Wearable electronic textiles are a demanding environment for reliable interconnects – the ability to function with movement and survive multiple cleanings and reuse. Good adhesion is particularly challenging in these wearable and conformable electronics applications. While solders provide the most conductive electrical connection, they are rigid and require not only the addition of an underfill adhesive but usually a post bond encapsulation. SunRay Scientific’s ZTACH® ACE, Anisotropic Conductive Epoxy, provides reliable interconnections between electronic components and circuitry on textiles with excellent structural bonding, without encapsulation, even under repeated stretching and washings. ZTACH® ACE has been shown as a scalable assembly process for e-Textile manufacturing in an SMT line. Video of resistors, voltage regulators and LEDs applied to stretchable conductive silver and carbon inks, printed on TPU, with no encapsulation, going through extreme stress and easily surviving to remain functional Anisotropic electrically conductive adhesive compatible with automated SMT Processing ZTACH® ACE, an Anisotropic Conductive Epoxy, allows for simultaneous Z-axis connections of all the devices on a board, sheet or fabric, across large formats. It requires no patterning, no bonding pressure, and can be cured at low temperatures. ZTACH® ACE can adhere to a wide range of substrates, including PET, TPU, various textiles and PCBs. This material acts as its own underfill, providing superior adhesion and shear strength, eliminating the need for a secondary underfill or post-bond encapsulation. ZTACH® ACE can achieve fine pitch down to 100-microns. Less than 50 microns pitch is currently in development. Figure 1: ZTACH® ACE - Columns This video is a high magnification x-ray cross-section in real-time of ZTACH® ACE, placed upon the ZMAG™ Magnetic Pallet, while simultaneously undergoing curing. ZTACH® ACE works by the magnetic alignment of ferromagnetic-conductive particles through SunRay’s patented ZMAG™ magnetic pallet. As illustrated in Figure 1 and shown in the video, once placed on the ZMAG™ Pallet, these particles immediately align into z-axis “wires” magnetically held in place while the resin is hardened by the curing process. This electrically connects the device to the circuit. Because of the very low particle filler percentage, the resin creates exceptionally higher bond strength for the device versus traditional attachment methods. Since ZTACH® ACE is basically an underfill with conductive Z-axis columns throughout, it creates electrical conductivity at the pad locations and thermal dissipation between – all done while maintaining electrical insulation in the X-Y plane. Good performance of ZTACH® ACE has been demonstrated through thousands of components interconnected on hundreds of sheets on high volume SMT/reflow lines. ZTACH® ACE overcomes limitations of conventional solders Unlike solder, ZTACH® ACE provides both the electrical connection and the underfill. Most solder connections on a flexible substrate traditionally require the addition of an encapsulant for protection and for maintaining adhesion of the less flexible interconnection joints. ZTACH® ACE has demonstrated reliability without the need for an encapsulant. This eliminates a manufacturing step and the localized rigidizing created by an encapsulant, with a less bulky product profile. No encapsulant is especially beneficial in LED applications as the clarity of the LEDs are not interfered by the addition of an optically clear covering. Nor is the performance over time impacted by the aging characteristics of an encapsulating material. This is particularly useful for the optimal performance of UV LEDs in medical applications. Figure 2* shows the results of reliability testing of components attached with ZTACH® ACE on printed silver circuits, successfully assembled at Molex’s Printed Circuit Solutions SMT line. All parts tested with and without an encapsulation coating passed! Figure 2: *This material is based on research sponsored by Army Research Laboratory under Cooperative Agreement Number W911NF-19-2-0345. The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the official policies, either expressed or implied, of the Army Research Laboratory or the U.S. Government. The U.S. Government is authorized to reproduce and distribute reprints for Government purposes notwithstanding any copyright notation thereon. Wearable electronics present challenges beyond traditional SMT circuit boards or flexible circuits Electrically functional textiles require maintaining good connections between devices and circuitry printed on or woven into, the wearable fabric. Adhesion is particularly a challenge between the rigid die and the stretching or moving fabric. ZTACH® ACE is applied in a single stencilling step, followed by magnetizing and curing. The material is applied across the entire footprint of the component to provide both interconnection and structural bonding to the electrical circuitry on the fabric. ZTACH® ACE stabilizes the interconnect sites - the Z-axis columns of aligned particles, held in place by the epoxy resin, allow for flexing of the surrounding textile while maintaining electrical connection. Based on a funded project by Advanced Functional Fabrics of America (AFFOA), a United States Manufacturing Innovation Institute, Project Call 2.0 program, SunRay Scientific and UMASS Lowell developed functional e-Textile sheet-to-sheet fabrication and demonstrated scalability on a SMT line. The project[1], “Reliable High Density Conformal Electrical Interconnects for Dynamically Active Flexible Textile Functionalization”, attached LEDs to woven conductive wire circuits in fabric. Figure 3 (Left): LEDs attached on SMT line with ZTACH® ACE on fabric with woven conductive wires and Video (right) showing post-assembly functionality1. These operational e-Textiles were subjected to washing and drying cycle testing. [1] This