Multi-Functional Print Head for Automated Stencil Changeover

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Solution Overview

Problem

Stencil printers require manual intervention for routine operations such as changing stencils, replacing solder paste cartridges, and maintaining squeegee blades, leading to prolonged downtime and inefficiencies in PCB fabrication.

Innovation Solution

A delivery system with a translatable carriage and end effector is introduced to automate the delivery and replacement of items like stencils, squeegee blades, and paste cartridges, using a movable cart that interfaces with the stencil printer to facilitate automated changeovers and replenishments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If manual operations are used for changing stencils, replacing paste cartridges, and maintaining squeegee blades, then the operator can perform these tasks, but the changeover time increases significantly (up to 30 minutes) and the stencil printer remains non-operational

Engineering Contradiction:
Improvemanual operation capabilityVSAvoidchangeover time
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The system segments the changeover process into distinct automated functions: stencil handling, paste cartridge replacement, and squeegee blade maintenance. Each function is handled by dedicated automated mechanisms, allowing parallel processing and eliminating sequential manual operations. The stencil carrier assembly, paste cartridge assembly, and squeegee blade assembly operate independently to perform their respective tasks simultaneously.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The stencil printer performs self-service through automated detection and replacement mechanisms. The system automatically detects when stencils need changing, when paste cartridges are depleted, and when squeegee blades require maintenance, then executes the replacement operations without operator intervention. This self-service capability eliminates the 30-minute changeover period and keeps the printer continuously operational.

Inventive Principle:
Principle #25Self-service

2Ease of operation

If manual replacement of consumables is performed, then the operator can replace items, but the stencil printer experiences prolonged downtime during replacement operations

Engineering Contradiction:
Improvereplacement capabilityVSAvoidoperational efficiency
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The system prepares replacement items in advance through automated loading mechanisms. Stencils are pre-loaded onto the stencil carrier assembly, paste cartridges are pre-positioned in the paste delivery system, and squeegee blades are readily available for immediate replacement. This preliminary preparation eliminates waiting time during changeovers and maintains continuous production flow.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Manual mechanical operations are replaced with automated mechanical systems. The stencil carrier assembly uses automated lifting and positioning mechanisms, the paste cartridge assembly employs robotic handling, and the squeegee blade assembly utilizes automated detection and replacement tools. These mechanical substitution systems perform replacements in seconds rather than minutes, dramatically improving operational efficiency.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Ease of operation

If the stencil printer is stopped for changeover operations, then manual tasks can be completed, but the PCB fabrication line cannot operate

Engineering Contradiction:
Improvetask completion capabilityVSAvoidline operation continuity
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The system maintains continuous useful action by eliminating stoppages during changeover operations. Automated mechanisms allow stencils, paste cartridges, and squeegee blades to be replaced without stopping the PCB fabrication line. The stencil carrier assembly, paste cartridge assembly, and squeegee blade assembly operate continuously, ensuring that the production line never halts and maximizing overall productivity.

Inventive Principle:
Principle #20Continuity of useful action

4Loss of time

If automated delivery systems are implemented, then changeover time is reduced, but the device complexity increases

Engineering Contradiction:
Improvechangeover timeVSAvoidsystem complexity
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The system achieves universality by designing multi-functional assemblies that handle multiple tasks. The stencil carrier assembly not only transports stencils but also performs alignment and positioning. The paste cartridge assembly handles both paste delivery and cartridge replacement. The squeegee blade assembly performs both cutting and blade replacement functions. This multi-functionality reduces the need for separate dedicated mechanisms, thereby limiting the increase in system complexity while maintaining automated changeover capabilities.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3983232B1Multi-functional print head for a stencil printer
Publication Date: 2025.09.17 ILLINOIS TOOL WORKS INC
  • EP3983232B1 patent drawingFigure 1
  • EP3983232B1 patent drawingFigure 2
  • EP3983232B1 patent drawingFigure 3

AI summary

A stencil printer includes a frame, a stencil coupled to the frame, and a support assembly coupled to the frame, with the support assembly including tooling configured to support the electronic substrate in a print position beneath the stencil. The stencil printer further includes a print head assembly coupled to the frame in such a manner that the print head assembly is configured to traverse the stencil during print strokes. The print head assembly includes a squeegee blade assembly and at least one paste cartridge to deposit solder paste on the stencil. The stencil printer further includes an end effector configured to pick up and release items from a tooling tray. The stencil printer further includes a movable cart configured to interface with the stencil printer to deliver changeover and/or replacement items within a stencil printer.