Periodic Reporting for period 1 - BAMBAM (Building Active MicroLED displays By Additive Manufacturing)
Período documentado: 2022-09-01 hasta 2025-08-31
All electronic displays sold in the EU use panels made in Asia. This drastically limits Europe’s strategic autonomy and leads to a lack of control over the environmental impacts of display manufacturing. Liquid Crystal Display (LCD) and Organic LED (OLED) displays - the leading display technologies - are driven by a rigid Thin Film Transistor (TFT) array covering the whole display size. TFT manufacturing is energy consuming, uses Super fluorinated greenhouse gasses and require an investment of a few billion euros for each factory. This makes the relocation of display manufacturing in Europe not competitive with existing Asian value chains. TFT arrays are thus a major technological lock for a European and green display industry.
µLEDs offer higher brightness than LCDs and OLEDs while consuming less energy. Current µLED based displays have a passive µLED at each pixel and rely on a TFT panel to control the µLEDs light emission. µLEDs are already used for high-resolution small screens (smartwatches) but current manufacturing technologies cannot produce high-brightness, very fine pitch, µLED displays at TV sizes or larger.
BamBam's objective is to support Europe’s entry into the display industry. To achieve this BamBam aimed at developing and demonstrating a breakthrough Additive Manufacturing process based on active μLED pixels and microprinting of electrical and optical structures. In contrast to OLED or Liquid Crystal matrices, active μLED pixels include their own driver thus eliminating the need for a TFT panel. This enables to develop new fine pitch, high brightness, large and potentially flexible µLED displays. From an industrial standpoint, this represents an opportunity for European players to upscale the BamBam manufacturing process and create a green display manufacturing industry in Europe.
µLEDs offer higher brightness than LCDs and OLEDs while consuming less energy. Current µLED based displays have a passive µLED at each pixel and rely on a TFT panel to control the µLEDs light emission. µLEDs are already used for high-resolution small screens (smartwatches) but current manufacturing technologies cannot produce high-brightness, very fine pitch, µLED displays at TV sizes or larger.
BamBam's objective is to support Europe’s entry into the display industry. To achieve this BamBam aimed at developing and demonstrating a breakthrough Additive Manufacturing process based on active μLED pixels and microprinting of electrical and optical structures. In contrast to OLED or Liquid Crystal matrices, active μLED pixels include their own driver thus eliminating the need for a TFT panel. This enables to develop new fine pitch, high brightness, large and potentially flexible µLED displays. From an industrial standpoint, this represents an opportunity for European players to upscale the BamBam manufacturing process and create a green display manufacturing industry in Europe.
BamBam included 4 technical work packages.
WP1 established the specifications for materials, processes, and pixel integration, resulting in a disruptive design based on an advanced European printing technology: the Ultra Precise Deposition (UPD). The BAMBAM concept has been benchmarked against LCD and OLED technologies, using iterative Life Cycle Assessments to guide design choices and highlight environmental hotspots. These analyses confirmed that the concept outperforms LCD in most environmental impact categories but also identified technical areas to further improve environmental performance. Market and industrial studies pinpointed professional video walls for simulation and healthcare as promising applications for the BamBam concept. Current pixel costs estimates highlight the need for process parallelization and automation.
WP2 focused on developing and validating BamBam core technological building blocks. Using UPD to print thin conductive lines over the large 3D topology of microIC and µLED was a major challenge. The team systematically investigated and optimized pixel substrates, conductive inks, and printing conditions to yield high-resolution printing and reliable electrical connections. Another challenge was to develop a colour conversion module based on Quantum Dots (QD) inks deposited on top of the µLED by UPD to convert the blue light emitted by µLED into red and green. The development of these QD inks and of the printing process conditions required several iterations to avoid clogging of the printer. The feasibility to integrate these technologies was demonstrated in a series of test vehicles, culminating in the successful light-up of a 4×4 pixel matrix. This milestone validated the feasibility of the BamBam approach and provided critical insights into process optimization, yield improvement, and material compatibility.
WP3 tackled the complex challenge of assembling all technological bricks—µLEDs, QDs, printed interconnects, and advanced substrates—into functional display demonstrators. WP2 used ALEDIA’s R&D µLED which is not compatible with the specifications of the BamBam demonstrator. A µLED package based on the nanowire technology was thus developed to be compatible with the BamBam pixel integration process. The partners also optimized and automated the printing of conductive lines and QD inks using UPD. The BamBam concept requires the transfer of thousands of microIC and µLED onto a PCB, from which pixels can be singulated before being picked and placed onto a display board. This transfer is achieved using the mass transfer technology. The consortium used a mature technology – i.e. mass transfer with anchor and tether - to transfer microICs. In parallel, significant effort were dedicated to develop a new µLED mass transfer process using stamp and adhesive. Through iterative process optimization and collaborative engineering, the team achieved the successful fabrication and provisional light-up of integrated pixels, validating the core concepts and compatibility of the BamBam approach. While some technical challenges remain—particularly in scaling up yields and finalizing the back-end processes—WP3 delivered a nearly complete demonstrator and provided essential insights for future industrialization.
WP4 aimed at optimizing and calibrating the display demonstrator. The consortium faced several technical challenges and could not deliver a fully populated display demonstrator before the end of the project. Activities WP4, thus concentrated on derisking the optimization of the demonstrator.
The consortium gained significant knowledge in pixel integration, covering areas such as surface treatment, printing sequence and interdependencies, wire printing mapping and automation, as well as colour conversion module design and optimization. Aledia has filed two patents, and the consortium has published numerous scientific papers.