material is based on research sponsored by U.S. Army ARDEC under Agreement number W15QKN-16-3-0001. The U.S. Government is authorized to reproduce and distribute reprints for Governmental purposes. Despite notable progress being made in e-Textiles, significant challenges remain relative to functionality, reliability, scalability, and cost. Robust interconnects have been repeatedly noted as a primary challenge in both conformal Flexible Hybrid Electronics and Stretchable e-Textiles. SunRay Scientific’s innovative z-axis conductive adhesive is compatible with integrating into an SMT line with reduced steps, no pressure, and at low temperature. ZTACH® ACE, with minimal design requirements, is easily incorporated into current or new product designs while supporting miniaturization and light-weighting of electronic assemblies and wearable e-textiles. ZTACH® ACE has been shown to be a reliable interconnect solution over conventional methods and has demonstrated scalable production of wearable electronics. 22 Meridian Road, Unit 1 * Eatontown, NJ 07724 * www. sunrayscientific.com This research was, in part, funded by the U.S. Government. The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the official policies, either expressed or implied, of the U.S. Government

Electrochromic technology enables layers that can change color or become transparent using an electrical current. Compared to other color-changing technologies such as photochromism and thermochromism, electrochromic devices can be perfectly controlled to achieve the desired transparency at any time. While the technology has been discovered almost 50 years ago, only recently have commercial applications emerged, mainly in electrochromic glass for automotive rearview mirrors and airplane windows. A large potential market for electrochromic devices is in smart windows, where they show promise to save energy. The building sector accounts for over 50% of greenhouse gases produced annually, and building operations, including heating and cooling, account for close to 30% of this number (source: 2021 Global Status ABC Report). Using electrochromic devices, it is possible to implement energy-saving control strategies that beat any other glazing with static optical properties. However, the main challenge remaining to having this technology becoming more widespread is the high cost of electrochromic modules. Brilliant Electrochromic Materials Seeing this market challenge, we saw an opportunity for using our organic semiconductors (OSCs) to create a line of products dedicated to electrochromic devices. As OSCs can be modified, it is possible to devise them to be easy to formulate into inks, which opens cost-effective manufacturing from simple printing techniques on rigid (ex: glass) or flexible (ex: plastic, fabric) substrates. Being carbon-based and easy to modify at the molecular level, just like dyes and pigments, our products are color-tunable and can create more aesthetic and colorful electrochromic glass than any competing technology. As a first line of product, we created four individual materials close to the primary colors used in CMYK printing inks (CMYK, for Cyan, Magenta, Yellow and Black). The materials were tested individually in test devices and all produce color change when a voltage below 5V is applied. See our video of a demonstration device of the magenta material. All devices are completely haze-free. Figure 1: Colorful CMYK organic semiconductors from Brilliant Matters (deposited using spin-coating on glass) All the products are equally soluble in solvents such as toluene or xylene, which enables their use in fluid inks compatible with most current deposition techniques, including slot-die, inkjet, or spray coating. Their soluble, particle-free nature also ensures they form haze-free and uniform layers with controllable thickness. For example, using a single color, the color changes from pale to very intense by varying the film thickness when changing ink deposition parameters or ink loading. Figure 2: Example of color tuning from our magenta color using various thicknesses (deposited using spin-coating on glass) This ability to make soluble inks also brings another benefit, where it is possible to be creative and make other colors from the originals by blending the materials. We tested mixing the materials together to create new colors, for example, by mixing yellow and magenta to make an orange electrochromic device. A peculiar behaviour coming from this is that the materials, even incorporated into a single layer, will change color separately at their respective switching voltages. In this case, we observe a gradual switch from orange to yellow to light blue (transmissive state). This happens because the magenta material switches color at a lower voltage than the yellow one, enabling multiple color changes from a single device if needed, without adding any complexity to the manufacturing process. (see video). Figure 3: Example of color tuning from our magenta color using various thicknesses More importantly, this opens the possibility to achieve a very wide range of colors from a basic set of materials. By measuring the optical properties of the materials, namely their light-absorption spectra and absorption coefficients, we can make a predictive tool to blend the materials to achieve the desired color. This ability to blend colors predictably like regular inks is key to enable electrochromic devices that are printed into complex graphical designs, for example with inkjet printing. The materials show good robustness in devices, as we observed only small changes in the device visual transmittance over 500 cycles. However, the devices we made at this stage are not optimized, and choices in electrolyte and electrodes, as well as contaminant management, can play a large role in electrochromic device durability. In our ongoing developments on our technology, and through strategic partnerships, we believe we can