In recent years, leading display manufacturers worldwide have accelerated their strategic investments, focusing on optimizing LCD product structures and rapidly advancing OLED and MLED technologies. Next-generation display solutions have become a key growth driver for the industry. According to DSCC estimates, Mini-LED panel shipments reached 24.47 million units in 2023 and are projected to exceed 37 million units by 2026. Mini-LED backlight technology is poised for a significant increase in market penetration over the next 2-3 years.

As a provider of upstream core components, Quark Research Institute has taken a leading role in the field of precision fluid control for display manufacturing. With a series of high-efficiency, intelligent fluid control equipment and solutions, we are committed to providing reliable technical support to industry partners, helping to drive continuous breakthroughs in display quality, size, and energy efficiency.

Quark's independently developed high-precision piezoelectric jet valve utilizes an advanced piezoelectric ceramic drive mechanism. It achieves a dispensing accuracy of ±1%, with a minimum single-dot volume of 0.1 nl (10⁻⁶ ml). It delivers high-quality, micro-scale dispensing for straight lines, arcs, and complex irregular patterns. Furthermore, it excels at suppressing defects such as splatter and irregular dot shapes, earning consistent recognition within the industry. It offers significant advantages in applications including display surface protection, conductive adhesive dispensing for PCBs/LCDs/circuits, Mini-LED lens encapsulation, screen edge sealing, and adhesive application in flexible screen bending zones.

01 Display Surface Protection

This process involves dispensing Tuffy protective adhesive on display circuit boards. Tuffy adhesive is a resin-based compound specifically designed for electronics, offering fast surface drying, low moisture permeability, resistance to glass cleaners, and ease of rework. Commonly used in display manufacturing, it prevents circuit corrosion from moisture, protects against scratches from dust and contaminants, and insulates ITO step circuits. It enhances the vibration resistance, corrosion resistance, and stability of components to safeguard ICs and microcircuits.

The primary challenge lies in incomplete deaeration of the Tuffy adhesive, leading to bubbles or wavy, uneven lines. The standard adhesive line width typically ranges from 0.4 to 1.5mm. Quark's piezoelectric valve, with its optimized configuration and parameters, effectively suppresses bubbles and improves precision, achieving a minimum line width of <0.3mm with a width variation of <50µm.

02 Conductive Adhesive Dispensing for PCBs / LCDs / Other Circuits

Conductive silver adhesive serves as a lead-free alternative to solder in electronic packaging. It offers advantages like high resolution, relatively low curing temperature, good mechanical properties, and strong adhesion to most materials. It aligns with the trend of electronic miniaturization and highly integrated PCBs. Its simple process and suitability for production lines make it an ideal choice for conductive connections in display panels.

The adhesive is applied during the module assembly stage of LCD manufacturing. It is dispensed along the stepped interface formed between LCD panels and circuit boards of varying thicknesses. The adhesive bonds conductive particles to form electrical pathways, enabling connections between components.

Due to component miniaturization, the dispensing gaps are extremely fine. This demands extremely tight control over line width, thickness, and weight, with a post-cure thickness requirement of under 0.05mm. Furthermore, the silver particles within the adhesive can cause nozzle clogging during continuous operation or after idle periods, leading to misalignment or breaks in the adhesive line.

Leveraging extensive manufacturing and process expertise, Quark Research Institute has optimized the design and parameters of key components. Its proprietary piezoelectric valve effectively addresses these issues. It achieves a minimum line width of 0.2mm. Meeting the common industry requirement for a 1.5mm dot diameter, on-site tests show the valve maintains a defect rate below 0.5%, with effective suppression of bubble formation and nozzle clogging.

03 Mini-LED Display Lens Encapsulation

As an advanced iteration of LCD technology, Mini-LED backlighting uses a direct-lit design with densely packed LED arrays for precise local dimming. This places extreme demands on dispensing precision. Optical adhesives are applied via spraying, coating, dam building, or filling to achieve specific optical designs, enabling superior display performance.

The Mini-LED lens process involves jetting transparent silicone adhesive to encapsulate individual Mini-LED chips, forming optical lenses that enhance light concentration and brightness. It is suitable for backlight units with larger chip pitches, primarily used in medium-to-large displays like monitors and TVs.

This process requires exceptional consistency in single-dot volume, adhesive shape, and concentricity. Multiple adhesive dots are dispensed per chip, with the center deviation between the dot and the chip requiring ≤0.1mm or less. The process must also be entirely free of bubbles.

Quark's high-precision piezoelectric jet valve, developed for micro-dispensing, achieves bubble suppression throughout the jetting process and ensures dispensing consistency through optimized electrical drive control. The adhesive volume deviation is ≤2%. Its dual-valve synchronous solution achieves a cycle time of ≤60ms per chip, ensuring uniform luminance across the entire panel.

04 Adhesive Application in Screen Bending Zones

Flexible OLED displays are widely adopted in high-performance applications due to their deformable nature and slim profile. Their flexible substrates are bent to specific curvatures. The bending area undergoes repeated stress, demanding exceptional encapsulation performance.

The high-precision piezoelectric valve applies protective adhesive (UV/thermal-curing) to the bending area of flexible OLED screens, achieving a minimum line width of <0.3mm. This protects internal circuits from damage during bending, improving product yield.

05 Screen Edge Sealing

This process involves dispensing UV adhesive along screen edges for sealing, light blocking, dust prevention, and moisture resistance. The fast-curing and low-temperature curing properties of UV adhesive make it ideal for LCD bezel bonding, compatible with automated production.

The main challenges are the adhesive's tendency to string at the nozzle and the formation of wavy lines. Quark's high-performance piezoelectric jet valve, applied to edge sealing, can automatically program dispensing paths and inspect adhesive lines for each specific scenario. It achieves adhesive line widths ranging from 0.4 mm to 2.0mm.