For our high voltage multiplier boards we hand solder, then "touch up" to add a solder ball on the non-component side.  This process assumes that there is proper flow through, regardless of "source side".  The addition of liquid flux greatly improves the results when generating the solder ball.



We do have a new vendor that has an automatic solder balling machine.



Phil



-----Original Message-----

From: TechNet [mailto:[log in to unmask]] On Behalf Of Larry Dzaugis

Sent: Monday, October 17, 2016 12:10 PM

To: [log in to unmask]

Subject: Re: [TN] Solder source side



It moves around based on process.



Pin in Paste is the topside/component side.



Selective solder is the side opposite the component.



Rare hand soldering for components only accessible from the top side, not the preferred situation for DFM.

Select components in module assemblies come to mind.

Some designers do not accept sockets.



Inspection callout should include the situation so that the Inspector does not reject valid joints.



Had large problem when selective solder connector went to pin in paste with Inspectors rejecting good joints.



Larry Dzaugis