lower cost modules with our materials and reach state-of-the-art durability of over 10000 cycles of color change, a milestone that is often reached with R&D organic electrochromic devices. Table 1. Average visual transmittance of a magenta non-optimized electrochromic test device after 1 to 500 voltage cycling tests Conclusion and outlook In conclusion, Brilliant Matters has developed a unique set of materials for producing colorful electrochromic devices. The main features we demonstrate for the products are: - Colorful organic electrochromic materials in CMYK colors. - Blending materials can create predictable new colors. - All materials are processable into fluid inks that form haze-free films. - Demonstrated reversibly cycle from colored to bleached state. - Forms fluid ink formulations compatible with slot-die, inkjet and spray coating. Using this line of products, improved aesthetics can be achieved for smart windows as well as other applications including automotive, smart labels, IoT or advertising. From this line of products, Brilliant Matters hopes to create a complete set of compatible and ready to use inks to make fully functional and robust modules using standard printing equipment. Company summary Brilliant Matters was created in 2016 by passionate material scientists to bring to market a new generation semiconductor that are the foundation to create a new sustainable electronics industry. Our company operates as a research and chemical manufacturing company for organic electronics materials used in emerging printed electronics, who need a specialized partner to develop and reliably supply key materials that critically impact their product’s competitivity on the market. By using our material development platform and clean production technologies, we provide reliable and highly customizable semiconductors from R&D to pilot scale for applications that include printed solar cells, electrochromic devices, SWIR sensors, microchips and more. www.brilliantmatters.com

The three themes are closely linked since QDs can be digitally printed as color conversation materials atop blue microLEDs to enable wide color gamut RGB uLED displays without requiring a separate transfer step for each color. Join TechBlick's event on microLEDs to learn more https://lnkd.in/eDRi5kp2 Inkjet is the common technology investigated for such a purpose. As shown below by Prof.Armin Wedel, however, its 4pL droplet is too large, allowing at best a 40um pixel and not able to reach even 850 dpi Electrohydrodynamic printing (EHD) can however address this issue. In EHD, the droplets are pulled out by an electric field from a nozzle which sits close (50um or so) to the surface and thus requires a good printing facility. As shown below, the droplet volume is only 0.5pL, enabling 1-10um pixels in the lab and 15um reproducibly. This will enable one to achieve 850ppi and 1000ppi! Slide 2 shows an example of a QD color filter (QD-CF) for a microLED display deposited using EHDJet. Here, 15um pitch is reported, achieving 1000ppi. The roadmap will be to evolve the technology towards even 2000ppi! These are excellent advacements of the art and technology, paving the way for the development of high-PPI microLED technology Of course, EHDJet is a relatively new technology. It is mainly single head and slow, although multi-head print heads are emerging. Nonetheless, it is an elegant solution for depositing color filters on high-PPI microLED displays. To learn the latest about these technologies joint TechBlick's specialist event on microLEDs and Quantum Dots where Prof. Wedel will also present: www.TechBlick.com/microLED You can hear from the likes of Samsung, Sharp, Yole, ASMP, Coherent, Nanosys, CEA, AUO, Allos Semiconductor, KIMM, Luxnour, Omdia, Playnitride, micromac, and many many more Manuel GenslerYohan KimFraunhofer-Institut für Angewandte Polymerforschung IAP

Printed batteries offer thinness and flexibility, enabling new applications, but their production is deceivingly complex. Gunter Hübner from Stuttgart Media University offered some insights at the e-Swiss conference last week. The first slide shows an excellent benchmarking of different battery chemistries for printed batteries. The Zinc/manganese dioxide system is the most popular option. As shown in slide 2, we see that these batteries can be manufactured in two architectures: coplanar and stacked. The former is simpler to print and is more flexible, but offers lower performance. In slide 3, a closer look at the layers in a stacked printed battery is offered. As seen here, even this so-called 'simple' device involves many printing step! Since Ag is not electrochemically inert, a carbon black layer is also printed. The particles in the anode and cathode are typically in the 10-50um range and thus can only be screen printed. Note that the cathode is typically 1.5x thicker than the anode. The printed battery layers typically have 150um thickness and the batteries achieve something in the range of 2-6mAh per cm2. Furthermore, in printing them, strong adhesion of the electrodes to the current carriers is essential. All these show how complicated it is to print even a simple zinc/manganese battery - it involves significant know-how and learning, which can not be achieved overnight! The final slide shows an elegant clever approach to printing the system. Here, the materials are printed on a planar sheet and then folded to create the full battery stack. This technology is now being commercialized by VARTA AG . It also has commercial orders in applications such as tracking items in the chemical industry. To learn more about printed batteries join us on 12 & 13 October 2022 | Eindhoven, Netherlands at the TechBlick show- where the printed electronics community connects www.TechBlick.com/electronicsreshaped

