electrical connectivity is achieved, but substrate board planarity deteriorates causing warping and sagging

Engineering Contradiction:

Improveelectrical connectivityVSAvoidsubstrate board planarity

Core Design Contradiction:

ReliabilityVSShape

Solution Approach 1:

The patent applies local quality by adding reinforcing or balancing layers specifically in zones free from metal portions, rather than uniformly across the entire substrate. This localized approach compensates for the irregular metal distribution only where needed, maintaining electrical connectivity while restoring planarity in affected areas.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent uses composite materials by combining the substrate board with reinforcing layers made of different materials (epoxy resin, polyimide, PTFE, or ceramic) in specific zones. This composite structure compensates for the irregular metal distribution and prevents warping while maintaining the electrical connection network.

Inventive Principle:

Principle #40Composite materials

2Object-affected harmful factors

If zones near high-frequency signal connections are kept free from metal portions to prevent electromagnetic interference, then electromagnetic compatibility is improved, but substrate board stability deteriorates

Engineering Contradiction:

Improveelectromagnetic interferenceVSAvoidsubstrate board stability

Core Design Contradiction:

Object-affected harmful factorsVSStability of the object's composition

Solution Approach 1:

The patent applies local quality by adding reinforcing or balancing layers specifically in zones free from metal portions, rather than uniformly across the entire substrate. This localized approach compensates for the irregular metal distribution only where needed, maintaining electrical connectivity while restoring planarity in affected areas.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The reinforcing or balancing layers act as intermediary elements in zones free from metal portions. These layers mediate between the irregular metal distribution and the substrate structure, providing the necessary mechanical support and stability without introducing additional metal that would cause electromagnetic interference.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Shape

If reinforcing layers are added to zones free from metal portions, then substrate board planarity is improved, but device complexity increases

Engineering Contradiction:

Improvesubstrate board planarityVSAvoidsubstrate structure complexity

Core Design Contradiction:

ShapeVSDevice complexity

Solution Approach 1:

The patent applies local quality by adding reinforcing or balancing layers specifically in zones free from metal portions, rather than uniformly across the entire substrate. This localized approach compensates for the irregular metal distribution only where needed, maintaining electrical connectivity while restoring planarity in affected areas.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent applies partial action by adding reinforcing layers only in specific zones where metal portions are absent, rather than covering the entire substrate. This partial approach is sufficient to compensate for the irregular metal distribution and prevent warping, avoiding the complexity of a complete uniform reinforcement.

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentUS9420685B2Electronic device comprising a substrate board equipped with a local reinforcing or balancing layer

Publication Date: 2016.08.16 STMICROELECTRONICS INT NV

AI summary

A substrate board includes an electrical connection network on a face thereof. An integrated-circuit chip is mounted to the face of the substrate board in electrical contact with the electrical connection network. A local reinforcing or balancing layer made of a non-metallic material is mounted to the face of the substrate board in at least one local zone free of the face which is free of metal portions of the electrical connection network.