Nozzles for Highly Controlled Dispensing
Tecdia’s innovative ARQUÉ precision dispensing nozzle is designed to maintain blend consistency and application accuracy.
Electronic component assemblies often rely upon the application of very small quantities of solder or adhesive in precise locations. Precision machined dispensing needles and nozzles are used to accomplish this accurately. This tutorial examines the influence of nozzle design on blending separation in solder paste when dispensed under high pressure.
The Challenge：
Solving the problem of maintaining the right mix of solder paste during the dispensing processes.
This application required attaching electronic components on substrate circuits using solder paste. The paste must be placed at each attachment location in sufficient volume and blend to properly secure the die, and a good electrical connection while avoiding excess paste that could affect circuit performance. The process must be repeatable in high volume at a rapid pace.
Paste description: a mixture of solids (solder particles) and liquids (fluxes) which must remain blended in the correct proportions when dispensed out of the nozzle tip.
Paste mixture control: automated dispensing requires precise control of the pressure applied to push the paste out of the nozzle with the correct application at the right speed.
The correct application refers to the volume, shape, and blend of the paste. When solder paste is dispensed under high pressure, the differences in the coefficients of the resistance of the solids and liquids affect the flow rate. As they are pushed through the needle or nozzle blend separation can occur. This phenomenon leads to changes in the viscosity of the paste material that can clog the needle, causing inconsistent application amounts, and overall defective adhesion. This can cause a myriad of problems when mass producing electronic products.
The Solution:
Nozzles designed with an internal shape that minimizes flow interference and maintains consistent high flow rate with applied pressure.
The instantaneous changes in the mixing ratio of the adhesive paste material is affected by the dispensing pressure. The key to this approach was to analyze the dispensing pressure and develop a nozzle that would increase the flow of the material in order to reduce the unblending of the solder. This required that we improve the alignment of the nozzle intake to the dispenser syringe so that the pressure on the dispersant was evenly distributed with minimum back pressure. We also wanted the flow to be as frictionless as possible.
We succeeded in machining the interior of the nozzle to be the same diameter as the connecting syringe. By using a machining precision of only 0.001mm, we produced nozzles that eliminate separation due to differences in material flow.
Paste Dispensing data comparison of nozzle designs (application quantity and diameter)
Ratio of Solder Particle to Flux
The Design Rationale
1.We developed the nozzle’s interior shape and surface to lower the resistance inside the nozzle for better flow and reduced friction.
Tecdia Nozzle
Conventional Nozzle A
Conventional Nozzle B
2.By making the diameter of the apertures of the nozzle body and syringe the same, we achieved a smooth flow of solder.
The Result:
Increased the percentage of separating materials from 20% to 80%.
Separation of material in the syringe can now be contained by 80% as opposed to 20% previously. In terms of clogging, our nozzles can be used for a full day on average, saving a great deal of time and cost spent changing and cleaning nozzles. In conventional nozzles, separation would begin to occur after only 20% of the material was used in the syringe and would have to be later discarded with 40-50% of remaining material. Tecdia’s precision nozzles are able to prevent separation and clogging, allowing more than 90% of the material to be used. This not only saves nozzle changing costs, but also material waste. The internal shape of the nozzles also makes cleaning more effective, saving time and cleaning solution.
Client Information
【Client Industries】
Manufacturing of electronic components for communications devices (mobile phones, and digital cameras etc…)
Manufacturing of electronic components for communications devices (mobile phones, and digital cameras etc…)
【Business Description】 Mobile phone/digital camera lens unit assembly (CCD/CMOS image sensors) and Crystal transmitter/crystal oscillators manufacturing