At the e-Swiss conference last week we came across an interesting technology showcased in a poster. Here, the process is called "Multi-metal electrohydrodynamic redox 3D printing" and developed by R. Spolenak's team at ETH Zurich Slide one shows the working principle: "Solvated metal ions Mz+ are generated within the printing nozzle via electrocorrosion of a metal electrode M0 immersed in a liquid solvent. (2) Ion-loaded solvent droplets are ejected by electrohydrodynamic forces. (3) Upon landing, Mz+ ions are reduced to zero valence metal M0 through electron transfer from the substrate." As shown the metal ions are generated in a solvent from an immersed wire thus eliminating the need for a liquid formulated ink in the deposition technique. Furthermore, as seen below, the ability to print multi materials using a single voltage-controlled nozzle enables one to adjust the chemistry and composition of the deposited materials on-the-fly, thus not only enabling layer-by-layer variation of materials but also enabling much more granular changes in composition and alloying Given that this is based on electrohydrodynamic printing- in which the droplets are injected under the application of a voltage- the feature sizes are in the sub-micron range. Slide 2 shows various examples of printed Cu structure, using the extreme control of the process as well as its excellent feature size capability This is a very promising technology with a high potential for future development. It is of course still early stage but could it be the basis of a holy grail process which combines ink-free, micro-scale features, digital printing, and on-the-fly multimaterial compositional control? To learn more about printing electronics join us in Eindhoven where the printed electronics community connects: https://www.techblick.com/electronicsreshaped Source: https://doi.org/10.1038/s41467-019-09827-1

Nano-Ops is commercialising an automated wafer-based process and fab-in-a-box based on the directed assembly technology which can 'print' features down to 20nm. Here, In the first step a pattern is first etched into a template wafer. This is achieved using conventional photolithography-based techniques. Next, the template wafer is 'inked' using a directed assembly process. In the key step, the template wafer is immesed in a solution containing the nanomaterial of choice - which could, for example be metals (Au, Ag, Cu, etc) or even organic polymers. Under the application of a voltage, the directed assembly process ensures the inking of the template wafer, i.e., the deposition of the nanomaterials onto the etched patterns on the template wafers. The 'inked' wafer is then used as a printing plate. The automated machine takes the wafer and brings it into precision contact with the target substrate, which could be PET. Under pressure, contract printing takes place, transfering the ink from the inked wafer onto the final substarte. The process is then repeated to achieve high-throughput wafer-based printing. The template wafer is said to be resubale upto 100 times or more. Nano-Ops has shown that all types of materials can be deposited using various directed assembly techniques (electrophoretic and fludic). Slides one and two below shows example of different materials and patterns deposited on an patterned wafer (on the template wafer) using this technique. The feature sizes range from a few mironmeters down to 20 nanometers. In slides three and four show an example of a fan-out circuit printed. The gold structure are 12um feature. The thicknesses are typically between 300nm and 1um with upto 50% of bulk conductivity achieved on the inked wafer. Indeed, as seen in slide 4, the I-V characteristics of the 800nm-thick 'printed' Cu lines are comparable to that of 800nm sputtered Cu lines. This is a unique technique full of potential. When the entire process (directed assembly + alignment + transfer + consistency across multiple print runs ) is optimized for a given material set and layer structure in a given application, then it could lead to rapid 'printing' of nanoscale complex multiplayer and multi-material devices at costs far below standard silicon fabs and at resolutions far beyond the reach of stnadard printing techniques. Ahmed et al will be showcasing and presenting this technology in Eindhoven on 12-13 OCT 2022 at the TechBlick show. Learn more here https://www.techblick.com/electronicsreshaped

Speaker: Margaud Lecuyer | Company: BlueSolutions | Date: 9-10 Feb 2022 | Full Presentation BlueSolutions has been commercializing all-solid state batteries since 2011. EVs, buses and stationary applications are the main targets of its research and development program. After more than 15 years, this Bolloré group subsidiary masters all the industrial processes for the production of a unique solid state battery technology. The know-how goes from the transformation of the lithium ingots to the integration of the battery packs within the applications. Importantly, a low-ecological footprint process has been stated for both the positive electrode and the polymer electrolyte manufacturing. In order to get incomparable energy densities, today, all the industrial actors of lithium batteries are hardly working on the lithium metal technology. In this context, BlueSolutions has a unique 10 years feedback regarding both the behavior of this special anode and of the solid-state electrolyte. After having spread the first pack generation for 8 years all-over the world, an optimized 650V battery pack addressing the e-buses market is being delivered for one year. To match with customers expectations this new generation offers optimized performance and a very long cyclability. In the meanwhile, BlueSolutions has already started working on its future generation products. While the current battery is LFP-based and cycles at a nominal temperature of 80°C, a lot of efforts are dedicated to improve the actual chemistry. Research programs are conducted on the development of a new positive electrode with higher energy density, new electrolytes that will be compatible with high-voltage materials and