Industrial Pick & Place Automation
Intelligent Wafer Mapping for LED Printhead Manufacturing
1) Project Context
At Océ Printing Systems in Poing, high-performance industrial printers used LED-based printheads, internally referred to as Zeichengeneratoren (ZG). These printheads were assembled by a highly specialized Pick & Place machine placing LED and IC chips onto the printhead carrier.
The project started during my student work at Océ and later became the technical foundation of my diploma thesis at the Munich University of Applied Sciences. The diploma thesis documented the industrial software work performed on the machine: integration of new chip variants, support for third-generation printheads and development of an intelligent wafer mapping approach.
The task was not a laboratory prototype. It was real production software for an industrial machine used in the manufacturing process of high-speed printing systems.
2) Problem Context
The existing Pick & Place process had to be extended because the next generation of printheads required:
- support for new LED chip variants
- support for new IC chip variants
- integration of third-generation printhead carriers (ZG3)
- handling of larger IC wafers
- more flexible chip selection depending on printhead type
- better use of manufacturer wafer data instead of simple sequential chip access
The central challenge: How can a specialized production machine be extended for new semiconductor variants without turning the existing control software into a collection of special cases?
3) Earlier Foundation: Automated Night Stress Test Framework
Before the Pick & Place project, I developed a reusable night stress test program for Océ printers. The program controlled motors, sensors, magnetic valves and general state changes, verified their functionality and automatically logged detected errors.
This work created an early foundation for my later engineering style: automate repetitive tests, interact directly with hardware components, generate reproducible protocols and make the tool reusable for production and diagnostics.
4) Architectural Core Idea
The core idea was to extend the production software with a structured selection mechanism for wafer chips. Instead of simply accessing chips sequentially, the machine should use wafer data supplied by the chip manufacturer to decide which chip is suitable for a specific printhead type.
Guiding principle: manufacturer wafer data · chip classification · coordinate transformation · automated placement.
5) Intelligent Wafer Mapping
The wafer mapping component interpreted wafer map information and used it during the selection of LED chips. A chip was no longer evaluated only by a simple good/bad criterion; additional status and quality information could be considered depending on the printhead variant.
- Parsing and handling of wafer map files
- Chip classification based on status information
- Conversion between wafer map positions and machine coordinates
- Selection of usable chips according to product-specific criteria
- Integration of the wafer mapping logic into the existing Pick & Place process
6) Machine Integration
The software changes touched several machine areas and production routines:
- initialization and job entry
- ZG carrier selection and positioning
- chip wafer positioning
- camera-based recognition and alignment
- chip pickup from the wafer
- chip placement on the printhead carrier
- quality assurance and production testing
7) Integration of New Product Variants
The production software was extended to support the third generation of Océ printheads and new LED/IC components. This required both process-level changes and low-level adaptations in machine behavior, including wafer handling, chip selection, graphical operator workflows and positioning logic.
- Integration of new ZG3 printhead types into the functional program
- Adaptation of job input and operator selection
- Support for new IC and LED chip variants
- Handling of larger IC wafers
- Extension of image recognition models for new components
8) Engineering Outcome
- Improved wafer usage by avoiding unnecessary access to unusable chips
- Reduced assembly time through selective chip access
- Enabled assembly with selected chip quality
- Increased manufacturing flexibility for new printhead generations
- Integrated new semiconductor variants into an existing industrial machine
- Documented and validated the complete approach as a diploma thesis
9) Technologies & Methods
- C / C++
- Industrial automation
- Pick & Place machine control
- Wafer mapping
- Machine vision / camera-based alignment
- Coordinate transformation
- Hardware-oriented test automation
- Production software
- GUI and operator workflow integration
This project became one of my first real industrial software engineering experiences: analyzing an existing production system, extending it for new hardware variants, implementing reusable automation logic and validating the result in a manufacturing environment.