Composite Substrate Support Member for Flexible PCB Bonding

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional inkjet heads face issues with the drive interconnect substrate breaking or bending when a flexible printed circuit board is bonded, due to the gap between the channel forming substrate and the drive interconnect substrate, which affects the reliability of the bonding process.

Innovation Solution

A composite substrate design with a support member between the substrates, where the flexible printed circuit board is bonded between the driver circuit and the support member, ensuring the entire bonding region is covered, preventing the drive interconnect substrate from breaking or bending during bonding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a gap is maintained between the channel forming substrate and the drive interconnect substrate during bonding, then the bonding process can be performed, but the drive interconnect substrate becomes susceptible to breaking or bending

Engineering Contradiction:

Improvebonding process reliabilityVSAvoiddrive interconnect substrate strength

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

A support member is introduced as an intermediary element between the channel forming substrate and the drive interconnect substrate. This support member provides mechanical reinforcement to the drive interconnect substrate during the bonding process, preventing it from breaking or bending while maintaining the necessary gap for bonding operations.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The support member is positioned in advance on the drive interconnect substrate before the bonding process begins. This pre-positioning provides protective reinforcement that cushions the substrate against potential damage during subsequent bonding operations, ensuring structural integrity throughout the process.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

2Strength

If the flexible printed circuit board is bonded to the drive interconnect substrate over a large area, then bonding strength is improved, but the drive interconnect substrate is more prone to bending and breaking

Engineering Contradiction:

Improvebonding strengthVSAvoidsubstrate structural stability

Core Design Contradiction:

StrengthVSStability of the object's composition

Solution Approach 1:

The support member acts as a mediator that distributes the bonding pressure and mechanical stresses across a wider area. This allows the flexible printed circuit board to be bonded over a larger area for increased bonding strength, while the support member prevents the drive interconnect substrate from bending or breaking by providing underlying structural support.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS10525702B2Composite substrate that prevents flexible print circuit board from peeling off from drive interconnect substrate

Publication Date: 2020.01.07 BROTHER KOGYO KK

AI summary

A composite substrate has a first substrate having a surface; a second substrate having a first surface and a second surface opposite to the first surface in a thickness direction and facing the surface of the first substrate with a gap therebetween, the second substrate extending in a longitudinal direction perpendicular to the thickness direction, the second substrate having first and second ends in the longitudinal direction, and a driver circuit being provided on the first surface; a flexible print circuit board has a portion bonded a position on the first substrate between the first end and the driver circuit, the bonding region being defined on the first surface, and a support member positioned between the surface of the first substrate and the second surface of the second substrate, the support member overlapping all of the bonding region, as viewed in the thickness direction.