WP1 established the specifications for materials, processes, and pixel integration, resulting in a disruptive design based on an advanced European printing technology: the Ultra Precise Deposition (UPD). The BAMBAM concept has been benchmarked against LCD and OLED technologies, using iterative Life Cycle Assessments to guide design choices and highlight environmental hotspots. These analyses confirmed that the concept outperforms LCD in most environmental impact categories but also identified technical areas to further improve environmental performance. Market and industrial studies pinpointed professional video walls for simulation and healthcare as promising applications for the BamBam concept. Current pixel costs estimates highlight the need for process parallelization and automation.
WP2 focused on developing and validating BamBam core technological building blocks. Using UPD to print thin conductive lines over the large 3D topology of microIC and µLED was a major challenge. The team systematically investigated and optimized pixel substrates, conductive inks, and printing conditions to yield high-resolution printing and reliable electrical connections. Another challenge was to develop a colour conversion module based on Quantum Dots (QD) inks deposited on top of the µLED by UPD to convert the blue light emitted by µLED into red and green. The development of these QD inks and of the printing process conditions required several iterations to avoid clogging of the printer. The feasibility to integrate these technologies was demonstrated in a series of test vehicles, culminating in the successful light-up of a 4×4 pixel matrix. This milestone validated the feasibility of the BamBam approach and provided critical insights into process optimization, yield improvement, and material compatibility.
WP3 tackled the complex challenge of assembling all technological bricks—µLEDs, QDs, printed interconnects, and advanced substrates—into functional display demonstrators. WP2 used ALEDIA’s R&D µLED which is not compatible with the specifications of the BamBam demonstrator. A µLED package based on the nanowire technology was thus developed to be compatible with the BamBam pixel integration process. The partners also optimized and automated the printing of conductive lines and QD inks using UPD. The BamBam concept requires the transfer of thousands of microIC and µLED onto a PCB, from which pixels can be singulated before being picked and placed onto a display board. This transfer is achieved using the mass transfer technology. The consortium used a mature technology – i.e. mass transfer with anchor and tether - to transfer microICs. In parallel, significant effort were dedicated to develop a new µLED mass transfer process using stamp and adhesive. Through iterative process optimization and collaborative engineering, the team achieved the successful fabrication and provisional light-up of integrated pixels, validating the core concepts and compatibility of the BamBam approach. While some technical challenges remain—particularly in scaling up yields and finalizing the back-end processes—WP3 delivered a nearly complete demonstrator and provided essential insights for future industrialization.
WP4 aimed at optimizing and calibrating the display demonstrator. The consortium faced several technical challenges and could not deliver a fully populated display demonstrator before the end of the project. Activities WP4, thus concentrated on derisking the optimization of the demonstrator.
The consortium gained significant knowledge in pixel integration, covering areas such as surface treatment, printing sequence and interdependencies, wire printing mapping and automation, as well as colour conversion module design and optimization. Aledia has filed two patents, and the consortium has published numerous scientific papers.
The BamBam consortium successfully demonstrated the ability to design and manufacture a 325 µm RGB digital pixel by (1) printing the µIC and µLED by mass transfer onto a PCB and (2) by using UPD to print interconnections (silver-based wiring), and quantum dots for light conversion.
BamBam demonstrated for the first time the feasibility to print very fine interconnection (5µm width) onto objects with a challenging 3D topology and placed onto a flexible substrates. This has the potential to reduce the size requirements of interconnects in design rules for flexible display, hence reducing the cost of their production.
BamBam demonstrated the feasibility to use UPD to print a QD-based colour conversion layer on top of blue µLEDs. This could represent a significant competitive advantage for displays where costs constraints prevent the use of native RGB µLEDs.
Finally, BamBam demonstrated that the micro-transfer printing technology (i.e. mass transfer) can operate even beyond its initially intended scope (Anchor & Tether) for the transfer of small µLEDs from tape. However, significant challenges remain to be addressed.
To transition from prototype to industrial production, a robust manufacturing process flow must be consolidated, including the selection and adaptation of the necessary equipment. For example, a multi-nozzle printer is essential for quantum dot deposition, and switching from wire printing to electroplating is a sensible choice for interconnections. µLEDs should also be reduced in size to achieve the cost targets for the final product. Adopting an industrial production mindset, with the final product in view, is critical to advancing toward large-scale manufacturing.
BamBam demonstrated for the first time the feasibility to print very fine interconnection (5µm width) onto objects with a challenging 3D topology and placed onto a flexible substrates. This has the potential to reduce the size requirements of interconnects in design rules for flexible display, hence reducing the cost of their production.
BamBam demonstrated the feasibility to use UPD to print a QD-based colour conversion layer on top of blue µLEDs. This could represent a significant competitive advantage for displays where costs constraints prevent the use of native RGB µLEDs.
Finally, BamBam demonstrated that the micro-transfer printing technology (i.e. mass transfer) can operate even beyond its initially intended scope (Anchor & Tether) for the transfer of small µLEDs from tape. However, significant challenges remain to be addressed.
To transition from prototype to industrial production, a robust manufacturing process flow must be consolidated, including the selection and adaptation of the necessary equipment. For example, a multi-nozzle printer is essential for quantum dot deposition, and switching from wire printing to electroplating is a sensible choice for interconnections. µLEDs should also be reduced in size to achieve the cost targets for the final product. Adopting an industrial production mindset, with the final product in view, is critical to advancing toward large-scale manufacturing.