Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


PIHR

Jeanette

#6374

PIHR | 20 July, 2000

When dispensing paste would you reccomend dispensing the paste first then inserting the component or inserting the component, clinching the leads and then dispensing the paste. I have heard that the latter may cause dry joints.

Would you use the same volume of paste for dispensing as with using a stencil.

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Bob Willis

#6375

Re: PIHR | 20 July, 2000

Well you can do both but why clinch the leads ? You are not referring to the SPOT process my friends at Camelot talked about some years back are you ?

You can dispense paste but it�s a lot slower than printing. You can select a pin and dispense directly over it Camelot had a high speed video of this some years back.

As the majority of applications for this process are connectors, sockets headers there is no need to clinch. I have been involved with a process of dispensing where a multi pin was used to place paste onto the hole board at once but that is a high tooling cost.

The volume of paste to meet you inspection criteria is the same, however the normal dispense grade of paste does have a slightly lower metal content ?

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SMT fluid dispensing