which have high conductivity at ambient temperature and optimized lithium electrode. In fine, the goal is to keep the intrinsic safety of the polymer solid electrolyte, while benefiting from the promising performances of new electrode materials. Join TechBlick on an annual pass to join all live online conference or online version of onsite conference access library of on-demand talks (600 talks + PDFs) portfolio of expert led masterclass year-round platform https://www.techblick.com/ Our next battery-related event will take place on 15-16 FEB 2023, covering 1) Solid-State Batteries: Innovations, Promising Start-Ups, & Future Roadmap 2) Battery Materials: Next-Generation & Beyond Lithium Ion The speakers include: General Motors, Graphenix Development, Brookhaven National Laboratory, Fraunhofer IKTS, RWTH Aachen University, Lawrence Livermore National Laboratories, Meta Materials Inc, Skeleton Technologies, Solid State Battery Inc, Argonne National Laboratories, OneD Battery Sciences, VTT, Leyden Jar Technologies B.V., b-Science, Rho Motion, Wevo-Chemie, LiNA Energy, CNM Technologies, Ionblox, Empa, Zinc8 Energy Solutions, Avicenne Energy, Echiontech, South8 Technologies, Basquevolt, NanoXplore, Chasm, Li Metal, Sila Nanotechnologies, Quantumscape (tentative), Fraunhofer ISI, etc https://www.techblick.com/

of Today’s Advanced High Performance Systems Speaker: Alfred Zinn | Company: Kuprion Inc| Date: 10-11 March 2021 | Full Presentation In today’s market, electronic systems have become ever more complex while current design methods for PCBs are limiting and inadequate. New approaches are needed to meet reliability demands for increased power dissipation and thermal management of advanced high performance systems. In this presentation, Kuprion, a spinout of Lockheed Martin, will not only detail these challenges, but demonstrate how new, innovative technologies like Active Cu (ActiveCopper™) filled thermal vias are addressing the requirements for more robust interconnect structures to enable thinner, cooler, more compact and reliable operating devices. Join TechBlick on an annual pass to join all live online conference or online version of onsite conference access library of on-demand talks (600 talks + PDFs) portfolio of expert led masterclass year-round platform https://www.techblick.com/ And do NOT miss our flagship event in Berlin on 17-18 OCT 2023 focused on Reshaping the Future of Electronics. This event attracts 550-600 participants from all the world and offers a superb ambience and dynamic exhibition floor. To learn more visit https://www.techblick.com/electronicsreshaped To see feedback about previous event see https://www.techblick.com/events-agenda

Printable dielectrics for RF, Bonding in heterogeneous integration Welcome to this week edition of our technology newsletter with a focus on additive electronics. One housekeeping note: the masterclass and tour spaces taking place before our inaugural conference and exhibition in Eindhoven (Future of Electronics RESHAPED | 12-13 OCT 2022) are almost full. We are now in tocuh with venue to see if additional space can be released. We recommend that your reserve your spot ASAP. Topics for this week: EHDjet printed QDs on microLEDs | R2R single-step gravure printed perovskite photovoltaics | Gravure printed microbumps for microLEDs | 3600ppi full color "silicon" displays | Lasers in microLEDs | Printable dielectrics for RF and MW devices | Pitch scaling and bonding in heterogeneous integration | Microfluidics and Electrohydrodynamic printing | Graphene to market: breaking down regulatory barriers. High-PPI RGB microLEDs, printed electronics, and quantum dots? The three themes are closely linked since QDs can be digitally printed as color conversation materials atop blue microLEDs to enable wide color gamut RGB uLED displays without requiring a separate transfer step for each color. Join TechBlick's event on microLEDs to learn more www.TechBlick.com/microLED Inkjet is the common technology investigated for such a purpose. As shown below by Prof.Armin Wedel, however, its 4pL droplet is too large, allowing at best a 40um pixel and not able to reach even 850 dpi. Electrohydrodynamic printing (EHD) can however address this issue. In EHD, the droplets are pulled out by an electric field from a nozzle which sits close (50um or so) to the surface and thus requires a good printing facility. As shown below, the droplet volume is only 0.5pL, enabling 1-10um pixels in the lab and 15um reproducibly. This will enable one to achieve 850ppi and 1000ppi! Slide 2 shows an example of a QD color filter (QD-CF) for a microLED display deposited using EHDJet. Here, 15um pitch is reported, achieving 1000ppi. The roadmap will be to evolve the technology towards even 2000ppi! These are excellent advacements of the art and technology, paving the way for the development of high-PPI microLED technology. Of course, EHDJet is a relatively new technology. It is mainly single head and slow, although multi-head print heads are emerging. Nonetheless, it is an elegant solution for depositing color filters on high-PPI microLED displays. To learn the latest about these technologies joint TechBlick's specialist event on microLEDs and Quantum Dots where Prof. Wedel will also present: www.TechBlick.com/microLED You can hear from the likes of Samsung, Sharp, Yole, ASMP, Coherent, Nanosys, CEA, AUO, Allos Semiconductor, KIMM, Luxnour, Omdia, Playnitride, micromac, and many many more R2R gravure print perovskite photovoltaics in a single step without antisolvents? This would be a major step towards industrialization. Here, we discuss the transition from 2-step printing to one step printing with antisolvent to one-step printing with no antisolvents. Riikka Suhonen et al discussed the latest developments at TechBlick's event in Dec 2022. Here is a summary 2-step approach: In general, most approaches are based on a 2-step printing in which the lead iodide (from PbI2-DMSO