What is this stuff on this pc board?

underlining

warning.

Are you using Agent?

I referred the problem to Agent support and received this reply;

Hello, Ross.

Your problem has been noted to development.

The URL recognition is a RegEx in the agent.ini file, it's the key "Pattern6". Unfortunately, I don't know RegEx well enough to suggest a modification myself.

-- Jeffrey Kaplan Agent Support Team

of

with a

copper of

of the

To anyone who knows anything about electronics soldering and or pcb populating it is very obvious that this IS what happened.

>

Is this

Not in this case it isn't. This is the result of failing to clean the flux away at all after a manual part placement and soldering procedure. Such instances may occur when an OEM does not trust that reflow or wave soldering will be ultra reliable where heavy component leads are involved. The reflow time has to be adequate to ensure proper wetting of the heavy leads but where other very small componets may be damaged by heat this is not recommended. The reflow time is always set to ensure the most sensitive components will not be damaged by heat and this may require that heavy leaded components are fitted manually afterwards.

The result of inadequate cleaning after finished board manufacture is usually a much lighter white ring or anulus of residue, nothing as thick or heavy as in the picture.

This is more like what you are talking about

Ross, we manufactured both surface mount and through hole boards, plus some items like connectors were hand soldered on our surface mount PC boards. We had a VERY high standard of cleaning, because most of our equipment was sold to the aerospace industry. I've seen probably every possible defect in a new PC board, including a batch we received with a missing internal power plane. I have seen this exact type of residue on boards that just came out of the dryer, after being washed.

--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

soldered.

and

the

component

componets

damaged

fitted

is

qualifies

by

resemblance

residue

soldered.

and

the

component

componets

damaged

fitted

is

qualifies

by

You are right with regard to reflow - my mistake for mentioning it. However, with regard to the component and reasons why it would have been manually fitted, I was just giveing an example. It wasn't meant to be the ONLY reason why the component might have been added manually yo this particular board although I admit it would have been wise to stick to this point.

resemblance

In my experience it is. It is obvious that there has been some "scratching around" in the residue which has removed some of it (perhaps by the OP). In its natural state it would have been far more regular and quite thick as it appears to me. I would wager that after this component was manually soldered the operator didn't even so much as wave cleaning fluid over it let alone attack it with a brush. After adding a single component I doubt too many manufacturers would put the whole board through a clean and dry cycle since it takes a lot longer than doing it by hand immediately after soldering.

residue

Incompletely cleaned flux in my experience has always been more in keeping with this effect

but a water soluble flux applied by hand and which has not been cleaned at all is more akin to the OP's situation.

I have seen 'cold joint' issues with TO-220 devices.

Graham

Sure, from crappy board houses.

--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida