From pre‑fixing components before placement, to underfill and encapsulation after reflow soldering, dispensing runs through multiple critical steps in SMT assembly, directly affecting the electrical reliability, mechanical strength, and service life of printed circuit boards.

As electronic products rapidly evolve toward miniaturization and higher integration, SMT (Surface Mount Technology) processes demand ever‑greater precision, stability, and flexibility from dispensing operations.

As a precision dispensing application expert, QUARK Industrial Research Institute has built a complete product portfolio covering accuracy levels from microliters (μL) down to femtoliters (fL), offering end‑to‑end dispensing solutions for the entire SMT lifecycle.

Pre‑Fixation Before Component Placement：Precise SMT Red Adhesive Dispensing

Process scenario: In double‑sided SMT assembly, components on the first side may fall off during the second reflow when solder paste melts again. To prevent this, red SMT adhesive is dispensed on the first side to temporarily fix components onto the PCB, ensuring they do not detach or shift during subsequent wave soldering.

Key process challenges: Dot size must precisely match pad spacing without contaminating the pads. Viscosity variations in the adhesive can lead to stringing, missing dots, or inconsistent glue volume.

QUARK Solution

 

DOT V20 Piezoelectric Jetting Valve: High precision, strong versatility, optimized design effectively suppresses satellite dots and bubbles, maintaining stable performance over long‑term operation.

Paired with the DOT C30 Piezoelectric Controller – supports multiple operation modes (dot, pulse, level, jet clearing, line dispensing), and features RS232 and PLC interfaces for equipment interconnection. Together they form a robust dispensing system for SMT pre‑fixation.

Red adhesive dot dispensing case

 

QUARK Process Capabilities:

• Minimum dot diameter 200 μm, glue volume error ±1%

• Non‑contact jetting eliminates board damage and contamination

• Adapts to variations in red adhesive viscosity and flow properties for precise and stable dispensing

• Relevant parameters validated by QUARK LAB

 

Structural Fixation and Reinforcement：Precision Protection to Enhance Mechanical Strength

Process scenario: Chip structures are delicate and complex. Areas prone to stress‑induced fracture – such as bending points of FPCs and bond wires, solder joints, and connector interfaces – require reinforcement with UV adhesive or epoxy adhesive. Also, the bonding between IC chips / silicon chips and substrates must eliminate effects from physical property mismatches and external mechanical shock.

Key process challenges: Chips are compact and structurally complex. FPC substrates are flexible, and dispensing heights are often less than 2 mm. Reinforcement adhesives have high adhesion, easily stringing on the nozzle. High consistency is required, with no voids or air pockets.

QUARK Solution

 

DOT V30 Integrated Quick‑Release Cartridge Valve: Designed for easy maintenance, featuring quick‑remove nozzle and firing pin to significantly shorten maintenance time and reduce operating costs. It also flexibly integrates cartridge heating for a more compact structure. Paired with the DOT C30 Piezoelectric Controller – supports multiple operation modes, RS232 and PLC interfaces, and integrated heating control for one‑valve, one‑controller media heating.

| Solder joint conformal coating

 | Underfill 

| FPC gold wire reinforcement

| Chip side‑coating reinforcement

 

QUARK Process Capabilities:

• Minimum glue line width 250 μm, glue width tolerance < 50 μm, CPK > 1.67

• Modular quick‑release design, easy maintenance, low consumables

• Widely compatible with UV adhesive, underfill, epoxy, acrylic, structural adhesive, Dam & Fill, and other media

*Relevant parameters validated by QUARK LAB

 

Mixed Assembly / Flexible Manufacturing：Non‑Contact Precision Solder Paste Jetting

Process scenario: In SMT mixed assembly or fine‑pitch pad applications, solder paste jetting replaces traditional screen printing, providing fast changeover for small‑batch, high‑mix production.

Key process challenges: Solder powder particles can clog nozzles easily. Extended continuous operation may cause stringing or breaks. Solder paste viscosity varies with temperature and time, affecting shot‑to‑shot consistency. High stability for #6, #7, and finer ultra‑fine solder pastes is essential.

QUARK Solution

 

DOT V60 Piezoelectric Jetting Valve: Specifically developed for precision solder paste jetting, suitable for #6, #7, and finer pastes. Enables long‑term stable production with low clogging risk.

Paired with the DOT C30 Piezoelectric Controller – multiple operation modes and standard communication interfaces for seamless integration into a flexible dispensing system.

Solder paste jetting application

 

QUARK Process Capabilities:

• Minimum dot diameter 200 μm, minimum line width 250 μm, meeting various precision jetting requirements

• No stringing or breaks during prolonged dispensing

• High‑frequency jetting up to 1000 times/second, providing an efficient solder paste solution for flexible SMT lines

*Relevant parameters validated by QUARK LAB

 

Thermal Management：Precision Coating of Thermal Interface Materials

Process scenario: As high‑end consumer electronic devices demand more power, heat generation becomes severe. Thermal grease and liquid metal coating processes have become critical for enabling chips to deliver their full computing performance.

Key process challenges: Liquid metal has high surface tension and strong fluidity, easily causing tailing, stringing, and residue. Thermal grease contains a high filler content, prone to settling and nozzle clogging.

As electronics manufacturing approaches the limits of precision and component sizes continue to shrink, QUARK Industrial Research Institute leverages its piezoelectric valve product matrix covering all process nodes, precise fluid control algorithms, and flexible modular kits to provide end‑to‑end precision dispensing systems for SMT processes.

With core capabilities of precision, efficiency, and reliability, QUARK continues to help industry players build higher‑quality, higher‑yield assembly loops.