ink) is first gravure printed on a printed SnO2 NPs layer and then dried. The DSMO is then washed away in a water and isopropanol path and the remaining porous layer is dipped into a chemical second path to form MAPbl3. The 'pilot' R2R runs yield PCE of 9.7%. This approach requires two chemical steps, slowing the process. Furthermore, handling the porous Pbl3 layer is difficult in R2R environment and oncersion to FA- or FACs-perovskite challenging 1 step printing + antisolvet: the standard antisolvent is ether but this can not be printed due to high volatility. Therefore, there has been huge effort in developing an antisolvent which could be printed industrially and was environmentally friendly. VTT et al developed the tBuOH:EA system. This way they achieved fully R2R gravure printed perovskites with efficiency of 13.8%. This is an elegant solution. Nonetheless, There is a desire to eliminate the antisolvent step as it will require a spray or bath step together with solvent fumes. 1 step printing: Here they used starch as a rheology modifier with perovskite precursor, forming a viscous ink which can be used to print well-defined patterns. In this R2R 'lab' printing starch-based MAPb3I inks they used IR annealing and hot air annealing. The first lab runs showcased a champion result of PCE 9.9%. This is still an early stage development but shows that reasonble efficiencies can be achieved using R2R gravure printing with only a single step! Of course - these results are early stage. Lifetime remains an issue and development area. Nonetheless, this is an important field to watch further. We will soon announce the agenda for our 2022 edition of TechBlick's event on organic, perovskite, and tandem photovoltaics. Riikka Suhonen, Antti Kemppainen, Ari Alastalo, Jani-Mikael Kuusisto, Thomas Kraft, Henrik Sandberg Gravure printed microbumps for microLEDs As microLEDs inevitably shrink in size, the micro-bumping requirements for the microLED dies becomes more challenging. Direct wafer-based printing based on gravure offset techniques offers a promising solution in this regard. Indeed, this is another field where printed electronics can play a role. Komori has recently achieved excellent results, which will be unveiled at TechBlick's upcoming microLED event on 30 Nov-1 Dec 2022: www.TechBlick.com/microLED As seen in the slides below, gravure printing can print microbumps printed using flux paste, achieving a printing precision of 5 µm within a range of 300 mm. The first slides show the precision of the printing position on a wafer. In particular, it compares it with screen printing, showing how gravure printing advances the fine feature printing capability w.r.t screen printing (+/-10 um although screen printing too can and will also advance) As shown in slide two, the minimum diameter that can be printed with SAC (Sn, Ag, Cu) solder paste is 6 μm and the distance between the centers of the bumps is 30 μm. Reflow has been successful with a minimum diameter of 10 µm. This way for example, a microLED die in the size of 30um by 50 or 80um can be supported. Furthermore, as shown in slide three, this technique also offers the possibility to control the thickness by printing several diameters. The smaller the bump diameter, the higher the aspect ratio. This are very nice results, showing the viability of gravure printing technique for microbumps. This technology can support current and near-term generations of microLEDs but will it evolve as microLED dies further shrink in the longer term? Join Komori and other members of the community to learn about all aspects of microLEDs from GaN microLED technology to transfer and tiling technology to bumping and color conversion technology and beyond. You can hear from the likes of Samsung, Sharp, Yole, ASMP, Coherent, Nanosys, CEA, AUO, Allos Semiconductor, KIMM, Luxnour, Omdia, Playnitride, micromac, and many many more www.TechBlick.com/microLEDs “Silicon” Displays with an incredible 3600ppi full color using microLED and QD technology? Sharp (HIRANO Yasuakie et al) will join us from Japan to explain this technology at the upcoming TechBlick event on microLEDs and quantum dots (www.TechBlick.com.microLEDs). As shown in the slide below, first blue-only uLEDs are formed on a sapphire substrate. Here, one LED array contains 352 x 198 micro LED dies of 24 um x 8 um in size. In parallel, an LSI chip containing the driving circuitry is formed on a silicon wafer. Here, the cathode (N-type electrode) and anode (P-type electrode) are fabricated for each micro LED die to apply driving voltage independently to each die. The Au bump electrodes are fabricated in accordance with the pitch of the LED dies. The two substrates are flip-chip bonded using Au-Au bonding. Here one can already see the parallel to the silicon and optoelectronic industry (vs. the traditional thin film display industry!). Next, the sapphire layer is removed via laser lift-off. Finally, Cd-free quantum dots (green and red) are deposited atop the microLED dies to enable R G color conversion. This way one achieves RGB colors. The device architecture is shown in slide 2- here one can see the location of GaN uLED dies, Au bumps, as well as light shielding walls and quantum dots (QDs). This way, a full color 1,053 ppi display is formed. However, given the small size of the emissive area of uLEDs, the brightness is low. An innovative solution here is to switch from individual driving cathode electrodes to a common one, thus freeing up more spaces for uLEDs. As shown in slide three, the light emission in one pixel was improved from 23% to 38%. As a result, brightness of 11 knits was achieved. This is an excellent progress. Of course, it is not the final game as even at 11 knits the brightness is not yet not sufficient for outdoor AR applications. Join us and your industry peers on 30 NOV – 1 DEC 2022 at our first-ever specialist microLED and QD event to hear more about this technology from Yasuakie-san et