In general, dispensing can be defined as transfer of fluid from a container (typically a syringe) to a substrate in a form of pattern or calculated volumes to host a die or component. In electronics industry, there are various methods that have evolved to keep up with the rapid development of manufacturing need for adhesives and epoxies in a wide array of packaging assemblies. Over the years, dispensing applications have expanded to other areas needed for new types of packaging encapsulation techniques. A wide variety of fluid materials with different viscosity are being used, from solder paste, conductive adhesives and damming compound to fluxes, thermal paste and underfills.
Our EDT for die attach applications are available in many designs to cater to your dispensing needs. Consistent coverage and void free adhesion are the main criteria to be satisfied. In order to achieve these, precisefabrication and optimized tool design must be properly carried out.
In most programmable dispensing pumps, typical nozzle designs have been optimized to dispense consistent pattern and volume. Most of these standard nozzles have a chamfered feature that reduces surface tension between the needle and material at the point of separation. Therefore, less probable to tailing or bridging.
In the realm of micro-dispensing application, the challenge takes place on methods to achieve small volumes or dots of 200 microns (8mils) or below with high repeatability. The nozzle requires small orifice with tighter tolerance. Smooth internal finishing is also an important factor to enhance fluid flow. SPT positioned itself in meeting the challenge by introducing this fully injection molded ceramic dispensing nozzle.
Stainless tubing with tapered tip inserted into standard Luer type body with full double lead thread, 2-piece construction. Fixed overall length with variable needle height. Tungsten carbide tip with cross groove option is available for cross print pattern dispensing.
The tip of the EDN, traditionally delivered in tungsten carbide, is now replaced by a ceramic material. The very smooth inner walls of the ceramic nozzle greatly helps a regular fluid flow and facilitates the cleaning process. Due to a higher thermal resistance of ceramic compared to tungsten carbide, the ceramic nozzle further prevents adhesive tailing on heated dispensing head.
This nozzle is used in conjunction with dedicated pump system.
Rubber stamping tools are still used regularly by many companies. 3 different dot sizes are available : 0.3mm, 0.5mm and 0.6mm with a pitch of 0.8mm forthe former and 1mm for the other two types.
Usually made in stainless steel, those stamping tools are also proposed in a harder material when the tip wear becomes a problem. Many different tip designs have been developed and optimized based on the application parameters. The most popular and requested types are the ROUND, RECTANGULAR and STAR shape. The other designs are : DAUB, FRAME, GRID or a combination of them.