Keyword guide: SMT (plastic mesh) red glue thick mesh, water-based cleaning technology, red glue water-based stencil cleaning technology
Foreword
At present, in the process of wave soldering in the power supply and home appliance industry, applying red glue to the front is an important process.
In early screen printing cleaning processes with red glue, aerosol cleaning with volatile organic solvents was used to clean misprinted plates, plastic plates, and thick copper plates.
Because society places ever higher demands on environmental protection and safety. Stencil cleaning with red glue, especially the pneumatic spray cleaning machine, which is still widely used in the industry, has many unsatisfactory results.
Red plastic SMT stencil
Because the spray force is linear, the copper mesh with parallel plastic meshes with deep holes and complex structure is difficult to clean and needs to be cleaned many times. The cavitation force generated by the ultrasonic wave is dissipated and can penetrate at any angle to clean it.
So, for cleaning red plastic stencils, it is very important to choose products and equipment. One is to choose a water-based cleaner that dissolves the red gum better, and the other is to choose to use the physical force of ultrasonic waves to accelerate the dispersion and dissolution of the red chewing gum to achieve a cleaning effect.
1. Necessity and difficulty of cleaning SMT red plastic stencil:
Red glue stencil cleaning has always been a problem in the industry, and red glue stencil cleaning is an important link in the whole red glue process, and its cleaning effect directly affects the quality of the process. If the cleaning is not thorough, the pores of the copper mesh will become smaller or even clogged, resulting in insufficient printing adhesive and the possibility of the stencil gradually falling out and breaking.
2. Traditional cleaning method for SMT red plastic stencil
In view of the red glue stencil, especially the thick mesh with relatively large hole depth and hole, it is usually cleaned with simple manual or pneumatic spray equipment, which cannot completely clean the red glue residue on the inner wall of the thin hole. Incomplete cleaning will result in that the red glue residue on the inner wall will accumulate and compact, resulting in narrowing and even blocking of the pores. The manual needle dredge method cannot completely solve the problem, which is extremely easy to scratch and form burrs and other damage to the screen, and the use of artificial needles requires a lot time and labor, and the desired effect cannot be achieved.
Printed with red SMT glue
Therefore, manual and pneumatic spray cleaning equipment is used, and the organic solvent cleaning method requires repeated blowing and piercing by hand. This cleaning method is time-consuming, laborious and inefficient. In addition, volatile organic solvents are easily inhaled by workers on site. If this continues, it will cause relatively large damage to the bodies of workers on site. The hidden danger of organic solvents being flammable and explosive "time bomb" .
3. New water-based cleaning technology with thick mesh SMT red glue and technological application
Using water-based electronic environmental protection cleaner and supporting automatic ultrasonic steel mesh cleaning machine, it is now a thorough and efficient cleaning of red plastic stencils.
The cleaning principle of red plastic stencil cleaning technology: using the physical "cavitation effect" of ultrasonic waves to create tens of thousands of tiny bubbles in the cleaning liquid, the formation, growth and rapid burst of such tiny bubbles make objects Nozzles and dirt on the surface, gaps, deep holes , fine holes and blind holes are quickly removed mechanically, and the red glue is chemically dissolved with environmental protection water-based electronic cleaning agent solvent to make the epoxy and hardener in the red glue composition, pigments, fillers, etc. dissolve into cleaning agent, and the cleaning agent is circulated and filtered in the ultrasonic equipment to achieve the fast cleaning effect.
Because of the safety, environmental protection, non-flammability and non-volatility of the water-based cleaning agent, it can completely eliminate the safety hazards caused by solvent-based cleaning agents in the past; its combined application with ultrasonic cleaning equipment can solve the cleaning problem of pneumatic spray equipment. The strength is not very good, and red gum residue in deep pores cannot be penetrated and cleaned.
SMT red plastic stencil ultrasonic automatic cleaning
The fourth process of cleaning the thick red plastic mesh (screen):
The cleaning process of the red plastic stencil is as follows: the thick mesh is offline blown through the mesh with compressed air at a time, and then put into the special ultrasonic cleaning equipment to complete cleaning with one click. The cleaning process is simple and practical, and has strong reachability. The cleaning effect is good, there is no red glue residue on the inner wall of the mesh, the mesh's permeability can reach 100%, and the total cleaning time is about 15 minutes, which can greatly shorten the cleaning time and improve the cleaning efficiency. . Adopting the red glue stencil cleaning process effectively improves the red glue cleaning working environment, which is safe and environmentally friendly, completely eliminates fire and explosion hazards, and avoids the risk of chronic solvent poisoning of operators; At the same time, water-based cleaning agent is not volatilized, recyclable, can save cleaning costs, reduce comprehensive utility costs.