al: www.TechBlick.com/microLED How lasers help in MicroLED display production? See slides below to learn. One of the biggest manufacturing challenges in uLED display production is the transfer step given the speed and yield requirements. As shown in the slides below by Oliver Haupt from Coherent Inc., lasers can play an important role in this step, both when all three colors (R G B) microLEDs and also when only blue microLEDs need to be transferred. To learn more join TechBlick's first ever specialist event on microLEDs on 30 NOV - 1 Dec where Oliver will present this technology www.TechBlick.com/microLED The process flow for both cases is shown below. In case of RGB MicroLEDs, first a temporary carrier is attached to the sapphire substrate on which GaN uLEDs are grown. Laser Lift Off (LLO) is deployed to de-bond the sapphire substrate, releasing the carrier wafer with the detached GaN microLEDs. Next, controlled UV spots are used to release the individual microLEDs onto the final substrate holding the TFT active backplane layers. These process can be repeated three times, each time for a different uLED color. In all steps, of course, excellent and optimized control of the laser profile/parameters in harmony with the right adhesive material properties are required. In the case of blue-only microLEDs, the final backplane substrate is brought into contact with the GaN sapphire substrate. The GaN uLEDs transfer to the final substrate via the LLO process. Three color capability is then achieved by color conversation, e.g., QDs or small-sized phosphors. The results show the example of microLED RGVB transfer. The parameters are shown in the slide including microLED size, pitch, laser energy density, donor-receiver distance, etc. It can be shown that a different color is transferred with each shot. Thus, in three shots all R G B microLEDs are placed at the right spot! As the subset in slide 2 shows, the laser can in each step/shot process an area of roughly 2.83cm2. To learn more join our world-class event on microLEDs and QDs. More info on www.techblick.com/microLEDs Heterogenous integration is the key to the future of computing Here, the limiting factor is often the interconnect density (pitch) as well as bandwidth and energy consumption of the I/O. Indeed, as we move towards platforms where multiple dies, potentially from different foundries, are all integrated into the same package, the issue becomes extremely important because die-to-die communication becomes the bottleneck. The first slide below are from Intel, presented by Dr Sabi at a conference in Sept 2021 online. Here, you can see the intended evolution of the technology. First, EMIB was launched. Here, a silicon bridge with <55um pitches serves as a small (2x2mm to 8x8mm) communication link between two separate dies in a package. This approach is an alternative to the standard silicon interposer technology. Next was the development of Foveros platform, allowing face-to-face integration of dies from different foundries onto a single package all connected via silicon base logic die. As you can see, this technology will evolve with aggressive pitch scaling and a potential transition to direct Cu-to-Cu bonding from microbumps. The second slide shows this trend further. It shows the evolution of interconnect pitch as heterogeneous integration advances. The common technology is flip chip BGA (FCBGA). The pitch here is limited to around >120um. Next, EMIB was launched. Here, the pitch was reduced to 55um thanks to the silicon bridge technology. Now there is Fovereos which is based on die on wafer technology. The next generation will based on HBI or hybrid bonding. These heterogenous integration platforms can enable the integration of dies from different foundries. The challenge is though that each foundry has its own I/O designs, making easy compatibility difficult. It is helpful for the industry to develop common standards to enable a plug-and-play solution. The third slide shows the need to transition towards Cu-Cu bonding. As the left chart shows, solder based microbumps can support the technology until around 15-20um. Beyond this pitch level, a transition to Cu-Cu bonding becomes necessary. With this transition comes the possibility to increase bump density to over 10000/mm2. This is vital so that the I/O size and bandwidth do not limit overall system performance in complex multi-die packages. But will all suffice? The fourth slide shows need to transition from Cu bonding to optical I/O technology. As the table shows, optical I/O (OIO) can increase shoreline density by a factor of 4, reaching 1.6 Tb/s/mm. It will also improve power efficiency by some 35%. Finally, as shown in the fifth and final slide, this technology will need to evolve. The current (Sept 2021) demonstration was for an on-package OIO able to achieve >1Tpbs/mm @ 6 pJ/bit. The target is a fully integrated OIO able to achieve 10 Tbps/mm @ just 1pJ/bit conversation. Heterogeneous integration is THE technology space to watch babak sabi Challenge: printable dielectric materials for RF and MW devices? The dielectric material is often the bottleneck against fully printed high-performance RF and MW devices. This is often a neglected challenge as the emphasis is mainly on the conductive layer. Indeed, the development of a suitable low-loss digitally-printable dielectric material with high and controlld resolution is a technical challenge. In this 3-min video, Yuri Piro from University of Massachusetts Lowell explains why this is challenging: "So coming up with a non-polar material that you can form on the spot with low processing conditions and low polarity is difficult and you really can't use these conventional approaches." Microfluidics and Electrohydrodynamic printing (EHD)? EHD is a promising digital printing technology for going beyond the resolution limits of inkjet. Most examples showcase electronic or display related applications. However, in a recent TechBlick talk, as shown in slide 1, Dr Aart-Jan Hoeven showed an example in microfluidics where EHD could delvier value. Here, this technology could enable the electrode widths or pitches to be narrowed from 30-40um (possible with industrial inkjet) to perhaps 1-5um using EHD, thus saving space. This will support the miniaturization trend of microfluidics, making possible to even integrate them into the human body. In slide 2 DoMicro BV 's laboratory-scale nano printer can be seen in more detail. It is able to deposit ultrafine features digitally! This DM50-ENP printer is generating significant interest and was developed as part of E-Nanoprint-Pro project

