SMT (Surface Mount Technology) dispensing and soldering technology addresses the issue that certain specialized electronic components cannot be soldered using traditional solder paste, which could affect product usability and service life.
This article will explore dispensing and soldering technologies for SMT dispensing machines, as well as the dispensing methods used by dispensers in SMT assembly production.
Dispensing Technology in SMT Assembly Production
In SMT assembly production, dispensing technology is a key process used to secure specific electronic components. These dispensing technologies are typically categorized into manual and automated types to meet different production needs. Among these dispensing technologies, the dispensing head of the dispenser plays a crucial role.
Dispensing Head for SMT Dispensers
There are different types of dispensing heads for SMT dispensing machines, including time-pressure-fed, screw pump, linear positive displacement, and jet pump types. The following is a brief introduction to these four types of dispensing heads.
1. Time-Pressure Distribution Head
Time-pressure dispensing heads utilize the time-pressure principle and are activated by controlled pulses of air generated by a compressor. During operation, the longer the duration of the air pulse, the greater the proportion of coating dispensed from the nozzle. This type of dispensing head is widely used in SMT production.
2. Screw Pump Dispensing Head
Screw pump dispensing heads offer a high degree of flexibility and are suitable for dispensing a wide variety of surface-mount adhesives. They are not sensitive to air entrapped in the adhesive but are relatively sensitive to changes in viscosity, and the dispensing speed can also affect dispensing consistency.
3. Linear positive-phase-shift dispensing head
Linear positive-phase-shift dispensing heads exhibit good droplet consistency during high-speed dispensing and can dispense over larger areas. However, they require a complex cleaning procedure and are sensitive to air in the placement adhesive.
4. Jet-pump-type dispensing head
A jet pump dispensing head is a non-contact dispensing head that offers relatively fast dispensing speeds and is not sensitive to PCB warpage or variations in height. However, it produces relatively large adhesive dots, requiring multiple dispensing passes and a complex cleaning procedure.
Three Soldering Processes in SMT Assembly
There are three common soldering techniques used in SMT assembly: wave soldering, reflow soldering, and laser reflow soldering.
1. Wave Soldering Technology
Wave soldering technology uses SMT stencils and adhesive to secure electronic components to a printed circuit board, which is then immersed in molten tin for soldering. This technology helps reduce the size of electronic products but is not suitable for high-density SMT assembly.
2. Reflow Soldering Technology
Reflow soldering technology uses SMT stencils of the appropriate specifications and models to print solder paste onto the pad areas of electronic components. The components are then reheated to cause the solder to flow and solidify, thereby connecting the electronic components to the circuit. This is a simple, fast, and commonly used technique in SMT manufacturing.
3. Laser Reflow Soldering Technology
Laser reflow soldering technology is similar to conventional reflow soldering technology, with the key difference being that it uses a laser to directly heat the soldering area. Once the laser beam is turned off, the solder solidifies again, forming a stable and reliable solder joint. This method is faster and more precise than conventional reflow soldering technology and represents an improvement over it.
Dispensing and soldering technology in SMT dispensing machines plays a critical role in SMT assembly production, addressing the need to secure specific electronic components. Different types of dispensing heads are suited for various production requirements, and three common soldering techniques make SMT assembly more efficient and reliable.
Frequently Asked Questions
1. What is the dispensing and soldering technology used in SMT dispensers?
Dispensing and soldering technology used in SMT dispensers is a method for securing specific electronic components; different types of dispensing heads are typically used to meet various production needs.
2. What dispensing technologies are used in SMT assembly?
Dispensing technology in SMT assembly includes both manual and automated methods, with the dispensing head serving as a key component.
3. What is wave soldering technology?
Wave soldering technology uses molten tin to secure electronic components to printed circuit boards, helping to reduce the size of electronic products.
4. What is reflow soldering technology?
Reflow soldering technology uses solder paste to secure electronic components to a circuit board, which is then reheated to form solder joints. This is a common SMT manufacturing technique.
5. What is laser reflow soldering technology?
Laser reflow soldering technology uses a laser to directly heat the soldering area, making it faster and more precise than traditional reflow soldering technology; it is an improved soldering technique.
