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Adhesive Dispensing using PDP head

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#64501

Adhesive Dispensing using PDP head | 15 June, 2011

Hello,

My company recently installed a Positive Displacement Pump on a GSM Pick @ Place machine for dispensing chipbonder (loctite 3621) dots before mounting chip components. The head uses Universal stand nozzles (single port-small dot, dual port 0 deg, dual port 90 deg, single port-large dot). We plan to use single port nozzles with dual stand off on all 4 spindles. These nozzles are very costly if purchased from Universal and the lead time is 3-4 weeks.

I would appreciate if anybody knows about a company that manufacture's these type of dispensing nozzles for PDP head and are cheaper with less lead time.

Also, it took us several trial and error to settle down with a setup on the head for a specific dot size. Is it a normal practice? OR Is there any easier way to setup the dot size?

How much critical is the nozzle ID for dispensing specific chipbonder dots? Can I use a nozzle with ID 0.008" to dispense dot sizes .020" and above? Can I achieve this by setting up the head to dispense lowest amount of dot and add repetitions in the program to achieve desired dot size?

Thank you all in advance, Prasad K, Manufacturing Process Engineer

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#64606

Adhesive Dispensing using PDP head | 7 July, 2011

Prasad, It is typical when experimenting with new materials to have to adjust the airpressure on the syringe and the stroke of the PDP piston (screw adjust on top of the PDP pump). You can add mutiple cycles in the comp Db to make larger dots with the same size nozzle but be aware that you may cause tip contamination and stringing if you go too big. Also be aware that there are multiple selections of piston diameters to match certain nozzles.

BTW.. not all materials are meant to be dispensed with a system such at the PDP. Depending on cure time, operating temp, etc you may find the need to clean the pump more often if not in constant use. Good luck.

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