high-PPI RGB microLEDs, printed electronics, and quantum dots? The three themes are closely linked since QDs can be digitally printed as color conversation materials atop blue microLEDs to enable wide color gamut RGB uLED displays without requiring a separate transfer step for each color. Join TechBlick's event on microLEDs to learn more www.TechBlick.com/microLEDs Inkjet is the common technology investigated for such a purpose. As shown below by Armin Wedel, however, its 4pL droplet is too large, allowing at best a 40um pixel and not able to reach even 850 dpi Electrohydrodynamic printing (EHD) can however address this issue. In EHD, the droplets are pulled out by an electric field from a nozzle which sits close (50um or so) to the surface and thus requires a good printing facility. As shown below, the droplet volume is only 0.5pL, enabling 1-10um pixels in the lab and 15um reproducibly. This will enable one to achieve 850ppi and 1000ppi! Slide 2 shows an example of a QD color filter (QD-CF) for a microLED display deposited using EHDJet. Here, 15um pitch is reported, achieving 1000ppi. The roadmap will be to evolve the technology towards even 2000ppi! Of course, EHDJet is a relatively new technology. It is mainly single head and slow, although multi-head print heads are emerging. Nonetheless, it is an elegant solution for depositing color filters on high-PPI microLED displays. To learn the latest about these technologies joint TechBlick's specialist event on microLEDs and Quantum Dots where Prof. Wedel will also present: www.TechBlick.com/microLED You can hear from the likes of Samsung, Sharp, Yole, ASMP, Coherent, Nanosys, CEA, AUO, Allos Semiconductor, KIMM, Luxnour, Omdia, Playnitride, micromac, and many many more

As microLEDs inevitably shrink in size, the micro-bumping requirements for the microLED dies becomes more challenging. Direct wafer-based printing based on gravure offset techniques offers a promising solution in this regard. Indeed, this is another field where printed electronics can play a role. Komori has recently achieved excellent results, which will be unveiled at TechBlick's upcoming microLED event on 30 Nov-1 Dec 2022: www.TechBlick.com/microLEDs As seen in the slides below, gravure printing can print microbumps printed using flux paste, achieving a printing precision of 5 µm within a range of 300 mm. The first slides show the precision of the printing position on a wafer. In particular, it compares it with screen printing, showing how gravure printing advances the fine feature printing capability w.r.t screen printing (+/-10 um although screen printing too can and will also advance) As shown in slide two, the minimum diameter that can be printed with SAC (Sn, Ag, Cu) solder paste is 6 μm and the distance between the centers of the bumps is 30 μm. Reflow has been successful with a minimum diameter of 10 µm. This way for example, a microLED die in the size of 30um by 50 or 80um can be supported. Furthermore, as shown in slide three, this technique also offers the possibility to control the thickness by printing several diameters. The smaller the bump diameter, the higher the aspect ratio. This are very nice results, showing the viability of gravure printing technique for microbumps. This technology can support current and near-term generations of microLEDs but will it evolve as microLED dies further shrink in the longer term? Join Komori and other members of the community to learn about all aspects of microLEDs from GaN microLED technology to transfer and tiling technology to bumping and color conversion technology and beyond. You can hear from the likes of Samsung, Sharp, Yole, ASMP, Coherent, Nanosys, CEA, AUO, Allos Semiconductor, KIMM, Luxnour, Omdia, Playnitride, micromac, and many many more www.TechBlick.com/microLEDs

A milestone or a watershed moment in the world of graphene commercial development took place this week: NanoXplore Inc. acquired the many of the assets of XG Sciences! NanoXplore has been a pioneer in commercialising graphene. Many know it for its ambitious activities in breaking down the cost and availability barrier of graphene by massively scaling up a well-engineered production process. This is a prerequisite for market development but is not sufficient. Another often-neglected prerequisite is overcoming regulatory hurdles before tonnes of the nano material in different continents can be sold! This is an essential yet arduous and expensive (!) undertaking . NanoXplore led the way here too, paving the way for itself and also possibly for other suppliers in the field. In this 5-min video- a throwback to a presentation by Nima Moghimian at TechBlick's Graphene and CNT event in 2021, you can learn about the steps that NanoXplore took to obtain regulatory approval and the results of their studies. Some of the results may be surprising to some, but it is worth remembering that graphene is often only a nanomaterial in one dimension. Also- lets not forget that carbon black- an old material with 18M tons of sales per year- is also a nanomaterials as 70% of carbon blacks posses a particle size <100nm To learn more visit www.TechBlick.com Congratulations to NanoXplore for yet another leapfront in this field #graphene #CNT #carbonblack #additives #graphite #Sianode #conductiveplastics #nanomaterials